Effect of external peer review on cesarean delivery rates: a statewide program.

OBJECTIVE: To assess the effectiveness of a joint-specialty society and health department statewide peer-review program to reduce cesarean rates. METHODS: Forty-five of the 165 hospitals with active delivery services were reviewed between 1989 and 1993. Differences in total and repeat cesarean rates and vaginal birth after cesarean (VBAC) rates were compared by hospital review status using Student t tests and linear regression for the years before and after completion of the program. RESULTS: Reviewed hospitals reduced their total cesarean rate by 3% and repeat cesarean rate by 0.7%, and increased their VBAC rate by 14.6% compared with nonreviewed hospitals, for which the respective reduction in rates was 1%, 0.6%, and 12.7%. Statistically, there was no difference between reviewed and nonreviewed hospitals in terms of rate changes. CONCLUSION: This joint-specialty society and health department peer review had no apparent impact on cesarean rates.

Depletion and refilling of intracellular calcium pools in bovine chromaffin cells.

To investigate Ca2+ uptake by Ca(2+)-depleted bovine chromaffin cells, we depleted these cells of Ca2+ by incubating them in Ca(2+)-free buffer, then measured changes in cytoplasmic Ca2+ concentration ([Ca2+]i), 45Ca2+ uptake, and Mn2+ uptake in response to added Ca2+ or MN2+. In depleted cells, the increase in [Ca2+]i after Ca2+ addition, and the Mn2+ and 45Ca2+ uptakes were higher than in control cells, and were inhibited by verapamil. The size of the intracellular Ca2+ pools in depleted cells increased after Ca2+ addition. The times for [Ca2+]i rise and Mn2+ entry to reach plateau levels were much shorter than the time for refilling of intracellular Ca2+ stores. In Ca(2+)-depleted cells and cells which had been loaded with BAPTA, 45Ca2+ uptake was much higher than in control cells. These results suggest that extracellular Ca2+ enters the cytoplasm first before refilling the intracellular stores. The rate of Mn2+ influx depended on the level of filling of the Ca2+ stores, suggesting that some signalling takes place between the intracellular stores and Ca2+ entry pathways through the plasma membrane.

K+ activity and regulation of intracellular pH in the sea urchin egg during fertilization.

Fertilization of the sea urchin egg is accompanied by changes in intracellular ion activities and transmembrane fluxes, which regulate the sequence of biochemical events of metabolic derepression. Changes in intracellular K+ activity during fertilization have been controversial and here we report our measurements using intracellular K+-sensitive microelectrodes. A small, but statistically significant, transient rise in internal K+ activity was detected during the first 10 min of fertilization. Since this change in K+ activity was ouabain sensitive, intracellular K+ activity in the fertilized egg appears to be regulated by the increased Na+, K+ ATPase activity, rather than the previously suggested K+ decompartmentalization. Increasing external K+ concentration was found to stimulate ouabain-sensitive alkalinization in the fertilized egg. The data are consistent with the possibility that Na+, K+ ATPase may regulate cytoplasmic pH by recycling Na+ that enters the cell through Na+-H+ antiport.