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<p><b>OBJECTIVE</b>To establish a modified method for microculturing whole human blood for cytogenetic analysis.</p><p><b>METHODS</b>A novel tube rack was designed to overcome the drawbacks of directly culturing the cells within centrifuge tubes. The fractions of human plasma, human serum and two commercial fetal bovine sera were analyzed with 15% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The influence of adding 0%, 5%, 10%, 15%, 20%, 25% and 30% autologous plasma to the culture on lymphocyte transformation rate and mitotic index (MI) was examined.</p><p><b>RESULTS</b>The SDS-PAGE analysis showed a significant difference between commercial fetal bovine sera, and that the components of human plasma were similar to those of fetal bovine serum. The value of MI in lymphocyte was evidently increased along with addition of autologous plasma. However, this has exerted no significant effect on the transformation rate. With the addition of 10% autologous plasma, the MI value has become much higher than the conventional method.</p><p><b>CONCLUSION</b>A modified method was established by application of a novel tube inclined rack and optimization of whole blood inoculation. This method is easier and cheaper, and is suitable for application in clinical practice.</p>
Subject(s)
Adolescent , Adult , Female , Humans , Male , Cell Culture Techniques , Methods , Cytogenetics , Lymphocytes , Mitotic IndexABSTRACT
Objective To construct a recombinant Escherichia coli ( E. coli) with surface-dis-played lead specific binding protein PbrR and to further study intestinal colonization by the recombinant bac-teria in mice and gastrointestinal tolerance of the bacterial surface-displayed PbrR. Methods Chimeric pro-tein Lpp-OmpA coding sequence was chemically synthesized and inserted into the expression vector pET-21a to construct the outer membrane display vector pLOA. PbrR coding sequence was also obtained by chemical-ly synthesis and inserted into pLOA to generate the outer membrane display plasmid pLOA-pbrr. E. coli BL21 (DE3)pLysS was transformed with pLOA-pbrr and induced by IPTG. The expressed recombinant proteins were analyzed by 15% SDS-PAGE and Western blot assay. Lead adsorption capacity of the cell surface-dis-played PbrR in the simulated intestinal juice and tolerance of the recombinant E. coli to simulated gastric juice were analyzed, respectively. KM mice were orally given the induced recombinant bacteria by gastric lavage for 7 consecutive days and then were continually fed until day 30. The contents of recombinant bacte-ria in stool samples were detected by dilution plate method on day 7, 15 and 30. The recombinant protein with His tag was detected by immunoblotting on day 7 and 15. Results Based on Lpp-OmpA, the PbrR outer membrane display vector was successfully constructed. The recombinant fusion protein Lpp-OmpA-PbrR-His tag was highly expressed in E. coli. The recombinant E. coli strains displaying PbrR on their outer membrane accumulated a significant level of Pb2+ in simulated intestinal juice. Moreover, those strains showed a tolerance to gastric acid in vitro and could colonize in the intestinal tracts of mice via oral infection. The surface-displayed recombinant fusion protein showed a better tolerance to the environment of digestive tract. Conclusion The recombinant E. coli strain displaying PbrR on its surface showed a stronger capabili-ty of lead accumulation from simulated intestinal environment and could colonize in the intestinal tracts of mice. The surface-displayed recombinant PbrR also showed a good tolerance to digestive juice. This study paved the way for further researches on the selective elimination of lead by biosorption based on animal mod-els.
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Objective To investigate the clinical application of ALT detection based on microtiter plate kinetic method in the au‐tomatic enzyme immunoassay system .Methods By beference to the IFCC recommended kinetic method ,microtiter plate kinetic method was established in the automatic enzyme immunoassay system of ALT detection .The linear ,intro‐batch and inter‐batch du‐plicability of the method were evaluated .ALT test results of 823 samples with microtiter plate kinetic method and automatic bio‐chemistry analyzer method were compared .Results Microtiter plate kinetic method had good linearity where ALT activity <303 U/L ,the intra batch and inter batch variation coefficients < 1/5TEa .The detection results of the clinical samples were correlated with the biochemical analyzer .Conclusion Microtiter plate kinetic method to detection ALT in the automatic enzyme immunoassay system is an ideal method for simultaneous detection of ALT and ELISA in large batch samples ,which is worth popularizing .
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<p><b>OBJECTIVE</b>To investigate the cytotoxicity of indium chloride (InCl₃) and its effects on micro-nucleus formation in primary human lymphocytes cultured in vitro.</p><p><b>METHODS</b>The CCK-8 assay was used to evaluate the cytotoxicity of 24 h exposure to different concentrations of InCl₃(4, 40, 80, 200, 500, and 1 000 µmol/L) in lymphocytes cultured in vitro. The cytokinesis-block method was used to determine the micronucleus level in lymphocytes exposed to different concentrations of InCl₃and the effects of anti-oxidant vitamin C on micronucleus frequency.</p><p><b>RESULTS</b>Lymphocytes exposed to InCl₃of no less than 500 µmol/L had significantly lower survival rates than those in the control group (P < 0.05). Lymphocytes exposed to 80 µmol/L InCl₃had a significantly higher micronucleus frequency than those in the control group (P < 0.05). However, there was no further increase in micronucleus frequency of lymphocytes exposed to 200 µmol/L InCl₃. Lymphocytes cultured in whole blood and exposed to 500 or 1000 µmol/L InCl₃had a significantly increased micronucleus frequency than those in the control group (P < 0.001). The increase in micronucleus frequency of lymphocytes induced by indium could be partially antagonized by 20 or 100 µmol/L vitamin C.</p><p><b>CONCLUSION</b>InCl₃can induce an increase in micronucleus frequency of primary human lymphocytes cultured in vitro, which might be associated with DNA damage induced by oxidative stress.</p>
Subject(s)
Humans , Cell Nucleus , Metabolism , Cytokinesis , DNA Damage , In Vitro Techniques , Indium , Toxicity , Lymphocytes , Oxidative StressABSTRACT
<p><b>OBJECTIVE</b>To study the effects of indium exposure on the relative content of mitochondrial ND1 gene in lymphocytes.</p><p><b>METHODS</b>Venous blood was obtained from 14 healthy workers and anticoagulated with heparin. Blood lymphocytes were separated and divided into three tube cultures. For two tubes in the exposed group, indium chloride was added to final concentrations of 0.2 mmol/L and 0.8 mmol/L, respectively. For one tube in the control group, an equal volume of normal saline solution was added. After incubation for 72 h, the relative content of mitochondrial gene in each group was determined using quantitative real-time PCR.</p><p><b>RESULTS</b>Lymphocytes exposed to 0.8 mmol/L indium chloride had a significantly higher relative content of mitochondrial gene than those exposed to 0.2 mmol/L indium chloride and those in the control group (P < 0.05, P < 0.05).</p><p><b>CONCLUSION</b>Lymphocytes exposed to a high concentration of indium and its compounds have an elevated relative content of mitochondrial ND1 gene, indicating increased oxidative DNA damage induced by exposure to a high concentration of indium and its compounds.</p>
Subject(s)
Humans , DNA Damage , DNA, Mitochondrial , Genetics , Indium , Toxicity , Lymphocytes , NADH Dehydrogenase , Genetics , Occupational ExposureABSTRACT
Objective To study the effect of DNA damage induced by H2 O2 on the micronucleus frequency in lymphocytes. Methods Resting lymphocytes were treated with different levels of H2 O2 (10,50,100,1 000 μmol/L).1 000 μmol/L H2 O2 was added into mitogen-stimulated lymphocyte cultures at different time intervals.Then micronucleus rate was examined by the conven-tional culture method.Results There was no significant change of the micronucleus frequency in the experimental groups.Conclu-sion H2 O2 could induce lymphocyte DNA damage rapidly,but exerts no effect on the formation of micronuclei,which may be relat-ed to the type of DNA damage and rapid DNA repair.
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Hepatitis C virus (HCV) genome is of high variation,which results in persistent infection of HCV and increases the incidence of liver cirrhosis and hepatocellular carcinoma.Following the successful paradigm established for HIV protease inhibitors,HCV NS3-4A serine protease has been selected as the main target for the development of small molecule antiviral agents.In this article,we review recent progress in the discovery and development of HCV NS3-4A protease inhibitors,and discuss their antiviral activities,pharmacokinetic properties,side effects and resistance profiles.
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Objective To investigate the virulence role of ompT of Escherichia coli in the patho-genesis of neonatal meningitis .Methods Adhesive abilities of the parent strain E 44 and the isogenic ompT-deletion mutant strain ( E44 ∶ΔompT) to human brain microvascular endothelial cells were evaluated in in vitro model.Low-copy-number plasmid pST containing ompT locus and point mutant plasmid pST 85 were transferred into E44 ∶ΔompT to construct the complemented mutant strain , and its adhesive ability was ana-lyzed.Influences of ompT deletion on E44 strain in its ability of bacterial intestinal colonization and ability of penetrating the blood-brain barrier were determined . Results In comparison with the parent strain , E44 ∶ΔompT strain showed significantly impaired adhesive ability to human brain microvascular endothelial cells, which could be partly restored by inserting the complementary plasmids of pST and pST 85.Deletion of the ompT did not affect Escherichia coli K1 in normal intestinal colonization in in vivo model.E44 ∶ΔompT strain could induce bacteremia , which was similar to that induced by the parent strain , but its ability of crossing the blood-brain barrier was significantly declined .Conclusion The study demonstrate that ompT plays an important role as the virulence element of Escherichia coli in binding to brain microvascular endothe-lial cells and penetrating the blood-brain barrier .Further study should be performed to investigate the influ-ences of OmpT proteinase on the virulence of Escherichia coil.