Concentraciones de oxígeno intermitentes tienen impacto en el desarrollo postnatal temprano de ratas Sprague-Dawley: efectos en CA1 del hipocampo / Intermittent oxygen concentrations have an impact on the early postnatal development of Sprague-Dawley rats: effects on hippocampal CA1

El periodo postnatal temprano se caracteriza por rápido crecimiento cerebral, posiblemente relacionado con variaciones del oxígeno tisular. Esto ha motivado el estudio de protocolos que suministran diferentes concentraciones de oxígeno intermitentes, para observar sus efectos morfológicos y cerebrales. Se utilizaron 52 crías de ratas Sprague Dawley, distribuidas en igual número a cuatro grupos experimentales, Control (C, 21 %O2), Hipoxia Intermitente (HI, 11 %O2), Hiperoxia Intermitente (HOI, 30 %O2) e Hipoxia Hiperoxia Intermitente (HHI, 11 % -30 %O2). Los protocolos consideraron 5 ciclos de 5 minutos de dosificación, durante 50 minutos diarios. Se realizó en una cámara semihermética entre los días 5 al 11 postnatales. Las evaluaciones de crecimiento corporal y cuantificación neuronal, se realizaron en las crías macho, en el día 28 postnatal. El peso corporal en el grupo hipoxia intermitente mostró diferencias significativas respecto al grupo hiperoxia intermitente (HI vs HOI, p<0,01) y al grupo hipoxia-hiperoxia Intermitente (HI vs HHI, p< 0,001). La talla corporal disminuyó en el grupo hipoxia-hiperoxia intermitente con diferencias significativas respecto del grupo control (C vs HHI, p<0,05) y respecto del grupo hipoxia intermitente (HHI vs HI, p< 0,01). El conteo neuronal en el área CA1 del hipocampo aumentó en el grupo hipoxia intermitente con diferencias significativas respecto a los grupos control (C vs HI; p<0,05), al grupo hiperoxia intermitente (HI vs HOI; p<0,001) y al grupo hipoxia-hiperoxia intermitente (HI vs HHI; p<0,001). Finalmente, el grupo hipoxia- hiperoxia Intermitente disminuyó significativamente en la cantidad de neuronas en comparación al grupo hiperoxia intermitente (HHI vs HOI; p<0,001). La hipoxia intermitente mostró resultados beneficiosos en el crecimiento corporal y cantidad de neuronas en el área CA1 del hipocampo, en contraste, la hipoxia hiperoxia intermitente experimentó resultados adversos con disminución de estas variables, en el periodo postnatal temprano de la rata.

SUMMARY: The early postnatal period is characterized by rapid brain growth, possibly related to variations in tissue oxygen. This has motivated the study of protocols that supply different intermittent oxygen concentrations, to observe their morphological and cerebral effects. Fifty-two pups Sprague-Dawley rats were distributed in equal numbers into four experimental groups, Control (C, 21 %O), Intermittent Hypoxia (HI, 11 %O), Intermittent Hyperoxia (HOI, 30 %O2) and Intermittent Hypoxia Hyperoxia (HHI, 11 % - 30 %O2). The protocols considered 5 cycles of 5 min of dosing, for 50 min diary. It was performed in a semi- hermetic chamber between 5 to 11postnatal days. The evaluations of body growth and neuronal quantification were analyzed in male pups, on postnatal day 28. Body weight in the intermittent hypoxia group showed significant differences compared to the intermittent hyperoxia group (HI vs HOI, p<0.01) and the intermittent hypoxia- hyperoxia group (HI vs HHI, p<0.001). Body size decreased in the Intermittent hypoxia-hyperoxia group with significant differences compared to the control group (C vs HHI, p<0.05) and with respect to the intermittent hypoxia group (HHI vs HI, p<0.01). The neuronal count in the area CA1 of the hippocampus increased in the intermittent hypoxia group with significant differences compared to the control groups (C vs HI; p<0.05), to the intermittent hyperoxia group (HI vs HOI; p< 0.001) and the intermittent hypoxia-hyperoxia group (HI vs HHI; p<0.001). Finally, the intermittent hypoxia- hyperoxia group decreased significantly in the number of neurons compared with the intermittent hyperoxia group (HHI vs HOI; p<0.001). Intermittent hypoxia showed beneficial results in body growth and the number of neurons in the CA1 area of the hippocampus, in contrast, intermittent hypoxia-hyperoxia experienced adverse results with a decrease in these variables, in the early postnatal period of the rat.

The GM2 ganglioside inhibits iNKT cell responses in a CD1d-dependent manner.

Invariant natural killer T (iNKT) cells are a subset of T lymphocytes that recognize lipid antigens presented on CD1d molecules at the surface of antigen-presenting cells. GM2 is a glycosphingolipid abundant in cellular membranes and known to bind CD1d molecules, but the functional consequences of this binding are not completely clarified. Herein, we analyzed the effect of GM2 in iNKT cell activation. We found that culturing antigen-presenting cells or total peripheral blood mononuclear cells with GM2 did not induce activation of human iNKT cells, implying that this lipid is not antigenic for human iNKT cells. To investigate if this lipid could inhibit iNKT cell activation, we simultaneously incubated antigen-presenting cells with GM2 and the iNKT cell antigen α-Galactosylceramide (α-GalCer) and used them to stimulate iNKT cells. We found that GM2 reduced human iNKT cell activation in a dose-dependent manner. An explanation for this effect could be a direct competition of GM2 with antigenic lipids for CD1d binding. This was demonstrated by the use of an antibody (L363) that stains mouse CD1d:α-GalCer complexes, as in the presence of GM2 the amount of CD1d:α-GalCer complexes are reduced. We further explored the consequences of chronic GM2 overload on human iNKT cells by analyzing iNKT cells in patients diagnosed with GM2 gangliosidoses. We found that pediatric patients present a higher frequency of circulating CD4+ iNKT cells and concomitant lower frequency of CD4-CD8- iNKTs. A lower percentage of iNKT cells expressing the NK marker CD161 was also observed in these patients. In contrast, in two adult patients studied, no differences on iNKT cell phenotype were observed. Altogether, this study uncovers a new role for GM2 in the modulation of iNKT cell activation, thus strengthening the central role of lipid metabolism in iNKT cell biology.

A systematic review of powered vs manual toothbrushes in periodontal cause-related therapy.

BACKGROUND: Power-driven toothbrushes (PDT) have been designed to improve the efficacy of oral hygiene. It is not clear how they compare in efficacy with manual toothbrushes in cause-related periodontal therapy. OBJECTIVES: To evaluate the effectiveness of the use of a PDT as compared with a manual toothbrush (MT), in terms of gingival bleeding or inflammation resolution, in cause-related periodontal therapy. MATERIAL AND METHODS: An electronic (MEDLINE and Cochrane Oral Health Group Specialised Trials Register) and a manual search were made to detect studies which permitted the evaluation of the efficacy of PDT in the reduction of gingival bleeding or inflammation, and their effect on other secondary variables. Only randomized studies in adults, published in English up to June 2001, which compared a PDT with an MT, and evaluated the evolution of gingival bleeding or inflammation were included. The selection of articles, extraction of data and assessment of validity were made independently by several reviewers. RESULTS: Twenty-one studies were finally selected. The heterogeneity of the data prevented a quantitative analysis. A higher efficacy in the reduction of gingival bleeding or inflammation in the PDT patients was detected in 10 studies. This effect appears to be related to the capacity to reduce plaque, and is more evident in counter-rotational and oscillating-rotating brushes. No solid evidence was found for a higher efficacy of sonic brushes. In short-term studies with prophylaxis after initial examination, independently of the type of PDT tested, no significant differences were found. CONCLUSION: The use of PDT, especially counter-rotational and oscillating-rotating brushes, can be beneficial in reducing the levels of gingival bleeding or inflammation. There is a need for methodological homogeneity in future studies in this field to enable quantitative analysis of their results.

[Carotid stenosis and lacunar infarct]. / Estenosis carotídea e infarto lacunar.

INTRODUCTION: Perforating artery disease is still the main cause of lacunar infarcts (LI), while the relationship between this type of ischemia and carotid stenosis (CS) is controversial. OBJECTIVE: To assess the association between CS and LI in patients with criteria of localized ischemia in the carotid territory separately analyzing isolated LI and multiples LIs. PATIENTS AND METHODS: Three hundred and thirty patients with a first episode of cerebral infarct in the area supplied by the carotid artery were registered prospectively. There were 205 LI (135 isolated and 70 multiple) which could be differentiated from 125 non-lacunar infarcts (NLI). The vascular risk factors were determined and the degree of carotid stenosis measured by duplex-colour ultrasound exploration. RESULTS: In the isolated LI group the frequency of presentation of CS greater than 50% was 22% for the artery ipsilateral to the LI and 8% for the contralateral artery. For significant CS (> 70%) frequencies of 14% (ipsilateral) and 8% (contralateral) were observed. On comparative analysis with the NLI group, the presence of stenosis greater than 50 to 70% was significantly higher in these for both ipsilateral and contralateral arteries. In the LI group, isolated CS was significantly more frequent on the side which was homolateral to the ischemia as compared to its isolated presence on the contralateral side (22/30 vs 4/12; OR: 5.5 [95% CI: 1.2-23]). Ipsilateral CS greater than 70% behaved as a factor which was significantly associated with the multiple LI subtype with a unilateral pattern. CONCLUSION: CS should be considered a risk factor for LI.

Enfermedades respiratorias crónicas y recurrentes de la infancia y la niñez en un hospital general / Respiratory chronic and recurrent diseases in infancy and childhood in a general hospital

En un formulario preparado Epiinfo 5.0 se registraron los diagnósticos principal, derivados, asociados y de las complicaciones o secuelas (codificados según la clasificación internacional de enfermedades), los exámenes de laboratorio realizados en cada caso. Los costes de hospitalización se estimaron valorizándolos con el arancel del Fondo Nacional de Salud (FONASA, Chile). En 21,2 porciento de las admisiones por enfermedades respiratorias y el 11,1 porciento del total de ingresos se trataba de enfermedades respiratorias crónicas propiamente tal y los restantes eran pacientes con enfermedades de base no respiratoria (preferentemente neurológica) y afección broncopulmonar secundaria. Las causas predominantes de la admisión, fueron en los 3 grupos, descompensaciones funcionales por neumonías o episodios de obstrucción bronquial intercurrentes. Los exámenes de laboratorio tradicionales de estas hospitalizaciones costaron 15,3 porciento del gasto total del Servicio de Pediatría por este concepto ($ 9.607.535 entre $ 62.735.330), sin considerar $ 5.338.240 adicionales en otro tipo de exámenes de apoyo

Manual BITNIS / BITNIS manual

Este manual presenta la operacion del sistema Batch Internet to NLM Intercommunication System (BITNIS) para acceder a las bases de datos de la National Library of Medicine de los Estados Unidos, via correo electronico= Operations manual of the Batch Internet to NLM Intercommunication System (BITNIS) to access the NLM data bases through electronic mail

Manual BITNIS / Manual BITNIS / BITNIS manual

Este manual presenta la operación del sistema Batch Internet to NLM Intercommunication System (BITNIS) para acceder a las bases de datos de la National Library of Medicine de los Estados Unidos, vía correo electrónico= Operations manual of the Batch Internet to NLM Intercommunication System (BITNIS) to access the NLM data bases through electronic mail