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31.
Time course measurements of the action of muscarinic antagonists were performed in the spontaneously beating carp atrium. Several high affinity drugs, which embody the quinuclidine structure were examined. The structural flexibility of these molecules was reflected in the dissociation of the drugs from the muscarinic receptor. The dissociation of rigid drugs was very much prolonged as compared to flexible drugs of the same affinity. 相似文献
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Cloning of the mycobacterial epitope recognized by T lymphocytes in adjuvant arthritis 总被引:112,自引:0,他引:112
W van Eden J E Thole R van der Zee A Noordzij J D van Embden E J Hensen I R Cohen 《Nature》1988,331(6152):171-173
Adjuvant arthritis (AA) is a chronic disease inducible in rats by immunization with an antigen of Mycobacterium tuberculosis. After the isolation of arthritogenic T-cell lines and clones, it became possible to demonstrate that the critical M. tuberculosis antigen contained an epitope cross-reactive with a self-antigen in joint cartilage. Like AA rats, patients suffering from rheumatoid arthritis demonstrated specific T-lymphocyte reactivity to the M. tuberculosis fraction containing the cross-reactive epitope. To characterize the critical M. tuberculosis epitope we used AA T-cell clones to screen mycobacterial antigens expressed in Escherichia coli and genetically engineered truncated proteins and synthetic peptides. The AA T-cell clones recognized an epitope formed by the amino acids at positions 180-188 in the sequence of a Mycobacterium bovis BCG antigen. Administration of this antigen to rats induced resistance to subsequent attempts to produce AA. 相似文献
34.
Endogenous mammary tumour virus DNA varies among wild mice and segregates during inbreeding. 总被引:44,自引:0,他引:44
Proviruses of the mouse mammary tumour virus (MMTV) endogenous to normal mice can be identified by molecular hybridisation and distinguished using restriction endonucleases. Feral mice display marked heterogeneity with respect to the number of copies and the sites of insertion of endogenous MMTV-specific DNA, with occasional mice apparently free of MMTV DNA. Several different MMTV proviruses present in laboratory mice have segregated like stable, independent genetic elements during the inbreeding which followed a cross between Bagg albino and DBA mice 60 years ago. The results favour the hypothesis that endogenous proviruses have been established by multiple, independent infections of germ cells rather than by somatic mutation of ancestral proviruses or of cellular genes. 相似文献
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36.
Structure of antibody molecules 总被引:5,自引:0,他引:5
37.
38.
M. M. Cohen Ch. C. Huang H. F. Clark 《Cellular and molecular life sciences : CMLS》1967,23(9):769-771
Zusammenfassung Die somatischen Chromosomen der 3 EidechsenartenGekko gecko (2N=38),Iguana iguana (2N=34) undCrotophytus collaris (2N=36), werden dargestellt.G. gecko besitzt metazentrische, subteleozentrische und teleozentrische Elemente, aber keine Mikrochromosomen.I. iguana undC. collaris besitzen Makrochromosomen (6 Paare) und Mikrochromosomen. Bei den ArtenG. gecko undI. iguana waren in keinen von beiden Geschlechtern heteromorphische Chromosomenpaare nach zuweisen.
Supported by Project No. 417 from the U.S. Children's Bureau and Grant No. 08737 from the National Cancer Institute. 相似文献
Supported by Project No. 417 from the U.S. Children's Bureau and Grant No. 08737 from the National Cancer Institute. 相似文献
39.
Experimental autoimmune encephalomyelitis (EAE) induced by immunization to the basic protein of central nervous system myelin (BP) is a paralytic disease in which T lymphocytes attack the individual's own central nervous system. As the target is in white matter, EAE has been considered an experimental model of some aspects of human disease such as multiple sclerosis. To investigate whether autoimmune T lymphocytes could produce paralysis, we studied the effects on the electrophysiology of isolated nerves produced by T-lymphocyte lines reactive specifically to BP or other antigens. We now report that propagation of action potentials evoked by electrical stimulation was blocked by incubating optic nerves with specific anti-BP T cells. This blockade could be reversed for up to two hours by removing the anti-BP line cells from the optic nerve. The anti-BP line cells had no effect on conduction along allogeneic optic nerves or syngeneic peripheral nerves. This indicates that disruption of the function of myelin in neuroimmunological disease may result from an immunologically specific interaction between autoimmune T lymphocytes and myelin antigens. 相似文献
40.
We have partially characterized the specificity of serum lectins from the scorpion Vaejovis spinigerus Wood. Agglutination, crossed-absorption and hemagglutination-inhibition patterns were similar but not identical to serum lectins from other members from the family Vaejovidae , and different from the Buthidae species studied so far. V. spinigerus serum lectins bind sialic acids and sialoconjugates , but also bind 2-keto-3-deoxyoctonate, uronic acids and N- acylaminosugars , all substances present in bacterial cell walls suggesting that they might be involved in defense functions. 相似文献