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81.
The sympathetic nervous control of the vascular bed of cat gastrocnemius muscle was studied with a new whole-organ technique which permits simultaneous, continuous and quantitative measurements of capillary pressure (Pc), capillary fluid exchange and resistance reactions in the whole vascular bed and in its three consecutive sections: large-bore arterial vessels (> 25 μm), arterioles (< 25 μm) and veins. The results demonstrated a distinct neural control of all three consecutive vascular sections, graded in relation to the rate of nerve excitation up to maximum at 16 Hz. Stimulation at high rates, which in the steady state caused an average rise of overall regional resistance from 15.3 to 120 PRU (7.8-fold increase), thus raised large-bore arterial vessel resistance from 8.8 to 64 PRU (7.3-fold increase), arteriolar resistance from 4.5 to 49 PRU (10.9-fold increase) and venous resistance from 2.0 to 7 PRU (3.5-fold increase). The rate of resistance development (PRU s-1) of the sympathetic constrictor response was much higher in the arteriolar than in the other sections, which indicates that the neural control is especially prompt and efficient in the arterioles. A passive component was shown to contribute to the described responses only on the venous side, but in no case by more than 10% of the total sympathetic venous resistance response, which thus is mainly active. Of special functional importance was that the new technique provided information about the adrenergic control of Pc, in absolute figures. From the control value of 19 mmHg, graded sympathetic stimulation caused a graded decline in Pc, at maximum constriction by about 7 mmHg. This resulted in marked net transcapillary fluid absorption, in turn increasing plasma volume.  相似文献   
82.
Summary The primary purpose of this investigation was to study the eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man using a recently developed combined isometric, concentric and eccentric controlled velocity dynamometer (the SPARK System). A secondary purpose was to compare the method error associated with maximal voluntary concentric and eccentric torque output over a range of testing velocities. 21 males (21–32 years) performed on two separate days maximal voluntary isometric, concentric and eccentric contractions of the quadriceps femoris at 4 isokinetic lever arm velocities of 0° · s–1 (isometric), 30° · s–1 120° · s–1 and 270° · s–1. Eccentric peak torque and angle-specific torques (measured every 10° from 30° to 70°) did not significantly change from 0° · s–1 to 270° · s–1 (p>0.05) (with the exception of angle-specific 40° torque, which significantly increased;p<0.05). The mean method error was significantly higher for the eccentric tests (10.6%±1.6%) than for the concentric tests (8.1%±1.7%) (p<0.05). The mean method error decreased slightly with increasing concentric velocity (p>0.05), and increased slightly with increasing eccentric velocity (p>0.05). A tension restricting neural mechanism, if active during maximal eccentric contractions, could possibly account for the large difference seen between the present eccentric torque-velocity results and the classic results obtained from isolated animal muscle.  相似文献   
83.
认知暴露疗法治疗创伤后应激障碍的研究   总被引:3,自引:0,他引:3  
目的 探讨认知暴露疗法治疗创伤后应激障碍(PTSD)的效果.方法 连续病例20名被随机分成两组,一组采取药物干预,另一组采用认知暴露疗法结合药物干预.疗效采用创伤后应激障碍症状清单量表(PCLS)、症状自评量表(SCL-90)、贝克抑郁问卷(BDI)、状态-特质焦虑问卷(STAI-Form Y)、汉密顿抑郁量表(HAMD)、汉密顿焦虑量表(HAMA)进行盲法评定.结果 药物治疗和结合治疗都在一定程度上改善了PTSD的症状,但是在再经历方面,结合治疗组下降稳定.其余各量表纵向效应明显.随访时用创伤后应激障碍症状清单量表(PCLS)进行测量,发现结合治疗组有两名被试已经不再符合PTSD诊断阶段,但是统计检验显示两治疗组之间并无差异.结论 认知暴露疗法有助于PTSD患者的心理康复.  相似文献   
84.
用苯肼使动物造成急性溶血性贫血的方法,诱发动物体内新生网织红细胞大量增多,通过对新生网织红细胞的电泳率、渗透脆性、膜的流动性等生物物理指标连续72h的测量,发现网织红细胞在由网织红细胞转变为成熟红细胞的过程中.其生物物理特性有明显改变。这对研究由于贫血等原因造成的网织红细胞增多情况下,全血的微观流变学特性具有重要的临床意义,同时对新生网织红细胞膜的生物物理特性加以系统研究,具有重要的基础理论研究价值。  相似文献   
85.
To overcome the present shortage of liver donors by expansion of the existing donor pool and possibly lengthening of the storage time, hypothermic machine perfusion of the liver as a dynamic preservation method is revisited. The three most important aspects are defined to be the type of preservation solution, the characteristics of perfusion dynamics, and the oxygen supply. Reviewing hypothermic liver machine perfusion experiments, the University of Wisconsin machine preservation solution is the solution most used. It is also found that nothing conclusive can be said about the optimal perfusion characteristics, since either perfusion pressure or perfusion flow is reported. The best estimation is perfusion of the liver in a physiological manner, i.e. pulsatile arterial perfusion and continuous portal venous perfusion. The applied pressures could be chosen to be somewhat lower than physiological pressures to prevent possible endothelial cell damage. Oxygen supply is necessary to achieve optimal preservation of the liver. The minimal amount of partial oxygen pressure required is inversely related to the normalized flow. Incorporating these features in a system based on existing standard surgical and organ sharing procedures and which is able to work stand-alone for 24 h, weighing less than 23 kg, could successfully implement this technique into every day clinical practise.  相似文献   
86.

Background

Myositis is a heterogeneous group of muscular auto-immune diseases with clinical and pathological criteria that allow the classification of patients into different sub-groups. Inclusion body myositis is the most frequent myositis above fifty years of age. Diagnosing inclusion body myositis requires expertise and is challenging. Little is known concerning the pathogenic mechanisms of this disease in which conventional suppressive-immune therapies are inefficacious.

Objectives

Our aim was to deepen our understanding of the immune mechanisms involved in inclusion body myositis and identify specific biomarkers.

Methods

Using a panel of thirty-six markers and mass cytometry, we performed deep immune profiling of peripheral blood cells from inclusion body myositis patients and healthy donors, divided into two cohorts: test and validation cohorts. Potential biomarkers were compared to myositis controls (anti-Jo1-, anti-3-hydroxyl-3-methylglutaryl CoA reductase-, and anti-signal recognition particle-positive patients).

Results

Unsupervised analyses revealed substantial changes only within CD8+ cells. We observed an increase in the frequency of CD8+ cells that expressed high levels of T-bet, and containing mainly both effector and terminally differentiated memory cells. The senescent marker CD57 was overexpressed in CD8+T-bet+ cells of inclusion body myositis patients. As expected, senescent CD8+T-bet+ CD57+ cells of both patients and healthy donors were CD28nullCD27nullCD127null. Surprisingly, non-senescent CD8+T-bet+ CD57- cells in inclusion body myositis patients expressed lower levels of CD28, CD27, and CD127, and expressed higher levels of CD38 and HLA-DR compared to healthy donors. Using classification and regression trees alongside receiver operating characteristics curves, we identified and validated a frequency of CD8+T-bet+ cells >51.5% as a diagnostic biomarker specific to inclusion body myositis, compared to myositis control patients, with a sensitivity of 94.4%, a specificity of 88.5%, and an area under the curve of 0.97.

Conclusion

Using a panel of thirty-six markers by mass cytometry, we identify an activated cell population (CD8+T-bet+ CD57- CD28lowCD27lowCD127low CD38+ HLA-DR+) which could play a role in the physiopathology of inclusion body myositis, and identify CD8+T-bet+ cells as a predominant biomarker of this disease.  相似文献   
87.
目的探讨上海市宝山城区初、高中学生的心理特点及相关因素。方法以整群抽样的方法调查了上海市宝山区6所重点和非重点中学的学生共1289名,其中初中组544名,高中组745名,使用自编"中学生成长情况调查表"(共37题),均以"是"、"否"选择作答,由学生当场独立完成并立即收回。结果社会支持和家庭、学校、自身等方面都有较多的因素对中学生成长有重要影响,高中组和初中组部分项目存在显著性差异(P<0.05)。结论现代社会、家庭学校教育背景下中学生的健康成长与良好的社会支持、综合性教育、家长的正确参与密切相关,针对不同年龄阶段的学生应采取不同的教育、干预方式。  相似文献   
88.
Electromyographic activity of m. rectus femoris at submaximal and maximal voluntary contractions was quantified by conventional integration technique and also be a more “qualitative” procedure of automated motor unit averaging and frequency spectrum analysis. By relating the EMG parameters to produced muscle tension it was observed that the integrated EMG increased in a slightly nonlinear fashion with the increase in muscle force. The other EMG variables also showed clear changes as a function of muscle tension. The averaged motor unit potential (AMUP) and its specific parameters (number of spikes, amplitude, rise time and amplitude-rise time ratio) showed such changes with muscle tension that they may be useful in estimation of the recruitment pattern of the different types of motor units.  相似文献   
89.
Summary In single-fibre preparations the afferent discharges from prepolarized ampullae of Lorenzini responding to graded temperature steps were investigated in the dogfish (Scyliorhinus canicula).The transformation characteristics of the ampullary receptors, especially their differential thermosensitivity interfering with electrosensitivity, were analyzed. Prepolarization significantly influenced the dynamic component of differential thermosensitivity, while the static component remained practically unchanged. Hyperpolarization reduced positive and negative dynamic thermal responses: depolarization amplified them.Biological consequences of this bimodal interference for receptor transformation of superimposed thermal and electric stimuli and for decoding afferent ampullary impulse patterns are discussed.This investigation was supported by the Deutsche Forschungsgemeinschaft  相似文献   
90.
神经症的研究进展   总被引:1,自引:1,他引:1  
目的探讨神经症的病因,防御机制,应对方式,心理治疗及药物治疗的研究进展,以便为其研究、预防和治疗工作提供科学依据。方法以最近20年国内外有关神经症研究的成果为基础,采用文献研究法分析总结了近50余篇有关的研究论文的研究成果。结果神经症患者多内向,情绪明显不稳定,神经质影响心理症状最大;他们的父母较正常人的父母对子女缺乏情感温暖,并有过度的拒绝和过度保护,家庭不和睦,其在发病前一年内负性生活事件数目与严重程度均高于对照组(P<0.01);情绪表达受限,生活单调乏味,父母采取不良教养方式,人际关系紧张等。患者存在防御上的不适当,多使用不成熟或中间型防御机制,缺乏良好的应对方式。心理疗法主要有支持心理治疗,森田疗法,认知领悟疗法和精神分析疗法;而药物以三环类药物,苯二氮卓类为主。药物与心理疗法相结合的疗效比单纯应用心理治疗或药物治疗要好。结论神经症的病因主要有人格特征,家庭环境,生活事件,教养方式,人际关系等。采用心理干预与药物治疗相结合的方法是目前比较公认的。  相似文献   
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