Estimate the population size of transgender women based on the capture-recapture method in Tianjin / 中华流行病学杂志

Objective: To investigate the population size of transgender women (TGW) in Tianjin and analyze the characteristics of their sexual behaviors to provide a basis for AIDS prevention and control. Methods: To estimate the population size of TGW in Tianjin using the capture-recapture method. At the same time, an anonymous questionnaire was collected to conduct a multi-factor logistic analysis of the TGW population's sexual behavior. Results: A total of 213 TGW were investigated. Tianjin's estimated TGW population size was 599 (95%CI: 407-792). Multivariate logistic analysis of the use of condoms consistently showed that compared with TGW without regular sex partners, those with regular sex partners had a lower proportion of consistent condom use (aOR=0.44, 95%CI: 0.23-0.82) and had received HIV tests in the last year were more likely to adhere to condom use than those who had not been tested (aOR=2.73, 95%CI: 1.06-6.99). Conclusion: It is necessary to strengthen HIV mobilization testing among the TGW population and their regular sexual partners to improve condom use.

Analysis on psychoactive substances use in men who have sex with men in Tianjin / 中华流行病学杂志

Objective: To understand the use of psychoactive substances and its related factors in men who have sex with men (MSM) in Tianjin. Methods: A cross-sectional survey was conducted in MSM recruited in Tianjin by snowball sampling from September 2017 to December 2020, the information about their social demographic information, use of psychoactive substances and behavioral characteristics were collected, meanwhile the blood samples were taken from them for HIV/syphilis detections. Multivariate logistic regression was used to explore related factors about psychoactive substances use. Results: A total of 9 218 MSM were included in the study, in whom 43.5% (4 013/9 218) had ever used psychoactive substances, including 92.6% (3 718/4 013)who used Rush and 17.2% (692/4 013) who used multi substances. Multivariate analysis showed that, the OR of psychoactive substances use in MSM who were in Han ethnic group was 0.68 (95%CI:0.51-0.91) compared with those who were in minor ethnic group; the OR of psychoactive substances use in MSM who were married or cohabited, divorced or widowed were 0.65 (95%CI: 0.57-0.71), 0.80 (95%CI: 0.65-0.97) respectively compared with those who were unmarried; the OR of psychoactive substances use in MSM who had the first homosexual sex at age of ≥30 years was 0.57 (95%CI: 0.44-0.74) compared with those who had the first homosexual sex at age of <30 years; the OR of psychoactive substances use in local MSM in Tianjin was 1.12 (95%CI: 1.03-1.23) compared with those who were not local residents in Tianjin; the OR of psychoactive substances use in MSM with education level of college or above was 1.29 (95%CI: 1.12-1.49) compared with those with education level of junior middle school or below; the OR of psychoactive substances use in MSM who had anal sex in the past six months was 1.93 (95%CI: 1.34-2.77) compared with those who had no anal sex; the OR of psychoactive substances use in MSM who had >2 homosexual partners in the last week was 1.62 (95%CI: 1.41-1.87) compared with those who had ≤2 homosexual partners; the OR of psychoactive substances use in MSM who had homosexual commercial sex in the past six months was 1.99 (95%CI: 1.62-2.45) compared with those who had no homosexual commercial sex; the OR of psychoactive substances use in MSM who had sexually transmitted diseases in the last year was 2.39 (95%CI: 1.82-3.12) compared with those who had no sexually transmitted diseases and the OR of psychoactive substances use in MSM who received peer education services in the last year was 1.63 (95%CI: 1.50-1.78) compared with those who received no peer education services. Conclusion: The prevalence of psychoactive substances use is high in MSM in Tianjin, and there are many influencing factors. It is necessary to conduct targeted interventions according to the influencing factors.

Survey on recent infection of human immunodeficiency virus among men who have sex with men in Tianjin during 2008-2009 / 中华流行病学杂志

Objective To study the situation of HIV infections among men who have sex with men (MSM) in Tianjin during 2008-2009 and to provide reasonable evidence for intervention strategy.Methods Transect investigations in MSM were conducted three times during 2008-2009.Blood samples were collected and detected to identify the recent HIV infection with IgG-capture BED-enzyme immunoassay (BED-CEIA) before HIV incidence was estimated.Results 1799 specimens were tested and the HIV prevalence rates of each study were 6.7％,8.6％ and 6.2％,while the incidence rates were 2.7％,2.5％ and 2.8％,respectively.The estimated incidence rates among these testees were 5.36％ and 5.52％ per year in 2008 and 2009.Conclusion Results of this study showed that the HIV incidence stabilized at high level among MSM in Tianjin,calling for the effective interventions be taken for HIV/AIDS control and prevention.

Prokaryotic expression, purification, and immunogenicity analysis of Mycobacterium tuberculosis specific excretive proteins / 中国医学科学院学报

<p><b>OBJECTIVE</b>To obtain the recombinant rv1837c and rv3803c of Mycobacterium tuberculosis using gene engineering technology and explore their prokaryotic expression, purification, and immunogenicity.</p><p><b>METHODS</b>The Mycobacterium tuberculosis rv1837c and rv3803c genes were amplified by polymerase chain reaction, and then cloned into the vector pTA2, followed by the subclone into the expression vector pET30a (+). The resulting plasmids, named pET30a (+): rv1837c and pET30a (+): rv3803c, encode recombinant protein containing a hexa-histidine tag on its N-terminus. pET30a (+): rv1837c and pET30a (+): rv3803c were introduced into E. coli BL21 (DE3) by transformation respectively, and the recombinant gene was induced with 0.4 mmol/L isopropyl-D-thiogalactopyranoside. The expressed products were identified by Western blot with hexa-histidine tag antibody and serum from tuberculotic patients. The histidine tagged protein was purified by nickel nitrilotriacetic acid His-Bind resin. Rabbits were immunized with purified recombinant Rv1837c and Rv3803c proteins. Then the purified recombinant Rv1837c and Rv3803c proteins were used to detect antibody in rabbit serum, which had been immunized by Western blot.</p><p><b>RESULTS</b>After transformation of the E. coli and induction with 0.4 mmol/L of isopropyl-D-thiogalactopyranoside, recombinant target proteins Rv1837c (relative molecular mass: 92000) and Rv3803c (relative molecular mass: 38 000) were expressed in pET30a (+): rv1837c and pET30a (+): rv3803c system. The expressed protein existed in cytoplasm in an unsoluble form and amounted to 30% and 50% of the total proteins of E. coli. The purity of the purified protein reached 90%. The immunogenicity of the recombinant proteins Rv1837c and Rv3803c was strong, as identified by Western blot.</p><p><b>CONCLUSION</b>The prokaryotic expression recombinant plasmids pET30a (+): rv1837c and pET30a (+): rv3803c was successfully constructed and the recombinant proteins Rv1837c and Rv3803c were obtained, which laid a basis for the optimized diagnosis of active tuberculosis.</p>

Establishment and evaluation of nitrate reductase combined with mycobacteriophage assay / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a rapid, inexpensive, and simple drug susceptibility test (DST) for Mycobacterium tuberculosis (M. tb) and evaluate its feasibility.</p><p><b>METHOD</b>We used nitrate reductase combined with mycobacteriophage assay (PhaB-NRA) to test 49 clinical M. tb isolates of, and the results were compared with those of PhaB-NRA and traditional absolute concentration method.</p><p><b>RESULTS</b>The sensitivity, specificity, and accuracy of PhaB-NRA for rifampicin were 89.1%, 91.67%, and 89.8%; on the contrary, those of isonicotinyl hydrazide were 86.21%, 90.0%, and 87.8%, respectively. The coincidence between PhaB-NRA and traditional assay were 0.746 for rifampicin and 0.750 for isonicotinyl hydrazide.</p><p><b>CONCLUSIONS</b>PhaB-NRA is an inexpensive, rapid, and simple DST method. It is a promising rapid screening technique for DST of M. tb.</p>

Relationship between the resuscitation promoting role of resuscitation promoting factor and the initial bacteria amount of dormant Mycobacterium tuberculosis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the relationship between the resuscitation promoting role of resuscitation promoting factor and the initial bacteria amount of dormant Mycobacterium tuberculosis.</p><p><b>METHODS</b>Mycobacterium tuberculosis (dormant bacteria) was cultured for 100 days, then diluted into 1 mg/ml concentration with 7H9, and further diluted into 0.5, 0.25, 0.125, 0.0625, and 0.03125 mg/ml. Twelve new tubes added with 5 ml 7H9 and divided into two groups: the first group was added with the resuscitation-promoting factor protein, and the second group as control was added with 7H9. In each group the above diluted solutions were added. The tubes were located at 37 degrees C for culture. Optical density (OD) was detected on day 15, 25, 30, and 35. From each tube 1 microl culture solution was plated on 7H11 medium for colony counting.</p><p><b>RESULTS</b>OD detection showed that bacteria proliferation in each group had positive linear correlation (P < 0.05, P < 0.01), indicating that the resuscitation-promoting factor played a similiar role in solutions with different dilution concentrations. 7H11 results and the OD results show that these two detection methods in each group had linear correlation (P < 0.05, P < 0.01), indicating that these two methods showed consistent test results.</p><p><b>CONCLUSION</b>The resuscitation-promoting factor has no effect on the resuscitation of dormant Mycobacterium tuberculosis and its initial bacteria amount.</p>

Rapid testing on drug susceptibility of Mycobacterium tuberculosis with nitrate reducrase assay / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish a rapid method for testing drug sussceptibility on Mycobacterium tuberculosis.</p><p><b>METHODS</b>Taking absolute Concentration method for drug susceptibility testing of M. tuberculosis as the "gold standard", we examined the drug-resistant of M. tuberculosis strain with nitrate reducrase assay (NRA) and the drug-resistant of M. tuberculosis germ in sputum with NRA.</p><p><b>RESULTS</b>NRA and absolute concentration method was basically comparable with NRA susceptibility as 96.5% and the specificity was 100%, When comparing with traditional absolute concentration method, NRA could shorten the time about 3 weeks. Using NRA to test the drug-resistant of M. tuberculosis germ in sputum, its susceptibility was more than 66.7% and specificity was 100%, within 10-20 days.</p><p><b>CONCLUSION</b>NRA could be used as a rapid drug susceptibility testing on M. tuberculosis.</p>

DNA fingerprinting of Mycobacterium tuberculosis strains from Beijing, Guangdong and Ningxia / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the epidemic distribution of Mycobacterium tuberculosis isolates from Beijing, Guangdong and Ningxia, and to determine M. tuberculosis strains of the "Beijing Family".</p><p><b>METHODS</b>Two hundred and six IS6110 DNA fingerprinting patterns of M. tuberculosis strains from three provinces (city) were transferred to digital data, compared with the world M. tuberculosis DNA fingerprinting database, and then clustered by Gel compare 4.1 software. The clustering values in different patients with tuberculosis were compared by chi(2) test. Risk factors for recent transmission were calculated using odd ratios.</p><p><b>RESULTS</b>No M. tuberculosis strains were found the same as those of DNA fingerprint database. 56.8% (117/206) fingerprinting patterns of M. tuberculosis shared by least two-thirds of the IS6110 fragments and their Spoligotyping fingerprinting patterns were consistent with those of M.tuberculosis strains of the "Beijing Family". There were significant differences between female and male, different age groups (< 42 years old) and older (>or= 42 years old) (P < 0.05). Odd ratio was 5.06 in the group younger than 42 years old (95% CI: 1.00 - 34.34) and was 4.43 (95% CI: 0.94 - 28.76) in males.</p><p><b>CONCLUSION</b>M. tuberculosis strains of "Beijing Family" were popular in Beijing, Guangdong and Ningxia. Men and younger age group (< 42) were shown to be infected by identical strains more often than women and older aged which might play an important role in the recent transmission of tuberculosis in these areas. IS6110 DNA fingerprinting of M. tuberculosis could be used to trace the source of tuberculosis infection.</p>