[Prevalence of syphilis in HIV-infected patients with transmission risk and influencing factors in Zhejiang Province]

Objective: To investigate the prevalence of syphilis in HIV-infected patients with transmission risk and influencing factors in Zhejiang Province. Method: The information about the HIV-infected patients, who were alive, had been diagnosed with HIV for >1 year, had received no antiviral treatment or had HIV viral load ≥50 copies/ml, and were aged ≥15 years, reported in Zhejiang as of December 31, 2018 were collected from China Information System for Disease Control and Prevention. The information included general demographic characteristics, sexual behavior characteristics and antiretroviral therapy and syphilis serological test results. The prevalence of syphilis and the influencing factors were analyzed by logistic regression model. The SPSS 19.0 software was used for statistical analysis. Results: A total of 2 275 HIV-infected patients were at risk of HIV transmission, and 75.5% (1 717/2 275) of them were tested for syphilis, the prevalence rate of syphilis was 8.7% (150/1 717). Among the HIV-infected patients with syphilis, 11.3% (17/150) received no antiviral treatment, 38.7% (58/150) had viral load of 50-999 copies/ml and 50.0% (75/150) had ≥1 000 copies/ml. Multivariate logistic regression analysis showed that being men (aOR=2.04, 95%CI:1.06-3.96), homosexual transmission (aOR=1.53, 95%CI:1.04-2.27), history of sexually transmitted diseases (STDs) before HIV diagnosis (aOR=1.98, 95%CI:1.35-2.92) and HIV viral load ≥1 000 copies/ml (aOR=1.90, 95%CI:1.09-3.30) were the risk factors for syphilis. Marriage (aOR=0.47, 95%CI: 0.29-0.76) was a protective factor for syphilis. Conclusions: The prevalence of syphilis was high in HIV-infected patients with transmission risk in Zhejiang. It is urgent to carry out classified management and targeted intervention in HIV-infected patients, explore multi-disease prevention and treatment mechanism, strengthen syphilis screening and treatment in HIV-infected patients to reduce the transmission of HIV and syphilis.

[A clustered epidemic investigation of non-marital non-commercial heterosexual contact of HIV in Zhejiang Province]

Objective: To identify the transmission relationship between HIV infection cases the non-marital non-commercial heterosexual contact in Zhejiang Province. Methods: When HIV positive was informed during January 2020 to January 2022, the staff conducted an epidemiological investigation to collect cases information on sociodemographic characteristics, mobility information, past HIV testing history, high-risk sexual behaviors, sexual partners, and etcetera. At the same time, 6-8 ml of blood from the new diagnosis of people infected with HIV before antiviral treatment was collected to separate the bleeding plasma. pol gene was amplified by nucleic acid extraction and PCR, sequenced by Sequencer 5.0 software, and Cytoscape 3.6.0 software was used to draw HIV molecular transmission network. Results: From January 2020 to January 2022, 88 HIV infected individuals were found in Pujiang County, of which 74 were transmitted through heterosexual transmission, of which 31 were infected through non-marital non-commercial heterosexual contact. Preliminary case studies have found that three female cases have engaged in unprotected non-marital non-commercial heterosexual contact with one male case. Among the 4 infected individuals, 2 of their spouses tested positive for HIV antibodies. Molecular transmission network monitoring was carried out on 65 newly diagnosed cases of heterosexual transmission with acquired sequences, forming 9 transmission clusters. The largest cluster contained 10 cases. A total of 11 HIV-infected individuals were involved in this HIV cluster epidemic. They were 3 males and 8 females, all over 50 years old and were farmers or rural housewives. They were traced to 7 sexual partners (6 negatives of HIV, 1 undetected). Among the 18 respondents' sexual social network relationships, there were 6 couples, 8 permanent partners, and 3 temporary partners. Among 11 HIV infected individuals, there were 9 cases of non-marital non-commercial heterosexual transmission and 2 cases of intramarital transmission. The epidemiological association between 7 non-married non-commercial heterosexual partners and case 2 (56-year-old male farmer), 3 cases confirmed by epidemiological investigation and molecular transmission cluster results, 3 cases confirmed by molecular transmission cluster and epidemiological investigation results, and 1 case confirmed by epidemiological investigation results. Conclusions: The transmission mode of this cluster epidemic was to spread HIV through heterosexual sex with a male case as the core, then cause the transmission within marriage and between fixed sexual partners. The combination of epidemiological investigation and molecular transmission network traceability survey supports the conclusion of this study.

[Status of personal information sharing on HIV between sexual partners among men who have sex with men who met casual sexual partners on the internet in Zhejiang province]

Objective: To identify the status and determinants of sharing personal HIV information with sexual partners among men who have sex with men (MSM) meeting their casual sexual partners on the internet. Methods: A cross-sectional study was conducted in five cities (Hangzhou, Ningbo, Wenzhou, Taizhou and Shaoxing) in Zhejiang province. The recruitment was enrolled by MSM social organization and in voluntary counseling and testing clinics, with a sample size of 793. A self-designed network questionnaire collected essential characteristics, HIV knowledge, sexual behavior, and sharing personal HIV status. SPSS 20.0 software was used for statistical analysis. Results: Among 767 MSM enrolled 302 MSM who reported finding casual sexual partners on the internet were enrolled in the analysis. MSM reported finding casual partners on the internet only, finding sexual partners online and in places were 62.6% (189/302) and 37.4% (113/302), respectively. Among those reporting web-based sexual behavior in the last six months, 54.6% (165/302) informed their partners of their HIV status, 49.2% (146/297) inquired about HIV status, and 42.9% (82/191) knew HIV status before sex intercourse, 75.8% (113/149) reported consistent condom use with HIV negative partners. The multivariable logistic regression analysis showed that related factors of inconsistent inquired HIV status of partners included 25-34 years old (aOR=2.17, 95%CI: 1.20-3.91), >2 partners on the internet in the last six months (aOR=2.13, 95%CI: 1.27-3.57), low-risk perception of HIV infection with online partners (aOR=1.96, 95%CI:1.14-3.35), numbers of HIV testing >1 times (aOR=0.38, 95%CI: 0.22-0.66). Conclusions: The willingness to know the HIV status of partners among MSM who met sexual partners on the internet was high but with a low rate of knowing their sex partner's HIV status in Zhejiang province. However, the successful implementation proportion was low. Therefore, it is necessary to pay attention to people who are elderly, with less conscience about the risk of the sex partners on the internet, have more sex partners, and have received few HIV tests. In addition, peer education was needed to promote related intervention programs.

[Mechanical analysis of the impact of the morphology of the iris and ciliary body on the central vault after posterior chamber phakic intraocular lens implantation]

Objective: To investigate the impact of the iris and ciliary body morphology on the central vault after phakic posterior chamber intraocular lens (pIOL) implantation. Methods: This research was based on the retrospective analysis of 123 patients (123 eyes) who underwent pIOL implantation in the Department of Ophthalmology, Affiliated Hospital of Qingdao University between June 2018 and June 2020. The anterior segment structure was observed with an ultrasound biomicroscope before surgery, and all morphological parameters of the iris and ciliary body were measured manually using the ImageJ software, including iris span (IS), iris convexity (IC), iris-ciliary body contact distance (ICCD) and iris-lens contact distance (ILCD). The ICCD was divided into Q1, Q2 and Q3 groups according to the equidistant distance of 0.36 mm. The lens thickness was measured with the IOLMaster. The horizontal corneal diameter and anterior chamber depth were measured using the Pentacam. The central vaults were measured by optical coherence tomography at 1 week, 3 months and 1 year after surgery. The relationships between vault values and preoperative parameters of the anterior segment were evaluated using the Pearson correlation analysis, Spearman correlation analysis, and multiple linear regression. The repeated measures ANOVA was applied to identify changes of vault values over time. Results: The mean values of the vaults at 1 week, 3 months and 1 year after surgery were (723±265) μm, (642±255) μm and (613±280) μm, respectively. The difference among them was statistically significant (F=50.143, P<0.001). The vaults continued to decline within 1 year after pIOL implantation, and the total decline was (122±86) μm. The vaults declined by (69±98) μm from postoperative 1 week to 3 months and by (52±54) μm from postoperative 3 months to 1 year. The regression formula showed that the pIOL size and ILCD were positively related with the vault, while the LT, IS and IC were negatively related with the vault at 1 week postoperatively (adjusted R²=0.404, P<0.001). The pIOL size and ILCD were positively related with the vault, while the IS and IC were negatively related with the vault at 3 months postoperatively (adjusted R²=0.342, P<0.001). The pIOL size was positively related with the vault, while the IS and IC were negatively related with the vault at 1 year postoperatively (adjusted R²=0.661, P<0.001). The vault values were higher in group Q3 compared to group Q1 at every timepoint, and the vault value was higher in group Q2 compared to Q1 at 1 year postoperatively. Conclusions: In the early postoperative period, eyes with a larger pIOL, shorter iris span, longer contact distance between the iris and ciliary body, and longer contact distance between the iris and lens were associated with a higher rate of excessive vaults. Meanwhile, eyes with a thicker lens and larger iris reverse convexity were more likely to obtain insufficient vaults. Within one year after surgery, the pIOL size, IS, IC and ICCD continued to impact on the vault. The ICCD, ILCD and IC can reflect the posterior chamber volume and change the haptic location and force, thus affecting the vault.

[Analysis on the relationship of molecular transmission between HIV infected men who have sex with men and their sexual partners]

Objective: To investigate the relationship between HIV-infected men who have sex with men and their sexual partners in Zhejiang province. Methods: A cross-sectional survey was conducted to recruit newly confirmed HIV/AIDS among MSM from 2015 to 2017, including sexual partner identification and molecular epidemiological study. Plasma was collected to extract RNA, and the pol gene of HIV-1 was amplified by RT-PCR/nested PCR. Phylogenetic tree and molecular transmission cluster were analyzed to identify the transmission relationship between sexual partners. Results: A total of 937 HIV/AIDS among MSM were recruited to promote HIV testing for their sexual partners, and 173 positive sexual partners were identified. 50.8% (61/120) of the gene sequences were clustered among the positive sex partners. Seven pairs of clustered sex partners combined with the results of recent infection preliminarily determined the transmission direction. In the clusters, there were statistical differences between the partners who were diagnosed in the same year (OR=12.190, 95%CI: 1.563-95.054) or with current residence in the different districts (OR=17.054, 95%CI: 1.742-166.982). Conclusions: Combined with a molecular transmission network, HIV test for the sexual partners of HIV/AIDS among MSM can improve the accurate tracking of cases and preliminarily determine the direction of transmission, according to the results of recent infection. It is suggested that after HIV is confirmed for HIV/AIDS among MSM, HIV tests should be carried out as soon as possible for their sexual partners, including a cross-regional sexual partner tracking test, which is helpful to improve the tracing procedure.

[Conducting analysis on HIV tracing and molecular network for promoting precise detection,prevention and control of AIDS]

The current sexual transmission of newly infected HIV cases is complicated in China. It is crucial for interrupting HIV transmission by HIV tracing and molecular network analysis,conducting early detection and precise prevention among HIV-positive individuals. The articles in this issue focused on the global situation of HIV tracing, and molecular network analysis in promoting accurate detection and prevention of AIDS started from analyzing the reported epidemiological characteristics of HIV/AIDS in Ningbo city from 2017 to 2020. Relations of HIV transmission between HIV positive individuals and sex partners by tracing investigation were also, analyzed. Data on HIV transmission mode by combining social and molecular networks were gathered to provide evidence for applied research on precise detection, prevention, and control of AIDS.

[Analysis on the HIV-1 molecular transmission characteristics of newly confirmed HIV/AIDS in Jiaxing city, 2017-2018]

Objective: To analyze the relationship between infection and transmission of HIV/AIDS, explore the characteristics of the HIV-1 transmission network, and provide evidence for formulating targeted prevention and control measures. Methods: The newly confirmed HIV/AIDS in Jiaxing from 2017 to 2018 were selected for the study. The sociodemographic and infection transmission-related information was gathered. The blood samples were collected and RNA was extracted, RT-PCR and nested PCR amplified the pol gene of HIV-1. The phylogenetic tree was constructed by Mega 6.0 software for subtype analysis. The genetic distance between strains was calculated, and the molecular transmission network was drawn by using Cytoscape 3.6.0 software. The results of the epidemiological study based on the molecular transmission network were analyzed. Results: There were fifteen HIV-1 gene subtypes in 517 cases of HIV/AIDS. The main subtypes were CRF01_AE (37.1%)、CRF07_BC (36.2%) and CRF08_BC (11.8%). Under the 1.0% gene distance threshold, 87 molecular clusters were established, and the total clustering rate was 45.8% (237/517). The cluster risk factors were 60-81 age group (compared with 14-24 age group, OR=2.690, 95%CI:1.058-6.844), married (compared with unmarried, OR=1.698, 95%CI:1.003-2.875), CRF07_BC subtype (compared with CRF01_AE, OR=2.203, 95%CI:1.426-3.404). The largest molecular cluster, CRF07_BC-1, consisted of 50 cases (including 21 cases confirmed in 2017 cases and 29 confirmed in 2018). Multivariate analysis showed that characteristics of unmarried (compared with married, OR=2.482, 95%CI:1.140-5.402), gays (compared with heterosexual, OR=3.163, 95%CI:1.543-6.483), cases with high-risk transmission (compared with other cases, OR=7.631, 95%CI:1.783-32.654), confirmed in Nanhu and Pinghu districts of Jiaxing (compared with other districts, OR=2.225, 95%CI:1.074-4.608) were risks for entering the largest molecular cluster. There were seven suspected high-risk transmission MSM in the largest molecular cluster. The first debut of homosexual behavior was from 2010 to 2018, and the median number of gay partners was 20 (P₂₅, P₇₅：10, 100) within two years before being diagnosed. Six reported a recent history of looking for gay partners in an MSM dating place in Nanhu district. Conclusions: The HIV-1 subtypes of newly confirmed HIV/AIDS were diverse, mainly sporadic in Jiaxing from 2017 to 2018. There were geographical aggregation characteristics and suspected some high-risk transmission cases, suggesting that rapid transmission and targeted intensive intervention are needed.

[Epidemiological characteristic of newly reported HIV/AIDS cases with non-martial and non-commercial heterosexual behaviors in Zhejiang province, 2017-2019]

Objective: To understand the epidemiological characteristics and transmission routes of newly reported HIV/AIDS cases with non-martial and non-commercial (NMNC) heterosexual behaviors in Zhejiang province. Methods: A retrospective survey was conducted among HIV/AIDS cases that had NMNC heterosexual behavior history and diagnosed with HIV infection in Zhejiang between January 1^st, 2017 and September 30^th, 2019. The multiple correspondence analysis (MCA) was used to explore the association of social demographic characteristics with NMNC heterosexual partner types in the cases. Results: A total of 406 participants with NMNC heterosexual behaviors before HIV diagnoses were recruited in this study. Most of them were males (67.2%, 273/406), aged 25-49 years at HIV diagnoses (59.1%, 240/406). Prior to HIV infection confirmation, 36.0% (146/406) participants only had casual sexual partners, 52.0% (211/406) only had regular sexual partners, and 12.0% (49/406) had both. Statistical differences in marital status, occupation and income level were found among participants with different types of NMNC heterosexual partners (all P<0.05). Result of MCA indicted that monthly income ≤3 000 yuan RMB, self-employed, being married were only associated with casual NMNC heterosexual partner; working in service industry, education level of junior high school were only associated with regular heterosexual partner; working in enterprise, high school education level or above, monthly income ≥5 000 yuan RMB were associated with both casual and regular sexual partner. Conclusion: The HIV/AIDS cases with NMNC heterosexual behaviors before HIV diagnoses accounted for a large proportion in Zhejiang province during 2017-2019. Active intervention efforts should be made to improve the health awareness of the public to reduce the risk behaviors for HIV transmission.

[Willingness of post-exposure prophylaxis and possible related factors in men who have sex with men]

Objective: To analyze the willingness of post-exposure prophylaxis (PEP) to prevent HIV transmission and related factors in men who have sex with men (MSM). Methods: Cross sectional survey design was used in this study. After informed consent, MSM aged 18 years or above and having had homosexual anal or oral sex in the past 6 months were recruited through "i WeChat" official account between September and November, 2019. Results: Of 1 517 MSM were surveyed, the proportion of MSM who had ever heard of PEP were 72.5% (1 100/1 517) and 87.9%(1 333/1 517) of the MSM said they would like to use PEP if it is needed.Multivariate logistic regression analysis suggested that aged above 25 year (OR=1.807, 95%CI: 1.090-2.995), HIV test history (OR=1.953, 95%CI: 1.171-3.256) and being aware of PEP (OR=2.163, 95%CI: 1.468-3.186) were the positive factors for PEP use, but an aware of the HIV status of sexual partner was the negative factor for PEP (OR=0.602, 95%CI: 0.407-0.890). Among MSM who had ever heard of PEP, the positive factors for PEP use included living in Zhejiang (OR=1.942, 95%CI: 1.097-3.438), aged above 25 years (OR=2.431, 95%CI: 1.331-4.439), being aware of PEP (OR=3.714, 95%CI: 1.532-9.007) obtaining information about PEP service from MSM organization/volunteer/health organization. Conclusions: MSM's willingness to use PEP services was relatively high. Age, awareness of PEP related knowledge, and awareness of sexual partner's HIV infection status were the related factors. MSM organization/volunteer/health organization were the main forces for PEP promotion in MSM.

[Related factors on sexual partners regarding receipt of HIV test among HIV positive men who have sex with men in Zhejiang province]

Objective: To understand the situation and influencing factors related to the promotion of HIV testing program among sex partners in newly diagnosed HIV positive MSM in Zhejiang province during 2015 to 2017. Methods: Newly diagnosed HIV positive MSM in Zhejiang province from 2015 to 2017 were collected and provided four rounds of testing services to their sexual partners so as to study the consequences. Chi-square test was conducted to compare the difference between groups while multivariate logistic regression was conducted to analyze the related influencing factors. Results: A total of 6 269 HIV positive MSM were provided with four rounds of testing services to their sexual partners. 1 925 HIV positive MSM (30.7%, 1 925/6 269) were successfully persuaded in mobilizing their sexual partners to participate in the HIV testing services. However, 4 344 HIV positive MSM (69.3%, 4 344/6 269) refused to do so. A total of 2 126 sexual partners received HIV testing and the HIV positive rates of those sexual partners appeared as 13.0% (277/2 126, 95%CI:11.6%-14.5%) and 78.7% (218/277, 95%CI: 73.8%-83.6%). Results from the multivariate logistic regression analysis indicated that factors as: HIV positive MSM that participated in the study in 2016 (compared with participated in the study in 2015, OR=1.581, 95%CI: 1.370-1.823), in 2017 (compared with participated in the study in 2015, OR=1.394, 95%CI: 1.208-1.608), living in the reporting city (compared with lived outside the reporting city, OR=1.518, 95%CI: 1.320-1.745), being married (compared with unmarried/divorced/widowed, OR=4.449, 95%CI: 3.837-5.160), having education level of junior high school or below (compared with education level of senior high school or above, OR=1.203, 95%CI: 1.058-1.367), numbers of homosexual partners >5, (compared with numbers of homosexual partner from past between 1-5, OR=1.236, 95%CI: 1.095-1.395), active detection (compared with passive detection, OR=1.340, 95%CI: 1.193-1.506) were more likely to relate to the successful persuasion on their sexual partners to receive the HIV testing. There was no statistical difference noticed between HIV-infected homosexual partners and their corresponding HIV positive MSM, in terms of socio-demographic situations. Conclusions: HIV positive MSM should promote their sexual partners to receive HIV testing. This seemed an important role in expanding the HIV testing in this population. However, the program needs to be further improved and included in daily work, focusing on those partners with similar social and demographic characteristics with those infected MSM.

[Analysis on the transmission characteristics of newly reported human immunodeficiency virus/acquired immunodeficiency syndrome cases based on the molecular transmission network in Huzhou, Zhejiang, 2017]

Objective: Using field epidemiological investigation and molecular analysis to construct the molecular transmission network of human immunodeficiency virus/acquired immunodeficiency syndrome cases (HIV/AIDS) newly diagnosed in Huzhou in 2017, Zhejiang Province. Methods: A total of 160 participants were obtained through a web-based system from Chinese Center for Disease Control and Prevention (CCDC) with the features of diagnosed in Huzhou in 2017 who also had been collected samples for the first follow-up. The basic information of demographic characteristics and risk factors was extracted from the website. RNA was extracted from plasma samples of untreated cases, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing. Phylogenetic tree was constructed by MEGA software for HIV gene subtyping. TN93 model was used for calculating the distance between two sequences. Cytoscape software was used for drawing molecular transmission network. And then an epidemiological survey was conducted to cases in the primary cluster. Results: A total of 138 sequenced individuals (86.3%) were acquired from 160 individuals. Among which, 123 (89.1%) were male. The highest proportion of subtype was CRF07_BC (60, 43.5%), followed by CRF01_AE (46, 33.3%), and with four cases of Unique Recombinant Form (URF, CRF01_AE and CRF07_BC) and one case of URF (subtype B and C). A total of 18 molecular clusters included 56 individuals (40.6%) were found in the transmission network under the optimal genetic distance threshold (1.0%). The clustering proportion of CRF07_BC (66.1%, 37 cases) was higher than that of CRF01_AE. There were 9 clusters formed among CRF07_BC, including 37 cases (accounting for 61.7%, 37/60). The primary transmission cluster contained 11 cases, among which 9 cases were transmitted by homosexual sex. The first time of the cases to have homosexual behavior is range from 2010 to 2016, whose media number (P(25), P(75)) of partners was 6 (3.5, 8.5). Most of the cases come from Anhui Province and engaged in garment industry (5 cases), between which there were 8 cases used Blued software to seek for casual partners, 1 case seeking for casual partners in garden. Conclusion: With CRF07_BC and CRF01_AE predominantly circulating, HIV genetic diversity had been noticed in this area. The primary cluster was consisted of high proportion of locally new infections, and a specific population aggregation in limited place existed.

[Status and associatied factors of anal sexual intention in casual sex behavior among heterosexual college students in Zhejiang Province]

Objective: To identify the status and risky factors of anal sexual intention in casual sex behavior in Zhejiang province. Methods: Stratified cluster sampling was conducted among college students in 13 colleges in 11 cities between October to November, 2018. 482 students were enrolled who self-reported "heterosexuality "and" ever had casual sex behavior". A self-designed network questionnaire was complimented containing basic information, knowledge of HIV, sexual behavior. Chi-square test was used to compared the difference of anal sex intention between different characteristic. The multivariate logistic regression methods was used to analyze the influence factors. Results: Among 482 students, the age was (20±1.442) years old. And 87.3% (421) were male and 29.0% (140) were from other province. The rate of anal sex intention were 19.4% (94/482) in total, with the rates of 38.1% (24/63) and 14.4% (53/367) in students with sexual number more than 5 and less than 5 (P<0.001), separately. Compared with students searching casual sexual partner with non-internet access (17.0%, 16/201), students searching sexual partner with internet access had higher risk of anal sex practice (27.8%, 78/281) (P<0.001). The rate of anal sex practice among students reporting "ever had casual sex after drinking "and" never had casual sex after drinking" were 30.5% (64/210) and 9.4% (25/266) (P<0.001). The multivariate logistic regression results revealed that compared with students searching casual sexual partner with non-internet access and reporting "never had casual sex after drinking", subjects searching sexual partner with internet access(OR (95%CI)=2.65 (1.34-5.23)) and "ever had casual sex after drinking" OR (95%CI)=3.02 (1.65-5.33) were more likely had higher risk of anal sex practice. Conclusion: Heterosexual college students in Zhejiang Province tend to have anal intercourse with causal sexual partners. Searching for causal sexual partners on internet or mobile phone dating software and having temporary sexual behavior after drinking were correlated factors.

[Epidemiological characteristics of molecular transmission cluster among reported HIV/AIDS cases in Jiaxing city, Zhejiang province, 2017]

Objective: To understand the epidemiological characteristics of one large HIV molecular transmission cluster in Jiaxing city, Zhejiang province, 2017 in order to select those people under high-risk and providing basis for programs on prevention. Methods: During 2017, newly diagnosed HIV/AIDS cases in this city were recruited. Plasma samples were collected from subjects, followed by RNA extraction, RT-PCR and nest-PCR for pol gene amplification, before being sequenced and aligned. Mega 6.0 software was used to construct phylogenetic tree, and Cytoscape 3.6.0 software was used to identify HIV molecular transmission clusters. Cases within the large transmission clusters were investigated, using a field-epidemiology-questionnaire. Data related to socio-demographics and previous sexual behaviors were collected and EpiData 3.0 and SPSS 20.0 software were used. Results: In the large transmission cluster with subtype identified as CRF07_BC, in Jiaxing, 2017, 26 cases of the total 30 cases were investigated. A total of 80.8% (21/26) could be identified as newly infected within the last two years and 30.8%(8/26) could be identified as newly infected within the last one year, including 22 cases infected locally. Among several infected cases who were at age 45 years or older, they admitted that they had experienced unprotected sexual contacts in local city for long time and having had more than 10 disclosed sexual contacts within the last two years at the local venues. Conclusions: This molecular cluster had been formed and scaled up quickly in recent two years, it has played an important role in promoting and scaling up the HIV transmission. Three cases identificed as high risk played an importantrde role in scaling up this cluster.

[Survey of HIV infection in men who have sex with men living for 5 years or less in Wenzhou, Zhejiang province]

Objective: To assess the prevalence of HIV infection and related factors in men who have sex with men (MSM) living for ≤5 years in Wenzhou of Zhejiang province. Methods: MSM who were aged ≥16 years, had lived in Wenzhou for ≥3 months and had anal sex and/or oral sex with men in the last 12 months were recruited through respondent-driven sampling (RDS) from February to October in 2015. The MSM recruited completed a questionnaire for the information collection on socio-demographic characteristics, sexual behavior, awareness of HIV and related intervention, mental health status. Blood samples were collected from them for serological detection of HIV and syphilis antibodies. Software SPSS 18.0 was used to analyze HIV infection and related factors. Results: A total of 454 MSM were investigated, 108 of them (23.7%) were HIV positive. There were 267 MSM who lived in Wenzhou for ≤5 years, and 73 of them (27.3%) were HIV positive. Most of them were workers and commercial servants aged ≥25 years with personal monthly income <4 000 yuan and educational level of junior high school or below. According to multiple logistics regression analysis, age of 25-68 years old (OR=12.19, 95%CI: 2.29-65.02), heterosexual behavior in recent 6 months (OR=0.42, 95%CI: 0.18-0.96), believing it was possible to be infected with HIV (OR=0.06, 95%CI: 0.01-0.95), believing it was impossible to be infected with HIV (OR=0.03, 95%CI: 0.01-0.35) and syphilis status (OR=3.32, 95%CI: 1.05-10.52) were the risk factors associated with HIV infection. Conclusion: Compared with MSM who lived in Wenzhou for >5 years, MSM who lived in Wenzhou for ≤5 years had higher HIV infection rate and higher prevalence of risk behavior. It is necessary to conduct targeted intervention among them.

[Molecular epidemiology and transmission of HIV-1 infection in Zhejiang province, 2015]

Objective: To understand the distribution of HIV-1 subtype diversity and its transmission characteristics in Zhejiang province. Methods: A total of 302 newly diagnosed HIV-1 positive patients were selected through stratified random sampling in Zhejiang in 2015. HIV-1 pol genes were sequenced successfully with reverse transcription PCR/nested PCR and phylogenetic analysis was conducted for 276 patients. Then a molecular epidemiologic study was performed combined with field epidemiological investigation. Results: Of 276 sequence samples analyzed, 122 CRF07_BC strains (44.2%), 103 CRF01_AE strains (37.3%), 17 CRF08_BC strains (6.1%), 9 B strains (3.2%), 6 CRF55_01B strains (2.2%), 5 C strains (1.8%), 1 CRF59_01B strain (0.4%), 1 CRF67_01B strain (0.4%), 1 A1 strain (0.4%), and 11 URFs strains (4.0%) were identified. Phylogenetic analysis revealed 16 clusters with only 15.1% (34/225) sequences involved among CRF07_BC and CRF01_AE strains. The clustered cases in MSM were higher than that in populations with other transmission routes. And clusters existed between the populations with different transmission routes. Conclusion: The major strains of HIV-1 in Zhejiang are CRF07_BC and CRF01_AE. The HIV subtypes showed more complexity in Zhejiang. It is necessary to strengthen the surveillance for HIV subtypes, carry out classified management and conduct effective prevention and control in the population at high risk.

[Previous HIV testing behavior and related factors in men who have sex with men in gay bathroom in Hangzhou, Zhejiang province]

Objective: To understand the related factors on previous HIV testing behavior among MSM who visit gay bathroom in Hangzhou, Zhejiang province. Methods: Through time-location sampling (TLS) survey, men who had oral sex or anal sex with men in past 6 months were interviewed in the gay bathroom in Hangzhou from October 2015 to January 2016. Software SPSS 22.0 was used to analyze the HIV testing acceptance, sexual behaviors and condom usage of MSM during past 6 months, and χ(2) test and logistic regression model were used for univariate and multivariate analyses. Results: Our study planned to recruit 480 gay bathroom MSM, due to the unwilling or other factors, 465 MSM were surveyed. A total of 47.3% (220/465) gay bathroom MSM received HIV testing during past 6 months. Multivariate analysis indicated that being married (OR=0.35, 95%CI: 0.18-0.69), peer education (OR=4.31, 95%CI: 1.32-14.09), homosexual behavior during past 6 months (OR=1.85, 95%CI: 1.08-3.14), extramarital heterosexual behavior during past 6 months (OR=4.12, 95%CI: 2.45-6.91) might be positive factors related with HIV testing acceptation in MSM. Conclusion: Being married, homosexual behavior during past 6 months, extramarital heterosexual behavior, partner education might be the positive factors related with acceptance of HIV testing among gay bathroom MSM. Therefore, peer education needs to be strengthened. HIV testing after high risk sexual behavior needs to be promoted in MSM.

[Effect and mechanism of antimicrobial peptide cathelicidin secreted by tumor associated macrophage on the growth of colorectal cancer in mice]

Objective: To investigate the effect and mechanism of the antibacterial peptide cathelicidin secreted by tumor associated macrophages on the growth of colorectal cancer in mice. Methods: Azoxymethane (AOM)/ dextran sodium sulfate (DSS) method was used to establish a mouse model of colitis associated colon cancer. To induce tumor formation, cathelicidin antibody, IgG antibody (positive control) or PBS (negative control) was respectively injected into mice once every 3 days and lasted one month. Then the pictures of mice colon were taken, and the numbers of tumor were counted and evaluated. Expressions of cathelicidin in tumor associated macrophages isolated from tumor and adjacent normal tissues of mice were examined by quantitative RT-PCR (qRT-PCR) and Western blot. Expressions of the tumor proliferating antigen Ki-67, macrophage marker CD68 and cathelicidin in tumor and non-tumor tissues were determined by immunohistochemistry analysis. Apoptosis of cells from tumor tissues was analyzed by using TdT-mediated dUTP nick-end labeling (TUNEL). Results: In colon tumor tissues, cathlicidin strongly expressed in inflammatory cells (macrophages), but weakly expressed in tumor cells. The tumor number and size in mice injected with cathelicidin neutralizing antibody were 4.50±1.18 and (1.74±0.18) mm, respectively, significantly lower than 13.88±1.98 and (3.74±0.38) mm of mice injected with PBS (t=4.07, t=4.72; P< 0.01) and 15.25±1.82 and (3.40±0.36) mm of mice injected with IgG antibody (t=4.96, t=4.08; P<0.01). The Ki-67 positive rate of cells in tumor tissues of mice injected with cathelicidin neutralizing antibody was (28.20±3.44) %, significantly lower than (68.20±3.51) % of mice injected with PBS (t=8.135, P<0.01) and (69.20±3.41) % of mice injected with IgG antibody (t=8.461, P<0.01). Immunohistochemistry analyses showed that the expression of CD68 in tumor tissues of mice injected with cathelicidin antibody was significantly lower than that of mice injected with IgG antibody or PBS. TUNEL result showed that treatment with cathelicidin neutralizing antibody had negligible effect on the apoptosis of tumor cells. Conclusions: Cathelicidin secreted by tumor associated macrophages can promote the growth of colorectal cancer in mice, and neutralizing cathelicidin activity can inhibit the growth and proliferation of colorectal cancer. Cathelicidin mediated promotion of colon cancer proliferation may mainly be exerted by recruiting inflammatory cells such as macrophages into the tumor microenvironment.

[Analysis on HIV-1 subtypes and transmission clusters in newly reported HIV/AIDS cases in Yiwu, Zhejiang Province, 2016]

Objective: To understand the characteristics of distribution on HIV-1 subtypes and the transmission clusters in Yiwu in Zhejiang province. Methods: A cross-sectional study of molecular epidemiology was carried out on newly reported HIV/AIDS cases in Yiwu. RNA was extracted from 168 plasma samples, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing, phylogenetic tree construction used for analyzing the subtypes and transmission clusters. Mutations on drug resistance was analyzed by CPR 6.0 online tool. Results: Subjects were mainly males (86.3%, 145/168), with average age as (39.1±13.4) years old and most of them were migrants (66.7%, 112/168). The major routes of transmission included homosexual (51.2%, 86/168) and heterosexual (48.8%, 82/168) contacts. The rate of success for sequence acquisition was 89.9% (151/168). The dominant subtypes showed as CRF01_AE (74, 49.0%) and CRF07_BC (64, 42.4%), followed by CRF08_BC (5, 3.3%), CRF55_01B (3, 2.0%), each case of subtype B, CRF45_cpx, CRF59_01B, CRF85_BC and URF (B/C). CRF45_cpx and CRF85_BC were discovered the first time in Zhejiang province. Twenty-six transmission clusters involving 65 cases were found, with the total clustered rate as 43.0% (65/151), in which the CRF01_AE clustered rate appeared as 54.1% (40/74), higher than that of CRF07_BC (21/64, 32.8%). The average size of cluster was 2.5 cases/cluster, with average size of cluster in CRF01_AE patients infected through heterosexual transmission as the largest (3.5 cases/cluster). The prevalence of transmitted drug resistance was 4.6% (7/151). Seven cases with surveillance drug resistant mutations (SDRM) were found, including 5 cases of M46L (3.3%), and one case of F77L or Y181C. Conclusion: HIV genetic diversity and a variety of transmission clusters had been noticed in this study area (Yiwu). Programs on monitoring the subtypes and transmission clusters should be continued and strengthened.

Thiamine supplementation facilitates thiamine transporter expression in the rumen epithelium and attenuates high-grain-induced inflammation in low-yielding dairy cows

An experiment was conducted to uncover the effects of increasing dietary grain levels on expression of thiamine transporters in ruminal epithelium, and to assess the protective effects of thiamine against high-grain-induced inflammation in dairy cows. Six rumen-fistulated, lactating Holstein dairy cows (627 ± 16.9 kg of body weight, 180 ± 6 d in milk; mean ± standard deviation) were randomly assigned to a replicated 3 × 3 Latin square design trial. Three treatments were control (20% dietary starch, dry matter basis), high-grain diet (HG, 33.2% dietary starch, DM basis), and HG diet supplemented with 180 mg of thiamine/kg of dry matter intake. On d 19 and 20 of each period, milk performance was measured. On d 21, ruminal pH, endotoxic lipopolysaccharide (LPS), and thiamine contents in rumen and blood, and plasma inflammatory cytokines were detected; a rumen papillae biopsy was taken on d 21 to determine the gene and protein expression of toll-like receptor 4 (TLR4) signaling pathways. The HG diet decreased ruminal pH (5.93 vs. 6.49), increased milk yield from 17.9 to 20.2 kg/d, and lowered milk fat and protein from 4.28 to 3.83%, and from 3.38 to 3.11%, respectively. The HG feeding reduced thiamine content in rumen (2.89 vs. 8.97 μg/L) and blood (11.66 vs. 17.63 μg/L), and the relative expression value of thiamine transporter-2 (0.37-fold) and mitochondrial thiamine pyrophosphate transporter (0.33-fold) was downregulated by HG feeding. The HG-fed cows exhibited higher endotoxin LPS in rumen fluid (134,380 vs. 11,815 endotoxin units/mL), and higher plasma concentrations of lipopolysaccharide binding protein and pro-inflammatory cytokines when compared with the control group. The gene and protein expression of tumor necrosis factor α (TNFα), IL1B, and IL6 in rumen epithelium increased when cows were fed the HG diet, indicating that local inflammation occurred. The depressions in ruminal pH, milk fat, and protein of HG-fed cows were reversed by thiamine supplementation. Thiamine supplementation increased thiamine contents in rumen and blood, and also upregulated the relative expression of thiamine transporters compared with the HG group. Thiamine supplementation decreased ruminal LPS (49,361 vs. 134,380 endotoxin units/mL) and attenuated the HG-induced inflammation response as indicated by a reduction in plasma IL6, and decreasing gene and protein expression of pro-inflammatory cytokines in rumen epithelium. Western bottling analysis showed that thiamine suppressed the protein expression of TLR4 and the phosphorylation of nuclear factor kappa B (NFκB) unit p65. In conclusion, HG feeding inhibits thiamine transporter expression in ruminal epithelium. Thiamine could attenuate the epithelial inflammation during high-grain feeding, and the protective effects may be due to its ability to suppress TLR4-mediated NFκB signaling pathways.

[Production of recombinant human interleukin-38 and its inhibitory effect on the expression of proinflammatory cytokines in THP-1 cells]

Interleukin (IL)-38 is the latest member of the IL-1 cytokine family. However, as a result of lacking efficient method to generate relatively large quantity of IL-38, its precise functions are poorly understood. In the present study, the cloning, expression, purification, and activity analysis of recombinant human IL-38 was described. Human IL-38 cDNA was cloned into the prokaryotic expression vector pET-44. The recombinant IL-38 containing a C-hexahistidine tag was expressed in Escherichia coli BL21 (DE3) which induced by isopropyl-β-D-thiogalactoside. The expressed fusion protein was purified by Ni-NTA affinity chromatography. IL-38 protein was largely found in the soluble fraction. The purified IL-38 appeared a single band on SDS-PAGE, the yield of IL-38 was 4 mg from 1 L of bacterial culture, and the purity was more than 98% with low endotoxin level (<0.1 EU/μg). Western blotting confirmed the identity of the purified protein. Activity analysis showed that IL-38 can inhibit effectively the expression of proinflammatory cytokines, such as tumor necrosis factor-α, IL-1β, IL-17, and monocyte chemoattractant protein-1 in lipopolysaccharide-activated THP-1 cells. The production and characterization of biologically active IL-38 will be beneficial for its potential role in clinical applications.

Large degree of polarization of photoluminescence caused by anisotropic strain in nonpolar a-plane MgxZn1-xO layers grown by plasma-assisted molecular beam epitaxy

A large degree of polarization (ρ) of photoluminescence (PL) approximate to 1 is obtained in each nonpolar a-plane Mg_xZn_1-xO layer grown by plasma-assisted molecular beam epitaxy (MBE) with x=0.01, 0.03, and 0.10, respectively. Anisotropic in-plane strains are selectively introduced by using foreign substrates and doping with different Mg contents, which strongly modify the valence band structures, leading to anisotropic optical properties. A polarized Raman measurement shows that anisotropic in-plane strains along the y and z axes increase with the increasing Mg contents. Polarized PL spectra show that ρ gradually increases to 0.97 with decreasing in-plane strains, resulting from an increasing difference in transition energy (ΔE) between E⊥c and E‖c caused by a lift of the degeneracy of valence band structures. The obtained highly polarized emission is close to linear polarized light, which is desirable in the backlighting of liquid crystal displays.

Relationship between thiamine and subacute ruminal acidosis induced by a high-grain diet in dairy cows

Two experiments were conducted to reveal the effects of grain-induced subacute rumen acidosis (SARA) on thiamine status in blood and rumen fluid in dairy cows. In both experiments, 6 multiparous, rumen-fistulated Holstein dairy cows were used in a 2-treatment, 2-period crossover design. Each experimental period consisted of 21d (total of 42d). Experiment 1 was to investigate the effects of SARA on thiamine status in blood and rumen fluid. Treatments were either control (20% starch, dry matter basis) or SARA-inducing diet (SAID, 33.2% starch, dry matter basis). In experiment 2, the effects of dietary thiamine supplementation on attenuating SARA and ruminal fermentation characteristics in dairy cows were studied. All cows received the same SAID diet during the whole experimental period; treatments were with or without thiamine (180mg of thiamine/kg of dry matter intake). In both experiments, rumen fluid samples were collected at 0, 3, 6, 9, and 12h after morning feeding on d 21 and 42 of the experiments for measurement of pH, thiamine, volatile fatty acid, and lactate contents. Peripheral blood was also collected at 3h after morning feeding on d 21 and 42 to measure thiamine, carbohydrate metabolites, and enzyme activities. In experiment 1, cows fed the SAID diet had lower ruminal and plasma thiamine concentrations and higher lactate than cows fed the control diet. The ruminal thiamine contents were positively related to pH and the concentrations of acetate in the rumen, and negatively correlated with the lactate contents. Experiment 2 demonstrated that ruminal pH and the concentrations of thiamine, acetate, and total volatile fatty acids in the rumen were increased, whereas ruminal lactate contents were reduced by thiamine supplementation. The concentrations of lactate and the activity of lactate dehydrogenase in blood were reduced in the thiamine supplemented group, and the opposite was true for the nonesterified fatty acids and α-ketoneglutarate dehydrogenase contents. In conclusion, the thiamine status was affected by SARA in dairy cows and ruminal infusion of thiamine could help attenuate SARA by improving theproportions of ruminal volatile fatty acids and reducing lactate contents in rumen fluid and blood.

Electrochemiluminescent detection of mucin 1 protein and MCF-7 cancer cells based on the resonance energy transfer

A novel sensing strategy for sensitive detection of mucin 1 protein (MUC1) and MCF-7 cells based on electrochemiluminescence (ECL) resonance energy transfer (ERET) from bis(2,2'-bipyridine)-(5-aminophenanthroline)ruthenium(II) (Ru1) to graphene oxide (GO) was proposed. The MUC1 aptamer was covalently combined with Ru1 (Ru1-aptamer) using aqueous carbodiimide coupling chemistry. Due to the strong noncovalent interaction between the Ru1-aptamer and GO, the ECL of Ru1 was efficiently quenched because of the ERET. In the presence of a target MUC1 protein, the binding between the Ru1-aptamer and MUC1 disturbed the interaction between the Ru1-aptamer and GO. These interactions led to the release of the Ru1-aptamer from GO, and resulted in the restoration of Ru1 ECL. This was shown to detect MUC1 protein sensitively in a linear range from 64.9 to 1036.8 nM with a detection limit of 40 nM. With further application in the detection of MCF-7 cells, the presented method could respond at concentrations as low as 30 cancer cells per mL. By substituting the aptamer and the corresponding target, this method could be conveniently extended for the sensitive detection of other biomolecules.

[HLA-DQ molecules associated with myasthenia gravis in Chinese patients]

Myasthenia Gravis (MG) is an autoimmune disease which is a neuromuscular disorder of autoimmune origin. MG in different races or ethnic groups has different genetic susceptibility. To search for the associations of MG in the Chinese patients with HLA-DQ molecules, PCR-RFLP method was employed for genotyping HLA-DQA1 and -DQB1 genes of MG patients and the normal Chinese. The distributions of alleles of DQA1 and DQB1 in the normal Chinese and the MG patients were listed. The DQB allele, DQB1 * 0302 was positively associated with MG (RR = 2.990, Pc = 0.0307), and a negative association was found for DQA1 * 0501 (RR = 0.4166, Pc = 0.0315). DQ haplotype DQA1 * 0301-DQB1 * 0302 was significantly increased in patients when compared to controls (RR = 7.727, Pc = 0.0109).

The effect of Epstein-Barr virus gene BHRF1 expression on radioresistance of nasopharyngeal carcinoma cells

In order to investigate the effect of the expression of Epstein-Barr virus gene BHRF1 on the apoptotic resistance of nasopharyngeal carcinoma cells to radiation, a highly expressing vector for BHRF1 was constructed and transfected into the nasopharyngeal carcinoma cell line CNE2. Then, the biologic alterations of the cells were tested after 60Co radiation. The results showed that, in the BHRF1-expressing cells, the apoptotic index was far lower than in the control groups after 60Co radiation, and cells recovered faster from the radiation, with a higher cell-proliferative rate, stronger ability of colony formation and tumor development in nude mice than that in the control groups. Given the functional homology of BHRF1 with bcl-2, our data indicate that BHRF1 expression could prohibit nasopharyngeal carcinoma cellular apoptosis caused by radiation and in this way contribute to oncogenic transformation.

Epstein-Barr virus BHRF1 prohibits the cells of nasopharyngeal carcinoma from apoptosis

Epstein-Barr virus (EBV) is associated with nasopharyngeal carcinoma (NPC). The BHRF1 EBV protein is expressed at high levels in productively infected cells and certain latently infected cells. In order to investigate the effect of expression of BHRF1 on the biological behaviour of NPC cells, we constructed the BHRF1 high expression vector and transfected it into the NPC cell line, CNE2. Then, the alteration of proliferation and apoptotic rates in the cells were tested before and after camptothecin treatment. After treatment by camptothecin, BHRF1-CNE2 cells could constantly and slowly proliferate and its apoptotic rate was less than in control groups, and the number of cells in the G phase decreased and in the S phase increased. So, it suggests that BHRF1 expression can enhance the resistibility of CNE2 cells to DNA-damaging agents that cause apoptosis.

[Evaluation on the effect of supplementary immunization for poliomyelitis elimination in Hainan province]

We appraised the effect on poliomyelitis elimination programme in Hainan Province, based on data as incidences of poliomyelitis in last years, the routine immunization and the activities on National Immunization Day (NID) and Provincial Immunization Day (PID). The result indicated that the effect of NID in 1993/1994 was remarkable. In Hainan Province, there has been no poliomyelitis case caused by wild strain of poliovirus since 1994. Laboratory data also demonstrated that NID could break the circulation of wild strain of type I poliovirus. We found that routine immunization alone could not effectively eliminate poliomyelitis but other activities of NID must be carried out in order to form an immunity-barrier within a short period.