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Biomedical subjects

A M Tomkins

Publications and source records attributed to A M Tomkins.

At least 19 recordsLinked to original sources
PubMed1992

Intensity of reinfection with Ascaris lumbricoides and its implications for parasite control.

Intestinal helminths are among the most common and widespread of human infections. Because it is typical to find that most worms are aggregated in a few potential hosts it has been suggested that some individuals are predisposed to heavy infections and that morbidity could be controlled by the treatment of heavily infected individuals only. We have studied the prevalence and intensity of reinfection with the intestinal nematode Ascaris lumbricoides among people living in Dhaka, Bangladesh. 880 people were treated with pyrantel pamoate three times at six month intervals, and on each occasion they collected all their stools for 48 h after treatment. Worms expelled by each subject were counted and weighed. The prevalence of infection at round 1 of treatment was 89% and the mean burden was 18.5 worms. Reinfection was rapid and at rounds 2 and 3 the prevalence was 82% and 80%, respectively, with mean burdens of 14.0 and 11.5 worms. The intensity of reinfection was not random: more subjects than expected became heavily reinfected (greater than or equal to 15 worms) and more subjects than expected remained lightly infected (less than or equal to 14 worms) (p less than 0.001). Worms were highly aggregated at each round of treatment but although just over 10% of all subjects were heavily infected at each and every round of treatment, over 60% of all subjects were heavily infected at least once. The findings show that some individuals seem to be susceptible to heavy infection whereas others are not, that deworming has a greater effect on the intensity of infection than on the prevalence, and that mass chemotherapy is likely to be a more effective means to control morbidity than is selective treatment of heavily infected individuals only.

Adolescent↗
PubMed1992

Raised resting energy expenditure in Parkinson's disease and its relationship to muscle rigidity.

1. Resting energy expenditure was measured, by indirect calorimetry, in 12 patients with Parkinson's disease and in eight healthy age-matched control subjects. In the patients with Parkinson's disease measurements were made in both the untreated state and after an injection of the dopamine agonist apomorphine (treated state). In each state muscle rigidity was recorded. 2. Resting energy expenditure was higher in patients with Parkinson's disease in both the treated and untreated states than in the control subjects. Of the patients with Parkinson's disease, seven showed no difference in resting energy expenditure between the two treatment states, whereas four showed markedly increased resting energy expenditure in the untreated state. The change in resting energy expenditure in the untreated state, as compared with the treated state, was significantly related to the development of muscle rigidity in the untreated state. 3. In Parkinson's disease, even in optimally treated patients, resting energy expenditure is raised and this may contribute to the weight loss seen in this disease. Severe muscle rigidity occurring during untreated periods results in a further increase in resting energy expenditure.

Apomorphine↗
PubMed1992

Impact of zinc supplementation on intestinal permeability in Bangladeshi children with acute diarrhoea and persistent diarrhoea syndrome.

Zinc has been shown to enhance intestinal mucosal repair in patients suffering from acrodermatitis enteropathica; but the impact on mucosal integrity during acute (AD) or persistent (PD) diarrhoea is unknown. One hundred eleven children with AD and 190 with PD aged between 3 and 24 months received, randomly and blind to the investigators, either an elemental zinc supplement of 5 mg/kg body wt/day or placebo in multivitamin syrup for 2 weeks while intestinal permeability and, biochemical and anthropometric markers were serially monitored. The permeability test was administered as an oral dose of 5 g lactulose/l g mannitol in a 20-ml solution followed by a 5-h urine collection. The ratio of the urinary probe sugars was correlated to clinical, biochemical, and microbiological parameters. At presentation, lactulose excretion was increased and mannitol excretion decreased in both AD and PD as compared with age-matched asymptomatic children. The lactulose/mannitol ratio (L/M) was higher in subjects with mucosal invasive pathogens (rotavirus and enteropathogenic Escherichia coli) compared with children excreting Vibrio cholera and enterotoxigenic E. coli. Two-week zinc supplementation significantly reduced lactulose excretion in both AD and PD, whereas the change in mannitol excretion and L/M was similar between study groups in both studies. Changes in lactulose excretion were significantly influenced by zinc supplementation in children with E. coli, Shigella sp., and Campylobacter jejuni stool isolates. The greatest reduction in total lactulose excretion was seen in supplemented children who on presentation were lighter (wt/age less than 80%), thinner (wt/ht less than 85%), and undernourished [middle upper arm circumference (MUAC) less than 12.5 cm] or with hypozincaemia (less than 14 mumol/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Acrodermatitis↗
PubMed1991

Antimicrobial effect of fermented Ghanaian maize dough.

Unhygienic conditions of a typical rural community in a developing country were simulated in the laboratory by inoculating fermented maize dough porridge with Shigella flexneri and enterotoxigenic Escherichia coli (ETEC). The antimicrobial effects of the different processes involved in the preparation of fermented maize dough porridge were assessed. The soaking process reduced the pH but no antimicrobial effect against shigella and ETEC was noted. Unfermented maize dough did not inhibit any of the test strains. When the fermentation process had become established, half of the strains tested were inhibited by the fermented maize dough when examined 8 h after inoculation. Cooking the fermented maize dough into porridge reduced the antimicrobial effect but there was still significant inhibition of pathogens. This suggests that the antimicrobial effect of fermented maize dough is not due to pH per se. Fermentation of maize dough appears to be a useful strategy for reducing contamination of weaning foods by Sh. flexneri and ETEC. The possible nature of the antimicrobial agent(s) produced during the fermentation of maize dough is discussed.

Escherichia coli↗
PubMed1990

Fermentation of cereals for reduction of bacterial contamination of weaning foods in Ghana.

Unfermented and fermented maize dough weaning foods prepared by mothers in a Ghanaian village were examined for gram-negative bacilli (GNB) immediately after preparation and during storage to assess the antimicrobial effect of fermentation. GNB were cultured from all samples of unfermented dough (51) and from 16 of 51 samples of fermented dough. The extent of contamination was significantly higher in the unfermented dough than in fermented dough (5.9 [SEM 0.1] vs 4.0 [0.4] log10 colony forming units/g). After 6 h and 12 h storage, a higher proportion of samples of porridge made from unfermented dough contained GNB than did those made with fermented dough (45/51 vs 22/55; 49/51 vs 20/51, respectively) and levels of GNB were significantly higher in the porridge made from unfermented dough after 6 h (4.2 [0.2] vs 3.8 [0.2]). Fermentation of maize dough is an effective method to reduce contamination of maize dough weaning foods with GNB.

Diarrhea, Infantile↗
PubMed1988

Effect of fermentation of Ghanaian maize dough on the survival and proliferation of 4 strains of Shigella flexneri.

Fermented and non-fermented Ghanaian maize dough was seeded with approximately 10(7) colony forming units of 4 strains of Shigella flexneri which had been isolated from patients with dysentery. In the non-fermented maize dough (pH 6.2) the shigellae were detectable in large numbers for up to 24 h after exposure. In the maize dough that had been fermented for 3 d (pH 3.2) 3 strains were detectable in small numbers for up to 6 h after inoculation. Thereafter none was isolated. The fourth strain, though detectable for up to 24 h after inoculation, had its numbers reduced considerably. This suggests that traditional methods of food preparation using fermentation have important anti-diarrhoeal functions and the current decline in popularity of such food technologies in certain developing countries may increase the risk of childhood diarrhoea.

Colony Count, Microbial↗
PubMed1988

The strength, contractile properties and radiological density of skeletal muscle before and 1 year after gastroplasty.

1. Skeletal muscle strength, contractile properties and radiological composition have been studied in seven morbidly obese adults (six female) before and 1 year after gastroplasty operations. The mean body weight fell from 138.3 kg (SD 25.2) to 99.7 kg (SD 23.0) (P less than 0.001). 2. The strength and contractile properties (force/frequency, relaxation rate and fatiguability) of both the adductor pollicis and quadriceps muscles were unaffected by the weight loss. 3. Computerized axial tomography scans obtained 1 year after surgery showed that the quadriceps contained an abnormally high proportion of fat. The mean fat content was 10.8% (range 3.0-30.1%) compared with 1.6% (range 0-5%) for normal muscle. Two individuals were scanned before and after surgery and the fat content of their quadriceps fell from 12.6% and 6.9% to 3.1% and 3.0%, respectively. 4. It is concluded that in obese individuals large amounts of weight can be lost, from both subcutaneous and intramuscular fat stores, without compromising either the strength or contractile properties of skeletal muscles. These results do not support the claim that skeletal muscle contractility is a sensitive indicator of changes in nutritional status.

Adult↗
PubMed1988

Increased resting energy expenditure in cystic fibrosis.

To explore the hypothesis that there is an increased metabolic rate in cystic fibrosis, resting energy expenditure was measured by indirect calorimetry in 23 subjects with cystic fibrosis in a stable clinical state and in 42 normal control subjects. Resting energy expenditure was found to be elevated by an average of 0.45 MJ/24 h [95% confidence interval (CI) = 0.26-0.64, t = 4.91, P less than 0.001] (108 kcal/24 h), or 9.2% above expected values derived from the regression relating resting energy expenditure to whole body weight and sex in control subjects. When related to lean body mass, values were still elevated by 0.36 MJ/24 h (95% CI = 0.18-0.53, t = 4.15, P less than 0.001) (86 kcal/24 h), or 7.2%. The increased values were found to be independent of age, sex, or body size. There were significant correlations between increased values and poor pulmonary function as measured by the ratio of the forced expiratory volume in 1 s to forced vital capacity (r = -0.44, P less than 0.05) and subclinical infection as indicated by the blood leukocyte count (r = 0.40, P less than 0.05). However, the correlations were low, suggesting that other factors may contribute to the increased resting energy expenditure, possibly including the putative metabolic defect in cystic fibrosis.

Adolescent↗
PubMed1987

Alternative measures of diarrhoeal morbidity and their association with social and environmental factors in urban children in The Gambia.

Diarrhoeal morbidity was studied during a 15-week period of the rainy season in 244 children aged 6 to 35 months in an urban Gambian community. The average prevalence of diarrhoea was 12.0% and the mean number of episodes per child varied between 2.4 and 2.9 depending on the definition of an episode. The number of chronic episodes lasting 14 d or more was tripled when 7 rather than one diarrhoea-free days were required to define a new episode. Neither prevalence nor the number of episodes varied significantly with age or sex. There was little association between the social and environmental characteristics of the children and diarrhoeal morbidity. The implications of using differing measures of diarrhoeal morbidity are discussed.

Child, Preschool↗
PubMed1986

Diet and faecal flora in three dietary groups in rural northern Nigeria.

Quantitative bacterial counts, concentrations of bile acids and bacterial enzyme profiles were measured in faecal samples from three tribal groups with distinctive dietary patterns in a rural area of northern Nigeria. Samples were obtained from Maguzawa (with a predominantly cereal diet), Hausa (cereal with regular meat consumption) and Fulani (cereal with frequent consumption of cows' milk). Numbers of bacteroides, clostridia and concentrations of bile acids were lower in the Maguzawa than the other dietary groups but these differences were not statistically significant. Bacterial enzyme profiles in each group were similar. The results are discussed with respect to possible influences of diet on the human intestinal microflora.

Adult↗
PubMed1986

Seasonal variations in the nutritional status of urban Gambian children.

1. Children aged 6-35 months in an urban community in The Gambia, West Africa, were weighed and their lengths measured at four surveys over an 18-month period, twice towards the end of the rains, and twice during the dry season. 2. Relative to international standards, height-for-age deteriorated steadily with age, while weight-for-age fell sharply in the second-half of infancy but showed no further deterioration from 12 to 35 months of age. 3. Height-for-age showed little seasonal variation, but weight-for-age and weight-for-height were lower at the end of the rains than during the dry season. Weight and height velocities were much lower during the rains than in the dry season, with more than 20% of the children losing weight during the rains. Possible reasons for these seasonal variations are discussed. Compensatory weight gain in the dry season exceeded the velocity expected from the standards in children aged 12 months or more, but height velocity fell below the standards all year. 4. The results are compared with previous findings from Keneba, a rural Gambian village. Weight velocity during the dry season was similar in the two communities, but the village children experienced a sharper decline in weight gain during the rains. 5. These results suggest that seasonal ecological factors may seriously influence the nutritional status of children living in an urban environment with adequate availability of food.

Body Height↗
PubMed1986

Contractile properties of the adductor pollicis in obese patients on a hypocaloric diet for two weeks.

The muscle function of 21 obese patients on a hypocaloric diet (450 kcal/day) was studied. On days 1, 7, and 12 the maximal isometric force and contractile properties (force:frequency relationship, relaxation rate, and fatigability) of the adductor pollicis were measured. The patients lost a mean of 5.7 kg but there was no significant change in the muscle strength or contractile properties. Twenty normal and three malnourished patients were also studied; the latter demonstrated abnormalities of muscle function. The use of such tests to monitor changes in nutritional status must be treated with caution.

Adult↗
PubMed1979

The effect of starvation on the rate of protein synthesis in rat liver and small intestine.

1. A method is described that allows for measurement of protein synthesis in liver and intestine in the rat. By injecting a massive amount of [14C]leucine (100 mumol/100 g body wt.) an attempt has been made to over come problems of precursor specific radioactivity and problems arising from the breakdown of labelled protein that are encountered when tracer amounts of amino acids are used. 2. Starvation for 2 days resulted in decline in the rate of total liver protein synthesis from 87%/day to 62%/day. 3. In jejunal mucosa the rate of protein synthesis was 136%/day. This declined to 105%/day after 2 days of starvation.

Animals↗