1,993 publications from this institution
Physical activity (PA) is one of the most important factors for improving population health, but no standardised systems exist for international surveillance. The International Physical Activity Questionnaire (IPAQ) was developed for international surveillance. The purpose of this study was a comparative international study of population physical activity prevalence across 20 countries. Between 2002–2004, a standardised protocol using IPAQ was used to assess PA participation in 20 countries [total N = 52,746, aged 18–65 years]. The median survey response rate was 61%. Physical activity levels were categorised as "low", "moderate" and "high". Age-adjusted prevalence estimates are presented by sex. The prevalence of "high PA" varied from 21–63%; in eight countries high PA was reported for over half of the adult population. The prevalence of "low PA" varied from 9% to 43%. Males more frequently reported high PA than females in 17 of 20 countries. The prevalence of low PA ranged from 7–41% among males, and 6–49% among females. Gender differences were noted, especially for younger adults, with males more active than females in most countries. Markedly lower physical activity prevalence (10% difference) with increasing age was noted in 11 of 19 countries for males, but only in three countries for women. The ways populations accumulated PA differed, with some reporting mostly vigorous intensity activities and others mostly walking. This study demonstrated the feasibility of international PA surveillance, and showed that IPAQ is an acceptable surveillance instrument, at least within countries. If assessment methods are used consistently over time, trend data will inform countries about the success of their efforts to promote physical activity.
Habitual physical activity in children is related to physical fitness and appears to mediate cardiovascular disease (CVD) risk factors. We studied the physical activity patterns and associated variables of a large bi-ethnic cohort of 4-year-old children from low to middle socioeconomic families. Trained observers coded the behavior of 351 children (150 Anglo-American, 201 Mexican-American; 182 boys, 169 girls) during two 60-minute home visits and two unstructured recesses lasting up to 30 minutes each at 63 different preschools. Findings indicated that although children were much less active at home, there were low but significant correlations between their activity patterns at home and during recess (r = .13). Children who had activity-promoting toys at home also tended to have them available during preschool recess (r = .20). Ethnic differences were evident for both activity and environmental variables. Mexican-American children were less active than Anglo children at home (p less than .002) and during recess (p less than .03), thus adding to the adult literature that has found Mexican-Americans to be less active than Anglos, and supporting to the notion that physical activity life-style habits may be established in early childhood. In both settings, Mexican-American children spent more time in presence of adults (home, p less than .04; recess, p less than .03) and had access to fewer active toys (home, p less than .001; recess, p less than .05). Gender differences were also evident for both activity and environmental variables.(ABSTRACT TRUNCATED AT 250 WORDS)
Originally thought to be a B-cell-specific transcriptionfactor involved in regulation of the immunoglobulin κlight-chain gene (Sen and Baltimore 1986), NF-κB hasemerged as a ubiquitous, evolutionarily conserved transcription factor whose activity is rapidly induced in response to (mostly) proinflammatory stimuli (Baeuerleand Baltimore 1996). In most cell types, NF-κB, a heterogeneous collection of dimeric proteins composed ofmembers of the Rel family, resides in the cytoplasm because it is bound to members of the IκB family (for review, see Siebenlist et al. 1994; Baldwin 1996; Ghosh etal. 1998). The IκBs, of which there are several, directlybind to the DNA-binding and dimerization domain of theRel proteins, known as the Rel homology domain (RHD),interfering with the function of the nuclear localizationsignal (NLS) present near the carboxyl terminus of theRHD ( Siebenlist et al. 1994; Baldwin 1996; Ghosh et al.1998). According to recently solved three-dimensionalstructures of the core of IκBα in complex with the RHDsof the major NF-κB components, p50/NF-κB1 andp65/RelA, the amino terminus of the IκB core, which iscomposed of six to seven ankyrin repeats, is positionednext to the NLS and most likely sterically hinders thebinding of karyopherins to the latter (Huxford et al. 1998;Jacobs and Harrison 1998). Therefore, the only way toget NF-κB to its site of action, the nucleus, is to disruptthe NF-κB:IκB complex. Curiously, nature has come upwith only one major and unusually complex pathway toaccomplish disruption of the NF-κB:IκB complex in response to extracellular stimuli. This pathway involves thecoordinated action of a very large number of proteins (atleast 20) and an even larger number of ATP molecules. Itis estimated that the energy cost of activating NF-κB isalmost as high as the one invested in synthesis of its components. Despite this complexity, NF-κB activation occurs very rapidly, making it an ideal signaling system forproinflammatory stimuli, which trigger innate immuneresponses— the first line of defense against bacterial,fungal, and viral infections. Efficient defense against microbial infections requires rapid signaling responses thatdo not depend on de novo protein synthesis, yet are capable of coordinating the induction of a large number ofgenes, whose products cannot be constitutively expresseddue to potential autotoxicity. Due to this toxicity problem, an efficient signaling system should also feature abuilt-in ability to turn itself off when no longer needed.The NF-κB system has it all...
Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical activity differed by country. Population representative samples from 11 countries on five continents were surveyed using comparable methodologies and measurement instruments. Neighborhood environment × country interactions were tested in logistic regression models with meeting physical activity recommendations as the outcome, adjusted for demographic characteristics. Country-specific associations were reported. Significant neighborhood environment attribute × country interactions implied some differences across countries in the association of each neighborhood attribute with meeting physical activity recommendations. Across the 11 countries, land-use mix and sidewalks had the most consistent associations with physical activity. Access to public transit, bicycle facilities, and low-cost recreation facilities had some associations with physical activity, but with less consistency across countries. There was little evidence supporting the associations of residential density and crime-related safety with physical activity in most countries. There is evidence of generalizability for the associations of land use mix, and presence of sidewalks with physical activity. Associations of other neighborhood characteristics with physical activity tended to differ by country. Future studies should include objective measures of neighborhood environments, compare psychometric properties of reports across countries, and use better specified models to further understand the similarities and differences in associations across countries.
Latino adolescents in the United States and Mexico may have higher rates of tobacco experimentation than other ethnic groups, possibly due to cultural fact
The mammalian Rel/NF-kappaB family of transcription factors, including RelA, c-Rel, RelB, NF-kappaB1 (p50 and its precursor p105), and NF-kappaB2 (p52 and its precursor p100), plays a central role in the immune system by regulating several processes ranging from the development and survival of lymphocytes and lymphoid organs to the control of immune responses and malignant transformation. The five members of the NF-kappaB family are normally kept inactive in the cytoplasm by interaction with inhibitors called IkappaBs or the unprocessed forms of NF-kappaB1 and NF-kappaB2. A wide variety of signals emanating from antigen receptors, pattern-recognition receptors, receptors for the members of TNF and IL-1 cytokine families, and others induce differential activation of NF-kappaB heterodimers. Although work over the past two decades has shed significant light on the regulation of NF-kappaB transcription factors and their functions, much progress has been made in the past two years revealing new insights into the regulation and functions of NF-kappaB. This recent progress is covered in this review.
