Biomedical subjects

B Akerström

Publications and source records attributed to B Akerström.

76 records · Page 5Linked to original sources

PubMed1979

Occurrence of beta 2-microglobulin in mammalian lymphocytes and erythrocytes.

Cell-associated beta 2-microglobulin (beta 2m) has been studied by quantitative techniques in lymphocytes and erythrocytes of guinea pig, rabbit, rat and man. beta 2m was solubilized by sonication followed by treatment with acid, deoxycholate or thiocyanate, and then determined by radioimmunoassay. The average number of beta 2m molecules per lymphocyte, estimated after acidification, varied between 0.89 X 10(5) and 7.1 X 10(5). Rat erythrocytes contained 3.0 X 10(3) molecules per cell, whereas no beta 2m was detected in red blood cells from the three other species. A relatively large part of beta 2m in the mammalian lymphocytes and in rat erythrocytes was present on the cell surface according to a radioimmunoassay procedure using anti-beta 2m antisera that had been absorbed with the blood cells analyzed.

Animals↗

PubMed1979

In search of alpha 1-microglobulin on the lymphocyte surface.

alpha 1-Microglobulin was found by immunofluorescence not to be associated with human lymphoid and nonlymphoid cell lines. No accumulation of alpha 1-microglobulin was detected in culture media of these cell lines. A weak membrane fluorescence with anti-alpha 1-microglobulin on peripheral lymphocytes could not be blocked by the purified protein. No release of alpha 1-microglobulin into the growth medium was seen by normal cultured leukocytes. Treatment of normal lymphocytes, erythrocytes, and various cell lines with solubilization techniques did not yield any alpha 1-microglobulin. alpha 1-Microglobulin and protein HC display immunologic and biochemical identity. However, anti-protein HC stained almost all of the tested cell lines and normal lymphocytes. Blocking experiments with the purified protein were not successful. Antibodies reacting with a minor impurity (50,000 d) in the alpha 1-microglobulin or protein HC preparations could be absorbed from anti-alpha 1-microglobulin with normal leukocytes and a lymphoid cell line.

Absorption↗

PubMedDate not supplied

Binding properties of protein Arp, a bacterial IgA-receptor.

A cell surface receptor that binds to the Fc region of IgA is expressed by certain strains of group A streptococci. The physico-chemical properties and binding characteristics of this receptor, called protein Arp, were studied. Like bacterial receptors that bind IgG, protein Arp has an elongated shape and no disulfide bonds. The affinity constant of protein Arp for three different molecular forms of IgA was determined, and was found to be more than ten-fold higher for serum IgA than for two complexed forms of IgA: secretory IgA and IgA bound to alpha 1-microglobulin. Cleavage of protein Arp with CNBr resulted in a peptide corresponding to the region located outside the cell wall, except for the N-terminal 52 amino acids. This CNBr-fragment did not bind IgA, which strongly suggests that the IgA-binding region of protein Arp is located in the N-terminal part of the molecule. In addition to the binding of IgA, protein Arp also binds to IgG weakly. The pH-dependence of these two types of binding is different, with maximal binding of IgA at neutral pH (5-7) and maximal binding of IgG at acidic pH (3-5). Both for IgA and IgG, protein Arp shows strong specificity for immunoglobulins of human origin.

Bacterial Proteins↗

PubMedDate not supplied

Association of the haptoglobin phenotype (1-1) with falciparum malaria in Sudan.

The haptoglobin phenotypes of Sudanese patients with complicated and uncomplicated falciparum malaria, and those of uninfected randomly selected individuals, were determined by electrophoresis of sera on polyacrylamide gels followed by benzidine staining of the gels. Among 273 malaria patients, the proportions with haptoglobin phenotypes (1-1), (2-1) and (2-2) were 60.8%, 29.7% and 9.5%, respectively, and in 72 cerebral malaria patients the proportions were 63.9%, 29.2%, and 6.9%. The distribution among 208 control individuals was 26.0%, 55.8% and 18.3%, respectively. The difference between patients and controls was highly significant (P < 0.001). The distribution of the different haptoglobin phenotypes among the randomly selected group of 208 Sudanese individuals was comparable to that in many other populations. The results suggests that the haptoglobin phenotype (1-1) is associated with susceptibility to falciparum malaria and the development of severe complications; alternatively, the other phenotypes may confer resistance.

Adult↗