106 research outputs found
The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer
Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al
Autophagy and ATP-induced anti-apoptosis in antigen presenting cells (APC) follows the cytokine storm in patients after major trauma
Severe trauma and the systemic inflammatory response syndrome (SIRS) occur as a result of a cytokine storm which is in part due to ATP released from damaged tissue. This pathology also leads to increased numbers of immature antigen presenting cells (APC) sharing properties of dendritic cells (DC) or macrophages (MΦ). The occurrence of immature APC appears to coincide with the reactivation of herpes virus infections such as Epstein Barr virus (EBV). The aim of this study was the comparative analysis of the ultrastructural and functional characteristics of such immature APC. In addition, we investigated EBV infection/ reactivation and whether immature APC might be targets for natural killers (NK). Significant macroautophagy, mitochondrial degradation and multivesicular body formation together with the identification of herpes virus particles were morphological findings associated with immature APC. Exogenous stressors such as ATP further increased morphological signs of autophagy, including LC3 expression. Functional tests using fluorescent bacteria proved impaired phagolysosome fusion. However, immature APC were susceptible to NK-92-mediated cytolysis. We found evidence for EBV latency state II infection by detecting EBV-specific LMP1 and EBNA2 in immature APC and in whole blood of these patients. In summary, trauma-induced cytokine storms may induce maturation arrest of APC, promote ATP-induced autophagy, support EBV persistence and impair the degradation of phagocytozed bacteria through inefficient phagolysosome fusion. The susceptibility to NK-mediated cytolysis supports the hypothesis that NK function is likely to contribute to immune reconstitution after major trauma by regulating immature APC, and ATP-induced autophagy and survival
Effect of Cryogrinding on Chemical Stability of the Sparingly Water-Soluble Drug Furosemide
Purpose To investigate the effect of cryogrinding on chemical
stability of the diuretic agent furosemide and its mixtures with
selected excipients.
Methods Furosemide was ground at liquid nitrogen temperature
for 30, 60, 120 and 180 min. Mixtures of furosemide-PVP
and furosemide-inulin (1:1) were milled under cryogenic conditions.
Materials were analyzed by XRD, UPLC, MS and NMR.
Results Upon increasing the milling time, a significant build-up
of an unidentified impurity 1, probably the main degradation
product, was noticed. Cogrinding of furosemide with PVP and
inulin worsened chemical stabilization of the pharmaceutical.
The main degradation product formed upon cryomilling was
subsequently identified as 4-chloro-5-sulfamoylanthranilic acid
(CSA). Based on some theoretical considerations involving
specific milling conditions, the milling intensity and an expected
specific milling dose have been calculated. Results indicate that
cryogenic grinding is capable to initiate mechanically induced
decomposition of furosemide.Conclusions Cryogenic grinding can activate and accelerate
not only structural changes (solid state amorphization) but also
chemical decomposition of pharmaceuticals. A cryogenic
milling device should be considered as a chemical reactor,
where under favourable conditions chemical reactions could be
mechanically initiated
IL-1β Suppresses Innate IL-25 and IL-33 Production and Maintains Helminth Chronicity.
Approximately 2 billion people currently suffer from intestinal helminth infections, which are typically chronic in nature and result in growth retardation, vitamin A deficiency, anemia and poor cognitive function. Such chronicity results from co-evolution between helminths and their mammalian hosts; however, the molecular mechanisms by which these organisms avert immune rejection are not clear. We have found that the natural murine helminth, Heligmosomoides polygyrus bakeri (Hp) elicits the secretion of IL-1β in vivo and in vitro and that this cytokine is critical for shaping a mucosal environment suited to helminth chronicity. Indeed in mice deficient for IL-1β (IL-1β(-/-)), or treated with the soluble IL-1βR antagonist, Anakinra, helminth infection results in enhanced type 2 immunity and accelerated parasite expulsion. IL-1β acts to decrease production of IL-25 and IL-33 at early time points following infection and parasite rejection was determined to require IL-25. Taken together, these data indicate that Hp promotes the release of host-derived IL-1β that suppresses the release of innate cytokines, resulting in suboptimal type 2 immunity and allowing pathogen chronicity
Ordering dynamics of microscopic models with nonconserved order parameter of continuous symmetry
Numerical Monte Carlo temperature-quenching experiments have been performed on two three-dimensional classical lattice models with continuous ordering symmetry: the Lebwohl-Lasher model [Phys. Rev. A 6, 426 (1972)] and the ferromagnetic isotropic Heisenberg model. Both models describe a transition from a disordered phase to an orientationally ordered phase of continuous symmetry. The Lebwohl-Lasher model accounts for the orientational ordering properties of the nematic-isotropic transition in liquid crystals and the Heisenberg model for the ferromagnetic-paramagnetic transition in magnetic crystals. For both models, which have a nonconserved order parameter, it is found that the linear scale, R(t), of the evolving order, following quenches to below the transition temperature, grows at late times in an effectively algebraic fashion, R(t)∼tn, with exponent values which are strongly temperature dependent and furthermore vary for different measures of the time-dependent length scale. The results are discussed in relation to modern theories of ordering dynamics in systems with continuous order-parameter symmetry
Generation and characterization of standardized forms of trehalose dihydrate and their associated solid-state behavior
Trehalose dihydrate is a nonreducing disaccharide which has generated great interest in the food and pharmaceutical industries. However, it is well recognized that considerable batch to batch variation exists for supposedly identical samples, particularly in terms of the thermal response. In this investigation, two standardized forms of trehalose dihydrate were generated using two distinct crystallization pathways. The two batches were characterized using scanning electron microscopy, X-ray powder diffraction, and FTIR. The thermal responses of the two forms were then studied using modulated temperature differential scanning calorimetry (MTDSC) and thermogravimetric analysis (TGA). In particular, we describe the technique of quasi-isothermal MTDSC as a means of studying the change in equilibrium heat capacity as a function of temperature. Finally, variable temperature FTIR was utilized to assess the change in bonding configuration as a function of temperature. SEM revealed significant differences in the continuity and grain structure of the two batches. The TGA, MTDSC, and quasi-isothermal MTDSC studies all indicated significant differences in the thermal response and water loss profile. This was confirmed using variable temperature FTIR which indicated differences in bond reconfiguration as a function of temperature. We ascribe these differences to variations in the route by which water may leave the structure, possibly associated with grain size. The study has therefore demonstrated that chemically identical dihydrate forms may show significant differences in thermal response. We believe that this may assist in interpreting and hence controlling interbatch variation for this material
Effects of mobile vacancies on the dynamics of ordering and phase separation in nonconserved multicomponent systems
Association of stem cell factor gene expression with severity and atopic state in patients with bronchial asthma
The alarmin IL-1α is a master cytokine in acute lung inflammation induced by silica micro- and nanoparticles
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