Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.6.1.1 (aspartate aminotransferase)
21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The liver synthesizes prokallikrein and is the main organ to clear the active enzyme (plasma-kallikrein) from circulation. This clearance, a receptor-mediated endocytosis, is calcium-independent and not affected by the blockade of Kupffer cells. The effects of endothelial cells blockade and of acetaminophen intoxication on the clearance of 10 nM rat plasma-kallikrein (RPK) by the isolated, exsanguinated and perfused rat liver are now reported. Endothelial cells blockade obtained by the addition of large excess (30 uM) of formaldehyde-treated serum albumin to the perfusion fluid does not affect the hepatic clearance of RPK (the half-lives of hepatic uptake were 15.5 +/- 1.0 min in the absence versus 16.5 +/- 1.4 min in the presence of the treated protein, p > 0.05). Some livers were perfused 24 hours after acetaminophen intoxication: 6.6 mmol/kg given i.p. after a 42-hour period of fast. Hepatocyte injury suggested by elevated aminotransferase activity (ALT 10 times control value, AST 30 times control value), acute phase inflammatory response (serum alpha 2-macroglobulin increase) and reduced synthetic function (serum albumin decrease), was confirmed histologically and only zone 3 hepatocytes were necrotic. A 66-hour period of fast does not affect by itself the hepatic clearance of RPK (16.9 +/- 1.3 min of half-life of hepatic uptake) when compared with the control group (15.5 +/- 1.0 min, p > 0.05). On the other hand the RPK clearance by the livers of rats previously intoxicated with acetaminophen was markedly deficient (the half-life of hepatic uptake was 39.2 +/- 3.2 min). These findings suggest that RPK is internalized by hepatocytes, preferentially by those of the perivenular zone of the hepatic acinus.
...
PMID:Plasma-kallikrein clearance by the liver of acetaminophen-intoxicated rats. 846 45

This study examined clinico-histopathologic differences between North American patients who developed hepatocellular carcinoma with and without cirrhosis. Histologic slides and clinical records of cases were reviewed. Cases were classified according to defined histopathologic criteria. Analyses were performed using appropriate tests. A total of 42.6% of cases were noncirrhotic. The trabecular type of hepatocellular carcinoma was the most common growth pattern in both groups. Patients with cirrhosis were significantly older, had high grade tumors, and local portal venous invasion significantly more often than patients without cirrhosis. Encapsulated tumors occurred in significantly more in patients without cirrhosis. Patients without cirrhosis survived longer than patients with cirrhosis (P < .0001) and had a better 5-year survival experience. On average, in patients with cirrhosis, serum aspartate transaminase and total serum bilirubin were significantly greater, and serum albumin was significantly lower. In general, hepatocellular carcinoma in North American patients with cirrhosis tended to be less well differentiated than those found among patients without cirrhosis. The pathology, natural history, and prognosis of this tumor is significantly influenced by the presence or absence of cirrhosis in the nonneoplastic liver, and the presence of cirrhosis portends a poorer prognosis.
...
PMID:Hepatocellular carcinoma in cirrhotic and noncirrhotic livers. A clinico-histopathologic study of 804 North American patients. 856 Oct 84

Except for increased serum alkaline phosphatase (AP) levels, the changes in liver function test (LFT) values during normal pregnancy have not been clearly established, mainly because most studies do not include matched controls. We therefore measured the serum values of routine liver tests including 5'-nucleotidase and total bile acids in 103 healthy pregnant women (first trimester, n = 34; second trimester, n = 36; third trimester, n = 33) and in 103 age-matched controls not receiving oral contraception. Fasting blood samples were taken. Because of hemodilution, serum albumin levels were significantly lower during all trimesters. As expected, AP activity was significantly higher in the third trimester. Serum aspartate transaminase (AST) activity and total bile acid (TBA) concentrations did not differ between pregnant and nonpregnant women. Serum alanine transaminase (ALT) activity was slightly higher in the second-trimester pregnant women than in controls (6.8 +/- 4.5 vs. 8.2 +/- 5.8, P = .04), although all values remained within normal limits. In pregnant women, total and free bilirubin concentrations were significantly lower during all three trimesters, as was conjugated bilirubin during the second and third trimesters. Serum gamma-glutamyl transpeptidase (GGT) activity was significantly lower in the second and third trimesters. Serum 5'-nucleotidase activity was slightly but significantly higher in the second and third trimesters. The knowledge of these results is useful for the interpretation of LFT values and the management of liver diseases during pregnancy.
...
PMID:Liver function tests in normal pregnancy: a prospective study of 103 pregnant women and 103 matched controls. 862 Nov 29

There is no one test of liver function. Routine laboratory tests that are useful in screening for liver disease and following its course include serum AST, ALT, alkaline phosphatase, protein electrophoresis, prothrombin time, and bilirubin levels. The transaminase levels give a day-by-day account of the amount of hepatocellular injury and death that occurs. Alkaline phosphatase levels estimate the amount of impedance of bile flow. The prothrombin time and serum albumin level are excellent gauges of hepatic protein synthetic ability, whereas the bilirubin level is probably the best test of overall liver function. Many tests are now available that permit one to diagnose specific diseases of the liver.
...
PMID:Evaluation of tests used to screen patients with liver disorders. 888 44

Liver fibrosis was induced by chronically (7 weeks) administering CCl4 to rats. Animals were divided into four groups: (a) controls, (b) treated with CCl4 alone, (c) treated with CCl4 and colchicine and (d) treated with CCl4 and formyl-colchicine bound to lactosaminated serum albumin (FC-LASA). Liver dysfunction was monitored by biochemical tests (alkaline phosphatase [ALP], gamma-glutamyltransferase [gamma GT], aspartate and alanine transaminases [AST and ALT], albumin and total bilirubin). Fibrosis was evaluated by determining hydroxyproline and by microscopic examination. The exposure to CCl4 produced major alterations of liver structure and collagen deposition. These effects were partially counteracted by colchicine and to a greater extent by FC-LASA. Morphological findings paralleled biochemical data. The information reported here indicates that colchicine has an antifibrotic activity on the liver of intoxicated rats and that FC-LASA is more active than colchicine itself as an antifibrotic agent.
...
PMID:Formylcolchicine bound to lactosaminated serum albumin is a more active antifibrotic agent than free colchicine. 889 3

Haematological and biochemical changes in horses competing in the Endurance Test (Phase T and D) of an advanced Horse Trial (HT, n = 22) and the Endurance Test (Phases A-D) of an advanced (CCI) 3-day-event (TD, n = 11) over a similar course on the same day were studied. Environmental conditions during the event were cool (5.5-11.1 degrees C). Blood samples were collected from the horses in each group the evening prior to the Endurance Test, within 60 s after, and 10 min after, completion of Phase D (cross-country jumping). The following were determined in the blood samples and compared between the 2 groups of horses: packed cell volume (PCV), serum total protein [TP], serum albumin [ALB], plasma lactate [lactate], serum total calcium [TCa], plasma ionised calcium [Ca+2], serum inorganic phosphate [PO4], plasma pH, plasma sodium [Na], plasma potassium [K], serum chloride [Cl], serum urea nitrogen [SUN], serum creatinine [Cr] and serum glucose concentrations and aspartate aminotransferase (AST) and creatine kinase (CK) activities. The PCV and [Cr] were higher in the TD group and approached significance (P = 0.063 and P = 0.057, respectively). The [TP], [ALB], [Na], glucose concentration and CK, and AST were significantly higher and [Cl] and [PO4] were significantly lower in the TD group after exercise when compared to the HT group. It was deduced from these data that the horses competing in the 3-day-event experienced greater fluid and electrolyte losses, reduced glomerular filtration, higher glycogenolysis and had greater leakage of enzymes from working muscles during competition than horses competing in the horse trial.
...
PMID:Haematological and biochemical changes in horses competing in a 3 Star horse trial and 3-day-event. 893 86

Methotrexate (MTX) has become one of the most widely prescribed second-line agents world-wide for rheumatoid arthritis (RA). Studies have established efficacy in populations which have failed other second-line agents. Although MTX must be considered as a potential hepatotoxin, studies have shown that liver histologic changes can be predicted by monitoring of serum albumin and AST at four to eight week intervals. MTX pulmonary toxicity appears to be more common than liver disease. It most often presents with a subacute course with dry cough and dyspnea with or without fever. Clinicians must be aware of this presentation and withhold the drug when these symptoms appear. MTX may also cause mild renal impairment when used with NSAIDs. This effect has been observed with higher mean weekly doses in the 15 to 20 mg range, but not with a starting dose of 7.5 mg. Although MTX may exhibit a variety of effects in in vitro systems its mechanism of action in patients with RA has not yet been determined.
...
PMID:Methotrexate update. 899 67

In order to evaluate the pathogenetic role of iron in Porphyria cutanea tarda (PCT), the metabolism of iron was studied in 440 patient with PCT and associated chronic liver disease (CLD) and in 91 nonporphyric CLD patients (used as a control group). The parameters considered were the following: serum iron, ferritin, Total Iron Binding Capacity (TIBC) and percent saturation of transferrin. The statistical analysis showed that the differences between the means, in the two groups, were not significant in any of the parameters examined. To investigate the possible relationships between iron metabolism and other chemico-clinical parameters concerning the porphyric disease, the associated hepatic disease and hemometry, we studied the correlations between iron parameters and total urinary and serum porphyrins, serum copper, serum albumin, hemoglobin, red blood cells, ALT, AST, CHE and GLDH. This investigation was only possible in the last 99 cases. In addition to the obvious correlations between the parameters concerning iron metabolism, the highly significant (p < 0.001) correlation between ferritin and enzyme activities which indicate cytolysis (ALT, AST, GLDH) is extremely interesting. The results seem to point to the tentative conclusion that the alterations of iron metabolism are more related to the hepatocellular necrosis than to the metabolism of porphyrins.
...
PMID:Iron and porphyria cutanea tarda. 907 91

To determine whether decreases in plasma antithrombin (AT) level, as seen in non-gestational acquired AT deficiency, result from a hypercoagulable state and/or liver/kidney damage, AT activity was measured in 24 uncomplicated and 30 preeclamptic women. The fifth percentile of AT levels in the normal pregnancies was used as a cut-off value to subdivide the preeclamptic patients into two groups. Markers of activated coagulation, i.e, levels of thrombin-antithrombin complex (TAT), fibrin D-dimer, soluble fibrin, von Willebrand factor (vWF) and platelet counts, were determined. Indicators of hepatic or renal function, i.e. concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, urinary albumin (U-albumin) and serum albumin (S-albumin), were assayed. AT levels were lower in those with preeclampsia than in the normal pregnancy group (P < 0.01). In the group with AT levels less than the cut-off point, levels of fibrin D-dimer (P < 0.05), soluble fibrin (P < 0.05), vWF (P < 0.05), ALT (P < 0.05), AST (P < 0.05), creatinine (P < 0.01) and U-albumin (P < 0.01) were increased, whereas platelet counts (P < 0.05) and S-albumin (P < 0.05) were decreased. All patients with ALT levels > 0.46 mu kat/1, AST > 0.58 mu kat/1, S-albumin < 23 g/1 and/or U-albumin > 4.9 g/24 h had AT levels < or = cut off. AT levels correlated with vWF (rs = - 0.73, P < 0.01) and creatinine (Rs = -0.70, P < 0.01). It is suggested that in preeclampsia, acquired AT deficiency is secondary to a hypercoagulable state, and/or associated with impaired hepatic and/or renal function.
...
PMID:Acquired deficiency of antithrombin in association with a hypercoagulable state and impaired function of liver and/or kidney in preeclampsia. 919 20

SPAAT (short piece of alpha 1-antitrypsin [AAT]), the 44-residue C-terminal peptide of AAT, was originally isolated from human placenta [Niemann et al. (1992): Matrix 12:233-241]. It was shown to be a competitive inhibitor of serine proteases [Niemann et al. (in press): Biochem Biophys Acta]. The binding of SPAAT to one or more proteins of the extracellular matrix (ECM) was initially suggested on the basis of its recovery from tissue residues following a series of extractions designed to remove easily solubilized proteins [Niemann et al. (1992): Matrix 12:233-241]. Our binding studies with the model ECMs, Matrigel and Amgel, suggested that SPAAT might be bound by a specific collagen type as well as one or more non-collagenous ECM proteins. Individual ECM components were screened for their ability to bind SPAAT. When the four commonly occurring fiber-forming collagens (types I, II, III, and V) were evaluated, type III was found to be preferred. In addition, although SPAAT bound to preformed type III collagen fibers in a concentration dependent fashion, it did not bind to type III collagen molecules undergoing fibril formation. This is consistent with a physiological mode of interaction between SPAAT and type III collagen in vivo. Of the non-collagenous ECM macromolecules (laminin-1, fibronectin, entactin, and heparan sulfate) tested, laminin-1 was preferred. The binding of radiolabelled SPAAT to type III collagen and laminin-1 was competitively inhibited by unlabelled SPAAT as well as an unrelated protein, human serum albumin (HSA), to establish binding specificity. The kinetics of the release of the bound radiolabelled SPAAT were also examined to substantiate the non-covalent and reversible nature of this association. These results support the view that susceptible proteins of the ECM may actually be coated with SPAAT in vivo, possibly affording protection against inappropriate protease digestion.
...
PMID:Binding of SPAAT, the 44-residue C-terminal peptide of alpha 1-antitrypsin, to proteins of the extracellular matrix. 925 91


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---