[Analysis of BRAF and NRAS mutations in thyroid tumors in patients from Argentina].

Introduction: Molecular alterations in follicular cells in the BRAF or NRAS genes have been reported to be associated with the process of carcinogenesis. Our aim was to determine the mutational frequency of BRAF and NRAS in fine-needle aspiration (FNA) specimens in our population.

Methods: The mutational status of BRAF (codon 600) and NRAS (codon 61) was analysed by qPCR in 193 FNA specimens from suspicious nodules and compared with pathological data of 115 patients.

[Routine serum calcitonin measurement in thyroid nodules].

There is much controversy about the benefits of the use of serum calcitonin (CT) in the initial evaluation of patients with thyroid nodules. The objective of the study was to early identify medullary thyroid carcinoma (MTC) through the routine measurement of CT in thyroid nodular pathology in a large cohort of patients from Buenos Aires, Argentina. Consecutive patients with nodular thyroid disease (n=1017) were studied.

Life events are positively associated with luteinizing hormone in middle age adult men: role of cortisol as a third variable.

Previous studies have tested the relationship between chronic stress and sex hormones, but inconsistent results have been found. One possibility is that this association may depend on other biological factors. This study examined the relationship between stressful life events (LE) and sex hormones in men, and whether cortisol is involved in this relationship.

IGF-1 levels in different stages of liver steatosis and its association with metabolic syndrome.

Background And Aims: Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome related to insulin resistance. Insulin-like growth factor 1 (IGF-1) is mainly produced by hepatocytes and its secretion is stimulated by growth hormone. Our aim was to assess possible changes in IGF-1 levels in patients with different ultrasonography stages of NAFLD and its association with hyperlipidemia, impaired glucose tolerance, non-insulin dependant type 2 diabetes, waist circumference, obesity and arterial hypertension.

Serum insulin-like growth factor-1 measurement in the diagnosis and follow-up of patients with acromegaly: preliminary data.

Measurement of serum insulin-like growth factor-1 (IGF-I) is the current method for diagnosing and monitoring acromegaly. However, the use of commercially available kits needs to be validated. In our study, we have investigated the use of two different IGF-I immunoassays in patients already diagnosed with acromegaly.

Chromogranin A as a biochemical marker for the management of neuroendocrine tumors: a multicenter study developed in Argentina.

Elevated circulating levels of chromogranin A (CgA) are found in the neuroendocrine tumors (NETs), but diagnostic usefulness of this marker is still debatable. To assess the role of CgA for the identification and follow up of gastroenteropancreatic neuroendocrine tumors (GEP-NET), a multicenter prospective longitudinal study has been carried out in Argentina. CgA was measured by RIA in 119 histologically proven GEP-NET patients and in 39 healthy controls.

[Bilateral inferior petrosal sinus sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome].

Background: The features of pituitary ACTH-dependent Cushing syndrome are often indistinguishable from those of occult ectopic ACTH-dependent Cushing syndrome (CS).

Aim: To assess the diagnostic accuracy of bilateral inferior petrosal sinus sampling (BIPSS) in the differential diagnosis of ACTH-dependent Cushing's syndrome as compared with ACTH levels and the overnight high dose dexamethasone suppression test (HDDST).

Material And Methods: Retrospective review of medical records of 23 patients (aged 19 to 63 years, 16 women) with surgically proven CS, 20 pituitary microadenomas (CD) and 3 with occult ectopic ACTH secretion (EAS).

Aryl hydrocarbon receptor-interacting protein gene mutations in familial isolated pituitary adenomas: analysis in 73 families.

Context: An association between germline aryl hydrocarbon receptor-interacting protein (AIP) gene mutations and pituitary adenomas was recently shown.

Objective: The objective of the study was to assess the frequency of AIP gene mutations in a large cohort of patients with familial isolated pituitary adenoma (FIPA).

Design: This was a multicenter, international, collaborative study.

Effect of rosiglitazone on insulin resistance, growth factors, and reproductive disturbances in women with polycystic ovary syndrome.

Objective: To evaluate the effects of rosiglitazone on insulin resistance, growth factors, and reproductive disturbances in women with polycystic ovary syndrome (PCOS).

Design: Prospective study.

Setting: Women with PCOS attending as outpatients of the Endocrine Division, Hospital Durand, Buenos Aires.

Classical and nonclassical 21-hydroxylase deficiency: a molecular study of Argentine patients.

Objective: To characterize the molecular basis of the 21-hydroxylase deficiency in a group of Argentine patients presenting the classical and nonclassical forms of the disease.

Design: To analyse the frequency of point mutations in the CYP21 gene by DNA amplification and mutation detection.

Patients: Forty-one patients from 36 nonrelated families: 25 nonclassical (NC), 11 salt-wasting (SW) and five simple virilizing (SV).