Journal of the Society for Gynecologic Investigation最新文献

Objective: Ethanol exposure during pregnancy may result in fetal alcohol syndrome (FAS). The mechanism by which this occurs is unknown. Recent studies in several organ systems, including the placenta, suggest that oxidative stress is involved. In this study we investigated the presence and levels of three oxidative stress markers in placental villous tissue exposed to ethanol.

Methods: Villous tissues from normal placentas were perfused with Dulbeco's modified Eagle's medium (DMEM) with HEPES buffer, sodium bicarbonate, and glucose at pH 7.4. After stabilization, 100 mM ethanol was added to the perfusate. After 2 hours of perfusion, the tissue was removed, fixed and stained for nitrotyrosine, 4-hydroxy-2-nonenal (4HNE) and 8-hydroxyguanosine (8-OHDG). Staining within the trophoblasts was quantified with densitometry.

Results: Nitrotyrosine and 4HNE immunostaining was seen in the trophoblasts. 4HNE was also seen in the stroma. In contrast, 8-OHDG was seen only in the stroma and endothelial cells in the fetal circulation. Ethanol exposure significantly increased nitrotyrosine levels in the trophoblasts beyond levels in the control tissue. Nitrotyrosine and 8-OHDG levels were also increased in stroma.

Conclusion: Within the placental villi, markers of oxidative stress are present in the trophoblasts and stroma after a short period of ethanol exposure. There is an increase in oxidative stress, primarily involving the nitric oxide pathway, in the trophoblasts as well as DNA damage in the stroma. Lipid peroxidation is not acutely changed in our 2-hour exposure window.

Objective: Epidemiologic, pathophysiologic, and genetic data suggest a close link between gestational diabetes mellitus (GDM) and type 2 diabetes. Previous studies yielded controversial results on the impact of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1) gene variations on the development of type 2 diabetes mellitus. Therefore, we examined two common single nucleotide polymorphisms (SNP) of this gene in women with GDM.

Methods: We assessed a total of 875 women by oral glucose tolerance testing (OGTT). Two hundred women of this population, 100 patients with an abnormal OGTT and 100 normal controls, were randomly selected. DNA samples isolated from the blood of the control and study groups were analyzed with respect to the SNP Gly482Ser and Thr394Thr of the PGC-1 gene using polymerase chain reaction (PCR) amplification and restriction analysis. Furthermore, a potential interaction between the Gly482Ser and the Thr394Thr variant on the risk of GDM was investigated.

Results: Women with GDM were significantly older (32.2 +/-5.5 years vs 29.7 +/- 6.1 years; P = .005), had higher body mass indices (BMI; 28.0 +/- 7.1 kg/m2 vs 25.0 +/- 5.7 kg/m2; P = .002) and displayed higher hemoglobin A1c (HbA1c) values (5.6 +/- 0.9 vs 4.9 +/- 0.5; P <.001). There was no significant difference between the allele distribution of the two polymorphisms in women with and without GDM. No significant associations between the two polymorphisms and BMI or OGTT values were observed. When the different haplotype combinations of the two loci were analyzed for the risk of GDM, no significant association could be found.

Conclusion: Based on our data, the Gly482Ser and the Thr394Thr polymorphisms of the PGC-1 gene are not associated with the development of GDM.

Objective: Intrauterine infection has been linked to brain injury in human infants, although the mechanisms are not fully understood. We recently showed that repeated acute exposure of preterm fetal sheep to bacterial endotoxin (lipopolysaccharide [LPS]) results in fetal hypoxemia, hypotension, increased systemic proinflammatory cytokines, and brain damage, including white matter injury. However, it is not clear whether this injury is caused by reduced cerebral oxygen delivery or inflammatory pathways independent of hypoxia. The aim of the present study was to determine the effects on the fetal brain and placenta of a chronic intrauterine inflammatory state, induced by LPS infusion into the fetal circulation, a model that did not cause hypoxia.

Methods: At 0.65 of term, eight catheterized fetal sheep received intravenous infusions of LPS (5 to 15 mug) over 5 days; control fetuses received saline. Fetal physiologic responses were monitored throughout the infusion. Fetal brain and placental tissues were examined histologically 6 days after the conclusion of the infusion.

Results: LPS infusions did not result in physiologically significant alterations to fetal blood gases or mean arterial pressure; however, plasma proinflammatory cytokine levels were elevated. Following LPS exposure there was no difference in fetal body or brain weights (P >.05); placental weight was reduced (P <.05), consistent with reduced placentome cross-sectional area (P <.05). In the cerebral hemispheres subcortical white matter injury was present in six LPS-exposed fetuses and included axonal damage, microgliosis, oligodendrocyte injury, and increased beta amyloid precursor protein (beta-APP) expression.

Conclusions: Chronic, systemic exposure of the fetus to LPS resulted in fetal brain damage in the absence of hypoxemia or hypotension, although the resulting injury was less severe than following repeated acute exposure.

Objective: The objective of this investigation was to report the pharmacokinetic properties of misoprostol administered intravaginally to women at term via a controlled-release hydrogel polymer insert.

Methods: This open-label, dose escalation trial consisted of 31 nulliparous women at term who were treated intravaginally in cohorts of six with inserts containing reservoirs from 25 through 300 microg (7 at 200 microg) of misoprostol. Inserts remained intravaginally until the patient went into labor, developed adverse events, or completed 24 hours of treatment. Complete data about residual drug in the inserts and plasma concentrations of misoprostol acid were gathered for 27 and 25 patients, respectively.

Results: Misoprostol was released at a constant rate (5.1% total dose per hour) with the amount absorbed being directly proportional to the dose reservoir. For the 25-, 50-, 100-, 200-, and 300-microg reservoir doses, the maximum median plasma concentrations were 6.4, 11.3, 21.7, 40.8, and 74.2 pg/mL, respectively, and the area under the curve until drug removal was 39, 117, 223, 269, and 477 pg x h/mL. Regardless of dose, the peak plasma concentration occurred at approximately 7 hours after insertion and the elimination half-life of the misoprostol acid was 0.55 hours (95% confidence interval, 0.36 to 1.32 hours).

Conclusions: Misoprostol is released from the vaginal insert in a controlled manner and is eliminated rapidly after removal. Pharmacokinetic parameters are proportional to the reservoir dose.

Objectives: Uterine leiomyomas (ULMs) are estrogen-dependent tumors that are more common in African American women. The etiology for such ethnic disparity is currently unknown. Catechol-O-methyltransferase (COMT) is an essential enzyme in estrogen metabolism. In the current study, we investigated the association of the functional COMT Val158Met polymorphism with ULM in different ethnic groups. We also studied the biologic role of COMT in tumor formation in human and rat leiomyoma cell lines and the potential therapeutic utility of COMT inhibitors.

Methods: The genotype frequencies of the functional COMT Val158Met polymorphism among participants with (186 women) or without (142 women) ULMs were compared, as was the differential ethnic distribution of that polymorphism using polymerase chain reaction (PCR) and restriction-fragment linkage polymorphism. Proliferation, Western blot, and reporter transactivation analyses were applied to myometrial and leiomyoma cells representative of different COMT genotypes.

Results: Women with the high-activity COMT Val/Val genotype are 2.5 times more likely to develop ULMs than women with other genotypes (confidence interval, 1.017 to 6.151; P <.001). The prevalence of this genotype was significantly higher in African American women (47%) compared with white (19%) or Hispanic (30%) women (P = .003). Myometrial cell lines expressing the Val/Val genotype exhibited significantly enhanced responses to estrogen in proliferation and in estrogen-responsive element reporter assays. COMT-specific inhibitors reversed such a response and induced apoptosis. Myometrial specimens from Val/Val women demonstrated distinct estrogen-regulated gene expression that was consistent with enhanced proliferation and decreased apoptosis.

Conclusions: The high-activity COMT Val/Val genotype is associated with increased risk of ULM. Our results provide a possible explanation for the higher prevalence of ULMs among African American women and offer a potential new target for nonsurgical treatment using COMT inhibitors.

Objectives: The region of fetal membranes overlying the cervix, known as the zone of altered morphology (ZAM), is considered to be the principle site of membrane inflammatory activity and extracellular matrix remodelling. We wished to quantify the relative contribution of each area of fetal membranes to the inflammatory process of parturition. Specifically, we aimed to quantify and compare (1) leukocyte densities in three regions of fetal membranes and decidua before and during spontaneous labor at term, and (2) mRNA expression of interleukin (IL)-1beta, IL-6, IL-8, cyclo-oxygenase type 1 (COX-1), and COX-2 in three regions of fetal membranes and decidua before and during spontaneous labor at term.

Methods: Biopsies of fetal membranes and decidua were obtained from pregnant women delivered by cesarean section at term both before and during spontaneous labor (n = 8 both groups). Fetal membranes were sampled from three areas, the ZAM, midzone (MZ), and periplacental (PP) regions. Leukocytes were identified by immunohistochemistry and their density quantified. Inflammatory mediator expression was quantified using TaqMan technology (Applied Biosystems, Foster City, CA).

Results: There was a significantly greater density of leukocytes in (1) the PP region of membranes compared with the ZAM, and (2) the decidua compared with amnion, amniotic connective tissue, and chorion. IL-1beta, IL-6, and IL-8 mRNA expression was significantly greater in all regions following spontaneous labor compared with nonlaboring tissues. There were no regional differences in cytokine expression within the fetal membranes. Choriodecidua expressed significantly more IL-1beta mRNA than amnion. Amnion expressed more COX-2 mRNA than choriodecidua.

Conclusions: All regions of fetal membranes and decidua contribute to the inflammatory process of human parturition; however, their relative contributions differ in magnitude. Although the ZAM may be specifically important for membrane rupture, it does not appear to play a key or exclusive role in the other inflammatory processes of parturition. When studying fetal membranes, it is relevant to identify and define the area sampled for consistency and comparison with other studies.

Objective: Increasing evidence suggests that hyperinsulinemia plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). However, the timing for the onset of hyperinsulinemia is not clear. The objective of this study was to examine the effect of peripubertal hyperinsulinemia on the maturing female reproductive axis.

Methods: Hyperinsulinemia was induced in 28-day-old peripubertal female rats by infusing insulin (0.04 IU/d) via subcutaneously implanted Alzet minipumps (Model #2004; Durect Corp, Cupertino, CA; constant flow rate 0.25 muL/h) for 4 weeks. Control animals were administered normal saline. Estrus cyclicity was monitored regularly. Upon termination of the experimental period, the animals were killed, trunk blood and pituitaries were collected for hormone assays, and ovaries were collected for histological and immunocytochemical studies.

Results: In contrast to the control animals, hyperinsulinemic animals had (1) erratic estrus cycles, with prolonged (2 to 3 days) metestrus-diestrus or diestrus-proestrus stages; (2) significantly (P <.05) decreased levels of serum progesterone, and significantly (P <.05) increased levels of serum testosterone and dehydroepiandrostene sulfate; (3) prematurely luteinized ovarian follicles with prominent thecal and interfollicular stromal proliferation; and (4) markedly reduced expression of growth differentiation factor-9 (GDF-9) and activin receptors (ActR) I and IB in the ovaries.

Conclusion: Peripubertal hyperinsulinemia in rats causes hormonal and ovarian changes similar to those in women with PCOS. Based on these novel findings, we speculate that peripubertal hyperinsulinemia may be a risk factor for the development of PCOS later in life.

Immune mechanisms and circulating mediators may be important in the pathogenesis of preeclampsia. We review our findings on agonistic antibodies against the angiotensin II (Ang II) receptor (AT1-AA) and their possible role in the pathogenesis of this disorder. AT1-AA appear in the course of preeclampsia and are largely gone by 6 weeks after delivery. AT1-AA detection relies on a bioassay using spontaneously beating neonatal rat cardiomyocytes. Their specificity has been documented by other methods, including Western blotting, co-localization, and co-immunoprecipitation experiments. AT1-AA induce signaling in vascular cells and trophoblasts including transcription factor activation. The signaling results in tissue factor production and reactive oxygen species generation, both of which have been implicated in preeclampsia. The role of AT1-AA in preeclampsia and other severe hypertensive conditions has not yet been proved with certainty. However, we believe the findings are compelling and warrant further study.