Publications by authors named "Eduardo Chaler"

Context: The low-dose (1 µg) ACTH test (LDT) is widely used to assess central adrenal insufficiency (CAI); however, the serum cortisol cutoff value is controversial. Salivary cortisol (SC) may be a more accurate measurement for CAI.

Objective: To assess a new maximum cutoff value of serum cortisol after LDT in pediatric patients, taking into account serum and SC measurements.

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Background: Central adrenal insufficiency (CAI) is due to a decrease of CRH and/or ACTH secretion. ACTH-dependent dehydroepiandrosterone sulphate (DHEAS) has been postulated as a possible marker of adrenal function in adult patients.

Aims: To evaluate the usefulness of basal serum DHEAS determination to diagnose CAI in pubertal patients with a suspected diagnosis of CAI.

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Context: Steroid acute regulatory (StAR) protein is a mitochondria-targeted protein that is part of the transduceosome complex crucial for transport of cholesterol to mitochondria. Recessive mutations cause classic and nonclassic congenital lipoid adrenal hyperplasia.

Objective: The aim of this study was to report the clinical, hormonal, genetic, and functional data of a novel heterozygous mutation in the StAR gene found in a 46,XY patient with ambiguous genitalia and neonatal severe steroidogenic deficiency.

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In humans, steroidogenic factor 1 (NR5A1/SF-1) mutations have been reported to cause gonadal dysgenesis, with or without adrenal failure, in both 46,XY and 46,XX individuals. We have previously reported extreme within-family variability in affected 46,XY patients. Even though low ovarian reserve with preserved fertility has been reported in females harboring NR5A1 gene mutations, fertility has only been observed in one reported case in affected 46,XY individuals.

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Changes in the clinical presentation of diabetes mellitus in childhood and adolescence associated with obesity have resulted in an overlap of the two most common types of diabetes with a greater clinical heterogeneity. In order to characterize the type of diabetes at onset and assess the effect of obesity, 50 children with diabetes were studied. The patients were divided into two groups according to their nutritional status at diagnosis (over-weight/obese vs.

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Background: Establishment of reliable reference intervals remains valuable for confirming validity and advancing standardization across methods and populations. Moreover, knowledge of the measurement uncertainty (U) and of the reference change value (RCV) has important applications in clinical chemistry.

Methods: Starting from the information available in the laboratory data base (29,901 subjects) an initial selection was carried out by eliminating all subjects with a clinical or laboratory pathological report; data from 7581 0- to 20-year-old subjects (53.

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Objective: To report genotype-phenotype correlation in a large cohort of patients.

Context: Study of the CYP21A2 gene in 866 unrelated chromosomes of 21-hydroxylase deficiency in Argentinean patients with classic and nonclassic (NC) forms of congenital adrenal hyperplasia (CAH).

Methods: Eleven most common mutations were analysed by allele-specific polymerase chain reaction, restriction fragment length polymorphism (RFLP) or southern blot analysis.

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We analyzed the ability of the BaF3 cell line bioassay to select patients with biologically inactive GH. We first evaluated the biological response of the Ba/F3-hGHR cells to rhGH additional doses from 10 to 5000 pg/ml. The concentration points corresponding to the linear part of the curve were selected.

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Introduction: The term "euthyroid sick syndrome" (ESS) has been used to describe a pattern of thyroid hormone changes during the course of critical illness in adult patients without thyroid disease, often associated with reduced thyroid hormone secretion.

Objective: To describe the thyroid hormone profile in full-term newborns critically ill compared with thyroid hormone profile of healthy infants, and determine if alterations could be related to the severity of the disease and outcome.

Methods: A cross-sectional, observational, and prospective study of full-term infants admitted to the neonatal intensive care unit (NICU) of the Hospital de Pediatría J.

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Background: Three novel heterozygous SF-1 gene mutations affecting multiple members of two unrelated families with a history of 46,XY disorders of sex development (DSD) and 46,XX ovarian insufficiency are described.

Methods: clinical and mutational analysis of the SF-1 gene in 9 subjects of two families.

Results: family 1 had 2 affected 46,XY DSD subjects.

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Introduction: Prader-Willi syndrome (PWS) is a genetic disorder caused by the loss of expression of paternally transcribed genes in a highly imprinted region of chromosome 15q11-13. The clinical phenotype has been well characterized, mostly related to hypothalamic dysfunction. Even though central hypothyroidism has been documented in 20-30% of patients with PWS, thyroid function during the first 2 years of life has not been clearly defined.

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Introduction: Studies on people with low birth weight found metabolic syndrome associated with intrauterine growth restriction (IUGR).

Objective: To study the presence of early risk markers of metabolic syndrome in a prepubertal population with IUGR.

Design: We studied 45 prepubertal children with a history of IUGR, without apparent disease, and 47 children in a control group.

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Sex hormones are modulators of the GH/ IGF-I system. We have hypothesized that the inhibition of DHEAS in treated girls with congenital adrenal hyperplasia (CAH) might affect this modulation. We analyzed serum IGF-I, IGFBP-3 and DHEAS in 17 prepubertal (Pp) and 32 pubertal (Pu) girls with CAH, under hydrocortisone replacement therapy, in the presence of normal (Gr1) or high (Gr2) serum testosterone (T) and androstenedione (A) levels.

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The aim of this study was to analyze the possible implication of changes in the GH/IGF-I axis and in insulin sensitivity for the regulation of adrenal androgen secretion of normal prepubertal and adolescent girls. A total of 61 normal girls were evaluated in prepuberty [Group (Gr)1, n = 33; early (Gr1A, n = 16) and late (Gr1B, n = 17)]; puberty (Gr3, n = 28), early (Gr3A, n = 9) and late (Gr3B, n = 19); and during the transition between prepuberty and puberty (Gr2, n = 26). Insulin sensitivity was estimated by the fasting glucose/insulin ratio (G/I).

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In girls, but not in boys, pronounced adrenarche and precocious pubarche along with ovarian hyperandrogenism have been related to insulin resistance and reduced fetal growth. However, insulin secretion is increased during puberty in normal boys. The aim of this study was to analyze the possible implication of changes in the GH/IGF-I axis and in insulin sensitivity for the regulation of adrenal androgen secretion of normal prepubertal and adolescent boys.

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