4种药物防治高原脱适应的对比观察

目的筛选防治高原脱适应的药物品种。方法对驻守海拔5170m一年的57名某部官兵,在返回平原(海拔1400m)前5天随机分为5组,分别口服银杏叶片(12人)、复方红景天胶囊(12人)、刺五加片(11人)、复方党参胶囊(11人)、炒面胶囊(对照组,11人),至返回平原第7天停药,共服药12天。采用高原脱适应症状调查表调查部队返回平原第2天、4天、6天的高原脱适应情况,并计算出每天的总得分。采用二级定量负荷踏阶运动实验评价受试者返回平原第7天的PWC170和台阶指数。结果与对照组比较,复方党参组和复方红景天组高原脱适应症状显著减轻(P<0.01或P<0.05),且复方党参组明显优于银杏叶片组和刺五加组(P<0.05)。与对照组比较,复方党参组和复方红景天组PWC170和台阶指数均显著提高(P<0.05)。结论复方党参胶囊和复方红景天胶囊防治高原脱适应效果较好。     

高原适应者返平原后脱适应期心脏超声变化的初步探讨

目的对短期驻训高原官兵返平原后行心脏超声检查,初步探讨其脱适应期间心脏形态、血流及心功能的变化。方法采用便携式超声诊断仪对驻训海拔3900 m高原地区7个月的官兵急进返回平原(200 m)后第2天、第30天及第120天行心脏超声检查,并对所采集数据行统计学分析。结果与第2天超声检测结果比较,第30天心脏超声显示肺动脉和右室流出道内径减小,肺动脉收缩期流速、心率、左室Tei指数及平均肺动脉压降低,左室舒张期E、A峰流速增快;第120天左室舒张期E、A峰流速增快,肺动脉收缩期流速降低,右房收缩期横径、上下径,右室舒张期横径、肺动脉及右室流出道内径减小,心率、左室Tei指数及平均肺动脉压降低,左室缩短分数和射血分数升高。结论高原适应者返平原后脱适应期间心脏发生系列变化,其中心功能变化较心脏形态改善较早,需设置合理作训计划以促进身体恢复。     

Scaling down motor memories: de-adaptation after motor learning

Although adaptation to novel motor tasks is sometimes a very slow process, de-adaptation is usually extremely rapid. Such rapid de-adaptation is seen in dynamic learning in which subjects can take hundreds of movements to learn a novel force environment but only a few movements to de-adapt back to a normal or “null” force environment. We investigated whether this effect is unique to the null environment or reveals a more general rapid adaptation mechanism by studying how subjects behave when their dynamic environment changes. We observed that after learning a dynamic force field, subjects took longer to de-adapt when the forces were turned off than to adapt to a novel scaled-down version of the experienced field. This demonstrates that rapid adaptation is not unique to the “null” force environment. Moreover, we examined subjects’ ability to adapt from a learned field to either a scaled down field or to a field in which the sign of the forces changed. Even though in both conditions the required change in force output was identical, subjects were significantly faster at adapting to the scaled down field. The result suggests that rapid de-adaptation reflects a capacity to scale down the relative contribution of existing control modules to the motor output.     

Effect of exercise training on the disappearance of cold adaptability in rats

Summary Following the transfer of cold-adapted rats to a warm environment at 25‡ C, enhanced nonshivering thermogenesis and enlarged interscapular brown adipose tissue (BAT) decreased gradually and reached a steady state after 4 weeks of de-adaptation. Animals that were exercised in the process of de-adaptation, however, showed no decrease in enhanced nonshivering thermogenesis, but did show a decrease in BAT weight as compared with sedentarily de-adapted animals. Triiodothyronine (T₃), the physiologically most active thyroid hormone, was at a higher plasma level in cold-adapted rats than in de-adapted animals with or without exercise loads. Although the resting level of T₃ in running-trained rats was not higher than that in sedentary rats, some fluctuations of T₃ level were observed during running. The part of this work using radioisotopes was performed in the Central Institute of Isotope Science, Hokkaido University