Automated peritoneal dialysis as the modality of choice: a single-center, 3-year experience with 458 children in Mexico.

Automated peritoneal dialysis (APD) has been considered as the ideal dialysis modality for pediatric patients. This study reports the 3-year APD experience with 458 end-stage renal disease (ESRD) children who started APD in a single pediatric center in Mexico City between June 2003 and June 2006. By June 2003, there were 310 patients being treated with continuous ambulatory peritoneal dialysis (CAPD). At that time, these patients were gradually switched to APD, with priority being given to those prescribed more than four exchanges per day, younger than 6 years of age, or presenting complications [hernias or decreased ultrafiltration (UF)]. An improvement of daily UF was observed when the patients were switched from CAPD (590 +/- 340 ml/day) to APD (846 +/- 335 ml/day). The presence of edema decreased (from 67% to 8%) as well as the percentage of patients requiring antihypertensive drugs (from 83% to 38%), the peritonitis rate improved from one episode every 35 patient/month to one episode every 47 patient/month, the total number of hospitalizations decreased (from 384 to 51), and 85% of children attended school. While waiting for renal transplant, APD is the dialysis modality of choice for ESRD children at the La Raza Medical Center in Mexico City.

Antagonistic effects of TrkB and p75(NTR) on NMDA receptor currents in post-synaptic densities transplanted into Xenopus oocytes.

Brain-derived neurotrophic factor (BDNF) and its receptor TrkB are essential regulators of synaptic function in the adult CNS. A TrkB-mediated effect at excitatory synapses is enhancement of NMDA receptor (NMDA-R)-mediated currents. Recently, opposing effects of TrkB and the pan-neurotrophin receptor p75(NTR) on long-term synaptic depression and long-term potentiation have been reported in the hippocampus. To further study the regulation of NMDA-Rs by neurotrophin receptors in their native protein environment, we micro-transplanted rat forebrain post-synaptic densities (PSDs) into Xenopus oocytes. One-minute incubations of oocytes with BDNF led to dual effects on NMDA-R currents: either TrkB-dependent potentiation or TrkB-independent inhibition were observed. Pro-nerve growth factor, a ligand for p75(NTR) but not for TrkB, produced a reversible, dose-dependent, TrkB-independent and p75(NTR)-dependent inhibition of NMDA-Rs. Fractionation experiments showed that p75(NTR) is highly enriched in the PSD protein fraction. Immunoprecipitation and pull-down experiments further revealed that p75(NTR) is a core component of the PSD, where it interacts with the PDZ3 domain of the scaffolding protein SAP90/PSD-95. Our data provide striking evidence for a rapid inhibitory effect of p75(NTR) on NMDA-R currents that antagonizes TrkB-mediated NMDA-R potentiation. These opposing mechanisms might be present in a large proportion of forebrain synapses and may contribute importantly to synaptic plasticity.

Evaluación del potencial tóxico agudo y genotóxica de las hojas de Myrciaria dubia (Kunth) Mc. Vaugh en ratones albinos Mus musculus / Evaluation of the acute and genotoxic toxic potential of the leaves of Myrciaria dubia (Kunth) Mc. Vaugh in albino mice Mus musculus

El propósito del presente estudio fue Evaluar el Potencial Toxicológico Agudo mediante el Ensayo de Dosis Limite y Evaluar el potencial genotóxica en células germinales de ratón, mediante el ensayo de Anomalías en la Cabeza del Espermatozoide del Extracto Hidroalcohólico Liofilizado de las hojas de Myrciaria dubia. Para este estudio se utilizaron Ratones Albinos Mus musculus de la cepa BalbCNPB de ambos sexos con un peso promedio de 23 ± 2g. En el ensayo de Dosis limite al grupo tratado se les administró por vía oral el extracto a la dosis de 2000 mglkg p. e y al grupo control, solución salina 0.9%. Teniendo como resultado no poseer actividad toxicológica aguda por vía oral debido a la ausencia de los signos clínicos tóxicos en los animales de experimentación. Así mismo en el examen macroscópico no se observaron daños a nivel de órganos. En el ensayo de Anomalías en la Cabeza del Espermatozoide del ratón, se utilizaron 4 grupos de ratones albinos del sexo machos, se les administró durante 5 días consecutivos por vía oral el extracto de Myrciaria dubia a la dosis de 2000 y 1000 mg/kg/p.c. y solución salina al 0.9% como control negativo y por vía intraperitoneal una dosis de 50 mg/kg/p.c. de Ciclofosfamida como control positivo. A los 35 ·días de la primera administración, se procedió al sacrificio de los animales por dislocación cervical. Para luego pasar al conteo de los espermatozoides mediante un microscopio basándose en las cabezas normales, banana, amorfos y sin gancho. En este ensayo no se encontró daño a nivel de células germinales no encontrándose diferencias significativas en el porcentaje de anomalías morfológicas de los espermatozoides del ratón. En este estudio también se realizo el Tamizaje Fitoquímico del Extracto Hidroalcohólico de las hojas de· Myrciaria dubia; y se determinaron los siguientes metabolitos secundarios: flavonoides, triterpemos, esteroides, taninos, lactonas, saponinas, cumarinas volátiles en sus diferentes concentraciones.