OBJECTIVETo explore the relevant factors of the causes of sexual orientations of gay.

METHODFrom March to June 2013, 350 gays were recruited from one music bar and three bath centers where gays frequently visited in Changsha city, by proportional stratified sampling method. Meanwhile, another 332 males who identify themselves as non-homosexuality were also recruited considering the composition of ages, gender and educational background. Questionnaire survey was conducted to all the subjects, with 300 effective ones reclaimed. The questionnaire included the general demographic information, traits of character, the condition of foster in childhood and information of family members. The differences between the gays and non-homosexuality groups were analyzed to explore the causes of the sexual orientations of gays.

RESULTSThere were statistical significant differences between gays and non- homosexuality group on following indexes (χ(2) was 59.63, 5.90, 16.01, 84.99, 161.57, 77.77, 112.32, 190.84, 30.10 respectively, all of P < 0.05) :had a tender father and an impervious mother, were physically weak, not agile, physically inactive, attentive to details, highly conservative, not adventurous, and radical in childhood, were raised as girls before the age of 18, liked to dress as girls before the age of 18, don't liked to play toy knives and toy guns before the age of 18, suffered from sexual abuse before the age of 18 (e.g. forced to expose private parts or forced to have sex) by adults, had read or watched books or films about homosexual and experienced sexual pleasure from that before the age of 18. The rate of gays on these indexes was separately 62.3% (187/300), 57.7% (173/300) , 62.3% (187/300) , 63.0% (189/300), 67.3% (202/300) , 62.7% (189/300), 68.0% (204/300), 65.0% (195/300) and the rate on these indexes of non-homosexuality group was separately 21.3% (64/300), 28.0% (84/300) , 25.0% (75/300) , 12.7% (38/300), 31.3% (94/300), 17.7% (53/300) , 12.7% (38/300), 42.7% (128/300) . The rate of gays on these factors:the youngest boy in family, had the father or twin brothers who were homosexual or self identified as gay was 62.7% (188/300), 56.0% (168/300) and 62.0% (18/29) respectively; and the rate was 40.7% (122/300), 4.0% (12/300) and 20.0% (2/10), respectively among non-homosexuality group. The difference showed statistical significance (χ(2) was 34.52, 193.14, 5.27 respectively, all of P < 0.05).

CONCLUSIONThe correlative factor of sexual orientation of gays maybe was family relationship, tend and education since childhood, psychological characteristics, sexual experience during puberty.

Adult ; Homosexuality, Male ; psychology ; statistics & numerical data ; Humans ; Male ; Sexual Behavior ; statistics & numerical data ; Surveys and Questionnaires

Humans ; Molecular Epidemiology ; Pathology, Molecular

OBJECTIVETo understand the risks and associated factors of HIV transmission by sharing syringes among HIV-positive drug users.

METHODThe survey was conducted among HIV-positive injecting drug users (IDUs-HIV+) who received HIV counseling, testing and treatment in Changsha city Infectious Disease Hospital and Hengyang city No.3 People's Hospital from July 2012 to May 2013 to understand their socio-demographic characteristics, HIV prevalence and syringe sharing. A total of 503 IDUs-HIV+ were involved in and provided the contact list of 2 460 drug users who had the syringe sharing experience over one month with IDUs-HIV+. 420 IDUs-HIV+ among 503 were defined as infection sources due to sharing syringe with at least one drug user. Among them, 234 HIV-negative persons were in control group, and 186 HIV-positive were in cased group. A total of 1 220 drug users were followed up among 2 460 and defined as vulnerable population. The HIV transmission rate was calculated based on the HIV prevalence among vulnerable population. Based on the result of HIV transmission to vulnerable population from 420 infection sources, case-control study and the multivariate logistic regression analysis were adopted to explore the associated factors of HIV transmission among IDUs-HIV+.

RESULTSAs the sources of HIV transmission, 420 IDUs-HIV+ had an average duration of (4.5 ± 1.2) years for drug use. As a susceptible population, 1 220 drug users sharing syringes with the 420 IDUs-HIV+ had an average duration of (1.1 ± 0.5) years for drug use. There were 238 HIV-positive persons among 1 220 vulnerable drug users, with a transmission rate of 0.57. In the case-control study, the proportion of male subjects was 87.1% (162/186) in the case group, which was higher than that in the control group (77.8%, 182/234). The proportion of subjects who received support after knowing their HIV infection status was 51.1% (95/186) in the case group, which was lower than that in the control group (79.5%, 186/234). The proportion of subjects sharing syringes every time of using drugs was 47.8% (89/186) in the case group, which was higher than that in the control group (36.8%, 86/234). The proportion of subjects having AIDS awareness was 21.0% (39/186) in the case group, which was lower than that in the control group (64.5%, 151/234); the proportion of subjects having close contact with HIV-positive persons for more than 106 days was 60.2% (112/186) in the case group, which was higher than that in the control group (31.6%, 74/234). The proportion of subjects maintaining the original drug use method after being infected with HIV was 50.5% (94/186) in the case group, which was higher than that in the control group (16.7%, 39/234) (all P values < 0.05). The multivariate logistic regression analysis was carried out to analyse high correlate factors of HIV transmission by sources of transmission, and the AIDS awareness, duration of contact between sources of transmission and vulnerable population, access to support following confirmed HIV infection were protective factors, OR (95% CI) values were 0.155 (0.104-0.262), 0.170 (0.106-0.253), and 0.306 (0.189-0.450), respectively; while the frequency of syringe sharing and continuous drug use after being infected with HIV were risk factors, and the OR (95% CI) values were 3.06 (1.77-5.29), and 3.54 (2.16-5.80), respectively.

CONCLUSIONHIV transmission by IDUs-HIV+ might be contained by raising AIDS awareness, providing comprehensive psychological support, conducting needle exchange and methadone maintenance treatment and reducing syringe sharing.

Aged ; Case-Control Studies ; Drug Users ; HIV Infections ; Humans ; Male ; Methadone ; Needle Sharing ; Prevalence ; Risk Factors ; Substance Abuse, Intravenous

Epidemiologic Methods ; Translational Medical Research

OBJECTIVETo establish a practical and effective model in predicting the premature birth, using the Back-Propagation Artificial Neural Network (BPANN).

METHODSThis was a prospective cohort study. Data was gathered from pregnant women selected by cluster sampling method from 2010 to 2012 in Liuyang city, Hunan province and was randomly divided into training sample (to establish the prediction models), validation sample (to select the optimal network) and testing sample (to evaluate the prediction models) by ratio of 2:1:1. BPANN and logistic regression analysis were used to establish models while ROC was applied to evaluate the 'prediction models'.

RESULTSAmong the 6 270 pregnant women, 265 premature births were seen, with the premature incidence as 4.22%. The 7 variables which entered into the forecasting model would include abnormal uterine or uterine deformity, parity, number of pregnancies, gestational hypertension, placenta previa, premature rupture of membrane and regular prenatal examination. Sensitivity, specificity, agreement rate and area under the ROC curve of BPANN were 67.65% , 84.87%, 84.12% and 0.795, respectively. However, the sensitivity, specificity, agreement rate and area under the ROC curve of logistic regression were 64.71%, 85.60%, 84.69% and 0.783, respectively.

CONCLUSIONThe newly established BPANN model was practical and reliable, which proved that this model was slightly better than the logistic regression in the prediction of premature birth.

OBJECTIVETo research the influence of pregnancy-induced hypertension (PIH) on neonatal birth weight and its interaction with other factors.

METHODSA retrospective cohort study was conducted in this study. 14 townships were randomly selected by cluster random sampling method from 37 townships in Liuyang city, Hunan province. All pregnant women from these 14 townships with pregnancy care manual and delivery record, during April 1st, 2008 to March 31st, 2011 were selected as subjects of this study. Blood pressure during pregnancy and neonatal birth weight were recorded. Multinomial logistic regression model was used to adjust the confounding factors. Addictive effects model was used for interaction analysis.

RESULTSData from 6 102 subjects were collected, including 418 (6.9%) pregnant women with PIH, 166 (2.7%) infants with low birth weight and 333 (5.5%) with fetal macrosomia. Results from the Multinomial logistic regression analysis showed significant association between neonatal birth weight and PIH, premature birth, BMI <18.5 before pregnancy, and weight gain ≥ 16 kg during pregnancy. Data from the Interaction analysis showed that there was strong positive interactions between PIH and premature birth to low birth weight infants (RERI = 35.08, API = 0.435, S = 1.7), and between PIH and BMI<18.5 before pregnancy to low birth weight infants. However, no significant interaction was found between PIH and weight gain.

CONCLUSIONFactors as PIH, premature birth, BMI before pregnancy and weight gain showed impact on low birth weight or fetal macrosomia. PIH also showed significant interaction on neonatal birth weight with premature birth as well as BMI before pregnancy, respectively.

Adolescent ; Adult ; Birth Weight ; Female ; Fetal Macrosomia ; etiology ; Humans ; Hypertension, Pregnancy-Induced ; Infant, Low Birth Weight ; Logistic Models ; Pregnancy ; Retrospective Studies ; Young Adult

BACKGROUNDThe risk of HIV sexual transmission is much higher among people unaware of their HIV status than among those aware. Only a few studies have indicated that the incidence of unsafe sex can be reduced when people know their HIV status. This study was to investigate this effect in China.

METHODSA cohort study consisting of two surveys was conducted at two different times among a group of people living with HIV/AIDS, whose status was newly diagnosed with HIV via sexual contact, in Shanghai, Chongqing, and Kunming. The first survey was conducted among 823 people tested positive for HIV before notifying them of the HIV status. The second survey was conducted among 650 HIV-positive people at six months following the first survey (after notification of HIV status). The scope of survey covered unsafe sex practices, number of unsafe sexual partners, and frequency of unsafe sexual behaviors over the prior six months. Unsafe sex is defined as unprotected anal or vaginal sex with partners who are HIV positive or whose HIV status is unknown.

RESULTSThe proportion of unsafe sex was reduced by about 85% after HIV status notification. The risk of HIV sexual transmission was 15 times higher among persons unaware of their HIV status than among those aware. Approximately 95% of new sexually transmitted HIV infections stemmed from 56% of the infected persons unaware of their HIV status in China.

CONCLUSIONTimely HIV status notification has the potential to significantly reduce unsafe sex among HIV-infected persons and reduce the risk for HIV transmission via unsafe sex.

Adolescent ; Adult ; Aged ; China ; Cohort Studies ; Female ; HIV Infections ; epidemiology ; transmission ; Humans ; Male ; Middle Aged ; Sexually Transmitted Diseases ; complications ; Unsafe Sex ; Young Adult

OBJECTIVETo investigate the intrauterine growth retardation (IUGR) and its determinants so as to provide evidence for maternal and child health care programs to be carried out.

METHODSFourteen townships were selected by cluster random sampling from 37 townships in Liuyang. A total of 6 105 pregnant women who had established their health care programs during April 2008 and March 2011, were recruited in this study. Records on pregnancy care manual and delivery were collected. 6 105 single live births were divided into two groups (IUGR group and control group). Those whose birth weight was below the 10th percentile for mean weight corrected for gestation age were grouped as IUGR group. Chi-square test and Multivariate logistic Regression method were used to estimate the determinants of IUGR.

RESULTSA total of 6 105 women, pregnant with a singleton gestation were enrolled in the study: 528 of these pregnancies were complicated with IUGR (8.65%). Data from the multivariate logistic regression analysis showed that maternal age less than 25 (OR = 1.268), prim parity (OR = 1.706), BMI less than 18.5 kg/m² at first obstetrical examination (OR = 1.709), deficiency in weight gain during pregnancy (OR = 1.576) and pregnancy-induced hypertension syndrome (OR = 1.698) were related risk factors to intrauterine growth retardation.

CONCLUSIONMaternal age, prim parity, BMI, weight gain during pregnancy and pregnancy-induced hypertension syndrome were factors associated to the intrauterine growth retardation. Effective measures in reducing the intrauterine growth retardation should include factors as monitoring maternal weight and the change of weight during pregnancy in order to maintain the weight at normal ranges. Prevention and therapy for pregnancy-induced hypertension syndrome, should also be strengthened.

Birth Weight ; Body Weight ; Female ; Fetal Growth Retardation ; Humans ; Hypertension, Pregnancy-Induced ; Maternal Age ; Parity ; Pregnancy ; Pregnant Women ; Risk Factors ; Weight Gain