6-Aminonicotinamide: A vitamin antagonist which has teratogenic effects.Niacinamide: An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and PELLAGRA. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.Pentose Phosphate Pathway: An oxidative decarboxylation process that converts GLUCOSE-6-PHOSPHATE to D-ribose-5-phosphate via 6-phosphogluconate. The pentose product is used in the biosynthesis of NUCLEIC ACIDS. The generated energy is stored in the form of NADPH. This pathway is prominent in tissues which are active in the synthesis of FATTY ACIDS and STEROIDS.Teratogens: An agent that causes the production of physical defects in the developing embryo.Abnormalities, Drug-Induced: Congenital abnormalities caused by medicinal substances or drugs of abuse given to or taken by the mother, or to which she is inadvertently exposed during the manufacture of such substances. The concept excludes abnormalities resulting from exposure to non-medicinal chemicals in the environment.HexosephosphatesGlucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Phosphogluconate Dehydrogenase: An enzyme of the oxidoreductase class that catalyzes the reaction 6-phospho-D-gluconate and NADP+ to yield D-ribulose 5-phosphate, carbon dioxide, and NADPH. The reaction is a step in the pentose phosphate pathway of glucose metabolism. (From Dorland, 27th ed) EC DehydrogenaseStem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.Stem Cell Transplantation: The transfer of STEM CELLS from one individual to another within the same species (TRANSPLANTATION, HOMOLOGOUS) or between species (XENOTRANSPLANTATION), or transfer within the same individual (TRANSPLANTATION, AUTOLOGOUS). The source and location of the stem cells determines their potency or pluripotency to differentiate into various cell types.Embryonic Stem Cells: Cells derived from the BLASTOCYST INNER CELL MASS which forms before implantation in the uterine wall. They retain the ability to divide, proliferate and provide progenitor cells that can differentiate into specialized cells.Cell Culture Techniques: Methods for maintaining or growing CELLS in vitro.Pluripotent Stem Cells: Cells that can give rise to cells of the three different GERM LAYERS.Feeder Cells: Cells used in COCULTURE TECHNIQUES which support the growth of the other cells in the culture. Feeder cells provide auxillary substances including attachment substrates, nutrients, or other factors that are needed for growth in culture.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Brenner Tumor: A smooth, solid or cystic fibroepithelial (FIBROEPITHELIAL NEOPLASMS) tumor, usually found in the OVARIES but can also be found in the adnexal region and the KIDNEYS. It consists of a fibrous stroma with nests of epithelial cells that sometimes resemble the transitional cells lining the urinary bladder. Brenner tumors generally are benign and asymptomatic. Malignant Brenner tumors have been reported.Astrocytes: A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury.Cerebellum: The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.Purkinje Cells: The output neurons of the cerebellar cortex.Ganciclovir: An ACYCLOVIR analog that is a potent inhibitor of the Herpesvirus family including cytomegalovirus. Ganciclovir is used to treat complications from AIDS-associated cytomegalovirus infections.Thymidine Kinase: An enzyme that catalyzes the conversion of ATP and thymidine to ADP and thymidine 5'-phosphate. Deoxyuridine can also act as an acceptor and dGTP as a donor. (From Enzyme Nomenclature, 1992) EC, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Tolonium Chloride: A phenothiazine that has been used as a hemostatic, a biological stain, and a dye for wool and silk. Tolonium chloride has also been used as a diagnostic aid for oral and gastric neoplasms and in the identification of the parathyroid gland in thyroid surgery.Bullying: Aggressive behavior intended to cause harm or distress. The behavior may be physical or verbal. There is typically an imbalance of power, strength, or status between the target and the aggressor.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Communication: The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups.User-Computer Interface: The portion of an interactive computer program that issues messages to and receives commands from a user.ToluidinesPulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Superoxides: Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.Hydroxyeicosatetraenoic Acids: Eicosatetraenoic acids substituted in any position by one or more hydroxy groups. They are important intermediates in a series of biosynthetic processes leading from arachidonic acid to a number of biologically active compounds such as prostaglandins, thromboxanes, and leukotrienes.Constriction: The act of constricting.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC Oxidase: A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.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)Glyceraldehyde-3-Phosphate Dehydrogenases: Enzymes that catalyze the dehydrogenation of GLYCERALDEHYDE 3-PHOSPHATE. Several types of glyceraldehyde-3-phosphate-dehydrogenase exist including phosphorylating and non-phosphorylating varieties and ones that transfer hydrogen to NADP and ones that transfer hydrogen to NAD.Phosphates: Inorganic salts of phosphoric acid.NADP: Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)Neural Stem Cells: Self-renewing cells that generate the main phenotypes of the nervous system in both the embryo and adult. Neural stem cells are precursors to both NEURONS and NEUROGLIA.Pyruvic Acid: An intermediate compound in the metabolism of carbohydrates, proteins, and fats. In thiamine deficiency, its oxidation is retarded and it accumulates in the tissues, especially in nervous structures. (From Stedman, 26th ed)Hypoxia-Inducible Factor 1, alpha Subunit: Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.Glycolysis: A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.Integrases: Recombinases that insert exogenous DNA into the host genome. Examples include proteins encoded by the POL GENE of RETROVIRIDAE and also by temperate BACTERIOPHAGES, the best known being BACTERIOPHAGE LAMBDA.PyruvatesAntigens, Nuclear: Immunologically detectable substances found in the CELL NUCLEUS.ArchivesSleep Deprivation: The state of being deprived of sleep under experimental conditions, due to life events, or from a wide variety of pathophysiologic causes such as medication effect, chronic illness, psychiatric illness, or sleep disorder.Biological Science Disciplines: All of the divisions of the natural sciences dealing with the various aspects of the phenomena of life and vital processes. The concept includes anatomy and physiology, biochemistry and biophysics, and the biology of animals, plants, and microorganisms. It should be differentiated from BIOLOGY, one of its subdivisions, concerned specifically with the origin and life processes of living organisms.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.PubMed: 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.Directories as Topic: Lists of persons or organizations, systematically arranged, usually in alphabetic or classed order, giving address, affiliations, etc., for individuals, and giving address, officers, functions, and similar data for organizations. (ALA Glossary of Library and Information Science, 1983)