Search PubMed⌕ Search

Biomedical subjects

H T Delves

Publications and source records attributed to H T Delves.

At least 55 records · Page 3Linked to original sources
PubMed1988

The relationship between blood lead, blood pressure, stroke, and heart attacks in middle-aged British men.

The relationship between blood lead concentration and blood pressure is examined in a survey of 7371 men aged 40 to 59 from 24 British towns. After allowance for relevant confounding variables, including town of residence and alcohol consumption, there exists a very weak but statistically significant positive association between blood lead and both systolic and diastolic blood pressure. These cross-sectional data indicate that an estimated mean increase of 1.45 mm Hg in systolic blood pressure occurs for every doubling of blood lead concentration with a 95% confidence interval of 0.47 to 2.43 mm Hg. After 6 years of follow-up, 316 of these men had major ischemic heart disease, and 66 had a stroke. After allowance for the confounding effects of cigarette smoking and town of residence there is no evidence that blood lead is a risk factor for these cardiovascular events. However, as the blood lead-blood pressure association is so weak, it is unlikely that any consequent association between lead and cardiovascular disease could be demonstrated from prospective epidemiological studies. An overview of data from this and other large epidemiological surveys provides reasonably consistent evidence on lead and blood pressure. While NHANES II data on 2254 U.S. men indicate a slightly stronger association between blood lead and systolic blood pressure, data from two Welsh studies on over 2000 men did not show a statistically significant association. However, the overlapping confidence limits for all these studies suggest that there may be a weak positive statistical association whereby systolic blood pressure is increased by about 1 mm Hg for every doubling of blood lead concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Nickel dermatitis and diet: clinical improvement and a reduction in blood and urine nickel levels with a low-nickel diet.

A 27-year-old nickel-sensitive female who had had continuous spontaneous flare-ups of eczema, including at sites of previous metal contact, experienced a clearing of her eruption after commencing a low-nickel diet. When on the diet, whole-blood and urinary nickel levels fell to half or less of pre-diet values and this coincided with the clinical improvement. Low-nickel diets should be considered for patients who are highly nickel sensitive.

Adult↗
PubMed1988

Skin selenium content measured by hydride generation and atomic absorption spectroscopy.

The concentration of selenium in skin was measured using hydride generation and atomic absorption spectroscopy. The method used in this study was shown to be both accurate and precise, with mean recoveries of 92%-98% of added selenium and a within run relative standard deviation of better than 7% at a selenium concentration of less than 12 nmol/g dry tissue. The method is suitable for rapid analysis of large numbers of samples.

Biopsy↗
PubMed1987

UK Blood Lead Monitoring Programme 1984-1987: protocol and results for 1984.

The Department of the Environment (DOE) has undertaken an extensive programme to monitor blood lead concentrations annually over the period 1984 to 1987 in the context of the reduction in the maximum permissible lead content of petrol from 0.4 to 0.15 g/l from 1st January 1986. The study includes adults living in heavily trafficked urban areas and in occupational groups particularly exposed to petrol lead; children aged 6-7 years attending schools in heavily trafficked urban areas; and control groups of adults and children in rural areas. The surveys are planned to cover about 1500 adults and 1000 children in total each year. Cohorts of adults are being followed, with replacement where necessary owing to moving, etc. For ethical reasons, no child will be sampled more than once, although the schools concerned will be revisited each year; children's blood is also being examined for antibodies to measles and poliomyelitis. Blood samples are being analysed for lead by atomic absorption spectrophotometry (AAS); considerable efforts are being made to ensure the validity of the analytical results during the period of the study. Results for 1984 indicated that average blood lead concentrations in both adults and children were generally low and were in line with levels expected on the basis of earlier surveys; only a very small proportion of individuals had raised levels. A detailed statistical analysis has confirmed the results of the EEC Blood Lead Surveys (carried out in 1979-1981) that blood lead concentrations were related to a range of personal, social and environmental factors including age, sex and smoking and drinking habits. Comparisons of any trends during the survey period in blood level concentrations in the exposed and control groups, together with results from the monitoring of sources of environmental lead should enable a broad assessment to be made of the effect of the reduction in petrol lead.

Adolescent↗
PubMed1985

Assessment of trace element status.

Biochemical and clinical investigations involving trace elements are made for the diagnosis of inherited or acquired deficiencies of essential trace elements and their treatment, to monitor the efficacy of the therapeutic administration of non-essential trace elements in order to achieve maximum clinical response with minimum toxicity, and for the early detection of excessive ingestion of non-essential toxic trace elements. The wide range of tests used to assess trace element status in these three areas of clinical importance is discussed with examples of essential and of toxic trace elements since therapeutic use of trace elements is discussed elsewhere in this issue. Particular attention is given to zinc, copper, selenium, lead and cadmium because the various tests used to assess the status of these elements encompass the principles of all currently available tests. Although trace element analysis of body fluids and tissues is the most useful and most commonly used method of assessment of trace element status, this is of limited value and no single test may be considered as ideal for any element. The provision of more detailed information from elemental analysis of cellular and subcellular fractions and of protein fractions from plasma leads inexorably to measurements of element-dependent enzymes, metalloproteins and of low molecular weight element-binding ligands. Even at this level of discrimination the choice of body tissue or tissue fluid for investigation is determined by the trace element and its principal metabolic targets.

Cadmium↗
PubMed1984

Blood lead, behaviour and intelligence test performance in preschool children.

A variety of measures of behaviour and cognitive performance were taken on a group of preschool children together with a sample of venous blood. The relationship between blood lead and intelligence was small and statistically non-significant after controlling for other factors influencing cognitive performance.

Behavior↗
PubMed1984

The uptake and excretion of chromium by the elderly.

Metabolic balance studies for chromium have been carried out on 22 apparently healthy elderly people and one subject with impaired glucose tolerance. All subjects were aged between 69.7 and 85.5 yr, ate self-chosen diets, and lived in their own homes during the study. The mean daily intake of chromium for the healthy subjects was 471 nmol (24.5 micrograms) with a mean retention of 3 nmol (0.2 microgram). The subject with a raised plasma glucose was in positive balance for chromium. Although the daily chromium intake was below the lower limit of the estimated safe and adequate daily dietary intake proposed by the American Food and Nutrition Board it appeared to be adequate for these subjects.

Aged↗
PubMed1984

The intake and excretion of lead and cadmium by the elderly.

Metabolic balance for lead and cadmium were carried out in 23 healthy elderly people aged 69.7 to 85.5 yr while living in their own homes and eating self-selected diets. Mean intakes of lead and cadmium were 54.6 and 8.6 micrograms/day, with mean retentions of -8.7 and -1.7 micrograms/day, respectively. Daily dietary lead correlated (p less than 0.05) with the intake of energy, nitrogen, calcium, iron, and zinc but not with manganese or copper. Dietary intake of cadmium correlated (p less than 0.05) only with that of zinc and manganese. There was a highly significant (p less than 0.001) inverse correlation between the percentage cadmium absorbed and body iron stores measured as serum iron, percentage iron saturation, and ferritin. Mean whole blood concentrations were 138 micrograms/l for lead and 0.79 microgram/l for cadmium. The negative balances observed in these elderly people were very different from the positive balances found in a previous similar study in children.

Absorption↗
PubMed1984

Albumin bound and alpha 2-macroglobulin bound zinc concentrations in the sera of healthy adults.

Reference ranges for albumin bound and alpha 2-macroglobulin bound zinc concentrations have been determined in a study of sera obtained from 134 healthy adults. The concentrations of zinc bound to alpha 2-macroglobulin were remarkably constant with a mean (+/-SD) of 2.4 +/- 0.6 mumol/l; the variations in total serum zinc concentrations were almost entirely accounted for by variations in the zinc associated with albumin. There were no sex related differences in the transport of zinc in serum; neither was this sensitive to the use of oral contraceptives. These data provide a baseline for further investigations into the effects of zinc deficiency on the serum transport of the metal.

Adolescent↗
PubMed1984

Temporal stability of blood lead concentrations in adults exposed only to environmental lead.

The temporal stability of blood lead concentrations of 21 healthy adults (14 men and 7 women) exposed only to environmental lead was assessed by analysis of 253 blood specimens collected serially over periods from 7 to 11 months. Improved analytical sensitivity allowed detection of small (less than 1.0 microgram/100 ml) changes in blood lead concentrations and both within- and between-run analytical errors were minimized by a strict internal quality control protocol. The women had lower blood lead concentrations (mean 8.5, range 7.4-10.8 micrograms/100 ml) than did the men (mean 12.2, range 8.6-15.8 micrograms/100 ml). These are within the expected ranges for non-occupationally exposed persons. Blood lead concentrations in the serial specimens from both men and women changed very little over the study period, with standard deviations of less than 0.5 micrograms/100 ml for the majority of individual mean concentrations: for all except two subjects the standard deviations were less than 0.8 micrograms/100 ml. Two subjects showed significant changes in blood lead concentrations during the study (standard deviations of mean greater than 1.0 micrograms/100 ml). A temporary increase in oral lead intake was identified for one of these subjects. In the absence of substantial changes in lead exposure blood lead levels in adults are remarkably stable and for their environmental monitoring a single blood lead concentration is an excellent biological indicator.

Adult↗
PubMed1984

Reduction in exposure to lead from drinking water and its effect on blood lead concentrations.

The water supply in Ayr (Scotland, UK) was plumbosolvent and many dwellings in Ayr contained lead pipes. In 1981 treatment of the water supply to reduce its plumbosolvency was initiated. Measurements of water and blood lead concentrations were made before and subsequent to the treatment. Most of the measurements made before and after water treatment began were made on water samples from the same dwellings and blood samples from the same women. Water treatment produced a sharp fall in water lead concentrations and a decrease in the median blood lead concentration from 21 to 13 micrograms/100 ml. Two women had higher than expected blood lead concentrations, both these women had been removing old paint. Women who had lead pipes removed from their dwellings all showed substantial decreases in their blood lead concentrations. The curvilinearity of the relation between blood lead and water lead concentrations is confirmed. Even relatively low (less than 40 micrograms/l) water lead concentrations may make a substantial contribution to blood lead concentrations.

Adult↗
PubMed1983

Evaluation of the trace metal supplements for a synthetic low lactose diet.

A trace element supplement used with a synthetic low lactose milk (Galactomins 17 and 18) has been evaluated by means of metabolic balance studies in 4 infants with dissacharide intolerances. The supplement was considered satisfactory for iron and manganese but increases in its zinc and copper content are probably necessary to ensure adequate retentions of these metals.

Body Weight↗