Avner Hershlag

The effect of interleukin-1 on adhesion formation. in the rat***

The potential role of interleukin-1 in postoperative adhesion formation was examined. Cecal abrasion gave a consistently higher adhesion score when compared with sham laparotomy, on the basis of adhesion number, density, and vascularity, and so was chosen for use in further studies. The extent of serosal bleeding during cecal abrasion did not affect adhesion scores. Intraperitoneal injection of 10 micrograms murine recombinant interleukin-1 alpha in cecally abraded animals on the day of surgery and on the following 4 days resulted in a significant increase in adhesion scores when compared with those of cecally abraded animals injected with vehicle alone. Adhesions enhanced with murine recombinant interleukin-1 alpha, which were thicker and more vascular, were equivalently enhanced at doses from 10 to 10,000 ng, implying maximal response over that range. Rats not operated on and receiving recombinant interleukin-1 alpha 2 weeks after injury had increased adhesion formation. These results demonstrate that interleukin-1 alpha may be an important short-term mediator of postsurgical adhesion formation.

Heterogeneity in patient populations explains differences in in vitro fertilization programs.

OBJECTIVE To evaluate the efficacy of in vitro fertilization and embryo transfer (IVF-ET). DESIGN Two different models for pregnancy rates in IVF-ET have been developed: a beta-geometric model and a split population model. SETTINGS All IVF cycles were performed at the Yale University School of Medicine in New Haven, Connecticut. PATIENTS, PARTICIPANTS All patients undergoing 1,257 IVF-ET cycles performed between the years 1983 through 1987. INTERVENTIONS None. MAIN OUTCOME MEASURE The probability of achieving a viable pregnancy per cycle. RESULTS Because both models provide excellent explanations for our data distribution, the decline in the conditional probability of achieving pregnancy after a given number of unsuccessful cycles may be inferred. CONCLUSIONS These findings question the justification of continuing IVF-ET treatment beyond some threshold number of cycles.

The predictive value and the management of cycles with low initial estradiol levels

This study was undertaken to examine the predictive value of low estradiol (E2) after 5 days of human menopausal gonadotropin (hMG) stimulation response to therapy in that cycle. We further examined whether the outcome of such cycles can be improved by increasing the hMG dose. When 18 cycles in which day 8 E2 was less than or equal to 50 pg/mL were compared with 48 cycles with corresponding E2 levels of 51 to 150 pg/mL, the former showed a significantly worse response to subsequent hMG therapy. To determine the effect of an increase in hMG dose we studied 48 cycles with day 8 E2 of 51 to 150 pg/mL. In 32 cycles hMG dose was increased from three to a mean of five ampules a day, after 5 days of therapy. In 16 cycles it was kept constant at three ampules per day. Although a tendency towards lower fertilization rate was observed in the higher hMG groups, no significant differences were observed in the results between the two groups. We thus conclude that very low E2 levels after 5 days of gonadotropin therapy are predictive of low response in that cycle, and that in cycles with day 8 E2 of 51 to 150 pg/mL, increasing the dosage of hMG on day 8 and beyond does not alter the course of the cycle.

Comparison of singleton and multiple pregnancies in in vitro fertilization (IVF) and embryo transfer (ET).

The purpose of this study was to analyze factors associated with multiple gestations in IVF-ET. Twenty-seven multiple gestations conceived following IVF-ET resulted in the delivery of 20 sets of twins and three sets of triplets. One quadruplet pregnancy was terminated due to heavy bleeding. There were four “vanishing sacs,” two of which resulted in a twin pregnancy and two in singletons. These were compared to 88 singleton IVF-ET gestations. The only significant difference found was the higher numbers of embryos transferred in the multiple gestation group. No difference was found between the two groups in diagnosis, stimulation protocol, estradiol, response, number of eggs, fertilization, and cleavage rate. Maternal age was younger in the multiple-gestation group, though not statistically significant. It is thus suggested that limitation of the number of embryos transferred is the only means to reduce the incidence of multiple gestations in IVF-ET.

Selection bias in in vitro fertilization programs

Pregnancy rates per cycle reported from different in vitro fertilization-embryo transfer programs vary widely. While several programs have reported constant pregnancy rates per cycle, others report declining pregnancy rates. Selection biases at the point of entry and between cycles are discussed as possible explanations of these discrepancies.

The effect of calcium ion channel blockers on sperm fertilization potential*†*Supported in part by an office based research grant from the American Foundation for Urologic Disease with funds contributed by Searle.†The Society for Assisted Reproductive Technology Prize Paper presented at the 49th Annual Meeting of The American Fertility Society, Montreal, Quebec, Canada, October 11 to 14, 1993.

OBJECTIVE To evaluate the effects of calcium ion (Ca2+) channel blockers on male fertility potential. DESIGN A case comparison of the surface expression of mannose-ligand receptors on motile spermatozoa from 10 known fertile males and from 10 normospermic men taking Ca2+ channel blockers who were seeking infertility treatment. Examination of the effects of in vitro exposure of sperm from fertile donors (n = 14) to antihypertensive medications. SETTING Patients from a successful university hospital-based IVF-assisted reproductive technology program and from a male urology private practice. INTERVENTIONS Prescription of alternate hypotensive medications for four male patients; cholesterol loading and unloading in vitro of fertile donor sperm. MAIN OUTCOME MEASURES Motile sperm were tested for their ability to bind fluorescein isothiocyanate-labeled, mannosylated bovine serum albumin as an index of the surface expression of mannose-ligand receptors associated with fertility potential. Acrosome status was simultaneously evaluated by fluorescence microscopy with rhodamine-labeled Pisum sativum lectin. Sperm were assayed before and after an 18-hour or 3-day incubation under capacitating conditions in vitro. RESULTS Motile spermatozoa of normospermic men taking calcium antagonists for hypertension control do not express head-directed mannose-ligand receptors at high frequency, nor do they undergo spontaneous acrosome loss. Unexpectedly, mannose-ligand receptor translocation from the subplasmalemmal space over the acrosome to the sperm surface and aggregation over the equatorial-postacrosomal regions occurred in acrosome-intact sperm. This differs from fertile controls in whom receptor translocation to the equatorial-postacrosomal segment is coupled with the acrosome reaction (AR). Discontinuation of calcium antagonists results in complete recovery of parameters associated with sperm fertilizing potential: time-dependent increases in the percentages of spermatozoa exhibiting surface mannose-ligand binding and spontaneous ARs in vitro. The effects of in vivo administration of calcium antagonists is mimicked in control fertile donor sperm by inclusion of a Ca2+ channel blocker in the media employed during capacitating incubations. CONCLUSIONS Therapeutic administrations of calcium antagonists for hypertension control cause reversible male infertility associated with an IVF failure. A mechanism of inhibition of sperm fertilizing potential through insertion of lipophilic calcium ion antagonists into the lipid bilayer of the sperm plasma membrane is consistent with our in vitro studies.

Human sperm fertilizing potential in vitro is correlated with differential expression of a head-specific mannose-ligand receptor**Supported in part by grant RR05924 from the National Center for Research Resources Biomedical Research Support Program, National Institutes of Health, Bethesda, Maryland.††Presented in part at the 39th Annual Meeting of the Society for Gynecologic Investigation, San Antonio, Texas, March 18 to 21, 1992.

OBJECTIVE To determine whether different patterns of surface expression of mannose-ligand binding sites are correlated with capacitation and predictive of the ability of human sperm to recognize and fertilize eggs in vitro. DESIGN Analysis of motile sperm populations (from fertile donors, males presenting for routine semen analysis, and men undergoing IVF) before and after incubation in capacitating media. SETTING Patients from an infertility practice at a major university hospital. INTERVENTIONS None. MAIN OUTCOME MEASURES The mannose ligand-binding capacity of sperm populations were initially assayed by solid-phase mannosylated polyacrylamide bead binding studies. Sperm surface D-mannose binding sites thus detected were localized and visualized by fluorescence microscopy after reaction with a mannosylated fluorescein isothiocyanate-labeled neoglycoprotein probe. Results were correlated with acrosomal status, reproductive histories, and IVF outcomes. RESULTS The percent of sperm with head-directed surface expression of a mannose-specific receptor was increased in fertile donors and males exhibiting normal fertilization in IVF after incubation in albumin-supplemented Hams F-10 medium (GIBCO Laboratories, Grand Island, NY). In normospermic males exhibiting zona binding failure in IVF, mannose-specific receptor was observed over the head surface of few incubated sperm. CONCLUSIONS The appearance of D-mannose-ligand binding sites on the surface of heads of human spermatozoa is associated with zona binding ability in IVF and is a putative determinant in human gamete recognition and fertilization.

Hysteroscopy and Hysteroscopic Surgery

Why has it taken 120 years for hysteroscopy to attain its present position as an acceptable mode of diagnosis and treatment of intrauterine pathology? While access to the uterine cavity was always desired, unlike other cavities the uterus contained a potential space only, measuring about 3 to 8 mL. The frustration caused by the lack of good illumination and no means for distention of the uterine cavity led Munde in 18801 to describe hyststeroscopy as a “fleeting glimpse of the endometrium [that] is of little clinical value,” compared to the information derived from “using the tip of the index finger, the proverbial “edge of the gynecologist.” Indeed, only a glimpse of the uterine cavity was available when Panteloni2 performed the first hysteroscopy in 1869 using reflected candlelight from a concave mirror.

Clomiphene citrate directly impairs endometrial receptivity in the mouse**Presented at the 71st Annual Meeting of The Endocrine Society, June 21 to 24, 1989, Seattle, Washington.††Supported in part by a grant from the International College of Surgeons to A.H.

Clomiphene citrate (CC) has known antifecundity effects in animal models. To help define the site of action of this effect, we studied the direct effect of CC on endometrial receptivity by transferring embryos to hormonally prepared prepubertal mice. Prepubertal mice were begun on one of four blinded hormonal preparations consisting of two consecutive 3-day periods of daily injections: oil vehicle, oil-progesterone (P), estradiol (E2)-P, or CC-P. Blastocysts, which had not been exposed to CC, were then surgically transferred to these prepubertal recipients. Fourteen days after embryo transfer, implantations and term pregnancies were counted at necropsy. In this model, CC demonstrated no estrogen agonist effect, and had a significant adverse effect on endometrial receptivity. CC appeared to lower fecundity by a direct endometrial effect.