Radiosurgery
A radiological stereotactic technique developed for cutting or destroying tissue by high doses of radiation in place of surgical incisions. It was originally developed for neurosurgery on structures in the brain and its use gradually spread to radiation surgery on extracranial structures as well. The usual rigid needles or probes of stereotactic surgery are replaced with beams of ionizing radiation directed toward a target so as to achieve local tissue destruction.
Autacoids
DNA Helicases
Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.
Receptors, Somatostatin
Cell surface proteins that bind somatostatin and trigger intracellular changes which influence the behavior of cells. Somatostatin is a hypothalamic hormone, a pancreatic hormone, and a central and peripheral neurotransmitter. Activated somatostatin receptors on pituitary cells inhibit the release of growth hormone; those on endocrine and gastrointestinal cells regulate the absorption and utilization of nutrients; and those on neurons mediate somatostatin's role as a neurotransmitter.
Rad51 Recombinase
A Rec A recombinase found in eukaryotes. Rad51 is involved in DNA REPAIR of double-strand breaks.
Review Literature as Topic
Published materials which provide an examination of recent or current literature. Review articles can cover a wide range of subject matter at various levels of completeness and comprehensiveness based on analyses of literature that may include research findings. The review may reflect the state of the art. It also includes reviews as a literary form.
Homologous Recombination
An exchange of DNA between matching or similar sequences.
Rad52 DNA Repair and Recombination Protein
A DNA-binding protein that mediates DNA REPAIR of double strand breaks, and HOMOLOGOUS RECOMBINATION.
Saccharomyces cerevisiae Proteins
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Sumoylation
A type of POST-TRANSLATIONAL PROTEIN MODIFICATION by SMALL UBIQUITIN-RELATED MODIFIER PROTEINS (also known as SUMO proteins).
RecQ Helicases
A family of structurally-related DNA helicases that play an essential role in the maintenance of genome integrity. RecQ helicases were originally discovered in E COLI and are highly conserved across both prokaryotic and eukaryotic organisms. Genetic mutations that result in loss of RecQ helicase activity gives rise to disorders that are associated with CANCER predisposition and premature aging.
Indium Radioisotopes
Saccharomyces cerevisiae
Octreotide
A potent, long-acting synthetic SOMATOSTATIN octapeptide analog that inhibits secretion of GROWTH HORMONE and is used to treat hormone-secreting tumors; DIABETES MELLITUS; HYPOTENSION, ORTHOSTATIC; HYPERINSULINISM; hypergastrinemia; and small bowel fistula.
Recombination, Genetic
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
Computer Storage Devices
Cranial Irradiation
Suppression, Genetic
Mutation process that restores the wild-type PHENOTYPE in an organism possessing a mutationally altered GENOTYPE. The second "suppressor" mutation may be on a different gene, on the same gene but located at a distance from the site of the primary mutation, or in extrachromosomal genes (EXTRACHROMOSOMAL INHERITANCE).
Brain Neoplasms
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
Gastrinoma
A GASTRIN-secreting neuroendocrine tumor of the non-beta ISLET CELLS, the GASTRIN-SECRETING CELLS. This type of tumor is primarily located in the PANCREAS or the DUODENUM. Majority of gastrinomas are malignant. They metastasize to the LIVER; LYMPH NODES; and BONE but rarely elsewhere. The presence of gastrinoma is one of three requirements to be met for identification of ZOLLINGER-ELLISON SYNDROME, which sometimes occurs in families with MULTIPLE ENDOCRINE NEOPLASIA TYPE 1; (MEN 1).
Research Report
Small Ubiquitin-Related Modifier Proteins
Zollinger-Ellison Syndrome
A syndrome that is characterized by the triad of severe PEPTIC ULCER, hypersecretion of GASTRIC ACID, and GASTRIN-producing tumors of the PANCREAS or other tissue (GASTRINOMA). This syndrome may be sporadic or be associated with MULTIPLE ENDOCRINE NEOPLASIA TYPE 1.
DNA Repair
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.
Uniparental Disomy
The presence in a cell of two paired chromosomes from the same parent, with no chromosome of that pair from the other parent. This chromosome composition stems from non-disjunction (NONDISJUNCTION, GENETIC) events during MEIOSIS. The disomy may be composed of both homologous chromosomes from one parent (heterodisomy) or a duplicate of one chromosome (isodisomy).
Beckwith-Wiedemann Syndrome
A syndrome of multiple defects characterized primarily by umbilical hernia (HERNIA, UMBILICAL); MACROGLOSSIA; and GIGANTISM; and secondarily by visceromegaly; HYPOGLYCEMIA; and ear abnormalities.
Neurocytoma
A benign brain tumor composed of neural elements which most often arise from the SEPTUM PELLUCIDUM and the walls of the lateral ventricles. Immunohistochemistry and electron microscopy evaluations may reveal expression of neuron specific enolase and synaptophysin and cells containing microtubuli, neurosecretory granules, and presynaptic vesicles. (From Acta Med Port 1994 Feb;7(2):113-9)
Genomic Imprinting
The variable phenotypic expression of a GENE depending on whether it is of paternal or maternal origin, which is a function of the DNA METHYLATION pattern. Imprinted regions are observed to be more methylated and less transcriptionally active. (Segen, Dictionary of Modern Medicine, 1992)
Methyl Methanesulfonate
An alkylating agent in cancer therapy that may also act as a mutagen by interfering with and causing damage to DNA.
Proliferating Cell Nuclear Antigen
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.
SUMO-1 Protein
A 1.5-kDa small ubiquitin-related modifier protein that can covalently bind via an isopeptide link to a number of cellular proteins. It may play a role in intracellular protein transport and a number of other cellular processes.
Sphingomonas
Neuroendocrine Tumors
Tumors whose cells possess secretory granules and originate from the neuroectoderm, i.e., the cells of the ectoblast or epiblast that program the neuroendocrine system. Common properties across most neuroendocrine tumors include ectopic hormone production (often via APUD CELLS), the presence of tumor-associated antigens, and isozyme composition.
Chromosomes, Human, Pair 7
Abnormalities, Multiple
DNA, Cruciform
A cross-shaped DNA structure that can be observed under the electron microscope. It is formed by the incomplete exchange of strands between two double-stranded helices or by complementary INVERTED REPEAT SEQUENCES that refold into hairpin loops on opposite strands across from each other.
Radionuclide Imaging
The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.
Comamonadaceae
Growth Disorders
Mutation
Somatostatin
A 14-amino acid peptide named for its ability to inhibit pituitary GROWTH HORMONE release, also called somatotropin release-inhibiting factor. It is expressed in the central and peripheral nervous systems, the gut, and other organs. SRIF can also inhibit the release of THYROID-STIMULATING HORMONE; PROLACTIN; INSULIN; and GLUCAGON besides acting as a neurotransmitter and neuromodulator. In a number of species including humans, there is an additional form of somatostatin, SRIF-28 with a 14-amino acid extension at the N-terminal.
Pentetic Acid
Scavenger Receptors, Class A
Herbicides
Gene Deletion
Carcinoid Tumor
A usually small, slow-growing neoplasm composed of islands of rounded, oxyphilic, or spindle-shaped cells of medium size, with moderately small vesicular nuclei, and covered by intact mucosa with a yellow cut surface. The tumor can occur anywhere in the gastrointestinal tract (and in the lungs and other sites); approximately 90% arise in the appendix. It is now established that these tumors are of neuroendocrine origin and derive from a primitive stem cell. (From Stedman, 25th ed & Holland et al., Cancer Medicine, 3d ed, p1182)
Radioactive Waste
Liquid, solid, or gaseous waste resulting from mining of radioactive ore, production of reactor fuel materials, reactor operation, processing of irradiated reactor fuels, and related operations, and from use of radioactive materials in research, industry, and medicine. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Database Management Systems
DNA, Single-Stranded
DNA Replication
The process by which a DNA molecule is duplicated.
DNA Damage
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.
DNA Topoisomerases
Enzymes that regulate the topology of DNA by actions such as breaking, relaxing, passing, and rejoining strands of DNA in cells. These enzymes are important components of the DNA replication system. They are classified by their substrate specificities. DNA TOPOISOMERASE I enzymes act on a single strand of DNA. DNA TOPOISOMERASE II enzymes act on double strands of DNA.
Meta-Analysis as Topic
A quantitative method of combining the results of independent studies (usually drawn from the published literature) and synthesizing summaries and conclusions which may be used to evaluate therapeutic effectiveness, plan new studies, etc., with application chiefly in the areas of research and medicine.
Gastrointestinal Neoplasms
Dwarfism
Information Storage and Retrieval
SRS-A
A group of LEUKOTRIENES; (LTC4; LTD4; and LTE4) that is the major mediator of BRONCHOCONSTRICTION; HYPERSENSITIVITY; and other allergic reactions. Earlier studies described a "slow-reacting substance of ANAPHYLAXIS" released from lung by cobra venom or after anaphylactic shock. The relationship between SRS-A leukotrienes was established by UV which showed the presence of the conjugated triene. (From Merck Index, 11th ed)
Chromosomes, Fungal
Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.
Spectrum Analysis, Raman
Radiopharmaceuticals
Tomography, Emission-Computed, Single-Photon
A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.
Toxoplasmosis, Cerebral
Infections of the BRAIN caused by the protozoan TOXOPLASMA gondii that primarily arise in individuals with IMMUNOLOGIC DEFICIENCY SYNDROMES (see also AIDS-RELATED OPPORTUNISTIC INFECTIONS). The infection may involve the brain diffusely or form discrete abscesses. Clinical manifestations include SEIZURES, altered mentation, headache, focal neurologic deficits, and INTRACRANIAL HYPERTENSION. (From Joynt, Clinical Neurology, 1998, Ch27, pp41-3)
Databases, Factual
Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.
RNA, Long Noncoding
A class of untranslated RNA molecules that are typically greater than 200 nucleotides in length and do not code for proteins. Members of this class have been found to play roles in transcriptional regulation, post-transcriptional processing, CHROMATIN REMODELING, and in the epigenetic control of chromatin.
Epistasis, Genetic
A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.
DNA-Binding Proteins
DNA Breaks, Double-Stranded
Interruptions in the sugar-phosphate backbone of DNA, across both strands adjacently.
User-Computer Interface
Periostitis
Inflammation of the periosteum. The condition is generally chronic, and is marked by tenderness and swelling of the bone and an aching pain. Acute periostitis is due to infection, is characterized by diffuse suppuration, severe pain, and constitutional symptoms, and usually results in necrosis. (Dorland, 27th ed)
Ultraviolet Rays
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.
Phenotype
Molecular Sequence Data
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.
Meningeal Neoplasms
DNA Repair Enzymes
Enzymes that are involved in the reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule, which contained damaged regions.
Adenosine Triphosphatases
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
Trinucleotide Repeats
Radiation Tolerance
Genes, Suppressor
Genes that have a suppressor allele or suppressor mutation (SUPPRESSION, GENETIC) which cancels the effect of a previous mutation, enabling the wild-type phenotype to be maintained or partially restored. For example, amber suppressors cancel the effect of an AMBER NONSENSE MUTATION.
Toxoplasmosis, Animal
Acquired infection of non-human animals by organisms of the genus TOXOPLASMA.
Meningioma
A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)
Crossing Over, Genetic
The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.
Receptors, Scavenger
A large group of structurally diverse cell surface receptors that mediate endocytic uptake of modified LIPOPROTEINS. Scavenger receptors are expressed by MYELOID CELLS and some ENDOTHELIAL CELLS, and were originally characterized based on their ability to bind acetylated LOW-DENSITY LIPOPROTEINS. They can also bind a variety of other polyanionic ligand. Certain scavenger receptors can internalize micro-organisms as well as apoptotic cells.
GRB10 Adaptor Protein
Genomic Instability
Chromosomes, Human, Pair 11
Child Development Disorders, Pervasive
Paraganglioma
A neural crest tumor usually derived from the chromoreceptor tissue of a paraganglion, such as the carotid body, or medulla of the adrenal gland (usually called a chromaffinoma or pheochromocytoma). It is more common in women than in men. (Stedman, 25th ed; from Segen, Dictionary of Modern Medicine, 1992)
Lymphoma, T-Cell
Treatment Outcome
Internet
Neuroma, Acoustic
A benign SCHWANNOMA of the eighth cranial nerve (VESTIBULOCOCHLEAR NERVE), mostly arising from the vestibular branch (VESTIBULAR NERVE) during the fifth or sixth decade of life. Clinical manifestations include HEARING LOSS; HEADACHE; VERTIGO; TINNITUS; and FACIAL PAIN. Bilateral acoustic neuromas are associated with NEUROFIBROMATOSIS 2. (From Adams et al., Principles of Neurology, 6th ed, p673)
Toxoplasma
Ubiquitin-Conjugating Enzymes
A class of enzymes that form a thioester bond to UBIQUITIN with the assistance of UBIQUITIN-ACTIVATING ENZYMES. They transfer ubiquitin to the LYSINE of a substrate protein with the assistance of UBIQUITIN-PROTEIN LIGASES.
Intracranial Arteriovenous Malformations
Congenital vascular anomalies in the brain characterized by direct communication between an artery and a vein without passing through the CAPILLARIES. The locations and size of the shunts determine the symptoms including HEADACHES; SEIZURES; STROKE; INTRACRANIAL HEMORRHAGES; mass effect; and vascular steal effect.
Sequence Alignment
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Recombinational DNA Repair
Repair of DNA DAMAGE by exchange of DNA between matching sequences, usually between the allelic DNA (ALLELES) of sister chromatids.
Salvage Therapy
A therapeutic approach, involving chemotherapy, radiation therapy, or surgery, after initial regimens have failed to lead to improvement in a patient's condition. Salvage therapy is most often used for neoplastic diseases.
Hydroxyurea
An antineoplastic agent that inhibits DNA synthesis through the inhibition of ribonucleoside diphosphate reductase.
Sensitivity and Specificity
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
Evidence-Based Medicine
An approach of practicing medicine with the goal to improve and evaluate patient care. It requires the judicious integration of best research evidence with the patient's values to make decisions about medical care. This method is to help physicians make proper diagnosis, devise best testing plan, choose best treatment and methods of disease prevention, as well as develop guidelines for large groups of patients with the same disease. (from JAMA 296 (9), 2006)
Replication Protein A
A single-stranded DNA-binding protein that is found in EUKARYOTIC CELLS. It is required for DNA REPLICATION; DNA REPAIR; and GENETIC RECOMBINATION.
Base Sequence
Fetal Growth Retardation
Retrospective Studies
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Software
3-Iodobenzylguanidine
A guanidine analog with specific affinity for tissues of the sympathetic nervous system and related tumors. The radiolabeled forms are used as antineoplastic agents and radioactive imaging agents. (Merck Index, 12th ed) MIBG serves as a neuron-blocking agent which has a strong affinity for, and retention in, the adrenal medulla and also inhibits ADP-ribosyltransferase.
Patient Positioning
Two-Hybrid System Techniques
Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.
Prophase
Trinucleotide Repeat Expansion
An increased number of contiguous trinucleotide repeats in the DNA sequence from one generation to the next. The presence of these regions is associated with diseases such as FRAGILE X SYNDROME and MYOTONIC DYSTROPHY. Some CHROMOSOME FRAGILE SITES are composed of sequences where trinucleotide repeat expansion occurs.
RNA, Untranslated
Endodeoxyribonucleases
Microbial Viability
Kaplan-Meier Estimate
A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)
Exodeoxyribonucleases
A family of enzymes that catalyze the exonucleolytic cleavage of DNA. It includes members of the class EC 3.1.11 that produce 5'-phosphomonoesters as cleavage products.
Schizosaccharomyces pombe Proteins
Proteins obtained from the species Schizosaccharomyces pombe. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Protein Binding
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Epidemiology
Microscopy
The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.
Pancreatic Neoplasms
Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).
Leukemia Virus, Murine
Combined Modality Therapy
The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.
CDC28 Protein Kinase, S cerevisiae
A protein kinase encoded by the Saccharomyces cerevisiae CDC28 gene and required for progression from the G1 PHASE to the S PHASE in the CELL CYCLE.
Ribulose-Bisphosphate Carboxylase
A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.
Amino Acid Sequence
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.
Protozoan Vaccines
Magnetic Resonance Imaging
Mitosis
Dose Fractionation
Mutagens
Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.
Dihydroxyphenylalanine
A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.
Endonucleases
Gene Conversion
The asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.
Mosaicism
Diploidy
DNA Topoisomerases, Type I
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.
Substrate Specificity
Gene Rearrangement
The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.
Schizosaccharomyces
Prospective Studies
Ubiquitin-Protein Ligases
A diverse class of enzymes that interact with UBIQUITIN-CONJUGATING ENZYMES and ubiquitination-specific protein substrates. Each member of this enzyme group has its own distinct specificity for a substrate and ubiquitin-conjugating enzyme. Ubiquitin-protein ligases exist as both monomeric proteins multiprotein complexes.
Models, Biological
DNA
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).
DNA Methylation
Radiotherapy Planning, Computer-Assisted
Genes, Lethal
Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.
Alleles
Publication Bias
The influence of study results on the chances of publication and the tendency of investigators, reviewers, and editors to submit or accept manuscripts for publication based on the direction or strength of the study findings. Publication bias has an impact on the interpretation of clinical trials and meta-analyses. Bias can be minimized by insistence by editors on high-quality research, thorough literature reviews, acknowledgement of conflicts of interest, modification of peer review practices, etc.
Computational Biology
A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.
Gene Expression Regulation, Fungal
Soybeans
Rec A Recombinases
A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.
Follow-Up Studies
Models, Molecular
Cell Cycle Proteins
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
DNA Polymerase III
A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms but may be present in higher organisms. Use also for a more complex form of DNA polymerase III designated as DNA polymerase III* or pol III* which is 15 times more active biologically than DNA polymerase I in the synthesis of DNA. This polymerase has both 3'-5' and 5'-3' exonuclease activities, is inhibited by sulfhydryl reagents, and has the same template-primer dependence as pol II. EC 2.7.7.7.
Bias (Epidemiology)
Any deviation of results or inferences from the truth, or processes leading to such deviation. Bias can result from several sources: one-sided or systematic variations in measurement from the true value (systematic error); flaws in study design; deviation of inferences, interpretations, or analyses based on flawed data or data collection; etc. There is no sense of prejudice or subjectivity implied in the assessment of bias under these conditions.
Models, Genetic
Gamma Rays
Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.
Bibliometrics
Tomography, X-Ray Computed
Biomedical Research
Proteins
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Antigens, Protozoan
Computer Systems
Neoplasm Recurrence, Local
Databases, Nucleic Acid
Databases containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS; NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.
Soil Microbiology
Gene Duplication
Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.
Protein Interaction Domains and Motifs
CDC2 Protein Kinase
Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.
Research Design
Ligases
Checkpoint Kinase 2
Enzyme activated in response to DNA DAMAGE involved in cell cycle arrest. The gene is located on the long (q) arm of chromosome 22 at position 12.1. In humans it is encoded by the CHEK2 gene.
Databases, Protein
Databases containing information about PROTEINS such as AMINO ACID SEQUENCE; PROTEIN CONFORMATION; and other properties.
Mutagenesis
Recombinant Fusion Proteins
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Cell Cycle
The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
Receptors, Immunologic
Quaternary Ammonium Compounds
Sequence Homology, Amino Acid
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Proviruses
Duplex DNA sequences in eukaryotic chromosomes, corresponding to the genome of a virus, that are transmitted from one cell generation to the next without causing lysis of the host. Proviruses are often associated with neoplastic cell transformation and are key features of retrovirus biology.