A Culture-Centered Community-Grounded Approach to Disseminating Health Information among African Americans.

This study highlights the role of local communities in creating culturally rooted health information resources based on comparative effectiveness research (CER), depicting the role of culture in creating entry points for building community-grounded communication structures for evidence-based health knowledge. We report the results from running a year-long culture-centered campaign that was carried out among African American communities in two counties, Lake and Marion County, in Indiana addressing basic evidence-based knowledge on four areas of cardiovascular disease (CVD). Campaign effectiveness was tested through an experimental design with post-test knowledge of CER among African Americans in these counties compared to CER knowledge among African Americans in a comparable control county (Allen). Our campaign, based on the principles of the culture-centered approach (CCA), increased community CER knowledge in the experimental communities relative to a community that did not receive the culturally centered health information campaign. The CCA-based campaign developed by community members and distributed through the mass media, community wide channels such as health fairs and church meetings, postcards, and face-to-face interventions explaining the postcards improved CER knowledge in specific areas (ACE-I/ARBs, atrial fibrillation, and renal artery stenosis) in the CCA communities as compared to the control community.

Social defeat differentially affects immune responses in Siberian hamsters (Phodopus sungorus).

Social defeat is a complex, multi-faceted behavioral interaction capable of eliciting a wide range of physiological and behavioral responses. The behavioral components responsible for eliciting these changes, however, remain unspecified. The goal of the present study was to examine the effects of chronic social defeat on serum cortisol concentration as well as innate and acquired immune responses in adult male Siberian hamsters (Phodopus sungorus). Specifically, we experimentally manipulated the nature of the social interaction among conspecific animals (i.e., no social interaction, exposure to the sight or smell of a conspecific, or full social defeat) in order to determine the important components contributing to potential stress-induced changes in immunity. We found that immunoglobulin G (IgG) levels were decreased in defeated animals relative to both control animals and those exposed only to the olfactory cues of conspecifics. In contrast, serum bactericidal activity was increased in the defeated animals relative to controls. Prolonged social defeat did not elevate serum cortisol levels as compared with control animals. The results of this study suggest that social defeat alters immune responses and that specific behavioral components (i.e., defeat) contribute to this response. Importantly, these findings also demonstrate that social defeat exerts opposite effects on innate and acquired measures of immunity. Collectively, these results contribute to our understanding of complex social behaviors and their differential effects on endocrine and immune responses in vertebrates.

Aggressive encounters differentially affect serum dehydroepiandrosterone and testosterone concentrations in male Siberian hamsters (Phodopus sungorus).

The gonadal hormone testosterone (T) regulates aggression across a wide range of vertebrate species. Recent evidence suggests that the adrenal prohormone dehydroepiandrosterone (DHEA) may also play an important role in regulating aggression. DHEA can be converted into active sex steroids, such as T and estradiol (E(2)), within the brain. Previous studies show that circulating DHEA levels display diurnal rhythms and that melatonin increases adrenal DHEA secretion in vitro. Here we examined serum DHEA and T levels in long-day housed Siberian hamsters (Phodopus sungorus), a nocturnal species in which melatonin treatment increases aggression. In Experiment 1, serum DHEA and T levels were measured in adult male hamsters during the day (1200 h, noon) and night (2400 h, midnight). In Experiment 2, aggression was elicited using 5-min resident-intruder trials during the day (1800 h) and night (2000 h) (lights-off at 2000 h). Serum DHEA and T levels were measured 24 h before and immediately after aggressive encounters. In Experiment 1, there was no significant difference in serum DHEA or T levels between noon and midnight, although DHEA levels showed a trend to be lower at midnight. In Experiment 2, territorial aggression was greater during the night than the day. Moreover, at night, aggressive interactions rapidly decreased serum DHEA levels but increased serum T levels. In contrast, aggressive interactions during the day did not affect serum DHEA or T levels. These data suggest that nocturnal aggressive encounters rapidly increase conversion of DHEA to T and that melatonin may play a permissive role in this process.