Junko Hasegawa

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The novel gastroprokinetic agent acotiamide improves gastric motility by inhibiting acetylcholinesterase activity in stomach; however, the mechanism of distribution of acotiamide from blood to stomach has not been clarified. Here, the tissue distribution of acotiamide was investigated in rats. The tissue-to-plasma concentration ratio (K(p,app,in vivo)) for(More)
For the antiinflammatory drug zomepirac (Z), 5-(4-chlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2 acetic acid, the glucuronic acid conjugate (ZG) is the major metabolite. During analytical development ZG was found to be unstable at physiological pH, leading to four compounds other than Z. ZG and the other fractions were purified from urine by preparative HPLC and(More)
The first rapid and highly sensitive high-performance liquid chromatographic (HPLC) assay for triamterene, hydroxytriamterene, and hydroxytriamterene sulfate is reported. Plasma samples were processed by protein precipitation, while urine was used untreated. Three different solvent systems were used to analyze (a) triamterene in plasma (30% acetonitrile, pH(More)
The growth responses of Vibrio parahamolyticus to pH, NaCl concentration and temperature changes were studied using serotype O3:K6 and other strains. Growth curves were obtained for 27 different sets of conditions, comprised of three levels of NaCl concentration, pH and temperature. The temperature, pH and NaCl concentrations most favorable for growth were(More)
Asacol, a medication that delivers delayed release 5-aminosalicylic acid (5-ASA), is a useful therapeutic agent for inflammatory bowel disease (IBD), but the relationship between its pharmacological actions and intestinal concentrations has not been studied in detail. Therefore, our aim was to assess 5-ASA's pharmacological actions as a function of its(More)
The survival of Vibrio parahaemolyticus serovar O3:K6 strains and other serovars in the presence of acetic, citric and hydrochloric acids were studied. There were no differences in resistance to these acids between serovar O3:K6 and the other serovars. At pH 5.6, citric acid was more effective in reducing the number of viable cells of V. parahaemolyticus(More)
Sensitive, specific, and reproducible TLC methods are described for the determination of propranolol and its major metabolites in humans, conjugated propranolol, free and conjugated naphthoxylactic acid, and free and conjugated p-hydroxypropranolol. The drug or metabolites are extracted from plasma or urine with ether and applied to TLC plates of silica gel(More)
Earlier studies of triamterene (T) disposition in man have reported hydroxytriamterene (T-OH) and hydroxytriamterene sulfate (T-O-SO3H) conjugate to be the major metabolites. We describe T kinetics through use of an HPLC method and confirm that after hydroxylation, T is rapidly converted to T-O-SO3H. The intermediate T-OH metabolite could not be detected in(More)