骨骼肌快速收缩时的糖代谢--糖原短路模型

根据目前13C和31P核磁共振(NMR)关于运动骨骼肌的研究，对运动骨骼肌能量代谢有了新的认识，并提出了新的能量代谢模型．在10～40ms的快速收缩中，需要能量快速地传递，骨骼肌中慢速的碳水化合物氧化供能最终必须设法与快速的能量消耗相适应，因此有人提出一个新的能量代谢模型——糖原短路：骨骼肌快速收缩的能量来源于糖原分解，在收缩间期，糖原重新合成来补充消耗的糖原，糖原合成需要的能量来自于氧化磷酸化，这个机制主要利用磷酸化酶快速转变的重要的特征腓肠肌，此过程产生的乳酸是能量快速消耗与相对慢速能量供应之间的时间缓冲，这合理的解释了富氧组织产生乳酸的原因．糖原短路的模型符合多数的生化和生理实验的结果，这个模型提供了骨骼肌疲劳的可能原因，提示骨骼肌糖原水平低的时候，不能提供快速收缩所需要的能量．     

Dynamic laser light scattering studies of the effects of pyrophosphate on cyclic motions of cross-bridges in isolated thick myofilaments fromLimulus striated muscle

Pyrophosphate (PP_i) is a non-hydrolyzable ATP analogue known to affect the binding between myosin heads and actin. By using a dynamic laser light scattering method, we have shown that 1–2 mM PP_i enhances the increase in values induced by Ca²⁺ in isolated thick myofilaments fromLimulus striated muscle. However, similar treatment has no effect on the values of filaments suspended in either relaxing solution or ATP-free solution. is the average linewidth of the photoelectron count autocorrelation function of the light scattered. PP_i had no effect on the increase of values by Sr²⁺ but it substantially increased the values of the thick myofilaments suspended in Ba²⁺-substituted Ca²⁺ activating solution. The results show that PP_i also affects the energy-requiring cyclic cross-bridge motions.     

Seasonal variation in the phenotype of adult ferret (Mustela putorius furo) cremaster muscle

Using immunocytochemistry, electrophoresis and immunoblotting, we studied the expression of fast and slow myosin heavy chain isoforms in adult ferret muscles during quiescent and breeding periods. Adult cremaster muscle expressed slow and fast myosin heavy chain in relatively similar amounts during the quiescent period. During the breeding period, the expression of slow myosin heavy chain I, significantly decreased, and fast myosin heavy chain II, was predominant. No alteration of the MHC pattern in EDL and soleus muscles was detected between the quiescent and breeding periods. The possible involvement of androgens and mechanical factors in the regulation of myosin heavy chain expression in adult cremaster muscle is discussed.     

仔鹿白肌病的诊断与防治

白肌病发生于各种动物,是属硒—维生素E缺乏综合症,直接影响各种代谢机能。其侵害的部位和症状,与动物的种属有关,但病变的性质有其共同性。     

Zinc ions block the second but not the first phasic response to repetitive application of carbachol and histamine in guinea-pig taenia caeci

In the presence of Zn²⁺ (0.3 mM), carbachol (10^–6 M) or histamine (10^–5 M) induced the phasic response in guinea-pig taenia caeci while the tonic response was markedly inhibited. However, when the muscles were kept in Zn²⁺-containing medium following the first stimulation with either carbachol or histamine, neither application of carbachol nor of histamine elicited another phasic contraction. Caffeine (25 mM) did not induce contraction in the presence of Zn²⁺. After the washing out of caffeine in the presence of Zn²⁺, however, the muscle did then develop the phasic response on the application of carbachol or histamine. In conclusion, Zn²⁺ did not affect the carbachol or histamine-induced Ca²⁺ release from the storage sites. However, when Zn²⁺ was continuously present, Ca²⁺ was not supplied to the storage sites. Furthermore, carbachol and histamine mobilized a common cellular Ca²⁺ store, but they activated Ca²⁺ release channels different from the ones activated by caffeine in the Ca²⁺ storage sites.     

人胎儿子宫肌层的平滑肌细胞超微结构研究

利用电镜研究胎儿子宫肌层的平滑肌细胞在不同胎龄阶段（6个月、7个月、8个月、足月）的超微结构。结果发现随着胎龄的增长，平滑肌细胞显示下列形态变化：（a)胞质的细胞器减少；（b)核表面的凹陷增加和加深；（c)糖元颗粒聚集，细胞表面的半桥粒状致密斑及带有电子致密体的5nm微丝束逐渐增多；（d)到足月妊娠时，其形态与育龄妇女的子宫肌层的平滑肌细胞极为相似，在任何胎龄到足月妊娠时，其形态与育龄妇女的子宫肌层的平滑肌细胞极为相似，在任何胎龄的子宫肌层里均可见到平滑肌细胞间有间质细胞和一些成熟较差的平滑肌细胞。由于样本取自肌层中间部位，及肌层内间质细胞随着胎龄的增长而减少，歌曲以认为平滑肌细胞增多，可能是由于肌层里间质细胞分化的结果，由于在雌激素作用下，核体大量出现及黄体酮促使糖元颗粒聚集成团，本研究结果提示胎儿子宫肌层平滑肌细胞的成熟可能与雌激素主黄体酮的作用有关。     

生命容介态再识——“天、地、人”容介态信息循环初析

基于“自然容介态”、“生命容介态”的理论思路，从信息一物质交互影响的基本观点出发，针对信息宇宙空间一物质宇宙空间一人体内部信息控制体系三者之间的容介态信息循环交流系统，进行了初步分析；系统地揭示了人体内部的智能控制系统、DNA生长遗传控制系统、信息能量控制与存储系统同外在自然界的息息相关的客介态关系。这些原创性的论述有助于破译生命之谜。     

Mechanisms controlling cellular suicide: role of Bcl-2 and caspases

Apoptosis is an essential and highly conserved mode of cell death that is important for normal development, host defense and suppression of oncogenesis. Faulty regulation of apoptosis has been implicated in degenerative conditions, vascular diseases, AIDS and cancer. Among the numerous proteins and genes involved, members of the Bcl-2 family play a central role to inhibit or promote apoptosis. In this article, we present up-to-date information and recent discoveries regarding biochemical functions of Bcl-2 family proteins, positive and negative interactions between these proteins, and their modification and regulation by either proteolytic cleavage or by cytosolic kinases, such as Raf-1 and stress-activated protein kinases. We have critically reviewed the functional role of caspases and the consequences of cleaving key substrates, including lamins, poly(ADP ribose) polymerase and the Rb protein. In addition, we have presented the latest Fas-induced signalling mechanism as a model for receptor-linked caspase regulation. Finally, the structural and functional interactions of Ced-4 and its partial mam malian homologue, apoptosis protease activating factor-1 (Apaf-1), are presented in a model which includes other Apafs. This model culminates in a caspase/Apaf regulatory cascade to activate the executioners of programmed cell death following cytochrome c release from the mitochondria of mammalian cells. The importance of these pathways in the treatment of disease is highly dependent on further characterization of genes and other regulatory molecules in mammals. Received 18 February 1998; accepted February 1998     

臂丛神经根麻醉术的应用解剖

在20具成人干尸标本上解剖，观测了臂丛神经根的毗邻关系、第7颈神经根的深度。结果表明臂丛神经根C     

损伤肌纤维的椭圆偏振法研究

该文利用椭圆偏振技术研究骨骼肌受损伤时肌纤维内部分子运动状态的变化。实验测得，无论是完整的单根肌纤维还是去膜的单根肌纤维，衍射光的退偏率ｒ都呈增大的趋势。这一结果，可以用它造成肌纤维的膜损伤，破坏了兴奋耦联系统，导致肌质网释放钙离子的能力下降，从而使肌动蛋白上结构位点暴露减少，因此与横桥结合的几率小来加以说明。对损伤肌肉的完整单根肌纤维的张力测试结果证明这一假设是合理的。