握力大小与前臂肌肉表面肌电活动模式的相关性研究

目的 研究手部握力大小与前臂肌肉表面肌电信号特征的相关性.方法 9名健康被试者参加了试验,包括最大自主收缩力(maximum volunteer contraction,MVC),80% MVC及40% MVC,记录指浅屈肌和腕长伸肌的表面肌电信号,并采用均方根和小波分析方法提取其特征参数;运用SPSS软件统计以被试者自身的MVC为基准的不同握力水平的相对特征值,使不同的被试者具有可比性.结果 对于单个被试者握力水平与表面肌电活动模式存在正相关性,即握力越大则对应的表面肌电信号的特征值也越大;对于所有的被试者这种正相关性也存在.结论 握力水平与肌肉活动模式具有相关性,这提示通过表面肌电信号的特征值不但可以预测握力的大小,还可用于运动功能测试及康复的评价.     

Effect of psychotomimetics and some putative anxiolytics on stress-induced hyperthermia

Summary Stress-induced hyperthermia (SIH), which is seen in the last mice removed from the cage, is a novel animal model sensitive to anxiolytic drugs. SIH is antagonized by CL 218872 (25 and 50 mg/kg, os), by tracazolate (5 and 7.5 mg/kg, ip) and by 2-AP-5 (50 and 100 mg/kg, ip). At higher dose, CL 218872 (100 mg/kg, os) and tracazolate (12.5 mg/kg, ip) lose their activity.PK 9084 (5–40 mg/kg, ip) and CGS 9896 (2–20 mg/kg, both ip and os) were also ineffective in preventing SIH. The anti-hyperthermic effect of CL 218872 (25 mg/kg) and tracazolate (7.5 mg/kg) was blocked by the benzodiazepine antagonist Ro 15–1788 (15 mg/kg). CGS 9896 (10 mg/kg, os) also reversed the effect of CL 218872 (25 mg/kg) on SIH.Differently from anxiolytics, MK-801 (0.5–1 mg/kg, os), PCP (2.5 mg/kg, ip) and d-amphetamine (10 mg/kg, ip) evoked hyperthermia in the first set of mice and prevented a further stress-induced rise of body temperature in the last set of mice.     

Buspirone does not produce a 5-HT1A-mediated decrease in temperature in man

Summary Buspirone, a putative serotonin (5-HT)_1A partial agonist, did not produce hypothermia in 17 normal volunteers in a placebo controlled, single blind study. Thus, buspirone may be a weaker agonist at those 5-HT_1A receptors which mediate hypothermia compared to ipsapirone or gepirone, two other 5-HT_1A partial agonists which have been reported to produce hypothermia by a 5-HT_1A-mediated mechanism.     

Real-time refinement of subthalamic nucleus targeting using Bayesian decision-making on the root mean square measure.

The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.     

Flavor preference conditioning by oral self-administration of ethanol

 Oral self-administration and operant tasks have been used successfully to confirm ethanol′s positive reinforcing effects in rats. However, in flavor conditioning tasks, ethanol is typically found to have aversive effects. The present studies explored this apparent paradox by examining the change in value of a flavor paired with orally self-administered ethanol in two different limited-access procedures. Rats were food-deprived and trained to drink (experiment 1) or to barpress for (experiment 2) 10% (v/v) ethanol during daily 30-min sessions using prandial initiation techniques. All rats were then exposed to a differential flavor conditioning procedure in which banana or almond extract was added to the drinking solution. One flavor (counterbalanced) was always mixed with ethanol (CS+), whereas the other flavor was mixed with water (CS–). By the end of conditioning, rats in both experiments drank more flavored ethanol than flavored water, confirming ethanol’s efficacy as a reinforcer. Moreover, barpress rates for CS+ exceeded those for CS– in the operant task. Ethanol doses self-administered in final sessions averaged about 1 g/kg. The effect of the flavor-ethanol contingency was assessed in preference tests that offered a choice between the two flavor solutions without ethanol. In both experiments, subjects developed a preference for the flavor that had been paired with ethanol. Thus, the outcome of flavor conditioning was consistent with that of the oral self-administration tasks in providing evidence of ethanol’s rewarding effects. These experiments confirm and extend previous studies showing that flavor aversion is not the inevitable result of flavor-ethanol association in rats. It seems likely that ethanol’s nutrient and pharmacological effects both contributed to the development of conditioned flavor preference. Received: 15 February 1997 / Final version: 11 June 1997     

Seasonal covariation of the circadian phases of rectal temperature and slow wave sleep onset

There is a scarcity of well-controlled studies of the seasonal variation in circadian rhythmicity. In the present study, the circadian phase of rectal temperature and the onset of slow wave sleep were studied in a series of twelve 24-h experiments, one each month of the year, for six healthy subjects under controlled conditions in a climatic chamber. In winter, as compared with summer, the average circadian rhythm of rectal temperature was phase delayed by 45 min, and the average onset of slow wave sleep was phase delayed by 40 min. The temporal relationship between the circadian phase of rectal temperature and the timing of slow wave sleep was maintained throughout the year. Habitual rising and retiring times covaried as well. Furthermore, the circadian rhythm of rectal temperature followed the timing of the photoperiod across the year, but had a much smaller range of seasonal variation. Apparently, the seasonal variation in the photoperiodic zeitgeber is largely compensated for by the stabilizing influence of secondary zeitgebers. However, in healthy subjects some effect of photoperiodic variation can still be observed.     

196份恙虫病患者血清IgM抗体分析

采用斑点酶标染色技术对临床疑似恙虫病患者196份血清进行了IgM抗体的检测并作了初步统计分析。总检出率为92.3%；病后3天内检出率为50%，抗体滴度几何平均值（GMT）为226；4-7天检出率为83%，GMT为320；第4周抗体滴度达峰值，GMT为1585，检出率为100%，同时在4周内棋 GMT与发病时间呈正相关。提示应用本法进行IgM抗体的检测对恙虫病的早期诊断和流行病学调查有着重要意义。     

飞行员配穿两种囊式抗荷服在不同环境温度和代谢水平时的热应激

目的　探讨飞行员配穿囊式抗荷服在不同环境温度、不同代谢水平条件下的热应激 ,为评价囊式抗荷服的热负荷和制定相应的保障措施提供理论依据。方法　 6名受试者分别配穿KH - 3抗荷服及配套装备和KH - 7抗荷服及配套装备 (以下分别简称为“KH - 3”和“KH -7”) ,以不同代谢水平暴露于 2 0℃、2 5℃和 35℃环境。每次试验 70min。测量了受试者配穿KH- 3和KH - 7时的卫生学参数、皮肤温度、直肠温度、心率等 ,并以综合热应激指数 (CIHS)评定了热应激防护等级。结果　KH - 3和KH - 7的各项卫生学参数 (clo值、im、im/IJ)均无显著差别。KH - 3对照Ⅲ组和KH - 7对照Ⅳ组 (2 5℃ ,1178～ 132 5kJ·h- 115min ,36 8kJ·h- 15 5min)的CIHS均未超过生理安全限的 6 0 % (分别为 3.5 4和 3.4 6 ,属轻度热应激 ) ;KH - 3高代谢组和KH- 7高代谢组 (2 0℃ ,84 6～ 10 30kJ·h- 170min)的CIHS在生理安全限的 6 0 %～ 95 %之间 (分别为4 .2 4和 4 .6 0 ,属中度热应激 ) ;KH - 3高温组和KH - 7高温组 (35℃ ,1178～ 132 5kJ·h- 115min ,36 8kJ·h- 15 5min)的CIHS却超过生理安全限的 95 % (分别为 7.31和 7.87,属重度热应激 )。结论　受试者配穿KH - 3与KH - 7时的各项卫生学参数、热应激等均无显著差别 ,但配穿后者比     

术中输注氨基酸对硬膜外阻滞复合全麻开胸手术患者围术期体温的影响

目的评价术中输注氨基酸对硬膜外阻滞复合全麻食管癌和贲门癌手术患者围术期深部体温和代谢的影响。方法择期食管癌和贲门癌手术患者21例,ASAⅠ或Ⅱ级,随机分为3组(n =7):从麻醉诱导开始至手术结束,分别静脉输注氨基酸混合液240kJ·h-1(AA组)、等容量乳酸钠林格氏液(LR组)、葡萄糖溶液240kJ·h-1(GLU组)。麻醉诱导前至术后2h每5分钟测定鼓膜温度,于麻醉诱导前即刻、手术开始后1h和术后1h检测指尖血糖,采用4分表法评价术后2h内寒战的发生情况,采用间接测热仪测定术前与术后氧耗。结果与麻醉诱导前即刻比较,术后30min LR组和GLU组氧耗降低,AA组氧耗升高(P<0.01),术后2h LR组、GLU组鼓膜温度降低(P<0.05),AA组差异无统计学意义(P>0.05);与LR组和GLU组比较,AA组术后2h内寒战发生例数减少(P< 0.05),术后30min氧耗增多(P<0.05),LR组与GLU组比较差异无统计学意义(P>0.05)。结论硬膜外阻滞复合全麻开胸手术患者术中静脉输注氨基酸可通过提高基础代谢率,缓解围术期深部体温降低,减少术后寒战发生,而输注葡萄糖不产生此效应。