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Biomedical subjects

I Olsson

Publications and source records attributed to I Olsson.

At least 145 records · Page 8Linked to original sources
PubMed1981

Characterization of mononuclear blood cell-derived differentiation inducing factors for the human promyelocytic leukemia cell line HL-60.

A search was made for physiologically produced differentiation inducing factor(s) (DIF) for the human promyelocytic leukemia cell line HL-60. Mononuclear blood cells, when stimulated with various mitogens, produced DIF, which induced differentiation of HL-60 into phagocytizing nitro blue tetrazolium reducing cells with the morphologic characteristic of granulopoietic or myelomonocytic cells. Induction of differentiation occurred equally well in serum-containing and serum-free media. Protein synthesis was necessary for elaboration of DIF, which seems to be of a protein nature inasmuch as it is destroyed by proteases. Gel chromatography showed that one or two species of DIF with apparent molecular weights of 40,000 and 25,000 were produced, depending on the type of mitogen used. At least the 40,000-molecular weight DIF was distinct from the colony stimulating activity (CSA), which was produced simultaneously. Our results suggested a role of lymphocytes and/or monocytes for modulation of myelomonocytic hematopoiesis not mediated by CSA. The physiologic importance remains, however, to be demonstrated.

Cell Differentiation↗
PubMed1980

N-acetoxy-2-acetylaminofluorene induced unscheduled DNA synthesis of granulopoietic precursor cells in chronic myeloid leukemia.

Studies on N-acetoxy-2-acetylaminofluorene (NA-AAF) induced unscheduled DNA synthesis (UDS) of granulopoietic cells were performed in patients with chronic myeloid leukemia (CML). Sequential studies were carried out in some patients. Both biochemical and autoradiographic methods demonstrated that [3H]dT was incorporated into nonreplicating DNA of immature granulopoietic cells after NA-AAF damage and the 2 methods significantly correlated to each other (r = 0.63, n = 19). NA-AAF induced DNA synthesis was lower for myeloblasts than promyelocytes and myelocytes. Biochemically determined NA-AAF induced UDS was higher for immature granulopoietic cells in blood than in marrow. Sequential studies on granulopoietic blood cells suggested that phases of accelerated leukocytosis in CML can be preceded by increases of NA-AAF induced UDS. Whether increases in NA-AAF induced UDS relates to an amplification of repair enzymatic capacity closely correlated to the cellular replication capacity, or whether it reflects an increased sensitivity to DNA damage induction and the consequences thereof, was not resolved in this study. Nevertheless these results are consistent with the hypothesis that increases in NA-AAF induced UDS signal the evolution during chronic phase CML of cell populations of increasing malignancy which escape growth control.

Acetoxyacetylaminofluorene↗
PubMed1980

Separation of human bone marrow cells in density gradients of polyvinylpyrrolidone coated silica gel (Percoll).

A simple and highly reproducible method is described for separation and density distribution analysis of human bone marrow cells in continuous density gradients of polyvinylpyrrolidone coated silica gel (Percoll). Colony and cluster forming cells in agar separated from the bulk of cells and peaked at densities of 1.063-1.064 g/ml. The enrichment of clonogenic cells was approximately 10 times and recovery varied between 41-321%. The overall recovery of cells was 80% (60-94%). Density distribution analysis of morphologically identifiable cells demonstrated the progressive increase in density with maturation of cells within the granulocytic series: myeloblasts peaked at 1.0624 g/ml, promyelocytes at 1.0734 g/ml, myelocytes at 1.0776 g/ml, metamyelocytes at 1.0799 g/ml and mature neutrophils at 1.0864 g/ml. The eosinophil had the highest density, 1.0904 g/ml, of all cells analyzed. Monocytes and lymphocytes peaked at 1.0661 and 1.0681 g/ml respectively. The light density shift of clonogenic cells of AML and CML reported by other authors was confirmed.

Blood Cells↗
PubMed1980

Biochemical characterization of a leukemia-associated inhibitor (LAI) suppressing normal granulopoiesis in vitro.

Low-density (less than 1.077 g/ml) marrow or blood cells from patients with acute or chronic leukemia release a high molecular weight substance called "leukemia-associated inhibitor" (LAI) that reduces the fraction of normal marrow CFU-c in S-phase as measured with the 3H-TdR suicide technique. LAI from conditioned media or 3M KCl extracts of subcellular fractions behaved homogeneously on gel chromatography, showing an apparent molecular weight greater than 500,000. However, ion-exchange chromatography and isoelectric focusing indicated considerable charge heterogeneity for LAI molecules. Results from SDS-polyacrylamide gel electrophoresis indicated that the biologic activity resides in a subunit of 150,000-170,000 daltons. The findings of marked affinity for Con-A-Sepharose, marked susceptibility to mild periodate treatment, partial susceptibility to protease digestion, and relative resistance to heating suggest that LAI is a glycoprotein. Data from radiolabeling of cell surface components and sucrose density gradient centrifugation are consistent with LAI being a peripheral cell membrane glycoprotein, which may suppress normal granulopoiesis in leukemia.

Centrifugation, Density Gradient↗
PubMed1979

Effects of serum and cations on the selective release of granular proteins from human netrophils during phagocytosis.

The extracellular release from human neutrophils of the primary (azurophil) granule constituents, myeloperoxidase (MPO), chymotrypsin-like cationic protein (CCP), collagenase and lysozyme, and the secondary (specific) granule constituents, lactoferrin and lysozyme, was measured during ingestion of staphylococcus protein-A-IgG complexes. In buffer, lactoferrin release was consistently higher than that of the other protein. In serum, lactoferrin release increased concomitantly with ingestion, whereas the rate of lysozyme and especially of MPO release were stimulated to a higher degree than ingestion. Magnesium (0.5--2 mM) was more potent than calcium (0.5--2 mM) in promoting release but these cations worked synergistically. Zinc (0.5--4 mM) was found to be a potent and selective inhibitor of collagenase release. Manganese (0.25--4 mM), which inhibited the ingestion of SpA-IgG complexes, also inhibited release of CCP, collagenase, lysozyme and MPO, but actually stimulated lactoferrin release. The data suggests that lactoferrin and lysozyme may be confined to distinct granule populations or else released in a different fashion from the granules. When the effects on release of primary granule proteins are concerned it is suggested that the dissociation of binding of various agents to an anionic granule matrix may be affected differently by various cations.

Blood↗
PubMed1979

Blood eosinophils and eosinophil cationic protein after acute myocardial infarction or corticosteroid administration.

Measurements of eosinophil cationic protein in serum (S-ECP) have been made in patients with acute myocardial infarction. In spite of low numbers of blood eosinophils in the acute phase of the disease S-ECP levels fluctuated widely with often markedly raised levels. Peak levels of S-ECP were significantly correlated (P less than 0.001) to peak numbers of blood eosinophils, although the former usually occurred within the first 2-3 d of illness and the latter usually after the sixth day. Intravenous injection of 0.5 g methylprednisolone in healthy individuals reduced blood eosinophil counts for at least 24 h, but S-ECP levels remained within normal limits. These results suggest that ECP is released from eosinophils in vivo. The raised levels of S-ECP in patients with acute myocardial infarction are probably due to the active participation of eosinophils in the inflammatory process.

Acute Disease↗
PubMed1979

Serum and plasma myeloperoxidase, elastase and lactoferrin content in acute myeloid leukaemia.

Myeloperoxidase (MPO) and elastase, restricted to azurophil granules of neutrophils, as well as lactoferrin, restricted to specific granules of neutrophils, were determined in plasma and serum from patients with acute myeloid leukaemia (AML). Highly sensitive radio immuno assays were developed for detection of these proteins. Serum MPO was increased in 12/35 and decreased in 2/35 patients without correlation to WBC or neutrophil counts; these levels may reflect an abnormal production by leukaemic blasts or ineffective granulopoiesis in the bone marrow. Serum elastase was increased in 6/22 patients. Serum lactoferrin was decreased in 12/25 patients without correlation to neutrophil counts probably reflecting abnormal production. Serum elastase and MPO showed a covariation in chronic myeloid leukaemia but not in AML; the latter finding may indicate that the synthesis of these two proteins is not synchronized in AML-cells. Sequential studies of patients with AML demonstrated fluctuations of serum MPO and lactoferrin during remission most likely because of chemotherapeutic pertubation. Although a limited number of patients has been studied it is suggested that serum lactoferrin may be of help for prediction of relapse in AML.

Antineoplastic Agents↗
PubMed1979

Oscillations of marrow culture growth in acute myeloid leukemia during remission induction and remission.

Sequential studies in acute myeloid leukemia of bone marrow cells in agar culture showed striking fluctuations of colony and cluster formation during induction of remission. These oscillations may be initiated by recruitment of resting leukemic and normal cells upon chemotherapeutic perturbation. Striking oscillations of the colony and cluster formation occurred also during remission with or without maintenance therapy, but with a longer periodicity as compared sto the phase of induction of remission. Oscillations of the marrow growth capacity during remission may reflect potential relapses where the outcome depends on proliferative advantages of the normal or leukemic cell clone.

Adult↗
PubMed1979

Pteroylpolyglutamate hydrolase of human granulocytes. I. Partial purification and kinetic studies.

Pteroylpolyglutamate hydrolase was demonstrated in the lysosome-like cytoplasmic granules of human granulocytes. Partial purification of this enzyme from granulocytes, obtained from patients with chronic myeloid leukaemia, was achieved by chromatography of the granule extract on Sephadex G-75, Bio-Rex 70 and hydroxylapatite. The enzyme preparation obtained was slightly contaminated with myeloperoxidase. Synthetic pteroyltetraglutamate was used as a substrate for the enzyme. The pH optimum was 5.1; the Km was 6 x 10(-3) mol/l; and the enzyme was activated by divalent cations, e.g. Ca++, Mg++ and Mn++. Pteroylpolyglutamate hydrolase is suggested to be involved in the destruction of microorganisms in granulocytes during phagocytosis.

Biological Assay↗