AIM: To investigate the behaviour of total plasma homocysteine (tHcy) and its most common genetic determinant defect, the methylenetetrahydrofolate reductase C677T (C677TMTHFR) polymorphism in patients with early stag...AIM: To investigate the behaviour of total plasma homocysteine (tHcy) and its most common genetic determinant defect, the methylenetetrahydrofolate reductase C677T (C677TMTHFR) polymorphism in patients with early stage colorectal carcinoma. METHODS: tHcy was quantified by Abbott IMx immunoassay; screening for C677TMTHFR substitution was performed by PCR and restriction analysis. RESULTS: The frequency of the C/T and T/T genotypes of the C677TMTHFR gene polymorphism did not differ between the groups. The mean tHcy was statistically higher in cancer patients than in control subjects carrying the same C/C or C/T genotype, whereas there was no difference in the T/T homozygous carriers of the two groups. tHcy was significantly higher in the T/T homozygous carriers than in C/C and C/T genotype carriers. CONCLUSION: The statistically significant increase of tHcy observed in C/C and C/T genotype carriers among our cancer patients is related to substrate consumption dependent on the tumor cell proliferation rate, whereas the tHcy increase observed in T/T genotype carriers of both groups probably depends on the enzymatic deficit of the homocysteine conversion to methionine and/or on the folate deficiency.展开更多
Dengue virus(DENV) nonstructural protein 1(NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites(Asn-130 and Asn-207) and 12 conserved cysteine(Cys) residues. Here, we performed site-directed m...Dengue virus(DENV) nonstructural protein 1(NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites(Asn-130 and Asn-207) and 12 conserved cysteine(Cys) residues. Here, we performed site-directed mutagenesis to generate systematic mutants of viral strain TSV01. The results of the subsequent analysis showed that an alanine substitution at the second N-linked glycan Asn-207 in NS1 delayed viral RNA synthesis, reduced virus plaque size, and weakened the cytopathic effect. Three mutants at Cys sites(Cys-4, Cys-55, Cys-291) and a C-terminal deletion(ΔC) mutant significantly impaired RNA synthesis, and consequently abolished viral growth, whereas alanine mutations at Asn-130 and Glu-173 resulted in phenotypes that were similar to the wild-type(WT) virus. Further analysis showed that the Asn-207 mutation slightly delayed viral replication. These results suggest that the three conserved disulfide bonds and the second N-linked glycan in NS1 are required for DENV-2 replication.展开更多
Cysteine residues found in proteins have various functions such as metal binding, nitrosylation, and stabilization of structure. We have done a comparative, computational structural analysis of the cysteine residues i...Cysteine residues found in proteins have various functions such as metal binding, nitrosylation, and stabilization of structure. We have done a comparative, computational structural analysis of the cysteine residues in two proteins from bacteria to get some insight into the differences between metal binding cysteine residues and those involved in structure stabilization. The two target proteins in this study are the periplasmic mercury binding protein （MerP） and the 1-1eucine binding protein （LBP）. Both are periplasmic binding proteins from E. coli. We have shown key phenomenon that define cysteines as metal binding or structural in nature.展开更多
Objective To evaluate the effectiveness of ESWL for treating patients with cystine calculus. Methods Of 31 patients, 20 were subjected to ESWL only, 6 were subjected to combination therapy of PCNL and ESWL, 2 Pneumati...Objective To evaluate the effectiveness of ESWL for treating patients with cystine calculus. Methods Of 31 patients, 20 were subjected to ESWL only, 6 were subjected to combination therapy of PCNL and ESWL, 2 Pneumatic Lithotriptor-ESWL, 3 Laser lithotripsy-ESWL. Results For 14 renal stones, the fragmentation after ESWL manotherapy was 85. 7% and 14.3% after twice ESWL sessions. For 17 ureter calculus, the fragmentation after ESWL manotherapy was 82.3% and 11.7% after twice ESWL sessions. One patient （ 5.8% ） failed and changed to open surgery. Conclusion ESWL is an effective and reliable method for treating patients with cystine calculus, however, better effects and shorter treatment time could be obtained by the combination of ESWL with other therapy options.展开更多
基金Supported by a research grant from the University of Siena (PAR)
文摘AIM: To investigate the behaviour of total plasma homocysteine (tHcy) and its most common genetic determinant defect, the methylenetetrahydrofolate reductase C677T (C677TMTHFR) polymorphism in patients with early stage colorectal carcinoma. METHODS: tHcy was quantified by Abbott IMx immunoassay; screening for C677TMTHFR substitution was performed by PCR and restriction analysis. RESULTS: The frequency of the C/T and T/T genotypes of the C677TMTHFR gene polymorphism did not differ between the groups. The mean tHcy was statistically higher in cancer patients than in control subjects carrying the same C/C or C/T genotype, whereas there was no difference in the T/T homozygous carriers of the two groups. tHcy was significantly higher in the T/T homozygous carriers than in C/C and C/T genotype carriers. CONCLUSION: The statistically significant increase of tHcy observed in C/C and C/T genotype carriers among our cancer patients is related to substrate consumption dependent on the tumor cell proliferation rate, whereas the tHcy increase observed in T/T genotype carriers of both groups probably depends on the enzymatic deficit of the homocysteine conversion to methionine and/or on the folate deficiency.
基金supported by Important National Science & Technology Specific Projects (2012ZX10004219, 2012ZX10004403)the National Natural Scientific Fund of China (81072675)the Wuhan Key Laboratory on Emerging Infectious Diseases and Biosafety
文摘Dengue virus(DENV) nonstructural protein 1(NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites(Asn-130 and Asn-207) and 12 conserved cysteine(Cys) residues. Here, we performed site-directed mutagenesis to generate systematic mutants of viral strain TSV01. The results of the subsequent analysis showed that an alanine substitution at the second N-linked glycan Asn-207 in NS1 delayed viral RNA synthesis, reduced virus plaque size, and weakened the cytopathic effect. Three mutants at Cys sites(Cys-4, Cys-55, Cys-291) and a C-terminal deletion(ΔC) mutant significantly impaired RNA synthesis, and consequently abolished viral growth, whereas alanine mutations at Asn-130 and Glu-173 resulted in phenotypes that were similar to the wild-type(WT) virus. Further analysis showed that the Asn-207 mutation slightly delayed viral replication. These results suggest that the three conserved disulfide bonds and the second N-linked glycan in NS1 are required for DENV-2 replication.
文摘Cysteine residues found in proteins have various functions such as metal binding, nitrosylation, and stabilization of structure. We have done a comparative, computational structural analysis of the cysteine residues in two proteins from bacteria to get some insight into the differences between metal binding cysteine residues and those involved in structure stabilization. The two target proteins in this study are the periplasmic mercury binding protein （MerP） and the 1-1eucine binding protein （LBP）. Both are periplasmic binding proteins from E. coli. We have shown key phenomenon that define cysteines as metal binding or structural in nature.
文摘Objective To evaluate the effectiveness of ESWL for treating patients with cystine calculus. Methods Of 31 patients, 20 were subjected to ESWL only, 6 were subjected to combination therapy of PCNL and ESWL, 2 Pneumatic Lithotriptor-ESWL, 3 Laser lithotripsy-ESWL. Results For 14 renal stones, the fragmentation after ESWL manotherapy was 85. 7% and 14.3% after twice ESWL sessions. For 17 ureter calculus, the fragmentation after ESWL manotherapy was 82.3% and 11.7% after twice ESWL sessions. One patient （ 5.8% ） failed and changed to open surgery. Conclusion ESWL is an effective and reliable method for treating patients with cystine calculus, however, better effects and shorter treatment time could be obtained by the combination of ESWL with other therapy options.
基金supported by the the National Natural Science Foundation of China(No.31221091)the State Key Laboratory of Integrated Management of Pest Insects and Rodents,China(No.Chinese IPM1307,Chinese IPM405 and Chinese IPM1512)
