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J Geller

Publications and source records attributed to J Geller.

At least 73 records · Page 4Linked to original sources
PubMed1992

Inadequate adrenergic response to disopyramide-induced hypoglycemia.

OBJECTIVE: To report a case of disopyramide-induced hypoglycemia and to discuss the observed inadequate adrenergic response in this patient. Risk factors, possible etiologies, and preventive measures are also discussed. DATA SOURCES: References from case reports and review articles as identified by MEDLINE. DATA SYNTHESIS: A wide variety of drugs has been implicated as causing hypoglycemia. The mechanism for drug-induced hypoglycemia is known for the majority of these agents. Case reports of disopyramide-induced hypoglycemia have been reported in the literature, but the mechanism of action is unclear. We report a case of disopyramide-induced hypoglycemia in which counter-regulatory hormones, serum insulin, and C-peptide concentrations were obtained. From these data, it appears that disopyramide-induced hypoglycemia results from endogenous insulin secretion, with concomitant inadequate counterregulatory response. CONCLUSIONS: Although a rare occurrence, disopyramide-induced hypoglycemia is potentially life-threatening. Patients at risk for this reaction need to be identified prior to the institution of disopyramide therapy. Patients at risk for hypoglycemia should be monitored while on disopyramide and disopyramide blood concentrations should be maintained at the lower end of the therapeutic range, or alternative agents should be considered.

Aged↗
PubMed1992

Finasteride, an inhibitor of 5 alpha-reductase, suppresses prostatic dihydrotestosterone in men with benign prostatic hyperplasia.

The oral administration of finasteride, a 4-aza-steroid inhibitor of 5 alpha-reductase, decreases serum dihydrotestosterone levels, but has little effect on serum testosterone. The current study was designed to assess the effect of finasteride on dihydrotestosterone levels in the prostates of men with benign prostatic hyperplasia. In a double blind, placebo-controlled study, 69 men with symptomatic prostatic hyperplasia were treated with placebo or 1, 5, 10, 50, or 100 mg/day finasteride for 7 days before transurethral resection of the prostate. In the placebo group the mean concentration of prostatic dihydrotestosterone was 10.3 +/- 0.6 nmol/kg (+/- SE), and the mean concentration of testosterone was 0.7 +/- 0.1 nmol/kg. After 7 days of treatment with all doses of finasteride, prostatic dihydrotestosterone declined to 15% or less of control levels, and the testosterone concentration increased in a reciprocal fashion. Compared to the placebo group, there was no significant difference in the mean prostatic dihydrotestosterone level achieved in any of the finasteride-treated groups. However, prostatic dihydrotestosterone levels were lower in the groups receiving higher doses of the drug. In two additional patients, finasteride treatment for 2 days also caused a decrease in prostatic dihydrotestosterone levels. No significant adverse experiences occurred during the study. We conclude that finasteride causes profound decrease in prostatic dihydrotestosterone.

5-alpha Reductase Inhibitors↗
PubMed1991

The influence of lactose consumption on the association of oral contraceptive use and ovarian cancer risk.

The authors investigated the joint effects of diet and oral contraceptive use on ovarian cancer risk in 194 white women aged 65 years or less with epithelial ovarian cancer and 193 age- and residence-matched controls in Boston between 1984 and 1987 by using in-person interviews and self-administered food frequency questionnaires. Use of oral contraceptives for 3 months or more was associated with a modest protective effect for ovarian cancer (odds ratio (OR) = 0.7, 95 percent confidence interval (CI) 0.5-1.1). In women who consumed 11 g or less per day of lactose, use of oral contraceptives for 3 months or more was associated with a nonsignificant increased risk (OR = 1.6, 95 percent CI 0.8-3.2). In women who consumed more than 11 g per day of lactose, use of oral contraceptives for 3 months or more was associated with a substantially decreased risk of ovarian cancer (OR = 0.3, 95 percent CI 0.1-0.7). Within this group, the strongest association occurred with more than 4 years of total oral contraceptive use (OR = 0.2, 95 percent CI 0.1-0.6) and in those who had more than 2 years of oral contraceptive use after age 30 years (OR = 0.1, 95 percent CI 0.03-0.4). These results suggest that, with respect to ovarian cancer, lactose users may be the most likely to benefit from oral contraceptive use and that the benefit may be strongest when oral contraceptive use occurs after age 30 years.

Adult↗
PubMed1991

Benign prostatic hyperplasia: pathogenesis and medical therapy.

Epidemiologic studies in castrates strongly support the key role of the testis in the pathogenesis of benign prostatic hyperplasia (BPH). Since the testis secretes androgen and estrogen, both of these hormones have been implicated in BPH. Much information supports the important role of dihydrotestosterone (DHT) in BPH, including intraprostatic activities of enzymes that regulate DHT. Although controversy still exists, DHT levels in BPH may be higher than in normal prostate tissue. Based upon these findings and the ability to quantitate prostate size and function with reliable new techniques, suppression of androgen-mediated action has been tested to assess the validity of the DHT theory. A variety of drugs has been demonstrated to decrease prostate size by approximately 30% by either blocking secretion of circulating testosterone and adrenal androgen, inhibiting 5 alpha-reductase to prevent DHT formation, or blocking DHT binding to androgen receptors. Accompanying these changes in size was significant improvement in clinical symptoms of prostatism in about 50% of patients, when double-blind, large multicenter studies were conducted with one of these drugs. Although these results suggest a very important role for androgen, particularly DHT, in the pathogenesis of BPH, other abnormalities may coexist since significant numbers of patients do not show a total reversal of disease. There is strong indirect evidence for a possible role for estrogen in the pathogenesis of BPH, and studies are under way to test the effects of estrogen withdrawal on prostate size and symptoms. Similarly, dynamic aspects of prostatic obstruction, which are under alpha-adrenergic regulation, may also be a component of this disease and amenable to therapy with alpha-adrenergic blockers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1991

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Attitude of Health Personnel↗
PubMed1990

Effect of finasteride, a 5 alpha-reductase inhibitor on prostate tissue androgens and prostate-specific antigen.

Whole tissue dihydrotestosterone (DHT) and testosterone (T) concentrations have been measured after finasteride, a 5 alpha-reductase inhibitor, and this was compared to other methods of androgen inhibition. In 10 patients treated for 1 week with finasteride, whole tissue DHT decreased to a mean of 0.302 ng/g. This value was significantly less than DHT values in control patients (mean, 4.5 ng/g) and patients treated with either surgical castration (mean, 1.14 ng/g), megestrol (160 mg/day) plus diethylstilbestrol (0.1 mg), or megestrol plus ketoconazole (1200 mg/day; mean, 0.609). Tissue T levels were significantly increased in finasteride-treated patients (1.18 ng/g) compared to a mean of 0.171 ng/g in controls and 0.105 ng/g in megestrol-treated patients. Part of the prostate tissue obtained at surgery was mechanically separated into epithelium and stroma. The epithelial cells were homogenized, the supernate was assayed for prostate-specific antigen (PSA), an androgen-dependent protein, and the pellet was assayed for DHT and DNA. Epithelial cell PSA and DHT values significantly decreased in finasteride- and megestrol- plus estrogen-treated patients compared to controls. However, the slope and position of the regression lines for DHT vs. PSA in patients treated with megestrol plus low dose estrogen (r = 0.79) differed significantly (P less than 0.05) from the regression line relating epithelial DHT to PSA in patients treated with finasteride (r = 0.82). Since the regression slope for finasteride described a greater increase in PSA per unit change in DHT compared to the slope for megestrol plus estrogen, which lowers both DHT and T, finasteride, despite its drastic lowering of DHT, may have a modest residual androgenic effect related to its effect on tissue T.

5-alpha Reductase Inhibitors↗
PubMed1990

The effect of chromium picolinate on serum cholesterol and apolipoprotein fractions in human subjects.

Chromium has been implicated as a cofactor in the maintenance of normal lipid and carbohydrate metabolism. A deficiency of chromium results from diets low in biologically available chromium. Picolinic acid, a metabolite of tryptophan, forms stable complexes with transitional metal ions, which results in an improved bioavailability of the metal ion chromium. To determine whether or not chromium picolinate is effective in humans, 28 volunteer subjects were given either chromium tripicolinate (3.8 micromol [200 micrograms] chromium) or a placebo daily for 42 days in a double-blind crossover study. A 14-day period off capsules was used between treatments. Levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, and apolipoprotein B, the principal protein of the LDL fraction, decreased significantly while the subjects were ingesting chromium picolinate. The concentration of apolipoprotein A-I, the principal protein of the high-density lipoprotein (HDL) fraction, increased substantially during treatment with chromium picolinate. The HDL-cholesterol level was elevated slightly but not significantly during ingestion of chromium picolinate. Only apolipoprotein B, of the variables measured, was altered significantly during supplementation with the placebo. These observations show that chromium picolinate is efficacious in lowering blood lipids in humans.

Adult↗
PubMed1989

Comparison of dihydrotestosterone levels in prostatic cancer metastases and primary prostate cancer.

Dihydrotestosterone (DHT) concentration, a marker for biochemical differentiation and possible clonal origin of prostate tumors, was measured in cancer present in lymph nodes (LN) from patients with untreated metastatic prostate cancer and compared to levels in untreated primary prostate cancer. The mean DHT of 2.23 ng/g in LN (S.E. = 0.28, N = 22) was significantly less (P less than .001) than the mean DHT of 4.8 ng/g in primary cancer (S.E. = 0.52, N = 20). Since primary prostate cancer may be admixed with stromal tissue, while lymph node represents pure epithelial cell tumor, we chose for this comparison only the 20 prostate cancer tissues that were judged by our pathologist to contain 90% or more epithelial cell tumor. Using this selection criteria, we found that prostate stroma, which has an average DHT concentration 1.18 times higher than prostate epithelia, would have an insignificant effect on primary prostate tumor DHT concentration. These data suggest that the decreased DHT in prostate tumor cells present in LN metastases may be a marker for a clone of cells with metastatic potential. These findings are consistent with previous reports from this laboratory indicating that DHT concentration less than 2.4 ng/g in primary prostate cancer is a predictor of a reduced disease-free interval following androgen blockade in advanced prostate cancer.

Dihydrotestosterone↗
PubMed1989

Pathogenesis and medical treatment of benign prostatic hyperplasia.

Tissue concentrations of dihydrotestosterone (DHT) and the enzymes that regulate its level, such as 5 alpha-reductase, appear to play a major role in the pathogenesis of benign prostatic hyperplasia (BPH). This argument is strongly supported by the objective decreases in prostate size and improvement in symptoms of prostatism that occur following androgen withdrawal. A variety of androgen-withdrawal therapies for BPH have been reported since the early 1900s. Although success in the treatment of BPH has been claimed for all of them, including surgical castration, medical castration with progestational antiandrogens, gonadotropin-releasing hormone (GNRH)-agonist castration, or androgen-receptor blockade with pure antiandrogens such as flutamide, very few studies, until recently, have provided convincing objective evidence for therapeutic efficacy in BPH. Recently, magnetic resonance imaging (MRI) scanning and ultrasound have become available to quantify objective changes in prostate volume and have indisputably demonstrated that androgen withdrawal does significantly decrease prostate size. The consequences of this on clinical symptoms of prostatism are currently under study. Studies of the effect of 5 alpha-reductase inhibitors on prostatism are in progress. They hold promise for future treatment of BPH since they may decrease prostate size and DHT concentration without any effect on sexual function.

Adrenergic alpha-Antagonists↗
PubMed1989

Overview of benign prostatic hypertrophy.

Pathogenesis and therapy of benign prostatic hypertrophy (BPH) are reviewed. Elevated prostate dihydrotestosterone concentrations, increased 5 alpha-reductase activity in the hypertrophic prostate, and prostate atrophy following castration all suggest a significant role for dihydrotestosterone in the pathogenesis of BPH. An increasing plasma estrogen/testosterone ratio with age, and the presence of estrogen receptors in the prostatic stroma, indicate that estrogen also may be involved in the development of BPH. Symptomatic improvement of BPH with androgen withdrawal therapy (including castration, antiandrogens, GnRH agonists, and 5 alpha-reductase inhibitors), as well as effective estrogen withdrawal with tamoxifen, strongly supports the endocrine pathogenesis of BPH.

5-alpha Reductase Inhibitors↗