Scielo RSS http://ve.scielo.org/rss.php?pid=0798-026420050002&lang=en vol. 24 num. 2 lang. en http://ve.scielo.org/img/en/fbpelogp.gif http://ve.scielo.org http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-02642005000200002&lng=en&nrm=iso&tlng=en El estímulo eléctrico plantar (EEP) aplicado a ratas conscientes, incrementa la presión arterial media (PAM) y la frecuencia cardíaca (FC). En el presente trabajo evaluamos la hipótesis que la angiotensina II (ANG II) endógena media la respuesta simpática frente al EEP. Nuestros resultados muestran que el bloqueo del receptor AT1 con losartan, valsartan o eprosartan previene la respuesta vasopresora inducida por el EEP. La nefrectomía bilateral (NFX), la cual reduce los niveles circulantes de ANG, suprimió el incremento de la PAM y de las catecolaminas plasmáticas observada durante el EEP. La administración de una dosis subpresora de angiotensina II restauró la respuesta vasopresora inducida por el estrés en las ratas nefrectomizadas. La modulación de los niveles circulantes de angiotensina II alteró la respuesta presora frente al estrés. Así, la reducción de los niveles circulantes de ANG mediante una ingesta elevada de sodio, inhibió la respuesta presora frente al EEP. Por el contrario, el incremento del sistema renina-angiotensina inducido por una dieta baja en sal, facilitó la respuesta presora frente al estrés. Nuestros resultados indican que la angiotensina II endógena soporta la respuesta simpática frente al estrés, a través de la estimulación de los receptores AT1 presinápticos.<hr/>Footshocks (FS) increases mean arterial pressure (MAP) and heart rate (HR). We tested the hypothesis that endogenous angiotensin II (ANG) supports sympathetically mediated pressor response to FS. Our results show that AT1 receptor blockade with either losartan, valsartan or eprosartan blunted stress-response to FS. Reduction of circulating ANG induced by bilateral nephrectomy (NPHX), suppressed MAP increase and plasma catecholamines elevation observed after FS. Stress induced-pressor response to FS in nephrectomized rats was restored by the administration of a subpressor dose of synthetic ANG. Reduction of plasma ANG by high sodium diet suppressed, while increased ANG levels induced by low sodium diet facilitated stress-response to FS. Our results indicate that endogenous ANG supports sympathetic mediated stress-response, via stimulation of prejunctional AT1 receptors. http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-02642005000200003&lng=en&nrm=iso&tlng=en Objective: Hypertriacylglyceridemia and low HDLc combination is one of the most common lipidic abnormalities. Thus, the aim of this study was to determine the effects of Ciprofibrate on patients with Frederickson’s Type IV dyslipidemia phenotype. Research design and methods: 75 patients with type IV dyslipidemia were assigned at random to one of two therapeutic options: Group A, AHA diet and physical activity and B, AHA diet, physical activity and Ciprofibrate 100 mg daily for 12 weeks. All patients underwent lipidic profile quantification before and after therapeutic intervention. Results: Ciprofibrate treatment group exhibited significantly reduction in total cholesterol (-14,2% vs. -4,8%; p<0,02), triglycerides (-38% vs. -21,6%; p<0,007), VLDLc (-38% vs. -21,6%; p<0,007) Non-HDLc (-20,5% vs. -7,1%; p<0,007) and total cholesterol to HDLc ratio (-25,6% vs. -9,4%; p<0,01) when comparing with diet/physical activity group . HDLc showed an important increase in Ciprofibrate group when contrast with diet/physical activity group (+25% vs. +9,6%, p<0,02). Conclusions: Ciprofibrate treatment effectively reduced triglycerides rich particles and Non-HDLc and significantly increased HDLc, proving it’s usefulness in low HDLc syndrome and type IV Frederickson’s hyperlipidemia. http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-02642005000200004&lng=en&nrm=iso&tlng=en El desarrollo del proyecto de transformación de la Biblioteca "Gustavo H. Machado" en un Centro de Documentación e Información Pediátrica (CDIP) orientado al uso de las nuevas tecnologías en el manejo de información, se originó por la necesidad de mejorar la calidad en la prestación de los servicios a los usuarios que solicitan información en la especialidad de Pediatría y en el área de Biomedicina. Gracias al financiamiento obtenido a través del Fondo Nacional para la Ciencia, la Investigación y la Tecnología (FONACIT), adscrito al Ministerio de Ciencia y Tecnología, se logró instalar una plataforma tecnológica moderna y sistematizar el fondo documental. La automatización de los procesos técnicos del Centro ha permitido optimizar el tiempo de respuesta de la información que solicitan los usuarios. La búsqueda de la información se hace a través del software Documanager®, el cual administra todo el fondo documental, haciendo que el mismo se pueda ver vía Intranet y Internet, éste último, a través de su motor de búsqueda. A través del Portal Web del C.D.I.P., se han incrementado las relaciones con otras instituciones en el área Pediátrica o Biomédica, a nivel nacional e internacional, incentivando el intercambio, el canje y revisión de material documental. Sin duda alguna, el proyecto tecnológico implementado constituye una iniciativa muy importante que permitió crear nuevos servicios, incrementar la eficiencia y eficacia en cuanto a la satisfacción de las solicitudes de información y fortalecer la imagen institucional del Hospital de Niños J.M. de los Ríos.<hr/>The development of the project of transformation of the Library "Gustavo H. Machado" in a Center of Documentation and Pediatrics Information oriented to the use of the new technologies in the information handling, was made with the necessity to improve the quality in the benefit of the services to the users who ask for information in the specialty of Pediatrics and the area of Biomedicine. Thanks to the financial support obtained through the National Foundation for Science, Investigation and Technology (FONACIT), affiliated to the Ministry of Science and Technology, were managed to install a modern technological platform and to systematize the documentary project. The automatization of the technical processes of the Center has allowed optimizing the response time of the information that ask for the users. The search of the information becomes through software Documanager, which administers the entire documentary project, causing that the same one can be seen via Intranet and Internet, this one last one, through its motor search. Through the Vestibule Web of the C.D.I.P., the relations with other institutions in the area Pediatrics or Biomedical have been increased, at national and international level, stimulating the interchange, the exchange and documentary equipment teardown. Without a doubt some, the implemented technological project constitutes a very important initiative that it allowed to create new services, to increase the efficiency and effectiveness as far as the satisfaction of the information requests and to fortify the institutional image of the Hospital of Children J.M. de los Rios. http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-02642005000200005&lng=en&nrm=iso&tlng=en El sistema renina-angiotensina cerebral es uno de los sistemas más importantes que participan en la regulación del balance hidromineral. La administración central de renina o angiotensina II (Ang II) induce dipsogenia, apetito por la sal, aumento de presión arterial, natriuresis, liberación de oxitocina y vasopresina desde el núcleo paraventricular hipotalámico. La evidencia indica que la oxitocina es una hormona natriurética. Por ello, estudiamos el papel de la oxitocina como posible efector humoral de la natriuresis inducida por la administración intracerebroventricular (ICV) de Ang II en ratas euvolémicas, mediante el uso del atosiban (AT), un antagonista selectivo de los receptores de oxitocina. La administración central de renina o Ang II produjo un efecto antidiurético a la primera hora y un aumento en la excreción urinaria de sodio, de potasio y de GMPc a las 1, 3 y 6 horas. El AT potenció el efecto antidiurético e inhibió completamente la natriuresis, kaliuresis y aumento de la excreción de GMPc, inducidos por la Ang II. Los efectos renales de renina fueron independientes del óxido nítrico ya que el pretratamiento con L-NAME, un inhibidor de la sintasa del óxido nítrico, no alteró la respuesta renal inducida por la administración de renina-ICV. Nuestros resultados apoyan el papel de la oxitocina como efector de la acción natriurética mediada por el sistema renina angiotensina cerebral.<hr/>The renin angiotensin system (RAS) is considered to play an important physiological role in the regulation of body fluid. Intracerebroventricular administration of renin or angiotensin II (Ang II) increases blood pressure, sympathetic outflow, water intake, sodium excretion and oxytocin and vasopressin release and decreases urine volume. Evidence indicates tha oxytocin is a natriuretic hormone. Thus, with the use of a specific oxytocin receptor antagonist, atosiban (AT), we evaluated the role of oxytocin as a possible effector in the natriuretic action induced by intracerebroventricular (ICV) administration of Ang II or renin. Our results demonstrate that Ang II-ICV administration reduced urinary volume at 1 hour of collection and increased urinary excretion of sodium, potassium and cGMP at 1-, 3- and 6 hrs period of urine collection. Atosiban potentiated the Ang II antidiuretic effect and blunted natriuresis, kaliuresis and increased cGMP excretion induced by ICV-Ang II. The increase in urinary cGMP was independent of the stimulation of nitric oxide synthase activity, since L-NAME pretreatment did not modify the renal actions induced by ICV-renin. Our results support the concept that oxytocin mediated the natriuretic action of the brain renin angiotensin system. http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-02642005000200006&lng=en&nrm=iso&tlng=en Type 2 Diabetes mellitus is characterized by insulin resistance and defects in insulin secretion. These variables have been studied by the euglycemic/hyperinsulinemic clamp and MinMod, which difficult the insulin resistance and beta cell failure study in clinical practice. The aim of this study was to evaluate three different anti-diabetic therapeutic options using a mathematical model (Homeostasis model assessment, HOMA). Seventy type 2 diabetic patients were randomly assigned one of the next therapeutic options: A) Metformin + ADA Diet + Physical activity (Walk, 60 minutes/day). B) Metformin + Glimepiride + ADA Diet + Physical activity. C) Only ADA diet + Physical activity. A blood sample was taken before and after the treatment to determine basal and post-prandial blood glucose, basal insulin and HbA1c and to calculate HOMAbetacell and HOMA IR. Before treatment basal and post-prandial levels of glucose, HbA1c, basal insulin and HOMA IR and HOMAbetacell were significantly different when compared to after treatment levels for each group (p<0.01). Significant differences were also found when comparing basal blood glucose reduction (51.8%; p<0.01), post-prandial blood glucose (55.0%; p<0.05), and HOMA IR (65.3%; p<0.01) of group B (Metformin + low glimepiride dose) with the other therapeutic options. We conclude that metformin plus glimepiride at a low dose is a more effective treatment for type 2 diabetes than other therapeutic options. HOMA IR and HOMAbetacell are inexpensive and reliable methods to study IR and beta cell function in DM2.