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Biomedical subjects

M Shingu

Publications and source records attributed to M Shingu.

At least 109 records · Page 6Linked to original sources
PubMed1985

Neutrophil-generated active oxygens in linear IgA bullous dermatosis.

To examine the possible correlation between tissue injury and neutrophil-produced active oxygens (AOs) in patients with linear IgA bullous dermatosis (BD), we studied the capacity of neutrophils from six patients with BD to generate AOs. Cultured endothelial cells from human umbilical-cord vein were also incubated with the patients' neutrophils to assess AO-induced tissue injury. The AO production by patients' neutrophils was significantly elevated. The patients' neutrophils, as well as those from healthy controls preincubated with patients' serum, produced significantly increased levels of cytotoxic response on coincubation with chromium 51-labeled human endothelial cells. These results suggest that the tissue damage observed in BD may be partially due to both excessive production of AOs by neutrophils and a serum factor present in the patients, and further postulate the similar pathogenic process in dermatitis herpetiformis.

Adolescent↗
PubMed1984

Human umbilical cord vein smooth muscle cells lack receptors for C3b and the Fc portion of immunoglobulin G.

Under apparently normal conditions, the smooth muscle cells obtained from veins of human umbilical cord do not possess receptors for C3b or the Fc portion of IgG. These receptors were not expressed even after exposure to neutrophil lysate or a superoxide-generating system. The lack of these receptors argues against the possibility that smooth muscle cells participate in the pathogenesis of immune complex diseases through binding of C3b or Fc fragments.

Cells, Cultured↗
PubMed1984

Role of stimulated neutrophils from patients with systemic lupus erythematosus in disturbed immunoreactivity, with special reference to increased oxygen intermediates generated by the neutrophils.

Zymosan-stimulated neutrophils from 6 patients with untreated, active systemic lupus erythematosus (SLE), from patients with bacterial infections, and from healthy controls, were studied for production of oxygen intermediates (O-2, H2O2, OH . and chemiluminescence) and lysosomal enzymes. Oxygen intermediate production was highest in neutrophils from active SLE patients, while lysosomal enzyme release was highest in neutrophils from patients with bacterial infections. SLE neutrophils, upon culture with autologous or normal lymphocytes, markedly reduced the number of surviving OKT4+ cells and the proliferative response of the surviving cells to mitogens; a reduction was also observed amongst the surviving lymphocytes in the proportion of total T cells and OKT8+ cells, and in the generation of Con A induced suppressor activity. When superoxide dismutase and catalase were included in the neutrophil-lymphocyte co-cultures, the number of T- and OKT8+ cells, and the suppressor activity were restored but not completely (60-75%), the lymphocyte mitogenic response and number of OKT4+ cells were less well restored (40-50%). When lymphocytes were co-cultured with neutrophils from healthy or infected subjects, there was a mild decrease in mitogenic responses and OKT4+ cells, while the suppressor T-cell activity was markedly enhanced. These results were not affected by scavengers. These results suggest that in SLE, reduced T-lymphocyte subpopulations and altered immunoreactivity may be partially due to excessive production of oxygen intermediates and probably other factors by stimulated neutrophils; these results further suggest that in all the subjects, diseased or healthy, neutrophils generate unidentified factors other than oxygen intermediates that reduce the generation of OKT4+ cells and lymphocyte mitogenic responses, and that potentiate suppressor T-cell activity.

Adolescent↗
PubMed1984

Chemotactic activity generated in human serum from the fifth component of complement by hydrogen peroxide.

Exposure of normal human serum to various concentrations of hydrogen peroxide as low as 68.8 microM resulted in the generation of chemotactic activity for human neutrophils, which was inhibited by adding catalase prior to the exposure. Maximum chemotactic activity was obtained by hydrogen peroxide at a concentration of 1.1 mM, and the concentration greater than 1.1 mM expressed decreased activity. On the contrary, hydrogen peroxide less than 1.1 mM produced dose-dependent chemotactic activity. The generation of chemotactic activity is initiated at an incubation time of 5 minutes, and subsequently increases with up to 90 minutes. The suppression of chemotactic activity was minimum even after 180 minutes. The maximum activity was obtained by 1024-fold dilution of serum treated with 13.8 mM hydrogen peroxide. These results suggest that the disappearance of chemotactic activity at the high-dose range of hydrogen peroxide is due to neutrophil deactivation rather than inactivation of the chemotactic activity after it was generated. Similarly, purified human C5 exposed to hydrogen peroxide generated chemotactic activity. The chemotactic activity was inhibitable by antiserum to human C5. The molecular weight of chemotactically active substance was approximately 15,000. The generation of chemotactic activity was not inhibited by addition of EGTA or EDTA. These results imply that hydrogen peroxide generates C5a-like chemotactic factor through hydrolysis of C5.

Aminopeptidases↗
PubMed1983

Variant strain of Propionibacterium acnes: a clue to the aetiology of Kawasaki disease.

By means of anaerobic culture for 3-4 weeks a variant strain of Propionibacterium acnes was isolated from one lymph-node biopsy specimen, and from blood samples of five of twenty-three patients with early Kawasaki disease, but from only one of fifteen blood samples from patients after 8 days' illness. No anaerobe was isolated from sixty age-matched controls with various disorders, but the same bacillus with the same serotype was isolated from house-dust mites from six patients' homes. Patients had significantly higher serum agglutination titres to these strains than controls. The antigen moiety of P acnes was found in the patients' circulating immune complexes. Inoculation of animals caused various inflammatory lesions, particularly in the reticuloendothelial system, and coronary arteritis, myocarditis, and endocarditis in one of them, suggesting that the bacillus is pathogenic. The culture filtrate of this strain showed toxicity in tissue culture. This variant strain of P acnes may have a causative role in Kawasaki disease and house-dust mites a role as vectors.

Acute Disease↗
PubMed1983

Effect of stimulated neutrophils from the synovial fluid of patients with rheumatoid arthritis on lymphocytes--a possible role of increased oxygen radicals generated by the neutrophils.

Neutrophils from the synovial fluid (SFN) of 10 patients with active rheumatoid arthritis (RA) were investigated to determine the generation of oxygen intermediates (OI) (O2-, H2O2, OH .), chemiluminescence, and lysosomal enzymes (lysozyme and beta-glucuronidase). Lymphocytes from healthy individuals were cocultured at 37 degrees C for 17 hr with SFN from the patients and the number of OKT4+, OKT8+, and OKT3+ cells and the response to mitogens were determined. A markedly increased OI and slightly elevated lysosomal enzyme levels were observed in SFN from patients. Coculture of lymphocytes with SFN resulted in a decreased number of OKT4+ and OKT8+ cells and a greatly reduced response to Con A and mildly diminished response to PHA, while OKT3+ cells were not affected. The simultaneous addition of superoxide dismutase and catalase restored the impairment of monoclonal antibody reaction and lymphocyte responsiveness almost to control levels. It is suggested that the disturbed immunoreactivity of synovial fluid lymphocytes from RA patients may be due to increased OI generated by stimulated neutrophils.

Antibodies, Monoclonal↗
PubMed1983

Serum factors from patients with systemic lupus erythematosus enhancing superoxide generation by normal neutrophils.

It has been suggested that human neutrophils exposed to performed immune complexes or activated complement fragments generate O2- anions in extracellular medium. In vivo studies have revealed that oxygen intermediates produced by immune complex-activated neutrophils play an important role in subsequent tissue damage. Since it is difficult to obtain direct evidence that O2- is released into plasma in patients with systemic lupus erythematosus (SLE), we studied the capacities of their sera to stimulate O2- release by human neutrophils in vitro. Sera from patients with SLE significantly enhanced O2- generation by neutrophils compared to normal sera. The enhancing activity of serum in the induction of increased O2- generation correlated positively with the presence of serum immune complexes and negatively with serum complement levels. The enhancing factors were analyzed by serum fractionation on Sephadex G-200 gel filtration, and were concluded to be immune complexes of intermediate size containing an activated complement fragment.

Cytochrome c Group↗
PubMed1982

Auto-oxidative damage in Behçet's disease--endothelial cell damage following the elevated oxygen radicals generated by stimulated neutrophils.

The functions of phagocytes are enhanced in patients with Behçet's disease, therefore, we investigated the neutrophil-derived oxygen intermediates (OI) and lysosomal enzymes from 17 patients receiving glucocorticosteroids (steroids) and colchicine. Cultured endothelial cells were incubated with neutrophils to assess tissue injury. In cases of the complete type, in the active stage of the disease, OI production was markedly increased. The other patients showed significantly higher OI and higher lysosomal enzyme levels than patients with other diseases (controls) receiving drug therapy. Cytotoxicity tests showed that the 51Cr release was also significantly higher. The destruction of desmosomes and cell deformation were demonstrated electron microscopically. The simultaneous addition of superoxide dismutase and catalase in the cell culture decreased the 51Cr release to control levels. These findings suggest that neutrophils from patients with Behçet's disease generate high levels of OI, resulting in endothelial tissue damage.

Adolescent↗
PubMed1981

The role of cell mediated immunity in coxsackie B viral myocarditis.

The role of cell mediated immunity (CMI) in the pathogenesis of coxsackie B (Cox. B) viral myocarditis in the adult were immunologically investigated. The number of types of neutralizing antibody in patients with Cox. B viral myocarditis was more than that in controls. This fact suggested that these patients had a history of previous Cox. B viral infections. In the patient with Cox. B viral myocarditis, neutralizing antibody titer was increased as 20 folds by the reinfection. And also macrophage migration inhibition test showed that CMI was enhanced not only against the same type but also against the other types of Cox.B group viruses. In conclusion, it may be essential in the occurrence of adult myocarditis that the patient has been infected by Cox.B virus and immunized against the other types as well as the same type of Cox.B group viruses. CMI may also play a critical role in the occurrence of Cox.B viral myocarditis.

Antibodies, Viral↗