Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carbohydrate metabolism in 9 infants with biliary atresia (BA) was investigated preoperatively and during the early postoperative period when these infants were on parenteral nutrition for 7 days. Findings were compared with data on infants without liver dysfunction. Changes of plasma glucose, immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) in the biliary atresia group with moderate liver fibrosis were the same as those in the control group. However, in one patient with marked liver fibrosis, the molar IRI/CPR ratio was significantly low, thereby suggesting an increased hepatic insulin extraction. This change, however, was transient and the molar IRI/CPR ratio gradually returned to the level of other BA patients and the control groups after the 1st postoperative day. This study shows that in infants with BA, the glucose intolerance seen in adults with obstructive jaundice is absent and the parenteral nutrition can be performed without severe changes of carbohydrate metabolism.
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PMID:Carbohydrate metabolism in infants with biliary atresia. 355 81

Nine different liver function tests (LFT) were assessed in 175 unselected diabetic outpatients stabilized on diet, insulin, or oral hypoglycemic drugs. In another group of 72 diabetic inpatients having diagnostic liver biopsy, relationships between LFT and histologic changes in the liver were investigated. Abnormalities in at least one of the tests were noted in 57% of the outpatients, and two tests gave pathologic results in 27%. The non-insulin-dependent diabetic patients more often had abnormal LFT results than did the insulin-dependent diabetic patients. Serum chenodeoxycholic acid concentrations were increased in 27%, gamma-glutamyl transpeptidase (gGT) activities in 19%, and alanine aminotransferase (Alt) activities in 17% of the outpatients, but the increases were rarely more than twice the upper limit of normal. In multivariate analysis, outpatients who were overweight, showed poor diabetes control during a short duration of diabetes controlled by treatment with diet or oral agents, and had a mature age at onset of diabetes displayed the most significant clinical explanatory variables associated with abnormal Alt. In the inpatients, the percentages of abnormal Alt and gGT results were augmented, along with increasing severity of histologic changes, but the mean values of Alt and gGT did not differ significantly between the various histologic groups. In addition, the diabetic patients with nonspecific inflammatory changes or increase in liver fibrosis often showed normal or only minor elevations in these test values.
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PMID:Liver function tests in diabetic patients. 673 94

The liver is the largest organ in the body providing a large number of essential functions for the organism. It is the center for the metabolism of nutrients and drugs, and plays a key role in the unspecific immune system by harbouring Kupfer cells, the majority of all macrophages. The liver is the main site for the synthesis of many different metabolites and releases most of the plasma proteins. All these functions of the liver must be coordinated and regulated in response to metabolic changes and minor or major injuries. This is accomplished by metabolites, the autonomous nerve system, the endocrine system and by cytokines, which form a complex network of mediator molecules. Cytokines modulate liver metabolism in many ways. Synthesis of acute phase proteins is regulated by cytokines such as IL-1, IL-6, IL-11, leukemia inhibitory factor, TNF, transforming growth factor beta, epidermal growth factor, and ciliary derived neurotropic factor, which interact synergistically with corticosteroids and insulin. Hepatic lipid metabolism and hepatic carbohydrate metabolism are also regulated by cytokines and by classical hormones. Cytokines play an important role in the pathogenesis of liver diseases and liver fibrosis, which is the common morphological reaction after chronic injury of the liver. An uncontrolled production of extracellular matrix and its impaired degradation destroy the architecture of the liver and its function. Fat-storing cells (Ito cells, lipocytes, perisinusoidal cells) are the major source of extracellular matrix in the liver. They are activated to proliferate or to produce extracellular matrix compounds by cytokines like transforming growth factor beta, and platelet derived growth factor (PDGF). Interferon gamma and alpha inhibit this activation. Modulation of fibrogenesis by these cytokines may be helpful for future treatment of liver fibrosis.
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PMID:Cytokines and the liver in health and disease. Effects on liver metabolism and fibrogenesis. 752 63

A case of septicemia due to Aeromonas hydrophila (A. hydrophila) in a 54-year-old male suffering from progressive severe jaundice and fatigue is reported. The patient developed multiple organ failure despite aggressive therapy including plasma exchange and glucose-insulin therapy. Upon admission to our hospital, therapy was started with ampicillin (ABPC) 4 g/day, gentamicin (GM) 120 mg/day, hemodialysis, continuous hemofiltration, catecholamines and a respirator, but he expired on the 2nd hospital day. Blood culture and histology revealed A. hydrophila. Postmortem examination showed alcoholic liver fibrosis which was most likely liver cirrhosis. In the literature, patients with septicemia due to Aeromonas had underlying hepatic cirrhosis more often than did those with septicemia due to other gram-negative bacilli. Therefore, it is important-to consider the possibility of liver cirrhosis in patients with A. hydrophila septicemia.
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PMID:[A case of severe acute hepatorenal failure due to Aeromoas hydrophila septicemia]. 895 74

This case of hepatocellular carcinoma (HCC) with alcoholic liver fibrosis, which was not associated with hepatitis viruses, was accompanied by hypoglycaemia. The immunoreactive insulin level was low and other hormonal examinations were almost normal. Immunohistochemical studies showed a high level of insulin-like growth factor II (IGF2) peptide in the HCC section and the size heterogeneity of serum IGF2 investigated by western blot revealed a large form at approximately 15 kDa. These results suggest that the HCC with alcoholic liver fibrosis produced IGF2 and that the hypoglycaemia was caused by tumour-associated IGF2.
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PMID:Case report: Insulin-like growth factor II expression in hepatocellular carcinoma with alcoholic liver fibrosis accompanied by hypoglycaemia. 973 71

Insulin and insulin-like growth factor (IGF-1) are mitogenic for fibroblasts and smooth muscle cells. IGF-1 increases in inflamed and fibrotic tissues and induces proliferation of rat hepatic stellate cells (HSC). This study evaluates the potential roles of these hormones in the development of liver fibrosis. Insulin and IGF-1 receptor expression was evaluated by immunohistochemistry in both cultured human HSC and human liver tissue. Phosphorylation of both 70-kd S6 kinase and extracellular-regulated kinase (ERK), cell proliferation, type I collagen gene expression, and accumulation in HSC culture media were evaluated by Western blot, immunohistochemistry for bromodeoxyuridine (BrdU), Northern blot, and enzyme-linked immunosorbent assay, respectively. Insulin and IGF-1 receptors were detected in HSC in vitro and in liver sections from patients with chronic active hepatitis. Insulin and IGF-1 induced 70-kd S6 kinase phosphorylation in HSC, whereas IGF-1 only induced ERK phosphorylation. Insulin and IGF-1 stimulated HSC proliferation in a dose-dependent fashion, with IGF-1 being four to five times more potent than insulin. Cell exposure to specific inhibitors showed that both phosphatidylinositol 3-kinase (PI3-K) and ERK are involved in IGF-1-induced mitogenesis, whereas insulin stimulated mitogenesis through a PI3-K-dependent ERK-independent pathway. IGF-1 increased type I collagen gene expression and accumulation in HSC culture media through a PI3-K- and ERK-dependent mechanism. In conclusion, insulin and IGF-1, which stimulate HSC mitogenesis and collagen synthesis, may act in concert to promote liver fibrosis in vivo by a differential activation of PI3-K- and ERK1-dependent pathways.
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PMID:Insulin and insulin-like growth factor-1 stimulate proliferation and type I collagen accumulation by human hepatic stellate cells: differential effects on signal transduction pathways. 1034 17

Blood galactose clearance after an intravenous galactose load has been widely used for years as an index of liver function. We developed a noninvasive [13C]galactose breath test, which explores galactose oxidative metabolism; this test is well correlated with liver fibrosis in patients with chronic viral hepatitis. The goal of this study was to evaluate the influence of nonhepatic factors such as diabetes and ethanol on whole-body galactose clearance (measured as the serum galactose elimination capacity test) and oxidative metabolism (measured as the [13C]galactose-induced breath 13CO2 production) in rats. Acute ethanol administration induced a significant decrease of galactose clearance and 13CO2 production. There was a significant correlation between the amount of ethanol given and the inhibition of galactose metabolism (R2 = 0.72, p < 0.0001). In streptozotocin-induced diabetic rats, the [13C]galactose-induced breath 13CO2 production was significantly reduced (p < 0.0001) and normalized by insulin treatment. However, diabetes did not decrease whole-body galactose clearance, indicating an isotopic dilution of [13C]glucose produced from [13C]galactose metabolism into the enlarged glucose pool. These results must be taken into account when using the [13C]galactose breath test as a quantitative liver function test.
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PMID:Effects of ethanol and diabetes on galactose oxidative metabolism and elimination in rats. 1053 91

Obesity is associated with a number of metabolic and haemodynamic risk factors for cardiovascular disease and type 2 diabetes mellitus. This risk depends on a complex of metabolic and haemodynamic consequences of (visceral) fat accumulation, which probably results from the continuous delivery of fatty acids to the liver via the portal vein. Hypertriglyceridaemia, hyperinsulinaemia, hypertension, insulin resistance and increased hepatic glucose production are all independent risk factors for atherosclerosis. Their combination increases the risk of cardiovascular disease considerably. Triglyceride storage in hepatocytes is another consequence of increased fatty acid supply to the liver. Until recently, hepatic steatosis was considered a harmless condition secondary to obesity or alcoholism. However, it may lead to non-alcoholic hepatic steatosis, which predisposes to liver fibrosis and even cirrhosis.
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PMID:[Abdominal obesity: metabolic complications and consequences for the liver]. 1160 19

Nonalcoholic steatohepatitis (NASH) may progress to liver fibrosis and cirrhosis. Mechanisms directly involved in the development of fibrosis have been poorly investigated. Because connective tissue growth factor (CTGF) is an intermediate key molecule involved in the pathogenesis of fibrosing chronic liver diseases and is potentially induced by hyperglycemia, the aims of this study were to (1) study the expression of CTGF in vivo both in human liver biopsy specimens of patients with NASH and in an experimental model of obesity and type II diabetes (Zucker rats); and (2) analyze the effects of hyperglycemia and insulin in vitro on hepatic stellate cells. In vivo, CTGF overexpression was observed in the liver tissue of all of the 16 patients with NASH. CTGF immunostaining was mild in 7 cases (44%) and moderate or strong in 9 cases (56%). Staining was mainly detected in the liver extracellular matrix in parallel with the amount of liver fibrosis. Liver from fa/fa rats also showed CTGF overexpression by comparison with Fa/fa rats both at the messenger RNA (mRNA) level (3-fold increase) and protein level. In vitro, both CTGF mRNA and protein were significantly increased when hepatic stellate cells were incubated with either glucose or insulin. A slight increase in type I procollagen mRNA level was also observed in hepatic stellate cells incubated with glucose. In conclusion, this study suggests that hyperglycemia and insulin are key-factors in the progression of fibrosis in patients with NASH through the up-regulation of CTGF.
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PMID:High glucose and hyperinsulinemia stimulate connective tissue growth factor expression: a potential mechanism involved in progression to fibrosis in nonalcoholic steatohepatitis. 1158 70

The liver lobule is formed by parenchymal cells, i.e., hepatocytes and nonparenchymal cells. In contrast to hepatocytes that occupy almost 80% of the total liver volume and perform the majority of numerous liver functions, nonparenchymal liver cells, which contribute only 6.5% to the liver volume, but 40% to the total number of liver cells, are localized in the sinusoidal compartment of the tissue. The walls of hepatic sinusoid are lined by three different cell types: sinusoidal endothelial cells (SEC), Kupffer cells (KC), and hepatic stellate cells (HSC, formerly known as fat-storing cells, Ito cells, lipocytes, perisinusoidal cells, or vitamin A-rich cells). Additionally, intrahepatic lymphocytes (IHL), including pit cells, i.e., liver-specific natural killer cells, are often present in the sinusoidal lumen. It has been increasingly recognized that both under normal and pathological conditions, many hepatocyte functions are regulated by substances released from neighboring nonparenchymal cells. Liver sinusoidal endothelial cells constitute the lining or wall of the hepatic sinusoid. They perform important filtration function due to the presence of small fenestrations that allow free diffusion of many substances, but not of particles of the size of chylomicrons, between the blood and the hepatocyte surface. SEC show huge endocytic capacity for many ligands including glycoproteins, components of the extracellular matrix (ECM; such as hyaluronate, collagen fragments, fibronectin, or chondroitin sulphate proteoglycan), immune complexes, transferrin and ceruloplasmin. SEC may function as antigen-presenting cells (APC) in the context of both MHC-I and MHC-II restriction with the resulting development of antigen-specific T-cell tolerance. They are also active in the secretion of cytokines, eicosanoids (i.e., prostanoids and leukotrienes), endothelin-1, nitric oxide, and some ECM components. Kupffer cells are intrasinusoidally located tissue macrophages with a pronounced endocytic and phagocytic capacity. They are in constant contact with gut-derived particulate materials and soluble bacterial products so that a subthreshold level of their activation in the normal liver may be anticipated. Hepatic macrophages secrete potent mediators of the inflammatory response (reactive oxygen species, eicosanoids, nitric oxide, carbon monoxide, TNF-alpha, and other cytokines), and thus control the early phase of liver inflammation, playing an important part in innate immune defense. High exposure of Kupffer cells to bacterial products, especially endotoxin (lipopolysaccharide, LPS), can lead to the intensive production of inflammatory mediators, and ultimately to liver injury. Besides typical macrophage activities, Kupffer cells play an important role in the clearance of senescent and damaged erythrocytes. Liver macrophages modulate immune responses via antigen presentation, suppression of T-cell activation by antigen-presenting sinusoidal endothelial cells via paracrine actions of IL-10, prostanoids, and TNF-alpha, and participation in the development of oral tolerance to bacterial superantigens. Moreover, during liver injury and inflammation, Kupffer cells secrete enzymes and cytokines that may damage hepatocytes, and are active in the remodeling of extracellular matrix. Hepatic stellate cells are present in the perisinusoidal space. They are characterized by abundance of intracytoplasmic fat droplets and the presence of well-branched cytoplasmic processes, which embrace endothelial cells and provide focally a double lining for sinusoid. In the normal liver HSC store vitamin A, control turnover of extracellular matrix, and regulate the contractility of sinusoids. Acute damage to hepatocytes activates transformation of quiescent stellate cells into myofibroblast-like cells that play a key role in the development of inflammatory fibrotic response. Pit cells represent a liver-associated population of large granular lymphocytes, i.e., natural killer (NK) cells. They spontaneously kill a variety of tumor cells in an MHC-unrestricted way, and this antitumor activity may be enhanced by the secretion of interferon-gamma. Besides pit cells, the adult liver contains other subpopulations of lymphocytes such as gamma delta T cells, and both "conventional" and "unconventional" alpha beta T cells, the latter containing liver-specific NK T cells. The development of methods for the isolation and culture of main liver cell types allowed to demonstrate that both nonparenchymal and parenchymal cells secrete tens of mediators that exert multiple paracrine and autocrine actions. Co-culture experiments and analyses of the effects of conditioned media on cultures of another liver cell type have enabled the identification of many substances released from non-parenchymal liver cells that evidently regulate some important functions of neighboring hepatocytes and non-hepatocytes. To the key mediators involved in the intercellular communication in the liver belong prostanoids, nitric oxide, endothelin-1, TNF-alpha, interleukins, and chemokines, many growth factors (TGF-beta, PDGF, IGF-I, HGF), and reactive oxygen species (ROS). Paradoxically, the cooperation of liver cells is better understood under some pathological conditions (i.e., in experimental models of liver injury) than in normal liver due to the possibility of comparing cellular phenotype under in vivo and in vitro conditions with the functions of the injured organ. The regulation of vitamin A metabolism provides an example of the physiological role for cellular cross-talk in the normal liver. The majority (up to 80%) of the total body vitamin A is stored in the liver as long-chain fatty acid esters of retinal, serving as the main source of retinoids that are utilized by all tissues throughout the body. Hepatocytes are directly involved in the uptake from blood of chylomicron remnants, and the synthesis of retinol-binding protein that transfers retinol to other tissues. However, more than 80% of the liver retinoids are stored in lipid droplets of hepatic stellate cells. HSC are capable of both uptake and release of retinol depending on the body's retinol status. The activity of some major enzymes of vitamin A metabolism have been found to be many times higher per protein basis in stellate cells than in hepatocytes. Despite progress in the understanding of the roles played by these two cell types in hepatic retinoid metabolism, the way in which retinoids move between the parenchymal cells, stellate cells, and blood plasma has not been fully elucidated. Sinusoidal blood flow is, to a great extent, regulated by hepatic stellate cells that can contract due to the presence of smooth muscle alpha-actin. The main vasoactive substances that affect constriction or relaxation of HSC derive both from distant sources and from neighboring hepatocytes (carbon monoxide, leukotrienes), endothelial cells (endothelin, nitric oxide, prostaglandins), Kupffer cells (prostaglandins, NO), and stellate cells themselves (endothelin, NO). The cellular cross-talk reflected by the fine-tuned modulation of sinusoidal contraction becomes disturbed under pathological conditions, such as endotoxemia or liver fibrosis, through the excess synthesis of vasoregulatory compounds and the involvement of additional mediators acting in a paracrine way. The liver is an important source of some growth factors and growth factor-binding proteins. Although hepatocytes synthesize the bulk of insulin-like growth factor I (IGF-I), also other types of nonparenchymal liver cells may produce this peptide. Cell-specific expression of distinct IGF-binding proteins observed in the rat and human liver provides the potential for specific regulation of hepatic IGF-I synthesis not only by growth hormone, insulin, and IGF-I, but also by cytokines released from activated Kupffer (IL-1, TNF-alpha, TGF-beta) or stellate cells (TGF-alpha, TGF-beta). Hepatic stellate cells may affect turnover of hepatocytes through the synthesis of potent positive as well as negative signals such as, respectively, hepatocyte-growth-factor or TGF-beta. Although hepatocytes seem not to produce TGF-beta, a pleiotropic cytokine synthesized and secreted in the latent form by Kupffer and stellate cells, they may contribute to its actions in the liver by the intracellular activation of latent TGF-beta, and secretion of the biologically active isoform. Many mediators that reach the liver during inflammatory processes, such as endotoxins, immune-complexes, anaphylatoxins, and PAF, increase glucose output in the perfused liver, but fail to do so in isolated hepatocytes, acting indirectly via prostaglandins released from Kupffer cells. In the liver, prostaglandins synthesized from arachidonic acid mainly in Kupffer cells in a response to various inflammatory stimuli, modulate hepatic glucose metabolism by increasing glycogenolysis in adjacent hepatocytes. The release of glucose from glycogen supports the increased demand for energetic fuel by the inflammatory cells such as leukocytes, and additionally enables enhanced glucose turnover in sinusoidal endothelial cells and Kupffer cells which is necessary for effective defense of these cells against invading microorganisms and oxidative stress in the liver. Leukotrienes, another oxidation product of arachidonic acid, have vasoconstrictive, cholestatic, and metabolic effects in the liver. A transcellular synthesis of cysteinyl leukotrienes (LTC4, LTD4, and LTE4) functions in the liver: LTA4, an important intermediate, is synthesized in Kupffer cells, taken up by hepatocytes, converted into the potent LTC4, and then released into extracellular space, acting in a paracrine way on Kupffer and sinusoidal endothelial cells. Thus, hepatocytes are target cells for the action of eicosanoids and the site of their transformation and degradation, but can not directly oxidate arachidonic acid to eicosanoids. (ABSTRACT TRUNCATED)
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PMID:Cooperation of liver cells in health and disease. 1172 49


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