Two isozymes of PKC found in HL-60 cells show a difference in activation by the phorbol ester TPA.

Cytosol from untreated cells and a detergent extract of the particulate fraction from TPA-treated HL-60 cells were analyzed for protein kinase C activity by consecutive column chromatography on Mono Q and hydroxyapatite. From both preparations two separate peaks of enzyme activity were obtained. The first peak, eluting at lower salt concentrations, is activated at lower TPA concentrations (3 X 10(-9) M) than the other (10(-7) M), which was eluted at higher salt concentrations.

Inhibition of estrogen biosynthesis and its consequences on gonadotrophin secretion in the male.

Of the gonadal steroids in the male, testosterone is the most important regulator of gonadotrophin secretion. However, whether testosterone affects gonadotrophin secretion directly or whether it must first be aromatized to estrogens is controversial. We have reported extensively on the endocrine and anti-tumor effects of the non-steroidal aromatase inhibitors CGS 16949A and CGS 20267 in adult female rats. In these animals, both inhibitors potently and selectively inhibit estrogen biosynthesis. Thus these agents can be effectively used in studying estrogen-dependent processes. CGS 16949A was administered for 14 days to adult male rats, over a dose range which in females suppresses estradiol and elevates LH. In male rats a suppression of estradiol was seen, however, there was no significant effect on either serum LH or on the weights of androgen-dependent organs. CGS 16949A, when administered to healthy men at a dose of 1 mg b.i.d. for 10 days, causes a significant fall in plasma estradiol and significant elevations of plasma FSH and testosterone. Dose-dependent suppression of serum estradiol and an increase in serum testosterone and LH are seen after administration of single oral doses of CGS 20267. These results indicate that in the male rat, inhibition of aromatization of testosterone to estrogens does not influence gonadotrophin secretion whereas in men the negative feedback exerted by testosterone on gonadotrophin secretion is dependent on the aromatization of testosterone to estrogens.

Association of meningitis with infantile gastro-enteritis.

It is the policy at the Jordan University Hospital to perform lumbar puncture on children with gastroenteritis who present with one or more of the following: age less than 1 month, convulsions, hypoactivity or marked irritability, and depressed sensorium. Review of the records of 737 children admitted with gastro-enteritis between January 1980 and October 1984 showed that lumbar puncture was performed on 351 (47.6%) children. Acute bacterial meningitis was diagnosed in only three children, two of whom had already received treatment before admission and the third had obvious meningeal signs. These findings do not justify the present policy on lumbar puncture in children with gastroenteritis and it is proposed that the procedure be reserved for children in whom abnormal CNS findings persist after initial correction of fluid and electrolyte balance or with overt signs of meningitis.