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Biomedical subjects

U Schwartz

Publications and source records attributed to U Schwartz.

At least 37 records · Page 2Linked to original sources
PubMed1983

Effects of various replacement oestrogens on hepatic transcortin synthesis in climacteric women.

The influence of peri-menopausal oestrogen replacement therapy upon protein synthesis in the liver was investigated. Changes in the cortisol-binding capacity of transcortin (TC-BC) were utilized as an indicator of hepatic oestrogen sensitivity. Forty-two climacteric women were studied before and after treatment with various drugs at different doses (patients receiving identical compounds served as their own controls for the evaluation of dosage effects; duration of medication: 14 days at each dose). Oral administration of oestriol (1 and 2 mg daily; n = 6), oestriol (1 and 2 mg daily) + oestradiol-17 beta (2 and 4 mg daily; n = 8), oestradiol valerate (1, 2, 4 and 6 mg daily; n = 6), conjugated equine oestrogens (0.3 and 0.6 mg daily; n = 6), sodium oestrone sulphate (0.8 and 1.6 mg daily) + sodium equilin sulphate (0.2 and 0.4 mg daily; n = 6) and quinoestrol (25 micrograms daily; n = 6) failed to alter TC-BC. However, ingestion of higher doses of conjugated equine oestrogens (0.9 and 1.25 mg daily; n = 5) and quinoestrol (50 micrograms daily; n = 6) caused a significant rise (P less than 0.01). Ethinyloestradiol was given orally as a reference substance and elicited an elevation of expected magnitude. Vaginal administration of dienoestrol cream (1 mg daily; n = 4) did not change TC-BC. These data indicate that the hepatotrophic effects of replacement oestrogens vary depending on the preparation and dosage selected for treatment.

Climacteric↗
PubMed1982

Vaginal administration of ethinylestradiol: effects on ovulation and hepatic transcortin synthesis.

Ethinylestradiol (EE) was given vaginally to circumvent the intestinal metabolism and initial liver passage which follow oral intake. This route of administration was chosen in an effort to enhance the antiovulatory potency of EE, while decreasing adverse hepatic reactions. Vaginal tablets containing 20-30 micrograms of EE were taken daily by 7 ovulating volunteers from day 5 to day 25 of the menstrual cycle. The regimen resulted in serum EE levels of 62 +/- 27 pg/ml (mean +/- S.D.) 8-10 hours after insertion. Ovulation was inhibited in 5 women (monophasic basal body temperature curves, serum progesterone levels of 0.9 +/- 1.1 ng/ml during the second half of the treatment cycle). The cortisol-binding capacity of transcortin was significantly elevated in all subjects (52.3 +/- 6.4 micrograms/100 ml; controls 25.7 +/- 2.2 micrograms/100 ml). These findings indicate that intravaginal EE is twice as potent as oral EE in regard to inhibition of ovulation as well as stimulation of the hepatic transcortin synthesis. Vaginal administration apparently increases the bioavailability of EE; it does not facilitate a selective reduction of estrogenic effects upon the liver.

Adult↗
PubMed1982

Anti-estrogenic effects of contraceptive progestins on the dynamics of gonadotropin release.

The hypophysiotropic effects of ethinylestradiol (EE) alone and in combination with three different progestins at various doses were assessed in 39 normal women. The compounds were given orally for 7 to 21 days. Serum LH and FSH were measured before and after GnRH double stimulation (2 x 25 micrograms i.v. at a two-hour interval); the ratio between second and first response served as an index of gonadotropin-synthesis capacity. Compared to pretreatment early follicular phase controls (LH and FSH ratios of 1.3 and 1.4), administration of 40 and 50 micrograms of EE daily elicited a significant amplification of LH and FSH synthesis (LH ratios of 2.2 and 3.3; FSH ratios of 2.8 and 3.3). By contrast, 80 micrograms of EE daily caused little change. The EE-induced rise of pituitary responsiveness to GnRH could be counteracted by the addition of progestins. The degree of inhibition as dependent on the type and dose of the progestational compound. It is concluded that the standardization GnRH double stimulation technique may serve as a pharmacodynamic model to quantitate the estrogenic and anti-estrogenic effects of contraceptive steroids at the pituitary level.

Adult↗
PubMed1982

[Operative complications of laparoscopic tubal sterilization with Bleier clips (author's transl)].

The operative complications of 1613 laparoscopic tubal sterilization with Bleier clips were evaluated in a prospective study at the Stadtkrankenhaus Offenbach/M from March 1978 to July 1981 (1239 interval and 374 postabortal procedures; two-puncture technique under general endotracheal anaesthesia). No major complications requiring laparotomy occurred. Minor intraoperative complications were observed in 8.4% of cases. Clip-related problems were encountered in 1.9% (slight tubal or mesosalpingeal bleeding). Other complications included haemorrhage at the puncture site (2.4%), preperitoneal emphysema (1.8%) and uterine perforation during curettage (1,6%). Technical difficulties were recorded in 8,4% of sterilizations; in 6.6% more than one clip per tube was placed to effect complete tubal occlusion. Adnexal pathology prohibited bilateral clip application in 4 women (0.3%). Postoperative complications were negligible. No pregnancies have yet been reported during a mean follow-up period of 17 months. A successful refertilization procedure was performed on one patient. It is concluded that this technique represents a commendable alternative to convention methods of tubal sterilization due to its low operative morbidity, acceptable contraceptive safety and potential reversibility.

Abortion, Legal↗
PubMed1981

XY gonadal dysgenesis: aberrant testicular differentiation in the presence of H-Y antigen.

Six patients with pure nonmosaic 46,XY gonadal dysgenesis (XY GD) and histocompatibility H-Y antigen titers in the normal male range (H-Y+) are presented. Clinical characteristics included a female phenotype, masculine skeletal characteristics, signs of virilization, and primary amenorrhea. All individuals had unambiguous female external genitalia, a hypoplastic uterus, bilateral tubes, and streak gonads. Histomorphologic evaluation of the gonads revealed various abortive testicular and ovarian elements capable of steroid production. Gonadal tumors were found in 4 patients (gonadoblastoma, dysgerminoma, granulosa cell tumor, myxofibroma). Plasma and urinary androgens and basal and stimulated gonadotropin levels were elevated prior to gonadectomy. Data show that the presence of the H-Y antigen per se does not guarantee normal testicular organogenesis. It is hypothesized that defective H-Y antigen binding to its gonadal receptors triggers aberrant testicular differentiation in 46,XY H-Y+ GD.

Adult↗
PubMed1980

Medium dose cyproterone acetate (CPA): effects on hormone secretion and on spermatogenesis in men.

Medium dose cyproterone acetate (CPA; 10 mg daily p.o.) was administered to 10 fertile men for 12 weeks. Hormonal measurements and semen analyses were performed before, during (4th and 12th week) and after CPA treatment. At the hypothalamo-pituitary level CPA significantly reduced the hypophyseal storage and synthesis capacity for gonadotropins. Basal LH and FSH concentrations were suppressed by 30% and 40%, respectively; while basal prolactin was elevated by 75%. The episodic fluctuations of peripheral gonadotropins remained unaffected. At the testicular level CPA significantly decreased basal testosterone and dihydrotestosterone concentrations by 70% and 50%, respectively. The pulsatile pattern of androgen secretion was abolished. CPA also inhibited spermatogenesis and motility. No serious clinical side effects were observed. All changes appeared to be completely reversible. It is concluded that medium dose CPA induces progestational/anti-gonadotropic effects at the hypothalamo-pituitary level in addition to its antiandrogenic action at the testicular level.

Adult↗
PubMed1979

Short-term regulation of LH and FSH secretion in cyclic women. III. Effects of varying doses of two consecutive LH-RH injections on pituitary and ovarian response.

The effects of two consecutive LH-RH injections at 120 min intervals with either a varying first or second LH-RH dose on pituitary gonadotrophin response were investigated in 15 eugonadal women to study pituitary secretory processes. Each volunteer underwent a total of 4 LH-RH double stimulation tests. In group I (n = 8) the first LH-RH dose of each of the 4 tests was fixed at 25 microgram, whereas the second LH-RH dose consisted of either 6, 25, 100 or 400 microgram. In group II (n = 7) the first LH-RH dose varied between 6 and 400 microgram, while the second LH-RH dose was kept constant at 25 microgram. Serum gonadotrophin and serum ovarian steroid levels were determined by radioimmunoassay before and after LH-RH administration. The volunteers in both groups served as their own controls. A linear log-dose response relationship was found between the various doses of LH-RH injected and the corresponding LH and FSH elevations elicited. However, the dose of the first LH-RH injection also significantly influenced the gonadotrophin reaction after the second LH-RH injection in a linear log-dose response relationship. Serum levels of oestradiol, 17-hydroxyprogesterone and progesterone significantly increased in response to the elevated serum gonadotrophin levels after LH-RH stimulation during the 4 h test period, but the rise did not correlate to the LH-RH dose used. The results indicate that LH-releasing hormone stimulates not only the release, but also the synthesis of LH and FSH in a dose-related manner. These findings are consistent with our previously reported concept that the magnitude of LH and FSH response to the first LH-RH injection reflects the "storage capacity", while the increase observed after the second LH-RH injection represents the "synthesis capacity" of the gonadotrophs.

Adult↗
PubMed1976

Effects of ethinylestradiol on the renin-angiotensin-aldosterone-system and on plasma transcortin in women and men.

The effects of ethinylestradiol (1 mug/kg body weight daily) on plasma renin substrate concentration, other factors of the renin-aldosterone-system, and on the cortisol-binding capacity of transcortin were determined in 8 young men and 9 young women. The absolute and relative elevation of plasma renin substrate after 5, 14, and 24 days of ethinylestradiol administration was significantly (P less than 0.001) greater in females than males. Control and posttreatment transcortin levels were also higher in women than men, but the percentage increase did not differ between males and females. It is likely that sex differences in the response of plasma renin substrate to the estrogen are due to differences in hepatic synthesis and/or release of renin substrate. In females, plasma renin activity, angiotensin II concentration, and urinary aldosterone excretion rose significantly although less markedly than plasma renin substrate concentration, while in males only the increase in plasma angiotensin II concentration was significant. These results indicate that no safe conclusions on metabolic effects of estrogen treatment in women can be drawn from experiments carried out in male subjects.

Aldosterone↗
PubMed1975

A combined adsorption-gel filtration technique for the determination of the cortisol-binding capacity of transcortin.

A combined adsorption-gel filtration technique has been developed for the quantitation of the cortisol-binding capacity of transcortin: Endogenous steroids are removed from plasma by adsorption on uncoated charcoal. Saturation of the "stripped" binding sites of transcortin is accomplished by equilibrating the sample with a definite amount of labeled cortisol of low specific activity (0.1 muCi/mug). Transcortin-bound [4-14C]cortisol is isolated by gel filtration over Sephadex G-50 at 4 degrees C and measured by liquid scintillation counting. The cortisol-binding capacity of transcortin is calculated directly on the basis of the known specific activity of cortisol. The modification described eliminates methodological disadvantages associated with the original gel filtration procedures, i.e. the possible interference of various endogenous steroids with cortisol binding to transcortin, and the necessity of fluorometric or colorimetric determination of protein-bound cortisol. The values of the cortisol-binding capacity of transcortin in plasma obteined by this simplified assay are in close agreement with results reported in the literature (mean +/- S.D.): healthy males 261 +/- 23 mug/l) of transcortin-bound cortisol (n = 13), healthy nonpregnant females 255 +/- 31 mug/l (n = 15), and pregnant females prior to delivery 560 +/- 82 mug/l (n = 12).

Adsorption↗