Angiotensin II-Induced Hypertension in Apolipoprotein E-Deficient Rats

Abdominal aortic aneurysms (AAAs) are characterized by a weakened vessel wall and a diameter 50% greater than normal. AAA are usually asymptomatic until they are near rupturing, which can be fatal if not treated immediately. Apolipoprotein E-deficient (ApoE) mice are commonly used as a model to study aneurysm growth. Our lab has created a similar model using rats, which are more similar to humans. This study focuses on the analysis of blood pressures collected from ApoE rats for comparison with a known mouse model. Five ApoE rats (1 female, 4 males) received subcutaneous implants of osmotic mini pumps that released a continuous flow of angiotensin II (AngII) at 200 ng/kg/min. AngII is a protein known to increase blood pressure by acting on the renin-angiotensin system. Systolic, diastolic, and mean arterial pressures were measured using a non-invasive tail cuff system (CODA, Kent Scientific). Measurements were taken before pump implantation and on days 3, 7, 14, 21, and 28 after implantation. Mean arterial pressure increased from 133.8 ± 21.2 mmHg before pump implantation to 169.4 ± 20.3 mmHg on day 28. Systolic and diastolic pressures rose in a similar manner. Although the blood pressure increased in a manner similar to the mice, no aneurysms were observed in any of the rats. This may be due to species differences that affect vessel thickness and metabolic rate. Further investigations will be needed to determine why ApoE rats become hypertensive due to AngII, but do not develop suprarenal dissecting aortic aneurysms

Positive reform of tuna farm diving in South Australia in response to government intervention

© 2001 by Occupational and Environmental MedicineObjectives: Much of the tuna harvested in South Australia since 1990 has involved "farming" techniques requiring the use of divers. From 1993 to 1995, 17 divers from this industry were treated for decompression illness (DCI). In response, the State Government introduced corrective strategies. A decrease in the number of divers presenting for treatment was subsequently recorded. Consequently, the hypothesis was tested that the government intervention resulted in a decrease in the incidence of DCI in the industry and an improved clinical outcome of divers with DCI. Methods: The incidence of treated DCI in tuna farm divers was estimated from the number of divers with DCI treated and the number of dives undertaken extrapolated from a survey of the industry in 1997-8. General health was measured in the tuna farm diving population by a valid and reliable self assessment questionnaire. The outcome of the divers treated for DCI was analysed with a modified clinical severity scoring system. Results: The apparent incidence of treated DCI has decreased in tuna farm divers since the government intervention. The evidence supports a truly decreased incidence rather than underreporting. The general health of the tuna farm divers was skewed towards the asymptomatic end of the range, although health scores indicative of DCI were reported after 1.7% of the dives that did not result in recognised DCI. The clinical outcome of the divers treated since the intervention has improved, possibly because of earlier recognition of the disease and hence less time spent diving while having DCI. Conclusions: The government intervention in the tuna industry in South Australia has resulted in a reduced incidence of DCI in the industry

Usability and Psychosocial Impact of Decision Support to Increase Sexual Health Education in American Indian and Alaska Native Communities

Despite sexual and reproductive health disparities, few evidence-based sexual health education programs exist for American Indian/Alaska Native (AI/AN) youth, with even fewer tools available to assist AI/AN communities in adopting, implementing, and maintaining such programs. iCHAMPSS (Choosing And Maintaining effective Programs for Sex education in Schools) is a theory- and web-based decision-support-system designed to address dissemination barriers and increase the reach and fidelity of evidence-based programs (EBPs), specifically sexual health education programs. To investigate the potential of iCHAMPSS in AI/AN communities, we pilot-tested iCHAMPSS with adult stakeholders (N = 36) from agencies across the country that serve AI/AN communities. Stakeholders were recruited to review selected iCHAMPSS tools over two weeks in spring 2016. Pre- and post-surveys were administered to assess usability constructs, short-term psychosocial outcomes, and perceived feasibility. Data were analyzed using descriptive and non-parametric statistics. iCHAMPSS was perceived as acceptable, easy to use, credible, appealing, more helpful than current resources, and impactful of EBP adoption, implementation, and maintenance. Conversely, using iCHAMPSS significantly increased participants’ perceived barriers to adopting an EBP (p = 0.01). Overall, AI/AN stakeholders responded positively to iCHAMPSS, indicating the potential for adaptation to support the dissemination and implementation of evidence-based sexual health education in AI/AN communities

Real-time single-molecule imaging reveals a direct interaction between UvrC and UvrB on DNA tightropes

Nucleotide excision DNA repair is mechanistically conserved across all kingdoms of life. In prokaryotes, this multi-enzyme process requires six proteins: UvrA?D, DNA polymerase I and DNA ligase. To examine how UvrC locates the UvrB? DNA pre-incision complex at a site of damage, we have labeled UvrB and UvrC with different colored quantum dots and quantitatively observed their interactions with DNA tightropes under a variety of solution conditions using oblique angle fluorescence imaging. Alone, UvrC predominantly interacts statically with DNA at low salt. Surprisingly, however, UvrC and UvrB together in solution bind to form the previously unseen UvrBC complex on duplex DNA. This UvrBC complex is highly motile and engages in unbiased one-dimensional diffusion. To test whether UvrB makes direct contact with the DNA in the UvrBC?DNA complex, we investigated three UvrB mutants: Y96A, a b-hairpin deletion and D338N. These mutants affected the motile properties of the UvrBC complex, indicating that UvrB is in intimate contact with the DNA when bound to UvrC. Given the in vivo excess of UvrB and the abundance of UvrBC in our experiments, this newly identified complex is likely to be the predominant form of UvrC in the cell. © 2013 The Author(s)

Native IYG: Improving Psychosocial Protective Factors for HIV/STI and Teen Pregnancy Prevention among Youth in American Indian/Alaska Native Communities

Background: Few HIV/STI and pregnancy prevention programs for youth in American Indian and Alaska Native (AI/AN) communities have been rigorously evaluated despite sexual health disparities in this population. This study reports the evaluation of a culturally adapted Internet-based HIV/STI and pregnancy prevention program for AI/AN youth, Native It’s Your Game (Native IYG). Methods: A randomized study was conducted with 523 youth (12 to 14 years old), recruited from 25 tribal sites in Alaska, Arizona, and the Pacific Northwest. Participants were surveyed at baseline and upon completion of treatment or comparison interventions. Multivariable linear regression models were used to assess impact on short term psychosocial determinants of sexual initiation. Results: A sample of 402 intervention (n=290) and comparison (n=112) youth completed the post-intervention survey (76.9% retention) from 1 to 462 days post-baseline (mean = 114, SD = ±96.67). Participants were 55.5% female, mean age of 13.0 (± 0.97) years with 86.1% self-reporting as AI/AN. Reasons not to have sex, STI knowledge, condom knowledge, condom availability self-efficacy, and condom use self-efficacy were significantly impacted (all P ≤ .01). Limitations included variability in intervention exposure and time between data collection time points. Conclusions: Native IYG demonstrated efficacy to impact short-term psychosocial determinants of sexual behavior in a sample of predominantly AI/AN middle school youth

The Healthy Native Youth Implementation toolbox: Using Implementation Mapping to adapt an Online Decision Support System to Promote Culturally-Relevant Sexual Health Education For american indian and alaska Native Youth

BACKGROUND: American Indian and Alaska Native (AI/AN) youth experience serious disparities in sexual and reproductive health, including the highest teen birth rate among racial/ethnic groups, and disproportionate rates of sexually transmitted infections (STI), including HIV. A growing number of evidence-based programs (EBPs) that integrate the strengths and cultural teachings of Native communities exist. Yet, multiple factors, including lack of trained personnel, limited resources, and geographic isolation, may hinder their adoption and implementation. Innovative implementation strategies that facilitate the adoption and implementation of sexual health EBPs in Native communities may help reduce these disparities. METHODS: We applied Implementation Mapping, a systematic planning framework that utilizes theory, empirical evidence, and community input, to adapt a theory-based, online decision support system, iCHAMPSS (CHoosing And Maintaining Effective Programs for Sex Education in Schools), to support underlying dissemination and implementation processes unique to Native communities. We used an iterative design process, incorporating input from Native practitioners and academicians, to ensure that the adapted decision support system reflects cultural identification, community values, and experiences. RESULTS: Grounded in diffusion of innovations, organizational stage theory, and social cognitive theory, the CONCLUSION: There is a continued need to design, test, and evaluate D&I strategies that are relevant to Native communities. Th

Do female association preferences predict the likelihood of reproduction?

Sexual selection acting on male traits through female mate choice is commonly inferred from female association preferences in dichotomous mate choice experiments. However, there are surprisingly few empirical demonstrations that such association preferences predict the likelihood of females reproducing with a particular male. This information is essential to confirm association preferences as good predictors of mate choice. We used green swordtails (<i>Xiphophorus helleri</i>) to test whether association preferences predict the likelihood of a female reproducing with a male. Females were tested for a preference for long- or short-sworded males in a standard dichotomous choice experiment and then allowed free access to either their preferred or non-preferred male. If females subsequently failed to produce fry, they were provided a second unfamiliar male with similar sword length to the first male. Females were more likely to reproduce with preferred than non-preferred males, but for those that reproduced, neither the status (preferred/non-preferred) nor the sword length (long/short) of the male had an effect on brood size or relative investment in growth by the female. There was no overall preference based on sword length in this study, but male sword length did affect likelihood of reproduction, with females more likely to reproduce with long- than short-sworded males (independent of preference for such males in earlier choice tests). These results suggest that female association preferences are good indicators of female mate choice but that ornament characteristics of the male are also important

A Naturally Selected Dimorphism within the HLA-B44 Supertype Alters Class I Structure, Peptide Repertoire, and T Cell Recognition

HLA-B*4402 and B*4403 are naturally occurring MHC class I alleles that are both found at a high frequency in all human populations, and yet they only differ by one residue on the α2 helix (B*4402 Asp156→B*4403 Leu156). CTLs discriminate between HLA-B*4402 and B*4403, and these allotypes stimulate strong mutual allogeneic responses reflecting their known barrier to hemopoeitic stem cell transplantation. Although HLA-B*4402 and B*4403 share >95% of their peptide repertoire, B*4403 presents more unique peptides than B*4402, consistent with the stronger T cell alloreactivity observed toward B*4403 compared with B*4402. Crystal structures of B*4402 and B*4403 show how the polymorphism at position 156 is completely buried and yet alters both the peptide and the heavy chain conformation, relaxing ligand selection by B*4403 compared with B*4402. Thus, the polymorphism between HLA-B*4402 and B*4403 modifies both peptide repertoire and T cell recognition, and is reflected in the paradoxically powerful alloreactivity that occurs across this “minimal” mismatch. The findings suggest that these closely related class I genes are maintained in diverse human populations through their differential impact on the selection of peptide ligands and the T cell repertoire