Factors influencing stomatal conductance in response to water availability in grapevine: a meta-analysis.

The main factors regulating grapevine response to decreasing water availability were assessed under statistical support using published data related to leaf water relations in an extensive range of scion and rootstock genotypes. Matching leaf water potential (Ψ ) and stomatal conductance (g ) data were collected from peer-reviewed literature with associated information. The resulting database contained 718 data points from 26 different Vitis vinifera varieties investigated as scions, 15 non-V.

Airway collagen and elastic fiber content correlates with lung function in equine heaves.

The consequences on lung function and inflammation of alterations in the extracellular matrix affecting the peripheral airway wall in asthma are largely unknown. We hypothesized that remodeling of collagen and elastic fibers in the peripheral airway wall leads to airway obstruction and contributes to neutrophilic airway inflammation. Animals used were six heaves-affected horses and five controls.

Airway arginase expression and Nω-hydroxy-nor-arginine effect on methacholine-induced bronchoconstriction differentiate Lewis and Fischer rat strains.

Innate airway hyperresponsiveness (AHR) is well modeled by two strains of rat, the hyperresponsive Fischer 344 rat and the normoresponsive Lewis rat. Arginase has been implicated in AHR associated with allergic asthma models. We addressed the role of arginase in innate AHR using the Fischer-Lewis model.

Characterization of arginase expression by equine neutrophils.

Neutrophils are the predominant cells recruited in the airways of horses suffering from heaves. These cells have been shown to express arginase in some species. The metabolism of l-arginine is thought to be involved in chronic inflammation, and airway obstruction and remodeling.

Neutrophils are not less sensitive than other blood leukocytes to the genomic effects of glucocorticoids.

Background: Neutrophils are generally considered less responsive to glucocorticoids compared to other inflammatory cells. The reported increase in human neutrophil survival mediated by these drugs partly supports this assertion. However, it was recently shown that dexamethasone exerts potent anti-inflammatory effects in equine peripheral blood neutrophils.

Corticosteroids and antigen avoidance decrease airway smooth muscle mass in an equine asthma model.

Recent studies suggest that airway smooth muscle remodeling is an early event in the course of asthma. Little is known of the effects of long-term antigen avoidance and inhaled corticosteroids on chronically established airway remodeling. We sought to measure the effects of inhaled corticosteroids and antigen avoidance on airway remodeling in the peripheral airways of horses with heaves, a naturally occurring asthma-like disease.

Systemic inflammation and priming of peripheral blood leukocytes persist during clinical remission in horses with heaves.

Objective: To compare innate immune responses of peripheral blood leukocytes from healthy and asymptomatic heaves-affected horses.

Animals: Heaves-affected horses (n=5-6) and healthy controls (n=4-5) kept under low dust environments (pasture or shavings and pellets).

Methods: Blood neutrophil and neutrophil-depleted cell populations were isolated using MACS system.

Profiling of differentially expressed genes using suppression subtractive hybridization in an equine model of chronic asthma.

Background: Gene expression analyses are used to investigate signaling pathways involved in diseases. In asthma, they have been primarily derived from the analysis of bronchial biopsies harvested from mild to moderate asthmatic subjects and controls. Due to ethical considerations, there is currently limited information on the transcriptome profile of the peripheral lung tissues in asthma.

Heaves, an asthma-like disease of horses.

Animal models have been developed to investigate specific components of asthmatic airway inflammation, hyper-responsiveness or remodelling. However, all of these aspects are rarely observed in the same animal. Heaves is a naturally occurring disease of horses that combines these features.

Effect of antigenic exposure on airway smooth muscle remodeling in an equine model of chronic asthma.

Recent studies suggest that airway smooth muscle remodeling is an early event in asthma, but whether it remains a dynamic process late in the course of the disease is unknown. Moreover, little is known about the effects of an antigenic exposure on chronically established smooth muscle remodeling. We measured the effects of antigenic exposure on airway smooth muscle in the central and peripheral airways of horses with heaves, a naturally occurring airway disease that shares similarities with chronic asthma.

Optimization of a procedure to accurately detect equine TNFα in serum samples.

The systemic component of chronic inflammatory diseases may lead to clinical complications. High levels of TNFα, a pro-inflammatory cytokine, are found in human patients with COPD and asthma. Horses are also susceptible to an array of chronic inflammatory disorders possibly associated with systemic inflammation, including respiratory diseases.

IL-4 activates equine neutrophils and induces a mixed inflammatory cytokine expression profile with enhanced neutrophil chemotactic mediator release ex vivo.

Neutrophils are potent contributors to the lung pathophysiological changes occurring in allergic airway inflammation, which typically involve T helper type 2 (Th2) cytokine overexpression. We have previously reported that equine pulmonary endothelial cells are activated by the Th2 cytokine IL-4 and express chemotactic factors for neutrophils after stimulation. We have further explored the possible mechanisms linking Th2-driven inflammation and neutrophilia by studying the effects of recombinant equine IL-4, a prototypical Th2 cytokine, on peripheral blood neutrophils (PBN) isolated from normal animals and from horses with asthmatic airway inflammation (equine heaves).

IL-4 stimulates the expression of CXCL-8, E-selectin, VEGF, and inducible nitric oxide synthase mRNA by equine pulmonary artery endothelial cells.

Little is known concerning the possible contribution of T helper 2 (Th2)-type cytokines to the recruitment of neutrophils into the lung tissue. In the present study, endothelial cells from equine pulmonary arteries were cultured in the presence of recombinant equine (re) IL-4 and reIL-5, and the cytokine mRNA expression of molecules implicated in the chemotaxis and migration of neutrophils was studied using real-time RT-PCR. The functional response of reIL-4-induced endothelial cell stimulation on neutrophil migration was also studied using a chemotaxis chamber.