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Biomedical subjects

F Lawrence

Publications and source records attributed to F Lawrence.

At least 37 records · Page 2Linked to original sources
PubMed1991

Relationships between steps taken in selecting a nursing home and consumers' satisfaction.

Analysis of data related to selection of a nursing home by 411 families of nursing home residents led to the conclusion that steps selected and taken by consumers in the selection of a home were associated with their subsequent satisfaction with the home. Satisfaction was greater (a) for families in agreement about the home selected and (b) for families who investigated all homes in an area before selecting one. Less satisfied were families (a) who were forced to make an immediate decision about placement following illness of a patient, (b) who felt they lacked sufficient time to investigate homes, and (c) who chose the first home with space available.

Consumer Behavior↗
PubMed1991

A comparison of physical activity in Gambian and UK children aged 6-18 months.

The activity patterns of 81 Gambian and 53 UK children aged six, 12 or 18 months were compared by means of an activity diary technique. Major differences between communities were observed in the duration of play (2-3 times longer in UK compared to Gambian children) and in the duration of vigorous activities such as crawling, walking and running (2-4 times longer duration in the UK compared to the The Gambia). To investigate whether the lower activity of Gambian children could be explained by differences in nutritional or health status, subgroups of Gambian children were compared. Only small differences in activity pattern were found between Gambian children above and below 80% weight for age and between Gambian children who were or were not diagnosed ill within 10 days of study, suggesting that other factors (e.g. socio-cultural differences or the absence of conventional toys) may explain the lower activity of Gambian compared to UK children.

Analysis of Variance↗
PubMed1990

Bilateral uveal metastases from small-cell carcinoma of the lung.

Metastasis from small-cell carcinoma of the lung (SCCL) has most frequently been found in the lymph nodes, bones, brain, and liver. We have reported a case of metastatic SCCL located in the uveal layer of both eyes (choroidal in one and iridic in the other), an extremely rare occurrence.

Carcinoma, Small Cell↗
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

Inhibition of leishmanial DNA synthesis by sinefungin.

RNA, DNA and protein biosynthesis were studied in Leishmania donovani and L. tropica promastigotes cultured with or without sinefungin. Thymidine incorporation was significantly impaired by this compound. Neither the uptake of thymidine nor its phosphorylation were inhibited. Furthermore the ratios of deoxyribonucleotide to the corresponding ribonucleotide were not significantly affected by sinefungin. Analysis of the DNA indicates that the inhibition of thymidine incorporation affects mostly nuclear DNA, kDNA being less affected by this drug. No such effect on thymidine incorporation was observed in macrophages, the host cells of these parasites.

Adenosine↗
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↗
PubMed1987

[Effect of 5'-deoxy-5'-S-isobutyl adenosine (SIBA) on the synthesis of polyoma virus constituents in infected mouse cells].

At 100 microM 5'-S-isobutyladenosine (SIBA) inhibits polyoma virus production in infected mouse embryo fibroblasts and in mouse kidney cells, as measured by plaque formation and by haemagglutination assays. SIBA has no significant effect on the synthesis of T and V antigens as well as on viral DNA synthesized in infected cells. Analysis of virus production on CsCl gradients on CsCl gradients showed that in the presence of SIBA reduced amount of heavy viral particles is produced and that part of these particles are pseudovirions containing low density DNA instead of supercoiled viral DNA.

Animals↗
PubMed1986

Protein methylation and protein methylases in Leishmania donovani and Leishmania tropica promastigotes.

We studied the content of acid-stable methylated amino acids of soluble proteins in promastigotes of Leishmania donovani and L. tropica. epsilon-N-Trimethyllysine and NG,NG-dimethylarginine were found in both Leishmania species after culture in the presence of [methyl-14C]methionine. In addition, 3-N-methylhistidine was found only in L. tropica and epsilon-N-dimethyllysine only in proteins of L. donovani. As sinefungin, an antileishmanial nucleoside antibiotic, is a known transmethylase inhibitor, its effect on protein methylation was studied, in whole cells and in vitro. In the first case the drug had no effect on the content of methylated amino acid residues of soluble proteins. In vitro, histone methylation by crude extracts was studied at pH 7.2 and 9.0, known in other organisms as optimum pH values for arginine and lysine methylation, respectively. Surprisingly, arginine methylation by extracts of L. donovani was the same at both pH values while lysine residues were more efficiently methylated at pH 7.2 than at pH 9 by the extracts of the two species. These results indicate that the properties of protein methylases I and III of these parasites are different from those of other organisms hitherto studied. The inhibition constants of sinefungin for the leishmanial protein methylases were weak in comparison with those for enzymes from other sources, with the exception of the constant of L. donovani enzyme at pH 9.

Adenosine↗
PubMed1985

A quantification of child care and infant-caregiver interaction in a West-African village.

We have investigated infant-caregiver interactions in an isolated African subsistence farming community where women perform arduous agricultural tasks in addition to their normal domestic duties which include child care. 49 babies aged 3-18 months were studied on one or two occasions. Detailed observations were made of the level of care and of positive and negative stimulation offered to the child. Children were left in the charge of young nursemaids for up to 40% of the day while the mothers tended the crops. Despite this the total amount of positive and negative stimulation and care were similar whether or not the mother was engaged in fieldwork on the day of study. Grandmothers and fathers were both relatively unimportant caregivers. Total positive stimulation did not increase with age; on the contrary, young babies (3-9 months of age) were offered more positive stimulation and less negative stimulation than older ones (12-18 months). A positive correlation was found between total positive stimulation and developmental quotient (assessed by the Griffiths test). Similar amounts of care were given at all ages and there was no difference in the treatment of the two sexes.

Age Factors↗
PubMed1985

Induction of heat shock and stress proteins in promastigotes of three Leishmania species.

The induction of heat shock proteins in three species of Leishmania, L. tropica, L. enrietti, and L. donovani is reported. When cultures of promastigotes are shifted from 26 degrees C to 37 degrees C or 40 degrees C, the synthesis of proteins with apparent molecular weights of 88,000, 74,000, and 54,000 is stimulated. Actinomycin D added just prior to the shift prevented the appearance of these proteins but had no effect when present 30 min after the transfer onward, suggesting that the regulation of leishmanial heat shock proteins occurs at the transcriptional level. Exposure of L. tropica promastigotes to sodium arsenite elicits the synthesis of three major and four minor polypeptides. Their apparent molecular weights are, respectively, 94,000, 78,000, and 56,000 and 70,000, 45,000, 22,000, and 18,000. The response of Leishmania organisms to heat shock and to sodium arsenite is similar to that of other organisms, but some of the proteins identified as stress proteins in the parasite differ in size. The heat shock proteins might play a role in cytodifferentiation during the life cycle of the parasite and also in cellular adaptation to higher temperatures.

Animals↗
PubMed1985

The energy cost of common daily activities in African women: increased expenditure in pregnancy?

We have performed, by open-circuit indirect calorimetry, a total of 1546 measurements of energy expenditure on 142 nonpregnant, pregnant, or lactating Gambian village women. Of the 47 common daily activities measured, only 7 would be classified as moderate according to internationally accepted standards, the remainder being light (ie requiring less than 3.5 kcal/min). This was unexpected since many of the tasks, judged subjectively, appeared quite demanding. Furthermore there was no increase towards the end of pregnancy in the energy cost of a range of activities requiring 1-5 kcal/min and involving a variety of body movements, despite the substantial weight gains observed. Only for walking was there the expected increase in energy expenditure. Although in the past it has been assumed that the heavier pregnant women would require additional energy for activity, no special allowance for this is included in current dietary recommendations. The present results indicate that, for women from the developing world, no allowance is necessary. The finding that most activities were light is also of relevance to total energy requirements in this community.

Adolescent↗
PubMed1985

Differential effect of sinefungin and its analogs on the multiplication of three Leishmania species.

Sinefungin and seven analogs were evaluated in vitro for activity against promastigote multiplication of Leishmania donovani, L. tropica, and L. enrietti. Of these compounds, sinefungin, the cyclic derivative, and A9145C were leishmanicidal at concentrations ranging from 0.13 to 2.6 microM. Sinefungin was the most active of these three compounds against L. donovani, and A9145C was most active against L. enrietti. None of the remaining derivatives exhibited significant activity against any one of the three species at the highest dose tested. All agents were assayed for activity against protein methylases I and III. The results of these tests showed that there is no relationship between the inhibition of growth and inhibition of protein methylases I and III.

Adenosine↗
PubMed1985

[Decrease in the transforming action of Rous sarcoma virus produced by avian cells grown in the presence of 5'-deoxy-5'-S-isobutyladenosine (SIBA)].

Treatment of Rous Sarcoma virus transformed chick embryo fibroblasts with 1 mM 5'-deoxy-5'-S-isobutyladenosine for 24 hrs. leads to the inhibition of transforming virus production. A kinetic analysis of the inhibition of active virion production revealed that the effect of the drug was time and concentration dependent. After 24 hrs. with 1 mM SIBA, the production of transforming virus was inhibited 165 fold. However, under these conditions there was only a 2 fold inhibition in viral particle production. Thus, these viral particles were either non infective (non adsorbed on cell membrane) or non transforming. The majority of viral particles produced by cells cultured with the drug have a decreased density. Analysis of these virions showed a decrease of protein P19 and an accumulation of proteins with high molecular weight.

Animals↗
PubMed1984

Maintenance energy cost of pregnancy in rural Gambian women and influence of dietary status.

A major assumption in current dietary advice for pregnancy is that the amount of energy expended on tissue maintenance increases by 36 000 kcal over the whole gestation period. In a group of rural Gambian women engaged in subsistence farming, the increase was much smaller and depended on maternal dietary status. In women having the customarily low food intake the net extra cost of tissue maintenance was just 1000 kcal; even in those given a dietary supplement in amounts previously shown to increase birthweight it was only 13 000 kcal. This finding partly explains why mothers, particularly those in the Third World, can apparently accomodate pregnancy without substantially increasing their dietary energy intake. The findings are of importance in the formulation of realistic dietary health strategies for such communities.

Adult↗
PubMed1984

Comparative effect of farnesylacetone on macromolecular synthesis in gonads of crustaceans.

Farnesylacetone, a molecule isolated from the androgenic glands of Carcinus maenas, inhibits vitellogenesis in the ovaries. Here the effect of farnesylacetone on protein and RNA synthesis in cultured organs is described. Both leucine and uridine incorporation in ovaries were inhibited with low concentration of farnesylacetone. The action was gonad specific and not species specific. It was observable in the presence of cycloheximide but not in the presence of actinomycin. This result plus the fact that inhibition of protein synthesis paralleled that of RNA suggest that farnesylacetone modifies transcription and only indirectly affects protein synthesis.

Animals↗
PubMed1982

Effect of 5'-deoxy-5'-isobutylthioadenosine on putrescine uptake and polyamine biosynthesis by chick embryo fibroblasts.

The effect of 5'-deoxy-5'-S-isobutylthioadenosine (SIBA) on polyamine biosynthesis has been studied by using cultured chick embryo fibroblasts. It has been shown that the drug inhibits the uptake of [14C]putrescine and its conversion into labelled spermidine or spermine. The inhibitory effect is reversed by removing the inhibitor after exposing the cells to the drug for 24 h. SIBA also caused a significant decrease in cellular spermine levels and an accumulation of putrescine. These changes are reversed by removing the inhibitor. SIBA had the same effect on chick embryo fibroblasts transformed by Rous sarcoma virus; a decrease in cellular spermine levels in SIBA-treated cells was observed. In all the experiments SIBA caused a reduction in the spermine/putrescine and spermidine/putrescine ratios. It is suggested that SIBA is not only an inhibitor of transmethylation but also interferes with polyamine biosynthesis, probably by blocking aminopropyltransferase.

Animals↗
PubMed1982

Gastroenteritis associated with enteric type adenovirus in hospitalized infants.

Enteric types of adenovirus have recently been identified as a causative agent of infantile gastroenteritis. We utilized enzyme immunoassay and tissue culture techniques to evaluate prospectively the role of ET Ad in diarrhea occurring in hospitalized infants. We found that ET Ad was associated with 14 of 27 cases of diarrhea occurring during a 12-week study period in the late autumn and early winter months; ET Ad was found in the stool of only one of 72 children without diarrhea (P less than 0.001). Although adenoviruses other than ET Ad were found in the stools of two of the 27 children with diarrhea, such viruses were also found in the stools of five of 72 children without diarrhea and thus could not be statistically correlated with acute gastroenteritis. Children infected with ET Ad had diarrhea for a mean of 8.0 days, compared to a mean duration of 4.2 days for the children with gastroenteritis not associated with ET Ad. Thirteen of the 14 children with ET Ad gastroenteritis had respiratory symptoms such as cough, rhinorrhea, or wheezing, six had roentgenographic evidence of pneumonia, and three children had bilateral conjunctivitis. This study documents that ET Ad can be an important cause of acute gastrointestinal disease in hospitalized infants and young children and that gastrointestinal infections with ET Ad can be associated with a high rate of respiratory disease.

Adenoviridae Infections↗