diaphorase by the formation of blue for- N02 mazans from tetrazoliums can therefore be NO3 used to localise neuronal NOS.18A form of ONOO0 cNOS distinct from the neuronal form is fL-arginine localised to vascular endothelial cells.19 20 ivones cNOS from brain and endothelial cells have iettively by been cloned'922 and these are distinct ine methyl be oxidised enzymes with about 60% homology, which are also homologous to cytochrome P-450
I. Introduction The medications used to treat chronic obstructive pulmonary disease (COPD) are reviewed in detail in other chapters in this volume (chaps. 6 and 7). Effective management of the patient with COPD, however, requires implementation of an overall disease management strategy that integrates these medications with nonpharmacologic interventions as well as the treatment of concurrent conditions, which are frequently present in COPD patients. Currently available medications that treat COPD can improve patient well-being and prognosis in important ways. Unfortunately, the available therapies are often underused and when prescribed are often not used in ways that optimize their effectiveness. The current chapter will review the strategies of COPD management.
In COPD, the lower airways are colonised with bacteria that contribute to exacerbations. This may be due to defective macrophage phagocytosis. IFNγ is elevated in COPD and can suppress macrophage phagocytosis. IFNγ activates the JAK/STAT pathway, thus we hypothesise that inhibiting this pathway will ablate the IFNγ effect on macrophage phagocytosis. Human lung macrophages were treated with two structurally distinct JAK/STAT inhibitors (PF95 & PF13, 10-4-10-10M), stimulated with 10ng/ml IFNγ for 18h. Phagocytosis was measured after 4h exposure to beads, H. influenzae (HI) or S. pneumoniae (SP) . CXCL10 and IL-6 release after IFNγ or IFNγ+TNFα (10ng/ml) stimulation for 24h was measured by ELISA n=5. Cell viability was assessed by MTT. IFNγ increased bead phagocytosis by 30±6% which was not altered by PF95 or PF13. However IFNγ significantly inhibited uptake of HI by 24±9% and SP by 29±9%. Both PF95 and PF13 reversed these effects in a concentration-dependent manner [Table 1]. PF13, but not PF95, was cytotoxic at concentrations ≥10μM. Both PF95 and PF13 decreased CXCL10 release after IFNγ stimulation (EC50 0.31±0.17μM & 15±9.5nM respectively) and IFNγ+TNFα (EC50 0.57±0.2μM & 19±8.2nM respectively). Only PF13 decreased IL-6 after IFNγ or IFNγ+TNFα stimulation (EC50 0.45±0.72μM and 2.3±2.1μM respectively). View this table: Table 1. Effect of JAK/STAT inhibitors on IFNγ suppression of bacterial phagocytosis Inhibiting the JAK/STAT pathway diminishes the decrease in phagocytosis of HI and SP caused by IFNγ and decreases the release of inflammatory cytokines and has potential as a novel target in COPD.
Abstract Background/Aims: Biliary atresia (BA) is a progressive disease characterized by bile duct inflammation and fibrosis. The aetiology is unknown and may be due to a virus‐induced, autoimmune‐mediated injury of cholangiocytes. Cholangiocytes are not only targets of injury but may also modulate hepatic inflammation. The aim of this study was to determine the immune profile of murine cholangiocytes and the ability to function as antigen‐presenting cells (APCs) in culture with Rhesus rotavirus (RRV), poly I:C (viral mimic) or interferon‐γ/tumour necrosis factor‐α. Methods/Results: Both the cholangiocyte cell line (long‐term culture) and fresh, ex vivo cholangiocytes expressed APC surface markers major histocompatibility complex (MHC)‐class I and II and CD40, while only the cultured cell line expressed costimulatory molecules B7‐1 and B7‐2. Despite APC expression, cultured cholangiocytes were unable to function as competent APCs in T‐cell proliferation assays. Furthermore, both cultured and ex vivo cholangiocytes expressed RNA transcripts for many pro‐inflammatory cytokines and chemokines. Conclusions: Although cholangiocytes contain APC molecules, they are incompetent at antigen presentation and cannot elicit effective T‐cell activation. Upregulation of MHC‐class I and II found in BA mice may serve to prime the cholangiocyte as a target for immune‐mediated injury. Cholangiocytes produced many pro‐inflammatory cytokines and chemokines in the setting of RRV infection and T‐helper type 1 cytokine milieu, suggesting a role of cholangiocytes as immune modulators promoting the ongoing inflammation that exists in RRV‐induced BA.
The plastic collapse response of structural steel elliptical hollow section (EHS) profiles in compression is examined in this paper. As an initial step, a parametric study to identify the factors that determine which plastic mechanisms would arise has been carried out using finite element (FE) results from the current work and experimental data from the literature. Following this, an analytical model to describe the split flip disc plastic collapse mechanism in compressed EHS is derived. The parameters controlling the shape and size of the plastic hinges have been investigated and found to be of key importance; hence, special care has been taken in their definition. Finally, the analytically derived load- displacement curves have been compared with FE results. The comparisons have revealed good agreement, confirming the ability of the developed analytical models to predict the plastic collapse response of elliptical tubes.
DEP increase hospitalisation of patients with COPD. DEP comprise a carbon core with adsorbed compounds, including endotoxin. DEP deposit in the lungs, and are targets for macrophages. Macrophages drive COPD pathophysiology by releasing inflammatory mediators, potentially via mitogen-activated protein kinase (MAPK) pathways. We hypothesised that DEP stimulate macrophage mediator release via MAPK, and this is increased in COPD. MDM from non-smokers, smokers or COPD patients were treated with either DEP, standard reference material (SRM)-2975, SRM-1650b or inert beads (30, 11 and 0.2µm diameter, respectively) (1-100μg/ml) for 24h. CXCL8 release was analysed by ELISA, phagocytosis of fluorescent beads by fluorimetry, activation of MAPK by immunobloting, cell viability by MTT, and endotoxin levels by Limolas-amoebocyte lysate assay. DEP inhibited MDM phagocytosis of beads from all goups in a concentration-dependent manner, with 100μg/ml giving ∼60% inhibition (with ∼24% decrease in viability). DEP, but not SRMs or beads, stimulated CXCL8 release by MDM compared with non-stimulated controls (not due to the presence of endotoxin). MDM from non-smokers or COPD patients were twice as responsive to DEP than cells from smokers. DEP-treated MDM activated p38 and ERK 1/2 MAPK pathways, but not JNK. A p38 inhibitor (PF755616) suppressed DEP-treated MDM activation of p38 and CXCL8 release with no effect on viability. In conclusion, DEP, but not other particles, stimulated MDM chemokine release via p38 and ERK, suggesting that DEP composition drives this response and that p38 inhibition may have therapeutic potential in COPD.
Summary Human granulocyte–macrophage colony‐stimulating factor (GM‐CSF) reporter constructs containing up to 3·3 kb of upstream promoter sequence were transiently transfected into both Jurkat and HUT78 human T‐cell lines. In Jurkat cells, stimulation with phorbol 12‐myristate 13‐acetate (PMA) plus phytohemaglutinin (PHA) produced robust increases in reporter activity, whereas HUT78 cells showed low levels of reporter induction attributable to constitutive nuclear factor (NF)‐κB activity. Following mutation of either the proximal NF‐κB site (−85/−76) or the activator protein1 (AP‐1) motif within the conserved lymphokine element 0 (CLE0) site (−54/−31), reporter activity was markedly reduced in both cell lines. Despite this dependence on NF‐κB and CLE0/AP‐1, GM‐CSF reporter activity was unaffected by dexamethasone in either cell line. Similarly, an NF‐κB‐dependent reporter was also not repressed by dexamethasone, yet GM‐CSF release from HUT78 T cells was inhibited. These data therefore confirm a critical role for both NF‐κB and CLE0 sites in GM‐CSF promoter activation and indicate that NF‐κB may not mediate glucocorticoid‐dependent repression of GM‐CSF in these cells.
