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Biomedical subjects

M Lawrence

Publications and source records attributed to M Lawrence.

At least 73 records · Page 4Linked to original sources
PubMed1991

Prevention of adult heart disease beginning in childhood: intervention programs.

Multiple strategies are available to affect children's cardiovascular health. From clinic-based high-risk counseling to broad-based school or community programs, intervention strategies are being developed and tested to find the most effective means of changing the risk factors of youth to assure a healthier future for our children. Since adoption of new behaviors is improved by consistent messages from multiple sources, a concerted effort is needed. The involvement of health professionals, educators, community organizations, industry, and government together will be important to support the adoption of healthy lifestyles for succeeding generations. Intervention through cardiovascular health promotion for school children may well be the future direction for preventive cardiology.

Adolescent↗
PubMed1990

A total audit of preventive procedures in 45 practices caring for 430,000 patients.

OBJECTIVE: To develop and report the results of a system of audit of computer records in general practice. DESIGN: A retrospective audit of records in practices using the same computer system. Information about recorded preventive procedures was collected by sending the same audit program to each practice on floppy disk. Other characteristics of the practices were determined by postal questionnaire. SETTING: Forty five general practices, widely distributed in England and Wales. SUBJECTS: All 430,901 patients registered with the practices. MAIN OUTCOME MEASURES: Within each practice the percentage of patients in specified age groups for whom certain preventive procedures were recorded as having been carried out. These measures were analysed in relation to practice characteristics. RESULTS: Practice characteristics and recording rates for preventive procedures varied over a wide range. Recording rates were higher in practices with computer terminals on every doctor's desk. Only one practice achieved the new contract target of 90% coverage for recorded primary immunisations, and fewer than two thirds recorded 80% coverage for cervical cytology in the past five years. Practices holding clinics did no better than those without. Smaller partnerships and smaller doctors' list sizes were associated with better performance. CONCLUSIONS: Centrally programmed audit of computerised records is a feasible method of providing data on a regular basis for epidemiological purposes and for performance review. The fact that practices with smaller list sizes had higher levels of recorded preventive care suggests that the trend towards larger lists promoted by the new contract might militate against the intended effect of better preventive care.

Adolescent↗
PubMed1990

Monoclonal and polyclonal antibodies reactive with the 1-32 amino terminal sequence of the alpha subunit of human 32K inhibin.

A monoclonal antibody was made after immunization of mice with the 1-32 amino terminal peptide of the alpha subunit of 32K human ovarian inhibin. The IgG2a mouse antibody reacted 6 times better with bovine 1-32 peptide than it did with 32K bovine inhibin. By contrast sheep polyclonal antibodies made by a similar method had a 29 fold bias in reactivity towards the immunizing peptide. Relative to homologous 1-32 peptide standards, the monoclonal antibody measured apparently higher amounts of immunoreactive material(s) in human (13.5 fold) and bovine (27 fold) follicular fluids than did the polyclonal anti 1-32 peptide antibodies. Immunochemical studies revealed that the epitope recognized by the monoclonal antibody was different from the major epitope recognized by the polyclonal antibodies. The monoclonal antibody reacted much better with human inhibin 1-32 sequences than with bovine (73 fold) or porcine (23 fold). Although the 32K form of human inhibin has not yet been purified, it can be inferred that the monoclonal antibody would be able to detect as little as 2 ng/ml of 32K human inhibin in competitive radioimmunoassays. The antibody must also react with some of the multiple molecular forms of inhibin found in human follicular fluids, and it was shown to function well in the quantitative immunoaffinity extraction of inhibin-like immunoreactivity from follicular fluid. It seems likely that this monoclonal antibody will prove a useful tool for research on human inhibin.

Amino Acid Sequence↗
PubMed1990

Serum creatinine and its relation to cardiovascular disease risk variables in children and young adults from a biracial community. The Bogalusa Heart Study.

The distributions of serum creatinine levels and their relationship with selected anthropometric and cardiovascular risk variables have been described in 3983 children and young adults, aged 5 to 26 years, obtained from a biracial population, Bogalusa, Louisiana. For both blacks and whites serum creatinine levels increased slowly with age, until 11 years of age when a steeper increase occurred to around 19 years of age. Before this age there was a significant age by sex interaction (p less than 0.0001) in the distributions of serum creatinine. After the age of 19 years mean serum creatinine levels were significantly higher in black men than in white men (1.16 mg/dl vs 1.09 mg/dl, p less than 0.0005) and in black women than in white women (0.87 mg/dl vs 0.84 mg/dl, p less than 0.08). Creatinine levels were also significantly higher in men than in women (1.11 mg/dl vs 0.85 mg/dl, p less than 0.0001). Creatinine clearance, estimated from an equation using serum creatine, age, and weight, showed a steady increase until 13 years of age when a maximum range of 120 to 140 ml/min was reached. By the age of 19 years the clearance had declined to a relatively constant range of 100 to 120 ml/min. Black men had the highest correlation of serum creatinine concentration with height, weight, and lean body mass after adjusting for age. White men had the highest correlation of serum creatinine concentration with uric acid. Diastolic blood pressure becomes an important determinant of creatinine levels by the age of 11 years. The race-sex differences in serum creatinine levels in children and young adults are likely related to body mass.

Adolescent↗
PubMed1988

Predicting energy requirements: is energy expenditure proportional to the BMR or to body weight? An analysis of data collected in rural Gambian women.

It has been suggested that energy requirements are either proportional to the BMR (FAO/WHO/UNU, 1985) or to body weight (WHO, 1973). The present analysis sought to distinguish between these two possibilities by determining whether, in rural Gambian women, energy expenditure was more nearly proportional to the BMR or to body weight. For nine of eleven common daily activities energy expenditure expressed per kg body weight was significantly lower in heavier compared to lighter individuals, indicating that energy expenditure was not proportional to weight. Since, in a preliminary analysis, it was found that in Gambian women BMR was roughly proportional to weight raised to the power 0.5, energy expenditure was also compared per kg. For ten of the eleven activities there were no significant differences between different weight groups in the energy costs expressed per kg, and it follows from this that in Gambian women the energy cost of common daily activities was more nearly proportional to the BMR than it was to body weight. Possible reasons for and implications of these results are discussed.

Basal Metabolism↗
PubMed1988

Between-group differences in basal metabolic rates: an analysis of data collected in Scotland, the Gambia and Thailand.

Basal metabolic rate (BMR; using the Douglas bag method), body weight, and fat-free mass (FFM; using the skinfold method) were measured in 46 Scottish and 47 Gambian women in the non-pregnant non-lactating state and in 91 Scottish, 50 Gambian and 52 Thai women early in pregnancy. There were significant between-country differences in BMR (1) in absolute terms (MJ/d), (2) per kg body weight and (3) per kg FFM. However, these differences probably resulted from differences between the groups in average body weight and body composition. Differences per kg body weight were in part explained by differences in body fat content and the relatively low metabolic rate of adipose tissue. Differences in BMR/kg FFM were largely explained by between-group differences in the mass of the FFM, together with the finding that within each group, the BMR/kg FFM tended to decrease as weight increased. There were no significant differences in BMR between Scottish, Gambian and Thai women of similar FFM. There were, therefore, no apparent effects on BMR due to differences in race, climate, diet or nutritional status. Differences in the composition of the FFM could explain the 15 per cent lower BMR/kg FFM in the heaviest compared to the lightest subjects. This brings into question the widespread practice of using FFM as a metabolic reference standard. In contrast, BMR divided by the square root of FFM was similar in all three countries: for non-pregnant women, in MJ/kg0.5/d (mean and s.d.), Scotland 0.87 (0.07) and The Gambia 0.89 (0.07), and for pregnant women, Scotland 0.86 (0.07), The Gambia 0.87 (0.06) and Thailand 0.87 (0.08), and this may be a useful basis for comparing different groups in future. The accuracy of two equations for predicting BMR was assessed. The equation of FAO/WHO/UNU (1985) accurately predicted, from body weight, the average BMR of Scottish women, but under-estimated the average BMR of Gambian and Thai women by 5-10 per cent. The equation of Garby et al. (1988), which predicts BMR from FFM and fat mass, under-estimated the BMR of Scottish, Gambian and Thai women by 5, 10 and 14 per cent respectively, with the largest error within each group being for subjects with the smallest FFM.

Adipose Tissue↗
PubMed1988

Physical activity and total energy expenditure of child-bearing Gambian village women.

In a longitudinal study of pregnancy and lactation levels of physical activity and total energy expenditure (TEE) were measured in 32 rural Gambian women using an activity diary technique. TEE, which was higher than previously measured food intake in this community, ranged from a minimum of 9.6 MJ (2300 kcal)/d (1.7 X BMR) in the months January-March to a maximum of 11.3 MJ (2700 kcal)/d (2 X BMR) during the agricultural season (July-October). During pregnancy and early lactation women went less often to the fields and also reduced the amount of time spent walking and performing household tasks. Standardizing for season and for changes in BMR and the energy cost of activity, reductions in physical activity reduced TEE by 0.59 +/- 0.08 MJ (140 +/- 18 kcal)/d between the 28th week of gestation and 4 weeks post-partum (P less than 0.001). While reduced physical activity may have had an adverse effect on agricultural productivity, energy was spared for other processes including fetal growth and milk output immediately post-partum. Dietary supplementation was without effect on activity pattern.

Adult↗
PubMed1987

Energy requirements of pregnancy in The Gambia.

At most times of the year adjustments in maternal energy expenditure and energy balance in rural Gambian women can provide sufficient energy to sustain reasonable rates of fetal growth without an increase in food intake, although this study suggests that the overall level of energy intake has been substantially underestimated in the past. At certain times of year, however, pre-harvest food shortages and the energy demands of subsistence farming did substantially reduce maternal fat stores and fetal growth. Dietary supplementation, already known to increase birthweight, also had measurable effects on the mothers' physiology, resulting in increased energy expenditure on basal metabolism and improving maternal fat deposition. These findings suggest that the precise energy cost of pregnancy varies as a function of the additional energy intake consumed at this crucial period.

Activities of Daily Living↗
PubMed1987

Fat gain during pregnancy in rural African women: the effect of season and dietary status.

Body-fat gain during pregnancy (weight--total body water/0.73) was measured in 50 rural Gambian women exposed to seasonal energy demands of subsistence farming and to annual preharvest food shortages. Twenty-eight women received dietary supplements in amounts previously shown to increase birth weight. In unsupplemented women, fat gain was profoundly affected by the seasons through which the pregnancy progressed, ranging from an estimated loss of 4.7 kg to a net gain of 3 kg at various times of the year. Adjustment for season revealed, however, that pregnancy per se was without effect on body fat content. Supplementation increased fat gain during pregnancy by approximately 2 kg (p less than 0.05) and gave protection against the worst effects of season on energy balance. These findings contribute to our understanding of the consequences of low food intake during pregnancy and the effects of dietary supplementation on birth weight.

Adipose Tissue↗
PubMed1986

Biochemical genetics of TL antigens.

TL antigens are class I glycoproteins which are expressed on thymocytes and which are coded by the Tla region of the major histocompatibility complex of the mouse. Biochemical analysis of TL molecules from different strains of mice revealed structural variation determined by the Tla region which is detectable by peptide mapping, isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, two-dimensional gels, and by differential reactivity of allelic forms of TL molecules with a panel of anti-TL reagents. The quantity of TL expressed on thymocytes is also influenced by the Tla region; three quantitative phenotypes were identified: high (Tlaa, Tlad, Tlae), intermediate (Tlac, Tlaf), and low (Tlab). (Relative amounts: 1000: 100: 1.) Some thymic leukemias arising in (Tlab, Tlac) mice with genetically determined reduced levels of thymic TL were found to express TL molecules which were structurally indistinguishable from TL isolated from thymocytes but were present in larger amounts. This suggests that TL structural genes are intrinsically capable of full expression in all mice but that the Tla region of mice expressing an intermediate or low quantity of TL is marked by some feature which causes the thymocyte to express less than the full amount of TL possible.

Age Factors↗