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Biomedical subjects

R Theodor

Publications and source records attributed to R Theodor.

32 records · Page 2Linked to original sources
PubMed1980

Amniotic 17-alpha hydroxyprogesterone and HLA typing for the prenatal diagnosis of 21-alpha hydroxylase deficiency--congenital adrenal hyperplasia.

We have investigated a family with one child affected with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. Prenatal determination of 17-alpha hydroxyprogesterone (17OHP) in amniotic fluid (AF) and HLA typing of amniotic fibroblasts from a pregnancy at risk showed that the fetus was not affected. A healthy cousin with HLA haplotypes identical to those of the proposita (only one being identical by descent) had a normal plasma level of 17OHP. The prenatal diagnosis of a fetus affected with 21-hydroxylase deficiency CAH may be established by the determination of 17OHP in AF. This is a relatively quick procedure that can be confirmed by the HLA genotype, and is mandatory in families with a parent homozygous for an HLA haplotype and in certain recombinant haplotypes in the fetus.

Adrenal Hyperplasia, Congenital↗
PubMed1977

The metabolic effects of excess noradrenaline secretion from a pheochromocytoma.

We report a 14-year-old boy with severe hypertension who was cured by surgical removal of a pheochromocytoma. The tumor was shown biochemically and morphologically to secrete predominantly noradrenaline. The metabolic effects noted in this patient were raised free fatty acid levels and depressed insulin levels, hyperreninemia, hypercalcemia, and hypercalciuria with normal parathyroid function. All these abnormalities returned to normal after removal of the tumor. It is suggested that these effects were mediated via beta-adrenergic stimulation of the excess noradrenaline.

Adolescent↗
PubMed1977

Selective hypoaldosteronism in Iranian Jews: An autosomal recessive trait.

A salt-wasting syndrome associated with high plasma renin activity and inappropriately low aldosterone levels was observed among eight Jewish families from Iran. Aldosterone deficiency was due to an inborn error selectively involving the terminal portion of the bio-synthetic pathway and characterized by an enzymic block in the conversion of 18-hydroxy-corticosterone to aldosterone. The analysis of the eight pedigrees, including 12 affected children, shows a high coefficient of inbreeding. Genetic analysis, by two independent methods, strongly suggests an autosomal recessive mode of transmission of the syndrome.

Aldosterone↗
PubMed1977

The nature of the defect in a salt-wasting disorder in Jews of Iran.

Studies in 8 families of Iranian Jews revealed 12 patients with selective aldosterone deficiency due to a biosynthetic defect. There was a marked range in clinical severity which varied from acute salt-wasting crisis in infancy to an asymptomatic state in adults detectable only by biochemical screening. Manifestations of intermediate degrees of severity included unexplained short stature and postural hypotension. This clinical variability in the manifestations of aldosterone deficiency was not due entirely to quantitative differences in hormone secretion but also to a changing pattern of requirement throughout life in which deficiency during the first year of life had grave consequences while a similar degree of deficiency in the adult was well-tolerated, suggesting that the hormone was no longer essential. Most families came from a relatively isolated community in Isfahan with a high incidence of consanguinity and three were related. Aldosterone deficiency was due to an inborn error involving the terminal portion of the biosynthetic pathway and characterized by marked overproduction of glomerulosa zone 18-hydroxycorticosterone relative to aldosterone. The best diagnostic index was the excretory ratio of the major urinary metabolites of these steroids. This ratio, normally less than 3.0, was frequently greater than 100 in untreated patients with this defect. Plasma aldosterone was not a reliable index of the disorder since some patients achieved normal levels but at the expense of marked elevation in plasma renin activity and overproduction of precursors.

Adolescent↗
PubMed1977

Metabolic responses to the administration of angiotensin II, K and ACTH in two salt-wasting syndromes.

Metabolic responses to the administration of Angiotensin II, K and ACTH are described in two salt-wasting syndromes: hypoaldosteronism in Jews from Iran, which is characterized by an enzymic block in the conversion of 18-hydroxycorticosterone to aldosteron; and pseudohypoaldosteronism, a disorder in which aldosterone secretion is high in association with renal tubular unresponsiveness to mineralocorticoids. The response of plasma and urinary aldosterone to K and ACTH is qualitatively normal in hypoaldosteronism; however, infusion of Angiotensin II, in a dose that was pressor and elevated aldosterone levels threefold in control subjects, was only pressor in hypoaldosteronism. In pseudohypoaldosteronism, plasma and urinary aldosterone respond to Angiotensin II, K and ACTH, notwithstanding very high basal hormonal levels.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Absolute bioavailability of moxonidine.

In a randomized 2-way cross-over study with eighteen healthy male volunteers, two moxonidine preparations (tablets, treatment A vs. intravenous solution, treatment B) were tested to investigate absolute bioavailability and pharmacokinetics of moxonidine. The preparations were administered as single doses of 0.2 mg; prior to and up to 24 h after administration blood samples were collected and the plasma moxonidine concentrations determined. Urine samples were collected prior to and at scheduled intervals up to 24 h after administration for the determination of unchanged moxonidine. Moxonidine plasma and urine concentrations were determined by a validated gas chromatographic/mass spectrometric method with negative ion chemical ionization. The mean areas under the plasma concentration/time curves were calculated as [mean +/- standard deviation] 3438 +/- 962 pg.h/ml (AUC(0----Tlast)) and 3674 +/- 1009 pg.h/ml (AUC(0----infinity)) for treatment A; 3855 +/- 1157 pg.h/ml (AUC(0----Tlast)) and 4198 +/- 1205 pg.h/ml (AUC(0----infinity)) for treatment B. Mean peak plasma concentrations of 1495 +/- 646 pg/ml were attained at 0.56 +/- 0.28 h after oral treatment, mean peak plasma concentrations after intravenous treatment reached 3965 +/- 1342 pg/ml at 0.17 +/- 0.01 h (= coinciding with end of infusion). The mean terminal half-lives of moxonidine were derived as 1.98 h after administration of the tablet and as 2.18 h after infusion. The amounts of moxonidine excreted in urine during the 24 h following administration (Ae(24h)) in absolute figures and as percentage of the dose administered were 102 +/- 26 micrograms or 51 +/- 13% for the tablet and 122 +/- 33 micrograms or 61 +/- 16% for the infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗