A problem with her lead weight.

An autistic patient living in a residential home presented with symptoms of weight loss and abdominal pain. On investigation, she was found to have lead poisoning from an unusual source. Her treatment proved difficult due to failure to cooperate, and a 'best-case' protocol was devised. The positive identification of a source of exposure can be difficult in a single case of exposure, but this was eventually achieved by means of stable lead isotope analysis following painstaking detective work.

CSF copper in schizophrenia.

The authors measured copper levels in the cerebrospinal fluid of 8 schizophrenic subjects and 6 controls. The schizophrenic subjects had significantly lower CSF copper values than the controls, which is consistent with the hypothesis that there is reduced central activity of copper-dependent enzymes in schizophrenia. These enzymes, tyrosine hydroxylase and dopamine-beta-hydroxylase, are involved in the synthesis and catabolism of dopamine.

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.

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)

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.

PIP: The concentrations of albumin bound and alpha 2-macroglobulin bound zinc were investigated in the sera of 134 healthy human volunteers to provide control data for use in subsequent studies of zinc deficiency states. Whole blood was obtained from 86 men, aged 18-62 years, and 48 women, aged 19-60 years. 11 of the 48 women, aged 19-31 years, were taking combined oral contraceptives (OCs), 30 mcg ethinyl estradiol and 125-250 mcg levonorgestrel daily. Disposable plastic syringes and stainless steel needles were used to obtain venous blood, which was transferred to plain glass bottles which had been made zinc free by immersion in dilute nitric acid for 2 hours before being rinsed 6 times 6 times with deionized water and then dried. Serum was separated by centrifugation and stored in zinc-free polycarbonate tubes at -20 degrees Celsius until required for analysis. The summation of the concentrations of zinc found in association with albumin and alpha 2-macroglobulin were generally in good agreement with the total zinc concentration for each serum sample examined. The total recovery of zinc was 100.0 +or- 6.4% with a range of 88-114%. In percentage terms, the distribution of the recovered zinc was 16.3 +or- 4.1% (range 8.9-27.1%) with alpha -imacroglobulin and 83.7 +or- 4.1% (range 72.9-91.1%) with albumin. The molar ratios of albumin to albumin bound zinc and alpha 2-macroglobulin to alpha 2-macroglobulin bound zinc ere calculated each serum studied. Although the binding ratio between albumin and its associated zinc varied considerably, there was always a remarkable excess of albumin relative to zinc. Only 1.1-2.6% of the albumin present in the serum samples studied was engaged in zinc transport. The ratio of alpha 2-macroglobulin to alpha 2-macroglobulin bound zinc taken over the entire population was close to unity. No significant correlations were found between the concentrations of either albumin or alpha 2-macroglobulin and the concentrations of their associated zinc. The results arising from the analyses of the serum samples taken from the 11 women taking OCs were compared with similar data relating to 12 women, aged 40 years or less, who were not taking any drugs. There were no significant differences between these 2 populations for any of the parameters. The data provide a baseline for further investigations into the effects of zinc deficiency on the serum transport of the metal.

The preparation of a 'metal-free' nappy and its application to metabolic balances in children.

Disposable nappies (diapers) have been satisfactorily demineralized and used for the collection of excreta from infants and young children during mineral and trace metal balances. It was possible to investigate children of both sexes without immobilization.

Semi-automatic determination of lead in whole blood.

The procedure developed by Browett and Moss (1964) for the semi-automatic determination of the lead content of urine has been adapted for the determination of lead in blood. Determinations are normally carried out in duplicate on 2.0 ml. samples of whole blood and the minimum sample size is 0.5 ml. The organic substances present in blood are destroyed by a manual wet-oxidation procedure and the lead is determined colorimetrically as lead dithizonate using a Technicon AutoAnalyzer. The lower limit of detection, expressed as three times the standard deviation of the blank value, is 5 mug. Pb/100 ml. blood. The standard deviation of the method in the upper range of normal blood lead level of 30 mug. Pb/100 ml. blood (Moncrieff, Koumides, Clayton, Patrick, Renwick, and Roberts, 1964), is +/- 3 mug. Pb/100 ml. blood. Ten samples per hour may be estimated in duplicate.

Antimony in blood and urine of infants.

AIM: To establish a reference range for antimony in the serum and urine of infants in the first year of life. METHODS: 100 infants were selected randomly from the population. Each infant had a single blood and urine sample taken. Antimony was assayed using inductively coupled plasma mass spectrometry. RESULTS: The reference range for antimony in the serum of infants in the first year of life was established as 0.09-0.25 microgram/l. The upper 95% centile for urinary antimony, corrected for creatinine, in the same population was 2.6 ng/mg creatinine. There was a very weak correlation between the serum and urine concentrations. CONCLUSIONS: This study confirms the presence of low concentrations of antimony in the serum and urine of healthy infants.

The demonstration of nickel in the urease of Helicobacter pylori by atomic absorption spectroscopy.

Fast protein liquid chromatography and SDS-PAGE have been used to isolate and purify Helicobacter pylori urease. A nickel component of the urease was detected in the purified proteins by atomic absorption spectroscopy. The nickel was present only in the 61 kDa polypeptide and in the ratio of between five and six atoms to one molecule of urease, suggesting a hexameric structure. These results are discussed in relation to other bacterial ureases and urease activity at low pH.

The microdetermination of copper in plasma protein fractions.

Electrophoresis on cellulose acetate membranes and electrothermal atomization for atomic absorption spectrophotometry have been combined to allow the determination of copper in protein fractions separated from only 2 mul volumes of serum. The sensitivity of the method is 5.2 X 10(-11) g of copper for 1% absorption at 324.7 nm, and the precision of replicate analyses at the 1.7-ng level is 0.086 (Relative Standard deviation). The mean recovery of copper from the alpha2-protein fraction of a serum sample was 94%. The method has been applied to a study of the changes in the copper content of the various protein fractions of sera from patients with Menkes' syndrome.

Selenium status and associated factors in a British National Diet and Nutrition Survey: young people aged 4-18 y.

OBJECTIVE: Assessment of selenium status to provide normative reference values, and investigation of associated socio-demographic factors, in a national sample of British young people aged 4-18 y. SETTING: National Diet and Nutrition Survey-a nationwide cross-sectional sample of young people aged 4-18 y living in mainland Britain in 1997. METHODS: Selenium status was measured, mainly in fasting blood samples, by plasma selenium concentration in 1127 participants, by red blood cell (RBC) selenium concentration in 1112, and by whole-blood glutathione peroxidase (GPx) activity in 658. RESULTS: No evidence of severe selenium deficiency or toxicity was observed. Plasma selenium concentration was directly correlated with RBC selenium concentration, and both were associated directly, although less strongly, with GPx activity. Plasma and RBC selenium concentrations increased significantly with age, with RBC concentrations significantly higher in older girls than boys. Region of domicile exhibited a significant relationship. Associations also occurred with parental occupational social class, selenium concentrations being higher in more socially advantaged children. Black and Indian children had considerably higher concentrations than Caucasian children. Concentrations, especially of plasma selenium, were significantly lower in children either (or both) of whose parents were smokers, although, unexpectedly, there was no evidence that children who themselves smoked had lower levels. CONCLUSIONS: The observed associations between selenium status indices and age, gender, social class, parental smoking and ethnic group indicate a complex network of biological factors which determine selenium concentrations in blood components, and which thus need to be controlled for when using these indices to assess selenium status in young people. SPONSORSHIP: The survey was commissioned jointly by the Department of Health and the Ministry of Agriculture, Fisheries and Food, whose responsibility has since been transferred to the Food Standards Agency. Support for the further analysis presented in this paper was provided by the Department of Health.

Prevalence of maternal dietary iodine insufficiency in the north east of England: implications for the fetus.

BACKGROUND: Maternal subclinical hypothyroidism is a cause of poor neurodevelopment outcome in the offspring. Although iodine deficiency is the most common cause of hypothyroidism world wide, there are no screening programmes for it in the United Kingdom where the population is assumed to be iodine replete. OBJECTIVE: To determine the prevalence of reduced iodine intake by measuring urinary iodide concentrations in pregnant and non-pregnant women from the north east of England. METHODS: Urinary iodide excretion (UIE) rate was estimated using inductively coupled mass spectrometry in 227 women at 15 weeks gestation and in 227 non-pregnant age matched controls. A reduced intake of iodine is indicated by a concentration in urine of less than 50 microg/l or less than 0.05 microg iodine/mmol creatinine. RESULTS: Eight (3.5%) pregnant women and 13 (5.7%) controls had a reduced iodine/creatinine ratio. These values were higher when UIE was expressed as iodine concentration: 16 (7%) and 20 (8.8%) respectively. Ninety (40%) of the pregnant women had a UIE of 0.05-0.10, which is consistent with borderline deficiency. CONCLUSION: In this study, 3.5% of pregnant women had evidence of iodine deficiency, and 40% may be borderline deficient. Larger scale studies are required to estimate the true prevalence of iodine deficiency in the United Kingdom.

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.

In vivo degradation of tungsten embolisation coils.

It has been suggested that tungsten embolisation coils in intracranial aneurysms may dissolve in situ. These coils are also used, in much larger quantities, for the occlusion of larger vessels outside the cranium. This study was performed to investigate whether tungsten embolisation coils may become degraded in vivo and to examine whether this is radiographically evident on medium-term follow-up. 10 patients who had undergone aortic stent-graft repair of an abdominal aortic aneurysm (8 male and 2 female, mean age 69.7 years) and 10 age- and sex-matched controls were studied. The study group had also received an average of 64 cm of tungsten coil either to prevent or to treat an endoleak. Whole blood, serum and urine tungsten levels were assayed. Immediate post-operative and follow-up abdominal radiographs were reviewed by two consultant vascular radiologists to detect visible changes in the coils. Whole blood, serum and urine levels of tungsten were highly and significantly elevated (p < 0.001) in the study group compared with the controls. No radiographic changes in the coils were seen at an average of 16.7 months. In conclusion, tungsten embolisation coils dissolve in humans but radiographic changes are not apparent on medium-term follow-up. The clinical significance of these findings is uncertain but long-term follow-up is needed.

Systemic release of cobalt and chromium after uncemented total hip replacement.

We measured the levels of cobalt and chromium in the serum in three groups of patients after uncemented porous-coated arthroplasty. Group 1 consisted of 14 consecutive patients undergoing revision for aseptic loosening. Group 2 comprised 14 matched patients in whom the arthroplasty was stable and group 3 was 14 similarly matched patients with arthritis awaiting hip replacement. Specimens were analysed using atomic absorption spectrophotometry. Aseptic loosening of a component resulted in a significant elevation of serum cobalt (p < 0.05), but not of serum chromium. The relative risk of a component being loose, if the patient had a serum cobalt greater than 9.0 nmol/l, was 2.8.

Exposure to trace elements of flamingos living in a biosphere reserve, the Camargue (France).

Recent research has shown that some adult flamingos Phoenicopterus roseus collected from the Camargue Biosphere Reserve had tissue metal concentrations considerably higher than the average for this species. As the range of these birds is large, the origin of the contamination was unknown. Blood and feather samples from nestling flamingos were therefore analysed for trace metals to determine the presence and origin of local contamination. A comparison of elemental concentration in the feathers of nestling and adult flamingos revealed higher concentrations of Cd, Cu, Pb and Se in adults, and higher concentrations of Zn in juveniles. This was attributed to increased exposure to atmospheric pollutants of adults, and either differences in Zn requirements and metabolism between adults and juveniles, or a local contamination of the juveniles' food supply by Zn. Concentrations of Zn in serum were also very elevated compared with human standards. Cd, Cu, Zn and Se concentrations were analysed in outer (O) and inner (I) barbs (i.e. barbs that are, respectively, exposed or not exposed to external deposits) of greater coverts of nestling flamingos. A comparison of elemental concentrations in these two feather components indicates a local atmospheric contamination by Cd, Cu and Pb.

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.

Lead intake and blood lead in two-year-old U.K. urban children.

A comprehensive study of a group of 2-year-old urban children (n = 97), designed to provide quantitative information simultaneously for lead intakes via all identified pathways, has been carried out in Birmingham (U.K.). Results showed that for children whose blood levels and exposure to environmental lead were within the normal range for the U.K., blood lead concentration was significantly related to a combination of house dust lead loading and an overall rate of touching objects, to water lead concentration and to the parents' smoking habits. On the basis of assumptions used by the Royal Commission on Environmental Pollution (RCEP), the estimated average total uptake of lead was 36 micrograms day-1; of this, 97% was from ingestion from dust, food and water and only 3% from inhalation.

Uptake of aluminum and gallium into tissues of the rat: influence of antibody against the transferrin receptor.

Transport of aluminum and gallium from blood into rat tissues following continuous i.v. infusion of metals in different chemical forms has been investigated. Tissue uptake of aluminum and gallium was similar and highly dependent on the chemical species of the metals. Aluminum and gallium accumulated in liver and spleen when infused in the chloride form. Raised citrate markedly enhanced aluminum and gallium uptake into renal cortex and bone; in contrast with gallium-transferrin, citrate increased uptake of 67Ga into renal cortex and bone by 8- and 14-fold respectively. Uptake of 67Ga with citrate into renal cortex was around 3 times smaller than that of aluminum. The antitransferrin receptor antibody OX-26 enhanced 67Ga uptake from gallium citrate into all rat tissues. 67Ga from purified gallium-transferrin was also taken into all tissues in the presence of OX-26, the effect being greatest in renal cortex and bone. No influence of antibody on aluminum transport into rat tissues was, however, observed when aluminum was infused in the citrate form. Therefore, transport of aluminum and gallium into tissues is not similar under all conditions. Transport of each metal occurs into all tissues in the presence of antitransferrin receptor antibody. The potential for such transport is much greater in the case of gallium. Transport of aluminum and gallium citrate complexes appears important especially in the renal cortex and bone.