Biomedical subjects
Publications and source records attributed to L Beckman.
Individual differences with respect to the sneezing reflex are described. Visual exposure to strong light may induce a sneezing reaction in about 20% of the individuals in the Swedish population. Preliminary data indicate that the ' sneezer trait' may be inherited in an autosomal dominant fashion. The eventual selective advantage of ST is discussed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Frequencies of the MN blood groups were studied in a material of 3,312 conscripts and blood donors from the counties of Norrbotten and Västerbotten in northern Sweden. The individuals were distributed according to place of birth into 23 subpopulations. The frequency of the M gene was significantly higher in Norrbotten county than in Västerbotten county. The overall picture of geographical variation was, however, not explainable in terms of Lappish and Finnish influence. In Västerbotten county a significant departure from the Hardy-Weinberg equilibrium (excess of heterozygotes) was found. The inbreeding coefficient FST was found to be high (5.3 . 10(-3)) and significant (p less than 0.001) in Västerbotten county, but low (1.2 . 10(-3) and statistically not significance in Norrbotten county.
Haemoglobin variants, beta-thalassaemia and glucose-6-phosphate dehydrogenase (G-6-PD) types were studied in 702 individuals from Buchanan, Liberia. In this population haemoglobins S and C, beta-thalassaemia and G-6-PD deficiency were found together. There was a considerable tribal variation. In the tribes of eastern Liberia the S- and C-genes were uncommon and the beta-thalassaemia gene was rather frequent, while in western Liberia the S- and C-genes were more frequent and beta-thalassaemia uncommon. In the central and northern parts the S- and beta-thalassaemia genes were found together in relatively high frequencies. The rate of malaria infection was found to be lower in individuals with the sickle cell and beta-thalassaemia traits than in individuals with haemoglobin AA, but the difference was not statistically significant. The frequency of the delta-chain gene B2 was 1.4% in the total material and there was no significant tribal variation for this gene. The frequency of G-6-PD deficiency estimated in males was 16%.
Cultured human lymphocytes were exposed to trivalent (NaASO2) and pentavalent (Na2HAsO4) arsenic in concentrations comparable to the arsenic levels found in the urine of copper smelter workers. Significantly increased frequencies of chromosome aberrations (gaps, chromatid breaks, chromatid exchanges and chromosome breaks) were found after exposure to trivalent but not pentavalent arsenic. This effect was not found when nonstimulated (GO) lymphocytes were exposed to trivalent arsenic and then cultured. The rate of sister chromatid exchanges was also found to be increased after exposure to trivalent arsenic. Thus results suggest that trivalent arsenic is more genotoxic than pentavalent arsenic and that arsenic exerts its effect mainly during cell division.
A study was made of chromosome aberrations in cultured lymphocytes from a group of 14 miners exposed to diesel exhausts and a reference group of office employees and construction workers. No increased frequency of chromosomal aberrations was observed. The frequency of chromosomal aberrations (both gaps and breaks) was, however, found to be associated with smoking.
A previous study of patients with allergic contact dermatitis yielded results which supported the hypothesis that the presence of certain HLA antigens led to a predisposition to allergen-specific reactions and others to multiple contact sensitivity. The present study was performed to test this hypothesis. 129 patients sensitive to one allergen only (either chromium, nickel, formalin or balsam of Peru) and 83 patients sensitive to two or more allergens were HLA typed regarding the A and B loci. A series of 368 persons matched with regard to sex, age and place of residence were used as controls. A tendency towards an association between HLA B7 and contact allergy was observed. No other data confirming the hypothesis mentioned above were obtained. Among 37 patients who also had atopic diathesis a decreased frequency of HLA B7 was found.
In an epidemiological study of schizophrenia in a North Swedish isolate, Böök et al. (1978) reported an association between schizophrenia and the genetic marker Gc2. In an attempt to confirm this observation, we examined a series of schizophrenic patients from Västerbotton County in Northern Sweden. In our material there was no difference between schizophrenic patients and controls with respect to the frequencies of Gc groups or genes. A reanalysis of the material by Böök et al. (1978) showed that schizophrenics compared to controls had a significant increase in the frequency of the Gc 2-1 group, but not of the Gc2 gene. The Gc distribution in the material by Böök et al. (1978) was similar to that previously reported by us in a series of patients with cycloid psychosis.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Individuals with heterozygous Pi M subtypes were found to have higher serum levels of alpha 1-antitrypsin (alpha 1-AT) than homozygotes. The alpha 1-AT levels in heterozygotes showed a unimodal distribution. Among homozygotes, a tendency towards a bimodal distribution was found. The mechanism behind this difference is not known. The result can apparently not be explained as the result of a hitherto undiscovered deficiency gene.
By means of isoelectric focusing the alpha 1-antitrypsin phenotypes were examined in 1,869 Swedes from northern Sweden, 300 Finns and 217 Swedish Lapps. The M2 frequency was low among the Lapps and in the northeastern part of Sweden. The frequencies of the S and Z genes were low in the Lapps and in the north-Swedish population. The frequencies of rare phenotypes among Finns from northern Finland were significantly higher than among Finns from southwestern Finland and Aland Islanders.