Permanent dilation of preexisting blood vessels (CAPILLARIES; ARTERIOLES; VENULES) creating small focal red lesions, most commonly in the skin or mucous membranes. It is characterized by the prominence of skin blood vessels, such as vascular spiders.
An autosomal dominant vascular anomaly characterized by telangiectases of the skin and mucous membranes and by recurrent gastrointestinal bleeding. This disorder is caused by mutations of a gene (on chromosome 9q3) which encodes endoglin, a membrane glycoprotein that binds TRANSFORMING GROWTH FACTOR BETA.
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).
A group of PROTEIN-SERINE-THREONINE KINASES which activate critical signaling cascades in double strand breaks, APOPTOSIS, and GENOTOXIC STRESS such as ionizing ultraviolet A light, thereby acting as a DNA damage sensor. These proteins play a role in a wide range of signaling mechanisms in cell cycle control.
A group of rare, idiopathic, congenital retinal vascular anomalies affecting the retinal capillaries. It is characterized by dilation and tortuosity of retinal vessels and formation of multiple aneurysms, with different degrees of leakage and exudates emanating from the blood vessels.
Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
Bleeding from the nose.
One of the two types of ACTIVIN RECEPTORS. They are membrane protein kinases belonging to the family of PROTEIN-SERINE-THREONINE KINASES. The major type II activin receptors are ActR-IIA and ActR-IIB.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
Abnormal formation of blood vessels that shunt arterial blood directly into veins without passing through the CAPILLARIES. They usually are crooked, dilated, and with thick vessel walls. A common type is the congenital arteriovenous fistula. The lack of blood flow and oxygen in the capillaries can lead to tissue damage in the affected areas.
A mild form of LIMITED SCLERODERMA, a multi-system disorder. Its features include symptoms of CALCINOSIS; RAYNAUD DISEASE; ESOPHAGEAL MOTILITY DISORDERS; sclerodactyly, and TELANGIECTASIS. When the defect in esophageal function is not prominent, it is known as CRST syndrome.
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.
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.
A state of elevated cardiac output due to conditions of either increased hemodynamic demand or reduced cardiac oxygen output. These conditions may include ANEMIA; ARTERIOVENOUS FISTULA; THYROTOXICOSIS; PREGNANCY; EXERCISE; FEVER; and ANOXIA. In time, compensatory changes of the heart can lead to pathological form of high cardiac output and eventual HEART FAILURE.
One of the two types of ACTIVIN RECEPTORS or activin receptor-like kinases (ALK'S). There are several type I activin receptors. The major active ones are ALK-2 (ActR-IA) and ALK-4 (ActR-IB).
ELECTROMAGNETIC RADIATION or particle radiation (high energy ELEMENTARY PARTICLES) capable of directly or indirectly producing IONS in its passage through matter. The wavelengths of ionizing electromagnetic radiation are equal to or smaller than those of short (far) ultraviolet radiation and include gamma and X-rays.
Enzyme activated in response to DNA DAMAGE involved in cell cycle arrest. The gene is located on the long (q) arm of chromosome 22 at position 12.1. In humans it is encoded by the CHEK2 gene.
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.
Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.
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.
Retinal diseases refer to a diverse group of vision-threatening disorders that affect the retina's structure and function, including age-related macular degeneration, diabetic retinopathy, retinal detachment, retinitis pigmentosa, and macular edema, among others.
Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.
Interruptions in the sugar-phosphate backbone of DNA, across both strands adjacently.
A serine-threonine protein kinase that, when activated by DNA, phosphorylates several DNA-binding protein substrates including the TUMOR SUPPRESSOR PROTEIN P53 and a variety of TRANSCRIPTION FACTORS.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Acquired degenerative dilation or expansion (ectasia) of normal BLOOD VESSELS, often associated with aging. They are isolated, tortuous, thin-walled vessels and sources of bleeding. They occur most often in mucosal capillaries of the GASTROINTESTINAL TRACT leading to GASTROINTESTINAL HEMORRHAGE and ANEMIA.
Keto-pyrans.
Congenital vascular anomalies in the brain characterized by direct communication between an artery and a vein without passing through the CAPILLARIES. The locations and size of the shunts determine the symptoms including HEADACHES; SEIZURES; STROKE; INTRACRANIAL HEMORRHAGES; mass effect; and vascular steal effect.
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.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
Facial dermatoses refers to various skin conditions that affect the face, causing symptoms such as redness, inflammation, papules, pustules, scaling, or pigmentation changes, which can be caused by a range of factors including genetics, infections, allergies, and environmental factors.
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
An abnormal direct communication between an artery and a vein without passing through the CAPILLARIES. An A-V fistula usually leads to the formation of a dilated sac-like connection, arteriovenous aneurysm. The locations and size of the shunts determine the degree of effects on the cardiovascular functions such as BLOOD PRESSURE and HEART RATE.
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.
A growth differentiation factor that plays a regulatory role as a paracrine factor for a diverse array of cell types during EMBRYONIC DEVELOPMENT and in the adult tissues. Growth differentiation factor 2 is also a potent regulator of CHONDROGENESIS and was previously referred to as bone morphogenetic protein 9.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
The thin, horny plates that cover the dorsal surfaces of the distal phalanges of the fingers and toes of primates.
The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
A cutaneous disorder primarily of convexities of the central part of the FACE, such as FOREHEAD; CHEEK; NOSE; and CHIN. It is characterized by FLUSHING; ERYTHEMA; EDEMA; RHINOPHYMA; papules; and ocular symptoms. It may occur at any age but typically after age 30. There are various subtypes of rosacea: erythematotelangiectatic, papulopustular, phymatous, and ocular (National Rosacea Society's Expert Committee on the Classification and Staging of Rosacea, J Am Acad Dermatol 2002; 46:584-7).
A chromosome instability syndrome resulting from a defective response to DNA double-strand breaks. In addition to characteristic FACIES and MICROCEPHALY, patients have a range of findings including RADIOSENSITIVITY, immunodeficiency, increased cancer risk, and growth retardation. Causative mutations occur in the NBS1 gene, located on human chromosome 8q21. NBS1 codes for nibrin, the key regulator protein of the R/M/N (RAD50/MRE11/NBS1) protein complex which senses and mediates cellular response to DNA DAMAGE caused by IONIZING RADIATION.
Skin diseases affecting or involving the cutaneous blood vessels and generally manifested as inflammation, swelling, erythema, or necrosis in the affected area.
Complex cytotoxic antibiotic obtained from Streptomyces flocculus or S. rufochronmogenus. It is used in advanced carcinoma and causes leukopenia.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Established cell cultures that have the potential to propagate indefinitely.
A chronic multi-system disorder of CONNECTIVE TISSUE. It is characterized by SCLEROSIS in the SKIN, the LUNGS, the HEART, the GASTROINTESTINAL TRACT, the KIDNEYS, and the MUSCULOSKELETAL SYSTEM. Other important features include diseased small BLOOD VESSELS and AUTOANTIBODIES. The disorder is named for its most prominent feature (hard skin), and classified into subsets by the extent of skin thickening: LIMITED SCLERODERMA and DIFFUSE SCLERODERMA.
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
Cytokine-induced cell adhesion molecule present on activated endothelial cells, tissue macrophages, dendritic cells, bone marrow fibroblasts, myoblasts, and myotubes. It is important for the recruitment of leukocytes to sites of inflammation. (From Pigott & Power, The Adhesion Molecule FactsBook, 1993, p154)
A congenital abnormality in which the CEREBRUM is underdeveloped, the fontanels close prematurely, and, as a result, the head is small. (Desk Reference for Neuroscience, 2nd ed.)
Skin lesions due to abnormal infiltration of MAST CELLS. Cutaneous mastocytosis is confined to the skin without the involvement of other tissues or organs, and is mostly found in children. The three major variants are: URTICARIA PIGMENTOSA; diffuse cutaneous mastocytosis; and SOLITARY MASTOCYTOMA OF SKIN.
Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.
An individual having different alleles at one or more loci regarding a specific character.
Receptors for ACTIVINS are membrane protein kinases belonging to the family of PROTEIN-SERINE-THREONINE KINASES, thus also named activin receptor-like kinases (ALK's). Activin receptors also bind TRANSFORMING GROWTH FACTOR BETA. As those transmembrane receptors of the TGF-beta superfamily (RECEPTORS, TRANSFORMING GROWTH FACTOR BETA), ALK's consist of two different but related protein kinases, Type I and Type II. Activins initiate cellular signal transduction by first binding to the type II receptors (ACTIVIN RECEPTORS, TYPE II ) which then recruit and phosphorylate the type I receptors (ACTIVIN RECEPTORS, TYPE I ) with subsequent activation of the type I kinase activity.
The veins that return the oxygenated blood from the lungs to the left atrium of the heart.
The blood vessels which supply and drain the RETINA.
A family of BONE MORPHOGENETIC PROTEIN-related proteins that are primarily involved in regulation of CELL DIFFERENTIATION.
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
'Gingival diseases' is a general term for conditions affecting the soft tissues surrounding and supporting the teeth, primarily characterized by inflammation, bleeding, redness, or swelling, which can progress to periodontal disease if left untreated.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
The process by which a DNA molecule is duplicated.
The period of the CELL CYCLE following DNA synthesis (S PHASE) and preceding M PHASE (cell division phase). The CHROMOSOMES are tetraploid in this point.
A type of chromosomal aberration involving DNA BREAKS. Chromosome breakage can result in CHROMOSOMAL TRANSLOCATION; CHROMOSOME INVERSION; or SEQUENCE DELETION.
A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)
A noninvasive technique that enables direct microscopic examination of the surface and architecture of the SKIN.
Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.
Congenital, inherited, or acquired abnormalities involving ARTERIES; VEINS; or venous sinuses in the BRAIN; SPINAL CORD; and MENINGES.
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.
Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.
A subtype of bone morphogenetic protein receptors with low affinity for BONE MORPHOGENETIC PROTEINS. They are constitutively active PROTEIN-SERINE-THREONINE KINASES that can interact with and phosphorylate TYPE I BONE MORPHOGENETIC PROTEIN RECEPTORS.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.
Bleeding in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.
An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)
A method of hemostasis utilizing various agents such as Gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and INTRACRANIAL ARTERIOVENOUS MALFORMATIONS, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage.
Compounds that inhibit cell production of DNA or RNA.
Genes that code for proteins that regulate the CELL DIVISION CYCLE. These genes form a regulatory network that culminates in the onset of MITOSIS by activating the p34cdc2 protein (PROTEIN P34CDC2).
Hand dermatoses is a general term referring to various inflammatory skin conditions primarily affecting the hands, such as eczema, psoriasis, and contact dermatitis, characterized by erythema, scaling, vesiculation, fissuring, or lichenification.
A cell line derived from cultured tumor cells.
A single-stranded DNA-binding protein that is found in EUKARYOTIC CELLS. It is required for DNA REPLICATION; DNA REPAIR; and GENETIC RECOMBINATION.
Transient complete or partial monocular blindness due to retinal ischemia. This may be caused by emboli from the CAROTID ARTERY (usually in association with CAROTID STENOSIS) and other locations that enter the central RETINAL ARTERY. (From Adams et al., Principles of Neurology, 6th ed, p245)
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Phase of the CELL CYCLE following G1 and preceding G2 when the entire DNA content of the nucleus is replicated. It is achieved by bidirectional replication at multiple sites along each chromosome.
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.
A circumscribed collection of purulent exudate in the brain, due to bacterial and other infections. The majority are caused by spread of infected material from a focus of suppuration elsewhere in the body, notably the PARANASAL SINUSES, middle ear (see EAR, MIDDLE); HEART (see also ENDOCARDITIS, BACTERIAL), and LUNG. Penetrating CRANIOCEREBRAL TRAUMA and NEUROSURGICAL PROCEDURES may also be associated with this condition. Clinical manifestations include HEADACHE; SEIZURES; focal neurologic deficits; and alterations of consciousness. (Adams et al., Principles of Neurology, 6th ed, pp712-6)
The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.
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.
Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.
Enzymes that are involved in the reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule, which contained damaged regions.
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.
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.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
An increased tendency of the GENOME to acquire MUTATIONS when various processes involved in maintaining and replicating the genome are dysfunctional.
A spectrum of congenital, inherited, or acquired abnormalities in BLOOD VESSELS that can adversely affect the normal blood flow in ARTERIES or VEINS. Most are congenital defects such as abnormal communications between blood vessels (fistula), shunting of arterial blood directly into veins bypassing the CAPILLARIES (arteriovenous malformations), formation of large dilated blood blood-filled vessels (cavernous angioma), and swollen capillaries (capillary telangiectases). In rare cases, vascular malformations can result from trauma or diseases.
Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of causes.
Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.
A ubiquitously expressed telomere-binding protein that is present at TELOMERES throughout the cell cycle. It is a suppressor of telomere elongation and may be involved in stabilization of telomere length. It is structurally different from TELOMERIC REPEAT BINDING PROTEIN 1 in that it contains basic N-terminal amino acid residues.
An exudate between the RETINA and CHOROID from various sources including the vitreous cavity, SUBARACHNOID SPACE, or abnormal vessels.
The noninvasive microscopic examination of the microcirculation, commonly done in the nailbed or conjunctiva. In addition to the capillaries themselves, observations can be made of passing blood cells or intravenously injected substances. This is not the same as endoscopic examination of blood vessels (ANGIOSCOPY).
Increased VASCULAR RESISTANCE in the PULMONARY CIRCULATION, usually secondary to HEART DISEASES or LUNG DISEASES.
A characteristic symptom complex.
Enlarged and tortuous VEINS.
An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)
Biochemical identification of mutational changes in a nucleotide sequence.
A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.
CELL CYCLE regulatory signaling systems that are triggered by DNA DAMAGE or lack of nutrients during G2 PHASE. When triggered they restrain cells transitioning from G2 phase to M PHASE.
An antiviral antibiotic produced by Cephalosporium aphidicola and other fungi. It inhibits the growth of eukaryotic cells and certain animal viruses by selectively inhibiting the cellular replication of DNA polymerase II or the viral-induced DNA polymerases. The drug may be useful for controlling excessive cell proliferation in patients with cancer, psoriasis or other dermatitis with little or no adverse effect upon non-multiplying cells.
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).
Syndromes in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral.
A complex of related glycopeptide antibiotics from Streptomyces verticillus consisting of bleomycin A2 and B2. It inhibits DNA metabolism and is used as an antineoplastic, especially for solid tumors.
An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.

Evaluation of lidocaine as an analgesic when added to hypertonic saline for sclerotherapy. (1/144)

PURPOSE: The efficacy of sclerosing agents for the treatment of telangiectasias and reticular veins is well established. The injection of these agents is often associated with pain, and it is not uncommon for sclerotherapists to include lidocaine with the sclerosants in an attempt to reduce the pain associated with treatment. However, there are concerns that this may reduce the overall efficacy of the treatment because of dilution of the sclerosant. Patient comfort and overall outcome associated with treatment using HS with lidocaine (LIDO) versus that using HS alone was compared. METHODS: Forty-two patients were prospectively entered into the study and randomized blindly to sclerotherapy with 23.4% HS or 19% LIDO. Study subjects and treating physicians were blinded to the injection solution used. Injection sites were chosen for veins ranging in size from 0.1 to 3 mm. Photographs of the area to be treated were taken, and the patients rated their pain. They were then observed at regular intervals for four months, and clinical data was collected. Thirty-five subjects completed the full follow-up period, and photographs of the injected area were taken again. Three investigators blinded to the treatment assignment then evaluated the photographs and scored the treatment efficacy according to a standardized system. RESULTS: In the HS group, 61.9% (13 of 21) patients rated their pain as none or mild, whereas 90.5% (19 of 21) of patients in the LIDO group had no or mild discomfort. This difference is significant, with a P value of.034. There was no difference in the overall efficacy of treatment between the two groups. The groups had similar rates of vein thrombosis and skin necrosis. CONCLUSION: Although lidocaine is often used with sclerosing agents, there are no previous reports in the literature to evaluate its effectiveness in reducing the pain experienced by the patient. In this study, patients receiving LIDO experienced significantly less discomfort at the time of injection than patients who received HS alone. There were no differences in the effectiveness of treatment or in the incidence of complications between the two groups.  (+info)

Surgery of angiomas in the brainstem with a stress on the presence of telangiectasia. (2/144)

This report deals with the surgery of angiomas other than arteriovenous malformation in the brainstem. The surgical cases were three cavernomas, two telangiectasias, and two venous malformations. We performed surgery when an angioma bled and the resulting hematoma was situated near the surface of the brainstem or the fourth ventricle. The cases were operated on at the subacute or chronic stages after hemorrhage. Although a magnetic resonance (MR) image showed a subacute or chronic localized hematoma with a low intensity rim, the case was not always a cavernoma, but a telangiectasia. Cavernomas could be totally removed, but telangiectasia could not. In the cases of medullary venous malformation the diagnosis was obtained radiologically, and when the hematoma was large, only hematoma evacuation was performed. In all cases the postoperative Karnofsky scores were improved or unchanged. Postoperative rebleeding in the hematoma cavity continued insidiously in a case of telangiectasia. The abnormal vessels of telangiectasia in the brainstem were preoperatively not visualized by cerebral angiography or MR imaging, but became visualized by enhanced MR imaging after evacuation of hematoma in two cases. It is stressed that an angioma with a hematoma intensity core surrounded by a low intensity rim on MR images is not always a cavernoma, but possibly is a telangiectasia.  (+info)

MR high-resolution blood oxygenation level-dependent venography of occult (low-flow) vascular lesions. (3/144)

A new technique for detecting vascular malformations, high-resolution BOLD venography (HRBV), is described. This technique relies on the BOLD principle for detecting deoxygenated blood in low-flow malformations. HRBV images are acquired using a modified 3D gradient-echo with voxel volumes of 0.5 x 0.5 x 2 mm3. The magnitude data are masked with the phase images to enhance visibility of the venous structures and are displayed using the minimum intensity projection. Preliminary results for 10 patients show that HRBV is more sensitive in detecting cavernomas than is T2-weighted imaging, and lesions that are presumed to be telangiectasias are detected only with this technique.  (+info)

Coats' disease of the retina (unilateral retinal telangiectasis) caused by somatic mutation in the NDP gene: a role for norrin in retinal angiogenesis. (4/144)

Coats' disease is characterized by abnormal retinal vascular development (so-called 'retinal telangiectasis') which results in massive intraretinal and subretinal lipid accumulation (exudative retinal detachment). The classical form of Coats' disease is almost invariably isolated, unilateral and seen in males. A female with a unilateral variant of Coats' disease gave birth to a son affected by Norrie disease. Both carried a missense mutation within the NDP gene on chromosome Xp11.2. Subsequently analysis of the retinas of nine enucleated eyes from males with Coats' disease demonstrated in one a somatic mutation in the NDP gene which was not present within non-retinal tissue. We suggest that Coats' telangiectasis is secondary to somatic mutation in the NDP gene which results in a deficiency of norrin (the protein product of the NDP gene) within the developing retina. This supports recent observations that the protein is critical for normal retinal vasculogenesis.  (+info)

A retarded rate of DNA chain growth in Bloom's syndrome. (5/144)

The cytogenetic observation that homologous chromatid interchange occurs in Bloom's syndrome more often than normal prompted an investigation of DNA replication in that rare genetic disorder. Using DNA fiber autoradiography, an estimation was made of the rate of one component of ongoing DNA replication, DNA chain growth. The rate in Bloom's syndrome dermal fibroblasts in tissue culture was found to be significantly slower than that in normal control cells. (The rate was found to be normal in Fanconi's anemia cells.) The explanation for the retarded chain growth may be either that an enzyme concerned directly with semiconservative DNA replication is defective or that a defective enzyme not itself concerned directly with replication results in disturbed cellular metabolism which in turn affects replication.  (+info)

Coats' syndrome: long term follow up. (6/144)

AIM: To increase the understanding of the long term results in pseudo-retinoblastoma eyes with infantile Coats' syndrome. METHODS: This study design was a retrospective case review. 10 patients were analysed who were initially referred with a diagnosis of retinoblastoma but had Coats' syndrome on the basis of ocular oncological evaluation. Vision, fundus photography, ultrasonography, and computed tomography scans were obtained and evaluated. Changes in vision and retinal status were measured. RESULTS: The initial age at presentation was 2.4 years (range 0.25-4 years). All patients had retinal detachment at diagnosis. Nine of 10 retinas were reattached after various treatments. Reattached retinas had closure of peripheral telangiectasia and visible intraretinal crystals. Vision was dismal. At last follow up (mean 8.8 years), only two patients had 20/400 or better visual acuities. Five eyes had no light perception despite early treatment to reattach the retina. Nine of 10 eyes remain cosmetically acceptable. One patient wore a cosmetic shell. CONCLUSIONS: Long term results indicate that these eyes can be salvaged and the retina reattached but the visual outcome is poor.  (+info)

Coat's disease: an uncommon lesion of eye--a case report. (7/144)

Coat's Disease, first reported in 1908, is a rare disease which is usually seen in young males presenting with complaints of unilateral vision loss. Microscopically, retinal telangiectasis and exudative retinal detachment is seen. Attempts should be made for differentiating and early detection of this disease to avoid enucleation of eye ball. Here we discuss a case report of a child manifesting as coat's disease in which a clinical diagnosis of Retinoblastoma was given and eye was enucleated.  (+info)

Hereditary deficiency of the seventh component of complement. (8/144)

Deficiency of the seventh component of complement has been found in the serum of a 42-yr-old Caucasian woman who has Raynaud's phenomenon, sclerodactyly, and telangiectasia. Partial deficiency was found in the serum of the patient's parents and children, indicating a pattern of inheritance of autosomal codominance. Transfusion experiments indicated that exogenous C7 had a 91-h halk-life in the patient. There was no evidence for C7 synthesis after transfusion. No C7 inhibitors were detected in the patient's serum. The patient's serum was found to support the activation of complement by both the classical and properdin pathways to the C7 stage. The addition of C7 to the patient's serum permitted it to support hemolytic reactions initiated by either pathway. No defects could be detected in plasma or whole blood coagulation. The patient's serum was deficient in opsonizing unsensitized yeast particles in serum and in the generation of chemotactic factor by antigen-antibody complexes and endotoxin. Both deficiencies were corrected by the addition of C7. These observations suggest a key role for C7 for in vitro yeast phagocytosis and chemotaxis generation. However, the patient's lack of infections indicates a relatively minor role for C7 in human resistance to infection.  (+info)

Telangiectasia is a medical term that refers to the dilation and widening of small blood vessels called capillaries, leading to their visibility under the skin or mucous membranes. These dilated vessels often appear as tiny red lines or patterns, measuring less than 1 millimeter in diameter.

Telangiectasias can occur in various parts of the body, such as the face, nose, cheeks, legs, and fingers. They are typically harmless but may cause cosmetic concerns for some individuals. In certain cases, telangiectasias can be a sign of an underlying medical condition, like rosacea, hereditary hemorrhagic telangiectasia (HHT), or liver disease.

It is essential to consult with a healthcare professional if you notice any unusual changes in your skin or mucous membranes, as they can provide appropriate evaluation and treatment recommendations based on the underlying cause of the telangiectasias.

Hereditary Hemorrhagic Telangiectasia (HHT) is a rare genetic disorder that affects the blood vessels. It is also known as Osler-Weber-Rendu syndrome. This condition is characterized by the formation of abnormal blood vessels called telangiectases, which are small red spots or tiny bulges that can be found in the skin, mucous membranes (like those inside the nose, mouth, and GI tract), and sometimes in vital organs like the lungs and brain.

These telangiectases have a tendency to bleed easily, leading to potentially serious complications such as anemia due to chronic blood loss, and in some cases, strokes or brain abscesses if the telangiectases in the brain rupture. HHT is typically inherited in an autosomal dominant pattern, meaning that a child has a 50% chance of inheriting the gene from an affected parent. There are several genes associated with HHT, the most common being ACVRL1, ENG, and SMAD4.

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.

Ataxia telangiectasia mutated (ATM) proteins are a type of protein that play a crucial role in the maintenance and repair of DNA in cells. The ATM gene produces these proteins, which are involved in several important cellular processes such as:

1. DNA damage response: When DNA is damaged, ATM proteins help to detect and respond to the damage by activating various signaling pathways that lead to DNA repair or apoptosis (programmed cell death) if the damage is too severe.
2. Cell cycle regulation: ATM proteins regulate the cell cycle by controlling checkpoints that ensure proper DNA replication and division. This helps prevent the propagation of cells with damaged DNA.
3. Telomere maintenance: ATM proteins help maintain telomeres, which are the protective caps at the ends of chromosomes. Telomeres shorten as cells divide, and when they become too short, cells can no longer divide and enter a state of senescence or die.

Mutations in the ATM gene can lead to Ataxia-telangiectasia (A-T), a rare inherited disorder characterized by neurological problems, immune system dysfunction, increased risk of cancer, and sensitivity to ionizing radiation. People with A-T have defective ATM proteins that cannot properly respond to DNA damage, leading to genomic instability and increased susceptibility to disease.

Retinal telangiectasia is a medical condition characterized by the dilation and tortuosity (abnormal twisting or turning) of small retinal blood vessels, specifically the capillaries in the back part of the eye called the retina. This condition can be idiopathic (without a known cause), or it can be associated with various systemic diseases or genetic syndromes.

Retinal telangiectasia is often accompanied by other retinal abnormalities, such as microaneurysms, exudates, and hemorrhages. In some cases, it may lead to vision loss due to macular edema (fluid accumulation in the central part of the retina) or retinal detachment.

There are two main types of retinal telangiectasia:

1. Eales' disease: This is a rare idiopathic condition that primarily affects young adults, particularly males from Asian and Middle Eastern countries. It typically presents with retinal telangiectasia in the peripheral retina, along with inflammation, vitreous hemorrhage, and neovascularization (the growth of new blood vessels).
2. Coats' disease: This is a congenital or infantile disorder that affects the retinal vasculature. It primarily affects males and is characterized by unilateral retinal telangiectasia, exudates, and sometimes retinal detachment. Coats' disease can lead to severe vision loss if not treated promptly.

It is essential to monitor and manage retinal telangiectasia to prevent or treat associated complications and preserve vision. Treatment options may include laser photocoagulation, cryotherapy, intravitreal injections of anti-VEGF (vascular endothelial growth factor) drugs, or vitrectomy surgery, depending on the severity and progression of the condition.

Tumor suppressor proteins are a type of regulatory protein that helps control the cell cycle and prevent cells from dividing and growing in an uncontrolled manner. They work to inhibit tumor growth by preventing the formation of tumors or slowing down their progression. These proteins can repair damaged DNA, regulate gene expression, and initiate programmed cell death (apoptosis) if the damage is too severe for repair.

Mutations in tumor suppressor genes, which provide the code for these proteins, can lead to a decrease or loss of function in the resulting protein. This can result in uncontrolled cell growth and division, leading to the formation of tumors and cancer. Examples of tumor suppressor proteins include p53, Rb (retinoblastoma), and BRCA1/2.

Cell cycle proteins are a group of regulatory proteins that control the progression of the cell cycle, which is the series of events that take place in a eukaryotic cell leading to its division and duplication. These proteins can be classified into several categories based on their functions during different stages of the cell cycle.

The major groups of cell cycle proteins include:

1. Cyclin-dependent kinases (CDKs): CDKs are serine/threonine protein kinases that regulate key transitions in the cell cycle. They require binding to a regulatory subunit called cyclin to become active. Different CDK-cyclin complexes are activated at different stages of the cell cycle.
2. Cyclins: Cyclins are a family of regulatory proteins that bind and activate CDKs. Their levels fluctuate throughout the cell cycle, with specific cyclins expressed during particular phases. For example, cyclin D is important for the G1 to S phase transition, while cyclin B is required for the G2 to M phase transition.
3. CDK inhibitors (CKIs): CKIs are regulatory proteins that bind to and inhibit CDKs, thereby preventing their activation. CKIs can be divided into two main families: the INK4 family and the Cip/Kip family. INK4 family members specifically inhibit CDK4 and CDK6, while Cip/Kip family members inhibit a broader range of CDKs.
4. Anaphase-promoting complex/cyclosome (APC/C): APC/C is an E3 ubiquitin ligase that targets specific proteins for degradation by the 26S proteasome. During the cell cycle, APC/C regulates the metaphase to anaphase transition and the exit from mitosis by targeting securin and cyclin B for degradation.
5. Other regulatory proteins: Several other proteins play crucial roles in regulating the cell cycle, such as p53, a transcription factor that responds to DNA damage and arrests the cell cycle, and the polo-like kinases (PLKs), which are involved in various aspects of mitosis.

Overall, cell cycle proteins work together to ensure the proper progression of the cell cycle, maintain genomic stability, and prevent uncontrolled cell growth, which can lead to cancer.

Epistaxis is the medical term for nosebleed. It refers to the bleeding from the nostrils or nasal cavity, which can be caused by various factors such as dryness, trauma, inflammation, high blood pressure, or use of blood-thinning medications. Nosebleeds can range from minor nuisances to potentially life-threatening emergencies, depending on the severity and underlying cause. If you are experiencing a nosebleed that does not stop after 20 minutes of applying direct pressure, or if you are coughing up or vomiting blood, seek medical attention immediately.

Activin receptors, type II, are a subgroup of serine/threonine kinase receptors that play a crucial role in signal transduction pathways involved in various biological processes, including cell growth, differentiation, and apoptosis. There are two types of activin receptors, Type IIA (ACVR2A) and Type IIB (ACVR2B), which are single-pass transmembrane proteins with an extracellular domain that binds to activins and a cytoplasmic domain with kinase activity.

Activins are dimeric proteins that belong to the transforming growth factor-Ī² (TGF-Ī²) superfamily, and they play essential roles in regulating developmental processes, reproduction, and homeostasis. Activin receptors, type II, function as primary binding sites for activins, forming a complex with Type I activin receptors (ALK4, ALK5, or ALK7) to initiate downstream signaling cascades.

Once the activin-receptor complex is formed, the intracellular kinase domain of the Type II receptor phosphorylates and activates the Type I receptor, which in turn propagates the signal by recruiting and phosphorylating downstream effectors such as SMAD proteins. Activated SMADs then form a complex and translocate to the nucleus, where they regulate gene expression.

Dysregulation of activin receptors, type II, has been implicated in various pathological conditions, including cancer, fibrosis, and developmental disorders. Therefore, understanding their function and regulation is essential for developing novel therapeutic strategies to target these diseases.

Protein-Serine-Threonine Kinases (PSTKs) are a type of protein kinase that catalyzes the transfer of a phosphate group from ATP to the hydroxyl side chains of serine or threonine residues on target proteins. This phosphorylation process plays a crucial role in various cellular signaling pathways, including regulation of metabolism, gene expression, cell cycle progression, and apoptosis. PSTKs are involved in many physiological and pathological processes, and their dysregulation has been implicated in several diseases, such as cancer, diabetes, and neurodegenerative disorders.

Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels that directly connect arteries and veins, bypassing the capillary system. This results in a high-flow and high-pressure circulation in the affected area. AVMs can occur anywhere in the body but are most common in the brain and spine. They can vary in size and may cause symptoms such as headaches, seizures, or bleeding in the brain. In some cases, AVMs may not cause any symptoms and may only be discovered during imaging tests for other conditions. Treatment options include surgery, radiation therapy, or embolization to reduce the flow of blood through the malformation and prevent complications.

CREST syndrome is a subtype of a autoimmune connective tissue disorder called scleroderma (systemic sclerosis). The name "CREST" is an acronym that stands for the following five features:

* Calcinosis: The formation of calcium deposits in the skin and underlying tissues, which can cause painful ulcers.
* Raynaud's phenomenon: A condition in which the blood vessels in the fingers and toes constrict in response to cold or stress, causing the digits to turn white or blue and become numb or painful.
* Esophageal dysmotility: Difficulty swallowing due to weakened muscles in the esophagus.
* Sclerodactyly: Thickening and tightening of the skin on the fingers.
* Telangiectasias: Dilated blood vessels near the surface of the skin, causing red spots or lines.

It's important to note that not everyone with CREST syndrome will have all five of these features, and some people may have additional symptoms not included in the acronym. Additionally, CREST syndrome is a chronic condition that can cause a range of complications, including lung fibrosis, kidney problems, and digital ulcers. Treatment typically focuses on managing specific symptoms and slowing the progression of the disease.

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.

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.

Cardiac output is a measure of the amount of blood that is pumped by the heart in one minute. It is calculated by multiplying the stroke volume (the amount of blood pumped by the left ventricle in each beat) by the heart rate (the number of times the heart beats per minute).

A "high" cardiac output refers to a situation where the cardiac output is greater than normal. This can occur in various conditions such as hyperthyroidism, anemia, fever, pregnancy, or any other condition that increases the body's metabolic demand and requires more blood flow to tissues. It can also be seen in patients with certain heart conditions like a severely narrowed aortic valve or high output cardiac failure.

However, it is important to note that while a high cardiac output may be beneficial in some cases, such as during exercise or pregnancy, chronically elevated levels can lead to increased workload on the heart and potentially contribute to heart failure over time.

Activin receptors, type I are serine/threonine kinase receptors that play a crucial role in the activin signaling pathway. There are two types of activin receptors, Type I (ALK2, ALK4, and ALK7) and Type II (ActRII and ActRIIB). Activin receptors, type I are transmembrane proteins that bind to activins, which are cytokines belonging to the TGF-Ī² superfamily.

Once activated by binding to activins, activin receptors, type I recruit and phosphorylate type II receptors, leading to the activation of downstream signaling pathways, including SMAD proteins. Activated SMAD proteins then translocate to the nucleus and regulate gene expression, thereby mediating various cellular responses such as proliferation, differentiation, apoptosis, and migration.

Mutations in activin receptors, type I have been implicated in several human diseases, including cancer, fibrosis, and developmental disorders. Therefore, understanding the structure and function of activin receptors, type I is essential for developing novel therapeutic strategies to treat these diseases.

Ionizing radiation is a type of radiation that carries enough energy to ionize atoms or molecules, which means it can knock electrons out of their orbits and create ions. These charged particles can cause damage to living tissue and DNA, making ionizing radiation dangerous to human health. Examples of ionizing radiation include X-rays, gamma rays, and some forms of subatomic particles such as alpha and beta particles. The amount and duration of exposure to ionizing radiation are important factors in determining the potential health effects, which can range from mild skin irritation to an increased risk of cancer and other diseases.

Checkpoint Kinase 2 (Chk2) is a serine/threonine protein kinase that plays a crucial role in the DNA damage response and the regulation of the cell cycle. It is activated by various types of DNA damage, including double-strand breaks, and phosphorylates several downstream targets involved in cell cycle arrest, DNA repair, and apoptosis. Chk2 is a key player in the G2/M checkpoint, which prevents cells with damaged DNA from entering mitosis and dividing. Mutations in the Chk2 gene have been associated with increased risk of cancer.

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.

Gamma rays are a type of ionizing radiation that is released from the nucleus of an atom during radioactive decay. They are high-energy photons, with wavelengths shorter than 0.01 nanometers and frequencies greater than 3 x 10^19 Hz. Gamma rays are electromagnetic radiation, similar to X-rays, but with higher energy levels and the ability to penetrate matter more deeply. They can cause damage to living tissue and are used in medical imaging and cancer treatment.

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.

Retinal diseases refer to a group of conditions that affect the retina, which is the light-sensitive tissue located at the back of the eye. The retina is responsible for converting light into electrical signals that are sent to the brain and interpreted as visual images. Retinal diseases can cause vision loss or even blindness, depending on their severity and location in the retina.

Some common retinal diseases include:

1. Age-related macular degeneration (AMD): A progressive disease that affects the central part of the retina called the macula, causing blurred or distorted vision.
2. Diabetic retinopathy: A complication of diabetes that can damage the blood vessels in the retina, leading to vision loss.
3. Retinal detachment: A serious condition where the retina becomes separated from its underlying tissue, requiring immediate medical attention.
4. Macular edema: Swelling or thickening of the macula due to fluid accumulation, which can cause blurred vision.
5. Retinitis pigmentosa: A group of inherited eye disorders that affect the retina's ability to respond to light, causing progressive vision loss.
6. Macular hole: A small break in the macula that can cause distorted or blurry vision.
7. Retinal vein occlusion: Blockage of the retinal veins that can lead to bleeding, swelling, and potential vision loss.

Treatment for retinal diseases varies depending on the specific condition and its severity. Some treatments include medication, laser therapy, surgery, or a combination of these options. Regular eye exams are essential for early detection and treatment of retinal diseases.

Tumor suppressor protein p53, also known as p53 or tumor protein p53, is a nuclear phosphoprotein that plays a crucial role in preventing cancer development and maintaining genomic stability. It does so by regulating the cell cycle and acting as a transcription factor for various genes involved in apoptosis (programmed cell death), DNA repair, and cell senescence (permanent cell growth arrest).

In response to cellular stress, such as DNA damage or oncogene activation, p53 becomes activated and accumulates in the nucleus. Activated p53 can then bind to specific DNA sequences and promote the transcription of target genes that help prevent the proliferation of potentially cancerous cells. These targets include genes involved in cell cycle arrest (e.g., CDKN1A/p21), apoptosis (e.g., BAX, PUMA), and DNA repair (e.g., GADD45).

Mutations in the TP53 gene, which encodes p53, are among the most common genetic alterations found in human cancers. These mutations often lead to a loss or reduction of p53's tumor suppressive functions, allowing cancer cells to proliferate uncontrollably and evade apoptosis. As a result, p53 has been referred to as "the guardian of the genome" due to its essential role in preventing tumorigenesis.

Double-stranded DNA breaks (DSBs) refer to a type of damage that occurs in the DNA molecule when both strands of the double helix are severed or broken at the same location. This kind of damage is particularly harmful to cells because it can disrupt the integrity and continuity of the genetic material, potentially leading to genomic instability, mutations, and cell death if not properly repaired.

DSBs can arise from various sources, including exposure to ionizing radiation, chemical agents, free radicals, reactive oxygen species (ROS), and errors during DNA replication or repair processes. Unrepaired or incorrectly repaired DSBs have been implicated in numerous human diseases, such as cancer, neurodegenerative disorders, and premature aging.

Cells possess several mechanisms to repair double-stranded DNA breaks, including homologous recombination (HR) and non-homologous end joining (NHEJ). HR is a more accurate repair pathway that uses a homologous template, typically the sister chromatid, to restore the original DNA sequence. NHEJ, on the other hand, directly ligates the broken ends together, often resulting in small deletions or insertions at the break site and increased risk of errors. The choice between these two pathways depends on various factors, such as the cell cycle stage, the presence of nearby breaks, and the availability of repair proteins.

In summary, double-stranded DNA breaks are severe forms of DNA damage that can have detrimental consequences for cells if not properly repaired. Cells employ multiple mechanisms to address DSBs, with homologous recombination and non-homologous end joining being the primary repair pathways.

DNA-activated protein kinase (DNA-PK) is a type of serine/threonine protein kinase that plays a crucial role in the DNA damage response and repair processes in cells. It is composed of a catalytic subunit, DNA-PKcs, and a regulatory subunit, Ku, which binds to double-stranded DNA breaks and recruits DNA-PKcs to the site of damage.

Once activated by DNA damage, DNA-PK phosphorylates various downstream targets involved in DNA repair, including proteins involved in non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ is a major pathway for the repair of double-stranded DNA breaks, while HR is a more accurate but slower process that requires a template for repair.

Dysregulation of DNA-PK has been implicated in various human diseases, including cancer and neurological disorders. Inhibitors of DNA-PK are being investigated as potential therapeutic agents for the treatment of cancer, particularly in combination with other DNA damage response inhibitors or radiation therapy.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

Angiodysplasia is a vascular disorder characterized by the dilation and abnormal formation of blood vessels, particularly in the gastrointestinal (GI) tract. These abnormal blood vessels are prone to leakage or rupture, which can lead to bleeding. Angiodysplasia is most commonly found in the colon but can occur in other parts of the GI tract as well. It is more common in older adults and can cause symptoms such as anemia, fatigue, and bloody stools. The exact cause of angiodysplasia is not known, but it may be associated with chronic low-grade inflammation or increased pressure in the blood vessels. Treatment options include endoscopic therapies to stop bleeding, medications to reduce acid production in the stomach, and surgery in severe cases.

I believe there might be a misunderstanding in your question. "Pyrones" is not a medical term, but rather a chemical term used to describe a class of organic compounds known as lactones with a characteristic eight-membered ring. These compounds are found in various natural sources such as plants and fungi, and some have been studied for their potential biological activities.

However, if you meant "pyrexia" instead of "pyrones," then I can provide the medical definition:

Pyrexia is a term used to describe an abnormally elevated body temperature, also known as fever. In adults, a core body temperature of 100.4Ā°F (38Ā°C) or higher is generally considered indicative of pyrexia. Fever is often a response to an infection or inflammation in the body and can be part of the immune system's effort to combat pathogens.

Intracranial arteriovenous malformations (AVMs) are abnormal, tangled connections between the arteries and veins in the brain. These connections bypass the capillary system, which can lead to high-flow shunting and potential complications such as hemorrhage, stroke, or neurological deficits. AVMs are congenital conditions, meaning they are present at birth, although symptoms may not appear until later in life. They are relatively rare, affecting approximately 0.1% of the population. Treatment options for AVMs include surgery, radiation therapy, and endovascular embolization, depending on the size, location, and specific characteristics of the malformation.

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.

Histones are highly alkaline proteins found in the chromatin of eukaryotic cells. They are rich in basic amino acid residues, such as arginine and lysine, which give them their positive charge. Histones play a crucial role in packaging DNA into a more compact structure within the nucleus by forming a complex with it called a nucleosome. Each nucleosome contains about 146 base pairs of DNA wrapped around an octamer of eight histone proteins (two each of H2A, H2B, H3, and H4). The N-terminal tails of these histones are subject to various post-translational modifications, such as methylation, acetylation, and phosphorylation, which can influence chromatin structure and gene expression. Histone variants also exist, which can contribute to the regulation of specific genes and other nuclear processes.

Facial dermatoses refer to various skin conditions that affect the face. These can include a wide range of disorders, such as:

1. Acne vulgaris: A common skin condition characterized by the formation of comedones (blackheads and whiteheads) and inflammatory papules, pustules, and nodules. It primarily affects the face, neck, chest, and back.
2. Rosacea: A chronic skin condition that causes redness, flushing, and visible blood vessels on the face, along with bumps or pimples and sometimes eye irritation.
3. Seborrheic dermatitis: A common inflammatory skin disorder that causes a red, itchy, and flaky rash, often on the scalp, face, and eyebrows. It can also affect other oily areas of the body, like the sides of the nose and behind the ears.
4. Atopic dermatitis (eczema): A chronic inflammatory skin condition that causes red, itchy, and scaly patches on the skin. While it can occur anywhere on the body, it frequently affects the face, especially in infants and young children.
5. Psoriasis: An autoimmune disorder that results in thick, scaly, silvery, or red patches on the skin. It can affect any part of the body, including the face.
6. Contact dermatitis: A skin reaction caused by direct contact with an allergen or irritant, resulting in redness, itching, and inflammation. The face can be affected when allergens or irritants come into contact with the skin through cosmetics, skincare products, or other substances.
7. Lupus erythematosus: An autoimmune disorder that can cause a butterfly-shaped rash on the cheeks and nose, along with other symptoms like joint pain, fatigue, and photosensitivity.
8. Perioral dermatitis: A inflammatory skin condition that causes redness, small bumps, and dryness around the mouth, often mistaken for acne. It can also affect the skin around the nose and eyes.
9. Vitiligo: An autoimmune disorder that results in the loss of pigmentation in patches of skin, which can occur on the face and other parts of the body.
10. Tinea faciei: A fungal infection that affects the facial skin, causing red, scaly, or itchy patches. It is also known as ringworm of the face.

These are just a few examples of skin conditions that can affect the face. If you experience any unusual symptoms or changes in your skin, it's essential to consult a dermatologist for proper diagnosis and treatment.

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.

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).

An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. This connection causes blood to flow directly from the artery into the vein, bypassing the capillary network that would normally distribute the oxygen-rich blood to the surrounding tissues.

Arteriovenous fistulas can occur as a result of trauma, disease, or as a planned surgical procedure for patients who require hemodialysis, a treatment for advanced kidney failure. In hemodialysis, the arteriovenous fistula serves as a site for repeated access to the bloodstream, allowing for efficient removal of waste products and excess fluids.

The medical definition of an arteriovenous fistula is:

"An abnormal communication between an artery and a vein, usually created by surgical means for hemodialysis access or occurring as a result of trauma, congenital defects, or disease processes such as vasculitis or neoplasm."

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.

Growth Differentiation Factor 2 (GDF2), also known as Bone Morphogenetic Protein 9 (BMP9), is a protein that belongs to the transforming growth factor-beta (TGF-Ī²) superfamily. It is a cytokine with important roles in various biological processes, including angiogenesis (the formation of new blood vessels), cardiovascular development, and skeletal muscle regeneration. GDF2/BMP9 is primarily produced by liver cells called hepatocytes and circulates in the bloodstream. It exerts its effects by binding to specific receptors on the cell surface, which triggers intracellular signaling pathways that regulate gene expression and ultimately influence cell behavior.

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

In the context of medical terminology, "nails" primarily refer to the keratinous plates that are found at the tips of fingers and toes. These specialized structures are part of the outermost layer of the skin (epidermis) and are formed by a type of cells called keratinocytes. The nails serve to protect the delicate underlying tissues from trauma, and they also aid in tasks such as picking up small objects or scratching itches.

The medical term for fingernails and toenails is "unguis," which comes from Latin. Each nail consists of several parts:

1. Nail plate: The visible part of the nail that is hard and flat, made up of keratin.
2. Nail bed: The skin beneath the nail plate to which the nail plate is attached; it supplies blood to the nail.
3. Matrix: The area where new cells are produced for the growth of the nail plate; located under the cuticle and extends slightly onto the finger or toe.
4. Lunula: The crescent-shaped white area at the base of the nail plate, which is the visible portion of the matrix.
5. Cuticle: The thin layer of skin that overlaps the nail plate and protects the underlying tissue from infection.
6. Eponychium: The fold of skin that surrounds and covers the nail plate; also known as the "proximal nail fold."
7. Hyponychium: The area of skin between the free edge of the nail plate and the fingertip or toe tip.
8. Perionychiun: The skin surrounding the nail on all sides.

Understanding the anatomy and medical aspects of nails is essential for healthcare professionals, as various conditions can affect nail health, such as fungal infections, ingrown nails, or tumors.

The cell cycle is a series of events that take place in a cell leading to its division and duplication. It consists of four main phases: G1 phase, S phase, G2 phase, and M phase.

During the G1 phase, the cell grows in size and synthesizes mRNA and proteins in preparation for DNA replication. In the S phase, the cell's DNA is copied, resulting in two complete sets of chromosomes. During the G2 phase, the cell continues to grow and produces more proteins and organelles necessary for cell division.

The M phase is the final stage of the cell cycle and consists of mitosis (nuclear division) and cytokinesis (cytoplasmic division). Mitosis results in two genetically identical daughter nuclei, while cytokinesis divides the cytoplasm and creates two separate daughter cells.

The cell cycle is regulated by various checkpoints that ensure the proper completion of each phase before progressing to the next. These checkpoints help prevent errors in DNA replication and division, which can lead to mutations and cancer.

Rosacea is a chronic skin condition primarily characterized by persistent redness, inflammation, and visible blood vessels on the face, particularly the nose, cheeks, forehead, and chin. It can also cause small, red, pus-filled bumps. Rosacea typically affects adults between 30 and 50 years old, with fair skin types being more susceptible. The exact cause of rosacea is unknown, but it's believed to be a combination of genetic and environmental factors, including abnormal facial blood vessels, immune system issues, and certain triggers (such as sun exposure, emotional stress, hot or cold weather, heavy exercise, alcohol consumption, spicy foods, and certain skin care products). There is no cure for rosacea, but various treatments can help control its symptoms and improve the appearance of the skin. These may include topical medications, oral antibiotics, laser therapy, and lifestyle modifications to avoid triggers.

Nijmegen Breakage Syndrome (NBS) is a rare autosomal recessive disorder characterized by extreme sensitivity to ionizing radiation, progressive microcephaly, short stature, immunodeficiency, and an increased risk of developing malignancies, particularly lymphoid tumors. The syndrome is caused by mutations in the NBN gene, which encodes a protein called nibrin that plays a critical role in DNA repair and maintenance of genomic stability.

Individuals with NBS typically have microcephaly at birth or develop it in early childhood, accompanied by developmental delay, intellectual disability, and characteristic facial features such as a prominent forehead, recessed jaw, and widely spaced eyes. They may also have skin abnormalities, skeletal anomalies, and hearing loss.

Immunodeficiency is a common feature of NBS, with patients often experiencing recurrent infections due to impaired immune function. They may have low levels of immunoglobulins and T-cell lymphopenia, which can increase their susceptibility to infections.

NBS is associated with an increased risk of malignancies, particularly lymphoid tumors such as B-cell non-Hodgkin lymphoma and leukemia. The risk of cancer increases with age, and most patients develop a malignancy by their mid-20s.

The diagnosis of NBS is typically made based on clinical features, genetic testing, and confirmation of biallelic mutations in the NBN gene. Treatment may involve management of infections, immunoglobulin replacement therapy, and chemotherapy or radiation therapy for malignancies. However, these treatments can be challenging due to the increased sensitivity to ionizing radiation and potential toxicity of chemotherapeutic agents.

Overall, NBS is a rare but serious disorder that requires multidisciplinary care from specialists in genetics, immunology, oncology, and other fields.

Vascular skin diseases are a group of medical conditions that affect the blood vessels in the skin. These disorders can be caused by problems with the structure or function of the blood vessels, which can lead to various symptoms such as redness, discoloration, pain, itching, and ulcerations. Some examples of vascular skin diseases include:

1. Rosacea: a chronic skin condition that causes redness, flushing, and visible blood vessels in the face.
2. Eczema: a group of inflammatory skin conditions that can cause redness, itching, and dryness. Some types of eczema, such as varicose eczema, are associated with problems with the veins.
3. Psoriasis: an autoimmune condition that causes red, scaly patches on the skin. Some people with psoriasis may also develop psoriatic arthritis, which can affect the blood vessels in the skin and joints.
4. Vasculitis: a group of conditions that cause inflammation of the blood vessels. This can lead to symptoms such as redness, pain, and ulcerations.
5. Livedo reticularis: a condition that causes a net-like pattern of discoloration on the skin, usually on the legs. It is caused by abnormalities in the small blood vessels.
6. Henoch-Schƶnlein purpura: a rare condition that causes inflammation of the small blood vessels, leading to purple spots on the skin and joint pain.
7. Raynaud's phenomenon: a condition that affects the blood vessels in the fingers and toes, causing them to become narrow and restrict blood flow in response to cold temperatures or stress.

Treatment for vascular skin diseases depends on the specific condition and its severity. It may include medications, lifestyle changes, and in some cases, surgery.

Streptonigrin is not a medical condition, it is actually a naturally occurring antibiotic and antineoplastic agent. It is produced by the bacterium Streptomyces flocculus and has been studied for its potential use in cancer chemotherapy due to its ability to inhibit DNA synthesis in cancer cells. However, its clinical use is limited due to its toxicity.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

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.

Systemic Scleroderma, also known as Systemic Sclerosis (SSc), is a rare, chronic autoimmune disease that involves the abnormal growth and accumulation of collagen in various connective tissues, blood vessels, and organs throughout the body. This excessive collagen production leads to fibrosis or scarring, which can cause thickening, hardening, and tightening of the skin and damage to internal organs such as the heart, lungs, kidneys, and gastrointestinal tract.

Systemic Scleroderma is characterized by two main features: small blood vessel abnormalities (Raynaud's phenomenon) and fibrosis. The disease can be further classified into two subsets based on the extent of skin involvement: limited cutaneous systemic sclerosis (lcSSc) and diffuse cutaneous systemic sclerosis (dcSSc).

Limited cutaneous systemic sclerosis affects the skin distally, typically involving fingers, hands, forearms, feet, lower legs, and face. It is often associated with Raynaud's phenomenon, calcinosis, telangiectasias, and pulmonary arterial hypertension.

Diffuse cutaneous systemic sclerosis involves more extensive skin thickening and fibrosis that spreads proximally to affect the trunk, upper arms, thighs, and face. It is commonly associated with internal organ involvement, such as interstitial lung disease, heart disease, and kidney problems.

The exact cause of Systemic Scleroderma remains unknown; however, it is believed that genetic, environmental, and immunological factors contribute to its development. There is currently no cure for Systemic Scleroderma, but various treatments can help manage symptoms, slow disease progression, and improve quality of life.

CD (cluster of differentiation) antigens are cell-surface proteins that are expressed on leukocytes (white blood cells) and can be used to identify and distinguish different subsets of these cells. They are important markers in the field of immunology and hematology, and are commonly used to diagnose and monitor various diseases, including cancer, autoimmune disorders, and infectious diseases.

CD antigens are designated by numbers, such as CD4, CD8, CD19, etc., which refer to specific proteins found on the surface of different types of leukocytes. For example, CD4 is a protein found on the surface of helper T cells, while CD8 is found on cytotoxic T cells.

CD antigens can be used as targets for immunotherapy, such as monoclonal antibody therapy, in which antibodies are designed to bind to specific CD antigens and trigger an immune response against cancer cells or infected cells. They can also be used as markers to monitor the effectiveness of treatments and to detect minimal residual disease (MRD) after treatment.

It's important to note that not all CD antigens are exclusive to leukocytes, some can be found on other cell types as well, and their expression can vary depending on the activation state or differentiation stage of the cells.

Vascular Cell Adhesion Molecule-1 (VCAM-1) is a glycoprotein expressed on the surface of endothelial cells that plays a crucial role in the inflammatory response. It is involved in the recruitment and adhesion of leukocytes to the site of inflammation. VCAM-1 interacts with integrins on the surface of leukocytes, particularly very late antigen-4 (VLA-4), to facilitate this adhesion process. This interaction leads to the activation of signaling pathways that promote the migration of leukocytes across the endothelial barrier and into the surrounding tissue, where they can contribute to the immune response and resolution of inflammation. Increased expression of VCAM-1 has been associated with various inflammatory diseases, including atherosclerosis, rheumatoid arthritis, and multiple sclerosis.

Microcephaly is a medical condition where an individual has a smaller than average head size. The circumference of the head is significantly below the normal range for age and sex. This condition is typically caused by abnormal brain development, which can be due to genetic factors or environmental influences such as infections or exposure to harmful substances during pregnancy.

Microcephaly can be present at birth (congenital) or develop in the first few years of life. People with microcephaly often have intellectual disabilities, delayed development, and other neurological problems. However, the severity of these issues can vary widely, ranging from mild to severe. It is important to note that not all individuals with microcephaly will experience significant impairments or challenges.

Cutaneous mastocytosis is a condition characterized by the abnormal accumulation of mast cells in the skin. Mast cells are a type of immune cell that releases chemicals such as histamine, heparin, and leukotrienes, which play a role in allergic reactions and inflammation. In cutaneous mastocytosis, the excessive buildup of mast cells can cause various skin symptoms, including redness, itching, swelling, and formation of lesions or tumors.

The condition is typically divided into several subtypes based on the age of onset and the clinical presentation. The most common form in children is called urticaria pigmentosa, which presents as small, reddish-brown spots or bumps that may become raised and itchy when scratched or rubbed (Darier's sign). In adults, a more severe form known as diffuse cutaneous mastocytosis can occur, where the entire skin becomes thickened, red, and swollen.

Cutaneous mastocytosis is usually diagnosed based on the patient's medical history, physical examination, and results from skin biopsies. Treatment typically focuses on relieving symptoms and preventing mast cell activation. Medications such as antihistamines, topical steroids, and mast cell stabilizers may be used to control itching, flushing, and other symptoms associated with the condition. In some cases, systemic therapies or phototherapy may also be recommended.

Fluorescein angiography is a medical diagnostic procedure used in ophthalmology to examine the blood flow in the retina and choroid, which are the inner layers of the eye. This test involves injecting a fluorescent dye, Fluorescein, into a patient's arm vein. As the dye reaches the blood vessels in the eye, a specialized camera takes rapid sequences of photographs to capture the dye's circulation through the retina and choroid.

The images produced by fluorescein angiography can help doctors identify any damage to the blood vessels, leakage, or abnormal growth of new blood vessels. This information is crucial in diagnosing and managing various eye conditions such as age-related macular degeneration, diabetic retinopathy, retinal vein occlusions, and inflammatory eye diseases.

It's important to note that while fluorescein angiography is a valuable diagnostic tool, it does carry some risks, including temporary side effects like nausea, vomiting, or allergic reactions to the dye. In rare cases, severe adverse reactions can occur, so patients should discuss these potential risks with their healthcare provider before undergoing the procedure.

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.

Activin receptors are a type of serine/threonine kinase receptor that play a crucial role in various biological processes, including cell growth, differentiation, and apoptosis. They are activated by members of the TGF-Ī² (transforming growth factor-beta) superfamily, particularly activins.

There are two main types of activin receptors: ActR-I and ActR-II. ActR-I exists in two isoforms, ALK2 and ALK4, while ActR-II has two isoforms, ActR-IIA and ActR-IIB. Activation of these receptors leads to the phosphorylation of intracellular signaling molecules, which then translocate to the nucleus and regulate gene expression.

Abnormalities in activin receptor function have been implicated in various diseases, including cancer, fibrosis, and developmental disorders. Therefore, activin receptors are an important target for therapeutic intervention in these conditions.

Pulmonary veins are blood vessels that carry oxygenated blood from the lungs to the left atrium of the heart. There are four pulmonary veins in total, two from each lung, and they are the only veins in the body that carry oxygen-rich blood. The oxygenated blood from the pulmonary veins is then pumped by the left ventricle to the rest of the body through the aorta. Any blockage or damage to the pulmonary veins can lead to various cardiopulmonary conditions, such as pulmonary hypertension and congestive heart failure.

Retinal vessels refer to the blood vessels that are located in the retina, which is the light-sensitive tissue that lines the inner surface of the eye. The retina contains two types of blood vessels: arteries and veins.

The central retinal artery supplies oxygenated blood to the inner layers of the retina, while the central retinal vein drains deoxygenated blood from the retina. These vessels can be visualized during a routine eye examination using an ophthalmoscope, which allows healthcare professionals to assess their health and any potential abnormalities.

Retinal vessels are essential for maintaining the health and function of the retina, and any damage or changes to these vessels can affect vision and lead to various eye conditions such as diabetic retinopathy, retinal vein occlusion, and hypertensive retinopathy.

Growth differentiation factors (GDFs) are a subfamily of the transforming growth factor-beta (TGF-Ī²) superfamily of cytokines. They play crucial roles in various biological processes, including cell growth, differentiation, and apoptosis. Specifically, GDFs are involved in the development and maintenance of the skeletal, reproductive, and nervous systems. Some members of this family include GDF5, GDF6, and GDF7, which are essential for normal joint formation and cartilage development; GDF8 (also known as myostatin) is a negative regulator of muscle growth; and GDF11 has been implicated in the regulation of neurogenesis and age-related changes.

Protein kinases are a group of enzymes that play a crucial role in many cellular processes by adding phosphate groups to other proteins, a process known as phosphorylation. This modification can activate or deactivate the target protein's function, thereby regulating various signaling pathways within the cell. Protein kinases are essential for numerous biological functions, including metabolism, signal transduction, cell cycle progression, and apoptosis (programmed cell death). Abnormal regulation of protein kinases has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Gingival diseases are infections or inflammations that affect the gingiva, which is the part of the gum around the base of the teeth. These diseases can be caused by bacteria found in dental plaque and can lead to symptoms such as redness, swelling, bleeding, and receding gums. If left untreated, gingival diseases can progress to periodontal disease, a more serious condition that can result in tooth loss. Common types of gingival diseases include gingivitis and periodontitis.

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

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.

The G2 phase, also known as the "gap 2 phase," is a stage in the cell cycle that occurs after DNA replication (S phase) and before cell division (mitosis). During this phase, the cell prepares for mitosis by completing the synthesis of proteins and organelles needed for chromosome separation. The cell also checks for any errors or damage to the DNA before entering mitosis. This phase is a critical point in the cell cycle where proper regulation ensures the faithful transmission of genetic information from one generation of cells to the next. If significant DNA damage is detected during G2, the cell may undergo programmed cell death (apoptosis) instead of dividing.

Chromosome breakage is a medical term that refers to the breaking or fragmentation of chromosomes, which are thread-like structures located in the nucleus of cells that carry genetic information. Normally, chromosomes are tightly coiled and consist of two strands called chromatids, joined together at a central point called the centromere.

Chromosome breakage can occur spontaneously or be caused by environmental factors such as radiation or chemicals, or inherited genetic disorders. When a chromosome breaks, it can result in various genetic abnormalities, depending on the location and severity of the break.

For instance, if the break occurs in a region containing important genes, it can lead to the loss or alteration of those genes, causing genetic diseases or birth defects. In some cases, the broken ends of the chromosome may rejoin incorrectly, leading to chromosomal rearrangements such as translocations, deletions, or inversions. These rearrangements can also result in genetic disorders or cancer.

Chromosome breakage is commonly observed in individuals with certain inherited genetic conditions, such as Bloom syndrome, Fanconi anemia, and ataxia-telangiectasia, which are characterized by an increased susceptibility to chromosome breakage due to defects in DNA repair mechanisms.

A missense mutation is a type of point mutation in which a single nucleotide change results in the substitution of a different amino acid in the protein that is encoded by the affected gene. This occurs when the altered codon (a sequence of three nucleotides that corresponds to a specific amino acid) specifies a different amino acid than the original one. The function and/or stability of the resulting protein may be affected, depending on the type and location of the missense mutation. Missense mutations can have various effects, ranging from benign to severe, depending on the importance of the changed amino acid for the protein's structure or function.

Dermoscopy, also known as dermatoscopy or epiluminescence microscopy, is a non-invasive diagnostic technique used in dermatology to evaluate skin lesions, such as moles and pigmented skin tumors. This method involves the use of a handheld device called a dermoscope, which consists of a magnifying lens, a light source, and a transparent plate or immersion fluid that allows for better visualization of the skin's surface structures.

Dermoscopy enables dermatologists to examine the pigmented patterns, vascular structures, and other morphological features hidden beneath the skin's surface that are not visible to the naked eye. By observing these details, dermatologists can improve their ability to differentiate between benign and malignant lesions, leading to more accurate diagnoses and appropriate treatment decisions.

The primary uses of dermoscopy include:

1. Early detection and diagnosis of melanoma and other skin cancers, such as basal cell carcinoma and squamous cell carcinoma.
2. Monitoring the evolution of suspicious moles or lesions over time.
3. Assisting in the identification of various benign skin growths, like seborrheic keratoses, dermatofibromas, and nevi (moles).
4. Improving the diagnostic accuracy for infectious skin conditions, inflammatory processes, and other dermatological disorders.

Overall, dermoscopy is a valuable tool in the field of dermatology that enhances the clinician's ability to diagnose and manage various skin conditions accurately and effectively.

X-rays, also known as radiographs, are a type of electromagnetic radiation with higher energy and shorter wavelength than visible light. In medical imaging, X-rays are used to produce images of the body's internal structures, such as bones and organs, by passing the X-rays through the body and capturing the resulting shadows or patterns on a specialized film or digital detector.

The amount of X-ray radiation used is carefully controlled to minimize exposure and ensure patient safety. Different parts of the body absorb X-rays at different rates, allowing for contrast between soft tissues and denser structures like bone. This property makes X-rays an essential tool in diagnosing and monitoring a wide range of medical conditions, including fractures, tumors, infections, and foreign objects within the body.

Central nervous system (CNS) vascular malformations are abnormal tangles or masses of blood vessels in the brain or spinal cord. These malformations can be congenital (present at birth) or acquired (develop later in life). They can vary in size, location, and symptoms, which may include headaches, seizures, weakness, numbness, difficulty speaking or understanding speech, and vision problems.

There are several types of CNS vascular malformations, including:

1. Arteriovenous malformations (AVMs): These are tangles of arteries and veins with a direct connection between them, bypassing the capillary network. AVMs can cause bleeding in the brain or spinal cord, leading to stroke or neurological deficits.
2. Cavernous malformations: These are clusters of dilated, thin-walled blood vessels that form a sac-like structure. They can rupture and bleed, causing symptoms such as seizures, headaches, or neurological deficits.
3. Developmental venous anomalies (DVAs): These are benign vascular malformations characterized by an abnormal pattern of veins that drain blood from the brain. DVAs are usually asymptomatic but can be associated with other vascular malformations.
4. Capillary telangiectasias: These are small clusters of dilated capillaries in the brain or spinal cord. They are usually asymptomatic and found incidentally during imaging studies.
5. Moyamoya disease: This is a rare, progressive cerebrovascular disorder characterized by the narrowing or blockage of the internal carotid arteries and their branches. This can lead to decreased blood flow to the brain, causing symptoms such as headaches, seizures, and strokes.

The diagnosis of CNS vascular malformations typically involves imaging studies such as MRI or CT scans, and sometimes angiography. Treatment options may include observation, medication, surgery, or endovascular procedures, depending on the type, location, and severity of the malformation.

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.

Chromosome aberrations refer to structural and numerical changes in the chromosomes that can occur spontaneously or as a result of exposure to mutagenic agents. These changes can affect the genetic material encoded in the chromosomes, leading to various consequences such as developmental abnormalities, cancer, or infertility.

Structural aberrations include deletions, duplications, inversions, translocations, and rings, which result from breaks and rearrangements of chromosome segments. Numerical aberrations involve changes in the number of chromosomes, such as aneuploidy (extra or missing chromosomes) or polyploidy (multiples of a complete set of chromosomes).

Chromosome aberrations can be detected and analyzed using various cytogenetic techniques, including karyotyping, fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). These methods allow for the identification and characterization of chromosomal changes at the molecular level, providing valuable information for genetic counseling, diagnosis, and research.

Bone morphogenetic protein receptors, type II (BMPR2) are a type of cell surface receptor that bind to bone morphogenetic proteins (BMPs), which are growth factors involved in the regulation of various cellular processes such as cell proliferation, differentiation, and apoptosis. BMPR2 is a serine/threonine kinase receptor and forms a complex with type I BMP receptors upon BMP binding. This complex activation leads to the phosphorylation and activation of downstream signaling molecules, including SMAD proteins, which ultimately regulate gene transcription.

Mutations in the BMPR2 gene have been associated with several genetic disorders, most notably pulmonary arterial hypertension (PAH), a rare but life-threatening condition characterized by increased pressure in the pulmonary arteries that supply blood to the lungs. In addition, BMPR2 mutations have also been linked to Marfan syndrome, a genetic disorder that affects connective tissue and can cause skeletal, cardiovascular, and ocular abnormalities.

Apoptosis is a programmed and controlled cell death process that occurs in multicellular organisms. It is a natural process that helps maintain tissue homeostasis by eliminating damaged, infected, or unwanted cells. During apoptosis, the cell undergoes a series of morphological changes, including cell shrinkage, chromatin condensation, and fragmentation into membrane-bound vesicles called apoptotic bodies. These bodies are then recognized and engulfed by neighboring cells or phagocytic cells, preventing an inflammatory response. Apoptosis is regulated by a complex network of intracellular signaling pathways that involve proteins such as caspases, Bcl-2 family members, and inhibitors of apoptosis (IAPs).

Infrared rays are not typically considered in the context of medical definitions. They are a type of electromagnetic radiation with longer wavelengths than those of visible light, ranging from 700 nanometers to 1 millimeter. In the field of medicine, infrared radiation is sometimes used in therapeutic settings for its heat properties, such as in infrared saunas or infrared therapy devices. However, infrared rays themselves are not a medical condition or diagnosis.

Gastrointestinal (GI) hemorrhage is a term used to describe any bleeding that occurs in the gastrointestinal tract, which includes the esophagus, stomach, small intestine, large intestine, and rectum. The bleeding can range from mild to severe and can produce symptoms such as vomiting blood, passing black or tarry stools, or having low blood pressure.

GI hemorrhage can be classified as either upper or lower, depending on the location of the bleed. Upper GI hemorrhage refers to bleeding that occurs above the ligament of Treitz, which is a point in the small intestine where it becomes narrower and turns a corner. Common causes of upper GI hemorrhage include gastritis, ulcers, esophageal varices, and Mallory-Weiss tears.

Lower GI hemorrhage refers to bleeding that occurs below the ligament of Treitz. Common causes of lower GI hemorrhage include diverticulosis, colitis, inflammatory bowel disease, and vascular abnormalities such as angiodysplasia.

The diagnosis of GI hemorrhage is often made based on the patient's symptoms, medical history, physical examination, and diagnostic tests such as endoscopy, CT scan, or radionuclide scanning. Treatment depends on the severity and cause of the bleeding and may include medications, endoscopic procedures, surgery, or a combination of these approaches.

The fovea centralis, also known as the macula lutea, is a small pit or depression located in the center of the retina, an light-sensitive tissue at the back of the eye. It is responsible for sharp, detailed vision (central vision) and color perception. The fovea contains only cones, the photoreceptor cells that are responsible for color vision and high visual acuity. It has a higher concentration of cones than any other area in the retina, allowing it to provide the greatest detail and color discrimination. The center of the fovea is called the foveola, which contains the highest density of cones and is avascular, meaning it lacks blood vessels to avoid interfering with the light passing through to the photoreceptor cells.

Therapeutic embolization is a medical procedure that involves intentionally blocking or obstructing blood vessels to stop excessive bleeding or block the flow of blood to a tumor or abnormal tissue. This is typically accomplished by injecting small particles, such as microspheres or coils, into the targeted blood vessel through a catheter, which is inserted into a larger blood vessel and guided to the desired location using imaging techniques like X-ray or CT scanning. The goal of therapeutic embolization is to reduce the size of a tumor, control bleeding, or block off abnormal blood vessels that are causing problems.

Nucleic acid synthesis inhibitors are a class of antimicrobial, antiviral, or antitumor agents that block the synthesis of nucleic acids (DNA or RNA) by interfering with enzymes involved in their replication. These drugs can target various stages of nucleic acid synthesis, including DNA transcription, replication, and repair, as well as RNA transcription and processing.

Examples of nucleic acid synthesis inhibitors include:

1. Antibiotics like quinolones (e.g., ciprofloxacin), rifamycins (e.g., rifampin), and trimethoprim, which target bacterial DNA gyrase, RNA polymerase, or dihydrofolate reductase, respectively.
2. Antiviral drugs like reverse transcriptase inhibitors (e.g., zidovudine, lamivudine) and integrase strand transfer inhibitors (e.g., raltegravir), which target HIV replication by interfering with viral enzymes required for DNA synthesis.
3. Antitumor drugs like antimetabolites (e.g., methotrexate, 5-fluorouracil) and topoisomerase inhibitors (e.g., etoposide, doxorubicin), which interfere with DNA replication and repair in cancer cells.

These drugs have been widely used for treating various bacterial and viral infections, as well as cancers, due to their ability to selectively inhibit the growth of target cells without affecting normal cellular functions significantly. However, they may also cause side effects related to their mechanism of action or off-target effects on non-target cells.

I'm happy to help! However, I believe there may be a slight mistake in your question. The abbreviation "cdc" is not typically associated with genetics or genes in the context of medical definitions.

If you meant to ask for a definition of "genes," here it is:

Genes are segments of DNA (deoxyribonucleic acid) that contain the instructions for the development, function, and reproduction of all living organisms. They are the basic units of heredity, passed down from one generation to the next. Genes encode specific proteins or RNA molecules that play critical roles in the structure, function, and regulation of the body's cells, tissues, and organs.

If you had a different term in mind, please let me know, and I will be happy to provide a definition for it!

Hand dermatoses is a general term used to describe various inflammatory skin conditions that affect the hands. These conditions can cause symptoms such as redness, swelling, itching, blistering, scaling, and cracking of the skin on the hands. Common examples of hand dermatoses include:

1. Irritant contact dermatitis: A reaction that occurs when the skin comes into contact with irritants such as chemicals, soaps, or detergents.
2. Allergic contact dermatitis: A reaction that occurs when the skin comes into contact with allergens, such as nickel, rubber, or poison ivy.
3. Atopic dermatitis (eczema): A chronic skin condition characterized by dry, itchy, and inflamed skin.
4. Psoriasis: A chronic skin condition characterized by red, scaly patches that can occur anywhere on the body, including the hands.
5. Dyshidrotic eczema: A type of eczema that causes small blisters to form on the sides of the fingers, palms, and soles of the feet.
6. Lichen planus: An inflammatory skin condition that can cause purple or white patches to form on the hands and other parts of the body.
7. Scabies: A contagious skin condition caused by mites that burrow into the skin and lay eggs, causing intense itching and a rash.

Treatment for hand dermatoses depends on the specific diagnosis and may include topical creams or ointments, oral medications, phototherapy, or avoidance of triggers.

A cell line that is derived from tumor cells and has been adapted to grow in culture. These cell lines are often used in research to study the characteristics of cancer cells, including their growth patterns, genetic changes, and responses to various treatments. They can be established from many different types of tumors, such as carcinomas, sarcomas, and leukemias. Once established, these cell lines can be grown and maintained indefinitely in the laboratory, allowing researchers to conduct experiments and studies that would not be feasible using primary tumor cells. It is important to note that tumor cell lines may not always accurately represent the behavior of the original tumor, as they can undergo genetic changes during their time in culture.

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.

Amaurosis fugax is a medical term that describes a temporary loss of vision in one eye, which is often described as a "shade or curtain falling over the field of vision." It's usually caused by a temporary interruption of blood flow to the retina or optic nerve. This condition is often associated with conditions such as giant cell arteritis, carotid artery stenosis, and cardiovascular disease.

It's important to note that Amaurosis fugax can be a warning sign for a more serious medical event, such as a stroke, so it's essential to seek medical attention promptly if you experience any symptoms of this condition.

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

In the context of cell biology, "S phase" refers to the part of the cell cycle during which DNA replication occurs. The "S" stands for synthesis, reflecting the active DNA synthesis that takes place during this phase. It is preceded by G1 phase (gap 1) and followed by G2 phase (gap 2), with mitosis (M phase) being the final stage of the cell cycle.

During S phase, the cell's DNA content effectively doubles as each chromosome is replicated to ensure that the two resulting daughter cells will have the same genetic material as the parent cell. This process is carefully regulated and coordinated with other events in the cell cycle to maintain genomic stability.

"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.

A brain abscess is a localized collection of pus in the brain that is caused by an infection. It can develop as a result of a bacterial, fungal, or parasitic infection that spreads to the brain from another part of the body or from an infection that starts in the brain itself (such as from a head injury or surgery).

The symptoms of a brain abscess may include headache, fever, confusion, seizures, weakness or numbness on one side of the body, and changes in vision, speech, or behavior. Treatment typically involves antibiotics to treat the infection, as well as surgical drainage of the abscess to relieve pressure on the brain.

It is a serious medical condition that requires prompt diagnosis and treatment to prevent potentially life-threatening complications such as brain herniation or permanent neurological damage.

The pulmonary artery is a large blood vessel that carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation. It divides into two main branches, the right and left pulmonary arteries, which further divide into smaller vessels called arterioles, and then into a vast network of capillaries in the lungs where gas exchange occurs. The thin walls of these capillaries allow oxygen to diffuse into the blood and carbon dioxide to diffuse out, making the blood oxygen-rich before it is pumped back to the left side of the heart through the pulmonary veins. This process is crucial for maintaining proper oxygenation of the body's tissues and organs.

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.

Retinal pigments refer to the light-sensitive chemicals found in the retina, specifically within the photoreceptor cells called rods and cones. The main types of retinal pigments are rhodopsin (also known as visual purple) in rods and iodopsins in cones. These pigments play a crucial role in the process of vision by absorbing light and initiating a series of chemical reactions that ultimately trigger nerve impulses, which are then transmitted to the brain and interpreted as visual images. Rhodopsin is more sensitive to lower light levels and is responsible for night vision, while iodopsins are sensitive to specific wavelengths of light and contribute to color vision.

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.

Lymphocytes are a type of white blood cell that is an essential part of the immune system. They are responsible for recognizing and responding to potentially harmful substances such as viruses, bacteria, and other foreign invaders. There are two main types of lymphocytes: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).

B-lymphocytes produce antibodies, which are proteins that help to neutralize or destroy foreign substances. When a B-cell encounters a foreign substance, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies. These antibodies bind to the foreign substance, marking it for destruction by other immune cells.

T-lymphocytes, on the other hand, are involved in cell-mediated immunity. They directly attack and destroy infected cells or cancerous cells. T-cells can also help to regulate the immune response by producing chemical signals that activate or inhibit other immune cells.

Lymphocytes are produced in the bone marrow and mature in either the bone marrow (B-cells) or the thymus gland (T-cells). They circulate throughout the body in the blood and lymphatic system, where they can be found in high concentrations in lymph nodes, the spleen, and other lymphoid organs.

Abnormalities in the number or function of lymphocytes can lead to a variety of immune-related disorders, including immunodeficiency diseases, autoimmune disorders, and cancer.

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 "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Genomic instability is a term used in genetics and molecular biology to describe a state of increased susceptibility to genetic changes or mutations in the genome. It can be defined as a condition where the integrity and stability of the genome are compromised, leading to an increased rate of DNA alterations such as point mutations, insertions, deletions, and chromosomal rearrangements.

Genomic instability is a hallmark of cancer cells and can also be observed in various other diseases, including genetic disorders and aging. It can arise due to defects in the DNA repair mechanisms, telomere maintenance, epigenetic regulation, or chromosome segregation during cell division. These defects can result from inherited genetic mutations, acquired somatic mutations, exposure to environmental mutagens, or age-related degenerative changes.

Genomic instability is a significant factor in the development and progression of cancer as it promotes the accumulation of oncogenic mutations that contribute to tumor initiation, growth, and metastasis. Therefore, understanding the mechanisms underlying genomic instability is crucial for developing effective strategies for cancer prevention, diagnosis, and treatment.

Vascular malformations are abnormalities in the development and growth of blood vessels and lymphatic vessels that can occur anywhere in the body. They can be present at birth or develop later in life, and they can affect both the form and function of the affected tissues and organs. Vascular malformations can involve arteries, veins, capillaries, and/or lymphatic vessels, and they can range from simple, localized lesions to complex, multifocal disorders.

Vascular malformations are typically classified based on their location, size, flow characteristics, and the type of blood or lymphatic vessels involved. Some common types of vascular malformations include:

1. Capillary malformations (CMs): These are characterized by abnormal dilated capillaries that can cause red or pink discoloration of the skin, typically on the face or neck.
2. Venous malformations (VMs): These involve abnormal veins that can cause swelling, pain, and disfigurement in the affected area.
3. Lymphatic malformations (LMs): These involve abnormal lymphatic vessels that can cause swelling, infection, and other complications.
4. Arteriovenous malformations (AVMs): These involve a tangled mass of arteries and veins that can cause high-flow lesions, bleeding, and other serious complications.
5. Combined vascular malformations: These involve a combination of different types of blood or lymphatic vessels, such as capillary-lymphatic-venous malformations (CLVMs) or arteriovenous-lymphatic malformations (AVLMs).

The exact cause of vascular malformations is not fully understood, but they are believed to result from genetic mutations that affect the development and growth of blood vessels and lymphatic vessels. Treatment options for vascular malformations depend on the type, size, location, and severity of the lesion, as well as the patient's age and overall health. Treatment may include medication, compression garments, sclerotherapy, surgery, or a combination of these approaches.

Erythema is a term used in medicine to describe redness of the skin, which occurs as a result of increased blood flow in the superficial capillaries. This redness can be caused by various factors such as inflammation, infection, trauma, or exposure to heat, cold, or ultraviolet radiation. In some cases, erythema may also be accompanied by other symptoms such as swelling, warmth, pain, or itching. It is a common finding in many medical conditions and can vary in severity from mild to severe.

Intracellular signaling peptides and proteins are molecules that play a crucial role in transmitting signals within cells, which ultimately lead to changes in cell behavior or function. These signals can originate from outside the cell (extracellular) or within the cell itself. Intracellular signaling molecules include various types of peptides and proteins, such as:

1. G-protein coupled receptors (GPCRs): These are seven-transmembrane domain receptors that bind to extracellular signaling molecules like hormones, neurotransmitters, or chemokines. Upon activation, they initiate a cascade of intracellular signals through G proteins and secondary messengers.
2. Receptor tyrosine kinases (RTKs): These are transmembrane receptors that bind to growth factors, cytokines, or hormones. Activation of RTKs leads to autophosphorylation of specific tyrosine residues, creating binding sites for intracellular signaling proteins such as adapter proteins, phosphatases, and enzymes like Ras, PI3K, and Src family kinases.
3. Second messenger systems: Intracellular second messengers are small molecules that amplify and propagate signals within the cell. Examples include cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), diacylglycerol (DAG), inositol triphosphate (IP3), calcium ions (Ca2+), and nitric oxide (NO). These second messengers activate or inhibit various downstream effectors, leading to changes in cellular responses.
4. Signal transduction cascades: Intracellular signaling proteins often form complex networks of interacting molecules that relay signals from the plasma membrane to the nucleus. These cascades involve kinases (protein kinases A, B, C, etc.), phosphatases, and adapter proteins, which ultimately regulate gene expression, cell cycle progression, metabolism, and other cellular processes.
5. Ubiquitination and proteasome degradation: Intracellular signaling pathways can also control protein stability by modulating ubiquitin-proteasome degradation. E3 ubiquitin ligases recognize specific substrates and conjugate them with ubiquitin molecules, targeting them for proteasomal degradation. This process regulates the abundance of key signaling proteins and contributes to signal termination or amplification.

In summary, intracellular signaling pathways involve a complex network of interacting proteins that relay signals from the plasma membrane to various cellular compartments, ultimately regulating gene expression, metabolism, and other cellular processes. Dysregulation of these pathways can contribute to disease development and progression, making them attractive targets for therapeutic intervention.

Telomeric Repeat Binding Protein 2 (TRF2) is a protein that binds to the telomeres, which are the repetitive DNA sequences found at the ends of chromosomes. TRF2 plays a crucial role in protecting the telomeres from being recognized as damaged or broken DNA, which could otherwise lead to chromosomal instability and cellular senescence or apoptosis.

TRF2 is a member of the shelterin complex, a group of proteins that bind to and protect telomeres. TRF2 specifically binds to double-stranded TTAGGG repeats in the telomeric DNA through its N-terminal Myb-like DNA binding domain. By binding to the telomeres, TRF2 helps to prevent the activation of the DNA damage response (DDR) pathway and the subsequent activation of p53-dependent cell cycle checkpoints or apoptosis.

TRF2 has also been shown to play a role in regulating the length of telomeres. It can inhibit the activity of telomerase, an enzyme that adds repetitive DNA sequences to the ends of chromosomes, thereby limiting the extension of telomeres. TRF2 can also promote the formation of t-loops, a higher-order structure in which the 3' overhang of the telomere invades the double-stranded telomeric DNA, forming a displacement loop (D-loop). This helps to protect the telomere from being recognized as a double-strand break and degraded by nucleases.

Mutations in TRF2 have been associated with several human diseases, including premature aging disorders such as dyskeratosis congenita and Hoyeraal-Hreidarsson syndrome, as well as cancer.

Subretinal fluid (SRF) refers to the abnormal accumulation of fluid between the neurosensory retina and the pigment epithelium of the eye. This can occur due to various conditions such as age-related macular degeneration, central serous chorioretinopathy, or retinal detachment. The presence of subretinal fluid can distort vision and may require medical intervention depending on the underlying cause and severity of the condition.

Microscopic angioscopy is not a widely recognized or established medical term. However, based on the individual terms, it can be interpreted as the use of a microscope with an angioscope (a type of endoscope used for visualizing the interior of blood vessels) to examine the microscopic structures of the inner walls of blood vessels. This technique would allow for detailed examination of the vasculature at a cellular level, potentially providing valuable information for research and diagnosis of various vascular diseases. However, as this is not a standard medical procedure or term, it's essential to consult the relevant literature or experts in the field for more precise information.

Pulmonary hypertension is a medical condition characterized by increased blood pressure in the pulmonary arteries, which are the blood vessels that carry blood from the right side of the heart to the lungs. This results in higher than normal pressures in the pulmonary circulation and can lead to various symptoms and complications.

Pulmonary hypertension is typically defined as a mean pulmonary artery pressure (mPAP) greater than or equal to 25 mmHg at rest, as measured by right heart catheterization. The World Health Organization (WHO) classifies pulmonary hypertension into five groups based on the underlying cause:

1. Pulmonary arterial hypertension (PAH): This group includes idiopathic PAH, heritable PAH, drug-induced PAH, and associated PAH due to conditions such as connective tissue diseases, HIV infection, portal hypertension, congenital heart disease, and schistosomiasis.
2. Pulmonary hypertension due to left heart disease: This group includes conditions that cause elevated left atrial pressure, such as left ventricular systolic or diastolic dysfunction, valvular heart disease, and congenital cardiovascular shunts.
3. Pulmonary hypertension due to lung diseases and/or hypoxia: This group includes chronic obstructive pulmonary disease (COPD), interstitial lung disease, sleep-disordered breathing, alveolar hypoventilation disorders, and high altitude exposure.
4. Chronic thromboembolic pulmonary hypertension (CTEPH): This group includes persistent obstruction of the pulmonary arteries due to organized thrombi or emboli.
5. Pulmonary hypertension with unclear and/or multifactorial mechanisms: This group includes hematologic disorders, systemic disorders, metabolic disorders, and other conditions that can cause pulmonary hypertension but do not fit into the previous groups.

Symptoms of pulmonary hypertension may include shortness of breath, fatigue, chest pain, lightheadedness, and syncope (fainting). Diagnosis typically involves a combination of medical history, physical examination, imaging studies, and invasive testing such as right heart catheterization. Treatment depends on the underlying cause but may include medications, oxygen therapy, pulmonary rehabilitation, and, in some cases, surgical intervention.

A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.

For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.

It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.

Varicose veins are defined as enlarged, swollen, and twisting veins often appearing blue or dark purple, which usually occur in the legs. They are caused by weakened valves and vein walls that can't effectively push blood back toward the heart. This results in a buildup of blood, causing the veins to bulge and become varicose.

The condition is generally harmless but may cause symptoms like aching, burning, muscle cramp, or a feeling of heaviness in the legs. In some cases, varicose veins can lead to more serious problems, such as skin ulcers, blood clots, or chronic venous insufficiency. Treatment options include lifestyle changes, compression stockings, and medical procedures like sclerotherapy, laser surgery, or endovenous ablation.

The macula lutea, often simply referred to as the macula or fovea centralis, is a part of the eye that is responsible for central vision and color perception. It's located in the center of the retina, the light-sensitive tissue at the back of the eye. The macula contains a high concentration of pigments called xanthophylls, which give it a yellowish color and protect the photoreceptor cells in this area from damage by blue light.

The central part of the macula is called the fovea, which is a small depression that contains only cones, the photoreceptor cells responsible for color vision and high visual acuity. The fovea is surrounded by the parafovea and the perifovea, which contain both cones and rods, the photoreceptor cells responsible for low-light vision and peripheral vision.

Damage to the macula can result in a loss of central vision and color perception, a condition known as age-related macular degeneration (AMD), which is a leading cause of blindness in older adults. Other conditions that can affect the macula include macular edema, macular holes, and macular pucker.

DNA Mutational Analysis is a laboratory test used to identify genetic variations or changes (mutations) in the DNA sequence of a gene. This type of analysis can be used to diagnose genetic disorders, predict the risk of developing certain diseases, determine the most effective treatment for cancer, or assess the likelihood of passing on an inherited condition to offspring.

The test involves extracting DNA from a patient's sample (such as blood, saliva, or tissue), amplifying specific regions of interest using polymerase chain reaction (PCR), and then sequencing those regions to determine the precise order of nucleotide bases in the DNA molecule. The resulting sequence is then compared to reference sequences to identify any variations or mutations that may be present.

DNA Mutational Analysis can detect a wide range of genetic changes, including single-nucleotide polymorphisms (SNPs), insertions, deletions, duplications, and rearrangements. The test is often used in conjunction with other diagnostic tests and clinical evaluations to provide a comprehensive assessment of a patient's genetic profile.

It is important to note that not all mutations are pathogenic or associated with disease, and the interpretation of DNA Mutational Analysis results requires careful consideration of the patient's medical history, family history, and other relevant factors.

A telomere is a region of repetitive DNA sequences found at the end of chromosomes, which protects the genetic data from damage and degradation during cell division. Telomeres naturally shorten as cells divide, and when they become too short, the cell can no longer divide and becomes senescent or dies. This natural process is associated with aging and various age-related diseases. The length of telomeres can also be influenced by various genetic and environmental factors, including stress, diet, and lifestyle.

The G2 phase cell cycle checkpoint is a point in the cell cycle, specifically in the G2 phase, where the cell checks for any DNA damage or other issues that may have occurred during the DNA synthesis phase (S phase) before proceeding to mitosis. This checkpoint serves as a quality control mechanism to ensure that the genetic material is accurately and completely replicated and that the cell is ready to divide. If DNA damage or other problems are detected, the cell cycle is halted at the G2 checkpoint until the issues can be resolved. If the damage is too severe or cannot be repaired, the cell may undergo programmed cell death (apoptosis) to prevent the propagation of potentially harmful mutations.

Aphidicolin is an antimicrotubule agent that is specifically a inhibitor of DNA polymerase alpha. It is an antibiotic that is produced by the fungus Cephalosporium aphidicola and is used in research to study the cell cycle and DNA replication. In clinical medicine, it has been explored as a potential anticancer agent, although its use is not currently approved for this indication.

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.

Immunologic deficiency syndromes refer to a group of disorders characterized by defective functioning of the immune system, leading to increased susceptibility to infections and malignancies. These deficiencies can be primary (genetic or congenital) or secondary (acquired due to environmental factors, medications, or diseases).

Primary immunodeficiency syndromes (PIDS) are caused by inherited genetic mutations that affect the development and function of immune cells, such as T cells, B cells, and phagocytes. Examples include severe combined immunodeficiency (SCID), common variable immunodeficiency (CVID), Wiskott-Aldrich syndrome, and X-linked agammaglobulinemia.

Secondary immunodeficiency syndromes can result from various factors, including:

1. HIV/AIDS: Human Immunodeficiency Virus infection leads to the depletion of CD4+ T cells, causing profound immune dysfunction and increased vulnerability to opportunistic infections and malignancies.
2. Medications: Certain medications, such as chemotherapy, immunosuppressive drugs, and long-term corticosteroid use, can impair immune function and increase infection risk.
3. Malnutrition: Deficiencies in essential nutrients like protein, vitamins, and minerals can weaken the immune system and make individuals more susceptible to infections.
4. Aging: The immune system naturally declines with age, leading to an increased incidence of infections and poorer vaccine responses in older adults.
5. Other medical conditions: Chronic diseases such as diabetes, cancer, and chronic kidney or liver disease can also compromise the immune system and contribute to immunodeficiency syndromes.

Immunologic deficiency syndromes require appropriate diagnosis and management strategies, which may include antimicrobial therapy, immunoglobulin replacement, hematopoietic stem cell transplantation, or targeted treatments for the underlying cause.

Bleomycin is a type of chemotherapeutic agent used to treat various types of cancer, including squamous cell carcinoma, testicular cancer, and lymphomas. It works by causing DNA damage in rapidly dividing cells, which can inhibit the growth and proliferation of cancer cells.

Bleomycin is an antibiotic derived from Streptomyces verticillus and is often administered intravenously or intramuscularly. While it can be effective in treating certain types of cancer, it can also have serious side effects, including lung toxicity, which can lead to pulmonary fibrosis and respiratory failure. Therefore, bleomycin should only be used under the close supervision of a healthcare professional who is experienced in administering chemotherapy drugs.

Optical coherence tomography (OCT) is a non-invasive imaging technique that uses low-coherence light to capture high-resolution cross-sectional images of biological tissues, particularly the retina and other ocular structures. OCT works by measuring the echo time delay of light scattered back from different depths within the tissue, creating a detailed map of the tissue's structure. This technique is widely used in ophthalmology to diagnose and monitor various eye conditions such as macular degeneration, diabetic retinopathy, and glaucoma.

It is likely that patients with Macular telangiectasia type 1 with pronounced macular edema from leaky telangiectasis may ... Gass, J. D.; Blodi, B. A. (October 1993). "Idiopathic juxtafoveolar retinal telangiectasis. Update of classification and follow ... Nowilaty, Sawsan R.; Al-Shamsi, Hanan N.; Al-Khars, Wajeeha (2010). "Idiopathic Juxtafoveolar Retinal Telangiectasis: A Current ... Although J. D. Gass originally identified four types of idiopathic juxtafoveolar retinal telangiectasis in 1982, contemporary ...
... skin and mucosal telangiectasis; palpitations, irregular heart rate and fainting due to conduction abnormalities, hypertension ...
Hop.: 1322-3. Osler W (1901). "On a family form of recurring epistaxis, associated with multiple telangiectases of the skin and ... 12: 333-7. Weber FP (1907). "Multiple hereditary developmental angiomata (telangiectases) of the skin and mucous membranes ... doi:10.1016/S0140-6736(00)32590-9. Hanes FM (1909). "Multiple hereditary telangiectasis causing hemorrhage (hereditary ...
Small clusters of enlarged blood vessels (telangiectases) often appear in the rash; telangiectases can also occur in the eyes. ...
"Anatomical Examination of Leg Telangiectases with Duplex Scanning". The Journal of Dermatologic Surgery and Oncology. 19 (10): ...
These patterns are referred as telangiectases. Varicose veins: Enlarged, swollen and twisted veins. Congestive heart failure: ...
A spider angioma or spider naevus (plural: spider naevi), also nevus araneus, is a type of telangiectasis (swollen, spider-like ... Geronemus, R. G. (1991). "Treatment of spider telangiectases in children using the flashlamp-pumped pulsed dye laser". Pediatr ...
Lord Rumbelow has a complicated case of telangiectasis and acts superior towards the minor gout patient Sir Aylmer. Mortimer ...
... capillary telangiectasis, macular edema, and disc edema. Capillary non perfusion, documented by fluorescein angiography, is ...
... it can be differentiated from RICH by a greater elevation and coarse telangiectases. It mainly affects the head and neck region ...
This condition leads to frequent nose bleeds, telangiectases on skin and mucosa and may cause arteriovenous malformations in ...
... blue and red telangiectasis, and (c) capillary stasis spots. It was proposed that the presence of corona phlebectatica be ...
Geronemus' publications have covered treatments for port wine stains, hemangiomas, sun damaged skin, wrinkles, telangiectases, ...
... telangiectases, acral erythema, peripheral vasodilation with cyanosis, and a propensity to develop basal cell carcinomas. The ...
... telangiectases, vascular lesions (small blood vessels), pigmented lesions (freckles, liver spots, birth marks ), melasma, ...
... also having been reported in hemoglobin M disease and hereditary acrolabial telangiectases. In Wilson's disease the blue color ...
... to 3-cm annular patches composed of dark red telangiectases with petechiae. It is one of a group of disorders referred to as ...
Glioma Gliomatosis cerebri Gliosarcoma Globel disaccharide intolerance Glomerulonephritis sparse hair telangiectases ...
... telangiectases, and a shiny appearance of the skin.: 858 Skin lesion James, William; Berger, Timothy; Elston, Dirk (2005). ...
"Telangiectasis" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... This graph shows the total number of publications written about "Telangiectasis" by people in UAMS Profiles by year, and ... Below are the most recent publications written about "Telangiectasis" by people in Profiles over the past ten years. ... whether "Telangiectasis" was a major or minor topic of these publications. To see the data from this visualization as text, ...
"Telangiectasis" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... This graph shows the total number of publications written about "Telangiectasis" by people in this website by year, and whether ... Below are the most recent publications written about "Telangiectasis" by people in Profiles. ... "Telangiectasis" was a major or minor topic of these publications. To see the data from this visualization as text, click here. ...
Idiopathic juxtafoveal telangiectasis (IJFT) is a condition of uncertainetiology that is characterized by retinal ... Reese AB Telangiectasis of the retina and Coats disease. Am J Ophthalmol. 1956;421- 8PubMedGoogle Scholar ... Idiopathic Juxtafoveal Telangiectasis in Association With Celiac Sprue. Arch Ophthalmol. 2004;122(3):411-413. doi:10.1001/ ... Idiopathic juxtafoveal telangiectasis (IJFT) is a condition of uncertainetiology that is characterized by retinal ...
Chronic Effects: Hyperpigmentation, Keratoses, and Telangiectases Source: Dr. David Belyi, Research Center for Radiation ... and telangiectases over the knee and distal thigh. ...
It is likely that patients with Macular telangiectasia type 1 with pronounced macular edema from leaky telangiectasis may ... Gass, J. D.; Blodi, B. A. (October 1993). "Idiopathic juxtafoveolar retinal telangiectasis. Update of classification and follow ... Nowilaty, Sawsan R.; Al-Shamsi, Hanan N.; Al-Khars, Wajeeha (2010). "Idiopathic Juxtafoveolar Retinal Telangiectasis: A Current ... Although J. D. Gass originally identified four types of idiopathic juxtafoveolar retinal telangiectasis in 1982, contemporary ...
Nasal telangiectases were found in 68%, mucocutaneous telangiectases (fingers, lips, oral cavity) in 79%, pulmonary ... The initial manifestation of HHT is the appearance of cutaneous telangiectases or epistaxis. Fewer than 10% of patients who ... 8] Pulmonary arteriovenous malformations may be microscopic (ie, telangiectasis), but they are typically 1-5 cm. Occasionally, ... whereas other affected families predominantly have GI mucosal telangiectasis, which lead to GI bleeding and iron-deficiency ...
Telangiectases and/or reticular veins. C2. Varicose veins. C3. Edema. C4. ā€¢ C4A. ā€¢ C4B. Changes in skin and subcutaneous tissue ...
Small clusters of enlarged blood vessels (telangiectases) often appear in the rash; telangiectases can also occur in the eyes. ...
Categories: Telangiectasis Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, CopyrightRestricted 1 ...
Spider Vein Removal (Telangiectasis) * Deep Vein Thrombosis * Check-up * Family Planning * Foot Ulcer ...
Macular telangiectasis. Perifoveal exudative vascular anomalous complex (PEVAC).. Digital Access Springer 2020 ...
Gill lamellar dilitations (telangiectasis) related to sampling techniques. Trans Am Fish Soc 1985;114:911-913. ... Gill lamellar dilitations (telangiectasis) related to sampling techniques. Trans Am Fish Soc 1985;114:911-913. ... Gill lamellar dilitations (telangiectasis) related to sampling techniques. . Trans Am Fish Soc. 1985. ;. 114. :. 911. -. 913. . ... Gill lamellar dilitations (telangiectasis) related to sampling techniques. . Trans Am Fish Soc. 1985. ;. 114. :. 911. -. 913. . ...
3rd, during receiving hot mist and steaming moxibustion, local telangiectasis, stops hot mist and steams affected by ...
Mild epidermal atrophy, telangiectases, and dyspigmentation may persist, particularly if the skin lesions were very ...
Visceral AVMs and mucosal telangiectases are present in children with HHT and can lead to life-threatening events. Failure to ... Conclusions: Visceral AVMs and mucosal telangiectases are present in children with HHT and can lead to life-threatening events ... Two were referred because of skin telangiectases and 2, because of multiple episodes of epistaxis. Screening results revealed a ... Main outcome measures: Prevalence of epistaxis, telangiectases, pulmonary and cerebral AVMs, and genetic characteristics. ...
Fatal rupture of pulmonary arteriovenous malformation in hereditary haemorrhagic telangiectasis and severe PAH. Eur Respir Rev ...
Science - Telangiectases Last post by pfpcnews Ā« Tue Jun 12, 2012 6:57 am. ...
... broken capillaries/telangiectases; vascular and pigmented birth marks. Such treatment is best administered by a specialist ...
She had a 10-month history of fatigue, repetitive nosebleeds (epistaxis) and mucocutaneous telangiectases at the lips, chest ...
These fine red and purple wiggly lines are medically termed Telangiectasis. In some cases, these veins are also regarded as ... These fine red and purple wiggly lines are medically termed Telangiectasis. In some cases, these veins are also regarded as ...
Sclerodermatous skin is characterized by increased thickness, dryness, hair loss, pigment alteration, telangiectasis and ...
Humans; Prospective Studies; Reproducibility of Results; retina; Retinal Telangiectasis; Time Factors; Tomography, Optical ...
Retinal Telangiectasis; Retrospective Studies; Severity of Illness Index; Sleep Apnea, Obstructive ...
Idiopathic macular telangiectasia type 2 (idiopathic juxtafoveolar retinal telangiectasis type 2A, Mac Tel 2). Surv Ophthalmol ...
Telangiectases in Systemic Sclerosis. JAMA Dermatol. 2021 04 01; 157(4):457. Jacobson R, Agnihothri R, Haemel A. PMID: 33595597 ... Widespread Erythematous Plaques With Prominent Telangiectases. JAMA Dermatol. 2021 11 01; 157(11):1376-1377. Kusari A, LeBoit ...
After the first month of FK506 treatment, the internal and external telangiectases, epistaxes, and anemia disappeared. Here, we ... The clinical manifestations are epistaxis, mucocutaneous and gastrointestinal telangiectases, and arteriovenous malformations ...
Flat red marks, known as telangiectasis, may appear in various locations, usually the face, palms, lips, or the inside of the ...
  • Facial redness and broken blood vessels (facial spider veins, telangiectases ) are commonly seen on the face, neck, chest, and legs. (laserskinsurgery.com)
  • Broken blood vessels on the face (telangiectasis) and small spider veins can be caused by medical conditions, heredity, and most commonly, sun exposure. (puredermnola.com)
  • Idiopathic juxtafoveal telangiectasis (IJFT) is a condition of uncertainetiology that is characterized by retinal telangiectasias, superficial retinalcrystalline deposits, right-angle venules, and intraretinal pigment plaques.It is capable of causing visual loss in otherwise healthy patients, and treatmentremains controversial. (jamanetwork.com)
  • Telangiectases are dilated blood vessels near the surface of the skin that often have a twisted appearance and that whiten (blanch) when pressure is applied. (msdmanuals.com)
  • She had a 10-month history of fatigue, repetitive nosebleeds (epistaxis) and mucocutaneous telangiectases at the lips, chest and lower extremities. (nature.com)
  • Nose bleeding was the first symptom of disease in 90% of cases with mucocutaneous telangiectases appearing 5 to 20 years later. (bmj.com)
  • The clinical manifestations are epistaxis, mucocutaneous and gastrointestinal telangiectases, and arteriovenous malformations in internal organs. (aspetjournals.org)
  • In most patients, the main manifestation is recurrent bleeding from either nasal or gastrointestinal telangiectases that can lead to severe iron-deficiency anemia and require iron supplements and recurrent blood transfusions. (researchsquare.com)
  • It is likely that patients with Macular telangiectasia type 1 with pronounced macular edema from leaky telangiectasis may benefit functionally and morphologically from intravitreal anti-VEGF injections, but this warrants further studies. (wikipedia.org)
  • [ 8 ] Pulmonary arteriovenous malformations may be microscopic (ie, telangiectasis), but they are typically 1-5 cm. (medscape.com)
  • Two were referred because of skin telangiectases and 2, because of multiple episodes of epistaxis. (nih.gov)
  • Although J. D. Gass originally identified four types of idiopathic juxtafoveolar retinal telangiectasis in 1982, contemporary researchers describe three types collectively known as idiopathic juxtafoveal telangiectasia: macular telangiectasia type 1, macular telangiectasia type 2, and macular telangiectasia type 3. (wikipedia.org)
  • Results: Ten eyes of six patients with arRP (4 males, 2 females, mean age 33 years) demonstrated Coats-like features, namely inferotemporal peripheral retinal telangiectasis combined with unilateral inferotemporal vasoproliferative tumor (VPT) in 4 eyes. (lu.se)
  • Conclusions: Coats-like features in arRP range from retinal telangiectasis to VPTs with extensive ERD and occur predominantly in the inferotemporal retinal periphery. (lu.se)
  • Visceral AVMs and mucosal telangiectases are present in children with HHT and can lead to life-threatening events. (nih.gov)
  • The clinical presentation and long-term prognosis of HHT are heterogeneous depending on the number, type and location of telangiectases and AVMs. (researchsquare.com)
  • Fifteen years after severe ARS with severe skin effects from Chernobyl accidents, this patient developed hyperpigmentation, keratoses, and telangiectases over the knee and distal thigh. (hhs.gov)
  • Most commonly, telangiectases involve sodes of severe anaemia in the past and had the mucous membranes, the skin, the con- to have blood transfusions due to a decrease junctiva, the retina and the gastrointestinal in serum haemoglobin level to 9 g/dL. (who.int)
  • Typical telangiectasis on both lips and syndrome was considered when the patient on the tongue tip, along with gastrointes- was referred for dermatologic consultation tinal telangiectasia are all supportive of a because there were some telangiectatic diagnosis of Osler-Weber-Rendu disease. (who.int)
  • Telangiectasis" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (sdsu.edu)
  • Characteristic findings include mottled skin with erythema, telangiectases, solar elastosis and areas of atrophy as well as the development of numerous premalignancies and malignant tumours. (dermis.net)
  • Telangiectases may be present and are no longer classified as a separate variant (previously telangiectasia macularis eruptiva perstans or TMEP). (dermnetnz.org)
  • Below are the most recent publications written about "Telangiectasis" by people in Profiles over the past ten years. (uams.edu)
  • After the first month of FK506 treatment, the internal and external telangiectases, epistaxes, and anemia disappeared. (aspetjournals.org)
  • Although J. D. Gass originally identified four types of idiopathic juxtafoveolar retinal telangiectasis in 1982, contemporary researchers describe three types collectively known as idiopathic juxtafoveal telangiectasia: macular telangiectasia type 1, macular telangiectasia type 2, and macular telangiectasia type 3. (wikipedia.org)
  • It is likely that patients with Macular telangiectasia type 1 with pronounced macular edema from leaky telangiectasis may benefit functionally and morphologically from intravitreal anti-VEGF injections, but this warrants further studies. (wikipedia.org)
  • Typical telangiectasis on both lips and syndrome was considered when the patient on the tongue tip, along with gastrointes- was referred for dermatologic consultation tinal telangiectasia are all supportive of a because there were some telangiectatic diagnosis of Osler-Weber-Rendu disease. (who.int)
  • Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by epistaxis, telangiectases, and multiorgan vascular dysplasia. (bmj.com)
  • Retina vascular disease, non-occlusive includes diagnosis codes indicating hypertensive or exudative retinopathy, changes in retinal vascular appearance, retinal microaneurysms, retinal telangiectasis, neovascularization or vasculitis, intraretinal microvascular abnormalities, or unspecified background retinopathy. (cdc.gov)
  • 3. Ultrastructure and three-dimensional reconstruction of several macular and papular telangiectases. (nih.gov)
  • AT is caused by mutations in the ATM (ataxia-telangiectasis mutated) gene. (nih.gov)
  • How can I or my loved one help improve care for people with ataxia telangiectasis? (nih.gov)
  • [ 1 ] Flushing reactions can result from different causes and pathophysiologic mechanisms, so that they often represent a difficult diagnostic and management problem ( Table I ) Additionally, when frequent and intense, flushing can lead to a cluster of cutaneous stigmata, possibly identifiable in the erythrosis and telangiectases that characterize the second stage of rosacea. (medscape.com)
  • 7 g/dL) with slight abnormalities in liver normal vasculature, including telangiectases function tests. (who.int)
  • Whilst oculocutaneous telangiectasiae are an almost universal finding in this syndrome, bladder wall telangiectasis has not been reported previously. (nih.gov)
  • As A-T is a DNA repair disorder, it is possible that chemotherapy-mediated damage to the bladder mucosa prompted the development of clinically significant telangiectasis in these patients. (nih.gov)
  • 7. [Video-microscopic studies of telangiectases in Osler's disease and scleroderma]. (nih.gov)
  • Typically, discoid lupus is characterized by erythematous macules, papules, and plaques with telangiectases, scale, and follicular plugs, which results in a scaring process with atrophy and dyspigmentation [ 3 ]. (cdlib.org)
  • 9 It is usually asymptomatic in up to 50% of the affected individuals and reflects the presence of multiple intrahepatic telangiectases leading to the formation of shunts between the major vessels of the liver (from the hepatic artery to either portal or hepatic veins and from the portal vein to hepatic vein or vena cava). (bmj.com)
  • 6 Telangiectases can also develop in the gastrointestinal tract, particularly in the stomach and small bowel of older patients, who present with gastrointestinal haemorrhage and iron deficiency anaemia, usually in their fifth or sixth decades of life. (bmj.com)
  • In this basal cell carcinoma, dilated blood vessels (telangiectases) appear on the surface. (merckmanuals.com)
  • 4. Clinical Images: Systemic sclerosis-related telangiectases. (nih.gov)