Side-chain cleavage of cholesterol by gas chromatography-mass spectrometry in a selected ion monitoring mode.
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Biomedical subjects
Publications and source records attributed to M Morisaki.
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The endothelial cell is a rich source of plasminogen activator that is associated with fibrinolytic activity in blood vessel. Addition of sitosterol to the culture medium of endothelial cells from bovine carotid artery gave rise to a marked increment in the activity of plasminogen activator. Removal of sitosterol from the culture medium resulted in a decrease of plasminogen activator activity back to normal levels. Enhancement of plasminogen activator activity in cultured endothelial cells was not observed by cholesterol, 5-androsten-3 beta-ol and others.
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The effect of oxygenated sterols on platelet aggregation induced by thrombin and ADP has been studied. All oxygenated sterols tested with a hydroxyl group on the side chain enhanced thrombin-induced aggregation at 25 microM. In the case of ADP-induced aggregation, however, only 22S-hydroxycholesterol[(22S)-5-cholestene-3 beta,22-diol] enhanced the aggregation, and 22R-hydroxycholesterol[(22R)-5-cholestene-3 beta,22-diol], 24S-hydroxycholesterol[(24S)-5-cholestene-3 beta,24-diol], and 25-hydroxycholesterol[5-cholestene-3 beta,25-diol] inhibited it. These effects were observed within 10 min after the addition of oxygenated sterols to platelet suspensions in plasma.
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[14C]Formate is incorporated into the C-2 of the pyrimidine moiety of thiamin by Escherichia coli and Salmonella typhimurium. In Saccharomyces cerevisiae, it is incorporated into C-4. Radioactive carbons of [1-14C]glycine and [2-14C]glycine are incorporated by S. typhimurium into the C-4 and C-6 of the pyrimidine, respectively, but not by S. cerevisiae. These facts suggest that procaryotes and eucaryotes have different biosynthetic pathways for pyrimidine. In this study, the procaryotes tested incorporated [14C]formate into the C-2 and the eucaryotes incorporated it into the C-4 of the pyrimidine.
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Several cholesterol analogs structurally modified in nuclear substitutions were tested for sustaining the growth of the silkworm Bombyx mori. 5 alpha-Cholest-7-en-3 beta-o1, 5,7-cholestadien-3 beta-o1 and cholesteryl acetate can replace cholesterol as sterol source for B. mori. Considerably good growth was also obtained with 5 alpha-cholest-14-en-3 beta-o1 and 5 alpha-cholesta-6,8(14)-dien-3 beta-o1. Other sterols tested were either partially effective or ineffective as nutrients.
Several cholesterol analogs with modifications in the side chain were added to the artificial diet of the silkworm, and their effects on insect growth and development were determined. It was found that slight deviations of the cholesterol's side chain induced pronounced growth-retarding effects, suggesting an important functional role of the isooctane side chain of cholesterol.
UNLABELLED: It is conceivable that luteal function is varied with different menstrual cycles. A study was therefore undertaken to investigate for changes in luteal function during consecutive menstrual cycles. METHODS: From those women receiving ambulatory treatment at the hospital 30 displaying a biphasic basal body temperature (BBT) curve were chosen for the study. BBT records were obtained from each of these women for at least 3 consecutive cycles and a total of 194 cycles thus rendered available were evaluated for the pattern of BBT, the duration of high phase (DHP), high phase score (HPS) and planimetric luteal index (PLI). Twenty of these 30 women were subjected further to endometrial dating at the 7th-8th day of high phase with simultaneous determinations of serum estradiol (E2), progesterone (P) and prolactin (PRL) during 2 consecutive cycles. RESULTS: The incidences of abnormal values of the parameters for at least one of the consecutive cycles studied were: DHP; 13.3% pattern; 50-100%, HPS; 40.0%, PLI; 13.3%, E2; 25%, P; 25%, PRL; 30%, endometrial dating; 65%. These results indicate a considerable variability of luteal function.
Studies on the stereochemistry of 24,28-epoxy-24-ethylcholesterol, a key intermediate in sitosterol to cholesterol conversion in insects, were undertaken. In nutritional experiments, the 24R,28S and 24S,28R stereoisomers (isofucosterol epoxides) were unable to support growth and development of silkworm larvae. Incubation of 3 alpha-3H-labeled (24R,28R)- and (24S,28S)-epoxide (fucosterol epoxides) with a cell-free preparation from silkworm guts resulted in effective conversion into desmosterol and cholesterol; (24R,28R)-epoxide was the slightly better substrate. Fucosterol incubation yielded (24R,28R)-epoxide and the 24S,28S isomer in approximately equal amounts, while slightly preferential formation of the 24R,28R isomer was observed in in vivo experiments. These results indicate that both the formation of the epoxide from fucosterol and its conversion to desmosterol proceed with a low degree of stereospecificity.
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UNLABELLED: The ovulation-inducing effect of bromocriptine (CB-154) and the underlying mechanism in the management of anovulatory infertility with normoprolactinemia were investigated. Thirty-seven normoprolactinemic women (anovulatory cycle, 11 cases; 1st grade amenorrhea, 18; and 2nd grade amenorrhea 8) with anovulia showing plasma prolactin levels of less than 25 ng/ml were give CB-154 daily in doses of 2.5 mh from the second day of menstruation or withdrawal bleeding (1) to assess the ovulatory induction rate, (2) to determine the serum PRL, LH, FSH and E2 levels before and during the drug administration, (3) to measure the serum PRL concentration by TRH test prior to CB-154 medication and (4) to assess size heterogeneity of serum PRL with the use of lyophilization. RESULTS: (1) Ovulation occurred in 21 of the 37 patients, of a total of 42 menstrual cycles studied, 33 were ovulatory, indicating a high rate of repeated success. (2) There was a significant decrease of serum PRL following administration of CB-154, and the finding was the same in the group of women with successful ovulatory induction. Serum LH, FSH and E2 levels did not show any significant change following CB-154 therapy. (3) Prl concentrations were suppressed more in cases of unsuccessful induction than those in successful induction. (4) PRL responses to TRH tended to be lower in cases of successful induction than those in unsuccessful cases. (5) The Little PRL content ratio decreased after administration of CB-154, and this data have suggested that not only the problem of immunologically measured serum PRL levels but the qualitative problems also bear relations to the effect of this hormone on the endocrinological environment.