Effect of SP combined with CBL in endodontics / 中华医学教育探索杂志

Objective:To explore the application effect of standardized patients (SP) combined with case-based learning (CBL) teaching model in endodontics for stomatology undergraduates.Methods:Forty-eight five-year stomatology undergraduates of Southern Medical University School of Stomatology were randomized into 2 groups, the experimental group and the control group. The experimental group adopted SP combined with CBL teaching model while the control group adopted LBL alone. After the course, the teaching effect was evaluated comprehensively. The data was analyzed by SPSS 20.0, and the differences of measurement data were compared with t test and chi-square test. Results:There was no significant difference in theoretical test scores between the two groups ( P>0.05), but the practical test results and comprehensive evaluation scores of the experimental group were significantly higher than those of the control group ( P<0.01). The results of questionnaires indicated that students in the experimental group were much more satisfied with SP combined with CBL teaching model than the control group (88.8% vs. 56.3%). Conclusion:SP combined with CBL Teaching Model can achieves satisfactory teaching effect, and improves the learning efficiency of students.

Correlations between HIV-1 subtypes and changes in CD4+T cell count over time / 中华微生物学和免疫学杂志

Objective To understand the correlations between HIV-1 subtypes and changes in CD4+T cell count over time in patients with different subtypes of HIV-1 infection.Methods A total of 94 patients who were diagnosed with HIV-1 infection in Nanjing and received at least twice CD4+T cell counting test before antiretroviral therapy (ART) were recruited in this study.Descriptive analysis was used to present the rates of CD4+T cell decline for different HIV-1 subtypes.Logistic regression analysis and nonparametric test were conducted to investigate the factors responsible for CD4+T cell decline and to analyze the correlations between the rates of CD4+T cell decline and HIV-1 subtypes.Results The median monthly rate of CD4+T cell decline was-2.20 [interquartile range (IQR):-11.36-2.13] cell/μl.Of all patients,25.5% (24/94) had a significant decline (≥30%) in CD4+T cell count.Compared with the patients infected with CRF01_AE,those infected with CRF07_BC (OR=0.28,95%CI: 1.7-6.5) or other subtypes (OR=0.16,95%CI: 1.0-2.9) had a lower risk of significant decline in CD4+T cell count.In addition,results of the nonparametric test showed that the patients infected with CRF01_AE (M=-21.54,IQR:-30.97——11.92 cell/μl) had a faster CD4+T cell loss than those infected with CRF07_BC (M=-11.26,IQR:-14.06——5.63 cell/μl) (P=0.033).Conclusion HIV-1 subtype is associated with the rate of CD4+T cell decline.It is important to monitor the changes in CD4+T cell count in patients infected with CRF01_AE and to carry out timely ART.

Molecular characteristics of hemagglutinin gene of influenza A (H3N2) virus strains circulating in Jiangsu province, China, 2013-2014 / 中华微生物学和免疫学杂志

Objective To analyze the genetic characteristics and the evolution of the influenza A (H3N2) virus strains circulating in Jiangsu province between 2013 and 2014.Methods This study analyzed thirty-one representative strains of influenza A (H3N2) virus, which were isolated in different regions of Jiangsu province and during different time periods from 2013 to 2014.Results Genetic distances in nucleic acid and amino acid between a strain used for vaccine production (A/Texas/50/2012) and the 31 strains were 0.010 5 and 0.012 4.Similarities between them in nucleic acid and amino acid sequences were 97.9%-99.6% and 97.2%-99.3%.Phylogenetic analysis showed that the hemagglutinin (HA) genes of the 31 strains were divided into three different groups.Three strains isolated in 2013 and three strains isolated in 2014 belonged to Group 1 and Group 2, respectively, while the others belonged to Group 3.Three positive selection sites (237, 366 and 367) in HA protein were observed by REL model.Compared with the strain used for vaccine production, the 31 strains were characterized by amino acid substitutions (N128A/T and P198S/A) in HA protein and all of the mutations located in B-cell epitopes.The total number of mutation sites reached 24.Compared with the A/Texas/50/2012 strain, seven strains presented the glycosylation site 126NWT, and three strains showed disappeared glycosylation sites of 45NSS and 144NNS.Evaluation of vaccine efficacy for A(H3N2) virus strains showed that the vaccine efficacy was not very well.Conclusion The HA gene of A(H3N2) virus had undergone a greater variation and the vaccine efficacy was not very well in Jiangsu province during 2013 to 2014, which made the influenza A(H3N2) virus become the circulating strain.

Influence of growing experience on non-heterosexual orientation among male college students in Nanjing / 中华预防医学杂志

Objective@#To analyze the influence of growing experience on non-heterosexual orientation among male college students.@*Methods@#From October to November in 2015, a total of 2 535 male students from 96 classes in 14 colleges/departments were recruited from two colleges that participated in the experimental work of AIDS prevention by cluster random sampling method. A structured questionnaire was administered in this study, including general demographic information, growing experience and Kinsey scale (to evaluate sexual orientation). Out of 2 500 questionnaires distributed in this study, 2 332 effective copies were withdrew, with the effective rate at 93.3%. Chi square test was used to analyze the differences of non-heterosexual orientation among the individuals with different social demographic characteristics. Multivariate logistic regression model was used to analyze the influencing factors of non-heterosexual orientation.@*Results@#Among the 2 332 individuals, the proportion of self-reported non-heterosexual was 6.2% (144).The proportions of male students who identify as non-heterosexual from freshman to junior year were 5.2%(63/1216),6.9%(65/941),11.7%(13/111) and 4.7%(3/64), respectively (χ2=9.06,P=0.029). Compared with the individuals of very good relationship with parents, those with bad relationship (OR=3.3, 95%CI: 1.7-6.5) and general relationship (OR=1.7, 95%CI: 1.0-2.9) with parents had a higher risk of non-heterosexual orientation, respectively. Those encountered sexual assault had a higher risk of non-heterosexual orientation than those without encountered sexual assault (OR=5.9, 95%CI: 3.2-10.9).@*Conclusions@#This study reported a high proportion of self-reported non-heterosexual among college male students in Nanjing, and highlighted the importance of targeting students with poor parental relationships and who subjected to sexually abused.

Evolution analysis and trend prediction of neuraminidase gene of influenza A/H1N1(09pdm) virus in China from 2009 to 2016 / 临床检验杂志

Objective To analyze the evolutionary characteristics and predict the variation trend of neuraminidase (NA) gene of influenza A/H1N1 (09pdm) virus in China from 2009 to 2016 in order to provide the basis of assessment for flu vaccines.Methods A total of 1 141 sequences of NA gene of influenza A/H1N1 (09pdm) virus were screened out from the Global Initiative on Sharing All Influenza Data and National Center for Biotechnology Information.The phylogenetic trees and the mutations of amino acids sequences were constructed and analyzed by biological softwares.The prediction for epidemic trend of influenza was analyzed by Bayesian skyline Plot.Results Compared with the sequence of reference strain,the homology of nucleic acid sequence of NA gene decreased year by year from 2009 to 2016.The phylogenetic analysis showed that NA gene clustered nearly on the identical phylogenetic tree in one year.The positive selection pressure site of NA strain was observed by different models in each year except 2012.The dynamics analysis showed that the popularity of influenza A/H1N1 virus may continue to increase to a peak in 2017.Conclusion The amino acid encoded by NA gene of influenza A/H1N1 virus is varying gradually,so the importance of surveillance for influenza virus should be reinforced for every year.

TORCH serologic screening in fertile women and infants and its clinical values from 2008 to 2015 / 中华检验医学杂志

Objective To retrospectively study the serum IgG and IgM antibodies against toxoplasma, rubella virus, cytomegalovirus and herpes simplex virus type 1&2 in various populations, and analyze the clinical values.Methods From 2008 to 2015, 2 661 pregnant women, 324 infertile women, 2 492 women with abnormal pregnancy history, 623 women with recent abnormal pregnancy, 261 infants with intrauterine growth retardation and other diseases, 170 women for preconceptual examination, and 702 women for physical examination in Beijing were included .Commercial EIA kits were used to detect serum IgG and IgM antibodies to toxoplasma, rubella virus, cytomegalovirus and herpes simplex virus type 1&2. Positive reactions of IgM antibodies to any pathogens were re-tested with another kind of commercial EIA kit. PEMS3.1 software was used for statistical analysis.Results The prevalence of serum IgG or IgM antibodies against toxoplasma, rubella virus, cytomegalovirus and herpes simplex virus type 1& 2 were found within 0.7%-1.6%(0-1.2%) , 85.3%-92.0% ( 0.4%-2.7%) , 89.1%-94.9% ( 0.7%-1.7%) , 74.8%-86.0% ( 0 -0.7%) , 8.1% -17.4% ( 0 -4.1%) respectively in the studied population groups.The prevalence of TORCH IgG and IgM antibodies were not found to be higher in both populations with past suspicious exposure ( infertile women and women with abnormal pregnancy history ) and recent suspicious exposure ( women with recent abnormal pregnancy and infants with intrauterine growth retardation and other diseases) than that in pregnant women and women for preconceptual and physical examination. Conclusion No associations between TORCH infections and the suspicious exposure were found in the populations above.

Molecular transmission networks of human immunodeficiency virus-1 CRF01 AE strains in China / 中华微生物学和免疫学杂志

Objective To construct the molecular transmission networks of HIV-1 CRF01 AE strains circulating in China and to analyze their characteristics. Methods Sequences of the pol genes of Chinese CRF01 AE strains were downloaded from Los Alamos database and the related demographic informa-tion was checked. Transmission networks were created by four steps,including phylogenetic tree construc-tion,transmission cluster extraction,minimum genetic distance identification and network visualization. Chi-square test was performed to analyze the differences in the distribution of different populations in the networks and the differences in the distribution of subjects with different degrees among different sub-populations. De-scriptive analysis was used to investigate the transmission links between sub-populations and various regions. Results The 2 419 sequences constituted 250 separate networks including 847 nodes and 610 edges. The number of subjects covered by different networks ranged from 2 to 25. Subjects with degree ≥2 represented only 26. 4%(224 / 847)of network-individuals,but were connected with 66. 5%(563 / 847)of all network-individuals. There were 37. 6%(669 / 1 781)of men who have sex with men(MSM),28. 4%(102 / 359) of heterosexual men,16. 1%(10 / 62)of intravenous drug users(IDUs)and 30. 4%(66 / 217)of hetero-sexual women involved in the networks(χ2 =23. 774,P﹤0. 001). The percentage of subjects with degree ≥2 was high in MSM(10. 8% ,193 / 1 781)compared to that in heterosexual men(5. 6% ,20 / 359)(P =0. 002)and heterosexual women(4. 6% ,10 / 217)(P=0. 004). Of the 669 MSM in the networks,95. 5%(639 / 669)linked to other MSM and only 2. 4% (16 / 669)linked to heterosexual women. However, 15. 1%(10 / 66)of the heterosexual women in the networks linked to MSM. Of the heterosexual men in the networks,35. 3%(36 / 102)linked to heterosexual women,9. 8%(10 / 102)linked to MSM. Of the sub-jects in the networks,20. 9%(177 / 847)linked to other regions' individuals. Conclusion The super-spreaders played an important role in the molecular transmission networks of HIV-1 CRF01 AE strains even though they were in a minority. The transmission of HIV-1 CRF01 AE strains between sub-populations and various regions was complicated and active.

Meta-analysis on the two medications to prevent cytomegalovirus infection in recipients of renal transplants / 中华器官移植杂志

Objective To assess the efficacy of the two antiviral medications in preventing cytomegalovirus infection and cytomegalovirus disease in renal transplant recipients.Method We searched articles from Pubmed,EMbase,Cochrane Library,Wanfang Med Online,and China's biomedical journal citation database on line.Randomized controlled trials evaluating preemptive treatment and universal prophylaxis for cytomegalovirus infection and cytomegalovirus disease in renal transplant recipients were reviewed.Two reviewers screened studies and assessed study quality according to the study population,intervention measure and results.Finally data from included studies were subjected to meta-analysis.Result Six studies involving total 752 renal transplant recipients were included in this review.Compared with preemptive treatment,universal prophylaxis significantly reduced the risk of cytomegalovirus infection at 3 rd and 12 th month,and the risk of cytomegalovirus disease at 12 th month after transplantation (RR =12.13,95 ％ CI.6.59～22.36,P＜0.05; RR =2.21,95％CI:1.62～3.01,P＜0.05; RR=1.79,95％Chl.22～2.63,P＜0.05).There was no statistically significant difference in the incidence of other opportunistic infection and acute rejection.Conclusion Universal prophylaxis was more effective than preemptive treatment in preventing CMV infection and CMV disease in renal transplant recipients.

Bone metastasis of lung cancer in a mouse model with normal immune function / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a model bearing human lung cancer xenograft with bone metastasis in mice with normal immune function.</p><p><b>METHODS</b>Forty female C57BL/6J mice were randomly allocated into 4 equal groups, including a control group and 3 immunosuppression groups treated with low, moderate, and high doses of dexamethasone (50, 100, and 150 mg, respectively). Four days after immune suppression, the mice were subjected to percutaneous injection of1.0×10(9) L(-1) A549 cells into the tibial plateau, and the bone defects were assessed radiographically 28 days after modeling. HE staining and immunohistochemical staining were used to examine the tumor tissues and bone tissue damages.</p><p><b>RESULTS</b>In each of the 4 groups one mouse died during tumor cell injection. Only 1 mouse showed tumor formation in low-dose immunosuppression group, as compared to 7 and 4 in moderate- and high-dose immunosuppression groups. X-ray and microCT scan showed significant tibial bone destruction in moderate- and high-dose groups. The moderate- and high-dose groups showed similar ALP activities but both were significantly higher than those in the other two groups (P<0.05).</p><p><b>CONCLUSION</b>Immunosuppression with a moderate dose of dexamethasone results in longer survival time of the human lung cancer xenograft-bearing model mice as well as a higher tumor formation rate.</p>

Studies on expression, purification, crystal growth and optimization of putative transcription factor LytR from Streptococcus pneumoniae / 生物医学工程学杂志

The aim of the present study was to obtain the crystal of transcription factor LytR of streptococcus pneumoniae for X-ray crystal structure and function analysis. The LytR gene of D39 strains from Streptococcus pneumoniae (S. pn) was cloned into the prokaryotic expression vector pET32a(+), then overexpression was obtained in the E. coli BL21 (DE3) through transformation of the recombinant plasmid that had been verified by colony PCR and sequencing. Soluble fusion protein with His-tag highly expressed by the induction of 0.5 mmol/L IPTG and was purified by a three step procedure, the purity of the purified LytR recombinant protein was over 90%. Preliminary screening of crystallization conditions was performed using the hanging-drop vapour-diffusing method with Hampton Crystal screen and PEG screen kits. The protein crystals X-ray diffraction data were collected from a single crystal and more stick crystals whose X-ray diffraction reached 4.0 A were obtained. These works laid the foundation for further research on the 3D structure of putative transcription factor LytR and its biological aspects.

Streptococcus mutans gcp gene knockout strains expression profile gene chip / 中国组织工程研究

BACKGROUND:Previous studies have confirmed the presence of bis-(3'-5')-cyclic dimeric guanosine monophosphate signaling pathway in Streptococcus mutans, which construct the streptococcus mutans gcp gene knockout strains. OBJECTIVE:To compare the gene expression differences between Streptococcus mutans wild strains and gcp mutant strains, and to screen the biofilm-related genes from them for the fol ow-up study. METHODS:The total RNA of two kinds of strains were extracted and stained with cy3 and cy5 respectively after reverse transcription. The gene chip was scanned after hybridization and the differential gene were obtained through the data analysis. The different expression genes were verified by real-time PCR. RESULTS AND CONCLUSION:Differential genes were mainly relative about glucose metabolism and biofilm formation. We selected two genes for real-time PCR verification. The PCR results were consistent with the microarray results. After Streptococcus mutans gcp gene knockout, the gene expressions of gcp mutant strains were upregulated and the gene expressions of phosphotransferase system were downregulated, this result suggested that two different genes were related with the c-di-GMP signal pathway downstream.

Survey and analysis of dental medical students' concerns before and after their clinical internship / 中华医学教育探索杂志

ObjectiveTo survey and analyze the changes of dental medical students' concerns before and after their internship in order to provide practical evidences for intern orientation and junior students education.MethodsAnonymous questionnaires were designed with single choice and multiple-choices and were accomplished by 175 dental medical students of different grades to investigate their' concerns before and after the clinical internship and choices for future employment.Results 47％ freshmen,43％ junior,45％ graduates were willing to work in dental restoration field,30％sophomore and 39％ senior were willing to work in orthodontics field.Before the internship,the most concem of 97％ students was the teaching quality of the practice hospital; 67％ students worried that patients may unsatisfy with the treatment.After the internship,the quality of the practice hospital was considered most important by 79％ students; 51％ students worried that internship may influence the postgraduate entrance exam.ConclusionTeachers should strengthen their self-cultivation and cope with the key concerns before the practice based on the investigation and survey after the practice.Meanwhile teacher should provide employment guidance for students based on students' interests and practice skill ability,encourage them to broaden their horizon and pay attention to the long-term interests in an aim to pave the way for future employment.

Exogenous 3', 5'-cyclic diguanylic acid prevents caries formation in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of exogenous c-di-GMP in preventing dental caries formation in SD rats.</p><p><b>METHODS</b>Twenty-day-old SD rats with dental caries induced by S. Mutans infection were randomly divided into 3 groups for treatment with dental application of exogenous c-di-GMP, NaF solution or 0.9% NaCl, and changes in the bacterial number and scores of dental caries following the treatments were recorded.</p><p><b>RESULTS</b>Compared with 0.9% NaCl treatment, exogenous c-di-GMP treatment significantly lowered the scores of dental caries on the occlusal surface and smooth surface (P<0.05) but produced no obvious effect on the number of bacterial plagues (P>0.05).</p><p><b>CONCLUSION</b>Exogenous c-di-GMP can be a novel agent for prevention and treatment of tooth decay.</p>

Soft tissue profile of normal occlusion in the early permanent dentition:E line analysis / 中国组织工程研究

AIM:To explore the distance from the labrale superius and inferius of the soft tissue profile in early permanent dentition with normal occlusion to the esthetic line (E line) and the proportion among each section of E plane. METHODS: Thirty Han teenagers with normal occlusion including 15 males and 15 females with the average age of 11.5 years were selected from January 2000 to December 2005. They were examined cephalometrially to measure the distance between labrale superius (Ls) and E, labrale inferius (Li) and E, and the mean values and standard deviation of prenasale (Prn)-Ls/distance between Prn and pogonion (Pg') of soft tissue, Ls-Li/distance between Prn and Pg' and Li-Pg'/distance between Prn and Pg'. RESULTS: ①Distance of Ls-E and Li-E: Ls-E and Li-E of normal occlusion were (0.083 3?0.920 8) mm and (0.621 7?1.124 6) mm. ②Proportion of each segment to the distance of Prn and Pg': Prn-Ls/Prn-Pg', Ls-Li/Prn-Pg' and Li-Pg'/Prn-Pg' were 0.413 8?0.022 3, 0.200 9?0.023 1, 0.385 7?0.022 8, respectively. CONCLUSION: E plane analysis is a convenient and effective method in the diagnosis of soft tissue in clinic. The Ls and Li are exactly on the E plane in normal occlusion and the ratio of three sections is 2∶1∶2.