Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.1 (aspartate aminotransferase)
21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum IL-6 levels have been shown to correlate with disease severity and prognosis in patients with plasma cell dyscrasias. Among its pleiotropic actions, IL-6 is also the major regulator of the acute phase response in humans. The possible impact on survival of the major serum acute phase proteins (s.APP) [C-reactive protein (s.CRP), alpha-1-antitrypsin (s.AAT), haptoglobin, acid alpha-1-glycoprotein and alpha-2-macroglobulin (used as control)] was assessed on a population of 103 consecutive, previously untreated myeloma patients. Univariate analysis showed that among the acute phase proteins only s.AAT (P = 0.015) and s.CRP (P = 0.027) were significantly correlated with survival. The multivariate Cox proportional hazard model applied to s.APP and other common parameters showed that s.beta-2-microglobulin (s.b2M), s.calcium, s.creatinine, BM plasma cell percentage, age and s.AAT correlated significantly with survival. Combining s.b2M and s.AAT allowed stratification of myeloma patients: those with low levels of s.b2M (< or = 3 mg/l) and of s.AAT (< or = 3 g/l) presented an excellent prognosis (median survival exceeding 10 years) while those presenting higher values of the two parameters presented a median survival of 2.5 years (P = 0.002).
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PMID:Acute phase proteins and prognosis in multiple myeloma. 768 34

Laminin, a glycoprotein synthesised by Ito cells, has been considered a marker of fibrogenesis. The behaviour of laminin and clinical and laboratory data in 83 patients with cirrhosis were studied to find the factors associated with increases in this glycoprotein. There were increased concentrations of laminin in 62.7% of the patients (40% of the Child's A, 64.5% of the Child's B, and 75% of the Child's C categories). Significant differences in laminin concentrations were found between the Child's grades (p = 0.009) and between patients and controls (p < 0.0001). Correlations were found between laminin concentrations and mean corpuscular volume, aspartate aminotransferase, aspartate aminotransferase: alanine aminotransferase ratio, alkaline phosphatase activity, bilirubin and glycocholic acid concentrations, and hypoalbuminaemia--that is, variables related to liver insufficiency and alcohol intake. Moreover, patients with an alcohol intake higher than 100 g/day had higher laminin concentrations than those with a lower intake (p = 0.03). Conversely, there was no significant association with portal hypertension. Multivariate analysis showed that mean corpuscular volume, bilirubin concentrations, and hypoalbuminaemia were independently associated with laminin concentrations. Poor degradation associated with liver insufficiency seems to play an important part in the increase in serum laminin concentrations in these patients.
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PMID:Serum concentrations of laminin in cirrhosis of the liver. 834 86

Lipopolysaccharide binding protein (LBP) is a serum glycoprotein that complexes with lipopolysaccharide (LPS) to facilitate macrophage response to endotoxin. To determine the conditions that stimulate LBP production in vivo, we measured the induction of LBP in models of inflammation produced by LPS, Corynebacterium parvum, and turpentine injection. Plasma aspartate aminotransferase and alanine aminotransferase concentrations and hepatocyte fibrinogen synthesis were elevated in all models. Northern blot analysis revealed 17-, 14-, and 20-fold upregulation of hepatocyte LBP mRNA following treatment with LPS, C parvum, and turpentine, respectively. Peritoneal macrophage interleukin 6 and tumor necrosis factor production following endotoxin stimulation was augmented by cultured hepatocyte supernatants, suggesting increased LBP synthesis in these groups. The results show that LBP mRNA is induced during hepatic inflammation and suggest that LBP is an acute-phase protein important in regulating the in vivo response to endotoxin.
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PMID:Induction of hepatocyte lipopolysaccharide binding protein in models of sepsis and the acute-phase response. 841 76

Dolichols are long-chain polyprenols containing 14-22 isoprene units, present in mammalian tissues as free dolichol (Free-Dol), fatty acyl dolichyl esters (Dol-FA), and dolichyl phosphate (Dol-P). The hepatic level of Dol-P seems to be a rate-limiting factor for glycosylation processes. Previous studies from our laboratory demonstrated the susceptibility of the dolichol molecule to undergo radical attacks. Since the toxicity of 1,1,2,2-tetrachloroethane (TTCE)is dependent on the free-radical production during hepatic biotrasformation, it was of interest to determine whether this haloalkane might affect glycosylation mechanisms by changing dolichol levels and distribution in rat liver microsomes and Golgi apparatus (GA). Male Sprague-Dawley rats received a single dose of TTCE (574 mg/kg body weight) and were then sacrificed at different times (5, 15, 30, or 60 min). In the TTCE-treated rats both serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and hepatic triglycerides (TG) were significantly higher than control, while microsomal glucose 6-phosphatase (G6Pase) activity was decreased. In total microsomes Dol-P levels considered rate-limiting for the biosynthesis of the N-glycosylated proteins were significantly lower than in the control group 15 min after TTCE treatment. In normal rat liver, F1 secretory fraction of CA is 60-fold enriched in total dolichol content with respect to microsomes. In this compartment the total dolichol content, essential for the increase in membrane fluidity and permeability required for glycoprotein maturation and secretion, decreased significantly 5 min after TTCE treatment. Our results suggest that TTCE may affect dolichol functions in rat liver.
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PMID:1,1,2,2-Tetrachloroethane-induced early decrease of dolichol levels in rat liver microsomes and Golgi apparatus. 965 49

The respiratory burst activity of polymorphonuclear leucocytes (PMN) was evaluated in eight Holstein cows from 8 weeks before until 6 weeks after calving by chemiluminescence (CL). The CL response started to decrease 1 week before parturition, reaching a minimum during the first 2 weeks after calving. From week 3 of lactation, CL increased again and returned to original levels by week 6 of lactation. Plasma concentrations of 3-hydroxybutyric acid, total bilirubin and bovine pregnancy-associated glycoprotein started to increase before parturition to reach a maximum during the first or second week of lactation. The concentrations of glutamic-oxaloacetic transaminase, lactate dehydrogenase, non-esterified fatty acids and bilirubin increased after calving, reaching a maximum during the second week. A small decrease in plasma cholesterol during the week before and after calving was followed by an increase. The CL response of the PMN showed significant temporal relationships with the plasma concentrations of 3-hydroxybutyric acid, bovine pregnancy-associated glycoprotein, bilirubin, glutamic-oxaloacetic transaminase, non-esterified fatty acids; that with cholesterol was nearly significant. This means that the change in the CL response with time coincided with the changes in plasma concentrations of these substances with time and that these changes were significantly related with each other. The results of this study show that the decreased respiratory burst activity of bovine PMN around parturition may be related to the extent of the metabolic and hormonal changes. Although the causative relationships are not proven, these results support earlier results suggesting that 3-hydroxybutyric acid and bovine pregnancy-associated glycoprotein may directly affect neutrophil function, whereas non-esterified fatty acids, cholesterol, bilirubin, and liver enzymes may have potential as diagnostic markers of impaired neutrophil function and consequently increased disease risk around parturition.
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PMID:Chemiluminescence of bovine polymorphonuclear leucocytes during the periparturient period and relation with metabolic markers and bovine pregnancy-associated glycoprotein. 1084 Jun 79

Mammalian heteromeric amino acid transporters (HATs) are composed of a multi-transmembrane spanning catalytic protein covalently associated with a type II glycoprotein (e.g. 4F2hc, rBAT) through a disulfide bond. Caenorhabditis elegans has nine genes encoding close homologues of the HAT catalytic proteins. Three of these genes (designated AAT-1 to AAT-3) have a much higher degree of similarity to the mammalian homologues than the other six, including the presence of a cysteine residue at the position known to form a disulfide bridge to the glycoprotein partner in mammalian HATs. C. elegans also has two genes encoding homologues of the heteromeric amino acid transporter type II glycoprotein subunits (designated ATG-1 and ATG-2). Both ATG, and/or AAT-1, -2, -3 proteins were expressed in Xenopus oocytes and tested for amino acid transport function. This screen revealed that AAT-1 and AAT-3 facilitate amino acid transport when expressed together with ATG-2 but not with ATG-1 or the mammalian type II glycoproteins 4F2hc and rBAT. AAT-1 and AAT-3 covalently bind to both C. elegans ATG glycoproteins, but only the pairs with ATG-2 traffic to the oocyte surface. Both of these functional, surface-expressed C. elegans HATs transport most neutral amino acids and display the highest transport rate for l-Ala and l-Ser (apparent K(m) 100 microm range). Similar to their mammalian counterparts, the C. elegans HATs function as (near) obligatory amino acid exchangers. Taken together, this study demonstrates that the heteromeric structure and the amino acid exchange function of HATs have been conserved throughout the evolution of nematodes to mammals.
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PMID:Functional characterization of Caenorhabditis elegans heteromeric amino acid transporters. 1466 47

Ribonuclease inhibitor (RI) is an acidic cytosolic glycoprotein with molecular weight of about 50 kDa, which contains 32 cysteine residues. It is possibly that RI may have antioxidant effect by thiol-disulfide exchange reaction. We studied the effects of RI over-expression on the rat glial cell line C6 injured with H2O2. The transfected C6 cells with RI cDNA (C6') had higher viability, less LDH leakage and MDA contents, but more GSH contents compare that in the control C6 cells. In transfected C6 cells, the activities of CAT and GST were higher than that in the control C6 cells. Without H202 stress, the activities of CAT and GST in the C6' cells were 1.73 and 3.62 times that in the control C6 cells, respectively; With 1.00 mmol/L H2O2 stress, the activities of CATand GSTin the C6' cells were 3.38 and 2.11 times that in the C6 cells, respectively. These results suggest that the over-expression RI has antioxidant activity and it is able to protect cells from per-oxidative injuries. Moreover, we investigated whether RI has a protective role against mouse hepatic damage in vivo. The mice pretreated with different doses of human RI were injected by CC14. The results show that the SOD activities of therapy groups were significantly higher than that of the control group (p < 0.01), while the contents of MOD and activities of ALT and AST in blood were remarkably lower than that of the control group (p < 0.01). Pathological examination shows that the degree of damage was alleviated with RI therapy. These results suggest that RI has the protective role against mouse hepatic damage induced by CC14. The anti-oxidative effects of RI may play an important role in cell protection from per-oxidative injuries.
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PMID:The antioxidant effects of ribonuclease inhibitor. 1470 97

The Caenorhabditis elegans genome encodes nine homologues of mammalian glycoprotein-associated amino acid transporters. Two of these C. elegans proteins (AAT-1 and AAT-3) have been shown to function as catalytic subunits (light chains) of heteromeric amino acid transporters. These proteins need to associate with a glycoprotein heavy chain subunit (ATG-2) to reach the cell surface in a manner similar to that of their mammalian homologues. AAT-1 and AAT-3 contain a cysteine residue in the second putative extracellular loop through which a disulfide bridge can form with a heavy chain. In contrast, six C. elegans members of this family (AAT-4 to AAT-9) lack such a cysteine residue. We show here that one of these transporter proteins, AAT-9, reaches the cell surface in Xenopus oocytes without an exogenous heavy chain and that it functions as an exchanger of aromatic amino acids. Two-electrode voltage clamp experiments demonstrate that AAT-9 displays a substrate-activated conductance. Immunofluorescence shows that it is expressed close to the pharyngeal bulbs within C. elegans neurons. The selective expression of an aat-9 promoter-green fluorescent protein construct in several neurons of this region and in wall muscle cells around the mouth supports and extends these localization data. Taken together, the results show that AAT-9 is expressed in excitable cells of the nematode head and pharynx in which it may provide a pathway for aromatic amino acid transport.
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PMID:Aromatic amino acid transporter AAT-9 of Caenorhabditis elegans localizes to neurons and muscle cells. 1536 21

The tetrahydrochloride salt of astaxanthin di-L-lysinate (lys(2)AST) is a highly water-dispersible astaxanthin-amino acid conjugate, with an aqueous dispersibility of > or = 181.6 mg/mL. The statistical mixture of stereoisomers has been well characterized as an aqueous-phase superoxide anion scavenger, effective at micromolar (microM) concentrations. In the current study, the aqueous aggregation behavior and in vitro plasma protein binding [with fatty-acid-free human serum albumin (HSA) and alpha(1)-acid glycoprotein (AGP)] were investigated with a suite of techniques, including circular dichroism (CD) and UV-vis spectroscopy, ultrafiltration, competitive ligand displacement, and fluorescence quenching. Induced CD bands obtained in Ringer buffer solution of HSA demonstrated high affinity monomeric binding of the compound at low ligand per protein (L/P) ratios (in aqueous solution alone the carotenoid molecules formed card-pack aggregates). The binding constant ( approximately 10(6)M(-1)) and the binding stoichiometry (approximately 0.2 per albumin molecule) were calculated from CD titration data. CD displacement and ultrafiltration experiments performed with marker ligands of HSA indicated that the ligand binding occurred at a site distinct from the main drug binding sites of HSA (i.e., Sites I and II). At intermediate L/P ratios, both monomeric and aggregated ("chirally complexed") binding occurred simultaneously at distinct sites of the protein. At high L/P ratios, chiral complexation predominantly occurred on the asymmetric protein template. The tentative location of the chirally-complexed aggregation on the HSA template was identified as the large interdomain cleft of HSA, where carotenoid derivatives have been found to bind previously. Only weak binding to AGP was observed. These results suggest that parenteral use of this highly potent, water-dispersible astaxanthin-amino acid conjugate will result in plasma protein association, and plasma protein binding at sites unlikely to displace fatty acids and drugs bound at well-characterized binding sites on the albumin molecule.
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PMID:In vitro plasma protein binding and aqueous aggregation behavior of astaxanthin dilysinate tetrahydrochloride. 1545 27

In this study, we evaluated the effect of prostaglandin E2 (PGE2) on renal and hepatic function using an experimental cirrhosis model plus acute liver damage (ALD). Male Wistar rats treated with carbon tetrachloride (CCl4) for 8 weeks were used for the cirrhosis model. Cirrhotic rats were further exposed to an additional acute dose of CCl4 to induce ALD and then treated with PGE2 intramuscularly twice a day for 7 days (200 microg/Kg/day). PGE2 administration started 3 h after the additional dosing of CCl4 and PGE2 effect on hepatorenal function was examined on days 1, 2, 3, and 7. PGE2-treatment ameliorated the decrease in urinary sodium excretion, and normalized serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and plasma renin observed in cirrhotic rats with ALD. In addition, PGE2-treatment decreased mean arterial pressure, glomerular hypercellularity and thickening of the kidney capillary wall, and liver steatosis and cellular necrosis. Also, PGE2 increased the number of regenerative nodules. Finally, PGE2-treatment inhibited the increase in Alpha 1-acid glycoprotein (pAGP), fibrinogen, and Apo A-1 mRNA expression by 83%, 59%, and 77%, respectively. These results suggest that PGE2 administration may decrease the expression of acute phase proteins. In conclusion, PGE2-treatment improved hepatic and renal function and may be useful to down-regulate the acute phase response in cirrhotic rats presenting ALD induced by CCl4.
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PMID:PGE2 alleviates kidney and liver damage, decreases plasma renin activity and acute phase response in cirrhotic rats with acute liver damage. 1581 58


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