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Biomedical subjects

S Bennett

Publications and source records attributed to S Bennett.

At least 127 records · Page 7Linked to original sources
PubMed1995

A pilot safety and immunogenicity study of the malaria vaccine SPf66 in Gambian infants.

A pilot safety and immunogenicity trial of the malaria vaccine SPf66 has been undertaken in 150 Gambian infants. No significant systemic side effects were recorded but modest local reactions were seen after the administration of a third 1.0 mg dose. SPf66 produced in Colombia was more immunogenic than SPf66 produced in the USA and a 1.0 mg dose of each vaccine gave higher antibody levels than a 0.5 mg dose. However, antibody levels fell rapidly after administration of the third dose of vaccine and showed little change over the following malaria transmission season. The incidence of clinical malaria was higher among children who received SPf66 than among children who received inactivated polio vaccine, the effect being most marked among children who received 1.0 mg Colombian SPf66. As the trial was not designed to measure the effect of SPf66 on morbidity from malaria, the significance of this finding is uncertain.

Animals↗
PubMed1995

Cardiovascular risk factors in Australia: trends in socioeconomic inequalities.

STUDY OBJECTIVE: To examine trends in socioeconomic inequalities in cardiovascular risk factors using educational attainment to indicate socioeconomic status. DESIGN: Behavioural data, physical measurements, blood pressure, and lipid determination collected in three, successive multicentre cross sectional community surveys conducted in 1980, 1983, and 1989. SETTING: The six state capital cities of Australia; Sydney, Melbourne, Brisbane, Adelaide, Perth, and Hobart. PARTICIPANTS: A total of 19,315 randomly selected respondents stratified by age (25-44, 45-64) and sex. RESULTS: During the 1980s, average blood pressure declined for each level of educational attainment. Dietary messages to reduce the intake of saturated fat had little effect on the lipid profile of any population group. Height and educational attainment were positively associated. Women increased in weight from between 2 to 4 kg depending on age and educational attainment while older men experienced increases of around 2.5 kg regardless of educational attainment. Advice to avoid salt was adopted across the spectrum of educational attainment but with no suggestion that the socioeconomic gradient, which favoured the more highly educated, was diminishing. Men of all education levels responded positively to the anti-smoking initiatives of the 1980s but the relative disadvantage of those of lower education was maintained. Among women, the decline in smoking was less among those in the low education group. The prevalence of moderate to heavy drinkers was higher in men of lower educational attainment but declined significantly over the period. Walking for recreation or exercise became more popular, especially among older men of low education, while the prevalence of aerobic exercise and vigorous exercise remained largely unchanged. Overall, the clear socioeconomic gradient between leisure time physical activity and education attainment remained. CONCLUSIONS: The lower socioeconomic group has improved its risk factor profile but its relative disadvantage compared with the higher socioeconomic group persists. Health promotion activities in Australia seem to have been effective in reaching the lower socioeconomic groups but the challenge to reduce inequalities remains. The steady increase in educational attainment in Australia may have been an important factor in the general improvement in the nation's risk factor profile and in the decrease in mortality from coronary heart disease.

Adult↗
PubMed1994

Variables in the isolation and culture of human monocytes that are of particular relevance to studies of HIV.

Mononuclear phagocytes play an important role in human immunodeficiency virus (HIV) infection. However, knowledge of the extent of macrophage involvement in the pathogenesis of HIV infection is still incomplete. This is due in part to the technical difficulties associated with isolating, purifying, and culturing these cells. Isolation of a pure population of human monocytes is essential when studying the role of these cells in HIV infection. In addition, the differentiation, activation, and replication of human monocytes are critically affected by both isolation and culture conditions. This review examines the different monocyte isolation and purification methods and culture conditions that are currently being employed and assesses their suitability for studying the functions of monocytes in HIV infection.

Cell Separation↗
PubMed1994

Blood pressure measurement error: its effect on cross-sectional and trend analyses.

The measurement of blood pressure in epidemiological studies is difficult to standardize between centres in multi-centre studies and between repeat surveys over time. The use of standard mercury sphygmomanometers is common but especially prone to measurement error in terms of departure from the protocol and variation in measurement technique. Data from Australia's cardiovascular risk factor prevalence surveys on 21 independent populations, distributed geographically and temporally, has been examined to assess the effect of these errors on cross-sectional and trend analyses. The examination showed that last digit preference for zero may inflate estimates of proportions having high blood pressure. A tendency to record identical duplicate measurements could contribute 0.85 mmHg to time trends or geographic differences in mean systolic blood pressure (but not diastolic blood pressure). Epidemiological studies for geographic and trend differentials in systolic blood pressure need to be mindful of these effects in their analysis. There was some evidence of deterioration in data quality during data collection but no evidence that observers were influenced in their recording practice by observable respondents' characteristics. Training procedures for blood pressure measurement are of critical importance and adherence to the measurement protocol should be continuously monitored during data collection to ensure comparability of results.

Adult↗
PubMed1994

Subjective anxiety measurements and cortisol responses in adults who stutter.

Anxiety, as measured by self-report inventories and salivary cortisol levels, was examined in 11 males who stutter and 11 males who do not stutter during baseline, low stress, and high stress sessions. During the high stress session salivary cortisol was significantly greater in persons who stutter than in persons who do not stutter. No significant differences were found between the two groups on the State-Anxiety Inventory, Trait-Anxiety Inventory, or the Personal Report of Communication Apprehension. Significant differences in anxiety levels among the baseline, low stress, and high stress sessions for both groups of subjects were found for the State-Anxiety Inventory. No other significant differences or relationships were found between the two groups.

Adult↗
PubMed1994

Twin children in The Gambia: evidence for genetic regulation of physical characteristics in the presence of sub-optimal nutrition.

It has been demonstrated that physical growth characteristics are subject to genetic regulation. However, in developing countries, environmental factors such as food availability and frequent infections are associated with growth faltering which is particularly marked in infancy. We have conducted anthropometric measurements of a cohort of twin children aged less than 14 years living in a rural area of The Gambia to ascertain the extent to which genetic factors influence physical growth in the presence of a sub-optimal diet. Almost 25% of the children were more than 2SD below the median of the reference population in terms of their height-for-age Z score, indicating a marked level of undernutrition. Nevertheless, the within-pair variances were significantly less for monozygous than for dizygous twin pairs for the following variables: height, head circumference and body mass index (p < 0.01); weight (p < 0.02) and mid upper arm circumference (p < 0.1), indicating that there is a strong genetic influence on growth regulation despite the sub-optimal nutrition.

Adolescent↗
PubMed1994

A computer simulation of household sampling schemes for health surveys in developing countries.

BACKGROUND: Cluster sample surveys of health and nutrition in rural areas of developing countries frequently utilize the EPI (Expanded Programme on Immunization) method of selecting households where complete enumeration and systematic or simple random sampling (SRS) is considered impractical. The first household is selected by choosing a random direction from the centre of the community, counting the houses along that route, and picking one at random. Subsequent households are chosen by visiting that house which is nearest to the preceding one. METHODS: Using a computer, and data from a survey of all children in 30 villages in Uganda, we simulated the selection of samples of size 7, 15 and 30 children from each village using SRS, the EPI method, and four different modifications of the EPI method. RESULTS: The choice of sampling scheme for households had very little effect on the precision or bias of estimates of prevalence of malnutrition, or of recent morbidity, with EPI performing as well as SRS. However, the EPI scheme was inefficient and showed bias for variables relating to child care and for socioeconomic variables. Two of the modified EPI schemes (taking every fifth house and taking separate EPI samples in each quarter of the community) performed in general much better than EPI and almost as well as SRS. CONCLUSIONS: These results suggest that the unmodified EPI household sampling scheme may be adequate for rapid appraisal of morbidity prevalence or nutritional status of communities, but that it may not be appropriate for surveys which cover a wider range of topics such as health care, or seek to examine the association of health or nutrition with explanatory factors such as education and socioeconomic status. Other factors such as cost and the ability to monitor interviewers' performance should also be taken into account.

Bias↗
PubMed1994

Human antibody responses to Pfs 230, a sexual stage-specific surface antigen of Plasmodium falciparum: non-responsiveness is a stable phenotype but does not appear to be genetically regulated.

The 230 kD gamete surface protein of the malaria parasite Plasmodium falciparum (Pfs 230) is a target of transmission blocking antibodies. Anti-Pfs 230 antibodies are induced following natural infection with malaria but are not found in all P. falciparum-exposed individuals. In this study we have shown that approximately 40% of malaria-exposed Gambians do not make antibodies to the native Pfs 230 molecule. This phenotype is remarkably stable over time and does not appear to be related to age, malaria exposure or major histocompatibility complex genotype. Comparison of antibody responses in twins indicates that the anti-Pfs 230 response is not strictly genetically controlled, but a high degree of concordance within both dizygous and monozygous twin pairs suggests that factors associated with exposure to malaria in childhood may be important in determining the subsequent immune response.

Adolescent↗
PubMed1994

Review of child development teams.

Since the Court report was published in 1976 there has been a consensus that the needs of children with disabilities are best met by child development teams. This study explored the structure, facilities, and organisational elements of child development teams operating in the South East Thames region by means of a structured interview with senior professionals involved with organising services for children with disabilities in 14 of 15 health districts in the region. Although all districts had a designated child development team, not all core professionals were adequately represented and four of 14 districts had no child development centre. The quality of buildings and facilities was variable. Teams that did not have a physical base in the form of a centre had fewer staff in the service and poorer facilities. There is a need for further consensus work about broad guidelines on the requirements of child development teams. These will help to inform purchasing authorities about the needs of children with disabilities living in their districts.

Child↗
PubMed1994

Carrot and stick: state mechanisms to influence private provider behavior.

The behavior of private sector health care providers will depend critically on the environment within which they operate. A bewildering array of possible regulatory and incentive setting structures exist. Most developing countries have the basic legislation for regulation, but there are frequently difficulties in enforcing such controls. While process aspects of quality of care regulation are often the responsibility of professional organizations, these organizations may have limited incentives to be active in ensuring high quality medical car.e There has been less experience with the use of incentives to encourage appropriate behavior amongst private providers: this appears a promising area for further work. Above all, adequate information is essential both for the enforcement of regulations and the application of incentive mechanisms.

Consumer Organizations↗
PubMed1994

Nationwide survey of bednet use in rural Gambia.

A nationwide survey was carried out to investigate the use of bednets in rural areas of the Gambia, particularly among children under 5 years old and among pregnant women. A stratified multistage design was used; 360 compounds in 60 villages were visited. Overall, 58% of beds had a net, with very little difference between villages with primary health care (PHC) facilities and those without (non-PHC). Bednet use was higher in the Central Region (76%) than in the Western and Eastern Regions (both 51%). It was highest among the Jola ethnic group (77%) and lowest among Sarahulis and other minority groups. Use of bednets was higher among target groups (such as infants, children under 5 years old, and pregnant women) than among the general population, and reached a level of over 90% in these groups in the Central Region. Use was associated with possession of a metal bed and a radio. Previous trials of impregnated bednets in the Gambia have been carried out in the Central Region, where bednet use is highest. The efforts of the National Impregnated Bednet Programme should therefore concentrate on the other regions and among the minority ethnic groups in order to increase bednet ownership.

Adolescent↗