IFN-γ acts on the airway epithelium to inhibit local and systemic pathology in allergic airway disease

Inhibiting allergic airway inflammation is the goal of therapy in persistent asthma. Administration of medication via the airways delivers drug directly to the site of inflammation and avoids systemic side effects but often fails to modulate systemic features of asthma. We have shown that Th1 cells, through production of IFN-γ, inhibit many Th2-induced effector functions that promote disease. Using a newly generated mouse that expresses IFN-γR only on airway epithelial cells, we show that the airway epithelium controls a range of pathological responses in asthma. IFN-γ acting only through the airway epithelium inhibits mucus, chitinases, and eosinophilia, independent of Th2 cell activation. IFN-γ signaling through the airway epithelium inhibits eosinophil generation in the bone marrow, indicating that signals on the airway mucosal surface can regulate distant functions to inhibit disease. IFN-γ actions through the airway epithelium will limit airway obstruction and inflammation and may be therapeutic in refractory asthma.     

A novel pathway that regulates inflammatory disease in the respiratory tract

In animals with acute airway inflammation followed by repeated exposure to inhaled Ag, inflammation wanes over time and thus limits the study of chronic airway inflammatory diseases such as asthma. We developed a model of airway inflammation and inhalational exposure to investigate regulatory pathways in the respiratory tract. We show that Th1- and Th2-induced airway inflammation followed by repeated exposure to inhaled Ag leads to a state of immunosuppression. Challenge of these animals with a marked population of TCR transgenic effector Th1 or Th2 cells results in a striking inhibition of inflammation and effector Th cells. In Th2 models, airway hyperresponsiveness, mucus, and eosinophilia are reduced. The inhibitory effects observed are Ag nonspecific, can be induced in lymphocyte-deficient mice, and are associated with a population of TGF-beta1-expressing macrophages. Induction of this pathway may offer potent localized treatment of chronic T cell-mediated respiratory illnesses and provide insights into the development of such diseases.     

Congenital muscular dystrophies: new aspects of an expanding group of disorders

The congenital muscular dystrophies comprise a genetically and clinically heterogeneous group of disorders characterized by early onset of progressive muscle weakness and often involvement of other organ systems such as the brain and eyes. During the last decade, significant progress has been made to further characterize various forms of congenital muscular dystrophies based on their specific genetic and clinical appearance. This review represents an overview of the recent accomplishments as they relate to clinical, diagnostic, pathogenetic and therapeutic aspects of congenital muscular dystrophies.     

Endoscopic Vascular Harvest in Coronary Artery Bypass Grafting Surgery: A Meta-Analysis of Randomized Trials and Controlled Trials

OBJECTIVE:: This meta-analysis sought to determine whether endoscopic vascular graft harvesting (EVH) improves clinical and resource outcomes compared with conventional open graft harvesting (OVH) in adults undergoing coronary artery bypass surgery. METHODS:: A comprehensive search was undertaken to identify all randomized and nonrandomized trials of EVH versus OVH up to April 2005. The primary outcome was wound complications. Secondary outcomes included any other clinical morbidity and resource utilization. Odds ratios (OR), weighted mean differences (WMD), or standardized mean differences (SMD) and their 95% confidence intervals (95% CI) were analyzed. RESULTS:: Thirty-six trials of 9,632 patients undergoing saphenous vein harvest met the inclusion criteria (13 randomized; 23 nonrandomized). Risk of wound complications was significantly reduced by EVH compared with OVH (OR 0.31, 95% CI 0.23-0.41). Similarly, the risk of wound infections was significantly reduced (OR 0.23, 95% CI 0.20-0.53; P < 0.0001). Need for surgical wound intervention was also significantly reduced (OR 0.16, 95% CI 0.08-0.29). The incidence of pain, neuralgia, and patient satisfaction was improved with EVH compared with OVH. Postoperative myocardial infarction, stroke, reintervention for ischemia or angina recurrence, and mortality were not significantly different. Operative time was significantly increased (WMD 15.26 minutes; 95% CI 0.01, 30.51), hospital length of stay was reduced (WMD -0.85 days; 95% CI -1.55, -0.15), and readmissions were reduced (OR 0.53, 95% CI 0.29-0.98). Costs were insufficiently reported to allow for aggregate analysis. CONCLUSIONS:: Endoscopic vascular graft harvesting of the saphenous vein reduces wound complications and improves patient satisfaction and resource utilization. Further research is required to determine the incremental cost-effectiveness of EVH versus OVH.     

IL-13 receptor alpha2 selectively inhibits IL-13-induced responses in the murine lung

IL-13 is a critical cytokine at sites of Th2 inflammation. In these locations it mediates its effects via a receptor complex, which contains IL-4Ralpha and IL-13Ralpha1. A third, high-affinity IL-13 receptor, IL-13Ralpha2, also exists. Although it was initially felt to be a decoy receptor, this has not been formally demonstrated and the role(s) of this receptor has recently become controversial. To define the role(s) of IL-13Ralpha2 in IL-13-induced pulmonary inflammation and remodeling, we compared the effects of lung-targeted transgenic IL-13 in mice with wild-type and null IL-13Ralpha2 loci. We also investigated the effect of IL-13Ralpha2 deficiency on the OVA-induced inflammatory response. In this study, we show that in the absence of IL-13Ralpha2, IL-13-induced pulmonary inflammation, mucus metaplasia, subepithelial fibrosis, and airway remodeling are significantly augmented. These changes were accompanied by increased expression and production of chemokines, proteases, mucin genes, and TGF-beta1. Similarly, an enhanced inflammatory response was observed in an OVA-induced phenotype. In contrast, disruption of IL-13Ralpha2 had no effect on the tissue effects of lung-targeted transgenic IL-4. Thus, IL-13Ralpha2 is a selective and powerful inhibitor of IL-13-induced inflammatory, remodeling, and physiologic responses in the murine lung.