Rapamycin protects against Aß-induced synaptotoxicity by increasing presynaptic activity in hippocampal neurons.

The mammalian target of rapamycin (mTOR) is involved in the regulation of learning and memory. Recently, rapamycin has been shown to be neuroprotective in models for Alzheimer's disease in an autophagy-dependent manner. Here we show that rapamycin exerts neuroprotection via a novel mechanism that involves presynaptic activation. Rapamycin increases the frequency of miniature excitatory postsynaptic currents and calcium transients of rat hippocampal primary neurons by a mechanism that involves the up regulation of SV2, a presynaptic vesicular protein linked to neurotransmitter release. Under these conditions, rapamycin-treated hippocampal neurons are resistant to the synaptotoxic effect induced by Aß oligomers, suggesting that enhancers of presynaptic activity can be therapeutic agents for Alzheimer's disease.

Expresión del receptor del factor de crecimiento epidérmico en biopsias renales de pacientes con nefronoptisis del adolescente / Expression of epidermal growth factor receptor in renal biopsy from patients with adolescent nephronophthisis

Introducción: En Venezuela se ha descrito una nueva variedad de nefronoptisis, denominada nefronoptisis del adolescente, la cual expresa características clínicas e histológicas similares a las otras variedades ya descritas. Sin embargo, la patogenia de esta enfermedad aún no es bien conocida. El objetivo de este trabajo fue determinarla expresión del receptor del factor de crecimiento epidérmico (EGFR) humano en las células epiteliales tubulares de pacientes con nefronoptisis del adolescente. Métodos: Se estudiaron las biopsias renales de 8 pacientes con nefronoptisis del adolescente, mediante la técnica de inmunohistoquímica, para determinar la expresión renal del EGFR. Resultados: En todas las muestras la expresión del receptor del factor de crecimiento epidérmico fue negativa. Conclusión: Estos hallazgos indican una deficiencia del receptor del factor de crecimiento en los epitelios indiferenciados, lo cual podría ser uno de los factores desencadenantes del desarrollo de los quistes en la nefronoptisis (AU)

Introduction: In Venezuela has been described a new form of nephronophthisis, called adolescent nephronophthisis, with clinical and histological findings very similar to others varieties described. However, pathogenesis in not wellknown. The aim of this study was to determine the expression of human epidermal growth factor receptor (EGFR) in tubular epithelial cells of patients with adolescent nephronophthisis. Methods: Renal biopsies of 8 patients with adolescent nephronophthisis were studied by immunohistochemistry to determine renal expression of EGFR. Results: In all patients, there was no expression of epidermal growth factor receptor. Conclusion: These findings indicate a deficiency of growth factor receptor in undifferentiated epithelialcells, which could be one factor in the development of cysts in nephronophthisis (AU)

Mucopolisacaridosis tipo IV-B. A propósito de un caso / Mucopolysacharidosis type IV-B. A case report

Debido a la deficiencia de las enzimas encargadas de hidrolizar los glicoaminoglicanos intralisosomales se producen las mucopolisacaridosis como errores innatos del metabolismo. Se presenta el caso de un varón de 8 años de edad que fuera hospitalizado por bronconeumonía a germen desconocido – de la comunidad- en estado grave, que exhibía rasgos fenotípicos evocadores del síndrome de Morquio: patrón dismórfico facial, baja talla, máculas hipocrómicas diseminadas por toda la economía y hábito esquelético típico. Diagnóstico que se confirmó bioquímicamente por la ausencia de la enzima β-galactosidasa. Se exponen puntos de vista respecto al particular y se contrasta con la literatura sobre la entidad (AU)

Owing to the deficiency of enzymes responsible of intralysosomal hydrolysis of glycosaminoglycans are produced the mucopolysaccharidosis as inherited metabolic disorders. We repot the case of 8 years old male, who was hospitalized by severe community-acquired bronchopneumonia caused by unknown germ and shown phenotypical pattern of Morquio syndrome: dysmorphic facial pattern, hypochromic spots throughout the economy, short stature and typical skeletal habitus. The diagnose was biochemicaly confirmed by lack of β-galactosidase enzyme. Points of view regarding to the illness are commented taking into account the literature (AU)

[Factors associated with Streptococcus group B colonization in pregnant women in Los Altos, Chiapas]. / Factores asociados a la colonización por Streptococcus del grupo B en mujeres embarazadas de Los Altos, Chiapas.

OBJECTIVE: To estimate the prevalence and analyze the factors associated with group B Streptococcus (GBS) colonization in pregnant women of Los Altos, Chiapas, Mexico. MATERIAL AND METHODS: Between February and September 1999, a cross-sectional study was conducted among 910 women who sought delivery care at three public hospitals of San Cristobal de Las Casas, Chiapas. Vaginal and perianal samples were taken for GBS detection by bacteriological culture. Identification of groups and serotypes was performed using latex agglutination. The analysis of factors associated with colonization was done using chi-squared tests and log-linear modeling. RESULTS: GBS colonization was found in 8.6% (95% CI 6.8-10.5) of study subjects. Women with the greatest likelihood of colonization were those with > or = 5 pregnancies, residents of counties with high levels of poverty, working outside the home, and living in homes in which the head of household worked in agriculture (26.8%, OR = 7.25, 95% CI 1.83-28.67). CONCLUSIONS: In the study area, it is necessary that actions aiming to prevent and control infections by GBS be directed principally at those groups of women with the highest probability of colonization, in order to diminish the perinatal transmission of GBS.