Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.5 (urease)
 7,257 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ornithine carbamyl transferase activity was determined by estimation of the citrulline formed during the reaction. Citrulline is estimated by diacetylmonoxime in the presence of thiosemicarbazide. The conditions of enzyme analysis were then studied in buffer veronal-acetate medium at 37 degrees C. The optimum pH for activity depended on the ornithine concentration, but was independent of carbamyl-phosphate concentration. At pH 7.8, ornithine at concentrations higher than 1.6 mM inhibited enzyme activity, ornithine Km was 0.208 mM and that of carbamyl-phosphate was 1.92 mM. The incubation time for determination of OCT activity was 15 minutes. Citrulline production was proportional to the enzyme concentration up to activities of 180 units/l. Serum urea was destroyed by a urease of high quality, so that the formation of citrulline in the control reagents was minimal. Reference values, determined on a hospital population, without liver, heart or pulmonary disease, lay between 4.7 +/- 2.3 units/l. The coefficient of variation of the technique, determined on a pool of serum of moderate activity was 8 units/l i.e. 5.1 per cent.
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PMID:[Determination of the activity of serum ornithine carbamoyltranferase : working conditions in a veronal-acetate medium]. 0 89

Omeprazole 20 mg once (o.d.) or twice daily (b.d.), clarithromycin 250 mg b.d., and tinidazole 500 mg b.d. for 7 days (OCT) is an effective regimen against Helicobacter pylori, but the effect of 5-nitroimidazole resistance is unclear. We aimed to evaluate this using the disc diffusion technique (Mast Diagnostics, Bootle, UK) and E-test (Cambridge Diagnostics Services, Cambridge, UK) to assess 5-nitroimidazole resistance. H. pylori was cultured from antral biopsies of infected patients, as determined by 13C-urea breath test (13C-UBT), histology, and/or rapid urease test. Patients were prescribed OCT and H. pylori eradication was assessed by 13C-UBT at least 4 weeks after completion of therapy. Antibiotic sensitivities to metronidazole and clarithromycin were evaluated by the disc diffusion method and by the measurement of minimum inhibitory concentration (MIC) using the E-test. One hundred and forty-one H. pylori-infected patients were enrolled in the study and the organism was successfully cultured from 119 patients (84%). The overall eradication rate was 125/141 (89%). OCT was successful in 62/69 (90%) patients harboring fully sensitive strains of H. pylori, compared with 42/45 (93%) of patients with strains that were resistant to metronidazole alone (P = 0.74, Fisher's exact test). MIC was assessed in 22 samples. Using a cut-off point of >32 microg/ml to define metronidazole resistance eradication rates were higher against sensitive (9/12; 75%) than resistant (3/10; 30%) strains (P = 0.08, Fisher's exact test). 5-Nitroimidazole resistance assessed by the disc diffusion technique is not helpful in predicting OCT failure, but the E-test may be of value.
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PMID:Relevance of antibiotic sensitivities in predicting failure of omeprazole, clarithromycin, and tinidazole to eradicate Helicobacter pylori. 960 43

Omeprazole 20mg once (od) or twice daily (bd), clarithromycin 250mg bd, and tinidazole 500 mg bd for 7 days (OCT) is an effective regimen against Helicobacter pylori, but the effect of 5-nitroimidazole resistance is unclear. We aimed to evaluate this using the disc diffusion technique and E-test to assess 5-nitroimidazole resistance. H. pylori was cultured from antral biopsies of infected patients as determined by 13C-urea breath test (13C-UBT), histology, and/or rapid urease test. Patients were prescribed OCT, and H. pylori eradication was assessed by 13C-UBT at least 4 weeks after completion of therapy. Antibiotic sensitivities to metronidazole and clarithromycin were evaluated by the disc diffusion method and by minimum inhibitory concentration (MIC) using the E-test. One hundred and forty-one H. pylori-infected patients were enrolled into the study and the organism was successfully cultured in 119 patients (84%). The overall eradication rate was 125/141 (89%). OCT was successful in 62/69 (90%) patients harboring fully sensitive strains of H. pylori compared with 42/45 (93%) of patients with strains that were resistant to metronidazole alone (P = 0.74, Fisher's exact test). MIC was assessed in 22 samples. Using a cut-off point of > 32 microg/ml to define metronidazole resistance, eradication rates were higher against sensitive (9/12; 75%) compared with resistant (3/10; 30%) strains (P = 0.08, Fisher's exact test). 5-Nitroimidazole resistance assessed by the disc diffusion technique is not helpful in predicting OCT failure, but the E-test may be of value.
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PMID:Relevance of antibiotic sensitivities in predicting failure of omeprazole, clarithromycin, and tinidazole to eradicate Helicobacter pylori. 984 21