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Immunization with baculovirus-expressed VP4 protein passively protects against simian and murine rotavirus challenge. 总被引:16,自引:11,他引:5
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A baculovirus-expressed VP4 protein derived from the simian rhesus rotavirus (RRV) was used to parenterally immunize murine dams. VP4-immunized dams developed high levels of neutralizing antibodies against RRV and low levels of cross-reactive neutralizing antibodies against human strains Wa, ST3, and S2 and animal strains SA-11, NCDV, and Eb. Newborn mice suckled on VP4-immunized dams were protected against a virulent challenge dose of the simian strain RRV and against murine rotavirus Eb. The cross-reactive nature of the serum-neutralizing response generated by VP4 immunization and the protective efficacy of the immunization suggest that recombinant-expressed VP4 proteins should be considered as viable vaccine candidates. 相似文献
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Induction of cytotoxicity by biological response modifiers (BRMs) is only one aspect of macrophage activation. After the use of BRMs there were other changes in the functional activity of cells and in particular their increased production or secretion of a number of growth factors. Thus, activation of macrophage antitumor activity induced by BCG vaccine was transitory while activation of growth factor production was more stable in time which finally led to increased proliferation of tumor cells. Combined use of cyclophosphamide and BCG vaccine significantly increased not only the toxicity induced by BCG vaccine but also their liberation of the growth factors. Such macrophages lost their ability to control the growth of a small number of the tumor cells cultivated in their presence. Development of ways for directed activation of macrophages aimed at elimination of the tumor cells which survived the chemotherapy should include evaluation of the combined effect of various BRMs and chemotherapeutics on both antitumor and protumor activity i. e. ability to produce the factors stimulating the tumor growth. 相似文献
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A methodology is proposed for assessing the ecological value of streams in the catchment of the Moravská Dyje River. It is concluded that by using a wide range of parameters that a more objective assessment is achieved than if only one were used. The landscape of the catchment studied contains excessive amounts of nutrients and, in comparison to its natural state, has become too uniform. 相似文献
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The coenzyme-independent dihydroorotate dehydrogenase (EC 1.3.3.1) linking the pyrimidine biosynthetic pathway to the respiratory
chain, was ultracytochemically localized by the tetrazolium method in derepressed exponential-phase cultures ofSaccharomyces cerevisiae. Biochemical analysis showed a considerable variation of this enzyme activity in inverse proportion to the aeration of the
yeast cultures. The assay also showed that after prefixation of yeast cells with 1% glutaraldehyde at 0°C for 20 min, approximately
one-half of the enzyme activity was preserved. The cytochemical reaction mixture contained dihydroorotate (2 mmol/L), thiocarbamyl
nitroblue tetrazolium (0.44 mmol/L), phenazine methosulfate (0.16 mmol/L) and KCN (1.7 mmol/L) in Tris-HCl buffer (100 mmol/L)
of pH 8.0. The osmicated formazan deposits featured envelopes of mitochondria and of nuclei and were prominent in the mitochondrial
inclusions and in the vacuolar membranes. The latter sites of dihydroorotate dehydrogenase activity represent biosynthetic
activity in yeast vacuoles, still generally assumed to function as yeast lysosomes and storage organelles. In the light of
the generally observed invasions of juvenile yeast vacuoles into mitochondria, the enzymic sites observed in mitochondrial
inclusion were considered as evidence of the interactions of yeast vacuoles and mitochondria. Transfer of vacuolar membranes
with dihydroorotate dehydrogenase activity into mitochondrial matrix is suggested. 相似文献
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David Storch Jaroslav Koleček Petr Keil Zdeněk Vermouzek Petr Voříšek Jiří Reif 《Diversity & distributions》2023,29(4):572-585