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Biomedical subjects

M Notelovitz

Publications and source records attributed to M Notelovitz.

At least 73 records · Page 4Linked to original sources

The effects of benzodiazepines on hormones in women with idiopathic hirsutism.

A single blind study was planned to investigate whether benzodiapines would reduce androgens in women with idiopathic hirsutism. Placebo was given for the first month followed by four months of a benzodiazepine (chlorazepate 15 mg nocte or diazepam 10 mg nocte ). Plasma samples were collected during the follicular and luteal phases of each therapy month. Hair growth was assessed monthly. Eighteen women concluded the five months of the trial of whom ten received chlorazepate and eight diazepam. Comparison of follicular plasma samples during the placebo phase and fourth month of benzodiazepine found a significant increase in sex hormone binding globulin and a significant decrease in dehydroepiandrosterone sulphate with benzodiazepine therapy. No significant effects on hair growth were observed. A longer therapy time may be needed to demonstrate effects of benzodiapines on hirsutism. Further studies are needed to determine whether benzodiazepines affect hormonal parameters in normal men and women.

Adult↗

Coagulation and fibrinolysis in estrogen-treated surgically menopausal women.

The short-term effects of different types and doses of estrogen therapy on coagulation and fibrinolysis were studied in 35 surgically menopausal women. Dynamic tests of the coagulation cascade, tests indicative of ongoing, intravascular coagulation, and assessments of coagulation inhibition and fibrinolysis were performed. No clinically abnormal responses were found with the tested regimens--1 and 2 mg of 17 beta-estradiol and 0.625 and 1.25 mg of conjugated equine estrogens. Increased plasminogen antigen and activity were found with the conjugated estrogens but not with the 17 beta-estradiol preparations. The age of the woman had no effect on either the direction or magnitude of response to treatment. Estrogen therapy at the reported doses does not appear to adversely affect the coagulation-fibrinolysis systems of surgically menopausal women. Based on their ability to enhance plasminogen activity, conjugated estrogens may be preferred over the 17 beta-estradiol preparations for this clinical population.

Adult↗

Regulation of cytochrome P-450-dependent catechol estrogen formation in rat liver microsomes. Evidence for involvement of estrogen receptors.

Experiments were conducted to evaluate whether estrogen 2-hydroxylase activity in liver microsomes, the main pathway for oxidative metabolism of estrogens in the rat, is regulated by administration of synthetic estrogens. Ovariectomized rats were treated with ethinylestradiol (EE), 100 micrograms s.c. for 3 days. Liver microsomes from EE-treated animals showed a 2-fold increase over control in estrogen 2-hydroxylase activity measured over a substrate concentration range of 0.5 to 50 microM. Double-reciprocal plots of enzyme activity as a function of substrate concentration were linear; apparent Vmax values were 2-fold greater in microsomes from EE-treated animals while apparent Km values for control and EE preparations were not different. Administration of the triphenylethylene antiestrogen tamoxifen (TAM), 100 micrograms s.c. for 3 days, did not affect microsomal catechol estrogen formation activity, and apparent Km and Vmax values were comparable with controls. When EE and TAM were co-administered, no increase in microsomal estrogen 2-hydroxylase was observed, and apparent Km and Vmax values were not different from either control of TAM-treated preparations. Thus, acute administration of EE was associated with a specific increase in the apparent Vmax of estrogen 2-OHase activity, and this effect was not observed when TAM was co-administered with the estrogen.

Animals↗

Lipids and lipoproteins in women after oophorectomy and the response to oestrogen therapy.

The short-term effects of different types and doses of oestrogen on serum lipids and lipoproteins were studied in 35 oophorectomized women. After 3 months treatment, serum cholesterol levels were unaffected by 1 and 2 mg of micronized 17 beta-oestradiol or 0.625 and 1.25 mg of conjugated equine oestrogens. Triglyceride levels were significantly elevated after treatment with 1.25 mg of conjugated oestrogens. A trend towards a higher relative proportion of high-density lipoproteins and a lower relative proportion of low-density lipoproteins was observed for all four oestrogen regimens, however, statistical significance was not achieved. The proportion of very-low-density lipoprotein was unaffected by oestrogen treatment. The age of the oophorectomized women was found to have no effect on either the direction or magnitude of the lipid or lipoprotein responses to oestrogen. Using FSH depression as an index, 1.25 mg of conjugated oestrogens was found to be the most potent of the four oestrogen regimens tested. Therefore, with respect to lipid balance, little additional clinical benefit is achieved by using a more potent regimen and the risk of adverse side effects may be increased.

Adult↗

Combination estrogen and progestogen replacement therapy does not adversely affect coagulation.

Coagulation and fibrinolysis profiles of naturally menopausal women receiving conjugated estrogens (0.625 or 1.25 mg for 21 of 28 days) and medroxyprogesterone acetate (10 mg for seven of 28 days) for 18 months were compared with those of similar women receiving no hormone therapy. Tests indicative of the dynamics of the coagulation cascade, ongoing intravascular coagulation, and anticoagulation were performed. Hormone therapy had no effect on prothrombin times, activated partial thromboplastin times, or thrombin times. There was no evidence of intravascular coagulation in any of the groups as assessed by platelet counts, fibrinogen antigen and activity, and fibrin degradation products. Antithrombin III antigen and activity, alpha 1-antitrypsin antigen, and alpha 2-macroglobulin antigen, the natural inhibitors of coagulation, were also unaffected by hormone therapy. Plasminogen antigen levels were unaffected, but plasminogen activity was enhanced in the hormone-treated groups, suggesting a stimulatory effect on fibrinolysis. These data indicate that in terms of the coagulation system, healthy women can safely use a combined regimen of conjugated estrogens and medroxyprogesterone acetate.

Androstenedione↗

Effect of conjugated estrogens on vaginal blood flow in surgically menopausal women.

The effect of an intravenous bolus of 25 mg of conjugated estrogen (Premarin) on vaginal blood flow in seven surgically menopausal women was measured by a thermal conductance probe. Electrical power (0.8 W) was supplied to a resistance wire incorporated in the surface of the probe, and its surface temperature was monitored continuously for 30 minutes six times daily for 3 days. The mean temperature difference (delta T) between the heated probe surface and the vagina remained unchanged during a preinjection control day. While there were individual differences in response, analysis of mean delta T during the first day following the injection of the estrogen revealed a significant linear downward trend at delta T, indicating a rise in vaginal blood flow. Delta T plateaued on day 2 and showed a slight rise in the morning of day 3. It may be concluded that estrogen administered in this dose and form markedly increases vaginal blood flow.

Adult↗

Oestrogen--progestin therapy and the lipid balance of post-menopausal women.

The lipid and lipoprotein profiles of 20 post-menopausal women treated with cyclic conjugated oestrogens (0.625 or 1.25 mg) and medroxyprogesterone acetate (10 mg for 7 days) were compared to those of 18 untreated women of similar age and menopausal status. No statistically significant between-group differences were observed during the 18-mth period for cholesterol, triglycerides or lipoprotein distribution. After 12 mth, a significant shift in lipoprotein distribution manifested in the treated and untreated groups. The proportion of high-density lipoproteins significantly increased and that of the low-density lipoproteins significantly decreased. Although the shift was more pronounced in the treated group, there was no significant difference between the treated and untreated groups. These results indicated that such relatively nonandrogenic progestins as medroxyprogesterone acetate, have no adverse effects on the lipid milieu of post-menopausal women when used with long-term oestrogen therapy.

Cholesterol↗

Menopausal status associated with increased inhibition of blood coagulation.

Postmenopausal women receiving estrogen replacement therapy (ERT) are not as prone to inappropriate venous and arterial thrombosis as are younger women taking oral contraceptives. To establish whether menopausal status per se has any effect on the coagulation-fibrinolytic system normal premenopausal women (mean age 29 years) were compared with younger (mean age 23) and older (mean age 51) surgically menopausal women and a group of naturally postmenopausal women (mean age 53). The results show that in postmenopausal women, irrespective of age or type, the shift is away from clot formatiuon and toward clot inhibition and fibrinolysis as determined by static in vitro analysis. This was characterized by statistically significant increases in antithrombin III antigen, alpha 1-antitrypsin antigen, and plasminogen activity. These changes may help to explain in part why ERT does not appear to cause increased thrombosis in older women.

Adult↗

Low-dose oral contraceptive usage and coagulation.

A prospective investigation was initiated to assess the effect of a low-dose oral contraceptive containing 35 micrograms of ethinyl estradiol and 0.4 mg of norethindrone on blood coagulation and fibrinolysis. Twenty-four women were studied before, during, and after one year of treatment. Positive results included an accelerated activated partial thromboplastin time and an increase in fibrinolytic and anticoagulation factors as measured by alpha 1-antitrypsin antigen and plasminogen antigen and activity. Antithrombin III antigen was decreased but its activity was unaffected. There was no evidence of ongoing intravascular coagulation. No patient had a detectable thromboembolic event. In short, one year's usage of this low-dose oral contraceptive was not associated with a procoagulant hematologic profile.

Antigens↗

Effect of ethyl alcohol on maternal and fetal acid-base balance and cardiovascular status in chronic sheep preparations.

Thirteen chronically catheterized pregnant sheep were given intravenous infusions of 10 per cent ethyl alcohol in 5 per cent dextrose solution (15 mg/kg over two hours). Samples of blood from maternal femoral artery, uterine vein, and fetal brachiocephalic artery were drawn at hourly intervals before, during and after the infusions. Plasma was analyzed for alcohol concentration, protein concentration, haematocrit, PCO2 and pH. Maternal and fetal arterial blood pressures were monitored continuously. There were no significant differences between maternal and fetal arterial blood alcohol levels at any sampling interval nor was there any difference in elimination constants. Alcohol infusion did not produce any significant change in plasma protein concentration, haematocrit, PCO2 and pH, and mean arterial blood pressure in either mother or fetus. However, both maternal and fetal heart rate increased significantly following alcohol infusion.

Animals↗

Carbohydrate metabolism in relation to hormonal replacement therapy.

The effect of hormone replacement therapy on carbohydrate metabolism in menopausal women is briefly reviewed. Estrogen treatment has bi-phasic effect; abnormal glucose tolerance with a normal insulin level is commonly found within 3 months of treatment, followed by normalization of the glycemia when treatment is extended beyond one year. Normal tolerance usually occurs once treatment is stopped. Estrogens may therefore be regarded as being glucogenic (reversible blood glucose elevation) rather than diabetogenic (permanent hyperglycemia). With some exceptions, progestogens have little effect on glucose tolerance within the first 3-6 months of treatment; thereafter progressive hyperglycemia and hyperinsulinemia occur. Postulated mechanisms for the hormonal effect on carbohydrate metabolism are noted, including the possible synergistic effect of estrogens on progestogen glucogenic activity. The significance of chronic hyperglycemia and vascular disease is commented upon.

Blood Glucose↗