A rare, pigmentary, and atrophic autosomal recessive disease. It is manifested as an extreme photosensitivity to ULTRAVIOLET RAYS as the result of a deficiency in the enzyme that permits excisional repair of ultraviolet-damaged DNA.
A ZINC FINGER MOTIF protein that recognizes and interacts with damaged DNA. It is a DNA-binding protein that plays an essential role in NUCLEOTIDE EXCISION REPAIR. Mutations in this protein are associated with the most severe form of XERODERMA PIGMENTOSUM.
A DNA helicase that is a component of TRANSCRIPTION FACTOR TFIIH. It plays an essential role in NUCLEOTIDE EXCISION REPAIR, and mutations in this protein are associated with XERODERMA PIGMENTOSUM.
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.
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 syndrome characterized by multiple system abnormalities including DWARFISM; PHOTOSENSITIVITY DISORDERS; PREMATURE AGING; and HEARING LOSS. It is caused by mutations of a number of autosomal recessive genes encoding proteins that involve transcriptional-coupled DNA REPAIR processes. Cockayne syndrome is classified by the severity and age of onset. Type I (classical; CSA) is early childhood onset in the second year of life; type II (congenital; CSB) is early onset at birth with severe symptoms; type III (xeroderma pigmentosum; XP) is late childhood onset with mild symptoms.
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.
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.
Enzymes that catalyze the hydrolysis of the internal bonds and thereby the formation of polynucleotides or oligonucleotides from ribo- or deoxyribonucleotide chains. EC 3.1.-.
Autosomal recessive neuroectodermal disorders characterized by brittle sulfur-deficient hair associated with impaired intellect, decreased fertility, and short stature. It may include nail dystrophy, ICHTHYOSIS, and photosensitivity correlated with a NUCLEOTIDE EXCISION REPAIR defect. All individuals with this disorder have a deficiency of cysteine-rich KERATIN-ASSOCIATED PROTEINS found in the interfilamentous matrix. Photosensitive trichothiodystrophy can be caused by mutation in at least 2 separate genes: ERCC2 PROTEIN gene and the related ERCC3. Nonphotosensitive trichothiodystrophy can be caused by mutation in the TTDN1 gene.
A general transcription factor that is involved in basal GENETIC TRANSCRIPTION and NUCLEOTIDE EXCISION REPAIR. It consists of nine subunits including ATP-DEPENDENT DNA HELICASES; CYCLIN H; and XERODERMA PIGMENTOSUM GROUP D PROTEIN.
Diseases affecting the orderly growth and persistence of hair.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Abnormal responses to sunlight or artificial light due to extreme reactivity of light-absorbing molecules in tissues. It refers almost exclusively to skin photosensitivity, including sunburn, reactions due to repeated prolonged exposure in the absence of photosensitizing factors, and reactions requiring photosensitizing factors such as photosensitizing agents and certain diseases. With restricted reference to skin tissue, it does not include photosensitivity of the eye to light, as in photophobia or photosensitive epilepsy.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
An alkylating agent that forms DNA ADDUCTS at the C-8 position in GUANINE, resulting in single strand breaks. It has demonstrated carcinogenic action.
Tumors or cancer of the SKIN.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
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).
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.
A potent mutagen and carcinogen. This compound and its metabolite 4-HYDROXYAMINOQUINOLINE-1-OXIDE bind to nucleic acids. It inactivates bacteria but not bacteriophage.
The process by which a DNA molecule is duplicated.
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.
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
Established cell cultures that have the potential to propagate indefinitely.
DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair.
The so-called general transcription factors that bind to RNA POLYMERASE II and that are required to initiate transcription. They include TFIIA; TFIIB; TFIID; TFIIE; TFIIF; TFIIH; TFII-I; and TFIIJ. In vivo they apparently bind in an ordered multi-step process and/or may form a large preinitiation complex called RNA polymerase II holoenzyme.
A broad-spectrum spectrum antineoplastic antibiotic isolated from Streptomyces refuineus var. thermotolerans. It has low toxicity, some activity against Trichomonas and Endamoeba, and inhibits RNA and DNA synthesis. It binds irreversibly to DNA.
Linear furanocoumarins which are found in many PLANTS, especially UMBELLIFERAE and RUTACEAE, as well as PSORALEA from which they were originally discovered. They can intercalate DNA and, in an UV-initiated reaction of the furan portion, alkylate PYRIMIDINES, resulting in PHOTOSENSITIVITY DISORDERS.
A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)
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.
Enzymes that are involved in the reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule, which contained damaged regions.
Eukaryotic cell line obtained in a quiescent or stationary phase which undergoes conversion to a state of unregulated growth in culture, resembling an in vitro tumor. It occurs spontaneously or through interaction with viruses, oncogenes, radiation, or drugs/chemicals.
A genetic or pathological condition that is characterized by short stature and undersize. Abnormal skeletal growth usually results in an adult who is significantly below the average height.
An autosomal recessive inherited disorder characterized by choreoathetosis beginning in childhood, progressive CEREBELLAR ATAXIA; TELANGIECTASIS of CONJUNCTIVA and SKIN; DYSARTHRIA; B- and T-cell immunodeficiency, and RADIOSENSITIVITY to IONIZING RADIATION. Affected individuals are prone to recurrent sinobronchopulmonary infections, lymphoreticular neoplasms, and other malignancies. Serum ALPHA-FETOPROTEINS are usually elevated. (Menkes, Textbook of Child Neurology, 5th ed, p688) The gene for this disorder (ATM) encodes a cell cycle checkpoint protein kinase and has been mapped to chromosome 11 (11q22-q23).
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.
The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
Hydrolysate of DNA in which purine bases have been removed.
Disorders of increased melanin pigmentation that develop without preceding inflammatory disease.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A subdiscipline of genetics that studies RADIATION EFFECTS on the components and processes of biological inheritance.
Diseases of the uvea.
Diseases of the skin with a genetic component, usually the result of various inborn errors of metabolism.
Inherited disorders characterized by progressive atrophy and dysfunction of anatomically or physiologically related neurologic systems.
Tumors, cancer or other neoplasms produced by exposure to ionizing or non-ionizing radiation.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
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.
An injury to the skin causing erythema, tenderness, and sometimes blistering and resulting from excessive exposure to the sun. The reaction is produced by the ultraviolet radiation in sunlight.
A single-stranded DNA-binding protein that is found in EUKARYOTIC CELLS. It is required for DNA REPLICATION; DNA REPAIR; and GENETIC RECOMBINATION.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Any of several generalized skin disorders characterized by dryness, roughness, and scaliness, due to hypertrophy of the stratum corneum epidermis. Most are genetic, but some are acquired, developing in association with other systemic disease or genetic syndrome.
The geographical area of Africa comprising ALGERIA; EGYPT; LIBYA; MOROCCO; and TUNISIA. It includes also the vast deserts and oases of the Sahara. It is often referred to as North Africa, French-speaking Africa, or the Maghreb. (From Webster's New Geographical Dictionary, 1988, p856)
The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.
An individual having different alleles at one or more loci regarding a specific character.
The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.
The effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on food, drugs, and chemicals.
A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.
An abnormal congenital condition, associated with defects in the LAMIN TYPE A gene, which is characterized by premature aging in children, where all the changes of cell senescence occur. It is manifested by premature greying; hair loss; hearing loss (DEAFNESS); cataracts (CATARACT); ARTHRITIS; OSTEOPOROSIS; DIABETES MELLITUS; atrophy of subcutaneous fat; skeletal hypoplasia; elevated urinary HYALURONIC ACID; and accelerated ATHEROSCLEROSIS. Many affected individuals develop malignant tumors, especially SARCOMA.
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.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.
Preparations of cell constituents or subcellular materials, isolates, or substances.
A group of enzymes catalyzing the endonucleolytic cleavage of DNA. They include members of EC 3.1.21.-, EC 3.1.22.-, EC 3.1.23.- (DNA RESTRICTION ENZYMES), EC 3.1.24.- (DNA RESTRICTION ENZYMES), and EC 3.1.25.-.
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.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
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.
A type of mutation in which a number of NUCLEOTIDES deleted from or inserted into a protein coding sequence is not divisible by three, thereby causing an alteration in the READING FRAMES of the entire coding sequence downstream of the mutation. These mutations may be induced by certain types of MUTAGENS or may occur spontaneously.
Irradiation directly from the sun.
Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.
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.

Impaired translesion synthesis in xeroderma pigmentosum variant extracts. (1/663)

Xeroderma pigmentosum variant (XPV) cells are characterized by a cellular defect in the ability to synthesize intact daughter DNA strands on damaged templates. Molecular mechanisms that facilitate replication fork progression on damaged DNA in normal cells are not well defined. In this study, we used single-stranded plasmid molecules containing a single N-2-acetylaminofluorene (AAF) adduct to analyze translesion synthesis (TLS) catalyzed by extracts of either normal or XPV primary skin fibroblasts. In one of the substrates, the single AAF adduct was located at the 3' end of a run of three guanines that was previously shown to induce deletion of one G by a slippage mechanism. Primer extension reactions performed by normal cellular extracts from four different individuals produced the same distinct pattern of TLS, with over 80% of the products resulting from the elongation of a slipped intermediate and the remaining 20% resulting from a nonslipped intermediate. In contrast, with cellular extracts from five different XPV patients, the TLS reaction was strongly reduced, yielding only low amounts of TLS via the nonslipped intermediate. With our second substrate, in which the AAF adduct was located at the first G in the run, thus preventing slippage from occurring, we confirmed that normal extracts were able to perform TLS 10-fold more efficiently than XPV extracts. These data demonstrate unequivocally that the defect in XPV cells resides in translesion synthesis independently of the slippage process.  (+info)

Postnatal growth failure, short life span, and early onset of cellular senescence and subsequent immortalization in mice lacking the xeroderma pigmentosum group G gene. (2/663)

The xeroderma pigmentosum group G (XP-G) gene (XPG) encodes a structure-specific DNA endonuclease that functions in nucleotide excision repair (NER). XP-G patients show various symptoms, ranging from mild cutaneous abnormalities to severe dermatological impairments. In some cases, patients exhibit growth failure and life-shortening and neurological dysfunctions, which are characteristics of Cockayne syndrome (CS). The known XPG protein function as the 3' nuclease in NER, however, cannot explain the development of CS in certain XP-G patients. To gain an insight into the functions of the XPG protein, we have generated and examined mice lacking xpg (the mouse counterpart of the human XPG gene) alleles. The xpg-deficient mice exhibited postnatal growth failure and underwent premature death. Since XPA-deficient mice, which are totally defective in NER, do not show such symptoms, our data indicate that XPG performs an additional function(s) besides its role in NER. Our in vitro studies showed that primary embryonic fibroblasts isolated from the xpg-deficient mice underwent premature senescence and exhibited the early onset of immortalization and accumulation of p53.  (+info)

Mutational inactivation of the xeroderma pigmentosum group C gene confers predisposition to 2-acetylaminofluorene-induced liver and lung cancer and to spontaneous testicular cancer in Trp53-/- mice. (3/663)

Mice that are genetically engineered to mimic the human hereditary cancer-prone DNA repair-defective disease xeroderma pigmentosum (XP) are highly predisposed to UV radiation-induced skin cancer. It is not clear, however, whether XP mice or humans are predisposed to cancers in other tissues associated with exposure to environmental carcinogens. To test the importance of nucleotide excision repair in protection against chemical carcinogenesis in internal organs, we treated XPC mutant (XPC-/-) mice with 2-acetylaminofluorene and NOH-2-acetylaminofluorene. We observed a significantly higher incidence of chemically induced liver and lung tumors in XPC-/- mice compared with normal and heterozygous littermates In addition, the progression of liver tumors in XPC-/- Trp53+/- mice is accelerated compared with XPC-/- Trp53+/+ animals. Finally, we demonstrate a higher incidence of spontaneous testicular tumors in XPC-/- TrpS3-/- double mutant mice compared with XPC+/+ Trp53-/- mice.  (+info)

Resonance assignments, solution structure, and backbone dynamics of the DNA- and RPA-binding domain of human repair factor XPA. (4/663)

XPA is involved in the damage recognition step of nucleotide excision repair (NER). XPA binds to other repair factors, and acts as a key element in NER complex formation. The central domain of human repair factor XPA (residues Met98 to Phe219) is responsible for the preferential binding to damaged DNA and to replication protein A (RPA). The domain consists of a zinc-containing subdomain with a compact globular structure and a C-terminal subdomain with a positively charged cleft in a novel alpha/beta structure. The resonance assignments and backbone dynamics of the central domain of human XPA were studied by multidimensional heteronuclear NMR methods. 15N relaxation data were obtained at two static magnetic fields, and analyzed by means of the model-free formalism under the assumption of isotropic or anisotropic rotational diffusion. In addition, exchange contributions were estimated by analysis of the spectral density function at zero frequency. The results show that the domain exhibits a rotational diffusion anisotropy (Dparallel/Dperpendicular) of 1.38, and that most of the flexible regions exist on the DNA binding surface in the cleft in the C-terminal subdomain. This flexibility may be involved in the interactions of XPA with various kinds of damaged DNA.  (+info)

Nuclear foci of mammalian recombination proteins are located at single-stranded DNA regions formed after DNA damage. (5/663)

A sensitive and rapid in situ method was developed to visualize sites of single-stranded (ss) DNA in cultured cells and in experimental test animals. Anti-bromodeoxyuridine antibody recognizes the halogenated base analog incorporated into chromosomal DNA only when substituted DNA is in the single strand form. After treatment of cells with DNA-damaging agents or gamma irradiation, ssDNA molecules form nuclear foci in a dose-dependent manner within 60 min. The mammalian recombination protein Rad51 and the replication protein A then accumulate at sites of ssDNA and form foci, suggesting that these are sites of recombinational DNA repair.  (+info)

Mutations in XPB and XPD helicases found in xeroderma pigmentosum patients impair the transcription function of TFIIH. (6/663)

As part of TFIIH, XPB and XPD helicases have been shown to play a role in nucleotide excision repair (NER). Mutations in these subunits are associated with three genetic disorders: xeroderma pigmentosum (XP), Cockayne syndrome (CS) and trichothiodystrophy (TTD). The strong heterogeneous clinical features observed in these patients cannot be explained by defects in NER alone. We decided to look at the transcriptional activity of TFIIH from cell lines of XP individuals. We set up an immunopurification procedure to isolate purified TFIIH from patient cell extracts. We demonstrated that mutations in two XP-B/CS patients decrease the transcriptional activity of the corresponding TFIIH by preventing promoter opening. The defect of XPB in transcription can be circumvented by artificial opening of the promoter. Western blot analysis and enzymatic assays indicate that XPD mutations affect the stoichiometric composition of TFIIH due to a weakness in the interaction between XPD-CAK complex and the core TFIIH, resulting in a partial reduction of transcription activity. This work, in addition to clarifying the role of the various TFIIH subunits, supports the current hypothesis that XP-B/D patients are more likely to suffer from transcription repair syndromes rather than DNA repair disorders alone.  (+info)

Increased ultraviolet sensitivity and chromosomal instability related to P53 function in the xeroderma pigmentosum variant. (7/663)

The xeroderma pigmentosum (XP) variant (XPV) is a form of XP that has normal excision repair but shows defective DNA replication after UV irradiation. In developing various transformed fibroblast cell lines from these patients, we have found that there are significant phenotypic changes in transformed cells that seem to correlate with inactivation of p53. After transformation with SV40, XPV cell lines are only slightly UV sensitive, like their primary counterparts, but their sensitization with caffeine and the induction of sister chromatid exchanges (SCEs) by UV irradiation are greatly enhanced. After transformation by HPV16 E7, which targets the retinoblastoma cell cycle regulatory gene, there is no change in the UV sensitivity of XPV cells; but, when transformed by HPV16 E6 or E6 and E7 combined, there is a large increase in UV sensitivity and in the induction of SCEs. These changes are not associated with any detectable changes in the reactivation of an externally irradiated luciferase expression vector, the excision of cyclobutane pyrimidine dimers from bulk DNA, or unscheduled DNA synthesis and, therefore, do not involve excision repair. We suggest that if SCEs represent homologous recombination between sister chromatids, then in the absence of p53 function, the DNA chain arrest typical of UV-damaged XPV cells initiates strand exchange during recovery. In untransformed cells with normal p53, the preferred mode of recovery would then be replication bypass. The symptoms of elevated solar carcinogenesis in XPV patients may, therefore, be associated with increased genomic instability in cells of the skin in which p53 is inactivated by UV-induced mutations.  (+info)

Requirement of ATM in phosphorylation of the human p53 protein at serine 15 following DNA double-strand breaks. (8/663)

Microinjection of the restriction endonuclease HaeIII, which causes DNA double-strand breaks with blunt ends, induces nuclear accumulation of p53 protein in normal and xeroderma pigmentosum (XP) primary fibroblasts. In contrast, this induction of p53 accumulation is not observed in ataxia telangiectasia (AT) fibroblasts. HaeIII-induced p53 protein in normal fibroblasts is phosphorylated at serine 15, as determined by immunostaining with an antibody specific for phosphorylated serine 15 of p53. This phosphorylation correlates well with p53 accumulation. Treatment with lactacystin (an inhibitor of the proteasome) or heat shock leads to similar levels of p53 accumulation in normal and AT fibroblasts, but the p53 protein lacks a phosphorylated serine 15. Following microinjection of HaeIII into lactacystin-treated normal fibroblasts, lactacystin-induced p53 protein is phosphorylated at serine 15 and stabilized even in the presence of cycloheximide. However, neither stabilization nor phosphorylation at serine 15 is observed in AT fibroblasts under the same conditions. These results indicate the significance of serine 15 phosphorylation for p53 stabilization after DNA double-strand breaks and an absolute requirement for ATM in this phosphorylation process.  (+info)

Xeroderma Pigmentosum (XP) is a rare, genetic disorder that affects the body's ability to repair damage to DNA caused by ultraviolet (UV) radiation from sunlight. The condition results in extreme sensitivity to UV light. People with XP develop freckles and moles on sun-exposed skin at an early age, and are prone to developing various forms of skin cancer. In severe cases, the disease may also affect the eyes and nervous system.

The disorder is caused by mutations in genes that are responsible for repairing damaged DNA. If not diagnosed and managed properly, XP can lead to serious health complications, including disability and death. Treatment typically involves strict sun protection measures, such as avoiding sunlight, using sunscreen, wearing protective clothing, and in some cases, medication or surgery.

Xeroderma Pigmentosum Group A Protein, also known as XPA protein, is a crucial component of the nucleotide excision repair (NER) pathway in humans. The NER pathway is responsible for repairing damaged DNA, including DNA that has been damaged by ultraviolet (UV) light.

XPA protein plays a central role in the NER process by serving as a scaffold that helps to coordinate and regulate the activity of other NER proteins. XPA protein binds directly to the damaged DNA site, helping to recruit and position other NER proteins for efficient repair.

Mutations in the XPA gene can lead to Xeroderma Pigmentosum (XP), a rare genetic disorder characterized by extreme sensitivity to UV light. Individuals with XP are prone to developing skin cancer and other forms of cancer at an early age due to their inability to repair DNA damage caused by UV light.

Xeroderma Pigmentosum Group D Protein, also known as XPD protein, is a component of the nucleotide excision repair complex (NER) in humans. The NER complex is responsible for repairing damaged DNA, including DNA that has been damaged by ultraviolet (UV) light.

The XPD protein is an ATP-dependent helicase that unwinds double-stranded DNA during the NER process. Mutations in the gene that encodes the XPD protein can lead to a genetic disorder called xeroderma pigmentosum (XP), which is characterized by increased sensitivity to UV light and a high risk of skin cancer.

There are several subtypes of XP, and mutations in the XPD gene can cause XP group D. This form of XP is also associated with progressive neurodegeneration and cognitive impairment. The exact mechanism by which XPD mutations lead to these neurological symptoms is not fully understood, but it is thought to be related to defects in transcription-coupled repair (TCR), a subpathway of NER that preferentially repairs DNA damage in the transcribed strand of active genes.

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.

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.

Cockayne Syndrome is a rare genetic disorder that affects the body's ability to repair DNA. It is characterized by progressive growth failure, neurological abnormalities, and premature aging. The syndrome is typically diagnosed in childhood and is often associated with photosensitivity, meaning that affected individuals are unusually sensitive to sunlight.

Cockayne Syndrome is caused by mutations in either the ERCC6 or ERCC8 gene, which are involved in the repair of damaged DNA. There are two types of Cockayne Syndrome: Type I and Type II. Type I is the more common form and is characterized by normal development during the first year of life followed by progressive growth failure, neurological abnormalities, and premature aging. Type II is a more severe form that is apparent at birth or within the first few months of life and is associated with severe developmental delays, intellectual disability, and early death.

There is no cure for Cockayne Syndrome, and treatment is focused on managing symptoms and improving quality of life. This may include physical therapy, occupational therapy, speech therapy, and special education services. In some cases, medications may be used to treat specific symptoms such as seizures or gastrointestinal problems.

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.

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.

Endonucleases are enzymes that cleave, or cut, phosphodiester bonds within a polynucleotide chain, specifically within the same molecule of DNA or RNA. They can be found in all living organisms and play crucial roles in various biological processes, such as DNA replication, repair, and recombination.

Endonucleases can recognize specific nucleotide sequences (sequence-specific endonucleases) or have no sequence preference (non-specific endonucleases). Some endonucleases generate sticky ends, overhangs of single-stranded DNA after cleavage, while others produce blunt ends without any overhang.

These enzymes are widely used in molecular biology techniques, such as restriction digestion, cloning, and genome editing (e.g., CRISPR-Cas9 system). Restriction endonucleases recognize specific DNA sequences called restriction sites and cleave the phosphodiester bonds at or near these sites, generating defined fragment sizes that can be separated by agarose gel electrophoresis. This property is essential for various applications in genetic engineering and biotechnology.

Trichothiodystrophy (TTD) syndromes are a group of rare genetic disorders characterized by brittle, sparse, and easily breakable hair due to abnormal sulfur content. The syndromes can also involve various other symptoms such as intellectual disability, developmental delays, ichthyosis (dry, scaly skin), nail abnormalities, short stature, and increased sensitivity to light. TTD syndromens are caused by mutations in genes involved in DNA repair, particularly the ERCC2 and ERCC3 genes. These genetic defects lead to impaired DNA repair and decreased UV protection, which can result in increased risk of skin cancer. The condition is usually present from birth or early childhood and affects both males and females equally.

Transcription Factor IIH (TFIIH) is a multi-subunit protein complex that plays a crucial role in the process of transcription, which is the synthesis of RNA from DNA. Specifically, TFIIH is involved in the initiation phase of transcription for protein-coding genes in eukaryotic cells.

TFIIH has two main enzymatic activities: helicase and kinase. The helicase activity is provided by the XPB and XPD subunits, which are responsible for unwinding the DNA double helix at the transcription start site. This creates a single-stranded DNA template for the RNA polymerase II (Pol II) enzyme to bind and begin transcribing the gene.

The kinase activity of TFIIH is provided by the CAK subcomplex, which consists of the CDK7, Cyclin H, and MAT1 proteins. This kinase phosphorylates the carboxy-terminal domain (CTD) of the largest subunit of Pol II, leading to the recruitment of additional transcription factors and the initiation of RNA synthesis.

In addition to its role in transcription, TFIIH is also involved in DNA repair processes, particularly nucleotide excision repair (NER). During NER, TFIIH helps to recognize and remove damaged DNA lesions, such as those caused by UV radiation or chemical mutagens. The XPB and XPD subunits of TFIIH are essential for this process, as they help to unwind the DNA around the damage site and create a bubble structure that allows other repair factors to access and fix the lesion.

Mutations in the genes encoding various subunits of TFIIH can lead to several human diseases, including xeroderma pigmentosum (XP), Cockayne syndrome (CS), trichothiodystrophy (TTD), and combined XP/CS/TTD. These disorders are characterized by increased sensitivity to UV radiation, developmental abnormalities, and neurological dysfunction.

Hair diseases is a broad term that refers to various medical conditions affecting the hair shaft, follicle, or scalp. These conditions can be categorized into several types, including:

1. Hair shaft abnormalities: These are conditions that affect the structure and growth of the hair shaft. Examples include trichorrhexis nodosa, where the hair becomes weak and breaks easily, and pili torti, where the hair shaft is twisted and appears sparse and fragile.
2. Hair follicle disorders: These are conditions that affect the hair follicles, leading to hair loss or abnormal growth patterns. Examples include alopecia areata, an autoimmune disorder that causes patchy hair loss, and androgenetic alopecia, a genetic condition that leads to pattern baldness in both men and women.
3. Scalp disorders: These are conditions that affect the scalp, leading to symptoms such as itching, redness, scaling, or pain. Examples include seborrheic dermatitis, psoriasis, and tinea capitis (ringworm of the scalp).
4. Hair cycle abnormalities: These are conditions that affect the normal growth cycle of the hair, leading to excessive shedding or thinning. Examples include telogen effluvium, where a large number of hairs enter the resting phase and fall out, and anagen effluvium, which is typically caused by chemotherapy or radiation therapy.
5. Infectious diseases: Hair follicles can become infected with various bacteria, viruses, or fungi, leading to conditions such as folliculitis, furunculosis, and kerion.
6. Genetic disorders: Some genetic disorders can affect the hair, such as Menkes syndrome, which is a rare inherited disorder that affects copper metabolism and leads to kinky, sparse, and brittle hair.

Proper diagnosis and treatment of hair diseases require consultation with a healthcare professional, often a dermatologist or a trichologist who specializes in hair and scalp disorders.

DNA-binding proteins are a type of protein that have the ability to bind to DNA (deoxyribonucleic acid), the genetic material of organisms. These proteins play crucial roles in various biological processes, such as regulation of gene expression, DNA replication, repair and recombination.

The binding of DNA-binding proteins to specific DNA sequences is mediated by non-covalent interactions, including electrostatic, hydrogen bonding, and van der Waals forces. The specificity of binding is determined by the recognition of particular nucleotide sequences or structural features of the DNA molecule.

DNA-binding proteins can be classified into several categories based on their structure and function, such as transcription factors, histones, and restriction enzymes. Transcription factors are a major class of DNA-binding proteins that regulate gene expression by binding to specific DNA sequences in the promoter region of genes and recruiting other proteins to modulate transcription. Histones are DNA-binding proteins that package DNA into nucleosomes, the basic unit of chromatin structure. Restriction enzymes are DNA-binding proteins that recognize and cleave specific DNA sequences, and are widely used in molecular biology research and biotechnology applications.

Photosensitivity disorders refer to conditions that cause an abnormal reaction to sunlight or artificial light. This reaction can take the form of various skin changes, such as rashes, inflammation, or pigmentation, and in some cases, it can also lead to systemic symptoms like fatigue, fever, or joint pain.

The two main types of photosensitivity disorders are:

1. Phototoxic reactions: These occur when a substance (such as certain medications, chemicals, or plants) absorbs light energy and transfers it to skin cells, causing damage and inflammation. The reaction typically appears within 24 hours of exposure to the light source and can resemble a sunburn.

2. Photoallergic reactions: These occur when the immune system responds to the combination of light and a particular substance, leading to an allergic response. The reaction may not appear until several days after initial exposure and can cause redness, itching, and blistering.

It is important for individuals with photosensitivity disorders to avoid excessive sun exposure, wear protective clothing, and use broad-spectrum sunscreens with a high SPF rating to minimize the risk of phototoxic or photoallergic reactions.

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).

Acetoxyacetylaminofluorene is not a medical term, but a chemical compound. It's a derivative of the carcinogen N-acetyl-N-hydroxy-2-acetylaminofluorene, which has been used in research to study chemical carcinogenesis and mutagenesis.

The compound Acetoxyacetylaminofluorene is relatively unstable and can be hydrolyzed to release the active metabolite N-hydroxy-2-acetylaminofluorene, which can then interact with DNA and lead to the formation of DNA adducts. These adducts can cause mutations and contribute to the carcinogenic effects of this compound.

It's important to note that Acetoxyacetylaminofluorene is not used in medical treatments or therapies, and its use is limited to research purposes only.

Skin neoplasms refer to abnormal growths or tumors in the skin that can be benign (non-cancerous) or malignant (cancerous). They result from uncontrolled multiplication of skin cells, which can form various types of lesions. These growths may appear as lumps, bumps, sores, patches, or discolored areas on the skin.

Benign skin neoplasms include conditions such as moles, warts, and seborrheic keratoses, while malignant skin neoplasms are primarily classified into melanoma, squamous cell carcinoma, and basal cell carcinoma. These three types of cancerous skin growths are collectively known as non-melanoma skin cancers (NMSCs). Melanoma is the most aggressive and dangerous form of skin cancer, while NMSCs tend to be less invasive but more common.

It's essential to monitor any changes in existing skin lesions or the appearance of new growths and consult a healthcare professional for proper evaluation and treatment if needed.

A genetic complementation test is a laboratory procedure used in molecular genetics to determine whether two mutated genes can complement each other's function, indicating that they are located at different loci and represent separate alleles. This test involves introducing a normal or wild-type copy of one gene into a cell containing a mutant version of the same gene, and then observing whether the presence of the normal gene restores the normal function of the mutated gene. If the introduction of the normal gene results in the restoration of the normal phenotype, it suggests that the two genes are located at different loci and can complement each other's function. However, if the introduction of the normal gene does not restore the normal phenotype, it suggests that the two genes are located at the same locus and represent different alleles of the same gene. This test is commonly used to map genes and identify genetic interactions in a variety of organisms, including bacteria, yeast, and animals.

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.

DNA helicases are a group of enzymes that are responsible for separating the two strands of DNA during processes such as replication and transcription. They do this by unwinding the double helix structure of DNA, using energy from ATP to break the hydrogen bonds between the base pairs. This allows other proteins to access the individual strands of DNA and carry out functions such as copying the genetic code or transcribing it into RNA.

During replication, DNA helicases help to create a replication fork, where the two strands of DNA are separated and new complementary strands are synthesized. In transcription, DNA helicases help to unwind the DNA double helix at the promoter region, allowing the RNA polymerase enzyme to bind and begin transcribing the DNA into RNA.

DNA helicases play a crucial role in maintaining the integrity of the genetic code and are essential for the normal functioning of cells. Defects in DNA helicases have been linked to various diseases, including cancer and neurological disorders.

4-Nitroquinoline-1-oxide is a chemical compound that is often used in laboratory research as a carcinogenic agent. Its molecular formula is C6H4N2O3, and it is known to cause DNA damage and mutations, which can lead to the development of cancer. It is primarily used in scientific research to study the mechanisms of carcinogenesis and to test the effectiveness of potential cancer treatments.

It is important to note that 4-Nitroquinoline-1-oxide is not a medication or a treatment for any medical condition, and it should only be handled by trained professionals in a controlled laboratory setting.

DNA replication is the biological process by which DNA makes an identical copy of itself during cell division. It is a fundamental mechanism that allows genetic information to be passed down from one generation of cells to the next. During DNA replication, each strand of the double helix serves as a template for the synthesis of a new complementary strand. This results in the creation of two identical DNA molecules. The enzymes responsible for DNA replication include helicase, which unwinds the double helix, and polymerase, which adds nucleotides to the growing strands.

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.

A dose-response relationship in radiation refers to the correlation between the amount of radiation exposure (dose) and the biological response or adverse health effects observed in exposed individuals. As the level of radiation dose increases, the severity and frequency of the adverse health effects also tend to increase. This relationship is crucial in understanding the risks associated with various levels of radiation exposure and helps inform radiation protection standards and guidelines.

The effects of ionizing radiation can be categorized into two types: deterministic and stochastic. Deterministic effects have a threshold dose below which no effect is observed, and above this threshold, the severity of the effect increases with higher doses. Examples include radiation-induced cataracts or radiation dermatitis. Stochastic effects, on the other hand, do not have a clear threshold and are based on probability; as the dose increases, so does the likelihood of the adverse health effect occurring, such as an increased risk of cancer.

Understanding the dose-response relationship in radiation exposure is essential for setting limits on occupational and public exposure to ionizing radiation, optimizing radiation protection practices, and developing effective medical countermeasures in case of radiation emergencies.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

DNA-directed DNA polymerase is a type of enzyme that synthesizes new strands of DNA by adding nucleotides to an existing DNA template in a 5' to 3' direction. These enzymes are essential for DNA replication, repair, and recombination. They require a single-stranded DNA template, a primer with a free 3' hydroxyl group, and the four deoxyribonucleoside triphosphates (dNTPs) as substrates to carry out the polymerization reaction.

DNA polymerases also have proofreading activity, which allows them to correct errors that occur during DNA replication by removing mismatched nucleotides and replacing them with the correct ones. This helps ensure the fidelity of the genetic information passed from one generation to the next.

There are several different types of DNA polymerases, each with specific functions and characteristics. For example, DNA polymerase I is involved in both DNA replication and repair, while DNA polymerase III is the primary enzyme responsible for DNA replication in bacteria. In eukaryotic cells, DNA polymerase alpha, beta, gamma, delta, and epsilon have distinct roles in DNA replication, repair, and maintenance.

Transcription factors (TFs) are proteins that regulate the transcription of genetic information from DNA to RNA by binding to specific DNA sequences. They play a crucial role in controlling gene expression, which is the process by which information in genes is converted into a functional product, such as a protein.

TFII, on the other hand, refers to a general class of transcription factors that are involved in the initiation of RNA polymerase II-dependent transcription. These proteins are often referred to as "general transcription factors" because they are required for the transcription of most protein-coding genes in eukaryotic cells.

TFII factors help to assemble the preinitiation complex (PIC) at the promoter region of a gene, which is a group of proteins that includes RNA polymerase II and other cofactors necessary for transcription. Once the PIC is assembled, TFII factors help to recruit RNA polymerase II to the promoter and initiate transcription.

Some examples of TFII factors include TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH. Each of these factors plays a specific role in the initiation of transcription, such as recognizing and binding to specific DNA sequences or modifying the chromatin structure around the promoter to make it more accessible to RNA polymerase II.

Anthramycin is an antitumor antibiotic that is derived from the bacterium Streptomyces antibioticus. It works by binding to the DNA in cancer cells and inhibiting their ability to replicate, which can lead to cell death. Anthramycin has been studied in clinical trials for the treatment of various types of cancer, including small cell lung cancer and gastrointestinal tumors. However, its use as a therapeutic agent is limited due to its toxicity and the availability of other effective treatments.

Anthramycin is also known by its chemical name, nogalamycin. It belongs to a class of antibiotics called anthracyclines, which are characterized by their planar polycyclic aromatic structure and intercalation properties. Other examples of anthracycline antibiotics include doxorubicin, daunorubicin, and epirubicin.

It is important to note that the use of anthramycin and other anthracyclines should be supervised by a qualified healthcare professional, as they can cause serious side effects such as cardiotoxicity, myelosuppression, and mucositis.

Psoralens are a class of organic compounds that can be found in several plants such as figs, celery, and parsnips. They are primarily known for their use in the treatment of skin conditions like psoriasis and eczema. When combined with ultraviolet A (UVA) light therapy, psoralens can help to slow down the excessive growth of skin cells that lead to these conditions.

Psoralens work by intercalating into DNA, which means they fit between the base pairs of the double helix structure of DNA. When exposed to UVA light, the psoralen molecules undergo a chemical reaction that forms cross-links in the DNA, which can inhibit the replication and transcription of DNA. This effect on skin cells can help to reduce inflammation and slow down the growth of affected skin cells, leading to an improvement in symptoms of certain skin conditions.

It's important to note that psoralens can have side effects, including increased sensitivity to sunlight, which can lead to sunburn and an increased risk of skin cancer with long-term use. Therefore, it's essential to follow the instructions of a healthcare provider carefully when using psoralen therapy.

Carcinoma, basal cell is a type of skin cancer that arises from the basal cells, which are located in the lower part of the epidermis (the outermost layer of the skin). It is also known as basal cell carcinoma (BCC) and is the most common form of skin cancer.

BCC typically appears as a small, shiny, pearly bump or nodule on the skin, often in sun-exposed areas such as the face, ears, neck, hands, and arms. It may also appear as a scar-like area that is white, yellow, or waxy. BCCs are usually slow growing and rarely spread (metastasize) to other parts of the body. However, they can be locally invasive and destroy surrounding tissue if left untreated.

The exact cause of BCC is not known, but it is thought to be related to a combination of genetic and environmental factors, including exposure to ultraviolet (UV) radiation from the sun or tanning beds. People with fair skin, light hair, and blue or green eyes are at increased risk of developing BCC.

Treatment for BCC typically involves surgical removal of the tumor, along with a margin of healthy tissue. Other treatment options may include radiation therapy, topical chemotherapy, or photodynamic therapy. Prevention measures include protecting your skin from UV radiation by wearing protective clothing, using sunscreen, and avoiding tanning beds.

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.

DNA repair enzymes are a group of enzymes that are responsible for identifying and correcting damage to the DNA molecule. These enzymes play a critical role in maintaining the integrity of an organism's genetic material, as they help to ensure that the information stored in DNA is accurately transmitted during cell division and reproduction.

There are several different types of DNA repair enzymes, each responsible for correcting specific types of damage. For example, base excision repair enzymes remove and replace damaged or incorrect bases, while nucleotide excision repair enzymes remove larger sections of damaged DNA and replace them with new nucleotides. Other types of DNA repair enzymes include mismatch repair enzymes, which correct errors that occur during DNA replication, and double-strand break repair enzymes, which are responsible for fixing breaks in both strands of the DNA molecule.

Defects in DNA repair enzymes have been linked to a variety of diseases, including cancer, neurological disorders, and premature aging. For example, individuals with xeroderma pigmentosum, a rare genetic disorder characterized by an increased risk of skin cancer, have mutations in genes that encode nucleotide excision repair enzymes. Similarly, defects in mismatch repair enzymes have been linked to hereditary nonpolyposis colorectal cancer, a type of colon cancer that is inherited and tends to occur at a younger age than sporadic colon cancer.

Overall, DNA repair enzymes play a critical role in maintaining the stability and integrity of an organism's genetic material, and defects in these enzymes can have serious consequences for human health.

A "cell line, transformed" is a type of cell culture that has undergone a stable genetic alteration, which confers the ability to grow indefinitely in vitro, outside of the organism from which it was derived. These cells have typically been immortalized through exposure to chemical or viral carcinogens, or by introducing specific oncogenes that disrupt normal cell growth regulation pathways.

Transformed cell lines are widely used in scientific research because they offer a consistent and renewable source of biological material for experimentation. They can be used to study various aspects of cell biology, including signal transduction, gene expression, drug discovery, and toxicity testing. However, it is important to note that transformed cells may not always behave identically to their normal counterparts, and results obtained using these cells should be validated in more physiologically relevant systems when possible.

Dwarfism is a medical condition that is characterized by short stature, typically with an adult height of 4 feet 10 inches (147 centimeters) or less. It is caused by a variety of genetic and medical conditions that affect bone growth, including skeletal dysplasias, hormonal deficiencies, and chromosomal abnormalities.

Skeletal dysplasias are the most common cause of dwarfism and are characterized by abnormalities in the development and growth of bones and cartilage. Achondroplasia is the most common form of skeletal dysplasia, accounting for about 70% of all cases of dwarfism. It is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene and results in short limbs, a large head, and a prominent forehead.

Hormonal deficiencies, such as growth hormone deficiency or hypothyroidism, can also cause dwarfism if they are not diagnosed and treated early. Chromosomal abnormalities, such as Turner syndrome (monosomy X) or Down syndrome (trisomy 21), can also result in short stature and other features of dwarfism.

It is important to note that people with dwarfism are not "dwarves" - the term "dwarf" is a medical and sociological term used to describe individuals with this condition, while "dwarves" is a term often used in fantasy literature and media to refer to mythical beings. The use of the term "dwarf" can be considered disrespectful or offensive to some people with dwarfism, so it is important to use respectful language when referring to individuals with this condition.

Ataxia telangiectasia is a rare, inherited genetic disorder that affects the nervous system, immune system, and overall development. The condition is characterized by progressive difficulty with coordination and balance (ataxia), as well as the development of small, dilated blood vessels (telangiectasias) on the skin and eyes.

The underlying cause of ataxia telangiectasia is a mutation in the ATM gene, which provides instructions for making a protein that plays a critical role in DNA repair and maintaining genetic stability. When this gene is mutated, cells are unable to properly repair damaged DNA, leading to an increased risk of cancer and other health problems.

Individuals with ataxia telangiectasia typically begin to show symptoms during early childhood, with progressive difficulties in coordination and balance, slurred speech, and recurrent respiratory infections due to weakened immune function. Over time, these symptoms can worsen, leading to significant disability and reduced life expectancy.

There is currently no cure for ataxia telangiectasia, and treatment is focused on managing the symptoms and complications of the condition. This may include physical therapy, speech therapy, and medications to help control infections and other health problems.

"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.

In medical terms, the skin is the largest organ of the human body. It consists of two main layers: the epidermis (outer layer) and dermis (inner layer), as well as accessory structures like hair follicles, sweat glands, and oil glands. The skin plays a crucial role in protecting us from external factors such as bacteria, viruses, and environmental hazards, while also regulating body temperature and enabling the sense of touch.

Apurinic acid, also known as apurinic/apyrimidinic (AP) site, is a type of damage that can occur in DNA molecules. It is the result of the loss of a purine base, such as adenine or guanine, from the DNA backbone. This type of damage can be caused by various factors, including oxidative stress and exposure to certain chemicals or radiation.

Apurinic acid sites are biochemically unstable and can lead to further damage in the DNA molecule if not repaired. The body has several mechanisms for repairing apurinic acid sites, including the base excision repair pathway. If left unrepaired, apurinic acid sites can lead to mutations and contribute to the development of various diseases, including cancer.

Melanosis is a general term that refers to an increased deposit of melanin, the pigment responsible for coloring our skin, in the skin or other organs. It can occur in response to various factors such as sun exposure, aging, or certain medical conditions. There are several types of melanosis, including:

1. Epidermal melanosis: This type of melanosis is characterized by an increase in melanin within the epidermis, the outermost layer of the skin. It can result from sun exposure, hormonal changes, or inflammation.
2. Dermal melanosis: In this type of melanosis, there is an accumulation of melanin within the dermis, the middle layer of the skin. It can be caused by various conditions such as nevus of Ota, nevus of Ito, or melanoma metastasis.
3. Mucosal melanosis: This type of melanosis involves an increase in melanin within the mucous membranes, such as those lining the mouth, nose, and genitals. It can be a sign of systemic disorders like Addison's disease or Peutz-Jeghers syndrome.
4. Lentigo simplex: Also known as simple lentigines, these are small, benign spots that appear on sun-exposed skin. They result from an increase in melanocytes, the cells responsible for producing melanin.
5. Labial melanotic macule: This is a pigmented lesion found on the lips, typically the lower lip. It is more common in darker-skinned individuals and is usually benign but should be monitored for changes that may indicate malignancy.
6. Ocular melanosis: An increase in melanin within the eye can lead to various conditions such as ocular melanocytosis, oculodermal melanocytosis, or choroidal melanoma.

It is important to note that while some forms of melanosis are benign and harmless, others may indicate an underlying medical condition or even malignancy. Therefore, any new or changing pigmented lesions should be evaluated by a healthcare professional.

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.

Radiation genetics is a field of study that focuses on the effects of ionizing radiation on genetic material, including DNA and chromosomes. It examines how exposure to radiation can cause mutations in genes and chromosomes, which can then be passed down from one generation to the next. This field of study is important for understanding the potential health risks associated with exposure to ionizing radiation, such as those experienced by nuclear industry workers, medical professionals who use radiation in their practice, and people living near nuclear power plants or waste disposal sites. It also has applications in cancer treatment, where radiation is used to kill cancer cells but can also cause genetic damage.

Uveal diseases refer to a group of medical conditions that affect the uvea, which is the middle layer of the eye located between the sclera (the white of the eye) and the retina (the light-sensitive tissue at the back of the eye). The uvea consists of the iris (the colored part of the eye), the ciliary body (which controls the lens), and the choroid (a layer of blood vessels that provides nutrients to the retina).

Uveal diseases can cause inflammation, damage, or tumors in the uvea, leading to symptoms such as eye pain, redness, light sensitivity, blurred vision, and floaters. Some common uveal diseases include uveitis (inflammation of the uvea), choroidal melanoma (a type of eye cancer that affects the choroid), and iris nevus (a benign growth on the iris). Treatment for uveal diseases depends on the specific condition and may include medications, surgery, or radiation therapy.

Genetic skin diseases are a group of disorders caused by mutations or alterations in the genetic material (DNA), which can be inherited from one or both parents. These mutations affect the structure, function, or development of the skin and can lead to various conditions with different symptoms, severity, and prognosis.

Some examples of genetic skin diseases include:

1. Epidermolysis Bullosa (EB): A group of disorders characterized by fragile skin and mucous membranes that blister and tear easily, leading to painful sores and wounds. There are several types of EB, each caused by mutations in different genes involved in anchoring the epidermis to the dermis.
2. Ichthyosis: A family of genetic disorders characterized by dry, thickened, scaly, or rough skin. The severity and symptoms can vary widely, depending on the specific type and underlying genetic cause.
3. Neurofibromatosis: A group of conditions caused by mutations in the NF1 gene, which regulates cell growth and division. The most common types, NF1 and NF2, are characterized by the development of benign tumors called neurofibromas on the skin and nerves, as well as other symptoms affecting various organs and systems.
4. Tuberous Sclerosis Complex (TSC): A genetic disorder caused by mutations in the TSC1 or TSC2 genes, which control cell growth and division. TSC is characterized by the development of benign tumors in multiple organs, including the skin, brain, heart, kidneys, and lungs.
5. Xeroderma Pigmentosum (XP): A rare genetic disorder caused by mutations in genes responsible for repairing DNA damage from ultraviolet (UV) radiation. People with XP are extremely sensitive to sunlight and have a high risk of developing skin cancer and other complications.
6. Incontinentia Pigmenti (IP): A genetic disorder that affects the development and growth of skin, hair, nails, teeth, and eyes. IP is caused by mutations in the IKBKG gene and primarily affects females.
7. Darier's Disease: An inherited skin disorder characterized by greasy, crusted, keratotic papules and plaques, usually located on the trunk, scalp, and seborrheic areas of the body. Darier's disease is caused by mutations in the ATP2A2 gene.

These are just a few examples of genetic skin disorders. There are many more, each with its unique set of symptoms, causes, and treatments. If you or someone you know has a genetic skin disorder, it is essential to consult with a dermatologist or other healthcare professional for proper diagnosis and treatment.

Heredodegenerative disorders of the nervous system are a group of inherited conditions that involve progressive degeneration of the nervous system over time. These disorders are caused by genetic mutations that affect the development and function of nerve cells in the brain and spinal cord. The symptoms and severity of these disorders can vary widely, depending on the specific condition and the location and extent of nerve cell damage.

Examples of heredodegenerative disorders of the nervous system include:

1. Huntington's disease: a genetic disorder that causes the progressive breakdown of nerve cells in the brain, leading to uncontrolled movements, emotional problems, and cognitive decline.
2. Friedreich's ataxia: an inherited disorder that affects the nerves and muscle coordination, causing symptoms such as difficulty walking, poor balance, and speech problems.
3. Spinal muscular atrophy: a genetic disorder that affects the motor neurons in the spinal cord, leading to muscle weakness and wasting.
4. Hereditary sensory and autonomic neuropathies: a group of inherited disorders that affect the nerves that control sensation and automatic functions such as heart rate and digestion.
5. Leukodystrophies: a group of genetic disorders that affect the white matter of the brain, leading to symptoms such as motor and cognitive decline, seizures, and vision loss.

Treatment for heredodegenerative disorders of the nervous system typically focuses on managing symptoms and improving quality of life. There is no cure for most of these conditions, but research is ongoing to develop new treatments and therapies that may help slow or stop the progression of nerve cell damage.

Radiation-induced neoplasms are a type of cancer or tumor that develops as a result of exposure to ionizing radiation. Ionizing radiation is radiation with enough energy to remove tightly bound electrons from atoms or molecules, leading to the formation of ions. This type of radiation can damage DNA and other cellular structures, which can lead to mutations and uncontrolled cell growth, resulting in the development of a neoplasm.

Radiation-induced neoplasms can occur after exposure to high levels of ionizing radiation, such as that received during radiation therapy for cancer treatment or from nuclear accidents. The risk of developing a radiation-induced neoplasm depends on several factors, including the dose and duration of radiation exposure, the type of radiation, and the individual's genetic susceptibility to radiation-induced damage.

Radiation-induced neoplasms can take many years to develop after initial exposure to ionizing radiation, and they often occur at the site of previous radiation therapy. Common types of radiation-induced neoplasms include sarcomas, carcinomas, and thyroid cancer. It is important to note that while ionizing radiation can increase the risk of developing cancer, the overall risk is still relatively low, especially when compared to other well-established cancer risk factors such as smoking and exposure to certain chemicals.

HeLa cells are a type of immortalized cell line used in scientific research. They are derived from a cancer that developed in the cervical tissue of Henrietta Lacks, an African-American woman, in 1951. After her death, cells taken from her tumor were found to be capable of continuous division and growth in a laboratory setting, making them an invaluable resource for medical research.

HeLa cells have been used in a wide range of scientific studies, including research on cancer, viruses, genetics, and drug development. They were the first human cell line to be successfully cloned and are able to grow rapidly in culture, doubling their population every 20-24 hours. This has made them an essential tool for many areas of biomedical research.

It is important to note that while HeLa cells have been instrumental in numerous scientific breakthroughs, the story of their origin raises ethical questions about informed consent and the use of human tissue in research.

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.

Sunburn is a cutaneous condition characterized by redness, pain, and sometimes swelling of the skin caused by overexposure to ultraviolet (UV) radiation from the sun or other sources such as tanning beds. The skin may also blister and peel in severe cases. Sunburn is essentially a burn to the skin that can have both immediate and long-term consequences, including increased aging of the skin and an increased risk of skin cancer. It is important to protect the skin from excessive sun exposure by using sunscreen, wearing protective clothing, and seeking shade during peak sunlight hours.

Replication Protein A (RPA) is a single-stranded DNA binding protein complex that plays a crucial role in the process of DNA replication, repair, and recombination. In eukaryotic cells, RPA is composed of three subunits: RPA70, RPA32, and RPA14. The primary function of RPA is to coat single-stranded DNA (ssDNA) generated during these processes, protecting it from degradation, preventing the formation of secondary structures, and promoting the recruitment of other proteins involved in DNA metabolism.

RPA binds ssDNA with high affinity and specificity, forming a stable complex that protects the DNA from nucleases, chemical modifications, and other damaging agents. The protein also participates in the regulation of various enzymatic activities, such as helicase loading and activation, end processing, and polymerase processivity.

During DNA replication, RPA is essential for the initiation and elongation phases. It facilitates the assembly of the pre-replicative complex (pre-RC) at origins of replication, aids in the recruitment and activation of helicases, and promotes the switch from MCM2-7 helicase to polymerase processivity during DNA synthesis.

In addition to its role in DNA replication, RPA is involved in various DNA repair pathways, including nucleotide excision repair (NER), base excision repair (BER), mismatch repair (MMR), and double-strand break repair (DSBR). It also plays a critical role in meiotic recombination during sexual reproduction.

In summary, Replication Protein A (RPA) is a eukaryotic single-stranded DNA binding protein complex that protects, stabilizes, and regulates ssDNA during DNA replication, repair, and recombination processes.

Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.

Ichthyosis is a group of skin disorders that are characterized by dry, thickened, scaly skin. The name "ichthyosis" comes from the Greek word "ichthys," which means fish, as the skin can have a fish-like scale appearance. These conditions can be inherited or acquired and vary in severity.

The medical definition of ichthyosis is a heterogeneous group of genetic keratinization disorders that result in dry, thickened, and scaly skin. The condition may affect any part of the body, but it most commonly appears on the extremities, scalp, and trunk. Ichthyosis can also have associated symptoms such as redness, itching, and blistering.

The severity of ichthyosis can range from mild to severe, and some forms of the condition may be life-threatening in infancy. The exact symptoms and their severity depend on the specific type of ichthyosis a person has. Treatment for ichthyosis typically involves moisturizing the skin, avoiding irritants, and using medications to help control scaling and inflammation.

Northern Africa is a geographical region that broadly consists of the countries of the African Transverse, which are Algeria, Libya, Egypt, Tunisia, Morocco, and Western Sahara. Sometimes, it may also include Sudan, South Sudan, and Mauritania. This region is characterized by its proximity to the Mediterranean Sea and the Atlas Mountains, as well as its unique cultural and historical heritage. Northern Africa has a diverse climate, with a hot, dry desert climate in the interior and a milder, wetter climate along the coasts. The major languages spoken in this region include Arabic, Berber, and French.

Cell survival refers to the ability of a cell to continue living and functioning normally, despite being exposed to potentially harmful conditions or treatments. This can include exposure to toxins, radiation, chemotherapeutic drugs, or other stressors that can damage cells or interfere with their normal processes.

In scientific research, measures of cell survival are often used to evaluate the effectiveness of various therapies or treatments. For example, researchers may expose cells to a particular drug or treatment and then measure the percentage of cells that survive to assess its potential therapeutic value. Similarly, in toxicology studies, measures of cell survival can help to determine the safety of various chemicals or substances.

It's important to note that cell survival is not the same as cell proliferation, which refers to the ability of cells to divide and multiply. While some treatments may promote cell survival, they may also inhibit cell proliferation, making them useful for treating diseases such as cancer. Conversely, other treatments may be designed to specifically target and kill cancer cells, even if it means sacrificing some healthy cells in the process.

A heterozygote is an individual who has inherited two different alleles (versions) of a particular gene, one from each parent. This means that the individual's genotype for that gene contains both a dominant and a recessive allele. The dominant allele will be expressed phenotypically (outwardly visible), while the recessive allele may or may not have any effect on the individual's observable traits, depending on the specific gene and its function. Heterozygotes are often represented as 'Aa', where 'A' is the dominant allele and 'a' is the recessive allele.

Radiation tolerance, in the context of medicine and particularly radiation oncology, refers to the ability of tissues or organs to withstand and recover from exposure to ionizing radiation without experiencing significant damage or loss of function. It is often used to describe the maximum dose of radiation that can be safely delivered to a specific area of the body during radiotherapy treatments.

Radiation tolerance varies depending on the type and location of the tissue or organ. For example, some tissues such as the brain, spinal cord, and lungs have lower radiation tolerance than others like the skin or bone. Factors that can affect radiation tolerance include the total dose of radiation, the fractionation schedule (the number and size of radiation doses), the volume of tissue treated, and the individual patient's overall health and genetic factors.

Assessing radiation tolerance is critical in designing safe and effective radiotherapy plans for cancer patients, as excessive radiation exposure can lead to serious side effects such as radiation-induced injury, fibrosis, or even secondary malignancies.

Radiation effects refer to the damages that occur in living tissues when exposed to ionizing radiation. These effects can be categorized into two types: deterministic and stochastic. Deterministic effects have a threshold dose below which the effect does not occur, and above which the severity of the effect increases with the dose. Examples include radiation-induced erythema, epilation, and organ damage. Stochastic effects, on the other hand, do not have a threshold dose, and the probability of the effect occurring increases with the dose. Examples include genetic mutations and cancer induction. The severity of the effect is not related to the dose in this case.

Simian Virus 40 (SV40) is a polyomavirus that is found in both monkeys and humans. It is a DNA virus that has been extensively studied in laboratory settings due to its ability to transform cells and cause tumors in animals. In fact, SV40 was discovered as a contaminant of poliovirus vaccines that were prepared using rhesus monkey kidney cells in the 1950s and 1960s.

SV40 is not typically associated with human disease, but there has been some concern that exposure to the virus through contaminated vaccines or other means could increase the risk of certain types of cancer, such as mesothelioma and brain tumors. However, most studies have failed to find a consistent link between SV40 infection and cancer in humans.

The medical community generally agrees that SV40 is not a significant public health threat, but researchers continue to study the virus to better understand its biology and potential impact on human health.

Progeria, also known as Hutchinson-Gilford Progeria Syndrome (HGPS), is a rare and fatal genetic condition characterized by the rapid aging of children. The term "progeria" comes from the Greek words "pro," meaning prematurely, and "gereas," meaning old age.

Individuals with progeria typically appear normal at birth but begin to display signs of accelerated aging within the first two years of life. These symptoms can include growth failure, loss of body fat and hair, aged-looking skin, joint stiffness, hip dislocation, and cardiovascular disease. The most common cause of death in progeria patients is heart attack or stroke due to widespread atherosclerosis (the hardening and narrowing of the arteries).

Progeria is caused by a mutation in the LMNA gene, which provides instructions for making a protein called lamin A. This protein is essential for the structure and function of the nuclear envelope, the membrane that surrounds the cell's nucleus. The mutation leads to the production of an abnormal form of lamin A called progerin, which accumulates in cells throughout the body, causing premature aging.

There is currently no cure for progeria, and treatment is focused on managing symptoms and complications. Researchers are actively studying potential treatments that could slow or reverse the effects of the disease.

A gene suppressor, also known as a tumor suppressor gene, is a type of gene that regulates cell growth and division by producing proteins to prevent uncontrolled cell proliferation. When these genes are mutated or deleted, they can lose their ability to regulate cell growth, leading to the development of cancer.

Tumor suppressor genes work to repair damaged DNA, regulate the cell cycle, and promote programmed cell death (apoptosis) when necessary. Some examples of tumor suppressor genes include TP53, BRCA1, and BRCA2. Mutations in these genes have been linked to an increased risk of developing various types of cancer, such as breast, ovarian, and colon cancer.

In contrast to oncogenes, which promote cell growth and division when mutated, tumor suppressor genes typically act to inhibit or slow down cell growth and division. Both types of genes play crucial roles in maintaining the proper functioning of cells and preventing the development of cancer.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

DNA adducts are chemical modifications or alterations that occur when DNA molecules become attached to or bound with certain harmful substances, such as toxic chemicals or carcinogens. These attachments can disrupt the normal structure and function of the DNA, potentially leading to mutations, genetic damage, and an increased risk of cancer and other diseases.

DNA adducts are formed when a reactive molecule from a chemical agent binds covalently to a base in the DNA molecule. This process can occur either spontaneously or as a result of exposure to environmental toxins, such as those found in tobacco smoke, certain industrial chemicals, and some medications.

The formation of DNA adducts is often used as a biomarker for exposure to harmful substances, as well as an indicator of potential health risks associated with that exposure. Researchers can measure the levels of specific DNA adducts in biological samples, such as blood or urine, to assess the extent and duration of exposure to certain chemicals or toxins.

It's important to note that not all DNA adducts are necessarily harmful, and some may even play a role in normal cellular processes. However, high levels of certain DNA adducts have been linked to an increased risk of cancer and other diseases, making them a focus of ongoing research and investigation.

Cell extracts refer to the mixture of cellular components that result from disrupting or breaking open cells. The process of obtaining cell extracts is called cell lysis. Cell extracts can contain various types of molecules, such as proteins, nucleic acids (DNA and RNA), carbohydrates, lipids, and metabolites, depending on the methods used for cell disruption and extraction.

Cell extracts are widely used in biochemical and molecular biology research to study various cellular processes and pathways. For example, cell extracts can be used to measure enzyme activities, analyze protein-protein interactions, characterize gene expression patterns, and investigate metabolic pathways. In some cases, specific cellular components can be purified from the cell extracts for further analysis or application, such as isolating pure proteins or nucleic acids.

It is important to note that the composition of cell extracts may vary depending on the type of cells, the growth conditions, and the methods used for cell disruption and extraction. Therefore, it is essential to optimize the experimental conditions to obtain representative and meaningful results from cell extract studies.

Endodeoxyribonucleases are a type of enzyme that cleave, or cut, phosphodiester bonds within the backbone of DNA molecules. These enzymes are also known as restriction endonucleases or simply restriction enzymes. They are called "restriction" enzymes because they were first discovered in bacteria, where they function to protect the organism from foreign DNA by cleaving and destroying invading viral DNA.

Endodeoxyribonucleases recognize specific sequences of nucleotides within the DNA molecule, known as recognition sites or restriction sites, and cut the phosphodiester bonds at specific locations within these sites. The cuts made by endodeoxyribonucleases can be either "sticky" or "blunt," depending on whether the enzyme leaves single-stranded overhangs or creates blunt ends at the site of cleavage, respectively.

Endodeoxyribonucleases are widely used in molecular biology research for various applications, including DNA cloning, genome mapping, and genetic engineering. They allow researchers to cut DNA molecules at specific sites, creating defined fragments that can be manipulated and recombined in a variety of ways.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

Mutagenesis is the process by which the genetic material (DNA or RNA) of an organism is changed in a way that can alter its phenotype, or observable traits. These changes, known as mutations, can be caused by various factors such as chemicals, radiation, or viruses. Some mutations may have no effect on the organism, while others can cause harm, including diseases and cancer. Mutagenesis is a crucial area of study in genetics and molecular biology, with implications for understanding evolution, genetic disorders, and the development of new medical treatments.

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.

A frameshift mutation is a type of genetic mutation that occurs when the addition or deletion of nucleotides in a DNA sequence is not divisible by three. Since DNA is read in groups of three nucleotides (codons), which each specify an amino acid, this can shift the "reading frame," leading to the insertion or deletion of one or more amino acids in the resulting protein. This can cause a protein to be significantly different from the normal protein, often resulting in a nonfunctional protein and potentially causing disease. Frameshift mutations are typically caused by insertions or deletions of nucleotides, but they can also result from more complex genetic rearrangements.

I'm sorry for any confusion, but "sunlight" is not a term with a specific medical definition. However, sunlight does have various implications in the field of medicine. It is the light that comes from the sun, which is a star at the center of our solar system. Sunlight is essential for the production of vitamin D in humans, and it can also have effects on mood and sleep patterns due to its influence on circadian rhythms.

In a medical context, sunlight is often discussed in relation to its potential health benefits and risks. For instance, moderate sun exposure can help increase vitamin D levels, which are important for bone health, immune function, and other bodily processes. However, excessive sun exposure can lead to harmful effects, such as sunburn, premature skin aging, and an increased risk of skin cancer.

It's essential to balance the benefits and risks of sunlight exposure by practicing safe sun habits, such as wearing protective clothing, using a broad-spectrum sunscreen with an SPF of at least 30, seeking shade during peak sunlight hours, and avoiding intentional tanning.

p53 is a tumor suppressor gene that encodes a protein responsible for controlling cell growth and division. The p53 protein plays a crucial role in preventing the development of cancer by regulating the cell cycle and activating DNA repair processes when genetic damage is detected. If the damage is too severe to be repaired, p53 can trigger apoptosis, or programmed cell death, to prevent the propagation of potentially cancerous cells. Mutations in the TP53 gene, which encodes the p53 protein, are among the most common genetic alterations found in human cancers and are often associated with a poor prognosis.

... was first described in the 1870s by Moritz Kaposi. In 1882, Kaposi coined the term xeroderma pigmentosum ... "Xeroderma Pigmentosum". NORD (National Organization for Rare Disorders). 2017. Retrieved 28 June 2018. "Xeroderma pigmentosum ... Xeroderma pigmentosum was first described in 1874 by Hebra and Moritz Kaposi. In 1882, Kaposi coined the term xeroderma ... "Xeroderma pigmentosum". Genetics Home Reference. U.S. Library of Medicine. 26 June 2018. Retrieved 28 June 2018. "Xeroderma ...
... some genetic mutations that cause xeroderma pigmentosum are associated with neurodegeneration. Xeroderma pigmentosum may be ... Xeroderma pigmentosum may be associated with other internal cancers and benign tumors.[citation needed] In addition to cancer, ... Xeroderma pigmentosum is an autosomal recessive disorder characterized by sensitivity to ultra-violet (UV) light, massively ... Niedernhofer LJ, Bohr VA, Sander M, Kraemer KH (2011). "Xeroderma pigmentosum and other diseases of human premature aging and ...
Kraemer KH, DiGiovanna JJ (1993). "Xeroderma Pigmentosum". In Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJ, Stephens K, ... Certain genetic conditions, for example, xeroderma pigmentosum, increase a person's susceptibility to sunburn and subsequent ...
Xeroderma pigmentosum, which is commonly known as XP, is an inherited condition characterized by an extreme sensitivity to ... "xeroderma pigmentosum". Genetics Home Reference. Retrieved 2017-05-15. "ataxia-telangiectasia". Genetics Home Reference. ...
A deficiency of excinuclease occurs in a rare autosomal recessive disease called xeroderma pigmentosum. This disease can cause ... ISBN 978-1-4641-2610-9. "Xeroderma pigmentosum". Genetics Home Reference. U.S. Library of Medicine. May 2010. Retrieved 11 ...
Tian M, Jones DA, Smith M, Shinkura R, Alt FW (2004). "Deficiency in the nuclease activity of xeroderma pigmentosum G in mice ... Lehmann AR, McGibbon D, Stefanini M (2011). "Xeroderma pigmentosum". Orphanet J Rare Dis. 6: 70. doi:10.1186/1750-1172-6-70. ... "Correlation of phenotype/genotype in a cohort of 23 xeroderma pigmentosum-variant patients reveals 12 new disease-causing POLH ... Rothmund-Thomson syndrome and xeroderma pigmentosum display symptoms dominated by vulnerability to cancer, whereas progeria and ...
Risk is also elevated in certain genetic skin disorders, such as xeroderma pigmentosum and certain forms of epidermolysis ... Lehmann AR, McGibbon D, Stefanini M (November 2011). "Xeroderma pigmentosum". Orphanet Journal of Rare Diseases. 6 (1): 70. doi ...
This condition can occur alongside xeroderma pigmentosum, resulting in xeroderma pigmentosum-cockayne syndrome (XP-CS). OGG1 ... Xeroderma pigmentosum or XP is a rare genetic disorder that occurs worldwide. On affected people, exposure to UV radiation, ... Xeroderma Pigmentosum Study Group". Lancet. 357 (9260): 926-9. doi:10.1016/s0140-6736(00)04214-8. PMID 11289350. S2CID 54406695 ... However without this repair, conditions such as UV-sensitive syndrome, xeroderma pigmentosum, and Cockayne syndrome may arise. ...
XDH Xeroderma pigmentosum group A; 278700; XPA Xeroderma pigmentosum group B; 610651; ERCC3 Xeroderma pigmentosum group C; ... DDB2 Xeroderma pigmentosum group F; 278760; ERCC4 Xeroderma pigmentosum group G; 278780; ERCC5 Xeroderma pigmentosum, variant ... 278720; XPC Xeroderma pigmentosum group D; 278730; ERCC2 Xeroderma pigmentosum group E, DDB-negative subtype; 278740; ... RP2 Retinitis pigmentosa-25; 602772; EYS Retinitis pigmentosa-26; 608380; CERKL Retinitis pigmentosa-3; 300029; RPGR Retinitis ...
He suffers from Xeroderma pigmentosum. Cecelia Pike/Lia Beaumont: A suicidal woman featured in the present-day as well as in ...
Eczema Ichthyosis Xeroderma pigmentosum Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume ... Xeroderma can be caused by choline inhibitors. Detergents such as washing powder and dishwashing liquid can cause xeroderma. ... Bathing or hand washing too frequently, especially if one is using harsh soaps, can contribute to xeroderma. Xeroderma can be ... Xeroderma occurs most commonly on the scalp, lower legs, arms, hands, knuckles, the sides of the abdomen, and thighs. Symptoms ...
"Entrez Gene: XPA xeroderma pigmentosum, complementation group A". Sugitani N, Sivley RM, Perry KE, Capra JA, Chazin WJ (2016 ... Molecular analysis of xeroderma pigmentosum group A gene". The Japanese Journal of Human Genetics. 38 (1): 1-14. doi:10.1007/ ... Satokata I, Tanaka K, Okada Y (Mar 1992). "Molecular basis of group A xeroderma pigmentosum: a missense mutation and two ... Xpa mutant individuals often show the severe clinical symptoms of xeroderma pigmentosum, a condition involving extreme ...
Xeroderma pigmentosum (XP) is a human autosomal recessive disease, characterised by a high incidence of sunlight-induced skin ... Tanaka K, Wood RD (February 1994). "Xeroderma pigmentosum and nucleotide excision repair of DNA". Trends Biochem. Sci. 19 (2): ...
An example of such a hereditary cancer syndrome is xeroderma pigmentosum, which causes the development of skin cancers in ... Cleaver JE (May 1968). "Defective repair replication of DNA in xeroderma pigmentosum". Nature. 218 (5142): 652-656. Bibcode: ...
Members 1 though 5 are associated with Xeroderma Pigmentosum. Members 6 and 8 are associated with Cockayne syndrome. Wolfram ...
This gene is implicated in the xeroderma pigmentosum disorder. There are two alternatively spliced transcript variants of this ... "Defective interplay of activators and repressors with TFIH in xeroderma pigmentosum". Cell. 104 (3): 353-63. doi:10.1016/S0092- ...
Johnson RE, Kondratick CM, Prakash S, Prakash L (July 1999). "hRAD30 mutations in the variant form of xeroderma pigmentosum". ... Itoh T, Linn S, Kamide R, Tokushige H, Katori N, Hosaka Y, Yamaizumi M (2000). "Xeroderma pigmentosum variant heterozygotes ... GeneReviews/NIH/NCBI/UW entry on Xeroderma Pigmentosum This article incorporates text from the United States National Library ... Johnson RE, Kondratick CM, Prakash S, Prakash L (1999). "hRAD30 mutations in the variant form of xeroderma pigmentosum". ...
Chu G, Chang E (1988). "Xeroderma pigmentosum group E cells lack a nuclear factor that binds to damaged DNA". Science. 242 ( ... 1994). "Correction of the DNA repair defect in xeroderma pigmentosum group E by injection of a DNA damage-binding protein" (PDF ... Nichols AF, Ong P, Linn S (1996). "Mutations specific to the xeroderma pigmentosum group E Ddb- phenotype". J. Biol. Chem. 271 ... Keeney S, Chang GJ, Linn S (1993). "Characterization of a human DNA damage binding protein implicated in xeroderma pigmentosum ...
Samec S, Jones TA, Corlet J, Scherly D, Sheer D, Wood RD, Clarkson SG (May 1994). "The human gene for xeroderma pigmentosum ... Mutational defects in the Ercc5(Xpg) gene can cause either the cancer-prone condition xeroderma pigmentosum (XP) alone, or in ... O'Donovan A, Wood RD (May 1993). "Identical defects in DNA repair in xeroderma pigmentosum group G and rodent ERCC group 5". ... Nouspikel T, Clarkson SG (June 1994). "Mutations that disable the DNA repair gene XPG in a xeroderma pigmentosum group G ...
Sclérodermie, névromes plexiformes, lupus verruqueux, acné hypertrophique, xeroderma pigmentosum, impr. de G. Gounouilhou ( ...
"Entrez Gene: XPC xeroderma pigmentosum, complementation group C". "OMIM Entry - # 278720 - XERODERMA PIGMENTOSUM, ... Xeroderma pigmentosum, complementation group C, also known as XPC, is a protein which in humans is encoded by the XPC gene. XPC ... Legerski RJ, Liu P, Li L, Peterson CA, Zhao Y, Leach RJ, Naylor SL, Siciliano MJ (1994). "Assignment of xeroderma pigmentosum ... Yokoi M, Masutani C, Maekawa T, Sugasawa K, Ohkuma Y, Hanaoka F (2000). "The xeroderma pigmentosum group C protein complex XPC- ...
Tan T, Chu G (May 2002). "p53 Binds and activates the xeroderma pigmentosum DDB2 gene in humans but not mice". Molecular and ... Nichols AF, Ong P, Linn S (October 1996). "Mutations specific to the xeroderma pigmentosum group E Ddb- phenotype". The Journal ... Wittschieben BØ, Iwai S, Wood RD (December 2005). "DDB1-DDB2 (xeroderma pigmentosum group E) protein complex recognizes a ... GeneReviews/NIH/NCBI/UW entry on Xeroderma Pigmentosum (Articles with short description, Short description matches Wikidata, ...
Hengge, UR; Emmert, S (2009). "Clinical Features of Xeroderma Pigmentosum". Molecular Mechanisms of Xeroderma Pigmentosum. ... xeroderma pigmentosum (XP), trichothiodystrophy (TTD), combined xeroderma pigmentosum-Cockayne syndrome (XP-CS), restrictive ... a 16-year-old girl has xeroderma pigmentosum. DeSanctis-Cacchione syndrome, an extremely rare variant of xeroderma pigmentosum ... Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder, affecting about one per million in the United States and ...
Xeroderma pigmentosum List of cutaneous conditions RESERVED, INSERM US14-- ALL RIGHTS. "Orphanet: De Sanctis Cacchione syndrome ... DeSanctis-Cacchione syndrome is a genetic disorder characterized by the skin and eye symptoms of xeroderma pigmentosum (XP) ... mutations in the CSB gene associated with either Cockayne syndrome or the de Sanctis-Cacchione variant of xeroderma pigmentosum ... mutations in the CSB gene associated with either Cockayne syndrome or the DeSanctis-cacchione variant of xeroderma pigmentosum ...
He set up research into genetic disorders, especially xeroderma pigmentosum (XP). For this research Bootsma used human cells, ...
Examples of such genetic disorders include xeroderma pigmentosum and Bloom syndrome. Balding: AKs are commonly found on the ...
... xeroderma pigmentosum, and epidermolysis bullosa. Recently, it was shown that TALEN can be used as tools to harness the immune ... "Targeted gene therapy of xeroderma pigmentosum cells using meganuclease and TALEN™". PLOS ONE. 8 (11): e78678. Bibcode: ...
... is a summer camp for children with xeroderma pigmentosum. All activities are held after sundown, to ensure that ...
February 2001). "Defective interplay of activators and repressors with TFIH in xeroderma pigmentosum". Cell. 104 (3): 353-363. ...
June 1999). "The XPV (xeroderma pigmentosum variant) gene encodes human DNA polymerase eta". Nature. 399 (6737): 700-4. Bibcode ...
Xeroderma pigmentosum was first described in the 1870s by Moritz Kaposi. In 1882, Kaposi coined the term xeroderma pigmentosum ... "Xeroderma Pigmentosum". NORD (National Organization for Rare Disorders). 2017. Retrieved 28 June 2018. "Xeroderma pigmentosum ... Xeroderma pigmentosum was first described in 1874 by Hebra and Moritz Kaposi. In 1882, Kaposi coined the term xeroderma ... "Xeroderma pigmentosum". Genetics Home Reference. U.S. Library of Medicine. 26 June 2018. Retrieved 28 June 2018. "Xeroderma ...
Xeroderma pigmentosum (XP) is a rare condition passed down through families. XP causes the skin and tissue covering the eye to ... Xeroderma pigmentosum (XP) is a rare condition passed down through families. XP causes the skin and tissue covering the eye to ... National Organization for Rare Disorders - rarediseases.org/rare-diseases/xeroderma-pigmentosum/. *Xeroderma Pigmentosum ... Xeroderma pigmentosum (XP) is a rare condition passed down through families. XP causes the skin and tissue covering the eye to ...
Xeroderma Pigmentosum (XP) is a photosensitive condition characterized by high susceptibility to skin cancers. This article ... Xeroderma pigmentosum clinical practice guidelines revision committee (2017). Xeroderma pigmentosum clinical practice ... What is Xeroderma Pigmentosum?. News-Medical. https://www.news-medical.net/health/What-is-Xeroderma-Pigmentosum.aspx. ( ... Image Credit: Xeroderma Pigmentosum/Shutterstock. History. Dermatologist Moriz Kaposi originally reported XP in 1874 after ...
In 1882, Kaposi coined the term xeroderma pigmentosum for the condition, referring to its characteristic dry, pigmented skin. ... Xeroderma pigmentosum (XP) was first described in 1874 by Hebra and Kaposi. ... encoded search term (Xeroderma Pigmentosum) and Xeroderma Pigmentosum What to Read Next on Medscape ... Xeroderma pigmentosum (XP) was first described in 1874 by Hebra and Kaposi. In 1882, Kaposi coined the term xeroderma ...
Xeroderma pigmentosum (XP) is a hereditary condition characterized by extreme sun sensitivity, leading to a very high risk of ... What is xeroderma pigmentosum?. Xeroderma pigmentosum (XP) is a hereditary condition characterized by extreme sun sensitivity, ... Xeroderma Pigmentosum Society. American Academy of Dermatology. National Organization for Rare Disorders. To find a genetic ...
Xeroderma pigmentosum. Disease definition Xeroderma pigmentosum (XP) is a rare genodermatosis characterized by extreme ...
Xeroderma of Kaposi, Xeroderma Pigmentosum, Xeroderma pigmentosum, NOS, Xeroderma, pigmentosum, XP - Xeroderma pigmentosum ... Cockayne´s Syndrome (6)Ephelides (8)Xeroderma Pigmentosum Tardivum (2) related links. Search www.startpage.com for Xeroderma ... Xeroderma Pigmentosum. definition. A rare autosomal recessive disease characterized by photosensitivity, photodamage, cutaneous ... Angioma pigmentosum atrophicum, Atrophoderma pigmentosum, Disease, Kaposi, Disease, Kaposis, Kaposi dermatosis, Kaposi Disease ...
Learn about Xeroderma Pigmentosum Group D Protein at online-medical-dictionary.org ... Xeroderma Pigmentosum Group D Protein. Synonyms. ERCC2 Protein. Excision Repair Cross Complementing Rodent Repair Deficiency, ... and mutations in this protein are associated with XERODERMA PIGMENTOSUM. ...
Xeroderma pigmentosum (XP) is a rare, recessive, photosensitive and cancer-prone syndrome, the biochemical hallmark of which is ... Reconstruction of DNA Repair-deficient Xeroderma Pigmentosum Skin In Vitro: A Model to Study Hypersensitivity to UV Light. ... "Reconstruction of DNA Repair-deficient Xeroderma Pigmentosum Skin In Vitro: A Model to Study Hypersensitivity to UV Light," ... "Reconstruction of DNA Repair-deficient Xeroderma Pigmentosum Skin In Vitro: A Model to Study Hypersensitivity to UV Light," ...
... a homolog of the human xeroderma pigmentosum (XP) group E gene which encodes a UV-damaged DNA binding protein. The repE gene ... repE--the Dictyostelium homolog of the human xeroderma pigmentosum group E gene is developmentally regulated and contains a ... We have cloned and characterized the Dictyostelium discoideum repE gene, a homolog of the human xeroderma pigmentosum (XP) ...
Xeroderma pigmentosum is a skin condition that affects very young individuals. The condition can lead to skin cancer and death ... Xeroderma Pigmentosum. Xeroderma pigmentosum or XP is classified as a rare skin disease. ... xeroderma pigmentosum , sun poisoning rash , sunless tanning , sunscreen products , anti-aging skin care , find a skin care ... Xeroderma Pigmentosum Symptoms. There are seven to eight classes of this skin condition. The symptoms are: the presence of many ...
Mouse Models for Xeroderma Pigmentosum Group A and Group C Show Divergent Cancer Phenotypes Joost P.M. Melis; Joost P.M. Melis ... Sugasawa K. The xeroderma pigmentosum group C protein complex and ultraviolet-damaged DNA-binding protein: functional assays ... Yokoi M, Masutani C, Maekawa T, Sugasawa K, Ohkuma Y, Hanaoka F. The xeroderma pigmentosum group C protein complex XPC-HR23B ... The autosomal recessive disorder Xeroderma pigmentosum (XP) is an elucidative example of the influence of a DNA repair defect ...
Social MediaXeroderma Pigmentosum. Fact-check: Xeroderma pigmentosum does not cause ones skin to melt. Published on : Jun 28, ...
Both Anne and Nicholas suffered from a rare inherited illness called xeroderma pigmentosum that caused severe photosensitivity ...
Le Xeroderma pigmentosum (XP) est une g nodermatose rare, fr quente au Maghreb vu le taux lev de mariage consanguin. Ses ... Le Xeroderma pigmentosum (XP) est une g nodermatose rare, fr quente au Maghreb vu le taux lev de mariage consanguin. Ses ... Xeroderma pigmentosum et dermoscopie. Kawtar Inani, Fatimazahra Mernissi. Corresponding author: Kawtar Inani, Service de ... Keywords: Xeroderma pigmentosum, dermoscopie, génodermatose. ©Kawtar Inani et al. Pan African Medical Journal (ISSN: 1937-8688 ...
... patients with Xeroderma Pigmentosum simply have to avoid exposure to UV light. Find Xeroderma Pigmentosum and more DNA Repair ... Xeroderma Pigmentosum is caused by a defect in nucleotide excision repair, which is a DNA repair process used to remove thymine ... Xeroderma Pigmentosum (XP) is a rare skin disorder causing extreme sensitivity to sunlight, premature skin ageing, and an ... patients with Xeroderma Pigmentosum simply have to avoid exposure to UV light.. Find Xeroderma Pigmentosum and more DNA Repair ...
In 1882, Kaposi coined the term xeroderma pigmentosum for the condition, referring to its characteristic dry, pigmented skin. ... Xeroderma pigmentosum (XP) was first described in 1874 by Hebra and Kaposi. ... encoded search term (Xeroderma Pigmentosum) and Xeroderma Pigmentosum What to Read Next on Medscape ... Xeroderma pigmentosum (XP) was first described in 1874 by Hebra and Kaposi. In 1882, Kaposi coined the term xeroderma ...
Xeroderma Pigmentosum; Kaposi Disease. On-line free medical diagnosis assistant. Ranked list of possible diseases from either ... 2/5. xeroderma pigmentosum: resurfacing versus dermabrasion. Three patients of xeroderma pigmentosum (XP) have been managed for ... 4/5. Management of a young patient with xeroderma pigmentosum. xeroderma pigmentosum is a group of rare autosomal recessive ... 3/5. The role of dermabrasion and chemical peels in the treatment of patients with xeroderma pigmentosum. We describe our ...
A case of xeroderma pigmentosum (XP), whose initial treatment included excision of multisentric cutaneous malignancies ...
... a documentary on patients with xeroderma pigmentosum two television programs ... 3 videos in Arabic on patients with xeroderma pigmentosum to watch! ... a documentary on patients with xeroderma pigmentosum. two television programs on photo protection for children with xeroderma ... 31 October 2018 - Girls of the moon : a successful documentary movie about Xeroderma Pigmentosum ...
XERODERMA PIGMENTOSUM, VARIANT TYPE; XPV description, symptoms and related genes. Get the complete information in our medical ... Xeroderma pigmentosum variant is a milder subtype of xeroderma pigmentosum (XP; see this term), a rare genetic photodermatosis ... Xeroderma Pigmentosum Variant Is also known as xeroderma pigmentosum with normal dna repair rates, photosensitivity with ... Xeroderma pigmentosum variant type (sequence analysis of POLH gene). By CGC Genetics (Portugal). POLH ...
xeroderma pigmentosum, complementation group C. Molecular. skeletal muscle. Human. XPC. 7.0% Increase Gene Expression Level. ... xeroderma pigmentosum, complementation group C. Molecular. skeletal muscle. Human. XPC. 6.0% Increase Gene Expression Level. ...
Mutation spectra induced by α-acetoxytamoxifen-DNA adducts in human DNA repair proficient and deficient (Xeroderma pigmentosum ... Mutation spectra induced by α-acetoxytamoxifen-DNA adducts in human DNA repair proficient and deficient (Xeroderma pigmentosum ... Mutation spectra induced by α-acetoxytamoxifen-DNA adducts in human DNA repair proficient and deficient (Xeroderma pigmentosum ... Mutation spectra induced by α-acetoxytamoxifen-DNA adducts in human DNA repair proficient and deficient (Xeroderma pigmentosum ...
Ciliary body melanoma (see the image below) is a rare tumor. It is encountered approximately one tenth as often as is choroidal melanoma.
Xeroderma pigmentosum service (All Ages) *PDF. *105 KB. *1 pages. *Terms and conditions ...
Xeroderma pigmentosum, group G, 278780, Autosomal recessive (Xeroderma pigmentosum) (ERCC5 gene) (Sequence Analysis-All Coding ... Xeroderma pigmentosum, group G, 278780, Autosomal recessive (Xeroderma pigmentosum) (ERCC5 gene) (Sequence Analysis-All Coding ... Xeroderma pigmentosum, group G/Cockayne syndrome, 278780, Autosomal recessive (Xeroderma pigmentosum) (ERCC5 gene) (Sequence ... Xeroderma pigmentosum, group G/Cockayne syndrome, 278780, Autosomal recessive (Xeroderma pigmentosum) (ERCC5 gene) (Sequence ...
Xeroderma pigmentosum. Deficiencies of iron or vitamins A, C, or E. Fanconi anemia ...
Supplementary Table 1 from Loss of Xeroderma Pigmentosum C (Xpc) Enhances Melanoma Photocarcinogenesis in Ink4a-Arf-Deficient ... Supplementary Table 1 from Loss of Xeroderma Pigmentosum C (Xpc) Enhances Melanoma Photocarcinogenesis in Ink4a-Arf-Deficient ... Supplementary Table 1 from Loss of Xeroderma Pigmentosum C (Xpc) Enhances Melanoma Photocarcinogenesis in Ink4a-Arf-Deficient ... by deletion of the xeroderma pigmentosum C (Xpc) gene, will heighten melanoma photocarcinogenesis in an Ink4a-Arf-deficient ...
Ciliary body melanoma (see the image below) is a rare tumor. It is encountered approximately one tenth as often as is choroidal melanoma.
Xeroderma pigmentosum: Examination of clinical and laboratory abnormalities in patients with defective DNA repair: xeroderm. ... Xeroderma pigmentosum. Xeroderma pigmentosum is a genetic disorder of DNA repair in which the bodys normal ability to fix ... The most common defect in xeroderma pigmentosum is an inherited defect that alters the nucleotide excision repair enzymes, and ... Four rare genetic diseases, xeroderma pigmentosum (XP), Cockayne syndrome (CS), the XP/CS complex and trichothiodystrophy (TTD ...
  • Xeroderma pigmentosum is a rare disorder transmitted in an autosomal recessive manner. (medscape.com)
  • We identified homozygous mutations in each of these BPS in two newly diagnosed Turkish families with the autosomal recessive disorder xeroderma pigmentosum (XP). (yyu.edu.tr)
  • Many of the xeroderma pigmentosum genes are involved in a DNA-repair mechanism called nucleotide excision repair (NER). (news-medical.net)
  • The basic defect in xeroderma pigmentosum is in nucleotide excision repair (NER), leading to deficient repair of DNA damaged by UV radiation. (medscape.com)
  • It plays an essential role in NUCLEOTIDE EXCISION REPAIR , and mutations in this protein are associated with XERODERMA PIGMENTOSUM . (online-medical-dictionary.org)
  • Xeroderma pigmentosum (XP) is a rare, recessive, photosensitive and cancer-prone syndrome, the biochemical hallmark of which is a defect in nucleotide excision repair of ultraviolet (UV)-induced mutagenic lesions. (bioone.org)
  • One of the most versatile defense mechanisms against the accumulation of DNA damage is nucleotide excision repair, in which, among others, the Xeroderma pigmentosum group C (XPC) and group A (XPA) proteins are involved. (aacrjournals.org)
  • Xeroderma Pigmentosum is caused by a defect in nucleotide excision repair , which is a DNA repair process used to remove thymine dimers (T-T dimers) created by UV light damage . (pixorize.com)
  • Because heritable mutations in both INK4a and the nucleotide excision repair (NER) pathway predispose individuals to melanoma development, we set out to test the hypothesis that abrogation of NER, by deletion of the xeroderma pigmentosum C (Xpc) gene, will heighten melanoma photocarcinogenesis in an Ink4a-Arf-deficient background. (figshare.com)
  • The most common defect in xeroderma pigmentosum is an inherited defect that alters the nucleotide excision repair enzymes, and hinders their functionality. (the-medical-dictionary.com)
  • The data show that ERCC5, encoding Xeroderma pigmentosum protein G (XPG), essential for DNA excision repair, and ribonucleotide reductase subunit M1 (RNRM1), encoding a gene necessary for providing the nucleotides needed for DNA repair, were down-regulated in cells treated with diazinon. (cdc.gov)
  • We have cloned and characterized the Dictyostelium discoideum repE gene, a homolog of the human xeroderma pigmentosum (XP) group E gene which encodes a UV-damaged DNA binding protein. (nih.gov)
  • Xeroderma pigmentosum variant type (sequence analysis of POLH gene). (mendelian.co)
  • Xeroderma Pigmentosum via POLH Gene Sequencing with CNV Detection. (mendelian.co)
  • Xeroderma Pigmentosum: Gene Variants and Splice Variants. (cdc.gov)
  • Clinical utility gene card for: Xeroderma pigmentosum. (cdc.gov)
  • Seven xeroderma pigmentosum repair genes, XPA through XPG, have been identified. (medscape.com)
  • In addition to the defects in the repair genes, UV-B radiation also has immunosuppressive effects that may be involved in the pathogenesis of xeroderma pigmentosum. (medscape.com)
  • Xeroderma pigmentosum is a genetic disorder of DNA repair in which the body's normal ability to fix mutations caused by UV light is disabled. (the-medical-dictionary.com)
  • Signs and symptoms of xeroderma pigmentosum may include:[citation needed] Severe sunburn when exposed to only small amounts of sunlight. (wikipedia.org)
  • The main symptoms of xeroderma pigmentosum are caused by an accumulation of unrepaired DNA damage. (news-medical.net)
  • [ 10 ] Although typical symptoms of immune deficiency, such as multiple infections, are not usually observed in patients with xeroderma pigmentosum, several immunologic abnormalities have been described in the skin of patients with xeroderma pigmentosum. (medscape.com)
  • Patients with xeroderma pigmentosum must protect themselves from sunlight all their lives, but they nevertheless develop multiple skin carcinomas, and in about one-third of cases, also progressive neurological abnormalities. (the-scientist.com)
  • Four rare genetic diseases, xeroderma pigmentosum (XP), Cockayne syndrome (CS), the XP/CS complex and trichothiodystrophy (TTD) have defective DNA excision repair although only XP has increased cancer susceptibility. (the-medical-dictionary.com)
  • Basal transcription defect discriminates between xeroderma pigmentosum and trichothiodystrophy in XPD patients. (igbmc.fr)
  • Clinical studies of the skin of patients with xeroderma pigmentosum indicate prominent depletion of Langerhans cells induced by UV radiation. (medscape.com)
  • Since there is no definitive treatment, patients with Xeroderma Pigmentosum simply have to avoid exposure to UV light. (pixorize.com)
  • We describe our experience with two patients with xeroderma pigmentosum who underwent periodic trichloroacetic acid chemical peels. (lookfordiagnosis.com)
  • 3 videos in Arabic on patients with xeroderma pigmentosum to watch! (frt-rareskin.org)
  • relatively mild XP patients are sometimes designated as having pigmented xerodermoid or xerodermoid pigmentosum (XP-V), a variant of XP. (bvsalud.org)
  • Xeroderma pigmentosum clinical practice guidelines. (cdc.gov)
  • A rare inherited disorder, Xeroderma Pigmentosum (XP) is a photosensitive condition characterized by high susceptibility to skin cancers. (news-medical.net)
  • A xeroderma pigmentosum variant has also been described. (medscape.com)
  • In the xeroderma pigmentosum variant, a mutation occurs in DNA polymerase η. (medscape.com)
  • Xeroderma Pigmentosum Variant Is also known as xeroderma pigmentosum with normal dna repair rates, photosensitivity with defective dna synthesis, xpv. (mendelian.co)
  • Molecular diagnosis of xeroderma pigmentosum variant in an isolated population: the interface between precision medicine and public health. (cdc.gov)
  • Various other defects in cell-mediated immunity have been reported in xeroderma pigmentosum. (medscape.com)
  • A case of xeroderma pigmentosum (XP), whose initial treatment included excision of multisentric cutaneous malignancies resurfaced with a pedicled upper arm flap and dermal grafts simultaneously, is reported. (deu.edu.tr)
  • Both Anne and Nicholas suffered from a rare inherited illness called xeroderma pigmentosum that caused severe photosensitivity. (lydiaschoch.com)
  • In addition to their role in DNA repair, xeroderma pigmentosum proteins also have additional functions. (medscape.com)
  • The case of an 11-year-old boy with a diagnosis of xeroderma pigmentosum who underwent mechanical dermabrasion and chemical peeling with phenol and then developed severe cardiac arrhythmias is reported. (lookfordiagnosis.com)
  • Xeroderma pigmentosum (XP) is a genetic disorder in which there is a decreased ability to repair DNA damage such as that caused by ultraviolet (UV) light. (wikipedia.org)
  • Find Xeroderma Pigmentosum and more DNA Repair topics among Pixorize's visual mnemonics for the USMLE Step 1 and NBME Shelf Exams. (pixorize.com)
  • Xeroderma pigmentosum, for example, stems from a specific DNA repair deficiency. (the-scientist.com)
  • Many people, in fact up to 80 percent, suffering from xeroderma have very sensitive eyes and ultraviolet radiation exposure causes ocular problems such as conjunctivitis. (healthy-skincare.com)
  • Xeroderma pigmentosum (XP) is a rare genodermatosis characterized by extreme sensitivity to ultraviolet (UV)-induced changes in the skin and eyes, and multiple skin cancers. (orpha.net)
  • Xeroderma Pigmentosum (XP) is a rare skin disorder causing extreme sensitivity to sunlight, premature skin ageing, and an increased risk for skin cancer. (pixorize.com)
  • Xeroderma pigmentosum (XP) is a rare condition passed down through families. (medlineplus.gov)
  • Xeroderma pigmentosum (XP) is a hereditary condition characterized by extreme sun sensitivity, leading to a very high risk of skin cancer and other medical problems. (cancer.net)
  • The use of oral retinoids can help to decrease the occurrence of skin cancer in people suffering from xeroderma pigmentosum. (healthy-skincare.com)
  • In people with xeroderma pigmentosum, this damage is not repaired. (wikipedia.org)
  • The time course of induction of SOS-like stress responses such as enhanced reactivation (ER) and enhanced mutagenesis (EM) has been investigated in UV- C-irradiated skin fibroblasts from a xeroderma pigmentosum (XP) family, using herpes simplex virus type 1 as a probe. (johnshopkins.edu)
  • In 1882, Kaposi coined the term xeroderma pigmentosum for the condition, referring to its characteristic dry, pigmented skin. (wikipedia.org)
  • To report the youngest xeroderma pigmentosum patient ot have received the benefits of this procedure. (lookfordiagnosis.com)