Acute hypoxia blunts cold sensitivity through the inhibition of the lateral parabrachial nucleus in rats / 生理学报

To explore the changes of cold sensitivity after exposure to acute hypoxia and its mechanisms, Sprague-Dawley rats were divided into normoxia control group (21% O2, 25 °C), 10% O2 hypoxia group (10% O2, 25 °C), 7% O2 hypoxia group (7% O2, 25 °C), normoxia cold group (21% O2, 10 °C) and hypoxia cold group (7% O2, 10 °C). Cold foot withdrawal latency and preference temperature of each group were measured, skin temperatures were estimated using an infrared thermographic imaging camera, body core temperature was recorded by wireless telemetry system, immunohistochemical staining was used to detect the expression of c-Fos in the lateral parabrachial nucleus (LPB). The results showed that acute hypoxia significantly prolonged the latency of cold foot withdrawal and significantly enhanced the intensity of cold stimulation for foot withdrawal, and the rats under hypoxia preferred cold temperature. Cold exposure (10 °C) for 1 h significantly enhanced the expression of c-Fos in LPB of rats in normoxia, while hypoxia inhibited cold-induced c-Fos expression. Acute hypoxia significantly increased the skin temperature of feet and tails, decreased the skin temperature of interscapular region, and decreased the body core temperature of rats. These results indicate that acute hypoxia can significantly blunt cold sensitivity through the inhibition of LPB, suggesting actively keeping warm measures should be taken at the early stage after ascent to high altitude to prevent the upper respiratory infection and acute mountain sickness.

Association of changes in frequency of peripheral natural killer T cells with nonalcoholic fatty liver disease / 中华消化杂志

Objective To investigate the correlation of changes in peripheral natural killer T(NKT) cells and fatty liver disease(NAFLD).Methods Peripheral blood samples were obtained from 60 NAFLD patients and 60 age and gender matched healthy controls.The frequency of peripheral NKT cells was detected by flow cytometry.The differences of clinical presentation and laboratory data in two groups were analyzed.The risk factors of NAFLD were screened by Logistic regression analysis. Results NAFLD patients had lower frequency of peripheral NKT cells than healthy controls [median fre- quency was 1.12%(IQR0.87%～1.54%)in patients vs.1.48%(1.23%～1.98%) in controls,P