Stress, trauma, and risky sexual behaviour among American Indians in young adulthood

This paper examines the relationship of risky sexual behaviour to stress and trauma-often the mediators of the content and structure of everyday life-among young American Indians. School, work, social life, and home life bring about demands and stresses for youth; choices young people make may depend on the quantity and content of those demands. Traumatic events or highly distressing situations may shatter fragile (or even resilient) systems of external and internal support from which youth may draw. American Indians live in some of the most impoverished areas of the country, where everyday life includes a heavy burden of stress and trauma. Using data from a representative sample of youth from a Northern Plains tribe, bivariate and adjusted ordered logit models are used to show that stress and trauma do play a role in the sexual decision-making of young people, especially young women. For example, young women who have experienced a trauma have a 20% probability of having had multiple casual partners in the prior year compared to 9% for those who have not experiences a trauma. Types and levels of stress and trauma also make a difference by gender.     

Cover up or cool it? Sexual intercourse during therapy for bacterial sexually transmitted infections--a discussion of evidence for efficacy of condom use preventing transmission during an acute bacterial STI

Effective treatment of sexually transmitted infections (STIs) such as gonorrhoea and chlamydia needs sexual behaviour modification, in addition to antibiotics, to protect the index patient and their sexual partner from re-infection during treatment. This may mean advice to avoid sex, or to use condoms for intercourse, until all current sexual partners have completed treatment. This article discusses the effectiveness of condoms as re-infection protection during therapy of gonorrhoea and chlamydial infection. Indirect evidence from studies on primary prevention indicates that, although physically, condoms are impermeable to STI pathogens, the risk of failure depends on the experience of the user and the frequency of use. Health care workers may over-estimate the protective value of condoms in this situation. Patients should be made aware of the risk of infection present, even in experienced condom users, if they choose to continue protected sexual intercourse during therapy for acute bacterial STIs.     

Neutralization of the chemokine CXCL10 enhances tissue sparing and angiogenesis following spinal cord injury

After spinal cord injury, there is a chemoattractant-mediated inflammatory response that is associated with secondary degeneration. The chemoattractant CXCL10 recruits CD4 Th1 cells via the CXCR3A receptor and inhibits growth and chemotaxis of endothelial cells via the CXCR3B receptor. To test the hypothesis that CXCL10 inhibits angiogenesis following spinal cord injury, we assayed the brainstems and spinal cords of spinal cord-injured mice treated with anti-CXCL10 antibodies for expression of angiogenesis-associated genes and quantified blood vessels within their spinal cords. Brainstem microarray analysis indicated eight angiogenesis-associated genes that had significantly higher expression levels in the treated mice than in the untreated mice. Ribonuclease protection assays of the spinal cords showed a significant increase in eight angiogenesis-associated genes in treated animals compared with untreated animals. Histological analysis of the spinal cords of treated and untreated mice showed a significant increase in the number of blood vessels in treated animals. We conclude that CXCL10 plays a critical role in vasculature remodeling following spinal cord injury and that angiogenesis is enhanced following anti-CXCL10 treatment of spinal cord injuries. Improved blood flow and oxygen supply to the injury site may contribute to the functional improvement associated with this treatment.     

Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins

Onchocerciasis remains a major health hazard in many tropical countries. However, the existing tools for diagnosis of the disease have limitations, particularly regarding the detection of low level or early infections. To design an optimized reagent, we exploited the high antibody reactivity of patient sera against the Onchocerca volvulus proteins Ov20 and Ov33, which have been described as highly sensitive and specific immunodiagnostic reagents for producing hybrid proteins. The construct OvH2 was composed of Ov20 fused to Ov33, while OvH3 consisted of the C-terminus of Ov20 linked to Ov33. When these constructs were tested with sera from patients with onchocerciasis and control sera, OvH2 showed a sensitivity of 98.5% and a specificity of 97.7% and OvH3 showed a sensitivity of 98.5% and a specificity of 95.35%. All non-responders were from Ecuador. These results surpass those of existing single recombinant antigens, suggesting that our hybrid proteins combined the sensitivity of the two parent proteins. Tests based on OvH2 should prove suitable for monitoring onchocerciasis control programs and individual diagnosis.     

Identification of infants with significant refractive error and strabismus in a population screening program using noncycloplegic videorefraction and orthoptic examination

PURPOSE: The second Cambridge Infant Vision Screening Program examined whether screening for accommodative errors by using videorefraction without cycloplegia could effectively serve as a first stage of screening for refractive errors, measured by standard cycloplegic retinoscopy. The screening also included an orthoptic examination for detection of strabismus. METHODS: All infants born in the Cambridge (UK) Health District, over a 2-year period, were invited for screening. Of those 5142 (76%) with mean age 8.1 +/- 0.8 months (SD) attended and received noncycloplegic videorefraction and an orthoptic examination. All those with a focusing error or orthoptic problem, as well as a randomly selected sample of visually normal control subjects, were invited to follow-up a month later for cycloplegic retinoscopy, repeat noncycloplegic videorefraction and orthoptic examination. RESULTS: Of the 5142 screened, 514 had a focusing error or orthoptic problem (positives). Four hundred thirty-nine of these and 284 visually normal control subjects (negatives) attended follow-up. A refractive or orthoptic condition was confirmed in 59.0% of the positive cases, whereas infants in 96.8% of the negative cases were confirmed normal. Adjusting for the proportions of the population represented by those infants seen at follow-up, sensitivity for the screening procedure was calculated at 0.67 and specificity at 0.96. Detailed results are presented in terms of the different conditions detected at screening (far, near, and anisometropic focus and orthoptic error), distribution of greatest axes at screening, and a comparison of initial videorefraction with repeat videorefraction and cycloplegic retinoscopy. CONCLUSIONS: A noncycloplegic screening procedure, simpler to perform than cycloplegic screening, succeeded in detecting a large proportion of infants with significant ametropia, particularly those with significant hyperopia, which is considered to be a strabismogenic and amblyogenic risk factor.     

Aboriginal social organization,contemporary experience and American Indian adolescent alcohol use

OBJECTIVE: Anthropologists with an interest in American Indian alcohol use have long held that how native people drink has been conditioned by aspects of the social organization of their societies prior to the disruptive influences of European colonialism. Our goal in this article was to explicitly test the importance of these factors in four contemporary American Indian cultural groups. METHOD: Using data on adolescent alcohol use drawn from the first full wave of the longitudinal Voices of Indian Teens Project (N = 1,651, 51% female), we tested whether patterns of quantity-frequency of alcohol use and the negative consequences of alcohol use predicted by social organzational variables were found among contemporary adolescents and, subsequently, whether these differences persisted when other, more proximal, variables were included. RESULTS: Cultural differences appeared to account for a small percentage of the variance in both quantity-frequency of alcohol use and negative consequences in the initial steps of our analyses, but the pattern in these data was not consistent with the predictions of existing theories regarding aboriginal social organization. Moreover, these cultural differences were no longer significant in the final step of our analyses, suggesting that the cultural differences that did exist were better explained by other factors, at least among these adolescents. CONCLUSIONS: Although these analyses did not indicate that culture was irrelevant in understanding adolescent alcohol use in American Indian communities, classic formulations of these effects were of limited utility in understanding the experiences of contemporary American Indian adolescents.     

The relationship between distance to hospital and patient mortality in emergencies: an observational study

Objectives

Reconfiguration of emergency services could lead to patients with life‐threatening conditions travelling longer distances to hospital. Concerns have been raised that this could increase the risk of death. We aimed to determine whether distance to hospital was associated with mortality in patients with life‐threatening emergencies.

Methods

We undertook an observational cohort study of 10 315 cases transported with a potentially life‐threatening condition (excluding cardiac arrests) by four English ambulance services to associated acute hospitals, to determine whether distance to hospital was associated with mortality, after adjustment for age, sex, clinical category and illness severity.

Results

Straight‐line ambulance journey distances ranged from 0 to 58 km with a median of 5 km, and 644 patients died (6.2%). Increased distance was associated with increased risk of death (odds ratio 1.02 per kilometre; 95% CI 1.01 to 1.03; p<0.001). This association was not changed by adjustment for confounding by age, sex, clinical category or illness severity. Patients with respiratory emergencies showed the greatest association between distance and mortality.

Conclusion

Increased journey distance to hospital appears to be associated with increased risk of mortality. Our data suggest that a 10‐km increase in straight‐line distance is associated with around a 1% absolute increase in mortality.     

Evaluating Community-Based Translational Interventions Using Historical Controls: Propensity Score vs. Disease Risk Score Approach

Many community-based translations of evidence-based interventions are designed as one-arm studies due to ethical and other considerations. Evaluating the impacts of such programs is challenging. Here, we examine the effectiveness of the lifestyle intervention implemented by the Special Diabetes Program for Indians Diabetes Prevention (SDPI-DP) demonstration project, a translational lifestyle intervention among American Indian and Alaska Native communities. Data from the landmark Diabetes Prevention Program placebo group was used as a historical control. We compared the use of propensity score (PS) and disease risk score (DRS) matching to adjust for potential confounder imbalance between groups. The unadjusted hazard ratio (HR) for diabetes risk was 0.35 for SDPI-DP lifestyle intervention vs. control. However, when relevant diabetes risk factors were considered, the adjusted HR estimates were attenuated toward 1, ranging from 0.56 (95% CI 0.44–0.71) to 0.69 (95% CI 0.56–0.96). The differences in estimated HRs using the PS and DRS approaches were relatively small but DRS matching resulted in more participants being matched and smaller standard errors of effect estimates. Carefully employed, publicly available randomized clinical trial data can be used as a historical control to evaluate the intervention effectiveness of one-arm community translational initiatives. It is critical to use a proper statistical method to balance the distributions of potential confounders between comparison groups in this kind of evaluations.