Antonio Andres

The most common asymptotic procedure for analyzing a 2 × 2 table (under the conditioning principle) is the ‰ chi-squared test with correction for continuity (c.f.c). According to the way this is applied, up to the present four methods have been obtained: one for one-tailed tests (Yates') and three for two-tailed tests (those of Mantel, Conover and Haber). In this

This article presents new evidence on the relationship between corruption and income inequality. Using a panel data methodology, we find that lower corruption is associated with higher income inequality in Latin America. This result is in contrast to other empirical studies but it makes sense in Latin America for a number of reasons. The finding of an inverse relationship between

... are several criteria for arranging the values of X,: from smallest to greatest probability (Irwin, 1935), from the largest to the smallest value of Ixl/nl - x2/n21 (Armsen, 1955), from the largest to the smallest value of the odds ratio xly2/x2yl (Hill & Pike, 1965) etc. Luna del Castillo & ...

The 2 × 2 tables used to present the data in an experiment for comparing two proportions by means of two observations of two independent binomial distributions may appear simple but are not. The debate about the best method to use is unending, and has divided statisticians into practically irreconcilable groups. In this article, all the available non-asymptotic tests are reviewed (except the Bayesian methodology). The author states which is the optimal (for each group), referring to the tables and programs that exist for them, and contrast the arguments used by supporters of each of the options. They also sort the tangle of solutions into "families", based on the methodology used and/or prior assumptions, and point out the most frequent methodological mistakes committed when comparing the different families.

Abstract The most powerful non-asymptotic unconditioned method for comparing two proportions (independent samples) is that of Barnard (1945), but the complexity of computation has led to several simplifying versions being produced. There is no complete ...

Lactante de 2 meses asintomática remitida para estudio de una masa abdominal de consistencia dura en flanco izquierdo. En la ecografía se observa tumoración yuxtarrenal izquierda solido-quística. La alfa-fetoproteina cercana a 2.000 ng/ml. La metayodobenzilguanidina (123-I-MIBG) no demostró captación tumoral. A las 48 h, presenta cuadro de shock hipovolemico. En la radiografía de tórax presenta cardiomegalia con índice cardiotorácico de 0,7 y congestión pulmonar. La ecocardiografía muestra dilatación de ventrículo izquierdo con fracción de eyección del 35–40%. Se descartaron anemia, hipertensión, hipervolemia e hipersecreción de catecolaminas. Los estudios virológicos y de despistaje metabólico fueron normales. Se resecó un tumor retroperitoneal muy vascularizado sin incidencias y se confirmó el diagnóstico de teratoma inmaduro grado 2 de Norris. A los 3 meses la evolución fue satisfactoria. Los teratomas son tumores raros en la infancia que tienen en general un comportamiento benigno. Está descrita la miocardiopatía dilatada (MCD) secundaria a tumores de células cromafines (feocromocitoma, neuroblastoma, ganglioneuroblastoma), así como a infiltrados leucémicos y secundariamente al tratamiento con antraciclinas, pero no existe ningún caso publicado en la literatura que relacione el teratoma con la miocardiopatía dilatada. Diversas citocinas como INF-α, IL-1, IL-6 podrían ser secretadas por el tumor, promoviendo a nivel cardiaco la actividad de los fibroblastos, induciendo la apoptosis celular y la fibrosis miocárdica. Así, la resección de la masa tumoral responsable de la producción de las mismas, permitiría la regresión de la disfunción miocárdica, como en el caso expuesto.Asymptomatic 2 month-old infant referred for evaluation of a hard abdominal mass on the left side. The ultrasound examination showed a solid-cystic tumour above the left kidney. The alpha-fetoprotein level was 2000 ng/ml. The meta-iodobenzylguanidine (123-I-MIBG) showed no tumour uptake. At 48 h, she showed signs of hypovolemic shock. The chest X-ray showed cardiomegaly with a cardiothoracic ratio of 0.7 and pulmonary congestion. The echocardiogram showed a dilated left ventricle with ejection fraction 35–40%. Anaemia, hypertension, hypervolemia and hyper-secretion of catecholamines were ruled out. The virology and metabolic screens were normal. The highly vascularised retroperitoneal tumour was resected without incident and confirmed the diagnosis of an immature Norris grade 2 teratoma grade. At 3 months the outcome was satisfactory. Teratomas are rare tumours in childhood that generally have a benign course. Dilated cardiomyopathy (DCM) secondary to, chromaffin cell tumours (phaeochromocytoma, neuroblastoma, ganglioneuroblastoma), leukaemia infiltrates, and treatment with anthracyclines have been described, but there is no case reported in the literature regarding a teratoma with dilated cardiomyopathy. Various cytokines, such as INF-α, IL-1, IL-6 may be secreted by tumour, promoting fibroblast activity in the heart and inducing apoptosis and myocardial fibrosis. Thus, in the case presented resection of the tumour mass responsible for this production, enables the heart to return to normal.

The test for comparing two proportions (based on the use of independent samples) is one of the best-known in statistics, and at the same time is the one that generates most disagreement, both in the asymptotic and non-asymptotic versions. The present article offers a critical review of the former, grouping them by "families", points out their theoretical relation to the

Los tumores cardíacos primarios son muy poco frecuentes en la edad pediátrica, y su incidencia varía entre el 0,0017 y el 0,28 %. Más del 90 % son de naturaleza benigna. La variedad más frecuente es el rabdomioma, asociado en más del 60 % de los casos con esclerosis tuberosa.Se realizó un análisis retrospectivo de historias clínicas con diagnóstico de tumor cardíaco primario entre marzo de 1977 y marzo de 2007, y se encontró a un total de 27 pacientes.La edad de diagnóstico inicial es más frecuente en el período neonatal, a partir del hallazgo de un soplo cardíaco (11 casos). No hubo diferencias en la distribución por sexos. En 14 pacientes se encontró cardiomegalia en la radiografía de tórax. De acuerdo con las características ecocardiográficas, se diagnosticaron 20 rabdomiomas, 2 fibromas, 2 teratomas pericárdicos y 3 tumores no clasificables. La mayor parte se localizaron en el ventrículo izquierdo. Además de la ecocardiografía, se realizó cateterismo cardíaco en 3 casos y angiorresonancia en 5 casos. Durante su evolución se constataron episodios de arritmias en 11 pacientes. En 5 se requirió algún tipo de procedimiento quirúrgico, en los que se obtuvo el diagnóstico anatomopatológico. La mortalidad inicial de causa cardiológica fue de 3 pacientes. El 75 % de casos con rabdomiomas presentaba o desarrolló esclerosis tuberosa. En la mayoría de los rabdomiomas (13 casos) se produjo regresión espontánea.En primer lugar, se evidencia la baja prevalencia de esta patología en la infancia. El rabdomioma es el tumor cardíaco primario más frecuente y en nuestro estudio se asoció en el 75 % de los casos a esclerosis tuberosa. El diagnóstico es más frecuente en el período neonatal precoz tras la auscultación de un soplo cardíaco y la ecocardiografía, la técnica diagnóstica de elección, mientras que no se ha encontrado utilidad de otras técnicas de imagen, como la angiorresonancia, para su diagnóstico en la población infantil. La aparición de la ecocardiografía fetal permite descubrirlos precozmente. El curso es benigno en la mayoría de los tumores, con tendencia a la regresión espontánea en los rabdomiomas. Debe vigilarse la aparición de arritmias durante su evolución, que precisará tratamiento médico. La cirugía es necesaria en los casos con síntomas graves, debidos a obstrucción en los tractos de salida ventricular. Una opción quirúrgica es el transplante cardíaco en caso de tumores irresecables con riesgo vital.Primary cardiac tumours are very rare in the paediatric age, their incidence varies from 0.0017 % to 0.28 %. More than 90 % are benign in nature. The most common vari-ety is the rhabdomyoma, present in over 60 % of cases with tuberous sclerosis.We performed a retrospective analysis of medical records with a diagnosis of primary cardiac tumor between March 1977 and March 2007, finding a total of 27 patients.The age of initial diagnosis is more prevalent in the neonatal period, beginning with the discovery of a heart murmur (11 cases). There was no difference in gender dis-tribution. In 14 patients were found cardiomegaly on chest radiograph. According to the echocardiography characteristics there were diagnosed 20 rhabdomyomas, 2 fibromas, 2 pericardial teratomas and 3 non classifiable tumours. Most were located in the left ventricle. Echocardiography, cardiac catheterization was also performed in 3 cases and angioresonance in 5 cases. During their evolution, episodes of arrhythmias were observed in 11 patients, 5 patients required some sort of surgical procedure, which confirmed the histopathology diagnosis. In 3 patients the initial cause of death was cardiological. The 75 % of cases with rhabdomyomas presented or developed tuberous sclerosis. In most of the rhabdomyomas (13 cases), there was a spontaneous regression.Firstly, there is shown to be a low prevalence of this disorder in children. Rhabdomyoma is the most common primary cardiac tumour in our study and it was associated in 75 % of cases with tuberous sclerosis. The diagnosis is more common in the early neonatal period after auscultation of a cardiac murmur and echocardiography, the diagnostic technique of choice, other imaging techniques, such as angioMRI not being of much for diagnosis in children. The emergence of foetal echocardiography allows early de-tection. The course is benign in most tumours, rhabdomyomas tending to regress spontaneously. It must be monitored as the occurrence of arrhythmias during its evolution will require medical treatment. Surgery is needed in cases with severe symptoms, due to obstruction in the ventricular output tracts. One option is the surgical cardiac transplant in non-resectable life-threatening tumours.

Insulin, like leptin, is considered as a lipostatic signal acting at a central level. Aging and age-associated adiposity have been related to the development of leptin resistance in Wistar rats. In the present article, hypothalamic insulin response during aging has been studied in Wistar rats. Thus, the effects of intracerebroventricular infusion of insulin during a week on food intake and body weight as well as insulin signal transduction after acute intracerebroventricular insulin administration have been studied in 3-, 8-, and 24-month-old rats. To explore the possible role of age-associated adiposity, these experiments were also performed in 8- and 24-month-old rats after 3 months of food restriction to reduce visceral adiposity index to values below those of young animals. Intracerebroventricular administration of insulin during a week was more efficient at reducing food intake and body weight in 3-month-old rats than in 8- and 24-month-old rats. Hypothalamic insulin-stimulated insulin receptor, GSK3, AKT, and p70S6K phosphorylation decreased with aging. Insulin receptor and IRS-2 phosphoserine was increased in 24-month-old rats. Food restriction improved both insulin responsiveness and insulin signaling. These data suggest that Wistar rats develop hypothalamic insulin resistance with aging. This can be explained by alterations of the signal transduction pathway. The fact that food restriction improves central insulin response and signal transduction points to the age-associated adiposity as a key player in the development of central insulin resistance.

Introducción La resistencia a insulina se ha relacionado con un aumento de la expresión y/o actividad de proteínas tirosina fosfatasas, especialmente PTP1B, tanto a nivel central como periférico. Las ratas viejas presentan resistencia central a insulina debido a múltiples alteraciones en su vía de señalización. En este trabajo hemos estudiado el posible papel de las PTPs en la resistencia central a insulina durante el envejecimiento y su relación con la restricción nutricional. Material y métodos En extractos hipotalámicos de ratas Wistar macho de 3 y 24 meses de edad, y de 24 meses sometidas a restricción nutricional crónica se determinó: la actividad fosfatasa total utilizando PNPP y la capacidad de desfosforilar a un péptido fosforilado en tirosina en los sitios de autofosforilación de la cadena [beta] del receptor de insulina mediante el kit PTP assay kit 1; la activación de la PTP1B y su asociación con el receptor de insulina (RI) mediante inmunoprecipitación y western blot. Re...

Model for Nominal agreement between two raters When two raters independently classify n objects within K nominal categories, the level of agreement between them is usually assessed by means of Cohen’s Kappa coefficient. However, the coefficient Kappa has been the subject to several criticisms, the main one is that it is very sensitive to the marginal distributions. Additionally, when a more detailed analysis is needed, it requires the evaluation of the degree of agreement class by class, and traditionally, non-chance corrected indexes are used for this purpose. Our model Delta, does not possess the limitations aforementioned of kappa and it allows to define measures of agreement class by class which are chance-corrected. Additionally, Delta distinguishes the case where one of the two raters is a standard, from the case where neither rater is a standard (Kappa doesn't), and also the samplig type which has been considered. Model for Multiple Choice Tests evaluation When a test-tak...

Primary cardiac tumours are very rare in the paediatric age, their incidence varies from 0.0017 % to 0.28 %. More than 90 % are benign in nature. The most common variety is the rhabdomyoma, present in over 60 % of cases with tuberous sclerosis. We performed a retrospective analysis of medical records with a diagnosis of primary cardiac tumor between March 1977 and March 2007, finding a total of 27 patients. The age of initial diagnosis is more prevalent in the neonatal period, beginning with the discovery of a heart murmur (11 cases). There was no difference in gender distribution. In 14 patients were found cardiomegaly on chest radiograph. According to the echocardiography characteristics there were diagnosed 20 rhabdomyomas, 2 fibromas, 2 pericardial teratomas and 3 non classifiable tumours. Most were located in the left ventricle. Echocardiography, cardiac catheterization was also performed in 3 cases and angioresonance in 5 cases. During their evolution, episodes of arrhythmias ...

Asymptomatic 2 month-old infant referred for evaluation of a hard abdominal mass on the left side. The ultrasound examination showed a solid-cystic tumour above the left kidney. The alpha-fetoprotein level was 2000ng/ml. The meta-iodobenzylguanidine (123-I-MIBG) showed no tumour uptake. At 48h, she showed signs of hypovolemic shock. The chest X-ray showed cardiomegaly with a cardiothoracic ratio of 0.7 and pulmonary congestion. The echocardiogram showed a dilated left ventricle with ejection fraction 35-40%. Anaemia, hypertension, hypervolemia and hyper-secretion of catecholamines were ruled out. The virology and metabolic screens were normal. The highly vascularised retroperitoneal tumour was resected without incident and confirmed the diagnosis of an immature Norris grade 2 teratoma grade. At 3 months the outcome was satisfactory. Teratomas are rare tumours in childhood that generally have a benign course. Dilated cardiomyopathy (DCM) secondary to, chromaffin cell tumours (phaeoch...

Introducción Los tumores cardíacos primarios son muy poco frecuentes en la edad pediátrica, y su incidencia varía entre el 0,0017 y el 0,28 %. Más del 90 % son de naturaleza benigna. La variedad más frecuente es el rabdomioma, asociado en más del 60 % de los casos con esclerosis tuberosa. Material y métodos Se realizó un análisis retrospectivo de historias clínicas con diagnóstico de tumor cardíaco primario entre marzo de 1977 y marzo de 2007, y se encontró a un total de 27 pacientes. Resultados La edad de diagnóstico inicial es más frecuente en el período neonatal, a partir del hallazgo de un soplo cardíaco (11 casos). No hubo diferencias en la distribución por sexos. En 14 pacientes se encontró cardiomegalia en la radiografía de tórax. De acuerdo con las características ecocardiográficas, se diagnosticaron 20 rabdomiomas, 2 fibromas, 2 teratomas pericárdicos y 3 tumores no clasificables. La mayor parte se localizaron en el ventrículo izquierdo. Además de la ecocardiografía, se rea...

ABSTRACT It is very important to understand that the univentricular heart surgery is just palliative, not being in anyway a definitive or curative surgery, but nowadays it's the best initial treatment of this complex heart disease. The fundamental philosophy of treatment of every univentricular heart is to ensure the flow system and/or restrict the lung flow. Thus, initially a patient with univentricular heart who is undergoing surgery may need to ensure systemic flow (reconstruction of the aortic arch type Norwood), to restrict the lung flow (pulmonary banding) or to provide enough pulmonary flow (pulmonary-systemic fistulae). However, some heart diseases with univentricular physiology remain " balanced " autonomously, until the " second " stage of palliation is performed (cavo-pulmonary anastomosis type Glenn), but others require performance of pulmonary banding, if there's no native lung protection and/or repair of the systemic circuit in a first stage, to reach next pa-lliation steps in the best possible conditions.

ABSTRACT In addition to the general consequences of surgery and cardiopulmonary bypass , lesion-specific complications can occur after surgery for congenital heart disease. It is important for the pediatric intensive care specialist to fully understand the preoperative anatomy and the intraoperative details of these patients. This allows a timely and appropriate treatment of general and lesion-specific complications. In this article we provide a list of commonly-performed surgical procedures and possible associated problems to be anticipated in the early postoperative period. Then it follows a discussion about the diagnosis and management of these complications, based on their pathophy-siological features.