gamma-Glutamyltransferase: An enzyme, sometimes called GGT, with a key role in the synthesis and degradation of GLUTATHIONE; (GSH, a tripeptide that protects cells from many toxins). It catalyzes the transfer of the gamma-glutamyl moiety to an acceptor amino acid.Glycylglycine: The simplest of all peptides. It functions as a gamma-glutamyl acceptor.Alanine Transaminase: An enzyme that catalyzes the conversion of L-alanine and 2-oxoglutarate to pyruvate and L-glutamate. (From Enzyme Nomenclature, 1992) EC 2.6.1.2.Alkaline Phosphatase: An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.Aspartate Aminotransferases: Enzymes of the transferase class that catalyze the conversion of L-aspartate and 2-ketoglutarate to oxaloacetate and L-glutamate. EC 2.6.1.1.Clinical Enzyme Tests: Analyses for a specific enzyme activity, or of the level of a specific enzyme that is used to assess health and disease risk, for early detection of disease or disease prediction, diagnosis, and change in disease status.Diazooxonorleucine: An amino acid that inhibits phosphate-activated glutaminase and interferes with glutamine metabolism. It is an antineoplastic antibiotic produced by an unidentified species of Streptomyces from Peruvian soil. (From Merck Index, 11th ed)Borates: Inorganic or organic salts and esters of boric acid.Liver Function Tests: Blood tests that are used to evaluate how well a patient's liver is working and also to help diagnose liver conditions.Electrophoresis, Cellulose Acetate: Electrophoresis in which cellulose acetate is the diffusion medium.Antigens, CD13: Zinc-binding metalloproteases that are members of the type II integral membrane metalloproteases. They are expressed by GRANULOCYTES; MONOCYTES; and their precursors as well as by various non-hematopoietic cells. They release an N-terminal amino acid from a peptide, amide or arylamide.Liver Diseases: Pathological processes of the LIVER.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Glutathione: A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.Alcohol Drinking: Behaviors associated with the ingesting of alcoholic beverages, including social drinking.Isoxazoles: Azoles with an OXYGEN and a NITROGEN next to each other at the 1,2 positions, in contrast to OXAZOLES that have nitrogens at the 1,3 positions.Erythrocyte Indices: ERYTHROCYTE size and HEMOGLOBIN content or concentration, usually derived from ERYTHROCYTE COUNT; BLOOD hemoglobin concentration; and HEMATOCRIT. The indices include the mean corpuscular volume (MCV), the mean corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC).MaleatesGlucaric Acid: A sugar acid derived from D-glucose in which both the aldehydic carbon atom and the carbon atom bearing the primary hydroxyl group are oxidized to carboxylic acid groups.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.2-Acetylaminofluorene: A hepatic carcinogen whose mechanism of activation involves N-hydroxylation to the aryl hydroxamic acid followed by enzymatic sulfonation to sulfoxyfluorenylacetamide. It is used to study the carcinogenicity and mutagenicity of aromatic amines.Alcoholism: A primary, chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. The disease is often progressive and fatal. It is characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking, most notably denial. Each of these symptoms may be continuous or periodic. (Morse & Flavin for the Joint Commission of the National Council on Alcoholism and Drug Dependence and the American Society of Addiction Medicine to Study the Definition and Criteria for the Diagnosis of Alcoholism: in JAMA 1992;268:1012-4)Transferrin: An iron-binding beta1-globulin that is synthesized in the LIVER and secreted into the blood. It plays a central role in the transport of IRON throughout the circulation. A variety of transferrin isoforms exist in humans, including some that are considered markers for specific disease states.Aminopeptidases: A subclass of EXOPEPTIDASES that act on the free N terminus end of a polypeptide liberating a single amino acid residue. EC 3.4.11.Leucyl Aminopeptidase: A zinc containing enzyme of the hydrolase class that catalyzes the removal of the N-terminal amino acid from most L-peptides, particularly those with N-terminal leucine residues but not those with N-terminal lysine or arginine residues. This occurs in tissue cell cytosol, with high activity in the duodenum, liver, and kidney. The activity of this enzyme is commonly assayed using a leucine arylamide chromogenic substrate such as leucyl beta-naphthylamide.Methionine SulfoximineFreeze Drying: Method of tissue preparation in which the tissue specimen is frozen and then dehydrated at low temperature in a high vacuum. This method is also used for dehydrating pharmaceutical and food products.Bilirubin: A bile pigment that is a degradation product of HEME.Cholestasis, Extrahepatic: Impairment of bile flow in the large BILE DUCTS by mechanical obstruction or stricture due to benign or malignant processes.No-Reflow Phenomenon: Markedly reduced or absent REPERFUSION in an infarct zone following the removal of an obstruction or constriction of an artery.Enzymes: Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).Coffee: A beverage made from ground COFFEA beans (SEEDS) infused in hot water. It generally contains CAFFEINE and THEOPHYLLINE unless it is decaffeinated.Acetylglucosaminidase: A beta-N-Acetylhexosaminidase that catalyzes the hydrolysis of terminal, non-reducing 2-acetamido-2-deoxy-beta-glucose residues in chitobiose and higher analogs as well as in glycoproteins. Has been used widely in structural studies on bacterial cell walls and in the study of diseases such as MUCOLIPIDOSIS and various inflammatory disorders of muscle and connective tissue.L-Lactate Dehydrogenase: A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.Kinetics: The rate dynamics in chemical or physical systems.Glutamate-Ammonia Ligase: An enzyme that catalyzes the conversion of ATP, L-glutamate, and NH3 to ADP, orthophosphate, and L-glutamine. It also acts more slowly on 4-methylene-L-glutamate. (From Enzyme Nomenclature, 1992) EC 6.3.1.2.Dipeptides: Peptides composed of two amino acid units.Chemistry, Clinical: The specialty of ANALYTIC CHEMISTRY applied to assays of physiologically important substances found in blood, urine, tissues, and other biological fluids for the purpose of aiding the physician in making a diagnosis or following therapy.Glutamate Dehydrogenase: An enzyme that catalyzes the conversion of L-glutamate and water to 2-oxoglutarate and NH3 in the presence of NAD+. (From Enzyme Nomenclature, 1992) EC 1.4.1.2.Coumarins: Synthetic or naturally occurring substances related to coumarin, the delta-lactone of coumarinic acid.Transglutaminases: Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.Nucleotidases: A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Liver Neoplasms: Tumors or cancer of the LIVER.Microvilli: Minute projections of cell membranes which greatly increase the surface area of the cell.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.