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Biomedical subjects

C J Pauerstein

Publications and source records attributed to C J Pauerstein.

At least 55 records · Page 3Linked to original sources

The role of cilia in fertility: an evaluation by selective microsurgical modification of the rabbit oviduct.

Fertility, ovum transport, and ciliary activity were examined in 35 rabbits after either unilateral microsurgical reversal or double transection (surgical controls) of 1 cm. segments of distal, middle, or proximal ampulla. Fertility was also examined following similar segmental reversal at the level of the distal and proximal isthmus in eight additional rabbits. Reversal of 1 cm. segments of distal, middle, or proximal ampulla effectively prevented pregnancy. In contrast, control animals that underwent double transection without reversal experienced unaltered fertility. Reversal of 1 cm. segments of distal or proximal isthmus was also consistent with normal fertility. Ova placed on the fimbrial surface of oviducts that had undergone ampullary segmental reversal were arrested at the distal anastomosis of the reversed segment. When mechanically displaced into the reversed segment, such ova were transported toward the ovary and were again arrested at the distal anastomosis. Transampullary transport of ova was normal in doubly transected controls. Ova were transported across both anastomosis sites to the ampullary isthmic junction. Studies of ciliary activity confirmed that cilia within reversed segments of ampulla beat in the ovarian direction, counter to that in the rest of the oviduct. Direction of ciliary beat remained unaltered in surgical controls. These experiments demonstrate a critical role of tubal cilia in ovum transport through the rabbit ampulla. In contrast, other mechanisms control ovum transport into and through the tubal isthmus.

Animals↗

Temporal relationships of estrogen, progesterone, and luteinizing hormone levels to ovulation in women and infrahuman primates.

These studies were undertaken to ascertain the interval between the estrogen and LH peaks and ovulation in women, rhesus monkeys, and baboons. Estrogen, progesterone, and LH were measured by RIA. Ovulation was documented by visual examination of the ovaries, histology of the corpora lutea, and recovery of ova. The data for human subjects was based on a group of 23 normal women scheduled for surgical sterilization. Blood was drawn daily between 8:30 and 10:30 P.M. beginning on day 10 of the cycle. Surgery was performed 1 to 5 days after the LH peak. The hormonal findings were correlated with the histology of the corpus luteum. The mean interval from the estrogen peak to ovulation was 34 hours, the interval from the estrogen peak to the LH peak was 24 hours, and that from the LH peak to ovulation was 9 hours. In 46 rhesus monkey cycles and in 53 baboon cycles diagnostic serial laparoscopic examinations were initiated following the estrogen peak and repeated every 24 hours until ovulation was confirmed. The mean interval between the estrogen peak and ovulation was 34 hours in the monkey and 41 hours in the baboon. The intervals from the estrogen peaks to the LH peaks were 12 hours in the monkey and 23 hours in the baboon. The intervals from LH peak to ovulation were 22 hours in the monkey and 18 hours in the baboon. Plasma progesterone levels were significantly increased prior to the LH peak in all three species.

Adult↗

Demonstration of a chorionic gonadotropin-like substance in rabbit morulae.

Rabbit morulae were treated with specific indirect immunofluorescence and immunoperoxidase histochemical techniques. The first antibody in both systems was rabbit anti-human chorionic gonadotropin (hCG) beta-subunit. Negative controls revealed a complete absence of reaction. All morulae incubated with the double-antibody system showed a positive reaction. Rabbit morulae thus present a substance with antigenic determinants similar to the beta-subunit of hCG. The physiologic role of this substance is unknown.

Animals↗

Deciliation in the puerperal fallopian tube.

Tubal segments obtained from patients at cesarean section and at intervals during the first 5 postpartum days were examined to evaluate puerperal changes in the tubal epithelium. The specimens of tubal epithelium were examined under the scanning and transmission electron microscopes. Ciliated cells were most densely distributed on the fimbria and in the ampulla, and were relatively sparsely distributed in the isthmus. Progressive diminution of numbers of ciliated cells and deciliated of individual cells were noted in specimens obtained during the puerperium. Nonciliated cells were in the resting stage at term pregnancy. Secretory activity returned during the puerperium.

Adult↗

Failure of seminal plasma to enter the uterus and oviducts of the rabbit following artificial insemination.

Twelve adult does in estrus were artificially inseminated with 1 ml of semen from bucks that had received injections of 3H-thymidine 22 to 32 days previously. The ejaculates contained radioactive seminal plasma and unlabeled sperm. The reproductive tracts of the does were removed at selected intervals after insemination, divided into segments of no more than 300 mg, and processed for scintillation counting. Significant levels of radioactivity were never detected in any uterine or oviductal segment. The technique was capable of detecting as little as 1.5 X 10(-4) ml of semen in a segment. These results demonstrate that seminal plasma is not transported from the vagina into the uterus or oviducts in the rabbit, emphasizing the importance of the motility of spermatozoa in their passage to the site of fertilization.

Animals↗

Time course of ovum transport in guinea pigs.

The time course of ovum transport was determined in cycling guinea pigs. The occurrence of ovulation was determined in assessing changes in vaginal cytology. The day of the postovulatory leukocyte influx was considered day 1 of the cycle. Ovum transport in guinea pigs is characterized by a relatively long sojourn in the ampulla, followed by rapid transport through the isthmus. This pattern is similar to that seen in women and subhuman primates and different from the pattern in rabbits.

Animals↗

Effect of inhibitors of prostaglandin synthesis and metabolism on ovum transport in the rabbit.

Several drugs known to affect prostaglandin synthesis, release, or metabolism have been tested for their effects on ovum transport in the rabbit after systemic or local administration. Acceleration of transport was obtained with several drugs; among the most effective were benzydamine, a blocker of thromboxane production, and L11204, an inhibitor of prostaglandin metabolism.

Animals↗

Immunodetection of a human chorionic gonadotropin-like substance in human sperm.

The presence of a human chorionic gonadotropin (hCG)-like substance in human spermatozoa is reported. A highly sensitive immunocytochemical procedure was utilized (double-antibody immunofluorescence technique). Rabbit anti-hCG or rabbit anti-hCG beta-subunit was used as the first antibody. A positive fluorescence reaction was found in all human specimens analyzed and in positive controls (choriocarcinoma cells). No fluorescence was detected in other species studied (sheep, pig, goat, horse, bull, and guinea pig), nor in the negative controls. These findings open a new research area on the physiologic role of this hCG-like substance in human reproduction.

Antigen-Antibody Reactions↗

Pharmacologic modification of the time course of ovum transport in guinea pigs.

Various agents were examined for their effects on ovum transport in the guinea pig. Estrogen significantly accelerated ovum transport in this species. The experiments further demonstrated that estrogen did not act by inducing prostaglandin synthesis, nor by altering plasma progesterone levels. The estrogen-induced acceleration was significantly antagonized by tamoxifen, an antiestrogen that acts by interfering with estrogen receptor synthesis. Cycloheximide also antagonized the effects of estrogen on ovum transport. These data suggest that the modification of ovum transport by estrogen is due to the entrance of estrogen into the nuclei of target cells, and subsequent protein synthesis. Although we assume that this action occurs at the level of the oviduct, our experiments do not prove this assumption.

Animals↗

Comparison of two techniques of suturing in microsurgical anastomosis of the rabbit oviduct.

Microsurgical reconstruction of the rabbit oviduct was undertaken utilizing either through-and-through sutures including the mucosa, or sutures penetrating the serosa and myosalpinx but not the mucosa. Patency and pregnancy rates did not seem to vary with the suturing technique. However, scanning electron microscopic observation revealed abnormal mucosal fold patterns at 3 weeks after surgery. Fibrinous exudates over the surface of the intraluminal sutures increased with time until the entire surface was thickly veiled by 9 weeks. The observation also revealed regeneration of epithelial cells along the suture. These cells included many abnormal forms such as giant cells and misshapen cells. The majority of these were nonciliated. In theory, the intraluminal suture could form a nidus for epithelial hyperplasia which might cause future tubal obstruction. However, the patency and pregnancy rates obtained with through-and-through suturing were similar to those obtained when the endosalpinx was excluded, both in this study and in previous studies from these laboratories.

Animals↗

Effect of ovulation and hormonal treatment on the in vitro response of rabbit oviducts to prostaglandins E1 and F2alpha.

Rabbit oviductal circular muscle isometric contractile response was measured in relation to treatment with prostaglandin E1 (PGE1) and prostaglandin F2alpha (PGF2alpha). PGE1 (1 mug/ml) inhibition of the contractile response of the rabbit oviduct to field stimulation was increased in the proximal isthmus after ovulation. Estrogen and progesteron, in doses known to alter ovum transport, did not affect the response of the oviduct to PGE1. In comparison to the response of estrous tissues, the stimulatory effect of PGF2alpha on the isthmus was decreased 24 hours after administration of human chorionic gonadotropin (HCG). Treatment with estrogen and progesterone did not affect these postovulatory changes. The response of the ampullary-isthmic junction to PGF2alpha was significantly reduced 72 hours after administration of HCG. Neither ovulation nor steroid treatment affected the response of the ampulla to PGF2alpha. Changes in the sensitivity of the oviduct to prostaglandins after ovulation may be necessary for successful ovum transport.

Animals↗

Fertility following microsurgical removal of the ampullary-isthmic junction in rabbits.

The role of the ampullary-isthmic junction (AIJ) in fertility was investigated in the rabbit by using microsurgical tuboplastic techniques. Microsurgical transection or resection of the AIJ failed to alter fertility significantly. Nine of ten rabbits which underwent unilateral transection of the AIJ became pregnant on the operated side and eight of the ten became pregnant on the unoperated control side. Of the ten rabbits which underwent unilateral AIJ resection, all became pregnant bilaterally. The results of this study indicate that the AIJ is not necessary for normal fertility in the rabbit.

Animals↗

Pregnancy following segmental isthmic reversal of the rabbit oviduct.

Microsurgical reversal of a segment of rabbit proximal tubal isthmus has been followed by normal pregnency in the first two animals to undergo the procedure. Establishment of pregnancy despite radical modification of the oviduct furnishes the opportunity to gain new insights into the mechanisms controlling tubal ovum transport and emphasizes the evolving feasibility and importance of tuboplastic microsurgery both as a research tool and clinical procedure.

Animals↗

Rate of transport of radioactive ovum models through the oviducts of individual rabbits.

The transport of radioactive ovum models of 100, 200, 400, 800, and 1,000 mu diameter through the oviducts was measured. Four surrogates of a given size were transferred into each oviduct 6 hours after injection of human chorionic gonadotropin (HCG). The surrogates were located in the oviducts 24, 48, 60, 66, and 72 hours after HCG injection with a collimated end-window Geiger-Mueller tube. Thus the time-course of the transport of each surrogate, from ampulla to uterus in the same animal, was plotted. The time-course of surrogate transport was directly related to surrogate size. Our data suggest that normal tubal patency and ovum transport function can be tested by introducing radioactive ovum surrogates of appropriate size into the oviducts and monitoring their time of arrival at the uterus.

Animals↗