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Biomedical subjects

E Sivan

Publications and source records attributed to E Sivan.

At least 37 records · Page 2Linked to original sources
PubMed1996

Dietary vitamin E prophylaxis and diabetic embryopathy: morphologic and biochemical analysis.

OBJECTIVE: In this study we sought to determine whether dietary supplementation with vitamin E, a known antioxidant, would reduce the incidence of diabetic embryopathy in an in vivo rat model. STUDY DESIGN: Eighty-day-old Sprague-Dawley rats were assigned to one of five groups: two control groups (groups 1 and 2) and three diabetic groups (groups 3, 4, and 5). One group of controls (group 2) and one group of diabetic rats (group 4) received dietary supplements of vitamin E (440 mg/day). The other three groups (groups 1, 3, and 5) received a normal diet only. Group 5 received insulin therapy to control glucose levels. On day 6 of gestation diabetes was induced in groups 3, 4, and 5 with streptozotocin (65 mg/kg). Animals were killed on day 12; embryos were examined for size, protein content, evidence of malformations, and superoxide dismutase activity. RESULTS: In both groups (groups 3 and 4) of diabetic rats the mean blood glucose level than was significantly higher in controls. Insulin-treated animals (group 5) had glucose levels that were comparable to those of controls. The unsupplemented diabetic group had a neural tube defect rate of 21.48% +/- 9.6% (percentage of neural tube defects per rat) and a resorption rate of 21.37% +/- 20.39% (percentage of resorptions per rat) as compared with rates in the supplemented diabetic group of 6.92% +/- 4.08% and 2.17% +/- 3.74%, respectively (p < 0.01). Groups 1, 2, and 5 had similar neural tube defect rates (6.63% +/- 5.0%, 5.01% +/- 4.87%, and 3.55% +/- 5.92%, respectively. Vitamin E levels, measured by high-performance liquid chromatography, were significantly higher in maternal serum and embryos in the supplemented groups (p < 0.001) than in controls. Superoxide dismutase activity was reduced in the diabetes groups and was not affected by vitamin E therapy. CONCLUSIONS: Supplementation with the antioxidant vitamin E confers a significant protective effect against diabetic embryopathy and may potentially serve as a dietary prophylaxis in the future. We postulate that this protective effect is mediated by a reduction in the oxidative load induced by hyperglycemia.

Animals↗
PubMed1996

The changing presentations of diabetic ketoacidosis during pregnancy.

The purpose of the present study was to examine the presentation and outcomes associated with diabetic ketoacidosis (DKA) in pregnancies complicated by diabetes. Eleven episodes (2%) of DKA were diagnosed during the 10-year study period. All patients were under close observation by the Diabetes-in-Pregnancy Service. Plasma glucose levels of less than 200 mg/dL were present in 4 of the 11 patients (36%), 10 (90%) of whom presented with nausea, vomiting, and decreased caloric intake. Two subsequently had fetal distress necessitating cesarean section. One fetal death occurred in a patient treated with subcutaneous insulin. Despite contemporary methods of diabetes care, near-normal plasma glucose levels are not enough to preclude diabetic ketoacidosis. Nausea, vomiting, and decreased caloric intake in an otherwise normal pregnant, diabetic woman requires evaluation to exclude ketosis.

Diabetes, Gestational↗
PubMed1996

Endometrial resection vs. abdominal hysterectomy for menorrhagia. Correlated sample analysis.

OBJECTIVE: To compare hysteroscopic endometrial resection with transabdominal hysterectomy in women with menorrhagia who failed to respond to conservative treatment. STUDY DESIGN: In order to attain correlated samples, only patients with a normal-sized or moderately enlarged uterus were included in the study. RESULTS: The operating time, hospital stay and number of women requiring postoperative blood transfusion was significantly lower in the hysteroscopy group. Following hysteroscopy, uterine perforation occurred in three patients, fluid overload in two and dilutional hyponatremia in one. Laparotomy was performed for suspected bowel injury in two cases. The main complication in women undergoing hysterectomy was postoperative fever (36.5%). One case of vesicovaginal fistula was diagnosed seven days postoperatively. CONCLUSION: The results indicate that endometrial resection, with its low cost and prompt recovery, offers a promising alternative treatment for women with abnormal uterine bleeding.

Adult↗
PubMed1995

Modulated excitability: a new way to obtain bursting neurons.

Classical burster models are based on a fast system that either oscillates or is quiescent, depending on temporarily fixed values of slow variables. In a study of the lobster heart ganglion, we found a new type of burster for which the fast system is globally stable for all relevant fixed values of the slow variables. We describe how this burster works and speculate on its biological significance.

Animals↗
PubMed1995

Glyburide crosses the placenta in vivo in pregnant rats.

Non-insulin-dependent diabetes mellitus (NIDDM) is normally treated by oral hypoglycaemic agents, but their use is excluded during pregnancy because of their potential teratogenic and hypoglycaemic effects on the fetus. This caveat was recently questioned as glyburide was shown to cross an isolated cotyledon in vitro in insignificant amounts. In the present study, placental transport of glyburide in vivo was examined as an indispensable step towards clinical trials. Tritiated glyburide, C14 albumin or C14-labelled diazepam were injected into 13, 9 and 11 pregnant rats, respectively and the radioactivity was measured thereafter in maternal blood and in whole fetal extracts. The ratios between radioactivity in fetal tissue to that in maternal blood for glyburide (0.535 +/- 0.068) were similar to those of diazepam (0.641 +/- 0.057) which readily crosses the placenta. However, they differed significantly from those for albumin (0.048 +/- 0.0004) which does not cross. Moreover, glyburide in fetal tissue consistently reflected its concentration in maternal blood when measured at consecutive intervals after intravenous injection in the mother. In contrast, albumin in fetal tissue was low at all time points regardless of its levels in maternal blood when measured at different times after injection. These data suggest that glyburide crosses the placenta of pregnant rats and should therefore be considered with caution as a hypoglycaemic agent in the treatment of gestational diabetes.

Animals↗
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

Outcome of hysteroscopic resection of submucous myomas for infertility.

OBJECTIVE: To examine the reproductive outcome after operative hysteroscopic resection of submucous myomas in women for whom no other infertility factor was identified. DESIGN: Fifteen infertile women with submucous myomas underwent an intensive workup to exclude other causes of infertility. Operative hysteroscopy for resection of the submucous myomas was performed using a rigid 26 French resectoscope (Karl Storz GmbH & Co., Tuttlingen, Germany). SETTING: Academic tertiary referral center. RESULTS: The mean +/- SD duration of the procedure was 25.5 +/- 5.6 minutes. No operative or postoperative complications occurred and all patients were discharged within 6 hours. The follow-up period was 12.0 +/- 4.2 months (mean +/- SD). Seven women conceived (pregnancy rate of 47%) and six of them subsequently delivered at term. CONCLUSION: The results of this study indicate that operative hysteroscopy achieved a pregnancy rate comparable to myomectomy via laparotomy. These results suggest that operative hysteroscopy is the procedure of choice for the resection of submucous myomas in infertile women.

Adult↗
PubMed1995

Changes mimicking endometrial neoplasia in postmenopausal, tamoxifen-treated women with breast cancer: a transvaginal Doppler study.

In menopausal patients with breast cancer who receive tamoxifen therapy, transvaginal sonography may show an abnormal endometrium. Our objective was to evaluate the effects of prolonged tamoxifen therapy on endometrial blood flow in postmenopausal patients with breast cancer, and to correlate blood flow characteristics with the sonographic appearance of the endometrium and its pathology. Transvaginal color Doppler ultrasound examinations were performed on 45 postmenopausal women (age range 54-70 years) with breast cancer, who had been treated with tamoxifen for 1-3 years. Twenty women (Group 1) had a thick, irregular, cystic endometrium of > or = 5 mm, and 25 (Group 2) showed a thin endometrium of < 5 mm. The blood flow response was assessed by visualization of arterial waveforms in the endometrial and subendometrial regions with a transvaginal color flow imaging system. Resistance indexes (RI) were calculated for analysis and correlated with endometrial appearance and histology. The mean RI in Group 1 was 0.39 +/- 0.10 (range 0.32-0.54), while the mean RI in Group 2 was 0.79 +/- 0.10 (range 0.54-0.90; p < 0.001). On histology, 12 patients in Group 1 showed atrophic endometria confirmed by hysteroscopy, while in the remaining eight, endometrial polyps were found. In Group 2, all patients had scanty, atrophic endometria. Six of the eight patients with endometrial polyps had an RI of < 0.4 and none had malignant changes. These data suggest that tamoxifen therapy in women with postmenopausal breast cancer induces endometrial, morphological and blood flow changes, mimicking endometrial neoplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Reproductive outcome following hysteroscopic management of intrauterine septum and adhesions.

The reproductive outcome of women with repeated abortions or infertility was assessed following treatment by operative hysteroscopy for an intrauterine septum or adhesions. A prospective follow-up study (mean +/- SD, 21.1 +/- 10.3 months) of 47 patients with an intrauterine septum (36 suffering from infertility and 11 from recurrent abortions) and 36 patients with intrauterine adhesions (24 complaining of infertility and 12 of recurrent abortions) was performed. The pregnancy rate in infertile women following hysteroscopic resection of an intrauterine septum or adhesions was 53 and 48% respectively. The pregnancy wastage in women with recurrent abortions who underwent hysteroscopic resection of an intrauterine septum or adhesions decreased postoperatively from 87.5 to 44.4% and from 86.5 to 42.8% respectively. Our results suggest that hysteroscopic resection of an intrauterine septum or adhesions may benefit patients suffering from infertility or recurrent pregnancy wastage.

Abortion, Habitual↗
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

The interrelationship between ethnicity and gestational diabetes in fetal macrosomia.

OBJECTIVE: To determine the possibility of an ethnic influence on the development of macrosomia (birth weight > 90th percentile for gestational age) in gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: We prospectively followed all African-American and Latino women enrolled in the Temple diabetes-in-pregnancy program. GDM was diagnosed in 103 African-American and 36 Latino women during the study period (1991-1994) according to the criteria of Carpenter and Coustan. All women were treated according to our previously published protocols. Data were collected on gestational weight gain, previous history of macrosomia, body mass index (BMI), and level of maternal glycemic control. RESULTS: Insulin therapy was required in 53 women (37.5%) to maintain fasting blood glucose levels at < 95 mg/dl and 2-h postprandial levels at < 120 mg/dl. Macrosomia developed in 50% of the neonates of Latino women versus 19% of neonates of African-American women (relative risk 2.68; 95% confidence interval 1.57-4.59). Potential confounding factors were not significantly different between the Latino and African-American women: mean blood glucose 96.6 +/- 15.7 vs. 96.5 +/- 22.4 mg/dl; BMI 29.0 +/- 5.5 vs. 31.5 +/- 8.2 kg/m2; pregnancy weight gain 29.2 +/- 12.7 vs. 30.9 +/- 20.5 lb; and parity 1.8 +/- 1.5 vs. 1.6 +/- 1.4, respectively. CONCLUSIONS: We have demonstrated that Latino women with GDM are at higher risk for having macrosomic infants in comparison with African-American women. This ethnic variation in fetal growth may be due to varying influences of in utero growth promoters among these populations as well as underlying genetic factors.

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↗
PubMed1994

Should lysis of adhesions be performed when in-vitro fertilization and embryo transfer are available?

This study was undertaken to report the results of microsurgical lysis of peri-adnexal adhesions and identify the patients who should be offered surgery and those who should be treated by in-vitro fertilization (IVF). In all, 19 women had filmy adhesions and 32 had dense adhesions; 68.4% of women with filmy adhesions conceived compared with 34.4% of women with dense adhesions (P = 0.02). In patients with filmy adhesions, the cumulative pregnancy rate 2 years after operation (47%) is similar to that reported after five cycles of IVF (52%), leading us to conclude that such patients should be offered surgery first. Dense adhesions are best treated by IVF. Lysis of filmy adhesions produces a similar intra-uterine pregnancy rate whether performed by laparotomy (57.9%) or laparoscopy (56.6%). As operative laparoscopy offers the greatest patient comfort, it is the treatment of choice in these patients.

Adnexal Diseases↗
PubMed1993

Currently recommended oral regimens for ritodrine tocolysis result in extremely low plasma levels.

OBJECTIVE: Our aim was to compare plasma drug levels in patients receiving ritodrine intravenously with those in patients receiving ritodrine orally at recommended dosages. STUDY DESIGN: Plasma samples from 20 pregnant patients treated with intravenous ritodrine (50 to 300 micrograms/min), 9 patients treated with oral ritodrine only (60 to 120 mg per 24 hours), and 9 patients treated first with intravenous and subsequently with oral ritodrine were analyzed for ritodrine concentration with the use of high-performance liquid chromatography. RESULTS: Average plasma ritodrine levels of patients receiving different intravenous dosages ranged from 27.8 +/- 3.5 to 113.3 +/- 38.8 ng/ml. Levels during oral therapy ranged between 9.8 +/- 3.2 and 13.8 +/- 4.4 ng/ml. In both modes of drug delivery, concentrations were significantly correlated with doses. In patients treated first with intravenous ritodrine and subsequently with the oral form, plasma concentrations during oral therapy averaged 27.7% +/- 18.8% of those obtained during intravenous infusion. CONCLUSION: Subtherapeutic plasma concentrations might be responsible for the failure to demonstrate clinical benefits of oral ritodrine in prevention of recurrent preterm labor. A twofold to threefold increase in the maximum recommended oral dosage of ritodrine should be considered, especially for patients who had previously required relatively high intravenous infusion rates (> 100 micrograms/min).

Administration, Oral↗
PubMed1992

Acoustic stimulation as a diagnostic test: comparison with oxytocin challenge test.

The usefulness of an acoustic stimulation test as a marker of fetal well-being was evaluated in a randomized controlled study of 121 pregnant women exhibiting a non-reactive fetal non-stress test at term. The women were randomly divided into two groups; those in the first group (n = 62) underwent an acoustic stimulation test immediately prior to an oxytocin challenge test, while those in the second (n = 59) underwent an oxytocin challenge test only. Fetal response to the acoustic stimulation was non-reactive in 22.5% of the women tested in the first group. The incidence of abnormal oxytocin challenge test among the women who were previously subjected to an acoustic stimulation was somewhat lower than among those who did not (14.5% vs. 23.7%), but the difference was not significant. In the prediction of an abnormal oxytocin challenge test, a non-reactive acoustic stimulation test had a sensitivity of 100%, a positive predictive value of 64% and a specificity of 91%. As a single test for the prediction of fetal distress in labor (n = 62), the acoustic stimulation test had a specificity and a positive predictive value similar to those of the oxytocin challenge test (n = 121), and its sensitivity was even higher (88% vs. 71%). We conclude that the acoustic stimulation test is at least as reliable as the oxytocin challenge test in the evaluation of fetal well-being in women exhibiting a non-reactive non-stress test at term.

Acoustic Stimulation↗