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991.
992.
Glycogen of enteric bacteria   总被引:7,自引:7,他引:0       下载免费PDF全文
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993.
Five new species of Passiflora subgenera Plectostemma and Tacsonia from Ecuador are described, viz. P. discophora, P. monadelpha, P. subpurpurea, P. hirtiflora and P. sanctaebarbarae . Section Discophora of subg. Plectostemma is proposed.  相似文献   
994.
ELISA is used for detecting the soluble staphylococcal antigen in patients with purulent septic infections. The optimum conditions for the assay have been established: the dose of staphylococcal gamma globulin for plate sensitization should be 5.0-10.0 micrograms/ml, the pH of the buffer solution 9.6-10.0, the time and temperature of incubation 18-20 hours at 4 degrees C or 5 hours at 37 degrees C. The possibility of using plates manufactured in the USSR has been shown. The sensitivity of the above diagnostic test system is 0.005 microgram/ml.  相似文献   
995.
Somatic embryogenesis and plantlet formation were obtained from 60–75 day old cell cultures of carnation. Callus was generated on MS basal medium supplemented with 2,4-dichchlorophenoxy acetic acid (2,4-D). Removal of 2,4-D during subsequent subculturing of cell suspensions resulted in formation of embroids. These somatic embryos originated from single cells and their early development proceeded normally with clearly defined apical and root meristems. Some embryos developed into plants and were acclimatized to ex vitro conditions.  相似文献   
996.
Antibody responses in mice immunized by a single gene gun inoculation of plasmid expressing the influenza virus H1 hemagglutinin and in mice immunized by a sublethal H1 influenza virus infection have been compared. Both immunizations raised long-lived serum responses that were associated with the localization of antibody-secreting cells (ASC) to the bone marrow. However, the kinetics of these responses were 4 to 8 weeks slower in the DNA-immunized than in the infection-primed mice. Following a gene gun booster, the presence of ASC in the inguinal lymph nodes, but not in other lymph nodes, revealed gene gun responses being initiated in the nodes that drain the skin target site. Both pre- and postchallenge, the DNA-immunized mice had 5- to 10-times-lower levels of antibody and ASC than the infection-primed mice.  相似文献   
997.
998.
Synthesis and properties of nucleotides containing 4-thio-D-ribofuranose   总被引:1,自引:0,他引:1  
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999.
We have studied the immunomodulatory properties of epithelial cells from the small intestine on T cell immune function in vitro. Proliferation of lymph node cells stimulated either with antigen or with mitogen was inhibited by epithelial cells in a dose-dependent fashion. The epithelial cell-mediated suppression of lymphocyte proliferation was blocked by indomethacin, a cyclooxygenase pathway inhibitor, demonstrating that the suppressive effect of epithelial cells was related to prostaglandin secretion. Furthermore, the action of epithelial cell-secreted prostaglandin on lymphocytes was related to its effect on IL-2 as the suppressive effect of epithelial cells was abrogated by the addition of exogenous IL-2. As previously reported, epithelial cells constitutively express MHC class II and we found them able to present antigen in a class II-restricted fashion when their suppressive effects were blocked by indomethacin. Furthermore, epithelial cells activated by LPS secrete an IL-1 like molecule in a fashion analogous to other antigen-presenting cells. These results demonstrate that epithelial cells can both enhance and suppress in vitro T cell immune responses and further characterize the mechanisms by which intestinal epithelial cells may function in gut-associated immune responses.  相似文献   
1000.
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