tailieunhanh - Báo cáo y học: " Direct antimicrobial activity of antithrombin"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Direct antimicrobial activity of antithrombin? | Wiedermann and Djanani Critical Care 2010 14 440 http content 14 5 440 CRITICAL CARE LETTER L_ Direct antimicrobial activity of antithrombin Christian J Wiedermann 1 and Angela Djanani2 See related research by Hofstra etal. http content 13 5 R145 In a study by Hofstra and colleagues 1 in a recent issue of Critical Care nebulization of drotrecogin-alfa activated antithrombin heparin or danaparoid attenuated pulmonary coagulopathy during Streptococcus pneumoniae pneumonia in rats only antithrombin additionally exerted lung-protective effects and reduced bacterial outgrowth. Adding antithrombin to culture medium had no effect on the outgrowth of S. pneumoniae in vitro thus less neutralizing of endogenous antimicrobicidals by reduced bronchoalveolar fluid levels of inflammatory proteins could have permitted better endogenous microbicidal effects in the antithrombin group 1 . Direct microbicidal effects of antithrombin would not have been surprising since antimicrobial peptides are known to bind to glycosaminoglycans similar to antithrombin 2 . Structural motifs associated with heparin affinity confer antimicrobial properties to a given peptide 3 . Thus heparin-binding peptides for example from laminin isoforms von Willebrand factor vitronectin protein C inhibitor complement factor C3 and fibronectin exerted antimicrobial activities against bacteria 3 . Similar results had been obtained using consensus sequences for heparin binding Cardin and Weintraub motifs determined as -X-B-B-X-B-X- and -X-B-B-B-X-X-B-X- B probability of a basic residue X hydropathic residue 4 . Antithrombin contains such a consensus sequence 130L-Y-R-K-A-N-K-S 4 5 . When investigating the ligation of glycosaminoglycans with endogenous antimicrobials 2 we also studied the direct effects of antithrombin on bacterial growth and growth inhibition was found . Wiedermann A. Djanani unpublished data . It is therefore unclear why Hofstra and colleagues 1 failed to observe a