Effects of a neutrophil elastase inhibitor (ONO-5046) on acute pulmonary injury induced by tumor necrosis factor alpha (TNFalpha) and activated neutrophils in isolated perfused rabbit lungs

Acute effects of smoke exposure on the cellular and cytokine profile in isolated perfused lungs

The aim of this study was to assess the acute effects of cigarette smoke exposure on cellular and cytokine profile in BAL fluids in an isolated perfused rabbit assay. The experimental animals were categorized into four groups: (1) unexposed controls and (2) cigarette smoke-exposed animals perfused with autologous whole blood; (3) unexposed controls and cigarette smoke-exposed; (4) cigarette smoke-exposed animals perfused with Krebs' Ringer solution containing 5% bovine serum albumin and glucose. Cigarette smoke induced an increase in total cell numbers (mainly alveolar macrophages in BAL fluids) and an increase in the permeability index of BAL. Levels of interleukin 8 were also significantly decreased in BAL fluids due to acute effects of cigarette smoke exposure. The most likely explanation for cigarette smoke-induced increase of inflammatory cells in BAL in lungs is because of the release of pre-existing cells from reservoirs within the lungs. The acute effects of cigarette smoke-induced increase of pulmonary epithelial permeability may also play an important role in the cellular recruitment into airspaces from the lung reservoirs.

Thirty years of clinical trials in acute respiratory distress syndrome

OBJECTIVE

To systematically review clinical trials in acute respiratory distress syndrome (ARDS).

DATA SOURCES

Computerized bibliographic search of published research and citation review of relevant articles.

STUDY SELECTION

All clinical trials of therapies for ARDS were reviewed. Therapies that have been compared in prospective, randomized trials were the focus of this analysis.

DATA EXTRACTION

Data on population, interventions, and outcomes were obtained by review. Studies were graded for quality of scientific evidence.

MAIN RESULTS

Lung protective ventilator strategy is supported by improved outcome in a single large, prospective trial and a second smaller trial. Other therapies for ARDS, including noninvasive positive pressure ventilation, inverse ratio ventilation, fluid restriction, inhaled nitric oxide, almitrine, prostacyclin, liquid ventilation, surfactant, and immune-modulating therapies, cannot be recommended at this time. Results of small trials using corticosteroids in late ARDS support the need for confirmatory large clinical trials.

CONCLUSIONS

Lung protective ventilator strategy is the first therapy found to improve outcome in ARDS. Trials of prone ventilation and fluid restriction in ARDS and corticosteroids in late ARDS support the need for large, prospective, randomized trials.

beta(2)-Integrin blockade driven by E-selectin promoter prevents neutrophil sequestration and lung injury in mice

Interaction of CD11/CD18 beta(2) integrins on polymorphonuclear leukocytes (PMNs) with their counterreceptor, intercellular adhesion molecule-1, on the surface of vascular endothelial cells is a critical event mediating stable PMN adhesion and migration across the pulmonary vascular endothelial barrier. Neutrophil inhibitory factor (NIF), a 41-kDa glycoprotein isolated from the canine hookworm (Ancylostoma caninum), binds to the I domain of CD11a and CD11b and inhibits beta(2) integrin-dependent PMN adhesion. We describe a novel strategy using the endothelial cell-specific E-selectin promoter to induce NIF expression in an inflammation-specific manner in pulmonary vascular endothelial cells. A construct containing NIF cDNA driven by the inducible endothelial cell-specific E-selectin promoter (pESNIF) was transfected into human pulmonary artery endothelial cells (HPAECs). Lipopolysaccharide challenge (known to activate E-selectin) resulted in NIF mRNA and protein expression in transfected HPAECs. NIF expression induced by the E-selectin promoter prevented PMN adhesion to the activated HPAECs, whereas PMNs adhered avidly to activated HPAECs in the absence of NIF expression. To address the utility of this approach in conditionally preventing in vivo PMN sequestration, we injected mice intravenously with cationic liposomes containing the pESNIF construct. Analysis of lung tissue showed that intraperitoneal challenge of Escherichia coli resulted in NIF expression. Inflammation-specific NIF expression induced by the E-selectin promoter prevented lung PMN sequestration and vascular injury induced by E coli challenge. These studies suggest the feasibility of conditionally blocking beta(2) integrin function at sites where the endothelium is activated and thereby of locally preventing PMN activation and migration responses that lead to tissue inflammation.

Current management of tuberculosis

Current chemotherapeutic regimens against tuberculosis give excellent cure rates and low relapse rates if implemented and monitored correctly. This is fortunate since only two new drugs have been approved for use in this condition in the last 30 years. However, shortcomings in management and in patient compliance have resulted in an increasing prevalence of drug-resistant organisms. The global decline in the disease has been reversed due to a combination of factors including the HIV epidemic, ageing populations, poverty, and translocation of refugee populations due to conflict.

Posthemorrhagic shock mesenteric lymph primes circulating neutrophils and provokes lung injury

Mesenteric lymph has recently been invoked as an avenue for gut-derived factors that may result in distant organ injury following hemorrhagic shock. We demonstrate that posthemorrhagic shock mesenteric lymph primes neutrophils (PMNs) and causes lung injury. Methods. Mesenteric lymph was collected from Sprague-Dawley rats from their mesenteric lymph duct prior to, during, and following hemorrhagic shock (MAP 40 for 90 min). The rats were then resuscitated with shed blood plus lactated Ringers (2X shed blood) over 3 h. Lung leak was assessed by transudation of Evan's blue dye into the alveolus as measured by bronchoalveolar lavage. Isolated human PMNs were incubated with 1 and 10% lymph; priming was measured by the fMLP (1 microM)-stimulated production of superoxide and surface expression of CD11b determined by flow cytometry. Results. Mesenteric lymph flow increased significantly during resuscitation: preshock 144.4 microl/h, shock 44.5 microl/h, resuscitation 566.6 microl/h. Furthermore, diversion of this lymph abrogated lung injury as compared to rats without lymph diversion. Finally, mesenteric lymph from postshock animals primed PMNs for superoxide production (nearly three times control cells) as well as increased surface expression of CD11b (2-fold over control). Conclusion. Mesenteric lymph primes PMNs and causes lung injury following hemorrhagic shock. Mesenteric lymph provides a conduit for proinflammatory mediators that may participate in the pathogenesis of MOF.