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71.
Leonard Weiss 《The Journal of cell biology》1965,26(3):735-739
The deformability of the surface membranes of Sarcoma 37 and Ehrlich murine ascites tumor cells was assessed by the pressure required to suck a hemispherical bulge from these cells into a micropipette. It was shown that treatment with neuraminidase allowed the cells to be deformed with significantly less suction, and that enzymatic treatment also produced a significant reduction in surface charge as determined by measurement of cellular electrophoretic mobility. It is suggested that the increase in cellular deformability may be related to charge reduction, and that the charge at the cell periphery may affect not only the magnitude of the potential energy barriers hindering contact between cells, but also the ease with which cells can form low radius of curvature probes in order to help overcome these barriers. 相似文献
72.
Leonard Marmor 《The Western journal of medicine》1960,92(6):407-408
An unlimited supply of bones, obtained post-mortem and irradiated to make them sterile, is stored for as long as six months in a freezer, ready for use. After an immune response at first, bone thus treated is readily incorporated by the host in grafting procedures. 相似文献
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74.
Alpharadiography: A Simple Method for Determination of Mass Concentration in Cells and Tissues
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Leonard F. Blanger 《The Journal of cell biology》1959,6(2):197-202
A simple apparatus for the production of contact microradiographs with the help of a polonium alpha source and nuclear emulsion plates is described. This apparatus best adapted for soft tissue and low grade mineralization studies offers advantages as to resolution, geometry of specimen as well as ease of operation and cost. 相似文献
75.
Leonard L. Ross 《The Journal of cell biology》1959,6(2):253-262
Carotid bodies were removed from cats, fixed in buffered 1 per cent osmic acid, embedded in deaerated, nitrogenated methacrylate, and cut into thin sections for electron microscopic study. The carotid body is seen to be composed of islands of chemoreceptor and sustentacular cells surrounded by wide irregular sinusoids. These cells are separated from the sinusoids by relatively broad interstitial spaces which are filled with collagen, fibroblasts, and many unmyelinated nerve fibers with their Schwann cell sheaths. The chemoreceptor cells are surrounded by the flattened, multiprocessed sustentacular cells which serve to convey the axons from an interstitial to a pericellular location. These sustentacular cells are assumed to be lemmoblastic in origin. Relatively few axons are seen to abut on the chemoreceptor cells. The cytoplasm of the chemoreceptor cell is characterized by numerous small mitochondria, units of granular endoplasmic reticulum, a small Golgi complex, and a variety of vesicles. There are many small vesicles diffusely scattered throughout the cytoplasm. In addition, there is a small number of dark-cored vesicles of the type which has been previously described in the adrenal medulla. These are usually associated with the Golgi complex. These findings are discussed in relation to the concepts of the origin of the chemoreceptor cell and the nature of the synapse. 相似文献
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77.
Attraction of male gametes of Allomyces to sirenin concentrations as low as 10−-10 m has been demonstrated. Increasingly strong responses are observed to concentrations up to 10−-6 m. The response is slightly weaker at 10−-5 m and very weak at 10−-4 m. Microscopic studies suggest that the attraction comes into the category of tropotaxis, a direct approach to a sirenin source occurring. Male gametes have been shown to inactivate sirenin. The possibility that this inactivation is an adaptation process enabling the gametes to maintain sirenin sensitivity over a 100,000-fold concentration range is discussed. 相似文献
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Experience in the anesthetic and surgical management of 25 patients with myasthenia gravis is recorded. These are subdivided into two groups: those operated on during the period 1950-1958 and those operated on during the period 1959-1964. The purpose of this paper is to indicate improvement in mortality and morbidity due to three major advances: (1) use of the decamethonium diagnostic test in a myasthenia gravis clinic; (2) improvements in assessment and management of respiratory insufficiency; and (3) avoidance of anticholinesterase treatment in the immediate and early postoperative recovery period.Fourteen patients with myasthenia gravis, including five with thymoma and two who were refractory to medication, were in the second (1959-1964) group. There were no deaths and no myasthenic or cholinergic crises. Three prophylactic tracheostomies were performed. No emergency bronchoscopies or tracheostomies were required. 相似文献