Glucose regulates protein turnover and growth-related mechanisms in rainbow trout myogenic precursor cells.

Rainbow trout are considered glucose intolerant because they are poor utilizers of glucose, despite having functional insulin receptors and glucose transporters. Following high carbohydrate meals, rainbow trout are persistently hyperglycemic, which is likely due to low glucose utilization in peripheral tissues including the muscle. Also, rainbow trout myogenic precursor cells (MPCs) treated in vitro with insulin and IGF1 increase glucose uptake and protein synthesis, whereas protein degradation is decreased. Given our understanding of glucose regulation in trout, we sought to understand how glucose concentrations affect protein synthesis, protein degradation; and expression of genes associated with muscle growth and proteolysis in MPCs. We found that following 24 h and 48 h of treatment with low glucose media (5.6 mM), myoblasts had significant decreases in protein synthesis. Also, low glucose treatments affected the expression of both mstn2a and igfbp5. These findings support that glucose is a direct regulator of protein synthesis and growth-related mechanisms in rainbow trout muscle.

Cultural and medical perspectives on geophagia.

Geophagia, the eating of dirt, usually clay, has been recorded in every region of the world both as idiosyncratic behavior of isolated individuals and as culturally prescribed behavior of particular societies. The behavior has long been viewed as pathological by the medical profession, and it has been claimed to be both a cause and a consequence of anemia. While there is now reason to believe that the consumption of some clays may interfere with the absorption of elemental iron, zinc, and potassium, there is little evidence for the position that geophagia, especially its culturally prescribed form, is caused by anemia. These and other maladaptive consequences of clay consumption may be offset by the adaptive value of its antidiarrheal, detoxification, and mineral supplementation potentials.

A longitudinal psycho-physiological study of active and inactive men.

After an interval of ten years, physically active and inactive male university teachers were re-examined across four measures; predicted maximum oxygen uptake, percentage body fat, personality and attitudes towards physical activity. Both groups showed a decrease in predicted oxygen uptake and an increase in body fat although the active subjects continued to possess higher predicted maximum oxygen uptake values and have a lower percentage body fat than the inactive subjects. In general the psychological assessments revealed no major changes but minor shifts in attitudes towards physical activity were noted.

A multivariate analysis of fatness and relative fat patterning.

Skinfold measurements (triceps, subscapular, suprailiac and medial calf) in four samples (376 boys, 352 girs, 338 men and 380 women from rural Colombia) were subjected to principal components analysis to identify components of obesity and relative fat patterning. Three components emerged which were similar in the four samples: a first component of fatness explaining 70-80% of the variance and two fat pattern components each explaining 10-15% of the variance: trunk-extremity and upper-lower body. Fatness and the trunk-extremity pattern components changed with age in children (7-12 years), but none of the components changed with age in adults (25-60+). The fatter tended to be more patterned in both age groups. Canonical correlation analysis revealed that socioeconomic status was more related to fatness than to patterning. With the exception of brothers, all first degree relatives (sib, parent-off-spring) and spouses were correlated in fatness. Some of the correlations between relatives--usually sibs, but not spouses--were also significant for the pattern components, suggesting a genetic basis for the known stability of this characteristic (Garn, '55a). Principal components analysis is a useful multivariate alternative for quantitative studies of anthropometric patterning.

Attitude and personality differences in physically active and inactive university teachers.

This study assessed peronality factors and attitudes toward physical activity in a sample of university teachers. One group (N = 20) of subjects regularly participated in various forms of physical activity; the second (N = 20) showed no such interest. The psychological measures used were the Cattell 16 PF Form A and the Kenyon questionnaire on attitudes toward physical activity. Attitudes about physical activity rather than personality traits were shown to be important within the subpopulation studied.