Modulación de la apoptosis por cytomegalovirus en la perspectiva del sistema nervioso central / Modulation of apoptosis by cytomegalovirus, from the perspective of the central nervous system

Apoptosis is one of the most effective mechanisms against the spread of pathogens such as viruses. However, viruses have developed measures to counter the protective role of apoptosis in infected cells. Cytomegalovirus (CMV) represents the major cause of congenital infection worldwide triggering important damage in the developing central nervous system (CNS). Several mechanisms of apoptosis prevention during CMV infection have been described, among them, viral proteins and RNAs are capable of prevent apoptosis by the intrinsic and extrinsic pathways as well as the one mediated by stress in the endoplasmic reticulum. Nevertheless, the CMV pro-apoptotic effect remains enigmatic and it has been suggested as a bystander effect in non-infected cells. This review summarizes the mechanisms by which CMV modulates the signaling pathways involved in apoptosis. It also includes a brief description of the permissiveness of the CNS to CMV infection and the generated cell death after infection, which may relate to the observed damage during a congenital infection.

La apoptosis representa uno de los mecanismos de defensa más eficaces frente a la propagación de patógenos como lo son los virus. No obstante, éstos han desarrollado medidas para contrarrestar el papel protector de la apoptosis en las células infectadas. Citomegalovirus (CMV) es considerado la principal causa de infecciones congénitas a nivel mundial, afectando de forma importante el sistema nervioso central (SNC) en desarrollo. Diversos mecanismos de prevención de apoptosis durante la infección por CMV han sido descritos, entre los cuales, se encuentran proteínas y ARNs virales capaces de evitar la apoptosis por las vías intrínseca, extrínseca y la mediada por estrés del retículo endoplásmico. Sin embargo, aún representa un enigma el efecto pro-apoptótico de CMV que se sugiere actúe como un efecto espectador sobre las células no infectadas. En el presente trabajo se ofrece una revisión de los mecanismos mediante los cuales CMV modula las vías de señalización involucradas en la apoptosis. Asimismo se incluye una breve descripción de la permisividad del SNC a la infección por CMV y sobre la muerte celular generada tras la infección, que pueden relacionarse con el daño observado durante una infección congénita.

Há equivalência entre a temperatura da membrana timpânica e a temperatura retal em ovinos Santa Inês normotérmicos? / Is there equivalence between the tympanic membrane temperature and the rectal temperature in normothermic Santa Ines sheep?

A utilização do termômetro de raios infravermelhos para a aferição da temperatura timpânica em animais tem se tornado uma alternativa prática na clínica veterinária. Em ovinos, a mensuração da temperatura timpânica não foi suficientemente comparada com a aferição da temperatura retal. Este estudo avaliou a equivalência entre a temperatura timpânica e a temperatura retal em 16 ovinos da raça Santa Inês. Durante a coleta de dados, a temperatura e a umidade relativa do ar foram monitoradas e não houve correlação entre estas e a temperatura corporal. A análise da equivalência, pelo método da diferença entre as temperaturas, resultou em temperaturas timpânicas mais baixas (entre 35 e 36,9ºC, para ambos os ouvidos) que a temperatura retal (entre 39 e 38ºC). Os limites de concordância das comparações entre a temperatura retal e as temperaturas timpânicas foram acima do valor pré-estabelecido. A localização anatômica dos locais aferidos e o tipo de termômetro contribuíram para as diferenças de temperatura. A temperatura retal e a temperatura timpânica foram independentes, sugerindo não haver equivalência entre ambas.

The use of infrared thermometers to obtain the tympanic temperature in animals has become a convenient alternative in veterinarian medicine practice. In sheep, tympanic and rectal temperatures have not yet been compared enough. This study evaluated the equivalence between the tympanic and the rectal temperatures in sixteen Santa Ines sheep. During data collection, air temperature and humidity were monitored and there was no discernible correlation between these and the ovine body temperature. The analysis of the equivalence, as measured by the method of the difference amongst temperatures, resulted in lower tympanic temperature (between 35 and 36.9ºC, for both ears) than the rectal temperature (between 38 and 39ºC). The agreement limit of the comparisons between the rectal and tympanic temperatures was above values established previously in the literature. The anatomical site used for the temperature measurement and the type of thermometer used contributed to these temperature differences. The rectal and tympanic temperatures were independent, suggesting that there is no equivalence between them.