Lancet
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By contrast with patients with asthma, those with chronic obstructive pulmonary disease (COPD) are poorly responsive to the anti-inflammatory actions of corticosteroids, and these drugs provide little clinical benefit. In both diseases, multiple inflammatory genes are activated, which results from acetylation of core histones around which DNA is wound. This acetylation opens up the chromatin structure allowing gene transcription and synthesis of inflammatory proteins to proceed. ⋯ We propose that in patients with COPD, HDAC2 function is impaired by cigarette smoking and oxidative stress, leading to a pronounced reduction in responsiveness to corticosteroids. Oxidative stress could generate peroxynitrite, which impairs HDAC2 activity through nitration of critical tyrosine residues. This hypothesis raises the possibility that novel therapeutic approaches might unlock this corticosteroid resistance, leading to more effective anti-inflammatory treatments for COPD and other severe inflammatory diseases.
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Comparative Study
Relation of CD4+CD25+ regulatory T-cell suppression of allergen-driven T-cell activation to atopic status and expression of allergic disease.
Allergic diseases are frequent and rising in prevalence, and result from activation of T-helper (Th) 2 cells by allergens. CD4+CD25+ regulatory T cells suppress T-cell activation in vitro and prevent pathological findings in animal models of disease. We aimed to investigate whether the amount of inhibition of allergic responses by CD4+CD25+ T cells was related to atopy and allergic disease. ⋯ Allergic disease can result from an inappropriate balance between allergen activation of regulatory CD4+CD25+ T cells and effector Th2 cells. This imbalance could result from a deficiency in suppression by regulatory T cells or strong activation signals could overcome such regulation. Treatment to enhance regulatory T-cell responses, in concert with reduction of Th2 cell activation, might be useful in prevention and treatment of allergic disease.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of procalcitonin-guided treatment on antibiotic use and outcome in lower respiratory tract infections: cluster-randomised, single-blinded intervention trial.
Lower respiratory tract infections are often treated with antibiotics without evidence of clinically relevant bacterial disease. Serum calcitonin precursor concentrations, including procalcitonin, are raised in bacterial infections. We aimed to assess a procalcitonin-based therapeutic strategy to reduce antibiotic use in lower respiratory tract infections with a new rapid and sensitive assay. ⋯ Procalcitonin guidance substantially reduced antibiotic use in lower respiratory tract infections. Withholding antimicrobial treatment did not compromise outcome. In view of the current overuse of antimicrobial therapy in often self-limiting acute respiratory tract infections, treatment based on procalcitonin measurement could have important clinical and financial implications.