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Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many tests for hepatitis C virus (HCV) infection have been developed and have proved useful for prevention of post-blood transfusion hepatitis C. However, there are at least 4 genotypes of HCV and the predominant type is different among countries. None of the tests using antigens from one genotype are sensitive in detecting the antibodies against another genotype. More sensitive tests using a more stable part of the HCV RNA sequences such as 5'-noncoding region must be developed for clinical use. Automated PCR methods and DNA sandwich hybridization methods using branched DNA amplification multimers may be candidates. Recently a hepatocyte growth factor test has been developed in Japan. Multicenter trials of this test reveal that it is useful for assessment of acute severe hepatitis. Tests for collagen type IV, fibronectin receptor, and prolyl hydroxylase have been reported useful for assessment of liver fibrosis. However, serum prolyl hydroxylase is prone to increase in response to hepatocellular damage as well as fibrotic processes. Enzymatic methods for determination of branched amino acids and tyrosine have been developed. The molar ratio of branched amino acids to tyrosine seems to have same pathophysiological meaning as the ratio of branched amino acids to aromatic amino acids (Fischer ratio) in assessment of liver cirrhosis. Lidocaine test is reported to be useful for predicting survival of transplanted liver and also assessing the function of the cirrhotic liver. Profiles of alpha-fetoprotein subfractions based on lectin-reactivity and galactosyl transferase II isoenzyme have been reported to be useful for detecting hepatocellular carcinoma but this remains to be proved.
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PMID:[Recent advances in laboratory tests for liver diseases]. 130 30

Hepatic lipocytes (perisinusoidal, Ito cells) are the primary matrix-producing cells in liver fibrosis. During liver injury they undergo activation, a process characterized by cell proliferation and increased fibrogenesis. We and others have established a culture model in which in vivo features of lipocyte activation can be mimicked by cells grown on plastic. Additionally, we recently showed that activation is associated with new expression of smooth muscle-specific alpha-actin both in vivo and in culture. Although interferon-gamma is known to inhibit collagen production in some systems, its action as a general modulator of lipocyte activation has not been examined; this issue forms the basis for our study. In culture-activated lipocytes, interferon-gamma (1,000 U/ml) significantly inhibited lipocyte proliferation as assessed by [3H]thymidine incorporation assay and nuclear autoradiography. In time-course studies of activation, it also markedly reduced expression of smooth muscle-specific alpha-actin and its messenger RNA. In dose-response experiments, maximal inhibitory effects on smooth muscle-specific alpha-actin mRNA gene expression were achieved with as little as 10 U interferon-gamma/ml. Inhibition of cellular activation was reversible; after interferon-gamma withdrawal, messenger RNA levels of smooth muscle-specific alpha-actin returned to untreated control levels. The effect of interferon-gamma extended to extracellular matrix gene expression, with reduction of type I collagen, type IV collagen and total fibronectin messenger RNAs to 3%, 24% and 15% of untreated control levels, respectively. In contrast to the marked effects on smooth muscle-specific alpha-actin and extracellular matrix gene expression, interferon-gamma reduced total protein synthesis by only 17.7%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibition of rat hepatic lipocyte activation in culture by interferon-gamma. 150 21

Hepatocyte growth factor (HGF) has been detected in non-parenchymal cells but not in hepatocytes. We performed Northern blot analysis of total RNA extracted from rat hepatocytes, Kupffer cells, endothelial cells and fat-storing (Ito-) cells. Total RNA was extracted from fat-storing cells at different times after isolation and from cells treated with different amounts of transforming growth factor beta. The RNA was hybridized with HGF, fibronectin-, and alpha-actin-specific cDNA probes, consecutively. We found an abundant amount of HGF mRNA in freshly isolated fat-storing cells, but not in other liver cells. The amount of the HGF transcripts decreases significantly in FSC during the time of culture, while fibronectin gene expression increases and alpha-actin gene expression as well. TGF-beta dramatically inhibits HGF gene expression, but causes an enhanced fibronectin mRNA level. Northern blot hybridisation of total RNA from CCl4-chronically damaged liver with HGF cDNA shows a significant increase of HGF mRNA during development of liver fibrosis. We suggest that in damaged liver either non-parenchymal cells, others than FSC, became able to express the HGF in vivo, or other mediators overcome the inhibitory effect of TGF-beta.
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PMID:The gene of hepatocyte growth factor is expressed in fat-storing cells of rat liver and is downregulated during cell growth and by transforming growth factor-beta. 153 9

Most liver diseases lead to a pathobiochemical reaction termed liver fibrosis. This is a dynamic process implying different rates of progression or regression. Thus, histological examination of a liver biopsy is essential for a diagnosis but biochemical tests are necessary for assessing the activity of the process and monitoring its evolution. We review the most important constituents of liver connective tissue and the biochemical tests developed for evaluating liver fibrosis. The aminopeptide of type III procollagen is the most widely used parameter: two different radioimmunoassays have been developed with different affinities for the two circulating forms of the molecule. The determination of serum P3P reveals an elevation of blood levels both in acute and chronic liver diseases. In the first, serum P3P is an index of hepatic necrosis and inflammation which correlates with other biochemical parameters. In the second it is an index of active fibrogenesis. Moreover, in primary biliary cirrhosis this parameter is an independent prognostic variable and an important predictor of survival. Other immunoassays exist for different collagen cleavage products, but their clinical value is not established. Laminin and fibronectin are the principal structural glycoproteins in liver. Fibronectin determination does not seem to be of clinical value in liver disease. In contrast, serum laminin correlates with the severity of portal venous pressure in advanced liver disease. Its concentration parallels the severity of varices and may indicate the risk of bleeding. Hyaluronate is a high molecular weight polysaccharide, raised serum concentrations reflect both its increased synthesis by activated fibroblasts and its impaired catabolism by the liver. Thus, it may be useful for evaluating and monitoring the progression of chronic liver disease. The measurement of the activity of prolyl 4-hydroxylase as well as that of lysine oxidase and other enzymes has been proposed, but their clinical value is not sufficiently demonstrated. A panel of tests (e.g., laminin, hyaluronate and the aminopeptide of type III procollagen) seems to be recommended for a biochemical assessment of liver fibrosis in clinical practice.
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PMID:Biochemical markers of hepatic fibrosis. 165 19

Hepatic fibrosis is characterized by a progressive increase in extracellular matrix in the liver, formed by collagens, proteoglycans and glycoproteins, qualitatively similar but quantitatively different from that in normal liver. A great number of matrix-related substances have been investigated in serum in order to identify reliable serum markers of liver fibroplasia. Among the various cleavage products of collagen precursor, the NPIIIP collagen is at present considered the most reliable serum marker of active fibrogenesis in liver, useful in monitoring the progression of fibrosis and in assessing the therapeutic efficacy of antifibrotic drugs. Lam-P1 and type IV collagen are now regarded as putative markers of basement membrane formation and sinusoids capillarization, an important pathological process in fibrosing disease, related to the impairment of hepatic circulation. Other serum-measured matrix-related substances, e.g. enzymes involved in collagen metabolism, fibronectin and proteoglycans, have not proved to reflect liver fibroplasia reliably. In spite of the availability of useful serum markers, the assessment of hepatic fibrosis is still based on liver biopsy.
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PMID:Hepatic fibrosis and its serum markers: a review. 175 69

Liver fibrosis was induced in rats after administration of dimethylnitrosamine (DMN) intraperitoneally three times a week for 3 weeks. Incomplete septa appeared after 7 days and evidence of nodulation of the parenchyma was observed after 21 days. Both distribution of extracellular matrix components (collagen type I, type III and type IV, laminin, fibronectin, heparan sulphate proteoglycan) and the distribution of desmin as a marker of lipocytes (Ito cells) and of iso-alpha-smooth muscle actin were studied with immunoperoxidase. Changes in the distribution of extracellular matrix components outlined both the formation of septa and the development of nodules with changes in the sinusoidal pattern evoking aspects of capillarization. The number of desmin-positive cells increased in DMN-treated animals, showing a prominent reaction in the fibrous septa. In the normal liver, lipocytes were positive for laminin and negative for actin, but septal and juxta-septal lipocytes were positive for both antigens, suggesting the presence of transitional cells with mixed immunoreactivity. This was confirmed by ultrastructural studies which showed typical intraseptal myofibroblasts and other elements exhibiting the structural features of both myofibroblasts and lipocytes.
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PMID:Modulation of extracellular matrix components during dimethylnitrosamine-induced cirrhosis. 225 31

Liver fibrosis and extracellular matrix play a central role in liver function impairment. Little information is available on the dynamic aspects and the natural history of fibroplasia, even if there is growing evidence that extracellular matrix accumulation (collagen I, III, IV, fibronectin, laminin, proteoglycans, etc.) is not to be considered only a passive structural support for damaged hepatic tissue, but may actively modulate liver cell behaviour. Clinicians need to date liver fibrosis and to monitor connective tissue synthesis and degradation, but attempts to develop reliable serological markers for collagen metabolism are hampered by the absence of a well defined golden standard to validate them. Nevertheless, serum type III aminoterminal procollagen peptide, at the moment, seems to be the most acceptable parameter of fibrogenesis. The data concerning the mechanisms of collagen production-degradation are becoming so precise and numerous that even if they have not, to date, led to 'routine' advantages for patients, they will end up becoming important tools in the clinical practice and management of liver fibrosis.
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PMID:Liver fibrosis and extracellular matrix. 264 66

In order to clarify the significance of procollagen III peptide (PIIIP) and fibronectin (FN) blood concentration in alcohol related chronic liver disease (ALD), we have investigated their relationships with histological liver features and biochemical liver tests in 44 ALD patients. PIIIP was measured in serum by radioimmunoassay whereas FN was determined in plasma using an immunonephelometric method. In each liver biopsy, steatosis, portal infiltrate, lobular necro-inflammation, portal fibrosis and lobular fibrosis were semiquantitatively assessed by scoring from 0 to 3. A close correlation of PIIIP was found with morphological features of fibrosis (both of lobular and portal type), but not with necro-inflammation or steatosis. PIIIP was also positively correlated with ALP and GGT and exhibited a good diagnostic value in liver fibrosis. On the contrary, FN did not distinguish between normals and patients and was not correlated with any morphological liver feature or biochemical liver test. We also conclude that serum NP3P effectively reflects liver fibrosis, whereas plasma FN seems not related to any of the main histological aspects of liver damage in ALD.
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PMID:Procollagen III peptide and fibronectin in alcohol-related chronic liver disease: correlations with morphological features and biochemical tests. 271 4

Immunofluorescence techniques were used to examine the distribution of Types I, III, IV and V collagen and fibronectin in the liver biopsy specimens from children with congenital liver fibrosis (CLF), extrahepatic portal blood circulation block, and cirrhosis developed following viral hepatitis. Both common patterns and characteristic features of the development of sclerotic processes were established. The common feature is the development of periportal connective tissue (CT) fibrosis mainly at the expense of Types I, III and V collagen and the accumulation of Types I, III, IV, V collagen and fibronectin in the walls of sinusoids during their "collagenization". The distinctive characteristic of posthepatic cirrhosis is the location of fibronectin and Type IV collagen in fibrous CT. Characteristic of CLF is high fibronectin concentrations in the areas of CT neoplasms along the periphery of portal tracts.
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PMID:[Collagen and fibronectin of the liver in children with congenital fibrosis, an extrahepatic portal circulation block and post-hepatitis cirrhosis (an immunohistochemical study)]. 274 28

The possible effects of a synthetic progesterone, medroxyprogesterone acetate (MPA), on carbon tetrachloride/phenobarbital (CCl4/PB)-induced rat liver injury were studied by morphological methods. CCl4/PB-treated rats showed extensive liver fibrosis consisting of procollagen type III aminoterminal propeptide-positive strands and fibres with concomitant extensive basement membrane deposits and fibronectin synthesis. MPA treatment after CCl4/PB-induced liver damage reduced alterations in cytoplasmic organelles, inflammation and hemorrhages and reversed the fibrosis, mostly around individual liver cells, possibly due to the normalization of cellular structure and function with a decrease in fibronectin deposits.
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PMID:Reversibility of rat liver cirrhosis by medroxyprogesterone acetate. 274 35


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