Steroid and thyroid hormones, and vitamins A and D bind to nuclear receptors, which act as ligand-modulated transcription factors. In many cases, ligand-activated nuclear receptor binds to positively acting hormone response elements (p-HREs) to induce gene transcription. However, ligand-activated receptors also repress transcription of specific genes and several mechanisms that account for negative regulation have recently emerged. One major form of negative regulation is based on transcriptional interference between nuclear receptors and other transcription factors, such as AP-1. In this case, the liganded receptor prevents AP-1 or other positively acting transcription factors from fruitful interaction with the transcription initiation complex. A second form of negative regulation is based on binding of nuclear receptors to specialized negative HREs (n-HREs). Binding of unliganded receptor to such an element results in constitutive activation, which is terminated by the binding of ligand. While transcriptional interference with AP-1 has been described for many members of the nuclear receptor family, negative regulation through n-HREs so far has been shown only for one of the thyroid hormone receptors. However, this type of negative regulation is likely to be widespread.
Leisure researchers have long examined the many ways in which people use their leisure time and interact with leisure-related resources including parks and recreation facilities. This special issue...
Most adolescents do not meet national recommendations for nutrition and physical activity. However, no studies of physical activity and nutrition interventions for adolescents conducted in health care settings have been published. The present study was an initial evaluation of the PACE+ (Patient-centered Assessment and Counseling for Exercise plus Nutrition) program, delivered in primary care settings.Adolescents aged 11 to 18 years (N = 117) were recruited from 4 pediatric and adolescent medicine outpatient clinics. Participants' mean (SD) age was 14.1 (2.0) years, 37% were girls, and 43% were ethnic minorities.Behavioral targets were moderate physical activity, vigorous physical activity, fat intake, and fruit and vegetable intake. All patients completed a computerized assessment, created tailored action plans to change behavior, and discussed the plans with their health care provider. Patients were then randomly assigned to receive no further contact or 1 of 3 extended interventions: mail only, infrequent telephone and mail, or frequent telephone and mail.Brief, validated, self-report measures of target behaviors were collected at baseline and 4 months later.All outcomes except vigorous physical activity improved over time, but adolescents who received the extended interventions did not have better 4-month outcomes than those who received only the computer and provider counseling components. Adolescents who targeted a behavior tended to improve more than those who did not target the behavior, except for those who targeted vigorous physical activity.A primary care-based interactive health communication intervention to improve physical activity and dietary behaviors among adolescents is feasible. Controlled experimental research is needed to determine whether this intervention is efficacious in changing behaviors in the short- and long-term.
PURPOSE: The study tested the hypothesis that walking for both leisure and transportation purposes is higher in people living in high walkability neighborhoods. Method: Thirty-two neighborhoods were selected in Seattle-King County, Washington, and Baltimore-Washington, DC regions that varied in “walkability” and income. High walkability means neighborhoods have high residential density, street connectivity, and mixed land use, consistent with the potential for active transportation. Adults aged 20–65 years were recruited from study neighborhoods (n=2199; 48% female; mean age=45 years; 26% ethnic minority). Minutes of walking for leisure and transportation purposes in the past week were reported separately using items from the long form of the International Physical Activity Questionnaire. Neighborhood walkability was objectively measured with land use and street network data using Geographic Information System software. Neighborhood income was based on census data. Multilevel mixed effect regressions were conducted, accounting for clustering within neighborhood and covarying for individual-level demographic variables including age, gender, education, ethnicity, and time at address. RESULTS: There was a significant walkability X income interaction (p<.027) for walking for transportation, indicating a greater positive effect of walkability in higher income neighborhoods. Overall, participants living in high-walk ability neighborhoods walked significantly more for transportation than those living in low-walkability neighborhoods (adjusted means, 44.3 vs 12.8 min/day). Walking for leisure also was significantly higher (p<.012) for residents living in highwalkability versus low-walkability neighborhoods (adjusted means, 18.5 vs 14.2 min/day); neither the income effect nor the interaction was significant for leisure walking. CONCLUSION: In most studies, walkability has been associated only with walking for transportation, so the present finding of more walking for leisure in high walkable neighborhoods indicates walkability supports physical activity for multiple purposes. Reasons for the smaller effect of neighborhood walkability on walking for transportation among low income participants need to be explored.
Background. The interrelationships among health behaviors are not well understood. The present study examines health behaviors and their relations to various types of physical activity among university seniors. Methods. The study sample was an ethnically diverse group of 576 men and women (mean age 24.5 ± 2 years) recruited from a large urban university. Physical activity was assessed with a modification of the Blair Seven-Day Recall by telephone interview, and health behaviors were assessed with the CDC's Youth Risk Behavior Survey, College Version. Hierarchical multiple regressions were conducted to determine whether health behaviors of men and women were associated with physical activity after adjusting for potential demographic confounders. Results. Nineteen health behavior items were factor analyzed, yielding 5 factors: tobacco use, drinking and driving, unsafe sex, eating fatty foods, and eating healthy foods. Physical activity measures included leisure-time moderate and vigorous activities, flexibility, and strengthening activities. For men, a significant relation was found between three of four indices of physical activity and eating healthy foods (P>0.05), but no association was noted with other health behaviors. For women, vigorous physical activity was related to eating healthy foods, and strengthening activities were related to eating fewer fatty foods (P<0.05). Conclusions. Consistent with previous studies, physical activity was found to have modest associations with eating behaviors but not with other health-related behaviors.
Purpose The purpose of this study was to evaluate age and gender differences in objectively measured physical activity (PA) in a population-based sample of students in grades 1–12. Methods Participants (185 male, 190 female) wore a CSA 7164 accelerometer for 7 consecutive days. To examine age-related trends, students were grouped as follows: grades 1–3 (N = 90), grades 4–6 (N = 91), grades 7–9 (N = 96), and grades 10–12 (N = 92). Bouts of PA and minutes spent in moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) were examined. Results Daily MVPA and VPA exhibited a significant inverse relationship with grade level, with the largest differences occurring between grades 1–3 and 4–6. Boys were more active than girls; however, for overall PA, the magnitudes of the gender differences were modest. Participation in continuous 20-min bouts of PA was low to nonexistent. Conclusion Our results support the notion that PA declines rapidly during childhood and adolescence and that accelerometers are feasible alternatives to self-report methods in moderately sized population-level surveillance studies.
This study evaluated the validity of a parental report measure of children's solar protection behaviors.Fifty-eight children had skin color assessed twice with a colorimeter. Between measurement sessions, parents were interviewed by telephone to assess children's indoor-outdoor status and solar protection across 40 hourly intervals.Parental report of child's indoor-outdoor status was significantly correlated with the colorimeter values, whereas the use of sunscreen and protective clothing was not.This measure was feasible for assessing ultraviolet exposure in young children. The component that assessed the number of intervals spent outdoors evidenced predictive validity.
