Development of a high-throughput suspension microarray technology for detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-beta-estradiol / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish a novel suspension microarray technology for the detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-beta-estradiol (CAP, CL and E2).</p><p><b>METHODS</b>The three conjugates that veterinary drug coupled with bovine serum albumin (BSA) were synthesized and identified by ultraviolet (UV) spectrophotometry and mass spectrum. The veterinary drug conjugates were immobilized on the polystyrene fluorescent microspheres/beads. There were competitive reactions between the veterinary drugs in the aqueous phase and that on the beads for combination with their specific biotinylated monoclonal antibodies. The optimum amount of the veterinary drug conjugates and the antibodies were optimized and selected. The detective standard curves were plotted. The specificity and the unknown samples were also determined by grouping according to different concentrations of the interferes and the samples. Meantime, the different microstructures of the surfaces of the beads were also observed by scanning electron microscope.</p><p><b>RESULTS</b>Couplings were completed between small molecular veterinary drugs and BSA. The amounts of the three conjugates and the antibodies were optimized. The detective standard curves of the suspension array and their corresponding coefficients of determination (R2) were good (R2 > 0.99). The detection ranges of the three veterinary drugs were (40.00 - 6.25) x 10(5) ng/L, (50.00-7.81) x 10(5) ng/L and 1.00 x 10(3) - 7.29 x 10(5) ng/L respectively. Simultaneously, the specific detection of the suspension microarray was excellent and did not indicate significant cross-reactions. Errors between the found and the real are in the range of 8.09% - 17.03%. It can be considered that the relative standard deviations were relatively small. Successful couplings were also directly confirmed by the observation for microstructures of the surfaces of the beads by scanning of electron microscope and laid good foundation for the following responses.</p><p><b>CONCLUSION</b>The high-throughput suspension microarray should provide a novel method for multi-analysis of the veterinary drugs and have a wide applicative prospects with simple operation, sensitive, rapid and low cost.</p>

Oxidative damage to lung tissue and peripheral blood in endotracheal PM2.5-treated rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the oxidative damage to lung tissue and peripherial blood in PM2.5-treated rats.</p><p><b>METHODS</b>PM2.5 samples were collected using an auto-sampling instrument in summer and winter. Treated samples were endotracheally instilled into rats. Activity of reduced glutathione peroxidase (GSH-Px) and concentration of malondialdehyde (MDA) were used as oxidative damage biomarkers of lung tissue and peripheral blood detected with the biochemical method. DNA migration length (microm) and rate of tail were used as DNA damage biomarkers of lung tissue and peripheral blood detected with the biochemical method.</p><p><b>RESULTS</b>The activity of GSH-Px and the concentration of MDA in lung tissue significantly decreased after exposure to PM2.5 for 7-14 days. In peripheral blood, the concentration of MDA decreased, but the activity of GSH-Px increased 7 and 14 days after experiments. The two indicators had a dose-effect relation and similar changing tendency in lung tissue and peripheral blood. The DNA migration length (microm) and rate of tail in lung tissue and peripheral blood significantly increased 7 and 14 days after exposure to PM2.5. The two indicators had a dose-effect relation and similar changing tendency in lung tissue and peripheral blood.</p><p><b>CONCLUSION</b>PM2.5 has a definite oxidative effect on lung tissue and peripheral blood. The activity of GSH-Px and the concentration of MDA are valuable biomarkers of oxidative lung tissue damage induced by PM2.5. The DNA migration length (microm) and rate of tail are simple and valuable biomarkers of PM2.5-induced DNA damage in lung tissues and peripheral blood. The degree of DNA damage in peripheral blood can predict the degree of DNA damage in lung tissue.</p>

Directed molecular evolution of nitrite oxido-reductase by DNA-shuffling / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop directly molecular evolution of nitrite oxido-reductase using DNA-shuffling technique because nitrobacteria grow extremely slow and are unable to nitrify effectively inorganic nitrogen in wastewater treatment.</p><p><b>METHODS</b>The norB gene coding the ndtrite oxido-reductase in nitrobacteria was cloned and sequenced. Then, directed molecular evolution of nitrite oxido-reductase was developed by DNA-shuffling of 15 norB genes from different nitrobacteria.</p><p><b>RESULTS</b>After DNA-shuffling with sexual PCR and staggered extension process PCR, the sequence was different from its parental DNA fragments and the homology ranged from 98% to 99%. The maximum nitrification rate of the modified bacterium of X16 by DNA-shuffling was up to 42.9 mg/L x d, which was almost 10 times higher than that of its parental bacteria. Furthermore, the modified bacterium had the same characteristics of its parental bacteria of E. coli and could grow rapidly in normal cultures.</p><p><b>CONCLUSION</b>DNA-shuffling was successfully used to engineer E. coli, which had norB gene and could degrade inorganic nitrogen effectively.</p>

8-hydroxydeoxyguanosine as a biomarker of oxidative DNA damage induced by environmental tobacco side-stream smoke and its mechanism / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the genotoxicity effect of environmental tobacco side-stream smokes (ETSS) on oxidative DNA damage and its molecular mechanism.</p><p><b>METHODS</b>DNA adduct 8-hydroxydeoxyguanosine (8-OHdG) was used as a biomarker of oxidative DNA damage. The level of 8-OHdG in DNA exposed to ETSS was detected by high performance liquid chromatography with electrochemical detection. Organic and inorganic components in ETSS were analyzed by gas chromatography-mass spectrum and atomic absorption spectrum respectively.</p><p><b>RESULTS</b>Particle matters (PMs) and volatile organic compounds (VOCs) in ETSS could directly induce oxidative DNA damage and formation of 8-OHdG. There were 123 and 84 kinds of organic components in PMs and VOCs respectively, and 7 kinds of inorganic components in ETSS. Some components, especially quinones and polyphenols in ETSS, could produce free radicals in vitro by auto-oxidation without any biological activity systems, and with the catalytic reaction of metals, the DNA adduct 8-OHdG was produced.</p><p><b>CONCLUSION</b>ETSS have biological oxidative effect on DNA in vitro and in vivo, and expressed direct genotoxicity. 8-OHdG is a valuable biomarker of oxidative DNA damage.</p>

Effects of formaldehyde inhalation on lung of rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To analyze protein changes in the lung of Wistar rats exposed to gaseous formaldehyde (FA) at 32-37 mg/m3 for 4 h/day for 15 days using proteomics technique.</p><p><b>METHODS</b>Lung samples were solubilized and separated by two-dimensional electrophoresis (2-DE), and gel patterns were scanned and analyzed for detection of differently expressed protein spots. These protein spots were identified by MALDI-TOF-MS and NCBInr protein database searching.</p><p><b>RESULTS</b>Four proteins were altered significantly in 32-37 mg/m3 FA group, with 3 proteins up-regulated, 1 protein down-regulated. The 4 proteins were identified as aldose reductase, LIM protein, glyceraldehyde-3-phosphate dehydrogenase, and chloride intracellular channel 3.</p><p><b>CONCLUSION</b>The four proteins are related to cell proliferation induced by FA and defense reaction of anti-oxidation. Proteomics is a powerful tool in research of environmental health, and has prospects in search for protein markers for disease diagnosis and monitoring.</p>

A study on detecting and identifying enteric pathogens with PCR / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop a rapid and definite diagnostic test of bacterial enteritis caused by pathogenic enterobacteria, the most frequent etiologic agent of infectious enteritis in the world.</p><p><b>METHODS</b>A set of conventional PCR assays were applied to detect and identify salmonella, shigella, and E. coli O157:H7 directly from pure culture and fecal samples. The general primers of pathogenic enterobacteria were located on the uidA gene, which were found not only in E. coli nuclear acid, but also in shigella and salmonella genes. Shigella primer was from ipaH gene whose coded invasive plasmid relative antigen existed both in plasmid and in genome. The primers of salmonella were designed from the 16SrRNA sequence. The primer of E. coli O157:H7 was taken from eaeA gene. Five random primers were selected for RAPD. The detection system included common PCR, semi-nested PCR and RAPD.</p><p><b>RESULTS</b>This method was more sensitive, specific and efficient and its processing was rapid and simple. For example, the method could be used to specifically detect and identify salmonella, shigella, and E. coli O157:H7, and its sensitivity ranged from 3 to 50 CFU, and its detection time was 4 hours.</p><p><b>CONCLUSION</b>This PCR method, therefore, can serve as a routine and practical protocol for detecting and identifying pathogenic microorganisms from clinical samples.</p>

Detection of RNA of SARS coronavirus in hospital sewage / 中华预防医学杂志

<p><b>OBJECTIVE</b>In order to explore the existence of SARS coronavirus (Co-V) and/or its RNA in sewage of hospitals administered SARS patients.</p><p><b>METHODS</b>A novel electropositive filter was used to concentrate the SARS-CoV from the sewage of two hospitals administered SARS patients in Beijing, including twelve 2,500 ml sewage samples from the hospitals before disinfection, and ten 25,000 ml samples after disinfection; as well as cell culture, RT-PCR and sequencing of gene to detect and identify the viruses from sewage.</p><p><b>RESULTS</b>There was no live SARS-CoV detected in the sewage in this study. The nucleic acid of SARS-CoV had been found in the 12 sewage samples before disinfection from both hospitals by semi-nested PCR. After disinfection, SARS-CoV RNA could only be detected from the samples from the 309th Hospital, and the others were negative.</p><p><b>CONCLUSION</b>It provides evidence that there is no live SARS-Cov in the sewage from hospitals with SARS patients though SARS-CoV RNA can be detected.</p>

Attenuation of chronic stress-induced hippocampal damages following physical exercise / 生理学报

The long-term potentiation (LTP) in the hippocampal dentate gyrus and the plasma glucocorticoids level were observed in rats to study the effects of physical exercise on chronic stress-induced hippocampal damages. Eight-week spontaneous wheel running exercise could attenuate the suppression of LTP induced by 21-day restraint stress, and maintain the normal plasma glucocorticoids levels. It is suggested that long-term physical exercise may protect the hippocampus from stress-induced damages.