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Biomedical subjects

S Yagel

Publications and source records attributed to S Yagel.

At least 91 records · Page 5Linked to original sources
PubMed1995

Transvaginal ultrasonography at early pregnancy cannot be used alone for targeted organ ultrasonographic examination in a high-risk population.

OBJECTIVE: A study was performed to evaluate whether early second-trimester (13 to 16 weeks) transvaginal scan can be used alone for structure evaluation of the fetus or whether it should be followed by a transabdominal scan performed at 18 to 20 weeks of gestation. STUDY DESIGN: A total of 536 pregnant women at high risk for birth defects were examined by transvaginal ultrasonography at 13 to 16 weeks' gestation. This was followed by a transabdominal scan at 18 to 20 weeks of pregnancy. Aborted specimens were examined by a pediatric pathologist in terminated pregnancies, and newborn babies were examined by a pediatrician to detect congenital anomalies. RESULTS: Transvaginal ultrasonography performed at 13 to 16 weeks' gestation identified 42 structural anomalies. Of these, 24 pregnancies were terminated and one fetus died. The other 17 fetuses and the rest of the population underwent a second transabdominal survey at 18 to 20 weeks' gestation, which identified eight structural anomalies that were not diagnosed by the previous examination. In five cases the diagnosed anomaly disappeared. Together, the scans brought about the detection of 41 of 46 abnormal fetuses (89%). CONCLUSIONS: Because a significant number of birth defects (17.4%) was not detected by early second-trimester vaginal scan, we recommend that whenever early transvaginal ultrasonographic examination is performed it should be followed by a transabdominal scan at the most advanced stage of pregnancy at which an abortion is still feasible.

Adult↗
PubMed1995

Expectant management of twin pregnancies discordant for anencephaly.

OBJECTIVE: To study the clinical course and perinatal outcome of twin pregnancies discordant for anencephaly, without selective termination. METHODS: We conducted a descriptive retrospective study of 14 cases of dichorionic twin pregnancies discordant for anencephaly, which were managed expectantly in five Israeli perinatal centers. RESULTS: None of the patients miscarried. The mean gestational age at delivery was 35.9 +/- 2.8 weeks (range 29-39). Only three patients (21%) delivered before 35 weeks' gestation. Polyhydramnios occurred in six of the anencephalic amniotic sacs. Nevertheless, most occurrences were mild and none necessitated therapeutic amniocentesis. The mean birth weight of the normal fetus was 2610 +/- 690 g (range 1100-3200). One apparently normal twin had a cardiac anomaly and died shortly after birth, and one was electively delivered at 33 weeks because of severe intrauterine growth retardation and subsequently developed cerebral palsy. The rest had normal short- and long-term outcomes. CONCLUSION: Expectant management of a twin gestation discordant for anencephaly diagnosed at the second trimester is associated with a favorable outcome for the unaffected fetus.

Adult↗
PubMed1995

Fetal lateral neck cysts: early second-trimester transvaginal diagnosis, natural history and clinical significance.

The objective of the study was to explore the natural history and clinical significance of lateral neck cysts during the early second trimester of pregnancy. A survey was conducted of pregnant women at 12-15 weeks' gestation who presented at the ultrasonographic unit between January 1991 and December 1994. During the 4-year period, of the 1500 fetuses scanned, 42 fetuses with lateral neck cysts were detected by high-resolution transvaginal ultrasonography. Twenty-six of the 42 fetuses were seen to have isolated lateral neck cysts, and 16 demonstrated a combination of nuchal thickness of > or = 4 mm and lateral neck cysts. Natural history, fetal karyotype and pregnancy outcome were compared between these two groups. None of the fetuses with isolated neck cysts had an abnormal karyotype, and all cysts resolved spontaneously at 16-20 weeks. No congenital abnormalities were found among the 26 cases. Four chromosomal abnormalities (three trisomy 21 and one monosomy XO) were detected among the 16 fetuses with combined lesions, resulting in termination of pregnancy in all. Among the remaining 12 fetuses, spontaneous resolution of the neck findings occurred between 16 and 20 weeks' gestation. The finding of isolated lateral neck cysts in the early second trimester is not associated with increased risk of aneuploidy. However, the combination with nuchal thickness of > or = 4 mm should prompt genetic counselling and consideration of karyotyping, since this delay in maturation of the cervical jugular lymphatic communication may be associated with chromosomal aberrations.

Adult↗
PubMed1995

Interleukin-1-mediated stimulation of prostaglandin E production is without effect on plasminogen activator activity in human granulosa lutein cell cultures.

In continuation of earlier observations on the involvement of interleukin-1 (IL-1) in ovarian function, we examined the ability of IL-1 to modulate plasminogen activator (PA) activity and prostaglandin (PG) synthesis in human granulosa lutein cells (GLCs). Toward this goal, GLCs were obtained from women undergoing in vitro fertilization, preincubated with 10% fetal calf serum for 48 h, and subsequently cultured for 48 h in serum-free media in the absence or presence of IL-1 beta (10 ng/mL). Cellular PA activity was measured by plasminogen-dependent cleavage of the chromogenic substrate H-D-valyl-L-leucyl-L-lysine-p-nitroanilide (S-2251). Prostaglandin E (PGE) levels were assayed by conventional RIA. Exposure of GLCs to IL-1 resulted in a 50% increase in PGE production, a 33% suppression of PA activity, and a 75% increase in the ability of the corresponding conditioned media to inhibit exogenous urokinase activity. The inhibitory capacity was attributable to an IL-1-mediated increase in PA inhibitor type-1 (PAI-1) production, inasmuch as urokinase inhibition could be abolished by the administration of a polyclonal antihuman PAI-1 immunoglobulin G. IL-1 treatment had no effect on plasmin or trypsin inhibition. Exposure of GLCs to IL-1 receptor antagonist abolished the ability of IL-1 to enhance PA inhibitory activity and PGE production, thereby establishing specific IL-1 receptor-mediated effects. The ability of IL-1 to suppress PA activity and to produce PAI-1 persisted in the presence of indomethacin, a potent inhibitor of PG synthesis. Likewise, transforming growth factor-beta 1 suppressed the ability of IL-1 to stimulate PGE production without affecting the IL-1-induced effects on the PA system. The present findings suggest a pluripotent response of GLCs to IL-1, characterized by the induction of PAI-1 and the suppression of PA occurring concurrent with, but independent of, PG production. These observations support the potential involvement of IL-1 in the regulation of human ovulatory processes.

Amino Acid Sequence↗
PubMed1995

Interleukin-1 stimulates prostaglandin E production by human trophoblast cells from first and third trimesters.

Prostaglandins (PGs) play a major role during implantation and labor, and their level is regulated by various cytokines. Interleukin-1 (IL-1) is a known mediator of prostaglandin E (PGE) production in various cell types, including endothelial, amniotic, and endometrial cells; however, its role in the regulation of PGE production in the trophoblast cells is yet unknown. As IL-1 and PGE are both known to be synthesized in the human trophoblast cells, we examined the possibility that IL-1 regulates PG production in human trophoblast cells. To this end, use was made of first and third trimester trophoblast cells, obtained from first trimester terminations of pregnancies and elective cesarean sections. The trophoblast cells were separated by trypsin degradation and fractionation on Percoll gradients, and cultured for 18 h under serum-free conditions in the absence or presence of IL-1 (10 ng/mL). IL-1 induced a 5-fold increase in PGE production, a response that was cell density, time, and dose dependent. IL-1-induced PGE biosynthesis was prevented in the presence of either IL-1 receptor antagonist or the soluble IL-1 receptor, suggesting a receptor-mediated response. Significantly, de novo production of PGE by trophoblast cells in the absence of IL-1 was also markedly (50%) reduced by either the IL-1 receptor antagonist or the soluble IL-1 receptor, further supporting the notion that IL-1 is involved in PGE synthesis even under basal conditions. Transforming growth factor-beta 1, a putative modulator of the effects of IL-1, significantly attenuated IL-1-stimulated PGE production, supporting the possibility that transforming growth factor-beta 1 may serve as a regulator of the effects of IL-1 in trophoblast cells. These observations suggest a pivotal role of IL-1 in the regulation of PGE economy by trophoblast cells. As trophoblast cells are in intimate contact with maternal cells, understanding the regulation of PGE levels may explain crucial processes at the feto-maternal interface, including implantation of the developing blastocyst, immunosurveilance, and the initiation of labor.

Cell Count↗
PubMed1994

Fetal echocardiography: the identification of two of the pulmonary veins from the four-chamber view during the second trimester of pregnancy.

Identification of two of the pulmonary veins as they enter the left atrium is important to the diagnosis of the visceroatrial situs for fetuses with normal and abnormal echocardiographic findings. In this study, we investigated the ability to demonstrate these veins in 734 fetuses varying in gestational age from 13 to 21 weeks. Transvaginal and transabdominal B-mode ultrasound and color flow Doppler were used for the examination. With the use of the transvaginal route, the highest visualization rate, 85-95%, was achieved in fetuses of 14-15 weeks of gestation. With the use of the transabdominal route, the highest visualization rate, 95-97%, was achieved in fetuses of 20-21 weeks of gestation. This examination enabled the correct diagnosis to be made of complex cardiac anomaly.Visualization of the pulmonary veins with B-mode ultrasound aided by color flow Doppler can be accomplished in the majority of fetuses, while the four-chamber view is studied.

Journal Article↗
PubMed1994

Monosomy 8q: prenatal diagnosis and autopsy findings.

The autopsy findings of a fetus with deletion of the long arm of chromosome 8 are described. Many of the features are similar to those of the tricho-rhino-phalangeal syndromes, types I and II, which are associated with deletions on chromosome 8q24. Other findings in this case, such as total absence of the corpus callosum and intestinal malrotation, have not been described in these syndromes. Genes involved in the development of the latter malformations may reside in adjacent regions on the long arm of chromosome 8. An elevated serum level of beta human chorionic gonadotropin (beta hCG) was found during pregnancy. This aberration should be included with other chromosomal disorders which may be detected by this test.

Abortion, Induced↗
PubMed1994

Developmental regulation of the expression of 72 and 92 kd type IV collagenases in human trophoblasts: a possible mechanism for control of trophoblast invasion.

OBJECTIVE: During early pregnancy fetal cytotrophoblast cells invade the uterus and penetrate the basement membrane, a property that is characteristic of malignant cells. However, unlike tumor invasion, trophoblast invasion of the uterus is under strict control. This control limits invasion, so that it primarily remains confined to the endometrial aspect of the myometrium and continues only until midgestation. The invasive properties of the trophoblast cells are made possible by the activity of proteolytic enzymes that belong to the metalloproteinases and serine proteinases. Type IV collagenase (metalloproteinase) is considered crucial in the extracellular matrix remodeling that takes place during the invasion process. In this study we set out to characterize the invasive properties of trophoblast cells at different stages of pregnancy. STUDY DESIGN: Human trophoblast cells were isolated from first- and third-trimester placentas by trypsin digestion and Percoll fractionation and were then cultured under serum-free conditions. The invasive ability of trophoblast cells was determined by the in vitro invasion assay, in which the ability of cells to penetrate an artificial basement membrane was examined. Metalloproteinase activity was measured by zymography, and the expression of messenger ribonucleic acid transcripts of 72 and 92 kd type IV collagenases was examined by reverse transcriptase polymerase chain reaction. RESULTS: First-trimester trophoblasts were 3.5 time more invasive in vitro than were third-trimester trophoblast cells (p < 0.005). Although first-trimester trophoblasts secreted both species of type IV collagenase, 72 and 92 kd, in large amounts, third-trimester cells secreted the 92 kd and only minimal amounts of 72 kd type IV collagenase. Moreover, first-trimester trophoblasts secreted significantly more (p < 0.05) 92 kd type IV collagenase than did third-trimester trophoblast. The messenger ribonucleic acid transcript expression of 72 and 92 kd type IV collagenases correlated with the activity of these enzymes secreted by first- and third-trimester trophoblasts. CONCLUSION: The described high in situ invasive capacity of first-trimester trophoblast might be explained by the increased expression and production of 72 kd type IV collagenase and the higher expression of 92 kd type IV collagenase by first-trimester trophoblast cells.

Base Sequence↗
PubMed1994

Post-term pregnancies with normal cardiotocographs and amniotic fluid columns: the role of Doppler evaluation in predicting perinatal outcome.

OBJECTIVE: To study the role of Doppler ultrasound examination in predicting an abnormal perinatal outcome, among post-term pregnancies uncomplicated by an abnormal non-stress test (NST) or reduced amount of amniotic fluid. DESIGN: A prospective study. SETTING: High-risk pregnancy unit, Hadassah Mt. Scopus University Hospital, Jerusalem. SUBJECTS: Seventy-eight women with confirmed gestational age of > 287 days, who had normal initial evaluation and unfavourable cervical examination. INTERVENTIONS: Doppler flow velocity waveforms were recorded from the umbilical and middle cerebral arteries, and from the descending thoracic aorta. MAIN OUTCOME MEASURES: Correlation between Doppler measurements and data regarding delivery. RESULTS: Women who developed signs of fetal distress during labour, or who required intervention because of fetal distress, had elevated umbilical artery systolic/diastolic ratio, decreased middle cerebral artery pulsatility index, and decreased time average aortic blood flow velocity. Umbilical artery Doppler measurements could significantly predict the need for intervention due to fetal distress. CONCLUSIONS: Doppler examination of uncomplicated post-term pregnancies may identify patients with normal results as having a low risk of developing fetal distress during labour. Patients with abnormal Doppler results are prone to need intervention following fetal distress in labour.

Adult↗
PubMed1994

Cytokine-mediated regulation of rat ovarian function: interleukin-1 inhibits plasminogen activator activity through the induction of plasminogen activator inhibitor-1 (PAI-1).

Intraovarian IL-1 has recently been implicated as a mediator in the ovulatory process. Since PA activation is an established component of the ovulatory cascade, consideration was given in this report to the possibility that IL-1 may modulate ovarian PA economy. Whole ovarian dispersates from immature rats (25-27-days-old) were cultured under serum-free conditions for 48 h in the absence or presence of IL-1beta. Cellular PA activity was measured by plasminogen-dependent cleavage of 14C-labeled globin. Cells grown in the absence of IL-1 exhibited appreciable PA activity, as assessed by the cleavage of 0.074 +/- 0.026 mg [14C]-globin/5 x 10(5) cells (mean +/- SD). Exposure to IL-1 (10 ng/ml) led to a 30% reduction in cell-associated PA activity (p < 0.001). The IL-1-mediated inhibition occurred concurrently with a 10-fold increase in the ability of the corresponding conditioned media to inhibit exogenous urokinase activity. At similar cell densities of 5 x 10(5) cells/well, isolated cultures of theca and granulosa cells exhibited comparable PA activity in the absence of IL-1. However, only theca cells responded to IL-1 with inhibition of plasminogen activation and enhancement of urokinase inhibitory activity. Granulosa cells in turn failed to respond to IL-1. Both the inhibition of PA activity and the increase in urokinase inhibitory activity proved cell-density- and IL-1 dose-dependent. The IL-1-induced inhibition of urokinase was abolished by the administration of a polyclonal anti-rat PAI-1 IgG. Both effects of IL-1 were counteracted in a dose-dependent fashion by the soluble IL-1 receptor (which specifically complexes with IL-1), and by a highly-specific IL-1 receptor antagonist suggesting that the IL-1 effects are receptor-mediated. The present observations indicate that ovarian PA activity is subject to inhibition by IL-1 probably by way of PAI-1 of theca-interstitial origin. Inasmuch as IL-1 may be involved in initiating and maintaining the preovulatory cascade, the periovulatory activation of plasminogen must be accomplished by agents other than IL-1.

Animals↗
PubMed1994

Ultrasound transmission gel in the vagina can impair sperm motility.

The effect of ultrasound transmission gel on sperm motility was assessed because of a few unsatisfactory post-coital tests, encountered after vaginal ultrasonography in otherwise normal couples. Swim-up samples of spermatozoa from donors and patients with asthenozoospermia were incubated in ultrasonic transmission gel at various concentrations. Sperm progressive motility and viability were checked. Donor sperm progressive motility declined from 90.9 +/- 2.5% (mean +/- SD) to 30.6 +/- 2.7% (P < or = 0.001) within 18 h at a gel concentration of only 10% (by volume). There were no progressive motile spermatozoa after incubation in 80% gel. In the swim-up fraction from asthenozoospermic patients, motility declined from 92.2 +/- 2.5% to 11.6 +/- 2.1% (P < or = 0.001) within 130 min at a gel concentration of 10% (by volume). Eosin staining for viability demonstrated that the loss of motility was mostly due to loss of viability. The use of ultrasound transmission gel should be avoided during follicular follow-up close to the date of expected ovulation in couples who practise dated natural intercourse or cervical insemination. Normal saline is an adequate substitute in this period with relatively large follicles.

Cell Survival↗
PubMed1994

Trophoblasts circulating in maternal blood as candidates for prenatal genetic evaluation.

Trophoblasts have been detected in uterine venous blood, lung parenchyma and maternal blood in the first trimester. Their dilution within maternal leukocytes has been recently estimated to be 1:10(-6). The objectives of this study were to enrich peripheral maternal blood preparations for trophoblast cells, to isolate trophoblasts from the enriched preparation by highly specific markers and to assess fetal cell total number of chromosomal copies by fluorescence in-situ hybridization (FISH). Negative and positive selections for trophoblasts were performed. To assess the efficacy of the enrichment methods, a model mimicking the in-vivo conditions was established. Purified first trimester trophoblasts were prepared from first trimester placentas and were mixed with leukocytes from non-pregnant women in various concentrations. Magnetic beads coupled with antibodies to the common leukocyte antigen (CD45) or to antitrophoblast specific antigens (Trop1, Trop2 and GB25), were attached to peripheral maternal blood cells or to the prepared mixed cell populations. The expression of alpha human chorionic gonadotrophin (alpha HCG) or of human placental lactogen (HPL) by the remaining cells was examined by two means: (i) immunocytochemistry, using monoclonal antibodies against HPL and alpha HCG to stain fetal cells; (ii) reverse transcriptase polymerase chain reaction (RT-PCR), using specific primers for exons of the HPL or alpha HCG mRNAs. Results revealed that HPL- and alpha HCG-expressing cells could be identified in maternal blood only in very rare instances. On the other hand, expression of alpha HCG and HPL by only 100 purified first trimester trophoblasts artificially mixed with peripheral leukocytes at a ratio of 1:10(-5) could be identified by both immunocytochemistry and RT-PCR.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1993

[Adverse effects of tamoxifen on the female genital tract].

Tamoxifen is an established adjuvant therapy for breast cancer. It exerts both estrogenic agonist and antagonist effects on target tissues. Since the use of tamoxifen is expanding, it is expected that more women will suffer from its side-effects. 3 women aged 48, 48, and 65, respectively, who were treated with tamoxifen, were referred for evaluation of possible side-effects. They had, respectively, endometrial hyperplasia, a unique sonographic appearance of the endometrium resembling neoplasia, and an ovarian cyst.

Aged↗