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Biomedical subjects

M I New

Publications and source records attributed to M I New.

At least 163 records · Page 9Linked to original sources
PubMed1985

Late-onset adrenal steroid 3 beta-hydroxysteroid dehydrogenase deficiency. I. A cause of hirsutism in pubertal and postpubertal women.

To investigate the adrenal cause of hyperandrogenism in peri- and postpubertal hirsute women, baseline and ACTH-stimulated serum concentrations of delta 5-17-hydroxypregnenolone (delta 5-17P), dehydroepiandrosterone (DHEA) and its sulfate, 17-hydroxyprogesterone (17-OHP), cortisol, delta 4-androstenedione, and testosterone were determined in 116 women with hirsutism or acne of peri- and postpubertal onset with or without menstrual abnormalities. The results were compared with the same steroid concentrations in 30 normal age-matched women. Sixteen of the 116 women with hirsutism whose ACTH-stimulated 17-OHP levels (mean +/- SD, 5404 +/- 3234 ng/dl; normal, 334 +/- 194) were markedly elevated while their ratios of delta 5-17P to 17-OHP (0.4 +/- 0.2; normal, 3.4 +/- 1.5) were low were diagnosed as having nonclassical symptomatic 21-hydroxylase deficiency. Seventeen other hirsute women, including 3 siblings, had very high responses of delta 5-17P (2276 +/- 669 ng/dl; normal, 985 +/- 327) and DHEA (2787 +/- 386 ng/dl; normal, 1050 +/- 384) to ACTH stimulation, with significantly elevated ratios of delta 5-17P to 17-OHP (11 +/- 2.0; normal, 3.4 +/- 1.5) and DHEA to delta 4-androstenedione (7.5 +/- 2.3; normal, 4.6 +/- 1.5). In these hirsute women, the morning serum delta 5-17P and DHEA concentrations were elevated, had a diurnal variation, and were suppressed with dexamethasone administration. We propose that partial adrenal 3 beta-hydroxysteroid dehydrogenase deficiency is the cause of hirsutism in these women. This may represent an allelic variant at the genetic locus for 3 beta-hydroxysteroid dehydrogenase deficiency similar to that reported for symptomatic nonclassical 21-hydroxylase deficiency producing peripubertal excess androgen syndrome.

3-Hydroxysteroid Dehydrogenases↗
PubMed1985

Pitfalls of prenatal diagnosis of 21-hydroxylase deficiency congenital adrenal hyperplasia.

Hormonal measurements and HLA genotyping of amniotic fluid at midgestation correctly predicted the postnatal diagnosis of congenital adrenal hyperplasia (CAH) in 29 of 32 fetuses at risk. Of these 29, 7 were predicted to have prenatal-onset classical 21-hydroxylase deficiency (21-OH def) based on elevated amniotic fluid 17-hydroxyprogesterone (17-OHP) and delta 4-androstenedione (delta 4-A) levels. These 7 fetuses and their index cases were ultimately proven to have salt-wasting classical 21-OH def. Of 5 who were HLA typed, the genotype was identical to the index case in 4; in one, HLA prediction was not possible, because the parents shared identical HLA antigens. Normal amniotic fluid 17-OHP and delta 4-A levels in the remaining 22 fetuses predicted that they were not affected with classical CAH. These children have been clinically asymptomatic to date or proven biochemically not to have classical or nonclassical CAH. Of the 22 fetuses, 11 were predicted by HLA genotyping to be homozygous normal or heterozygous for 21-OH def. In 3 of the 32 fetuses, prenatal diagnosis was incorrect. In one, the fetus was predicted to have CAH based on HLA identity to the index case. However, amniotic fluid 17-OHP and delta 4-A were normal, and the fetus was normal. The index case of this family did not have CAH, but was a normal child. Thus, amniotic fluid hormone levels accurately predicted a normal fetus, while HLA genotyping was not relevant in prenatal diagnosis because the index case was unaffected. The second fetus was predicted to be affected on the basis of HLA genotyping and to be unaffected based on normal amniotic fluid 17-OHP and delta 4-A. During infancy, this female infant had postnatal-onset nonclassical CAH. The index case in this family, presumed to have classical simple virilizing CAH, was later diagnosed to have nonclassical CAH. Thus, in nonclassical CAH, hormonal measurement of 17-OHP and delta 4-A is not useful in prenatal diagnosis; only HLA genotyping of the fetus is valuable. In the third case, the fetus was predicted to be a heterozygote by HLA genotyping and to be unaffected by hormonal measurement. Postnatally, at age 2 7/12 yr, the male child was found to have classical simple virilizing CAH and to be HLA-B-DR identical to his brother (index case) who also has classical simple virilizing CAH.(ABSTRACT TRUNCATED AT 400 WORDS)

17-alpha-Hydroxyprogesterone↗
PubMed1985

Excess mineralocorticoid receptor activity in patients with dexamethasone-suppressible hyperaldosteronism is under adrenocorticotropin control.

Total mineralocorticoid activity in human serum was assessed by the rat renal slice receptor assay (RRA). RRA values were compared to RIA-derived aldosterone (aldo) equivalents. Our data demonstrate that in normal subjects, mineralocorticoid receptor-binding steroids can be almost totally accounted for by immunoreactive deoxycorticosterone, corticosterone, cortisol, and aldo (RRA, 4.73 +/- 1.34 ng/ml aldo; RIA, 3.91 +/- 1.52 ng/ml aldo equivalents), while in 8 patients with dexamethasone-suppressible hyperaldosteronism (DSH), RRA values were greater than RIA values in the basal state (RRA, 7.57 +/- 0.75; RIA, 3.24 +/- 0.34; P less than 0.01). DSH patients had a RRA to RIA ratio after ACTH stimulation similar to the ratio in these patients in the basal state (basal, 2.34; ACTH-stimulated, 2.04). During dexamethasone treatment, RRA values fell markedly (1.82 +/- 0.26). Thus, total mineralocorticoid activity, as measured by RRA in DSH patients, was greater than RIA-measurable deoxycorticosterone, corticosterone, cortisol, and aldo, indicating the presence of an unidentified steroid which is dexamethasone suppressible and ACTH stimulable.

Adrenocorticotropic Hormone↗
PubMed1985

High frequency of nonclassical steroid 21-hydroxylase deficiency.

Nonclassical steroid 21-hydroxylase deficiency is an autosomal recessive disorder that is defined by clinical and hormonal criteria that distinguishes it from the classical 21-hydroxylase deficiency. No estimates of the gene frequency of nonclassical 21-hydroxylase deficiency, also called attenuated, late-onset, acquired, and cryptic adrenal hyperplasia, have been published thus far. Here, we have used HLA-B genotype data in families containing multiple members affected with nonclassical 21-hydroxylase deficiency together with the results of quantitative hormonal tests to arrive at estimates of gene and disease frequencies for this disorder. We found nonclassical 21-hydroxylase deficiency to be a far more common disorder than classical 21-hydroxylase deficiency, which occurs in 1/8,000 births. The prevalence of the disease in Ashkenazi Jews was 3.7%; in Hispanics, 1.9%; in Yugoslavs, 1.6%; in Italians, 0.3%; and in the diverse Caucasian population, 0.1%. The gene for nonclassical 21-hydroxylase deficiency is in genetic linkage disequilibrium with HLA-B14 in Ashkenazi Jews, Hispanics, and Italians, but not in Yugoslavs or in a diverse, non-Jewish, Caucasian group. The penetrance of nonclassical 21-hydroxylase deficiency gene in the HLA-B14 containing haplotypes was incomplete. Thus, nonclassical 21-hydroxylase deficiency is probably the most frequent autosomal recessive genetic disorder in man and is especially frequent in Ashkenazi Jews, Hispanics, Italians, and Yugoslavs.

Adrenal Hyperplasia, Congenital↗
PubMed1984

Clinical applications of the rapid high-performance liquid chromatographic determination of serum cortisol.

We report a rapid and specific analytical method for the measurement of serum cortisol by reversed-phase high-performance liquid chromatography (HPLC). The method allows the diagnostic measurement of cortisol in emergency clinical circumstances of glucocorticoid deficiency or excess. Results obtained by HPLC are comparable to those by radioimmunoassay. The lower limit of sensitivity is 6 ng cortisol per ml of serum.

Chromatography, High Pressure Liquid↗
PubMed1984

HLA-linked congenital adrenal hyperplasia results from a defective gene encoding a cytochrome P-450 specific for steroid 21-hydroxylation.

We have determined the molecular genetic basis of congenital adrenal hyperplasia due to 21-hydroxylase (21-OHase) deficiency. This common disorder of cortisol biosynthesis is HLA-linked. The haplotype HLA-(A3);Bw47;DR7 is strongly associated with 21-OHase deficiency and always carries a null allele at the locus encoding the C4A (Rodgers) form of the fourth component (C4) of complement. It seemed likely that this haplotype carries a deletion encompassing the genes encoding both C4A and 21-OHase. We hypothesized that the HLA-linked defect involved a structural gene for the adrenal microsomal cytochrome P-450 specific for steroid 21-hydroxylation. Using a plasmid with a 520-base-pair bovine adrenal cDNA insert encoding the middle third of the cytochrome P-450 polypeptide, we compared hybridization patterns in DNA from normal and 21-OHase-deficient individuals. Normal human DNA yielded two fragments that hybridized with the probe after digestion with either restriction endonuclease EcoRI [12- and 14-kilobase (kb) fragments] or Taq I (3.7 and 3.2 kb). One of these bands (the first mentioned in each digest) was absent in DNA from a cell line derived from a patient homozygous for HLA-Bw47. DNA from six unrelated patients homozygous for 21-OHase deficiency who were heterozygous for HLA-Bw47 yielded diminished relative intensity of the 3.7-kb Taq I band in five patients, consistent with a heterozygous deletion, and complete disappearance of the 3.7-kb band in one. This deletion segregated with HLA-Bw47 in a large pedigree carrying 21-OHase deficiency and HLA-Bw47. Thus, 21-OHase deficiency sometimes results from the deletion of a specific cytochrome P-450 gene and sometimes, presumably, from smaller mutations. This gene is probably located very near the C4A gene.

Adrenal Hyperplasia, Congenital↗
PubMed1984

Cloning and expression of cDNA encoding a bovine adrenal cytochrome P-450 specific for steroid 21-hydroxylation.

We isolated a cDNA clone encoding a bovine adrenal cytochrome P-450 specific for steroid 21-hydroxylation (P-450C21). Serum from rabbits immunized with purified P-450C21 precipitated a single protein from the products of an in vitro translation reaction using bovine adrenal mRNA. This protein migrated with P-450C21 on NaDodSO4/polyacrylamide gel electrophoresis. After sucrose gradient sedimentation, mRNA encoding P-450C21 was found in the 19S fraction. This fraction was reverse transcribed into double-stranded cDNA and inserted into the Pst I site of pBR322 by the dC X dG tailing procedure. Escherichia coli cells transformed with recombinant plasmids were screened with an in situ immunoassay using anti-P-450C21 serum and 125I-labeled staphylococcal protein A. Two colonies consistently bound anti-P-450C21 serum. They were identified as carrying the same plasmid by restriction mapping. This plasmid, pC21a, contains an insert of 520 base pairs. It hybridizes with mRNA encoding P-450C21. The peptide encoded by the insert in pC21a is highly homologous to two peptides isolated from porcine P-450C21 and shows limited homology to the P-450 induced by phenobarbital in rat liver. This clone may be useful in studying the molecular genetics of human congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Adrenal Glands↗
PubMed1984

Recovery of adrenal function after treatment of adrenocortical carcinoma with o,p'-DDD.

The adrenolytic agent, 2,2-bis[2-chlorophenyl-4-chlorophenyl] 1,1 dichloroethane (o,p'-DDD), was used over a 20-month period following surgery in a 2 3/12-year-old girl for treatment of adrenocortical carcinoma. The child remained free of disease and was maintained on glucocorticoid and mineralo-corticoid supplements for 7 years. Hormonal evaluation was undertaken at 9 9/12 years of age to determine remaining adrenal steroidogenic capacity. Following discontinuation of both hydrocortisone and 9 alpha-fludrocortisone, she remained stable and asymptomatic. Immediately after discontinuing 9 alpha-fludrocortisone, the adrenal glomerulosa was able to respond to stimulation by the renin-angiotensin system as shown by the ability to achieve renal sodium conservation on a restricted sodium intake (less than 10 mEq/d for 5 d). The response of the adrenal fasciculata to ACTH stimulation showed a slower recovery. Baseline levels of cortisol were in the low normal range, but there was no increase in plasma cortisol or urinary 17-hydroxysteroids following stimulation with ACTH. The responses of cortisol, deoxycorticosterone, and corticosterone to ACTH stimulation gradually improved to achieve normal stimulated levels 18 months after stopping medications. Serum testosterone and delta 4-androstenedione were initially increased for level of puberty, while levels of dehydroepiandrosterone were prepubertal. Testosterone and delta 4-androstenedione did not suppress with dexamethasone (2 mg/d for 2 d; 4 mg/d for 2 d), and dehydroepiandrosterone decreased only slightly. However, administration of norethindrone (Norlutin) (10 mg orally, three times a day for 3 d) resulted in suppression while human chorionic gonadotrophin (hCG; 5000 U i.m. daily for 3 d) produced stimulation of testosterone, delta 4-androstenedione and dehydroepiandrosterone. Thus the androgens were felt be predominantly of ovarian origin. Dehydroepiandrosterone rose to low normal levels by 18 months after discontinuation of hydrocortisone. We thus demonstrate for the first time that both the adrenal glomerulosa and fasciculata have the capacity to recover normal function following treatment with o,p'-DDD. Further, we suggest that early exposure to excess adrenal androgens may result in mild alteration of gonadal function.

Adenocarcinoma↗
PubMed1984

Recent advances in 21-hydroxylase deficiency.

A deficiency of 21-hydroxylase in the adrenal cortex results in insufficient cortisol production. The salt-wasting form of 21-hydroxylase deficiency is characterized by inadequate aldosterone production, as well. Because the hypothalamic-adrenal negative feedback system is broken, excess adrenal androgens are produced. This disordered corticosteroid production causes hormonal and clinical symptoms, including pseudohermaphroditism in genetic females and disordered puberty in both males and females. There is a spectrum of the time of onset and the severity of these symptoms. This disorder is inherited in an autosomal recessive manner. The 21-hydroxylase deficiency is genetically linked to the human leukocyte antigen (HLA) complex; in addition, nonclassical and classical 21-hydroxylase deficiency have each been shown to be in genetic linkage disequilibrium with specific HLA-B antigens. This genetic linkage, used in conjunction with baseline and stimulated serum hormonal levels, is useful in the diagnosis of this disorder. Prenatal diagnosis of homozygote, heterozygote, and unaffected fetuses is also available. Adequate treatment with glucocorticoid and mineralocorticoid replacement resolves symptoms and enables a normal life.

Adrenal Cortex Hormones↗
PubMed1984

Biochemical studies of a patient with hereditary hepatorenal tyrosinemia: evidence of glutathione deficiency.

Metabolic and enzymatic studies in a patient with hereditary tyrosinemia demonstrated for the first time a deficiency of erythrocyte and hepatic glutathione. Markedly decreased hepatic fumarylacetoacetate hydrolase activity was demonstrated in this patient. The activities of hepatic enzymes not involved in tyrosine metabolism were also determined. Assay of mixed function oxidase activity demonstrated low levels of aryl hydrocarbon hydroxylase and 7-ethoxycoumarin deethylase, suggesting decreased hepatic detoxification capacity. 5-Aminolevulinic acid dehydratase activity was undetectable. Succinylacetone (4,6-dioxoheptanoic acid), an abnormal metabolic product secondary to fumarylacetoacetate hydrolase deficiency was found in serum and urine. Succinylacetone was demonstrated to inhibit 5-aminolevulinic acid dehydratase in vitro, as did the urine, plasma, and red cell lysates of the patient.

Erythrocytes↗