The effect of temperature on motility and survival of ejaculated human spermatozoa was investigated with the aid of the multiple exposure photography (MEP) method for objective sperm motility determination. Fresh specimens from healthy donors were analyzed while being heated or cooled gradually, or during their storage at various temperatures from 0 to 48 degrees C. Sperm velocity increased steadily from zero to 50.4 nm/sec between freezing point and body temperature. Thereafter, their activity dropped dramatically and total immobilization occurred at 45 degrees C. The induced immobilization was reversible providing exposure to those extreme temperatures was short enough to prevent permanent damage. Sperm survived up to 24-48 h when stored at 23 degrees C, while at body temperature, their survival in vitro was much shorter and rarely extended beyond 12 h. Their longevity was still shorter at higher or lower temperatures, especially when approaching 48 degrees C. With the aid of the combined supravital staining and MEP methods it was found that temperatures of extreme levels induced mainly immobilization rather than a spermicidic effect. The possible mechanism of thermal effect on sperm motility and some of its practical implications are discussed.
1984)Fetal breathing movements and body movements after maternal ritodrine administration, Journal of Obstetrics and Gynaecology, 5:1,[9][10][11][12] To link to this article: http://dx.
SummaryThe effect of ritodrine on fetal activity was studied in 1 1 healthy women at 34-37 weeks of pregnancy. None of them had premature uterine contractions. All fetuses were presenting by the breech.Following maternal intake of ritodring. 20mg by mouth. a reduction was noted in the number and incidence of fetal trunk movements and in the number of breathing periods. Murata Y., Martin C. B., Miyoke K., Socol M. and Druzin M. (1981) Effect of catecholamine on fetal breathing activity in rhesus monkeys. American Journal of Obstetrics and Gynecology 139; 942-947. Murillis A. J., Barrington P., Harris P. D. and Wheeler T. (1983) Influence of doppler ultasound on fetal activity.
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