NLK-NML/MeSH-CZ-2025-notes huggingface dataset:
Cholestenes: steroids with methyl groups at c-10 and c-13 and a branched 8-carbon chain at c-17. members include compounds with any degree of unsaturation; however, cholestadienes is available for derivatives containing two double bonds
Cholestenone 5 alpha-Reductase: an oxidoreductase that catalyzes the conversion of 3-oxo-delta4 steroids into their corresponding 5alpha form. it plays an important role in the conversion of testosterone into dihydrotestosterone and progesterone into dihydroprogesterone
Cholestenones: cholestenes with one or more double bonds and substituted by any number of keto groups
Cholesterol: the principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils
Cholesterol 24-Hydroxylase: a steroid hydroxylase that functions in cholesterol homeostasis in the brain. it converts cholesterol into 24s-hydroxycholesterol, which is transported over the blood-brain barrier more rapidly than unmetabolized cholesterol
Cholesterol 7-alpha-Hydroxylase: a membrane-bound cytochrome p450 enzyme that catalyzes the 7-alpha-hydroxylation of cholesterol in the presence of molecular oxygen and nadph-ferrihemoprotein reductase. this enzyme, encoded by cyp7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of bile acids
Cholesterol Ester Storage Disease: an autosomal recessive disorder caused by mutations in the gene for acid lipase (sterol esterase). it is characterized by the accumulation of neutral lipids, particularly cholesterol esters in leukocytes, fibroblasts, and hepatocytes
Cholesterol Ester Transfer Proteins: proteins that bind to and transfer cholesterol esters between lipoproteins such as low-density lipoproteins and high-density lipoproteins
Cholesterol Esters: fatty acid esters of cholesterol which constitute about two-thirds of the cholesterol in the plasma. the accumulation of cholesterol esters in the arterial intima is a characteristic feature of atherosclerosis
Cholesterol Oxidase: an enzyme that catalyzes the oxidation of cholesterol in the presence of molecular oxygen to 4-cholesten-3-one and hydrogen peroxide. the enzyme is not specific for cholesterol, but will also oxidize other 3-hydroxysteroids. ec 1.1.3.6
Cholesterol Side-Chain Cleavage Enzyme: a mitochondrial cytochrome p450 enzyme that catalyzes the side-chain cleavage of c27 cholesterol to c21 pregnenolone in the presence of molecular oxygen and nadph-ferrihemoprotein reductase. this enzyme, encoded by cyp11a1 gene, catalyzes the breakage between c20 and c22 which is the initial and rate-limiting step in the biosynthesis of various gonadal and adrenal steroid hormones
Cholesterol pneumonia: pneumonia caused by the presence of lipids in the bronchi. congenital cases in neonates may be fatal and are characterized by cyanosis, cough and tachypnea. omim: 215030
Cholesterol, HDL: cholesterol which is contained in or bound to high-density lipoproteins (hdl), including cholesterol esters and free cholesterol
Cholesterol, LDL: cholesterol which is contained in or bound to low density lipoproteins (ldl), including cholesterol esters and free cholesterol
Cholesterol, VLDL: cholesterol which is contained in or bound to very low density lipoproteins (vldl). high circulating levels of vldl cholesterol are found in hyperlipoproteinemia type iib. the cholesterol on the vldl is eventually delivered by low-density lipoproteins to the tissues after the catabolism of vldl to intermediate-density lipoproteins, then to ldl
Cholestyramine Resin: a strongly basic anion exchange resin whose main constituent is polystyrene trimethylbenzylammonium cl(-) anion
Cholic Acid: a major primary bile acid produced in the liver and usually conjugated with glycine or taurine. it facilitates fat absorption and cholesterol excretion
Cholic Acids: the 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholanic acid family of bile acids in man, usually conjugated with glycine or taurine. they act as detergents to solubilize fats for intestinal absorption, are reabsorbed by the small intestine, and are used as cholagogues and choleretics
Choline: a basic constituent of lecithin that is found in many plants and animal organs. it is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism
Choline Deficiency: a condition produced by a deficiency of choline in animals. choline is known as a lipotropic agent because it has been shown to promote the transport of excess fat from the liver under certain conditions in laboratory animals. combined deficiency of choline (included in the b vitamin complex) and all other methyl group donors causes liver cirrhosis in some animals. unlike compounds normally considered as vitamins, choline does not serve as a cofactor in enzymatic reactions. (from saunders dictionary & encyclopedia of laboratory medicine and technology, 1984)
Choline Dehydrogenase: an enzyme bound to the inner mitochondrial membrane that catalyzes the oxidation of choline to betaine
Choline Kinase: an enzyme that is active in the first step of choline phosphoglyceride (lecithin) biosynthesis by catalyzing the phosphorylation of choline to phosphorylcholine in the presence of atp. ethanolamine and its methyl and ethyl derivatives can also act as acceptors. ec 2.7.1.32
Choline O-Acetyltransferase: an enzyme that catalyzes the formation of acetylcholine from acetyl-coa and choline. ec 2.3.1.6
Choline-Phosphate Cytidylyltransferase: an enzyme that catalyzes the transfer of cytidylate (cmp) to choline phosphate to form cdpcholine. it is the rate-limiting enzyme in the choline pathway for the biosynthesis of phosphatidylcholine. its activity is increased by glucocorticoids. ec 2.7.7.15
Cholinergic Agents: any drug used for its actions on cholinergic systems. included here are agonists and antagonists, drugs that affect the life cycle of acetylcholine, and drugs that affect the survival of cholinergic neurons. the term cholinergic agents is sometimes still used in the narrower sense of muscarinic agonists, although most modern texts discourage that usage
Cholinergic Agonists: drugs that bind to and activate cholinergic receptors
Cholinergic Antagonists: drugs that bind to but do not activate cholinergic receptors, thereby blocking the actions of acetylcholine or cholinergic agonists
Cholinergic Fibers: nerve fibers liberating acetylcholine at the synapse after an impulse
Cholinergic Neurons: neurons whose primary neurotransmitter is acetylcholine
Cholinesterase Inhibitors: drugs that inhibit cholinesterases. the neurotransmitter acetylcholine is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. when cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system
Cholinesterase Reactivators: drugs used to reverse the inactivation of cholinesterase caused by organophosphates or sulfonates. they are an important component of therapy in agricultural, industrial, and military poisonings by organophosphates and sulfonates
Chondro-4-Sulfatase: an enzyme from the sulfuric ester hydrolase class that breaks down one of the products of the chondroitin lyase ii reaction. ec 3.1.6.9
Chondroblastoma: a usually benign tumor composed of cells which arise from chondroblasts or their precursors and which tend to differentiate into cartilage cells. it occurs primarily in the epiphyses of adolescents. it is relatively rare and represents less than 2% of all primary bone tumors. the peak incidence is in the second decade of life; it is about twice as common in males as in females. (from dorland, 27th ed; holland et al., cancer medicine, 3d ed, p1846)
Chondrocalcinosis: presence of calcium pyrophosphate in the connective tissues such as the cartilaginous structures of joints. when accompanied by gout-like symptoms, it is referred to as pseudogout
Chondrocalcinosis 2: a hereditary autosomal dominant form of chondrocalcinosis that is caused by mutations in the ankh gene. omim: 118600
Chondrodysplasia Punctata: a heterogeneous group of bone dysplasias, the common character of which is stippling of the epiphyses in infancy. the group includes a severe autosomal recessive form (chondrodysplasia punctata, rhizomelic), an autosomal dominant form (conradi-hunermann syndrome), and a milder x-linked form. metabolic defects associated with impaired peroxisomes are present only in the rhizomelic form
Chondrodysplasia Punctata, Rhizomelic: an autosomal recessive form of chondrodysplasia punctata characterized by defective plasmalogen biosynthesis and impaired peroxisomes. patients have shortened proximal limbs and severely disturbed endochondral bone formation. the metabolic defects associated with the impaired peroxisomes are present only in the rhizomelic form of chondrodysplasia punctata. (from scriver et al, metabolic basis of inherited disease, 6th ed, p1497)
Chondrogenesis: the formation of cartilage. this process is directed by chondrocytes which continually divide and lay down matrix during development. it is sometimes a precursor to osteogenesis
Chondroitin: a mucopolysaccharide constituent of chondrin. (grant & hackh's chemical dictionary, 5th ed)
Chondroitin ABC Lyase: an enzyme that catalyzes the eliminative degradation of polysaccharides containing 1,4-beta-d-hexosaminyl and 1,3-beta-d-glucuronosyl or 1,3-alpha-l-iduronosyl linkages to disaccharides containing 4-deoxy-beta-d-gluc-4-enuronosyl groups. (enzyme nomenclature, 1992)
Chondroitin Lyases: enzymes which catalyze the elimination of delta-4,5-d-glucuronate residues from polysaccharides containing 1,4-beta-hexosaminyl and 1,3-beta-d-glucuronosyl or 1,3-alpha-l-iduronosyl linkages thereby bringing about depolymerization. ec 4.2.2.4 acts on chondroitin sulfate a and c as well as on dermatan sulfate and slowly on hyaluronate. ec 4.2.2.5 acts on chondroitin sulfate a and c
Chondroitin Sulfate Proteoglycans: proteoglycans consisting of proteins linked to one or more chondroitin sulfate-containing oligosaccharide chains
Chondroitin Sulfates: derivatives of chondroitin which have a sulfate moiety esterified to the galactosamine moiety of chondroitin. chondroitin sulfate a, or chondroitin 4-sulfate, and chondroitin sulfate c, or chondroitin 6-sulfate, have the sulfate esterified in the 4- and 6-positions, respectively. chondroitin sulfate b (beta heparin; dermatan sulfate) is a misnomer and this compound is not a true chondroitin sulfate
Chondroitinases and Chondroitin Lyases: enzymes which catalyze the elimination of glucuronate residues from chondroitin a, b, and c or which catalyze the hydrolysis of sulfate groups of the 2-acetamido-2-deoxy-d-galactose 6-sulfate units of chondroitin sulfate. ec 4.2.2.-
Chondroitinsulfatases: a group of enzymes that catalyze the hydrolysis of various sulfate bonds of chondroitin sulfate. ec 3.1.6.-
Chondroma: a benign neoplasm derived from mesodermal cells that form cartilage. it may remain within the substance of a cartilage or bone (true chondroma or enchondroma) or may develop on the surface of a cartilage (ecchondroma or ecchondrosis). (dorland, 27th ed; stedman, 25th ed)
Chondromalacia Patellae: a degeneration of the articular cartilage of the patella, caused by a decrease in sulfated mucopolysaccharides in the ground substance. when accompanied by pain, it is sometimes considered part of or confused with patellofemoral pain syndrome
Chondromatosis: multiple formation of chondromas. (dorland, 27th ed)
Chondromatosis, Synovial: rare, benign, chronic, progressive metaplasia in which cartilage is formed in the synovial membranes of joints, tendon sheaths, or bursae. some of the metaplastic foci can become detached producing loose bodies. when the loose bodies undergo secondary calcification, the condition is called synovial osteochondromatosis
Chondrosarcoma: a slowly growing malignant neoplasm derived from cartilage cells, occurring most frequently in pelvic bones or near the ends of long bones, in middle-aged and old people. most chondrosarcomas arise de novo, but some may develop in a preexisting benign cartilaginous lesion or in patients with enchondromatosis. (stedman, 25th ed)
Chondrosarcoma, Clear Cell: a chondrosarcoma of adolescence to old age of the proximal epiphyses of long bones. it has variably clear cytoplasm of the mostly neoplastic chondrocytes with little intervening matrix
Chondrosarcoma, Extraskeletal Myxoid: a rare malignant soft tissue neoplasm that originates from chondroblasts. it is most common in male middle-aged and elderly individuals and often presents as deep lesions in soft tissue of the extremities. malignancy is low, but recurrence and metastasis can occur many years after the initial diagnosis. histologically, the tumors consist of a mixture of cellular and myxoid stromal components. can be caused by somatic chromosomal translocations resulting in fusions between the nr4a3 and ewsr1 genes, and nr4a3 and taf15 genes. omim: 612237
Chondrosarcoma, Mesenchymal: a rare aggressive variant of chondrosarcoma, characterized by a biphasic histologic pattern of small compact cells intermixed with islands of cartilaginous matrix. mesenchymal chondrosarcomas have a predilection for flat bones; long tubular bones are rarely affected. they tend to occur in the younger age group and are highly metastatic. (devita jr et al., cancer: principles & practice of oncology, 3d ed, p1456)
Chondrus: a genus of red algae, in the family gigartinaceae. the species chondrus crispus is a source of carrageenan
Chondrus: rod kmene červených řas (kmen rhodophyta) z čeledi gigartinaceae. druh chondrus crispus (puchratka kadeřavá) je zdrojem karagenanu
Chorda Tympani Nerve: a branch of the facial (7th cranial) nerve which passes through the middle ear and continues through the petrotympanic fissure. the chorda tympani nerve carries taste sensation from the anterior two-thirds of the tongue and conveys parasympathetic efferents to the salivary glands
Chordae Tendineae: the tendinous cords that connect each cusp of the two atrioventricular heart valves to appropriate papillary muscles in the heart ventricles, preventing the valves from reversing themselves when the ventricles contract
Chordata: kmen druhoústých živočichů, který zahrnuje obratlovce a několik blízce příbuzných skupin bezobratlých. jsou dvoustranně souměrní, v některém období svého života mají strunu hřbetní, nervovou trubici, žaberní štěrbiny, endostyl a svalnatou ocasní část až za řitním otvorem. přitom platí, že nervová trubice je na hřbetní straně, struna hřbetní probíhá centrálně a srdce je umístěno na břišní straně. (upraveno podle wikipedie 2019 http://www.cs.wikipedia.org/)
Chordata: phylum in the domain eukarya, comprised of animals either with fully developed backbones (vertebrates), or those with notochords only during some developmental stage (chordata, nonvertebrate)
Chordata, Nonvertebrate: a portion of the animal phylum chordata comprised of the subphyla cephalochordata; urochordata, and hyperotreti, but not including the vertebrata (vertebrates). it includes nonvertebrate animals having a notochord during some developmental stage
Chordoma: a malignant tumor arising from the embryonic remains of the notochord. it is also called chordocarcinoma, chordoepithelioma, and notochordoma. (dorland, 27th ed)
Chordopoxvirinae: a subfamily of the family poxviridae, containing eight genera comprising all the vertebrate poxviruses
Chordopoxvirinae: podčeleď virů čeledi poxviridae, která zahrnuje osm rodů obsahujících všechny poxviry obratlovců
Chorea: involuntary, forcible, rapid, jerky movements that may be subtle or become confluent, markedly altering normal patterns of movement. hypotonia and pendular reflexes are often associated. conditions which feature recurrent or persistent episodes of chorea as a primary manifestation of disease are referred to as choreatic disorders. chorea is also a frequent manifestation of basal ganglia diseases
Chorea Gravidarum: a rare movement disorder developed during pregnancy, characterized by involuntary jerky motion (chorea) and inability to maintain stable position of body parts (athetosis). rheumatic fever and collagen vascular disorders are frequently associated with this disease. chorea may vary from mild to severe and occurs in approximately 1 per 2,000 to 3,000 pregnancies. (from md med j 1997 sep;46(8):436-9)
Choreoathetosis, Hypothyroidism, And Neonatal Respiratory Distress: associated with mutation of thyroid transcription factor 1 gene nkx2
Choreoathetosis-Spasticity, Episodic: mutation in gch1
Chorioallantoic Membrane: a highly vascularized extra-embryonic membrane, formed by the fusion of the chorion and the allantois. it is mostly found in birds and reptiles. it serves as a model for studying tumor or cell biology, such as angiogenesis and tissue transplantation
Chorioamnionitis: inflammation of the placental membranes (chorion; amnion) and connected tissues such as fetal blood vessels and umbilical cord. it is often associated with intrauterine ascending infections during pregnancy
Choriocarcinoma: a malignant metastatic form of trophoblastic tumors. unlike the hydatidiform mole, choriocarcinoma contains no chorionic villi but rather sheets of undifferentiated cytotrophoblasts and syncytiotrophoblasts (trophoblasts). it is characterized by the large amounts of chorionic gonadotropin produced. tissue origins can be determined by dna analyses: placental (fetal) origin or non-placental origin (choriocarcinoma, non-gestational)
Choriocarcinoma, Non-gestational: a highly malignant choriocarcinoma derived from the non-placental origin such as the totipotent cells in the testis, the ovary, and the pineal gland. it produces high levels of chorionic gonadotropin and can metastasize widely through the bloodstream to the lungs, brain, liver, bone, and other viscera by the time of diagnosis
Chorion: the outermost extra-embryonic membrane surrounding the developing embryo. in reptiles and birds, it adheres to the shell and allows exchange of gases between the egg and its environment. in mammals, the chorion evolves into the fetal contribution of the placenta
Chorionic Gonadotropin: a gonadotropic glycoprotein hormone produced primarily by the placenta. similar to the pituitary luteinizing hormone in structure and function, chorionic gonadotropin is involved in maintaining the corpus luteum during pregnancy. cg consists of two noncovalently linked subunits, alpha and beta. within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (tsh, lh, and fsh), but the beta subunit is unique and confers its biological specificity (chorionic gonadotropin, beta subunit, human)
Chorionic Gonadotropin, beta Subunit, Human: the beta subunit of human chorionic gonadotropin. its structure is similar to the beta subunit of luteinizing hormone, except for the additional 30 amino acids at the carboxy end with the associated carbohydrate residues. hcg-beta is used as a diagnostic marker for early detection of pregnancy, spontaneous abortion (abortion, spontaneous); ectopic pregnancy; hydatidiform mole; choriocarcinoma; or down syndrome
Chorionic Villi: threadlike vascular projections of the chorion. chorionic villi may be free or embedded within the decidua forming the site for exchange of substances between fetal and maternal blood (placenta)
Chorionic Villi Sampling: a method for diagnosis of fetal diseases by sampling the cells of the placental chorionic villi for dna analysis, presence of bacteria, concentration of metabolites, etc. the advantage over amniocentesis is that the procedure can be carried out in the first trimester
Chorioretinal atrophy, progressive bifocal: a rare, autosomal dominant congenital chorioretinal dystrophy. the disorder is characterized by progressive macular and nasal retinal atrophic lesions, nystagmus; myopia, and poor vision there are 2 distinct foci of atrophy, a temporal focus that is present at birth and a nasal focus that appears early in life. retinal detachment is an additional complication of the disease. omim: 600790
Chorioretinitis: inflammation of the choroid in which the sensory retina becomes edematous and opaque. the inflammatory cells and exudate may burst through the sensory retina to cloud the vitreous body
Chorismate Mutase: an isomerase that catalyzes the conversion of chorismic acid to prephenic acid. ec 5.4.99.5
Chorismic Acid: a cyclohexadiene carboxylic acid derived from shikimic acid and a precursor for the biosynthesis of ubiquinone and the aromatic amino acids
Choroid: the thin, highly vascular membrane covering most of the posterior of the eye between the retina and sclera
Choroid Diseases: disorders of the choroid including hereditary choroidal diseases, neoplasms, and other abnormalities of the vascular layer of the uvea
Choroid Neoplasms: tumors of the choroid; most common intraocular tumors are malignant melanomas of the choroid. these usually occur after puberty and increase in incidence with advancing age. most malignant melanomas of the uveal tract develop from benign melanomas (nevi)
Choroid Plexus: a villous structure of tangled masses of blood vessels contained within the third, lateral, and fourth ventricles of the brain. it regulates part of the production and composition of cerebrospinal fluid
Choroid Plexus Carcinoma: malignant neoplasms originating from the choroid plexus.they are neuroectodermal in origin and can range from benign choroid plexus papillomas (cpps) to malignant choroid carcinomas (cpcs). these rare tumors generally occur in childhood, but have also been reported in adults. patients typically present with signs and symptoms of increased intracranial pressure including headache, hydrocephalus; papilledema, nausea, vomiting, cranial nerve deficits, gait impairment, and seizures. tumor cells show anaplastic features and often invade neighboring brain structures. cerebrospinal fluid metastases are common. germline mutations in the tp53 gene have been identified. omim: 260500
Choroid Plexus Neoplasms: benign or malignant tumors which arise from the choroid plexus of the ventricles of the brain. papillomas (see papilloma, choroid plexus) and carcinomas are the most common histologic subtypes, and tend to seed throughout the ventricular and subarachnoid spaces. clinical features include headaches, ataxia and alterations of consciousness, primarily resulting from associated hydrocephalus. (from devita et al., cancer: principles and practice of oncology, 5th ed, p2072; j neurosurg 1998 mar;88(3):521-8)
Choroidal Dystrophy, Central Areolar 2: mutation in prph2
Choroidal Effusions: finding of fluid accumulation between the choroid and the sclera
Choroidal Neovascularization: a pathological process consisting of the formation of new blood vessels in the choroid
Choroidal sclerosis: a hereditary retinal disorder that affects the macula lutea, often resulting in a well-defined area of atrophy of the retinal pigment epithelium and choriocapillaris in the center of the macula. dysfunction of macular photoreceptors usually leads to a decrease in visual acuity. onset is usually between 30 and 60 years of age, omim: 215500
Choroideremia: an x chromosome-linked abnormality characterized by atrophy of the choroid and degeneration of the retinal pigment epithelium causing night blindness
Chorvatsko: evropský stát, který se geograficky nachází na pomezí střední a jižní evropy; jde o jeden z nástupnických států bývalé jugoslávie. nezávislost byla uznána 15. ledna 1992 evropským společenstvím. hlavním městem je záhřeb. (upraveno podle wikipedie 2021 http://www.cs.wikipedia.org/)
Christian Science: a religion founded by mary baker eddy in 1866 that was organized under the official name of the church of christ, scientist. it includes the practice of spiritual healing
Christianity: the religion stemming from the life, teachings, and death of jesus christ: the religion that believes in god as the father almighty who works redemptively through the holy spirit for men's salvation and that affirms jesus christ as lord and savior who proclaimed to man the gospel of salvation. (from webster, 3d ed)
Chromadorea: a class of invertebrate freshwater roundworms of the phylum nematoda. most members are parasites with well-adapted body surfaces and sophisticated esophageal glands and pharynx
Chromadorea: třída hlístic parazitujících ve sladkovodních bezobratlých. většina zástupců má dobře přizpůsobený povrch těla a složité jícnové žlázy a hltan
Chromaffin Cells: cells that store epinephrine secretory vesicles. during times of stress, the nervous system signals the vesicles to secrete their hormonal content. their name derives from their ability to stain a brownish color with chromic salts. characteristically, they are located in the adrenal medulla and paraganglia (paraganglia, chromaffin) of the sympathetic nervous system
Chromaffin Granules: organelles in chromaffin cells located in the adrenal glands and various other organs. these granules are the site of the synthesis, storage, metabolism, and secretion of epinephrine and norepinephrine
Chromaffin System: the cells of the body which stain with chromium salts. they occur along the sympathetic nerves, in the adrenal gland, and in various other organs
Chromatiaceae: a family of phototrophic purple sulfur bacteria that deposit globules of elemental sulfur inside their cells. they are found in diverse aquatic environments
Chromatiaceae: čeleď fototrofních, purpurových sirných bakterií, které mohou uvnitř svých buněk ukládat granula elementární síry. vyskytují se v různých vodních habitatech
Chromatids: either of the two longitudinally adjacent threads formed when a eukaryotic chromosome replicates prior to mitosis. the chromatids are held together at the centromere. sister chromatids are derived from the same chromosome. (singleton & sainsbury, dictionary of microbiology and molecular biology, 2d ed)
Chromatin: the material of chromosomes. it is a complex of dna; histones; and nonhistone proteins (chromosomal proteins, non-histone) found within the nucleus of a cell
Chromatin Assembly Factor-1: a histone chaperone protein that plays a role in the deposition of nucleosomes on newly synthesized dna. it is comprised of three different subunits of 48, 60, and 150 kda molecular size. the 48 kda subunit, retinoblastoma-binding protein 4, is also a component of several other protein complexes involved in chromatin remodeling
Chromatin Assembly and Disassembly: the mechanisms effecting establishment, maintenance, and modification of that specific physical conformation of chromatin determining the transcriptional accessibility or inaccessibility of the dna
Chromatin Immunoprecipitation: a technique for identifying specific dna sequences that are bound, in vivo, to proteins of interest. it involves formaldehyde fixation of chromatin to crosslink the dna-binding proteins to the dna. after shearing the dna into small fragments, specific dna-protein complexes are isolated by immunoprecipitation with protein-specific antibodies. then, the dna isolated from the complex can be identified by pcr amplification and sequencing
Chromatin Immunoprecipitation Sequencing: a technique for identifying the binding sites on nucleic acid sequences that are associated with binding proteins
Chromatium: a genus of gram-negative, ovoid to rod-shaped bacteria that is phototrophic. all species use ammonia as a nitrogen source. some strains are found only in sulfide-containing freshwater habitats exposed to light while others may occur in marine, estuarine, and freshwater environments
Chromatium: rod gramnegativních, fototrofních bakterií ovoidního až tyčinkovitého tvaru. všechny druhy využívají amoniak jako zdroj dusíku. někteří zástupci se vyskytují pouze v osvětlených sladkých vodách s obsahem sulfidů, jiní mohou žít v mořích, v ústích řek a ve sladkých vodách
Chromatography: techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. a mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. usage is both analytical for small amounts and preparative for bulk amounts
Chromatography, Affinity: a chromatographic technique that utilizes the ability of biological molecules, often antibodies, to bind to certain ligands specifically and reversibly. it is used in protein biochemistry. (mcgraw-hill dictionary of scientific and technical terms, 4th ed)
Chromatography, Agarose: a method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million
Chromatography, DEAE-Cellulose: a type of ion exchange chromatography using diethylaminoethyl cellulose (deae-cellulose) as a positively charged resin. (from mcgraw-hill dictionary of scientific and technical terms, 4th ed)
Chromatography, Gas: fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix
Chromatography, Gel: chromatography on non-ionic gels without regard to the mechanism of solute discrimination
Chromatography, High Pressure Liquid: liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed
Chromatography, Ion Exchange: separation technique in which the stationary phase consists of ion exchange resins. the resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins
Chromatography, Micellar Electrokinetic Capillary: a hybrid separation technique combining both chromatographic and electrophoretic separation principles. while the method was invented to separate neutral species, it can also be applied to charged molecules such as small peptides
Chromatography, Paper: an analytical technique for resolution of a chemical mixture into its component compounds. compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase)
Chromatography, Reverse-Phase: a chromatography technique in which the stationary phase is composed of a non-polar substance with a polar mobile phase, in contrast to normal-phase chromatography in which the stationary phase is a polar substance with a non-polar mobile phase
Chromatography, Supercritical Fluid: a chromatography method using supercritical fluid, usually carbon dioxide under very high pressure (around 73 atmospheres or 1070 psi at room temperature) as the mobile phase. other solvents are sometimes added as modifiers. this is used both for analytical (sfc) and extraction (sfe) purposes
Chromatography, Thin Layer: chromatography on thin layers of adsorbents rather than in columns. the adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (mcgraw-hill dictionary of scientific and technical terms, 4th ed)
Chromatophores: the large pigment cells of fish, amphibia, reptiles and many invertebrates which actively disperse and aggregate their pigment granules. these cells include melanophores, erythrophores, xanthophores, leucophores and iridiophores. (in algae, chromatophores refer to chloroplasts. in phototrophic bacteria chromatophores refer to membranous organelles (bacterial chromatophores).)
Chromium: a trace element that plays a role in glucose metabolism. it has the atomic symbol cr, atomic number 24, and atomic weight 52. according to the fourth annual report on carcinogens (ntp85-002,1985), chromium and some of its compounds have been listed as known carcinogens
Chromium Alloys: specific alloys not less than 85% chromium and nickel or cobalt, with traces of either nickel or cobalt, molybdenum, and other substances. they are used in partial dentures, orthopedic implants, etc
Chromium Compounds: inorganic compounds that contain chromium as an integral part of the molecule
Chromium Isotopes: stable chromium atoms that have the same atomic number as the element chromium, but differ in atomic weight. cr-50, 53, and 54 are stable chromium isotopes
Chromium Radioisotopes: unstable isotopes of chromium that decay or disintegrate emitting radiation. cr atoms with atomic weights of 46-49, 51, 55, and 56 are radioactive chromium isotopes
Chromobacterium: a genus of gram-negative, facultatively anaerobic, rod-shaped bacteria occurring in soil and water. its organisms are generally nonpathogenic, but some species do cause infections of mammals, including humans
Chromobacterium: rod gramnegativních, fakultativně anaerobních, tyčinkovitých bakterií žijících v půdě a ve vodě. tyto organismy obvykle nejsou patogenní, ale některé druhy způsobují infekční onemocnění savců včetně člověka
Chromoblastomycosis: scaly papule or warty growth, caused by five fungi, that spreads as a result of satellite lesions affecting the foot or leg. the extremity may become swollen and, at its distal portion, covered with various nodular, tumorous, verrucous lesions that resemble cauliflower. in rare instances, the disease may begin on the hand or wrist and involve the entire upper extremity. (arnold, odom, and james, andrew's diseases of the skin, 8th ed, p362)
Chromobox Protein Homolog 5: a protein located within beta-heterochromatin that is involved in suppression of position effect variegation
Chromogenic Compounds: colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens)
Chromogranin A: a type of chromogranin which was first isolated from chromaffin cells of the adrenal medulla but is also found in other tissues and in many species including human, bovine, rat, mouse, and others. it is an acidic protein with 431 to 445 amino acid residues. it contains fragments that inhibit vasoconstriction or release of hormones and neurotransmitter, while other fragments exert antimicrobial actions
Chromogranin B: a type of chromogranin which was initially characterized in a rat pheochromocytoma cell line. it is found in many species including human, rat, mouse, and others. it is an acidic protein with 626 to 657 amino acid residues. in some species, it inhibits secretion of parathyroid hormone or insulin and exerts bacteriolytic effects in others
Chromogranins: a group of acidic proteins that are major components of secretory granules in the endocrine and neuroendocrine cells. they play important roles in the aggregation, packaging, sorting, and processing of secretory protein prior to secretion. they are cleaved to release biologically active peptides. there are various types of granins, usually classified by their sources
Chromohalobacter: a genus of gram-negative, moderately halophilic bacteria in the family halomonadaceae. they are chemoorganotrophic and grow optimally in media containing 8-10% salt
Chromohalobacter: rod gramnegativních, mírně halofilních bakterií čeledi halomonadaceae. jsou chemoorganotrofní a optimálně rostou v kultivačním médiu obsahujícím 8-10% soli
Chromolaena: a plant genus of the family asteraceae. the common name of thoroughwort is also used for other plants including eupatorium; chromolaena, hebeclinium and koanophyllon. eupolin is the aqueous extract of the leaves
Chromomycin A3: glycosidic antibiotic from streptomyces griseus used as a fluorescent stain of dna and as an antineoplastic agent
Chromomycins: a complex of several closely related glycosidic antibiotics from streptomyces griseus. the major component, chromomycin a3, is used as a fluorescent stain of dna where it attaches and inhibits rna synthesis. it is also used as an antineoplastic agent, especially for solid tumors
Chromophore-Assisted Light Inactivation: a technique for causing a targeted loss of molecular function from reactive oxygen species that are formed by the illumination of dyes placed in the immediate vicinity of the target molecule
Chromosomal Instability: an increased tendency to acquire chromosome aberrations when various processes involved in chromosome replication, repair, or segregation are dysfunctional
Chromosomal Position Effects: the effects on gene expression that depend on the location of a gene with respect to its neighboring genes and region of chromosome. stable position effects are sequence dependent. variegated position effects depend on whether the gene is located in or adjacent to heterochromatin or euchromatin
Chromosomal Proteins, Non-Histone: nucleoproteins, which in contrast to histones, are acid insoluble. they are involved in chromosomal functions; e.g. they bind selectively to dna, stimulate transcription resulting in tissue-specific rna synthesis and undergo specific changes in response to various hormones or phytomitogens
Chromosomal Puffs: regions along polytene chromosomes that are uncondensed and active in dna replication or rna transcription (genetic transcription)
Chromosome 1, monosomy 1p: deletion of a portion of the p region of crhomosome 1. monosomy 1p36 (omim: 607872) is the most common terminal deltion syndrome in humans, occuring in 1 in 5000 births. it causes severe craniofacial abnormalities and developmental disabilities, including delayed growth, craniosynostoses; microcephaly; cleft palate; eye and ear defects; congenital heart defects, seizures, and intellectual disability
Chromosome 11q trisomy: a chromosomal abnormality characterized by an extra copy or duplication of the long (q) arm of chromosome 11. severity of symptoms depend on the size and location of the duplication and which genes are involved. affected individuals may experience developmental delay, psychomotor and intellectual disability, behavioral problems, and have distinct facial features (facies)
Chromosome 12, 12p trisomy: an extremely rare duplication of the p region (short arm) of chromosome 12, occurring in about 1 in 50,000 births. affected individuals have severe craniofacial malformations, postnatal growth and psychomotor developmental delay, intellectual disability, seizures, hyptonia, and abnormally short, wide hands
Chromosome 13 ring: ring chromosome 13 arises when breaks occur at both ends of the chromosome, forming a circular structure. affected individuals may experience delayed growth and short stature, have microcephaly; characteristic facial anomalies (facies); abnormal skin pigmentation, and intellectual disability. the severity of symptoms depends on the region of the chromosome where the break occurs and which genes are involved
Chromosome 15q, trisomy: an extremely rare chromosomal disorder in which there is a duplication of the distal portion of the long (q arm) of the chromosome 15. it is characterized by pre- and post-natal growth delay, intellectual disability, and craniofacial malformations
Chromosome 15q13.3 Microdeletion Syndrome: heterozygous deletion of chromosome 15q13.3 is associated with a highly variable phenotype. individuals with the deletion may have mild to moderate intellectual disability or learning difficulties, or may have no cognitive deficits. some individuals have epilepsy and dysmorphic features may occur, but there is no consistent or recognizable phenotype. patients with homozygous deletions in this region have severe neurodevelopmental problems, with epileptic encephalopathy, muscle hypotonia, and poor growth. omim: 612001
Chromosome 16, trisomy: a chromosomal abnormality characterized by a third copy of chromosome 16. full trisomy 16 is lethal in utero and is the most common chromosomal trisomy that results in miscarriage. mosaic trisomy 16, where affected individuals carry an extra chromosome 16 only in some tissues, may result in intrauterine growth retardation and congenital heart defects
Chromosome 17 trisomy: duplication of chromosome 17 in some tissues (trisomy 17 mosaicism) is among the rarest trisomy in humans and full trisomy 17 has never been observed in living individuals. in mosaic cases, where trisomy occurs only in some cell populations, affected individuals may experience developmental delays, body asymmetry, slow growth, and cerebellar hypoplasia
Chromosome 18 deletion syndrome: deletion of chromosome 18q results in highly variable phenotypes including intellectual disability; hypotonia; hearing loss, short stature, and foot deformities. tapered digits and wide mouth may also occur. inheritance of this deletion is autosomal dominant. omim: 601808
Chromosome 18 ring: ring chromosome 18 arises when breaks occur at both ends of the chromosome, forming a circular structure. affected individuals may have microcephaly; hypertelorism; intellectual disability, and speech impairment. the severity of the disorders depends on how much genetic material is lost from the breaks
Chromosome 18, trisomy 18p: condition characterized by an aberrant third copy of the p arm of chromosome 18, resulting in developmental and intellectual disabilities
Chromosome 18, trisomy 18q: duplication of the long (q) arm of chromosome 18. affected children may have various abnormalities that include intra-uterine growth retardation, craniofacial abnormalities, heart malformations; and psychomotor delay
Chromosome 18p deletion syndrome: a deletion of chromosome 18p region that manifests as autosomal dominant abnormalities characterized by intellectual disability, growth retardation, craniofacial dysmorphism including round face which may lengthen with linear growth of the height of the face; dysplastic ears, wide mouth, dental anomalies, and abnormalities of the limbs, genitalia, brain, eyes, and heart also occur. omim: 146390
Chromosome 1p36 Deletion Syndrome: a disorder that results from deletion of chromosome 1p36 region. it is characterized by multiple congenital craniofacial and skeletal abnormalities, heart septal defects; hypothyroidism; seizures, and severe neuordevelopmental and intellectual disability. it is the most common terminal deletion syndrome, occurring in 1 in 5,000 births. omim: 607872
Chromosome 21 monosomy: the loss (aneuploidy) of portions of of chromosome 21 result in an increased probability of congenital abnormalities, developmental delay, and intellectual disability. the severity depends on the location and size of the deleted region: proximal and distal deletions are more moderate, whereas deletion of the 21q22 region can cause craniofacial abnormalities, heart septal defects, and severe intellectual disability
Chromosome 22, microdeletion 22 q11: chromosomal disorders, including digeorge syndrome, where a portion of the long arm of chromosome 22 is deleted, resulting in a variety of growth, anatomical, cardiovascular and developmental abnormalities due to insufficiency of the tbx1 gene. omim: 188400
Chromosome 22, trisomy: a chromosomal abnormality characterized by a third copy of chromosome 22. most cases of complete trisomy 22 are lethal in utero, resulting in miscarriage. cases in which there is a mosaic duplication (mosaic trisomy 22) may cause cardiac defects, growth, and developmental delays in affected children
Chromosome 3, monosomy 3p: deletion of the distal portion of the short arm (p) of chromosome 3 may result in a range of abnormalities that vary in severity. among the more common are prenatal and postnatal growth deficiency; severe intellectual disability; craniofacial abnormalities; eyebrows that grow together (synophrys), hypertrichosis; and polydactyly. omim: 613792
Chromosome 4, trisomy 4q: a chromosomal abnormality characterized by an extra copy or duplication of the long (q) arm of chromosome 4. affected individuals may have intellectual disability, seizures, microcephaly; growth delay, hearing impairment, craniofacial and endocrine abnormalities, and malformed thumbs
Chromosome 4q- Syndrome: a chromosomal abnormality characterized by loss of a portion of the long (q) arm of chromosome 4. severity of the syndrome depends on the size and location of the deletion and the genes that are lost. affected individuals generally have distinct craniofacial features (facies), skeletal abnormalities, heart defects, intellectual disability, and short stature
Chromosome 5, trisomy 5q: a chromosomal abnormality characterized by an extra copy or duplication of the long (q) arm of chromosome 5. severity of symptoms depend on the size and location of the duplication and which genes are involved. affected individuals may experience developmental delay, intellectual disability, behavioral problems, and have distinct facial features (facies)
Chromosome 5q Deletion Syndrome: a myelodysplastic syndrome that arises from a defect in erythroid differentiation. patients present with severe macrocytic anemia, normal or elevated platelet counts, normal or reduced neutrophil counts, erythroid hypoplasia in the bone marrow, and hypolobated micromegakaryocytes. a somatic deletion of the rps14 gene has been identified. omim: 153550
Chromosome 6, monosomy 6q: a chromosomal abnormality that occurs when there is a deletion of the long (q) arm of chromosome 6. the severity of the condition depend on the size and location of the deletion and which genes are involved. affected individuals may experience developmental delay, intellectual disability, and have distinctive facial features (facies)
Chromosome 7, monosomy: conditions associated with loss of segments of chromosome 7, such as williams syndrome, resulting in growth abnormalities, intellectual disability, and immunologic disorders
Chromosome 8, mosaic trisomy: a chromosomal disorder characterized by the presence of a third copy of chromosome 8 in some cell populations. affected individuals may have craniofacial abnormalities, mild intellectual disability, joint, urinary, cardiac, and skeletal defects. they are also at higher risk for developing wilms tumor and myelodysplastic syndromes
Chromosome 8, trisomy: a condition caused by an extra copy of chromosome 8. the effects can vary from normal development in some individuals, to facial, growth, and limb abnromalities, as well as delayed speech and intellectual disability. trisomy 8 may also cause kidney, heart, and bone abnormalities
Chromosome 9, partial trisomy 9p: a chromosomal abnormality characterized by an extra copy of a portion of the short (p) arm of chromosome 9, which may arise from a chromosomal translocation in one of the parents. the severity of the symptoms depends on the size and location of the duplicated region and the genes involved. affected individuals may have intellectual disability, developmental delay, behavioral problems, and craniofacial abnormalities
Chromosome 9, trisomy: a chromosomal disorder characterized by the presence of a third copy of chromosome 9. complete trisomy 9, where all cells have an extra copy, usually results in miscarriage or death in the neonatal period. thus, most viable individuals have partial trisomy 9, where only certain portions of the chromosome are duplicated, or mosaic trisomy 9p, where there is an extra copy only in certain tissues. such individuals may have craniofacial and growth abnormalities, congenital heart defects, and intellectual disability. the severity of these symptoms depends on which genes are duplicated and which cell populations are affected
Chromosome 9p Deletion Syndrome: an autosomal dominant abnormality (partial deletion) of chromosome 9 that is characterized by trigonocephaly, flattened occiput, prominent forehead, broad flat nasal bridge, anteverted nares, malformed external ears, hypertelorism; muscle hypertonia and intellectual disability. patent ductus arteriosus; ventricular septal defects and hernias may also be present. omim: 158170
Chromosome Aberrations: abnormal number or structure of chromosomes. chromosome aberrations may result in chromosome disorders
Chromosome Banding: staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping