Jagiellonian University

About: Jagiellonian University is a education organization based out in Krakow, Poland. It is known for research contribution in the topics: Population & Catalysis. The organization has 17438 authors who have published 44092 publications receiving 862633 citations. The organization is also known as: Academia Cracoviensis & Akademia Krakowska.

Heightened immune response to autocitrullinated Porphyromonas gingivalis peptidylarginine deiminase: a potential mechanism for breaching immunologic tolerance in rheumatoid arthritis.

Abstract: Background Rheumatoid arthritis (RA) is characterised by autoimmunity to citrullinated proteins, and there is increasing epidemiologic evidence linking Porphyromonas gingivalis to RA. P gingivalis is apparently unique among periodontal pathogens in possessing a citrullinating enzyme, peptidylarginine deiminase (PPAD) with the potential to generate antigens driving the autoimmune response. Objectives To examine the immune response to PPAD in patients with RA, individuals with periodontitis (PD) and controls (without arthritis), confirm PPAD autocitrullination and identify the modified arginine residues. Methods PPAD and an inactivated mutant (C351A) were cloned and expressed and autocitrullination of both examined by immunoblotting and mass spectrometry. ELISAs using PPAD, C351A and another P gingivalis protein arginine gingipain (RgpB) were developed and antibody reactivities examined in patients with RA (n=80), individuals with PD (n=44) and controls (n=82). Results Recombinant PPAD was a potent citrullinating enzyme. Antibodies to PPAD, but not to Rgp, were elevated in the RA sera (median 122 U/ml) compared with controls (median 70 U/ml; p<0.05) and PD (median 60 U/ml; p<0.01). Specificity of the anti-peptidyl citrullinated PPAD response was confirmed by the reaction of RA sera with multiple epitopes tested with synthetic citrullinated peptides spanning the PPAD molecule. The elevated antibody response to PPAD was abolished in RA sera if the C351A mutant was used on ELISA. Conclusions The peptidyl citrulline-specific immune response to PPAD supports the hypothesis that, as a bacterial protein, it might break tolerance in RA, and could be a target for therapy.

Singlet oxygen photogeneration at surface modified titanium dioxide.

Abstract: Substitution of surface -OH groups of TiO2 may influence competition between photoinduced energy and electron-transfer processes and lead to improved singlet oxygen generation. In contrast to neat TiO2, surface modified titanium dioxide can photocatalyze degradation of a very stable substance, cyanuric acid. Presented results are in contradiction to usually accepted hypothesis of the mechanism of cyanuric acid photodegradation in the presence of fluorinated TiO2 (F-TiO2) in which "bulk" hydroxyl radicals play a key role. It seems plausible that the difference of activity observed for TiO2 and F-TiO2 is not related to various types of generated hydroxyl radicals, but rather to competition between electron-transfer processes (formation of radicals) and energy-transfer processes (formation of singlet oxygen).

Aspirin Alters the Cardioprotective Effects of the Factor XIII Val34Leu Polymorphism

Abstract: Background— The mechanism underlying decreased risk for myocardial infarction in carriers of the Leu34 polymorphism of the factor (F) XIII A-subunit is unclear. Given that acetylation of fibrinogen by aspirin can alter its clotting properties and the presence of fibrin stimulates thrombin-mediated activation of FXIII, we have tested the hypothesis that treatment with aspirin differentially modulates the influence of the FXIII Val34Leu polymorphism on its activation in vivo. Methods and Results— The rates of the disappearance of FXIIIA chain and the appearance of its activated form (FXIIIAa) in sequential 30-second blood samples collected at the site of microvascular injury were compared in 14 healthy carriers of the Leu34 allele and 23 Val34 homozygotes both before and after a 7-day aspirin ingestion (75 mg/d), with the use of quantitative Western blotting. The presence of the Leu34 allele was associated with a significant increase in the maximum rate of FXIII activation by thrombin. Although the Leu34-po...