American journal of obstetrics and gynecology
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Am. J. Obstet. Gynecol. · Apr 2000
The role of diacylglycerol as a modulator of oxytocin-stimulated phasic contractions in myometrium from pregnant and nonpregnant rats.
The role of diacylglycerol in the phosphatidylinositol-signaling pathway is to activate protein kinase C. In the myometrium, protein kinase C activation leads to inhibition of phasic contractions. These studies are designed to determine why stimulation of the phosphatidylinositol-signaling pathway caused by oxytocin does not cause a paradoxical suppression of contractions through diacylglycerol production and protein kinase C activation. Specifically, these studies were performed to test the hypothesis that diacylglycerol catabolism is significant in myometrial tissue, thereby precluding its availability for the activation of protein kinase C. ⋯ These studies have demonstrated that prevention of diacylglycerol degradation, especially in response to inhibition of myometrial diacylglycerol kinase, results in the paradoxic oxytocin-mediated suppression of total myometrial contractile activity. These observations support the hypothesis that, when its catabolism is prevented, diacylglycerol produced in response to stimulation of the phosphatidylinositol-signaling pathway by oxytocin becomes available for protein kinase C activation, resulting in inhibition of myometrial contractile activity.
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Am. J. Obstet. Gynecol. · Apr 2000
Expression and regulation of the messenger ribonucleic acid encoding the prostaglandin F(2alpha) receptor in the rat myometrium during pregnancy and labor.
We examined expression of messenger ribonucleic acid encoding the prostaglandin F(2alpha) receptor in the rat myometrium throughout late gestation and its regulation by progesterone and mechanical stretch. ⋯ Increased myometrial expression of prostaglandin F(2alpha) receptor messenger ribonucleic acid during term and preterm labor is temporally associated with progesterone withdrawal but is not dependent on mechanical stretch of the myometrium.
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Am. J. Obstet. Gynecol. · Mar 2000
Review Comparative StudyPerineal application of talc and cornstarch powders: evaluation of ovarian cancer risk.
Some epidemiologic studies have reported associations between perineal talc exposure and epithelial ovarian cancer, which raises parallel questions about the consequences of perineal exposure to cornstarch. Cornstarch powder is an alternative to talc powder that by its nature is a completely different substance. In this review of the literature the epidemiologic data on ovarian cancer risk and perineal application of both powders are reviewed, and the chemical natures of the two powders are compared. All available data indicate that whereas associations between talc exposure and ovarian cancer have suggested but not proved a casual relationship, the application of perineal powder containing cornstarch exclusively is not predicted to be a risk factor for ovarian cancer.
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Am. J. Obstet. Gynecol. · Mar 2000
The Preterm Prediction Study: sequential cervical length and fetal fibronectin testing for the prediction of spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
This study was undertaken to further elucidate the pathogenesis of preterm birth by means of traditional risk factors and new markers for preterm birth derived from the Preterm Prediction Study. ⋯ Regardless of other risk factors, a short cervix predicts a subsequent positive fetal fibronectin result, and a positive fetal fibronectin result predicts subsequent cervical shortening. These data do not support a single sequence of events leading to spontaneous preterm birth.
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Am. J. Obstet. Gynecol. · Mar 2000
Review Comparative StudyThe Filshie clip for female sterilization: a review of world experience.
Laparoscopic tubal electrocoagulation continues to be widely practiced; however, mechanical devices such as the Yoon band, the Hulka clip, and, most recently, the Filshie clip are becoming more popular because of the avoidance of accidental electrical burns, the diminished likelihood of subsequent ectopic pregnancy, and, in the case of the clips, the minimal degree of tubal destruction, thus allowing for maximum reversibility. This survey of worldwide reports from 1981 to the present reveals a high level of acceptance of the Filshie clip because of its effective design and ease of application.