The role of micronutrients in the response to ambient air pollutants: Potential mechanisms and suggestions for research design

People living in regions of low socioeconomic status are thought to be prone to higher exposures to environmental pollutants, poor nutrition, and numerous preventable diseases and infections. Poverty correlates with pollution and malnutrition; however, limited studies examined their interrelationship. The well-studied, deleterious health effects attributed to environmental pollutants and poor nutrition may act in combination with produce more severe adverse health outcomes than any one factor alone. Deficiencies in specific nutrients render the body more susceptible to injury which may influence the pathways that serve as the mechanistic responses to ambient air pollutants. This review (1) explores specific micronutrients that are of global concern, (2) explains how these nutrients may impact the body’s response to ambient air pollution, and (3) provides guidance on designing animal models of nutritional deficiency. It is likely that those individuals who reside in regions of high ambient air pollution are similarly malnourished. Therefore, it is important that research identifies specific nutrients of concern and their impact in identified regions of high ambient air pollution.     

Contact area affects frequency-dependent responses to vibration in the peripheral vascular and sensorineural systems

Repetitive exposure to hand-transmitted vibration is associated with development of peripheral vascular and sensorineural dysfunctions. These disorders and symptoms associated with it are referred to as hand-arm vibration syndrome (HAVS). Although the symptoms of the disorder have been well characterized, the etiology and contribution of various exposure factors to development of the dysfunctions are not well understood. Previous studies performed using a rat-tail model of vibration demonstrated that vascular and peripheral nervous system adverse effects of vibration are frequency-dependent, with vibration frequencies at or near the resonant frequency producing the most severe injury. However, in these investigations, the amplitude of the exposed tissue was greater than amplitude typically noted in human fingers. To determine how contact with vibrating source and amplitude of the biodynamic response of the tissue affects the risk of injury occurring, this study compared the influence of frequency using different levels of restraint to assess how maintaining contact of the tail with vibrating source affects the transmission of vibration. Data demonstrated that for the most part, increasing the contact of the tail with the platform by restraining it with additional straps resulted in an enhancement in transmission of vibration signal and elevation in factors associated with vascular and peripheral nerve injury. In addition, there were also frequency-dependent effects, with exposure at 250 Hz generating greater effects than vibration at 62.5 Hz. These observations are consistent with studies in humans demonstrating that greater contact and exposure to frequencies near the resonant frequency pose the highest risk for generating peripheral vascular and sensorineural dysfunction.     

Parents’ Willingness to Pay for Biologic Treatments in Juvenile Idiopathic Arthritis

BackgroundBiologic therapies are considered the standard of care for children with the most severe forms of juvenile idiopathic arthritis (JIA). Inconsistent and inadequate drug coverage, however, prevents many children from receiving timely and equitable access to the best treatment.ObjectiveThe objective of this study was to evaluate parents’ willingness to pay (WTP) for biologic and nonbiologic disease-modifying antirheumatic drugs (DMARDs) used to treat JIA.MethodsUtility weights from a discrete choice experiment were used to estimate the WTP for treatment characteristics including child-reported pain, participation in daily activities, side effects, days missed from school, drug treatment, and cost. Conditional logit regression was used to estimate utilities for each attribute level, and expected compensating variation was used to estimate the WTP. Bootstrapping was used to generate 95% confidence intervals for all WTP estimates.ResultsParents had the highest marginal WTP for improved participation in daily activities and pain relief followed by the elimination of side effects of treatment. Parents were willing to pay $2080 (95% confidence interval $698–$4065) more for biologic DMARDs than for nonbiologic DMARDs if the biologic DMARD was more effective.ConclusionsParents’ WTP indicates their preference for treatments that reduce pain and improve daily functioning without side effects by estimating the monetary equivalent of utility for drug treatments in JIA. In addition to evidence of safety and efficacy, assessments of parents’ preferences provide a broader perspective to decision makers by helping them understand the aspects of drug treatments in JIA that are most valued by families.     

Cognitive Overload? An Exploration of the Potential Impact of Cognitive Functioning in Discrete Choice Experiments with Older People in Health Care

ObjectivesThis exploratory study sought to investigate the effect of cognitive functioning on the consistency of individual responses to a discrete choice experiment (DCE) study conducted exclusively with older people.MethodsA DCE to investigate preferences for multidisciplinary rehabilitation was administered to a consenting sample of older patients (aged 65 years and older) after surgery to repair a fractured hip (N = 84). Conditional logit, mixed logit, heteroscedastic conditional logit, and generalized multinomial logit regression models were used to analyze the DCE data and to explore the relationship between the level of cognitive functioning (specifically the absence or presence of mild cognitive impairment as assessed by the Mini-Mental State Examination) and preference and scale heterogeneity.ResultsBoth the heteroscedastic conditional logit and generalized multinomial logit models indicated that the presence of mild cognitive impairment did not have a significant effect on the consistency of responses to the DCE.ConclusionsThis study provides important preliminary evidence relating to the effect of mild cognitive impairment on DCE responses for older people. It is important that further research be conducted in larger samples and more diverse populations to further substantiate the findings from this exploratory study and to assess the practicality and validity of the DCE approach with populations of older people.     

Age-Related Changes in the Spontaneous Motor Rhythms of theSenescence-Accelerated Mouse (SAMP8)

The present study examined the effect of age on the spontaneous motor rhythms of mice during wheel running. The spontaneous motor tempo (SMT) of wheel running was measured for the P8 strain of the senescence-accelerated mouse (SAMP8) by recording the sequence of time intervals (measured in milliseconds) for successive revolutions of a run-wheel over the course of 16 days. Analyses of the distribution of interrevolution intervals of 2-, 7-, and 12-month-old SAMP8 revealed an age-related slowing of wheel running and a corresponding increase in variability consistent with Weber's law. All three age groups also demonstrated a practice effect over the course of testing best described by a power law. These findings provide evidence of age-related changes in the spontaneous motor rhythms of the SAMP8 that occur as early as 7 months of age. The results are consistent with age-related changes in human subjects and suggest that spontaneous wheel-running behavior in rodents may be a good model for studying SMT.