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M Nordberg

Publications and source records attributed to M Nordberg.

At least 19 recordsLinked to original sources

Metallothionein gene expression in peripheral lymphocytes from cadmium-exposed workers.

Metallothionein (MT) plays an important role in the detoxification of cadmium. To investigate the usefulness of MT gene expression in peripheral blood lymphocytes (PBLs) as a biomarker of cadmium exposure and susceptibility, reverse transcriptase-polymerase chain reaction was used to measure the MT gene expression in PBLs from cadmium-exposed workers. Both basal and induced MT expressions were found to increase with increased blood cadmium (BCd) and urinary cadmium (UCd) levels. Both basal and induced MT expression levels were significantly correlated with the logarithm of BCd and the logarithm of UCd levels. The dose-response relationship between internal dose of cadmium and MT expression suggested the validity of MT expression in PBLs as a biomarker of cadmium exposure. In vitro induced MT expression level in PBLs was found to be inversely related to the level of renal dysfunction indicator, urinary N-acetyl-beta-D-glucosaminidase (UNAG). The latter finding indicates that MT expression in PBLs may be a useful biomarker of susceptibility to renal toxicity of cadmium.

Acetylglucosaminidase↗

Lead concentrations in elderly urban people related to blood pressure and mental performance: results from a population-based study.

BACKGROUND: The Kungsholmen project is a longitudinal study of ageing and dementia conducted in Stockholm in 1987. In a 1994-96 follow-up, 804 subjects had their blood samples analyzed for lead. METHODS: Lead concentration in blood in an elderly population aged 75+ (mean age of 88.4 years) was studied in relation to age, blood pressure (BP), body mass index (BMI), cognitive function measured with Mini-Mental State Examination (MMSE), gender, and smoking. RESULTS: The mean blood lead level (n = 762) was 3.7 microg/dL (0.18 micromol/L) whole blood with a standard deviation of 2.3, (0.11). There was a contribution of gender with men having higher blood lead levels than women (beta = -0.20; P = 0.000001) but not of smoking habits (beta = 0.07; P = 0.08) when these variables were entered into a multiple regression model with lead as the dependent variable (R = 0.22; P < 0.000001). Different multiple regression models were tested with lead as the dependent variable. No relation was found between lead concentrations and age, BMI, systolic BP, diastolic BP, or MMSE. Systolic and diastolic BP were correlated to BMI (R = 0.10; P = 0.01 and R = 0.22; P = 0.000 001, respectively). CONCLUSIONS: In this elderly population from a specified area of Stockholm it is unlikely that lead exposure affects BP or cognition. However, high lead levels in blood may reflect earlier occupational exposure or life style factors.

Age Factors↗

Cadmium concentration in blood in an elderly urban population.

Concentration of cadmium in blood in an elderly population with a mean age of 87 years was studied in relation to age, blood pressure, BMI, cognitive function, gender and smoking. This population-based study consisted of 804 subjects both men and women. Clinical examination included medical and social history, physical and neurologic examination, and assessment of cognitive functions with Mini-Mental State Examination (MMSE). Information on prescription and non-prescription drug use was collected. Anti-hypertensive drugs included all medicines potentially used for treating high blood pressure. Blood pressure was measured. Whole blood from 763 subjects was analysed for cadmium by atomic absorption spectrophotometry (GFAAS) with Zeeman background correction and with a graphite furnace using the L'vov platform technique including quality control. Differences in cadmium concentrations were related to non-smokers (3.9 nmol/l), previous smokers (4.4 nmol/l) and current smokers (7.5 nmol/l). There were no relations between cadmium and age, blood pressure or cognitive functions. In conclusion, increased cadmium levels were found in smokers. A possible contribution from previous occupational exposure needs to be further evaluated.

Aged↗

Toxicological aspects of metallothionein.

Metallothionein (MT) is expressed to a certain extent in almost all mammalian tissues. The biological significance of MT is related to its various forms MT-1, MT-2, MT-3 and MT4. For MT-1 several isoforms of the protein exist and it is likely that these isoforms are related to various functions involved in developmental processes occurring at various stages of gestation. Toxicokinetics and biochemistry of essential and toxic metals such as cadmium, zinc, mercury and copper in organs e.g. kidney, CNS, are often related to metallothionein. It is debated whether there is a relation or not for other metals e.g. selenium and bismuth. For the toxicokinetics of cadmium, MT plays an important role. By expanding techniques from experimental toxicology and biochemistry to include molecular biology methods, more specific and relevant studies can be performed of the actual role and biological function of MT. The present paper on toxicological aspects of metallothionein, presents an overview and evaluation of present knowledge concerning differences among organs and within organs of the expression of MT and how this affects tissue sensitivity to toxicity.

Animals↗