Yumao Cai

Shenzhen Center for Disease Control and Prevention, Shen-ch’üan-shih, Zhejiang Sheng, China

Are you Yumao Cai?

Claim your profile

Publications (8)17.72 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: IntroductionMale sexual orientation is thought to have a genetic component. However, previous studies have failed to generate positive results from among candidate genes. Catechol-O-methyltransferase (COMT), located on chromosome 22, has six exons, spans 27 kb, and encodes a protein of 271 amino acids. COMT has an important role in regulating the embryonic levels of catecholamine neurotransmitters (such as dopamine, norepinephrine, and epinephrine) and estrogens. COMT is also thought to be related to sexual orientation.AimsThis study aimed to investigate the relationship between the COMT Val158Met variant and male sexual orientation. We performed association analysis of the COMT gene single nucleotide polymorphism, Val158Met, in 409 homosexual cases and 387 heterosexual control Chinese men. COMT polymorphism status was determined using a polymerase chain reaction-based assay.Methods Polymerase chain reaction was performed to genotype the COMT Val158Met polymorphism.Main Outcome MeasuresThe frequency differences of the genotype and alleles distribution between the male homosexual and control groups.ResultsSignificant differences, both in genotype and alleles, between male homosexual individuals and controls indicated a genetic component related to male homosexuality. The Val allele recessive model could be an interrelated genetic model of the cause of male homosexuality.Conclusion The COMT Val158Met variant might be associated with male sexual orientation and a recessive model was suggested. Yu W, Tu D, Hong F, Wang J, Liu X, Cai Y, Xu R, Zhao G, Wang F, Pan H, Wu S, Feng T, and Wang B. Analysis of the association between catechol-O-methyltransferase Val158Met and male sexual orientation. J Sex Med **;**:**–**.
    Journal of Sexual Medicine 09/2015; 12(9). DOI:10.1111/jsm.12978 · 3.15 Impact Factor
  • Yumao Cai · Hui Liu · Yajuan Song · Fuchang Hong ·
    [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the distribution and factors associated with HIV and syphilis infection among Men who have sex with men blood donors (MSMBD) in Shenzhen. A total of 813 MSMBD were recruited using snowball sampling and respondent driven sampling from 2009 to 2012 in Shenzhen. Questionnaire-based interviews were conducted on a one-on-one basis. Data were collected including socio-demographic information, HIV testing history, self-identified sexual orientation, role in homosexual behavior, information about having sex with male sexual partners in the past six months and information about having sex with female sexual partners in the past six months.5 ml blood samples were taken and tested for treponema pallidum and HIV antibodies. Comparisons of syphilis and HIV infection among different years were analyzed by the Cochran-Armitage trend test. Factors associated with syphilis and HIV infection were analyzed by the univariate logistic regression and multivariate unconditional logistic regression. The prevalence of syphilis, HIV, and syphilis-HIV co-infection among 813 participants were 22.0% (179/813), 8.0% (65/813), and 4.2% (34/813), respectively. In the multivariate logistic regression analysis, ever tested for HIV (versus without HIV testing history, OR (95%CI) = 0.369(0.213-0.641)) will decrease the risk of HIV infection among MSMBD in comparison with never tested for HIV (OR (95%CI) = 0.37 (0.21-0.64) ); having five or more anal sexual partners in the past six months and co-infected with syphilis will increase the risk of HIV infection among MSMBD in comparison with having 0-1 sexual partners (OR (95%CI) = 2.04 (1.03-4.06) ) and negative syphilis (OR (95%CI) = 4.52(2.64-7.73)), respectively, bisexual orientation, having 2-4 anal sexual partners and having five or more anal sexual partners in the past six months, using condoms not for every act of anal sex, co-infected with HIV will increase the risk of syphilis infection among MSMBD in comparison with homosexual orientation (OR (95%CI) = 1.60(1.12-2.27)), having 0-1 sexual partner in the past six months (OR (95%CI) = 1.77 (1.09-2.87) and OR (95%CI) = 1.84(1.09-3.08) ) , using condoms for every act of anal sex (OR (95%CI) = 1.61 (1.10-2.36) ) and negative HIV (OR (95%CI) = 4.02 (2.33-6.96)), respectively. The prevalence of HIV and syphilis among MSMBD in Shenzhen are much higher with complex influence factors. The relevant government should pay great attention to it and ensure the blood safety.
    Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 02/2014; 48(2):128-32.
  • Source
    Jian Li · Hongjie Liu · Hui Liu · Tiejian Feng · Yumao Cai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Little research has assessed the degree of severity and ordering of different types of sexual behaviors for HIV/STI infection in a measurement scale. The purpose of this study was to apply the Rasch model on psychometric assessment of an HIV/STI sexual risk scale among men who have sex with men (MSM). A cross-sectional study using respondent driven sampling was conducted among 351 MSM in Shenzhen, China. The Rasch model was used to examine the psychometric properties of an HIV/STI sexual risk scale including nine types of sexual behaviors. The Rasch analysis of the nine items met the unidimensionality and local independence assumption. Although the person reliability was low at 0.35, the item reliability was high at 0.99. The fit statistics provided acceptable infit and outfit values. Item difficulty invariance analysis showed that the item estimates of the risk behavior items were invariant (within error). The findings suggest that the Rasch model can be utilized for measuring the level of sexual risk for HIV/STI infection as a single latent construct and for establishing the relative degree of severity of each type of sexual behavior in HIV/STI transmission and acquisition among MSM. The measurement scale provides a useful measurement tool to inform, design and evaluate behavioral interventions for HIV/STI infection among MSM.
    BMC Public Health 10/2011; 11(1):763. DOI:10.1186/1471-2458-11-763 · 2.26 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Male sexual orientation has been proposed to have genetic components, but previously suggested candidate genes have all received negative results. The human sonic hedgehog (SHH) gene is located in the 7q36 region, which was linked to male sexual orientation in a previous genome-wide association study. SHH is known to play an important role in embryo patterning, and there is evidence connecting it to sexual orientation. In this study, we performed an association analysis of the SHH tag single nucleotide polymorphism rs9333613 in 361 subjects and 319 Chinese male controls. We find a significant difference in genotype and allele distribution between identified homosexuals and heterosexual control subjects, suggesting that the SHH gene could potentially be associated with male sexual orientation.
    Journal of Andrology 09/2011; 33(5):951-4. DOI:10.2164/jandrol.110.012849 · 2.47 Impact Factor
  • Source
    Hongjie Liu · Tiejian Feng · Toan Ha · Hui Liu · Yumao Cai · Xiaoli Liu · Jian Li ·
    [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: The objective of this study was to examine the interrelationships among individualism, collectivism, homosexuality-related stigma, social support, and condom use among Chinese homosexual men. METHODS: A cross-sectional study using the respondent-driven sampling approach was conducted among 351 participants in Shenzhen, China. Path analytic modeling was used to analyze the interrelationships. RESULTS: The results of path analytic modeling document the following statistically significant associations with regard to homosexuality: (1) higher levels of vertical collectivism were associated with higher levels of public stigma [β (standardized coefficient) = 0.12] and self stigma (β = 0.12); (2) higher levels of vertical individualism were associated with higher levels self stigma (β = 0.18); (3) higher levels of horizontal individualism were associated with higher levels of public stigma (β = 0.12); (4) higher levels of self stigma were associated with higher levels of social support from sexual partners (β = 0.12); and (5) lower levels of public stigma were associated with consistent condom use (β = -0.19). CONCLUSIONS: The findings enhance our understanding of how individualist and collectivist cultures influence the development of homosexuality-related stigma, which in turn may affect individuals' decisions to engage in HIV-protective practices and seek social support. Accordingly, the development of HIV interventions for homosexual men in China should take the characteristics of Chinese culture into consideration.
    02/2011; 1(1):27-35. DOI:10.5463/sra.v1i1.16
  • Toan H Ha · Hongjie Liu · Hui Liu · Yumao Cai · Tiejian Feng ·
    [Show abstract] [Hide abstract]
    ABSTRACT: The HIV epidemic spreads among men who have sex with men (MSM) in China. The objective of this study was to examine and compare HIV/AIDS knowledge and sexual risk for HIV between MSM who engaged in concurrent sexual partnerships and MSM who did not. A cross-sectional study using respondent driven sampling was conducted among 351 MSM in Shenzhen, China. About half (49%) of respondents reported having concurrent sexual partnerships during the past 6 months. Among MSM with concurrent sexual partnerships, 62% had only male partners and 38% had both male and female partners. The proportion of inconsistent condom use was 42% among MSM with concurrent partners and 30% among MSM without. These 2 groups reported a similar level of self-perceived risk for HIV. Compared to MSM without concurrent sexual partners, those with such partners were more likely to work in entertainment venues and had a lower level of HIV/AIDS knowledge. The large number of MSM engaging in concurrent sexual partnerships and the high prevalence of bisexuality could accelerate the spread of HIV to the general population unless effective HIV interventions for MSM are implemented in China.
    Sexually transmitted diseases 05/2010; 37(8):506-11. DOI:10.1097/OLQ.0b013e3181d707c9 · 2.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Research on risk behaviors among men who have sex with men (MSM) is often based on individualistic models of health behavior, but sexual behavior is inherently social in nature and often determined by constituents of social networks. The objective of this study was to examine relationships among social networks, network norms of condom use, and safer sex. A respondent-driven sampling study recruited 350 MSM in the Shenzhen region of China between November and December 2007 and collected information on network components (relations, structures, and functions) and HIV risk behavior among egos (those interviewed) and their network alters. A total of 2385 alters were nominated by the 350 egos. Egos reported an average of 4 nonsexual relation alters and 2 sexual-partner alters. Egos perceived receiving more tangible and emotional support from nonsexual relation alters than from sexual-partner alters. Two thirds (69%) of egos consistently used condoms. Sixty-seven percent of egos reported having 1 or more alters who always encouraged egos to use condoms, 84% had 1 or more alters who consistently used condoms, and 55% had 1 or more alters who insisted on condom use. Both subjective and descriptive norms were positively associated with consistent condom use. Network components were associated with the levels of the two norms. These findings suggest that social network components may activate or strengthen condom use norms within networks, which, in turn, determine consistent condom use among MSM. HIV behavioral interventions need to target the promotion of safer sex practices through enhancing peer norms of condom use within networks.
    AIDS patient care and STDs 10/2009; 23(10):885-93. DOI:10.1089/apc.2009.0043 · 3.50 Impact Factor
  • Hongjie Liu · Hui Liu · Yumao Cai · Anne G Rhodes · Fuchang Hong ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Money boys (MBs) are male sex workers who sell sex to men who have sex with men (MSM). This study estimates the proportion of MBs in the Chinese MSM, compares HIV risks between MBs and non-MB MSM, and examines the associations between practicing safer sex and peer norms of condom use. Respondent-driven sampling (RDS) was used to sample 351 MSM in the city of Shenzhen in 2007. The RDS-adjusted proportion of MBs among MSM was 9%. Compared to non-MB MSM, more MBs reported having had multiple male and female sexual partners. Half of MBs and non-MB MSM had consistently used condoms. Both descriptive and subjective norms were positively associated with condom use. The MB proportion of 9% in MSM implies a relatively large population of MBs in China. The association between peer norms and consistent condom use can assist with the development of culturally competent HIV interventions that promote safer sex.
    AIDS and Behavior 11/2008; 13(4):652-62. DOI:10.1007/s10461-008-9475-0 · 3.49 Impact Factor