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Biomedical subjects

C A Powell

Publications and source records attributed to C A Powell.

52 records · Page 3Linked to original sources
PubMed1986

Follow up study of workers manufacturing chrysotile asbestos cement products.

A cohort study has been carried out of 2167 subjects employed between 1941 and 1983 at an asbestos cement factory in England. The production process incorporated the use of chrysotile asbestos fibre only, except for a small amount of amosite during four months in 1976. Measured airborne fibre concentrations available since 1970 from personal samplers showed mean levels below 1 fibre/ml, although higher levels had probably occurred previously in certain areas of the factory. No excess of lung cancer was observed in the mortality follow up by comparison with either national or local death rates, and analyses of subgroups of the workforce by job, exposure level, duration of employment, duration since entry, or calendar years of employment gave no real suggestion of an asbestos related excess for this cause of death. There was one death from pleural mesothelioma and one with asbestosis mentioned as an associated cause on the death certificate, but neither is thought to be linked to asbestos exposure at this factory. Other suggested asbestos related cancers, such as laryngeal and gastrointestinal, did not show raised risks. Although the durations of exposure were short in this study, the findings are consistent with two other studies of workers exposed to low concentrations of chrysotile fibre in the manufacture of asbestos cement products which reported no excess mortality.

Asbestos↗
PubMed1985

The ecology of nutritional status and development in young children in Kingston, Jamaica.

A survey of two poor neighborhoods in Kingston, Jamaica is reported. The nutritional status in children under 48 months (309) and the developmental levels of children between six and thirty months (168) were assessed. Characteristics of children with poor nutritional status and development were identified. Thirty-one percent of the children had Gomez grade 1 malnutrition, 9% had Gomez grade 2, and 1.6% had Gomez grade 3. There was somewhat more stunting than wasting. Nutritional indicators, weight for age and weight for height, as well as developmental levels declined with the children's age. Children with poor nutritional status tended to be girls, have poor housing, mothers with low levels of education, and mothers who worked. Children with low developmental quotients (DQs) tended to be boys and have mothers who worked. Multiple regression analysis showed that stunting (ht/age) and weight for age had significant effects on DQ, whereas wasting (wt/ht) did not.

Age Factors↗
PubMed1977

Replication of pea enation mosaic virus RNA in isolated pea nuclei.

Isolated nuclei from healthy pea plants were primed with pea enation mosaic virus (PEMV), southern bean mosaic virus (SBMV), radish mosaic virus (RdMV), tobacco mosaic virus (TMV), PEMV RNA, SBMV RNA, RdMV RNA, or TMV RNA. RNA replication occurred only with PEMV RNA and not with intact PEMV or any of the other viruses or RNAs, as judged by ensuing actinomycin D-insensitive polymerase activity. Molecular hybridization experiments showed that some of the product of the polymerase was PEMV-specific (-)RNA. The substrate and ionic requirements of this polymerase were the same as those for the RNA-dependent RNA polymerase present in nuclei isolated from PEMV-infected pea plants. No virus particles could be recovered from nuclei primed with PEMV RNA. These results are discussed in relation to the possible mechanism for in vivo infection of pea cells.

Journal Article↗
PubMedDate not supplied

Effects of a hurricane on growth and morbidity in children from low-income families in Kingston, Jamaica.

This is the first report of the effects of a hurricane on children's health and nutritional status in which data were available preceding and following the event. When Hurricane Gilbert struck Jamaica in 1988, a longitudinal study was in progress in which children's weights and heights were recorded every 2 months and their morbidity histories taken every week. The investigation included 127 stunted (low height-for-age) and 32 non-stunted children aged 23-44 months, living in poor areas of Kingston. The data from the 4 months before and after the hurricane were compared. There was an increase in the occurrence of respiratory symptoms including rapid or difficult breathing (P < 0.04), coughs (P < 0.001) and nasal discharges (P < 0.001) during the first 2-month period after the hurricane. However there was no significant effect on the occurrence of diarrhoea and injuries. Deficits were also found in height gain (P < 0.001) during the same period. These adverse effects were found in spite of the large amount of food aid received and the aggressive health education programme implemented after the hurricane.

Body Height↗
PubMedDate not supplied

The effect of nutritional supplementation and stunting on morbidity in young children: the Jamaican study.

Infection and undernutrition in young children are thought to act synergistically. However, studies of the relationship between low height-for age (stunting) and morbidity in young children have had inconsistent findings and there are few adequate data on the effects of nutritional supplementation on morbidity. 129 stunted and 21 non-stunted children aged between 9 and 24 months, from poor Kingston neighbourhoods, identified from a house-to-house survey, were studied. The stunted children were randomly assigned to supplementation or no supplementation. Every week for 24 months the mothers were asked about the occurrence of any symptoms of illness. Supplementation had no consistent effect on the incidence or duration of symptoms. The stunted children had significantly more attacks of diarrhoea, fever, anorexia and apathy than the non-stunted children. The differences remained after controlling for social background and previous attacks of diarrhoea. There was also some indication of more severe illness in the stunted than in the non-stunted children.

Body Height↗