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Biomedical subjects

O Stendahl

Publications and source records attributed to O Stendahl.

At least 127 records · Page 7Linked to original sources
PubMed1981

Deactivation of leucocyte chemotaxis in vivo. Locomotion of cells isolated from a patient with meningococcal meningitis.

This report concerns the properties of polymorphonuclear leucocytes isolated from a patient with meningococcal meningitis. No differences in phagocytic capacity and random locomotion between the patient's polymorphonuclear leucocytes and normal PMNL were found, but by using activated normal human serum as chemo-attractant it was found that PMNL isolated from the cerebrospinal fluid had lost their ability to respond chemotactically. The deactivation was found to be accompanied by surface property changes of the cells.

Aged↗
PubMed1980

Modulation of polymorphonuclear leukocyte locomotion by synthetic amphiphiles: effect of saturated fatty acid esters (C2-C18) of poly(ethyleneglycol) 6000.

The capacity of synthetic amphiphiles poly(ethyleneglycol) 6000 (PEG) esterified with saturated fatty acids (C2-C18), to modify polymorphonuclear leukocyte (PMNL) locomotion has been investigated. It was noticed that PEG-myristate (M-PEG; C14) stimulated the random locomotion of PMNL populations in concentrations up to about 1 g/L. The esters with shorter aliphatic chains had negligible effects, whereas those with longer chains, PEG-palmitate (P-PEG; C16) and PEG-stearate (S-PEG; C18) reduced the locomotion, irrespectively of concentration. The ability of the PMNL to be stimulated by an attractant liberated from normal human serum was slightly impaired by M-PEG, but not by P-PEG. The response to M-PEG of individual PMNL was heterogeneous in that some cells were stimulated and others were inhibited. However, the average result was a reduction of the motility. This indicates that methods used for the study of the locomotion of cell populations may not always reflect the average behavior of the whole population. It was also concluded that the different effects of M-PEG and P-PEG owed to dissimilar effects on the membrane structure of the PMNL since (1) M-PEG perturbated the PMNL membrane more than P-PEG, as assayed by the release of superoxide anion (O2-), although the binding was smaller, and (2) M-PEG and P-PEG increased and decreased the membrane fluidity, respectively, as measured with fluorescent bleaching and recovery after bleaching of labeled PMNL. The results indicate a subtle coupling between membrane structure and PMNL locomotion.

Cell Membrane↗
PubMed1979

The effect of sulfasalazine and its active components on human polymorphonuclear leukocyte function in relation to ulcerative colitis.

Sulfasalazine and its active components, 5-aminosalicylic acid (5-ASA) and sulfapyridine (SP), are potent modulators of inflammatory reactions but with somewhat different modes of action. Investigating the effect of these compounds on normal human polymorphonuclear leukocytes in vitro, we show inhibition of different stages in the phagocytic process, such as migration (sulfasalazine and SP), superoxide production (sulfasalazine and SP), myeloperoxidase-mediated iodination and cytotoxicity (5-ASA and SP). It is thus suggested that sulfasalazine is not just a vehicle for delivering its active components in the colon, but that its therapeutic effect is ulcerative colitis and other inflammatory reactions is a result of the concurrent action of the three compounds.

Adolescent↗
PubMed1979

Influence of O and K antigens on the surface properties of Escherichia coli in relation to phagocytosis.

Strains of Escherichia coli with different O and K antigens were investigated with respect to physicochemical surface characteristics and liability to phagocytosis. Using two-phase partitioning analysis for the surface characterization, three main groups of strains emerged: Group I (O1:K1, O2:K1, O3:K2ab) showing both smooth hydrophilic O antigens and negatively-charged K antigen which rendered the strains maximally resistant to phagocytosis. Group II (O55:K59, O111:K58) showed no acidic K antigen but only smooth hydrophilic O antigen properties. However, these strains were as resistant to phagocytosis as the strains in group I. A third group (O14:K7, O24:K +) contained strains with rough, hydrophobic O antigen and negatively-charged K antigen. When the K antigen was removed by heat treatment these strains became more sensitive to phagocytosis. Certain other strains (O28:K-, O56:K + and O118:K-) did not fit into the three groups. These experiments show that the physicochemical surface effects and biological significance of the K antigen must be evaluated in relation to the properties conveyed by the corresponding O antigens.

Animals↗
PubMed1979

Surface characteristics of Escherichia coli strains in relation to development of bacteraemia.

Three groups of E. coli bacteria isolated from blood, urine and faeces were analysed with respect to physicochemical surface properties in aqueous polymer two-phase systems. Eighty-eight per cent of the bacteria isolated from blood cultures showed affinity for the dextran-rich bottom phase, whereas 60% and 30% of the bacteria isolated from urine and faeces, respectively, collected to the same phase. Further two-phase analysis indicated that the bacteraemia strains exposed more negative surface than the other groups of bacteria, and that this charge was reduced after heat treatment (70 degrees C, 40 min). These results thus indicate that the strains causing bacteraemia possess similar surface properties, and may have been selected from the more heterogeneous group of bacteria found in urine and faeces. It is further conceivable to propose that bacteria found in the blood expose more heatsensitive, negatively-charged K antigen than the other groups of bacteria.

Antigens, Bacterial↗
PubMed1979

Reduction of phagocytosis, surface hydrophobicity and charge of Salmonella typhimurium 395 MR10 by reaction with secretory IgA (SIgA).

Binding of human colostral secretory IgA (SIgA) to Salmonella typhimurium 395 MR10 decreased the liability to hydrophobic interaction of the bacteria, as analysed by hydrophobic interaction chromatography on Octyl-Sepharose and partition in an aqueous polymer two-phase system consisting of dextran, poly(ethyleneglycol) (PEG) and poly-(ethyleneglycol)-palmitate (P--PEG). SIgA also reduced the negative charge of the bacteria. Treatment of the bacteria with centrifuged but not further fractionated colostrum added positive charge to the bacteria which was removed by treatment with pepsin. Colostral SIgA reduced the in vitro phagocytosis of S. typhimurium MR10 by polymorphonuclear leucocytes. The adhesion of the bacteria to cellulose membrane filters in the absence of phagocytes was also reduced after the interaction with SIgA. It is proposed that the binding of SIgA to bacterial surfaces has hydrophilic and anti-adhesive effects, which may serve to exclude antigen from mucosal surfaces.

Cell Membrane↗
PubMed1979

The effect of large doses of vitamin C on leukocyte function and some laboratory parameters.

Consumption of large doses of vitamin C has been ascribed several beneficial effects e.g. on serum cholesterol, haemoglobin synthesis, leucocyte function. Other authors have warned against large doses which could cause renal stones, disturbed vitamin C metabolism, a diabetogenic effect. To test certain statements 24 healthy women received either placebo, 1000 mg or 4000 mg ascorbic acid daily in a double blind study. Blood was drawn at regular intervals. Those women who received large doses of vitamin C increased their serum levels of vitamin C, during the medication, but otherwise we found no differences neither in leucocyte levels of vitamin C, leucocyte function nor other laboratory parameters between women who received placebo or large doses of ascorbic acid.

Adolescent↗
PubMed1978

The effect of colostrum and colostral antibody SIgA on the physico-chemical properties and phagocytosis of Escherichia coli o86.

A hydrophilic effect of human colostrum and colostral antibody SIgA binding on Escherichia coli o86 has been demonstrated by hydrophobic interaction chromatography on Octyl-Sepharose and partition in a polymer two-phase system containing dextran, poly(ethyleneglycol) and poly(ethyleneglycol)-palmitate. Furthermore, antibody SIgA binding reduced the negative surface charge of the E. coli bacteria. The reaction between centrifuged but not further purified colostrum and bacteria yielded a complex which, compared to bacteria alone, showed decreased negative and increased positive surface charges, the latter being sensitive to pepsin. Binding of SIgA or colostrum to E. coli showed no definite effect on the attachment to and phagocytosis by polymorphonuclear cells in vitro. The effects observed are discussed in relation to the structure of SIgA.

Bacteriological Techniques↗
PubMed1978

The inhibition of polymorphonuclear leukocyte cytotoxicity by dapsone. A possible mechanism in the treatment of dermatitis herpetiformis.

The effect of the sulfone compound 4,4'-diaminodiphenyl sulfone (dapsone) on normal human polymorphonuclear leukocytes (PMNL) has been investigated in vitro. The drug has a dramatically beneficial effect in dermatitis herpetiformis in which the PMNL and immune complexes has been stressed to be of importance for the development of the skin lesions. Pruritus disappears and the inflammatory eruptions clear within a few days of starting therapy. The effect of dapsone has been evaluated on the different stages of phagocytosis. Using dapsone concentrations (1-30 mug/ml) comparable with those found after therapeutic doses, we have found that the drug interferes primarily with the myeloperoxidase (MPO)-H(2)O(2)-halide-mediated cytotoxic system in the PMNL. No effect was observed on random locomotion, chemotaxis, phagocytic ingestion, oxidative metabolism, or the release of lysosomal enzymes. Kinetic studies in a cell-free system with purified MPO revealed a competitive type of inhibition using varying concentrations of NaI. Furthermore, the inhibition resulted in reduced candidicidal activity during phagocytosis of Candida albicans, and reduced cytotoxicity to adjacent mammalian cells measured as the (51)Cr release from virus-induced lymphoma cells. Because the MPO-H(2)O(2)-halide system not only fulfills the antimicrobial activity but is suggested to be a modulator of the inflammatory reaction as well, the action of dapsone in dermatitis herpetiformis may in part be explained by its effect on this system.

Adolescent↗
PubMed1977

Enhancing effect of levamisole on the phagocytic activity of human neutrophil polymorphonuclear leucocytes in vitro.

The effect of levamisole on the phagocytic activity of normal human polymorphonuclear neutrophil leucocytes has been studied in vitro. In concentrations comparable with the serum levels obtained in treatment with levamisole perorally, the engulfment of heat-killed yeast cells is moderately but significantly increased. It is shown that levamisole can only stimulate phagocytosis of adequately opsonized particles. The action of the drug is still unknown but appears to be directly linked to the phagocytic cell.

Depression, Chemical↗