The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism to optimise lung gas exchange. We aimed to decipher the proposed oxygen sensing mechanism of mitochondria in HPV. Cytochrome redox state was assessed by remission spectrophotometry in intact lungs and isolated pulmonary artery smooth muscle cells (PASMC). ⋯ Pharmacological inhibition of mitochondria revealed analogous kinetics of cytochrome redox state and strength of HPV. Our data suggest inhibition of complex IV as an essential step in mitochondrial oxygen sensing of HPV. Concomitantly, increased superoxide release from complex III and mitochondrial membrane hyperpolarisation may initiate the cytosolic calcium increase underlying HPV.
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Multicenter Study
Riociguat for chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension: a phase II study.
We assessed the therapeutic potential of riociguat, a novel soluble guanylate cyclase stimulator, in adults with chronic thromboembolic pulmonary hypertension (CTEPH; n = 42) or pulmonary arterial hypertension (PAH; n = 33) in World Health Organization (WHO) functional class II/III. In this 12-week, multicentre, open-label, uncontrolled phase II study, patients received oral riociguat 1.0-2.5 mg t.i.d. titrated according to systemic systolic blood pressure (SBP). Primary end-points were safety and tolerability; pharmacodynamic changes were secondary end-points. ⋯ Study discontinuation because of AEs was 4%. These preliminary data show that riociguat has a favourable safety profile and improves exercise capacity, symptoms and pulmonary haemodynamics in CTEPH and PAH. Randomised controlled trials are underway.
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Recent studies suggest that use of inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD) may be associated with a higher incidence of pneumonia. However, it is unclear whether COPD subjects on ICS who develop pneumonia have worse outcomes. Therefore, our aim was to examine the association of prior outpatient ICS therapy with mortality in hospitalised COPD subjects with pneumonia. ⋯ Mortality was 9% at 30 days and 16% at 90 days. In regression analyses, outpatient ICS therapy was associated with lower mortality at both 30 days (OR 0.76, 95% CI 0.70-0.83), and 90 days (OR 0.80, 95% CI 0.75-0.86). Outpatient therapy with ICS was associated with a significantly lower 30- and 90-day mortality in hospitalised COPD patients with pneumonia.
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Plasmacytoid dendritic cells (pDCs) are professional antigen-presenting cells with antiviral and tolerogenic capabilities. Viral infections and autoimmunity are proposed to be important mechanisms in the pathogenesis of chronic obstructive pulmonary disease (COPD). The study aimed to quantify blood dendritic cell antigen 2-positive pDCs in lungs of subjects with or without COPD by immunohistochemistry and flow cytometry, combined with the investigation of the influence of cigarette smoke extract (CSE) on the function of pDCs in vitro. pDCs were mainly located in lymphoid follicles, a finding compatible with their expression of lymphoid homing chemokine receptors CXCR3 and CXCR4. pDC accumulated in the lymphoid follicles and in lung digests of patients with mild to moderate COPD, compared with smokers without airflow limitation and patients with COPD Global Initiative for Chronic Obstructive Lung disease (GOLD) stage III-IV. ⋯ Maturing pDC from patients with COPD produced higher levels of tumour necrosis factor (TNF)-α and interleukin (IL)-8 compared to pDC from healthy subjects. CSE significantly impairs the antiviral function of pDCs. In COPD, a GOLD stage dependent accumulation of pDC in lymphoid follicles is present, combined with an enhanced production of TNF-α and IL-8 by maturing pDCs.
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The primary objective of the present study was to evaluate the effect on hospital mortality of a delay in intensive care unit (ICU) admission for severe community-acquired pneumonia (CAP). The secondary objectives were to assess if such delays were associated with treatment variations by the emergency department (ED) and deterioration in the general wards, and to evaluate the prognostic ability of the Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) minor criteria. We retrospectively compared patients who were admitted straight from the ED to the ICU (direct group, n = 54) and those who were first admitted from the ED to the general wards before ICU transfer (delayed group, n = 49), over 2.5 yrs. ⋯ The delayed group received fewer fluid boluses in the ED and rapidly deteriorated in the general wards. The presence of ≥3 IDSA/ATS minor criteria was associated with increased mortality in the delayed group. In conclusion, prompt recognition of severe CAP using the IDSA/ATS minor criteria, followed by aggressive management at the ED and direct ICU admission, are all crucial toward improving outcomes.