Development of factors to convert frequency to rate for beta-cell replication and apoptosis quantified by time-lapse video microscopy and immunohistochemistry

An obstacle to development of methods to quantify beta-cell turnover from pancreas tissue is the lack of conversion factors for the frequency of beta-cell replication or apoptosis detected by immunohistochemistry to rates of replication or apoptosis. We addressed this obstacle in islets from 1-mo-old rats by quantifying the relationship between the rate of beta-cell replication observed directly by time-lapse video microscopy (TLVM) and the frequency of beta-cell replication in the same islets detected by immunohistochemistry using antibodies against Ki67 and insulin in the same islets fixed immediately after TLVM. Similarly, we quantified the rate of beta-cell apoptosis by TLVM and then the frequency of apoptosis in the same islets using TdT-mediated dUTP nick-end labeling and insulin. Conversion factors were developed by regression analysis. The conversion factor from Ki67 labeling frequency (%) to actual replication rate (%events/h) is 0.025 +/- 0.003 h(-1). The conversion factor from TdT-mediated dUTP nick-end labeling frequency (%) to actual apoptosis rate (%events/h) is 0.41 +/- 0.05 h(-1). These conversion factors will permit development of models to evaluate beta-cell turnover in fixed pancreas tissue.     

Early developmental stages of greasyback shrimp,Metapenaeus ensis (de Haan, 1844) (Crustacea, Decapoda, Penaeidae)

Metapenaeus ensis was spawned and laboratory cultured untilthe post-larval stage to illustrate and describe its embryonicand larval development. Fecundities ranged between 454 000 and689 000 eggs, and {small tilde}99.2% of spawned eggs hatchedafter 12 h and 40 min at 33.5 p.p.t. and 29.0-29.1°C. Sixnaupliar, three protozoeal, three mysis and one post-larvalstages were noted. A minimum of {small tilde}10 days (249 h20 min) from the time of hatching were required to completethe larval stages by subsisting only on Chaeioceros gracilisand Tetraselmis tetrathele at varying temperature and salinityof 28.1-29.8°C and 33.5—34.5 p.p.t., respectively.The embryonic and larval developmental stages of M.ensis aregenerally similar to those of other known penaeid species, exceptfor the size and structure of diagnostic characters, setationof appendages and duration of metamorphoses.     

A reversed-phase high-performance liquid chromatographic method for the simultaneous determination of serum concentrations of cyproterone acetate and 15 beta-hydroxycyproterone acetate

A reversed-phase high-performance liquid chromatographic method for the simultaneous determination of cyproterone acetate (CPA), 15 beta-hydroxycyproterone acetate (15 beta-OH-CPA) and cyproterone (CP) was reported. This method was specific, sensitive, precise, easy and rapid for determination of the serum concentrations of these steroids in patients receiving CPA. Although no peak corresponding to CP was observed for serum, peaks corresponding to CPA and 15 beta-OH-CPA were detected and well separated in all subjects undergoing long-term CPA therapy. In these patients, there seemed to be a dose-dependent relationship between the amount of CPA administered and the serum concentrations of these steroids, and the serum concentrations of CPA were either similar or low compared with those of 15 beta-OH-CPA. In conclusion, this simplified method is thought to be very valuable for studies on the pharmacokinetics of CPA and 15 beta-OH-CPA, and on the relationship between the CPA dosage and the therapeutic or side effects on adrenal and gonadal steroid production.