D-Aspartate increases human chorionic gonadotropininduced testosterone production in purified rat Leydig cells. L-Aspartate, D-,L-glutamate or D-,L-asparagine could not substitute for D-aspartate and this effect was independent of glutamate receptor activation. Testosterone production was enhanced only in cells cultured with D-aspartate for more than 3 h. The increased production of testosterone was well correlated with the amounts of D-aspartate incorporated into the Leydig cells, and L-cysteine sulfinic acid, an inhibitor of D-aspartate uptake, suppressed both testosterone production and intracellular D-aspartate levels. D-Aspartate therefore is presumably taken up into cells to increase steroidogenesis. Intracellular D-aspartate probably acts on cholesterol translocation into the inner mitochondrial membrane, the rate-limiting process in steroidogenesis.z 1999 Federation of European Biochemical Societies.

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d-Lactic and l-lactic acids were simultaneously determined by means of a column-switching high-performance liquid chromatography (HPLC) with fluorescence detection. As a fluorescence reagent, 4-nitro-7-piperazino-2,1,3-benzoxadiazole (NBD-PZ) was employed for the fluorescence derivatization of lactic acid. The proposed HPLC system adopted both octylsilica (Cadenza CD-C8) and amylose-based chiral columns (CHIRALPAK AD-RH), which proved to give a sufficient enantiomeric separation of the lactic acid derivatives with a separation factor ( alpha) of 1.32 and a resolution ( R(s)) of 1.98. Moreover, the features of the first elution of d-lactic acid peak in the proposed HPLC were convenient for the determination of trace amount of serum d-lactic acid, which is known to increase under diabetes. Intra-day and inter-day accuracies were in the range of 90.5-101.2 and 89.0-100.7%, and the intra-day and inter-day precisions were 0.3-1.2 and 0.4-4.8%, respectively. The proposed method was applied to determine d-lactic and l-lactic acids in human serum of normal subjects and diabetic patients, showing that both d-lactic and l-lactic acid concentrations were significantly increased in the serum of diabetic patients ( n=31) as compared with normal subjects ( n=21). This fact was found for the first time owing to the development of the proposed HPLC method which is able to determine d-lactic and l-lactic acid simultaneously. Finally, serum d-lactic acid concentrations determined by the proposed HPLC method were compared with those from a reported enzymatic assay, and the smaller p value between normal subjects and diabetic patients was shown by the proposed HPLC method.

Objectives. To survey the knowledge, attitudes, and practices towards safe medication use of first-year college students in Taiwan. Methods. One hundred forty-seven departments in 27 universities were sampled by stratified randomization. Three sections of the questionnaire were developed, including 10 true/false questions to measure knowledge, 4 questions for attitude in a 5-point scale, and 10 questions for practice in a 5-point scale.Results. A total of 6270 subjects completed the survey instrument for a valid response rate of 91.9%. Students who were health science majors had safer medication practices than non-health science majors. However, students in both groups had low scores on appropriate antibiotics use, with a correctness rate of 45.8%. Knowledge relating to antacid use had the lowest number of correct responses among the 10 items included in the survey. Overall, the students showed positive attitudes toward (12.6 6 2.2) and trusted (3.6 6 0.7) pharmacists' consultation. Conclusions. College students lack appropriate knowledge, attitudes, and practices related to the safe use of medications, and efforts are warranted in Taiwan.