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Objective@#To investigate the associated factors of myopia among primary and secondary school students in Shenzhen, and to provide reference for the prevention and control of myopia.@*Methods@#By stratified cluster sampling, 3 073 students of 14 schools including primary,junior,regular and vocational senior schools from two districts in Shenzhen were selected and investigated.@*Results@#For primary school students, the time of using computer for 2-<3 hours per day (OR=2.23，95%CI=1.19-4.20) , and no physical education class(2 sections per week OR=0.34, 95%CI=0.13-0.91; 4 sections per week OR=0.23, 95%CI=0.08-0.62; 5 sections or more per week OR=0.33, 95%CI=0.11-0.97) were positively associated with myopia. Teachers finishing class on time at break (occasionally delaying OR=1.99, 95%CI=1.51-2.63; frequently delaying OR=2.07, 95%CI=1.29-3.30), taking 0.5-1 hour break when using eyes at close range (1-<2 hours OR=1.33，95%CI=1.03-1.70; ≥3 hours OR=1.87, 95%CI=1.17-3.00), no parents with myopia(one parent with myopia OR=1.69, 95%CI=1.32-2.17; two parents with myopia OR=2.13, 95%CI=1.50-3.02) were negatively associated with myopia. For junior high school students, without parents with myopia (one parent with myopia OR=3.27, 95%CI=2.17-4.94; two parents with myopia OR=5.38, 95%CI=2.78-10.42) was the protective factor of myopia. For senior high school students, male (female OR=1.52, 95%CI=1.07-2.14), doing eye exercises twice a day in school (OR=0.41, 95%CI=0.23-0.75), and accumulating outdoor activities for ≥2 hours a day (OR=0.70, 95%CI=0.49-1.00) were negatively associated with myopia.@*Conclusion@#There are different risk factors for myopia among different students in Shenzhen. Students with high risk factors are the key objects of prevention and control.
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Objective To summarize the funding of scientific research projects on obstetrics and gynecology by National Natural Science Foundation of China (NSFC) from 2007 to 2016 and to display the hotspots of scientific research on obstetrics and gynecology. Methods A systemic search was performed for the information of projects supported by NSFC from 2007 to 2016. The indicators for analysis included the number of projects, total investment, project categories, research units and research field. The research direction of each project was decided based on title, summary and key words provided by the profile of each project. Results The total investment on obstetrics and gynecology by NSFC was 23.214 million with a total of 82 projects in 2007. It increased year by year and reached the peak in 2014 (359 projects 208.990 million). The investment and number of projects remained stable after 2014. General projects (1109 projects 608.000 million) formed the majority of projects. Youth science fund projects (1035 projects 214.976 million) increased steadily and the number was nearly equal to general projects. There were only a small amount of key projects (20 projects 54.720 million) and major projects (7 projects 38.400 million). The investment varied in different research units. The greatest 10 units (less than 6% of total), including 7 comprehensive universities, 2 medical universities and 1 institute of medicine, got 1113 projects invested (43.84% of total,1113/2539). The hot areas like gynecological tumor (920 projects 350.615 million),hypertensive disorders complicating pregnancy (91 projects 37.470 million) and polycystic ovarian syndrome (77 projects 29.540 million) were more likely to receive investment, while some interdisciplinary science like maternal and child health (28 projects 12.050 million), imaging and biomedicine (37 projects 14.770 million) began to achieve attention in recent years. Conclusions The number of researches invested will be increased for the scientific research in obstetrics and gynecology especially the areas of research focus, although the amount allocated for each will be decreased relatively. Besides, multidisciplinary work will be performed so as to develop obstetrics and gynecology of China to a high level.
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After a description of the basic situation of medical literature retrieval course for foreign undergraduates studying in Sun Yat-sen University, the problems in their teaching contents and teaching methods were pointed out with measures proposed for improving the teaching of their medical literature retrieval course.
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Lysostaphin (Lysn) is an antibacterial metalloendopeptidase that cleaves the pentaglycin bridges in the cell wall of Staphylococci. Although many studies have demonstrated its high activity in vitro, the medical application of Lysn has been hampered by its short half-life in vivo. In order to enhance its stability in vivo without significantly suppressing the enzymatic activity, we designed and tested eight single cysteine substitutions in Lysn for covalent attachment of polyethylene glycol chains (PEGylation). The purified mutants, fully reduced by Dithiothreitol (DTT), were treated with mPEG-MAL(20 kDa). The PEG modification efficiency was above 70% as determined by reverse-phase high-pressure liquid chromatography (HPLC) analysis. The PEG-Lysn proteins were further purified by cation exchange chromatography (MacroCap SP), reaching at least 95% purity. The activities of the PEG-Lysn proteins were determined by the turbidity and minimum inhibitory concentration (MIC) assays. We found that the PEGylated V240C and T244C mutants retained about 50% of the original antibacterial activity of Lysn. Overall, this study will help develop highly stable and active PEG-Lysn to treat systemic S. aureus infections.
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Substituição de Aminoácidos , Lisostafina , Química , Polietilenoglicóis , Química , Engenharia de Proteínas , Proteínas Recombinantes , Química , Staphylococcus aureusRESUMO
After a description of the application of education game in literature retrieval teaching and the practical activities of information literacy education game in our library, suggestions were put forward for the problems that need to be concerned in performing information literacy education game, namely pursuing the benefits and avoi-ding the hazards, making entertainment a medium of education, rational application of small game in classroom teaching, taking immediate action, and leaving it undone as it is small.
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Objective To summarize the funding of scientific research projects on solid organ transplantation by National Natural Science Foundation of China (NSFC) from 1998 to 2014 as well as the publications produced by these projects, and to display the hotspots of scientific research on solid organ transplantation.Method A systemic search was performed for the information of projects supported by NSFC from 1998 to 2014 and their papers published in Science Citation Index (SCI) journals.The indicators for analysis included the number of projects, total investment, average investment in each project, the number of papers published in SCI journals, total number of citations, average number of citations of each paper, H index and average investment in each paper.The research direction of each project was decided based on title, summary and key words provided by the profile of each project.Result The total investment on solid organ transplantation by NSFC was 1.55 million with a total of seven projects.It increased year by year and reached the peak in 2011.The investment in 2011 was 42.7 million yuan RMB with a total of 78 projects.The investment and number of projects remained stable after 2011.The median investment in each project was increased by 380 thousand yuan RMB from 1998 to 2014.From 1998 to 2010, the number of papers and total number of citations increased.H index increased steadily and slowly before 2005, followed by a surge in 2005.It stayed stable between 13 and 19 from 2005 to 2010.Investment in each SCI paper had never exceeded 110 thousand since 2004.Through analysis of research direction of all the projects, we found that the investment in the research projects on immune regulation and immune tolerance,ischemia-reperfusion injury and inflammation and immune rejection dominated total investment from 1998 to 2014.Investment in the research projects on artificial organs and xenotransplantation was distributed unevenly.Projects associated with stem cell had received increasing investment.Conclusion The fundingby NSFC has largely promoted the development and progress of research on science of organ transplantation.More investment will be required for the scientific research in this field.
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Objective To investigate the phenotypic and genetic characteristics of the lysostaphin‐resistant Staphylococcus aureus variants induced by recombinant lysostaphin in vitro .Methods Three clinical isolates of S . aureus ,including two resistant to methicillin (MRSA ) and one susceptible to methicillin (MSSA ) were induced by treatment with sub‐MIC of recombinant lysostaphin via one‐step selection in vitro .Susceptibility of the variants to antibiotics were determined and compared with their parental strains .The full length of femABX genes was amplified by polymerase chain reaction and sequenced to identify the potential mutation sites in these genes .The growth‐curve in liquid medium and virulence in a mouse systemic infection model of both parental and variant strains were observed . Results The frequency of lysostaphin resistance in S . aureus was between 10-4 to 10-8 following induction by lysostaphin . Resistance to lysostaphin was associated with a significant decrease in growth rate in vitro and virulence in vivo ,as well as increased susceptibility toβ‐lactams evidenced by the M IC of β‐lactams against the variants as low as 1/4 000 to 1/2 of the M IC against their parental strains . Sequencing of f emA BX genes showed mutation in femA gene in both variants ,which resulted in a premature termination codon .Conclusions Resistance of S . aureus to lysostaphin may develop following induction by recombinant lysostaphin in vitro . The lysostaphin‐resistant S . aureus variants are characteristic of lower growth rate , decreased virulence ,and higher susceptibility to β‐lactams .
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After a description of the new connotations of information literacy education in medical undergraduates in the era of omnimedica such as visual information literacy education, media information literacy education and mobile information literacy education, new strategies were proposed for the information literacy education in medical undergraduates in the era of omnimedia, including updating teaching model, adding education contents, and improving omnimedia presentation ability.
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Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.
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Lysostaphin, a specific endopeptidase enzyme derived from Staphylococcus aureus, is a bactericidal agent against Staphylococcus and difficult to be drug-resistant. This study established the monoclonal antibody affinity chromatography to obtain lysostaphin of high purity for drug-use standard. The purified Lysostaphin was of > 95% purity and its recovery rate more than 90%. Moreover, the affinity column kept its efficiency of purification invariable after more than 30 times repeat. Also, the dye release assay validated that the purified lysostaphin had significant bactericidal activity. This method was simple and of high efficacy for the lysostaphin purification and showed its potency in commercial production.