Inhibition of rat embryo implantation in the gossypol-treated uterine horn

We have developed a method to test the effect of gossypol on prevention of embryo implantation in the uterine horn. On the day of proestrus, gossypol (at a dose of 50, 100, 150, 200 and 500 mug per uterine horn was injected directly into the lumen of the right uterine horn. The left uterine horn was injected with 100 mul buffer. The rats were then mated with fertility proven males on the same day. The day of sperm-positive vaginal smear was designated as Day 0 of pregnancy. The number of implantation sites in both control and gossypol-treated horns was examined on Day 8 of pregnancy by laparotomy. The number of pups born was counted after parturition. At laparotomy, the percentages of pregnant animals with positive implantation sites in the gossypol-treated uterine horn (at a dose of 500, 200, 150, 100 and 50 mug per uterine horn) were 0, 0, 0, 10 and 44%, respectively. By contrast, implantation sites were present in 100% of the control horns of the same rats. The average numbers of total implantation sites in both horns vs the number of pups born to gossypol-treated animals using 500, 200, 150, 100, and 50 mug doses were 5.60 +/- 1.25 vs 4.00 +/- 1.00, 5.83 +/- 1.30 vs 4.70 +/- 1.10, 5.80 +/- 1.10 vs 5.50 +/- 1.20, 11.50 +/- 1.00 vs 9.50 +/- 1.50 and 11.67 +/- 1.20 vs 9.30 +/- 1.20, respectively. Gossypol metabolite completely inhibited embryo implantation when administered at 5.30 mug per uterine horn. The potency of the gossypol metabolite in preventing embryo implantation is estimated to be at least 28 times higher than the parent compound.     

Use of prostheses made of ePTFE in anastomoses of the rat uterine horn

ePTFE prostheses were used in the microsurgical anastomosis of the rat uterine horn. Handling characteristics of this synthetic material during the performance of anastomosis were tested. Patency rates, infections and local tissue reaction were evaluated after thirty and sixty days. Connective tissue infiltration and incomplete endothelialization by normal endometrial elements were observed on the luminal surface of the prosthesis.     

Blood supply as a factor regulating pacemaker activity of the rat uterine horn

The effect of ischemia of the uterine artery supplying blood to the main rhythmogenic ovarian zone of the uterine horn in non-pregnant rats was investigated. Parameters of pacemaker activity of the given locus and all the subsequent pacemaker areas up to the cervix were studied under the influence of ischemia. The greatest changes of the amplitude, frequency and burst duration time of spike activities were recorded in the ovarian end of horn. The uterine corpus and cervical end of horn were less affected by ischemia. However, amplitude of the slow-wave oscillations increased by more than one and a half in these conditions. Data obtained allow us to state about presence of certain connection between the ovarian end of horn and uterine cervix. Morphological studies revealed strong vascularization of the upper part of uterine horn.     

Unilateral luteotropic effect of uterine venous effluent of a gravid uterine horn in sheep.

The involvement of the main uterine vein in the unilateral maintenance of CL was studied in bilaterally ovulating unilaterally pregnant ewes. Ewes were mated at estrus (Day 0) and bilaterally ovulating ewes were randomized into three groups at surgery on Day 5. In all ewes, the uterine horns were separated through the intercornual area and one was ligated and transected near the internal bifurcation to produce a nongravid horn. One group served as controls (five ewes). In the other two groups the main uterine vein on one side was surgically anastomosed (end to side) to the corresponding vein of the opposite side (gravid side to nongravid side in one group--three ewes, and nongravid side to gravid side in the other--three ewes). Necropsies were done on Day 20. Mean CL weight was less, (P less than .01) on the nongravid side in control ewes than on the gravid side in control ewes or for either side in the other two groups. There were no significant differences among mean weights of CL on the gravid side in control ewes and either side in the other two groups. The CL regressed when the ipsilateral uterine vein contained blood from only the nongravid horn whereas the CL was maintained when the ipsilateral uterine vein contained venous blood from a gravid horn, whether or not it also contained blood from a nongravid horn. Results indicate that the uterine venous effluent from a gravid uterine horn in sheep has a luteotropic effect on the ipsilateral CL.     

Protective effect of melatonin against oxidative stress on adhesion formation in the rat cecum and uterine horn model

This experimental study was designed to evaluate the degree of adhesion formation and peritoneal tissue levels of malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NO) and the effect of melatonin on these metabolites in a postoperative intraperitoneal adhesion formation model in rats. Thirty adult female Wistar albino rats were subjected to standardized lesions by cecal and uterine horn abrasion and were randomly divided into three groups. Control rats were treated with 5% ethanol. Melatonin treated rats received 4 mg/kg melatonin before closure and for 10 consecutive days intraperitoneally after surgery. Rats in the sham operation group underwent a surgical procedure similar to the other groups however the peritoneal abrasion was not performed. On postoperative day 10 relaparatomy was performed. After the assessment of the adhesions, the rats in each group were sacrificed and peritoneal tissues were harvested to determine the tissue levels of MDA, GSH and NO activity. Adhesion formation scores in the melatonin group were significantly lower than that of control and sham group (p<0.01 and p<0.02, respectively). Tissue levels of MDA and NO were significantly lower in the melatonin treated rats when compared with control and sham groups. The levels of GSH in the melatonin treated rats were significantly higher than those of control and sham groups (p<0.01). The results demonstrate that in this experimental model, intraperitoneal administration of melatonin decreases the extent of peritoneal adhesions and causes a decrease in MDA and NO and an increase in GSH levels.     

Spacing of conceptuses in the uterine horn and local effects on fetal and placental weights throughout gestation in the rat

Longitudinal growth of the uterine horn and distances between implantation sites and the extremities of the horn were measured in 30 albino Wistar rats at Days 7, 10, 13, 16 or 22 of gestation. Growth of the uterus was most rapid over Days 13-16 but continued over Days 16-22. Distances between implantation sites and between the extremities of the uterine horn and neighbouring implantation sites were relatively even in that the coefficients of variation of these distances were 28, 32, 19, 35 and 35% at Days 7, 10, 13, 16 and 22, respectively. This indicates that an active mechanism promotes even spacing since the expected coefficients of variation given completely random spacing of conceptuses was calculated to be about 100%. Local crowding of fetuses in the uterine horn did not appear to affect fetal or placental growth except at Day 22 when there was a weak but significant correlation (r = 0.3) between fetal weight and the harmonic mean distance to neighbouring implantations.     

Carcinoma of the rectum; low abdominal transverse incision for resection with end-to-end anastomosis

On the basis of published studies of the lymphatic spread of carcinoma of the rectum, tumors lying as low as the anterior peritoneal reflection may be treated by segmental resection with end-to-end anastomosis. Statistics of five-year survivals in these published studies indicate that for tumors in such locations, a segmental resection offers the same chance for cure as an abdominoperineal resection. The transverse low abdominal incision previously described by the author permits better exposure, facilitates the performance of anastomosis which can be made at a greater depth, and thus enables the surgeon to resect a wider margin distal to the tumor.     

Enzymatic activity of Ammon's horn in the ontogenetic development of the rat.

Studies were performed on the activity of several enzymes in Ammon's horn of rat during an individual postembryonal development. For the studies rats of Wistar strain were used that were killed on the 1st, 3rd, 8th, 17th, 40th and 60th day after birth. In the experiment the brains were removed, cut, and the activity of dehydrogenases, phosphatases and esterases was revealed. During the performed studies some considerable differences were shown in the activity of several dehydrogenases, in each particular field of Ammon's horn, undergoing changes in the periods of ontogenetic development under study. Furthermore, some distinct differences in the phosphatases and esterases activity were revealed in each area of the Ammon's horn. Attention was drawn to a comparatively late histo-enzymatic maturation of Ammon's horn in comparison with other structures of the limbic system.     

The use of arteriovenous anastomosis for replantation of the distal phalanx of the fingers.

Microvascular replantation at the distal phalangeal level has recently been reported by several authors, but as yet the rate of success has not been constant owing to the technical difficulties associated with small vessels. To solve this problem, over the last 4 years we have used arteriovenous anastomosis to reestablish either the arterial system or the venous drainage system in the 33 digits of our 23 patients. The results have been excellent, with a 91 percent success rate. Such results for replantation of the distal phalanx may be maintained and improved if a small venous graft with several branches is also utilized.