A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.
A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They include several nucleic acid constituents (CYTOSINE; THYMINE; and URACIL) and form the basic structure of the barbiturates.
Inborn errors of purine-pyrimidine metabolism refer to genetic disorders resulting from defects in the enzymes responsible for the metabolic breakdown and synthesis of purines and pyrimidines, leading to the accumulation of toxic metabolites or deficiency of necessary nucleotides, causing various clinical manifestations such as neurological impairment, kidney problems, and developmental delays.
Errors in metabolic processes resulting from inborn genetic mutations that are inherited or acquired in utero.
Pyrimidines with a RIBOSE and phosphate attached that can polymerize to form DNA and RNA.
Pyrimidines with a RIBOSE attached that can be phosphorylated to PYRIMIDINE NUCLEOTIDES.
An enzyme that catalyzes the transfer of ribose from uridine to orthophosphate, forming uracil and ribose 1-phosphate.
An enzyme that catalyzes the phosphorylation of uridine and cytidine to uridine 5'-phosphate and cytidine 5'-phosphate, respectively. ATP, dUTP, dGTP, and dATP are effective phosphate donors. EC 2.7.1.48.
Orotic acid, also known as pyrophosphoric acid dihydrate, is a organic compound that plays a role in the biosynthesis of pyrimidines, and elevated levels of orotic acid in urine can indicate certain genetic disorders or liver dysfunction.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Uracil is a nitrogenous base, specifically a pyrimidine derivative, which constitutes one of the four nucleobases in the nucleic acid of RNA (ribonucleic acid), pairing with adenine via hydrogen bonds during base-pairing. (25 words)
Disorders affecting amino acid metabolism. The majority of these disorders are inherited and present in the neonatal period with metabolic disturbances (e.g., ACIDOSIS) and neurologic manifestations. They are present at birth, although they may not become symptomatic until later in life.
Uridine is a nucleoside, specifically a derivative of pyrimidine, that is composed of a uracil molecule joined to a ribose sugar molecule through a β-N1 glycosidic bond, and has significant roles in RNA synthesis, energy transfer, and cell signaling.
Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.
Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.
Dimers found in DNA chains damaged by ULTRAVIOLET RAYS. They consist of two adjacent PYRIMIDINE NUCLEOTIDES, usually THYMINE nucleotides, in which the pyrimidine residues are covalently joined by a cyclobutane ring. These dimers block DNA REPLICATION.
Purines with a RIBOSE attached that can be phosphorylated to PURINE NUCLEOTIDES.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Errors in the metabolism of LIPIDS resulting from inborn genetic MUTATIONS that are heritable.
The identification of selected parameters in newborn infants by various tests, examinations, or other procedures. Screening may be performed by clinical or laboratory measures. A screening test is designed to sort out healthy neonates (INFANT, NEWBORN) from those not well, but the screening test is not intended as a diagnostic device, rather instead as epidemiologic.
Errors in metabolic processing of STEROIDS resulting from inborn genetic mutations that are inherited or acquired in utero.
Inborn errors of carbohydrate metabolism are genetic disorders that result from enzyme deficiencies or transport defects in the metabolic pathways responsible for breaking down and processing carbohydrates, leading to accumulation of toxic intermediates or energy deficits, and typically presenting with multisystem clinical manifestations.
Rare congenital metabolism disorders of the urea cycle. The disorders are due to mutations that result in complete (neonatal onset) or partial (childhood or adult onset) inactivity of an enzyme, involved in the urea cycle. Neonatal onset results in clinical features that include irritability, vomiting, lethargy, seizures, NEONATAL HYPOTONIA; RESPIRATORY ALKALOSIS; HYPERAMMONEMIA; coma, and death. Survivors of the neonatal onset and childhood/adult onset disorders share common risks for ENCEPHALOPATHIES, METABOLIC, INBORN; and RESPIRATORY ALKALOSIS due to HYPERAMMONEMIA.
Brain disorders resulting from inborn metabolic errors, primarily from enzymatic defects which lead to substrate accumulation, product reduction, or increase in toxic metabolites through alternate pathways. The majority of these conditions are familial, however spontaneous mutation may also occur in utero.
Rare autosomal recessive disorder of the urea cycle which leads to the accumulation of argininosuccinic acid in body fluids and severe HYPERAMMONEMIA. Clinical features of the neonatal onset of the disorder include poor feeding, vomiting, lethargy, seizures, tachypnea, coma, and death. Later onset results in milder set of clinical features including vomiting, failure to thrive, irritability, behavioral problems, or psychomotor retardation. Mutations in the ARGININOSUCCINATE LYASE gene cause the disorder.
An enzyme that catalyzes the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. EC 2.4.2.1.
Elevated level of AMMONIA in the blood. It is a sign of defective CATABOLISM of AMINO ACIDS or ammonia to UREA.
The chemical reactions involved in the production and utilization of various forms of energy in cells.
Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
An enzyme which catalyzes an endonucleolytic cleavage near PYRIMIDINE DIMERS to produce a 5'-phosphate product. The enzyme acts on the damaged DNA strand, from the 5' side of the damaged site.
A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).
Pentosyltransferases that catalyze the reaction between a pyrimidine nucleoside and orthophosphate to form a free pyrimidine and ribose-5-phosphate.
An autosomal recessive disorder of CHOLESTEROL metabolism. It is caused by a deficiency of 7-dehydrocholesterol reductase, the enzyme that converts 7-dehydrocholesterol to cholesterol, leading to an abnormally low plasma cholesterol. This syndrome is characterized by multiple CONGENITAL ABNORMALITIES, growth deficiency, and INTELLECTUAL DISABILITY.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A subclass of enzymes which includes all dehydrogenases acting on carbon-carbon bonds. This enzyme group includes all the enzymes that introduce double bonds into substrates by direct dehydrogenation of carbon-carbon single bonds.
A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.
Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
A purine nucleoside that has hypoxanthine linked by the N9 nitrogen to the C1 carbon of ribose. It is an intermediate in the degradation of purines and purine nucleosides to uric acid and in pathways of purine salvage. It also occurs in the anticodon of certain transfer RNA molecules. (Dorland, 28th ed)
An infant during the first month after birth.
Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.
Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
The enzyme catalyzing the formation of orotidine-5'-phosphoric acid (orotidylic acid) from orotic acid and 5-phosphoribosyl-1-pyrophosphate in the course of pyrimidine nucleotide biosynthesis. EC 2.4.2.10.
A mononuclear Fe(II)-dependent oxygenase, this enzyme catalyzes the conversion of homogentisate to 4-maleylacetoacetate, the third step in the pathway for the catabolism of TYROSINE. Deficiency in the enzyme causes ALKAPTONURIA, an autosomal recessive disorder, characterized by homogentisic aciduria, OCHRONOSIS and ARTHRITIS. This enzyme was formerly characterized as EC 1.13.1.5 and EC 1.99.2.5.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Autosomal recessive inborn error of methionine metabolism usually caused by a deficiency of CYSTATHIONINE BETA-SYNTHASE and associated with elevations of homocysteine in plasma and urine. Clinical features include a tall slender habitus, SCOLIOSIS, arachnodactyly, MUSCLE WEAKNESS, genu varus, thin blond hair, malar flush, lens dislocations, an increased incidence of MENTAL RETARDATION, and a tendency to develop fibrosis of arteries, frequently complicated by CEREBROVASCULAR ACCIDENTS and MYOCARDIAL INFARCTION. (From Adams et al., Principles of Neurology, 6th ed, p979)
A clinical syndrome characterized by development, usually in infancy or childhood, of a chronic, often widespread candidiasis of skin, nails, and mucous membranes. It may be secondary to one of the immunodeficiency syndromes, inherited as an autosomal recessive trait, or associated with defects in cell-mediated immunity, endocrine disorders, dental stomatitis, or malignancy.
A purine base and a fundamental unit of ADENINE NUCLEOTIDES.
Hereditary disorders of pyruvate metabolism. They are difficult to diagnose and describe because pyruvate is a key intermediate in glycolysis, gluconeogenesis, and the tricarboxylic acid cycle. Some inherited metabolic disorders may alter pyruvate metabolism indirectly. Disorders in pyruvate metabolism appear to lead to deficiencies in neurotransmitter synthesis and, consequently, to nervous system disorders.
The rate dynamics in chemical or physical systems.
An enzyme that catalyzes the hydrolysis of terminal, non-reducing alpha-D-galactose residues in alpha-galactosides including galactose oligosaccharides, galactomannans, and galactolipids.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
An inherited urea cycle disorder associated with deficiency of the enzyme ORNITHINE CARBAMOYLTRANSFERASE, transmitted as an X-linked trait and featuring elevations of amino acids and ammonia in the serum. Clinical features, which are more prominent in males, include seizures, behavioral alterations, episodic vomiting, lethargy, and coma. (Menkes, Textbook of Child Neurology, 5th ed, pp49-50)
An enzyme that, in the course of pyrimidine biosynthesis, catalyzes ring closure by removal of water from N-carbamoylaspartate to yield dihydro-orotic acid. EC 3.5.2.3.
An X-linked inherited metabolic disease caused by a deficiency of lysosomal ALPHA-GALACTOSIDASE A. It is characterized by intralysosomal accumulation of globotriaosylceramide and other GLYCOSPHINGOLIPIDS in blood vessels throughout the body leading to multi-system complications including renal, cardiac, cerebrovascular, and skin disorders.
The key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides.
A territory of Australia consisting of Canberra, the national capital and surrounding land. It lies geographically within NEW SOUTH WALES and was established by law in 1988.
An enzyme that, in the course of purine ribonucleotide biosynthesis, catalyzes the conversion of 5'-phosphoribosyl-4-(N-succinocarboxamide)-5-aminoimidazole to 5'-phosphoribosyl-4-carboxamide-5-aminoimidazole and the conversion of adenylosuccinic acid to AMP. EC 4.3.2.2.
This amino acid is formed during the urea cycle from citrulline, aspartate and ATP. This reaction is catalyzed by argininosuccinic acid synthetase.
An enzyme that catalyzes the reactivation by light of UV-irradiated DNA. It breaks two carbon-carbon bonds in PYRIMIDINE DIMERS in DNA.
The chemical reactions that occur within the cells, tissues, or an organism. These processes include both the biosynthesis (ANABOLISM) and the breakdown (CATABOLISM) of organic materials utilized by the living organism.
A mitochondrial flavoprotein, this enzyme catalyzes the oxidation of 3-methylbutanoyl-CoA to 3-methylbut-2-enoyl-CoA using FAD as a cofactor. Defects in the enzyme, is associated with isovaleric acidemia (IVA).
A genetic metabolic disorder resulting from serum and bone alkaline phosphatase deficiency leading to hypercalcemia, ethanolamine phosphatemia, and ethanolamine phosphaturia. Clinical manifestations include severe skeletal defects resembling vitamin D-resistant rickets, failure of the calvarium to calcify, dyspnea, cyanosis, vomiting, constipation, renal calcinosis, failure to thrive, disorders of movement, beading of the costochondral junction, and rachitic bone changes. (From Dorland, 27th ed)
A pyrimidine nucleoside that is composed of the base CYTOSINE linked to the five-carbon sugar D-RIBOSE.
A malonic acid derivative which is a vital intermediate in the metabolism of fat and protein. Abnormalities in methylmalonic acid metabolism lead to methylmalonic aciduria. This metabolic disease is attributed to a block in the enzymatic conversion of methylmalonyl CoA to succinyl CoA.
An enzyme that catalyzes the conversion of methylmalonyl-CoA to succinyl-CoA by transfer of the carbonyl group. It requires a cobamide coenzyme. A block in this enzymatic conversion leads to the metabolic disease, methylmalonic aciduria. EC 5.4.99.2.
Incorrect diagnoses after clinical examination or technical diagnostic procedures.
Acquired or inborn metabolic diseases that produce brain dysfunction or damage. These include primary (i.e., disorders intrinsic to the brain) and secondary (i.e., extracranial) metabolic conditions that adversely affect cerebral function.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
An enzyme that catalyzes the conversion of carbamoyl phosphate and L-aspartate to yield orthophosphate and N-carbamoyl-L-aspartate. (From Enzyme Nomenclature, 1992) EC 2.1.3.2.
Injectable form of VITAMIN B 12 that has been used therapeutically to treat VITAMIN B 12 DEFICIENCY.
Pentanoic acid, also known as valeric acid, is a carboxylic acid with a 5-carbon chain (C5H10O2), having a distinctive pungent and rancid odor, found in some animals' sweat, certain foods, and produced through wood fermentation.
A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.
A purine nucleoside that has guanine linked by its N9 nitrogen to the C1 carbon of ribose. It is a component of ribonucleic acid and its nucleotides play important roles in metabolism. (From Dorland, 28th ed)
Orotidine-5'-phosphate carboxy-lyase. Catalyzes the decarboxylation of orotidylic acid to yield uridylic acid in the final step of the pyrimidine nucleotide biosynthesis pathway. EC 4.1.1.23.
A purine or pyrimidine base bonded to DEOXYRIBOSE.
Inborn errors of metal metabolism refer to genetic disorders resulting from mutations in genes encoding proteins involved in the transportation, storage, or utilization of essential metals, leading to imbalances that can cause toxicity or deficiency and subsequent impairment of normal physiological processes.
The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
An enzyme that catalyzes the formation of carbamoyl phosphate from ATP, carbon dioxide, and glutamine. This enzyme is important in the de novo biosynthesis of pyrimidines. EC 6.3.5.5.
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
Inherited abnormalities of fructose metabolism, which include three known autosomal recessive types: hepatic fructokinase deficiency (essential fructosuria), hereditary fructose intolerance, and hereditary fructose-1,6-diphosphatase deficiency. Essential fructosuria is a benign asymptomatic metabolic disorder caused by deficiency in fructokinase, leading to decreased conversion of fructose to fructose-1-phosphate and alimentary hyperfructosemia, but with no clinical dysfunction; may produce a false-positive diabetes test.
Complex sets of enzymatic reactions connected to each other via their product and substrate metabolites.
Nucleosides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
Glutarates are organic compounds, specifically carboxylic acids, that contain a five-carbon chain with two terminal carboxyl groups and a central methyl group, playing a role in various metabolic processes, including the breakdown of certain amino acids. They can also refer to their salts or esters. Please note that this definition is concise and may not cover all aspects of glutarates in depth.
Uracil nucleotides are chemical compounds that consist of a uracil base, a sugar molecule called ribose, and one or more phosphate groups, which play crucial roles in DNA replication, repair, and gene expression as well as in RNA synthesis.
An enzyme that in the course of pyrimidine biosynthesis, catalyzes the oxidation of dihydro-orotic acid to orotic acid utilizing oxygen as the electron acceptor. This enzyme is a flavoprotein which contains both FLAVIN-ADENINE DINUCLEOTIDE and FLAVIN MONONUCLEOTIDE as well as iron-sulfur centers. EC 1.3.3.1.
Thymine is a pyrimidine nucleobase, one of the four nucleobases in the nucleic acid of DNA (the other three being adenine, guanine, and cytosine), where it forms a base pair with adenine.
Uridine 5'-(tetrahydrogen triphosphate). A uracil nucleotide containing three phosphate groups esterified to the sugar moiety.
An autosomal recessive inherited disorder with multiple forms of phenotypic expression, caused by a defect in the oxidative decarboxylation of branched-chain amino acids (AMINO ACIDS, BRANCHED-CHAIN). These metabolites accumulate in body fluids and render a "maple syrup" odor. The disease is divided into classic, intermediate, intermittent, and thiamine responsive subtypes. The classic form presents in the first week of life with ketoacidosis, hypoglycemia, emesis, neonatal seizures, and hypertonia. The intermediate and intermittent forms present in childhood or later with acute episodes of ataxia and vomiting. (From Adams et al., Principles of Neurology, 6th ed, p936)
Enzymes of a subclass of TRANSFERASES that catalyze the transfer of an amidino group from donor to acceptor. EC 2.1.4.
Generic term for diseases caused by an abnormal metabolic process. It can be congenital due to inherited enzyme abnormality (METABOLISM, INBORN ERRORS) or acquired due to disease of an endocrine organ or failure of a metabolically important organ such as the liver. (Stedman, 26th ed)
An autosomal recessive porphyria that is due to a deficiency of UROPORPHYRINOGEN III SYNTHASE in the BONE MARROW; also known as congenital erythropoietic porphyria. This disease is characterized by SPLENOMEGALY; ANEMIA; photosensitivity; cutaneous lesions; accumulation of hydroxymethylbilane; and increased excretion of UROPORPHYRINS and COPROPORPHYRINS.
A flavoprotein enzyme that is responsible for the catabolism of LYSINE; HYDROXYLYSINE; and TRYPTOPHAN. It catalyzes the oxidation of GLUTARYL-CoA to crotonoyl-CoA using FAD as a cofactor. Glutaric aciduria type I is an inborn error of metabolism due to the deficiency of glutaryl-CoA dehydrogenase.
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
A rare autosomal recessive disorder of the urea cycle. It is caused by a deficiency of the hepatic enzyme ARGINASE. Arginine is elevated in the blood and cerebrospinal fluid, and periodic HYPERAMMONEMIA may occur. Disease onset is usually in infancy or early childhood. Clinical manifestations include seizures, microcephaly, progressive mental impairment, hypotonia, ataxia, spastic diplegia, and quadriparesis. (From Hum Genet 1993 Mar;91(1):1-5; Menkes, Textbook of Child Neurology, 5th ed, p51)
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A condition of substandard growth or diminished capacity to maintain normal function.
Guanine is a purine nucleobase, one of the four nucleobases in the nucleic acid of DNA and RNA, involved in forming hydrogen bonds between complementary base pairs in double-stranded DNA molecules.
Disorders in the processing of iron in the body: its absorption, transport, storage, and utilization. (From Mosby's Medical, Nursing, & Allied Health Dictionary, 4th ed)
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
An NAD-dependent 3-hydroxyacyl CoA dehydrogenase that has specificity for acyl chains containing 8 and 10 carbons.
An inborn error of amino acid metabolism resulting from a defect in the enzyme HOMOGENTISATE 1,2-DIOXYGENASE, an enzyme involved in the breakdown of PHENYLALANINE and TYROSINE. It is characterized by accumulation of HOMOGENTISIC ACID in the urine, OCHRONOSIS in various tissues, and ARTHRITIS.
Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
A large group of diseases which are characterized by a low prevalence in the population. They frequently are associated with problems in diagnosis and treatment.
Inosine 5'-Monophosphate. A purine nucleotide which has hypoxanthine as the base and one phosphate group esterified to the sugar moiety.
5'-Uridylic acid. A uracil nucleotide containing one phosphate group esterified to the sugar moiety in the 2', 3' or 5' position.
A group of diseases related to a deficiency of the enzyme ARGININOSUCCINATE SYNTHASE which causes an elevation of serum levels of CITRULLINE. In neonates, clinical manifestations include lethargy, hypotonia, and SEIZURES. Milder forms also occur. Childhood and adult forms may present with recurrent episodes of intermittent weakness, lethargy, ATAXIA, behavioral changes, and DYSARTHRIA. (From Menkes, Textbook of Child Neurology, 5th ed, p49)
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
Elements of limited time intervals, contributing to particular results or situations.
A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.
An autosomal recessive disorder of fatty acid oxidation, and branched chain amino acids (AMINO ACIDS, BRANCHED-CHAIN); LYSINE; and CHOLINE catabolism, that is due to defects in either subunit of ELECTRON TRANSFER FLAVOPROTEIN or its dehydrogenase, electron transfer flavoprotein-ubiquinone oxidoreductase (EC 1.5.5.1).
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Ribose substituted in the 1-, 3-, or 5-position by a phosphoric acid moiety.
Group of lysosomal storage diseases each caused by an inherited deficiency of an enzyme involved in the degradation of glycosaminoglycans (mucopolysaccharides). The diseases are progressive and often display a wide spectrum of clinical severity within one enzyme deficiency.
2'-Deoxyuridine. An antimetabolite that is converted to deoxyuridine triphosphate during DNA synthesis. Laboratory suppression of deoxyuridine is used to diagnose megaloblastic anemias due to vitamin B12 and folate deficiencies.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 3.1.3.5.
A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
A flavoprotein oxidoreductase that has specificity for medium-chain fatty acids. It forms a complex with ELECTRON TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.
An inherited metabolic disorder caused by deficient enzyme activity in the PYRUVATE DEHYDROGENASE COMPLEX, resulting in deficiency of acetyl CoA and reduced synthesis of acetylcholine. Two clinical forms are recognized: neonatal and juvenile. The neonatal form is a relatively common cause of lactic acidosis in the first weeks of life and may also feature an erythematous rash. The juvenile form presents with lactic acidosis, alopecia, intermittent ATAXIA; SEIZURES; and an erythematous rash. (From J Inherit Metab Dis 1996;19(4):452-62) Autosomal recessive and X-linked forms are caused by mutations in the genes for the three different enzyme components of this multisubunit pyruvate dehydrogenase complex. One of the mutations at Xp22.2-p22.1 in the gene for the E1 alpha component of the complex leads to LEIGH DISEASE.
Inborn errors of metabolism characterized by defects in specific lysosomal hydrolases and resulting in intracellular accumulation of unmetabolized substrates.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
A pyridoxal phosphate enzyme that catalyzes the formation of glutamate gamma-semialdehyde and an L-amino acid from L-ornithine and a 2-keto-acid. EC 2.6.1.13.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
3-((4-Amino-2-methyl-5-pyrimidinyl)methyl)-5-(2- hydroxyethyl)-4-methylthiazolium chloride.
A nonspecific term referring both to the pathologic finding of swelling of distal portions of axons in the brain and to disorders which feature this finding. Neuroaxonal dystrophy is seen in various genetic diseases, vitamin deficiencies, and aging. Infantile neuroaxonal dystrophy is an autosomal recessive disease characterized by arrested psychomotor development at 6 months to 2 years of age, ataxia, brain stem dysfunction, and quadriparesis. Juvenile and adult forms also occur. Pathologic findings include brain atrophy and widespread accumulation of axonal spheroids throughout the neuroaxis, peripheral nerves, and dental pulp. (From Davis & Robertson, Textbook of Neuropathology, 2nd ed, p927)
The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.
An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.
A genetic disorder characterized by excretion of large amounts of OXALATES in urine; NEPHROLITHIASIS; NEPHROCALCINOSIS; early onset of RENAL FAILURE; and often a generalized deposit of CALCIUM OXALATE. There are subtypes classified by the enzyme defects in glyoxylate metabolism.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)
An amino acid produced in the urea cycle by the splitting off of urea from arginine.
Diseases that are caused by genetic mutations present during embryo or fetal development, although they may be observed later in life. The mutations may be inherited from a parent's genome or they may be acquired in utero.
An enzyme catalyzing the formation of AMP from adenine and phosphoribosylpyrophosphate. It can act as a salvage enzyme for recycling of adenine into nucleic acids. EC 2.4.2.7.
A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids.
A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
Adenosine molecules which can be substituted in any position, but are lacking one hydroxyl group in the ribose part of the molecule.
An enzyme, involved in the early steps of purine nucleotide biosynthesis, that catalyzes the formation of 5-phosphoribosylamine from glutamine and phosphoribosylpyrophosphate. EC 2.4.2.14.
An individual in which both alleles at a given locus are identical.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
Pentosephosphates are monosaccharides, specifically pentoses, that have a phosphate group attached, playing crucial roles in carbohydrate metabolism, such as being intermediates in the pentose phosphate pathway and serving as precursors for nucleotide synthesis.
An enzyme that catalyzes the transfer of a formyl group from N10-formyltetrahydrofolate to N1-(5-phospho-D-ribosyl)glycinamide to yield N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide and tetrahydrofolate. It plays a role in the de novo purine biosynthetic pathway.
Proteins involved in the transport of NUCLEOSIDES across cellular membranes.
Genetic defects in the selective or non-selective transport functions of the KIDNEY TUBULES.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
A pyrimidine base that is a fundamental unit of nucleic acids.
An enzyme of the urea cycle which splits argininosuccinate to fumarate plus arginine. Its absence leads to the metabolic disease ARGININOSUCCINIC ACIDURIA in man. EC 4.3.2.1.
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
An enzyme that catalyzes the hydrolysis of ADENOSINE to INOSINE with the elimination of AMMONIA.
A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.

Nucleotide pool imbalance and adenosine deaminase deficiency induce alterations of N-region insertions during V(D)J recombination. (1/71)

Template-independent nucleotide additions (N regions) generated at sites of V(D)J recombination by terminal deoxynucleotidyl transferase (TdT) increase the diversity of antigen receptors. Two inborn errors of purine metabolism, deficiencies of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP), result in defective lymphoid development and aberrant pools of 2'-deoxynucleotides that are substrates for TdT in lymphoid precursors. We have asked whether selective increases in dATP or dGTP pools result in altered N regions in an extrachromosomal substrate transfected into T-cell or pre-B-cell lines. Exposure of the transfected cells to 2'-deoxyadenosine and an ADA inhibitor increased the dATP pool and resulted in a marked increase in A-T insertions at recombination junctions, with an overall decreased frequency of V(D)J recombination. Sequence analysis of VH-DH-JH junctions from the IgM locus in B-cell lines from ADA-deficient patients demonstrated an increase in A-T insertions equivalent to that found in the transfected cells. In contrast, elevation of dGTP pools, as would occur in PNP deficiency, did not alter the already rich G-C content of N regions. We conclude that the frequency of V(D)J recombination and the composition of N-insertions are influenced by increases in dATP levels, potentially leading to alterations in antigen receptors and aberrant lymphoid development. Alterations in N-region insertions may contribute to the B-cell dysfunction associated with ADA deficiency.  (+info)

Capillary electrophoresis for detection of inherited disorders of purine and pyrimidine metabolism. (2/71)

BACKGROUND: Measurement of purine and pyrimidine metabolites presents complex problems for separations currently performed by HPLC and thin-layer chromatography in clinical practice. We developed a novel capillary electrophoresis method for this purpose. METHODS: Separations were performed in 60 mmol/L borate-2-amino-2-methyl-1-propanol-80 mmol/L sodium dodecyl sulfate (pH 9.6) at 35 degrees C. RESULTS: The conditions reported allowed separation of all diagnostic metabolites from major urinary constituents in an analysis time of 3 min and with a separation efficiency of 220 000 theoretical plates/m. The clinically important metabolites were detectable at concentrations of 0.85-4.28 micromol/L. The method was linear over the range 5-500 micromol/L (r >0.99). The within-run and intra- and interday imprecision (CV) was <5%. Characteristic abnormalities were detected in the electropherograms of urine samples from patients with purine and pyrimidine enzyme deficiencies. We provide the electrophoretic and spectral characteristics of many intermediates in purine and pyrimidine metabolism and describe common artifacts from medication and ultraviolet-absorbing compounds. CONCLUSION: Capillary electrophoresis is a valuable screening tool in the detection of inborn errors of purine and pyrimidine metabolism.  (+info)

Hypoxanthine phosphoribosyltransferase deficiency: association of reduced catalytic activity with reduced levels of immunologically detectable enzyme protein. (3/71)

In the present study hemolysates from fourteen patients with a genetically determined deficiency of hypoxanthine phosphoribosyltransferase (EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase) activity were examined immunologically for the presence of material that crossreacts with the normal enzyme. A quantitative assay for crossreacting material in enzyme-deficient hemolysates was based on the inhibition of the immunoprecipitation of the normal enzyme. As little as 3% of normal crossreacting material could be detected. One patient in this series was found to have a normal amount of crossreacting material, whereas the remainder had no detectable crossreacting protein. The lack of detectable crossreacting material in these patients raises the possibility that a defect in synthesis or degradation of enzyme protein may be present in many patients deficient in hypoxanthine phosphoribosyltransferase.  (+info)

Rapid screening of high-risk patients for disorders of purine and pyrimidine metabolism using HPLC-electrospray tandem mass spectrometry of liquid urine or urine-soaked filter paper strips. (4/71)

BACKGROUND: A rapid and specific screening method for patients at risk of inherited disorders of purine and pyrimidine metabolism is desirable because symptoms are varied and nonspecific. The aim of this study was to develop a rapid and specific method for screening with use of liquid urine samples or urine-soaked filter paper strips. METHODS: Reverse-phase HPLC was combined with electrospray ionization (ESI), tandem mass spectrometry (MS/MS), and detection performed by multiple reaction monitoring. Transitions and instrument settings were established for 17 purines or pyrimidines. Stable-isotope-labeled reference compounds were used as internal standards when available. RESULTS: Total analysis time of this method was 15 min, approximately one-third that of conventional HPLC with ultraviolet detection. Recoveries were 96-107% in urine with added analyte, with two exceptions (hypoxanthine, 64%; xanthine, 79%), and 89-110% in urine-soaked filter paper strips, with three exceptions (hypoxanthine, 65%; xanthine, 77%; 5-hydroxymethyluracil, 80%). The expected abnormalities were easily found in samples from patients with purine nucleoside phosphorylase deficiency, ornithine transcarbamylase deficiency, molybdenum cofactor deficiency, adenylosuccinase deficiency, or dihydropyrimidine dehydrogenase deficiency. CONCLUSIONS: HPLC-ESI MS/MS of urine allows rapid screening for disorders of purine and pyrimidine metabolism. The filter paper strips offer the advantage of easy collection, transport, and storage of the urine samples.  (+info)

A deoxyribonucleotidase in mitochondria: involvement in regulation of dNTP pools and possible link to genetic disease. (5/71)

Three cytosolic and one plasma membrane-bound 5'-nucleotidases have been cloned and characterized. Their various substrate specificities suggest widely different functions in nucleotide metabolism. We now describe a 5'-nucleotidase in mitochondria. The enzyme, named dNT-2, dephosphorylates specifically the 5'- and 2'(3')-phosphates of uracil and thymine deoxyribonucleotides. The cDNA of human dNT-2 codes for a 25.9-kDa polypeptide with a typical mitochondrial leader peptide, providing the structural basis for two-step processing during import into the mitochondrial matrix. The deduced amino acid sequence is 52% identical to that of a recently described cytosolic deoxyribonucleotidase (dNT-1). The two enzymes share many catalytic properties, but dNT-2 shows a narrower substrate specificity. Mitochondrial localization of dNT-2 was demonstrated by the mitochondrial fluorescence of 293 cells expressing a dNT-2-green fluorescent protein (GFP) fusion protein. 293 cells expressing fusion proteins without leader peptide or with dNT-1 showed a cytosolic fluorescence. During in vitro import into mitochondria, the preprotein lost the leader peptide. We suggest that dNT-2 protects mitochondrial DNA replication from overproduction of dTTP, in particular in resting cells. Mitochondrial toxicity of dTTP can be inferred from a severe inborn error of metabolism in which the loss of thymidine phosphorylase led to dTTP accumulation and aberrant mitochondrial DNA replication. We localized the gene for dNT-2 on chromosome 17p11.2 in the Smith-Magenis syndrome-critical region, raising the possibility that dNT-2 is involved in the etiology of this genetic disease.  (+info)

Clinical and biochemical observations on three cases of hypoxanthine-guanine phosphoribosyltransferase deficiency. (6/71)

Clinical and enzymatic studies on two brothers with severe deficiencies of erythrocyte hypoxanthineguanine phosphoribosyltransferase (HGPRTase) are described, and are compared with similar studies of a classical case of the Lesch-Nyhan syndrome from another family. The two brothers have no neurological abnormalities, only traces of erythrocyte HGPRTase, erythrocyte adenine phosphoribosyltransferase activities approaching the high levels found in the Lesch-Nyhan patient, and similarly raised plasma and urinary concentrations of uric acid. Despite these strong biochemical similarities between the three patients, there were wide differences in the clinical case histories. In both families the enzyme deficiency appeared to be inherited as an X-linked character through asymptomatic carrier females. The relationship of HGPRTase deficiencies to the Lesch-Nyhan syndrome is discussed. Some observations relating to techniques are reported. Cellulose acetate has been found to give much better separations of labelled reaction products in low-level phosphoribosyltransferase assays than filter paper, when used as a supporting medium for electrophoresis. The analysis of hair follicles gives indications of individuals heterozygous for the enzyme deficiency, but the proportion of enzyme-deficient follicles was very small, and the test needs support from studies of other cell types. Using haemolysates, there were signs of a slow indirect conversion of hypoxanthine to inosinic acid, via inosine. Inosine appears to be labelled by a ribosyl-transfer reaction.  (+info)

Purinogenic immunodeficiency diseases. Differential effects of deoxyadenosine and deoxyguanosine on DNA synthesis in human T lymphoblasts. (7/71)

Deoxyadenosine and deoxyguanosine are toxic to human lymphoid cells in culture and have been implicated in the pathogenesis of the immunodeficiency states associated with adenosine deaminase and purine nucleoside phosphorylase deficiency, respectively. We have studied the relative incorporation of several labeled nucleosides into DNA and into nucleotide pools to further elucidate the mechanism of deoxyribonucleoside toxicity. In the presence of an inhibitor of adenosine deaminase [erythro-9-(2-hydroxy-3-nonyl)adenine [EHNA], 5 muM], deoxyadenosine (1-50 muM) progressively decreased the incorporation of thymidine, uridine, and deoxyuridine into DNA, but did not affect uridine incorporation into RNA. This decrease in DNA synthesis was associated with increasing dATP and decreasing dCTP pools. Likewise, incubation of cells with deoxyguanosine caused an elevation of dGTP, depletion of dCTP, and inhibition of DNA synthesis. To test the hypothesis that dATP and dGTP accumulation inhibit DNA synthesis by inhibiting the enzyme ribonucleotide reductase, simultaneous rates of incorporation of [(3)H]uridine and [(14)C]thymidine into DNA were measured in the presence of deoxyadenosine plus EHNA or deoxyguanosine, and in the presence of hydroxyurea, a known inhibitor of ribonucleotide reductase. Hydroxyurea (100 muM) and deoxyguanosine (10 muM) decreased the incorporation of [(3)H]uridine but not of [(14)C]thymidine into DNA; both compounds also substantially increased [(3)H]cytidine incorporation into the ribonucleotide pool while reducing incorporation into the deoxyribonucleotide pool. In contrast, deoxyadenosine plus EHNA did not show this differential inhibition of [(3)H]uridine incorporation into DNA, and the alteration in [(3)H]cytidine incorporation into nucleotide pools was less impressive. These data show an association between accumulation of dATP or dGTP and a primary inhibition of DNA synthesis, and they provide support for ribonucleotide reductase inhibition as the mechanism responsible for deoxyguanosine toxicity. Deoxyadenosine toxicity, however, appears to result from another, or perhaps a combination of, molecular event(s).  (+info)

Persistence and expression of the adenosine deaminase gene for 12 years and immune reaction to gene transfer components: long-term results of the first clinical gene therapy trial. (8/71)

The first human gene therapy experiment begun in September 1990 used a retroviral vector containing the human adenosine deaminase (ADA) cDNA to transduce mature peripheral blood lymphocytes from patients with ADA deficiency, an inherited disorder of immunity. Two patients who had been treated with intramuscular injections of pegylated bovine ADA (PEG-ADA) for 2 to 4 years were enrolled in this trial and each received a total of approximately 10(11) cells in 11 or 12 infusions over a period of about 2 years. No adverse events were observed. During and after treatment, the patients continued to receive PEG-ADA, although at a reduced dose. Ten years after the last cell infusion, approximately 20% of the first patient's lymphocytes still carry and express the retroviral gene, indicating that the effects of gene transfer can be remarkably long lasting. On the contrary, the persistence of gene-marked cells is very low (< 0.1%), and no expression of the transgene is detectable in lymphocytes from the second patient who developed persisting antibodies to components of the gene transfer system. Data collected from these original patients have provided novel information about the longevity of T lymphocytes in humans and persistence of gene expression in vivo from vectors driven by the Moloney murine leukemia virus long-terminal repeat (LTR) promoter. This long-term follow-up has also provided unique evidence supporting the safety of retroviral-mediated gene transfer and illustrates clear examples of both the potential and the pitfalls of gene therapy in humans.  (+info)

Purines are heterocyclic aromatic organic compounds that consist of a pyrimidine ring fused to an imidazole ring. They are fundamental components of nucleotides, which are the building blocks of DNA and RNA. In the body, purines can be synthesized endogenously or obtained through dietary sources such as meat, seafood, and certain vegetables.

Once purines are metabolized, they are broken down into uric acid, which is excreted by the kidneys. Elevated levels of uric acid in the body can lead to the formation of uric acid crystals, resulting in conditions such as gout or kidney stones. Therefore, maintaining a balanced intake of purine-rich foods and ensuring proper kidney function are essential for overall health.

Pyrimidines are heterocyclic aromatic organic compounds similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring. They are one of the two types of nucleobases found in nucleic acids, the other being purines. The pyrimidine bases include cytosine (C) and thymine (T) in DNA, and uracil (U) in RNA, which pair with guanine (G) and adenine (A), respectively, through hydrogen bonding to form the double helix structure of nucleic acids. Pyrimidines are also found in many other biomolecules and have various roles in cellular metabolism and genetic regulation.

Inborn errors of purine-pyrimidine metabolism refer to genetic disorders that result in dysfunctional enzymes involved in the metabolic pathways of purines and pyrimidines. These are essential components of nucleotides, which in turn are building blocks of DNA and RNA.

Inherited as autosomal recessive or X-linked recessive traits, these disorders can lead to an accumulation of toxic metabolites, a deficiency of necessary compounds, or both. Clinical features vary widely depending on the specific enzyme defect but may include neurologic symptoms, kidney problems, gout, and/or immunodeficiency.

Examples of such disorders include Lesch-Nyhan syndrome (deficiency of hypoxanthine-guanine phosphoribosyltransferase), adenosine deaminase deficiency (leading to severe combined immunodeficiency), and orotic aciduria (due to defects in pyrimidine metabolism). Early diagnosis and management are crucial to improve outcomes.

Inborn errors of metabolism (IEM) refer to a group of genetic disorders caused by defects in enzymes or transporters that play a role in the body's metabolic processes. These disorders result in the accumulation or deficiency of specific chemicals within the body, which can lead to various clinical manifestations, such as developmental delay, intellectual disability, seizures, organ damage, and in some cases, death.

Examples of IEM include phenylketonuria (PKU), maple syrup urine disease (MSUD), galactosemia, and glycogen storage diseases, among many others. These disorders are typically inherited in an autosomal recessive manner, meaning that an affected individual has two copies of the mutated gene, one from each parent.

Early diagnosis and management of IEM are crucial to prevent or minimize complications and improve outcomes. Treatment options may include dietary modifications, supplementation with missing enzymes or cofactors, medication, and in some cases, stem cell transplantation or gene therapy.

Pyrimidine nucleotides are organic compounds that play crucial roles in various biological processes, particularly in the field of genetics and molecular biology. They are the building blocks of nucleic acids, which include DNA and RNA, and are essential for the storage, transmission, and expression of genetic information within cells.

Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring. Pyrimidine nucleotides are derivatives of pyrimidine, which contain a phosphate group, a pentose sugar (ribose or deoxyribose), and one of three pyrimidine bases: cytosine (C), thymine (T), or uracil (U).

* Cytosine is present in both DNA and RNA. It pairs with guanine via hydrogen bonding during DNA replication and transcription.
* Thymine is exclusively found in DNA, where it pairs with adenine through two hydrogen bonds.
* Uracil is a pyrimidine base that replaces thymine in RNA molecules and pairs with adenine via two hydrogen bonds during RNA transcription.

Pyrimidine nucleotides, along with purine nucleotides (adenine, guanine, and their derivatives), form the fundamental units of nucleic acids, contributing to the structure, function, and regulation of genetic material in living organisms.

Pyrimidine nucleosides are organic compounds that consist of a pyrimidine base (a heterocyclic aromatic ring containing two nitrogen atoms and four carbon atoms) linked to a sugar molecule, specifically ribose or deoxyribose, via a β-glycosidic bond. The pyrimidine bases found in nucleosides can be cytosine (C), thymine (T), or uracil (U). When the sugar component is ribose, it is called a pyrimidine nucleoside, and when it is linked to deoxyribose, it is referred to as a deoxy-pyrimidine nucleoside. These molecules play crucial roles in various biological processes, particularly in the structure and function of nucleic acids such as DNA and RNA.

Uridine phosphorylase is an enzyme that plays a role in the metabolism of nucleosides, specifically uridine. The medical definition of 'uridine phosphorylase' is:

An enzyme (EC 2.4.2.3) involved in the reversible phosphorolysis of uridine to uracil and ribose-1-phosphate. This enzyme also catalyzes the phosphorolytic cleavage of other pyrimidine nucleosides, such as cytidine and thymidine, into their respective bases and ribose-1-phosphate. Uridine phosphorylase has a role in the salvage pathway of pyrimidine nucleotide biosynthesis and is found in various tissues, including the liver, intestines, and blood cells. Deficiency or dysfunction of uridine phosphorylase can lead to impaired nucleotide metabolism and may be associated with certain medical conditions, such as hereditary orotic aciduria.

Uridine kinase is an enzyme that phosphorylates the pyrimidine nucleoside uridine to produce uridine monophosphate (UMP). This reaction plays a crucial role in the salvage pathway of pyrimidine nucleotide synthesis, which recycles nucleosides generated from the degradation of RNA.

The human genome encodes two isoforms of uridine kinase, UCK1 and UCK2, which share a high degree of sequence similarity but have distinct tissue expression patterns and subcellular localization. UCK1 is primarily expressed in the liver and kidney, while UCK2 is more widely expressed in various tissues.

Uridine kinase activity has been implicated in several physiological processes, including the regulation of intracellular nucleotide pools, the biosynthesis of glycosaminoglycans and proteoglycans, and the modulation of antiviral responses. Dysregulation of uridine kinase activity has been associated with various pathological conditions, such as cancer, viral infections, and neurological disorders.

Orotic acid, also known as pyrmidine carboxylic acid, is a organic compound that plays a role in the metabolic pathway for the biosynthesis of pyrimidines, which are nitrogenous bases found in nucleotides and nucleic acids such as DNA and RNA. Orotic acid is not considered to be a vitamin, but it is sometimes referred to as vitamin B13 or B15, although these designations are not widely recognized by the scientific community.

In the body, orotic acid is converted into orotidine monophosphate (OMP) by the enzyme orotate phosphoribosyltransferase. OMP is then further metabolized to form uridine monophosphate (UMP), a pyrimidine nucleotide that is an important precursor for the synthesis of RNA and other molecules.

Elevated levels of orotic acid in the urine, known as orotic aciduria, can be a sign of certain genetic disorders that affect the metabolism of pyrimidines. These conditions can lead to an accumulation of orotic acid and other pyrimidine precursors in the body, which can cause a range of symptoms including developmental delays, neurological problems, and kidney stones. Treatment for these disorders typically involves dietary restrictions and supplementation with nucleotides or nucleosides to help support normal pyrimidine metabolism.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Uracil is not a medical term, but it is a biological molecule. Medically or biologically, uracil can be defined as one of the four nucleobases in the nucleic acid of RNA (ribonucleic acid) that is linked to a ribose sugar by an N-glycosidic bond. It forms base pairs with adenine in double-stranded RNA and DNA. Uracil is a pyrimidine derivative, similar to thymine found in DNA, but it lacks the methyl group (-CH3) that thymine has at the 5 position of its ring.

Inborn errors of amino acid metabolism refer to genetic disorders that affect the body's ability to properly break down and process individual amino acids, which are the building blocks of proteins. These disorders can result in an accumulation of toxic levels of certain amino acids or their byproducts in the body, leading to a variety of symptoms and health complications.

There are many different types of inborn errors of amino acid metabolism, each affecting a specific amino acid or group of amino acids. Some examples include:

* Phenylketonuria (PKU): This disorder affects the breakdown of the amino acid phenylalanine, leading to its accumulation in the body and causing brain damage if left untreated.
* Maple syrup urine disease: This disorder affects the breakdown of the branched-chain amino acids leucine, isoleucine, and valine, leading to their accumulation in the body and causing neurological problems.
* Homocystinuria: This disorder affects the breakdown of the amino acid methionine, leading to its accumulation in the body and causing a range of symptoms including developmental delay, intellectual disability, and cardiovascular problems.

Treatment for inborn errors of amino acid metabolism typically involves dietary restrictions or supplementation to manage the levels of affected amino acids in the body. In some cases, medication or other therapies may also be necessary. Early diagnosis and treatment can help prevent or minimize the severity of symptoms and health complications associated with these disorders.

Uridine is a nucleoside that consists of a pyrimidine base (uracil) linked to a pentose sugar (ribose). It is a component of RNA, where it pairs with adenine. Uridine can also be found in various foods such as beer, broccoli, yeast, and meat. In the body, uridine can be synthesized from orotate or from the breakdown of RNA. It has several functions, including acting as a building block for RNA, contributing to energy metabolism, and regulating cell growth and differentiation. Uridine is also available as a dietary supplement and has been studied for its potential benefits in various health conditions.

Pentosyltransferases are a group of enzymes that catalyze the transfer of a pentose (a sugar containing five carbon atoms) molecule from one compound to another. These enzymes play important roles in various biochemical pathways, including the biosynthesis of nucleotides, glycoproteins, and other complex carbohydrates.

One example of a pentosyltransferase is the enzyme that catalyzes the addition of a ribose sugar to form a glycosidic bond with a purine or pyrimidine base during the biosynthesis of nucleotides, which are the building blocks of DNA and RNA.

Another example is the enzyme that adds xylose residues to proteins during the formation of glycoproteins, which are proteins that contain covalently attached carbohydrate chains. These enzymes are essential for many biological processes and have been implicated in various diseases, including cancer and neurodegenerative disorders.

Purine nucleotides are fundamental units of life that play crucial roles in various biological processes. A purine nucleotide is a type of nucleotide, which is the basic building block of nucleic acids such as DNA and RNA. Nucleotides consist of a nitrogenous base, a pentose sugar, and at least one phosphate group.

In purine nucleotides, the nitrogenous bases are either adenine (A) or guanine (G). These bases are attached to a five-carbon sugar called ribose in the case of RNA or deoxyribose for DNA. The sugar and base together form the nucleoside, while the addition of one or more phosphate groups creates the nucleotide.

Purine nucleotides have several vital functions within cells:

1. Energy currency: Adenosine triphosphate (ATP) is a purine nucleotide that serves as the primary energy currency in cells, storing and transferring chemical energy for various cellular processes.
2. Genetic material: Both DNA and RNA contain purine nucleotides as essential components of their structures. Adenine pairs with thymine (in DNA) or uracil (in RNA), while guanine pairs with cytosine.
3. Signaling molecules: Purine nucleotides, such as adenosine monophosphate (AMP) and cyclic adenosine monophosphate (cAMP), act as intracellular signaling molecules that regulate various cellular functions, including metabolism, gene expression, and cell growth.
4. Coenzymes: Purine nucleotides can also function as coenzymes, assisting enzymes in catalyzing biochemical reactions. For example, nicotinamide adenine dinucleotide (NAD+) is a purine nucleotide that plays a critical role in redox reactions and energy metabolism.

In summary, purine nucleotides are essential biological molecules involved in various cellular functions, including energy transfer, genetic material formation, intracellular signaling, and enzyme cofactor activity.

Pyrimidine dimers are a type of DNA lesion that form when two adjacent pyrimidine bases on the same strand of DNA become covalently linked, usually as a result of exposure to ultraviolet (UV) light. The most common type of pyrimidine dimer is the cyclobutane pyrimidine dimer (CPD), which forms when two thymine bases are linked together in a cyclobutane ring structure.

Pyrimidine dimers can distort the DNA helix and interfere with normal replication and transcription processes, leading to mutations and potentially cancer. The formation of pyrimidine dimers is a major mechanism by which UV radiation causes skin damage and increases the risk of skin cancer.

The body has several mechanisms for repairing pyrimidine dimers, including nucleotide excision repair (NER) and base excision repair (BER). However, if these repair mechanisms are impaired or overwhelmed, pyrimidine dimers can persist and contribute to the development of cancer.

Purine nucleosides are fundamental components of nucleic acids, which are the genetic materials found in all living organisms. A purine nucleoside is composed of a purine base (either adenine or guanine) linked to a sugar molecule, specifically ribose in the case of purine nucleosides.

The purine base and sugar moiety are joined together through a glycosidic bond at the 1' position of the sugar. These nucleosides play crucial roles in various biological processes, including energy transfer, signal transduction, and as precursors for the biosynthesis of DNA and RNA.

In the human body, purine nucleosides can be derived from the breakdown of endogenous nucleic acids or through the dietary intake of nucleoproteins. They are further metabolized to form uric acid, which is eventually excreted in the urine. Elevated levels of uric acid in the body can lead to the formation of uric acid crystals and contribute to the development of gout or kidney stones.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

Inborn errors of lipid metabolism refer to genetic disorders that affect the body's ability to break down and process lipids (fats) properly. These disorders are caused by defects in genes that code for enzymes or proteins involved in lipid metabolism. As a result, toxic levels of lipids or their intermediates may accumulate in the body, leading to various health issues, which can include neurological problems, liver dysfunction, muscle weakness, and cardiovascular disease.

There are several types of inborn errors of lipid metabolism, including:

1. Disorders of fatty acid oxidation: These disorders affect the body's ability to convert long-chain fatty acids into energy, leading to muscle weakness, hypoglycemia, and cardiomyopathy. Examples include medium-chain acyl-CoA dehydrogenase deficiency (MCAD) and very long-chain acyl-CoA dehydrogenase deficiency (VLCAD).
2. Disorders of cholesterol metabolism: These disorders affect the body's ability to process cholesterol, leading to an accumulation of cholesterol or its intermediates in various tissues. Examples include Smith-Lemli-Opitz syndrome and lathosterolosis.
3. Disorders of sphingolipid metabolism: These disorders affect the body's ability to break down sphingolipids, leading to an accumulation of these lipids in various tissues. Examples include Gaucher disease, Niemann-Pick disease, and Fabry disease.
4. Disorders of glycerophospholipid metabolism: These disorders affect the body's ability to break down glycerophospholipids, leading to an accumulation of these lipids in various tissues. Examples include rhizomelic chondrodysplasia punctata and abetalipoproteinemia.

Inborn errors of lipid metabolism are typically diagnosed through genetic testing and biochemical tests that measure the activity of specific enzymes or the levels of specific lipids in the body. Treatment may include dietary modifications, supplements, enzyme replacement therapy, or gene therapy, depending on the specific disorder and its severity.

Neonatal screening is a medical procedure in which specific tests are performed on newborn babies within the first few days of life to detect certain congenital or inherited disorders that are not otherwise clinically apparent at birth. These conditions, if left untreated, can lead to serious health problems, developmental delays, or even death.

The primary goal of neonatal screening is to identify affected infants early so that appropriate treatment and management can be initiated as soon as possible, thereby improving their overall prognosis and quality of life. Commonly screened conditions include phenylketonuria (PKU), congenital hypothyroidism, galactosemia, maple syrup urine disease, sickle cell disease, cystic fibrosis, and hearing loss, among others.

Neonatal screening typically involves collecting a small blood sample from the infant's heel (heel stick) or through a dried blood spot card, which is then analyzed using various biochemical, enzymatic, or genetic tests. In some cases, additional tests such as hearing screenings and pulse oximetry for critical congenital heart disease may also be performed.

It's important to note that neonatal screening is not a diagnostic tool but rather an initial step in identifying infants who may be at risk of certain conditions. Positive screening results should always be confirmed with additional diagnostic tests before any treatment decisions are made.

Inborn errors of steroid metabolism refer to genetic disorders that affect the synthesis or degradation of steroid hormones in the body. Steroids are a group of hormones that include cortisol, aldosterone, sex hormones (estrogens and androgens), and bile acids. These hormones are produced through a series of biochemical reactions called steroidogenesis, which involves several enzymes.

Inborn errors of steroid metabolism occur when there is a mutation in the gene encoding for one or more of these enzymes, leading to impaired steroid synthesis or degradation. This can result in an accumulation of abnormal steroid metabolites or deficiency of essential steroid hormones, causing various clinical manifestations depending on the specific steroid hormone affected and the severity of the enzyme deficiency.

Examples of inborn errors of steroid metabolism include congenital adrenal hyperplasia (CAH), which is caused by defects in the genes encoding for enzymes involved in cortisol synthesis, such as 21-hydroxylase and 11-beta-hydroxylase. CAH can lead to impaired cortisol production, increased production of androgens, and abnormal genital development in affected individuals.

Another example is lipoid congenital adrenal hyperplasia (LCAH), which is caused by a deficiency in the enzyme steroidogenic acute regulatory protein (StAR). LCAH results in impaired transport of cholesterol into the mitochondria, leading to deficient synthesis of all steroid hormones and accumulation of lipids in the adrenal glands.

Inborn errors of steroid metabolism can be diagnosed through various tests, including blood and urine tests to measure steroid levels and genetic testing to identify mutations in the relevant genes. Treatment typically involves replacement therapy with the deficient hormones or inhibition of excessive hormone production.

Inborn errors of carbohydrate metabolism refer to genetic disorders that affect the body's ability to break down and process carbohydrates, which are sugars and starches that provide energy for the body. These disorders are caused by defects in enzymes or transport proteins that play a critical role in the metabolic pathways involved in carbohydrate metabolism.

There are several types of inborn errors of carbohydrate metabolism, including:

1. Galactosemia: This disorder affects the body's ability to metabolize the sugar galactose, which is found in milk and other dairy products. It is caused by a deficiency of the enzyme galactose-1-phosphate uridylyltransferase.
2. Glycogen storage diseases: These disorders affect the body's ability to store and break down glycogen, which is a complex carbohydrate that serves as a source of energy for the body. There are several types of glycogen storage diseases, each caused by a deficiency in a different enzyme involved in glycogen metabolism.
3. Hereditary fructose intolerance: This disorder affects the body's ability to metabolize the sugar fructose, which is found in fruits and sweeteners. It is caused by a deficiency of the enzyme aldolase B.
4. Pentose phosphate pathway disorders: These disorders affect the body's ability to metabolize certain sugars and generate energy through the pentose phosphate pathway. They are caused by defects in enzymes involved in this pathway.

Symptoms of inborn errors of carbohydrate metabolism can vary widely depending on the specific disorder and its severity. Treatment typically involves dietary restrictions, supplementation with necessary enzymes or cofactors, and management of complications. In some cases, enzyme replacement therapy or even organ transplantation may be considered.

Inborn urea cycle disorders (UCDs) are a group of rare genetic metabolic disorders caused by deficiencies in one of the enzymes or transporters that make up the urea cycle. The urea cycle is a series of biochemical reactions that occur in liver cells, responsible for removing ammonia, a toxic byproduct of protein metabolism, from the bloodstream.

In UCDs, the impaired function of these enzymes or transporters leads to an accumulation of ammonia in the blood (hyperammonemia), which can cause irreversible brain damage and severe neurological symptoms if left untreated. These disorders are usually inherited in an autosomal recessive manner, meaning that an affected individual has two copies of the mutated gene, one from each parent.

There are six main types of UCDs, classified based on the specific enzyme or transporter deficiency:

1. Carbamoyl phosphate synthetase I (CPS1) deficiency
2. Ornithine transcarbamylase (OTC) deficiency
3. Argininosuccinic aciduria (ASA)
4. Citrullinemia type I or II (CTLN1, CTLN2)
5. Arginase deficiency
6. N-acetylglutamate synthetase (NAGS) deficiency

Symptoms of UCDs can vary widely depending on the severity and specific type of the disorder but may include:

* Vomiting
* Lethargy or irritability
* Seizures
* Tremors or seizure-like activity
* Developmental delays or intellectual disability
* Coma

Early diagnosis and treatment are crucial to prevent long-term neurological damage. Treatment options include dietary restrictions, medications that help remove ammonia from the body, and liver transplantation in severe cases. Regular monitoring of blood ammonia levels and other metabolic markers is essential for managing UCDs effectively.

Metabolic brain diseases are a group of disorders caused by genetic defects that affect the body's metabolism and result in abnormal accumulation of harmful substances in the brain. These conditions are present at birth (inborn) or develop during infancy or early childhood. Examples of metabolic brain diseases that are present at birth include:

1. Phenylketonuria (PKU): A disorder caused by a deficiency of the enzyme phenylalanine hydroxylase, which leads to an accumulation of phenylalanine in the brain and can cause intellectual disability, seizures, and behavioral problems if left untreated.
2. Maple syrup urine disease (MSUD): A disorder caused by a deficiency of the enzyme branched-chain ketoacid dehydrogenase, which leads to an accumulation of branched-chain amino acids in the body and can cause intellectual disability, seizures, and metabolic crisis if left untreated.
3. Urea cycle disorders: A group of disorders caused by defects in enzymes that help remove ammonia from the body. Accumulation of ammonia in the blood can lead to brain damage, coma, or death if not treated promptly.
4. Organic acidemias: A group of disorders caused by defects in enzymes that help break down certain amino acids and other organic compounds. These conditions can cause metabolic acidosis, seizures, and developmental delays if left untreated.

Early diagnosis and treatment of these conditions are crucial to prevent irreversible brain damage and other complications. Treatment typically involves dietary restrictions, supplements, and medications to manage the underlying metabolic imbalance. In some cases, enzyme replacement therapy or liver transplantation may be necessary.

Argininosuccinic aciduria (ASA) is a rare inherited metabolic disorder caused by a deficiency of the enzyme argininosuccinate lyase. This enzyme is necessary for the urea cycle, a process that helps rid the body of excess nitrogen produced from protein breakdown. When the urea cycle is not functioning properly, nitrogen accumulates in the form of ammonia, which can be toxic to the brain and other organs.

In ASA, argininosuccinic acid builds up in the blood and urine, giving the condition its name. Symptoms of ASA typically appear within the first few days or weeks of life and may include poor feeding, vomiting, lethargy, seizures, and developmental delay. If left untreated, ASA can lead to serious complications such as intellectual disability, coma, and even death.

Treatment for ASA usually involves a combination of dietary restrictions, medications to reduce ammonia levels, and supplementation with arginine, an amino acid that is not properly metabolized in people with ASA. In some cases, liver transplantation may be necessary. Early diagnosis and treatment are crucial for improving outcomes in individuals with ASA.

Purine-nucleoside phosphorylase (PNP) is an enzyme that plays a crucial role in the metabolism of purines, which are essential components of nucleic acids (DNA and RNA). The medical definition of 'Purine-Nucleoside Phosphorylase' refers to the physiological function of this enzyme in the human body.

PNP is responsible for catalyzing the phosphorolytic cleavage of purine nucleosides, such as inosine and guanosine, into their respective purine bases (hypoxanthine and guanine) and ribose-1-phosphate. This reaction is essential for the recycling and salvage of purine bases, allowing the body to conserve energy and resources needed for de novo purine biosynthesis.

In a clinical or medical context, deficiencies in PNP activity can lead to serious consequences, particularly affecting the immune system and the nervous system. A genetic disorder called Purine-Nucleoside Phosphorylase Deficiency (PNP Deficiency) is characterized by significantly reduced or absent PNP enzyme activity, leading to an accumulation of toxic purine nucleosides and deoxypurine nucleosides. This accumulation can cause severe combined immunodeficiency (SCID), neurological impairments, and other complications, making it a critical area of study in medical research.

Hyperammonemia is a medical condition characterized by an excessively high level of ammonia (a toxic byproduct of protein metabolism) in the blood. This can lead to serious neurological symptoms and complications, as ammonia is highly toxic to the brain. Hyperammonemia can be caused by various underlying conditions, including liver disease, genetic disorders that affect ammonia metabolism, certain medications, and infections. It is important to diagnose and treat hyperammonemia promptly to prevent long-term neurological damage or even death. Treatment typically involves addressing the underlying cause of the condition, as well as providing supportive care such as administering medications that help remove ammonia from the blood.

Energy metabolism is the process by which living organisms produce and consume energy to maintain life. It involves a series of chemical reactions that convert nutrients from food, such as carbohydrates, fats, and proteins, into energy in the form of adenosine triphosphate (ATP).

The process of energy metabolism can be divided into two main categories: catabolism and anabolism. Catabolism is the breakdown of nutrients to release energy, while anabolism is the synthesis of complex molecules from simpler ones using energy.

There are three main stages of energy metabolism: glycolysis, the citric acid cycle (also known as the Krebs cycle), and oxidative phosphorylation. Glycolysis occurs in the cytoplasm of the cell and involves the breakdown of glucose into pyruvate, producing a small amount of ATP and nicotinamide adenine dinucleotide (NADH). The citric acid cycle takes place in the mitochondria and involves the further breakdown of pyruvate to produce more ATP, NADH, and carbon dioxide. Oxidative phosphorylation is the final stage of energy metabolism and occurs in the inner mitochondrial membrane. It involves the transfer of electrons from NADH and other electron carriers to oxygen, which generates a proton gradient across the membrane. This gradient drives the synthesis of ATP, producing the majority of the cell's energy.

Overall, energy metabolism is a complex and essential process that allows organisms to grow, reproduce, and maintain their bodily functions. Disruptions in energy metabolism can lead to various diseases, including diabetes, obesity, and neurodegenerative disorders.

Lipid metabolism is the process by which the body breaks down and utilizes lipids (fats) for various functions, such as energy production, cell membrane formation, and hormone synthesis. This complex process involves several enzymes and pathways that regulate the digestion, absorption, transport, storage, and consumption of fats in the body.

The main types of lipids involved in metabolism include triglycerides, cholesterol, phospholipids, and fatty acids. The breakdown of these lipids begins in the digestive system, where enzymes called lipases break down dietary fats into smaller molecules called fatty acids and glycerol. These molecules are then absorbed into the bloodstream and transported to the liver, which is the main site of lipid metabolism.

In the liver, fatty acids may be further broken down for energy production or used to synthesize new lipids. Excess fatty acids may be stored as triglycerides in specialized cells called adipocytes (fat cells) for later use. Cholesterol is also metabolized in the liver, where it may be used to synthesize bile acids, steroid hormones, and other important molecules.

Disorders of lipid metabolism can lead to a range of health problems, including obesity, diabetes, cardiovascular disease, and non-alcoholic fatty liver disease (NAFLD). These conditions may be caused by genetic factors, lifestyle habits, or a combination of both. Proper diagnosis and management of lipid metabolism disorders typically involves a combination of dietary changes, exercise, and medication.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Phenylketonurias (PKU) is a genetic disorder characterized by the body's inability to properly metabolize the amino acid phenylalanine, due to a deficiency of the enzyme phenylalanine hydroxylase. This results in a buildup of phenylalanine in the blood and other tissues, which can cause serious neurological problems if left untreated.

The condition is typically detected through newborn screening and can be managed through a strict diet that limits the intake of phenylalanine. If left untreated, PKU can lead to intellectual disability, seizures, behavioral problems, and other serious health issues. In some cases, medication or a liver transplant may also be necessary to manage the condition.

Pyrimidine phosphorylases are a group of enzymes that play a crucial role in the metabolism of pyrimidines, which are nitrogenous bases found in nucleic acids such as DNA and RNA. These enzymes catalyze the reversible phosphorolytic cleavage of pyrimidine nucleosides into ribose-1-phosphate and a free base.

There are two main types of pyrimidine phosphorylases: cytosine phosphorylase (CP) and thymidine phosphorylase (TP). CP catalyzes the conversion of cytosine to uracil, while TP converts thymidine to thymine. These enzymes are important in maintaining the balance of pyrimidines in cells and are also involved in the salvage pathway for nucleotide synthesis.

Deficiencies or mutations in these enzymes can lead to various genetic disorders, including neurological and developmental abnormalities. Additionally, TP has been studied as a potential target for cancer therapy due to its role in angiogenesis and tumor growth.

Smith-Lemli-Opitz syndrome (SLOS) is a genetic disorder that affects the development of multiple body systems. It is caused by a deficiency in the enzyme 7-dehydrocholesterol reductase, which is needed for the production of cholesterol in the body.

The symptoms of SLOS can vary widely in severity, but often include developmental delays, intellectual disability, low muscle tone (hypotonia), feeding difficulties, and behavioral problems. Physical abnormalities may also be present, such as cleft palate, heart defects, extra fingers or toes (polydactyly), and genital abnormalities in males.

SLOS is an autosomal recessive disorder, which means that an individual must inherit two copies of the mutated gene (one from each parent) in order to develop the condition. It is typically diagnosed through genetic testing and biochemical analysis of blood or body fluids. Treatment for SLOS may include cholesterol supplementation, special education services, and management of associated medical conditions.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Oxidoreductases acting on CH-CH group donors are a class of enzymes within the larger group of oxidoreductases, which are responsible for catalyzing oxidation-reduction reactions. Specifically, this subclass of enzymes acts upon donors containing a carbon-carbon (CH-CH) bond, where one atom or group of atoms is oxidized and another is reduced during the reaction process. These enzymes play crucial roles in various metabolic pathways, including the breakdown and synthesis of carbohydrates, lipids, and amino acids.

The reactions catalyzed by these enzymes involve the transfer of electrons and hydrogen atoms between the donor and an acceptor molecule. This process often results in the formation or cleavage of carbon-carbon bonds, making them essential for numerous biological processes. The systematic name for this class of enzymes is typically structured as "donor:acceptor oxidoreductase," where donor and acceptor represent the molecules involved in the electron transfer process.

Examples of enzymes that fall under this category include:

1. Aldehyde dehydrogenases (EC 1.2.1.3): These enzymes catalyze the oxidation of aldehydes to carboxylic acids, using NAD+ as an electron acceptor.
2. Dihydrodiol dehydrogenase (EC 1.3.1.14): This enzyme is responsible for the oxidation of dihydrodiols to catechols in the biodegradation of aromatic compounds.
3. Succinate dehydrogenase (EC 1.3.5.1): A key enzyme in the citric acid cycle, succinate dehydrogenase catalyzes the oxidation of succinate to fumarate and reduces FAD to FADH2.
4. Xylose reductase (EC 1.1.1.307): This enzyme is involved in the metabolism of pentoses, where it reduces xylose to xylitol using NADPH as a cofactor.

Hypoxanthine is a purine derivative and an intermediate in the metabolic pathways of nucleotide degradation, specifically adenosine to uric acid in humans. It is formed from the oxidation of xanthine by the enzyme xanthine oxidase. In the body, hypoxanthine is converted to xanthine and then to uric acid, which is excreted in the urine. Increased levels of hypoxanthine in the body can be indicative of various pathological conditions, including tissue hypoxia, ischemia, and necrosis.

Hypoxanthine is not a medical condition but a purine base that is a component of many organic compounds, including nucleotides and nucleic acids, which are the building blocks of DNA and RNA. In the body, hypoxanthine is produced as a byproduct of normal cellular metabolism and is converted to xanthine and then uric acid, which is excreted in the urine.

However, abnormally high levels of hypoxanthine in the body can indicate tissue damage or disease. For example, during intense exercise or hypoxia (low oxygen levels), cells may break down ATP (adenosine triphosphate) rapidly, releasing large amounts of hypoxanthine. Similarly, in some genetic disorders such as Lesch-Nyhan syndrome, there is an accumulation of hypoxanthine due to a deficiency of the enzyme that converts it to xanthine. High levels of hypoxanthine can lead to the formation of kidney stones and other complications.

According to the medical definition, ultraviolet (UV) rays are invisible radiations that fall in the range of the electromagnetic spectrum between 100-400 nanometers. UV rays are further divided into three categories: UVA (320-400 nm), UVB (280-320 nm), and UVC (100-280 nm).

UV rays have various sources, including the sun and artificial sources like tanning beds. Prolonged exposure to UV rays can cause damage to the skin, leading to premature aging, eye damage, and an increased risk of skin cancer. UVA rays penetrate deeper into the skin and are associated with skin aging, while UVB rays primarily affect the outer layer of the skin and are linked to sunburns and skin cancer. UVC rays are the most harmful but fortunately, they are absorbed by the Earth's atmosphere and do not reach the surface.

Healthcare professionals recommend limiting exposure to UV rays, wearing protective clothing, using broad-spectrum sunscreen with an SPF of at least 30, and avoiding tanning beds to reduce the risk of UV-related health problems.

Inosine is not a medical condition but a naturally occurring compound called a nucleoside, which is formed from the combination of hypoxanthine and ribose. It is an intermediate in the metabolic pathways of purine nucleotides, which are essential components of DNA and RNA. Inosine has been studied for its potential therapeutic benefits in various medical conditions, including neurodegenerative disorders, cardiovascular diseases, and cancer. However, more research is needed to fully understand its mechanisms and clinical applications.

A newborn infant is a baby who is within the first 28 days of life. This period is also referred to as the neonatal period. Newborns require specialized care and attention due to their immature bodily systems and increased vulnerability to various health issues. They are closely monitored for signs of well-being, growth, and development during this critical time.

Refractive errors are a group of vision conditions that include nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. These conditions occur when the shape of the eye prevents light from focusing directly on the retina, causing blurred or distorted vision.

Myopia is a condition where distant objects appear blurry while close-up objects are clear. This occurs when the eye is too long or the cornea is too curved, causing light to focus in front of the retina instead of directly on it.

Hyperopia, on the other hand, is a condition where close-up objects appear blurry while distant objects are clear. This happens when the eye is too short or the cornea is not curved enough, causing light to focus behind the retina.

Astigmatism is a condition that causes blurred vision at all distances due to an irregularly shaped cornea or lens.

Presbyopia is a natural aging process that affects everyone as they get older, usually around the age of 40. It causes difficulty focusing on close-up objects and can be corrected with reading glasses, bifocals, or progressive lenses.

Refractive errors can be diagnosed through a comprehensive eye exam and are typically corrected with eyeglasses, contact lenses, or refractive surgery such as LASIK.

A nucleoside is a biochemical molecule that consists of a pentose sugar (a type of simple sugar with five carbon atoms) covalently linked to a nitrogenous base. The nitrogenous base can be one of several types, including adenine, guanine, cytosine, thymine, or uracil. Nucleosides are important components of nucleic acids, such as DNA and RNA, which are the genetic materials found in cells. They play a crucial role in various biological processes, including cell division, protein synthesis, and gene expression.

Orotate phosphoribosyltransferase (OPRT) is an enzyme that catalyzes the conversion of orotate to oximine monophosphate (OMP), which is a key step in the biosynthesis of pyrimidines, a type of nucleotide. This enzyme plays a crucial role in the metabolism of nucleic acids, which are the building blocks of DNA and RNA.

The reaction catalyzed by OPRT is as follows:

orotate + phosphoribosyl pyrophosphate (PRPP) -> oximine monophosphate (OMP) + pyrophosphate

Defects in the gene that encodes for OPRT can lead to orotic aciduria, a rare genetic disorder characterized by an accumulation of orotic acid and other pyrimidines in the urine and other body fluids. Symptoms of this condition may include developmental delay, mental retardation, seizures, and megaloblastic anemia.

Homogentisate 1,2-dioxygenase (HGD) is an enzyme that plays a crucial role in the catabolism of tyrosine, an aromatic amino acid. This enzyme is involved in the third step of the tyrosine degradation pathway, also known as the tyrosine breakdown or catabolic pathway.

The homogentisate 1,2-dioxygenase enzyme catalyzes the conversion of homogentisic acid (HGA) into maleylacetoacetic acid. This reaction involves the cleavage of the aromatic ring of HGA and the introduction of oxygen, hence the name 'dioxygenase.' The reaction can be summarized as follows:

Homogentisate + O2 → Maleylacetoacetate

Deficiency or dysfunction in homogentisate 1,2-dioxygenase leads to a rare genetic disorder called alkaptonuria. In this condition, the body cannot break down tyrosine properly, resulting in an accumulation of HGA and its oxidation product, alkapton, which can cause damage to connective tissues and joints over time.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Homocystinuria is a genetic disorder characterized by the accumulation of homocysteine and its metabolites in the body due to a deficiency in the enzyme cystathionine beta-synthase (CBS). This enzyme is responsible for converting homocysteine to cystathionine, which is a critical step in the metabolic pathway that breaks down methionine.

As a result of this deficiency, homocysteine levels in the blood increase and can lead to various health problems, including neurological impairment, ocular abnormalities (such as ectopia lentis or dislocation of the lens), skeletal abnormalities (such as Marfan-like features), and vascular complications.

Homocystinuria can be diagnosed through newborn screening or by measuring homocysteine levels in the blood or urine. Treatment typically involves a low-methionine diet, supplementation with vitamin B6 (pyridoxine), betaine, and/or methylcobalamin (a form of vitamin B12) to help reduce homocysteine levels and prevent complications associated with the disorder.

Chronic mucocutaneous candidiasis (CMC) is a group of rare disorders characterized by persistent or recurrent Candida infections of the skin, nails, and mucous membranes. The infection can affect various sites such as the mouth, esophagus, respiratory tract, gastrointestinal tract, and genitourinary tract.

CMC is typically caused by an impaired immune response to Candida albicans, a type of fungus that commonly exists on the skin and mucous membranes. In CMC, the immune system fails to control the growth of Candida, leading to chronic or recurrent infections.

The symptoms of CMC can vary depending on the site of infection. Common manifestations include:

* Chronic or recurrent thrush (oral candidiasis)
* Esophagitis (inflammation of the esophagus)
* Chronic nail infections (onychomycosis)
* Skin lesions, such as redness, swelling, and cracks
* Genital infections, including vaginitis and balanitis (inflammation of the head of the penis)

CMC can be associated with other immune disorders, such as endocrine dysfunction, autoimmune diseases, and primary immunodeficiencies. The diagnosis of CMC is based on clinical manifestations, laboratory tests, and imaging studies. Treatment typically involves antifungal medications, such as topical or systemic azoles, echinocandins, or polyenes. In some cases, immunomodulatory therapy may be necessary to manage the underlying immune dysfunction.

Adenine is a purine nucleotide base that is a fundamental component of DNA and RNA, the genetic material of living organisms. In DNA, adenine pairs with thymine via double hydrogen bonds, while in RNA, it pairs with uracil. Adenine is essential for the structure and function of nucleic acids, as well as for energy transfer reactions in cells through its role in the formation of adenosine triphosphate (ATP), the primary energy currency of the cell.

Inborn errors of pyruvate metabolism refer to genetic disorders that affect the body's ability to properly metabolize pyruvate, a key intermediate in glucose metabolism. Pyruvate is produced in the cells during the breakdown of glucose for energy production. Normally, pyruvate can be converted into acetyl-CoA and enter the citric acid cycle (also known as the Krebs cycle) for further energy production. However, in individuals with inborn errors of pyruvate metabolism, this conversion process is impaired due to defects in enzymes or transport proteins involved in pyruvate metabolism.

There are several types of inborn errors of pyruvate metabolism, including:

1. Pyruvate dehydrogenase deficiency: This is a genetic disorder caused by mutations in the genes encoding components of the pyruvate dehydrogenase (PDH) complex, which catalyzes the conversion of pyruvate to acetyl-CoA. PDH deficiency can lead to lactic acidosis, neurological problems, and developmental delay.
2. Pyruvate carboxylase deficiency: This is a rare genetic disorder caused by mutations in the gene encoding pyruvate carboxylase, an enzyme that converts pyruvate to oxaloacetate, which can then be used to synthesize glucose. Pyruvate carboxylase deficiency can cause lactic acidosis, seizures, and developmental delay.
3. Mitochondrial disorders: Some mitochondrial disorders can affect pyruvate metabolism by impairing the function of the electron transport chain, which is necessary for energy production in the cells. These disorders can lead to lactic acidosis, muscle weakness, and neurological problems.
4. Other inborn errors: There are several other rare genetic disorders that can affect pyruvate metabolism, including defects in the mitochondrial pyruvate carrier protein, which transports pyruvate into the mitochondria, and deficiencies in enzymes involved in the citric acid cycle.

Treatment for these disorders typically involves managing symptoms, such as controlling lactic acidosis and providing supportive care for neurological problems. In some cases, dietary modifications or supplements may be recommended to help improve pyruvate metabolism.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Alpha-galactosidase is an enzyme that breaks down complex carbohydrates, specifically those containing alpha-galactose molecules. This enzyme is found in humans, animals, and microorganisms. In humans, a deficiency of this enzyme can lead to a genetic disorder known as Fabry disease, which is characterized by the accumulation of these complex carbohydrates in various tissues and organs, leading to progressive damage. Alpha-galactosidase is also used as a medication for the treatment of Fabry disease, where it is administered intravenously to help break down the accumulated carbohydrates and alleviate symptoms.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Ornithine Carbamoyltransferase (OCT) Deficiency Disease, also known as Ornithine Transcarbamylase Deficiency, is a rare inherited urea cycle disorder. It is caused by a deficiency of the enzyme ornithine carbamoyltransferase, which is responsible for one of the steps in the urea cycle that helps to rid the body of excess nitrogen (in the form of ammonia).

When OCT function is impaired, nitrogen accumulates and forms ammonia, leading to hyperammonemia (elevated blood ammonia levels), which can cause neurological symptoms such as lethargy, vomiting, irritability, and in severe cases, coma or death.

Symptoms of OCT deficiency can range from mild to severe and may include developmental delay, seizures, behavioral changes, and movement disorders. The diagnosis is typically made through newborn screening tests, enzyme assays, and genetic testing. Treatment usually involves a combination of dietary restrictions, medications that help remove nitrogen from the body, and in some cases, liver transplantation.

Dihydroorotase is an enzyme that plays a crucial role in the synthesis of pyrimidines, which are essential components of nucleic acids such as DNA and RNA. Specifically, dihydroorotase catalyzes the conversion of N-carbamoyl-L-aspartate into L-dihydroorotate and L-carbamoyl aspartate in the third step of de novo pyrimidine biosynthesis.

The reaction catalyzed by dihydroorotase is:

N-carbamoyl-L-aspartate + H2O → L-dihydroorotate + L-carbamoyl aspartate

Dihydroorotase is a member of the amidohydrolase superfamily and functions as a homodimer or homotetramer. In humans, dihydroorotase is encoded by the DHODH gene and is found in the cytoplasm of cells. Defects in this enzyme can lead to a rare genetic disorder called dihydropyrimidine dehydrogenase deficiency, which is characterized by an accumulation of pyrimidines and their precursors in the body.

Fabry disease is a rare X-linked inherited lysosomal storage disorder caused by mutations in the GLA gene, which encodes the enzyme alpha-galactosidase A. This enzyme deficiency leads to the accumulation of glycosphingolipids, particularly globotriaosylceramide (Gb3 or GL-3), in various tissues and organs throughout the body. The accumulation of these lipids results in progressive damage to multiple organ systems, including the heart, kidneys, nerves, and skin.

The symptoms of Fabry disease can vary widely among affected individuals, but common manifestations include:

1. Pain: Acroparesthesias (burning or tingling sensations) in the hands and feet, episodic pain crises, chronic pain, and neuropathy.
2. Skin: Angiokeratomas (small, red, rough bumps on the skin), hypohidrosis (decreased sweating), and anhydrosis (absent sweating).
3. Gastrointestinal: Abdominal pain, diarrhea, constipation, nausea, and vomiting.
4. Cardiovascular: Left ventricular hypertrophy (enlargement of the heart muscle), cardiomyopathy, ischemic heart disease, arrhythmias, and valvular abnormalities.
5. Renal: Proteinuria (protein in the urine), hematuria (blood in the urine), chronic kidney disease, and end-stage renal disease.
6. Nervous system: Hearing loss, tinnitus, vertigo, stroke, and cognitive decline.
7. Ocular: Corneal opacities, cataracts, and retinal vessel abnormalities.
8. Pulmonary: Chronic cough, bronchial hyperresponsiveness, and restrictive lung disease.
9. Reproductive system: Erectile dysfunction in males and menstrual irregularities in females.

Fabry disease affects both males and females, but the severity of symptoms is generally more pronounced in males due to the X-linked inheritance pattern. Early diagnosis and treatment with enzyme replacement therapy (ERT) or chaperone therapy can help manage the progression of the disease and improve quality of life.

Phosphoribosyl Pyrophosphate (PRPP) is defined as a key intracellular nucleotide metabolite that plays an essential role in the biosynthesis of purine and pyrimidine nucleotides, which are the building blocks of DNA and RNA. PRPP is synthesized from ribose 5-phosphate and ATP by the enzyme PRPP synthase. It contributes a phosphoribosyl group in the conversion of purines and pyrimidines to their corresponding nucleotides, which are critical for various cellular processes such as DNA replication, repair, and gene expression. Abnormal levels of PRPP have been implicated in several genetic disorders, including Lesch-Nyhan syndrome and PRPP synthetase superactivity.

The Australian Capital Territory (ACT) is a federal territory of Australia that serves as the country's capital and is home to the city of Canberra. It is not a state, but rather a separate territorial jurisdiction that is self-governing, with its own legislative assembly responsible for local governance.

The ACT was established in 1911 as the site for Australia's capital city, following a compromise between the two largest cities in the country at the time, Sydney and Melbourne, which both sought to be named the national capital. The territory covers an area of approximately 2,358 square kilometers (910 square miles) and has a population of around 430,000 people.

The ACT is home to many important government buildings and institutions, including Parliament House, the High Court of Australia, and the Australian War Memorial. It also boasts a diverse range of natural attractions, such as the Namadgi National Park and the Tidbinbilla Nature Reserve, which offer opportunities for hiking, camping, and wildlife viewing.

In medical terms, the ACT has its own healthcare system and infrastructure, with several hospitals, clinics, and medical centers located throughout the territory. The Australian Government provides funding for public health services in the ACT, while private health insurance is also available to residents. The territory's main hospital, Canberra Hospital, offers a range of specialist medical services, including emergency care, cancer treatment, and mental health services.

Adenylosuccinate Lyase is a crucial enzyme in the purine nucleotide biosynthesis pathway. Its primary function is to catalyze the conversion of adenylosuccinate into adenosine monophosphate (AMP) and fumarate in two consecutive steps. This enzyme plays an essential role in the metabolism of purines, which are vital components of DNA, RNA, and energy transfer molecules like ATP. Deficiency in this enzyme can lead to a rare genetic disorder known as Adenylosuccinase Deficiency or Adenylosuccinate Lyase Deficiency, characterized by neurological symptoms, developmental delays, and physical disabilities.

Argininosuccinic acid is a chemical compound that is an intermediate in the metabolic pathway for the synthesis of arginine, an essential amino acid. This process occurs in the urea cycle, which is responsible for removing excess nitrogen from the body in the form of urea.

In the urea cycle, citrulline reacts with aspartate to form argininosuccinic acid, which is then converted into arginine and fumarate by the enzyme argininosuccinate lyase. Arginine is a semi-essential amino acid that plays important roles in various physiological processes, including protein synthesis, nitric oxide production, and hormone secretion.

Argininosuccinic aciduria is a rare inherited metabolic disorder caused by a deficiency of the enzyme argininosuccinate lyase. This results in an accumulation of argininosuccinic acid in the blood and urine, leading to hyperammonemia (elevated levels of ammonia in the blood), neurological symptoms, and developmental delay. Treatment typically involves a low-protein diet, supplementation with arginine and citrulline, and nitrogen scavenging medications to reduce ammonia levels.

Deoxyribodipyrimidine photo-lyase is an enzyme involved in the repair of DNA damage, specifically the repair of cyclobutane pyrimidine dimers (CPDs) that are formed when DNA is exposed to ultraviolet (UV) light. CPDs can distort the structure of DNA and interfere with replication and transcription, so it's important for cells to have mechanisms to repair this damage.

Deoxyribodipyrimidine photo-lyase works by cleaving the bond between two adjacent pyrimidines in the DNA strand that form the CPD, releasing one of the pyrimidines and allowing the remaining portion of the strand to be repaired. This enzyme is also known as photolyase or DNA repair photolyase.

It's worth noting that there are different types of photolyases that can repair different kinds of DNA damage, but deoxyribodipyrimidine photo-lyase specifically repairs CPDs caused by UV light.

Metabolism is the complex network of chemical reactions that occur within our bodies to maintain life. It involves two main types of processes: catabolism, which is the breaking down of molecules to release energy, and anabolism, which is the building up of molecules using energy. These reactions are necessary for the body to grow, reproduce, respond to environmental changes, and repair itself. Metabolism is a continuous process that occurs at the cellular level and is regulated by enzymes, hormones, and other signaling molecules. It is influenced by various factors such as age, genetics, diet, physical activity, and overall health status.

Isovaleryl-CoA Dehydrogenase (IVD) is an enzyme that plays a crucial role in the catabolism of leucine, an essential amino acid. This enzyme is located in the mitochondrial matrix and is responsible for catalyzing the third step in the degradation pathway of leucine.

Specifically, Isovaleryl-CoA Dehydrogenase facilitates the conversion of isovaleryl-CoA to 3-methylcrotonyl-CoA through the removal of two hydrogen atoms from the substrate. This reaction requires the coenzyme flavin adenine dinucleotide (FAD) as an electron acceptor, which gets reduced to FADH2 during the process.

Deficiency in Isovaleryl-CoA Dehydrogenase can lead to a rare genetic disorder known as isovaleric acidemia, characterized by the accumulation of isovaleryl-CoA and its metabolic byproducts, including isovaleric acid, 3-hydroxyisovaleric acid, and methylcrotonylglycine. These metabolites can cause various symptoms such as vomiting, dehydration, metabolic acidosis, seizures, developmental delay, and even coma or death in severe cases.

Hypophosphatasia is a rare inherited metabolic disorder characterized by defective bone mineralization due to deficiency of alkaline phosphatase, an enzyme that is crucial for the formation of strong and healthy bones. This results in skeletal abnormalities, including softening and weakening of the bones (rickets in children and osteomalacia in adults), premature loss of teeth, and an increased risk of fractures.

The disorder can vary widely in severity, from mild cases with few symptoms to severe forms that can lead to disability or even be life-threatening in infancy. Hypophosphatasia is caused by mutations in the ALPL gene, which provides instructions for making the tissue non-specific alkaline phosphatase (TNSALP) enzyme. Inheritance is autosomal recessive, meaning an individual must inherit two copies of the mutated gene (one from each parent) to have the condition.

Cytidine is a nucleoside, which consists of the sugar ribose and the nitrogenous base cytosine. It is an important component of RNA (ribonucleic acid), where it pairs with guanosine via hydrogen bonding to form a base pair. Cytidine can also be found in some DNA (deoxyribonucleic acid) sequences, particularly in viral DNA and in mitochondrial DNA.

Cytidine can be phosphorylated to form cytidine monophosphate (CMP), which is a nucleotide that plays a role in various biochemical reactions in the body. CMP can be further phosphorylated to form cytidine diphosphate (CDP) and cytidine triphosphate (CTP), which are involved in the synthesis of lipids, glycogen, and other molecules.

Cytidine is also available as a dietary supplement and has been studied for its potential benefits in treating various health conditions, such as liver disease and cancer. However, more research is needed to confirm these potential benefits and establish safe and effective dosages.

Methylmalonic acid (MMA) is an organic compound that is produced in the human body during the metabolism of certain amino acids, including methionine and threonine. It is a type of fatty acid that is intermediate in the breakdown of these amino acids in the liver and other tissues.

Under normal circumstances, MMA is quickly converted to succinic acid, which is then used in the Krebs cycle to generate energy in the form of ATP. However, when there are deficiencies or mutations in enzymes involved in this metabolic pathway, such as methylmalonyl-CoA mutase, MMA can accumulate in the body and cause methylmalonic acidemia, a rare genetic disorder that affects approximately 1 in every 50,000 to 100,000 individuals worldwide.

Elevated levels of MMA in the blood or urine can be indicative of various metabolic disorders, including methylmalonic acidemia, vitamin B12 deficiency, and renal insufficiency. Therefore, measuring MMA levels is often used as a diagnostic tool to help identify and manage these conditions.

Methylmalonyl-CoA mutase is a mitochondrial enzyme that plays a crucial role in the metabolism of certain amino acids and fatty acids. Specifically, it catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA, which is an important step in the catabolic pathways of valine, isoleucine, threonine, methionine, odd-chain fatty acids, and cholesterol.

The enzyme requires a cofactor called adenosylcobalamin (vitamin B12) for its activity. In the absence of this cofactor or due to mutations in the gene encoding the enzyme, methylmalonyl-CoA mutase deficiency can occur, leading to the accumulation of methylmalonic acid and other toxic metabolites, which can cause a range of symptoms including vomiting, dehydration, lethargy, hypotonia, developmental delay, and metabolic acidosis. This condition is typically inherited in an autosomal recessive manner and can be diagnosed through biochemical tests and genetic analysis.

Diagnostic errors refer to inaccurate or delayed diagnoses of a patient's medical condition, which can lead to improper or unnecessary treatment and potentially serious harm to the patient. These errors can occur due to various factors such as lack of clinical knowledge, failure to consider all possible diagnoses, inadequate communication between healthcare providers and patients, and problems with testing or interpretation of test results. Diagnostic errors are a significant cause of preventable harm in medical care and have been identified as a priority area for quality improvement efforts.

Metabolic brain diseases refer to a group of conditions that are caused by disruptions in the body's metabolic processes, which affect the brain. These disorders can be inherited or acquired and can result from problems with the way the body produces, breaks down, or uses energy and nutrients.

Examples of metabolic brain diseases include:

1. Mitochondrial encephalomyopathies: These are a group of genetic disorders that affect the mitochondria, which are the energy-producing structures in cells. When the mitochondria don't function properly, it can lead to muscle weakness, neurological problems, and developmental delays.
2. Leukodystrophies: These are a group of genetic disorders that affect the white matter of the brain, which is made up of nerve fibers covered in myelin, a fatty substance that insulates the fibers and helps them transmit signals. When the myelin breaks down or is not produced properly, it can lead to cognitive decline, motor problems, and other neurological symptoms.
3. Lysosomal storage disorders: These are genetic disorders that affect the lysosomes, which are structures in cells that break down waste products and recycle cellular materials. When the lysosomes don't function properly, it can lead to the accumulation of waste products in cells, including brain cells, causing damage and neurological symptoms.
4. Maple syrup urine disease: This is a genetic disorder that affects the way the body breaks down certain amino acids, leading to a buildup of toxic levels of these substances in the blood and urine. If left untreated, it can cause brain damage, developmental delays, and other neurological problems.
5. Homocystinuria: This is a genetic disorder that affects the way the body processes an amino acid called methionine, leading to a buildup of homocysteine in the blood. High levels of homocysteine can cause damage to the blood vessels and lead to neurological problems, including seizures, developmental delays, and cognitive decline.

Treatment for metabolic brain diseases may involve dietary changes, supplements, medications, or other therapies aimed at managing symptoms and preventing further damage to the brain. In some cases, a stem cell transplant may be recommended as a treatment option.

Magnetic Resonance Spectroscopy (MRS) is a non-invasive diagnostic technique that provides information about the biochemical composition of tissues, including their metabolic state. It is often used in conjunction with Magnetic Resonance Imaging (MRI) to analyze various metabolites within body tissues, such as the brain, heart, liver, and muscles.

During MRS, a strong magnetic field, radio waves, and a computer are used to produce detailed images and data about the concentration of specific metabolites in the targeted tissue or organ. This technique can help detect abnormalities related to energy metabolism, neurotransmitter levels, pH balance, and other biochemical processes, which can be useful for diagnosing and monitoring various medical conditions, including cancer, neurological disorders, and metabolic diseases.

There are different types of MRS, such as Proton (^1^H) MRS, Phosphorus-31 (^31^P) MRS, and Carbon-13 (^13^C) MRS, each focusing on specific elements or metabolites within the body. The choice of MRS technique depends on the clinical question being addressed and the type of information needed for diagnosis or monitoring purposes.

Aspartate carbamoyltransferase (ACT) is a crucial enzyme in the urea cycle, which is the biochemical pathway responsible for the elimination of excess nitrogen waste from the body. This enzyme catalyzes the second step of the urea cycle, where it facilitates the transfer of a carbamoyl group from carbamoyl phosphate to aspartic acid, forming N-acetylglutamic semialdehyde and releasing phosphate in the process.

The reaction catalyzed by aspartate carbamoyltransferase is as follows:

Carbamoyl phosphate + L-aspartate → N-acetylglutamic semialdehyde + P\_i + CO\_2

This enzyme plays a critical role in maintaining nitrogen balance and preventing the accumulation of toxic levels of ammonia in the body. Deficiencies or mutations in aspartate carbamoyltransferase can lead to serious metabolic disorders, such as citrullinemia and hyperammonemia, which can have severe neurological consequences if left untreated.

Hydroxocobalamin is a form of vitamin B12 that is used in medical treatments. It is a synthetic version of the naturally occurring compound, and it is often used to treat vitamin B12 deficiencies. Hydroxocobalamin is also used to treat poisoning from cyanide, as it can bind with the cyanide to form a non-toxic compound that can be excreted from the body.

In medical terms, hydroxocobalamin is defined as: "A bright red crystalline compound, C21H30CoN4O7·2H2O, used in the treatment of vitamin B12 deficiency and as an antidote for cyanide poisoning. It is converted in the body to active coenzyme forms."

It's important to note that hydroxocobalamin should only be used under the supervision of a medical professional, as improper use can lead to serious side effects or harm.

I am sorry for any confusion, but "Pentanoic Acids" is not a recognized medical term or concept. Pentanoic acid, also known as valeric acid, is an organic compound with the formula CH3CH2CH2CH2CO2H. It is a fatty acid with five carbon atoms, and it may have some uses in industry, but it does not have specific relevance to medical definition or healthcare.

Carnitine is a naturally occurring substance in the body that plays a crucial role in energy production. It transports long-chain fatty acids into the mitochondria, where they can be broken down to produce energy. Carnitine is also available as a dietary supplement and is often used to treat or prevent carnitine deficiency.

The medical definition of Carnitine is:

"A quaternary ammonium compound that occurs naturally in animal tissues, especially in muscle, heart, brain, and liver. It is essential for the transport of long-chain fatty acids into the mitochondria, where they can be oxidized to produce energy. Carnitine also functions as an antioxidant and has been studied as a potential treatment for various conditions, including heart disease, diabetes, and kidney disease."

Carnitine is also known as L-carnitine or levocarnitine. It can be found in foods such as red meat, dairy products, fish, poultry, and tempeh. In the body, carnitine is synthesized from the amino acids lysine and methionine with the help of vitamin C and iron. Some people may have a deficiency in carnitine due to genetic factors, malnutrition, or certain medical conditions, such as kidney disease or liver disease. In these cases, supplementation may be necessary to prevent or treat symptoms of carnitine deficiency.

Guanosine is a nucleoside that consists of a guanine base linked to a ribose sugar molecule through a beta-N9-glycosidic bond. It plays a crucial role in various biological processes, such as serving as a building block for DNA and RNA during replication and transcription. Guanosine triphosphate (GTP) and guanosine diphosphate (GDP) are important energy carriers and signaling molecules involved in intracellular regulation. Additionally, guanosine has been studied for its potential role as a neuroprotective agent and possible contribution to cell-to-cell communication.

Orotidine-5’-phosphate decarboxylase (ODC) is an enzyme that is involved in the synthesis of pyrimidines, which are essential nucleotides required for the production of DNA and RNA. The gene that encodes this enzyme is called UMPS.

ODC catalyzes the decarboxylation of orotidine-5’-phosphate (OMP) to form uridine monophosphate (UMP), which is a precursor to other pyrimidines such as cytidine triphosphate (CTP) and thymidine triphosphate (TTP). This reaction is the fifth step in the de novo synthesis of pyrimidines.

Defects in the ODC enzyme can lead to a rare genetic disorder called orotic aciduria, which is characterized by an accumulation of orotic acid and orotidine in the urine, as well as neurological symptoms such as developmental delay, seizures, and ataxia. Treatment for this condition typically involves supplementation with uridine and a low-protein diet to reduce the production of excess orotic acid.

Deoxyribonucleosides are chemical compounds that constitute the basic building blocks of DNA, one of the two nucleic acids found in cells. They consist of a sugar molecule called deoxyribose, a nitrogenous base (either adenine, guanine, cytosine, or thymine), and a phosphate group.

The nitrogenous base is attached to the 1' carbon atom of the deoxyribose sugar, forming a glycosidic bond. The phosphate group is linked to the 5' carbon atom of the deoxyribose sugar through an ester linkage, creating a phosphodiester bond with another deoxyribonucleoside.

When multiple deoxyribonucleosides are joined together through their phosphate groups, they form a polynucleotide chain, which is the backbone of DNA. The sequence of nitrogenous bases along this chain encodes genetic information that determines the characteristics and functions of living organisms.

Deoxyribonucleosides play a crucial role in various biological processes, including DNA replication, repair, and transcription. They are also used as therapeutic agents for the treatment of certain genetic disorders and cancer.

Inborn errors of metal metabolism refer to genetic disorders that affect the way the body processes and handles certain metallic elements. These disorders can result in an accumulation or deficiency of specific metals, leading to various clinical manifestations. Examples of such conditions include:

1. Wilson's disease: An autosomal recessive disorder caused by a mutation in the ATP7B gene, which results in abnormal copper metabolism and accumulation in various organs, particularly the liver and brain.
2. Menkes disease: An X-linked recessive disorder caused by a mutation in the ATP7A gene, leading to impaired copper transport and deficiency, affecting the brain, bones, and connective tissue.
3. Hemochromatosis: An autosomal recessive disorder characterized by excessive iron absorption and deposition in various organs, causing damage to the liver, heart, and pancreas.
4. Acrodermatitis enteropathica: A rare autosomal recessive disorder caused by a mutation in the SLC39A4 gene, resulting in zinc deficiency and affecting the skin, gastrointestinal system, and immune function.
5. Disturbances in manganese metabolism: Rare genetic disorders that can lead to either manganese accumulation or deficiency, causing neurological symptoms.

These conditions often require specialized medical management, including dietary modifications, chelation therapy, and/or supplementation to maintain appropriate metal homeostasis and prevent organ damage.

Nucleotides are the basic structural units of nucleic acids, such as DNA and RNA. They consist of a nitrogenous base (adenine, guanine, cytosine, thymine or uracil), a pentose sugar (ribose in RNA and deoxyribose in DNA) and one to three phosphate groups. Nucleotides are linked together by phosphodiester bonds between the sugar of one nucleotide and the phosphate group of another, forming long chains known as polynucleotides. The sequence of these nucleotides determines the genetic information carried in DNA and RNA, which is essential for the functioning, reproduction and survival of all living organisms.

Glucose is a simple monosaccharide (or single sugar) that serves as the primary source of energy for living organisms. It's a fundamental molecule in biology, often referred to as "dextrose" or "grape sugar." Glucose has the molecular formula C6H12O6 and is vital to the functioning of cells, especially those in the brain and nervous system.

In the body, glucose is derived from the digestion of carbohydrates in food, and it's transported around the body via the bloodstream to cells where it can be used for energy. Cells convert glucose into a usable form through a process called cellular respiration, which involves a series of metabolic reactions that generate adenosine triphosphate (ATP)—the main currency of energy in cells.

Glucose is also stored in the liver and muscles as glycogen, a polysaccharide (multiple sugar) that can be broken down back into glucose when needed for energy between meals or during physical activity. Maintaining appropriate blood glucose levels is crucial for overall health, and imbalances can lead to conditions such as diabetes mellitus.

Inborn errors of fructose metabolism refer to genetic disorders that affect the body's ability to break down and process fructose, a simple sugar found in fruits, vegetables, and honey. These disorders are caused by mutations in genes responsible for encoding enzymes involved in fructose metabolism.

The two main types of inborn errors of fructose metabolism are:

1. Hereditary Fructose Intolerance (HFI): This is a rare genetic disorder caused by a deficiency of the enzyme aldolase B, which is necessary for the breakdown of fructose in the liver. When individuals with HFI consume fructose or sucrose (a disaccharide that contains fructose and glucose), they experience a buildup of toxic metabolites, leading to symptoms such as vomiting, abdominal pain, hypoglycemia, and in severe cases, liver damage and failure.
2. Fructose-1,6-bisphosphatase Deficiency (FBPase Deficiency): This is a rare autosomal recessive disorder caused by a deficiency of the enzyme fructose-1,6-bisphosphatase, which is essential for gluconeogenesis (the process of generating glucose from non-carbohydrate sources). Individuals with FBPase Deficiency experience symptoms such as hypoglycemia, lactic acidosis, and hyperventilation, particularly during periods of fasting or illness.

Both disorders can be managed through dietary restrictions and close monitoring of blood sugar levels. In severe cases, enzyme replacement therapy or liver transplantation may be considered.

Metabolic networks and pathways refer to the complex interconnected series of biochemical reactions that occur within cells to maintain life. These reactions are catalyzed by enzymes and are responsible for the conversion of nutrients into energy, as well as the synthesis and breakdown of various molecules required for cellular function.

A metabolic pathway is a series of chemical reactions that occur in a specific order, with each reaction being catalyzed by a different enzyme. These pathways are often interconnected, forming a larger network of interactions known as a metabolic network.

Metabolic networks can be represented as complex diagrams or models, which show the relationships between different pathways and the flow of matter and energy through the system. These networks can help researchers to understand how cells regulate their metabolism in response to changes in their environment, and how disruptions to these networks can lead to disease.

Some common examples of metabolic pathways include glycolysis, the citric acid cycle (also known as the Krebs cycle), and the pentose phosphate pathway. Each of these pathways plays a critical role in maintaining cellular homeostasis and providing energy for cellular functions.

Ribonucleosides are organic compounds that consist of a nucleoside bound to a ribose sugar. Nucleosides are formed when a nitrogenous base (such as adenine, guanine, uracil, cytosine, or thymine) is attached to a sugar molecule (either ribose or deoxyribose) via a beta-glycosidic bond. In the case of ribonucleosides, the sugar component is D-ribose. Ribonucleosides play important roles in various biological processes, particularly in the storage, transfer, and expression of genetic information within cells. When ribonucleosides are phosphorylated, they become the building blocks of RNA (ribonucleic acid), a crucial biomolecule involved in protein synthesis and other cellular functions. Examples of ribonucleosides include adenosine, guanosine, uridine, cytidine, and inosine.

Glutarates are compounds that contain a glutaric acid group. Glutaric acid is a carboxylic acid with a five-carbon chain and two carboxyl groups at the 1st and 5th carbon positions. Glutarates can be found in various substances, including certain foods and medications.

In a medical context, glutarates are sometimes used as ingredients in pharmaceutical products. For example, sodium phenylbutyrate, which is a salt of phenylbutyric acid and butyric acid, contains a glutaric acid group and is used as a medication to treat urea cycle disorders.

Glutarates can also be found in some metabolic pathways in the body, where they play a role in energy production and other biochemical processes. However, abnormal accumulation of glutaric acid or its derivatives can lead to certain medical conditions, such as glutaric acidemia type I, which is an inherited disorder of metabolism that can cause neurological symptoms and other health problems.

Uracil nucleotides are chemical compounds that play a crucial role in the synthesis, repair, and replication of DNA and RNA. Specifically, uracil nucleotides refer to the group of molecules that contain the nitrogenous base uracil, which is linked to a ribose sugar through a beta-glycosidic bond. This forms the nucleoside uridine, which can then be phosphorylated to create the uracil nucleotide.

Uracil nucleotides are important in the formation of RNA, where uracil base pairs with adenine through two hydrogen bonds during transcription. However, uracil is not typically found in DNA, and its presence in DNA can indicate damage or mutation. When uracil is found in DNA, it is usually the result of a process called deamination, where the nitrogenous base cytosine is spontaneously converted to uracil. This can lead to errors during replication, as uracil will pair with adenine instead of guanine, leading to a C-to-T or G-to-A mutation.

To prevent this type of mutation, cells have enzymes called uracil DNA glycosylases that recognize and remove uracil from DNA. This initiates the base excision repair pathway, which removes the damaged nucleotide and replaces it with a correct one. Overall, uracil nucleotides are essential for proper cellular function, but their misincorporation into DNA can have serious consequences for genome stability.

Dihydroorotate oxidase is a mitochondrial enzyme that plays a crucial role in the de novo biosynthesis of pyrimidines, which are essential nucleotides required for the synthesis of DNA, RNA, and other vital molecules in the body.

The enzyme catalyzes the oxidation of dihydroorotate to orotate, using molecular oxygen as an electron acceptor. This reaction is the third step in the pyrimidine biosynthesis pathway, following the condensation of carbamoyl phosphate and aspartate to form carbamoylaspartate, and the decarboxylation of carbamoylaspartate to form dihydroorotate.

Dihydroorotate oxidase is a flavoprotein that contains a FAD cofactor, which accepts electrons from dihydroorotate and transfers them to molecular oxygen, generating hydrogen peroxide as a byproduct. The enzyme is inhibited by the drug leflunomide, which is used in the treatment of rheumatoid arthritis and other autoimmune diseases.

In humans, dihydroorotate oxidase is encoded by two genes, DHODH and SUOX, which are located on different chromosomes. Mutations in these genes can lead to deficiencies in pyrimidine biosynthesis and result in various genetic disorders, such as Miller syndrome, a rare autosomal recessive disorder characterized by craniofacial abnormalities, limb defects, and hearing loss.

Thymine is a pyrimidine nucleobase that is one of the four nucleobases in the nucleic acid double helix of DNA (the other three being adenine, guanine, and cytosine). It is denoted by the letter T in DNA notation and pairs with adenine via two hydrogen bonds. Thymine is not typically found in RNA, where uracil takes its place pairing with adenine. The structure of thymine consists of a six-membered ring (pyrimidine) fused to a five-membered ring containing two nitrogen atoms and a ketone group.

Uridine Triphosphate (UTP) is a nucleotide that plays a crucial role in the synthesis and repair of DNA and RNA. It consists of a nitrogenous base called uracil, a pentose sugar (ribose), and three phosphate groups. UTP is one of the four triphosphates used in the biosynthesis of RNA during transcription, where it donates its uracil base to the growing RNA chain. Additionally, UTP serves as an energy source and a substrate in various biochemical reactions within the cell, including phosphorylation processes and the synthesis of glycogen and other molecules.

Maple Syrup Urine Disease (MSUD) is a rare inherited metabolic disorder characterized by an inability to break down certain amino acids (leucine, isoleucine, and valine) due to deficiency of the enzyme complex branched-chain keto acid dehydrogenase. This results in their accumulation in body fluids, including urine, which gives it a characteristic sweet smell, reminiscent of maple syrup.

The disease can lead to serious neurological complications if left untreated, including seizures, vomiting, mental retardation, and even death. There are different forms of MSUD, ranging from severe (classic) to milder (intermittent or variant). Treatment typically involves a strict lifelong diet low in these amino acids, regular monitoring of blood and urine, and sometimes supplementation with enzymes or medications.

Amidinotransferases are a group of enzymes that play a role in the metabolism of amino acids and other biologically active compounds. These enzymes catalyze the transfer of an amidino group (-NH-C=NH) from one molecule to another, typically from an amino acid or related compound donor to an acceptor molecule.

The amidinotransferases are classified as a subgroup of the larger family of enzymes known as transferases, which catalyze the transfer of various functional groups between molecules. Within this family, the amidinotransferases are further divided into several subfamilies based on their specific functions and the types of donor and acceptor molecules they act upon.

One example of an amidinotransferase is arginine:glycine amidinotransferase (AGAT), which plays a role in the biosynthesis of creatine, a compound that is important for energy metabolism in muscles and other tissues. AGAT transfers an amidino group from arginine to glycine, forming guanidinoacetate and ornithine as products.

Abnormalities in the activity of amidinotransferases have been implicated in various diseases, including neurological disorders and certain genetic conditions. For example, mutations in the gene encoding AGAT have been associated with a rare inherited disorder called cerebral creatine deficiency syndrome type 1 (CCDS1), which is characterized by developmental delay, intellectual disability, and other neurological symptoms.

Metabolic diseases are a group of disorders caused by abnormal chemical reactions in your body's cells. These reactions are part of a complex process called metabolism, where your body converts the food you eat into energy.

There are several types of metabolic diseases, but they most commonly result from:

1. Your body not producing enough of certain enzymes that are needed to convert food into energy.
2. Your body producing too much of certain substances or toxins, often due to a genetic disorder.

Examples of metabolic diseases include phenylketonuria (PKU), diabetes, and gout. PKU is a rare condition where the body cannot break down an amino acid called phenylalanine, which can lead to serious health problems if left untreated. Diabetes is a common disorder that occurs when your body doesn't produce enough insulin or can't properly use the insulin it produces, leading to high blood sugar levels. Gout is a type of arthritis that results from too much uric acid in the body, which can form crystals in the joints and cause pain and inflammation.

Metabolic diseases can be inherited or acquired through environmental factors such as diet or lifestyle choices. Many metabolic diseases can be managed with proper medical care, including medication, dietary changes, and lifestyle modifications.

Erythropoietic Porphyria (EP) is a rare inherited disorder of the heme biosynthesis pathway, specifically caused by a deficiency of the enzyme uroporphyrinogen III synthase. This results in the accumulation of porphyrin precursors, particularly uroporphyrin I and coproporphyrin I, in erythrocytes (red blood cells), bone marrow, and other tissues. The accumulation of these porphyrins leads to photosensitivity, hemolysis, and iron overload.

The symptoms of EP typically appear in childhood or early adulthood and include severe skin fragility and blistering, particularly on sun-exposed areas, which can result in scarring, disfigurement, and increased susceptibility to infection. Other features may include anemia due to hemolysis, iron overload, and splenomegaly (enlarged spleen).

The diagnosis of EP is based on clinical symptoms, laboratory tests measuring porphyrin levels in blood and urine, and genetic testing to confirm the presence of pathogenic variants in the UROS gene. Treatment for EP includes avoidance of sunlight exposure, use of sun-protective measures, and management of anemia with blood transfusions or erythropoietin injections. In some cases, bone marrow transplantation may be considered as a curative treatment option.

Glutaryl-CoA Dehydrogenase (GCDH) is an enzyme that plays a crucial role in the catabolism of the amino acids lysine and hydroxylysine. It is located in the inner mitochondrial membrane and functions as a homotetramer, with each subunit containing one molecule of FAD as a cofactor.

GCDH catalyzes the oxidative decarboxylation of glutaryl-CoA to form succinyl-CoA, which is then further metabolized in the citric acid cycle. This reaction also involves the reduction of FAD to FADH2, which can subsequently be used in the electron transport chain to generate ATP.

Deficiency in GCDH function can lead to a rare inherited disorder called glutaric acidemia type I (GA-I), which is characterized by an accumulation of glutaryl-CoA and its metabolites, including glutaric acid and 3-hydroxyglutaric acid. These metabolites can cause neurological damage and intellectual disability if left untreated.

DNA repair is the process by which cells identify and correct damage to the DNA molecules that encode their genome. DNA can be damaged by a variety of internal and external factors, such as radiation, chemicals, and metabolic byproducts. If left unrepaired, this damage can lead to mutations, which may in turn lead to cancer and other diseases.

There are several different mechanisms for repairing DNA damage, including:

1. Base excision repair (BER): This process repairs damage to a single base in the DNA molecule. An enzyme called a glycosylase removes the damaged base, leaving a gap that is then filled in by other enzymes.
2. Nucleotide excision repair (NER): This process repairs more severe damage, such as bulky adducts or crosslinks between the two strands of the DNA molecule. An enzyme cuts out a section of the damaged DNA, and the gap is then filled in by other enzymes.
3. Mismatch repair (MMR): This process repairs errors that occur during DNA replication, such as mismatched bases or small insertions or deletions. Specialized enzymes recognize the error and remove a section of the newly synthesized strand, which is then replaced by new nucleotides.
4. Double-strand break repair (DSBR): This process repairs breaks in both strands of the DNA molecule. There are two main pathways for DSBR: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ directly rejoins the broken ends, while HR uses a template from a sister chromatid to repair the break.

Overall, DNA repair is a crucial process that helps maintain genome stability and prevent the development of diseases caused by genetic mutations.

Hyperargininemia is a rare genetic disorder characterized by an excess of arginine in the blood. Arginine is an amino acid, which are the building blocks of proteins. In hyperargininemia, there is a deficiency or dysfunction of the enzyme argininosuccinate synthetase, leading to an accumulation of arginine and related compounds in the body. This can cause various symptoms such as intellectual disability, seizures, spasticity, and feeding difficulties. It is inherited in an autosomal recessive manner, meaning that an individual must receive two copies of the defective gene (one from each parent) to develop the condition.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

"Failure to Thrive" is a medical term used to describe a condition in infants and children who are not growing and gaining weight as expected. It is typically defined as significant deviation from normal growth patterns, such as poor weight gain or loss, slow increase in length/height, and delayed developmental milestones. The condition can have various causes, including medical, psychological, social, and environmental factors. Early identification and intervention are crucial to address the underlying cause and promote healthy growth and development.

Guanine is not a medical term per se, but it is a biological molecule that plays a crucial role in the body. Guanine is one of the four nucleobases found in the nucleic acids DNA and RNA, along with adenine, cytosine, and thymine (in DNA) or uracil (in RNA). Specifically, guanine pairs with cytosine via hydrogen bonds to form a base pair.

Guanine is a purine derivative, which means it has a double-ring structure. It is formed through the synthesis of simpler molecules in the body and is an essential component of genetic material. Guanine's chemical formula is C5H5N5O.

While guanine itself is not a medical term, abnormalities or mutations in genes that contain guanine nucleotides can lead to various medical conditions, including genetic disorders and cancer.

Iron metabolism disorders are a group of medical conditions that affect the body's ability to absorb, transport, store, or utilize iron properly. Iron is an essential nutrient that plays a crucial role in various bodily functions, including oxygen transportation and energy production. However, imbalances in iron levels can lead to several health issues.

There are two main types of iron metabolism disorders:

1. Iron deficiency anemia (IDA): This condition occurs when the body lacks adequate iron to produce sufficient amounts of hemoglobin, a protein in red blood cells responsible for carrying oxygen throughout the body. Causes of IDA may include inadequate dietary iron intake, blood loss, or impaired iron absorption due to conditions like celiac disease or inflammatory bowel disease.
2. Hemochromatosis: This is a genetic disorder characterized by excessive absorption and accumulation of iron in various organs, including the liver, heart, and pancreas. Over time, this excess iron can lead to organ damage and diseases such as cirrhosis, heart failure, diabetes, and arthritis. Hemochromatosis is typically caused by mutations in the HFE gene, which regulates iron absorption in the intestines.

Other iron metabolism disorders include:

* Anemia of chronic disease (ACD): A type of anemia that occurs in individuals with chronic inflammation or infection, where iron is not efficiently used for hemoglobin production due to altered regulation.
* Sideroblastic anemias: These are rare disorders characterized by the abnormal formation of ringed sideroblasts (immature red blood cells containing iron-laden mitochondria) in the bone marrow, leading to anemia and other symptoms.
* Iron-refractory iron deficiency anemia (IRIDA): A rare inherited disorder caused by mutations in the TMPRSS6 gene, resulting in impaired regulation of hepcidin, a hormone that controls iron absorption and distribution in the body. This leads to both iron deficiency and iron overload.

Proper diagnosis and management of iron metabolism disorders are essential to prevent complications and maintain overall health. Treatment options may include dietary modifications, iron supplementation, phlebotomy (bloodletting), or chelation therapy, depending on the specific disorder and its severity.

Oxidoreductases are a class of enzymes that catalyze oxidation-reduction reactions, which involve the transfer of electrons from one molecule (the reductant) to another (the oxidant). These enzymes play a crucial role in various biological processes, including energy production, metabolism, and detoxification.

The oxidoreductase-catalyzed reaction typically involves the donation of electrons from a reducing agent (donor) to an oxidizing agent (acceptor), often through the transfer of hydrogen atoms or hydride ions. The enzyme itself does not undergo any permanent chemical change during this process, but rather acts as a catalyst to lower the activation energy required for the reaction to occur.

Oxidoreductases are classified and named based on the type of electron donor or acceptor involved in the reaction. For example, oxidoreductases that act on the CH-OH group of donors are called dehydrogenases, while those that act on the aldehyde or ketone groups are called oxidases. Other examples include reductases, peroxidases, and catalases.

Understanding the function and regulation of oxidoreductases is important for understanding various physiological processes and developing therapeutic strategies for diseases associated with impaired redox homeostasis, such as cancer, neurodegenerative disorders, and cardiovascular disease.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Long-chain-3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) is a mitochondrial enzyme that plays a crucial role in the beta-oxidation of fatty acids. Specifically, LCHAD catalyzes the third step of this process by oxidizing long-chain 3-hydroxyacyl-CoA molecules to 3-ketoacyl-CoAs, using NAD+ as an electron acceptor. This reaction is essential for generating energy in the form of ATP and reducing equivalents (NADH and FADH2) through the citric acid cycle.

Deficiencies in LCHAD can lead to a rare autosomal recessive disorder known as long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD). This condition impairs the body's ability to metabolize long-chain fatty acids, particularly during periods of fasting or increased energy demands. Symptoms can include hypoketotic hypoglycemia, muscle weakness, cardiomyopathy, and retinal damage, among others. Early diagnosis and management are crucial for improving outcomes in affected individuals.

Alkaptonuria is a rare inherited metabolic disorder characterized by the accumulation of homogentisic acid in various tissues and body fluids due to a deficiency in the enzyme homogentisate 1,2-dioxygenase. This enzyme deficiency leads to an inability to break down tyrosine and phenylalanine amino acids properly, causing their byproduct, homogentisic acid, to build up in the body.

The accumulation of homogentisic acid can result in several clinical manifestations:

1. Dark urine: Homogentisic acid oxidizes and turns dark brown or black when exposed to air, giving the condition its name "alkaptonuria," derived from Greek words 'alos' (meaning 'strange') and 'kapto' (meaning 'I become black').
2. Arthritis: Over time, homogentisic acid deposits in connective tissues, particularly cartilage, causing damage and leading to a form of arthritis called ochronosis. This can result in stiffness, pain, and limited mobility in affected joints.
3. Heart problems: Homogentisic acid accumulation in heart valves may lead to thickening and calcification, potentially resulting in heart disease and valve dysfunction.
4. Kidney stones: The accumulation of homogentisic acid can form kidney stones, which can cause pain and potential kidney damage if they become lodged in the urinary tract.

There is no cure for alkaptonuria; however, treatment aims to manage symptoms and slow disease progression. A low-protein diet may help reduce tyrosine and phenylalanine intake, while increased hydration can help prevent kidney stone formation. Nitisinone, a medication that inhibits the production of homogentisic acid, has shown promise in managing alkaptonuria symptoms. Regular monitoring and early intervention are crucial to minimize complications associated with this rare condition.

Ribonucleotides are organic compounds that consist of a ribose sugar, a phosphate group, and a nitrogenous base. They are the building blocks of RNA (ribonucleic acid), one of the essential molecules in all living organisms. The nitrogenous bases found in ribonucleotides include adenine, uracil, guanine, and cytosine. These molecules play crucial roles in various biological processes, such as protein synthesis, gene expression, and cellular energy production. Ribonucleotides can also be involved in cell signaling pathways and serve as important cofactors for enzymatic reactions.

A rare disease, also known as an orphan disease, is a health condition that affects fewer than 200,000 people in the United States or fewer than 1 in 2,000 people in Europe. There are over 7,000 rare diseases identified, and many of them are severe, chronic, and often life-threatening. The causes of rare diseases can be genetic, infectious, environmental, or degenerative. Due to their rarity, research on rare diseases is often underfunded, and treatments may not be available or well-studied. Additionally, the diagnosis of rare diseases can be challenging due to a lack of awareness and understanding among healthcare professionals.

Inosine monophosphate (IMP) is a nucleotide that plays a crucial role in the metabolic pathways of energy production and purine synthesis in cells. It is an ester of the nucleoside inosine and phosphoric acid. IMP is an important intermediate in the conversion of adenosine monophosphate (AMP) to guanosine monophosphate (GMP) in the purine nucleotide cycle, which is critical for maintaining the balance of purine nucleotides in the body. Additionally, IMP can be converted back to AMP through the action of the enzyme adenylosuccinate lyase. IMP has been studied for its potential therapeutic benefits in various medical conditions, including neurodegenerative disorders and ischemia-reperfusion injury.

Uridine Monophosphate (UMP) is a nucleotide that is a constituent of RNA (Ribonucleic Acid). It consists of a nitrogenous base called Uridine, linked to a sugar molecule (ribose) and a phosphate group. UMP plays a crucial role in various biochemical reactions within the body, including energy transfer and cellular metabolism. It is also involved in the synthesis of other nucleotides and serves as an important precursor in the production of genetic material during cell division.

Citrullinemia is a rare inherited metabolic disorder characterized by the body's inability to properly process and eliminate certain toxic byproducts that are generated during the breakdown of proteins. This condition results from a deficiency of the enzyme argininosuccinate synthetase, which is required for the normal functioning of the urea cycle. The urea cycle is a series of biochemical reactions that occur in the liver and help to convert ammonia, a toxic substance, into urea, which can then be excreted by the kidneys.

There are two main types of citrullinemia: type I (also known as classic citrullinemia) and type II (also known as citrullinemia type II or adult-onset citrullinemia). Type I is typically more severe and can present in newborns with symptoms such as poor feeding, vomiting, seizures, and developmental delays. If left untreated, it can lead to serious complications, including intellectual disability, coma, and even death.

Type II citrullinemia, on the other hand, tends to present later in life, often in adulthood, and may cause symptoms such as confusion, seizures, and neurological problems. It is important to note that some individuals with type II citrullinemia may never develop any symptoms at all.

Treatment for citrullinemia typically involves a combination of dietary restrictions, supplements, and medications to help manage the buildup of toxic byproducts in the body. In severe cases, liver transplantation may be considered as a last resort.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Ammonia is a colorless, pungent-smelling gas with the chemical formula NH3. It is a compound of nitrogen and hydrogen and is a basic compound, meaning it has a pH greater than 7. Ammonia is naturally found in the environment and is produced by the breakdown of organic matter, such as animal waste and decomposing plants. In the medical field, ammonia is most commonly discussed in relation to its role in human metabolism and its potential toxicity.

In the body, ammonia is produced as a byproduct of protein metabolism and is typically converted to urea in the liver and excreted in the urine. However, if the liver is not functioning properly or if there is an excess of protein in the diet, ammonia can accumulate in the blood and cause a condition called hyperammonemia. Hyperammonemia can lead to serious neurological symptoms, such as confusion, seizures, and coma, and is treated by lowering the level of ammonia in the blood through medications, dietary changes, and dialysis.

Multiple Acyl Coenzyme A Dehydrogenase Deficiency (MADD) is a rare inherited metabolic disorder that affects the body's ability to break down certain fats and proteins. It is caused by mutations in genes that code for enzymes involved in the electron transfer flavoprotein-ubiquinone (ETF-QO) complex, which is responsible for transferring electrons from various acyl-CoA dehydrogenases to the electron transport chain during fatty acid and amino acid oxidation.

As a result of these genetic defects, there is a buildup of unoxidized acyl-CoA molecules in the body, leading to the accumulation of toxic intermediates that can damage organs and tissues. This can cause a wide range of symptoms, including hypoglycemia, metabolic acidosis, cardiac arrhythmias, muscle weakness, and developmental delays.

MADD is typically classified into three types based on the age of onset and severity of symptoms: neonatal, infantile, and late-onset. The neonatal form is the most severe and often leads to death in early infancy, while the infantile and late-onset forms can present with milder symptoms that may not become apparent until later in life.

Treatment for MADD typically involves a combination of dietary modifications, such as restricting long-chain fatty acids and supplementing with medium-chain triglycerides, and oral supplementation with riboflavin (vitamin B2), which has been shown to improve the activity of the ETF-QO complex in some cases.

Nucleic acid conformation refers to the three-dimensional structure that nucleic acids (DNA and RNA) adopt as a result of the bonding patterns between the atoms within the molecule. The primary structure of nucleic acids is determined by the sequence of nucleotides, while the conformation is influenced by factors such as the sugar-phosphate backbone, base stacking, and hydrogen bonding.

Two common conformations of DNA are the B-form and the A-form. The B-form is a right-handed helix with a diameter of about 20 Å and a pitch of 34 Å, while the A-form has a smaller diameter (about 18 Å) and a shorter pitch (about 25 Å). RNA typically adopts an A-form conformation.

The conformation of nucleic acids can have significant implications for their function, as it can affect their ability to interact with other molecules such as proteins or drugs. Understanding the conformational properties of nucleic acids is therefore an important area of research in molecular biology and medicine.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

Adenosine is a purine nucleoside that is composed of a sugar (ribose) and the base adenine. It plays several important roles in the body, including serving as a precursor for the synthesis of other molecules such as ATP, NAD+, and RNA.

In the medical context, adenosine is perhaps best known for its use as a pharmaceutical agent to treat certain cardiac arrhythmias. When administered intravenously, it can help restore normal sinus rhythm in patients with paroxysmal supraventricular tachycardia (PSVT) by slowing conduction through the atrioventricular node and interrupting the reentry circuit responsible for the arrhythmia.

Adenosine can also be used as a diagnostic tool to help differentiate between narrow-complex tachycardias of supraventricular origin and those that originate from below the ventricles (such as ventricular tachycardia). This is because adenosine will typically terminate PSVT but not affect the rhythm of VT.

It's worth noting that adenosine has a very short half-life, lasting only a few seconds in the bloodstream. This means that its effects are rapidly reversible and generally well-tolerated, although some patients may experience transient symptoms such as flushing, chest pain, or shortness of breath.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Ribose monophosphates are organic compounds that play a crucial role in the metabolism of cells, particularly in energy transfer and nucleic acid synthesis. A ribose monophosphate is formed by the attachment of a phosphate group to a ribose molecule, which is a type of sugar known as a pentose.

In biochemistry, there are two important ribose monophosphates:

1. Alpha-D-Ribose 5-Phosphate (ADP-Ribose): This compound serves as an essential substrate in various cellular processes, including DNA repair, chromatin remodeling, and protein modification. The enzyme that catalyzes the formation of ADP-ribose is known as poly(ADP-ribose) polymerase (PARP).
2. Ribulose 5-Phosphate: This compound is a key intermediate in the Calvin cycle, which is the process by which plants and some bacteria convert carbon dioxide into glucose during photosynthesis. Ribulose 5-phosphate is formed from ribose 5-phosphate through a series of enzymatic reactions.

Ribose monophosphates are essential for the proper functioning of cells and have implications in various physiological processes, as well as in certain disease states.

Mucopolysaccharidoses (MPS) are a group of inherited metabolic disorders caused by the deficiency of specific enzymes needed to break down complex sugars called glycosaminoglycans (GAGs or mucopolysaccharides). As a result, these GAGs accumulate in various tissues and organs, leading to progressive cellular damage and multi-organ dysfunction. There are several types of MPS, including Hurler syndrome, Hunter syndrome, Sanfilippo syndrome, Morquio syndrome, Maroteaux-Lamy syndrome, and Sly syndrome, each resulting from a deficiency in one of the eleven different enzymes involved in GAGs metabolism. The clinical presentation, severity, and prognosis vary among the types but commonly include features such as developmental delay, coarse facial features, skeletal abnormalities, hearing loss, heart problems, and reduced life expectancy.

Deoxyuridine is a chemical compound that is a component of DNA. It is a nucleoside, which means it consists of a sugar (deoxyribose) linked to a nitrogenous base (uracil). In the case of deoxyuridine, the uracil is not methylated, which differentiates it from thymidine.

Deoxyuridine can be converted into deoxyuridine monophosphate (dUMP) by the enzyme thymidine kinase. The dUMP can then be converted into deoxythymidine triphosphate (dTTP), which is a building block of DNA, through a series of reactions involving other enzymes.

Deoxyuridine has been used in research and medicine as a marker for DNA synthesis and repair. It can also be used to inhibit the growth of certain types of cells, such as cancer cells, by disrupting their DNA synthesis.

Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.

5'-Nucleotidase is an enzyme that is found on the outer surface of cell membranes, including those of liver cells and red blood cells. Its primary function is to catalyze the hydrolysis of nucleoside monophosphates, such as adenosine monophosphate (AMP) and guanosine monophosphate (GMP), to their corresponding nucleosides, such as adenosine and guanosine, by removing a phosphate group from the 5' position of the nucleotide.

Abnormal levels of 5'-Nucleotidase in the blood can be indicative of liver or bone disease. For example, elevated levels of this enzyme in the blood may suggest liver damage or injury, such as that caused by hepatitis, cirrhosis, or alcohol abuse. Conversely, low levels of 5'-Nucleotidase may be associated with certain types of anemia, including aplastic anemia and paroxysmal nocturnal hemoglobinuria.

Medical professionals may order a 5'-Nucleotidase test to help diagnose or monitor the progression of these conditions. It is important to note that other factors, such as medication use or muscle damage, can also affect 5'-Nucleotidase levels, so results must be interpreted in conjunction with other clinical findings and diagnostic tests.

Nucleotidases are a class of enzymes that catalyze the hydrolysis of nucleotides into nucleosides and phosphate groups. Nucleotidases play important roles in various biological processes, including the regulation of nucleotide concentrations within cells, the salvage pathways for nucleotide synthesis, and the breakdown of nucleic acids during programmed cell death (apoptosis).

There are several types of nucleotidases that differ in their substrate specificity and subcellular localization. These include:

1. Nucleoside monophosphatases (NMPs): These enzymes hydrolyze nucleoside monophosphates (NMPs) into nucleosides and inorganic phosphate.
2. Nucleoside diphosphatases (NDPs): These enzymes hydrolyze nucleoside diphosphates (NDPs) into nucleoside monophosphates (NMPs) and inorganic phosphate.
3. Nucleoside triphosphatases (NTPs): These enzymes hydrolyze nucleoside triphosphates (NTPs) into nucleoside diphosphates (NDPs) and inorganic phosphate.
4. 5'-Nucleotidase: This enzyme specifically hydrolyzes the phosphate group from the 5' position of nucleoside monophosphates, producing nucleosides.
5. Pyrophosphatases: These enzymes hydrolyze pyrophosphates into two phosphate groups and play a role in regulating nucleotide metabolism.

Nucleotidases are widely distributed in nature and can be found in various tissues, organs, and biological fluids, including blood, urine, and cerebrospinal fluid. Dysregulation of nucleotidase activity has been implicated in several diseases, such as cancer, neurodegenerative disorders, and infectious diseases.

Gas Chromatography-Mass Spectrometry (GC-MS) is a powerful analytical technique that combines the separating power of gas chromatography with the identification capabilities of mass spectrometry. This method is used to separate, identify, and quantify different components in complex mixtures.

In GC-MS, the mixture is first vaporized and carried through a long, narrow column by an inert gas (carrier gas). The various components in the mixture interact differently with the stationary phase inside the column, leading to their separation based on their partition coefficients between the mobile and stationary phases. As each component elutes from the column, it is then introduced into the mass spectrometer for analysis.

The mass spectrometer ionizes the sample, breaks it down into smaller fragments, and measures the mass-to-charge ratio of these fragments. This information is used to generate a mass spectrum, which serves as a unique "fingerprint" for each compound. By comparing the generated mass spectra with reference libraries or known standards, analysts can identify and quantify the components present in the original mixture.

GC-MS has wide applications in various fields such as forensics, environmental analysis, drug testing, and research laboratories due to its high sensitivity, specificity, and ability to analyze volatile and semi-volatile compounds.

Acyl-CoA dehydrogenase is a group of enzymes that play a crucial role in the body's energy production process. Specifically, they are involved in the breakdown of fatty acids within the cells.

More technically, acyl-CoA dehydrogenases catalyze the removal of electrons from the thiol group of acyl-CoAs, forming a trans-double bond and generating FADH2. This reaction is the first step in each cycle of fatty acid beta-oxidation, which occurs in the mitochondria of cells.

There are several different types of acyl-CoA dehydrogenases, each specific to breaking down different lengths of fatty acids. For example, very long-chain acyl-CoA dehydrogenase (VLCAD) is responsible for breaking down longer chain fatty acids, while medium-chain acyl-CoA dehydrogenase (MCAD) breaks down medium-length chains.

Deficiencies in these enzymes can lead to various metabolic disorders, such as MCAD deficiency or LC-FAOD (long-chain fatty acid oxidation disorders), which can cause symptoms like vomiting, lethargy, and muscle weakness, especially during periods of fasting or illness.

Pyruvate Dehydrogenase Complex (PDH) Deficiency is a genetic disorder that affects the body's ability to convert certain food molecules into energy. The pyruvate dehydrogenase complex is a group of enzymes that converts pyruvate, a byproduct of glucose metabolism in the cell's cytoplasm, into acetyl-CoA, which then enters the citric acid cycle (also known as the Krebs cycle) in the mitochondria to produce energy in the form of ATP.

PDH deficiency results from mutations in one or more genes encoding the subunits of the PDH complex or its activators, leading to reduced enzymatic activity. This impairs the conversion of pyruvate to acetyl-CoA and causes an accumulation of pyruvate in body tissues and fluids, particularly during periods of metabolic stress such as illness, infection, or fasting.

The severity of PDH deficiency can vary widely, from mild to severe forms, depending on the extent of enzyme dysfunction. Symptoms may include developmental delay, hypotonia (low muscle tone), seizures, poor feeding, and metabolic acidosis. In severe cases, it can lead to neurological damage, lactic acidosis, and early death if not diagnosed and treated promptly.

PDH deficiency is typically diagnosed through biochemical tests that measure the activity of the PDH complex in cultured skin fibroblasts or muscle tissue. Genetic testing may also be used to identify specific gene mutations causing the disorder. Treatment usually involves a low-carbohydrate, high-fat diet and supplementation with thiamine (vitamin B1), which is an essential cofactor for PDH complex activity. In some cases, dialysis or other supportive measures may be necessary to manage metabolic acidosis and other complications.

Lysosomal storage diseases (LSDs) are a group of rare inherited metabolic disorders caused by defects in lysosomal function. Lysosomes are membrane-bound organelles within cells that contain enzymes responsible for breaking down and recycling various biomolecules, such as proteins, lipids, and carbohydrates. In LSDs, the absence or deficiency of specific lysosomal enzymes leads to the accumulation of undigested substrates within the lysosomes, resulting in cellular dysfunction and organ damage.

These disorders can affect various organs and systems in the body, including the brain, nervous system, bones, skin, and visceral organs. Symptoms may include developmental delays, neurological impairment, motor dysfunction, bone abnormalities, coarse facial features, hepatosplenomegaly (enlarged liver and spleen), and recurrent infections.

Examples of LSDs include Gaucher disease, Tay-Sachs disease, Niemann-Pick disease, Fabry disease, Pompe disease, and mucopolysaccharidoses (MPS). Treatment options for LSDs may include enzyme replacement therapy, substrate reduction therapy, or bone marrow transplantation. Early diagnosis and intervention can help improve the prognosis and quality of life for affected individuals.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

Ornithine-oxo-acid transaminase (OAT), also known as ornithine aminotransferase, is a urea cycle enzyme that catalyzes the reversible transfer of an amino group from ornithine to α-ketoglutarate, producing glutamate semialdehyde and glutamate. This reaction is an essential part of the urea cycle, which is responsible for the detoxification of ammonia in the body. Deficiencies in OAT can lead to a genetic disorder called ornithine transcarbamylase deficiency (OTCD), which can cause hyperammonemia and neurological symptoms.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

Thiamine, also known as vitamin B1, is a water-soluble vitamin that plays a crucial role in certain metabolic reactions, particularly in the conversion of carbohydrates into energy in the body. It is essential for the proper functioning of the heart, nerves, and digestive system. Thiamine acts as a cofactor for enzymes involved in the synthesis of neurotransmitters and the metabolism of carbohydrates, lipids, and proteins. Deficiency in thiamine can lead to serious health complications, such as beriberi (a disease characterized by peripheral neuropathy, muscle wasting, and heart failure) and Wernicke-Korsakoff syndrome (a neurological disorder often seen in alcoholics due to chronic thiamine deficiency). Thiamine is found in various foods, including whole grains, legumes, pork, beef, and fortified foods.

Neuroaxonal dystrophies (NADs) are a group of inherited neurological disorders characterized by degeneration of the neuronal axons, which are the long extensions of nerve cells that transmit impulses to other cells. This degeneration leads to progressive loss of motor and cognitive functions.

The term "neuroaxonal dystrophy" refers to a specific pattern of abnormalities seen on electron microscopy in nerve cells, including accumulation of membranous structures called "spheroids" or "tubulovesicular structures" within the axons.

NADs can be caused by mutations in various genes that play a role in maintaining the structure and function of neuronal axons. The most common forms of NADs include Infantile Neuroaxonal Dystrophy (INAD) or Seitelberger's Disease, and Late-Onset Neuroaxonal Dystrophy (LONAD).

Symptoms of INAD typically begin between ages 6 months and 2 years, and may include muscle weakness, hypotonia, decreased reflexes, vision loss, hearing impairment, and developmental delay. LONAD usually presents in childhood or adolescence with symptoms such as ataxia, dysarthria, cognitive decline, and behavioral changes.

Currently, there is no cure for NADs, and treatment is focused on managing symptoms and improving quality of life.

Biotransformation is the metabolic modification of a chemical compound, typically a xenobiotic (a foreign chemical substance found within an living organism), by a biological system. This process often involves enzymatic conversion of the parent compound to one or more metabolites, which may be more or less active, toxic, or mutagenic than the original substance.

In the context of pharmacology and toxicology, biotransformation is an important aspect of drug metabolism and elimination from the body. The liver is the primary site of biotransformation, but other organs such as the kidneys, lungs, and gastrointestinal tract can also play a role.

Biotransformation can occur in two phases: phase I reactions involve functionalization of the parent compound through oxidation, reduction, or hydrolysis, while phase II reactions involve conjugation of the metabolite with endogenous molecules such as glucuronic acid, sulfate, or acetate to increase its water solubility and facilitate excretion.

Carbon isotopes are variants of the chemical element carbon that have different numbers of neutrons in their atomic nuclei. The most common and stable isotope of carbon is carbon-12 (^{12}C), which contains six protons and six neutrons. However, carbon can also come in other forms, known as isotopes, which contain different numbers of neutrons.

Carbon-13 (^{13}C) is a stable isotope of carbon that contains seven neutrons in its nucleus. It makes up about 1.1% of all carbon found on Earth and is used in various scientific applications, such as in tracing the metabolic pathways of organisms or in studying the age of fossilized materials.

Carbon-14 (^{14}C), also known as radiocarbon, is a radioactive isotope of carbon that contains eight neutrons in its nucleus. It is produced naturally in the atmosphere through the interaction of cosmic rays with nitrogen gas. Carbon-14 has a half-life of about 5,730 years, which makes it useful for dating organic materials, such as archaeological artifacts or fossils, up to around 60,000 years old.

Carbon isotopes are important in many scientific fields, including geology, biology, and medicine, and are used in a variety of applications, from studying the Earth's climate history to diagnosing medical conditions.

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is an enzyme that plays a crucial role in the salvage pathway of nucleotide synthesis. This enzyme catalyzes the conversion of hypoxanthine and guanine to their respective nucleotides, inosine monophosphate (IMP) and guanosine monophosphate (GMP), by transferring the phosphoribosyl group from 5-phosphoribosyl-1 pyrophosphate (PRPP) to the purine bases.

HGPRT deficiency is a genetic disorder known as Lesch-Nyhan syndrome, which is characterized by mental retardation, self-mutilation, spasticity, and uric acid overproduction due to the accumulation of hypoxanthine and guanine. This disorder is caused by mutations in the HPRT1 gene, leading to a decrease or absence of HGPRT enzyme activity.

Primary hyperoxaluria is a rare genetic disorder characterized by overproduction of oxalate in the body due to mutations in specific enzymes involved in oxalate metabolism. There are three types of primary hyperoxaluria (PH1, PH2, and PH3), with PH1 being the most common and severe form.

In primary hyperoxaluria type 1 (PH1), there is a deficiency or dysfunction in the enzyme alanine-glyoxylate aminotransferase (AGT), which leads to an accumulation of glyoxylate. Glyoxylate is then converted to oxalate, resulting in increased oxalate production. Oxalate is a compound that naturally occurs in the body but is primarily excreted through the kidneys. When there is an overproduction of oxalate, it can lead to the formation of calcium oxalate crystals in various tissues, including the kidneys. This can cause recurrent kidney stones, nephrocalcinosis (calcium deposits in the kidneys), and eventually chronic kidney disease or end-stage renal failure.

Primary hyperoxaluria type 2 (PH2) is caused by a deficiency or dysfunction in the enzyme glyoxylate reductase/hydroxypyruvate reductase (GRHPR), leading to an accumulation of glyoxylate, which is subsequently converted to oxalate. PH2 has a milder clinical presentation compared to PH1.

Primary hyperoxaluria type 3 (PH3) is a rare form caused by mutations in the gene HOGA1, which encodes for 4-hydroxy-2-oxoglutarate aldolase. This enzyme deficiency results in an increase in glyoxylate and, subsequently, oxalate production.

Early diagnosis and management of primary hyperoxaluria are crucial to prevent or slow down the progression of kidney damage. Treatment options include increased fluid intake, medications to reduce stone formation (such as potassium citrate), and in some cases, liver-kidney transplantation.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Fatty acids are carboxylic acids with a long aliphatic chain, which are important components of lipids and are widely distributed in living organisms. They can be classified based on the length of their carbon chain, saturation level (presence or absence of double bonds), and other structural features.

The two main types of fatty acids are:

1. Saturated fatty acids: These have no double bonds in their carbon chain and are typically solid at room temperature. Examples include palmitic acid (C16:0) and stearic acid (C18:0).
2. Unsaturated fatty acids: These contain one or more double bonds in their carbon chain and can be further classified into monounsaturated (one double bond) and polyunsaturated (two or more double bonds) fatty acids. Examples of unsaturated fatty acids include oleic acid (C18:1, monounsaturated), linoleic acid (C18:2, polyunsaturated), and alpha-linolenic acid (C18:3, polyunsaturated).

Fatty acids play crucial roles in various biological processes, such as energy storage, membrane structure, and cell signaling. Some essential fatty acids cannot be synthesized by the human body and must be obtained through dietary sources.

Ornithine is not a medical condition but a naturally occurring alpha-amino acid, which is involved in the urea cycle, a process that eliminates ammonia from the body. Here's a brief medical/biochemical definition of Ornithine:

Ornithine (NH₂-CH₂-CH₂-CH(NH₃)-COOH) is an α-amino acid without a carbon atom attached to the amino group, classified as a non-proteinogenic amino acid because it is not encoded by the standard genetic code and not commonly found in proteins. It plays a crucial role in the urea cycle, where it helps convert harmful ammonia into urea, which can then be excreted by the body through urine. Ornithine is produced from the breakdown of arginine, another amino acid, via the enzyme arginase. In some medical and nutritional contexts, ornithine supplementation may be recommended to support liver function, wound healing, or muscle growth, but its effectiveness for these uses remains a subject of ongoing research and debate.

Inborn genetic diseases, also known as inherited genetic disorders, are conditions caused by abnormalities in an individual's DNA that are present at conception. These abnormalities can include mutations, deletions, or rearrangements of genes or chromosomes. In many cases, these genetic changes are inherited from one or both parents and may be passed down through families.

Inborn genetic diseases can affect any part of the body and can cause a wide range of symptoms, which can vary in severity depending on the specific disorder. Some genetic disorders are caused by mutations in a single gene, while others are caused by changes in multiple genes or chromosomes. In some cases, environmental factors may also contribute to the development of these conditions.

Examples of inborn genetic diseases include cystic fibrosis, sickle cell anemia, Huntington's disease, Duchenne muscular dystrophy, and Down syndrome. These conditions can have significant impacts on an individual's health and quality of life, and many require ongoing medical management and treatment. In some cases, genetic counseling and testing may be recommended for individuals with a family history of a particular genetic disorder to help them make informed decisions about their reproductive options.

Adenine Phosphoribosyltransferase (APRT) is an enzyme that plays a crucial role in the metabolism of purines, specifically adenine, in the body. The enzyme catalyzes the conversion of adenine to AMP (adenosine monophosphate) by transferring a phosphoribosyl group from 5-phosphoribosyl-1-pyrophosphate (PRPP) to adenine.

Deficiency in APRT can lead to a rare genetic disorder known as Adenine Phosphoribosyltransferase Deficiency or APRT Deficiency. This condition results in the accumulation of 2,8-dihydroxyadenine (DHA) crystals in the renal tubules, which can cause kidney stones and chronic kidney disease. Proper diagnosis and management, including dietary modifications and medication, are essential to prevent complications associated with APRT Deficiency.

Urea is not a medical condition but it is a medically relevant substance. Here's the definition:

Urea is a colorless, odorless solid that is the primary nitrogen-containing compound in the urine of mammals. It is a normal metabolic end product that is excreted by the kidneys and is also used as a fertilizer and in various industrial applications. Chemically, urea is a carbamide, consisting of two amino groups (NH2) joined by a carbon atom and having a hydrogen atom and a hydroxyl group (OH) attached to the carbon atom. Urea is produced in the liver as an end product of protein metabolism and is then eliminated from the body by the kidneys through urination. Abnormal levels of urea in the blood, known as uremia, can indicate impaired kidney function or other medical conditions.

N-Glycosyl hydrolases (or N-glycanases) are a class of enzymes that catalyze the hydrolysis of the glycosidic bond between an N-glycosyl group and an aglycon, which is typically another part of a larger molecule such as a protein or lipid. N-Glycosyl groups refer to carbohydrate moieties attached to an nitrogen atom, usually in the side chain of an amino acid such as asparagine (Asn) in proteins.

N-Glycosyl hydrolases play important roles in various biological processes, including the degradation and processing of glycoproteins, the modification of glycolipids, and the breakdown of complex carbohydrates. These enzymes are widely distributed in nature and have been found in many organisms, from bacteria to humans.

The classification and nomenclature of N-Glycosyl hydrolases are based on the type of glycosidic bond they cleave and the stereochemistry of the reaction they catalyze. They are grouped into different families in the Carbohydrate-Active enZymes (CAZy) database, which provides a comprehensive resource for the study of carbohydrate-active enzymes.

It is worth noting that N-Glycosyl hydrolases can have both beneficial and detrimental effects on human health. For example, they are involved in the normal turnover and degradation of glycoproteins in the body, but they can also contribute to the pathogenesis of certain diseases, such as lysosomal storage disorders, where mutations in N-Glycosyl hydrolases lead to the accumulation of undigested glycoconjugates and cellular damage.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

Carbon radioisotopes are radioactive isotopes of carbon, which is an naturally occurring chemical element with the atomic number 6. The most common and stable isotope of carbon is carbon-12 (^12C), but there are also several radioactive isotopes, including carbon-11 (^11C), carbon-14 (^14C), and carbon-13 (^13C). These radioisotopes have different numbers of neutrons in their nuclei, which makes them unstable and causes them to emit radiation.

Carbon-11 has a half-life of about 20 minutes and is used in medical imaging techniques such as positron emission tomography (PET) scans. It is produced by bombarding nitrogen-14 with protons in a cyclotron.

Carbon-14, also known as radiocarbon, has a half-life of about 5730 years and is used in archaeology and geology to date organic materials. It is produced naturally in the atmosphere by cosmic rays.

Carbon-13 is stable and has a natural abundance of about 1.1% in carbon. It is not radioactive, but it can be used as a tracer in medical research and in the study of metabolic processes.

Deoxyadenosine is a chemical compound that is a component of DNA, one of the nucleic acids that make up the genetic material of living organisms. Specifically, deoxyadenosine is a nucleoside, which is a molecule consisting of a sugar (in this case, deoxyribose) bonded to a nitrogenous base (in this case, adenine).

Deoxyribonucleosides like deoxyadenosine are the building blocks of DNA, along with phosphate groups. In DNA, deoxyadenosine pairs with thymidine via hydrogen bonds to form one of the four rungs in the twisted ladder structure of the double helix.

It is important to note that there is a similar compound called adenosine, which contains an extra oxygen atom on the sugar molecule (making it a ribonucleoside) and is a component of RNA, another nucleic acid involved in protein synthesis and other cellular processes.

Amidophosphoribosyltransferase is an enzyme involved in the metabolic pathway of purine synthesis. Its systematic name is phosphoribosylamine-phosphate transaminase, and it catalyzes the reaction between phosphoribosyl pyrophosphate (PRPP) and glutamine to produce 5-phosphoribosyl-α-[glutamate-1-formimino]-triose phosphate (GAR) and ammonia.

This enzyme plays a crucial role in the biosynthesis of purine nucleotides, which are essential components of DNA, RNA, and many other important molecules in the body. Deficiencies in this enzyme can lead to serious medical conditions, such as Lesch-Nyhan syndrome, a rare genetic disorder characterized by mental retardation, self-mutilation, spasticity, and an excess of uric acid in the blood (hyperuricemia).

A homozygote is an individual who has inherited the same allele (version of a gene) from both parents and therefore possesses two identical copies of that allele at a specific genetic locus. This can result in either having two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive). In contrast, a heterozygote has inherited different alleles from each parent for a particular gene.

The term "homozygote" is used in genetics to describe the genetic makeup of an individual at a specific locus on their chromosomes. Homozygosity can play a significant role in determining an individual's phenotype (observable traits), as having two identical alleles can strengthen the expression of certain characteristics compared to having just one dominant and one recessive allele.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

I must clarify that the term "pedigree" is not typically used in medical definitions. Instead, it is often employed in genetics and breeding, where it refers to the recorded ancestry of an individual or a family, tracing the inheritance of specific traits or diseases. In human genetics, a pedigree can help illustrate the pattern of genetic inheritance in families over multiple generations. However, it is not a medical term with a specific clinical definition.

Pentose phosphates are monosaccharides that contain five carbon atoms and one phosphate group. They play a crucial role in various metabolic pathways, including the pentose phosphate pathway (PPP), which is a major source of NADPH and ribose-5-phosphate for the synthesis of nucleotides.

The pentose phosphate pathway involves two main phases: the oxidative phase and the non-oxidative phase. In the oxidative phase, glucose-6-phosphate is converted to ribulose-5-phosphate, producing NADPH and CO2 as byproducts. Ribulose-5-phosphate can then be further metabolized in the non-oxidative phase to produce other pentose phosphates or converted back to glucose-6-phosphate through a series of reactions.

Pentose phosphates are also important intermediates in the synthesis of nucleotides, coenzymes, and other metabolites. Abnormalities in pentose phosphate pathway enzymes can lead to various metabolic disorders, such as defects in erythrocyte function and increased susceptibility to oxidative stress.

Phosphoribosylglycinamide formyltransferase (PGTF) is an enzyme involved in the biosynthesis of purine nucleotides, which are essential components of DNA and RNA. The systematic medical definition of PGTF is:

"An enzyme that catalyzes the transfer of a formyl group from 10-formyltetrahydrofolate to the amino group of phosphoribosylglycinamide, forming N-formylphosphoribosylglycinamide and tetrahydrofolate as byproducts. This reaction is the fourth step in the de novo synthesis pathway of purine nucleotides."

PGTF's gene name is GART (Glycinamide Ribonucleotide Transformylase), and it is located on human chromosome 10q24.32-q25.1. Mutations in the GART gene can lead to a rare autosomal recessive disorder called Lesch-Nyhan syndrome, which is characterized by hyperuricemia, neurological symptoms, and self-mutilating behavior.

Nucleoside transport proteins (NTTs) are membrane-bound proteins responsible for the facilitated diffusion of nucleosides and related deoxynucleosides across the cell membrane. These proteins play a crucial role in the uptake of nucleosides, which serve as precursors for DNA and RNA synthesis, as well as for the salvage of nucleotides in the cell.

There are two main types of NTTs: concentrative (or sodium-dependent) nucleoside transporters (CNTs) and equilibrative (or sodium-independent) nucleoside transporters (ENTs). CNTs mainly facilitate the uptake of nucleosides against a concentration gradient, using the energy derived from the sodium ion gradient. In contrast, ENTs mediate bidirectional transport, allowing for the equalization of intracellular and extracellular nucleoside concentrations.

Nucleoside transport proteins have been identified in various organisms, including humans, and are involved in numerous physiological processes, such as cell proliferation, differentiation, and survival. Dysregulation of NTTs has been implicated in several pathological conditions, including cancer and viral infections, making them potential targets for therapeutic intervention.

Inborn errors of renal tubular transport refer to genetic disorders that affect the normal functioning of the kidney tubules. The kidney tubules are responsible for the reabsorption and secretion of various substances, including electrolytes and nutrients, as urine is formed. Inherited defects in the proteins that mediate these transport processes can lead to abnormal levels of these substances in the body and may result in a variety of clinical symptoms.

These disorders can affect different parts of the renal tubule, including the proximal tubule, loop of Henle, distal tubule, and collecting duct. Depending on the specific transporter affected, inborn errors of renal tubular transport can present with a range of clinical manifestations, such as electrolyte imbalances, acid-base disorders, growth retardation, kidney stones, nephrocalcinosis, or even kidney failure.

Examples of inborn errors of renal tubular transport include:

1. Distal renal tubular acidosis (dRTA): A genetic disorder that affects the ability of the distal tubule to acidify urine, leading to metabolic acidosis, hypokalemia, and nephrocalcinosis.
2. Bartter syndrome: A group of autosomal recessive disorders characterized by impaired sodium reabsorption in the loop of Henle, resulting in hypokalemia, metabolic alkalosis, and hyperreninemic hyperaldosteronism.
3. Gitelman syndrome: An autosomal recessive disorder caused by a defect in the thiazide-sensitive sodium chloride cotransporter in the distal tubule, leading to hypokalemia, metabolic alkalosis, and hypocalciuria.
4. Liddle syndrome: An autosomal dominant disorder characterized by increased sodium reabsorption in the collecting duct due to a gain-of-function mutation in the epithelial sodium channel (ENaC), resulting in hypertension, hypokalemia, and metabolic alkalosis.
5. Dent disease: An X-linked recessive disorder caused by mutations in the CLCN5 gene, which encodes a chloride channel in the proximal tubule, leading to low molecular weight proteinuria, hypercalciuria, and nephrolithiasis.
6. Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC): An autosomal recessive disorder caused by mutations in the CLCN5 or CLDN16 genes, which encode chloride channels in the thick ascending limb of Henle's loop, resulting in hypomagnesemia, hypercalciuria, and nephrocalcinosis.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

Cytosine is one of the four nucleobases in the nucleic acid molecules DNA and RNA, along with adenine, guanine, and thymine (in DNA) or uracil (in RNA). The single-letter abbreviation for cytosine is "C."

Cytosine base pairs specifically with guanine through hydrogen bonding, forming a base pair. In DNA, the double helix consists of two complementary strands of nucleotides held together by these base pairs, such that the sequence of one strand determines the sequence of the other. This property is critical for DNA replication and transcription, processes that are essential for life.

Cytosine residues in DNA can undergo spontaneous deamination to form uracil, which can lead to mutations if not corrected by repair mechanisms. In RNA, cytosine can be methylated at the 5-carbon position to form 5-methylcytosine, a modification that plays a role in regulating gene expression and other cellular processes.

Argininosuccinate Lyase is an enzyme that plays a crucial role in the urea cycle, which is the metabolic pathway responsible for eliminating excess nitrogen waste from the body. This enzyme is responsible for catalyzing the conversion of argininosuccinate into arginine and fumarate.

The urea cycle occurs primarily in the liver and helps to convert toxic ammonia, a byproduct of protein metabolism, into urea, which can be safely excreted in urine. Argininosuccinate lyase is essential for this process, as it helps to convert argininosuccinate, an intermediate compound in the cycle, into arginine, which can then be recycled back into the urea cycle or used for other physiological processes.

Deficiencies in argininosuccinate lyase can lead to a rare genetic disorder known as citrullinemia, which is characterized by elevated levels of citrulline and ammonia in the blood, as well as neurological symptoms such as seizures, developmental delays, and intellectual disability. Treatment for citrullinemia typically involves a low-protein diet, supplementation with arginine and other essential amino acids, and in some cases, liver transplantation.

DNA damage refers to any alteration in the structure or composition of deoxyribonucleic acid (DNA), which is the genetic material present in cells. DNA damage can result from various internal and external factors, including environmental exposures such as ultraviolet radiation, tobacco smoke, and certain chemicals, as well as normal cellular processes such as replication and oxidative metabolism.

Examples of DNA damage include base modifications, base deletions or insertions, single-strand breaks, double-strand breaks, and crosslinks between the two strands of the DNA helix. These types of damage can lead to mutations, genomic instability, and chromosomal aberrations, which can contribute to the development of diseases such as cancer, neurodegenerative disorders, and aging-related conditions.

The body has several mechanisms for repairing DNA damage, including base excision repair, nucleotide excision repair, mismatch repair, and double-strand break repair. However, if the damage is too extensive or the repair mechanisms are impaired, the cell may undergo apoptosis (programmed cell death) to prevent the propagation of potentially harmful mutations.

Adenosine Deaminase (ADA) is an enzyme that plays a crucial role in the immune system by helping to regulate the levels of certain chemicals called purines within cells. Specifically, ADA helps to break down adenosine, a type of purine, into another compound called inosine. This enzyme is found in all tissues of the body, but it is especially active in the immune system's white blood cells, where it helps to support their growth, development, and function.

ADA deficiency is a rare genetic disorder that can lead to severe combined immunodeficiency (SCID), a condition in which babies are born with little or no functional immune system. This makes them extremely vulnerable to infections, which can be life-threatening. ADA deficiency can be treated with enzyme replacement therapy, bone marrow transplantation, or gene therapy.

Xanthine is a purine base, which is a naturally occurring heterocyclic aromatic organic compound. It is formed in the body during the metabolism of purines, and it's a normal intermediate in the breakdown of nucleotides to uric acid. Xanthine is also found in various foods and beverages, such as coffee, tea, and chocolate. In the medical field, xanthine may refer to a class of drugs called xanthine derivatives, which include theophylline and caffeine, that act as bronchodilators and cardiac stimulants.

Tandem mass spectrometry (MS/MS) is a technique used to identify and quantify specific molecules, such as proteins or metabolites, within complex mixtures. This method uses two or more sequential mass analyzers to first separate ions based on their mass-to-charge ratio and then further fragment the selected ions into smaller pieces for additional analysis. The fragmentation patterns generated in MS/MS experiments can be used to determine the structure and identity of the original molecule, making it a powerful tool in various fields such as proteomics, metabolomics, and forensic science.

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Inborn errors of purine-pyrimidine metabolism). ... an inborn error (or deviation) of metabolism". Lancet. 266 ( ... "Biochemical studies on the purine metabolism of four cases with hereditary xanthinuria". Clin Chim Acta. 137 (2): 189-98. doi: ... There is no specific treatment beyond maintaining a high fluid intake and avoiding foods that are high in purine. Dent CE, ...
Inborn errors of purine-pyrimidine metabolism, Combined T and B-cell immunodeficiencies). ... In contrast to adenosine deaminase deficiency (another deficiency of purine metabolism), there is minimal disruption to B cells ... PNP is a key enzyme in the purine catabolic pathway, and is required for purine degradation. Specifically, it catalyzes the ... "eMedicine - Purine Nucleoside Phosphorylase Deficiency : Article by Alan P Knutsen". Retrieved July 25, 2010. "Boy first in UK ...
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Inborn errors of purine-pyrimidine metabolism, Inflammatory polyarthropathies, Rheumatology, Wikipedia medicine articles ready ... Kaneko, Kiyoko; Aoyagi, Yasuo; Fukuuchi, Tomoko; Inazawa, Katsunori; Yamaoka, Noriko (2014). "Total Purine and Purine Base ... Gout is a disorder of purine metabolism, and occurs when its final metabolite, uric acid, crystallizes in the form of ... Skin conditions resulting from errors in metabolism, Steroid-responsive inflammatory conditions, Uric acid, Crystal deposition ...
... purine-pyrimidine metabolism, inborn errors MeSH C18.452.648.798.368 - gout MeSH C18.452.648.798.368.410 - arthritis, gouty ... amino acid metabolism, inborn errors MeSH C18.452.648.066.102 - albinism MeSH C18.452.648.066.102.090 - albinism, ocular MeSH ... fructose metabolism, inborn errors MeSH C18.452.648.202.251.221 - fructose-1,6-diphosphatase deficiency MeSH C18.452.648.202. ... pyruvate metabolism, inborn errors MeSH C18.452.648.202.810.444 - Leigh disease MeSH C18.452.648.202.810.666 - pyruvate ...
... purine-pyrimidine metabolism, inborn errors MeSH C16.320.565.798.368 - gout MeSH C16.320.565.798.368.410 - arthritis, gouty ... amino acid metabolism, inborn errors MeSH C16.320.565.066.102 - albinism MeSH C16.320.565.066.102.090 - albinism, ocular MeSH ... fructose metabolism, inborn errors MeSH C16.320.565.202.251.221 - fructose-1,6-diphosphatase deficiency MeSH C16.320.565.202. ... pyruvate metabolism, inborn errors MeSH C16.320.565.202.810.444 - Leigh disease MeSH C16.320.565.202.810.666 - pyruvate ...
Inborn errors of purine-pyrimidine metabolism, Syndromes affecting the nervous system, Syndromes affecting the eye). ...
Inborn errors of purine-pyrimidine metabolism, Autosomal recessive disorders). ... an enzyme involved in the metabolism of uracil and thymine. Individuals with this condition may develop life-threatening ...
Inborn errors of purine-pyrimidine metabolism, Autosomal recessive disorders, Rare diseases). ... probably because purines are furnished via the purine salvage pathway. The second is the buildup of accumulating ... the first is that they result from decreased concentrations of purine nucleotides needed for purine biosynthesis. Decreased ... ADSL catalyzes two distinct reactions in the synthesis of purine nucleotides, both of which involve the β-elimination of ...
Inborn errors of purine-pyrimidine metabolism). ... The disorder results in accumulation of the insoluble purine 2, ... the enzyme adenine phosphoribosyltransferase and therefore have difficulties breaking down dietary substances called purines, ...
Inborn errors of purine-pyrimidine metabolism, Combined T and B-cell immunodeficiencies). ... an increase in S-adenosylhomocysteine since the enzyme adenosine deaminase is important in the purine salvage pathway; both ...
Inborn errors of purine-pyrimidine metabolism, Syndromes affecting the eye, Syndromes with cleft lip and/or palate, Rare ... the fourth enzymatic step in de novo pyrimidine biosynthesis. The protein is normally located on the outer surface of the inner ...
Inborn errors of purine-pyrimidine metabolism, Rare diseases). ... In muscle cells with normal AMPD activity, the purine ... Because magnesium is essential to aerobic metabolism, over time, magnesium loss may lead to a vicious cycle, where the citric ... Wagner, D.R.; Gresser, U.; Zöllner, N. (1991). "Effects of Oral Ribose on Muscle Metabolism during Bicycle Ergometer in AMPD- ... Functional and metabolic abnormalities associated with disruption of the purine nucleotide cycle". Journal of Clinical ...
Balasubramaniam S, Duley JA, Christodoulou J (September 2014). "Inborn errors of pyrimidine metabolism: clinical update and ... Ashihara H, Stasolla C, Loukanina N, Thorpe TA (2000). "Purine and pyrimidine metabolism in cultured white spruce (Picea glauca ... A distinguishing characteristic of pyrimidine synthesis is that the pyrimidine ring is fully synthesized before being attached ... It is reasoned that the smoking causes the pyrimidine biosynthesis process in the mother to be altered thus causing the orotic ...
... inborn errors of lipid metabolism (fatty acid metabolism disorder), inborn error of purine-pyrimidine metabolism (such as AMP ... Metabolic myopathies are further categorized by the system that they affect: inborn errors of carbohydrate metabolism ( ... Metabolic myopathies are inherited inborn errors of metabolism that affect the ability of the muscle to produce ATP, either ...
Disorders of porphyrin metabolism acute intermittent porphyria Disorders of purine or pyrimidine metabolism Lesch-Nyhan ... Inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of enzyme activities. The ... Inborn errors of metabolism are now often referred to as congenital metabolic diseases or inherited metabolic disorders. To ... Finally, inborn errors of metabolism were studied for the first time by British physician Archibald Garrod (1857-1936), in 1908 ...
Jiménez RT, Puig JG (2012). "Purine Metabolism in the Pathogenesis of Hyperuricemia and Inborn Errors of Purine Metabolism ... Nucleotides contain either a purine or a pyrimidine nitrogenous base. All intermediates in purine biosynthesis are constructed ... doi:10.1016/b978-0-12-391909-0.50015-3. ISBN 978-0-12-391909-0. Pelley JW (2011). "Purine, Pyrimidine, and Single-Carbon ... PRPP also plays an important role in pyrimidine ribonucleotide synthesis. During the fifth step of pyrimidine nucleotide ...
... of porphyrin metabolism Porphyria Acute intermittent porphyria 277.2 Other disorders of purine and pyrimidine metabolism Lesch- ... disorders of metabolism 277.81 Primary carnitine deficiency 277.82 Carnitine deficiency due to inborn errors of metabolism ... transport and metabolism 271.9 Unspecified disorder of carbohydrate transport and metabolism 272 Disorders of lipoid metabolism ... mineral metabolism 275.0 Disorders of iron metabolism Aceruloplasminemia Hemochromatosis 275.1 Disorders of copper metabolism ...
"Analysis of Catecholamines and Pterins in Inborn Errors of Monoamine Neurotransmitter Metabolism-From Past to Future". Cells. 8 ... Folates are also essential for the biosynthesis of purines and one pyrimidine. Substituted pteridines are intermediates in the ... Tetrahydromethanopterin is a cofactor in methanogenesis, which is a metabolism adopted by many organisms, as a form of ...
Stasolla C, Katahira R, Thorpe TA, Ashihara H (November 2003). "Purine and pyrimidine nucleotide metabolism in higher plants". ... Measuring versus elapsed time the net rate of heat flow Inborn errors of metabolism - Class of genetic diseases Iron-sulfur ... The first pathways of enzyme-based metabolism may have been parts of purine nucleotide metabolism, while previous metabolic ... classified as purines or pyrimidines. Nucleotides also act as coenzymes in metabolic-group-transfer reactions. Metabolism ...
Archibald Garrod discovered inborn errors of metabolism. An explanation for epistasis is an important manifestation of Garrod's ... Lastly, Chargaff and his team found the proportion of pyrimidines and purines correspond each other. 1952: The Hershey-Chase ... Webarchive template wayback links, CS1 errors: missing periodical, Articles with short description, Short description is ... Second, the concentration of purines (cytosine and thymine) are also always the same. ...
However, some mutations (glycogen storage diseases and other inborn errors of carbohydrate metabolism) are seen with one ... Furthermore, citric acid intermediates are constantly used to form a variety of substances such as the purines, pyrimidines and ... Inborn errors of carbohydrate metabolism Pentose phosphate pathway Pyruvate decarboxylation Triose kinase Alfarouk KO, Verduzco ... For simple fermentations, the metabolism of one molecule of glucose to two molecules of pyruvate has a net yield of two ...
Inborn errors of purine-pyrimidine metabolism are a class of inborn error of metabolism disorders specifically affecting purine ... April 1999). "1H-NMR spectroscopy of body fluids: inborn errors of purine and pyrimidine metabolism". Clin. Chem. 45 (4): 539- ... Inborn errors of purine-pyrimidine metabolism, All stub articles, Endocrine, nutritional and metabolic disease stubs, ... metabolism and pyrimidine metabolism. An example is Lesch-Nyhan syndrome. Urine tests may be of use in identifying some of ...
Catabolism of purines and pyrimidines. Therapeutic agents directed against nucleotide metabolism. Examples of inborn errors of ... Nitrogen metabolism, amino acid biosynthesis and catabolism. Biosynthesis of neurotransmitters, pigments, hormones and ... metabolism of nitrogen containing compounds. The urea cycle, nitrogen excretion. Online activities include training in ...
The purine and pyrimidine composition of some deoxyribonucleic. Inborn errors of purine and pyrimidine metabolism have been ... Disorders of purine and pyrimidine metabolism rebecca s. Difference between purine and pyrimidine purine vs pyrimidine. This ... Disorders of purine and pyrimidine metabolism clinical gate. The inherited disorders of purine and pyrimidine metabolism cover ... Disorders of purine, pyrimidine and porphyrin metabolism. Disorders of purine and pyrimidine metabolism harrisons. Marked ...
Classify works on purine-pyrimidine metabolism inborn errors in QU 265.5.P8. ... Classify works on specific inborn errors or groups of errors of metabolism in QU 265.5. ... Classify works on inborn errors of amino acid metabolism in QU 265.5.A5. ... Classify works on inborn errors of lipid metabolism disorders in QU 265.5.L5. ...
No article was found for Purine-Pyrimidine Metabolism, Inborn Errors and LRRC16A[original query]. ...
HPLC analysis for the clinical-biochemical diagnosis of inborn errors of metabolism of purines and pyrimidines. Tavazzi, ... HPLC analysis for the clinical-biochemical diagnosis of inborn errors of metabolism of purines and pyrimidines.. ...
Overview of Purine and Pyrimidine Metabolism Disorders - Etiology, pathophysiology, symptoms, signs, diagnosis & prognosis from ... inborn errors of metabolism) are rare, and therefore their diagnosis requires a high index of suspicion. Timely diagnosis leads ... There are a number of pyrimidine metabolism disorders Pyrimidine Metabolism Disorders Pyrimidines may be synthesized de novo or ... Purine metabolism disorders (see the table Purine Metabolism Disorders ) are categorized as ...
The diagnosis of inborn errors of purine and pyrimidine metabolism is often difficult. De-novo synthesis of Pyrimidines (Uracil ... Disorders of Purine and Pyrimidine Metabolism Rebecca S. Wappner PURINE AND PYRIMIDINE METABOLISM Purine and pyrimidine ... pyrimidines. Overview of Purine and Pyrimidine Metabolism Disorders. Pyrimidine metabolism. Purine and pyrimidine nucleotides ... PURINE & PYRIMIDINE METABOLISM - PowerPoint PPT Presentation. Disorders of Purine and Pyrimidine Metabolism. There are several ...
Purine-Pyrimidine Metabolism, Inborn Errors. *Renal Tubular Transport, Inborn Errors. *Steroid Metabolism, Inborn Errors ... Inborn errors of metabolism characterized by defects in specific lysosomal hydrolases and resulting in intracellular ... Metabolism, Inborn Errors. *Amino Acid Metabolism, Inborn Errors. *Amino Acid Transport Disorders, Inborn ...
... purines and pyrimidines; organic acids; oligosaccharides; and glycosaminoglycans). Each one of these screening tests gets the ... Background Inborn errors of metabolism (IEMs) have already been anecdotally reported. Background Inborn errors of metabolism ( ...
... energy metabolism, mucopolysaccharide, sphingolipid storage, purine/pyrimidine, peroxisomal and creatine synthesis disorders ... Over recent years we have been able to distribute samples from patients with a wide range of inborn errors including amino acid ...
Purine-Pyrimidine Metabolism, Inborn Errors - 25 Studies. *Purpura - 25 Studies. *Purpura, Schoenlein-Henoch - 19 Studies ...
... often referred to as inborn errors of metabolism, comprise a large class of genetic diseases involving disorders of metabolism ... Disorders of purine or pyrimidine metabolism (purine and pyrimidine metabolism disorders). Lesch-Nyhan syndrome ... Inborn errors of metabolism are inherited genetic disorders that affect one or more of the hundreds of biochemical pathways in ... Inborn errors of metabolism in infancy and early childhood: an update. Am Fam Physician 2006;73:1981-90. ...
... disorders of metabolism 277.81 Primary carnitine deficiency 277.82 Carnitine deficiency due to inborn errors of metabolism ... disorders of purine and pyrimidine metabolism (277.1-277.2) gout (274.0-274.9) 270.0 Disturbances of amino-acid transport ... Porphyrinuria Protocoproporphyria Protoporphyria Pyrroloporphyria 277.2 Other disorders of purine and pyrimidine metabolism ... 270.3 Disturbances of branched-chain amino-acid metabolism Disturbances of metabolism of leucine, isoleucine, and valine ...
Purine-Pyrimidine Metabolism, Inborn Errors. *Renal Tubular Transport, Inborn Errors. *Steroid Metabolism, Inborn Errors ... Inborn Errors" by people in this website by year, and whether "Lipid Metabolism, Inborn Errors" was a major or minor topic of ... Lipid Metabolism, Inborn Errors [C18.452.584.562]. *Metabolism, Inborn Errors [C18.452.648]. *Lipid Metabolism, Inborn Errors [ ... "Lipid Metabolism, Inborn Errors" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ( ...
Purine-Pyrimidine Metabolism, Inborn Errors [C16.320.565.798] * Renal Tubular Transport, Inborn Errors [C16.320.565.893] ... Genetic Diseases, Inborn [C16.320] * Metabolism, Inborn Errors [C16.320.565] * Amino Acid Metabolism, Inborn Errors [C16.320. ... Metabolism, Inborn Errors [C18.452.648] * Amino Acid Metabolism, Inborn Errors [C18.452.648.100] ... Purine-Pyrimidine Metabolism, Inborn Errors [C18.452.648.798] * Renal Tubular Transport, Inborn Errors [C18.452.648.893] ...
Impaired MS activity results from inadequate dietary intake or malabsorption of B12 and inborn errors of Cbl metabolism (IECM ... considered as the consequence of the disruption of the folate cycle and related synthesis of purines and pyrimidines and the ... which deactivate nuclear receptors and lead to impaired energy metabolism and neuroplasticity. The reversibility of these ... Impaired MS activity results from inadequate dietary intake or malabsorption of B12 and inborn errors of Cbl metabolism (IECM ...
Purine-Pyrimidine Metabolism, Inborn Errors. *Renal Tubular Transport, Inborn Errors. *Steroid Metabolism, Inborn Errors ... Genetic Diseases, Inborn [C16.320]. *Metabolism, Inborn Errors [C16.320.565]. *Cytochrome-c Oxidase Deficiency [C16.320.565.240 ... Metabolism, Inborn Errors. *Amino Acid Metabolism, Inborn Errors. *Amino Acid Transport Disorders, Inborn ...
Purine-Pyrimidine Metabolism, Inborn Errors [C16.320.565.798] * Renal Tubular Transport, Inborn Errors [C16.320.565.893] ... METAB INBORN ERR. Entry Term(s). Inborn Errors of Metabolism Metabolism Errors, Inborn Public MeSH Note. 65. History Note. 65. ... Metabolism, Inborn Errors [C16.320.565] * Amino Acid Metabolism, Inborn Errors [C16.320.565.100] ... Metabolism, Inborn Errors [C18.452.648] * Amino Acid Metabolism, Inborn Errors [C18.452.648.100] ...
Purine-Pyrimidine Metabolism, Inborn Errors. *Renal Tubular Transport, Inborn Errors. *Steroid Metabolism, Inborn Errors ... This graph shows the total number of publications written about "Amino Acid Transport Disorders, Inborn" by people in this ... "Amino Acid Transport Disorders, Inborn" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, ... Below are the most recent publications written about "Amino Acid Transport Disorders, Inborn" by people in Profiles. ...
Metabolism of Amino Acids - General Aspects: Inborn Errors of Amino Acid Metabolism-A Summary: The best answers are voted up ... purine and pyrimidine bases. The first two enzymes are present in mitochondria while the rest are localized in cytosol. Various ... The metabolism of the carbon chains of amino acids is varied. The predominant metabolism of phenylalanine occurs through ... Urea is the end product of protein metabolism (amino acid metabolism). Amino acids are continuously degraded. An adult man ...
Biosynthesis of purine and pyrimidine nucleotides and their regulation, Purine salvage pathways, Catabolic pathways of purine ... Glycogen Metabolism:​ Glycogenolysis and Glycogenesis and their regulation, ​ Regulation of Carbohydrate Metabolism. April 11, ... Inborn errors of Amino acid catabolic pathways. May 18, 2022. Lipoproteins (Chylomicrons, VLDL, LDL & HDL); Defects in ... General reactions of amino acid metabolism: Transamination, Oxidative and Non-oxidative Deamination and Decarboxylation. April ...
Stasolla C, Katahira R, Thorpe TA, Ashihara H (November 2003). "Purine and pyrimidine nucleotide metabolism in higher plants". ... Measuring versus elapsed time the net rate of heat flow Inborn errors of metabolism - Class of genetic diseases Iron-sulfur ... The first pathways of enzyme-based metabolism may have been parts of purine nucleotide metabolism, while previous metabolic ... classified as purines or pyrimidines. Nucleotides also act as coenzymes in metabolic-group-transfer reactions. Metabolism ...
102 An Approach To Inborn Errors Of Metabolism. 103 Defects In Metabolism Of Amino Acids ... 108 Disorders Of Purine And Pyrimidine Metabolism. 109 Hutchinson-Gilford Progeria Syndrome (Progeria) ... 575 Other Abnormalities Of Arginine Vasopressin Metabolism And Action. 576 Hyperpituitarism, Tall Stature, And Overgrowth ...
... inborn errors of metabolism, myelodysplastic syndromes, and problems with DNA synthesis (eg, from chemotherapy). However, ... These drugs include immunomodulators and antineoplastic agents that act on purine metabolism or pyrimidine synthesis (eg, ... Drugs that induce megaloblastic anemia typically interfere with vitamin B12 or folate absorption or metabolism. ...
Other Carbohydrate Metabolism Disorders - Etiology, pathophysiology, symptoms, signs, diagnosis & prognosis from the Merck ... inborn errors of metabolism) are rare, and therefore their diagnosis requires a high index of suspicion. Timely diagnosis leads ... Overview of Purine and Pyrimidine Metabolism Disorders. Purine Catabolism Disorders. Purine Nucleotide Synthesis Disorders ... Metabolism Disorders Overview of Carbohydrate Metabolism Disorders Carbohydrate metabolism disorders are errors of metabolism ...
... inborn errors of metabolism) are rare, and therefore their diagnosis requires a high index of suspicion. Timely diagnosis leads ... Overview of Purine and Pyrimidine Metabolism Disorders. Purine Catabolism Disorders. Purine Nucleotide Synthesis Disorders ... inborn errors of metabolism) are rare, and therefore their diagnosis requires a high index of suspicion. Timely diagnosis leads ... Phenylketonuria is a disorder of amino acid metabolism Overview of Amino Acid and Organic Acid Metabolism Disorders The kidneys ...
Untargeted metabolomics as an unbiased approach to the diagnosis of inborn errors of metabolism of the non-oxidative branch of ... Urine Purine Metabolite Determination by UPLC-Tandem Mass Spectrometry. Methods Mol Biol. 2016; 1378:227-35. PMID: 26602134. ... Urine Pyrimidine Metabolite Determination by HPLC Tandem Mass Spectrometry. Methods Mol Biol. 2016; 1378:237-42. PMID: 26602135 ... Erratum to: Untargeted metabolomic analysis for the clinical screening of inborn errors of metabolism. J Inherit Metab Dis. ...
... inborn errors of metabolism. One such patient was an eight-year-old girl with homocysteinuria associated with high methionine ... carbon unit transfer in amino acid conversions including homocysteine conversion to methionine and in purine and pyrimidine ... Although this pathway had been described by Du Vigneaud and Mary Bennett (Bennett, 1950), its significance in the metabolism of ... The exact role of folate deficiency or abnormal metabolism in the pathogenesis of neurological and vascular diseases, neural ...
  • The purines and pyrimidines are nucleotides which form the building blocks of nucleic acids. (web.app)
  • Multiple choice questions chemistry and metabolism of nucleotides solved 1 which statement best describes xanthine. (web.app)
  • Mar 25, 2016 prpp purine nucleotides pyrimidine nucleotides denovo and salvage pathways. (web.app)
  • Biosynthesis and catabolism of purine and pyrimidine nucleotides. (web.app)
  • Purine and pyrimidine nucleotides are synthesized by both de novo and salvage pathways (Figures 46-1 and 46-2).The de novo pathways create these complex phosphorylated molecules from simple precursors, such as CO 2, glycine, and glutamine, in stepwise fashion, whereas the salvage pathways serve the reuse of purine and pyrimidine bases of metabolic and dietary sources. (tempsite.ws)
  • Pyrimidine nucleotides are also newly synthesized or recovered. (tempsite.ws)
  • Purines are biologically synthesized as nucleotides and in particular as ribotides, i.e. (tempsite.ws)
  • Disorders of Purine and Pyrimidine Metabolism Rebecca S. Wappner PURINE AND PYRIMIDINE METABOLISM Purine and pyrimidine nucleotides are important constituents of RNA, DNA, nucleotide sugars, and other high-energy compounds and of cofactors such as adenosine triphosphate and nicotinamide-adenine dinucleotide. (tempsite.ws)
  • NUCLEOTIDE METABOLISM Mark Rush Nucleotides serve various metabolic functions. (tempsite.ws)
  • For example, an upregulated metabolism may result in the build up of toxic metabolites, including lactate and noncanonical nucleotides, which must be disposed of (F). Moreover, cancer cells may also exhibit a high energetic demand, for which they must either increase flux through normal ATP-generating processes, or else rely on an increased diversity of fuel sources (G). (pharmaceuticalintelligence.com)
  • Over recent years we have been able to distribute samples from patients with a wide range of inborn errors including amino acid, organic acid, energy metabolism, mucopolysaccharide, sphingolipid storage, purine/pyrimidine, peroxisomal and creatine synthesis disorders but now our resources are becoming stretched and it is becoming difficult to source suitable samples for use as EQA materials. (erndim.org)
  • A wide range of inborn errors of metabolism have been reported in cats and the incidence may be higher than suspected as affected kittens may simply be dismissed as fading kittens unless specialized studies are performed. (vin.com)
  • Catabolism of purinespurine nucleotide degradation refers to a regulated series of reactionsby which purine ribonucleotides and deoxyribonucleotides are degradedto uric acid in humans. (web.app)
  • Disorders that involve abnormalities of nucleotide metabolism range from relatively common diseases such as hyperuricemia and gout, in which there is increased production or impaired excretion of a metabolic end product of purine metabolism (uric acid), to rare enzyme deficiencies that affect purine and pyrimidine synthesis or degradation. (tempsite.ws)
  • Pyrimidine metabolism disorders pediatrics msd manual. (web.app)
  • Nitrogen metabolism, amino acid biosynthesis and catabolism. (up.ac.za)
  • Categories of cell mutant selections purine biosynthesis, salvage pathways, and inhibitors. (web.app)
  • Diseases of pyrimidine biosynthesis are rarer, but include orotic acidurias. (tempsite.ws)
  • Advantages (C-E). The altered metabolism of cancer cells is likely to imbue them with several proliferative and survival advantages, such as enabling cancer cells to execute the biosynthesis of macromolecules (C), to avoid apoptosis (D), and to engage in local metabolite-based paracrine and autocrine signaling (E). Potential Liabilities (F and G). This altered metabolism, however, may also confer several vulnerabilities on cancer cells. (pharmaceuticalintelligence.com)
  • Decreased SAM and SIRT1 activity induce ER stress through impaired SIRT1-deacetylation of HSF1 and hypomethylation/hyperacetylation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α), which deactivate nuclear receptors and lead to impaired energy metabolism and neuroplasticity. (univ-lorraine.fr)
  • Amino acids also contribute to cellular energy metabolism by providing a carbon source for entry into the citric acid cycle (tricarboxylic acid cycle), especially when a primary source of energy, such as glucose, is scarce, or when cells undergo metabolic stress. (wikipedia.org)
  • Human diseases that involve abnormalities in purine metabolism include gout, Lesch-Nyhan syndrome, adenosine deaminase deficiency, and purine nucleoside phosphorylase deficiency. (tempsite.ws)
  • Pyrimidines and purines, first isolated from hydrolysates of nucleic acids 18741900, were identified using classical methods of organic chemistry see table 11. (web.app)
  • Purine metabolism refers to the metabolic pathways to synthesize and break down purines that are present in many organisms. (tempsite.ws)
  • The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, each step being facilitated by a specific enzyme. (wikipedia.org)
  • A striking feature of metabolism is the similarity of the basic metabolic pathways among vastly different species. (wikipedia.org)
  • Cellular metabolism consists of numerous interconnected pathways that are catalyzed by enzymes in a series of stepwise biochemical reactions. (newworldencyclopedia.org)
  • In 1908, physician Sir Archibald Garrod coined the term "inborn errors of metabolism" to suggest that defects in specific biochemical pathways were due to an inadequate supply or a lack of a given enzyme. (newworldencyclopedia.org)
  • Commonly the term metabolism defines the breakdown of food and how its components (carbohydrates, fats and proteins) are transformed into energy via a sequence of chemical reactions (metabolic pathways) which are controlled by large numbers of different enzymes. (oncohemakey.com)
  • Although our emphasis on the Warburg effect reflects the focus of the field, we would also like to encourage a broader approach to the study of cancer metabolism that takes into account the contributions of all interconnected small molecule pathways of the cell. (pharmaceuticalintelligence.com)
  • The related immunodeficiency, adenosine deaminase (ADA) deficiency, which also affects purine degradation, is discussed separately. (medilib.ir)
  • Classify works on inborn errors of lipid metabolism disorders in QU 265.5.L5 . (nih.gov)
  • Lipid Metabolism, Inborn Errors" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (musc.edu)
  • This graph shows the total number of publications written about "Lipid Metabolism, Inborn Errors" by people in this website by year, and whether "Lipid Metabolism, Inborn Errors" was a major or minor topic of these publications. (musc.edu)
  • Below are the most recent publications written about "Lipid Metabolism, Inborn Errors" by people in Profiles. (musc.edu)
  • Therapeutic agents directed against nucleotide metabolism. (up.ac.za)
  • Nevertheless, it has been shown that in nucleated cells, P5′N‐1 deficiency results in abnormal pyrimidine nucleotide metabolism (Hopkinson et al, 1990). (tempsite.ws)
  • 1) Lesch-Nyhan syndrome (pages 6-7) The Lesch-Nyhan syndrome is a sex linked defect of the Hypoxanthine, guanine, phosphoribosyl transferase (HGPRT) gene … Nucleotide Metabolism is an important issue in medical studies and therefore you can learn in this biochemistry article everything about purine & pyrimidines. (tempsite.ws)
  • Purine Nucleotide Synthesis Disorders. (tempsite.ws)
  • Genetic defects involving enzymes essential for pyrimidine nucleotide metabolism have provided new insights into the vital physiological functions of these molecules in addition to nucleic acid synthesis. (tempsite.ws)
  • Purines and pyrimidines may be synthesized de novo or recycled by a salvage pathway from normal catabolism. (msdmanuals.com)
  • Pyrimidine Metabolism Disorders Pyrimidines may be synthesized de novo or recycled by a salvage pathway from normal catabolism. (msdmanuals.com)
  • This gene encodes the protein PNP, one of the ubiquitous enzymes involved in the purine salvage pathway [ 31 ]. (medilib.ir)
  • The inherited defects involving pyrimidine metabolism lead to nervous system, hematologic and mitochondrial disease. (tempsite.ws)
  • Because a decreased dependence on aerobic respiration becomes advantageous, cell metabolism is shifted toward glycolysis by the increased expression of glycolytic enzymes, glucose transporters, and inhibitors of mitochondrial metabolism. (pharmaceuticalintelligence.com)
  • Background Inborn errors of metabolism (IEMs) have already been anecdotally reported in the literature as presenting with top features of cerebral palsy (CP) or misdiagnosed as atypical CP. (healthcarecoremeasures.com)
  • Multiple groups have made recommendations regarding additional testing for fragile X syndrome (FXS), inborn errors of metabolism (IEMs), X-linked intellectual disability, MECP2 -related disorders, PTEN -related disorders, and/or chromosome analysis, depending on clinical findings and family history. (arupconsult.com)
  • Classify works on inborn errors of metal metabolism in QU 265 . (nih.gov)
  • Causes of megaloblastic anemia include vitamin B 12 or folate deficiency (as a result of decreased intake, decreased absorption, or increased demand), specific drugs, inborn errors of metabolism, myelodysplastic syndromes , and problems with DNA synthesis (eg, from chemotherapy). (arupconsult.com)
  • INTRODUCTION - Purine nucleoside phosphorylase (PNP) deficiency (MIM #613179) is a rare, autosomal recessive, inborn error of immunity (IEI) [ 1-3 ]. (medilib.ir)
  • Heightened awareness coupled with the use of next-generation sequencing for patients with suspected inborn errors of immunity (IEI) have led to increased identification of patients with PNP deficiency [ 16-22 ]. (medilib.ir)
  • Disorders of Pyrimidine Metabolism Disorder Defective Enzyme Comments. (tempsite.ws)
  • Disorders in the metabolism of pyrimidine are mostly caused by enzyme defects (highlighted in pink, one disease is depicted in orange, since there appears to be no clinical difference between type 2 and 1 of orotic aciduria, therefore researchers believe that type 2 does not exist officially). (tempsite.ws)
  • Furthermore, unlike other inborn errors of metabolism, unfortunately enzyme replacement therapy and substrate inhibition are not yet (as of March 2019) available 1 . (radiopaedia.org)
  • Inborn errors of metabolism characterized by defects in specific lysosomal hydrolases and resulting in intracellular accumulation of unmetabolized substrates. (umassmed.edu)
  • Uncertain role of purine depletion not confirmed variable neurological findings stereotypic movement, pmr, seizures, hypotonia facial dysmorphy in some patients saicar detection in urine by a simple test treatment unknown. (web.app)
  • Sun Q . Quantitation of Purine in Urine by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry. (viictr.org)
  • Liu N , Sun Q . Quantitation of Pyrimidine in Urine by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry. (viictr.org)
  • Drugs that induce megaloblastic anemia typically interfere with vitamin B 12 or folate absorption or metabolism. (arupconsult.com)
  • Biochemical genetic testing and newborn screening are essential laboratory services for the screening, detection, diagnosis, and monitoring of inborn errors of metabolism or inherited metabolic disorders. (cdc.gov)
  • Errors in the metabolism of LIPIDS resulting from inborn genetic MUTATIONS that are heritable. (musc.edu)
  • Errors in metabolic processes resulting from inborn genetic mutations that are inherited or acquired in utero. (nih.gov)
  • Although many birth defects are the result of errors in the genetic code, others are caused by environmental factors and some result from a combination of genetic and environmental factors. (vin.com)
  • Disease processes may be incited or exacerbated by a variety of external and internal influences, including trauma , infection , poisoning , loss of blood flow , autoimmunity , inherited or acquired genetic damage, or errors of development . (bionity.com)
  • The mechanisms at the origin of the high variability of clinical presentation of impaired MS activity are classically considered as the consequence of the disruption of the folate cycle and related synthesis of purines and pyrimidines and the decreased synthesis of endogenous methionine and SAM. (univ-lorraine.fr)
  • Figure 17.1 illustrates the metabolic processes involved in the overall metabolism of carbohydrates, fats and protein including the catabolic processes to produce energy and urea (the product of the detoxification of the nitrogen moiety of amino acids) and anabolic processes to form tissue protein and energy stores, glycogen and lipids. (oncohemakey.com)
  • Cellular carbohydrate (CHO) metabolism involves both catabolic (glycolysis, glycogenolysis) and anabolic processes (glycogenesis, gluconeogenesis). (oncohemakey.com)
  • Classify works carbohydrate metabolism inborn errors in QU 265.5.C3 . (nih.gov)
  • Overview of Carbohydrate Metabolism Disorders Carbohydrate metabolism disorders are errors of metabolism that affect the catabolism and anabolism of carbohydrates. (merckmanuals.com)
  • An lcmsms assay allowing the simultaneous, sensitive and reliable diagnosis of an extended range of purine and pyrimidine disorders has been developed. (web.app)
  • HPLC analysis for the clinical-biochemical diagnosis of inborn errors of metabolism of purines and pyrimidines. (unicatt.it)
  • Approach to the Patient With a Suspected Inherited Disorder of Metabolism Most inherited disorders of metabolism (inborn errors of metabolism) are rare, and therefore their diagnosis requires a high index of suspicion. (msdmanuals.com)
  • Untargeted metabolomics as an unbiased approach to the diagnosis of inborn errors of metabolism of the non-oxidative branch of the pentose phosphate pathway. (viictr.org)
  • The instructions for building nearly all the enzymes involved in metabolism are stored as deoxyribonucleic acid (DNA) in the nucleus of the cell. (newworldencyclopedia.org)
  • A number of disorders of purine metabolism lead to immunodeficiency. (web.app)
  • The purine and pyrimidine composition of some deoxyribonucleic. (web.app)
  • Impaired MS activity results from inadequate dietary intake or malabsorption of B12 and inborn errors of Cbl metabolism (IECM). (univ-lorraine.fr)
  • Cellular metabolism, involving the synthesis and breakdown of complex organic molecules, requires harmonious coordination of the various enzymes, biochemical reactions, and so forth. (newworldencyclopedia.org)
  • Unlike purine synthesis, pyrimidines are synthesized as bases and latter it is added to ribose sugar, i.e., the ring is completed before being it is linked to ribose-5-phosphate. (tempsite.ws)
  • Amino acid metabolism has extremely extensive effects in cancer cells, including, but not limited to, (1) establishing amino acid pools as building blocks, especially the production of non-essential amino acids … An overview of the metabolism of the sulfur amino acids is depicted in Fig. The outline of glycine metabolism is depicted in Fig. Oxidation via TCA cycle to produce energy (about 10-15% of body needs). (slimwithlynne.com)
  • Urea is the end product of protein metabolism (amino acid metabolism). (slimwithlynne.com)
  • The liver is the major site of amino acid metabolism in the body and the major site of urea synthesis. (slimwithlynne.com)
  • Classify works on glucose metabolism disorders in QU 260.5.G6 . (nih.gov)
  • Here, we show that nucleic acid bases adenine, cytosine, guanine, thymine, and uracil, as well as 2,6-diaminopurine and the "core" nucleic acid bases purine and pyrimidine, are stable in sulfuric acid in the Venus cloud temperature and sulfuric acid concentration range, using UV spectroscopy and combinations of 1D and 2D 1H 13C 15N NMR spectroscopy. (bvsalud.org)
  • 67.20, an outline of glutamate and glutamine metabolism is given. (slimwithlynne.com)
  • Protein metabolism is more appropriately learnt as metabolism of amino acids. (slimwithlynne.com)
  • The training program includes intensive interactions with children and adults with inborn errors of metabolism. (ucla.edu)
  • Inborn errors of purine and pyrimidine metabolism have been documented in 14 different disorders, representing a broad spectrum of clinical manifestations. (web.app)
  • Background: Clinical presentation and disease severity in disorders of purine and pyrimidine metabolism vary considerably. (tempsite.ws)
  • Clinical Significances of Pyrimidine Metabolism. (tempsite.ws)