The signal for maternal recognition of pregnancy in cattle is bovine trophoblast protein-1 (bTP-1), a Type I trophoblast interferon. One of the many functions of interferons is the induction of the 2',5'-oligoadenylate (2-5[A]) system, which is involved in cell division and selective degradation of mRNA. The present study focused on the cellular changes of 2-5(A) synthetase in bovine endometrium during the estrous cycle and early pregnancy. Ability of recombinant bTP-1 to stimulate activity of the enzyme in uterine cells throughout the estrous cycle was also evaluated in vitro. Surface epithelium, glandular epithelium, and stroma were enzymatically separated in cows on Day 5, 10, 15, or 18 postestrus and on Day 15 or 18 of pregnancy. Cell samples were lysed and frozen for determination of the endogenous cellular content of 2-5(A) synthetase. Additional cells obtained during the estrous cycle were cultured and treated with increasing doses of recombinant bovine interferon alpha (rbIFN-alpha) or recombinant bTP-1 (rbTP-1). During the estrous cycle, 2-5(A) synthetase was greatest on Day 5 and declined approximately 10-fold by Day 15 (p < 0.01). Cellular content of 2-5(A) synthetase was similar among all three endometrial cell types. In the gravid horn of pregnant animals, presence of a conceptus significantly increased (p < 0.01) 2-5(A) synthetase in all endometrial cell types compared to levels on Days 15 and 18 of the estrous cycle. On Day 18, levels of 2-5(A) synthetase were 30-fold greater (p < 0.01) in epithelium (surface and glandular) from pregnant cows compared to that from cyclic cows.(ABSTRACT TRUNCATED AT 250 WORDS)

Endometrial polypeptide synthesis, which is regulated through ovarian steroid secretion and steroid production by the developing conceptus, not only provides the necessary secretory components vital to conceptus development but also presents the adhesive changes in the epithelial surface essential for conceptus attachment. In the present study, a 30-kDa, basic endometrial glycoprotein (pGP30) was isolated and characterized during the estrous cycle and early pregnancy of the pig. Uterine flushings and endometrial culture media were obtained from gilts on Days 0, 5, 10, 12, 15, and 18 of the estrous cycle and Days 10, 12, 15, and 18 of pregnancy. A polyclonal antibody was generated to pGP30 after isolation of medium from Day 15 pregnant endometrial cultures separated by gel filtration and PAGE. Western blot analysis indicated that the antiserum reacted with isoforms of pGP30 and cross-reacted with a 90-kDa component in serum that was not removed after cleavage of the oligosaccharide chains from the 90-kDa glycoprotein. Antiserum did not detect a 30-kDa band in media from cultures of kidney, fat, heart, muscle, liver, or serum; however, heart and muscle did contain bands of different molecular masses that cross-reacted with the antiserum. Multiple bands of higher molecular mass (35-40 kDa) were detected in the endometrial cultures from gilts on Days 0 through 10 of the estrous cycle. Treatment of ovariectomized gilts with estradiol-17 beta stimulated a similar response. During the mid- to late luteal phase of the estrous cycle (Days 12-18), the 30-kDa band as well as an additional 32-kDa band was present on Western blots. Administration of progesterone for 14 days stimulated the synthesis of both the 30- and 32-kDa products in ovariectomized gilts. However, only the pGP30 was detected on Days 12-18 of pregnancy. Immunocytochemical localization with antiserum to pGP30 indicated that the glycoprotein is present in the endometrial epithelium, with the surface epithelium demonstrating the strongest reaction product. Discrete changes in staining and cellular localization were observed during the early stages of the estrous cycle (Days 0-5) and the midluteal (Day 10) phase. A similar response was achieved with administration of steroids to ovariectomized gilts. Data indicate that discrete changes in epithelial synthesis of the endometrial glycoprotein occur at the time of conceptus trophoblastic elongation and placental attachment in the pig.

Experiments were conducted to test the hypothesis that estrogen treatment will regress a persistent dominant follicle developed during melengestrol acetate (MGA) treatment in the absence of a functional corpus luteum (CL) with normal fertility following development and ovulation of a newly recruited follicle. In Exp. 1, nonlactating beef cows (n = 31) were administered .5 mg.cow-1.d-1 of MGA (d 0) for 14 d with 25 mg of prostaglandin F2 alpha (PGF2 alpha) administered on d 6 and 8 to regress the CL. On d 11 of treatment, approximately half the MGA-treated cows received 5 mg of estradiol valerate (EV) i.m. (MGAEV, n = 14) and the remainder were maintained on MGA (n = 17). Ovaries were checked with ultrasound on d 8, 10, 12, and 14 of MGA treatment and every day until ovulation. A persistent dominant follicle developed in 90% of the MGA-treated cows by d 10 of treatment. Most of the MGA-treated cows ovulated the persistent dominant follicle (n = 13/17), whereas EV treatment regressed the persistent dominant follicle (n = 10/14) with the recruitment of a new follicle that ovulated (n = 8/10). Diameter of the ovulatory follicle was larger (P < .05) for the MGA (19.8 +/- .6 mm) than for the control (15.1 +/- .8 mm) and MGAEV (14.8 +/- .7 mm) cows. In Exp. 2, nonlactating, multiparous beef cows (n = 97) and yearling heifers (n = 38) were equally allotted to either a control, MGA alone, or MGA + estradiol-17 beta (MGAE) group with the same dose of MGA as administered in Exp. 1. The 1st d of MGA feeding was the 1st d of treatment. On d 10 of treatment half the MGA-treated animals were injected i.m. with 5 mg of estradiol-17 beta. In controls, behavioral estrus was detected and animals were artificially inseminated (AI) for 5 d (d 10 to 14 of experiment). All controls not exhibiting estrus by d 15 of experiment were injected with 25 mg of PGF2 alpha. The remaining controls and all MGA cows were observed for behavioral estrus and AI commenced for 7 d following withdrawal of MGA (d 15 to 21 of experiment). More (P < .05) controls (90.3%) than MGA (84.8%) or MGAE (63.6%) cows showed estrus within 7 d after MGA withdrawal. The percentage of animals conceiving to the synchronized estrus did not differ (P > .05) among treatments. The data support our hypothesis that a persistent dominant follicle developed and can be regressed with exogenous estrogen treatment followed by the recruitment and ovulation of a new follicle after MGA withdrawal and fertility of that estrus does not seem to be significantly compromised.

Delayed unilateral pulmonary embolectomy via the peripheral approach has been performed in 12 patients suffering from chronic pulmonary vascular obstruction after a single or repeated embolisms. Arterial hypoxemia and pulmonary hypertension were present in all cases. Embolectomy was performed several months or years after the initial event. There were 2 early and one late death. The surviving patients are doing well clinically and show definite hemodynamic and angiographic improvement.

A 9-month-old male baby was investigated for a massive left-to-right shunt at the arterial level. On right heart catheterization a patent ductus could not be demonstrated but retrograde arterial angiography showed an aorto-pulmonary window. During corrective surgery on cardiac bypass, the left coronary artery was found to arise from the aorto-pulmonary window, this was corrected by dividing the communication distal to the origin of the left coronary artery. On follow-up investigation 6 months after operation the baby was without symptoms and showed a fully functional left coronary artery. To our knowledge this is the first case of such a congenital anomaly to be described.