This study supports previous findings of both, increased local and systemic inflammation in acute exacerbation of COPD. In virus-associated exacerbations, IL-6 is significantly increased and negatively correlated to FEV1 indicating a relation between virus-induced inflammation and airway obstruction. However, regarding our finding and previous data, it is becoming increasingly clear that the mediators investigated so far do not permit identifying the etiology of AE-COPD. Hence, further studies are needed to better define the inflammatory response in AE-COPD in general and in viral exacerbations in particular.

This mini-review examines the role of the pro-inflammatory cytokine interleukin (IL)-1β in the interaction of Pseudomonas aeruginosa and the host immune system during lung infection. Different studies show that the reduction of the inflammatory response, especially a decrease in IL-1β, leads to a better outcome in acute lung infection with this bacterium. This includes a higher survival rate, reduced damage to the lung tissue and, in particular, a better clearance of the airways and the tissue of the lungs from P. aeruginosa.

Objective: Clinical observation has suggested that stress and asthma morbidity are associated, though underlying mechanisms are not clearly understood. After having established a mouse model of stress-exacerbated allergic airway inflammation, we demonstrated a stress-mediating role for neurokinin-1 receptor, the main substance P (SP) receptor. Here, our aim was to investigate the influence of stress or exogenously applied SP on airway inflammation and on the local cytokine production of immune cells. Methods: BALB/c mice were systemically sensitized to ovalbumin (OVA) and repeatedly challenged with OVA aerosol. Sound stress was applied to the animals for 24 h, starting with the first airway challenge. Alternatively, one group of non-stressed mice received intranasal SP before airway challenges. Cell numbers were determined in bronchoalveolar lavage (BAL) fluid. Leukocytes from mediastinal lymph nodes were analyzed by flow cytometry to determine the percentages of T cells producing interleukin-4, interferon-γ and tumor necrosis factor-α. Results: In BAL fluids of stressed or SP-treated animals, significantly higher total cell counts were found compared to non-stressed mice. In lymph nodes, the percentage of TNF-α-positive T cells was higher in stressed mice and mice after application of SP. In contrast, the influence of stress did not increase the percentages of interferon-γ-positive CD3+ cells, meanwhile the application of SP increased the percentages of T cells positive for this cytokine. Conclusion: Our data provide further evidence for a stress-mediating neuroimmunological pathway that, putatively via SP, is able to influence the composition of immune cells in different compartments of allergic airway inflammation.

We experimentally investigate the influence of interfacial tension on liquid/ liquid microflows for fluids having large viscosity contrasts. A coaxial microdevice is employed to examine the situation where a less-viscous fluid is injected in a sheath of a more-viscous fluid using both immiscible and miscible fluid pairs. Data obtained from high-speed imaging reveal a variety of regular flow regimes, including dripping, jetting, wavy, core-annular, diffusive jet, mist, and inverted thread flow patterns. Flow maps are delineated over a wide range of injection flow rates, and an original methodology based on periodic pattern analysis is developed to clarify relationships between interfacial dynamics and fluid properties of multiphase materials. Specifically, we show the smooth evolution of droplet size and spacing at the transition between dripping and jetting flows and develop scaling relationships based on capillary numbers to predict droplet flow morphologies. For similar flow conditions, reducing interfacial tension leads to a significant decrease in droplet size. For miscible fluid pairs, diffusive jets are observed at low Pećlet numbers, whereas wavy core-annular flows are obtained at moderate Reynolds numbers for both immiscible and miscible fluids. This work provides a unifying description of the influence of interfacial properties on viscous microflow phenomena.

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