Biomedical subjects

Guang Guo

Publications and source records attributed to Guang Guo.

9 recordsLinked to original sources

PubMed2006

Gene-environment contributions to young adult sexual partnering.

To date, there has been relatively little work on gene-environment contributions to human sexuality, especially molecular analyses examining the potential contributions of specific polymorphisms in conjunction with life experiences. Using Wave III data from 717 heterozygous young adult sibling pairs included in the National Longitudinal Study of Adolescent Health, this article examined the combined contributions of attendance at religious services and three genetic polymorphisms (in the dopamine D4 receptor [DRD4]), dopamine D2 receptor [DRD2]), and the serotonin transporter promoter [5HTT]) to sensation seeking, a personality construct related to sexual behavior, and the number of vaginal sex partners participants had in the year before interview. Data analyses used an Allison mixed model approach to account for population stratification and correlated observations. DRD4 was unrelated to sensation seeking and to the number of sex partners in tests of both main effects and in interaction with religious attendance. Contrary to hypothesis, presence of the A1 DRD2 allele was associated with having had fewer sex partners in the past year. Associations between the 5HTT allele and sex partners varied by religious attendance, but again the patterns of associations were contrary to hypothesized relationships and were small in magnitude. These findings underscore the necessity of using more comprehensive multiple gene-multiple life experience approaches to investigations of complex behaviors such as sexual patterns.

Adult↗

PubMed2006

Contributions of the DAT1 and DRD2 genes to serious and violent delinquency among adolescents and young adults.

As far as we know, this is the first national study that reports compelling evidence for the main effects of genetic variants on serious and violent delinquency among adolescents and young adults. This study investigated the association between the self-reported serious and violent delinquency and the TaqI polymorphism in the DRD2 gene and the 40-bp VNTR in the DAT1 gene. The study was based on a cohort of more than 2,500 adolescents and young adults in the National Longitudinal Study of Adolescent Health in the United States. The trajectories of serious delinquency for the DAT1*10R/10R and DAT1*10R/9R genotypes are about twice as high as that for the DAT1*9R/9R genotype (LR test, P = 0.018, 2 df). For DRD2, the trajectory of serious delinquency for the heterozygotes (A1/A2) is about 20% higher than the A2/A2 genotype and about twice as high as the A1/A1 genotype, a phenomenon sometimes described as heterosis (LR test, P = 0.005, 2 df). The findings on violent delinquency closely resemble those on serious delinquency. The trajectories of violent delinquency for the DAT1*10R/9R and DAT1*10R/10R genotype are again about twice as high as that for DAT1*9R/9R (LR test, P = 0.021, 2 df). The two homozygotes of DRD2*A1/A1 and DRD2*A2/A2 scored lower (LR test, P = 0.0016, 2 df) than the heterozygotes. The findings in the models that consider DAT1 and DRD2 jointly (serious delinquency P = 0.0016, 4 df; violent delinquency P = 0.0006, 4 df) are essentially the same as those in the single-gene models, suggesting the absence of a significant correlation between the two genetic variants. These results only apply to males. Neither variant is associated with delinquency among females.

Adolescent↗

PubMed2006

DRD4 gene variant associated with body mass: the National Longitudinal Study of Adolescent Health.

In this article we report a novel statistically significant association between the D4.7/D4.7 genotype of the DRD4 gene and the body mass of black and Hispanic participants in the National Longitudinal Study of Adolescent Health (Add Health). We investigated the role of the 48-bp repeat polymorphism of the dopamine receptor 4 gene (DRD4) in body mass regulation in 2,277 adolescents and young adults followed in 1995 (12-18 years old), 1996, and 2002 by Add Health. After the effects of age, sex, and ethnicity were adjusted, the D4.7/D4.7 genotype reduced the body mass index (BMI)-percentile score by 15 and 12.5, as compared to those with other genotypes, for African-Americans (P = 0.0047) and Hispanic-Americans (P = 0.037), respectively. Although the D4.7/D4.7 genotype was associated with a lower BMI-percentile score in white individuals compared to other genotypes, the difference was not significant. Individuals heterozygous for D4.7 did not differ from those with the other/other genotype.

Adolescent↗

PubMed2006

Genetic contribution to suicidal behaviors and associated risk factors among adolescents in the U.S.

This paper examines genetic contribution to suicidal behaviors and other risk factors associated with suicidal behavior among adolescents in the U.S. Using adolescent twin data in the National Longitudinal Study of Adolescent Health (N = 1448), we compared concordance in suicidal ideation and attempt among monozygotic (MZ) and dizygotic (DZ) twins. Heritability of risk factors for suicidal behaviors also was examined using Pearson correlation and mixed-model analyses. A trend of higher concordance in suicidal ideation and attempt was found among MZ than DZ twins but the difference was not statistically significant by the stringent test of bootstrapping analysis. Evidence of heritability was found for several suicide risk factors. The percentage of variance explained by heritability was larger among female twins for depression, aggression, and quantity of cigarettes smoked in comparison to heritability estimates for male twins. However, estimated heritability was larger among male than female twins for alcohol use and binge drinking. Heritability influence was negligible among both sexes for other drug use. Risk factors for suicidal behaviors among adolescents may be heritable. Gender differences found in the heritability of some suicide risk factors suggest these genetic contributions are gender specific. Future research examining potential interactions between expression of genetic influence and particular environmental contexts may enhance prevention and intervention efforts.

Adolescent↗

PubMed2006

Genetic similarity shared by best friends among adolescents.

Two observations suggest a genetic similarity among close friends: (1) the observed similarity among friends in certain traits and behaviors; (2) the evidence that many of these traits and behaviors have a genetic component. This hypothesis is tested using monozygotic (MZ) twins, dizygotic (DZ) twins, full biological siblings, and their best friends from the National Longitudinal Study of Adolescent Health (Add Health). Whether the resemblance between MZ twins' friends is larger than that between friends of DZ twins and full siblings is investigated with respect to 4 individual traits or behaviors: grade point average (GPA), AHPVT (the version Peabody Picture Vocabulary Test [PPVT] designed for Add Health), aggressive behavior, and depression. Our hypothesis is supported in analyses among same-sex friends (not among different-sex friends) for GPA, aggressive behavior, and AHPVT.

Adolescent↗

PubMed2006

Sexy media matter: exposure to sexual content in music, movies, television, and magazines predicts black and white adolescents' sexual behavior.

OBJECTIVE: To assess over time whether exposure to sexual content in 4 mass media (television, movies, music, and magazines) used by early adolescents predicts sexual behavior in middle adolescence. METHODS: An in-home longitudinal survey of 1017 black and white adolescents from 14 middle schools in central North Carolina was conducted. Each teen was interviewed at baseline when he or she was 12 to 14 years old and again 2 years later using a computer-assisted self interview (audio computer-assisted self-interview) to ensure confidentiality. A new measure of each teen's sexual media diet (SMD) was constructed by weighting the frequency of use of 4 media by the frequency of sexual content in each television show, movie, music album, and magazine the teen used regularly. RESULTS: White adolescents in the top quintile of sexual media diet when 12 to 14 years old were 2.2 times more likely to have had sexual intercourse when 14 to 16 years old than those who were in the lowest SMD quintile, even after a number of other relevant factors, including baseline sexual behavior, were introduced. The relationship was not statistically significant for black adolescents after controlling for other factors that were more predictive, including parental disapproval of teen sex and perceived permissive peer sexual norms. CONCLUSIONS: Exposure to sexual content in music, movies, television, and magazines accelerates white adolescents' sexual activity and increases their risk of engaging in early sexual intercourse. Black teens appear more influenced by perceptions of their parents' expectations and their friends' sexual behavior than by what they see and hear in the media.

Adolescent↗

PubMed2006

Influences of socio-demographic and social context risk factors on labor force aged mortality from communicable disease.

OBJECTIVE: Study the influences of socio-demographic and social context risk factors on labor force aged mortality from communicable disease. MATERIAL AND METHOD: A sample of 28,298 individuals were used to build a piece-wise exponential hazard model. Investigation of the cause of death used "verbal autopsy". RESULT: It was found that more males are likely to die than females (Exp. = 1.54, S.E. = 0.19). Mortality risk for those who work is lower than for the jobless while mortality risk for laborers is greater than for the jobless (Exp. = 2.80, S.E. = 0.54). Migrants are more likely to die than those who have not migrated (Exp. = 12.68, S.E. = 0.22). People who live in households with debt are more likely to die than those who live in debt-free households (Exp. = 1.21, S.E. = 0. 17). Environmental problems and drinking water quality have significant positive relationship with death due to communicable disease. CONCLUSION: A health prevention plan for individual, household, and community level for this labor force aged population needs to be provided.

Adolescent↗

PubMed2002

The mixed or multilevel model for behavior genetic analysis.

We propose the mixed model or multilevel model as a general alternative approach to existing behavior genetic analysis-an alternative to correlation analysis, the DeFries-Fulker analysis, and structural equation modeling. The mixed or multilevel model handles readily families of behavioral genetic data, which include paired sibling data (e.g., pairs of MZ and DZ twins) and clustered sibling data (e.g., a family of more than two biological siblings) as special cases. Not only can a family of behavioral genetic data have more than two siblings, it can also contain multiple types of siblings (e.g., a pair of MZ twins, a pair of DZ twins, a full sibling, and a half sibling). In contrast to the traditional approaches, the mixed or multilevel model is insensitive to the order of the siblings in a sibling cluster. We apply our approach to a large, nationally representative behavior genetic sample collected recently by the Add Health Study. We demonstrate the approach through several applications using both clustered and family complex behavioral genetic data: conventional variance decomposition analysis, analysis of interactions between genetic and environmental influences, and analysis of the possible genetic basis for friendship selection. We compare results from the mixed or multilevel model, Pearson's correlation analysis, and the structural equation model.

Adolescent↗

PubMed2002

[Investigation of chronic prostatitis and altered bowel habits].

OBJECTIVES: To explore the incidence, causes, and significance of altered bowel habits in chronic prostatitis. METHODS: Investigating the incidence of altered bowel habits in chronic prostatitis, analyzing some possible causes to induce the symptom, such as course of disease, vegetative nerve functional disturbance, inflammation in expressed prostatic secretions, and digital rectal examination. Following up the improvement of altered bowel habits after effective treatment of chronic prostatitis. RESULTS: The incidence of altered bowel habits was 31.40% in 379 chronic prostatitis patients. The detected congestion and swelling of prostate was closed related to altered bowel habits in chronic prostatitis. The incidence of improvement of altered bowel habits after effective treatment of chronic prostatitis reached to 78.79%. CONCLUSIONS: Congestion and swelling of prostate might be the main causes for altered bowel habits in chronic prostatitis. Altered bowel habits should be considered as a common symptom and cure standard for chronic prostatitis.

Chronic Disease↗