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.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.Alanine Transaminase: An enzyme that catalyzes the conversion of L-alanine and 2-oxoglutarate to pyruvate and L-glutamate. (From Enzyme Nomenclature, 1992) EC 22.214.171.124.Aspartate Aminotransferases: Enzymes of the transferase class that catalyze the conversion of L-aspartate and 2-ketoglutarate to oxaloacetate and L-glutamate. EC 126.96.36.199.Liver Cirrhosis: Liver disease in which the normal microcirculation, the gross vascular anatomy, and the hepatic architecture have been variably destroyed and altered with fibrous septa surrounding regenerated or regenerating parenchymal nodules.Bilirubin: A bile pigment that is a degradation product of HEME.Liver Transplantation: The transference of a part of or an entire liver from one human or animal to another.Respiratory Function Tests: Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.Drug-Induced Liver Injury: A spectrum of clinical liver diseases ranging from mild biochemical abnormalities to ACUTE LIVER FAILURE, caused by drugs, drug metabolites, and chemicals from the environment.Liver Neoplasms: Tumors or cancer of the LIVER.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.Jaundice: A clinical manifestation of HYPERBILIRUBINEMIA, characterized by the yellowish staining of the SKIN; MUCOUS MEMBRANE; and SCLERA. Clinical jaundice usually is a sign of LIVER dysfunction.Fatty Liver: Lipid infiltration of the hepatic parenchymal cells resulting in a yellow-colored liver. The abnormal lipid accumulation is usually in the form of TRIGLYCERIDES, either as a single large droplet or multiple small droplets. Fatty liver is caused by an imbalance in the metabolism of FATTY ACIDS.Alkaline Phosphatase: An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 188.8.131.52.Thyroid Function Tests: Blood tests used to evaluate the functioning of the thyroid gland.Hepatitis: INFLAMMATION of the LIVER.Hepatectomy: Excision of all or part of the liver. (Dorland, 28th ed)Hepatomegaly: Enlargement of the liver.Liver Regeneration: Repair or renewal of hepatic tissue.Hepatitis, Autoimmune: A chronic self-perpetuating hepatocellular INFLAMMATION of unknown cause, usually with HYPERGAMMAGLOBULINEMIA and serum AUTOANTIBODIES.Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).Indocyanine Green: A tricarbocyanine dye that is used diagnostically in liver function tests and to determine blood volume and cardiac output.Cholestasis, Intrahepatic: Impairment of bile flow due to injury to the HEPATOCYTES; BILE CANALICULI; or the intrahepatic bile ducts (BILE DUCTS, INTRAHEPATIC).Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Steatitis: A disease of cats and mink characterized by a marked inflammation of adipose tissue and the deposition of "ceroid" pigment in the interstices of the adipose cells. It is believed to be caused by feeding diets containing too much unsaturated fatty acid and too little vitamin E. (Merck Veterinary Manual, 5th ed; Stedman, 25th ed)Liver Failure: Severe inability of the LIVER to perform its normal metabolic functions, as evidenced by severe JAUNDICE and abnormal serum levels of AMMONIA; BILIRUBIN; ALKALINE PHOSPHATASE; ASPARTATE AMINOTRANSFERASE; LACTATE DEHYDROGENASES; and albumin/globulin ratio. (Blakiston's Gould Medical Dictionary, 4th ed)Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Pancreatic Function Tests: Tests based on the biochemistry and physiology of the exocrine pancreas and involving analysis of blood, duodenal contents, feces, or urine for products of pancreatic secretion.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Hepatitis, Chronic: INFLAMMATION of the LIVER with ongoing hepatocellular injury for 6 months or more, characterized by NECROSIS of HEPATOCYTES and inflammatory cell (LEUKOCYTES) infiltration. Chronic hepatitis can be caused by viruses, medications, autoimmune diseases, and other unknown factors.Sulfobromophthalein: A phenolphthalein that is used as a diagnostic aid in hepatic function determination.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Hepatitis, Viral, Human: INFLAMMATION of the LIVER in humans due to infection by VIRUSES. There are several significant types of human viral hepatitis with infection caused by enteric-transmission (HEPATITIS A; HEPATITIS E) or blood transfusion (HEPATITIS B; HEPATITIS C; and HEPATITIS D).Carcinoma, Hepatocellular: A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.Hobbies: Leisure activities engaged in for pleasure.Jaundice, Obstructive: Jaundice, the condition with yellowish staining of the skin and mucous membranes, that is due to impaired BILE flow in the BILIARY TRACT, such as INTRAHEPATIC CHOLESTASIS, or EXTRAHEPATIC CHOLESTASIS.Liver Circulation: The circulation of BLOOD through the LIVER.Choledocholithiasis: Presence or formation of GALLSTONES in the COMMON BILE DUCT.Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Hepatic Artery: A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Portal Vein: A short thick vein formed by union of the superior mesenteric vein and the splenic vein.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Splenomegaly: Enlargement of the spleen.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.Biliary Tract: The BILE DUCTS and the GALLBLADDER.Gallstones: Solid crystalline precipitates in the BILIARY TRACT, usually formed in the GALLBLADDER, resulting in the condition of CHOLELITHIASIS. Gallstones, derived from the BILE, consist mainly of calcium, cholesterol, or bilirubin.Living Donors: Non-cadaveric providers of organs for transplant to related or non-related recipients.Liver Failure, Acute: A form of rapid-onset LIVER FAILURE, also known as fulminant hepatic failure, caused by severe liver injury or massive loss of HEPATOCYTES. It is characterized by sudden development of liver dysfunction and JAUNDICE. Acute liver failure may progress to exhibit cerebral dysfunction even HEPATIC COMA depending on the etiology that includes hepatic ISCHEMIA, drug toxicity, malignant infiltration, and viral hepatitis such as post-transfusion HEPATITIS B and HEPATITIS C.Cholelithiasis: Presence or formation of GALLSTONES in the BILIARY TRACT, usually in the gallbladder (CHOLECYSTOLITHIASIS) or the common bile duct (CHOLEDOCHOLITHIASIS).Serum Albumin: A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Hepatitis B: INFLAMMATION of the LIVER in humans caused by a member of the ORTHOHEPADNAVIRUS genus, HEPATITIS B VIRUS. It is primarily transmitted by parenteral exposure, such as transfusion of contaminated blood or blood products, but can also be transmitted via sexual or intimate personal contact.Liver Cirrhosis, Biliary: FIBROSIS of the hepatic parenchyma due to obstruction of BILE flow (CHOLESTASIS) in the intrahepatic or extrahepatic bile ducts (BILE DUCTS, INTRAHEPATIC; BILE DUCTS, EXTRAHEPATIC). Primary biliary cirrhosis involves the destruction of small intra-hepatic bile ducts and bile secretion. Secondary biliary cirrhosis is produced by prolonged obstruction of large intrahepatic or extrahepatic bile ducts from a variety of causes.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.Mitochondria, Liver: Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)Bile Ducts: The channels that collect and transport the bile secretion from the BILE CANALICULI, the smallest branch of the BILIARY TRACT in the LIVER, through the bile ductules, the bile ducts out the liver, and to the GALLBLADDER for storage.Hepatic Veins: Veins which drain the liver.Ursodeoxycholic Acid: An epimer of chenodeoxycholic acid. It is a mammalian bile acid found first in the bear and is apparently either a precursor or a product of chenodeoxycholate. Its administration changes the composition of bile and may dissolve gallstones. It is used as a cholagogue and choleretic.Hypertension, Portal: Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.Cholangiopancreatography, Endoscopic Retrograde: Fiberoptic endoscopy designed for duodenal observation and cannulation of VATER'S AMPULLA, in order to visualize the pancreatic and biliary duct system by retrograde injection of contrast media. Endoscopic (Vater) papillotomy (SPHINCTEROTOMY, ENDOSCOPIC) may be performed during this procedure.Albumins: Water-soluble proteins found in egg whites, blood, lymph, and other tissues and fluids. They coagulate upon heating.Chronic Disease: Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)Cholagogues and Choleretics: Gastrointestinal agents that stimulate the flow of bile into the duodenum (cholagogues) or stimulate the production of bile by the liver (choleretic).Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Common Bile Duct: The largest bile duct. It is formed by the junction of the CYSTIC DUCT and the COMMON HEPATIC DUCT.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Cholecystectomy: Surgical removal of the GALLBLADDER.Cholangiopancreatography, Magnetic Resonance: Non-invasive diagnostic technique for visualizing the PANCREATIC DUCTS and BILE DUCTS without the use of injected CONTRAST MEDIA or x-ray. MRI scans provide excellent sensitivity for duct dilatation, biliary stricture, and intraductal abnormalities.Lidocaine: A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of PROCAINE but its duration of action is shorter than that of BUPIVACAINE or PRILOCAINE.Cholecystectomy, Laparoscopic: Excision of the gallbladder through an abdominal incision using a laparoscope.Common Bile Duct Diseases: Diseases of the COMMON BILE DUCT including the AMPULLA OF VATER and the SPHINCTER OF ODDI.Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Hepatitis C, Chronic: INFLAMMATION of the LIVER in humans that is caused by HEPATITIS C VIRUS lasting six months or more. Chronic hepatitis C can lead to LIVER CIRRHOSIS.Liver Diseases, Alcoholic: Liver diseases associated with ALCOHOLISM. It usually refers to the coexistence of two or more subentities, i.e., ALCOHOLIC FATTY LIVER; ALCOHOLIC HEPATITIS; and ALCOHOLIC CIRRHOSIS.Cholangiography: An imaging test of the BILIARY TRACT in which a contrast dye (RADIOPAQUE MEDIA) is injected into the BILE DUCT and x-ray pictures are taken.Hepatitis C: INFLAMMATION of the LIVER in humans caused by HEPATITIS C VIRUS, a single-stranded RNA virus. Its incubation period is 30-90 days. Hepatitis C is transmitted primarily by contaminated blood parenterally, and is often associated with transfusion and intravenous drug abuse. However, in a significant number of cases, the source of hepatitis C infection is unknown.Hepatitis A: INFLAMMATION of the LIVER in humans caused by a member of the HEPATOVIRUS genus, HUMAN HEPATITIS A VIRUS. It can be transmitted through fecal contamination of food or water.Hemochromatosis: A disorder of iron metabolism characterized by a triad of HEMOSIDEROSIS; LIVER CIRRHOSIS; and DIABETES MELLITUS. It is caused by massive iron deposits in parenchymal cells that may develop after a prolonged increase of iron absorption. (Jablonski's Dictionary of Syndromes & Eponymic Diseases, 2d ed)Cholangitis, Sclerosing: Chronic inflammatory disease of the BILIARY TRACT. It is characterized by fibrosis and hardening of the intrahepatic and extrahepatic biliary ductal systems leading to bile duct strictures, CHOLESTASIS, and eventual BILIARY CIRRHOSIS.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Hepatocytes: The main structural component of the LIVER. They are specialized EPITHELIAL CELLS that are organized into interconnected plates called lobules.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Liver Cirrhosis, Alcoholic: FIBROSIS of the hepatic parenchyma due to chronic excess ALCOHOL DRINKING.Hepatitis B Surface Antigens: Those hepatitis B antigens found on the surface of the Dane particle and on the 20 nm spherical and tubular particles. Several subspecificities of the surface antigen are known. These were formerly called the Australia antigen.Forced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.Pulmonary Diffusing Capacity: The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.Liver, Artificial: Devices for simulating the activities of the liver. They often consist of a hybrid between both biological and artificial materials.Hepatitis B virus: The type species of the genus ORTHOHEPADNAVIRUS which causes human HEPATITIS B and is also apparently a causal agent in human HEPATOCELLULAR CARCINOMA. The Dane particle is an intact hepatitis virion, named after its discoverer. Non-infectious spherical and tubular particles are also seen in the serum.Liver Neoplasms, Experimental: Experimentally induced tumors of the LIVER.Bile Acids and Salts: Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.Immunosuppressive Agents: Agents that suppress immune function by one of several mechanisms of action. Classical cytotoxic immunosuppressants act by inhibiting DNA synthesis. Others may act through activation of T-CELLS or by inhibiting the activation of HELPER CELLS. While immunosuppression has been brought about in the past primarily to prevent rejection of transplanted organs, new applications involving mediation of the effects of INTERLEUKINS and other CYTOKINES are emerging.Acetamides: Derivatives of acetamide that are used as solvents, as mild irritants, and in organic synthesis.Galactose: An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.Metabolic Clearance Rate: Volume of biological fluid completely cleared of drug metabolites as measured in unit time. Elimination occurs as a result of metabolic processes in the kidney, liver, saliva, sweat, intestine, heart, brain, or other site.Hepatitis B, Chronic: INFLAMMATION of the LIVER in humans caused by HEPATITIS B VIRUS lasting six months or more. It is primarily transmitted by parenteral exposure, such as transfusion of contaminated blood or blood products, but can also be transmitted via sexual or intimate personal contact.Liver Extracts: Extracts of liver tissue containing uncharacterized specific factors with specific activities; a soluble thermostable fraction of mammalian liver is used in the treatment of pernicious anemia.Liver Cirrhosis, Experimental: Experimentally induced chronic injuries to the parenchymal cells in the liver to achieve a model for LIVER CIRRHOSIS.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Drug Monitoring: The process of observing, recording, or detecting the effects of a chemical substance administered to an individual therapeutically or diagnostically.Platelet Function Tests: Laboratory examination used to monitor and evaluate platelet function in a patient's blood.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Imino AcidsCohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.Graft Survival: The survival of a graft in a host, the factors responsible for the survival and the changes occurring within the graft during growth in the host.Spirometry: Measurement of volume of air inhaled or exhaled by the lung.Acute Disease: Disease having a short and relatively severe course.End Stage Liver Disease: Final stage of a liver disease when the liver failure is irreversible and LIVER TRANSPLANTATION is needed.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.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)Pancreatitis: INFLAMMATION of the PANCREAS. Pancreatitis is classified as acute unless there are computed tomographic or endoscopic retrograde cholangiopancreatographic findings of CHRONIC PANCREATITIS (International Symposium on Acute Pancreatitis, Atlanta, 1992). The two most common forms of acute pancreatitis are ALCOHOLIC PANCREATITIS and gallstone pancreatitis.Liver Abscess: Solitary or multiple collections of PUS within the liver as a result of infection by bacteria, protozoa, or other agents.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Lung Diseases: Pathological processes involving any part of the LUNG.para-Aminobenzoates: Benzoic acids, salts, or esters that contain an amino group attached to carbon number 4 of the benzene ring structure.Kidney Function Tests: Laboratory tests used to evaluate how well the kidneys are working through examination of blood and urine.Carrier State: The condition of harboring an infective organism without manifesting symptoms of infection. The organism must be readily transmissible to another susceptible host.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Graft Rejection: An immune response with both cellular and humoral components, directed against an allogeneic transplant, whose tissue antigens are not compatible with those of the recipient.Chi-Square Distribution: A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.Hepatic Encephalopathy: A syndrome characterized by central nervous system dysfunction in association with LIVER FAILURE, including portal-systemic shunts. Clinical features include lethargy and CONFUSION (frequently progressing to COMA); ASTERIXIS; NYSTAGMUS, PATHOLOGIC; brisk oculovestibular reflexes; decorticate and decerebrate posturing; MUSCLE SPASTICITY; and bilateral extensor plantar reflexes (see REFLEX, BABINSKI). ELECTROENCEPHALOGRAPHY may demonstrate triphasic waves. (From Adams et al., Principles of Neurology, 6th ed, pp1117-20; Plum & Posner, Diagnosis of Stupor and Coma, 3rd ed, p222-5)Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Carbon Tetrachloride: A solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and a starting material in the manufacturing of organic compounds. Poisoning by inhalation, ingestion or skin absorption is possible and may be fatal. (Merck Index, 11th ed)Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Cholesterol: The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.IndiaTechnetium Tc 99m Aggregated Albumin: A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in cardiovascular and cerebral circulation.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Prothrombin Time: Clotting time of PLASMA recalcified in the presence of excess TISSUE THROMBOPLASTIN. Factors measured are FIBRINOGEN; PROTHROMBIN; FACTOR V; FACTOR VII; and FACTOR X. It is used for monitoring anticoagulant therapy with COUMARINS.Hepatic Insufficiency: Conditions in which the LIVER functions fall below the normal ranges. Severe hepatic insufficiency may cause LIVER FAILURE or DEATH. Treatment may include LIVER TRANSPLANTATION.Hepacivirus: A genus of FLAVIVIRIDAE causing parenterally-transmitted HEPATITIS C which is associated with transfusions and drug abuse. Hepatitis C virus is the type species.Total Lung Capacity: The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Recurrence: The return of a sign, symptom, or disease after a remission.Portoenterostomy, Hepatic: Operation for biliary atresia by anastomosis of the bile ducts into the jejunum or duodenum.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Sex Factors: Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.