Gynecologic investigation最新文献

Placenta-specific antigens and alpha-fetoprotein were detected in the urine of rats with induced abnormal pregnancies. Moreover, in those cases, in which the presumptive diagnosis of intrauterine fetal death or resorption was made, urinary excretion of placental antigens persisted for at least 5 days.

The tubal environment holds a strategic location with respect to the reproductive processes. Histological visualization and biochemical analysis have shown that both oviductal tissue activity and fluid constituents are influenced by the hormonal state of the female. Also, tubal epithelial synthetic activity appears to be affected by the proximal embryo. The functional importance of differential oviductal secretions is presently unclear. However, the techniques of in vitro fertilization, embryo transfer, and culture aid in defining minimal developmental requirements and effects of cyclic secretions on embryologic events.

An increase in the incidence of thromboembolic disorders has been associated with oral contraceptive use, though the causative mechanisms remain unclear. Our studies indicate that the contraceptive steroids, irrespective of the intermediary metabolic processes involved, cause changes in the surface charge characteristics of the blood vessel wall and blood cells in the following cases: (i) in experiments using dogs, the hormonal steroids result in a greater reduction in the pore surface charge of veins than in arteries; (ii) in rats, the current induced mesenteric occlusion times are significantly lowered following administration of combined contraceptives steroids; (iii) in humans, the electrophoretic mobilities of erythrocytes and platelets from women taking Ovral and Demulen are lower than in controls, and (iv) there is no significant alteration of plasma coagulation times of women who are on injectable progestin therapy. Demulen and Ovral appear to result in a slight decrease in activated partial thromboplastin times compared to controls.

The effects of prostaglandins (PGs) on muscular activity of the oviductal isthmus and on the rate of tubal egg transport are reviewed. In consideration of the available data a mechanism by which PGs contribute to the physiological control of egg transport is suggested. In vivo experiments have demonstrated that E-series PGs relax while F-series PGs stimulate muscular activity of the oviduct in humans, subhuman primates and rabbits. These effects are mutually antagonistic. The response of oviductal muscle to PGs appears to be affected by ovarian steroids; progesterone increases the response to PGE1 and decrease the response to PGF2alpha. Oviductal tissue concentrations of PGF increase in a distal to proximal sequence following ovulation-induction in the rabbit. Also, proximal isthmus binding of PGE1 t tended to be greater in 72-hour pregnant rabbits than in estrous rabbits, while binding of PGF2alpha was greater in estrous than in 72-hour pregnant animals. It is suggested that the preovulatory increase in ovarian estradiol secretion stimulates PGF synthesis in the oviductal tissue in a sequential fashion, the peak value occurring when the oviductal isthmus is most sensitive to stimulation by PGF2alpha. The changes in tissue concentration of PGF and in sensitivity to PGF2alpha could contribute to occlusion of the isthmus and prevent premature passage of eggs into the uterus. An increase in ovarian progesterone secretion after ovulation may decrease tissue PGF, decrease the response to PGF2alpha stimulation, and increase the response to PGF1. These changes may then allow a progressive movement of eggs through the isthmus into the uterus. Several questions regarding this proposed mechanism remain unanswered.

The binding of progesterone and other C21 steroids by rat uterine cytosol preparations was studied by equilibrium dialysis. Scatchard plots and preliminary computer-assisted analysis indicated at least two types of binding sites for progestrone. Individual Scatchard plots for cortisol and corticosterone binding were linear with Ka's 0.4 and 1.4 times 10(9) M-1, respectively. Inhibition analyses and modeling of competition experiments suggest, however, that the situation is more complex. There was no binding of labeled dexamethasone.

5alpha-Pregnane-3,20-dione and progesterone were isolated from a pregnancy plasma pool and were identified by using a combination of chromatographic techniques and mass spectrometry. Antibodies to progesterone were obtained in rabbits by immunization with progesterone-1alpha-carboxyethyl-thioether-thyroglobulin. The raised antibodies were of high affinity and one of them cross-reacted (137%) with 5alpha-pregnane-3,20-dione. This property was used to develop radioimmunoassays for measuring circulating levels of both progesterone and 5alpha-pregnane-3,20-dione in pregnancy plasma. The levels of both progesterone and 5alpha-pregnane-3,20-dione increase throughout pregnancy, but a highly significant increase is observed only after the 32nd week of gestation.

In studying oviductal physiology, it is important to sort out the complex interrelationships between muscle, cilia, nerves and secretory processes as they each of themselves, or in concert, effect gamete transport. In this review, a variety of physiological techniques and bioengineering approaches which have been used to monitor contractile and ciliary activity, are described and critically evaluated.

Experimental evidence justifying the selection of primary variables in ovum isthmic transport is evaluated. Peristaltic pumping alone cannot account for the observed ovum motions, however, the theory of pressure forcing of pellets through narrow tubes when combined with the dynamic and motile properties of the mucosal and muscular layers of the isthmus, appears capable of modeling the physiological mechanism. In this model the hormonally dependent tubal compliance is a controlling element of transport rate. The contractile activity statistically distributed both spatially and temporally, provides a persistent though irregular directionality to the movement.

Design and development of a portable and self-contained vaginal probe, consisting of an acetone-filled silver cylinder attached to a pressure gauge, is described. Qualitative changes in vaginal thermal conductance were inferred from rates of thermal expansion of precooled acetone measured as a pressure rise. Administration of 10 mg estradiol-17 beta i.v. to ovariectomized heifers resulted in significant increases in rate of thermal expansion.

Current investigations of the oviduct including methods for studying oviductal physiology, electrophysiology, contractility, roles of the autonomic nervous system and prostaglandins on oviductal motility and egg transport are summarized in this article. In addition, current knowledge of the transport and survival of sperm, egg transport, capacitation, ovum maturation, fertilization, and preimplantation development in the oviduct and the biochemistry and physiology of oviductal secretions are reviewed. An attempt is made to place these investigations in clinical context and to identify promising area for future investigations pertinent to human reproduction.