Process evaluation of intervention program for prevention of early sexual activity and alcohol use among Hispanic teenagers

Hispanic teens are a high-risk population for initiation of early sexual activity and alcohol use which in turn has numerous social and health consequences. One strategy to address prevention of these behaviors is to implement a capacity building intervention that promotes parent child communication, encompasses their cultural values and community participation. This study describes the process evaluation of a pilot intervention program amongst Hispanic teens and their families living along the Texas-Mexico border. “Girls Lets Talk” is a small group intervention with 10-14 year old teens and their female adult family members that involves education regarding effects of alcohol use and sexual activity as well as activities for monitoring and refusal skills to prevent risky behaviors. Two waves of the program each consisting of at least seven mother daughter dyads were conducted. During the designing process, community advisory board meetings and focus groups were held to review course materials and ensure they were appropriate to the Mexican American culture. Parent and adolescent surveys were administered at the beginning and end of the intervention to assess for psychosocial outcome variables. All sessions received high mean satisfactory scores (mean of 4.00 or better on a five point scale) for both adult and adolescent participants. Qualitative feedback was obtained via debriefing sessions to evaluate experience as well as alter recruitment strategies. A Wilcoxon Sign Rank analysis of the pre and post intervention surveys was done that showed significant changes in some outcome variables such as intentions and confidence for monitoring behaviors for adults and beliefs regarding sexual activity. “Girls Lets Talk” is a promising example of how a process evaluation plan can help develop a theory based health promotion program using the community based participatory research approach. The intervention may also be effective in altering intentions and enhancing self-efficacy among parents and teens in order to decrease risky behaviors such as early sexual activity and alcohol use.^

Binding of the HIV-1 gp120 -V3 to cellular glycosphingolipids is necessary for CXCR4 recruitment and infection

Infection by human immunodeficiency virus type 1 (HIV-1) is a multi-step process, and detailed analyses of the various events critical for productive infection are necessary to clearly understanding the infection process and identifying novel targets for therapeutic interventions. Evidence from this study reveals binding of the viral envelope protein to host cell glycosphingolipids (GSLs) as a novel event necessary for the orderly progression of the host cell-entry and productive infection by HIV-1. Data obtained from co-immunoprecipitation analyses and confocal microscopy showed that the ability of viral envelope to interact with the co-receptor CXCR4 and productive infection of HIV-1 were inhibited in cells rendered GSL-deficient, while both these activities were restored after reconstitution of the cells with specific GSLs like GM3. Furthermore, evidence was obtained using peptide-inhibitors of HIV-1 infection to show that binding of a specific region within the V3-loop of the envelope protein gp120 to the host cell GSLs is the trigger necessary for the CD4-bound gp120 to recruit the CXCR4 co-receptor. Infection-inhibitory activity of the V3 peptides was compromised in GSL-deficient cells, but could be restored by reconstitution of GSLs. Based on these findings, a revised model for HIV-1 infection is proposed that accounts for the established interactions between the viral envelope and host cell receptors while enumerating the importance of the new findings that fill the gap in the current knowledge of the sequential events for the HIV-1 entry. According to this model, post-CD4 binding of the HIV-1 envelope surface protein gp120 to host cell GSLs, mediated by the gp120-V3 region, enables formation of the gp120-CD4-GSL-CXCR4 immune-complex and productive infection. The identification of cellular GSLs as an additional class of co-factors necessary for HIV-1 infection is important for enhancing the basic knowledge of the HIV-1 entry that can be exploited for developing novel antiviral therapeutic strategies. ^