Publications by authors named "Zachman K"

The study objective was to determine if mutations in mitochondrial DNA polymerase gamma (POLG) are associated with spontaneous 46,XX primary ovarian insufficiency (sPOI) using restriction fragment length polymorphism analysis of genomic DNA. Of 201 women with 46,XX sPOI analyzed, we found only one case (0.5%, 95% confidence interval 0-3%) of heterozygosity for a POLG mutation, suggesting that this is not a common genetic etiology for this form of infertility.

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Context: Interindividual variations in glucocorticoid sensitivity have been associated with manifestations of cortisol excess or deficiency and may be partly explained by polymorphisms in the human glucocorticoid receptor (hGR) gene. We studied a 43-yr-old female, who presented with manifestations consistent with tissue-selective glucocorticoid hypersensitivity. We detected a novel, single, heterozygous nucleotide (G --> C) substitution at position 1201 (exon 2) of the hGR gene, which resulted in aspartic acid to histidine substitution at amino acid position 401 in the amino-terminal domain of the hGRalpha.

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Immunogenetic mechanisms operating within the immune system are known to influence cytokine profiles and disease susceptibility. Yet the role of the individual's neurohormonal background in these processes remains undefined. Hormonal imbalances are documented in immune-related diseases, but it is unclear whether this represents a secondary phenomenon or a primary "defect" related to specific neurohormonal immune phenotype(s).

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Background: Generalized glucocorticoid resistance is a rare condition characterized by partial, end-organ insensitivity to glucocorticoids, compensatory elevations in adrenocorticotropic hormone and cortisol secretion, and increased production of adrenal steroids with androgenic and/or mineralocorticoid activity. We have identified a new case of glucocorticoid resistance caused by a novel mutation of the human glucocorticoid receptor (hGR) gene and studied the molecular mechanisms through which the mutant receptor impairs glucocorticoid signal transduction.

Methods And Results: We identified a novel, single, heterozygous nucleotide (T --> C) substitution at position 2209 (exon 9alpha) of the hGR gene, which resulted in phenylalanine (F) to leucine (L) substitution at amino acid position 737 within helix 11 of the ligand-binding domain of the protein.

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Objective: To investigate mutations in the human KIT ligand gene (KITLG) gene as a mechanism of 46,XX spontaneous premature ovarian failure. The human KIT ligand gene, known also as human stem cell factor, is the ligand of the c-kit transmembrane tyrosine kinase receptor (KIT). This ligand-receptor interaction is known to play important roles in mouse germ cell migration and proliferation.

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Background: Glucocorticoid resistance is often a result of mutations in the human glucocorticoid receptor alpha (hGRalpha) gene, which impair one or more of hGRalpha's functions. We investigated the molecular mechanisms through which two previously described mutant receptors, hGRalphaR477H and hGRalphaG679S, with amino acid substitutions in the DNA- and ligand-binding domains, respectively, affect glucocorticoid signal transduction.

Methods And Results: In transient transfection assays, hGRalphaR477H displayed no transcriptional activity, whereas hGRalphaG679S showed a 55% reduction in its ability to stimulate the transcription of the glucocorticoid-responsive mouse mammary tumor virus promoter in response to dexamethasone compared with the wild-type hGRalpha.

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Glucocorticoid resistance is a rare, familial or sporadic condition characterized by partial end-organ insensitivity to glucocorticoids. The clinical spectrum of the condition is broad, ranging from completely asymptomatic to severe hyperandrogenism and/or mineralocorticoid excess. The molecular basis of glucocorticoid resistance has been ascribed to mutations in the human glucocorticoid receptor-alpha (hGRalpha) gene, which impair one or more of the molecular mechanisms of GR action, thus altering tissue sensitivity to glucocorticoids.

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The prevalence of insomnia associated with emotional stress increases markedly in middle-age. Both the top and end hormones of the hypothalamic-pituitary-adrenal axis, i.e.

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Patients with pathologically increased daytime sleepiness and fatigue have elevated levels of circulating interleukin-6 (IL-6). The latter is an inflammatory cytokine, which causes sickness manifestations, including somnolence and fatigue, and activation of the hypothalamic-pituitary-adrenal axis. In this study, we examined: 1) the relation between serial measurements of plasma IL-6 and quantity and depth of sleep, evaluated by polysomnography; and 2) the effects of sleep deprivation on the nyctohemeral pattern of IL-6 secretion.

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Pseudohypoaldosteronism (PHA) is characterized by congenital resistance of the kidney and/or other mineralocorticoid target tissues to aldosterone, resulting in excessive salt wasting. Mineralocorticoid receptor (MR) and postreceptor defects in the aldosterone-responsive amiloride-sensitive sodium channel (ENaC) subunits have been suggested as potential loci of the defect in this disease, whereas recently defects in MR and ENaC subunits were reported in familial PHA cases. Here we studied the ENaC subunit alpha, beta, and gamma complementary DNAs (cDNAs) in a series of five sporadic cases of PHA, whose MR cDNA contained nonconservative homozygous (C944-->T944, Ala241-->Val241) and/or a conservative heterozygous substitutions (A760-->G760, Ileu180-->Val180), which, however, were also present at high frequencies in a control population with apparently normal salt conservation.

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The aim of this study was to assess whether there is an association between chronic insomnia and the activity of the stress system. Fifteen young adult insomniacs (<40 years) were studied. After an adaptation night, each subject was recorded in the sleep laboratory for three consecutive nights.

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Approximately half of children and adolescents with Cushing's syndrome develop hypertension. To examine the role of hypercortisolism in the pathogenesis of hypertension in young patients and to establish its reversibility, we studied 31 hypertensive children and adolescents with Cushing's syndrome (systolic, diastolic, and/or mean blood pressure more than 2 SD U for age and sex) from a total of 63 patients before, and for a period of 1 yr after surgical cure. Preoperatively, 93.

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Familial male-limited precocious puberty (FMPP) is an autosomal dominant gonadotropin-independent disorder. Affected males generally develop signs of precocious puberty in early childhood. They typically show Leydig cell hyperplasia and increased testosterone production typical for their age, whereas circulating LH concentrations remain prepubertal.

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Pseudohypoaldosteronism (PHA) is characterized by congenital resistance of the kidney and/or other mineralocorticoid target tissues to aldosterone, resulting in excessive salt wasting. Although the mineralocorticoid receptor (MR) was suggested as a potential locus of the defect in this disease, no such abnormality was found in 3 recently reported cases, one of whom belongs to this series of 5 patients. Molecular studies of the MR complementary DNA and gene in this series of sporadic cases of pseudohypoaldosteronism are reported.

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