Gynecologic and Obstetric Investigation

Hanson, Gunilla C.; Wide-Swenson, Dag; Andersson, Karl-Erik; Lindberg, B. Fredrik

doi: 10.1159/000009913pmid: 9473154

Objectives: To study the conversion of human big endothelin-1 (bigET-1) to endothelin-1 (ET-1) and to characterize contractile ET-1 receptors in human placental arteries. Methods: BigET-1 was incubated with artery membranes and the formation of ET-1 was investigated. ET-1 and bigET-1-induced contractile responses were studied in the absence or presence of the metalloprotease inhibitor phosphoramidon, the ET_A-receptor antagonist BQ 123, or the ET_B-receptor antagonists IRL 1038 and RES 701-1. Results: The artery membranes hydrolysed bigET-1 to ET-1 through a partly phosphoramidon-sensitive pathway. The contractile responses to ET-1 and bigET-1 were similar, with pEC_50% values of 8.1 ± 0.2 and 7.8 ± 0.1, respectively (NS; n = 17). Phosphoramidon decreased pEC_50% for bigET-1-evoked contractions (p < 0.05; n = 8), without affecting the response to ET-1. A Schild plot of BQ 123 effects on ET-1 and bigET-1-induced contractions resulted in identical pA₂ values and a slope of 0.56 ± 0.2 and 0.47 ± 0.01, respectively. IRL 1038 and RES 701-1 did not affect the contractile responses. Conclusion: BigET-1-evoked contractions in isolated human placental arteries depend on a rapid and metalloprotease-dependent hydrolytic conversion to ET-1, which in turn causes a, mainly ET_A-receptor-mediated, contraction.

van der Linden, Paul J.Q.; de Goeij, Anton F.P.M.; Dunselman, Gerard A.J.; Erkens, Heleen W.H.; Evers, Johannes L.H.

doi: 10.1159/000009914pmid: 9473155

The aim of the study was to develop an in vitro model to study the interaction between endometrial cells and extracellular matrix (ECM) and to evaluate the expression of cell adhesion molecules in endometrial cells and tissue fragments under in vitro conditions. Endometrial biopsies were collected from 32 patients. Samples were either digested using collagenase type I, or dissected mechanically. Adhesion of isolated cells and tissue fragments to stripped amniotic membranes and to coverslips coated with ECM components was studied. The expression of β1 integrins and cadherins was assessed using immunohistochemistry. Collagenase digestion of endometrial biopsies yielded viable single cells. These cells did not adhere to either side of stripped amniotic membranes, and did not show expression of the cell adhesion molecules. In contrast, mechanically fragmented endometrium samples adhered to both sides of stripped amniotic membranes and showed immunohistochemical expression of E- and P-cadherin and integrin subunits α2, α3, α4, α5 and α6. Amniotic membranes, after stripping of epithelial lining, are suitable to study interactions between endometrial tissue and ECM in functional and structural studies. Endometrial cells after collagenase type I digestion do not adhere to stripped amniotic membrane and have lost expression of β1 integrins and E- and P-cadherin.

Verma, Ram S.; Kleyman, Svetlana M.; Conte, Robert A.

doi: 10.1159/000009915pmid: 9473156

Chromosomal mosaicism during prenatal diagnosis has been a major concern. Nondisjunctional events can lead to mosaicism in a number of ways, including failure of chromosomal pairing, failure to separate, anaphase lag and abnormal segregation. We provide a concise review on various types of mosaicism with their clinical significance.

Lau, Tze Kin; Fung, Tak Yuen; Fu Wong, Yick; Fung, Hedy Yun Mei

doi: 10.1159/000009916pmid: 9473157

Coelomic fluid and fetal parts were obtained in 35 patients undergoing surgical termination of pregnancy. Fetal gender was determined by Y-sequence-specific polymerase chain reactions (PCR). Fourteen male pregnancies out of 35 cases were identified by examination of fetal parts. The overall concordance rate of gender determination between coelomic fluid and fetal parts was 91.4%. There were 2 cases of male pregnancies not being identified and 1 case of false positive result by coelocentesis. The gestation of pregnancy and the volume of coelomic fluid obtained appeared not to be related to the discrepancy in the paired results. We conclude that sex determination using coelocentesis and PCR remains unreliable to be used as a definitive prenatal diagnostic test for sex-linked disorders.

Ergün, Ali; Atay, Vedat; Pabuçcu, Recai; Başer, İskender; Duru, Namιk Kemal; Tokaç, Gökalp

doi: 10.1159/000009917pmid: 9473158

Amniotic fluid volumes were measured in 1,659 pregnant women to determine the predictive value of these measurements on perinatal outcome. All cases were evaluated by other tests of fetal well-being. 128 cases were oligohydramniotic, and 1,531 cases were normal. In all cases, several parameters were assayed, e.g. fetal distress, way of delivery, meconium in amniotic fluid, Apgar score, transfer to pediatric clinics and early-late neonatal complications. The results of the perinatal evaluation of oligohydramnios were as follows: assessing fetal distress: specificity 94.2%, sensitivity 18.4%, positive predictive value 35.9%, negative predictive value 86.7% and accuracy 82.8%, and assessing low Apgar score the values were 93.0, 21.3, 95.9 and 89.5%, respectively. As a result, measurement of the amniotic fluid volume is an important parameter predicting perinatal outcome, and its predictive value increases if it is combined with other fetal well-being tests with different end points.

Williams, Michelle A.; Luthy, David A.; Zingheim, Rosalee W.; Zebelman, Arthur M.; Sorensen, Tanya K.; Resta, Robert G.

doi: 10.1159/000009918pmid: 9473159

Objective: Elevated maternal serum human chorionic gonadotropin (hCG) is an important marker of Down syndrome. Notably, women with unexplained elevated serum hCG in the second trimester experience a 2- to 5-fold increase risk of preeclampsia. Urinary gonadotropin peptide (UGP), thought to be a metabolite of hCG that is excreted into urine, has recently been shown to be elevated in Down syndrome pregnancies. We sought to examine urinary UGP levels in preeclamptic and normotensive pregnant women. Methods: We measured UGP levels in urine collected during the third trimester from 18 women with preeclampsia and 20 normotensive controls. UGP levels were determined using enzyme immunoassay and were corrected for dilution using urinary creatinine. Statistical significance testing was done using the Wilcoxon-Mann-Whitney Rank Sum test and Student t test statistics. Results: There was a statistically significant elevation in urinary UGP levels among preeclamptic cases as compared to normotensive control subjects (p = 0.013). Mean urinary UGP levels were 80.7 and 31.3 pmol/mg creatinine for preeclampsia cases and controls, respectively. Elevations in UGP levels among women with preeclampsia as compared with normotensive control subjects persisted after adjustments for possible confounding factors. Conclusion: These early findings suggest that elevations in urinary UGP may be a risk marker for preeclampsia. Prospective studies should further clarify the relation between urinary UGP levels and adverse pregnancy outcomes. These results are consistent with results suggesting a role of placental hypoperfusion in the etiology of preeclampsia.

Yam, J.; Chua, S.; Razvi, K.; Arulkumaran, S.

doi: 10.1159/000009919pmid: 9473160

To evaluate a new reflectance photometer (Accusport^®) for blood lactate determination, a prospective non-interventional study was performed on blood obtained from the umbilical cord artery immediately after delivery of the baby in 109 consecutive women. For each sample, the results of cord arterial blood lactate values measured with the reflectance photometer were compared with those obtained using a reference method in the laboratory. The values obtained using Accusport were comparable in accuracy with those obtained using a laboratory reference method (Ektachem 9501RC). The instrument provides a simple and reliable method for determining cord arterial blood lactate levels in a small blood sample.

Yamada, Tetsuo; Minakami, Hisanori; Matsubara, Shigeki; Yatsuda, Tomomi; Sato, Ikuo

doi: 10.1159/000009920pmid: 9473161

To evaluate changes in vaginal polymorphonuclear leukocytes (vPMNL) in patients with preterm labor, we obtained vPMNL-rich suspensions from vaginal fluids of 77 women (21 with preterm labor and 56 control women with uncomplicated pregnancy). Total counts of vPMNL and % viability of vPMNL (viable vPMNL:total vPMNL) were significantly higher in patients with preterm labor (37 ± 92 × 10⁵, 23 ± 29%) vs. controls (11 ± 15 × 10⁵, 6.9 ± 8.3%). The concentration of granulocyte elastase in vaginal fluid diluted to 20 ml was also higher in patients with preterm labor than in controls (4,806 ± 3,818 vs. 2,739 ± 2,556 ng/ml). We conclude that PMNL and granulocyte elastase are abundant in the vagina in patients with preterm labor, which suggests that the PMNL may be involved in the pathogenesis of preterm labor.

Matsubara, Shigeki; Yamada, Tetsuo; Minakami, Hisanori; Sato, Ikuo

doi: 10.1159/000009921pmid: 9473162

The purpose of this study was to examine evidence for the presence of activated vaginal leukocytes in women with preterm labor. Vaginal polymorphonuclear leukocytes from 7 patients in preterm labor (24–32 weeks of gestation) as well as from 7 control women with uncomplicated pregnancy were analyzed morphologically using transmission electron microscopy. Peroxidase and NADPH oxidase cytochemistry was also performed. Viable leukocytes were abundant in patients in preterm labor. Phagosomes, phagocytosis of bacteria, attachment of primary granules to the phagosomal membrane, and cell surface projections were observed in the vaginal leukocytes but not in the peripheral blood leukocytes. Peroxidase activity was visible on the cell surface, the phagosomal membrane, and the primary granules. NADPH oxidase activity was demonstrated on the cell surface of leukocytes. Morphological and cytochemical features indicated that vaginal polymorphonuclear leukocytes were stimulated in situ. Such stimulated leukocytes may play a role in the pathogenesis or pathophysiology of preterm labor.

Tsai, E.M.; Chiang, P.H.; Lee, J.N.

doi: 10.1159/000009922pmid: 9473163

The effect of adenosine on intracellular free calcium concentration ([Ca²⁺]_i) was studied in human uterine myocyte. Adenosine 10^–6 M elicited a rapid followed by a maintained increase in [Ca²⁺]_i in Fluo-3-loaded myocytes. Compared with basal [Ca²⁺]_i level, adenosine induced a 2.6-fold increase in the absence of extracellular calcium, and a 2.4-fold increase in the presence of extracellular calcium. There was no significant difference between the two groups in the initial response. After depletion of intracellular calcium stores by repetitive caffeine (10 mM) applications, adenosine could not induce increase in [Ca²⁺]_i. The initial rise could be induced in the absence of extracellular calcium, whereas the maintained phase after 120 s of adenosine application was dependent on the presence of extracellular calcium. The maintained phase response was 1.39- and 0.90-fold compared with basal [Ca²⁺]_i level in the presence and absence of extracellular calcium respectively. There was significant (p < 0.01) maintenance of [Ca²⁺]_i in the presence of extracellular calcium, which appeared to be associated with calcium influx. The data suggest that in human uterine myocytes, adenosine stimulates release of Ca²⁺ from intracellular stores and influx of extracellular Ca²⁺ through Ca²⁺ entry pathway.