Joseph W Kosh

Learn More
We characterized the NADPH-dependent metabolism of 17beta-estradiol (E2) by liver microsomes from 21 male and 12 female human subjects. A large number of radioactive estrogen metabolite peaks were detected following incubations of [3H]E2 with male or female human liver microsomes in the presence of NADPH. The structures of 18 hydroxylated or keto estrogen(More)
Acetylcholine-rich synaptic vesicles were isolated from myenteric plexus-longitudinal muscle strips derived from the guinea pig ileum by the method of Dowe, Kilbinger, and Whittaker [J. Neurochem. 35, 993-1003 (1980)] using either unstimulated preparations or preparations field-stimulated at 1 Hz for 10 min using pulses of 1 ms duration and 10 V . cm-1(More)
We characterized the NADPH-dependent metabolism of estrone (E1) by liver microsomes of 21 male and 12 female human subjects. The structures of 11 hydroxylated or keto metabolites of E1 formed by human liver microsomes were identified by chromatographic and mass spectrometric analyses. 2-Hydroxylation of E1 was the dominant metabolic pathway with all human(More)
1. Choline, and the choline analogues monoethylcholine (MEC) and N-aminodeanol (NAD) were examined for prophylactic activity in acute acetylcholinesterase inhibitor toxicity in mice. The rank order of potency of the compounds was MEC greater than NAD greater than choline. 2. Simultaneous administration of MEC (60 mg kg-1) or NAD (200 mg kg-1) with(More)
A capillary gas chromatography/mass spectrometry (GC/MS) assay for the simultaneous quantitation of arecoline (ARE), acetylcholine (ACh), and choline (Ch) in biological tissue has been developed. The method utilizes hexadeuterated ARE and nonadeuterated ACh and Ch as internal standards. The compounds were ion-pair extracted from tissue using sodium(More)
In recent years, development of potent inhibitors for estrogen sulfatases has become an actively pursued strategy for chemoprevention and/or chemotherapy of estrogen-dependent human breast cancers. We report here our findings that pregnenolone 16alpha-carbonitrile (PCN) is a potent inhibitor of estrone-3-sulfatase activity of rats and also humans. PCN(More)
1. The metabolism of arecoline (ARE) was examined in homogenates of mouse blood, brain, kidney, and liver tissue. 2. Liver and kidney tissues exhibited the greatest rates of ARE metabolism. 3. The specific carboxylesterase inhibitor TOCP (tri-o-tolyl-phosphate) as well as ISO-OMPA (tetraisopropyl-pyrophosphoramide) completely blocked ARE metabolism in liver(More)
A series of N-aryl-2-[[[5-[(dimethylamino)methyl]-2- furanyl]methyl]thio]ethylamino analogs of the H2-antagonist, ranitidine, was synthesized and the abilities of the compounds to alleviate the cholinergic deficit characteristic of Alzheimer's disease evaluated. The compounds were initially tested for their ability to inhibit human erythrocyte(More)
A more rapid cell-counting technique using an electronic cell counter was developed as an improvement over the slower hemocytometer method. The electronic counting method produced cell counts that had a smaller standard deviation but were not significantly different from the hemocytometer method. The acetate, hexanoate, and decanoate esters of(More)