Journal of the Society for Gynecologic Investigation最新文献

Objectives: We have previously shown that after exposure to long-term hypoxia, fetal coronary flow is maintained at control levels despite a 25% reduction in cardiac output. We also demonstrated that coronary vascular rings isolated from the long-term hypoxic fetuses and studied in well-oxygenated bath system displayed significantly reduced depolarization-induced contraction strength in response to KCl. To study the mechanism of reduced fetal coronary vascular responses to KCl-induced contractions following exposure to long-term hypoxia, we measured tension and intracellular calcium simultaneously, as well as L-type Ca2+ channel density and sensitivity.

Methods: Pregnant ewes were housed at altitude (3820 m) for approximately 110 days. At 138 to 141 days of gestation, long-term hypoxic and control animals were killed and fetal and adult left anterior descending coronary artery (LAD) was isolated and studied in a well-oxygenated bath system. Tension and intracellular calcium ([Ca2+]i) were measured simultaneously in response to increasing concentrations of KCl and, in addition, the sensitivity to the calcium channel blocker nifedipine was measured at a half maximal concentration of KCl. We also measured L-type Ca2+ channel density with (+)-[3H]PN200-110.

Results: L-type Ca2+ channel density was decreased by approximately 31% in the long-term hypoxic fetal, but not adult, LAD. Tension in the long-term hypoxic fetal and adult LAD was significantly lower at all concentrations of KCl. [Ca2+]i was lower at rest in both fetal and adult LAD from long-term hypoxic animals and increased to lower levels at all concentrations of KCl. The ratio of tension to [Ca2+]i was also lower at all concentrations of KCl. Sensitivity to nifedipine was unchanged.

Conclusions: The reduced L-type Ca2+ channel density and the reduced [Ca2+]i response to KCl, as well as the reduced tension response to [Ca2+]i, could potentially be involved in the reduction in depolarization-induced contractions in LAD from long-term hypoxic fetuses. In hypoxic adults, reduced [Ca2+]i and reduced tension response to [Ca2+]i may be involved in the lower tension response to KCl-induced contractions.

Objective: To determine and correlate midtrimester amniotic fluid concentrations of interferon gamma-inducible T-cell alpha chemoattractant (ITAC, a chemokine directing the migration of activated T lymphocytes toward inflammation sites) and C-reactive protein (CRP) in women undergoing amniocentesis and subsequently delivering pre-or full-term infants.

Methods: Among 312 women undergoing midtrimester transabdominal amniocentesis, 13 progressed to spontaneous delivery at less than 37 gestational weeks (GW). Subjects were matched for maternal age, parity, and GW at amniocentesis with 21 controls who delivered at greater than 37 GW. Amniotic fluid ITAC and CRP levels were determined by enzyme-linked immunosorbent assay (ELISA) and by nephelometry, respectively.

Results: Both ITAC and CRP values were significantly higher (P = .005 and P = .04, respectively) in the amniotic fluid of women delivering at less than 37 GW. A statistically significant correlation between amniotic fluid ITAC and CRP concentrations was also found (r = .366, P < .05). The receiver operator curve (ROC) analysis of delivery at less than 37 GW gave the best cutoff point for ITAC at a concentration of 44 pg/mL and for CRP at a concentration of 0.16 mg/dL. Positive and negative predictive values for ITAC were 82% and 85%, respectively, and for CRP, 55% and 76%, respectively.

Conclusions: Present data indicate that from the second trimester of pregnancy elevated amniotic fluid concentrations of ITAC are found in women delivering at less than 37 GW, as compared to women delivering at term. Therefore, ITAC in combination with other cytokines or CRP could possibly serve as predictor of preterm delivery.

Objective: The multinucleate syncytiotrophoblast is the transporting epithelium of the human placental villus, formed throughout pregnancy by fusion and differentiation of underlying mononucleate cytotrophoblast cells. Similar to other epithelia, K+ channels will impact on syncytiotrophoblast transport properties during its development and differentiation. Therefore we investigated expression and activity of the two-pore domain K+ channels TASK1 and 2 in relation to gestation and differentiation, using villous tissue from first and third trimester and cultured cytotrophoblast cells at mononucleate and multinucleate stages of culture.

Methods: Quantitative real-time polymerase chain reaction (PCR), immunofluorescence, and 86Rb+ (K) efflux were used to investigate TASK channel expression and function.

Results: TASK2 mRNA expression was higher in first trimester than term (10 to 13 vs 38 to 40 weeks, P < .05). Other K+ alpha-subunit mRNAs, including TASK1, remained unaltered but the regulatory BKCa beta-subunit, like TASK2, was higher in first trimester than term (P < .001). Immunofluorescence showed that TASK2 had an intracellular localization within the trophoblast of first trimester villi but was less abundant and restricted to stem villi at term. TASK2 also showed intracellular localization in mononucleate cytotrophoblast cells in culture and expression was lost with multinucleation. By contrast, TASK1 was localised, independently of cell nucleation, to cytotrophoblast cell plasma membranes. 86Rb+ (K) efflux was measured from multinucleated cytotrophoblast cells. Both basal and pH 8.0-stimulated efflux was inhibited by the TASK1 antagonist anandamide (n = 5 for both conditions; P < .01 and P < .001, respectively).

Conclusion: TASK1 and 2 are expressed in placental trophoblast cells and TASK1 activity may have a role in regulating syncytiotrophoblast homeostasis and/or solute transport functions.

Objectives: To study the effects of green tea on body weight, and biochemical and hormonal profiles in obese Chinese women with polycystic ovary syndrome (PCOS).

Methods: Thirty-four obese Chinese women with PCOS were randomized into either treatment with green tea capsules or placebo for 3 months. The anthropometric measurements, and biochemical and hormonal profiles before and after treatment in each group were compared.

Results: The body weight of the green tea group decreased by a nonsignificant 2.4% after treatment; whereas the body weight, body mass index (BMI), and body fat content of the control group were significantly higher after 3 months. There were no differences in any of the hormone levels measured in either group. The biochemical profiles of the two groups were also similar except that there was a small but significant rise in the triglyceride level in the green tea group. Fewer patients in the green tea group remained amenorrhoeic, but this was not significantly different from the control group.

Conclusions: Green tea supplementation did not significantly reduce body weight in obese women with PCOS, nor did it alter the glucose or lipid metabolism.

Objective: Besides its important role in immune response and inflammatory processes the cytokine interleukin-6 (IL-6) is crucially involved in carcinogenesis. A common polymorphism within the gene encoding IL-6 (IL6) is known to alter IL-6 protein expression and has been associated with patients' prognosis in various malignancies. No data are available with respect to vulvar cancer. Therefore, we determined the prognostic potential of the common -174(G-->C) single nucleotide polymorphism in the promoter region of IL6 in a series of patients with this disease.

Methods: The IL6 promoter polymorphism was investigated in 81 Caucasian patients with surgically treated squamous cell vulvar cancer using pyrosequencing. Results were correlated with clinical data.

Results: No association was ascertained between the IL6 promoter polymorphism and the investigated clinicopathologic parameters, ie, tumor stage, lymph node involvement, tumor grade, and patient's age at diagnosis. In an univariate analysis, lymph node involvement and patients' age at diagnosis were associated with patient prognosis. In a multivariate analysis, including tumor stage and lymph node involvement as established prognostic factors and the IL6 promoter polymorphism, lymph node involvement, and the presence of at least one mutant allele, but not tumor stage, were associated with increased disease-free and overall survival.

Conclusion: Our data suggest that the IL6 -174(G-->C) promoter polymorphism might serve as an additional prognostic parameter in patients with vulvar cancer.

Objective: The current study was undertaken to determine simultaneous changes in amniotic fluid (AF) volume and composition across gestation in the pregnant mouse.

Methods: Young adult mice (6 to 7 weeks old) of the CB6F1 strain were mated overnight. AF was collected on consecutive days from embryonic days 9.5 through 18.5 for measurements of volume and composition. Statistical analysis included one-factor analysis of variance (ANOVA).

Results: AF volume increased from 18 +/- 4 (SE) microL on day 9.5 to a maximum of 147 +/- 4 microL on days 15.5 to 16.5 and decreased sharply to 17 +/- 3 microL on day 18.5. AF osmolality was unchanged except for a rise prior to delivery on day 19.5 to 20.5. AF sodium, calcium, and glucose concentrations increased and subsequently decreased as gestation progressed. AF potassium, chloride, and lactate concentrations initially decreased and then increased across gestation. Prior to day 9.5 and after day 18.5, AF volume was too small for volume or compositional determinations.

Conclusions: In the mouse, the rise in AF volume from mid gestation to a maximum late in gestation is similar to that in humans while the sharp fall prior to delivery is not. As observed in the fetal sheep, the changes in fluid volume are associated with AF osmolality and solute concentration changes that are correlated with advancing gestational age. These observations together with the feasibility of quantifying AF volume and composition in the mouse fetus demonstrate the possibility of using genetically altered mice as a model for future studies on the molecular mechanisms underlying the regulation of AF volume and composition.

Objectives: This study has a twofold aim: 1) to investigate whether protein expression and enzyme activity of phosphodiesterase 5 (PDE5) can be detected in human myometrium and undergo changes in relation to the presence of pregnancy and/or labor; 2) to evaluate whether PDE5 expression and activity in myometrial cells can be influenced by human chorionic gonadotropin (HCG).

Methods: Primary cultures of myometrial cells, obtained from non-pregnant women and from pregnant women at term, either before or during labor, were carried out in the presence of HCG or dibutyryl-cyclic AMP (db-cAMP), the non-hydrolizable analogue of cAMP. PDE5 expression in cultures of myometrial cells was detected by immunocytochemistry and western blot. PDE5 activity was detected in cell extracts by enzyme assay.

Results: PDE5 is expressed and is functionally active in smooth muscle cells. Treatment of cell cultures with HCG and db-cAMP results in a reduction of PDE5 expression and activity. The effects of HCG and db-cAMP are exerted irrespective of the functional status of the myometrium (non-pregnant, pregnant not in labor, pregnant in labor).

Conclusions: PDE5 protein is expressed in human non-pregnant and pregnant myometrium. HCG reduces PDE5 expression and enzyme activity in smooth muscle cells, possibly through a pathway involving cAMP.

Objective: Preeclampsia is associated with oxidative stress, elevated plasma levels of linoleic acid (LA), and increased vascular smooth muscle expression of the inflammatory chemokine, interleukin-8 (IL-8). We hypothesized that increased levels of LA under conditions of oxidative stress would increased production of IL-8 by vascular smooth muscle cells because LA is the dietary precursor to arachidonic acid (AA) and its metabolites that mediate inflammation. We also hypothesized that oleic acid (OA), which is not metabolized to AA metabolites, would not increase IL-8 under conditions of oxidative stress.

Methods: To test this hypothesis, we cultured placental arterial smooth muscle (PASM) cells with an oxidizing solution enriched with LA (OxLA) or OA (OxOA). Media concentrations were analyzed for IL-8 and AA metabolites. Inhibitors were used to block the lipoxygenase and cyclooxygenase pathways.

Results: Exposure of cells to OxLA, but not to OxOA, significantly increased production of IL-8. OxLA also significantly increased production of AA metabolites. Nordihydroguaiaretic acid, an inhibitor of the lipoxygenase pathway, blocked IL-8 and leukotriene B4 (LTB4) production induced by OxLA, whereas indomethacin, an inhibitor of the cyclooxygenase pathway, blocked IL-8, prostaglandin E2 (PGE2), and thromboxane B2 (TXB2) production. Reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated gene expression in PASM cells for representative lipoxygenase (LTB4) and cyclooxygenase (thromboxane) metabolite receptors.

Conclusion: PASM cells produced IL-8 in response to LA, but not OA, under conditions of oxidative stress. The IL-8 response was mediated by AA metabolites.

Objectives: The consequences of female sex hormone deficiency and the effects of hormone replacement therapy are controversial because individual hormones and their derivates can result in partially antagonistic activities. This intricate system involving cerebral autoregulatory mechanisms caused by ovariectomy and female sex hormone replacement was studied in rats.

Methods: The lower limit of cerebral blood flow autoregulation was determined by stepwise reduction of systemic arterial pressure while simultaneously measuring the changes of the hypothalamic blood flow (HBF) using the hydrogen gas-clearance method.

Results: In ovariectomized rats resting HBF decreased substantially and the threshold of cerebrovascular autoregulation decreased to 40 mm Hg. Estrogen replacement prevents the former change and shifts the latter upwards. Similarly, progestin replacement restores autoregulation to the physiological levels found in control animals, whereas it has no influence on the ovariectomy-induced reduction of resting blood flow.

Conclusions: Steady-state HBF and compensatory changes of regional cerebral vascular autoregulation are altered significantly following ovariectomy. Estrogen or progestin replacement has an opposite effect on these cerebral circulatory parameters. Our observations highlight the essential role of female sex hormones in hypothalamic autoregulation during hypotensive stress.

Objective: Increased endothelial permeability is associated with increased oxidative stress in the maternal vasculature in women with preeclampsia. This study was to determine if oxidative stress elicited by peroxynitrite could lead to an increase in endothelial permeability.

Methods: Endothelial oxidative stress was produced by adding 3-morpholinosydnonimine (SIN-1, a peroxynitrite generator) to the cell culture. Confluent endothelial cells (ECs) grown in cell culture inserts were treated with SIN-1 at a concentration of 0.5 mM alone or in combination with MnTMPyP (a peroxynitrite scavenger) or superoxide dismutase (SOD). EC permeability was determined by measuring EC electrical resistance (ER) and horseradish peroxide (HRP) leakage. Data are presented as means +/- SE and analyzed by analysis of variance (ANOVA). Junctional protein expression and distribution for vascular endothelial (VE)-cadherin, occludin, and phosphorylated focal adhesion kinase (FAK) at tyrosine 397 [pY397] were examined by fluorescent staining of ECs.

Results: First, ER was significantly reduced and HRP leakage was significantly increased in ECs treated with SIN-1 compared to those in control cells, ER: 26.97 +/- 1.41 versus 42.27 +/- 0.40 Omega.cm2, P <.01; HRP: 0.26 +/- 0.07 versus 0.02 +/- 0.01 OD 470 nm, P <.01, respectively. Second, cells treated with SIN-1 showed formation of gaps and disorganized VE-cadherin and occludin distribution at cell contact regions. FAK[pY397] expression was completely lost in cells treated with SIN-1. Finally, these functional and morphologic changes in ECs induced by SIN-1 were blocked in cells pretreated with MnTMPyP and SOD.

Conclusions: Disorganization of junctional proteins and dephosphorylation of FAK[pY397] may account for the increased endothelial permeability induced by oxidative stress associated with preeclampsia.