Sympathetic a-adrenergic control of large-bore arterial vessels,arterioles and veins,and of capillary pressure and fluid exchange in whole-organ cat skeletal muscle

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 (P_c), 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 P_c, in absolute figures. From the control value of 19 mmHg, graded sympathetic stimulation caused a graded decline in P_c, at maximum constriction by about 7 mmHg. This resulted in marked net transcapillary fluid absorption, in turn increasing plasma volume.     

Eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man

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.     

Character and frequency of pathological changes in the solitary rat kidney after removal of the other kidney in old age

One kidney was removed from male rats weighing 500–850 g; the remaining kidney underwent compensatory hypertrophy and, after 1–2 months, it was larger (index of hypertrophy 70–92%) in rats weighing 700–850 g than in animals weighing 500–600 g (56–58%). Histological investigation showed that this marked hypertrophy of the solitary kidney in old rats was not the result of disease of the organ, for pathological changes such as are sometimes found in intact and hypertrophied kidneys were found in only 38 of 223 animals. The results suggest that the ability of the kidneys to undergo, compensation and regeneration is not reduced in old age.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 362–366, September, 1977.     

网织红细胞膜生物物理特性的研究

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。     

Hypothermic Machine Preservation in Liver Transplantation Revisited: Concepts and Criteria in the New Millennium

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.     

CD8+T-bet+ cells as a predominant biomarker for inclusion body myositis

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.

中学生的心理特点及相关因素分析

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。     

Signal Characteristics of EMG at Different Levels of Muscle Tension

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.     

Effect of some stressors on mitosis in the corneal epithelium and the bone marrow aneuploid cell level in adrenalectomized albino rats

It was shown previously that exposure to stressors led to a decrease in the number of mitoses in the cornea as a result of G₂–M delay. The index of labeled nuclei and level of pathological mitoses were unchanged. It is now shown that injection of pyrogenal or contact hypothermia for 1 h to 28–30°C did not cause reactive inhibition to develop in adrenalectomized rats, but led to a significant increase in the level of pathological mitoses in the cornea from 4.3–6.3% in intact and adrenalectomized rats to 10.6–12.5% in adrenalectomized rats exposed to stress. Karyotypic analysis of the bone marrow cells under these conditions revealed a significant increase in the number of aneuploid cells (both hypo- and hyperdiploid).Central Research Laboratory, Khabarovsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 9, pp. 338–341, September, 1979.     

Wolffian附件肿瘤的临床病理观察

目的 观察Wolffian附件肿瘤的临床病理特点，探讨其病理诊断与鉴别诊断。方法 对3例Wolffian附件肿瘤进行HE及免疫组化染色（EnVision法），并进行病理观察。结果 3例Wolffian附件肿瘤均为单侧，位于阔韧带或输卵管系膜。镜下肿瘤细胞呈弥漫实体状分布，可见成片的梭形或多边形细胞及排列紧密的管状结构。管腔内衬立方或柱状上皮，细胞无明显异型，核分裂象少见。管周有PAS阳性的基膜物质。免疫组化示肿瘤细胞vimentin、AE1／AE3、α-inhibin、calretinin和WT1均呈阳性，CD99呈灶性阳性，EMA和CK7呈阴性。结论 Wolffian附件肿瘤是具有独特发病部位和组织病理学特点的妇科肿瘤，需要和一系列其他妇科肿瘤鉴别。