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941.
Electron Microscopy of Herpes Simplex Virus: I. Entry 总被引:45,自引:31,他引:14
Although capsids of herpes simplex virus were encountered within phagocytic vesicles, they were more commonly observed free within the cytoplasm. Stages in the release of virus from vesicles were not seen. There appeared to be five distinct steps in the process whereby the virus initiates infection: attachment, digestion of the viral envelope, digestion of the cell wall, passage of the capsid directly into the cytoplasm, and digestion of the capsid with release of the core. Antibody probably interferes with the first two stages. 相似文献
942.
Evidence for Anion-Permselective Membrane in Crayfish Muscle Fibers and Its Possible Role in Excitation-Contraction Coupling 总被引:26,自引:11,他引:15
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Lucien Girardier John P. Reuben Philip W. Brandt Harry Grundfest 《The Journal of general physiology》1963,47(1):189-214
Under certain conditions only, isolated crayfish skeletal muscle fibers change in appearance, becoming grainy, darkening, and seemingly losing their striations. These changes result from development of large vesicles on both sides of the Z-line. The longitudinal sarcoplasmic reticulum remains unaffected. The vesicles are due to swelling of a transverse tubular system (TTS) which is presumably homologous with the T-system tubules of other muscle fibers. The vesiculations occur during efflux of water or on reducing external K or Cl, but only when KCl can leave the fiber. They never result from osmotic, ionic, or electrical changes when KCl cannot leave. Inward currents, applied through a KCl-filled intracellular cathode, also cause the vesiculations. These are not produced when the cathode is filled with K-propionate, nor by outward or longitudinal currents. Thus the transverse tubules swell only when Cl leaves the cell. Accordingly, their membrane is largely or exclusively anion-permselective. These findings also indicate that the TTS forms part of a current loop, connecting with the exterior of the fiber probably through radial tubules (RT) possessing membrane of low conductivity. Thus, part of the current flowing inward across the sarcolemma during activity can return to the exterior through the membrane of the TTS. The structure and properties of the latter offer the possibility for an efficient electrical mechanism to initiate excitation-contraction coupling. 相似文献
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Yutaka Nakamura Shigehiro Nakajima Harry Grundfest 《The Journal of general physiology》1965,49(2):321-349
Voltage clamp analyses, combined with pharmacological tools demonstrate the independence of reactive Na and K channels in electrically excitable membrane of eel electroplaques. Spike electrogenesis is due to Na activation and is eliminated by tetrodotoxin or mussel poison, or by substituting choline, K, Cs, or Rb for Na in the medium. The K channels remain reactive, but K activation is always absent, the electroplaques responding only with K inactivation. This is indicated by an increased resistance when the membrane is depolarized by more than about 30 mv. The resting resistance (1 to 5 ohm cm2) is dependent upon the ionic conditions, but when K inactivation occurs the resistance becomes about 10 ohm cm2 in all conditions. K inactivation does not change the EMF significantly. The transition from low to high resistance may give rise to a negative-slope voltage current characteristic, and to regenerative inactivation responses under current clamp. The further demonstration that pharmacological K inactivation (by Cs or Rb) leaves Na activation and spike electrogenesis unaffected emphasizes the independence of the reactive processes and suggests different chemical compositions for the membrane structures through which they operate. 相似文献
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Harry B. Reynolds 《The Western journal of medicine》1914,12(3):102-103
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Harry Grey 《BMJ (Clinical research ed.)》1909,1(2529):1514-1515
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