RESUMO
"Cytokines and the ageing brain". Held in Palais de Congres, Arcachon, France on 1-3 June 2002.
Assuntos
Envelhecimento/fisiologia , Encéfalo/fisiologia , Citocinas/fisiologia , Envelhecimento/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Humanos , Inflamação/dietoterapia , Inflamação/tratamento farmacológico , Inflamação/metabolismoRESUMO
The nychthemeral activity patterns of a population of female black wildebeest inhabiting a shadeless environment were surveyed periodically over 1 year. The wildebeest fed mostly at night, with the proportion of feeding at night increasing when ambient conditions were hotter. Inactive periods were spent mostly lying during cooler weather but standing as days became hotter. We suggest that the entire suite of behavioural adjustments is beneficial to heat exchange with the environment. Behaviour patterns were markedly different during one warm weather survey, from the other warm weather surveys, when an 8-month dry spell had just been broken. We suggest that this may reflect the availability of water for autonomic thermoregulation, a consequent decreased reliance on behavioural thermoregulation, and a release of the thermal constraints on foraging. Our results help to explain the ability of black wildebeest to maintain body core temperature within a very narrow range despite being exposed to an environment with large nychthemeral variations in thermal conditions and offering little in the way of microclimate selection.
Assuntos
Comportamento Animal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Ritmo Circadiano/fisiologia , Atividade Motora/fisiologia , Ruminantes/fisiologia , Estações do Ano , Adaptação Fisiológica/fisiologia , Animais , Meio Ambiente , Periodicidade , Fotoperíodo , Comportamento Social , TemperaturaRESUMO
A comparison between humans and rabbits was performed based on stimulation of whole blood with well-known pyrogens from Gram-negative and Gram-positive bacteria, such as lipopolysaccharide (LPS) and lipoteichoic acid (LTA), respectively. The reactivity was measured as release of IL-1 beta and IL-8 by ELISA. The reactivity of the two species towards LPS was found to be similar, whereas their reactivity towards LTA differed considerably. Differences between the levels of IL-1 beta and IL-8 release were observed in both species. This finding suggests that the In vitro Pyrogen Test (IPT) which uses human blood to detect contaminations, e.g. of injectable drugs, might predict the human reaction to the contamination better than the "gold standard" rabbit pyrogen test.