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Biomedical subjects

S Mashiach

Publications and source records attributed to S Mashiach.

At least 19 recordsLinked to original sources
PubMed1995

Sperm capacitation in humans is transient and correlates with chemotactic responsiveness to follicular factors.

In humans, only a small fraction (2-12%) of a sperm population can respond by chemoattraction to follicular factors. This recent finding led to the hypothesis that chemotaxis provides a mechanism for selective recruitment of functionally mature spermatozoa (i.e., of capacitated spermatozoa, which possess the potential to undergo the acrosome reaction and fertilize the egg). This study aimed to examine this possibility. Capacitated spermatozoa were identified by their ability to undergo the acrosome reaction upon stimulation with phorbol 12-myristate 13-acetate. Under capacitating conditions, only a small portion (2-14%) of the spermatozoa were found to be capacitated. The spermatozoa were then separated according to their chemotactic activity, which resulted in a subpopulation enriched with chemotactically responsive spermatozoa and a subpopulation depleted of such spermatozoa. The level of capacitated spermatozoa in the former was approximately 13-fold higher than that in the latter. The capacitated state was temporary (50 min < life span < 240 min), and it was synchronous with the chemotactic activity. A continuous process of replacement of capacitated/chemotactic spermatozoa within a sperm population was observed. Spermatozoa that had stopped being capacitated did not become capacitated again, which indicates that the capacitated state is acquired only once in a sperm's lifetime. A total sperm population depleted of capacitated spermatozoa stopped being chemotactic. When capacitated spermatozoa reappeared, chemotactic activity was restored. These observations suggest that spermatozoa acquire their chemotactic responsiveness as part of the capacitation process and lose this responsiveness when the capacitated state is terminated. We suggest that the role of sperm chemotaxis in sperm-egg interaction in vivo may indeed be selective recruitment of capacitated spermatozoa for fertilizing the egg.

Acrosome↗
PubMed1995

Macroglossia: prenatal ultrasonographic diagnosis and proposed management.

A case in which macroglossia was the sole unusual prenatal sonographic finding in a fetus affected with trisomy 21 is presented. The differential diagnosis of fetal macroglossia is given, emphasizing its strong relationship to fetal aneuploidy, together with the principles for evaluation and management.

Adult↗
PubMed1995

The development of the fetal eye: in utero ultrasonographic measurements of the vitreous and lens.

Our objective was to establish nomograms for fetal eye measurements from 12 weeks' gestation by using transvaginal and transabdominal high-resolution ultrasound techniques. A prospective cross-sectional study was performed on 450 normal singleton pregnancies between 12 and 37 weeks' gestation. Vitreous and lens circumferences were measured by transvaginal ultrasonography until 17 weeks, and by abdominal ultrasound between 18 and 37 weeks' gestation. Regression analyses were used to create nomograms, and several transformations were done to obtain linearity. Eye measurements of 12 fetuses at risk for ocular disturbances were plotted on the constructed nomograms. Linear relationships were fitted between vitreous (r2 = 0.79) and lens (r2 = 0.88) circumferences and gestational age. In addition, there was a significant correlation between these measurements and the biparietal diameter. Data of the fetuses at risk showed that disturbances in ocular growth were associated mainly with abnormal cerebral development. These normative data may be helpful in the prenatal diagnosis of suspected congenital syndromes that include, among their manifestations, ocular growth disturbances such as microphthalmos and anophthalmos.

Cross-Sectional Studies↗
PubMed1995

Atrial natriuretic peptide plasma level remains unchanged in various hypertensive disorders of pregnancy.

The decreased volume of maternal extracellular fluid in preeclamptics may result in a different rate of atrial natriuretic peptide secretion and thus affect its plasma levels. Our objectives were to determine whether there was a difference in plasma levels of atrial natriuretic peptide in the various hypertensive disorders of pregnancy. Forty-nine pregnant women in the third trimester of pregnancy were evaluated: 21 with preeclampsia, 17 with chronic hypertension during pregnancy and 11 normotensives. The atrial natriuretic peptide concentration was 13.9 +/- 5.9 pg/ml, 17.8 +/- 13.5 pg/ml and 16.7 +/- 7.4 pg/ml in the preeclamptics, chronic hypertensives and normotensives, respectively. The differences between the three groups were not statistically significant. Atrial natriuretic peptide plasma levels remained stable in the various hypertensive disorders of pregnancy.

Adult↗
PubMed1995

Endometrial blood flow response to hormone replacement therapy in women with premature ovarian failure: a transvaginal Doppler study.

OBJECTIVE: To evaluate the endometrial blood flow response to hormone replacement therapy (HRT) in women with premature ovarian failure who plan to enter an oocyte donation program. DESIGN: Transvaginal color Doppler ultrasound examinations were performed in women with ovarian failure before and during a cycle of standard HRT and in those with normal menstrual cycles. Blood flow response was assessed by visualization of arterial wave forms in the endometrial region. The transvaginal color flow mapping system was used. Resistance indexes were calculated for analysis and correlated with plasma E2 and P concentrations. PATIENTS: Eighteen women with ovarian failure (study group), and 12 volunteers with normal ovarian cycles (control group). RESULTS: Data for resistance indexes were divided into five phases according to the day of hormonal cycle: 0, pretreatment phase; I, early follicular phase (days 5 to 7); II, late follicular phase (days 11 to 13); III, early luteal phase (days 17 to 21); and IV, late luteal phase (days 23 to 25). All women with ovarian failure demonstrated continuous forward end-diastolic flow velocities at phase I, whereas none showed this pattern during the pretreatment period (phase 0). Women with ovarian failure in the early follicular phase had a significantly higher resistance index (0.85 +/- 0.1; mean +/- SD) than that in the late follicular phase (0.57 +/- 0.1), and the resistance index in the early luteal phase (0.67 +/- 0.1) was significantly higher than that of the late follicular phase. There was no difference in the resistance index between early and late luteal phases. A similar pattern of lower resistance index around midcycle was observed in the control group. However, a comparison of the resistance indexes between ovarian failure and control patients revealed a significant difference between values in the early follicular phase only (0.85 +/- 0.1 versus 0.68 +/- 0.1). In the late follicular phase and during the entire luteal phase, the mean resistance index did not differ between the study and control groups. CONCLUSIONS: The observed data suggest that standard HRT in women with premature ovarian failure enables restoration of endometrial blood flow to normal. This may imply uterine receptivity for oocyte donation.

Diastole↗
PubMed1995

Endometrial blood flow response to estrogen replacement therapy and tamoxifen in asymptomatic, postmenopausal women: a transvaginal Doppler study.

This study was conducted to evaluate endometrial blood flow characteristics in response to estrogen replacement therapy (ERT) and tamoxifen in asymptomatic postmenopausal women, and to correlate the resistance index (RI) with plasma estradiol levels. Transvaginal color Doppler ultrasound examinations were performed in 30 asymptomatic, postmenopausal women who demonstrated thin endometria (< 0.5 cm). Ten healthy women receiving ERT and ten women with breast cancer receiving tamoxifen comprised the study groups. Ten postmenopausal women free of any hormonal treatment comprised the control group. Blood flow response was assessed by visualization of arterial waveforms in the endometrial region. Resistance indices were calculated for analysis and correlated with peripheral blood levels of estradiol. All postmenopausal women treated with tamoxifen or ERT showed continuous forward end-diastolic flow velocities, while the menopausal women without treatment demonstrated partial forward end-diastolic flow. Resistance index values of non-treated women were invariably higher (mean 0.89, range 0.85-0.91) than in those on tamoxifen (mean 0.79, range 0.54-0.90; p < 0.05), while the lowest RI was obtained in women taking ERT (mean 0.66, range 0.54-0.90; p < 0.05). The plasma concentrations of estradiol in women on ERT were found to be significantly higher than those of the tamoxifen and control groups. The observed data suggest that ERT and tamoxifen modify normal postmenopausal endometrial perfusion. Tamoxifen had a weaker estrogenic effect on the endometrial blood flow resistance, and ERT enhanced endometrial blood perfusion through vasodilatation.

Antineoplastic Agents, Hormonal↗
PubMed1995

Adjuvant growth hormone therapy in poor responders to in-vitro fertilization: a prospective randomized placebo-controlled double-blind study.

The objective of the study was to assess the effect of growth hormone (GH) supplementation to a combined gonadotrophin-releasing hormone agonist/human menopausal gonadotrophin (GnRHa/HMG) treatment protocol on ovarian response in 'poor responders' undergoing in-vitro fertilization (IVF). GH or a placebo were administered in a prospective randomized double-blind manner. A total of 14 poor-responder patients (oestradiol < 500 pg/ml, less than three oocytes retrieved in two previous IVF cycles) were randomly allocated to a combined treatment of either GnRHa/HMG/GH (18 IU on alternate days, total dose 72 IU) or GnRHa/HMG placebo. No difference was found between the study and control groups in the number of HMG ampoules used, the number of follicles (> 14 mm) and serum oestradiol concentrations on the day of administration of human chorionic gonadotrophin (HCG), the number of oocytes retrieved and fertilized, and the number of embryos transferred. The GH group (n = 7) did not show a better ovulatory response in the study cycles; mean +/- SD serum oestradiol on day of HCG 411 +/- 124 versus 493 +/- 291 pg/ml, aspirated oocytes 2.2 +/- 1.5 versus 1.9 +/- 2.0. Interestingly, when the above results for the placebo group were compared with their previous cycles (serum oestradiol 403 +/- 231 pg/ml; 0.4 +/- 0.5 aspirated oocytes), a non-specific effect was found. Follicular recruitment, oestradiol secretion by mature follicles and the number of oocytes retrieved in poor responders were not improved by GH supplementation.

Adult↗
PubMed1995

The clinical value of umbilical artery Doppler velocimetry in the management of intrauterine growth-retarded fetuses before 32 weeks' gestation.

The objective of this study was to investigate the clinical utility of umbilical artery Doppler velocimetry in the management of very premature growth-retarded fetuses. The study comprised 34 fetuses between 26 and 34 weeks' gestation, diagnosed ultrasonically as suffering from intrauterine growth retardation. Based on the umbilical artery Doppler findings, patients were divided into 3 groups: group 1 (10 fetuses) with normal Doppler systolic/diastolic (S/D) ratios (within 2 SD of the mean for gestational age); group 2 (9 fetuses) with significant abnormal umbilical artery S/D ratios (above 2 SD of the mean for gestational age), and group 3 (15 fetuses) with absent or reverse end-diastolic flow. Fetal outcome was assessed in terms of neonatal mortality and morbidity, i.e. low umbilical artery pH (pH < 7.20) and Apgar scores. In group 1, all fetuses had a stable, normal S/D ratio; in group 2, 2 fetuses (22%) showed deterioration in the Doppler findings and were transferred to group 3, while in group 3, 3 of 15 fetuses (20%) showed improvement in the absence of end-diastolic flow and were thus transferred to group 2. Emergency cesarean section due to antenatal deterioration of the biophysical profile occurred in only 1 patient (10%) in group 1, compared to 33 and 87% in groups 2 and 3, respectively (p < 0.05). The other 9 patients in group 1 had normal vaginal deliveries at 36-37 weeks' gestation, with no perinatal complications. The mean expectant interval from admission to delivery in group 3 was 8.2 days, while in groups 1 and 2 it was 23.8 and 22.2, respectively (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Fetal pleural effusion: the risk of fetal trisomy.

Our objective was to review the association between fetal pleural effusion (FPE) and fetal aneuploidy. We conducted a retrospective survey of pregnant women who presented to our ultrasonographic unit between 1990 and 1991, and in whom the diagnosis of FPE was reached. All fetuses had karyotype investigation and a complete ultrasonographic search for associated anomalies. Six cases of FPE were identified. Trisomy 21 was found in 2 (33%). The English literature was reviewed and an additional 147 cases with FPE were collected, among them 6 cases of trisomy 21 and 1 of monosomy 45X. In this accumulated series the risk of aneuploidy in a fetus with an incidental finding of FPE was 5.8% (9 of 153), thus warranting a karyotype study.

Adult↗
PubMed1995

Polycystic ovarian syndrome: pregnancy outcome following in vitro fertilization-embryo transfer.

A retrospective study of a series of pregnant patients with polycystic ovarian syndrome following in vitro fertilization-embryo transfer was conducted to assess the outcome after ovarian stimulation by different protocols. Forty-one pregnancies were evaluated in patients with polycystic ovarian syndrome who conceived during in vitro fertilization-embryo transfer using human menopausal gonadotropin alone (17 pregnancies), or combined with gonadotropin releasing hormone analog (24 pregnancies). The demographic data of in vitro fertilization-embryo transfer cycles and pregnancy outcome were compared with the use of Student's t-test, the Mann-Whitney U test and Fisher's exact test, where appropriate. Among the pregnancies that were initiated following treatment, the protocol of the combination of the two was not associated with a higher rate of deliveries. The rate of first-trimester abortions was not statistically different between the two groups. These results suggest that the combined use of gonadotropin releasing hormone agonist and human menopausal gonadotropin in an in vitro fertilization program may not have beneficial effects on pregnancy outcome in patients with polycystic ovarian syndrome.

Adult↗
PubMed1995

Sonohysterography for ultrasonographic evaluation of tamoxifen-associated cystic thickened endometrium.

Most menopausal patients with breast cancer receive tamoxifen therapy. In these patients, TVS may show thickened, irregular cystic endometria. For better visualization of these patients' uterine cavities, we performed transvaginal sonohysterography. During vaginal ultrasonography, sterile saline was introduced by transcervical 8 French Foley catheter into the uterine cavity of 20 women who were referred with tamoxifen-associated cystic thickened endometria. In eight women, transvaginal sonohysterography provided the means to diagnose occult, free-floating endometrial polyps, whereas in 12 women, the fluid contrast augmented the diagnosis of an irregular cystic endometrial-myometrial junction. All 20 patients underwent diagnostic hysteroscopy: eight polyps, none of which were malignant, were confirmed and removed by hysteroscopic resection. Of the remaining 12 patients with an irregular endometrial-myometrial junction, endometrial curettage showed no significant pathologic findings. Transvaginal sonohysterography seems to enhance the differentiation between endometrial polyps that should be resected by operative hysteroscopy and an abnormal endometrial-myometrial junction that may benefit from biopsy sampling only.

Aged↗
PubMed1995

Twin pregnancies complicated by the death of one fetus.

The death of one fetus in a twin pregnancy can affect both the mother and the cotwin. Thirty women with twin pregnancies in whom the death of one fetus was diagnosed during the second half of pregnancy and a matched group of 30 women with uncomplicated twin pregnancies were investigated. The mean gestational age at delivery for the study and control groups was 32.0 +/- 5.0 (mean +/- SD) weeks and 32.8 +/- 3.9, respectively. Twelve pregnancies (40%) were monochorionic. In 15 (50%) the diagnosis was made during active labor. The cesarean delivery rate was higher in the study group than in the control group (18 vs. 11, chi 2 = 5.43, P < .02). The mean neonatal weight was similar in both groups (1,586 +/- 725 g vs. 1,543 +/- 691 g). The subgroup of neonates (n = 15) whose cotwins were diagnosed as dead during labor had higher birth weight as compared to the neonates (n = 15) in whom the diagnosis was made prior to delivery and were managed expectantly (1,829 +/- 859 vs. 1,346 +/- 474 g, P < .01). The week of delivery was similar in both subgroups. Neonatal mortality was 30% and 26.6%, while neonatal morbidity was 26.6% and 21.7%, respectively (NS). All the cases of neonatal mortality were in the subgroup of twins in which the diagnosis of in utero death was made before 32 weeks' gestation. The death of one fetus from a twin pregnancy did not significantly jeopardize maternal health, and the neonatal outcome in the remaining twins was primarily a function of gestational age.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1995

Combined vaginal-abdominal delivery of twins.

All cases of combined vaginal-abdominal deliveries at the Department of Obstetrics and Gynecology, Chaim Sheba Medical Center, over an eight-year period (1984-1991) were reviewed. During this period a total of 38,821 deliveries took place. Of 722 (1.9%) twin deliveries, 354 (48.8%) were by cesarean section; 19 were combined deliveries, including 5% of all twins delivered by cesarean section and 2.6% of all twins delivered. High transverse lie and prolapse of the umbilical cord were the main indications for delivery by cesarean section of the second twin. In order to diminish the number of combined deliveries and to increase obstetric skills and experience, a program or protocol for vaginal twin deliveries is indicated.

Breech Presentation↗