The Framingham Disability Study: physical disability among community-dwelling survivors of stroke

The relationship between stroke and physical disability was examined in a cohort of adult, Framingham, Massachusetts, residents who, between 1948 and 1951, were assembled for a longitudinal examination of cardiovascular disease. Multivariate analyses examined the amount of residual disability attributable to stroke among 2540 community-dwelling survivors, 27 years after their initial examination, after controlling for age, cardiovascular risk factors, other cardiovascular diseases, and eight general health conditions related to physical disability. Among men living in the community, a history of stroke explained 12% of the variance in physical disability. Suffering a stroke, however, was not as strongly related to physical disability among women living in the community, accounting for only 3% of the variance. Results suggest that although older men and women die from the same major causes, they may not be disabled by the same conditions.     

Decision analysis: a tool for infection control

The medical world would seem to be one of increasing technology and shrinking financial resources. New tests and therapies constantly appear on the market. Most have been examined for efficacy and side effects. The real question is: where does the new test or therapy fit in with all previous products? Decision analysis is a mathematical tool adapted to assess the relative cost-effectiveness of complex diagnostic and therapeutic strategies.     

Factors affecting the toxicity of rotting carcasses containing Clostridium botulinum type E

Mice killed shortly after receiving c. 2000 spores of a type E strain of Clostridium botulinum per os were incubated at one of five chosen temperatures together with bottles of cooked meat medium seeded with a similar inoculum. After incubation the rotting carcasses were homogenized. Sterile membrane filtrates of the homogenates (10%, w/v) and pure cultures were then titrated for toxicity. Some of the main findings were confirmed with two further type E strains. Toxicity produced at 37 degrees C was poor in both carcasses and cultures (200-20,000 mouse intraperitoneal LD/g or ml). It was good in both systems at 30 and 23 degrees C, usually reaching 20,000-200,000 LD/g or ml, and in carcasses occasionally more; at 30 degrees C maximal toxicity was reached more quickly in carcasses than in cultures. Prolonged incubation (36-118 days) at 30 or 23 degrees C resulted in complete loss of toxicity in virtually all carcasses but not in cultures. At 16 degrees C the development of toxicity in carcasses was strikingly greater than in cultures. At 9 degrees C neither system produced more than slight toxicity after prolonged incubation. Trypsinization increased the toxicity of cultures but not usually of carcasses. Unfiltered carcass homogenate (10%, w/v) with maximal intraperitoneal toxicity was harmless for mice by mouth in doses of 0.25 ml. These findings differed in important respects from those made earlier with a type C strain.     

Theoretical and practical considerations in the doubly-labelled water (2H2(18)O) method for the measurement of carbon dioxide production rate in man

In the doubly-labelled water (2H2(18)O) method for the measurement of carbon dioxide production rate in man, single exponential disappearance curves for 2H2O and H2(18)O in body water are used; the precision with which the slopes and intercepts of the curves are estimated determines the precision of the estimate of carbon dioxide production rate. In studies with infants, and in computer simulations, the effect of different experimental regimes on the overall precision of the carbon dioxide production estimate was investigated. When the number of data points used was progressively reduced by shortening the total observation period from 7 d (about 3 biological half-lives for the isotopes) to 1 d there was a deleterious effect on precision and in the infants there was an upward bias in the values for carbon dioxide production. When the number of data points was reduced by removing points from the middle of the exponential curves with the maintenance of the 7-d experimental period, precision was also reduced but by less than in the former procedure and there were no consistent trends in the average values for carbon dioxide production.     

Dietary intake of healthy subjects before and one year after dietary advice

This study was conducted to follow up healthy subjects from a previous study (Warwick & Williams, 1987) in which favourable dietary changes were achieved during 1 week immediately after dietary advice but were accompanied by reduced energy intakes and weight loss. Twenty-one subjects (8m, 13f; 57 per cent of the original group) participated in the follow-up study. Dietary intakes were measured using 7-d weighed records on three occasions: before, immediately after and 1 year after receiving dietary advice. Intakes 1 year after dietary advice continued to show some of the favourable changes observed immediately after the advice but were not accompanied by reduced energy intakes and weight loss. Intakes before, immediately after, and 1 year after dietary advice respectively were: energy, 9.0, 7.8 and 8.9 MJ/d (2150, 1860 and 2120 kcal/d); fat, 36.9, 32.9 and 31.5 per cent of total energy; carbohydrate, 44.2, 47.9 and 49.6 per cent of total energy; dietary fibre, 32, 36 and 36 g/d; sodium, 116, 97 and 110 mmol/d; and Na:K ratio, 1.4, 1.2 and 1.2 mmol. Nutrient densities for fibre and most micronutrients tended to be higher 1 year after dietary advice than before, but were highest immediately after the advice. Nutrient densities for sodium and total sugars did not vary between the 3 study weeks. It was concluded that our healthy subjects adapted their intakes to maintain energy balance while retaining favourable dietary changes for at least 1 year after dietary advice.