TLR4 Asp299Gly polymorphism may be protective against chronic periodontitis.

BACKGROUND AND OBJECTIVE: Periodontitis results from interplay between genetic and environmental factors. Single nucleotide polymorphisms (SNPs) in the coding region of the toll-like receptor 4 gene (TLR4) may be associated with periodontitis, although previous studies have been inconclusive. Moreover, the interaction between environmental factors, such as cigarette smoking (a major risk factor for periodontitis), and Porphyromonas gingivalis (a major periodontal pathogen) with the TLR4 coding region Asp299Gly SNP (rs4986790; a SNP associated with lipopolysaccharide-mediated inflammatory responses in periodontitis), have been largely ignored in previous reports. Therefore, the objective of this study was to examine the association between TLR4 Asp299Gly (rs4986790) with alveolar bone height loss (ABHL) and periodontitis, accounting for interactions between this SNP with smoking and P. gingivalis prevalence. The CD14/-260 SNP (rs2569190) served as a control, as a recent meta-analysis suggested no relationship between this SNP and periodontitis. MATERIAL AND METHODS: This multicenter study included 617 participants who had rheumatoid arthritis or osteoarthritis. This report presents a secondary outcome from the primary case-control study examining the relationship of periodontitis with established rheumatoid arthritis. The Centers for Disease Control/American Academy of Periodontology case definitions of periodontitis were used for this analysis. Participants received a full-mouth clinical periodontal examination and panoramic radiograph. Percentage ABHL was measured on posterior teeth. The TLR4 Asp299Gly and CD14/-260 SNPs were selected a priori and genotypes were determined using the ImmunoChip array (Illumina(®) ). Minor allele frequencies and associations with periodontitis and ABHL did not differ according to rheumatoid arthritis vs. osteoarthritis status; therefore, data from these two groups were pooled. The presence of P. gingivalis was detected in subgingival plaque by PCR. Multivariate ordinal logistic regression examined associations between the SNPs and periodontitis or ABHL. SNP interactions with smoking and P. gingivalis were analyzed. RESULTS: A significant, negative interaction was observed between the TLR4 SNP and the presence of P. gingivalis (p = 0.045) with respect to periodontitis. The TLR4 minor variant was also associated with less ABHL: 16.8% of individuals with low ABHL, 9.0% with moderate ABHL and 11.2% with high ABHL had the minor allele [p = 0.029; odds ratio = 0.58 (95% confidence interval: 0.36-0.95)]. The interaction between the TLR4 SNP and smoking was not significant with respect to periodontitis or ABHL. The CD14 SNP was not associated with periodontitis or ABHL. CONCLUSION: The TLR4 Asp299Gly SNP significantly interacted with P. gingivalis in conferring a decreased risk of periodontitis and may be protective against ABHL, a feature of periodontitis. Agents blocking TLR4 signaling, a strategy currently under investigation for the treatment of other inflammatory conditions, may warrant investigation in the context of periodontitis related to the presence of P. gingivalis.

The relationship between racial identity and self-esteem in African American college and high school students.

The Multidimensional Model of Racial Identity was used to examine the relationship between racial identity and personal self-esteem (PSE) in a sample of African American college students (n = 173) and a sample of African American high school students (n = 72). Racial identity was assessed using the Centrality and Regard scales of the Multidimensional Inventory of Black Identity, whereas the Rosenberg Self-Esteem Scale was used to assess PSE. Four predictions were tested: (a) racial centrality is weakly but positively related to PSE; (b) private regard is moderately related to PSE; (c) public regard is unrelated to PSE; and (d) racial centrality moderates the relationship between private regard and PSE. Multiple regression analysis found that racial centrality and public racial regard were unrelated to PSE in both samples. Private regard was positively related to PSE in the college sample. Racial centrality moderated the relationship between private regard and PSE in both samples, such that the relationship was significant for those with high levels of centrality but nonsignificant for those with low levels.

Multidimensional model of racial identity: a reconceptualization of African American racial identity.

Research on African American racial identity has utilized 2 distinct approaches. The mainstream approach has focused on universal properties associated with ethnic and racial identities. In contrast, the underground approach has focused on documenting the qualitative meaning of being African American, with an emphasis on the unique cultural and historical experiences of African Americans. The Multidimensional Model of Racial Identity (MMRI) represents a synthesis of the strengths of these two approaches. The underlying assumptions associated with the model are explored. The model proposes 4 dimensions of African American racial identity: salience, centrality, regard, and ideology. A description of these dimensions is provided along with a discussion of how they interact to influence behavior at the level of the event. We argue that the MMRI has the potential to make contributions to traditional research objectives of both approaches, as well as to provide the impetus to explore new questions.

The college life experiences of African American women athletes.

The present study provides a descriptive analysis of four areas of African American women student athletes' college life experiences: academic performance; alienation and abuse; perceived social advantage as the result of athletics; and life satisfaction. Multivariate comparisons were made between the four areas of college life experiences of 154 African American women student athletes and 793 White women student athletes, 250 African American women nonathletes, and 628 African American men student athletes from a national sample of 39 NCAA Division I universities. Overall, African American women student athletes are performing adequately academically, integrating socially within the university, perceiving some social advantage as the result of being athletes, and are fairly satisfied with their life. Their experiences seem most consistent with African American women nonathletes. Results are discussed in the context of potential policy recommendations as well as the need for more research on this particular population.

Extreme social isolation, use of community-based senior support services, and mortality among African American elderly women.

The effect of extreme social isolation and use of community-based senior services on longevity was examined in a national sample of African American elderly women (ages 55-96). Consistent with previous research on the social integration/mortality link, African American elderly women who were extremely socially isolated were hypothesized to have a higher 5-year mortality rate. It was also hypothesized that use of community senior services would be negatively associated with 5-year mortality. Results of logistic regression analysis controlling for age, education, income, and health status found that extremely socially isolated African American elderly women were three times more likely than the nonisolated women to die within the 5-year period from the initial survey. Use of community senior services did not have a relationship on mortality. Results are discussed in terms of directions for future research and intervention.