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Biomedical subjects

O Vesterberg

Publications and source records attributed to O Vesterberg.

At least 37 records · Page 2Linked to original sources

Liver function tests and urinary albumin in house painters with previous heavy exposure to organic solvents.

The serum activities or concentrations of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), alkaline phosphatase (ALP), albumin, gamma-glutamyl transpeptidase (GGT), bilirubin (BIL), cholic acid (CHOL), chenodeoxycholic acid (CHENO), and transferrin with isoelectric point 5.7, and the urinary excretion of albumin were determined among male current or former house painters (n = 135) and house carpenters (n = 71) who had worked in their trades for at least 10 years before 1970. Workers who showed a value above the 90th percentile among the carpenters in at least one of the tests ASAT, ALAT, GGT, BIL, CHOL, or CHENO were regarded as showing "possible signs of liver dysfunction". Each participant's lifetime solvent exposure was evaluated by interview. The painters were divided into categories with low, intermediate, and heavy cumulative exposure during life (LTSE) or during the most exposed year (MEYSE). All participants stated none or slight recent exposure. The prevalence of possible signs of liver dysfunction increased with solvent exposure category according to LTSE as well as MEYSE with a numerically higher risk estimate in the heavy exposure category for MEYSE than for LTSE. ALP activity increased with exposure category according to both exposure estimates. This increase seemed to be due to an interaction between exposure to solvents and current or previous long term intake of medicines potentially toxic to the liver. None of these results was affected by whether or not the subjects had been exposed to solvents during the year before the investigation. The exposure to solvents was not significantly related to any other outcome variable. It is concluded that long term heavy exposure to solvents may elicit changes in conventional liver function tests indicative of a mild chronic effect on the liver. The findings also suggest that heavy solvent exposure during short time periods is a more likely cause of the findings than lifetime cumulative solvent exposure and that an interaction between solvent exposure and medicines potentially harmful to the liver may be important in the causation of the effects.

Aged↗

DMSA administration to patients with alleged mercury poisoning from dental amalgams: a placebo-controlled study.

The present investigation was performed to determine the effect of 14-day oral administration of meso-2.3-dimercaptosuccinic acid (DMSA) on the urinary mercury excretion and the potential reduction of blood and plasma mercury concentrations, and also to relate these effects to possible decrease of symptoms, allegedly associated with amalgam fillings. Twenty subjects, relating their symptoms to mercury from amalgam fillings, received 20 mg/kg DMSA or placebo for 14 days. Their symptoms and mood states were recorded during the study and at a check-up 3 months later. Interpretation was based on intra-individual differences. DMSA-treatment resulted in an average increase in urinary mercury excretion by 65% and a decrease in blood mercury levels of 0.04 microgram/L/day. At the check-up after 3 months, urinary mercury excretion had returned to the pre-treatment level. No treatment effect of DMSA was apparent on subjective symptoms and mood state. One statistically significant treatment effect was noted-a decrease in fatigue-inertia in the DMSA-group-but there was no demonstrable correlation with increased urinary excretion or decreased blood concentration of mercury. Three subjects showed hypersensitive reactions, probably DMSA-specific, at the end of the treatment period. This placebo-controlled study provides no scientific support for diagnostic or therapeutic administration of DMSA for symptoms allegedly associated with chronic mercury exposition from dental amalgam fillings.

Administration, Oral↗

A short history of electrophoretic methods.

High resolution separation of proteins, based on charge differences, is possible with disc electrophoresis, displacement electrophoresis (isotachophoresis) and notably isoelectric focusing (IEF). Size separation is obtained in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The combination of gel IEF, followed by SDS-PAGE in a second-dimensional slab gel, i.e. two-dimensional gel electrophoresis, affords the highest resolution with up to several thousand spots per gel. Staining of proteins gives high resolution patterns which can be scanned and stored in comprehensive databases. Over the last 10 years the electrophoretic separation in gels and subsequent visualization of nucleic acids (DNA, RNA) and even genes as well as nucleotides have been much improved, making possible efficient mapping of the genes in humans and all other organisms. This has led to the biggest concerted endeavor in the history of science, i.e. the mapping of the human genome, which will be of importance as long as mankind exists. In the last years electrophoresis in capillaries has attracted much interest because for numerous substances, such as proteins nucleic acids, pharmaceuticals, metabolites, and peptides, it offers high resolution on the analytical scale with over 1 million theoretical plates. Electrophoretic methods have unprecedented impact on life sciences, providing a basis for unique advances in biochemistry, molecular biology, genetics, gene technology and medicine.

Electrophoresis↗

Electrophoretic analysis of stimulated cat parotid saliva.

The proteins of parasympathetically stimulated cat parotid saliva were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and high resolution two-dimensional electrophoresis (2-DE). SDS-PAGE revealed up to 30 polypeptide bands in microliter volumes of unconcentrated saliva. The patterns were highly reproducible and characterized by prominent bands of M(r) 57,000, M(r) 30,000 and M(r) 15,000. The major protein (M(r) 30,000) appeared as a dimer (M(r) 60,000) when electrophoresed under non-reducing conditions but dissociated into its monomeric form when the SDS concentration of the denatured samples was increased from 1 to 5%. This indicates a noncovalent association. The protein patterns of saliva from different cats differed slightly but sequential samples from the same cat (collected during 90 min of stimulation) showed little change in protein pattern apart from a fall in total protein content. Following 2-DE, the major protein (M(r) 30,000) appeared as a complex array of at least eight spots in two tiers (pI 5.2-6.2; M(r) 28,000 and 32,000). The characteristics of this protein are discussed with reference to allergy to cats.

Animals↗

Apolipoprotein D and alpha 1-microglobulin in human urine: effect of cadmium exposure.

Apolipoprotein D is a previously unrecognized urinary protein of unknown function which we have tested as a potential marker for kidney malfunction. This protein and alpha 1-microglobulin have been quantified by zone immunoelectrophoresis assay in urine samples from a group of eight men occupationally exposed to cadmium-containing welding fumes for many years. All these workers had highly elevated concentrations of urinary cadmium and indications of tubular proteinuria, as compared to a group of 50 apparently healthy normal men analyzed in parallel. The cadmium-exposed workers demonstrated three- and 15-fold average increases in apolipoprotein D and alpha 1-microglobulin, respectively, over normal values in urine, estimated both as excretion rates and as milligrams of protein per mmol of creatinine. All these increments were highly significantly different (P < 0.001) from the corresponding values of the reference group. Essentially the same results were obtained for each of the proteins from two independent consecutive samplings of the workers' urine. There were good linear (R = 0.70, 0.80) and logarithmic (R = 0.84, 0.81) correlations between the urinary concentrations of alpha 1-microglobulin and apolipoprotein D for both the reference and the study group. Although not as sensitive an indicator for tubular proteinuria as alpha 1-microglobulin, apolipoprotein D, being a storage-stable urinary protein, seems a valuable complement for the diagnosis of tubular malfunction.

Adult↗

International project for producing reference values for concentrations of trace elements in human blood and urine--TRACY.

In assessing the concentrations of toxic metals, such as cadmium, chromium, and mercury, in human blood and urine samples to determine whether they are abnormal or not, reliable reference values are needed from populations of nonoccupationally exposed subjects. Numerous publications present concentrations claimed to be typical for the study populations, but they can differ by up to an order of magnitude for a particular element. This is the consequence of general problems that are related to the definition of the reference groups, and the sampling and analytical procedures used, and that make it difficult to define typical and unbiased values. An international group of experts now establishes criteria and procedures to evaluate publications containing information on the concentrations of metals in tissues and body fluids for reference populations. These evaluations have been compiled in a data base (TRACY).

Hazardous Substances↗

The ICOH and IUPAC international programme for establishing reference values of metals.

In cooperation with the ICOH Scientific Committee on the Toxicology of metals and IUPAC Commission on Toxicology, we have developed evaluation criteria for derivation of reference values for metal concentrations in human tissues and fluids. In a first attempt to illustrate how these criteria may be used, tentative reference values for mercury in human blood were derived. For persons who do not eat fish, a mean value of 10 mumol/1 (2 micrograms/1) was suggested. It was pointed out, however, that this value was based on information that did not meet the desired quality requirements, which, unfortunately were not met by any of the published reports.

Animals↗

Kidney effects in long term exposed lead smelter workers.

Occupational exposure to lead may cause kidney damage. This study was carried out on a cohort of 70 active and 30 retired long term exposed lead smelter workers. Their kidney function was compared with 31 active and 10 retired truck assembly workers who had no occupational exposure to lead. The lead workers had been regularly followed up with measurements of lead concentration in blood since 1950. Previous exposure to lead was calculated as a time integrated blood lead index for each worker. Blood and urine samples were obtained from all subjects. The concentration of lead in blood (B-Pb) and urine (U-Pb) was analysed. The urinary concentrations of several sensitive indicators of early tubular (U-beta 2-microglobulin (U-beta 2-m); U-N-acetyl-beta-glucosaminidase (U-NAG)) and glomerular kidney damage (U-albumin) were determined. The B-Pb and U-Pb values were significantly higher among active and retired lead workers compared with their corresponding control groups. The highest concentrations were found among the active lead workers. The concentrations of the parameters of kidney function investigated were of the same magnitude for exposed workers and controls. No clinical signs of renal impairment were found among the workers. No correlations of clinical importance existed between concentrations of U-albumin, U-beta 2-m, and U-NAG activity on the one hand and the concentrations of B-Pb, cumulative blood lead index, U-Pb, and lead concentrations in the calcaneus and tibia on the other, among lead workers and controls. Despite many years of moderate to heavy exposure to lead, particularly for the retired lead workers, no signs of adverse effects on the kidney such as early tubular or glomerular malfunction were found. Reversible changes in kidney function during the 1950s and 1960s could not be excluded, however, due to a greater exposure to lead during that time.

Adult↗

Renal and immunological effects of occupational exposure to inorganic mercury.

Seven parameters of renal dysfunction (urinary excretion of albumin, orosomucoid, beta 2-microglobulin, N-acetyl-beta-glucosaminidase (NAG), and copper; serum creatinine concentration, and relative clearance of beta 2-microglobulin) were examined in a group of chloralkali workers exposed to mercury vapour (n = 89) and in an unexposed control group (n = 75). Serum concentrations of immunoglobulins (IgA, IgG, IgM) and auto-antibodies towards glomeruli and other tissues were also determined. The parameters examined were compared between the two groups and related to different exposure parameters. In the chloralkali group median blood mercury concentration (B-Hg) was 55 nmol/l, serum mercury (S-Hg) 45 nmol/l, and urine mercury concentration (U-Hg) 14.3 nmol/mmol creatinine (25.4 micrograms/g creatinine). Corresponding concentrations for the control group were 15 nmol/l, 4 nmol/l, and 1.1 nmol/mmol creatinine (1.9 micrograms/g creatinine) respectively. None of the parameters of renal dysfunction differed significantly between the two groups, but there was a tendency to increased excretion of NAG in the exposed group compared with the controls. Also, a statistically significant relation existed between U-Hg and U-NAG (p less than 0.001). Serum immunoglobulin concentrations did not differ between the groups, and serum titres of autoantibodies (including antiglomerular basement membrane and antilaminin antibodies) were low in both groups. Thus the results gave no evidence of glomerular damage or of a tubular reabsorption defect at the current relatively low exposures. The findings still indicate slight, dose related tubular cell damage in the mercury exposed group. There were no signs of a mercury induced effect on the immune system.

Acetylglucosaminidase↗

Electrophoresis and silver staining of rat urinary proteins including alpha 2u-globulin (rat n II).

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining have been used to monitor the fractionation of rat urinary proteins by Amicon Centriprep C30/C10 ultrafiltration and to assess the purification of alpha 2u-globulin, a laboratory animal allergen, precipitated by exhaustive dialysis. Factors influencing the protein composition of rat urine have been identified. Dialysis procedures have been evaluated for precipitation of alpha 2u-globulin and ultrafiltration used for further purification of the allergen.

Alpha-Globulins↗

Biological monitoring of environmental and occupational exposure to mercury.

Biological monitoring was used to assess mercury exposure from occupational and environmental sources in a group of chloralkali workers (n = 89) and in a control group (n = 75). In the control group, the median value for blood mercury (B-Hg) was 15 nmol/l, that for serum mercury (S-Hg) was 4 nmol/l and that for urinary mercury (U-Hg) was 1.1 nmol/mmol creatinine. Corresponding levels in the chloralkali group were 55 nmol/l, 45 nmol/l and 14.3 nmol/mmol creatinine, respectively. In the control group, there were statistically significant relationships between fish consumption and both B-Hg and S-Hg values (P less than 0.001), whereas U-Hg correlated best with the individual amalgam burden (P less than 0.01). In the chloralkali group, the mercury levels in blood and urine were significantly related to the type of work (P less than 0.001) but not to the length of employment, to fish consumption or to the quantity of dental amalgam fillings. In both groups there were poor correlations between smoking or alcohol intake and the mercury levels in blood and urine. The results strongly suggest that fish is an important source of methylmercury exposure and that amalgam fillings are probably the most important source of inorganic mercury exposure among occupationally unexposed individuals. In the chloralkali group, mercury exposure from fish and amalgam was overshadowed by occupational exposure to inorganic mercury.

Adult↗

A review of normal concentrations of mercury in human blood.

The present survey is a critical review and quality grading of 98 publications in the international scientific literature presenting mercury concentrations in human whole blood, blood cells and plasma of individuals who have not been occupationally exposed to mercury ("normal values"). Most of the papers reviewed were published after 1976 and were found in the Medline database. Additional information has been obtained in response to requests addressed to scientists with high reputation from different parts of the world working in the field of trace element analysis. The evaluation system includes separate grade scales for sampling and chemical analysis. In no case were the requirements justifying the highest Grade 1 i.e. superior quality, fulfilled. Most reports suffered from various degrees of a lack of information concerning description of individuals, diet, experimental design or analytical and statistical treatment. Nineteen papers were rejected because of insufficient information or obvious erroneous sampling or analytical treatment (Part I). The influence on blood mercury level of various non-occupational exposures, particularly fish consumption, but also medication with mercury-containing drugs, presence of amalgam restorations, etc., has been surveyed. The levels have been systematized according to such parameters. The evaluated and systematized data have been stored in a PC database "Tracy", which includes information about concentrations of total, inorganic or organic mercury in whole blood, blood cells or plasma. Mercury in maternal-cord blood is also included. One hundred and thirty-two data sets from 79 reports were included in the database (Part II). Because of the shortcomings of the available information, only tentative reference values for mercury in whole blood, blood cells and plasma were established (Part III). There is an obvious need for additional high-quality data.

Humans↗

Quantification of apolipoprotein D in human urine by zone immunoelectrophoresis assay: a methodological and clinical study.

A zone immunoelectrophoresis assay (ZIA) has been developed for the quantification of apolipoprotein D (apo D) in unconcentrated native human urine. A standard curve, linear between 1 and 8 mg apo D/l was obtained with ZIA. The relative coefficients of variation for this method were 5-9% (n = 15 x 6) with a mean +/- SD of 7 +/- 1.4% and below 11% (n = 6 x 15) for within-run and between-run reproducibility, respectively. Equal amounts of apo D in unconcentrated and diluted urines, in serum and of the purified protein produced the same zone migration distances indicating parallelism between the immunologic reactions of apo D in different sample matrixes. Storage experiments with normal urines demonstrated good stability of apo D in both acidic and alkalinized urine over at least 2 days at +5 degrees C and during several days at -20 degrees C to -40 degrees C. Using ZIA, urine samples from 50 normal healthy men aged 23-65 years were analyzed for apo D. Mean and SD were: 2.8 +/- 2.1 mg/l, 2.6 +/- 1.8 micrograms/min and 0.24 +/- 0.13 mg/mmol for concentration, rate of excretion and mass/creatinine concentration, respectively.

Adult↗