Microhabitats, thermal heterogeneity, and patterns of physiological stress in the rocky intertidal zone

Thermal stress has been considered to be among the most important determinants of organismal distribution in the rocky intertidal zone. Yet our understanding of how body temperatures experienced under field conditions vary in space and time, and of how these temperatures translate into physiological performance, is still rudimentary. We continuously monitored temperatures at a site in central California for a period of two years, using loggers designed to mimic the thermal characteristics of mussels, Mytilus californianus. Model mussel temperatures were recorded on both a horizontal and a vertical, north-facing microsite, and in an adjacent tidepool. We periodically measured levels of heat shock proteins (Hsp70), a measure of thermal stress, from mussels at each microsite. Mussel temperatures were consistently higher on the horizontal surface than on the vertical surface, and differences in body temperature between these sites were reflected in the amount of Hsp70. Seasonal peaks in extreme high temperatures ("acute" high temperatures) did not always coincide with peaks in average daily maxima ("chronic" high temperatures), suggesting that the time history of body temperature may be an important factor in determining levels of thermal stress. Temporal patterns in body temperature during low tide were decoupled from patterns in water temperature, suggesting that water temperature is an ineffective metric of thermal stress for intertidal organisms. This study demonstrates that spatial and temporal variability in thermal stress can be highly complex, and "snapshot" sampling of temperature and biochemical indices may not always be a reliable method for defining thermal stress at a site.

Adjusting the thermostat: the threshold induction temperature for the heat-shock response in intertidal mussels (genus Mytilus) changes as a function of thermal history

Spatio-temporal variation in heat-shock gene expression gives organisms the ability to respond to changing thermal environments. The temperature at which heat-shock genes are induced, the threshold induction temperature, varies as a function of the recent thermal history of an organism. To elucidate the mechanism by which this plasticity in gene expression is achieved, we determined heat-shock protein (Hsp) induction threshold temperatures in the intertidal mussel Mytilus trossulus collected from the field in February and again in August. In a separate experiment, threshold induction temperatures, endogenous levels of both the constitutive and inducible isoforms of Hsps from the 70 kDa family and the quantity of ubiquitinated proteins (a measure of cellular protein denaturation) were measured in M. trossulus after either 6 weeks of cold acclimation in the laboratory or acclimatization to warm, summer temperatures in the field over the same period. In addition, we quantified levels of activated heat-shock transcription factor 1 (HSF1) in both groups of mussels (HSF1 inducibly transactivates all classes of Hsp genes). Lastly, we compared the temperature of HSF1 activation with the induction threshold temperature in the congeneric M. californianus. It was found that the threshold induction temperature in M. trossulus was 23°C in February and 28°C in August. This agreed with the acclimation/acclimatization experiment, in which mussels acclimated in seawater tables to a constant temperature of 10–11°C for 6 weeks displayed a threshold induction temperature of 20–23°C compared with 26–29°C for individuals that were experiencing considerably warmer body temperatures in the intertidal zone over the same period. This coincided with a significant increase in the inducible isoform of Hsp70 in warm-acclimatized individuals but no increase in the constitutive isoform or in HSF1. Levels of ubiquitin-conjugated protein were significantly higher in the field mussels than in the laboratory-acclimated individuals. Finally, the temperature of HSF1 activation in M. californianus was found to be approximately 9°C lower than the induction threshold for this species.

Temperature interactions of the molecular chaperone Hsc70 from the eurythermal marine goby Gillichthys mirabilis

Molecular chaperones participate in many aspects of protein biogenesis. Mechanistically, they recognize and bind to non-native proteins, prevent the aggregation of unfolded proteins and also, in some cases, facilitate refolding. Although a great deal is known about the cellular function of molecular chaperones in general, very little is known about the effect of temperature on molecular chaperones in non-model organisms, particularly in ectotherms that fold proteins under variable-temperature conditions in nature. To address this issue, we studied the temperature interactions of a major cytosolic molecular chaperone, Hsc70, from the eurythermal marine goby Gillichthys mirabilis. Using in vitro assays, we measured the intrinsic activity, unfolded-protein-stimulated activity, temperature sensitivity and heat stability of the ATPase activity of native Hsc70 purified from G. mirabilis white muscle. Similar to other chaperones in the 70kDa heat-shock protein family, G. mirabilis Hsc70 exhibited a low intrinsic ATPase activity that was stimulated in vitro by the addition of unfolded protein. Across the environmentally relevant temperature range (10–35°C), the ATPase activity of G. mirabilis Hsc70 displayed differential thermal sensitivity, with the greatest sensitivity occurring between 10 and 15°C and the least sensitivity between 15 and 25°C. In addition, the activity of Hsc70 was not significantly different between the unstimulated and unfolded-protein-stimulated treatments, suggesting that the ATPase activity and the peptide-binding domain of Hsc70 have similar thermal sensitivities in vitro. Finally, the thermal stability of Hsc70 ATPase activity greatly exceeded environmental temperatures for G. mirabilis, with activity up to 62.5°C. Overall, the biochemical characterization of the ATPase activity suggests that, although Hsc70 is not an extraordinarily thermally stable protein, it is capable of protein chaperoning cycles even at the extremes of environmental temperatures encountered by G. mirabilis in nature.

Recurrent pregnancy loss and diminished ovarian reserve

OBJECTIVE

To determine the incidence of diminished ovarian reserve (OR) in patients with recurrent pregnancy loss (RPL).

DESIGN

Retrospective chart review.

SETTING

Tertiary fertility center.

PATIENT(S)

Six hundred ninety-two women undergoing a fertility evaluation.

INTERVENTION(S)

Clomiphene citrate challenge test (CCCT).

MAIN OUTCOME MEASURE(S)

FSH concentrations measured on menstrual days 3 and 10.

RESULT(S)

Forty-four women were diagnosed with RPL (+RPL), and 648 women had non-RPL diagnoses (-RPL). Compared with -RPL women, women with +RPL were younger (following statistics are listed as +RPL vs. -RPL, respectively; 34 +/- 5 vs. 35 +/- 4 y) but had similar menstrual cycle length (29 +/- 4 vs. 28 +/- 4 d), and lower day 3 FSH levels (8.9 + 7 vs. 11 +/- 9 mIU/mL) and similar day 10 FSH levels (11 +/- 8 vs. 12 +/- 11 mIU/mL). Eight of 44 women with +RPL (18%) had an abnormal CCCT, compared with 117/648 (18%) of women in the -RPL group. For women with normal OR, delivery rates were similar for -RPL and +RPL patients. For women with an abnormal CCCT, delivery rates were < 5%.

CONCLUSION(S)

Women with RPL have a similar incidence of diminished OR as the general infertile population. Reproductive outcome for patients with an abnormal CCCT is equally poor for both groups. Ovarian reserve screening should be considered in the work-up of RPL before initiation of anticoagulant or immunotherapy.

Heat-shock protein expression is absent in the antarctic fish Trematomus bernacchii (family Nototheniidae)

The heat-shock response, the enhanced expression of one or more classes of molecular chaperones termed heat-shock proteins (hsps) in response to stress induced by high temperatures, is commonly viewed as a ‘universal’ characteristic of organisms. We examined the occurrence of the heat-shock response in a highly cold-adapted, stenothermal Antarctic teleost fish, Trematomus bernacchii, to determine whether this response has persisted in a lineage that has encountered very low and stable temperatures for at least the past 14–25 million years. The patterns of protein synthesis observed in in vivo metabolic labelling experiments that involved injection of (35)S-labelled methionine and cysteine into whole fish previously subjected to a heat stress of 10 degrees C yielded no evidence for synthesis of any size class of heat-shock protein. Parallel in vivo labelling experiments with isolated hepatocytes similarly showed significant amounts of protein synthesis, but no indication of enhanced expression of any class of hsp. The heavy metal cadmium, which is known to induce synthesis of hsps, also failed to alter the pattern of proteins synthesized in hepatocytes. Although stress-induced chaperones could not be detected under any of the experimental condition used, solid-phase antibody (western) analysis revealed that a constitutively expressed 70 kDa chaperone was present in this species, as predicted on the basis of requirements for chaperoning during protein synthesis. Amounts of the constitutively expressed 70 kDa chaperone increased in brain, but not in gill, during 22 days of acclimation to 5 degrees C. The apparent absence of a heat-shock response in this highly stenothermal species is interpreted as an indication that a physiological capacity observed in almost all other organisms has been lost as a result of the absence of positive selection during evolution at stable sub-zero temperatures. Whether the loss of the heat-shock response is due to dysfunctional genes for inducible hsps (loss of open reading frames or functional regulatory regions), unstable messenger RNAs, the absence of a functional heat-shock factor or some other lesion remains to be determined.

Expression of 70 kDa heat shock proteins in antarctic and New Zealand notothenioid fish

The cold and constant water temperature of the Southern Ocean surrounding Antarctica provides a natural laboratory to address questions of temperature adaptation in marine organisms. In this study, endogenous levels and the number of isoforms of the 70 kDa heat shock protein multigene family (hsp70) of Antarctic and cold temperate notothenioid fishes were determined by SDS-polyacrylamide gel electrophoresis and Western blotting. Tissues from three Antarctic Trematomus congeners had significantly lower levels of 70 kDa Hsp isoforms than their temperate confamilial from New Zealand waters. However, these two thermally disparate sets of fish did not differ in number or pattern of 70 kDa Hsp isoforms expressed under normal physiological conditions. Additionally, levels of 70 kDa Hsp isoforms in specimens of one Antarctic species, Trematomus bernacchii, acclimated to 4 degrees C were significantly higher than non-acclimated conspecifics, indicating a direct effect of temperature on Hsp expression in this species. This study shows that constitutive expression of some members of the 70 kDa Hsp multigene family have been maintained, despite the absence of environmental heat stress for at least 2.5 million years.

Heat-shock proteins, molecular chaperones, and the stress response: evolutionary and ecological physiology

Molecular chaperones, including the heat-shock proteins (Hsps), are a ubiquitous feature of cells in which these proteins cope with stress-induced denaturation of other proteins. Hsps have received the most attention in model organisms undergoing experimental stress in the laboratory, and the function of Hsps at the molecular and cellular level is becoming well understood in this context. A complementary focus is now emerging on the Hsps of both model and nonmodel organisms undergoing stress in nature, on the roles of Hsps in the stress physiology of whole multicellular eukaryotes and the tissues and organs they comprise, and on the ecological and evolutionary correlates of variation in Hsps and the genes that encode them. This focus discloses that (a) expression of Hsps can occur in nature, (b) all species have hsp genes but they vary in the patterns of their expression, (c) Hsp expression can be correlated with resistance to stress, and (d) species' thresholds for Hsp expression are correlated with levels of stress that they naturally undergo. These conclusions are now well established and may require little additional confirmation; many significant questions remain unanswered concerning both the mechanisms of Hsp-mediated stress tolerance at the organismal level and the evolutionary mechanisms that have diversified the hsp genes.

Inhibin-B: the physiologic basis of the clomiphene citrate challenge test for ovarian reserve screening

OBJECTIVE

To determine inhibin-B concentrations during ovarian reserve screening in women with normal and diminished ovarian reserve as determined by the clomiphene citrate challenge test.

DESIGN

Retrospective.

SETTING

Tertiary fertility center.

PATIENT(S)

Women undergoing ovarian reserve screening for a routine fertility evaluation.

INTERVENTION(S)

Clomiphene citrate challenge test.

MAIN OUTCOME MEASURE(S)

Inhibin-B concentrations on menstrual days 3 and 10.

RESULT(S)

Nineteen patients with normal ovarian reserve and 15 with diminished ovarian reserve had serum inhibin-B concentrations determined during ovarian reserve screening. For all patients, day 10 inhibin-B concentrations were higher than day 3. Women with normal ovarian reserve had higher inhibin-B concentrations on both days 3 and 10 than women with diminished ovarian reserve. Inhibin-B concentrations demonstrated a negative correlation with FSH levels on both cycle days 3 and 10 and a positive correlation with E2 on cycle day 10.

CONCLUSION(S)

Women with diminished ovarian reserve during ovarian reserve screening had reduced granulosa cell inhibin-B production compared with women with normal ovarian reserve. The lower inhibin-B concentrations may be responsible for the elevated FSH concentrations and may be indicative of the aging follicular apparatus.

The effect of intrauterine diethylstilbestrol exposure on ovarian reserve screening

OBJECTIVE

Our goal was to evaluate the effect of intrauterine diethylstilbestrol exposure on ovarian reserve.

STUDY DESIGN

Four hundred two women underwent ovarian reserve screening. Twenty had intrauterine diethylstilbestrol exposure, and 382 women did not have exposure. The groups were compared regarding age, the incidence of diminished ovarian reserve, and cycle length. Nine women with and 204 women without diethylstilbestrol exposure underwent comparison of the total human menopausal gonadotropin dose, the day of human chorionic gonadotropin administration, the peak estradiol level, and the number of mature follicles.

RESULTS

The diethylstilbestrol-exposed women were similar in age (37 +/- 3.4 years) to the non-diethylstilbestrol-exposed women (35 +/- 4.4 years, p > 0.05). Three of 20 exposed women (15.8%) and 57 of 382 nonexposed women (15.3%) had diminished ovarian reserve (p = 0.41). When the exposed women were compared with the nonexposed subjects, the amounts of human menopausal gonadotropin (30 +/- 10 vs 33.7 +/- 10.6 ampules) required to achieve peak estradiol levels (633 +/- 323 vs 817 +/- 518 pg/ ml) with comparable numbers of follicles (5.7 +/- 2.7 vs 5.4 +/- 2.8) on the day of human chorionic gonadotropin administration were similar (p > 0.05).

CONCLUSIONS

The diethylstilbestrol-exposed and nonexposed women had a similar incidence of diminished ovarian reserve and a similar follicular response to gonadotropins.

[Phospholipase A2--acute phase protein after liver surgery?]

INTRODUCTION

The exact source of phospholipase A2 is unknown. In this context the liver is discussed because the secretion of phospholipase A2 could be initiated during an acute phase response.

PATIENTS AND METHODS

Three groups of patients were prospectively established: A liver resection (n = 12); B control (n = 22; oesophageal resection, gastrectomy, rectum resection); C sepsis (n = 5). Blood was collected preoperatively, each day postoperatively for seven days and at the day of discharge. Biochemical procedures: Phospholipase A2, PMN-elastase, C-reactive protein, GPT, GOT, GLDH, cholinesterase.

RESULTS

Postoperatively phospholipase A2 is unchanged in the liver resection and control group, whereas it increases significantly in septic patients. Only following liver resection GPT, GOT and GLDH increase. C-reactive protein is increased in all groups.

DISCUSSION

Unchanged phospholipase A2 after liver surgery despite an acute phase response indicated by C-reactive protein does not support the view of phospholipase A2 being of hepatic origin.

Heat-Shock Protein Expression in Mytilus californianus: Acclimatization (Seasonal and Tidal-Height Comparisons) and Acclimation Effects

Heat-shock protein (hsp) expression was examined in gill of field-acclimatized and laboratory-acclimated mussels (Mytilus californianus) from the Oregon coast. Endogenous levels of heat-shock proteins in the 70-kDa class (hsp70 isoforms) and profiles of induction temperature for newly synthesized hsp 70 were measured in freshly field-collected specimens as functions of location height in the intertidal and season, and in mussels after 7 weeks of laboratory thermal acclimation. There were significant differences in endogenous levels of hsp70 as functions of season and collection height. Strong induction of new hsp70 synthesis occurred at body temperatures within the range measured in field specimens. Profiles of hsp70 thermal induction varied significantly with season, but not with height of collection. In contrast to the large differences in hsp70 expression between winter- and summer-acclimatized mussels, no differences related to temperature occurred in the differently acclimated mussels. The differences found between the effects of field acclimatization and laboratory thermal acclimation suggest that the stress response is modulated by environmental factors in addition to body temperature. Thus, caution is required in extrapolating from laboratory acclimation studies to acclimatization effects in field populations. The seasonal and tidal-height variations in the heat-shock response are discussed in the context of energy costs of protein turnover.

Premature luteinization during controlled ovarian hyperstimulation for in vitro fertilization-embryo transfer has no impact on pregnancy outcome

OBJECTIVE

To determine if elevated serum P concentration on the day of hCG administration or P area under the curve (AUC) impacts on pregnancy rates (PRs) in IVF-ET cycles.

DESIGN

Retrospective study.

PATIENT(S)

One hundred thirty-three couples underwent IVF-ET using luteal GnRH-agonist suppression followed by hyperstimulation with gonadotropins. Patient cycles were controlled for female age, ovarian reserve, male factor with intracytoplasmic sperm injection (ICSI), endometrial thickness and pattern, number of embryos, and number of high-quality embryos transferred, and cell stage at transfer. Pregnancy was defined as an ongoing pregnancy > 20 weeks.

RESULT(S)

Patients and cycle parameters did not differ significantly based on the control parameters. Similar numbers of severe male factors treated by ICSI were in each group with similar PRs. Pregnancy rates and implantation rates did not differ based on P levels < or = 0.9, < or = 1.1, and < or = 1.4 ng/mL (conversion factor to SI unit, 3.18). Serum P concentrations per total eggs retrieved or per mature egg retrieved did not influence pregnancy outcome. Efficiency curves for serum P levels and P AUC did not demonstrate any differences in PR. At very high serum P (P > 2.0 ng/mL) samples size limits the ability of these data to rule out a negative effect.

CONCLUSION(S)

Serum P levels (and P AUC) commonly encountered during cycles of IVF-ET have no impact on pregnancy outcome.

Endometrial thickness is predictive of histologic endometrial maturation in women undergoing hormone replacement for ovum donation

OBJECTIVE

To determine if ultrasonographic endometrial pattern or thickness is predictive of histologic endometrial maturation in women undergoing hormone replacement for ovum donation.

DESIGN

Ultrasonographic endometrial thickness and pattern were determined and compared with histologic assessment of endometrial maturation.

PATIENTS

Forty-six women underwent 52 preparatory cycles for ovum donation. Transvaginal ultrasound (US) was performed after 14 days of E2 replacement and, after 12 days of P, an endometrial biopsy was performed. In 12 cycles, a continuous dose of 2 mg/d E2 was administered. In cycles with out-of-phase biopsies (dated earlier than day 24) and in the last 34 cycles, all women received an escalating dose of E2 before initiation of P. Additionally, the 46 women underwent 55 ETs with USs performed on cycle day 15.

RESULTS

Six women had abnormal biopsies in their first preparatory cycle on the continuous E2 protocol, which normalized with the escalating protocol. All other women had normal biopsies. Women with abnormal biopsies had significantly thinner endometrium (< or = 6 mm) but similar endometrial patterns compared with women with normal biopsies. In women having US in preparatory and transfer cycles, there were no differences in endometrial thickness or pattern between examinations.

CONCLUSIONS

Endometrial thickness > or = 7 mm in hormone replacement cycles predicts in phase endometrial histology and can replace the endometrial biopsy.

Efficacy of selection criteria for ovarian reserve screening using the clomiphene citrate challenge test in a tertiary fertility center population

OBJECTIVE

To examine selection criteria for ovarian reserve screening.

DESIGN

Retrospective study.

PATIENTS

Two hundred nineteen women underwent testing for ovarian reserve for woman's age > 35 years, any age with unexplained infertility, one ovary, or a poor response to hMG.

INTERVENTIONS

Clomiphene citrate challenge test.

MAIN OUTCOME MEASURES

Frequency of abnormal ovarian reserve screening, menstrual cycle parameters, response to hMG, and pregnancy outcome by screening criteria.

RESULTS

One hundred eighty-four (84.0%) women had a normal ovarian reserve screening test; 35 (16.0%) had an abnormal ovarian reserve screening test. Twenty-six had abnormal ovarian reserve screening when screened by age, 14 for unexplained infertility, 5 for poor response to hMG, and 6 for one ovary. Fifteen women with abnormal ovarian reserve screening had more than one indication for screening. For women attempting pregnancy (n = 182), 49 of 148 (33.1%) with normal ovarian reserve screening became pregnant compared with 2 of 34 (5.9%) with abnormal ovarian reserve screening. Within each screening category, women with abnormal ovarian reserve had menstrual cycle parameters associated with a short follicular phase, required more hMG, and responded poorly to hMG.

CONCLUSIONS

One of six women undergoing ovarian reserve screening had an abnormal test, which was associated a poor reproductive outcome. Age was the most important single criteria. Selected ovarian reserve screening is simple and inexpensive and should be offered to all fertility patients meeting the specific screening criteria listed above.

Intraobserver, interobserver variation of sperm critical morphology: comparison of examiner and computer-assisted analysis

OBJECTIVE

To examine intraobservational and interobservational variation in sperm critical morphology analysis between trained andrologists and a computer over the range of 0% to 15% normal forms.

DESIGN

Retrospective.

SETTING

Fertility center.

PATIENTS

Twenty-four semen specimen slides were read five times in a randomized, blinded fashion by two andrologists and a computerized semen analyzer. Twenty-five samples were analyzed using a different stain and a centrifugation step.

MAIN OUTCOME MEASURE

Sperm strict morphology.

RESULTS

Mean average intraobserver deviation of normal forms was small (1.3% to 2.7%). Intraobserver deviation did not differ between andrologists, but both differed from the computer. Interobserver deviation for percent normal forms was similar for andrologists and computer. Mean average deviations were small over the variation was independent of the initial percent normal forms. The computer frequently evaluated significantly fewer cells than the andrologists. Updated software increased the number of cells read by the computer requiring more time than the andrologist.

CONCLUSIONS

Trained andrologists and a computer determine sperm critical morphology similarly over the range of 0% to 15% normal forms. A single evaluation is highly predictive of multiple evaluations. Improvements in the speed of computer assessment are still necessary.

Human intermediate trophoblasts express chorionic gonadotropin/luteinizing hormone receptor gene

Human cyto- and synchtiotrophoblasts have recently been shown to contain functional hCG/LH receptors. The present study investigated whether human intermediate trophoblasts also contain these receptors. Six implantation sites from 4-8 wk of pregnancy were processed for in situ hybridization for hCG/LH receptors coupled with immunocytochemistry for human placental lactogen (hPL), an endocrine marker for intermediate trophoblasts. In addition, the sections were also double-immunostained for hCG/LH receptor and hPL proteins. The results showed that some but not all the intermediate trophoblasts contained hCG/LH receptors. The intermediate trophoblasts in endovascular locations contained more receptors than those in perivascular locations. Villus syncytiotrophoblasts contained the highest level of receptors, followed by intermediate trophoblasts in endovascular and perivascular locations and then villus cytotrophoblasts. These data, demonstrating the presence of hCG/LH receptors in intermediate trophoblasts, suggest a possible role for hCG in trophoblast invasion and maternal recognition of pregnancy.

Relationship between circulating human chorionic gonadotropin levels and premature luteinization in cycles of controlled ovarian hyperstimulation

OBJECTIVE

To determine if premature luteinization (serum P levels > 1.1 ng/mL on or before the day of hCG administration) during controlled ovarian hyperstimulation (COH) is associated with elevated levels of serum hCG.

SETTING

Tertiary fertility center.

DESIGN

Retrospective evaluation of ovum donors undergoing COH.

PATIENTS

Forty-four women underwent COH. Comparisons of serum hCG levels and hormonal and cycle characteristics were made between cycles with premature luteinization (group I) and without premature luteinization (group II).

RESULTS

Group I (16 women) were similar to women in group II in age, amount of hMG, and the ratio of FSH:hMG received. Both groups received hCG on similar days, but women in group I had higher peak E2 levels. Serum hCG levels increased and correlated with serum P levels in group I only and were higher on the day of hCG administration (group I 1.8 +/- 0.9 mIU/mL versus group II 1.2 +/- 0.45 mIU/mL; conversion factor to SI unit, 1.00). Peak E2 and LH levels, ampules of hMG and the FSH:LH ratio, and day of hCG administration did not correlate with hCG levels. Human chorionic gonadotropin exposure, as measured by area under the curve, was significantly higher in group I compared with group II.

CONCLUSION

Higher serum levels of hCG and integrated hCG exposure are found in COH cycles with premature luteinization compared with cycles without premature luteinization. Higher hCG levels may be due to decreased clearance of hCG from the circulation and/or the hCG content of hMG.

Evaluation of the reproductive performance of women with elevated day 10 progesterone levels during ovarian reserve screening

OBJECTIVES

To evaluate the relationship of elevated day 10 P levels (> or = 1.1 ng/mL, conversion factor to SI unit, 3.18) during ovarian reserve screening and reproductive performance.

DESIGN

Prospective screening with longitudinal follow-up.

INTERVENTIONS

One hundred seven women underwent ovarian reserve screening with a clomiphene citrate challenge test.

MAIN OUTCOME MEASURES

Serum FSH, LH, and E2 levels were determined on cycle day 3 and FSH, LH, and P levels were determined on day 10. A fertility evaluation was completed and a treatment plan was instituted.

RESULTS

Twenty-two of 107 (20.6%) women had day 10 P levels > or = 1.1 ng/mL. Women with elevated day 10 P levels were similar in age to women with normal day 10 P levels (< or = 0.9 ng/mL) but had significantly shorter menstrual cycles, higher day 3 and day 10 FSH levels, higher day 3 E2 levels, and higher day 10 LH levels than women with normal day 10 P levels. During ovarian hyperstimulation, women with elevated day 10 P levels required more ampules of hMG, had lower peak E2 levels, and had fewer mature follicles than women with a normal day 10 P level. Sixteen of 85 (18.8%) women with normal day 10 P levels became pregnant, but none of the 22 women with elevated day 10 P levels became pregnant. The incidence of diminished ovarian reserve was higher in women with elevated day 10 P levels (13/22; 59%) when compared with women with a normal day 10 P levels (9/85; 10.6%).

CONCLUSIONS

Elevated day 10 P levels (> or = 1.1 ng/mL) during ovarian reserve screening is associated with diminished ovarian reserve and correlates with menstrual cycle parameters associated with a short follicular phase and poor reproductive performance.

Embryo quality and pregnancy potential of fresh compared with frozen embryos--is freezing detrimental to high quality embryos?

To determine the effect of cryopreservation on embryo quality and the pregnancy potential of embryos, donated oocytes from the same donor (n = 24) were randomly allocated, with subsequent transfer to two or more different ovum recipients resulting in at least one fresh and one frozen embryo transfer cycle from the same cohort of oocytes. Endometrial receptivity was controlled in all ovum recipients, and male factor patients were excluded. The number of embryos transferred, mean embryo grade transferred, number of high quality embryos (grade < or = 2.5, grade 1 being best) transferred and embryo implantation and live birth rates are reported. Significantly more embryos (4.4 +/- 1.2 versus 3.3 +/- 1.2, P < 0.00003) of higher quality (1.9 +/- 0.5 versus 2.1 +/- 0.5, P < 0.013) and of a more advanced cell stage (3.0 +/- 0.6 versus 2.6 +/- 0.7, P < 0.019) were transferred fresh than after cryopreservation respectively. Implantation rates/embryo [19/151 (12.6%) and 9/111 (8.1%)] and live birth rates/transfer [11/42 (26.2%) and 6/45 (13.3%)], from fresh and frozen transfers respectively, were not significantly different despite the larger number of high quality embryos transferred fresh. Embryo cryopreservation adversely affects embryo quality, but does not have detrimental effects on the implantation or pregnancy potential of high quality embryos. Because of the loss of embryos during freeze-thawing during frozen embryo cycles, every effort should be made to attempt a fresh transfer.

Prognostic assessment of ovarian reserve

OBJECTIVE

To review the literature regarding diminished ovarian reserve, the screening techniques that are currently available, and their appropriate application in clinical practice.

DATA RESOURCES

Directed Medline searches.

RESULTS

Ovarian reserve screening identifies women with greatly diminished chances of achieving pregnancy. The screening techniques include the clomiphene citrate challenge test, basal day 3 FSH measurements, and the GnRH agonist stimulation test. All have been evaluated in assisted reproduction programs and the predictive values of an abnormal test for failing to conceive is very high. When abnormal, these tests allow physicians to counsel patients that their prognosis for conception is poor. Although the presence of a normal result does indicate better long-term chances for conception, an age-related decline in fecundity remains and patient age should still be considered when counseling patients with normal screening results. Clinicians are urged to validate the threshold values with the assay system used in their own laboratory before the application of these tests.

CONCLUSION

The literature consistently demonstrates the value of diminished ovarian reserve screening.

Global arrest of translation during invertebrate quiescence

Comparing the translational capacities of cell-free systems from aerobically developing embryos of the brine shrimp Artemia franciscana vs. quiescent embryos has revealed a global arrest of protein synthesis. Incorporation rates of [3H]leucine by lysates from 4-h anoxic embryos were 8% of those from aerobic (control) embryos, when assayed at the respective pH values measured for each treatment in vivo. Exposure of embryos to 4 h of aerobic acidosis (elevated CO2 in the presence of oxygen) suppressed protein synthesis to 3% of control values. These latter two experimental treatments promote developmental arrest of Artemia embryos and, concomitantly, cause acute declines in intracellular pH. When lysates from each treatment were assayed over a range of physiologically relevant pH values (pH 6.4-8.0), amino acid incorporation rates in lysates from quiescent embryos were consistently lower than values for the aerobic controls. Acute reversal of pH to alkaline values during the 6-min assays was not sufficient to return the incorporation rates of quiescent lysates to control values. Thus, a stable alteration in translational capacity of quiescent lysates is indicated. Addition of exogenous mRNA did not rescue the suppressed protein synthesis in quiescent lysates, which suggests that the acute blockage of amino acid incorporation is apparently not due to limitation in message. Thus, the results support a role for intracellular pH as an initial signaling event in translational control during quiescence yet, at the same time, indicate that a direct proton effect on the translational machinery is not the sole proximal agent for biosynthetic arrest in this primitive crustacean.

Comparison of leuprolide acetate and human chorionic gonadotropin for the induction of ovulation in clomiphene citrate-stimulated cycles

OBJECTIVE

To examine the relative efficacies of leuprolide acetate (LA) and hCG in inducing ovulation and a normal luteal phase during clomiphene citrate (CC)-stimulated superovulation cycles.

DESIGN

Prospective, randomized, blinded, and cross-controlled in consecutive cycles.

SETTING

Large military tertiary care center.

PATIENTS

Twenty-one ovulatory patients undergoing superovulation with CC and IUIs for the treatment of unexplained or male factor infertility.

INTERVENTIONS

Clomiphene citrate (100 mg/d) on cycle days 5 through 9 in both of the study cycles. Administration of 2 mg SC LA in one cycle and 10,000 IU IM hCG in another cycle for induction of the midcycle surge.

MAIN OUTCOME MEASURES

Serum LH, FSH, E2, and P levels every 12 hours for 36 hours after administration of either LA or hCG to characterize the midcycle hormonal dynamics. Luteal phase duration and serum P levels during the midluteal phase were used to estimate the adequacy of the luteal phase. Serial ultrasounds also were done to determine the incidence of luteinized unruptured follicle syndrome.

RESULTS

Serum FSH levels in the periovulatory interval were significantly higher after the administration of LA. There were no differences in the periovulatory E2 or P levels or the incidence of sonographic evidence of ovulation after administration of either LA or hCG. Although midluteal serum P levels were higher in the cycles in which hCG was administered, all 42 treatment cycles had adequate luteal phases as assessed by luteal phase duration and three midluteal P levels. Ongoing pregnancies occurred after both LA- and hCG-stimulated cycles.

CONCLUSION

Leuprolide acetate and hCG were equivalent in their abilities to induce ovulation. Further evaluation of the adequacy of the luteal phase and the ensuing pregnancy rates after LA induction of an endogenous gonadotropin surge are indicated.

Immunohistochemical localization of transforming growth factor-beta in human implantation sites

Transforming growth factor-beta (TGF beta), a protein known to antagonize many of the functions of the epidermal growth factor-receptor system, was localized immunohistochemically in unruptured ectopic pregnancies (EP) removed by salpingectomy (n = 8), uterine decidua from EP (n = 4), and decidua and trophoblast from electively terminated first trimester pregnancies (ETP; n = 8). Two rabbit polyclonal antisera that recognize both TGF beta 1 and beta 2 were used. Immunostaining for TGF beta was identified in all three forms of trophoblast, cytotrophoblasts, intermediate trophoblasts, and syncytiotrophoblasts, which were differentiated histologically and immunohistochemically. Moderate cytoplasmic immunostaining was found in villous cytotrophoblasts in both EP and ETP. Nonvillous (anchoring) cytotrophoblasts in these same tissues demonstrated moderate immunostaining adjacent to the villous and light immunostaining distal to the villous. In intermediate trophoblasts, moderate to intense immunostaining was seen in EP and ETP. Syncytiotrophoblasts demonstrated moderate cytoplasmic immunostaining in EP and ETP as well as moderate to intense staining of plasma membranes and microvilli. Nuclear staining was not evident in any form of trophoblast. TGF beta immunostaining was demonstrated in both glands and stroma of decidua from both EP and ETP; however, staining was more intense in decidua from ETP. With the known presence of TGF beta receptors and mRNA in placenta, these results suggest an autocrine/paracrine role for TGF beta regulation of endometrial-trophoblast function during human implantation.

Immunohistochemical localization of urokinase-type plasminogen activator and the plasminogen activator inhibitors 1 and 2 in early human implantation sites

OBJECTIVE

Our purpose was to immunolocalize urokinase-type plasminogen activator and the plasminogen activator inhibitors 1 and 2 in human implantation sites, with emphasis on the types of trophoblast expressing the plasminogen activator and the inhibitors.

STUDY DESIGN

Urokinase and the plasminogen activator inhibitors 1 and 2 were localized immunohistochemically in early human implantation sites in unruptured ectopic pregnancies from patients in an in vitro fertilization program.

RESULTS

Urokinase kinase and the plasminogen activator inhibitors 1 and 2 were localized in the cytoplasm of cytotrophoblasts and in the cytoplasm and plasma membranes of intermediate and syncytiotrophoblast. Greater staining was noted in nonvillous, relative to villous, cytotrophoblasts for urokinase and both inhibitors.

CONCLUSIONS

Urokinase-type plasminogen activator and the plasminogen activator inhibitors 1 and 2 were localized in all three forms of trophoblast at the maternal-fetal interface in early human implantation sites, particularly the differentiated and invasive forms of trophoblast. These results support a role for the plasminogen activator or inhibitors in the controlled invasion of the maternal decidua by the trophoblast during human implantation.

Age-related decline in female fertility is not due to diminished capacity of the uterus to sustain embryo implantation

OBJECTIVE

To evaluate the contribution of the uterus to age-related reproductive failure in women.

PATIENTS

Thirty-eight ovum donors (30.2 +/- 4.9 years [mean +/- SD]) donating oocytes throughout 102 ovum donations. Fifty-one cycles were documented in "younger" recipients (35.8 +/- 3.1 years) and 51 in "older" recipients (44.0 +/- 3.1 years). The study was prospectively designed; same-cohort oocytes obtained from one young donor during a specific cycle were evenly distributed between "young" and "old" ovum recipients. Use of oocytes from a single source and a unique ovulatory cohort provides strict control over oocyte quality. Uterine age is varied by design, according to the age of the recipient at the time of ET. The role of the aging uterus in the decline of female fertility can be thus isolated and scrutinized.

RESULTS

No significant (NS) difference in the number of ova received (7.9 +/- 3.4 versus 7.0 +/- 3.5), ova fertilized (4.4 +/- 1.5 versus 4.5 +/- 2.3), or embryos transferred (4.1 +/- 1.5 versus 4.1 +/- 1.6) was observed between the < 40 and > or = 40 recipient age groups. A total of 23 pregnancies occurred among the 102 ETs (22.6%). Eleven clinical pregnancies (21.6%) resulting in 10 deliveries were observed in the < 40 recipient age group, and 12 clinical pregnancies (23.5%) leading to 10 deliveries occurred in the > or = 40 recipient age group (NS). The pregnancy loss rates were 9.1% (1 of 11) and 16.7% (2 of 12) for the two recipient age groups, respectively, (NS).

CONCLUSION

The capacity to conceive and to gestate a conception to term when oocyte quality is controlled appears to be independent of uterine aging through the fifth decade of life.

Premature luteinization in controlled ovarian hyperstimulation has no adverse effect on oocyte and embryo quality

OBJECTIVE

To determine if premature luteinization has an adverse effect on oocyte and, hence, embryo quality.

DESIGN

Retrospective evaluation of anonymous ovum donors/oocyte recipients.

SETTING

A large oocyte donation program.

PATIENTS, PARTICIPANTS

Sixty-eight women undergoing controlled ovarian hyperstimulation (COH) as ovum donors were matched to 68 women with ovarian failure as ovum recipients who had endometrial maturation exogenously controlled by an identical hormone replacement protocol.

INTERVENTIONS

Serum was collected for E2 and P in donors and recipients.

MAIN OUTCOME MEASURES

The incidence of premature luteinization was determined in donors. Cycle characteristics were compared between donors with and without premature luteinization, with emphasis on oocyte and embryo quality. Implantation rates per embryo and delivery rates per transfer were measured in recipients.

RESULTS

Twenty-one (31%) of the donors demonstrated premature luteinization. Serum P was higher on day before hCG, day of hCG, and day after hCG in women demonstrating premature luteinization. However, there were no differences between donor cycles with or without premature luteinization as determined by donor age, ampules of gonadotropins used, day of hCG administration, peak E2, total number of oocytes, and number of mature oocytes retrieved. Ovum recipients were of similar age and had similar E2 exposure (area under the E2 curve) before P administration. Similar fertilization rates, incidence of polyspermia, number of embryos transferred of similar embryo grade, and similar implantation rates and deliveries per transfer were observed in women receiving oocytes from donors with and without premature luteinization, respectively.

CONCLUSIONS

Similar oocyte quality, fertilization, and polyspermia rates, embryo quality, implantation, and delivery rates suggest that any negative impact of premature luteinization on pregnancy rates in COH cycles from young women is not due to an adverse effect of PL on oocyte and hence embryo quality, but rather on the endometrial environment.

A prospective evaluation of clomiphene citrate challenge test screening of the general infertility population

OBJECTIVE

To assess the results of screening an unselected general infertility population for diminished ovarian reserve with the clomiphene citrate challenge test.

METHODS

Two hundred thirty-six couples were followed prospectively and studied for the relationship between clomiphene citrate challenge test screening and final diagnoses and long-term fertility rates.

RESULTS

Abnormal clomiphene citrate challenge tests were found in two of 61 (3%) of the patients younger than 30 years, in five of 72 (7%) aged 30-34, in seven of 68 (10%) aged 35-39, and in nine of 35 (26%) aged 40 or older. An abnormal test predicted lower pregnancy rates; conception occurred in 92 of 213 (43%) of patients with normal results, but only two of 23 (9%) of patients with abnormal results (P < .004). Unexplained infertility (not considering the clomiphene citrate challenge test) was a common finding in patients with abnormal clomiphene citrate challenge test results (12 of 23). This incidence was significantly higher than that in patients with normal clomiphene citrate challenge test results (20 of 213) (P < .001).

CONCLUSIONS

Approximately 10% of the patients in the general infertility population had abnormal clomiphene citrate challenge tests. The incidence of abnormal results increases with age beginning in the early 30s, occurs with a higher frequency in patients who would otherwise be diagnosed with unexplained infertility, and prognosticates decreased long-term pregnancy rates.

The duration of leuprolide acetate administration prior to ovulation induction does not impact ovarian responsiveness to exogenous gonadotropins

OBJECTIVE

To evaluate the possible impact that the duration of GnRH agonist (GnRH-a) suppression has on subsequent ovarian responsiveness to exogenous gonadotropins.

DESIGN

Prospective evaluation of the relationship between the duration of GnRH-a and multiple parameters of ovarian responsiveness.

SETTING

Assisted reproduction program in a large military tertiary care center.

PATIENTS

One hundred sixty-five women being pretreated with leuprolide acetate (LA) before ovulation induction with exogenous gonadotropins.

INTERVENTIONS

Variable duration of LA administration before stimulation.

MAIN OUTCOME MEASURES

Outcome measures include duration of stimulation, days until doubling of basal E2, number of ampules of exogenous gonadotropins, peak E2, number of mature follicles, and number of mature oocytes.

RESULTS

The duration of LA pretreatment had no effect on any of the parameters of ovarian responsiveness analyzed.

CONCLUSION

Once complete suppression of gonadal function is attained, the duration of GnRH-a suppression has no impact on subsequent ovarian responsiveness to exogenous gonadotropins.

Evaluation of the significance of the estradiol response during the clomiphene citrate challenge test

OBJECTIVE

To evaluate the relationship between the E2 response during the clomiphene citrate (CC) challenge test and ovarian responsiveness to exogenous gonadotropins.

DESIGN

Performance of a CC challenge test followed by ovulation induction with exogenous gonadotropins as part of participation in an assisted reproduction program.

SETTING

Assisted reproduction program in a large military tertiary care center.

PATIENTS

Two hundred forty-seven women between the ages of 24 and 39 years with normal CC challenge tests within 1 year of their assisted reproduction cycle.

INTERVENTIONS

Performance of CC challenge tests and ovulation induction with exogenous gonadotropins as a component of an assisted reproduction cycle.

MAIN OUTCOME MEASURES

Correlation of the E2 response during the CC challenge test and peak E2, the duration of stimulation, number of ampules of exogenous gonadotropins, number of mature follicles, number of mature oocytes recovered, and fertilization and pregnancy rates in an assisted reproduction program.

RESULTS

No correlation exists between the E2 response during the CC challenge test and any of the parameters evaluated.

CONCLUSION

Monitoring of the E2 response during the CC challenge test did not predict ovarian responsiveness or pregnancy rates in patients participating in an assisted reproduction program and one may choose not to include it in routine testing.

Amniotic fluid epidermal growth factor concentrations. The effect of intra-amniotic thyroxine for acceleration of fetal maturation

Intra-amniotic thyroxine (200-500 ug) was administered weekly to 29 women in the third trimester to enhance fetal maturation. Lecithin-sphingomyelin ratio (L/S) and epidermal growth factor (EGF) were measured in amniotic fluid (AF) before (n = 58) and after (n = 92) administration of thyroxine. The AF L/S ratio and EGF concentration increased linearly with increasing gestational age both before (r = 0.76, p < 0.0001; r = 0.41, p < 0.001, respectively) and after (r = 0.62, p < 0.0001; r = 0.43, p < 0.001 respectively) initiation of thyroxine treatment. The slopes of gestational age vs L/S (0.07) and EGF (0.004) before T4 increased significantly after initiation of T4 therapy (L/S:0.23, p < 0.001; EGF:0.015, p < 0.01, respectively). L/S ratios correlated with AF EGF levels before (r = 0.77, p < 0.001) and after (r = 0.63, p < 0.001) initiation of T4 therapy. These results demonstrate that intra-amniotic thyroxine accelerates not only the progression of the amniotic fluid L/S ratio, but the appearance of EGF.

Premature luteinization is not eliminated by pituitary desensitization with leuprolide acetate in women undergoing gonadotrophin stimulation who demonstrated premature luteinization in a prior gonadotrophin-only cycle

A total of 40 women who demonstrated premature luteinization (serum progesterone > or = 3.5 nmol/l (1.1 ng/ml) on or before the day of human chorionic gonadotrophin (HCG) administration) during ovarian stimulation with human menopausal gonadotrophins (HMG) were restimulated in 46 subsequent cycles after pituitary desensitization with the gonadotrophin-releasing hormone agonist (GnRHa, 1 mg), leuprolide acetate. Five women were treated with a double dose of agonist (2 mg) when premature luteinization was determined on the single dose protocol. In HMG-only cycles, a frank luteinizing hormone (LH) surge was detected in 30 cycles; 15 cycles were cancelled because of premature ovulation. In agonist cycles there were no cancellations, although 25 cycles demonstrated premature luteinization and in six cycles a frank LH surge was detected. Doubling the dose of the agonist did not prevent premature luteinization. Agonist cycles with and without premature luteinization did not differ in any in-vitro fertilization (IVF) outcome parameters (ampoules of gonadotrophins, day of HCG administration, peak oestradiol concentration, number of oocytes retrieved, fertilized, transferred or cryopreserved). We conclude that in patients who demonstrate premature luteinization in a gonadotrophin-only cycle, pituitary desensitization may not completely eliminate subtle luteinization or a frank LH surge.

Transforming growth factor-alpha in human implantation trophoblast: immunohistochemical evidence for autocrine/paracrine function

Epidermal growth factor (EGF) and its receptor (EGF-R) have been demonstrated in human implantation sites. Transforming growth factor-alpha (TGF-alpha), a protein with extensive sequence homology to EGF and with equal affinity for the EGF-R, was localized immunohistochemically in early intrauterine and ectopic pregnancies. Within the same experiments, TGF-alpha immunostaining was more intense in ectopic than intrauterine pregnancies. In both groups, TGF-alpha immunostaining was moderate to intense in the syncytiotrophoblast (ST), light to moderate in the cytotrophoblast (CT), and moderate to intense in intermediate trophoblast (IT). In ST, TGF-alpha immunostaining localized to the cytoplasm and plasma membranes, including microvilli. No nuclear associated TGF-alpha was noted in ST. In CT, differential TGF-alpha immunostaining was noted between the villous and nonvillous CT. Villous CT demonstrated light to absent cytoplasmic TGF-alpha immunostaining with intense nuclear staining. In contrast, nonvillous CT revealed moderate to intense cytoplasmic staining without demonstrable nuclear staining. These results demonstrate the presence of immunoreactive TGF-alpha in all forms of trophoblast. The known presence of the EGF-R suggests an autocrine/paracrine role for TGF-alpha during human implantation.

Immunohistochemical localization of transforming growth factor-alpha in human endometrium, decidua, and trophoblast

Transforming growth factor-alpha (TGF-alpha) was localized immunohistochemically in human proliferative and secretory endometrium, decidua, and trophoblast from first, second, and third trimester pregnancies. In proliferative endometrium, TGF-alpha immunostaining was moderate to intense and localized predominantly to stromal cells, whereas glandular staining was absent to light. After ovulation, TGF-alpha staining was light within the stroma, but moderate to intense around spiral arterioles. Moderate to intense staining was also detected in glandular and surface epithelium in secretory endometrium, with no staining noted in subnuclear vacuoles. In hypersecretory endometrium, staining was predominantly epithelial. In decidua, TGF-alpha was detected in intermediate trophoblast and on the surface epithelium. In first trimester trophoblast, TGF-alpha was detected in both cytotrophoblast (CT) and syncytiotrophoblast. Cytoplasmic staining was light in CT and moderate to intense in ST, with particular staining of plasma membranes. Intense TGF-alpha staining of nuclear membranes in CT was noted. TGF-alpha staining was light to absent in second and absent in third trimester trophoblast. This study demonstrates immunoreactive TGF-alpha in tissues known to be responsive to epidermal growth factor, and also demonstrates the presence of immunoreactive TGF-alpha associated with nuclear membranes. Thus, TGF-alpha may play an autocrine/paracrine role in endometrial development and trophoblast function.

Extension of enzyme half-life during quiescence in Artemia embryos

Encysted gastrulae of Artemia franciscana are known to enter a reversible state of quiescence in which biosynthetic and catabolic pathways are markedly suppressed. Given that these embryos can survive months of anoxia, we investigated their ability to extend the half-life of cytochrome-c oxidase (COX), a key metabolic enzyme, during anoxia. We calculate that the half-life of COX is extended to 101 days under anoxia, an estimated 77-fold increase compared with aerobic values. During conditions of aerobic acidosis, the half-life of COX was extended sevenfold to a value of 9.7 days. We propose that the extended lifetimes of COX in both cases may be due to suppressed mitochondrial proteolysis under depressed pH. The shorter enzyme half-life observed under the latter condition may be due to the availability of ATP for degradative processes during aerobic acidosis. We also suggest that the presence of oxygen in aerobic acidosis may lead to increased rates of protein damage due to autooxidation.

Epidermal growth factor and its receptor in human implantation trophoblast: immunohistochemical evidence for autocrine/paracrine function

Epidermal growth factor (EGF) and its receptor (EGF-R) were immunohistochemically localized in trophoblast during human implantation from intrauterine and ectopic pregnancies. EGF immunostaining was absent to light in the cytotrophoblast (CT), light to moderate in intermediate trophoblast (IT), and intense in the syncytiotrophoblast (ST). In ST, EGF immunostaining was found mostly in the cytoplasm; however, staining of the plasma membrane was also noted. Immunostaining for the EGF-R was absent to light in the CT and moderate to intense in the IT. Immunostaining for the EGF-R was intense in the ST, with moderate staining in the cytoplasm and intense staining in the plasma membrane. Staining was most intense on the microvilli of the ST. Additionally, EGF-R immunostaining could be demonstrated on nuclear membranes. The increase in the intensity of the immunostaining for both EGF and EGF-R noted in CT, IT, and ST suggests a differentiated expression of this receptor-ligand system in human trophoblast and provides evidence for an autocrine/paracrine role for EGF in trophoblast function. The presence of this receptor-ligand system during early human implantation strongly supports a role for EGF and the EGF-R in embryo-uterine signalling and the implantation process.

Comparison of messenger RNA pools in active and dormant Artemia franciscana embryos: evidence for translational control

In response to environmental anoxia, embryos of the brine shrimp Artemia franciscana enter a dormant state during which energy metabolism and development are arrested. The intracellular acidification that correlates with this transition into anaerobic dormancy has been linked to the inhibition of protein synthesis in quiescent embryos. In this study, we have addressed the level of control at which a mechanism mediated by intracellular pH might operate to arrest protein synthesis. Two independent lines of evidence suggest that there is an element of translational control when protein synthesis is arrested in dormant embryos. First, as determined by in vitro translation techniques, there were no significant quantitative differences in mRNA pools in dormant as compared to actively developing embryos. In addition, fluorography of the translation products showed that there are no large qualitative changes in mRNA species when embryos become dormant. These data suggest that there was no net degradation of mRNA pools in dormant embryos and that protein synthesis may therefore be controlled more strongly at translation than at transcription. Second, polysome profile studies showed that dormant embryos possess reduced levels of polysomes relative to those found in cells or active embryos. The disaggregation of polysomes is an indication that the initiation step in protein synthesis is disrupted and is further evidence that the mechanism involved in protein synthesis arrest in dormant Artemia involves translational control.

Common technical errors in hysterosalpingography

Hysterosalpingograms from 100 consecutive patients referred for in vitro fertilization were reviewed to evaluate the adequacy of visualization of the uterine cavity. In 17 cases the hysterosalpingogram failed to demonstrate the entire uterine cavity. The most common reason for failure was an axial view of the uterus secondary to inadequate traction on the cervix in 82% (14/17) of the cases, followed by obstructed visualization of the lower uterine cavity and endocervical canal by the delivery catheter bulb in 21% (3/17). A speculum left in the vagina obscured visualization of the endocervical canal in 21% (3/17) of the cases. There were no significant differences in the mean number of radiographic exposures between the adequate and inadequate groups (4.7 vs. 5.9). This study suggests that failing (1) to remove the speculum before injecting contrast, (2) to evaluate the lower uterus and endocervix when using an intrauterine catheter, or (3) to place adequate traction on the cervix, may result in inadequate visualization of the uterine cavity and a need to repeat the study.

Immunohistochemical localization of epidermal growth factor in human endometrium, decidua, and placenta

Epidermal growth factor (EGF) was localized immunohistochemically in human endometrium throughout the menstrual cycle, in gestational decidua, and in first, second, and third trimester placenta using two polyclonal antihuman EGF antisera. In proliferative phase endometrium, moderate EGF immunostaining was localized to the cytoplasm of stromal cells, with absent to light staining of glandular epithelium. In the secretory phase, EGF immunostaining was intense and localized predominantly to stromal cells, particularly those surrounding spiral arterioles. There was absent to light EGF immunostaining within epithelial cells; however, there was no staining of subnuclear vacuoles. In addition, the luminal surface of exhausted secretory glands demonstrated moderate EGF immunostaining. In gestational decidua, EGF immunostaining was light to moderate in the stromal cells, but was intense in the surface epithelium. Intense EGF immunostaining was noted in the syncytiotrophoblast layer of first trimester placenta, with light to moderate staining of the cytotrophoblast. Immunostaining decreased in both layers of trophoblast as pregnancy progressed. Immunoreactive EGF is found in endometrium and trophoblast and may have a physiological role in endometrial and placental function.

Immunohistochemical localization of gonadotropin-releasing hormone during implantation in the New Zealand white rabbit

Gonadotropin-releasing hormone was localized immunohistochemically during implantation (gestational days 6 to 14) in the New Zealand White rabbit. During early implantation (days 7 to 9), intense gonadotropin-releasing hormone immunostaining was localized predominantly to the cytoplasm of the nonknob cytotrophoblast with light to moderate staining in the cytoplasm of the syncytiotrophoblast (knob). In later gestation, light to moderate staining of the cytoplasm of the trophoblast at the true placental site was detected. No appreciable change in staining was noted after day 10. Fetal membranes, identified after day 10, showed intense and unchanging immunostaining for gonadotropin-releasing hormone. Obplacental giant cells showed light to moderate nuclear and cytoplasmic gonadotropin-releasing hormone immunostaining. Light to moderate gonadotropin-releasing hormone immunostaining was also noted in the cytoplasm of uterine epithelium and glands. We conclude that immunoreactive gonadotropin-releasing hormone is present in the cytotrophoblast at the time of the earliest embryo-uterine interactions and may play a significant role in implantation and embryo survival.

An insight into early reproductive processes through the in vivo model of ovum donation

To gain insight into early reproductive processes we have prospectively designed ovum donation protocols to elucidate several phenomena relating to embryo implantation and pregnancy sustenance. Artificial endometrial cycles with variable follicular phases were induced in 60 recipients by sequential estrogen and progesterone. A total of 964 oocytes were retrieved throughout 43 ovum donation attempts, for an average of 22.4 (range, 16-41) eggs/retrieval. The overall delivery rate per egg retrieval (donors and recipients combined) was 72.1% (31 of 43). The shortest estrogen stimulation (short follicular phase) resulting in ongoing pregnancies was 5 days in duration, while the longest (long follicular phase) was 35 days in duration before progesterone initiation. Utilization of variable length follicular phases, artificially extended the stage of endometrial receptivity to over 4 weeks. To assess the window of implantation, same age embryos were transferred onto endometrium of different maturational stages. Pregnancies were documented with embryo transfers between luteal day 1 (day 15) to luteal day 6 (day 20), extending the window of implantation in the human to at least 6 consecutive days. To evaluate the relative contribution of oocyte quality and endometrial receptivity to pregnancy outcome, common source ova were transferred onto endometrium with variable hormonal exposure. Despite the drastically different follicular phase estradiol levels and periods of exposure, similar delivery rates were attained in donor cycles (29.4%) and recipient cycles during short follicular phases (29.6%). Slightly higher delivery rates (39.4%) were observed with long follicular phases. The comparable pregnancy rates in donors and recipients are attributed to the common source oocytes regardless of endometrial stimulation.

Effects of leuprolide acetate on follicular fluid hormone composition at oocyte retrieval for in vitro fertilization

The follicular fluid (FF) in 91 follicles from 17 women treated with leuprolide acetate (LA) before stimulation with gonadotropins for in vitro fertilization were analyzed for estradiol (E2), progesterone (P), androstenedione, prolactin, and human chorionic gonadotropin (hCG) and compared with the concentrations in 128 follicles from 31 women treated with gonadotropins alone. The FF E2 concentration in LA-treated patients was significantly lower than in non-LA patients for all oocyte maturational stages. Follicles containing metaphase II oocytes had significantly lower concentrations of P and hCG in LA-treated patients. These differences persisted when analysis was limited to follicles whose oocytes fertilized normally. These data indicate that in the presence of LA, normal oocyte maturation can occur despite lower intrafollicular concentrations of E2 and P.

Immunoreactive epidermal growth factor concentrations in follicular fluid obtained from in vitro fertilization

Immunoreactive epidermal growth factor (EGF) was measured in follicular fluid (FF) obtained at the time of oocyte retrieval for in vitro fertilization from cycles with (91 follicles) and without (128 follicles) the gonadotropin-releasing hormone agonist leuprolide acetate (LA). Follicular fluid immunoreactive EGF levels in the non-LA cycles correlated with androstenedione but not estradiol or progesterone levels from follicles with prophase I oocytes or from all follicles taken together, but not from metaphase I or metaphase II oocyte containing follicles alone. In non-LA cycles, FF immunoreactive EGF levels were lower in follicles that contained metaphase I or II oocytes than prophase I oocytes. Additionally, FF immunoreactive EGF levels were lower in follicles containing metaphase I or II oocytes from non-LA than LA cycles. We conclude that immunoreactive EGF is present in FF. Leuprolide acetate may affect FF immunoreactive EGF levels.

Intercycle variability of day 3 follicle-stimulating hormone levels and its effect on stimulation quality in in vitro fertilization

Prior studies have demonstrated that gonadotropin stimulation quality and pregnancy rates are better in in vitro fertilization (IVF) patients with low basal cycle day 3 follicle-stimulating hormone (FSH) levels. The records of 81 patients who had undergone three or more IVF attempts during a 2-year period were studied to determine the degree and potential impact of intercycle variability in basal FSH concentrations. The mean of the individual standard deviations for all 81 patients was 4.2 +/- 0.4 mIU/mL. However, the patients with a mean basal FSH of less than 15 mIU/mL had a mean deviation of only 2.6 +/- 0.2 mIU/mL, whereas those with a mean basal FSH of greater than or equal to 15 mIU/mL had a mean deviation of 7.3 +/- 0.7 mIU/mL. Intercycle variability in basal FSH values did not predict changes in ovarian response to gonadotropin stimulation and thus may not be used to select an optimal cycle in which to stimulate an individual patient. Furthermore, patients with large intercycle variation responded poorly to gonadotropin stimulation independent of their basal FSH concentration. This information allows more precise counseling of patients regarding their appropriateness for assisted reproduction.

Arrest of cytochrome-c oxidase synthesis coordinated with catabolic arrest in dormant Artemia embryos

We have examined cytochrome-c oxidase (COX) biosynthesis in brine shrimp (Artemia franciscana) embryos during preemergence development (PED), as well as its inhibition under anaerobic dormancy, to determine whether transitions in intracellular pH (pHi) have a regulatory influence on anabolic processes. Under control aerobic conditions (embryo pHi greater than or equal to 7.9), incorporation of radiolabeled amino acids shows that substantial biosynthesis of COX occurs during 12 h of PED (500% increase when corrected for enzyme turnover). This anabolic process is blocked under anoxia, a condition known to foster intracellular acidification (pHi less than or equal to 6.8). The arrest of COX synthesis is quantitatively identical when embryos are incubated aerobically during artifical acidification with CO2 (pHi = 6.8). The data suggest that pHi, directly or indirectly, is a regulator of protein synthesis in Artemia embryos during anaerobic dormancy. Previous work has established a fundamental role for pHi in the arrest of carbohydrate catabolism under anoxia. Thus there appears to be a coordinated suppression of energy-producing and energy-utilizing events as Artemia embryos enter quiescence that involves pHi as the common intracellular signal.

Gonadotropin stimulation for in vitro fertilization and embryo transfer in insulin-dependent diabetics: follicular response, oocyte quality, embryo development, and follicular environment

Two IDD patients were stimulated with gonadotropins for IVF and ET. Both patients had high E2 response and greater than or equal to 5 preovulatory oocytes retrieved, normal fertilization and cleavage rates, and transfer; neither conceived. Follicular fluid showed levels of E2, P, A, hCG, and PRL similar to non-IDD. Epidermal growth factor could not be detected in FF. Insulin-dependent diabetes patients can undergo gonadotropin stimulation for IVF with customary responses. Their follicular milieu resembles that of non-IDD patients except for a lack of EGF.