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461.
Preplating human adherent peripheral blood mononuclear cells (PBMC) for up to 24 hr results in a progressive decrease in their basal PGE release, and in the loss of their ability to increase PGE release during a subsequent 72-hr coculture period with allogeneic human thyroid cells. Phytohemagglutinin (PHA) present during a 24-hr adherent-cell preplating period prevents, in part, the loss of this PGE response to thyroid cells. These data indicate that adherent cells require continual stimulation by the thyroid cells or by PHA in order to maintain their ability to increase PGE secretion in response to thyroid cells. 相似文献
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Konstantina-Anna Caridis Paul Christakopoulos Basil J. Macris 《Applied microbiology and biotechnology》1991,34(6):794-797
Summary A number of factors affecting simultaneous production of cell-bound glucose oxidase and catalase by the fungus Alternaria alternata have been investigated. Consecutive optimization of the type and concentration of nitrogen and carbon source, the initial pH and growth temperature resulted in a simultaneous increase in glucose oxidase and catalase by 780% and 68% respectively. Two second-order equations, describing the combined effect of pH and temperature on the activity of each enzyme, revealed that glucose oxidase had its optima at pH 7.9 and 32.3°C and catalase at pH 8.5 and 18.1°C. Under certain growth conditions, yields as high as 23.5 and 18,100 units/g carbon source for glucose oxidase and catalase, respectively, were simultaneously obtained.Offprint requests to: B. J. Macris 相似文献
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Guy Beauregard Michel Potier Basil D. Roufogalis 《Biochemical and biophysical research communications》1980,96(3):1290-1295
The functional molecular weights of two kinetically distinct forms of bovine erythrocyte acetylcholinesterase were determined by irradiation inactivation. Whereas both forms have similar molecular weights by hydrodynamic measurements and contain 33 molecules of cardiolipin, the functional molecular weight of form α (140,000) was found to be twice that of form β (73,000). As form β is derived from form α by treatment with high salt concentration in alkaline Ca2+-chelating conditions, a procedure which is considered to disrupt the functional association of a Ca2+-cardiolipin complex with the enzyme, it is suggested that cardiolipin mediates the energy transfer between enzyme subunits, thereby modulating the kinetic properties of the lipoprotein. 相似文献
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Theresa M. Broglio Basil V. Worgul 《Virchows Archiv. B, Cell pathology including molecular pathology》1982,39(1):49-57
The effect of radiation upon the differentiating meridional row cells of the rat lens epithelium was studied by electron microscopy. X-irradiation of rat lenses was shown to disrupt the nuclear and, in some instances, the cytoplasmic organization of these cells. Indications of damage, 4.5 h post-irradiation, are a disruption in the shape of the nucleus and its membranes. This is typified by a bulging or blebbing of the nucleus. At 12 h the affected nuclei deteriorate with obvious membrane breakdown. The nucleoplasm at this time may appear highly condensed and shrunken. Disruption of the plasma membrane is also evident. Based upon previous findings it is likely that the nuclear changes are independent of the processes involved in normal fiber denucleation. 相似文献
469.
A brass cylindrical container 11.5 cm high and 7.5 cm in diameter was housed in an insulated wooden box. A 2.2 cm diameter hole was drilled in the centre of the removable brass lid on the underside of which a holder was attached for a cryostat tissue carrier. The container was filled with a mixture of acetone and solid CO2 to within 1.5 cm of the lid. The frozen tissue was placed in a drop of water on a tissue carrier which was then lowered into the holder through the hole in the lid. The tissue carrier was rapidly cooled by the acetone-solid CO2 mixture thus freezing the water and attaching the tissue to the carrier. 相似文献
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