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排序方式: 共有321条查询结果,搜索用时 31 毫秒
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Rapid determination of Trypanosoma cruzi urinary antigens in human chronic Chagas disease by agglutination test 总被引:2,自引:0,他引:2
Detection of Trypanosoma cruzi in man becomes particularly difficult during the chronic stage of Chagas disease because of the low parasitemia. We were able to develop a simple and straightforward method for determining the concentration of T. cruzi antigens in urine using nitrocellulose micellar suspension (Nitrocell-Mr, Polychaco Argentina) and for their subsequent detection through a "latex" type agglutination test. The latex used was an esferocell nitrocellulose suspension (Esferocell-Mr, Polychaco). Specific antigens for T. cruzi were detected in 54 of 58 urine samples from chronic chagasic patients. The antigens characterized by affinity chromatography and SDS-PAGE were glycoproteins with apparent molecular weights (and pIs) of 100 kDa (pI 5 to 5.5), 80 kDa (pI 6.0), and 50 kDa (pI 6.5 to 7.0). This method is practical and fulfills the requirement of large-scale epidemiological studies. It is also helpful in cases of conflictive serology. 相似文献
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Trypanosoma cruzi: experimental immunization of mice 总被引:2,自引:0,他引:2
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Marcelo J. Yanovsky Jorge J. Casal Juan P. Luppi 《The Plant journal : for cell and molecular biology》1997,12(3):659-667
Phytochromes play a key role in the perception of light signals by plants. In this study, the three classical phytochrome action modes, i.e. very-low-fluence responses (VLFR), low-fluence responses (LFR) and high-irradiance responses (HIR), were genetically dissected using phyA and phyB mutants of Arabidopsis thaliana (respectively lacking phytochrome A or phytochrome B) and a polymorphism between ecotypes Landsberg erecta and Columbia. Seed germination and potentiation of greening, hypocotyl growth inhibition and cotyledon unfolding in etiolated seedlings of the ecotype Landsberg erecta showed biphasic responses to the calculated proportion of active phytochrome established by one light pulse or repeated light pulses. The first phase, i.e. the VLFR, was absent in the phyA mutant, normal in the phyB mutant (both in the Landsberg erecta background) and severely deficient in Columbia. The second phase, i.e. the LFR, was present in the phyA mutant, deficient in the phyB mutant and normal in Columbia. Under continuous far-red light, HIR of etiolated seedlings were absent in phyA and normal in phyB and Columbia. The segregation of VLFR in recombinant inbred lines derived from a cross between Landsberg erecta and Columbia was analysed by MAPMAKER/QTL. Two quantitative trait loci, one on chromosome 2 ( VLF1 ) and another on chromosome 5 ( VLF2 ), were identified as responsible for the polymorphism. Phytochrome A is proposed to initiate two transduction pathways, VLFR and HIR, involving different cells and/or different molecular steps. This is the first application of the analysis of quantitative trait loci polymorphic between ecotypes to dissect transduction chains of environmental signals. 相似文献
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Demin Konstantin A. Refeld Aleksandr G. Bogdanova Anna A. Prazdnova Evgenya V. Popov Igor V. Kutsevalova Olga Yu. Ermakov Alexey M. Bren Anzhelica B. Rudoy Dmitry V. Chistyakov Vladimir A. Weeks Richard Chikindas Michael L. 《Probiotics and antimicrobial proteins》2021,13(4):926-948
Probiotics and Antimicrobial Proteins - Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is... 相似文献
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Pak Valeriy V. Kwon Dae Yong Khojimatov Olim K. Pak Aleksandr V. Sagdullaev Shomansur Sh. 《International journal of peptide research and therapeutics》2021,27(3):1923-1931
International Journal of Peptide Research and Therapeutics - This study presents a simple approach in design of tripeptides as a competitive inhibitor for 3-hydroxy-3-methylglutaryl CoA reductase... 相似文献
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Elena Iurova Evgenii Beloborodov Elizaveta Tazintseva Aleksandr Fomin Alexander Shutov Sergei Slesarev Yana Saenko Yury Saenko 《Journal of peptide science》2021,27(1)
Peptide toxins of arthropods are one of the potential sources of bioactive substances. Toxins are able to bind to calcium channels and block them. Ca2+ ions play an important role in many cell processes, in particular, in apoptosis. In this work, we study the effect of some arthropod toxins on intracellular processes associated with the induction of apoptosis. Synthetic analogs of U5‐scytotoxin‐Sth1a, ω‐hexatoxin‐Hv1a, ω‐theraphotoxin‐Hhn2a, and μ‐agatoxin‐Aa1a toxins—inhibitors of calcium L, P, and Q channels and sodium channels were used in the study. Apoptosis was induced by AC‐1001 H3 peptide. We study the effect of toxins on the level of apoptosis, ROS, mitochondrial potential, GSH, and ATP in CHO‐K1 cells. We show that all the tested toxins are able to dose dependently block the induction of apoptosis triggered by AC‐1001 H3 and reduce the level of natural apoptosis in CHO‐K1 cells. Cell incubation with apoptosis inducer AC‐1001 H3 in the presence and absence of toxins causes an increase in the intracellular concentrations of ROS, ATP, and mitochondrial potential and decreases the GSH concentration. The present study reveals the antiapoptotic effect of a number of arthropod peptide toxins. The toxins studied can represent a novel approach used in the treatment of pathologies associated with the activation of apoptotic mechanisms. 相似文献
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Aleksandr A Rubel Tatyana A Ryzhova Kirill S Antonets Yury O Chernoff Alexey P Galkin 《朊病毒》2013,7(6):469-476
Alzheimer disease is associated with the accumulation of oligomeric amyloid β peptide (Aβ), accompanied by synaptic dysfunction and neuronal death. Polymeric form of prion protein (PrP), PrPSc, is implicated in transmissible spongiform encephalopathies (TSEs). Recently, it was shown that the monomeric cellular form of PrP (PrPC), located on the neuron surface, binds Aβ oligomers (and possibly other β-rich conformers) via the PrP23–27 and PrP90–110 segments, acting as Aβ receptor. On the other hand, PrPSc polymers efficiently bind to Aβ monomers and accelerate their oligomerization. To identify specific PrP sequences that are essential for the interaction between PrP polymers and Aβ peptide, we have co-expressed Aβ and PrP (or its shortened derivatives), fused to different fluorophores, in the yeast cell. Our data show that the 90–110 and 28–89 regions of PrP control the binding of proteinase-resistant PrP polymers to the Aβ peptide, whereas the 23–27 segment of PrP is dispensable for this interaction. This indicates that the set of PrP fragments involved in the interaction with Aβ depends on PrP conformational state. 相似文献