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

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dormant and developing embryos of Artemia salina contain equivalent amounts of eIF-2, the eukaryotic initiation factor which forms a ternary complex with GTP and Met-tRNAf. The factor was purified from 0.5 M NH4Cl ribosomal washes by (NH4)2SO4 fractionation, followed by chromatography on heparin-Sepharose, DEAE-cellulose, hydroxyapatite and phosphocellulose. Purified preparations from dormant and developing embryos have similar specific activities and nucleotide requirements. The mobility of both proteins in dodecylsulfate gel electrophoresis is indistinguishable, and each contains three major polypeptide chains of molecular weight 52 000, 45 000 and 42 000. Both proteins are also immunologically identical, and each stimulates amino acid incorporation in a cell-free system of protein synthesis. The binding of [35S]Met-tRNAf to 40-S ribosomal subunits is catalyzed by eIF-2 isolated from dormant or developing embryos and is dependent upon GPT and AUG. Binding of [35S]Met-tRNAf to 40-S ribosomal subunits, and ternary complex formation with eIF-2, GTP, and [35S]Met-tRNAf is stimulated 2--3-fold by a factor present in the 0.5 M NH4Cl ribosomal wash and which elutes from DEAE-cellulose at 50 mM KCl. This protein does not exhibit GTP-dependent binding of [35S]Met-tRNAf. Binding of GDP and GTP was investigated with purified eIF-2 from developing embryos. The factor forms a binary complex with GDP or GTP, and eIF-2-bound [3H]GDP exchanges very slowly with free nucleotides. Our results suggest that eIF-2 does not limit resumption of embryo development following encystment, nor does it limit mRNA translation in extracts from dormant embryos.
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PMID:Protein synthesis in brine shrimp embryos. Dormant and developing embryos of Artemia salina contain equivalent amounts of chain initiation factors 2. 11 89

An enzyme-linked immunosorbent assay (ELISA) was developed by using a synthetic polypeptide (SP) whose sequence was derived from the structural region of hepatitis C virus (HCV). Results of several coded panels of sera obtained from volunteer blood donors and patients with apparent non-A, non-B hepatitis and/or hepatitis B virus used in this ELISA were compared with those of a commercially available first-generation C-100 ELISA (using nonstructural HCV antigens), an experimental second-generation C-200/C-22 ELISA (using both structural and nonstructural HCV antigens), and recombinant immunoblot assays RIBA-I and RIBA-II. In the majority of cases, the results obtained with the HCV-SP ELISA correlated well with those obtained by RIBA-II and C-200/C-22 ELISA. In contrast, many samples that were repeatedly reactive in the C-100 ELISA results were nonreactive with RIBA and HCV-SP ELISA. In addition, HCV-SP detected HCV-specific antibody that appeared within a month of infection and coincided with the earliest increase in alanine aminotransferase. In summary, we have developed an ELISA based on a structural HCV synthetic polypeptide, HCV-SP, that has high specificity and sensitivity and is capable of detecting specific antibodies in the acute phase of HCV infection.
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PMID:Detection of acute hepatitis C virus infection by ELISA using a synthetic peptide comprising a structural epitope. 137 3

Recently a recombinant polypeptide of hepatitis C virus (HCV) has been developed by the Chiron Corporation in California. This antigen has been used to develop an ELISA test (Ortho Diagnostic Systems for serum anti-HCV antibodies. Preliminary data have shown that this virus is the major cause of NANB hepatitis in the world. We examined differences in anti-HCV prevalence among subgroups of blood donors (total sera examined 639) classified for past or present exposure to HBV or not, and for ALT levels. The anti-HCV prevalence found in regular blood donors with normal ALT levels and no antibody to HBcAg was 1.2%. No significant difference in the anti-HCV prevalence was found among other subgroups of blood donors except that a higher prevalence (10%) was found in a group with both elevated ALT and HBV markers. These preliminary findings suggest that the policy of blood supply should take into account the advent of HCV antibody test.
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PMID:Antibodies to hepatitis C virus in blood donors. 217 95

In order to evaluate the behaviour of alpha-fetoprotein (AFP) and Tissue Polypeptide Antigen (TPA) in non neoplastic chronic hepatic diseases 60 patients suffering from chronic hepatitis have been studied, 28 of them with different ethiology cirrhosis, 4 with primary biliary cirrhosis (CBP), 18 with chronic active hepatitis (ECA), 5 with chronic persistent hepatitis (ECP), 3 suffering from alcoholic and 2 drug-induced hepatitis. In each case the diagnosis was biopsy-proved. We have found that TPA clearly shows an increase in about 90% of cirrhosis and in about 50% of ECA. Moreover, the group with non-A, non-B (NANB) cirrhosis and chronic hepatitis has shown a statistically significant correlation between TPA and alanine aminotransferase (ALT). On the other hand, AFP hants' shown statistically significant variations. The reasons of the TPA increase must probably be looked for in the marked sensitivity of this protein to non neoplastic tissues in rapid regeneration, in addition to the sensitivity to neoplastic tissues. Further studies will be carried out to evaluate the usefulness of TPA to tracing possible cytolitic relapses or any resumption of activity in hepatic cirrhosis.
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PMID:Alpha-fetoprotein and tissue polypeptide antigen in non neoplastic hepatic disorders. 248 Apr 32

A monoclonal antibody, GPT-1, was prepared by fusion of the splenic cells of mice immunized with guinea pig thymocytes with a mouse myeloma cell line. GPT-1 completely inhibited spontaneous rosette formation of T cells with papain-treated rabbit erythrocytes. GPT-1 reacted with 90% of thymocytes, 70% of peripheral blood lymphocytes, and 45% of splenic lymphocytes, but not with B cells. These results indicate that GPT-1 has pan-T reactivity. The antibody specifically bound to a single polypeptide chain with a molecular size of 50-65 kD. The surface density of the antigen was higher on thymocytes than on peripheral T cells, suggesting that the antigen is a certain differentiation antigen on T cells. Phytohemagglutinin-activated T cells expressed more antigen molecules than resting T cells. In addition, GPT-1 suppressed the proliferation of T cells induced by the mitogen, indicating that GPT-1 recognizes a T cell-specific surface antigen which is associated with T cell activation. Based on these results, it was concluded that GPT-1 reacts with a guinea pig T cell surface antigen which is similar to the E-receptor protein on human T cells (CD2 molecule).
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PMID:Characterization of a monoclonal antibody to guinea pig T cells that inhibits rosette formation of the cells with rabbit erythrocytes: similarity of the antigen to E-receptor on human T cells. 289 18

We have developed a system for the molecular analysis of mutations in mammalian cells. This system is based upon the use of mammalian cell lines containing mutant shuttle vector genes integrated into chromosomal DNA. The target for mutation was the Escherichia coli gpt gene, coding for the enzyme xanthine (guanine) phosphoribosyltransferase (GPT; EC 2.4.2.22). We have previously isolated a large number of cell lines containing mutant gpt genes with single base changes. From these lines, revertants were selected on the basis of the reappearance of GPT activity. In general, the frequency of revertants was below 10(-7). The gpt genes were recovered from 32 revertants and sequenced to determine the nature of the base changes associated with reversion. In the majority of the revertants, there was a base change within the originally mutated codon, leading to either restoration of the wild-type amino acid sequence or substitution of a different amino acid at the original mutated site. In no case did reversion of a base substitution mutant involve an amino acid residue other than that affected by the original mutation. The results have demonstrated a number of sites in the GPT polypeptide at which amino acid substitutions are compatible with enzyme activity and one site at which the loss of an amino acid is compatible with enzyme activity. This study establishes reversion analysis as a sensitive molecular assay for mutagenesis in mammalian cells.
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PMID:A sensitive molecular assay for mutagenesis in mammalian cells: reversion analysis in cells with a mutant shuttle vector gene integrated into chromosomal DNA. 305 1

Serum samples from a cohort of patients with chronic hepatitis C virus (HCV) infection were assayed for IgM anti-HCV/core reactivity with a "site-specific" ELISA, in which the solid phase was charged with the synthetic polypeptide analogue corresponding to the first 75 amino acids of the HCV core antigen (sp75). Thirteen of 24 (54%) patients exhibited IgM anti-sp75 reactivity. Both high-titered (1/16,000-1/32,000) and low-titered (1/1,000-1/4,000) IgM anti-sp75 reactive sera were found. IgM anti-sp75 antibodies persisted in the circulation over a long period in patients with fluctuating abnormal ALT levels. There was a striking association between detection of specific IgM anti-sp75 reactivity and the presence of HCV RNA in serum. Thus 11 of 15 (73%) sera containing HCV RNA also contained IgM anti-sp75 antibodies, while none of the HCV RNA-negative sera were IgM anti-sp75 reactive. Five of 11 patients without detectable levels of specific IgM anti-sp75 antibodies had their ALT levels returned to normal within 8 months to 3 years. Furthermore, a significant correlation was noted between the specific IgM anti-sp75 titers and the concentration of total plasma IgM, indicating that the immunological active region sp75 within the capsid of HCV has the capacity to induce an IgM secretion, which constitutes a substantial portion of the total plasma IgM, in patients with chronic HCV infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunoglobulin M reactivity towards the immunologically active region sp75 of the core protein of hepatitis C virus (HCV) in chronic HCV infection. 838 29

Carbamoylphosphate synthetase I (CPS I), a urea cycle enzyme, is located almost exclusively in the mitochondria of hepatocytes. The enzyme is unique in that it constitutes about 2-6% of total liver protein and is composed of a large subunit of 160 kD. We developed a sensitive enzyme-linked immunosorbent assay (ELISA) for measurement of the enzyme in plasma using an antibody against the rat enzyme. In galactosamine-induced rat acute hepatitis, plasma concentration of CPS I that was 1-2 micrograms/ml blood before the treatment, increased up to 125 micrograms/ml blood in 24 h after the treatment and decreased to a near control level in 72 h. Plasma concentration of ornithine carbamoyl-transferase (OCT), another urea cycle enzyme, reached a maximum in 24 h and then decreased a little more rapidly than that of CPS I. On the other hand, alanine aminotransferase activity reached a maximum in 36 h and decreased to a normal level in 96 h. In immunoblot analysis, the native CPS I polypeptide of 160 kD and its fragments of 140 and 125 kD were detected 24-48 h after the treatment. When purified rat CPS I and bovine OCT were injected intravenously into rats, the enzymes disappeared from blood roughly exponentially with apparent half-lives of about 67 and 18 min, respectively. Development of an ELISA for human CPS I and determination of the serum enzyme in various liver diseases remain to be performed.
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PMID:Enzyme-linked immunosorbent assay of carbamoylphosphate synthetase I: plasma enzyme in rat experimental hepatitis and its clearance. 882 9

It has recently been shown that thymosin-alpha1(T-alpha1), a synthetic polypeptide of thymic origin, is able to promote disease remission and inhibition of hepatitis B virus (HBV) replication in patients affected by hepatitis B e antigen (HBeAg)-positive chronic active hepatitis. We evaluated the efficacy and safety of T-alpha1 treatment in patients with hepatitis B e antibody (anti-HBe) and HBV-DNA-positive chronic hepatitis. Thirty-three patients were randomly assigned to receive either T-alpha1 900 microg/m2 body surface area twice weekly (17 patients) or 5 MU of interferon alfa (IFN-alpha) three times weekly (16 patients) for 6 months. At baseline, both groups were comparable concerning age, sex, liver histology, and alanine transaminase (ALT) levels. At the end of treatment, complete response (defined as ALT normalization and HBV-DNA loss) occurred in 5 of 17 (29.4%) in the T-alpha1 group and in 7 of 16 (43.8%) in the IFN-alpha group (P = not significant). After a follow-up period of 6 months, a complete response was observed in 7 of 17 (41.2%) in the T-alpha1 group and in 4 of 16 (25%) in the IFN-alpha group (P = n.s.). Compared with the results observed in a group of 15 patients never treated with IFN-alpha and followed for 12 months, the rate of complete response was significantly higher in the IFN-alpha group at the end of therapy (1 of 15 vs. 7 of 16, respectively; P < .05) and in the T-alpha1 group at the end of follow-up (1 of 15 vs. 7 of 17, respectively; P < .05). Unlike IFN-alpha, T-alpha1 was well tolerated by all patients. The only side effect, reported by some, was local discomfort at injection sites. The results of this trial suggest that T-alpha1 is able to reduce HBV replication in patients affected by anti-HBe-positive chronic hepatitis. Furthermore, compared with IFN-alpha, T-alpha1 is better tolerated and seems to induce a gradual and more sustained ALT normalization and HBV-DNA loss. In conclusion, T-alpha1 appears to be a safe and effective alternative treatment for anti-HBe-positive chronic hepatitis. The benefit of this agent in producing long-term inhibition of HBV replication must be confirmed by future trials.
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PMID:A randomized controlled trial of thymosin-alpha1 versus interferon alfa treatment in patients with hepatitis B e antigen antibody--and hepatitis B virus DNA--positive chronic hepatitis B. 885 75

A 9-year-old male German Shepherd Dog was presented with the primary complaints of vomiting, profuse watery diarrhea, anorexia, and severe weight loss. The dog developed hematemesis and melena, which were unresponsive to treatment with an H2-receptor antagonist and a gastrointestinal protectant. A marked neutrophilia, panhypoproteinemia, hypokalemia, and mildly increased activities of alkaline phosphatase and alanine aminotransferase were the only relevant abnormalities found on a CBC, serum biochemical profile, and urinalysis. An exploratory laparotomy revealed several small nonresectable masses at the root of the mesentery, which were identified histologically as a neuroendocrine neoplasm. Immunohistochemical staining of the neoplasm was positive for gastrin and negative for insulin, glucagon, pancreatic polypeptide, and vasoactive intestinal polypeptide. Fasting serum gastrin concentrations were high. Zollinger-Ellison syndrome was diagnosed, and the dog was treated with omeprazole, an H+,K(+)-ATPase inhibitor. All clinical signs resolved, and the dog remains asymptomatic 2 years later. Omeprazole may be the gastric acid antisecretory drug of choice for dogs with gastrinoma.
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PMID:Omeprazole in a dog with gastrinoma. 947 Jan 66


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