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Biomedical subjects

B K Butland

Publications and source records attributed to B K Butland.

At least 19 recordsLinked to original sources
PubMed1992

Mortality and occupational exposure to radiation: first analysis of the National Registry for Radiation Workers.

OBJECTIVE: To study cause specific mortality of radiation workers with particular reference to associations between fatal neoplasms and level of exposure to radiation. DESIGN: Cohort study. SETTING: United Kingdom. SUBJECTS: 95,217 radiation workers at major sites of the nuclear industry. MAIN OUTCOME MEASURE: Cause of death. RESULTS: Most standardised mortality ratios were below 100: 83 unlagged, 85 with a 10 year lag for all causes; 84 unlagged, 86 lagged for all cancers; and 80 for all known other causes, indicating a "healthy worker effect." The deficit of lung cancer (75 unlagged, 76 lagged) was significant at the 0.1% level. Standardised mortality ratios were significantly raised (214 unlagged, 303 lagged) for thyroid cancer, but there was no evidence for any trend with external recorded radiation dose. Dose of external radiation and mortality from all cancers were weakly correlated (p = 0.10), and multiple myeloma was more strongly correlated (p = 0.06); for leukaemia, excluding chronic lymphatic, the trend was significant (p = 0.03; all tests one tailed). The central estimates of lifetime risk derived from these data were 10.0% per Sv (90% confidence interval less than 0 to 24%) for all cancers and 0.76% per Sv (0.07 to 2.4%) for leukaemia (excluding chronic lymphatic leukaemia). These are, respectively, 2.5 times and 1.9 times the risk estimates recommended by the International Commission on Radiological Protection, but 90% confidence intervals are large and the commission's risk factors fall well within the range. The positive trend with dose for all cancers, from which the risk estimate was derived, was not significant. The positive association between leukaemia (except chronic lymphatic leukaemia) was significant and robust in subsidiary analyses. This study showed no association between radiation exposure and prostatic cancer. CONCLUSION: There is evidence for an association between radiation exposure and mortality from cancer, in particular leukaemia (excluding chronic lymphatic leukaemia) and multiple myeloma, although mortality from these diseases in the study population overall was below that in the general population. The central estimates of risk from this study lie above the most recent estimates of the International Commission on Radiological Protection for leukaemia (excluding chronic lymphatic leukaemia) and for all malignancies. However, the commission's risk estimates are well within the 90% confidence intervals from this study. Analysis of combined cohorts of radiation workers in the United States indicated lower risk estimates than the commission recommends, and when the American data are combined with our analysis the overall risks are close to those estimated by the commission. This first analysis of the National Registry for Radiation Workers does not provide sufficient evidence to justify a revision in risk estimates for radiological protection purposes.

Adult↗
PubMed1992

Prenatal irradiation and spatial memory in mice: investigation of critical period.

Pregnant CD1 mice were exposed on various gestational or postnatal days to 1 Gy of 250 kV X-rays. Ten adult, male offspring from each exposure condition were tested in a radial arm maze. Compared to sham-exposed control mice, acquisition of spatial information was unimpaired in animals exposed on gestational days 13 or 15, or on postnatal day 10, but animals exposed on gestational day 18 or postnatal day 1 showed sustained deficits in acquisition. These results appear consistent with the known time-course for the proliferation and migration of the dentate granule cells of the hippocampus in the mouse, and are discussed in relation to the dependence on hippocampal integrity of the acquisition and use of spatial information. The results suggest that comparable deficits in mental function might be expected in humans similarly exposed to ionizing radiation during periods of proliferation and migration of the dentate granule cells.

Animals↗
PubMed1990

The influence of pregnancy and reproductive span on the occurrence of autoimmune thyroiditis.

A study comparing the reproductive histories of 89 women affected by Hashimoto's thyroiditis (HT) with 89 matched controls has been carried out to determine whether endogenous hormones contribute to the development of the disease. There was no evidence of an association between HT and parity and no trend to an increasing disease risk with increasing parity. However, patients with HT had a longer reproductive span. There was a significant trend to a lower risk with later age at menarche (relative risk (RR) of menarche at 13-14 years compared with less than or equal to 12 years = 0.71, and greater than or equal to 15 years compared with less than or equal to 12 years = 0.45), and an increased risk with a later menopause (greater than or equal to 51 years compared with less than or equal to 50 years, RR = 3.00, P less than 0.025). An additional finding was an increased hysterectomy rate among the cases. These observations may be explained if the hyperoestrogenic state associated with a longer reproductive span acted to modulate the immune process in autoimmune thyroid disease.

Adolescent↗
PubMed1990

Body fatness and frame size: the Caerphilly study.

The effect of adjusting height-weight indices for frame size on the prediction of body fatness was investigated in a community sample of 2512 men aged 45-59 years. Body fatness was assessed from skinfold thickness measurements at four sites: triceps, biceps, subscapular and supra-iliac. Body diameters (biacromial, bi-iliocristal, wrist or knee) were used as estimates of frame size. Body diameters were not independent of body fatness, wrist diameter showing the lowest association with skinfold thickness measurements. Adjustment of weight/height2 (W/H2) for frame size had little effect on the prediction of body fatness, the correlation coefficient for body fatness with W/H2 (r = 0.76) being almost identical to that for W/H2 adjusted for wrist diameter (r = 0.74).

Adipose Tissue↗
PubMed1989

Changes in asthma prevalence: two surveys 15 years apart.

In 1973 a survey was conducted among 12 year old children living in a defined area of South Wales. In 1988 the survey was repeated in the same area, again among 12 year old children. Questionnaires were completed for all 965 children in the population sample; peak expiratory flow rates were performed on them all, and repeated (except for five children) after an exercise provocation test. The prevalence of a history of wheeze at any time had increased from 17% to 22%, while that of a history of asthma at any time had increased from 6% to 12%. Current asthma had increased from 4% to 9%, but wheezing in the past year not attributed to asthma had remained at 6%. The exercise provocation tests suggested that both mild and severe asthma had become more common. Increases had also occurred in the frequencies of a history of eczema (from 5% to 16%) and of hay fever (from 9% to 15%). It seems that the prevalence of asthma has risen, and that this cannot be wholly explained by a greater readiness to diagnose the disease.

Asthma↗
PubMed1989

Environmental factors and symptoms in infants at high risk of allergy.

STUDY OBJECTIVE: To identify environmental determinants of six symptoms associated with allergic disease in infancy. DESIGN: Infants were participants in a prospective randomised controlled trial of feeding practices in families with a history of atopy. SETTING: Infants were recruited in two maternity hospitals in S Wales and followed up in the community for 1 year. PARTICIPANTS: Mothers of 519 infants agreed to participate, but 36 were excluded (mainly for moving home or failing to attend for follow-up), leaving 483 in the study (253 male, 230 female). Infants were followed up and examined for evidence of allergic disease at 3, 6, and 12 months. MEASUREMENTS AND MAIN RESULTS: At each examination, mothers were questioned about episodes of illness in the infant, and the data presented relate to (reported and observed) eczema and nasal discharge, and (reported) wheeze, prolonged colds, diarrhoea and vomiting. Mothers kept a diary with details of feeding for the first 6 months. All homes were visited by a nurse who took samples of dust for dust mite antigen analysis. Extensive socio-demographic data were collected. None of the factors studied showed a convincing relationship with eczema. In a multiple logistic regression analysis breast feeding appeared to protect against wheeze, nasal discharge, colds, vomiting and diarrhoea. Having more siblings increased the likelihood of prolonged colds, and (together with overcrowding) of wheeze and nasal discharge. Maternal smoking and low social class were associated with wheeze, and house dust antigen with prolonged colds. Respiratory symptoms were associated with some aspects of housing but these could not be distinguished clearly from other social factors. Babies born in Autumn were at increased risk of wheeze, vomiting and diarrhoea. CONCLUSIONS: Environmental factors play an important part in determining risk of symptoms in potentially atopic babies. These factors are in principle open to manipulation.

Allergens↗
PubMed1989

Coffee, blood pressure and plasma lipids: a randomized controlled trial.

A randomized controlled trial was conducted to examine the effects of coffee (as commonly drunk in Britain) on blood pressure and plasma lipids in healthy subjects. Fifty-four subjects followed three regimens successively, the order being randomized according to a Latin square design: five or more cups of coffee daily for 4 weeks; five or more cups of decaffeinated coffee daily for 4 weeks but no ordinary coffee; no coffee for 4 weeks. Coffee appeared to cause a small rise (of 3 mm Hg) in recumbent systolic blood pressure; this effect was less than, and obscured by, changes induced by posture and mild stress. No consistent changes attributable to coffee were found in diastolic blood pressure or pulse rate. Small changes in the expected directions occurred in plasma high density lipoprotein (HDL) cholesterol and apolipoprotein AI (decrease), and in total cholesterol, non-HDL cholesterol and apolipoprotein B (increase), but none of these were statistically significant. The effect of coffee on risk of heart disease in Britain is probably small.

Adolescent↗
PubMed1988

Type A behaviour, eating pattern and nutrient intake: the Caerphilly Study.

Relationships between type A behaviour and eating pattern and nutrient intake were investigated in a representative sample of 532 employed men aged 45-59 years drawn from the Caerphilly study. Eating pattern and nutrient intake were assessed by 7-day weighed dietary records. A change in Framingham type A scores from the lower third to the upper third was associated with a 9% reduction in meal size and a 6% increase in meal frequency. No trends with type A were found for nutrient intake in absolute terms. For means of nutrient intake as a percentage of energy, however, higher values for sugar and lower values for starch and polyunsaturated fat were observed with higher type A scores. In multiple regression analysis, after control for the effects of age, height, social class and smoking, significant associations with type A were found only for meal size, dietary fibre per MJ and sugar as a percentage of energy. It is concluded that diet is unlikely to be an explanation of the relationship between type A and ischaemic heart disease.

Diet↗
PubMed1988

Heart disease in British vegetarians.

A prospective study was conducted among customers of health food shops and members of societies interested in health foods. A total of 10,896 persons were followed for 10-12 y, including 4671 vegetarians and 6225 nonvegetarians. Mortality from ischemic heart disease (IHD) was significantly lower in the vegetarians than in the nonvegetarians; the difference was especially marked among the men. In a subset of 300 subjects, serum cholesterol and body mass index were lower in the vegetarians than in the nonvegetarians but there were no consistent differences in blood pressure between the two groups. Vegetarianism seems to confer some protection against IHD but it is not clear whether this is due to abstinence from meat or to a high consumption of vegetables.

Blood Pressure Determination↗
PubMed1988

Prevention of mite infestation of bedding by means of an impregnated sheet. A randomized controlled trial.

A randomized controlled trial was conducted to test the effect of a sheet impregnated with benzyl benzoate in preventing mite infestation of new bedding. Impregnated sheets were placed on the mattresses of 17 subjects, while 19 subjects received placebo sheets. Over the following 2 years infestation occurred more commonly, and tended to be heavier, in the beds with inactive sheets than in those with impregnated sheets; among the 27 beds with three items of new bedding sampled on four occasions, a mite count of five or more occurred significantly more often where the sheet was inactive than where it was active (11 of 13 and 5 of 14 respectively). The application of a sheet impregnated with benzyl benzoate appears to prevent mite infestation and may be useful for patients with mite allergy who obtain new bedding as part of a mite-avoidance regimen.

Asthma↗
PubMed1988

Infant feeding and allergy.

The effect of withholding cows' milk was examined in 487 infants at high risk of allergic disease. Before birth they were randomly allocated either to a control group, most of whom received cows' milk preparations, or to an intervention group, who were offered a soya based substitute. Eczema and wheezing occurred to a similar extent in the two groups during the first year of life, although napkin rash, diarrhoea, and oral thrush were commoner in the intervention group, especially during the first three months. Breast feeding for any length of time was associated with a reduced incidence of wheezing and diarrhoea.

Animals↗
PubMed1988

Type A behaviour and prevalent heart disease in the Caerphilly study: increase in risk or symptom reporting?

Type A behaviour was assessed by modified Framingham scale in a total sample of 1956 employed men in the Caerphilly study. Prevalent heart disease was measured by cardiovascular questionnaire to obtain evidence of myocardial infarction and angina, and by electrocardiogram (ECG) for evidence of ischaemia. Type A was inversely related to age and systolic blood pressure and was positively related to social class and height. It was not related to serum cholesterol or alcohol consumption. After control for age, systolic blood pressure, height, smoking and social class, type A was found to be independent of angina but positively associated with an increased risk of possible myocardial infarction (MI). Type A was also associated with increased risk of confirmed MI. An inverse association was found between type A and asymptomatic ischaemic heart disease (IHD). The association between type A and symptomatic IHD could be due to symptom reporting.

Age Factors↗
PubMed1988

Infant feeding and allergy: 12-month prospective study of 500 babies born into allergic families.

This investigation studied 487 babies for symptoms of allergic disease during their first year of life. Because of their positive family histories all the babies are at high risk of becoming allergic. The babies were randomly divided such that cows' milk was deliberately withheld from one group; infants in this group were fed with a soya substitute where required. No benefit resulted from withholding cows' milk, indeed symptoms were more usually associated with this group. Breast feeding, even for a short period, was clearly associated with a lower incidence of wheeze, prolonged colds, diarrhoea, and vomiting. It seemed that the duration of breast feeding was less important than whether or not the child had been breast-fed at all. Wheezing was both more common among boys than girls (P less than .05) and if the mother was a smoker. Other environmental features related to wheezing were social class, month of birth, lack of breast feeding, exposure to dampness, mould and coal fires, but not to domestic pets nor to the numbers of mites found in bedding and carpets. Mite exposure was, however, associated with prolonged colds. Eczema was the only allergic symptom not positively associated with any environmental factor; moreover, it was neither associated with a lack of breast feeding nor with inclusion of cows' milk in the diet. Eczema was associated with the incidence of positive skin prick tests and IgE antibodies to egg white. IgE and IgG4 antibodies were estimated at birth (mothers' and cord bloods) and 3 and 12 months later.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Dietary determinants of plasma lipids and lipoproteins: the Caerphilly Study.

Associations between nutrient intakes and plasma lipids were examined in a representative sample of 653 middle-aged men in Caerphilly, South Wales. Nutrient intakes were calculated from 7-d weighed intake records and were expressed both as g/d and as a percentage of total energy intake. In multivariate analyses, after taking the effects of potential confounding factors (age, body mass index and smoking habit) into account, the percentage of variance in the plasma lipid concentrations which could be explained solely by the dietary variables was very small, ranging from 1 to 7 per cent. Associations which were statistically significant included a positive association between saturated fat intake and both total cholesterol and low density lipoprotein cholesterol; a negative association between carbohydrate intake and both total cholesterol and high density lipoprotein cholesterol (HDL-C); a positive association between magnesium intake and an HDL-C subfraction (HDL2-C); a positive association between alcohol intake and each of the following: HDL-C, its subfractions and triglyceride.

Cholesterol↗
PubMed1987

Effects of a fish oil supplement on serum lipids, blood pressure, bleeding time, haemostatic and rheological variables. A double blind randomised controlled trial in healthy volunteers.

Sixty male volunteers were randomised to take 10-16 ml of a fish oil supplement (MaxEPA) or 10-16 ml of olive oil for a period of 3-6 weeks. A fall in serum triglyceride of 54% (P less than 0.01) and a fall in diastolic blood pressure of 7% (P less than 0.05) was attributable to taking fish oil supplements. The bleeding time was prolonged by 12%, but this did not reach conventional levels of statistical significance. A global test of heparin-neutralising activity, the heparin thrombin clotting time, increased by 14% (P = 0.05) but there was no demonstrable effect on thrombin time, fibrinogen or (intraplatelet) platelet factor 4. A fall in red cell pore transit time of 23% was attributable to fish oil, but was not statistically significant. There was no convincing evidence of an effect of fish oil supplementation on total serum cholesterol, HDL-cholesterol, blood counts or platelet aggregation. A beneficial effect of fish oil on the cardiovascular risk profile was confirmed in this study. However, with this regime changes in total cholesterol, HDL-cholesterol and platelet aggregation are of unlikely clinical importance.

Adult↗
PubMed1987

Diet and ischaemic heart disease in the Caerphilly Study.

In a South Wales Community Study, 2512 men aged 45-59 years were screened for evidence of ischaemic heart disease. Dietary questionnaires were given to all the men and, in a representative sub-sample of 665 men, 7-day weighed intake records were completed. Nutrient intakes of those who had ECG evidence of ischaemia but no symptoms were compared with those of men who had no evidence of IHD. Differences between the two groups were small. Those who had evidence of ischaemia on ECG tended to have lower intakes of energy, alcohol and most other nutrients. However, most of these differences appeared to be due to the difference in energy intake between the two groups. Allowing for the effect of differences between the groups in the distributions of age and body mass index did not alter the overall conclusions.

Coronary Disease↗