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- Brimnes, J, et al.
(författare)
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Reactions of N-N and N-O compounds with horseradish peroxidase and peroxidases from Mycobacterium tuberculosis
- 1999
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - 1600-0463. ; 107:6, s. 555-565
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Tidskriftsartikel (refereegranskat)abstract
- Several N-N-and N-O-containing compounds were analysed for their ability to act as substrates for horseradish peroxidase and peroxidases in Mycobacterium tuberculosis extracts. Aminoguanidine, diaminoguanidine, isoniazid, hydroxylamine and hydrazine were found to be weak substrates for horseradish peroxidase in reaction I and to inhibit the reaction of horseradish peroxidase with hydrogen peroxide. The same compounds inhibited the reaction of Mycobacterium tuberculosis peroxidase-catalase with hydrogen peroxide, and hydroxylamine was found to be a weak substrate for this enzyme. In growth inhibition experiments, diaminoguanidine inhibited the growth of M. tuberculosis H37Rv at 50 microg/mL, but not the growth of two isoniazid-resistant strains. Isonicotinic acid hydroxamate inhibited the reaction of the peroxidases with hydrogen peroxide, but was not itself a substrate and had no growth-inhibitory effects. On the basis of these results we suggest that the effect of isoniazid on growth of M. tuberculosis results from increased oxidative stress due to inhibition of catalase-peroxidase as well as from generation of toxic radicals with the structure [structure in text].
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- Draborg, A. H., et al.
(författare)
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Epstein-Barr virus early antigen diffuse (EBV-EA/D)-directed immunoglobulin A antibodies in systemic lupus erythematosus patients
- 2012
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Ingår i: Scandinavian Journal of Rheumatology. - : Informa UK Limited. - 1502-7732 .- 0300-9742. ; 41:4, s. 280-289
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We sought to determine whether the serological response towards lytic cycle antigens of Epstein Barr virus (EBV) is altered in systemic lupus erythematosus (SLE) patients. Method: We used enzyme-linked immunosorbent assay (ELISA) to investigate the prevalence of EBV early antigen diffuse (EBV-EA/D) antibodies in sera from 60 patients with SLE, 40 with scleroderma (SSc), 20 with primary Sjogren's syndrome (pSS), 20 with rheumatoid arthritis (RA), 20 healthy controls, and also subjects with various circulating autoantibodies. Samples from patients were obtained from clinics specialized within the diseases in Denmark and Sweden and samples from healthy controls were obtained from volunteers. Results: A significant elevated titre of immunoglobulin (Ig)A, IgG, and IgM EBV-EA/D antibodies was found in SLE patients compared to healthy controls, a finding not explained by immunosuppressive treatment or disease activity. The largest difference was observed for IgA EBV-EA/D antibodies (p = 0.0013) with a seropositive rate of 58% in SLE patients and 0% in healthy controls. RA and SSc patients and individuals seropositive for anti-Scl-70 were additionally found to have elevated titres of IgA EBV-EA/D antibodies (40%, p = 0.014; 60%, p = 0.015; and 38.5%, p = 0.045, respectively). However, the titres were generally lower than in SLE patients. Conclusion: Our findings support an association between EBV and SLE. The elevated titre of EBV-EA/D-directed IgA antibodies found in SLE patients could suggest reactivation of EBV in epithelial cells or reinfection of epithelial cells after reactivation in B cells, indicating lack of control of the latent infection.
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- Olsson, Peter, et al.
(författare)
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Smoking, disease characteristics and serum cytokine levels in patients with primary Sjogren's syndrome
- 2018
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Ingår i: Rheumatology International. - : Springer Science and Business Media LLC. - 0172-8172 .- 1437-160X. ; 38:8, s. 1503-1510
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Tidskriftsartikel (refereegranskat)abstract
- Smoking affects several disease processes. Epidemiological studies have previously found a negative association between primary Sjogren's syndrome (pSS) and smoking. The aim of this study was to examine whether markers of disease activity and cytokine expression in pSS patients differ between ever and never smokers. Fifty-one consecutive pSS patients and 33 population controls were included in the study. Clinical and standard laboratory parameters were registered. Serum cytokines (IL-1 beta, IL-2, IL-3, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17, IL-18, IL-33, IFN-alpha, IFN-gamma, TNF-alpha, EGF, BAFF, Fas-ligand, RANTES, TGF-beta 1) were assessed. A positive lip biopsy was less prevalent among ever smoking patients compared to never smokers (81 vs 100%; p = 0.03). However, except for TNF-alpha, which was higher in ever smokers, no differences in cytokine levels were found when comparing ever and never smoking pSS patients. Furthermore, no significant differences were found between ever and never smoking patients in the ESSDAI total score, IgG levels, or complement levels. However, IL-6, IL-12, IL-17 and IL-18 were significantly increased in pSS patients compared to controls. In this study, a negative association between ever smoking and positive lip biopsy was found, confirming previous reports. Expected differences in cytokine levels compared to controls were noted, but no major differences were found between ever and never smoking pSS patients. Taking into account the negative association between pSS diagnosis and smoking in epidemiological studies, possible explanations include a local effect of smoking on salivary glands rather than systemic effects by cigarette smoke.
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