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Biomedical subjects

C A Eddy

Publications and source records attributed to C A Eddy.

At least 55 records · Page 3Linked to original sources

Electrophysiology of the rabbit oviduct following tubal microsurgery.

The ability of tuboplastic microsurgery to restore electrical continuity across an anastomosis site was investigated in the rabbit. Three to six weeks following transection and end-to-end anastomosis of the tubal ampulla or isthmus, the pattern of electrical activity adjacent to and across the anastomosis site was examined. Recordings were made in vitro using arrays of closely spaced suction electrodes 68 to 72 hours after an ovulating dose of human chorionic gonadotropin. The pattern of electrical activity across anastomosis sites was not significantly different from corresponding portions of unoperated control oviducts. Microsurgical anastomosis restored electrical continuity between anastomosed segments in both the ampulla and isthmus.

Action Potentials↗

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↗

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↗

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↗

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↗

Pattern and duration of ovum transport in the baboon (Papio anubis).

The normal pattern and duration of ovum transport was determined in a group of unmated, spontaneously ovulating baboons (Papio anubis) in which the time of ovulation had been determined directly using serial laparoscopy or indirectly using periovulatory estrogen values, perineal sex skin changes, and corpus luteum histology. At laparotomy, the reproductive tract was segmentally flushed at 24, 48, or 72 hours after ovulation and the position of the ova within the tract ascertained. Ova were consistently recovered from the ampulla 24 hours after ovulation, from both the ampulla and isthmus at 48 hours, and from the uterus 72 hours after ovulation. These results suggest that the baboon constitutes a potentially valuable animal model for the investigation and preclinical evaluation of contraceptive technics affecting tubal function.

Animals↗

Use of radioactive microspheres for studies of tubal ovum transport.

Experiments were designed to ascertain the fidelity with which radioactive plastic ovum models imitated the time-course of transport of natural ova through the rabbit oviduct. After location of the radioactive microspheres within the intact oviducts, the genital tracts were removed and cleared in benzyl benzoate. Natural ova and ovum surrogates were then visualized in situ. The radioactive microspheres were reasonably good models of transport of natural ova and their sojourn in the oviduct was shortened by progesterone and prolonged by estrogen. Thus they should be useful tools for future studies of own transport under various conditions.

Animals↗

The autonomic nervous system and its relationship to tubal ovum transport--a reappraisal.

The role of the autonomic nervous system in controlling ovum transport remains obscure. Although not studied extensively in the oviduct, the para-sympathetic nervous system does not appear to significantly influence ovum transport. The sympathetic nervous system of the oviduct and its pharmacology have been studied more thoroughly. Despite this, little information is available concerning cellular mechanisims of adrenergically altered motility or transport. In spite of much speculation, the weight of evidence suggests that, at least in the rabbit, the sympathetic nervous system plays a minor role in the control of ovum transport.

Animals↗