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Diazepam and its major metabolites, nordazepam, temazepam and oxazepam, in human urine samples, were analyzed by liquid chromatography (LC)/tandem mass spectrometry (MS/MS) using a hydrophilic polymer column (MSpak GF-310 4B), which enables direct injection of crude biological samples. Matrix compounds in urine were eluted first from the column, while the target compounds were retained on the polymer stationary phase. The analytes retained on the column were then eluted into an acetonitrile-rich mobile phase using a gradient separation technique. All compounds showed base-peak ions due to [M+H]+ ions on LC/MS with positive ion electrospray ionization, and product ions were produced from each [M+H]+ ion by LC/MS/MS. Quantification was performed by selected reaction monitoring. All compounds spiked into urine showed method recoveries of 50.1-82.0%. The regression equations for all compounds showed excellent linearity in the range of 0.5-500 ng/mL of urine. The limits of detection and quantification for each compound were 0.1 and 0.5 ng/mL of urine, respectively. The intra- and inter-day coefficients of variation for all compounds in urine were not greater than 9.6%. The data obtained from actual determination of diazepam and its three metabolites, oxazepam, nordazepam and temazepam, in human urine after oral administration of diazepam, are also presented.

A detailed procedure for the analysis of four beta-blockers, acebutolol, labetalol, metoprolol and propranolol, in human plasma by high-performance liquid chromatography (LC)-tandem mass spectrometry (MS-MS) using an MSpak GF column, which enables direct injection of crude plasma samples, is presented. Protein and/or macromolecule matrix compounds were eluted first from the column, while the drugs were retained on the polymer stationary phase of the MSpak GF column. The analytes retained on the column were then eluted into an acetonitrile-rich mobile phase using a gradient separation technique. All drugs showed base peak ions due to [M + H]+ ions by LC-MS with positive ion electrospray ionization, and the product ions were produced from each [M + H]+ ion by LC-MS-MS. Quantification was performed by selected reaction monitoring. The recoveries of the four beta-blockers spiked into plasma were 73.5-89.9%. The regression equations for all compounds showed excellent linearity in the range 10-1000 ng/mL of plasma, with the exception of propranolol (10-800 ng/mL). The limits of detection and quantification for each drug were 1-3 and 10 ng/mL, respectively, of plasma. The intra- and inter-day coefficients of variation for all drugs in plasma were not greater than 10.9%.

Objectives The aim of this study was to elucidate the prevalence of Heliobacter pylori and its distribution in order to clarify the frequency of H. pylori infection and the most appropriate site of endoscopie biopsy for studies of H. pylori infection associated with different gastric diseases. Designs and methods Swiss role mucosal strips from 275 resected stomachs, which included the greater curvature, anterior wall and lesser curvature of the antrum, incisura and corpus, were stained with haematoxylin-eosin and H. pylori antibody. Results The prevalence of H. pylori infection was 97% in duodenal ulcers, 98% in gastric ulcers, 98% in intestinal-type carcinomas and 99% in diffuse-type carcinomas. H. pylori was present at a rate of 100% in any site in cases of duodenal ulcer, but was diffusely distributed in the antrum and patchily distributed in the corpus. The detection rate of H. pylori was 50–100% in gastric ulcers, 30–100% in intestinal-type adenocarcinomas and 63–100% in diffuse-type adenocarcinomas depending on the site of the stomach examined. Conclusions The prevalence of H. pylori infection was very high in peptic ulcers of the duodenum and stomach and gastric carcinomas of Japanese patients. Biopsy specimens for evaluation of H. pylori infection should be taken routinely from both the greater curvature of the antrum and corpus. Immunohistochemical staining should be used to assay for H. pylori when few organisms are present or eradication therapy has been used.