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J Börjesson

Publications and source records attributed to J Börjesson.

At least 19 recordsLinked to original sources
PubMed2003

X-ray fluorescence analysis in medical sciences: a review.

Some elements have toxic effects on the human body and there is thus a need to control their levels in human organs and tissues. Moreover, it is important to increase our knowledge of relationships between observable toxic effects and element concentrations in man and his environment. Monitoring and basic occupational and environmental research rely on measurements directly in humans as well as samples from humans and the environment. This paper reviews recent advances in in vivo X-ray fluorescence methods and their applications.

Disease↗
PubMed2001

Kidney cadmium as compared to other markers of cadmium exposure in workers at a secondary metal smelter.

BACKGROUND: The aim of the study was to evaluate whether cadmium concentrations in kidney (K-Cd), blood (B-Cd) or urine (U-Cd) could reveal previous occupational cadmium exposure at a metal smelter. METHODS: The study included 90 smelters and 35 controls (B-Cd and U-Cd determination). In a subgroup (N = 33), K-Cd was also determined. RESULTS: B-Cd (median 4.6; range 0.5-53 nmol/L), U-Cd (0. 29; 0.04-1.9 micromol/mol creatinine) and K-Cd (14; 3-61 microg/g wet weight) were similar to reported concentrations in the general Swedish population. In the subgroup, significant associations (P<0. 001) were obtained between B-Cd and K-Cd (r = 0.70), U-Cd and K-Cd (r = 0.60) and between U-Cd and B-Cd (r = 0.62). Multiple regression analyses revealed smoking as the major predictor of K-Cd, B-Cd, and U-Cd. B-Cd and U-Cd were both associated with the duration of employment at the smelter. CONCLUSIONS: There was no statistically significant evidence of previous occupational exposure at the smelter from measurement of K-Cd.

Adult↗
PubMed2001

Long-term external radiation exposure of inhabitants in the western Bryansk region of Russia as a consequence of the Chernobyl accident.

The western Bryansk region in south-western Russia was highly contaminated with 137Cs and 134Cs due to the Chernobyl accident in 1986. In 1990, a joint Nordic-Russian project was initiated in order to make measurements and estimates of the absorbed doses to selected groups of inhabitants in this area. The participating individuals were living in small villages with contamination levels between 0.9 and 2.7 MBq m(-2). Only some villages had been decontaminated. Both school-children and adults participated in the study and the number of persons was between 100 and 130 each year, residing in 5 villages. Every year in September-October, from 1990 to 1998. we performed individual measurements of external absorbed doses, assessed with thermoluminescent (TL) dosemeters (LiF). The mean effective dose per year from external irradiation due to the Chernobyl accident of the inhabitants in the villages ranged between 0.8 and 2.9 mSv during the study period and decreased with an apparent half-time of 3.7-8.2 years, depending on village and group. The highest individual doses within one village were, on average higher by a factor of 3 than the mean value for that village. Under the conservative assumption of a decrease rate in the external effective dose of 2% per year after 1998, individuals in the most highly exposed village are assumed to receive a life-time effective dose of about 75 mSv (between 1986 and 2056) from external exposure to caesium radionuclides. The mean value for the villages under study was estimated to be around 65 mSv using the assumed rate of decrease.

Cesium Radioisotopes↗
PubMed2001

Normalisation with coherent scatter signal: improvements in the calibration procedure of the 57Co-based in vivo XRF bone-Pb measurement.

The feasibility of a normalised calibration variable to account for interpatient variability for in vivo 57Co XRF (X-ray fluorescence) finger bone-lead measurements was assessed. Normalising the lead X-ray intensities to the coherent scatter signal was investigated by experiment and Monte Carlo simulation. The X-ray to coherent ratios for a fixed lead concentration were within 5-10% of the mean, within uncertainty, over a physiologically relevant range of finger bone sizes and overlying tissue thicknesses. This is an acceptable level of variation to introduce, as it is less than the uncertainty of a typical in vivo measurement. Normalisation has several advantages compared with the current method of correcting for interpatient variation, as it eliminates the need for transporting extensive equipment to on-site measurements, reduces the subject dose by a factor of two, and increases the objectivity of the bone-Pb assessment.

Bone and Bones↗
PubMed1999

Chelated lead in relation to lead in bone and ALAD genotype.

In order to assess whether lead in bone is available for chelation by 2,3 meso-dimercaptosuccinic acid (DMSA), 21 workers (10 active and 11 retired) from a secondary lead smeltery were studied. A morning urine sample was obtained from all participants, followed by ingestion of 10 mg per kg body weight of the chelating agent DMSA. All urine produced during the following 24 h was collected in consecutive 6- and 18-h portions. Concentrations of lead in blood (B-Pb) and urine were determined by flameless atomic absorption spectrometry (AAS), in plasma (P-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), and in finger bone (Bone-Pb) by K X-ray fluorescence technique (XRF). DMSA-chelatable lead excreted in the 24-h portion correlated well with the excretion in the 6-h portion (U-Pb6h; rs=0.95; P<0.001). U-Pb6h showed a non-linear relationship to B-Pb (rs=0.84; P<0.001) and linear relationships to P-Pb (rs=0. 91; P<0.001) and lead in morning urine (rs=0.95; P<0.001). In active workers, but not in retired ones, P-Pb and U-Pb6h showed some relationship to Bone-Pb. In alternative multiple regression models B-Pb or P-Pb were both significant predictors of U-Pb6h, while Bone-Pb did not significantly improve the models. It can, thus, be concluded that DMSA-chelatable lead mainly reflects lead concentrations in blood, soft tissues, and possibly also trabecular bone. It is not a good index of total body burden and long-term exposure. For such estimations cortical Bone-Pb is more valid, as it contains the major fraction of long-term accumulated lead in the body. Further, the mobilization test did not give better information than measurements of lead levels in blood, plasma, or urine without chelation.

Age Factors↗
PubMed1997

A neurobehavioural study of long-term occupational inorganic lead exposure.

A group of 38 male workers at a secondary smelter (period of employment 2-35 years; median 10 years) was divided into two subgroups depending on bone-lead concentration, arranged as 19 matched pairs according to age, education and job level. The median concentrations for finger-bone lead (Bone-Pb) were 16 vs. 32 micrograms/g; for current blood-lead (B-Pb), 1.6 vs. 1.8 mumol/1; for retrospective peak blood-lead (Peak-Pb), 2.7 vs. 3.0 mumol/1; and for a retrospective cumulative blood lead index (CBLI), 143 vs. 233 mumol/l x months. Nineteen unexposed male workers from a nearby mechanical plant served as controls, using the same matching algorithm. The triplets were examined with a standardised neuropsychological test battery, and four questionnaires for self-rating of symptoms and activity/stress level related to work environment. No sign of behavioural deterioration was observed in the exposed groups, either in objective cognitive tests or in subjective symptom/mood self-rating scales. Despite the limited sample size, the statistical power was sufficient to conclude that a concealed lead-associated effect was unlikely. Covariations between behavioural measures and lead exposure indices were generally low and non-significant, as a whole not exceeding a random level. No confounding or effect-modifying factor was detected that could explain the results as a type II error. To conclude, a current B-Pb of 1.8 mumol/l was not associated with adverse behavioural effects, and a long-term lead exposure around 2.0 mumol/l for 13 years (mean values) was not associated with permanent brain dysfunction.

Adult↗
PubMed1997

In vivo measurements of lead in fingerbone in active and retired lead smelters.

OBJECT: The aim of this study was to determine the bone lead concentration in lead smelters and reference subjects, relate them to the lead concentration in blood (B-Pb) and urine (U-Pb), and to use the measured bone lead to calculate a biological half-life for lead in bone. METHOD AND DESIGN: The lead concentration in the second phalanx of the left index finger (bone-Pb) was determined in vivo using an X-ray fluorescence technique. The study population comprised 89 smelters with a history of long-term exposure to lead (71 active and 18 retired) and 35 reference subjects (27 active and 8 retired) with no known occupational exposure to lead. Bone-Pb was related to the previous lead exposure, estimated as a time-integrated B-Pb (CBLI). RESULTS: The retired smelters had the highest bone-Pb (median value 55 micrograms/g wet weight, as against 23 micrograms/g in active smelters) and 3 micrograms/g in the reference subjects. A strong positive correlation was observed between the bone-Pb and the CBLI among both active (rs = 0.73; P < 0.001) and retired (rs = 0.71; P = 0.001) smelters. The corresponding correlations between the bone-Pb and the period of employment were of the same magnitude. For retired workers, there were positive correlations between the bone-Pb and the B-Pb (rs = 0.58; P = 0.011) and U-Pb. (rs = 0.56; P = 0.02). Multiple regression analyses showed that bone-Pb was best described by the CBLI, which explained 29% of the observed variance (multiple r2) in bone-Pb in active workers and about 39% in retired workers. The estimated biological half-life of bone-Pb among active lead workers was 5.2 years (95% confidence interval 3.3-13.0 years). CONCLUSIONS: The high bone-Pb seen in retired workers can be explained by the long exposure periods, the higher exposure levels in earlier decades, and the slow excretion of lead accumulated in bone. The importance of the skeletal lead pool as an endogenous source of lead exposure in retired smelters was indicated by the associations between the B-Pb or U-Pb, on the one hand, and the bone-Pb, on the other. In active workers, the ongoing occupational exposure was dominant. The in vivo X-ray fluorescence technique is still mainly a research tool, and more work has to be done before it can be used more widely in clinical practice. However, over the next decade we can anticipate retrospective, prospective and cross-sectional epidemiological studies in which bone lead determinations reflecting the previous lead exposure in both occupationally and nonoccupationally lead exposed populations are related to various types of adverse health outcomes. Such studies will improve our knowledge of dose-response patterns and provide data that will have an impact on hygienic threshold limit values and prevention of lead-induced diseases.

Adult↗
PubMed1997

In vivo analysis of cadmium in battery workers versus measurements of blood, urine, and workplace air.

OBJECTIVES: To measure in vivo the cadmium concentrations in kidney cortex (kidney-Cd) and in superficial liver tissue (liver-Cd) of nickel cadmium battery workers, and to compare the results with other commonly used estimates of cadmium exposure (current concentrations of cadmium in blood (B-Cd) and urine (U-Cd)) or repeated measurements of cadmium in workplace air (CumAir-Cd). METHODS: The study comprised 30 workers with a range of duration of exposure of 11-51 years. 13 subjects were currently employed, whereas the other 17 had a median period without occupational exposure of eight years before the measurements. The in vivo measurements were made with an x ray fluorescence technique permitting average detection limits of 30 and 3 micrograms cadmium per g tissue in kidney and liver, respectively. RESULTS: 19 of 30 (63%) people had kidney-Cd and 13 of 27 (48%) had liver-Cd above the detection limits. Kidney-Cd ranged from non-detectable to 350 micrograms/g and liver-Cd from non-detectable to 80 micrograms/g. The median kidney-Cd and liver-Cd were 55 micrograms/g and 3 micrograms/g, respectively. Kidney-Cd correlated significantly with B-Cd (r, 0.49) and U-Cd (r, 0.70), whereas liver-Cd correlated significantly with U-Cd (r, 0.58). Neither kidney-Cd nor liver-Cd correlated with the CumAir-Cd. The prevalence of beta 2-microglobulinurea increased with increased liver-Cd. CONCLUSIONS: Current U-Cd can be used to predict the kidney-Cd and liver-Cd measured in vivo. In vivo measurements of kidney-Cd and liver-Cd were not shown to correlate with the individual cadmium exposure estimates, obtained by integration of the cadmium concentration in workplace air. There may be several reasons for this, including uncertainties in the estimate of the individual cumulative exposures as well as in the in vivo measurements. There was a suggestion of a relation between liver-Cd and tubular proteinuria.

Aged↗
PubMed1995

In vivo XRF analysis of mercury: the relation between concentrations in the kidney and the urine.

The objective of this study was to determine the concentrations of mercury in organs of occupationally exposed workers using in vivo x-ray fluorescence analysis. Twenty mercury exposed workers and twelve occupationally unexposed referents participated in the study. Their mercury levels in kidney, liver and thyroid were measured using a technique based on excitation with partly plane polarized photons. The mercury levels in blood and urine were determined using atomic absorption spectrophotometry. The detection limit for mercury in the kidney was exceeded in nine of the exposed workers, but in none of the referents. The mean kidney mercury concentration (including estimates below the detection limits) was 24 micrograms g-1 in the exposed workers, and 1 microgram g-1 in the referents. The association between mercury in the kidney and in urine was statistically significant, but it was unclear whether the relation was linear. The measurements on liver (n = 10) and thyroid (n = 8) in the exposed workers showed mercury levels below the detection limit. The study shows that it is now possible to measure the mercury concentrations in kidneys of occupationally exposed persons, using in vivo x-ray fluorescence. The estimated concentrations are in reasonable agreement with the limited human autopsy data, and the results of animal studies.

Adult↗
PubMed1995

Lead intoxication caused by skeletal disease.

BACKGROUND: Inorganic lead is accumulated in the skeleton, which harbors more than 90% of the body burden of lead. If rapidly mobilized, this pool may constitute a health risk. However, clear evidence of this theory has been lacking. HISTORY: A previously healthy 36-year-old Swedish man with more than 10 years of work-related lead exposure developed headache, musculoskeletal pain, and paresthesia of both arms. Two months after the cessation of exposure, the lead level in his blood (B-Pb) was 5.5 mumol.l-1, and treatment with chelating agents was started. Shortly after the treatment period, he had an accident causing a fracture of the right collum femoris. The B-Pb was fairly stable around 1.5 mumol.l-1 for about two years after the end of exposure (95th percentile 0.6 mumol.l-1 for occupationally unexposed Swedish men). The examination showed that the patient had high skeletal turnover and clearly reduced bone density, as well as signs of tubular dysfunction. He was given the diagnosis idiopathic osteoporosis. His moderately raised bone lead concentration (about 20 micrograms.g wet weight-1; normal level in Sweden 4 micrograms.g-1) can only partly explain the raised B-Pb, remaining for years after the cessation of exposure. Instead, the main explanation is probably the increased skeletal turnover. CONCLUSIONS: A combination of a moderately increased bone lead pool and skeletal disease seems to increase the risk for lead poisoning.

Adult↗
PubMed1991

Uptake and retention of platinum in patients undergoing cisplatin therapy.

Results of in vivo measurements of the platinum concentration in kidneys and tumours of patients treated with cisplatin for testicular carcinoma, head and neck tumours and brain tumours are presented. The measurements were performed with an x-ray fluorescence technique. Our earlier studies have shown that maximum platinum levels in kidneys were reached 3-4 h after an intravenous injection of cisplatin. The present study showed that, at that time, the ratio between the concentration of platinum in kidney and in blood serum was 22 +/- 7 (+/- 1 S.D.). Between 24 and 72 h after administration this ratio was 10 +/- 3, as shown in another group of patients. Measurements of platinum concentration in brain tumours showed varying maximum uptake, between 14 and 40 micrograms/g, 5-15 h after administration. There was an indication that radiotherapy may increase the uptake of cisplatin in normal brain tissue. The technique described can be used for further studies of the platinum concentration in tumours and risk organs in connection with cisplatin therapy. Such studies are needed to find out how to improve the therapeutic effects and lower the toxic ones.

Adolescent↗
PubMed1990

Experiences in the field of elemental analysis in vivo.

In this paper some radioanalytical methods will be described for assessing the contents of various elements in the human body. In vivo methods are necessary for this problem. Protein content can be estimated by means of in vivo measurements of nitrogen, bone minerals by means of the total body content of calcium. Fat contains a high concentration of carbon. Carbon in fat can be estimated and from this the total body fat can be calculated. Toxic elements such as lead, cadmium and mercury are assessed by in vivo measurements, both related to occupationally exposed workers and to members of the public.

Body Composition↗
PubMed1989

Digital chest radiography with a large image intensifier. An ROC study with an anthropomorphic phantom.

The diagnostic performance of two systems for chest radiography was studied. One system was based on a large image intensifier, the other was a conventional film-screen system. The images from the image intensifier were studied either on a digital TV screen or on 100 mm photofluorograms. Receiver operating characteristic curve analysis was performed on images of an anthropomorphic chest phantom. Low-contrast MMAP (methyl methacrylate polymer) nodules and simulated vessels were positioned over the parenchymal and the mediastinal region of the phantom. Five observers assessed the digital monitor images, photofluorograms, and conventional full-size radiograms. The results showed a significantly superior detectability for the full-size radiograms over the digital monitor images both in the parenchyma and in the mediastinum. No significant difference was found between photofluorograms and digital images.

Humans↗
PubMed1984

Amylase in human milk from mothers of preterm and term infants.

Amylase activity and isoenzyme pattern were determined in preterm human milk from 25 mothers during the first 55 days after delivery and from 25 mothers delivered at term. The diurnal variation in amylase activity and the variation during a feeding were studied in two mothers. There is a high amylase activity in preterm colostrum, which slowly decreases during the first 2 months. The individual variation in amylase activity is considerable. There is no difference in amylase activity in preterm and term human milk. The isoamylase of preterm milk is of the salivary type, just as in term milk. There is no great variation in amylase activity during a feeding or from one feeding to another.

Amylases↗