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

Using single-strand conformation polymorphism we have found two polymorphic sites, AAC to AAT at codon 511 (exon 12) and GCT to GCG at codon 708 (exon 15), in the MCC gene. These sites and an RsaI polymorphic site in APC allowed us to study 23 human small cell lung cancer (SCLC) and 7 non-small cell lung cancer samples for allele loss. Of the 23 SCLC samples, 21 (91%) were informative for one or more of these markers, and we found allele loss in more than 80% (17 of 21). In non-small cell lung cancer samples, 5 of 7 (71%) were informative, and reduction or loss of one allele was found in 2 of 5 (40%). Seven cases were informative for both genes, loss of heterozygosity occurred for both genes in five, one retained heterozygosity for both, and one SCLC had loss of heterozygosity for APC but not for MCC. We conclude that loss of heterozygosity occurs frequently for MCC and APC in lung cancer of all histological types and is very frequent in SCLC. This suggests the presence of tumor suppressor gene(s) in the MCC/APC region of 5q21 involved in human lung cancer.
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PMID:Polymorphic sites within the MCC and APC loci reveal very frequent loss of heterozygosity in human small cell lung cancer. 134 17

The cardiotoxic potential of the phenothiazine neuroleptic thioridazine and five of its metabolites, including two stereoisomeric forms of thioridazine 5-sulfoxide (ring sulfoxide), was characterized in the isolated perfused rat heart. Hearts from male Sprague-Dawley rats were perfused using a modified Langendorff technique. After a 30-min control period, hearts were perfused for 30 min with 15 or 30 microM thioridazine, racemic and isomeric forms of thioridazine 5-sulfoxide, or thioridazine 2-sulfoxide. Thioridazine disulfoxide, thioridazine 2-sulfone, and desmethylthioridazine 2-sulfoxide were perfused at 15 microM. Thioridazine (15 microM) severely reduced contractile tension and the rate of tension development (dT/dt), transiently increased coronary flow rate but prolonged conductance through the AV node. No arrhythmias were seen. At 30 microM, ventricular premature contractions and irregular rhythms occurred, progressing to asystole. Thioridazine 5-sulfoxide was arrhythmogenic at 15 and 30 microM. Atrial premature contractions and paroxysmal atrial tachycardia progressed to second degree AV block. Contractile tension and dT/dt declined although not as quickly when compared to thioridazine. Each isomeric form of thioridazine 5-sulfoxide was also cardiotoxic at 15 and 30 microM. There were minor differences in the onset and degree of toxicity but the overall results did not suggest a stereoselective effect. Lactic dehydrogenase and aspartate aminotransferase concentrations were unchanged after thioridazine 5-sulfoxide perfusion indicating no direct tissue damage. Thioridazine 5-sulfoxide induced arrhythmias could not be prevented or reversed by treatment with adrenergic agonists. They were reversible upon washout, however. The other metabolites were not arrhythmogenic at 15 microM. Racemic thioridazine 5-sulfoxide appears to be qualitatively and quantitatively more arrhythmogenic than thioridazine, an action that does not appear to be stereoselective.
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PMID:Cardiotoxicity of thioridazine and two stereoisomeric forms of thioridazine 5-sulfoxide in the isolated perfused rat heart. 376 35

Sialic acid storage diseases (SASD, MIM 269920) are autosomal recessive neurodegenerative disorders that may present as a severe infantile form (ISSD) or a slowly progressive adult form, which is prevalent in Finland (Salla disease). The main symptoms are hypotonia, cerebellar ataxia and mental retardation; visceromegaly and coarse features are also present in infantile cases. Progressive cerebellar atrophy and dysmyelination have been documented by magnetic resonance imaging (ref. 4). Enlarged lysosomes are seen on electron microscopic studies and patients excrete large amounts of free sialic acid in urine. A H+/anionic sugar symporter mechanism for sialic acid and glucuronic acid is impaired in lysosomal membranes from Salla and ISSD patients. The locus for Salla disease was assigned to a region of approximately 200 kb on chromosome 6q14-q15 in a linkage study using Finnish families. Salla disease and ISSD were further shown to be allelic disorders. A physical map with P1 and PAC clones was constructed to cover the 200-kb area flanked by the loci D6S280 and D6S1622, providing the basis for precise physical positioning of the gene. Here we describe a new gene, SLC17A5 (also known as AST), encoding a protein (sialin) with a predicted transport function that belongs to a family of anion/cation symporters (ACS). We found a homozygous SLC17A5 mutation (R39C) in five Finnish patients with Salla disease and six different SLC17A5 mutations in six ISSD patients of different ethnic origins. Our observations suggest that mutations in SLC17A5 are the primary cause of lysosomal sialic acid storage diseases.
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PMID:A new gene, encoding an anion transporter, is mutated in sialic acid storage diseases. 1058 Oct 36

Protein C is the zymogen of an anticoagulant serine protease and is converted to its active form (activated protein C: APC) by thrombin in the presence of thrombomodulin. APC plays an important role in regulating coagulation and fibrinolysis by inactivating not only blood coagulation factors Va and VIIIa but also type-1 plasminogen activator inhibitor (PAI-1). The aim of the present study was to examine the effect of a human APC product (designated as CTC-111), compared with that of heparin, on the disseminated intravascular coagulation (DIC) induced by lipopolysaccharide (LPS) in rats. LPS (1 mg/kg/h) infusion was performed through a femoral vein for 4 h. One-fifth amount of the total dosage of CTC-111 or heparin was injected into the other femoral vein, followed by a 4-h infusion of the remainder. Both CTC-111 (10,000-100,000 U/kg) and heparin (400-800 IU/kg) inhibited the decrease in platelet count and fibrinogen level equally. The prolonged activated partial thromboplastin time and prothrombin time observed in DIC rats were further elongated in both CTC-111- and heparin-treated rats. But, this prolongation was less in CTC-111-treated rats than in the heparin-treated ones. Heparin inhibited the increase in fibrin and fibrinogen degradation products more prominently than CTC-111. On the other hand, CTC-111 strongly inhibited the increase in PAI-1 activity but heparin did not. These results suggest that CTC-111 may enhance fibrinolysis through its direct inhibitory effect on PAI-1. The parameters for liver or renal damage, i.e., plasma glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), creatinine (Cre) and blood urea nitrogen (BUN), were significantly increased by LPS infusion. Both CTC-111 (100,000 U/kg) and heparin (800 IU/kg) decreased the increase in GOT and GPT levels significantly, whereas neither affected the increase in Cre or BUN. From these results, the activation of the blood coagulation system might partially contribute to the progression of liver damage caused by LPS, and might be less involved in the progression of renal damage in this model. In conclusion, CTC-111 showed both anticoagulant and profibrinolytic activity in the LPS-induced DIC model without excessive prolongation of coagulation time. From these results, CTC-111 is expected to be a useful remedy for DIC without the risk of bleeding.
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PMID:Effect of activated human protein C on disseminated intravascular coagulation induced by lipopolysaccharide in rats. 1105 Jun 97

It has previously been demonstrated that accumulated beta-catenin serves as an oncoprotein in synovial sarcoma and results in a poor overall survival rate, but the frequency of beta-catenin mutation was quite low (8.2%). The present study, using essentially the same study group of cases, screened for genetic alterations in the mutation cluster region (MCR) of the APC gene in 49 cases of synovial sarcoma. SSCP analysis followed by DNA direct sequencing revealed five missense APC mutations in four cases of synovial sarcoma (8.2%). The mutational sites comprised one case each at codons 1299 (GCT to ACT, Ala to Thr), 1412 (GGA to AGA, Gly to Arg), and 1414 (GTA to ATA, Val to Ile), in addition to one case with double point mutations at codon 1398 (AGT to AAT, Ser to Asn) and at codon 1413 (ATG to ATA, Met to Ile), together with beta-catenin mutation at codon 32 (GAC to TAC, Asp to Tyr). All four cases with APC mutations were histologically of the monophasic fibrous type and showed beta-catenin accumulation. All three cases with APC mutations available for follow-up data were long survivors. This study provides the first evidence that APC mutations also occur in the field of sarcoma, especially in synovial sarcoma.
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PMID:APC mutations in synovial sarcoma. 1192 Jul 41

The present study was attempted to assess the prophylactic and the therapeutic effect of human recombinant activated protein C (APC; drotrecogin-alpha, activated) in experimental heat stroke. Anesthetized rats were divided into two groups and given vehicle solution 1 h before the start or immediately after the termination of heat stress (isotonic sodium chloride solution, 2 mL kg(-1) of body weight, i.v.) or APC (1-10 mg in 2 mL of isotonic sodium chloride solution per kilogram of body weight, i.v.). They were exposed to ambient temperature of 40 degrees C for 100 min to induce heat stroke. When the vehicle-pretreated rats underwent heat stress, their survival time values were found to be 57 to 71 min. Pretreatment or treatment with APC significantly increased survival time (122-221 min). All vehicle-pretreated heat stroke animals displayed systemic inflammation (evidenced by increased TNF-alpha, IL-1alpha, and IL-6) and activated coagulation (evidenced by increased levels of activated partial thromboplastin time, prothrombin time, and D-dimer and decreased levels of both platelet count and protein C). Biochemical assay also revealed that both renal and hepatic dysfunction (e.g., increased plasma levels of blood urea nitrogen, creatinine, adenine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) were noted during heat stroke. A significant decrease in both cerebral blood flow and partial pressure of oxygen in hypothalamus were also observed in vehicle-pretreated heat stroke animals. These heat stroke reactions were all significantly reduced by pretreatment or treatment with human recombinant APC. The results indicate that human recombinant APC can be used as a prophylactic and a therapeutic agent for experimental heat stroke by ameliorating systemic inflammation, hypercoagulable state, and multiple organ dysfunction.
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PMID:Activated protein C can be used as a prophylactic as well as a therapeutic agent for heat stroke in rodents. 1929 93