Objectives Due to the time and cost effectiveness, online teaching has played a significant role in the provision of education and has been a well‐accepted strategy for higher education in the world. The aim of this study was to survey the current online undergraduate education status in dental medicine in mainland China during the critical stage of the COVID‐19 outbreak, as well to provide a better understanding of practicing this learning strategy for the improvement and development of dental education. Methods For the cross‐sectional survey, recruitment emails regarding to the implementation of online education were sent to 42 dental colleges and universities in mainland China between March and April 2020. Results Ninety‐seven percent of the respondents have opened online courses during COVID‐19 pandemic in China, 74% of which chose live broadcast as the major teaching way. As compared with theoretical courses, fewer specialized practical curriculums were set up online with a lower satisfaction from students in most dental schools. For the general evaluation of online learning from students of different dental schools, the “online learning content” received the highest support, while the “interaction between teachers and students” showed the lowest satisfaction. Most schools reported that the difficulty in assurance of students’ learning motivation was the main problem in online education. Conclusions Our findings indicate the necessity and efficacy of the overall online teaching for dental education during the epidemic that can be further improved with the education model and pedagogical means to boost the informationization of dental education for future reference.

Objective To assess the prevalence of HIV and selected STDs among MSM in Chengdu, China and the risk factors associated with HIV infection. Methods A cross-sectional study using a snowball sampling method was conducted from March to July, 2007. Participants were asked to complete a questionnaire about sexual history, high risk behaviors, STD infection history, HIV knowledge and testing, and an assessment of depression. Blood samples were taken for antibody testing for HIV, HSV-2, and syphilis. Results A total of 538 MSM were recruited and 513 (95.4%) consented to complete the questionnaire. HIV, HSV-2 and syphilis prevalence were 9.1%, 24.7%, and 28.1%, respectively. The rate of consistent condom use was low and varied by types of sexual partners. The highest was with casual male partners (38.6%) and the lowest was with wife or girl friend (17.8%). Money boys (MB) were 6 times more likely to be infected with HIV compare to clerks/students. Infection with either HSV or syphilis increased the risk of HIV infection more than 4 fold. Conclusions The prevalences of HIV and STDs were high among MSM in Chengdu. To prevent HIV/STDs, campaigns promoting condom use are needed not only to boost the frequency of condom use, but also to educate MSM about proper condom use.

Background In addition to SARS associated coronaviruses, 4 non-SARS related human coronaviruses (HCoVs) are recognized as common respiratory pathogens. The etiology and clinical impact of HCoVs in Chinese adults with acute upper respiratory tract infection (URTI) needs to be characterized systematically by molecular detection with excellent sensitivity. Methodology/Principal Findings In this study, we detected 4 non-SARS related HCoV species by real-time RT-PCR in 981 nasopharyngeal swabs collected from March 2009 to February 2011. All specimens were also tested for the presence of other common respiratory viruses and newly identified viruses, human metapneumovirus (hMPV) and human bocavirus (HBoV). 157 of the 981 (16.0%) nasopharyngeal swabs were positive for HCoVs. The species detected were 229E (96 cases, 9.8%), OC43 (42 cases, 4.3%), HKU1 (16 cases, 1.6%) and NL63 (11 cases, 1.1%). HCoV-229E was circulated in 21 of the 24 months of surveillance. The detection rates for both OC43 and NL63 were showed significantly year-to-year variation between 2009/10 and 2010/11, respectively (P<0.001 and P = 0.003), and there was a higher detection frequency of HKU1 in patients aged over 60 years (P = 0.03). 48 of 157(30.57%) HCoV positive patients were co-infected. Undifferentiated human rhinoviruses and influenza (Flu) A were the most common viruses detected (more than 35%) in HCoV co-infections. Respiratory syncytial virus (RSV), human parainfluenza virus (PIV) and HBoV were detected in very low rate (less than 1%) among adult patients with URTI. Conclusions/Significance All 4 non-SARS-associated HCoVs were more frequently detected by real-time RT-PCR assay in adults with URTI in Beijing and HCoV-229E led to the most prevalent infection. Our study also suggested that all non-SARS-associated HCoVs contribute significantly to URTI in adult patients in China.

Cariogenic virulence factors of Streptococcus mutans include acidogenicity, aciduricity, and extracellular polysaccharides (EPS) synthesis. The de novo designed antimicrobial peptide GH12 has shown bactericidal effects on S. mutans, but its interaction with virulence and regulatory systems of S. mutans remains to be elucidated. The objectives were to investigate the effects of GH12 on virulence factors of S. mutans, and further explore the function mechanisms at enzymatic and transcriptional levels. To avoid decrease in bacterial viability, we limited GH12 to subinhibitory levels. We evaluated effects of GH12 on acidogenicity of S. mutans by pH drop, lactic acid measurement and lactate dehydrogenase (LDH) assay, on aciduricity through survival rate at pH 5.0 and F1F0-ATPase assay, and on EPS synthesis using quantitative measurement, morphology observation, vertical distribution analyses and biomass calculation. Afterwards, we conducted quantitative real-time PCR to acquire the expression profile of related genes. GH12 at 1/2 MIC (4 mg/L) inhibited acid production, survival rate, EPS synthesis, and biofilm formation. The enzymatic activity of LDH and F1F0-ATPase was inhibited, and ldh, gtfBCD, vicR, liaR, and comDE genes were significantly downregulated. In conclusion, GH12 inhibited virulence factors of S. mutans, through reducing the activity of related enzymes, downregulating virulence genes, and inactivating specific regulatory systems.

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Dendritic cell (DC) based vaccines have emerged as a promising immunotherapy for cancers. However, most DC vaccines so far have achieved only limited success in cancer treatment. Photodynamic therapy (PDT), an established cancer treatment strategy, can cause immunogenic apoptosis to induce an effective antitumor immune response. In this study, we developed a DC-based cancer vaccine using immunogenic apoptotic tumor cells induced by 5-aminolevulinic acid (ALA) mediated PDT. The maturation of DCs induced by PDT-treated apoptotic cells was evaluated using electron microscopy, FACS, and ELISA. The anti-tumor immunity of ALA-PDT-DC vaccine was tested with a mouse model. We observed the maturations of DCs potentiated by ALA-PDT treated tumor cells, including morphology maturation (enlargement of dendrites and increase of lysosomes), phenotypic maturation (upregulation of surface expression of MHC-II, DC80, and CD86), and functional maturation (enhanced capability to secrete IFN-γ and IL-12, and to induce T cell proliferation). Most interestingly, PDT-induced apoptotic tumor cells are more capable of potentiating maturation of DCs than PDT-treated or freeze/thaw treated necrotic tumor cells. ALA-PDT-DC vaccine mediated by apoptotic cells provided protection against tumors in mice, far stronger than that of DC vaccine obtained from freeze/thaw treated tumor cells. Our results indicate that immunogenic apoptotic tumor cells can be more effective in enhancing a DC-based cancer vaccine, which could improve the clinical application of PDT-DC vaccines.

Background The study examined concurrent illicit heroin use among methadone maintenance clients in China and its association with clients’ demographic characteristics, treatment experience, and personal social network. Methods Face-to-face surveys were conducted with 178 clients randomly recruited from six methadone maintenance treatment (MMT) clinics in Sichuan, China. Concurrent heroin use was measured based on self-report of heroin use during the past 30 days and a confirmatory urine morphine test. The participants’ demographic characteristics and treatment factors were measured and examined. The drug use status of their family members and friends was also assessed. Results A total of 80 participants (44.9%) who either reported illicit heroin use in the past 30 days or had a positive urine test were defined as using heroin concurrently. Having drug-using friends was significantly associated with increased concurrent heroin use. Longer length of treatment (2 years or longer) was associated with increased concurrent heroin use. Among those who had both drug-using family members and friends, more women (71.4%) than men (50.0%) used heroin. For those who had no drug-using family members or friends, more men (34.8%) than women (20.8%) used heroin. Discussion Study findings indicate an urgent need to address concurrent illicit heroin use among MMT clients. Further examination of the influence of social networks on concurrent drug abuse behavior is encouraged. Results also highlight the importance of understanding gender differences in treatment seeking and behavioral changes, which is crucial to the development of gender-specific treatment strategies.

Photodynamic therapy (PDT) not only kills tumor cells directly but also rapidly recruits and activates immune cells favoring the development of antitumor adaptive immunity. It is believed that Topical 5-aminolevulinic acid mediated photodynamic therapy (ALA-PDT) can induce anti-tumor immune responses through dangerous signals damage-associated molecular patterns (DAMPs). In this study, we investigated the effect of ALA-PDT induced DAMPs on immune cells. We focused on the stimulation of dendritic cells by major DAMPs, enhanced the expression of calreticulin (CRT), heat shock proteins 70 (HSP70), and high mobility group box 1 (HMGB1), either individually or in combination. We evaluated in vitro and in vivo expressions of DAMPs induced by ALA-PDT using immunohistochemistry, western blot, and ELISA in a squamous cell carcinoma (SCC) mouse model. The role of DAMPs in the maturation of DCs potentiated by ALA-PDT-treated tumor cells was detected by FACS and ELISA. Our results showed that ALA-PDT enhanced the expression of CRT, HSP70, and HMGB1. These induced DAMPs played an important part in activating DCs by PDT-treated tumor cells, including phenotypic maturation (increase of surface expression of MHC-II, CD80, and CD86) and functional maturation (enhanced capability to secrete IFN-γ and IL-12). Furthermore, injecting ALA-PDT-treated tumor cells into naïve mice resulted in complete protection against cancer cells of the same origin. Our findings indicate that ALA-PDT can increase DAMPs and enhance tumor immunogenicity, providing a promising strategy for inducing a systemic anticancer immune response.