Journal of the Society for Gynecologic Investigation最新文献

Objectives: Triapine (Vion Pharmaceuticals, New Haven, CT) is a potent ribonucleotide reductase inhibitor which exerts its antineoplastic activity by inhibiting DNA synthesis and repair. The objectives of this study were: (1) to determine whether Triapine has cytotoxic effects on epithelial ovarian cancer (EOC) cells; (2) to characterize the apoptotic cascade induced in response to this agent; and (3) to determine its utility in combination treatment with carboplatin and paclitaxel.

Methods: Five EOC cell lines were treated with tenfold dilutions of Triapine (0.1 to 100 microM) for 24 and 48 hours. Cell viability was determined by the CellTiter 96 AQueous One Solution Cell Proliferation Assay (Promega Corp, Madison, WI) and the morphologic features of apoptosis were observed using Hoechst staining. The apoptotic cascade was characterized by Western blot analyses.

Results: All EOC cell lines treated with Triapine showed decreased cell viability in a time- and dose-dependent manner. Hoechst staining revealed nuclear shrinkage and chromatin condensation and fragmentation, which correlated with the occurrence of apoptosis. Western blots demonstrated that Bid activation was one of the initiating signals involved in the cascade. In addition, cleavage of XIAP and down-regulation of Akt were observed. We also demonstrated that Triapine enhances the cytotoxic effects of carboplatin and paclitaxel.

Conclusions: The present findings demonstrate that Triapine induces cell death through the induction of apoptosis. The initial activation of Bid indicates the involvement of the mitochondrial pathway. The demonstration that Triapine is an effective addition to a carboplatin regimen suggests the possibility of a new combination therapy for ovarian cancer.

Objective: Treatment of maternal opioid dependence with methadone is associated with a delay in fetal heart rate (FHR) accelerations in nonstress tests. The objective of this investigation was to determine the effect of methadone maintenance therapy on intrapartum FHR patterns.

Methods: This retrospective cohort study compared intrapartum FHR tracings from 56 methadone-treated patients > or =36 weeks gestation with a control group of nonsubstance using patients matched for maternal age, parity, gestational age, and ethnicity. Blinded FHR interpretation included the recording of baseline, variability, accelerations, and late or severe variable decelerations. The 8-point FHR scoring system was based on the National Institute of Child Health and Human Development Research Planning Workshop guidelines. We considered a 25% reduction in the score during the latent phase to be significant.

Results: The median maintenance dose of methadone was 70 mg daily, with a range between 20 mg and 130 mg. Each patient tested negative for other substances on urine screening before admission. The significantly lower FHR score in the methadone group (mean difference, 1.4; 95% confidence interval, 1.1 to 1.7) was attributed to a lower baseline (P <.05), less moderate or marked variability (P <.01), and a lower proportion of accelerations during the first stage of labor (P <.01). A higher proportion of methadone-exposed fetuses had late or severe variable decelerations in the second stage (44.2% vs 22.9%; P <.03). Analgesic needs, operative vaginal or cesarean delivery rates, and Apgar scores less than 7 at 1 and 5 minutes were not significantly different between the two groups.

Conclusions: Chronic maternal methadone treatment affects intrapartum FHR patterns by reducing the variability, baseline, and proportion of accelerations during the first stage. These subtle drug-induced effects do not compromise intrapartum decision-making or immediate newborn adjustments.

Objective: To assess the effect of the peroxisome proliferator-activated receptor (PPAR)-gamma agonist rosiglitazone on the induction of endometriosis in a rat model.

Methods: Endometriosis was surgically induced in 28 rats by transplanting an autologous fragment of endometrial tissue onto the inner surface of the abdominal wall. Group I was assigned as control and no medication was administered. Starting 3 days before the operation and continuing for 4 weeks, 0.2 mg/kg/d rosiglitazone was administered to the study group orally. Four weeks later rats were killed and ectopic uterine tissues were evaluated morphologically and histologically. Scoring systems were used to evaluate preservation of epithelia.

Results: Four rats in the study group and one rat in the control group died of complications related to surgery. There was a significant difference in post-treatment spherical volumes (64.00 mm3 [interquartile range (IQR): 354.42] vs 41.60 mm3 [IQR: 37.87], P = .018) and explant weights (77.97 mg [IQR: 431.27] vs 47.24 mg [IQR: 43.01], P = .005) between control and rosiglitazone-treated groups. The epithelia were found to be preserved significantly better in the control group when compared with the roziglitazone-treated group (2.00 [IQR:2.00] vs 0.00 [IQR:2.25], P = .014).

Conclusions: Rosiglitazone was found to affect the induction of endometriosis negatively in this experimental rat model and seemed to interfere with the growth and maintenance of the uterine explant.

Fetal overgrowth and higher adiposity are hallmarks of pregnancy with maternal obesity and poor glucose tolerance, two conditions associated with decreased maternal insulin sensitivity. In non-pregnant individuals, adipokines, vasoactive peptides, and components of the immune system crosstalk with metabolic factors to generate signals triggering obesity and impaired insulin action. We have investigated circulating maternal and fetal cytokines and growth-factors as potential biochemical markers of fetal adiposity. Mothers and neonates were classified into three tertiles (T1-T3) using total neonatal fat mass as the outcome with 309 +/- 25 g in T1, 478 +/- 40 g in T2, and 529 +/- 39 g in T3. Umbilical cord endothelin-1 (ET-1), C-peptide, and leptin were higher in T3 and T2 versus T1. Only cord leptin was strongly associated with fetal fat mass (P < .01), whereas neonatal lean body mass was negatively correlated with maternal insulin-like growth factor binding protein-I (IGFBP-I) (r = -0.53, P < .04). This study shows an association between increased fetal adiposity and maternal systemic interleukin-6 (IL-6). No such correlation was found with factors circulating in cord blood, suggesting that the stimuli favoring fetal fat accretion derive from maternal or placental sources rather than from the fetus.

Objective: To review the current understanding of the molecular causes of birth defects resulting from diabetic pregnancy, with a focus on neural tube defects.

Methods: A mouse model of diabetic pregnancy is described, in which embryo gene expression associated with neural tube defects is examined. Chemical, physiologic, or genetic manipulations are employed to elucidate critical pathways affected by increased glucose metabolism, and how abnormal gene expression disrupts neural tube closure.

Results: Increased glucose delivery to embryos, or activation of pathways that are stimulated by high glucose, such as the hexosamine biosynthetic pathway or hypoxia, increase oxidative stress in embryos, inhibit expression of Pax3, a gene that encodes a transcription factor that is required for neural tube closure, and increase neural tube defects. Conversely, blocking these pathways, or providing the antioxidants, reduced glutathione or vitamin E, suppress the adverse effects of excess glucose. Pax3 decreases steady-state levels of the p53 tumor-suppressor protein, such that when Pax3 is deficient, p53 protein increases, leading to increased neuroepithelial apoptosis prior to completion of neural tube closure. Embryos that lack both functional Pax3 protein and p53 do not display neuroepithelial apoptosis or neural tube defects.

Conclusions: Excess glucose metabolism by embryos resulting from maternal hyperglycemia disturbs a complex network of biochemical pathways, leading to oxidative stress. Oxidative stress inhibits expression of genes, such as Pax3, which control essential developmental processes. Pax3 protein is required during neural tube development to suppress p53-dependent cell death and consequent abortion of neural tube closure, but is not required to control expression of genes that direct neural tube closure. Impaired embryo gene expression resulting from oxidative stress, and consequent apoptosis or disturbed organogenesis, may be a general mechanism to explain diabetic embryopathy.

Objectives: Human umbilical vascular endothelial cells (HUVECs), seeded on Matrigel (BD Biosciences, Bedford, UK), undergo an angiogenic-like process. We hypothesized that placental explants from normal pregnancies, maintained in cultures of different oxygen, would liberate factors that could be measured in this system. We further tested the angiogenic potential of placentae from intrauterine growth-restricted (IUGR) pregnancies and the effects of vascular endothelial growth factor (VEGF) blockade.

Methods: Placental villous explants were maintained in culture at 3% and 20% O2. The resultant media was added to HUVECs seeded on 80% Matrigel. Cells were incubated at 6% O2 in accordance with the natural placental environment. After 6 hours, cells were fixed and stained and the length and number of tubules measured by morphometric imaging. Finally, VEGF and soluble VEGF receptor (sVEGFR-1) were recorded in the explant conditioned media.

Results: Within the angiogenic assay, recombinant human VEGF significantly enhanced tubule outgrowth (branching and elongation) and this effect was blocked with neutralising antibody. Compared to 20% O2, media of placental explants conditioned at 3% O2 significantly encouraged tubule length and numbers. Again this affect was ablated by VEGF blockade. In cases of IUGR, conditioned media at 3% O2 showed a significant reduction in tubule growth. This was paralleled by a decline in available VEGF brought about an exaggeration in liberated sVEGFR-1. Notably, venous cord serum from IUGR pregnancies showed a similar elevation in sVEGFR-1.

Conclusion: Under restricted oxygen, placental angiogenic potential is suppressed in IUGR pregnancies through the overproduction of placental sVEGFR-1. This reduction may discourage normal placental vascularization and impact on fetal development.

Objective: Prostaglandins (PGs) are key regulators of cervical dilatation and membrane breakdown at the onset of labor. PG synthase and receptor expression has been previously documented in uterine tissues; however, mechanisms governing the changes occurring in the cervix and amnion are less well established. The aim of the current study was to determine the level of expression of PG synthetic enzymes and receptors in these tissues in association with induced labor in sheep.

Methods: Labor was induced in sheep at 135 days of gestation by continuous fetal dexamethasone infusion. Amnion and cervical tissue was obtained before and after labor for measurement of mRNA encoding enzymes (cytosolic phospholipase A2 [cPLA2], PGH synthase-2 [PGHS-2], PGF synthase [PGFS], and PGE synthase [PGES]) and receptors (FP and EP1-4) by real-time polymerase chain reaction (PCR).

Results: cPLA2 expression increased significantly in cervical tissue at labor onset, whereas expression of the other enzymes measured did not change. There was a marked rise in EP3 expression in the cervix, but abundance of this receptor was lower than EP2 and FP expression, which did not change. The amnion exhibited a labor-associated decrease in PGHS-2, PGFS, and FP mRNA expression.

Conclusion: The regulation of PG synthesis and action occurring in the amnion and cervix in association with labor appear to differ markedly between the two tissues, indicating tissue-specific roles for PGs. The data support a role for increased PG synthesis and action in the cervix and suggest a decrease in PG production and action in the amnion, in sharp contrast to the pattern reported in human amnion.

Objective: Although the Four and a Half LIM domain protein 2 (FHL2) has been suggested to play an important role in tumor development, this has not been investigated in breast cancer.

Methods: Paraffin-embedded tissues from patients (n = 85) with primary breast cancer were submitted to immunohistochemical investigation of FHL2 expression and subsequent correlation with clinicopathologic parameters and patient survival.

Results: The expression of FHL2 was confined to the cytoplasm of the tumor cells. Forty (47%) of 85 samples showed weak expression of FHL2, whereas high expression was found in 45 tumors (53%). A statistically significant positive correlation was observed between FHL2 and androgen receptor expression (P = .029). Patients with tumors expressing low amounts of FHL2 were characterized by a significantly better survival compared to those with high intratumoral FHL2 expression (P = .0215, log-rank test). The additional stratification according to adjuvant tamoxifen treatment revealed a significantly improved survival rate for patients receiving tamoxifen and being diagnosed with a tumor expressing high amounts of FHL2. This might indicate that tamoxifen is at least partially capable of reversing the negative prognostic impact of high FHL2 expression. Multivariate Cox regression analysis revealed FHL2 expression as a significant independent predictor of survival.

Conclusion: The specific expression in tumor tissue points to an important functional role of FHL2 in human breast cancer. Our survival data indicate that the expression of FHL2 in primary breast cancer is a potentially relevant prognostic factor. Further studies are warranted to elucidate whether analysis of FHL2 expression is suitable to predict response to antihormonal treatment with tamoxifen.

Background: Preeclampsia is associated with enhanced sympathetic activity as well as subnormal plasma volume. Meanwhile, in over 50% of these complicated pregnancies, the subnormal plasma volume has been found to persist for a prolonged period after pregnancy. The objective of this study is to test the hypothesis that in normotensive formerly-preeclamptic women, persistence of a subnormal plasma volume coincides with enhanced sympathetic activity and with it, an altered autonomic control of blood pressure.

Methods: Forty-eight formerly-preeclamptic women participated in this study. After measurement of their plasma volume by iodine 125-albumin indicator dilution, they were subdivided into a group with a normal plasma volume (plasma volume > 48 ml/kg lean body mass) and a group with a subnormal plasma volume (< or = 48 ml/kg lean body mass). We performed spectral analysis on their beat-to-beat blood pressure and heart rate recordings and compared both groups using non-parametric tests.

Results: Formerly-preeclamptic women with a subnormal plasma volume had a higher sympathetic activity (P = .001) and a lower baroreflex sensitivity (P = .04) than their counterparts with a normal plasma volume.

Conclusion: In normotensive formerly-preeclamptic women, a subnormal plasma volume coincides with a higher sympathetic activity in the blood pressure regulation and lower baroreflex sensitivity. Whether these alterations in the autonomic control mechanisms are a cause or effect of the subnormal plasma volume remains to be elucidated.