Un primer análisis de la investigación en México sobre los determinantes sociales de la salud: 2005-2012 / A first analysis of research on social determinants of health in Mexico: 2005-2012

Objetivo. Examinar la investigación hecha en México sobre los determinantes sociales de la salud (DSS) durante el periodo 2005-2012 con base en la caracterización del sistema nacional de investigación en salud y la producción científica sobre este tema. Material y métodos. Análisis en dos etapas: revisión documental de fuentes oficiales sobre investigación en salud en México y búsqueda sistemática de literatura sobre DSS. Resultados. Los DSS fueron mencionados en el Programa de Acción Específico de Investigación en Salud 2007-2012, pero no figuran en las estrategias y objetivos; en su lugar, se enfatizan primordialmente aspectos de infraestructura y administrativos. En el periodo se publicaron 145 artículos sobre DSS, cuyas temáticas más abordadas fueron "condiciones de salud", "sistemas de salud" y "nutrición y obesidad". Conclusiones. A pesar de que existe investigación en México sobre DSS, la instrumentación de esos hallazgos en políticas de salud no se ha implementado. El Programa Sectorial de Salud 2013-2018 representa una ventana de oportunidad para posicionar resultados de investigación que promuevan políticas de equidad en salud.

Objective. To examine the research on social determinants of health (SDH) produced in Mexico during the period 2005-2012, based on the characterization of the national health research system and the scientific production on this topic. Materials and methods. Two-stage analyses: Review of Mexican documents and official sources on health research and systematic bibliographic review of the literature on SDH. Results. Although SDH were mentioned in the Specific Action Plan for Health Research 2007-2012, they are not implemented in strategies and goals, as the emphasis is put mostly in infrastructure and administrative aspects of research. In the period studied, 145 articles were published on SDH topics such as health conditions, health systems and nutrition and obesity. Conclusions. In spite of the availability of research on SDH in Mexico, the operationalization of such findings into health policies has not been possible. The current Sectorial Program on Health 2013-2018 represents a window of opportunity to position research findings that promote health equity policies.

Synaptic dimorphism in Onychophoran cephalic ganglia

The taxonomic location of the Onychophora has been controversial because of their phenotypic and genotypic characteristics, related to both annelids and arthropods. We analyzed the ultrastructure of the neurons and their synapses in the cephalic ganglion of a poorly known invertebrate, the velvet worm Peripatus sedgwicki, from the mountainous region of El Valle, Mérida, Venezuela. Cephalic ganglia were dissected, fixed and processed for transmission electron microscopy. The animal has a high degree of neurobiological development, as evidenced by the presence of asymmetric (excitatory) and symmetric (inhibitory) synapses, as well as the existence of glial cell processes in a wide neuropile zone. The postsynaptic terminals were seen to contain subsynaptic cisterns formed by membranes of smooth endoplasmic reticulum beneath the postsynaptic density, whereas the presynaptic terminal showed numerous electron transparent synaptic vesicles. From the neurophylogenetic perspectives, the ultrastructural characteristics of the central nervous tissue of the Onychophora show important evolutionary acquirements, such as the presence of both excitatory and inhibitory synapses, indicating functional synaptic transmission, and the appearance of mature glial cells.

Regulation of astroglia on synaptic plasticity in the CA1 region of rat hippocampus / 华中科技大学学报（医学）（英德文版）

The regulation of astroglia on synaptic plasticity in the CA1 region of rat hippocampus was examined. Rats were divided into three groups: the newly born (< 24 h), the juvenile (28-30 days) and the adult groups (90 - 100 days), with each group having 20 animals. The CA1 region of rat hippocampus was immunohistochemically and electron-microscopically examined, respectively, for the growth of astroglia and the ultrastructure of synapses. The high performance liquid chromatography was employed to determine the cholesterol content of rat hippocampus. In the newly-born rats, a large number of neurons were noted in the hippocampal CA1 region of the newly-born rats, and few astroglia and no synaptic structure were observed. In the juvenile group, a few astroglias and some immature synapses were found, which were less than those in adult rats (P < 0.01). The cholesterol content was 2.92 +/- 0.03 mg/g, 11.20 +/- 3.41 mg/g and 12.91 +/- 1.25 mg/g for newly born, the juvenile and the adult groups, respectively, with the differences among them being statistically significant (P < 0.01). Our study suggests that the astrocytes may play an important role in the synaptic formation and functional maturity of hippocampal neurons, which may be related to the secretion of cholesterol from astrocytes.

Macropatch technique on neuromuscular junction from toad tadpole tail

Se adaptó y empleó la corriente sináptica espontánea en la unión neuromusuclar de la cola de renacuajos de Bufo marinus

Ultrastructural study of reaggregated culture of brainstem: synaptogenesis

The synaptogenesis and the morphological differentiation of neural cells were studied in aggregating cultures. Brainstems of 14-15 days old rat embryos were removed and the area located between the mesencephalic flexure and the caudal portion of metencephalon was dissected and mechanically dissociated to single cells. These cells reassociated forming highly organized aggregates in which differentiation took place. Samples were harvested after different time periods, fixed and processed for electron-microscopic study. After one day in culture the aggregates were composed by rounded undifferentiated cells. These cells had a high nuclear/cytoplasmic relation, were devoid of processes and were separated by great intercellular spaces. At the end of the first week of culture cell differentiation and extension of processes were evident. A loose neuropil appeared: it was composed by abundant growing neurites and growth cones. Later, the neuropil became more compact and glial processes and synaptic terminals filled with vesicles appeared. The early appearance of vesicles in the synaptic endings was the first evidence of synaptogenesis. Post and presynaptic membrane densities appeared later, and fully mature synaptic contacts were seen by the end of the 3rd week in culture. Scarce myelin sheaths were observed after 35 days in vitro

Developmental changes in synapses of the retino-recipient layers of the opossum superior colliculus

Changes in synaptic structure were examined in junctions of the retino-recipient layers of the opossum superior colliculus (SC) at critical developmental stages (30, 40 and 61 dai-old pouch young and adult controls). Criteria of classification were the presence and direction of curvature (smile, flat, frown and irregula) and the degree of aggregation of paramembranous components vis-a-vis curvature in the assessment of maturational changes

An ultrastructural study of the geniculo-suprachiasmatic projection in the rat

A projeçäo geniculo-supraquiasmática foi estudada em ratos, examinando-se, ao microscópico eletrônico, as terminaçöes sinápticas em degeneraçäo que aparecem no núcleo suprachciasmático depois que uma lesäo por radiofrequência é feita no núcleo geniculado lateral ventral. Os elementos pré-sinápticos em degeneraçäo eram terminais de axônios e os elementos pós-sinápticos eram geralmente dendritos. Vesículas sinápticas claras, pleomórifcas e, as vêzes, vesículas granulares eram visíveis nas terminaçöes axonais em degeneraçäo. As sinapses degeneradas eram simétricas, ou do tipo II de Gray