Daily energy expenditure by five-year-old children, measured by doubly labeled water.

Current recommendations for daily energy requirements in 5-year-old children (90 kcal/kg per day) are based on energy intake associated with normal growth. It is not known, however, how these recommendations compare with total free-living energy expenditure (TEE) and how much of TEE is related to physical activity. The TEE and the resting metabolic rate (RMR) were measured in 28 white children, aged 5 years (15 boys, 13 girls; mean (+/- SD) weight 20.1 +/- 3.4 kg; height 113 +/- 6 cm; fat 20% +/- 5%). The TEE was calculated during a 7-day period from urinary elimination rates of deuterium (2H) and heavy oxygen (18O) by using a modification of the two-point slope-intercept method; RMR was measured by a ventilated-hood indirect calorimeter. Physical activity indexes were also collected from questionnaires completed by the parents. Measured TEE was considerably lower than the recommended dietary allowances (1370 +/- 222 kcal/day vs 1807 +/- 310 kcal/day; p < 0.0001), whereas measured RMR was slightly higher than predicted RMR (1001 +/- 119 kcal/day vs 952 +/- 78 kcal/day; p < 0.001). The energy cost of physical activity accounted for only 16% +/- 7% of TEE. An index of activity, assessed as the difference between the measured TEE and the predicted TEE, correlated positively with past-year sport-leisure activity assessed by questionnaire (r = 0.40; p < 0.05). We conclude that measured TEE in 5-year-old children yields lower values (approximately 400 kcal/day) than current estimates. A minute part of this difference (20 to 30 kcal/day) is related to the changes in energy stores during growth, but most seems due to lower-than-expected levels of physical activity. This might be related to increased television viewing, which replaces activities requiring energy.

Macrocyclic trichothecenes: cause of livestock poisoning by the Brazilian plant Baccharis coridifolia.

Nine macrocyclic trichothecenes, thought to cause toxic effects in herbivors, were isolated from the Brazilian shrub Baccharis coridifolia. The structures of two new components, named miophytocene A and B, are described. Structure analysis was mainly accomplished by application of two-dimensional Fourier transform NMR techniques. The trichothecenes are most likely produced by the soil fungus Myrothecium verrucaria, which was isolated from soil samples around B. coridifolia. It is concluded that the plant is able to absorb and accumulate these mycotoxins. Histopathological studies on rabbits which received roridin E and A per os revealed mainly necrosis and hemorrhages of the mucosa of the colon and in the case of roridin A also of the caecum. Lethality in mice was generally low, intoxication proceeding slowly. It has to be considered, however, that all trichothecenes tested are practically insoluble in aqueous solutions and were applied as emulsions (i.p. and per os application). No trichothecenes or other toxic substances were detected from the Brazilian species Baccharis dracunculifolia, although slight toxic effects have been reported in cattle.