Erythrocyte intracellular sodium concentration and transmembrane sodium flux were measured in nine healthy patients undergoing uncomplicated elective abdominal surgery. Intracellular sodium concentration was determined by in vitro washing of cells in a solution approximating to intracellular constituents and measuring extracellular sodium contamination with 51Cr EDTA. Sodium flux was determined by radioactive 22Na tracer both as influx and efflux. No change in erythrocyte intracellular sodium concentration or in sodium flux was found postoperatively. In 14 seriously ill surgical patients, all of whom had plasma sodium levels outside the tolerance range of our surgical population, erythrocyte intracellular sodium concentration decreased, but not significantly, compared with patients undergoing uncomplicated surgery (p = 0.16). Furthermore, sodium flux in seriously ill patients was proportional to intracellular sodium concentration. These results are at variance with the hypothesis of 'sick cell syndrome' which is said to be typified by a high intracellular sodium concentration and a reduced sodium efflux. In the surgical patients studied, it is more likely this hyponatremia does not result from a change in sodium flux but is dilutional.

Cell Membrane Permeability↗

PubMedDate not supplied

Factors affecting the incidence of polyploidy in a human in vitro fertilization program.

OBJECTIVE: To study the factors affecting the incidence of polyploidy in an assisted reproduction program. DESIGN: Retrospective analysis. SETTING: University-based subfertility clinic. PATIENTS AND METHODS: Subfertile patients were treated in 163 treatment cycles of in vitro fertilization (IVF) or pronuclear stage tubal transfer (PROST). The relationship between the incidence of polyspermy and the indication of subfertility, the stimulation protocol, the oocyte, and the semen parameters were analyzed. RESULTS: Eighty-nine of the 1,149 oocytes were polyploid (7.8%). The incidence of polyploidy was not affected by the indication for IVF, the age of the patients, the stimulation protocol, the maturity of oocytes as assessed by the appearance of the cumulus, the sperm concentration, the number of sperm inseminated, the serum estradiol level, and the number of oocytes retrieved. The incidence was increased when: (1) the serum estradiol fell before the administration of human chorionic gonadotrophin; (2) the oocyte retrieval-insemination interval was 6 hours or more; (3) the sperm motility was 70% or more; (4) the percentage of sperm with normal morphology was 50% or more. CONCLUSION: The incidence of polyploidy was affected by the serum estradiol pattern, the preinsemination interval, sperm motility, and percentage of morphologically normal sperm.

Adult↗