Biomedical subjects

O Vesterberg

Publications and source records attributed to O Vesterberg.

At least 55 records · Page 3Linked to original sources

PubMed1991

Haematological changes in house painters using epoxy paints.

Haematological parameters, iso-transferrin ratio in plasma and serotonin uptake in platelets were studied in 10 men (age range 21-54 years) with occupational long-term, low level exposure to vapours from epoxy paints. The control group consisted of 10 healthy men (age range 20-48 years) not occupationally exposed to chemicals or organic solvents. The mean cellular volume of erythrocytes was significantly higher for the house painters than the controls (p less than 0.05). The plasma concentration of iso-transferrin with isoelectric point 5.7 (Tf5.7) and the ratio between Tf5.7 and total transferrin (Tftot) were significantly higher in the exposed group (p less than 0.05). The uptake of serotonin in platelets (Vmax) from the exposed workers was significantly lower than the values for the controls (p less than 0.01). The results indicate an association between the observed biological effects and the chemical exposure, and we speculate that this is caused by changes in structure and function of the cell membranes.

Adult↗

PubMed1991

Identification of human blood plasma and serum proteins in two-dimensional gels by use of protein A-Sepharose: application to alpha 1-microglobulin.

The relative position identification of some of the proteins in human blood plasma and serum after separation by two-dimensional electrophoresis (2-DE) in gel slabs have been studied. Antibodies specific to the protein to be identified were first immobilized on Protein A-Sepharose. Serum or plasma samples devoid of this protein were obtained following adsorption and subsequently the protein itself was eluted. The preparations were examined by 2-DE, silverstaining and blotting with parallel analysis of the purified proteins. Position identification in 2-DE gels of the spots of alpha 1-microglobulin (= protein HC) is shown as an example. The technique has general applicability not only for identification of the positions in 2-DE gels of serum and plasma proteins but also for proteins in other fluids, tissues and organs from humans and other species.

Alpha-Globulins↗

PubMed1990

Increased isotransferrin ratio and reduced erythrocyte and platelet volumes in blood from thermoplastic industry workers.

Ten women (aged 31-61 years) and five men (aged 20-59 years) occupationally exposed to welding fumes of polyacetate containing diethylphthalate in a thermoplastic industry were studied. They had been employed 1-33 years (median: 11 years). Seven women (aged 35-55) and eight men (aged 26-73) acted as unexposed controls. The exposed persons showed increased isotransferrin ratio in blood serum and reduced volumes of erythrocytes and platelets in blood.

Adult↗

PubMed1990

On the possibility of differential diagnosis at elevated erythrocyte sedimentation rate by analysis of the concentrations of blood plasma proteins--a model study.

An elevated erythrocyte sedimentation rate is generally regarded as an unspecific and mostly pathological indicator of inflammation or tumour. However, we have determined the concentrations of plasma/serum proteins that influence the erythrocyte sedimentation rate in numerous samples from several groups of patients with different diseases, including 2 forms of cancer. Equations have been developed by which the 1 h value of erythrocyte sedimentation rate can be expressed as the sum of disease-specific coefficients for each protein multiplied by the measured concentrations of the respective proteins. These equations are shown to be disease-specific with 64-93% probability. Such equations may thus form the basis for differential diagnosis.

Adult↗

PubMed1989

History of electrophoretic methods.

Electrophoresis is the migration of electrically charged particles or ions in solutions due to an applied electric field. The ability to separate very similar substances including different proteins for analytical and preparative purposes has increased, especially since 1950, owing to the introduction of zone electrophoresis in paper and later in gels of polyacrylamide or agarose. After 1960, disc and displacement electrophoresis (isotachophoresis) and isoelectric focusing offered much increased resolution. Electrophoretic methods nowadays promote advances in biochemistry and molecular biology and will continue to be very important in science and for numerous applications in genetics, gene technology, sequencing of nucleic acids and proteins, studies of diseases and malfunctions including cancer, and in the identification of species and individuals, e.g., in forensic medicine.

Electrophoresis↗

PubMed1989

The N-acetylneuraminic acid content of five forms of human transferrin.

Five isoforms of human serum transferrin were separated by isoelectric focusing and their N-acetylneuraminic acid content was determined. The forms differed in isoelectric point by about 0.1 of a pH unit with the structural differences situated in the carbohydrate parts. Each form had one sialic acid molecule (NANA) less than the next most acidic form. GLC-MS showed that the most abundant form with isoelectric point 5.5 had two two-branched carbohydrate chains, each having the galactoses covered by terminal sialic acid. The form with isoelectric point 5.4 had one three-branched and one two-branched carbohydrate chain, and all branches terminated with a sialic acid residue. The form with isoelectric point 5.6 had a terminal galactose on one of its two two-branched carbohydrate chains. Comparison of the sialic acid content of the five transferrin forms and their carbohydrate structures showed that some of the forms expose terminal galactose without attracting the asialoglycoprotein receptors on hepatocytes.

Carbohydrate Sequence↗

PubMed1989

Urinary excretion of chromium in chromeplaters after discontinued exposure.

In a previous study [Lindberg and Vesterberg, 1983a], excretion of chromium in urine (U-Cr) in chromeplaters was proposed for biological monitoring of ongoing exposure. Published reports were found about the decline of U-Cr after discontinued exposure in welders working in chromium-alloyed stainless steel, but not in chromeplaters. In this study, half-times (t1/2) were calculated for ten chromeplaters over a weekend, and for 23 chromeplaters over 31 days vacation. The results suggest that the excretion of chromium can be approximated to a two-compartment model. Estimated from the median values, an initial rapid phase with an assumed t1/2 of 2-3 days is followed by a phase with a t1/2 of approximately a month. Differences between the decline of U-Cr in chromeplaters and welders are discussed.

Chromates↗

PubMed1988

Concentration differences in isoforms of transferrin in blood from alcoholics during abuse and abstinence.

At least five different forms of iron-saturated transferrin (Tf) from blood plasma can be separated by isoelectric focusing. These transferrin forms differ in the carbohydrate parts, especially the amount of sialic acid. The increased relative concentration of the form with isoelectric point 5.7 (Tf5.7) has been shown to be a good indicator for liver effects caused by alcohol abuse. However, in alcoholics during abstinence the newly formed transferrin has a higher sialic acid content than most of the transferrin already present in the blood. This indicates that the elevated concentration of Tf5.7 with a low sialic acid content, found in alcoholics is not due to a defect at sialylation, but most probably caused by an impaired uptake of sialic acid-deficient transferrin by the hepatocytes due to membrane dysfunction.

Adult↗

PubMed1988

Rat liver cytosolic protein changes after ethanol exposure studied by two-dimensional electrophoresis.

Rats were fed liquid food containing ethanol in concentrations ranging from 1-5% for 13 weeks. Livers were removed for histopathology and the liver cytosolic protein fraction was prepared and used for two-dimensional gel electrophoresis (2D-PAGE). Polypeptides were visualized by silver staining. Scanning was made for estimation of the relative abundance of protein in each polypeptide spot in the gels and for comparison between rats. Visual inspection and scanning of gels with the stained polypeptide spots obtained after equilibrium isoelectric focusing and non-equilibrium pH gradient electrophoresis revealed that: 1) within the control rat and ethanol-treated rat livers the numbers of polypeptide spots detected using isoelectric focusing in the first dimension were approximately 500 and for non-equilibrium pH gradient electrophoresis 400; 2) in the control group the variation in the estimated amount of protein in each spot was remarkably small; 3) pronounced differences in the relative abundance of protein in several of the spots was observed in the ethanol-exposed rats as compared to controls. Dose-response relations and possible causes for the effects of ethanol are discussed.

Animals↗

PubMed1988

Biological exposure limits estimated from relations between occupational styrene exposure during a workweek and excretion of mandelic and phenylglyoxylic acids in urine.

Styrene exposure of 18 workers in fiberglass reinforced plastic industries was measured for 30-min periods throughout each workday for a week. The styrene uptake was estimated using pulmonary ventilation measurements. All urine voidings were collected separately and the styrene metabolites, mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined. The relationship between both exposure and uptake versus excretion of these metabolites was studied. Styrene metabolite concentrations and excretion rates (with 95% tolerance limits) were calculated to correspond to a constant 8-h exposure at the Swedish exposure limit level (25 ppm) or an uptake of an exposure limit related styrene dose (6.3 mmol). The tightest tolerance limits were obtained for excretion rate of MA + PGA per 24 h. The calculated biological exposure limit was 3.4 (+/- 0.7) mmol MA + PGA/24h for a dose of 6.3 mmol styrene.

Air Pollutants, Occupational↗

PubMed1987

Differences among five main forms of serum transferrin.

Five forms of human serum transferrin with different isoelectric points were purified by isoelectric focusing in agarose gels. They constitute a set of main transferrin forms in serum of healthy individuals. Their relative proportions are changed in serum from alcoholic individuals, where the more basic of these forms are increased. Tryptic peptides of all forms were compared by high performance liquid chromatography (HPLC) patterns (fingerprint analysis). Two major differences were detected between corresponding tryptic peptides of the five transferrin forms. Some minor differences were also noticed. The corresponding peptides were purified from the main form and analyzed for total composition and amino acid sequence. The peptides with the major differences between the forms were found to be the two with the glycosylation attachment at positions 413 and 611. A minor peptide difference between the transferrin forms contains a product that is explained by incomplete stoichiometry in cleavage of the peptide bond at positions 217-218. Successive loss of sialic acid is compatible with the presence of different transferrin forms, and our results indicate that the main differences between the serum transferrin forms from healthy and alcoholic individuals are in successive changes of the carbohydrate chains attached at positions 413 and 611.

Amino Acid Sequence↗

PubMed1987

Studies of transferrin in serum of workers exposed to organic solvents.

Earlier studies have shown that determination of the serum concentration of different forms of transferrin (isotransferrins) may be used to detect hepatic effects caused by alcohol abuse. The isotransferrin variant with an isoelectric point of 5.7 has been compared with the total amount of serum transferrin in order to study hepatic effects caused by occupational exposure to organic solvents. Eighteen workers from a paint industry were tested before and after their holiday and compared with two different groups, a total of 60 subjects. The solvent workers had significantly higher values both before and after their holiday. This suggests that the effects on the liver caused by organic solvents are similar to those caused by alcohol abuse and that this is a long term effect. The level of exposure to organic solvents was below the Swedish threshold limit values.

Adult↗

PubMed1986

Quantification of human serum apolipoprotein A-I by zone immunoelectrophoresis assay and a procedure for the preparation of an A-I standard.

A zone immunoelectrophoresis assay (ZIA) for human serum apolipoprotein A-I (Apo A-I) is described. In this immunologic technique, glass capillaries filled with agarose gel containing anti-Apo A-I are used. Apo A-I produces zones of immunoprecipitates with migration distances directly proportional to the apolipoprotein concentration. Two plasmas and their isolated high density lipoprotein (HDL) fractions, having different particle size distribution patterns have been analyzed for Apo A-I using rocket electroimmunoassay in parallel with ZIA. A good agreement between the two methods was obtained. With ZIA, Apo A-I complexed with lipids in HDL yielded concentration values that were unaffected by lipoprotein particle size and by delipidation. A standard curve, linear between 0.5 and 3.5 mg Apo A-I/1, was obtained with ZIA. A protocol for the preparation of an Apo A-I standard without prior purification of the apolipoprotein is presented. Using ZIA, 75 serum samples representing a heterogeneous study population were analyzed for Apo A-I. A mean value of 1.23 g/l with a relative standard deviation of 28% was obtained. The corresponding mean for total HDL cholesterol was 1.64 mmol/l (RSD = 61%).

Apolipoprotein A-I↗

PubMed1986

Trichloroacetic acid accumulates in murine amniotic fluid after tri- and tetrachloroethylene inhalation.

The distribution of trichloroethylene (Tri) and tetrachloroethylene (Tetra) and their metabolites have been studied in pregnant mice by means of whole-body autoradiography (14C-labelled Tri and Tetra) and gas chromatography, with special emphasis on possible uptake and retention in the foetoplacental unit. Volatile (non-metabolized) activity appeared at short intervals after a 10 min. or 1 hr inhalation period in foetus and amniotic fluid. Most notable, however, was a strong accumulation and retention (peak at 4 hrs) in amniotic fluid of the metabolite trichloroacetic acid (TCA) after inhalation of either of the solvents. The main metabolite of Tri, trichloroethanol (TCE) (or conjugates), did not accumulate specifically as compared to maternal plasma. TCA infused intravenously in the maternal plasma was accumulated in amniotic fluid, but less pronounced than after Tri and Tetra inhalation, indicating that some metabolism of Tri and Tetra to TCA may occur in the foetoplacental unit. The results suggest that TCA may be transported to the foetus partly paraplacentally through foetal membranes and amniotic fluid, with the possibility of foetal swallowing or absorption through the skin. Foetal urinary activity also suggests that circulation between foetus and amniotic fluid may contribute to the long-term retention in the foetoplacental unit. In the mother, after inhalation exposures, and in intraperitoneally injected newborn mice, non-extractable radioactivity was found in the respiratory tract, liver, and kidney, indicating binding to these organs through metabolism.

Amniotic Fluid↗

PubMed1985

beta 2-Microglobulinuria among workers previously exposed to cadmium: follow-up and dose-response analyses.

Sixty workers (58 males, 2 females) who had previously been exposed to cadmium in connection with the use of cadmium-containing solders were examined. Exposure times ranged from 4 to 24 years. For each worker a cumulative cadmium dose estimate was calculated. This ranged from 0.35 to 9.9 mg/m3 X year. The prevalence of slight (U-beta 2 greater than 0.034 mg/mmole creatinine) and more pronounced (U-beta 2 greater than 0.1 mg/mmole creatinine) beta 2-microglobulinuria in the whole group was 40% and 23%, respectively. The prevalence of beta 2-microglobulinuria was strongly related to the cumulative dose estimate and to urinary cadmium level. Among workers with a cumulative dose estimate below 1 mg/m3 X yr there were only a few cases with slight tubular proteinuria, whereas for workers who had a cumulative dose estimate exceeding 3 mg/m3 X yr the prevalence of slight and pronounced beta 2-microglobulinuria was 77% and 54%, respectively. There was no significant relationship between the concentration of beta 2-microglobulin in serum and urine. This indicates that the beta 2-microglobulinuria is due to tubular damage and is not secondary to an increased endogenous production. Repeated examinations of 19 workers between 1976 and 1983 revealed that in almost all cases the beta 2-microglobulinuria was irreversible.

Adult↗

PubMed1985

Assessment of renal function in workers previously exposed to cadmium.

Cadmium induced renal effects were examined in 60 workers (58 men, 2 women) previously exposed to cadmium. Tubular damage in the form of beta 2-microglobulinuria was found in 40%, and urinary albumin and orosomucoid increased significantly with increasing urinary cadmium and increasing relative clearance of beta 2-microglobulin. It is suggested that increased albumin excretion is secondary to the tubular damage. In no case was typical glomerular proteinuria found that could be related to cadmium. Histories of renal stones were more common among the workers with high urinary cadmium concentrations. The glomerular filtration rate was measured in 17 of the workers who had pronounced tubular dysfunction. The average glomerular filtration rate for these men was less than the age adjusted predicted value (mean = 84%). Furthermore, there was a significant (p less than 0.05) correlation (r = -0.47) between tubular reabsorption loss and a decreased glomerular filtration rate.

Adult↗

PubMed1985

Plasma apolipoprotein pattern in fish-eye disease examined by high-resolution two-dimensional electrophoresis.

We compared the plasma protein patterns of the two living patients suffering from fish-eye disease with those of appropriate controls, using high-resolution two-dimensional electrophoresis. Quantitative abnormalities were detected in plasma polypeptides corresponding to the isoforms of apolipoproteins A-I and A-II. The disease was characterized by normal concentrations of proapo A-I but dramatically subnormal concentrations of the other apo A-I isoforms and apo A-II. No significant difference was detected in the concentrations of other plasma proteins. These findings are discussed in relation to other apolipoprotein disorders.

Apolipoprotein A-I↗

PubMed1984

Increased concentrations of a transferrin variant after alcohol abuse.

Isoelectric focusing in agarose gel has been used for separation of different molecular forms of transferrin (Tf) in sera and plasma from alcoholics and controls. One special form of transferrin with isoelectric point 5.7 (= Tf5.7) was quantified by using zone immunoelectrophoresis assay (ZIA). This method was also used for quantification of total transferrin (Tftot). Significant differences in the ratio Tf5.7/Tftot between the groups were obtained and the diagnostic sensitivities, specificities and predictive values of positive tests were 100, 97, 93.8%, respectively. Thus the results showed that this principle seems to be much better for detection of alcoholic abuse than currently used assays as gamma-glutamyltransferase, etc. Samples taken on days following hospitalization showed that the Tf5.7 values decreased over a two-week period of abstinence. Possible explanations for the abnormal quotient after ethanol abuse are discussed.

Adult↗