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Biomedical subjects

N H Ertel

Publications and source records attributed to N H Ertel.

At least 19 recordsLinked to original sources
PubMed1989

Decreased 3 alpha-androstanediol glucuronide levels in plasma and random urines in male pseudohermaphroditism caused by 5 alpha-reductase deficiency.

Concentrations of 3 alpha-diol glucuronide (3 alpha-diol G) in plasma and/or random urine samples were determined in seven subjects with familial male pseudohermaphroditism (FMP) due to 5 alpha-reductase deficiency (5 alpha-RD). All subjects were natives of an isolated Turkish village with a high incidence of consanguineous marriage. A specific and sensitive antibody to 3 alpha-diol was used for radioimmunoassay of 3 alpha-diol G after hydrolysis and chromatographic purification. The mean plasma 3 alpha-diol G in three subjects (31 ng/dL) was much lower than the normal male concentration (516 +/- 50) (+/- SE) and was even lower than normal female values (119 +/- 10.9 ng/dL). In five subjects, mean urinary 3 alpha-diol G in random urine samples was 7.6 (range 2.1 to 12.7) ng/mg creatinine. This was considerably decreased compared with the mean adult male concentration of 65.4 +/- 9.4 and even lower than normal age-matched nonhirsute female values (19.6 +/- 2.1 ng/mg Cr). To validate the use of 3 alpha-diol G/creatinine ratios in random urine samples, correlations of three consecutive eight-hour samples with 24-hour values were determined in 8 male and 3 female age-matched controls. There was an excellent correlation (r = .95) and the linear regression line (y = 0.51x + 2.58) indicates that the 24-hour excretion of 3 alpha-diol G in microgram/24 h is approximately twice the random urinary concentration in ng/mg Cr.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1988

Insulin and C-peptide in ascitic fluid and plasma and their relative responses to glucagon in patients with cirrhosis.

Insulin (IRI) and C-peptide dynamics were studied after iv glucagon in 5 nondiabetic patients with ascites due to cirrhosis of the liver. Plasma and ascitic fluid samples for glucose, IRI and C-peptide determinations were obtained before and 6, 10, 15, 20 and 30 min after glucagon injection. Ascitic fluid volumes, estimated by dilution of ip injected PAH, were 6.2 to 20.5 L. The mean fasting plasma glucose [88 +/- 6.7 mg/dl (SE)] and C-peptide (1.40 +/- 0.42 ng/ml) levels were normal; mean plasma insulin was increased (17.4 +/- 3.0 microU/ml). After glucagon injection, there was a subnormal rise in plasma glucose (PG) compared to 5 mild diabetic patients without liver disease (8.4 +/- 3.5 vs 76 +/- 7.4 mg/dl). The plasma C-peptide rise was less than that of plasma IRI (54% vs 192%). The mean basal ascitic fluid concentration of glucose was 86 +/- 9.4 mg/dl, IRI 13.2 +/- 2.9 microU/ml and C-peptide 3.09 +/- 0.49 ng/ml. Total calculated basal ascitic fluid contents of glucose was 5.2-23.3 g, IRI 47, 120-290,000 microU and C-peptide 15,750-66,420 ng. These were 3-10 times the quantity of these substances circulating in the plasma volume. After glucagon injection, there was no significant increase in ascitic fluid glucose or IRI, but there was a 43% increase in C-peptide concentration at 10 min. In ascitic fluid, the molar concentration of IRI was lower and C-peptide higher than plasma, resulting in a C-peptide: IRI molar ratio of 11.31, markedly higher than the published normal plasma ratio of 4.63.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Medical adrenalectomy for advanced prostatic cancer: clinical and hormonal effects.

We examined the effect of medical adrenalectomy on the clinical and hormonal responses in 50 men with disseminated prostatic carcinoma. Patients refractory to initial hormonal therapy were treated with aminoglutethimide and hydrocortisone (AG-HC) and evaluated by the criteria of the National Prostatic Cancer Project. Eight patients showed a partial response (PR), and 17 remained stable while receiving these medications. Survival times for these two groups averaged 87.8 and 38 weeks, respectively. In contrast, 17 men were unresponsive to this therapy, exhibiting progressive disease with a mean survival time of 18 weeks. Eight patients could not tolerate the drug regimen or were lost to follow-up. Serum and urinary hormone profiles determined serially during AG-HC therapy revealed that all measured serum androgens and estrogens were significantly lowered by AG-HC treatment; however, specific hormones, including free testosterone, dihydrotestosterone, estrone, and estradiol were suppressed to a greater degree in responders (R) as compared with nonresponders (NR). Urinary excretion of 17-ketosteroids did not change during AG-HC therapy, but specific androgen metabolites, including testosterone glucuronide and androstanediol glucuronide, were suppressed by 50% during AG-HC therapy. We showed modest clinical benefit of AG-HC therapy in advanced prostatic cancer. That greater hormonal suppression was associated with greater responsiveness to this therapy raises the hope that further manipulations directed against suppression of extratesticular androgens may be a useful approach as second-line treatment of advanced prostatic cancer.

Aged↗
PubMed1988

An eight-year experience with a very-low-calorie formula diet for control of major obesity.

We have utilized a very-low-calorie formula diet (VLCD) along with multidisciplinary group counselling in an attempt to achieve and maintain major weight loss in 4026 morbidity obese patients. Using a 420-cal protein supplement (Optifast), men lost weight, at an average of 4.6 +/- 0.9 lb/week and women, 3.1 +/- 1.1 lb/week. Men remained on the VLCD an average of 13.2 weeks, resulting in a mean weight loss of 66.0 +/- 8.1 lb; women remained on the fast an average of 14.1 weeks, with an average loss of 47.3 +/- 4.2 lb. Outcome analysis revealed that 25 percent of patients were unable to adapt to this approach, dropping out within the first 3 weeks. Of the patients remaining in the program, 68 percent lost considerable weight, but did not reach their goal; of this group, recidivism was extremely high, with only 5-10 percent maintaining weight loss after 18 months. Thirty-two percent of the patients successfully attained goal weight; the holding rate of this group has been considerably greater, with 30 percent of women and 58 percent of men maintaining weight loss (within 10 lbs) for a minimum of 18 months. Complications of obesity i.e. hypertension, type II diabetes mellitus, and hyperlipidemias were remarkably improved after weight loss. Complications of the VLCD including cardiac abnormalities, were minimal. Our 8-year experience strongly suggests that the VLCD approach using high quality protein supplement and multi-disciplinary counselling provides a reasonable success rate for achieving and maintaining weight loss in the morbidity obese population.

Adult↗
PubMed1987

The coexistence of male pseudohermaphrodites with 17-ketosteroid reductase deficiency and 5 alpha-reductase deficiency within a Turkish kindred.

Two distinct enzyme defects affecting androgen production and resulting in male pseudohermaphroditism were found in a Turkish kindred from a small isolated village in the Taurus mountains of southern Turkey. Pedigree analysis revealed the inter-relationships of 9 male pseudohermaphrodites. Six affected subjects had adequate steroid hormone analysis. Two adult male pseudohermaphrodites had 17-ketosteroid reductase deficiency with elevated concentrations of plasma androstenedione relative to testosterone, and elevated concentrations of urinary androsterone (A) and etiocholanolone (E) relative to tetrahydrocortisol (THF), 5 alpha-tetrahydrocortisol (5 alpha-THF) and tetrahydrocortisone (THE). Four affected males (three adults, one child) had 5 alpha-reductase deficiency (elevated ratios of plasma testosterone/dihydrotestosterone and urinary 5 beta/5 alpha C19 and C21 steroid metabolites). The homozygous state for both enzyme deficiencies was not demonstrable in the same affected subject, suggesting that the enzyme deficiencies are segregating separately within this kindred. Whether the mutant genes are segregating on allelic chromosomes or other autosomes cannot be determined from this study.

17-Hydroxysteroid Dehydrogenases↗
PubMed1987

Possible differences in potency of purified pork insulins: confirmation by the euglycemic clamp technique.

A 33-year-old female with insulin-dependent diabetes mellitus (IDDM) for 14 yr had been taking a constant insulin dose for 2 yr. She experienced frequent hypoglycemic reactions when switched from purified pork insulin Iletin II NPH (LILLY) to Protophane (NOVO) which could not be explained by a change in either diet or body wt. A 75% reduction in dose led to a restoration of prior control. The euglycemic clamp technique was utilized to determine whether a difference in potency existed between the 2 commercially available purified pork insulins in this patient and 4 additional subjects, one of whom was not diabetic. There was an 18% difference in potency between insulins in the patient leading to these studies. A difference of more than 10% was noted in 3 of the 5 paired tests, suggesting increased potency (18, 29, 55.1%) of Actrapid (NOVO) compared with Iletin II Regular (LILLY). Until these preliminary observations are confirmed or denied, it is prudent to observe patients closely when switching from one brand of insulin to another even when the species of origin and purity are the same.

Adult↗
PubMed1986

Familial male pseudohermaphroditism due to 5-alpha-reductase deficiency in a Turkish village.

Twelve persons with sexual ambiguity were identified in an isolated village in southern Turkey. Eleven were examined and had pseudovaginal perineoscrotal hypospadias; eight were studied. Serum and urine samples from five affected males and urine samples from three affected children were analyzed. Urine samples from another 26 villagers, mostly parents and siblings, were also analyzed. In all but one of the affected adult subjects, serum testosterone levels were either normal or increased, and in all adults, the dihydrotestosterone levels were low (8 to 20 ng/dl) and the testosterone/dihydrotestosterone ratios were elevated (to 36 or more); the levels of 4-androstenedione were normal. Thirty-four urine samples were analyzed for etiocholanolone/androsterone, 11-beta-hydroxyetiocholanolone/11-beta-hydroxyandrosterone, tetrahydrocorticosterone/5-alpha-tetrahydrocorticosterone and tetrahydrocortisol/5-alpha-tetrahydrocortisol ratios. In affected persons, all 5-beta/5-alpha urinary C19 and C21 steroid metabolite ratios measured were elevated. These findings are compatible with the diagnosis of male pseudohermaphroditism due to 5-alpha-reductase deficiency. In parents and some of the siblings of the affected subjects, the 5-beta/5-alpha urinary ratios were between affected and normal levels. The intermediate 5-beta/5-alpha ratios of the parents who were phenotypically normal, together with documented consanguinity, confirm an autosomal recessive mode of inheritance and are useful in identification of the carrier state. The urinary tetrahydrocortisol/5-alpha-tetrahydrocortisol ratios provided the highest index of discrimination between homozygotes (mean +/- SD, adults: 35.80 +/- 20.10; children: 15.48 +/- 7.91), heterozygotes (parents: 4.56 +/- 1.61; siblings and other relatives: 5.97 +/- 3.68), and normal subjects (1.07 +/- 0.36). Thus, this study identified a second community with inherited male pseudohermaphroditism due to 5-alpha-reductase deficiency, confirming the autosomal recessive inheritance of this condition and the generalized abnormality in both C19 and C21 steroid 5-alpha metabolism.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1985

Red cell sorbitol and diabetic control.

There is a disagreement about the value of red cell sorbitol as an indicator of diabetic control. We studied 7 insulin requiring diabetics, one for 10 days and 6 for 24 hours. In the 10-day study, blood samples were obtained every 4-6 hours. Sequential analysis of plasma glucose and red cell sorbitol levels showed that simultaneous levels had the best correlation r = 0.534, P less than .001. In the 24-hour studies, blood samples were obtained at 1 to 4-hour intervals. Three of the 6 patients showed the best correlation between simultaneous plasma glucose and red cell sorbitol, with r = 0.727 to 0.957 and P less than .001 to P less than .07. When plasma glucose values were compared to red cell sorbitol levels 1, 2, 4, 8 and 12 h later, correlation coefficients were not as good as the simultaneous comparison. We conclude that the measurement of red cell sorbitol correlates well with simultaneous plasma glucose in some but not all diabetic subjects and provides no additional information to the clinician.

Adult↗
PubMed1984

Role of endogenous opiates in the expression of negative feedback actions of androgen and estrogen on pulsatile properties of luteinizing hormone secretion in man.

We have tested the participation of endogenous opiate pathways in the negative feedback actions of gonadal steroids on pulsatile properties of luteinizing (LH) hormone release in normal men. To this end, sex steroid hormones were infused intravenously at dosages that under steady state conditions selectively suppressed either the frequency or the amplitude of the pulsatile LH signal. The properties of pulsatile LH secretion were assessed quantitatively by computerized analysis of LH series derived from serial blood sampling over 12 h of observation. When the pure (nonaromatizable) androgen, 5-alpha-dihydrotestosterone, was infused continuously for 108 h at the blood production rate of testosterone, we were able to achieve selective inhibition of LH pulse frequency akin to that observed in experimental animals after low-dosage androgen replacement. Under these conditions, serum concentrations of testosterone and estradiol-17 beta did not change significantly, but serum 5 alpha-dihydrotestosterone concentrations increased approximately two- to threefold, with a corresponding increase in levels of its major metabolite, 5 alpha-androstan-3 alpha, 17 beta-diol. In separate experiments, the infusion of estradiol-17 beta at its blood production rate over a 4.5-d interval selectively suppressed LH pulse amplitude without influencing LH pulse frequency. Estrogen infusion increased serum estradiol-17 beta levels approximately twofold without significantly altering blood androgen concentrations. We then used these schedules of selective androgen or estrogen infusion to investigate the participation of endogenous opiates in the individual inhibitory feedback actions of pure androgen or estrogen on pulsatile LH release by administering a potent and specific opiate-receptor antagonist, naltrexone, during the infusions. Our observations indicate that, despite the continuous infusion of a dosage of 5 alpha-dihydrotestosterone that significantly suppresses LH pulse frequency, co-administration of an opiate-receptor antagonist effectively reinstates LH pulse frequency to control levels. Moreover, during the infusion of a suppressive dose of estradiol-17 beta, opiate receptor blockade significantly augments LH pulse frequency and increases LH peak amplitude to control levels. Thus, the present studies in normal men demonstrate for the first time that the selective inhibitory action of a pure androgen on LH pulse frequency is effectively antagonized by opiate-receptor blockade. This pivotal observation indicates that opiatergic and androgen-dependent mechanisms specifically and coordinately control the hypothalamic pulse generator for gonadotropin-releasing hormone (GnRH)

Adult↗
PubMed1984

Elevated production and metabolic clearance rates of androgens in morbidly obese women.

Blood production rates of testosterone, dihydrotestosterone (DHT), and 3 alpha-androstanediol (3 alpha-diol) were found to be approximately 2-fold elevated in morbidly obese, nonhirsute, normally menstruating women. Values were intermediate between those found in normal women and those in a group of nonobese normally menstruating women with idiopathic hirsutism. Elevated androgen production rates in obese women were associated with 2- to 3-fold increases in MCRs, presumably due to decreased levels of sex hormone-binding globulin. Thus, increased production rates were offset by increased MCRs, resulting in plasma testosterone, DHT, and 3 alpha-diol concentrations that were similar in the obese and normal women. By contrast, women with hirsutism had increased production rates associated with elevated plasma androgens as well as increased MCRs. Urinary excretion of testosterone glucuronide and 3 alpha-diol glucuronide (3 alpha-diol G) were elevated in both obese and hirsute women, paralleling the increased androgen production rates. Despite increased production rates and excretion of androgens, obese women exhibited no menstrual abnormalities, hirsutism, or other signs of virilism. To explore the apparent ineffectiveness of increased androgen production to produce virilizing symptoms, we measured plasma 3 alpha-diol G levels as a measure of peripheral androgen action. The mean +/- SE plasma 3 alpha-diol G was 53 +/- 8 ng/dl in obese women and 36 +/- 6 in normal women; by contrast, women with idiopathic hirsutism had levels of 440 +/- 99, a 12-fold elevation. Plasma testosterone glucuronide in obese and hirsute women were only 2- to 3-fold elevated, while plasma DHT glucuronide was not increased in obese women and was only 2-fold elevated in hirsute women. Thus, obesity is a state of increased androgen production and accelerated clearance. 3 alpha-diol G levels in obese women were only minimally elevated, in contrast to values in the hirsute women, perhaps reflecting the apparent androgen ineffectiveness.

Adult↗
PubMed1983

Effects of chronic smoking on testosterone metabolism in dogs.

The effects of long-term cigarette smoking on androgen hydroxylases and peripheral hormones were studied in male beagles. In the testis, chronic smoking of high nicotine/tar cigarettes was associated with decreased activity of the 7 alpha-hydroxylase active on testosterone (68% of control, P less than 0.05). Testicular 6 beta and 16 alpha-hydroxylases were not altered. The hepatic androgen 6 beta-hydroxylase activity in control animals was approximately 6 times the testis levels and was stimulated markedly by smoking. This increase ranged from 221% in the low nicotine/tar group (P less than 0.02) to 304% in the high nicotine/tar group (P less than 0.006). Serum testosterone levels were reduced to 54% of control (P less than 0.02) and prostate size to 44% (P less than 0.001) of control with heavy smoking. Serum LH levels were elevated with smoking. These results suggest that chronic cigarette smoking increased hepatic metabolism of testosterone. In addition, serum testosterone levels and prostate size decreased and LH levels increased. Whether the hepatic and the endocrine effects are causally related cannot be determined from this preliminary study.

Animals↗
PubMed1983

The metabolic fate of exogenous sorbitol in the rat.

Dietary sorbitol is rapidly converted to fructose and other carbohydrates in the liver, but its metabolic fate has not been studied rigorously. Twenty-four rats were given 20.4 muCi [14C]sorbitol with 100 mg of sorbitol, and groups of six were killed at 1, 3, 6, and 24 hours after sorbitol administration. Rats were also fed 6.9 muCi [14C]sorbitol for 7 or 14 days. Serum, liver, and lens were analyzed for 14C-labeled sorbitol, fructose, and glucose by using high-performance liquid chromatography. Negligible radioactivity (1.1%) was found in the gastrointestinal content at 24 hours indicating virtually complete absorption. Most of the radioactivity was recovered in the glucose fraction in serum, liver and lens. Glucose and fructose concentrations showed some decline by day 14 compared with day 7 in serum and liver. However, in the lens, sorbitol showed a peak value at the end of the 14th day (37.5 +/- 9.9 micrograms/pair). These findings suggest that: 1) after oral administration, sorbitol is completely absorbed, and 2) that there is a finite accumulation of sorbitol and fructose in the lens in 14 days. Although the radioactive label indicated the exogenous origin of these carbohydrates, it is not certain whether the sorbitol is converted to glucose before entering and accumulating in the lens.

Administration, Oral↗
PubMed1983

Pheochromocytoma resistant to alpha-adrenergic blockade.

In a 54-year-old man with a norepinephrine-secreting pheochromocytoma, resistance developed to the alpha-adrenergic blocking agent, phenoxybenzamine hydrochloride. Dosages of 240 mg/day were ineffective. Intravenous phentolamine mesylate reduced his BP at first, but resistance developed to this also. Therapy with alpha-methylparatyrosine, an inhibitor of catecholamine biosynthesis, finally controlled his BP, and the tumor was removed.

Adrenal Gland Neoplasms↗