43 research outputs found
Prevalence of temporomandibular joint disorders and neck pain in musicians: a sytematic review
MyD88 and STING Signaling Pathways Are Required for IRF3-Mediated IFN-β Induction in Response to Brucella abortus Infection
Type I interferons (IFNs) are cytokines that orchestrate diverse immune responses to viral and bacterial infections. Although typically considered to be most important molecules in response to viruses, type I IFNs are also induced by most, if not all, bacterial pathogens. In this study, we addressed the role of type I IFN signaling during Brucella abortus infection, a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Herein, we have shown that B. abortus induced IFN-β in macrophages and splenocytes. Further, IFN-β induction by Brucella was mediated by IRF3 signaling pathway and activates IFN-stimulated genes via STAT1 phosphorylation. In addition, IFN-β expression induced by Brucella is independent of TLRs and TRIF signaling but MyD88-dependent, a pathway not yet described for Gram-negative bacteria. Furthermore, we have identified Brucella DNA as the major bacterial component to induce IFN-β and our study revealed that this molecule operates through a mechanism dependent on RNA polymerase III to be sensed probably by an unknown receptor via the adaptor molecule STING. Finally, we have demonstrated that IFN-αβR KO mice are more resistant to infection suggesting that type I IFN signaling is detrimental to host control of Brucella. This resistance phenotype is accompanied by increased IFN-γ and NO production by IFN-αβR KO spleen cells and reduced apoptosis
Estudo estereológico das células de Purkinje cerebelares submetidas à intoxicação alcoólica em ratos Wistar
Automobilismo: no calor da competição Automovilismo: en el calor de la competición Car racing: in the heat of competition
O presente artigo questiona o papel do calor como um fator de risco adicional para o acidente que vitimou Ayrton Senna. O automobilismo de competição constitui um desafio biológico, uma situação estressante do ponto de vista mental e fÃsico. A manutenção da performance depende da disponibilidade de carboidratos e oxigênio, hidratação adequada e temperatura interna constante entre 37 e 38 graus centÃgrados. A dissipação do calor produzido pelo metabolismo ocorre através do aumento do fluxo de sangue para pele e produção de suor e manter a temperatura cerebral constante se constitui num problema permanente. Verificou-se experimentalmente que a energia necessária para dirigir um automóvel de corrida é comparável a um esporte como o voleibol. Durante uma corrida, o indivÃduo está exposto a um microambiente quente na cabina, que pode atingir 50ºC, gerado por fontes de calor mecânicas e ambientais. O bloqueio da evaporação do suor pelo macacão resulta em umidade e desconforto pessoal, o que implica maior esforço mental para dirigir o carro. As medidas contra o calor começam antes da corrida, cuidando-se do estado nutricional, da hidratação e principalmente do condicionamento fÃsico através de exercÃcios aeróbios regulares e adequados, que permitem aumentar a capacidade de trabalho e a tolerância ao calor, o que resulta em menor fadiga durante a corrida. Outro procedimento importante deveria ser a aclimatação prévia dos pilotos aos ambientes quentes e úmidos. Deve-se fazer o possÃvel para reduzir o aquecimento do veÃculo e respeitar o sistema de bandeiras de advertência para os riscos de hipertermia. Em conclusão, embora Ayrton Senna fosse um indivÃduo com maior risco de desenvolver hipertermia, independentemente de outras causas, não parece ter havido tempo de corrida suficiente para haver produção de calor metabólico capaz de aumentar excessivamente a temperatura interna do piloto nas condições ambientais do autódromo no dia de sua morte.<br>El presente artÃculo cuestiona el papel del calor como un factor de riesgo adicional para el accidente que sufrió Ayrton Senna. El automovilismo de competición constituye un desafÃo biológico, una situación estresante desde el punto de vista mental y fÃsico. El mantenimiento de la performance depende de la disponibilidad de los carbohidratos y del oxÃgeno, hidratación adecuada y temperatura interna constante entre 37 y 38 grados centÃgrados. La disipación de calor producido por el metabolismo que ocurre a través del aumento del flujo de sangre para mantener la temperatura cerebral constante constituye un problema permanente. Se ha verificado experimentalmente que la energÃa requerida para conducir un auto de carrera es similar a la requerida para practicar un deporte como el voleibol. Durante una carrera, el individuo está expuesto a un microambiente caliente dentro de la cabina que puede llegar hasta los 50 grados centÃgrados generado por fuentes de calor como las mecánicas y las ambientales. El bloque del sudor por el mameluco resulta en humedad y disconfor personal, lo que implica un mayor esfuerzo personal para conducir el auto. Las medidas contra el calor comienzan antes de la carrera, cuidando el estado nutricional, la hidratación y principalmente el acondicionamiento fÃsico a través de ejercicios aeróbicos regulares y adecuados, que permitan aumentar la capacidad de trabajo y la tolerancia al calor, lo que resulta en una menor fatiga durante la carrera. Otro procedimiento importante deberÃa ser la aclimatación de los pilotos en ambientes calientes y húmedos. Se debe realizar lo posible en el acondicionamiento del vehÃculo para respetar el sistema de banderas de advertencia para los riesgos de hipertermia. En conclusión, si ahora Ayrton Senna fuera un individuo con mayor riesgo de desarrollar hipertermia, independientemente de otras causas, no parece haber habido tiempo suficiente en la carrera para la producción del calor metabólico capaz de aumentar excesivamente la temperatura interna del piloto en las condiciones ambientales del autódromo el dÃa de su muerte.<br>The present study discusses the role of heat as an additional risk factor for the accident that killed the pilot Ayrton Senna. The competition car racing is a biological challenge, a stressing situation from the physical and mental point of view. The maintenance of performance depends on the oxygen and carbohydrates availability, adequate hydration and constant internal temperature, between 37 and 38ºC. The dissipation of heat produced by the metabolism occurs through the increase on the cutaneous blood flow and sweat and maintaining brain temperature constant becomes a permanent problem. It was experimentally verified that the energy required to the racecar driving is comparable to a sport such as volleyball. During a car race, the individual is exposed to a hot microenvironment in the cockpit, sometimes reaching 50ºC, generated by mechanical and environmental sources of heat. The obstruction of the sweat evaporation by the racesuit results in humidity and personal discomfort, what leads to higher mental effort to drive the car. The anti-heat measures are adopted before the race, considering the nutritional state, hydration and specially the physical conditioning through adequate and regular aerobic exercises that enable increasing the work capacity and the heat tolerance, resulting in lower fatigue during the car racing. Another important procedure should be the previous acclimation of pilots to hot and humid environments. All efforts should be done to reduce the vehicle heating and to respect the warning flag system for the risks of hyperthermia. Finally, although Ayrton Senna was an individual with higher risk of developing hyperthermia, regardless other causes, it seems not to have elapsed sufficient time of race in order to produce metabolic heat capable to increase excessively the pilot's internal temperature in the environmental conditions of the autodrome in the day of his death
Domestic dogs in a fragmented landscape in the Brazilian Atlantic Forest: abundance, habitat use and caring by owners
This study aimed at estimating the population size and attitudes of residents towards caring for domestic dogs, through questionnaire surveys, as well as the frequency of these animals in different habitats (anthropic and forest patch), using scent stations. The study was conducted in a severely fragmented area of the Brazilian Atlantic Forest. A large number of unrestricted dogs was recorded, averaging 6.2 ind/km². These dogs have owners and are regularly fed. Dog records decreased from the anthropogenic matrix to the forest patch edge, which suggests that dogs act as an edge effect on forest patches. Encounters between domestic dog and wild animals can still be frequent in severely fragmented landscapes, mainly at the forest edges. However the fact that most dogs have an owner and are more frequent in the anthropic habitat suggests that their putative effects are less severe than expected for a carnivore of such abundance, but the reinforcement of responsible ownership is needed to further ameliorate such effects