Inducible Nitric Oxide Synthase Inhibition Attenuates Physical Stress-Induced Lung Hyper-Responsiveness and Oxidative Stress in Animals with Lung Inflammation

Mechanisms involved in stress-induced asthmatic alterations have been poorly characterised. We assessed whether inducible nitric oxide synthase (iNOS) inhibition modulates the stress-amplified lung parenchyma responsiveness, oxidative stress and extracellular matrix remodelling that was previously increased by chronic lung inflammation. Guinea pigs were subjected to 7 exposures to ovalbumin (1-5 mg/ml) or saline (OVA and SAL groups) over 4 weeks. To induce behavioural stress, animals were subjected to a forced swimming protocol (5 times/week, over 2 weeks; SAL-Stress and OVA-Stress groups) 24 h after the 4th inhalation. 1400W (iNOS-specific inhibitor) was administered intraperitoneally in the last 4 days of the protocol (SAL-1400W, OVA-1400W, SAL-Stress+1400W and OVA-Stress+1400W groups). Seventy-two hours after the last inhalation, animals were anaesthetised and exsanguinated, and adrenal glands were removed. Lung tissue resistance and elastance were evaluated by oscillatory mechanics and submitted for histopathological evaluation. Stressed animals had higher adrenal weights compared to non-stressed groups, which were reduced by 1400W treatment. Behavioural stress in sensitised animals amplified the resistance and elastance responses after antigen challenge, numbers of eosinophils and iNOS+ cells, actin content and 8-iso-PGF2 alpha density in the distal lung compared to the OVA group. 1400W treatment in ovalbumin-exposed and stressed animals reduced lung mechanics, iNOS+ cell numbers and 8-iso-PGF2a density compared to sensitised and stressed animals that received vehicle treatment. We concluded that stress amplifies the distal lung constriction, eosinophilic inflammation, iNOS expression, actin content and oxidative stress previously induced by chronic lung inflammation. iNOS-derived NO contributes to stress-augmented lung tissue functional alterations in this animal model and is at least partially due to activation of the oxidative stress pathway. copyright (C) 2012S. Karger AG, Basel

Hyaluronidase recruits mesenchymal-like cells to the lung and ameliorates fibrosis

Hyaluronidases (HYALs) comprise a group of enzymes that degrade hyaluronic acid (HA). In this report, we reveal that a single intranasal inoculation of HYAL induces an increase in mononuclear cells within the bronchoalveolar space demonstrating a mesenchymal-like phenotype, expressing stem cell antigen-1 (SCA-1), CD44 and CD73 but not CD34, CD45, CD3, CD4, CD8 or CD19. This influx of mesenchymal stem cell (MSC)-like cells was dependent on leukotriene production within the lung parenchyma. These findings prompted experiments demonstrating that HYAL treatment potently blocked bleomycin-induced lung injury and fibrosis while decreasing transforming growth factor (TGF)-β production and collagen deposition. These data suggest that HYAL is a novel and promising tool to use autologous MSC-like cells in the treatment of pulmonary fibrosis.

Effects of overinflation on procollagen type III expression in experimental acute lung injury

Abstract Introduction In acute lung injury (ALI), elevation of procollagen type III (PC III) occurs early and has an adverse impact on outcome. We examined whether different high-inflation strategies of mechanical ventilation (MV) in oleic acid (OA) ALI alter regional expression of PC III. Methods We designed an experimental, randomized, and controlled protocol in which rats were allocated to two control groups (no injury, recruited [alveolar recruitment maneuver after tracheotomy without MV; n = 4 rats] and control [n = 5 rats]) or four injured groups (one exposed to OA only [n = 10 rats] and three OA-injured and ventilated). The three OA-injured groups were ventilated for 1 hour according to the following strategies: LVHP-S (low volume-high positive end-expiratory pressure [PEEP], supine; n = 10 rats, tidal volume [VT] = 8 ml/kg, PEEP = 12 cm H2O), HVLP-S (high volume-low PEEP, supine; n = 10 rats, VT = 20 ml/kg, PEEP = 5 cm H2O), and HVLP-P (high volume-low PEEP, prone; n = 10 rats). Northern blot analysis for PC III and interleukin-1-beta (IL-1β) and polymorphonuclear infiltration index (PMI) counting were performed in nondependent and dependent regions. Regional differences between groups were assessed by two-way analysis of variance after logarithmic transformation and post hoc tests. Results A significant interaction for group and region effects was observed for PC III (p = 0.012) with higher expression in the nondependent region for HVLP-S and LVHP-S, intermediate for OA and HVLP-P, and lower for control (group effect, p < 0.00001, partial η2 = 0.767; region effect, p = 0.0007, partial η2 = 0.091). We found high expression of IL-1β (group effect, p < 0.00001, partial η2 = 0.944) in the OA, HVLP-S, and HVLP-P groups without regional differences (p = 0.16). PMI behaved similarly (group effect, p < 0.00001, partial η2 = 0.832). Conclusion PC III expression is higher in nondependent regions and in ventilatory strategies that caused overdistension. This response was partially attenuated by prone positioning.

GnRH analogs do not protect ovaries from chemotherapy-induced ultrastructural injury in Hodgkin's lymphoma patients

To determine the protective effect of gonadotropin-releasing hormone analogs (GnRHa) using several ultrasound and endocrine markers to detect ultrastructural ovarian damage in Hodgkin's lymphoma patients.

Effectiveness of nitric oxide during spontaneous breathing in experimental lung injury

Inhaled nitric oxide (iNO) improves gas exchange in about 60% of patients with acute respiratory distress syndrome (ARDS). Recruitment of atelectatic lung areas may improve responsiveness and preservation of spontaneous breathing (SB) may cause recruitment. Accordingly, preservation of SB may improve effectiveness of iNO. To test this hypothesis, iNO was evaluated in experimental acute lung injury (ALI) during SB. In 24 pigs with ALI, effects of 10 ppm iNO were evaluated during controlled mechanical ventilation (CMV) and SB in random order. Preservation of SB was provided by 4 different modes: Unassisted SB was enabled by biphasic positive airway pressure (BIPAP), moderate inspiratory assist was provided by pressure support (PS) and volume-assured pressure support (VAPS), maximum assist was ensured by assist control (A/C). Statistical analysis did not reveal gas exchange improvements due to SB alone. Significant gas exchange improvements due to iNO were only achieved during unassisted SB with BIPAP (P <.05) but not during CMV or assisted SB. The authors conclude that effectiveness of iNO may be improved by unassisted SB during BIPAP but not by assisted SB. Thus combined iNO and unassisted SB is possibly most effective to improve gas exchange in severe hypoxemic ARDS.

Cyclin D1 (CCND1) A870G gene polymorphism modulates smoking-induced lung cancer risk and response to platinum-based chemotherapy in non-small cell lung cancer (NSCLC) patients

PURPOSE: The cyclin D1 (CCND1) A870G gene polymorphism is linked to the outcome in patients with resectable non-small cell lung cancer (NSCLC). Here, we investigated the impact of this polymorphism on smoking-induced cancer risk and clinical outcome in patients with NSCLC stages I-IV. METHODS: CCND1 A870G genotype was determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis (RFLP) of DNA extracted from blood. The study included 244 NSCLC patients and 187 healthy control subjects. RESULTS: Patient characteristics were: 70% male, 77% smokers, 43% adenocarcinoma, and 27% squamous cell carcinoma. Eighty-one percent of the patients had stages III-IV disease. Median age at diagnosis was 60 years and median survival was 13 months. Genotype frequencies of patients and controls both conformed to the Hardy Weinberg equilibrium. The GG genotype significantly correlated with a history of heavy smoking (>or=40 py, P=0.02), and patients with this genotype had a significantly higher cigarette consumption than patients with AA/AG genotypes (P=0.007). The GG genotype also significantly correlated with tumor response or stabilization after a platinum-based first-line chemotherapy (P=0.04). Survival analysis revealed no significant differences among the genotypes. CONCLUSION: Evidence was obtained that the CCND1 A870G gene polymorphism modulates smoking-induced lung cancer risk. Further studies are required to explore the underlying molecular mechanisms and to test the value of this gene polymorphism as a predictor for platinum-sensitivity in NSCLC patients.

Stereological analysis of acute lung injury

Acute lung injury is associated with a variety of histopathological alterations, such as oedema formation, damage to the components of the blood–air barrier and impairment of the surfactant system. Stereological methods are indispensable tools with which to properly quantitate these structural alterations at the light and electron microscopic level. The stereological parameters that are relevant for the analysis of acute lung injury are reviewed in the present articl

Non-invasive neurally adjusted ventilatory assist in rabbits with acute lung injury

OBJECTIVE: Neurally adjusted ventilatory assist uses the electrical activity of the diaphragm (EAdi)-a pneumatically-independent signal-to control the timing and pressure of the ventilation delivered, and should not be affected by leaks. The aim of this study was to evaluate whether NAVA can deliver assist in synchrony and proportionally to EAdi after extubation, with a leaky non-invasive interface. DESIGN AND SETTING: Prospective, controlled experimental study in an animal laboratory. ANIMALS: Ten rabbits, anesthetized, mechanically ventilated. INTERVENTIONS: Following lung injury, the following was performed in sequential order: (1) NAVA delivered via oral endotracheal tube with PEEP; (2) same as (1) without PEEP; (3) non-invasive NAVA at unchanged NAVA level and no PEEP via a single nasal prong; (4) no assist; (5) non-invasive NAVA at progressively increasing NAVA levels. MEASUREMENTS AND RESULTS: EAdi, esophageal pressure, blood gases and hemodynamics were measured during each condition. For the same NAVA level, the mean delivered pressure above PEEP increased from 3.9[Symbol: see text]+/-[Symbol: see text]1.4[Symbol: see text]cmH(2)O (intubated) to 7.5[Symbol: see text]+/-[Symbol: see text]3.8[Symbol: see text]cmH(2)O (non-invasive) (p[Symbol: see text]<[Symbol: see text]0.05) because of increased EAdi. No changes were observed in PaO(2) and PaCO(2). Increasing the NAVA level fourfold during non-invasive NAVA restored EAdi and esophageal pressure swings to pre-extubation levels. Triggering (106[Symbol: see text]+/-[Symbol: see text]20[Symbol: see text]ms) and cycling-off delays (40[Symbol: see text]+/-[Symbol: see text]21[Symbol: see text]ms) during intubation were minimal and not worsened by the leak (95[Symbol: see text]+/-[Symbol: see text]13[Symbol: see text]ms and 33[Symbol: see text]+/-[Symbol: see text]9[Symbol: see text]ms, respectively). CONCLUSION: NAVA can be effective in delivering non-invasive ventilation even when the interface with the patient is excessively leaky, and can unload the respiratory muscles while maintaining synchrony with the subject's demand.

[Lung protective ventilation - supportive and adjunctive therapies in acute lung injury]

Various supportive and adjunctive therapies to conventional mechanical ventilation have been evaluated in patients with acute lung injury and acute respiratory distress syndrome (e.g. nitric oxide, prone position, surfactant, glucocorticoids). Although some investigations have shown promising improvements in oxygenation and physiological variables, large randomized trials of adjunctive and supportive therapies showed no impact on survival.

Targeted gene transfer of hepatocyte growth factor to alveolar type II epithelial cells reduces lung fibrosis in rats

Inefficient alveolar wound repair contributes to the development of pulmonary fibrosis. Hepatocyte growth factor (HGF) is a potent growth factor for alveolar type II epithelial cells (AECII) and may improve repair and reduce fibrosis. We studied whether targeted gene transfer of HGF specifically to AECII improves lung fibrosis in bleomycin-induced lung fibrosis. A plasmid encoding human HGF expressed from the human surfactant protein C promoter (pSpC-hHGF) was designed, and extracorporeal electroporation-mediated gene transfer of HGF specifically to AECII was performed 7 days after bleomycin-induced lung injury in the rat. Animals were killed 7 days after hHGF gene transfer. Electroporation-mediated HGF gene transfer resulted in HGF expression specifically in AECII at biologically relevant levels. HGF gene transfer reduced pulmonary fibrosis as assessed by histology, hydroxyproline determination, and design-based stereology compared with controls. Our results indicate that the antifibrotic effect of HGF is due in part to a reduction of transforming growth factor-β(1), modulation of the epithelial-mesenchymal transition, and reduction of extravascular fibrin deposition. We conclude that targeted HGF gene transfer specifically to AECII decreases bleomycin-induced lung fibrosis and may therefore represent a novel cell-specific gene transfer technology to treat pulmonary fibrosis.