Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hepatotoxic effects of alcohol have been described in detail, but factors responsible for its hepatotoxicity have only partially been characterized. For example, it is known that chronic ethanol ingestion increases hepatotoxicity and produces fatty liver, hepatitis and cirrhosis. However, acute ethanol consumption reduces endotoxin hepatotoxicity. It now appears that Kupffer cells participate in several aspects of these phenomena. Previously, most studies on the effects of alcohol on liver function have focused chiefly on the hepatocyte. Recently, attention has been directed towards the effect of ethanol ingestion on Kupffer cell function, which is stimulated by gut-derived endotoxins (lipopolysaccharides) via mechanisms dependent on increased gut permeability and the possible relationship between Kupffer cells and alcohol-induced liver injury. Here we will review new evidence for the proposal that Kupffer cells and endotoxins play a pivotal role in hepatotoxicity following alcohol exposure, based on studies using the continuous intragastric enteral feeding model developed by Tsukamoto and French and an acute model developed by us.
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PMID:Role of Kupffer cells and gut-derived endotoxins in alcoholic liver injury. 1075 16

The gut and the liver are the key organs in nutrient absorption and metabolism. Bile acids, drugs, and toxins undergo extensive enterohepatic circulation. Bile acids play a major role in several hepatic and intestinal diseases. Endotoxins deriving from intestinal Gram-negative bacteria are important in the pathogenesis of liver and systemic diseases. Chronic liver diseases can influence gastrointestinal motility, which together with other factors may contribute to bacterial overgrowth and in patients with ascites to an increased risk of spontaneous bacterial peritonitis. Patients with end-stage liver disease frequently develop portal hypertension leading to varices, gastric vascular ectasia, and portal hypertensive gastroenteropathy. Several liver and biliary abnormalities are observed in patients with inflammatory bowel disease (primary sclerosing cholangitis, autoimmune hepatitis, cholelithiasis). The primary defect in hemochromatosis is located in the intestine, causing an inappropriate increase in iron absorption, and the liver is the site of earliest and heaviest iron deposition. Elevated transaminases are observed in many patients with celiac disease, and steatohepatitis frequently develops in patients with jejunoileal bypass and short bowel syndrome. Furthermore, the liver is the primary organ for metastasis of intestinal cancer. Many viral, bacterial, fungal, and parasitic diseases affect the intestine as well as the liver and the biliary tract.
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PMID:Gut-liver axis. 1085 47

In North America, liver disease due to alcohol consumption is an important cause of death in adults, although its pathogenesis remains obscure. Despite the fact that resident hepatic macrophages are known to contribute to early alcohol-induced liver injury via oxidative stress, the exact source of free radicals has remained a mystery. To test the hypothesis that NADPH oxidase is the major source of oxidants due to ethanol, we used p47(phox) knockout mice, which lack a critical subunit of this major source of reactive oxygen species in activated phagocytes. Mice were treated with ethanol chronically, using a Tsukamoto-French protocol, for 4 weeks. In wild-type mice, ethanol caused severe liver injury via a mechanism involving gut-derived endotoxin, CD14 receptor, production of electron spin resonance-detectable free radicals, activation of the transcription factor NF-kappaB, and release of cytotoxic TNF-alpha from activated Kupffer cells. In NADPH oxidase-deficient mice, neither an increase in free radical production, activation of NF-kappaB, an increase in TNF-alpha mRNA, nor liver pathology was observed. These data strongly support the hypothesis that free radicals from NADPH oxidase in hepatic Kupffer cells play a predominant role in the pathogenesis of early alcohol-induced hepatitis by activating NF-kappaB, which activates production of cytotoxic TNF-alpha.
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PMID:NADPH oxidase-derived free radicals are key oxidants in alcohol-induced liver disease. 1101 74

Females have a greater susceptibility to ethanol-induced liver injury than males. Females who drink ethanol regularly and have been overweight for 10 years or more are at greater risk for both hepatitis and cirrhosis than males, and females develop ethanol-induced liver injury more rapidly and with less ethanol than males. Female rats on an enteral ethanol protocol exhibit injury more quickly than males and have widespread fatty changes over a larger portion of the liver lobule. Moreover, levels of plasma endotoxin, intracellular adhesion molecule-1, free radical adducts, infiltrating neutrophils and nuclear factor kappa B are doubled in female rat livers compared with male rat livers after enteral ethanol treatment. Additionally, estrogen treatment in vivo increases the sensitivity of hepatic macrophages or Kupffer cells to endotoxin. Evidence has been presented that Kupffer cells are pivotal in the development of ethanol-induced liver injury. Destroying Kupffer cells with gadolinium chloride or decreasing bacterial endotoxin by sterilizing the gut with antibiotics inhibits early inflammation due to ethanol. Similar results have been obtained with anti-tumour necrosis factor-alpha antibody. These data pointed to the hypothesis that ethanol-induced liver injury involves elevations in circulating endotoxin concentrations leading to activation of Kupffer cells, which causes a hypoxia-reoxygenation injury. This theory has been tested using pimonidazole, a 2-nitroimidazole marker, to quantify hypoxia in downstream, pericentral regions of the hepatic lobule. After chronic enteral ethanol treatment, pimonidazole binding doubles. Enteral ethanol also increases free radicals detected with electron spin resonance. Radical adducts, with coupling constants such as alpha-hydroxyethyl radical, have been shown to arise from ethanol. Importantly, hypoxia and radical production detected in bile are also decreased by the destruction of Kupffer cells with gadolinium chloride. These data support the hypothesis that Kupffer cells contribute to the vital sex differences in liver injury caused by ethanol.
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PMID:Sex-related liver injury due to alcohol involves activation of Kupffer cells by endotoxin. 1111 Jun 25

Misoprostol, a prostaglandin E1 analog, is a racemate of four stereoisomers. On administration it rapidly de-esterifies to its active form, misoprostolic acid. Misoprostolic acid is 85% albumin bound and has a half-life of approximately 30 minutes. It is excreted in urine as inactive metabolites. No significant drug interactions have been reported. Besides its gastrointestinal protective and uterotonic activities, misoprostol regulates various immunologic cascades. It inhibits platelet-activating factor and leukocyte adherence, and modulates adhesion molecule expression. It protects against gut irradiation injury, experimental gastric cancer, enteropathy, and constipation. It improves nutrient absorption in cystic fibrosis. Misoprostol has utility in acetaminophen and ethanol hepatotoxicity, hepatitis, and fibrosis. It is effective in asthmatics and aspirin-sensitive asthmatic and allergic patients. It lowers cholesterol and severity of peripheral vascular diseases, prolongs survival of cardiac and kidney transplantation, synergizes cyclosporine, and protects against cyclosporine-induced renal damage. It works against drug-induced renal damage, interstitial cystitis, lupus nephritis, and hepatorenal syndrome. It is useful in periodontal disease and dental repair. Misoprostol enhances glycosoaminoglycan synthesis in cartilage after injury. It prevents ultraviolet-induced cataracts and reduces intraocular pressure in glaucoma and ocular hypertension. It synergizes antiinflammatory and analgesic effects of diclofenac or colchicine and has been administered to treat trigeminal neuralgic pain. It reduces chemotherapy-induced hair loss and recovery time from burn injury, and is effective in treating sepsis, multiple sclerosis, and pancreatitis.
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PMID:Misoprostol therapeutics revisited. 1119 38

Mucosal addressin cell adhesion molecule (MAdCAM-1) plays a pivotal role in T-lymphocyte homing to the gut. Given the strong association between the autoimmune liver diseases primary sclerosing cholangitis and autoimmune hepatitis and inflammatory bowel disease, we investigated the role of MAdCAM-1 in recruiting mucosal lymphocytes to the liver. MAdCAM-1 was strongly expressed on inflamed portal vein/sinusoidal endothelium in autoimmune mediated liver disease. In modified Stamper-Woodruff assays, MAdCAM-1 on hepatic vessels supported adhesion of alpha4beta7+ lymphocytes (i.e., gut-derived T cells) from patients with inflammatory bowel disease and primary sclerosing cholangitis. This adhesion was inhibited by pretreatment with blocking antibodies to MAdCAM-1, alpha4beta7, or the integrin alpha4 chain indicating that MAdCAM-1 in inflamed liver is functionally active. Circulating lymphocytes from patients with primary sclerosing cholangitis showed rolling adhesion on MAdCAM-1 transfectants in a flow-based adhesion assay that could be blocked by anti-MAdCAM-1 or anti-alpha4beta7 mAbs. These findings indicate that, under certain circumstances, vessels in the human liver support adhesion of alpha4beta7+ mucosal lymphocytes via binding to aberrantly expressed MAdCAM-1 on liver endothelium. This provides a mechanism to explain the hepatic recruitment of mucosal lymphocytes in inflammatory liver disease complicating inflammatory bowel disease.
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PMID:MAdCAM-1 expressed in chronic inflammatory liver disease supports mucosal lymphocyte adhesion to hepatic endothelium (MAdCAM-1 in chronic inflammatory liver disease). 1134 33

The paper is devoted to the actual questions of gastrointestinal immunology. In the first part, structure and function of gut-associated mucosal tissue (GALT), including the role of secretory immunoglobulins and importance of oral tolerance are shown. In the second part, the pathogenesis of unknown origin gastrointestinal and liver diseases (gluten sensitive enteropathy, inflammatory bowel diseases, autoimmune liver diseases, autoimmune pancreatitis) is described. Then the immunology of some gastrointestinal infections (Helicobacter pylori, hepatitis virus B and C, and HIV) and of alcoholic and drug induced, liver diseases is briefly summarized.
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PMID:[Gastrointestinal immunology]. 1176 Apr 53

The tools available for monitoring necrotic enteritis caused by Clostridium perfringens in broiler chickens have been limited, particularly for identifying subclinical disease. In this study, a modified enzyme-linked immunosorbent assay was used to quantify levels of specific immunoglobulin G to C. perfringens alpha-toxin in serum from broilers. We found significantly higher antibody levels in broilers with a history of subclinical necrotic enteritis compared with a zinc-bacitracin-treated group with a low level of gut lesions. Furthermore, in 4.5-week-old commercial broiler flocks, there was an association between the occurrence of C. perfringens-associated hepatitis at slaughter and the immune response to alpha-toxin. Practical solutions for defining cut-off levels for positive serum samples at individual and flock levels are proposed, and were found to be useful on a set of samples available from flocks with different histories regarding the occurrence of C. perfringens-associated disease. This serological approach seems promising as a diagnostic tool in research and disease monitoring regarding C. perfringens-associated disease.
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PMID:Diagnosing Clostridium perfringens-associated necrotic enteritis in broiler flocks by an immunoglobulin G anti-alpha-toxin enzyme-linked immunosorbent assay. 1452 9

Despite the enormous interest in the field of tumour immunology, and the development of vaccine based strategies for immunotherapy of tumours, results in patients with cancer have been disappointing. This is partly due to the lack of development of clearly defined anti-tumour immune responses. The basis for the induction of specific anti-tumour non-responsiveness is not known. Recently, the liver has been recognised as an important organ in the regulation of peripheral immunological responses. It is characterised by a remarkable ability to induce tolerance to antigens from a variety of sources. Oral tolerance to food antigens, antigens from gut flora and other antigens administered via the oral route is partly dependent upon local immunoregulation in the liver. Transplantation of liver tissue shows a remarkable ability to induce tolerance in some species, not only to liver tissue but also to other organs and tissues transplanted at the same time. This tolerance can be transferred by adoptive transfer of lymphocytes. It has been suggested that the establishment of persistent infection in the liver by hepatitis viruses, may partly depend on the tolerogenic environment of the liver, and that this may also play a role in the development of hepatocellular carcinoma in patients with chronic infections with these viruses. The liver is also a common and an important site for the development of metastases from many primary tumours. This is partly dependent upon the anatomic location and structure of the liver, but may also partly reflect the exploitation of the tolerogenic environment in the liver, allowing micrometastases to colonise and grow. This may account for the fact that the liver is such a common site for metastasis. Furthermore, once tolerance to tumour antigens is established in the liver, tolerated lymphocytes may migrate from the liver back to primary tumours and exacerbate immunological non-responsiveness at tumour sites. Indeed, if this happens early in tumour development, liver dependent tolerance to tumour antigens may play a significant role in tumour progression, and may partly determine impaired tumour responses in vaccine based immunotherapy strategies.
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PMID:Is the liver an important site for the development of immune tolerance to tumours? 1569 92

Macrophage migration inhibitory factor (MIF) is a unique protein, participating in inflammation, immune response, and cell growth. MIF was first discovered as a lymphokine involved in delayed hypersensitivity and various macrophage functions, including phagocytosis, spreading, and tumoricidal activity. It has been reported that MIF is associated with the pathogenesis of a variety of diseases. MIF expression was increased at inflammatory sites in diseases such as rheumatoid arthritis and glomerulonephritis. In experimental inflammatory disease, blockade of MIF bioactivity inhibited the severity of disease activity. On the other hand, MIF expression is also increased in tumor lesions, and MIF plays a role as a cell growth factor. MIF has been reported to be constitutively expressed in gut, liver, and pancreas. In patients with gastritis, inflammatory bowel disease, hepatitis, and pancreatitis, MIF expression was remarkably increased in both the serum and the local lesions. Blockade of MIF bioactivity inhibited and prevented inflammation in experimental gastritis, colitis, hepatitis, and pancreatitis. On the other hand, MIF expression was higher than that in normal tissues in colonic carcinomas and hepatocellular carcinoma both in vivo and in vitro. Blockade of MIF bioactivity successfully inhibited tumor cell growth in vivo and in vitro. MIF plays important roles in the pathogenesis of gastrointestinal, hepatic, and pancreatic disorders.
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PMID:Pathophysiological roles of macrophage migration inhibitory factor in gastrointestinal, hepatic, and pancreatic disorders. 1577 Mar 93


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