Homogentisate 1,2-Dioxygenase: A mononuclear Fe(II)-dependent oxygenase, this enzyme catalyzes the conversion of homogentisate to 4-maleylacetoacetate, the third step in the pathway for the catabolism of TYROSINE. Deficiency in the enzyme causes ALKAPTONURIA, an autosomal recessive disorder, characterized by homogentisic aciduria, OCHRONOSIS and ARTHRITIS. This enzyme was formerly characterized as EC and EC Acid4-Hydroxyphenylpyruvate Dioxygenase: An enzyme that catalyzes the conversion of 4-hydroxyphenylpyruvate plus oxygen to homogentisic acid and carbon dioxide. EC An inborn error of amino acid metabolism resulting from a defect in the enzyme HOMOGENTISATE 1,2-DIOXYGENASE, an enzyme involved in the breakdown of PHENYLALANINE and TYROSINE. It is characterized by accumulation of HOMOGENTISIC ACID in the urine, OCHRONOSIS in various tissues, and ARTHRITIS.Ochronosis: The yellowish discoloration of connective tissue due to deposition of HOMOGENTISIC ACID (a brown-black pigment). This is due to defects in the metabolism of PHENYLALANINE and TYROSINE. Ochronosis occurs in ALKAPTONURIA, but has also been associated with exposure to certain chemicals (e.g., PHENOL, trinitrophenol, BENZENE DERIVATIVES).Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Dioxygenases: Non-heme iron-containing enzymes that incorporate two atoms of OXYGEN into the substrate. They are important in biosynthesis of FLAVONOIDS; GIBBERELLINS; and HYOSCYAMINE; and for degradation of AROMATIC HYDROCARBONS.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Chromosomes: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.MedlinePlus: NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.Molecular Sequence Annotation: The addition of descriptive information about the function or structure of a molecular sequence to its MOLECULAR SEQUENCE DATA record.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.Phenylalanine: An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.Tocopherols: A collective name for a group of closely related lipids that contain substitutions on the 2H-1-benzopyran-6-ol nucleus and a long hydrocarbon chain of isoprenoid units. They are antioxidants by virtue of the phenolic hydrogen. Tocopherols react with the most reactive form of oxygen and protect unsaturated fatty acids from oxidation.Vitamin E: A generic descriptor for all TOCOPHEROLS and TOCOTRIENOLS that exhibit ALPHA-TOCOPHEROL activity. By virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus, these compounds exhibit varying degree of antioxidant activity, depending on the site and number of methyl groups and the type of ISOPRENOIDS.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.gamma-Tocopherol: A natural tocopherol with less antioxidant activity than ALPHA-TOCOPHEROL. It exhibits antioxidant activity by virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus. As in BETA-TOCOPHEROL, it also has three methyl groups on the 6-chromanol nucleus but at different sites.Germination: The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)Lipid Peroxidation: Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.alpha-Tocopherol: A natural tocopherol and one of the most potent antioxidant tocopherols. It exhibits antioxidant activity by virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus. It has four methyl groups on the 6-chromanol nucleus. The natural d form of alpha-tocopherol is more active than its synthetic dl-alpha-tocopherol racemic mixture.Ear Cartilage: Cartilage of the EAR AURICLE and the EXTERNAL EAR CANAL.ResorcinolsHydroquinonesPubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Phenylpyruvic Acids: A group of compounds that are derivatives of phenylpyruvic acid which has the general formula C6H5CH2COCOOH, and is a metabolite of phenylalanine. (From Dorland, 28th ed)Rotifera: A class of minute animals of the phylum Aschelminthes.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Transcriptome: The pattern of GENE EXPRESSION at the level of genetic transcription in a specific organism or under specific circumstances in specific cells.Genome-Wide Association Study: An analysis comparing the allele frequencies of all available (or a whole GENOME representative set of) polymorphic markers in unrelated patients with a specific symptom or disease condition, and those of healthy controls to identify markers associated with a specific disease or condition.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Lesch-Nyhan Syndrome: An inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism; HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE. Affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. Self-destructive behaviors such as biting of fingers and lips are seen frequently. Intellectual impairment may also occur but is typically not severe. Elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. (Menkes, Textbook of Child Neurology, 5th ed, pp127)Hypoxanthine Phosphoribosyltransferase: An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC Nucleotides: Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.Purines: A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.Purine-Pyrimidine Metabolism, Inborn ErrorsPentosyltransferases: Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.Metabolomics: The systematic identification and quantitation of all the metabolic products of a cell, tissue, organ, or organism under varying conditions. The METABOLOME of a cell or organism is a dynamic collection of metabolites which represent its net response to current conditions.Tyrosinemias: A group of disorders which have in common elevations of tyrosine in the blood and urine secondary to an enzyme deficiency. Type I tyrosinemia features episodic weakness, self-mutilation, hepatic necrosis, renal tubular injury, and seizures and is caused by a deficiency of the enzyme fumarylacetoacetase. Type II tyrosinemia features INTELLECTUAL DISABILITY, painful corneal ulcers, and keratoses of the palms and plantar surfaces and is caused by a deficiency of the enzyme TYROSINE TRANSAMINASE. Type III tyrosinemia features INTELLECTUAL DISABILITY and is caused by a deficiency of the enzyme 4-HYDROXYPHENYLPYRUVATE DIOXYGENASE. (Menkes, Textbook of Child Neurology, 5th ed, pp42-3)Delftia acidovorans: A species of gram-negative rod-shaped bacteria found ubiquitously and formerly called Comamonas acidovorans and Pseudomonas acidovorans. It is the type species of the genus DELFTIA.Calorimetry: The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Peer Group: Group composed of associates of same species, approximately the same age, and usually of similar rank or social status.Video Games: A form of interactive entertainment in which the player controls electronically generated images that appear on a video display screen. This includes video games played in the home on special machines or home computers, and those played in arcades.Videotape Recording: Recording of visual and sometimes sound signals on magnetic tape.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Journal Impact Factor: A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.Peer Review, Research: The evaluation by experts of the quality and pertinence of research or research proposals of other experts in the same field. Peer review is used by editors in deciding which submissions warrant publication, by granting agencies to determine which proposals should be funded, and by academic institutions in tenure decisions.Peer Review: An organized procedure carried out by a select committee of professionals in evaluating the performance of other professionals in meeting the standards of their specialty. Review by peers is used by editors in the evaluation of articles and other papers submitted for publication. Peer review is used also in the evaluation of grant applications. It is applied also in evaluating the quality of health care provided to patients.