Activities contributing to energy expenditure among Guatemalan adults

<p>Abstract</p> <p>Background</p> <p>Guatemala has experienced a substantial increase in overweight and obesity in recent years, yet physical activity patterns and consequent energy expenditure are largely unexplored in this population.</p> <p>Methods</p> <p>To describe overall physical activity levels (PAL) and activities contributing to daily energy expenditure, we analyzed time spent in daily activities as reported by 985 women and 819 men, living in rural and urban areas of Guatemala in 2002–04.</p> <p>Results</p> <p>Physical activity levels recommended to prevent obesity (PAL ≥ 1.70) differed by residence/occupation among men (agricultural-rural: 77%; nonagricultural-rural: 36%; urban: 24%; P < 0.01), but not women (rural: 2%; urban: 3%; P = 0.5). Median energy expenditure was higher among agricultural-rural men (44 MET*h/d; MET = metabolic equivalent) compared to nonagricultural-rural (37 MET*h/d) and urban men (35 MET*h/d; P < 0.01); energy expenditure was slightly lower among rural compared to urban women (34 MET*h/d vs. 35 MET*h/d; P < 0.01). Occupation was the largest contributor to energy expenditure (19–24 MET*h/d); among women and nonagricultural-rural and urban men this was primarily of a light intensity. Energy expenditure in sedentary activities ranged from 2 MET*h/d among rural women to 6 MET*h/d among agricultural-rural men. Any sports/exercise time was reported by 35% and 5% of men and women, respectively. Nevertheless, the majority of participants believed they were significantly active to stay healthy.</p> <p>Conclusion</p> <p>Overall, energy expenditure was low in the population not dedicated to agricultural occupations; an increased focus on active leisure-time behaviors may be needed to counterbalance reductions in energy expenditure consequent to sedentarization of primary occupations.</p

Absence of the CAAX Endoprotease Rce1: Effects on Cell Growth and Transformation

After isoprenylation, the Ras proteins and other CAAX proteins undergo two additional enzymatic modifications—endoproteolytic release of the last three amino acids of the protein by the protease Rce1 and methylation of the carboxyl-terminal isoprenylcysteine by the methyltransferase Icmt. This postisoprenylation processing is thought to be important for the association of Ras proteins with membranes. Blocking postisoprenylation processing, by inhibiting Rce1, has been suggested as a potential approach for retarding cell growth and blocking cellular transformation. The objective of this study was to develop a cell culture system for addressing these issues. We generated mice with a conditional Rce1 allele (Rce1(flox)) and produced Rce1(flox/flox) fibroblasts. Cre-mediated excision of Rce1 (thereby producing Rce1(Δ/Δ) fibroblasts) eliminated Ras endoproteolytic processing and methylation and caused a partial mislocalization of truncated K-Ras and H-Ras fusion proteins within cells. Rce1(Δ/Δ) fibroblasts grew more slowly than Rce1(flox/flox) fibroblasts. The excision of Rce1 also reduced Ras-induced transformation, as judged by the growth of colonies in soft agar. The excision of Rce1 from a Rce1(flox/flox) skin carcinoma cell line also significantly retarded the growth of cells, and this effect was exaggerated by cotreatment of the cells with a farnesyltransferase inhibitor. These studies support the idea that interference with postisoprenylation processing retards cell growth, limits Ras-induced transformation, and sensitizes tumor cells to a farnesyltransferase inhibitor