Total energy expenditure (TEE) was measured simultaneously in 14 free-living adults over 15 d by the doubly labeled water (DLW) method and for 2-4 separate days by heart-rate (HR) monitoring. Individual curves for HR vs oxygen consumption (VO2) were obtained and an HR (FLEX HR: 97 +/- 8 beats/min, range 84-113 beats/min) that discriminated between rest and activity was identified. Calibration curves were used to assign an energy value to daytime HR above FLEX HR. Below FLEX HR energy expenditure was taken as resting metabolism. Sleeping energy expenditure was assumed to be equal to basal metabolic rate. Average HR TEE (12.99 +/- 3.83 MJ/d) and average DLW TEE (12.89 +/- 3.80 MJ/d) were similar. HR TEE discrepancies ranged from -22.2% to +52.1%, with nine values lying within +/- 10% of DLW TEE estimates. The FLEX HR method provides a close estimation of the TEE of population groups. However, an increased number of sampling days may improve the precision of individual estimates of TEE.
In established cases of multiple sclerosis (MS), the normal-appearing white matter (NAWM), as defined for magnetic resonance imaging (MRI), is abnormal in the majority of cases. The clinical significance of these NAWM abnormalities is the subject of debate, but there is strong correlation with degree and progression of disability. New lesions form in NAWM before blood-brain barrier breakdown, as evidenced by gadolinium enhancement. The pathological basis of these neuroimaging abnormalities is largely unknown. Definitive pathological studies on the NAWM are few and are often based on small numbers of samples and of cases. Despite a variety of MS NAWM pathological studies, major research questions, of importance to our understanding of basic pathogenetic mechanisms and consequent rational therapies, remain unanswered. These relate to the frequency and extent of oligodendrocyte/myelin and axonal abnormalities in MS NAWM, and to the cellular basis of very early MS lesions detected by neuroimaging. In a pilot study of MS NAWM, microglial activation was demonstrated in 9 of 10 MS cases. We are currently testing the hypothesis that microglial activation, as defined by altered phenotype and HLA-DR positivity, will act as a marker for oligodendrocyte/myelin and axonal pathology in MS NAWM.
~~~~ ~ ~ Total daily energy expenditure (TEE) by the doubly-labelled ('H,'*O) water method and basal metabolic rate (BMR) by indirect calorimetry were measured in thirty-two healthy free-living adults in Northern Ireland. Habitual physical activity patterns in occupational and discretionary activities were assessed by interview questionnaire. Expressed as a multiple of BMR the TEE values for the sixteen males In recent years increased mechanization in the workplace and the home has resulted in a marked trend towards very low levels of energy expenditure (Prentice et al. 1985). As a result predominantly sedentary populations can now achieve energy equilibrium at a level below that considered optimal for health. These secular changes have highlighted the importance of regular recreational exercise to overall health status, particularly in relation to coronary heart disease (CHD) and obesity. In the future, as lifestyles become increasingly leisure centred, recreational physical activity is likely to assume an even greater importance. Although vigorous efforts are currently being made to promote sport and active recreation there has been no systematic investigation of the real significance of discretionary physical activity in determining energy expenditure. There remains some doubt as to whether realistically achievable levels of exercise, compatible with modern lifestyles, can have any significant impact.In the present study total energy expenditure (TEE) measured by the doubly-labelled ('H,l8O) water method (DLW) in healthy free-living subjects and assessment of their patterns of physical activity by questionnaire have demonstrated that recreational activity has now emerged as the key determinant of energy expenditure in most sedentary people. The results suggest that reasonable levels of leisure-time activity can have an important available at https://www.cambridge.org/core/terms. https://doi
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