Biomedical subjects
Publications and source records attributed to L Beckman.
Serum protein markers (Hp, Pi, Bf, C4, C3 and Tf) were studied in 71 patients with ankylosing spondylitis. Significant associations were found with the alpha 1-antitrypsin (Pi) type MZ and with the BfS and C3FS types in female patients.
Serum protein variations were studied in a Liberian population living in Buchanan town. Of the alpha 1-antitrypsin genes only M1 and M3 were polymorphic. The frequencies of the haptoglobin and Gc genes were in accordance with earlier known estimates in African populations. There was, however, a relatively low frequency of Hp 0 which may be related to the low malarial parasite prevalence in this group. The transferrin C2 gene was found in a significantly lower frequency among Liberians compared to European and Asiatic populations. A new transferrin variant was observed by isoelectric focusing. This variant could not be identified with conventional starch or polyacrylamide electrophoresis.
In previous studies, transferrin C2 has been found to be associated with spontaneous abortion, prematurity, phototoxic eczema and rheumatoid arthritis. We have suggested that the mechanism behind these negative effects may be that transferrin C2 increases the risk for damage through hydroxyl radicals. This hypothesis predicts that the C2 frequency should decrease with age. Such an effect is demonstrated in this report. In a population from northern Sweden the C2 gene frequency was found to decrease from 0.173 in newborns to 0.099 in 70-year-old healthy individuals.
The clastogenic effects of arsenic, lead and sulphur dioxide and the protective effect of selenium were studied in short-term lymphocyte cultures. The three agents selected are the major toxic substances in emissions from copper smelters. Cells from non-smoking, healthy individuals were exposed to individual agents and combinations of the four agents (sodium arsenite, lead acetate, sodium sulphite and sodium selenite) and the cells were analysed for chromosome aberrations and sister chromatide exchanges. Selenium showed an antagonistic (protective) effect against the other agents. No synergistic effects were found, and the interactions between arsenic, lead and sulphur dioxide were mainly antagonistic. These rather unexpected findings indicate that mixed exposure from copper smelters, and other mixed exposures where arsenic, lead and sulphur dioxide are involved, may cause less genetic damage than expected and that an adequate dietary supplement of selenium may reduce the genotoxic effects of these agents.
Explore the source record for details and available documents.
In a factory in northern Sweden where 120 workers were uniformly exposed to photoactive substances 73 developed occupational facial eczema while 47 showed no reaction. The workers were examined with respect to 16 genetic marker systems: HLA, blood groups (ABO, Rh, MNSs, P, K, Le and Fy) and serum groups (Hp, Tf, Gc, Pi, Bf, C3, C4 and C6). Between reactors and nonreactors the following differences were found: (1) a significant decrease (p less than 0.05) of HLA A11 among the reactors; (2) a significant increase (p less than 0.05) of the C3 FS type among the reactors; (3) a highly significant increase (p less than 0.001) of the transferrin C2 gene and of the C2 variant among the reactors. The association with Tf C2 remained significant also after correction for number of significance tests. Since transferrin (iron) is known to catalyze the formation of hydroxyl radicals we hypothesize that the Tf C2 variant is more efficient in promoting radical formation and thereby cell damage. Other results supporting the notion that transferrin C2 may be associated with an increased susceptibility to toxic damage are discussed.
The complement factor C4 was studied in 165 schizophrenic patients and in 330 controls. A highly significant increase in the frequency of C4B deficiency (BQO) was found among the schizophrenic patients compared with controls (p less than 0.0005).
Bf and C3 complement types were studied in 100 male and 100 females patients from northern Sweden with erosive rheumatoid arthritis (RA) and compared with population controls. A significantly decreased frequency of the Bf FS phenotype was found particularly in males and in patients with a family history of polyarthritis. Significant Bf associations were also found with a more severe form of RA (functional classes III and IV) and with high titers of the rheumatoid factor. No significant difference with respect to C3 phenotype and gene frequencies was found between RA patients and controls. Thus, the association between RA and C3F found in some previous investigations was not confirmed.
C3 and C6 complement types were studied in schizophrenic patients and controls. The distributions of the three common C3 types (F, FS and S) among the patients was significantly different from that in the controls (p less than 0.005) and the frequency of the C3F gene was significantly increased (p less than 0.0005) among the patients. There were no significant differences in C6 gene or phenotype frequencies between patient and controls.
Transferrin C subtypes were studied in patients with rheumatoid arthritis (RA) and controls. A significant association was found between the C2 type and RA. This association concerned mainly male patients and patients with a family history of polyarthritis. The results were discussed in relation to previous studies of the role of oxygen free radicals in the pathogenesis of RA and to a recently proposed hypothesis that the TfC2 gene confers an increased risk for cellular damage by hydroxyl radicals.
Frequencies of alpha-1-antitrypsin (Pi) phenotypes were studied in 100 female and 100 male Swedish patients with classical rheumatoid arthritis and compared with the population frequencies. A significant increase of rare Pi types (MS, MZ, MF and SZ) was found among the patients. However, the increase concerned mainly Z heterozygotes and was more strongly pronounced in male patients. The M-subtypes showed no association with rheumatoid arthritis. Previous investigations of Pi types in rheumatoid arthritis have shown somewhat variable results. The results so far indicate, however, that an association between the Z allele and rheumatoid arthritis is likely to exist, while the evidence for a relationship between rheumatoid arthritis and other Pi alleles is considerably weaker.
Frequencies of blood groups (ABO, Rh, MNSs, P, Kell, Lewis and Duffy) and HLA antigens were studied in a series of patients from northern Sweden with abdominal aortic aneurysms. The following significant differences from the controls were found: a decreased frequency of the Rh-negative blood group and increased frequencies of the Kell-positive and MN blood groups. Previously reported associations with the ABO and Rh systems were not confirmed.
Chromosomal aberrations in lymphocytes were studied in patients with untreated cancers of the lung and skin (basal cell carcinoma) and in controls matched for sex, age, and smoking habits. Patients with skin cancer were found to have a significantly increased rate of chromosome type aberrations. Among the patients with lung cancer, there was a tendency towards an increased rate of aberrations which, however, did not reach statistical significance. The results suggest that an increased rate of chromosomal aberrations in cultured lymphocytes is an indicator of genetic damage which may increase the cancer risk.
Chromosomal aberrations were studied in lymphocytes of 15 workers exposed to styrene and 13 controls. The average styrene concentration in the work room air was 24 ppm, and the levels of urinary mandelic acid were below 2 mmol/l. No significant increase in the rates of gaps and breaks was found. However, the rate of micronuclei was significantly increased, which indicates that the mitotic spindle mechanism may be more sensitive to styrene and its metabolites than DNA.
Alpha-1-antitrypsin (alpha 1-AT) phenotypes and serum levels were measured in 518 employees at a sulphite pulp factory. There were 439 men and 79 women with the mean age of 42 years (range 18-65 years). Mean time of employment at the factory was 17.5 years and 216 (42%) individuals had been employed for more than 20 years. Chronic bronchitis was present in 47 (9.1%) individuals. alpha 1-AT rare types (MZ, MS, MF) were present in 12.8% of the individuals with chronic bronchitis compared to 8.4% in employees with no respiratory symptoms, the difference being not statistically significant. Individuals with chronic bronchitis and rare types were evenly distributed with regard to work place at the factory. Serum levels of alpha 1-AT were somewhat higher in smokers compared to non-smokers, but the difference was not statistically significant. Exposure to SO2 and chlorine did not seem to affect the serum levels of alpha 1-AT in M type individuals. In the present study, individuals heterozygous for alpha 1-AT deficiency phenotypes (MZ, MS, MF) did not seem to have an increased rate of chronic bronchitis. However, the rate of chronic bronchitis in factory employees was significantly increased compared to that among non-employees in the surrounding community. This increase appears to be due to a higher rate of smoking and to occupational exposure (SO2 and chlorine) among the sulphite pulp factory workers.
Explore the source record for details and available documents.
Frequencies of the Duffy blood groups were studied in 222 Swedish Lapps and in a series of 3,151 Swedish conscripts and blood donors from the counties of Norrbotten and V asterbotten in northern Sweden. The conscripts and blood donors were distributed according to place of birth into 23 subpopulations. The frequency of the Fya gene among the Lapps was significantly higher than that in the Norrbotten and V asterbotten populations. The inbreeding coefficient FST for northern Sweden was found to be 2.8 . 10(-3) and significant (p less than 0.05). The Fya gene frequency in V asterbotten county was significantly higher than that in Norrbotten county. The overall picture of geographical variation of the Fya gene was not explainable in terms of Lappish and Finnish influence, it was rather contrary to the expected ethnic influence. The reason for this discrepancy is discussed.
The haptoglobin groups were studied in a material of 4,333 conscripts and blood donors from the counties of Norrbotten and V asterbotten in northern Sweden. According to their place of birth, the individuals were distributed into 23 subpopulations. In all subpopulations a good consistency with the Hardy-Weinberg equilibrium was found. In contrast to this finding, patients from the same population with immunogenetic disorders (psoriasis, allergy) were found to have a significant deficiency of heterozygotes. The frequency of the Hp1 gene showed significant variations between subpopulations (from 0.24 to 0.45) and the FST in V asterbotten county was high (9.0 x 10(-3)). The variations were, however, not interpretable in terms of ethnic heterogeneity. The results indicate that random processes, most likely 'the four effect', have had a profound effect on the structure of the North-Swedish population.