Filter properties of root mean square successive difference (RMSSD) for heart rate

The root mean square successive difference (RMSSD) in heart period series is a time domain measure of heart period variability. The RMSSD is sensitive to high-frequency heart period fluctuations in the respiratory frequency range and has been used as an index of vagal cardiac control. By transfer function simulations, the RMSSD statistic is shown to represent a high-pass filter that effectively captures respiratory sinus arrhythmia but also passes lower frequency fluctuations that can include sympathetic influences. These simulations, together with analysis of actual heart period series, reveal that the RMSSD is biased by basal heart period. Although between-subjects levels of RMSSD covary highly with spectral estimates of high-frequency variability, within-subject RMSSD change scores account for only 50-60% of the variance in spectral estimates. The present findings raise caveats in the applications and interpretation of the RMSSD statistic.     

CMOSens~流量计和控制器在NO输送系统中的应用

本文在研究分析了CMOSens质量流量计和控制器的基础上,研究设计了一套能与呼吸机周期同步且成比例地释放NO标气的NO输送系统,并用N O/NO 2电化学传感器连续监测治疗气中NO浓度和二氧化氮(NO 2)浓度。在NO治疗气浓度为20 ppm的情况下,通过整定系统软件参数后,呼吸机的吸气流量和NO供给流量的相位差为0,NO检测浓度相比较整定前的检测值平均增大2.15 ppm,更接近于NO设定浓度值,NO 2检测浓度≤0.2 ppm属于安全范围。结果表明经过整定后的系统系实现了和呼吸机周期同步地供给NO标气,并且提高了NO治疗气的精度、降低了NO由于被氧化而生成NO 2的可能性。     

Time course for strength and muscle thickness changes following upper and lower body resistance training in men and women

 The purpose of this study was to investigate the time course of skeletal muscle adaptations resulting from high-intensity, upper and lower body dynamic resistance training (WT). A group of 17 men and 20 women were recruited for WT, and 6 men and 7 women served as a control group. The WT group performed six dynamic resistance exercises to fatigue using 8–12 repetition maximum (RM). The subjects trained 3 days a week for 12 weeks. One-RM knee extension (KE) and chest press (CP) exercises were measured at baseline and at weeks 2, 4, 6, 8, and 12 for the WT group. Muscle thickness (MTH) was measured by ultrasound at eight anatomical sites. One-RM CP and KE strength had increased significantly at week 4 for the female WT group. For the men in the WT group, 1 RM had increased significantly at week 2 for KE and at week 6 for CP. The mean relative increases in KE and CP strength were 19% and 19% for the men and 19% and 27% for the women, respectively, after 12 weeks of WT. Resistance training elicited a significant increase in MTH of the chest and triceps muscles at week 6 in both sexes. There were non-significant trends for increases in quadriceps MTH for the WT groups. The relative increases in upper and lower body MTH were 12%–21% and 7%–9% in the men and 10%–31% and 7%–8% in the women respectively, after 12 weeks of WT. These results would suggest that increases in MTH in the upper body are greater and occur earlier compared to the lower extremity, during the first 12 weeks of a total body WT programme. The time-course and proportions of the increase in strength and MTH were similar for both the men and the women. Accepted: 6 September 1999     

A simple method for multiple fluid exchange

A simple device for fluid exchange is described, which allows the exchange of an unlimited number of solutions at low (10–1000 nl/min) constant perfusion rate. The applicability of the system has been tested in microperfusion experiments of rat distal tubules. At a luminal perfusion rate of 40 nl/min, the lag time was some 20 sec and 80 % fluid exchange time some 3 sec. Simple modification allows further reduction of the lag time. Under control conditions, the potential difference across the late distal tubule (PDte) approaches –19.4±2.5 mV (n = 27). Increase of luminal potassium concentration from 5.4 to 40 mmol/l hyperpolanzes PDte to –29.9±4.3 mV (n = 8). Amiloride (10 mol/l) leads to a reversible depolarization to –3.2±1.0 mV (n = 19), barium (1 mmol/l) to a reversible hyperpolarization to –25.8±2.6 mV (n = 19). As expected, PDte is largely created by amiloride sensitive sodium channels and is partially blunted by barium sensitive potassium channels.     

41名肢残者十六项人格特质测验

应用“卡特尔十六项人格特质测验问卷”,对41名肢残者和40名健全人进行对照研究。结果表明,肢残人较健全人在孤独性上具有明显的差异,偏于缄默,固执,关注外界信息,具有一定的防卫倾向。肢残人富于实验性,较健全人更自由、激进、好学,具有较强的独立工作能力,希望生活更充实多彩。在各项能力水平上,肢残上与健全人没有显著差别。不同性别肢残人人格特质在敏感性上差异明显,女性较理智和着重现实,而男性则偏于敏感,易感情用事。     

Lack of effect of ouabain on sodium transport across the rat placenta

The umbilical vascular bed of the rat placenta was perfused in situ. Ouabain (10^–4M) in the perfusion fluid had no effect on the unidirectional flux of Na⁺ from the maternal (electrically negative) to the foetal (electrically positive) side of the placenta, or on the transplacental potential difference. This was taken to indicate that there is no significant active transport of Na⁺ across the placenta of the rat.     

Strain differences of the light-dark preference in inbred rats

he present study examined strain differences in the light-dark preference among four strains of rats. The test was done in the home-cage situation under 12L:12D cycles. Data from four strains were compared: BN/Kyo, BDIX/Nem, Wistar/Nu, and F344/NSlc. These strains differed in the light-dark preference measured by the ratio of the time spent in the field area of the home cage during the light period. BN/Kyo and BDIX/Nem spent the most time (approx. 23%) in the field during the light period, while F344/NSlc spent the least time (approx. 5%). Wistar/Nu fell between the two (approx. 12%).This study was conducted as partial fulfillment for the master's degree, submitted to Nagoya University by the first author. It was presented at the 47th Annual Conference of the Japanese Society of Animal Psychology.     

P-选择素启动子区C-2123G、T-1817C基因多态性的研究

目的研究P-选择素(P-selectin)基因启动子区C-2123G、T-1817C多态性在中国湖北地区健康汉族人群中的分布,同时比较不同种族间基因型及等位基因频率分布差异.方法应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)的分析方法,检测200名健康者P-selectin基因启动子区C-2123G、T-1817C的基因型并计算其基因型频率及等位基因频率.结果中国湖北地区健康人群P-selectin C-2123G基因各基因型频率:CC型8.0%,CG型40.5%,GG型51.5%;C,G各等位基因频率分别为28.2%,71.8%,这种基因多态性分布在男女间无显著性差异(P＞0.05).与德国和英国比较,发现不同种族间P-selectin C-2123G基因型分布及等位基因频率均存在显著差异(P＜0.001,P＜0.001).P-selectin T-1817C基因各基因型频率:TT型65.5%,TC型28.5%,CC型6.0%;T,C各等位频率分别为79.75%,20.25%,这种基因多态性分布在男女间无显著性差异(P＞0.05).与英国比较,发现不同种族间P-selectin T-2123基因型分布及等位基因频率均存在显著差异(P＜0.001).结论中国湖北地区汉族人群中存在P-selectin启动子区C-2123G、T-1817C基因多态性,这种多态性在同种族男女间无差异,在各族间存在着较大的差异.     

建立不同民族永生细胞株质量控制方法的探讨

目的以建立普米族、独龙族和怒族永生细胞为基础,探讨EB病毒转化细胞、细胞培养、冻存、复苏以及支原体检测等建立永生细胞株的技术要点及质量检测方法.方法采用EB病毒转化技术建立3个民族永生细胞株;培养法和PCR法对细胞株进行支原体污染检测;染色体G显带及核型分析细胞株的遗传稳定性.结果成功建立了3个民族B淋巴细胞永生细胞株,转化率分别为98%、86%和76%.对已建株保存的3个民族的永生细胞进行复苏培养,复苏成活率为100%.支原体污染检测均为阴性.染色体计数和G带分析显示,细胞株经早期传代培养后,仍然保持二倍体特征,未发现染色体结构畸变.结论本研究中传代培养、细胞冻存、细胞复苏和支原体污染防范等一整套技术过程是满足建库要求的.同时为大规模永生细胞库的建立和进行相应的质量监测提供了科学的依据.另外,本研究还对一些影响转化的因素和可能的机理进行了探讨.     

陕西、青海、新疆三省(区)部分人群庚型肝炎病毒血清学调查

目的：调查陕西、青海、新疆三省（区）部分人群庚型肝炎病毒（HGV／GBV）血清学特征。方法：采用ELISA方法，共调查三省（区）1469份血清中GBV－IgG抗体。结果：少数民族血清GBV－IgG抗体的阳性率（藏族4．11％，蒙古族5．36％，维吾尔族4．55％，回族4．00％）略高于汉族（1．36％－1．73％），但差异无显著性（P＞0．05）；吸毒人群GBV－IgG阳性率（11．30％，34／301）明显高于正常人群（2．44％，18／736），（P＜0．01）；献血员GBV－IgG阳性率为1．02％－7．68％。结论：三省区民族间GBV－IgG抗体阳性差异无显著性，血源性传播是其重要途径，应加强对献血员及吸毒人员的监管。