Metabolic balance studies for zinc and copper in housebound elderly people and the relationship between zinc balance and leukocyte zinc concentrations.

Five-day metabolic balance studies for zinc and copper were carried out in 20 housebound elderly people with stable chronic diseases. Subjects were age 70.0-85.1 y, lived in their own homes, and ate self-selected diets. Mean daily intakes for Zn and Cu were 90 mumol and 13.4 mumol with mean negative balances of -16 and -1.1 mumol, respectively. Both balance values significantly differed from equilibrium (p less than 0.05). For Zn and Cu, respectively, mean concentrations were 11.3 and 22.1 mumol/L plasma, 103 and 19.4 mumol/L whole blood, and 98 and 8.7 pmol/10(6) leukocytes. The results for Zn and Cu balance and leukocyte concentrations were different from those obtained by us for healthy elderly people (Am J Clin Nutr 1984;40: 1096-120). A highly significant (r = 0.75, p less than 0.001) correlation was observed between zinc balance and leukocyte zinc concentrations.

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.

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.

Assessment of zinc and copper status of healthy elderly people using metabolic balance studies and measurement of leucocyte concentrations.

Metabolic balance studies for zinc and copper were carried out in 24 apparently healthy elderly people aged 69.7 to 85.5 yrs, living in their own homes and eating self-selected diets. The zinc and copper concentration in whole blood, plasma, and leucocytes were also measured. Mean daily intakes for zinc and copper were 137 and 20.1 mumol with mean retentions of 1.0 and -0.8 mumol, respectively. These values did not differ significantly from equilibrium (p less than 0.01). For zinc and copper, respectively, mean concentrations were 11.0 and 19.4 mumol/l in plasma, 120 and 11.5 mumol/10(6) cells in leucocytes, and 99 and 13.4 mumol/l in whole blood. These data will provide normal standard values for elderly people in good health and should serve as a basis for the investigation of elderly people with suspected deficiencies of these trace metals.

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)

Micro methods and micro apparatus for chemical pathology with special reference to paediatrics.

This article describes methods and apparatus which permit the estimation of a particular substance without requiring more blood than can conveniently and safely be removed from a child by capillary puncture. No reference will be made to the use of methods on the Technicon Auto-Analyzer as that machine is not yet generally geared to paediatric work, although a few centres have made their own modifications to permit certain methods to be performed on capillary samples of blood.

Enzymes involved in phenylalanine metabolism in the human foetus and child.

The activities of phenylalanine p-hydroxylase, tyrosine: alpha-ketoglutarate and phenylalanine: pyruvate aminotransferases, and aromatic alpha-ketoacid reductase have been measured in liver biopsies obtained from children with a series of disorders other than phenylketonuria and from human foetuses aged 8.5 to 24 weeks. The importance of such a study in relation to the management of infants with hyperphenylalaninaemia and pregnant phenylketonuric women is discussed

Zinc and copper concentrations in leucocytes and erythrocytes in healthy adults and the effect of oral contraceptives.

The content of zinc and copper of whole blood, plasma, erythrocytes and white cells, has been measured in normal controls. The concentrations of zinc and copper in leucocytes are about seven and ten times respectively higher than those in erythrocytes. Women taking oral contraceptives showed significant increases in the concentrations of copper in plasma and whole blood but not in leucocytes or erythrocytes. Oral contraceptives did not alter the concentration of zinc in any of the fractions or in whole blood. These data provide a baseline for the assessment of the body status of zinc and copper in various disease states in which deficiencies may be present.

PIP: The content of zinc and copper of whole blood, plasma, erythrocytes, and white cells has been measured in normal controls. The concentrations of zinc and copper in leucocytes are about 7 and 10 times respectively higher than those in erythrocytes. Women taking oral contraceptives (OCs) showed significant increases in the concentrations of plasma in copper and whole blood but not in leucocytes or erythrocytes. OCs did not alter the concentration of zinc in any of the fractions or in whole blood. These data provide a baseline for the assessment of the body status of zinc and copper in various disease states in which deficiencies may be present.

Selenium and vitamin E in relation to risk factors for coronary heart disease.

Fasting blood samples taken from 116 apparently healthy men aged 30-50 years were assayed for selenium, glutathione peroxidase activity, vitamin E, cadmium, lead, glucose, lipids, and albumin. Blood pressure was measured in each subject, and details of height, weight, smoking habits, and alcohol consumption were recorded. Multivariate analysis of the data showed that the decrease in blood and serum concentrations of selenium and the increase in whole blood cadmium concentrations in the cigarette smokers was independent of alcohol consumption. There was no correlation between blood selenium concentrations or glutathione peroxidase activities and the risk factors for cardiovascular disease. Neither alcohol consumption nor smoking had an effect on the vitamin E concentrations. There was a strong association, however, between vitamin E and serum lipid concentrations, although the increase in triglyceride concentrations in the smokers was not matched by a comparable increase in vitamin E. The possible role of selenium in the aetiology of heart disease remains unresolved.

Uptake and excretion of iron by healthy elderly subjects.

Metabolic balance studies for iron have been carried out on 24 apparently healthy elderly people (11 men and 13 women) aged 69.7 to 85.5 years living in their own homes and eating self selected diets. Several biochemical and haematological indices of iron state were also measured. The mean daily iron intake was 176 mumol, with a range of 55-321 mumol. Eight women and six men consumed diets which provided less than the recommended daily dietary allowance for iron of 179 mumol/day. Mean daily retention of iron, however, was -7 mumol, a value which did not significantly differ from equilibrium. No sex difference was noted between any of the biochemical and haematological measurements. Mean values of iron concentration, iron binding capacity, iron binding saturation, and ferritin and haemoglobin concentrations were 20 mumol/l, 59 mumol/l, 34%, 77 micrograms/l, and 14.3 g/dl, respectively. We have shown that in apparently healthy elderly people who are in equilibrium for iron balance, several biochemical and haematological measurements of iron state do not differ from the normal ranges established in younger adults.

Dihydropteridine reductase activity in dried blood spots: effects of aging and senile dementia of the Alzheimer type.

Dihydropteridine reductase (EC 1.6.99.7) (DHPR) activity was measured in blood spots from 50 neonates, 52 healthy adults aged 30-62 years, and 21 elderly controls aged 67-97 years, as well as 32 demented patients of whom 25 had senile dementia of the Alzheimer type. Enzyme activity was stable for seven days at 4 degrees C and for at least 14 days at -20 degrees C. No important difference was found between the DHPR activity of venous and capillary blood. DHPR activity was considerably lower in the healthy adult group compared with neonates and the elderly group, and there was no sex difference at any age. The erythrocyte DHPR activity of patients with senile dementia of the Alzheimer type was similar to that of elderly controls. This result differs from that previously reported for leucocytes.

Effect of smoking, alcohol, and other factors on the selenium status of a healthy population.

In a study of selenium status in 391 apparently healthy subjects resident in the south of England statistical examination of the data showed a significant effect with regard to age, smoking, alcohol, and oral contraceptives. The most important of these factors seems to be a combination of alcohol and smoking habits in men over 30. Reference ranges have been established for glutathione peroxidase activities and the concentrations of selenium in whole blood plasma and erythrocytes.

Creatine kinase activity in the detection of carriers of Duchenne muscular dystrophy: comparison of two methods.

Serum creatine kinase activity was estimated in 48 control women and 22 female carriers of Duchenne muscular dystrophy by two different methods. One method is based on the colorimetric determination of creatine liberated from creatine phosphate; the other, an N-acetyl cysteine activated UV system, was used in an automated mode. The two methods were equally efficient in carrier detection, and results were closely correlated over the range of values encountered in controls and carriers. Log creatine kinase values appeared to be normally distributed in controls, but the distribution in carriers appeared skewed towards its upper end. If both distributions are assumed to be Normal, the probability, together with its standard error, that a consultand is a carrier, can be calculated from her creatine kinase value, and if the latter is expressed in standard deviation units of the control log creatine kinase distribution, probability estimates can be compared between laboratories.

Haematological and biochemical parameters in an industrial workforce.

Biochemical and haematological data for two consecutive years are presented on about 2000 people from the workforce of a large chemical company. The data are examined for the influence of sex, age, season, time of blood sampling, and patterns of work on the various indices. In addition to the results confirming previously published work relating to the effects of age and sex, they provide interesting new information on the possible influences of seasons and patterns of work, that is, whether the subjects were shift or day workers. Further studies on the influence of these various factors are required, and our on-going survey will perhaps provide more definite data in due course. The findings show the importance of quantifying these variables, particularly in an industrial workforce where minor changes may be of significance.

Seasonal variations in haematological and biochemical parameters.

Biochemical and haematological data obtained over five consecutive years are presented on the male workforce of a large chemical company. The data have been subjected to statistical analysis and quantify the influence of age and the month of the year in which the samples were taken. The red cell count, white cell count, serum gamma-glutamyl transferase, alanine transaminase and creatinine show significant and consistent seasonal variations. The previously published work on the influence of age on several indices is confirmed. Biochemical screening may be a method of detecting early signs of toxicity in man but such factors as age, sex and season must be taken into account when comparing the results obtained from exposed and non-exposed groups.

The effect of supplementation with selenium and vitamin E in psoriasis.

Since reduced concentrations of selenium in whole blood, plasma and white cells had previously been observed in psoriasis, 69 patients were supplemented daily with either 600 micrograms of selenium-enriched yeast, 600 micrograms of selenium-enriched yeast plus 600 IU of vitamin E or a placebo for 12 weeks. Before supplementation, the patients' mean concentrations of selenium in whole blood and plasma were reduced compared with those of matched healthy controls but their red cell glutathione peroxidase (GSH-Px) activity was normal. After 12 weeks supplementation the patients' mean whole blood, plasma and platelet selenium concentrations, platelet GSH-Px activity and plasma vitamin E concentration had risen significantly from the baseline values but their mean skin selenium concentration and red cell GSH-Px activity remained unchanged. The mean white cell selenium concentration rose only in the group receiving selenium alone. Neither supplementation regimen reduced the severity of psoriasis or produced side-effects. The increase in platelet GSH-Px activity suggests that the supplements were bioavailable and that the patients' selenium status may have been reduced prior to supplementation. The failure of the selenium content of the skin to increase may explain why the patients' psoriasis remained unchanged during supplementation.

An appraisal of the analytical significance of tooth-lead measurements as possible indices of environmental exposure of children to lead.

The analysis for lead of whole-crowns from deciduous incisors has been used as an index of the cumulative exposure to lead of children during the prenatal period and until the time of shedding the tooth. The lead was determined by solvent extraction followed by atomic absorption, and strict analytical quality control was employed. The concentrations of lead in pairs of central and lateral incisors from children revealed unexpectedly large differences for some individuals.

Programming and running radioimmunoassay in the h-TSH screening procedure using dried blood spots and the NE1600 gamma counter on line to the HP9815S calculator.

Screening for hypothyroidism has been achieved by seeking raised concentrations of thyroid stimulating hormone (h-TSH) in dried blood samples collected on absorbent paper from some 1700 newborn babies each week using double antibody radioimmunoassay and 125I-label counting on a NE1600 gamma counter linked to a HP9815S desk top calculator. Specificity, accuracy, and quality control of the assay have been investigated. The calculator programme stores all count, time, and calculated data and uses log-log function formation and third-power homoscedastic polynomial fit to the calibration data followed, if necessary, by elimination of outliers set at P = 0.5%. Branching in the calculation procedure provides the ability to process sample data in subgroups, completely to reprocess data (including presentation in a form suitable for making a histogram plot), and to reset without loss of data in case of instrument or main power failure. Variance analysis was used to select the minimum duration of count (50 s), and it was demonstrated that homoscedasticity pertains in the regression calculation.

Dietary supplementation and immunocompetence in housebound elderly subjects.

Immune function, particularly cell-mediated immunity (CMI), declines with age and it has been suggested that this may be secondary to the impaired nutritional status often found in the elderly. In the present study a balanced nutritional supplement consisting of several macro- and micro-nutrients was administered daily to 27 housebound elderly (aged 70-85 years) for 12 weeks. Thirty-one matched subjects served as a control group. Delayed cutaneous hypersensitivity (DCH) to seven recall antigens was measured using the Mérieux Multitest CMI device and total numbers of lymphocytes, B-cells, T-cells and T-cell sub-populations were determined using monoclonal antibodies. These tests and several indices of nutritional status were measured before and at the end of the 12-week study. Before supplementation 19% of the entire group of subjects were anergic and another 19% hypoergic, values greater than expected for healthy elderly subjects. A weak association (P = 0.056) was shown between plasma zinc concentration and the number of positive skin test responses. Supplementation had minimal effect on DCH, resulting in a significant (P < 0.05) increase only in the sum of positive indurations. Pre-study numbers of total lymphocytes and lymphocyte sub-populations were as expected for healthy elderly subjects, but a correlation was found between plasma selenium concentrations (mean 1.07, range 0.64-1.66 mumol/l) and the numbers of CD4 lymphocytes (P < 0.01). Supplementation did not result in a significant change in any of the lymphocyte populations.(ABSTRACT TRUNCATED AT 250 WORDS)