Nachman Eckstein
Sheba Medical Center
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Featured researches published by Nachman Eckstein.
American Journal of Cardiology | 1996
Amos Pines; Enrique Z. Fisman; Itzhak Shapira; Yaacov Drory; Avraham T. Weiss; Nachman Eckstein; Yoram Levo; Mordechai Averbuch; Michael Motro; Heshi H. Rotmensch; Daniel Ayalon
Rest and exercise echocardiography (at dynamic and isometric exercise) were performed in 30 postmenopausal women (aged 54 +/- 4 years) with borderline to mild hypertension. They were then divided into 2 groups: 17 women who started oral hormone replacement therapy (0.625 mg/day conjugated estrogens or 2 mg/day estradiol) and a control group of 13 nonusers. After 6 to 9 months, a second echocardiography was performed in 26 women (4 withdrew). There were only a few changes in values obtained in the 12 controls at the end of follow-up compared with baseline. Primarily, these changes included a slight decrease in systolic blood pressure at rest and on exercise. Several significant morphologic and hemodynamic alterations appeared in 14 hormone users. Left ventricular cavity dimensions and mass became smaller: mean end-diastolic diameter decreased from 45.9 +/- 3 mm at baseline to 44.4 +/- 3 mm at study termination (p = 0.007). The corresponding values for end-systolic diameter were 25.8 +/- 4 mm and 23.9 +/- 4 mm (p = 0.006); for left atrium diameter, it was 34.5 +/- 4 mm and 32.5 +/- 4 mm (p = 0.001); for left ventricular wall width, it was 19.9 +/- 2 mm and 19.3 +/- 2 mm (p = 0.02); for left ventricular mass, it was 197 +/- 28 g and 179 +/- 32 g (p = 0.006). The resting aortic blood flow velocity and acceleration increased: 119 +/- 18 cm/s before therapy versus 129 +/- 23 cm/s while on hormone substitution (p = 0.04), and 13.6 +/- 3 m/s2 versus 16.5 +/- 4 m/s2 (p = 0.008), respectively. Mean rest to peak exercise systolic blood pressure difference became smaller after hormones: 39 +/- 19 mm Hg versus 28 +/- 13 mm Hg (p = 0.03) during dynamic exercise, and 43 +/- 22 mm Hg versus 25 +/- 13 mm Hg (p = 0.004) during isometric exercise. The above data probably indicate that with hormone replacement therapy, there is an improvement in cardiac function both at rest and during exercise.
Menopause | 1998
Amos Pines; Enrique Z. Fisman; Yaacov Drory; Itzhak Shapira; Mordechai Averbuch; Nachman Eckstein; Michael Motro; Yoram Levo; Daniel Ayalon
To evaluate the acute hemodynamic effects of 4 mg estradiol given sublingually. Design Rest and exercise echocardiographies were performed prior to estradiol administration. Then, another set of tests was done post-dose: rest examination at 1 h post-dose, isometric exercise at 65 min post-dose, and dynamic exercise at 100 min post-dose. Results The administration of 4 mg sublingual estradiol to 24 postmenopausal women (aged 48–58 years) was followed 60 min post-dose by a surge in mean estradiol serum levels (1759 ± 704 pg/ml). At rest a slight drop in systolic and diastolic blood pressure was measured after estrogen ingestion: 132 ± 24 mm Hg versus 127 ± 21 mm Hg, p < 0.05; 83 ± 11 mm Hg versus 78 ± 10 mm Hg, p < 0.02. There were no changes in resting heart rate, double product, or vascular resistance. The left heart cavities became smaller: the left atrium diameter decreased from 33.7 ± 4 mm to 32.3 ± 4 mm, p < 0.01; the end-systolic diameter decreased from 24.9 ± 3 mm to 23.6 ± 4 mm, p < 0.01; the end-diastolic diameter decreased from 44.5 ± 4 mm to 42.7 ± 4 mm, p < 0.01. The peak aortic blood flow velocity fell from 120 ± 19 cm/s to 116 ± 22 cm/s (p < 0.05), and the flow velocity integral fell from 26.3 ± 4 cm to 24.9 ± 5 cm (p < 0.01); the cardiac output underwent a small change, with borderline significance: 7 ± 2 L/min versus 6.7 ± 2 L/min, p = 0.06. Only minor changes in the hemodynamic and echocardiographic parameters were recorded after estrogen for both isometric and dynamic exercises. Analyses were also made for two subgroups: 13 normotensive women were compared with 11 hypertensive women. The post-estrogen decreases in resting blood pressure and in peak blood velocity were observed only in the hypertensive subjects, whereas the changes in heart dimensions and in flow velocity integral were the same in both subgroups. Conclusions Sublingual estradiol was associated with acute hemodynamic alterations mainly at rest but also after exercise. (Menopause 1998;5:79–85. ± 1998, The North American Menopause Society.)
General Pharmacology-the Vascular System | 1998
Amos Pines; Nachman Eckstein; Iris Dotan; Daniel Ayalon; Dalia Varon; Ofer Barnea; Gabriel Shavit
1. Sex hormones may influence gastrointestinal motility and thus may be responsible for symptoms that are common during pregnancy or hormone replacement therapy. The purpose of this study was to evaluate the effect of estradiol on the gut. 2. Segments of rat ileum (n=9) were suspended in an organ bath and exposed to increasing concentrations of carbachol, in the presence or absence of 17beta-estradiol. 17beta-estradiol markedly reduced the force developed by the ileum in response to carbachol. 3. These results suggest that estradiol reduces gastrointestinal motility.
American Journal of Obstetrics and Gynecology | 1988
Daniel Ayalon; Moshe Graif; Miriam Hetman-Peri; Jacques S. Abramowicz; Nachman Eckstein; Israel Vagman; Joseph Papo; Yacov Itzhak; Eliahu Caspi
Virilizing ovarian tumors are rare and establishing their exact location before operation is difficult. We report a case in which a small left ovarian tumor was seen with magnetic resonance imaging.
Maturitas | 1992
Nachman Eckstein; J. Foldes; Y. Feinstein; I. Vagman; A. Eshel; R. Steinberg; M. Statter; R. Limor; Daniel Ayalon
Thirty-five women with symptomatic fibroids were treated with monthly injections of 3.2 mg microcapsulated D-Trp-6-LHRH for 6 months. During treatment serum 17 beta-oestradiol levels decreased, falling to castration levels associated with a reduction in the volume of the fibroids. In 16 patients a complete calcium homeostasis and bone metabolism work-up was carried out during treatment and subsequently for a 6-month follow-up period. Bone mineral content (BMC) and Compton bone densitometry readings remained unchanged. There were significant increases in serum calcium phosphate and alkaline phosphatase concentrations. A slight although not significant increase was observed in osteocalcin and parathyroid hormone (PTH) serum levels. Serum 1,25(OH)2D3 values decreased significantly after 3 months of treatment. Urinary hydroxyproline/creatinine and calcium/creatinine ratios as well as 24-h urinary calcium values increased significantly during the treatment period but decreased rapidly to pretreatment values after 3 months in the follow-up period. The endocrine changes induced by the GnRH-agonist treatment were associated with reversible biochemical signs of increased bone turnover and no significant changes in bone mass, suggesting that the treatment can be administered safely for a period of 6 months in patients with oestrogen-dependent diseases.
Gynecologic and Obstetric Investigation | 1983
Daniel Rozenman; Daniel Ayalon; Nachman Eckstein; Alexander Eshel; Moshe Lancet
In 4 patients with hypothalamic amenorrhea, the pituitary responsiveness to an intravenous challenge of 20 micrograms synthetic gonadotropin-releasing hormone (GnRH) was evaluated before and following a 3-days treatment course with GnRH (100 micrograms/per day i.m.) or ethinyl estradiol, (100 micrograms/day orally). The amenorrheic patients all had normal or reduced levels of serum gonadotropins, no evidence of galactorrhea and no other endocrine abnormality. Following GnRH treatment basal luteinizing hormone levels as well as the luteinizing hormone and follicle-stimulating hormone responses to GnRH were markedly reduced when compared with responses to GnRH before the treatment. Responses to GnRH were significantly augmented after treatment with estrogens. In patients with previous treatment with GnRH the augmented estrogen-induced LH response to GnRH was abolished. These preliminary results support the pathophysiological concept that in amenorrheic patients with hypothalamic dysfunction long-term administration of GnRH does not result in an improvement but rather in a deterioration of pituitary gonadotropic function.
Maturitas | 2003
Amos Pines; Nachman Eckstein; Gideon Kopernik; Daniel Ayalon; Doron Comaneshter; Yair Frenkel
OBJECTIVE To examine the predictive value of bone mineral density measurements done as early as months 3 and 6 after initiation of alendronate therapy (10 mg daily) in osteoporotic women already using long-term hormone replacement therapy. METHOD Lumbar spine and femoral neck bone density (DPX by Lunar) were performed at baseline, 3, 6, 12 months of combined therapy. The study group included 45 women at baseline, but 2 dropped-out at day 67 and at month 6 because of gastric complaints, leaving 43 women for analyses. RESULTS Group characteristics at baseline were as follows: mean age 61+/-5 years, mean duration of HRT use 7+/-3 years, lumbar spine bone density 0.863+/-0.089 g/cm(2), with a t-score of -2.75+/-0.8 S.D., and femoral neck density 0.706+/-0.085 g/cm(2) with a t-score of -2.28+/-0.7 S.D. Bone density increased during 1 year of combined therapy, totaling a 3.2% gain for the spine and a 2.4% gain for the femur. Most of the annual change was already observed at month 3: 2.1% for the spine and 1.4% for the femur. Moreover, the baseline to month 6 percentage difference showed a very good correlation with the yearly outcome (r=0.74, P<0.001 for both spine and femur). When different arbitrary cut-off definitions for a successful treatment (1%, 1.5% or 2% gain in density) were used in analyses, in the majority of cases the bone density at 1 year, whether elevated or not, could be predicted by months 3 and 6 results. Although urine deoxypyridinoline decreased throughout the study period, demonstrating a significant time trend (P=0.001), the baseline to month 3 changes did not correlate with baseline to annual bone density results. CONCLUSIONS In specific clinical settings when patients or physicians are looking for a good way to anticipate whether additional alendronate in hormone users would turn out to be beneficial, bone density measurements performed as early as 3-6 months after initiation of therapy might give the answer.
Journal of Ultrasound in Medicine | 1988
Richard Jaffe; Jacques S. Abramowicz; Nachman Eckstein; Israel Vagman; Moshe Fejgin; Daniel Ayalon
Polycystic ovarian disease is characterized by menstrual disorders, infertility, obesity, and large ovaries. Large ovaries with multiple cysts are the direct cause of the high incidence of ovarian hyperstimulation during ovulation induction. Lately, gonadotropin‐releasing hormone (GnRH) analogues have been employed to decrease ovarian steroidogenesis and thus reduce the incidence of ovarian hyperstimulation. In this study the ovarian size was ultrasonographically assessed during chronic GnRH analogue treatment, revealing a significant reduction in ovarian volume. This decrease in volume results in a reduced incidence of hyperstimulation, and we think the ultrasonic scanning can be effectively used to assess the success of GnRH treatment.
Gynecologic and Obstetric Investigation | 1983
Daniel Ayalon; Nachman Eckstein; S. Avidan; Alexander Eshel; M. L’Hermite; Anne Caufriez; Irving M. Spitz; Edit Zylber-Haran
The prolactin responses to an oral challenge of L-dopa (0.5 g) and bromocriptine (2.5 mg) were studied in 31 hyperprolactinemic females without radiological abnormalities of pituitary fossa, in 12 hyperprolactinemic patients with minor radiological evidence suggesting the presence of a pituitary adenoma and in 16 normal volunteers in the early puerperium with physiological hyperprolactinemia. Administration of bromocriptine was followed by a similar suppression of prolactin secretion in the functional as well as the adenomatous hyperprolactinemic patients. By contrast, a significantly blunted response to L-dopa was noted in the patients with pathological hyperprolactinemia (with and without radiological abnormalities of the pituitary fossa). These results suggest that the L-dopa suppression test might serve as a reliable indicator to detect prolactin-secreting microadenomas in patients with persistent hyperprolactinemia and radiologically normal pituitary fossae.
Maturitas | 1999
Amos Pines; Avraham T. Weiss; Nachman Eckstein; Etta Nadler; Ofer Barnea; Daniel Ayalon; Gabriel Shavit
Long-term hormone replacement therapy (HRT) may be considered for primary and secondary prevention of cardiovascular diseases in postmenopausal women [1–3]. This cardioprotective effect has been attributed to several alterations which occur during HRT, such as changes in lipid profile, carbohydrate metabolism, hemostatic balance, endothelial function, and rate of development of coronary atherosclerosis [4,5]. Calcium channel blocking effect was also suggested as one of the underlying pathophysiological mechanisms related to the action of estrogens [6]. In principle, such property could be manifested by changes in heart rate and in the function of the conduction system. Herein, we report on antiarrhythmic and rate control effects of estradiol in human atrial strips. 2. Methods