[Analysis of BRAF and NRAS mutations in thyroid tumors in patients from Argentina]. / Análisis de mutaciones BRAF y NRAS de tumores tiroideos en pacientes de 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. RESULTS: BRAF mutation was identified in 40 samples (74.1%) of FNAs classified as Bethesda VI (n = 54). In samples histologically diagnosed as classic papillary thyroid carcinoma (cPTC, n = 47), mutation was observed in 70% of cases, while in other subtypes the prevalence was lower (p = 0.013). In FNA specimens of follicular lesions (n = 36), positivity for NRAS was found in 50% of the follicular carcinomas (FTCs), but only in 6.7% of adenomas. Finally, there was a significant correlation between BRAF and PTC with lymph-node metastasis (p = 0.014) and increased relative risk of recurrence based on the Argentine Intersociety Consensus (RR = 6.77, p = 0.022). No significant differences were found between BRAF mutation and other features of aggressiveness in PTC. CONCLUSION: BRAF and NRAS mutations are observed in a significant number of PTCs and FTCs, in our population. There is a significant correlation between BRAF mutation and lymph-node metastasis.

Introducción: Se ha descrito que alteraciones moleculares de las células foliculares tiroideas en el gen BRAF o en NRAS están asociadas con el proceso de carcinogénesis. Nuestro objetivo fue conocer la frecuencia mutacional de BRAF y NRAS a partir de muestras de punción aspirativa con aguja fina (PAAF) en nuestra población. Métodos: Se analizó por qPCR el estado mutacional de BRAF (codón 600) y NRAS (codón 61) de 193 muestras obtenidas por PAAF de nódulos sospechosos y se comparó con los datos de la anatomía patológica de 115 pacientes. Resultados: La mutación BRAF se identificó en 40 muestras (74.1%) de las punciones categorizadas como Bethesda VI (n = 54). En las muestras que se correspondieron con carcinoma papilar de tiroides (CPT) variante clásica por histología (n = 47), el 70% presentó la mutación, mientras que en los otros subtipos la prevalencia fue más baja (p = 0.013). En muestras de lesión folicular (n = 36), el 50% de los carcinomas foliculares resultaron positivos para NRAS pero solo el 6.7% de los adenomas presentaron esta variación. La presencia de mutación BRAF y CPT se asociaron con metástasis en los ganglios linfáticos (p = 0.014) y mayor riesgo relativo de recurrencia según el Consenso Argentino Intersocietario (RR = 6.77, p = 0.022). No hubo diferencias significativas entre la mutación de BRAF y otras características de agresividad en CPT. Conclusión: La mutación de BRAF y NRAS se observa en un número significativo de CPT y carcinoma folicular, respectivamente, en nuestra población. La mutación BRAF se correlaciona significativamente con metástasis en los ganglios linfáticos.

Análisis de mutaciones BRAF y NRAS de tumores tiroideos en pacientes de Argentina / Analysis of BRAF and NRAS mutations in thyroid tumors in patients from Argentina

Resumen Introducción : Se ha descrito que alteraciones molecu lares de las células foliculares tiroideas en el gen BRAF o en NRAS están asociadas con el proceso de carcinogé nesis. Nuestro objetivo fue conocer la frecuencia muta cional de BRAF y NRAS a partir de muestras de punción aspirativa con aguja fina (PAAF) en nuestra población. Métodos : Se analizó por qPCR el estado mutacional de BRAF (codón 600) y NRAS (codón 61) de 193 mues tras obtenidas por PAAF de nódulos sospechosos y se comparó con los datos de la anatomía patológica de 115 pacientes. Resultados : La mutación BRAF se identificó en 40 muestras (74.1%) de las punciones categorizadas como Bethesda VI (n = 54). En las muestras que se correspon dieron con carcinoma papilar de tiroides (CPT) variante clásica por histología (n = 47), el 70% presentó la muta ción, mientras que en los otros subtipos la prevalencia fue más baja (p = 0.013). En muestras de lesión folicular (n = 36), el 50% de los carcinomas foliculares resultaron positivos para NRAS pero solo el 6.7% de los adenomas presentaron esta variación. La presencia de mutación BRAF y CPT se asociaron con metástasis en los gan glios linfáticos (p = 0.014) y mayor riesgo relativo de recurrencia según el Consenso Argentino Intersocietario (RR = 6.77, p = 0.022). No hubo diferencias significativas entre la mutación de BRAF y otras características de agresividad en CPT. Conclusión : La mutación de BRAF y NRAS se observa en un número significativo de CPT y carcinoma folicular, respectivamente, en nuestra población. La mutación BRAF se correlaciona significativamente con metástasis en los ganglios linfáticos.

Abstract 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. Results : BRAF mutation was identified in 40 samples (74.1%) of FNAs classified as Bethesda VI (n = 54). In samples histologically diagnosed as classic papillary thyroid carcinoma (cPTC, n = 47), mutation was observed in 70% of cases, while in other subtypes the prevalence was lower (p = 0.013). In FNA specimens of follicular lesions (n = 36), positivity for NRAS was found in 50% of the follicular carcinomas (FTCs), but only in 6.7% of adenomas. Finally, there was a significant correlation between BRAF and PTC with lymph-node metastasis (p = 0.014) and increased relative risk of recurrence based on the Argentine Intersociety Consensus (RR = 6.77, p = 0.022). No significant differences were found between BRAF mutation and other features of aggressiveness in PTC. Conclusion : BRAF and NRAS mutations are observed in a significant number of PTCs and FTCs, in our popu lation. There is a significant correlation between BRAF mutation and lymph-node metastasis.

Genetic characterization of a large cohort of Argentine 21-hydroxylase Deficiency.

CONTEXT: 21-hydroxylase deficiency is the most common cause of Congenital Adrenal Hyperplasia. It presents as severe or classical forms-salt wasting and simple virilizing-and a mild or nonclassical (NC). Several studies have reported the frequency of pathogenic variants in different populations, although few of them included a large number of NC patients. OBJECTIVE: To analyse the CYP21A2 gene defects in a large cohort of Argentine patients. DESIGN: Molecular characterization of 628 patients (168 classical, 460 nonclassical, representing 1203 nonrelated alleles), 398 relatives, 126 partners. METHODS: Genetic variants were assessed by allele-specific PCR, PCR-RFLP or direct sequencing. Deletions, duplications and large gene conversions (LGC) were studied by Southern blot/MLPA or long-range PCR. Biological implications of novel variants were analysed by structure-based in silico studies. RESULTS: The most frequent pathogenic variants were p.V282L (58%) in NC alleles and c.293-13C>G (31.8%) and p.I173N (21.1%) in classical. Deletions and LGC were found at low frequency (6.2%), 57 alleles had rare pathogenic variants, and 3 had novel variants: p.(S166F); p.(P189R), p.(R436L). Genotype-phenotype correlation was observed in 98.6% of the cases, 11 asymptomatic first-degree relatives had pathogenic variants in both alleles, and 21/126 partners were carriers. CONCLUSIONS: We conducted a comprehensive genetic characterization of the largest cohort of 21-hydroxylase patients from the region. In particular, we add to the molecular characterization of a large number of NC patients and to the estimation of the disease carrier's frequency in our population.

[Routine serum calcitonin measurement in thyroid nodules]. / Medición rutinaria de calcitonina sérica en nódulos tiroideos.

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. CT was measured by chemiluminescence, normal value: up to 18 pg/ml in men and 12 pg/ml in women. In two patients, hypercalcitoninemia was confirmed in repeated measurements. Fine needle aspiration with CT measurement in the needle wash fluid identified MTC in nodules with citology abnormalities. The genetic study was positive in one patient (mutation exon 14, Val804Met, MTC familiar). The other presented a polymorphism (exon 13 L769L heterozygous - exon 15 S904S heterozygous). In both cases, CT was normalized 3 months after surgery and remained normal after 6 years of follow-up. The routine measurement of CT in thyroid nodular pathology was useful to detect two cases of MTC, one of them sporadic and the other familiar in this cohort. The prevalence of MTC was 0.2%.

Existe mucha controversia sobre los beneficios de la medición de la calcitonina sérica (CT) durante la evaluación inicial de pacientes con nódulos tiroideos. El objetivo del estudio fue evaluar la identificación temprana del carcinoma medular de tiroides (CMT) a través de la medición rutinaria de CT sérica en una cohorte de Buenos Aires, Argentina. Se estudiaron consecutivamente a los pacientes con enfermedad nodular de la tiroides (n=1017). La CT se midió por quimioluminiscencia (valor normal: hasta 18 pg/ml en hombres y 12 pg/ml en mujeres). En dos pacientes, la hipercalcitoninemia se confirmó en mediciones repetidas. La aspiración con aguja fina con medición de CT en el líquido obtenido identificó la presencia del CMT. El estudio genético fue positivo en uno (mutación exón 14, Val804Met, CMT familiar). El otro presentó un polimorfismo (heterocigoto exón 13 L769L - heterocigoto exón 15 S904S). En ambos casos, la CT se normalizó 3 meses después de la cirugía y se mantuvo en valores normales después de 6 años de seguimiento. La medición rutinaria de la CT en nódulos tiroideos fue útil para detectar dos casos de CMT, uno de ellos esporádico y el otro familiar en la cohorte seguida. La prevalencia de CMT fue de 0.2%.

Medición rutinaria de calcitonina sérica en nódulos tiroideos / Routine serum calcitonin measurement in thyroid nodules

Existe mucha controversia sobre los beneficios de la medición de la calcitonina sérica (CT) durante la evaluación inicial de pacientes con nódulos tiroideos. El objetivo del estudio fue evaluar la identificación temprana del carcinoma medular de tiroides (CMT) a través de la medición rutinaria de CT sérica en una cohorte de Buenos Aires, Argentina. Se estudiaron consecutivamente a los pacientes con enfermedad nodular de la tiroides (n=1017). La CT se midió por quimioluminiscencia (valor normal: hasta 18 pg/ml en hombres y 12 pg/ml en mujeres). En dos pacientes, la hipercalcitoninemia se confirmó en mediciones repetidas. La aspiración con aguja fina con medición de CT en el líquido obtenido identificó la presencia del CMT. El estudio genético fue positivo en uno (mutación exón 14, Val804Met, CMT familiar). El otro presentó un polimorfismo (heterocigoto exón 13 L769L - heterocigoto exón 15 S904S). En ambos casos, la CT se normalizó 3 meses después de la cirugía y se mantuvo en valores normales después de 6 años de seguimiento. La medición rutinaria de la CT en nódulos tiroideos fue útil para detectar dos casos de CMT, uno de ellos esporádico y el otro familiar en la cohorte seguida. La prevalencia de CMT fue de 0.2%.

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. CT was measured by chemiluminescence, normal value: up to 18 pg/ml in men and 12 pg/ml in women. In two patients, hypercalcitoninemia was confirmed in repeated measurements. Fine needle aspiration with CT measurement in the needle wash fluid identified MTC in nodules with citology abnormalities. The genetic study was positive in one patient (mutation exon 14, Val804Met, MTC familiar). The other presented a polymorphism (exon 13 L769L heterozygous - exon 15 S904S heterozygous). In both cases, CT was normalized 3 months after surgery and remained normal after 6 years of follow-up. The routine measurement of CT in thyroid nodular pathology was useful to detect two cases of MTC, one of them sporadic and the other familiar in this cohort. The prevalence of MTC was 0.2%.

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. From a total number of 2906 men who completed a screening for the early detection of prostate cancer, 139 healthy men (mean ± SD age, 57.8 ± 5.7 years) were included in this study. Participants were assessed with the Holmes and Rahe questionnaire in relation to their experience of LE during the previous 1-5 years. Salivary and serum cortisol was measured at 08:00-09:00 h, as well as luteinizing hormone (LH), total testosterone, epinephrine (E) and norepinephrine (NE). LE weight sum and LE number positively correlated with LH (r = 0.293, p = 0.004; r = 0.220, p = 0.031, respectively). In a multiple regression analysis, LE-sum explained an additional and significant 10.4% of the variance in LH levels, after statistically controlling for the effects of age, waist circumference (WC) and BMI (F(1,90) = 6.61, p < 0.05). Importantly, cortisol interacted with LE in relation to total testosterone. In men with high cortisol values (≥15.4 µg/dl), there was a statistically significant positive relationship between LE number and total testosterone levels (p = 0.05), while LE were unrelated to total testosterone in men with low cortisol. LE correlated with sex hormones, predicting LH values, and in men with high cortisol levels shows a possible moderator effect of cortisol on the relationship between LE and total testosterone.

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. METHODS: One hundred and ten consecutive patients were evaluated. RESULTS: IGF-1 levels decreased as liver steatosis worsened. There was a statistically significant difference between mild-moderate steatosis on one hand, and severe steatosis on the other (142 vs. 110, P < 0.05). Homeostasis model assessment of insulin resistance (HOMA) and insulin levels showed a tendency to inverse association with IGF-1, but it was not statistically significant. HOMA significantly increased in severe liver steatosis when compared with mild-moderate steatosis (6.20 vs. 3.99, P < 0.05). Insulin levels also showed a significant increase (3.01 +/- 0.61 vs. 2.59 +/- 0.56, P < 0.05). Body mass index showed a significant inverse correlation with IGF-1 level (r = -0.19, P < 0.05) and a tendency to increase as liver steatosis worsened. Waist circumference increased significantly as liver steatosis worsened (severe vs. mild-moderate: 114 vs. 100, P < 0.05). CONCLUSIONS: IGF-1 levels showed a decrease as liver steatosis worsened. This difference was statistically significant between mild-moderate and severe stetaosis. Inverse correlation between IGF-1 levels and BMI was also statistically significant. There was no statistically significant correlation between IGF-1 levels and HOMA and insulin levels.

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. We compared a two-site immunoradiometric assay with ethanol-acid extraction (IRMA-DSL) and a solid-phase chemiluminescent immunometric assay (ICMA-IMMULITE), correlating the clinical finding with the biochemical results. A total of 102 samples (77 women and 25 men aged 18-79 years) were analyzed with the two different IGF-I assays. Sixty-four of samples had been taken from patients with acromegaly in different stages. Pearson regression showed a high correlation coefficient; otherwise, Bland and Altman analyses showed a mean difference of 177.6 ng/ml, with upper and lower limits of -183.5 and 538.7 ng/ml in the 102 samples studied. Normal serum IGF-I was found in 64 and 41.5% of patients with treated acromegaly when measured by ICMA and IRMA, respectively. In our study, IGF-I-ICMA had a better clinical correlation in patients with treated acromegaly. The reevaluation of current IGF-I immunoassays is necessary to correctly interpret treatment response in acromegalic patients and thus achieve a better correlation between clinical and biochemical results.

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. A cutoff value of 2.8 nmol/L was established from a receiver-operating characteristic (ROC) curve, as discriminating between controls and patients with active disease (specificity 100% and sensitivity 92.3%). CgA levels were higher in functioning than in no functioning tumors (median 55 nmol/L vs 5 nmol/L, p < 0.05). Metastases were present in 83 patients and their CgA levels were significantly higher than levels in the 36 patients without metastases (median 44 nmol/L vs 64 nmol/L, p < 0.0001). CgA levels are strongly correlated with tumor metastatic spread. Sensitivity differed between patients with localized disease (median 6 nmol/L), extensive disease (median 22 nmol/L) and very extensive disease (median 44 nmol/L) (p < 0.001). In conclusion, due to its high sensitivity and specificity, CgA is useful in a newly discovered GEP-NET especially when no abnormal hormone secretion can be demonstrated. CgA levels were significantly higher in functioning tumors than in non-functioning tumors and increased with metastatic spread. If serial evaluation of CgA levels is sufficient for the detection of tumor growth changes remains to be prospectively demonstrated.

La saliva y su utilidad en la evaluación de la función endocrinológica / Saliva, its utility in the evaluation of the endocrinological function

Los procedimientos habituales de diagnóstico en el laboratorio clínico implican el análisis de los componentes celulares y químicos de la sangre. Otros líquidos biológicos también se utilizan para el diagnóstico de distintas patologías, entre los cuales la saliva ofrece algunas ventajas distintivas. Constituye una muestra biológica que se puede obtener fácilmente por una técnica no invasiva, indolora y de bajo costo. La muestra de saliva para el diagnóstico de diferentes enfermedades es particularmente útil en pacientes pediátricos y en individuos añosos. Además, el análisis de la saliva puede proporcionar un método apropiado para la investigación de grandes poblcaciones, como lo avalan numerosos trabajos en los que se usa el análisis de este fluido, no solo para el diagnósticos, sino también para el monitoreo de la salud general. En los últimos años, se ha difundido el uso de muestras de saliva para el diagnóstico de diversas entidades clínicas por ser un fluido corporal que puede ser empleado para detecgtar la presencia y determinar concentraciones de una amplia variedad de anticuerpos, drogas, hormonas y marcadores tumorales.

La saliva y su utilidad en la evaluación de la función endocrinológica / Saliva, its utility in the evaluation of the endocrinological function

Los procedimientos habituales de diagnóstico en el laboratorio clínico implican el análisis de los componentes celulares y químicos de la sangre. Otros líquidos biológicos también se utilizan para el diagnóstico de distintas patologías, entre los cuales la saliva ofrece algunas ventajas distintivas. Constituye una muestra biológica que se puede obtener fácilmente por una técnica no invasiva, indolora y de bajo costo. La muestra de saliva para el diagnóstico de diferentes enfermedades es particularmente útil en pacientes pediátricos y en individuos añosos. Además, el análisis de la saliva puede proporcionar un método apropiado para la investigación de grandes poblcaciones, como lo avalan numerosos trabajos en los que se usa el análisis de este fluido, no solo para el diagnósticos, sino también para el monitoreo de la salud general. En los últimos años, se ha difundido el uso de muestras de saliva para el diagnóstico de diversas entidades clínicas por ser un fluido corporal que puede ser empleado para detecgtar la presencia y determinar concentraciones de una amplia variedad de anticuerpos, drogas, hormonas y marcadores tumorales. (AU)

[Bilateral inferior petrosal sinus sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome]. / El cateterismo bilateral y simultáneo de los senos petrosos inferiores en el diagnóstico diferencial del síndrome de Cushing.

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). RESULTS: No tumor was identifiable by imaging techniques. Mean plasma ACTH values were higher in patients with EAS than in CD (103+/- 110.2 and 73.1+/-41.98 pg/mL respectively, p=NS). Three patients with EAS and 3 patients with CD did not suppress cortisol with the HDDST. The sensitivity of the test was 86% and the specificity 100%. To improve the diagnostic outcome of BIPSS, an stimulation with Desmopressin (9 fig i.v) was performed in 9 patients. The threshold for a pituitary source, was defined as an inferior petrosal sinus to peripheral ACTH basal and post Desmopression ratio >2. BIPSS was successfully carried out in 22 patients and no complications occurred. In 6 patients BIPSS failed to meet the threshold criteria. In 3 patients, bronchial carcinoid tumors which proved to synthesize ACTH, were removed. The diagnostic sensitivity of BIPSS greatly improved from 86% to 100% after Desmopressin stimulation. BIPSS accurately predicted the inverted exclamation markateralization of the microadenoma in 8 of 12 patients (66%). CONCLUSIONS: The combination of Desmopressin stimulation with BIPSS was useful for the differential diagnosis of ACTH-dependent Cushing's Syndrome. However, the preoperative location of pituitary microadenomas was poorly predicted by BIPSS.

El cateterismo bilateral y simult neo de los senos petrosos inferiores en el diagnóstico diferencial del síndrome de Cushing / 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 pituitarymicroadenomas (CD) and 3 with occult ectopic ACTH secretion (EAS). Results: No tumor was identifiable by imaging techniques. Mean plasma ACTH values were higher in patients with EAS than in CD (103± 110.2 and 73.1±41.98 pg/mL respectively, p=NS). Three patients with EAS and 3 patients with CD did not suppress cortisol with the HDDST. The sensitivity of the test was 86 percent and the specificity 100 percent. To improve the diagnostic outcome of BIPSS, an stimulation with Desmopressin (9 fig i.v) was performed in 9 patients. The threshold for a pituitary source, was defined as an inferior petrosal sinus to peripheral ACTH basal and post Desmopression ratio >2. BIPSS was successfully carried out in 22 patients and no complications occurred. In 6 patients BIPSS failed to meet the threshold criteria. In 3 patients, bronchial carcinoid tumors which proved to synthesize ACTH, were removed. The diagnostic sensitivity of BIPSS greatly improved from 86 percent to 100 percent after Desmopressin stimulation. BIPSS accurately predicted the ¡ateralization of the microadenoma in 8 of 12 patients (66 percent). Conclusions: The combination of Desmopressin stimulation with BIPSS was useful for the differential diagnosis of ACTH-dependent Cushing's Syndrome. However, the preoperative location of pituitary microadenomas was poorly predicted by BIPSS.

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. SETTING: The study was conducted in 34 university endocrinology and genetics departments in nine countries. PATIENTS: Affected members from each FIPA family were studied. Relatives of patients with AIP mutations underwent AIP sequence analysis. MAIN OUTCOME MEASURES: Presence/absence and description of AIP gene mutations were the main outcome measures. INTERVENTION: There was no intervention. RESULTS: Seventy-three FIPA families were identified, with 156 patients with pituitary adenomas; the FIPA cohort was evenly divided between families with homogeneous and heterogeneous tumor expression. Eleven FIPA families had 10 germline AIP mutations. Nine mutations, R16H, G47_R54del, Q142X, E174frameshift, Q217X, Q239X, K241E, R271W, and Q285frameshift, have not been described previously. Tumors were significantly larger (P = 0.0005) and diagnosed at a younger age (P = 0.0006) in AIP mutation-positive vs. mutation-negative subjects. Somatotropinomas predominated among FIPA families with AIP mutations, but mixed GH/prolactin-secreting tumors, prolactinomas, and nonsecreting adenomas were also noted. Approximately 85% of the FIPA cohort and 50% of those with familial somatotropinomas were negative for AIP mutations. CONCLUSIONS: AIP mutations, of which nine new mutations have been described here, occur in approximately 15% of FIPA families. Although pituitary tumors occurring in association with AIP mutations are predominantly somatotropinomas, other tumor types are also seen. Further study of the impact of AIP mutations on protein expression and activity is necessary to elucidate their role in pituitary tumorigenesis in FIPA.

¿Es la acantosis nigricans un signo de insulinorresistencia en adolescentes obesos? / Is acanthosis nigrecans a marker of insulin-resistance in obese adolescents?

Introducción. La acantosis nigricans ha sido propuestacomo marcador de insulinorresistencia en adolescentes obesos. El propósito de este estudio fue determinar la asociación entre AN y: a) distintosmarcadores de insulinoerresistencia como,HOMA-IR, PF-IGF1, insulinemia en ayunas; b) índicede masa corporal, c) HDL, triglicéridos y otros predictores de insulinorresistencia o diabetesmellitus tipo 2.Población, material y métodos. Se evaluaron 1.255 adolescentes, multiétnicos, principalmente caucásicos,edad promedio 12,4más menos 1,4 años, que consultaronpara un control rutinario de salud entre abril y noviembre de 2001. Doscientos ochenta y ocho eran obesos (índice de masa corporal > percentilo 95); de éstos tomamos una muestra aleatorizada de 74 adolescentes obesos (40 mujeres). Se obtuvieron datos de: peso de nacimiento, antecedentes familiares de diabetes de tipo 2, índice de masa corporal,presencia de acantosis nigricans, tensión arterial yestadio de Tanner. Se realizaron: prueba de toleranciaoral a la glucosa, perfil lipídico, insulinemia yPF-IGF1.Resultados. De los 74 adolescentes obesos, todos se encontraban en estadios de Tanner manor o igual a 2 y tenían antecedentes familiares de obesidad, diabetes mellitus de tipo 2 o ambos. Cuarenta y uno (55,4%)presentaron acantosis nigricans. Cuatro presentaron intolerancia a la glucosa en el grupo conacantosis nigricans; en el otro, se observó estacaracterística en sólo 2 pacientes. Ninguno presentó diabetes de tipo 2. Se observó una asociación univariada con el índice de masa corporal (rS 0,45;p= 0,00038), peso de nacimiento (rS -0,37; p=0,0021), glucemia basal (rS 0,30; p=0,009) y HDLC(rS -0,25; p= 0,03). No hubo asociación univariada ni multivariada entre acantosis nigricans y todos los marcadores de resistencia insulínica: insulinemia basal (rS 0,16; p= 0,16), HOMA-IR (rS 0,2; p=0,06) y PF-IGF1 (rS 0,07; p= 0,69). En el análisis multivariado la presencia...

¿Es la acantosis nigricans un signo de insulinorresistencia en adolescentes obesos? / Is acanthosis nigrecans a marker of insulin-resistance in obese adolescents?

Introducción. La acantosis nigricans ha sido propuestacomo marcador de insulinorresistencia en adolescentes obesos. El propósito de este estudio fue determinar la asociación entre AN y: a) distintosmarcadores de insulinoerresistencia como,HOMA-IR, PF-IGF1, insulinemia en ayunas; b) índicede masa corporal, c) HDL, triglicéridos y otros predictores de insulinorresistencia o diabetesmellitus tipo 2.Población, material y métodos. Se evaluaron 1.255 adolescentes, multiétnicos, principalmente caucásicos,edad promedio 12,4más menos 1,4 años, que consultaronpara un control rutinario de salud entre abril y noviembre de 2001. Doscientos ochenta y ocho eran obesos (índice de masa corporal > percentilo 95); de éstos tomamos una muestra aleatorizada de 74 adolescentes obesos (40 mujeres). Se obtuvieron datos de: peso de nacimiento, antecedentes familiares de diabetes de tipo 2, índice de masa corporal,presencia de acantosis nigricans, tensión arterial yestadio de Tanner. Se realizaron: prueba de toleranciaoral a la glucosa, perfil lipídico, insulinemia yPF-IGF1.Resultados. De los 74 adolescentes obesos, todos se encontraban en estadios de Tanner manor o igual a 2 y tenían antecedentes familiares de obesidad, diabetes mellitus de tipo 2 o ambos. Cuarenta y uno (55,4%)presentaron acantosis nigricans. Cuatro presentaron intolerancia a la glucosa en el grupo conacantosis nigricans; en el otro, se observó estacaracterística en sólo 2 pacientes. Ninguno presentó diabetes de tipo 2. Se observó una asociación univariada con el índice de masa corporal (rS 0,45;p= 0,00038), peso de nacimiento (rS -0,37; p=0,0021), glucemia basal (rS 0,30; p=0,009) y HDLC(rS -0,25; p= 0,03). No hubo asociación univariada ni multivariada entre acantosis nigricans y todos los marcadores de resistencia insulínica: insulinemia basal (rS 0,16; p= 0,16), HOMA-IR (rS 0,2; p=0,06) y PF-IGF1 (rS 0,07; p= 0,69). En el análisis multivariado la presencia...(AU)

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. PATIENT(S): Twenty-four insulin-resistant women with PCOS. INTERVENTION(S): Hormonal evaluations and a standardized oral glucose tolerance test before and after a 3-month trial of 4 mg of rosiglitazone daily. MAIN OUTCOME MEASURE(S): Serum LH, FSH, T, IGF-1, IGFBP-1, IGFBP-3, leptin, 17alpha-hydroxyprogesterone, insulin, and glucose concentrations. The area under insulin curve (AUC-insulin), the HOMA index (insulin resistance), the QUICKI index (insulin sensitivity), and the beta-cell function were calculated. Body mass index (BMI) and the waist/hip ratio were evaluated. RESULT(S): A significant decrease was observed in serum fasting insulin, AUC insulin, HOMA index, beta-cell function, IGF-1, LH, and waist/hip ratio. The QUICKI index and IGFBP-1 increased significantly. Serum sex hormone-binding globulin, androgens, leptin, IGFBP-3, and BMI remained unchanged. Twenty-two of 23 females had their menses restored, and three patients became pregnant. One patient was excluded because she became pregnant at the second month. CONCLUSION(S): Associated with the decrease in LH, rosiglitazone improved insulin-resistance parameters and normalized the menstrual cycle, which suggests that this drug could improve the endocrine-reproductive condition in insulin-resistant women with PCOS.

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). A total of 27 parents and 13 nonaffected siblings were also analysed. MEASUREMENTS: Basal steroid hormones and 17-hydroxyprogesterone levels following adrenal stimulation with adrenocorticotrophic hormone were measured, together with an analysis of 10 point mutations in the CYP21 gene. RESULTS: A total of 83% and 74.4% classical and nonclassical chromosomes, respectively, were characterized. The intron 2 mutation was the most prevalent among classical alleles. In addition, a high frequency for R356W was observed in both groups (13.3 and 6.9%, respectively), while V281L was the most frequent mutation among the nonclassical patients with a frequency of 39.5%. No alleles containing P30L were observed, and one de novo mutation (R356W) was found. A total of 68.3% patients were fully genotyped, and all but one showed no genotype/phenotype discrepancy. Though the cut-off value for post-ACTH 17-hydroxyprogesterone stimulation was 30.25 nmol/l (10.00 microg/l), the lowest value observed in the fully genotyped nonclassical group was 42.35 nmol/l (14.00 microg/l). CONCLUSIONS: The high number of unidentified alleles in the nonclassical group suggests that less frequent mutations, or the presence of new ones, might be the cause of the disease in the Argentine population. Alternatively, the cut-off value in the ACTH-stimulated 17-hydroxyprogesterone test might overestimate the diagnosis of the nonclassical form by including some patients with heterozygous status.