Reactive oxygen or nitrogen species (ROS/RNS) generated endogenously or in response to environmental stress have long been implicated in tissue injury in the context of a variety of disease states. ROS/RNS can cause cell death by nonphysiological (necrotic) or regulated pathways (apoptotic). The mechanisms by which ROS/RNS cause or regulate apoptosis typically include receptor activation, caspase activation, Bcl-2 family proteins, and mitochondrial dysfunction. Various protein kinase activities, including mitogen-activated protein kinases, protein kinases-B/C, inhibitor-of-I-kappaB kinases, and their corresponding phosphatases modulate the apoptotic program depending on cellular context. Recently, lipid-derived mediators have emerged as potential intermediates in the apoptosis pathway triggered by oxidants. Cell death mechanisms have been studied across a broad spectrum of models of oxidative stress, including H2O2, nitric oxide and derivatives, endotoxin-induced inflammation, photodynamic therapy, ultraviolet-A and ionizing radiations, and cigarette smoke. Additionally ROS generated in the lung and other organs as the result of high oxygen therapy or ischemia/reperfusion can stimulate cell death pathways associated with tissue damage. Cells have evolved numerous survival pathways to counter proapoptotic stimuli, which include activation of stress-related protein responses. Among these, the heme oxygenase-1/carbon monoxide system has emerged as a major intracellular antiapoptotic mechanism.

Sevoflurane and isoflurane induce apoptosis in T lymphocytes via increased mitochondrial membrane permeability and caspase-3 activation, but independently of death receptor signaling.

Rationale: Ventilator-induced lung injury (VILI) leads to an unacceptably high mortality. In this regard, the antiinflammatory properties of inhaled carbon monoxide (CO) may provide a therapeutic option. Objectives: This study explores the mechanisms of CO-dependent protection in a mouse model of VILI. Methods: Mice were ventilated (12 ml/kg, 1-8 h) with air in the absence or presence of CO (250 ppm). Airway pressures, blood pressure, and blood gases were monitored. Lung tissue was analyzed for inflammation, injury, and gene expression. Bronchoalveolar lavage fluid was analyzed for protein, cell and neutrophil counts, and cytokines. Measurements and Main Results: Mechanical ventilation caused significant lung injury reflected by increases in protein concentration, total cell and neutrophil counts in the bronchoalveolar lavage fluid, as well as the induction of heme oxygenase-1 and heat shock protein-70 in lung tissue. In contrast, CO application prevented lung injury during ventilation, inhibited stress-gene up-regulation, and decreased lung neutrophil infiltration. These effects were preceded by the inhibition of ventilation-induced cytokine and chemokine production. Furthermore, CO prevented the early ventilationdependent up-regulation of early growth response-1 (Egr-1). Egr-1-deficient mice did not sustain lung injury after ventilation, relative to wild-type mice, suggesting that Egr-1 acts as a key proinflammatory regulator in VILI. Moreover, inhibition of peroxysome proliferatoractivated receptor (PPAR)-g, an antiinflammatory nuclear regulator, by GW9662 abolished the protective effects of CO. Conclusions: Mechanical ventilation causes profound lung injury and inflammatory responses. CO treatment conferred protection in this model dependent on PPAR-g and inhibition of Egr-1.

Inhalation of hydrogen sulfide during mechanical ventilation protects against VILI by the inhibition of inflammatory and apoptotic responses. Hydrogen sulfide confers lung protection independently of its ability to induce mild hypothermia during ventilation.

This study provides first evidence that pretreatment with the nontoxic and clinically approved anesthetic isoflurane induces hepatic HO-1 expression, and thereby protects rat livers from ischemia/reperfusion injury.

Objectives Carbon monoxide (CO) can confer anti-inflammatory protection in rodent models of ventilator-induced lung injury (VILI). Caveolin-1 exerts a critical role in cellular responses to mechanical stress, and has been shown to mediate cytoprotective effects of CO in vitro. We sought to determine the role of caveolin-1 in lung susceptibility to VILI in mice. Furthermore, we assessed the role of caveolin-1 in the tissue protective effects of CO in the VILI model. Design Prospective experimental study Setting University laboratory Subjects Wild type (wt) and caveolin-1 deficient (cav-−/−) mice Interventions Mice were subjected to tracheostomy and arterial cannulation. Wt and cav-1−/− mice were ventilated with a tidal volume of 12 ml/kg body weight and a frequency of 80/min for 5 min as control, or for 8h with air in the absence or presence of CO (250 parts per million). Bronchoalveolar lavage (BAL) and histology were used to determine lung injury. Lung sections or homogenates were analyzed for caveolin-1 expression by immunohistochemical staining or Western Blotting, respectively. Measurements and Main Results Ventilation led to an increase in BAL protein concentration, cell count, neutrophil recruitment, and edema formation that was prevented in the presence of CO. While ventilation alone slightly induced caveolin-1 expression in epithelial cells, the application of CO during the ventilation significantly increased the expression of caveolin-1. In comparison to wt mice, mechanical ventilation of cav-1−/− mice led to a significantly higher degree of lung injury as compared to wt mice. In contrast to its effectiveness in wt mice, CO-administration failed to reduce lung injury markers in cav-1−/− mice. Conclusions Caveolin-1 null mice are more susceptible to VILI. Carbon monoxide executes lung protective effects during mechanical ventilation that are dependent in part, on caveolin-1 expression.

Ventroposterior pallidotomy significantly improves motor performance and daily level of function in Parkinson disease. Cognition and behavior are not adversely affected in patients without dementia, and a cognitive screening battery is proposed.

BackgroundMechanical ventilation causes ventilator-induced lung injury in animals and humans. Mitogen-activated protein kinases have been implicated in ventilator-induced lung injury though their functional significance remains incomplete. We characterize the role of p38 mitogen-activated protein kinase/mitogen activated protein kinase kinase-3 and c-Jun-NH2-terminal kinase-1 in ventilator-induced lung injury and investigate novel independent mechanisms contributing to lung injury during mechanical ventilation.Methodology and Principle FindingsC57/BL6 wild-type mice and mice genetically deleted for mitogen-activated protein kinase kinase-3 (mkk-3 −/−) or c-Jun-NH2-terminal kinase-1 (jnk1 −/−) were ventilated, and lung injury parameters were assessed. We demonstrate that mkk3 −/− or jnk1 −/− mice displayed significantly reduced inflammatory lung injury and apoptosis relative to wild-type mice. Since jnk1−/− mice were highly resistant to ventilator-induced lung injury, we performed comprehensive gene expression profiling of ventilated wild-type or jnk1−/− mice to identify novel candidate genes which may play critical roles in the pathogenesis of ventilator-induced lung injury. Microarray analysis revealed many novel genes differentially expressed by ventilation including matrix metalloproteinase-8 (MMP8) and GADD45α. Functional characterization of MMP8 revealed that mmp8−/− mice were sensitized to ventilator-induced lung injury with increased lung vascular permeability.ConclusionsWe demonstrate that mitogen-activated protein kinase pathways mediate inflammatory lung injury during ventilator-induced lung injury. C-Jun-NH2-terminal kinase was also involved in alveolo-capillary leakage and edema formation, whereas MMP8 inhibited alveolo-capillary protein leakage.