Lung Lavage Fluid Research Articles

Apocynin attenuates ventilator-induced lung injury in an isolated and perfused rat lung model

Apocynin suppresses the generation of reactive oxygen species (ROS) that are implicated in ventilator-induced lung injury (VILI). We thus hypothesized that apocynin attenuates VILI. VILI was induced by mechanical ventilation with tidal volume (V(t)) of 15 ml/kg in isolated and perfused rat lung. Apocynin was administered in the perfusate at onset of mechanical ventilation. A group ventilated with low V(t) of 5 ml/kg served as control. Hemodynamics, lung injury indices, inflammatory responses, and activation of apoptotic pathways were determined upon completion of mechanical ventilation. There was an increase in lung permeability and lung weight gain after mechanical ventilation with high V(t), compared with low V (t). Levels of inflammatory cytokines including interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and macrophage inflammatory protein-2 (MIP-2) increased in lung lavage fluids; concentrations of carbonyl, thiobarbituric acid reactive substances, and H(2)O(2) were higher in perfusates and lung lavage fluids, and expression of myeloperoxidase, JNK, p38, and caspase-3 in lung tissue was greater in the high-V(t) than in the low-V(t) group. Administration of apocynin attenuated these inflammatory responses and lung permeability associated with decreased activation of nuclear factor-κB. VILI is associated with inflammatory responses including generation of ROS, cytokines, and activation of mitogen-activated protein kinase cascades. Administration of apocynin at onset of mechanical ventilation attenuates inflammatory responses and VILI in the isolated, perfused rat lung model.

Toxicological Evaluation of Lung Responses After Intratracheal Exposure to Non-Dispersed Titanium Dioxide Nanorods

Fine- and coarse-sized titanium dioxide (TiO2) particles are considered to be relatively inert when inhaled. The goal of this study was to assess potential lung toxicity associated with well-characterized, non-dispersed rutile TiO2 nanorods (10 × 40 nm). In vitro bioreactivity of TiO2 nanorods was determined by electron spin resonance (ESR) to measure free radical production. To assess pulmonary effects in vivo, Sprague-Dawley rats were intratracheally instilled with saline, silica, or TiO2 nanorods (10 μg, 100 μg, or 1 mg/rat). On d 1, 3, and 6 posttreatment, left lungs were preserved for microscopy and histopathology, and lung lavage was performed on right lungs. Additional rats were treated with saline or TiO2 nanorods (100 μg or 1 mg/rat) on d 0, intratracheally inoculated with 5 × 105 Listeria monocytogenes on d 3, and bacterial clearance was assessed. ESR showed a significant concentration-dependent generation of hydroxyl radicals by TiO2 nanorods in the presence and absence of macrophages; however, the hydroxyl radical signals from TiO2 samples were low compared to silica. Rats exposed to 1 mg of TiO2 nanorods had significantly elevated levels of lung injury, inflammation, and lavage fluid monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-2 on d 1 and 3 that subsided by d 6, unlike the silica response that persisted. Immune cytokine secretion in the lung and bacterial clearance were not affected by preexposure to TiO2 nanorods. To summarize, non-dispersed TiO2 nanorods were found to induce radical formation and cellular oxidant production, and to generate transient and reversible pneumotoxic effects, and to not markedly alter pulmonary immune function.

Differences in acute lung response to elastase instillation in two rodent species may determine differences in severity of emphysema development

Elastase intratracheal instillation induces early emphysema in rodents. However, Syrian Golden hamsters develop more severe emphysema than Sprague-Dawley rats. We have reported species differences in oxidant/antioxidant balance modulating antiprotease function early after instillation. We now hypothesize that other components of the initial lung response to elastase might also be species-dependent. Sprague-Dawley rats and Syrian Golden hamsters received a single dose of pancreatic elastase (0.55 U/100 g body wt) to study acute lung injury biomarkers. Using serum, lung, and bronchoalveolar lavage fluid (BALF) samples, we evaluated changes in alveolar-capillary permeability, alpha 1-antitrypsin (α(1)-AT) concentration and activity, glutathione content, and proinflammatory cytokines. Rats showed a large increase in alveolar-capillary permeability and few hemorrhagic changes, whereas hamsters exhibited large hemorrhagic changes (P < 0.01) and mild transendothelial passage of proteins. Western blots showed a 30-fold increase in BALF α(1)-AT concentration in rats and only a 7-fold increase in hamsters (P < 0.001), with [α(1)-AT-elastase] complexes only in rats, suggesting differences in antiprotease function. This was confirmed by the α(1)-AT bioassay showing 20-fold increase in α(1)-AT activity in rats and only twofold increase in hamsters (P < 0.001). In rats, results were preceded by a 3-, 60-, and 20-fold increase in IL-6, IL-1β, and TNF-α respectively (P < 0.001). In hamsters, only IL-1β and TNF-α showed mild increases. All parameters studied were back to baseline by 4 days. In conclusion, several components of the initial lung response showed species differences. Cytokine release pattern and functional inhibition of α(1)-AT were the most significant components differing among species and could account for differences in susceptibility to elastase.

Cyclooxygenase-2 Regulates Th17 Cell Differentiation during Allergic Lung Inflammation

Th17 cells comprise a distinct lineage of proinflammatory T helper cells that are major contributors to allergic responses. It is unknown whether cyclooxygenase (COX)-derived eicosanoids regulate Th17 cells during allergic lung inflammation. To determine the role of COX metabolites in regulating Th17 cell differentiation and function during allergic lung inflammation. COX-1(-/-), COX-2(-/-), and wild-type mice were studied in an in vivo model of ovalbumin-induced allergic inflammation and an in vitro model of Th17 differentiation using flow cytometry, cytokine assays, confocal microscopy, real-time polymerase chain reaction, and immunoblotting. In addition, the role of specific eicosanoids and their receptors was examined using synthetic prostaglandins (PGs), selective inhibitors, and siRNA knockdown. Th17 cell differentiation in lung, lymph nodes, and bronchoalveolar lavage fluid was significantly lower in COX-2(-/-) mice after ovalbumin sensitization and exposure in vivo. In vitro studies revealed significantly impaired Th17 cell differentiation of COX-2(-/-) naive CD4(+) T cells with decreased Stat3 phosphorylation and RORγt expression. Synthetic PGF(2α) and PGI(2) enhanced Th17 cell differentiation of COX-2(-/-) CD4(+) T cells in vitro. The selective COX-2 inhibitor, NS-398, and PGF(2α) receptor and PGI(2) receptor siRNA knockdown significantly decreased Th17 cell differentiation in vitro. Administration of synthetic PGs restored accumulation of Th17 cells in lungs of allergic COX-2(-/-) mice in vivo. COX-2 is a critical regulator of Th17 cell differentiation during allergic lung inflammation via autocrine signaling of PGI(2) and PGF(2α) through their respective cell surface receptors.

RhKGF stimulates lung surfactant production in neonatal rats in vivo

Surfactant deficiency and bronchopulmonary dysplasia (BPD), major obstacles in preterm infants, are addressed with pre- and postnatal glucocorticoids which also evoke harmful catabolic side-effects. Keratinocyte growth factor (KGF) accelerates surfactant production in fetal type II pneumocytes (PN-II), protects epithelia from injury and is deficient in lungs developing BPD, highlighting its potential efficacy in neonates. Neonatal rats were treated with recombinant human (rh)KGF, betamethasone, or their combination for 48 hr prior to sacrifice after which body weight, surfactant, and tissue phosphatidylcholines (PC) were investigated at postnatal d3, d7, d15, and d21. Pneumocyte proliferation, surfactant protein (SP) expression and SP-B/C in lung lavage fluid (LLF) were also determined at d7 and d21 to identify broader surfactant changes occurring at the beginning and end of the initial alveolarization phase. While all treatments increased secreted surfactant PC, BM compromised animal growth whereas rhKGF did not. At d3 rhKGF was more effective in male compared to female rats. Single treatments became less effective towards d21. Neither treatment altered PC composition in LLF. BM inhibited PN-II proliferation and increased surfactant PCs at the expense of tissue PCs. rhKGF however increased surfactant PCs without decreasing other PC species. Whereas SP-B/C gene expression was induced by all treatments, the changes in secreted SP-B/C mirrored those observed for surfactant PC. Our results encourage investigation of the mechanisms by which rhKGF improves surfactant homoeostasis, and detailed examination of its efficacy in neonatal lung injury models with a view to implementing it as a non-catabolic surfactant-increasing therapeutic in neonatal intensive care.

Pulmonary effects of inhaled oil dispersant (COREXIT® EC9500A) in rats

COREXIT® EC9500A (CE) was used to disperse crude oil during the 2010 Deepwater Horizon oil spill response. While the environmental impact of CE has been examined, the pulmonary effects of CE are unknown. Here we investigated whether inhaled CE elicits airway inflammation, alters pulmonary function, or affects airway reactivity to methacholine (MCh). Rats were exposed to CE (mean 27 mg/m3, 5 h) and examined 1 and 7 d post‐exposure. Under anesthesia, the lung lavage fluid was harvested. Lactate dehydrogenase (LDH) and albumin (A) were measured as indices of lung injury, recovered lung cells were differentiated (macrophages, neutrophils, lymphocytes, and eosinophils) to evaluate inflammation, and oxidant production by macrophages was measured. There were no significant differences in LDH, A, inflammatory cell levels or oxidant production between air‐ and CE‐exposed groups at either time point. Pulmonary function assessed in conscious animals indicated that neither breathing frequency nor specific airway resistance were altered at 1 and 7 d post‐exposure. Airway resistance responses to MCh aerosol in anesthetized animals were unaffected at 1 and 7 d post‐exposure, while dynamic compliance responses were decreased at 1 d but not at 7 d post‐exposure. Our findings suggest that CE inhalation does not initiate lung inflammation, but may transiently increase the difficulty of breathing.

Supplemental and Highly Elevated Tocopherol Doses Differentially Regulate Allergic Inflammation: Reversibility of α-Tocopherol and γ-Tocopherol’s Effects

We have reported that supplemental doses of the α- and γ-tocopherol isoforms of vitamin E decrease and increase, respectively, allergic lung inflammation. We have now assessed whether these effects of tocopherols are reversible. For these studies, mice were treated with Ag and supplemental tocopherols in a first phase of treatment followed by a 4-wk clearance phase, and then the mice received a second phase of Ag and tocopherol treatments. The proinflammatory effects of supplemental levels of γ-tocopherol in phase 1 were only partially reversed by supplemental α-tocopherol in phase 2, but were completely reversed by raising α-tocopherol levels 10-fold in phase 2. When γ-tocopherol levels were increased 10-fold (highly elevated tocopherol) so that the lung tissue γ-tocopherol levels were equal to the lung tissue levels of supplemental α-tocopherol, γ-tocopherol reduced leukocyte numbers in the lung lavage fluid. In contrast to the lung lavage fluid, highly elevated levels of γ-tocopherol increased inflammation in the lung tissue. These regulatory effects of highly elevated tocopherols on tissue inflammation and lung lavage fluid were reversible in a second phase of Ag challenge without tocopherols. In summary, the proinflammatory effects of supplemental γ-tocopherol on lung inflammation were partially reversed by supplemental levels of α-tocopherol but were completely reversed by highly elevated levels of α-tocopherol. Also, highly elevated levels of γ-tocopherol were inhibitory and reversible in lung lavage but, importantly, were proinflammatory in lung tissue sections. These results have implications for future studies with tocopherols and provide a new context in which to review vitamin E studies in the literature.

Apocynin attenuates ischemia-reperfusion lung injury in an isolated and perfused rat lung model

Apocynin suppresses the generation of reactive oxygen species (ROS) that are implicated in ischemia-reperfusion (I/R) lung injury. We thus hypothesized that apocynin attenuates I/R. Furthermore, we explored the mechanisms by which apocynin may attenuate I/R. I/R was induced in an isolated and perfused rat lung model with ischemia for 1 h followed by reperfusion for 1 h. Apocynin was administered in the circulating perfusate at the onset of ischemia. Hemodynamics, lung injury indices, inflammatory responses, and activation of apoptotic pathways were determined. An increase in lung permeability and lung weight gain was noted after I/R. Peak airway pressure was increased, and pH of circulating perfusate was decreased. The adhesion molecule of neutrophil (CD31) in perfusate was upregulated. The levels of albumin, white blood cell count, and inflammatory cytokines including interleukin-1β, tumor necrosis factor-α, and macrophage inflammatory protein-2 increased in lung lavage fluid; the concentrations of carbonyl and thiobarbituric acid reactive substances were greater in the circulating perfusate; and the expression of myeloperoxidase, JNK, P38, and caspase-3 in lung tissue was greater in the control group. Upregulation and activation of nuclear factor-κB (NF-κB) in nuclei were found in I/R. The administration of apocynin attenuated these inflammatory responses and lung permeability associated with decreased activation of NF-κB. We conclude that I/R is associated with inflammatory responses including the generation of ROS, adhesion protein of neutrophil, cytokines, and the activation of mitogen-activated proteinkinase and NF-κB cascade. The administration of apocynin attenuates the inflammatory responses and I/R in the isolated, perfused rat lung model.

Utility of a Panviral Microarray for Detection of Swine Respiratory Viruses in Clinical Samples

Several factors have recently converged, elevating the need for highly parallel diagnostic platforms that have the ability to detect many known, novel, and emerging pathogenic agents simultaneously. Panviral DNA microarrays represent the most robust approach for massively parallel viral surveillance and detection. The Virochip is a panviral DNA microarray that is capable of detecting all known viruses, as well as novel viruses related to known viral families, in a single assay and has been used to successfully identify known and novel viral agents in clinical human specimens. However, the usefulness and the sensitivity of the Virochip platform have not been tested on a set of clinical veterinary specimens with the high degree of genetic variance that is frequently observed with swine virus field isolates. In this report, we investigate the utility and sensitivity of the Virochip to positively detect swine viruses in both cell culture-derived samples and clinical swine samples. The Virochip successfully detected porcine reproductive and respiratory syndrome virus (PRRSV) in serum containing 6.10 × 10(2) viral copies per microliter and influenza A virus in lung lavage fluid containing 2.08 × 10(6) viral copies per microliter. The Virochip also successfully detected porcine circovirus type 2 (PCV2) in serum containing 2.50 × 10(8) viral copies per microliter and porcine respiratory coronavirus (PRCV) in turbinate tissue homogenate. Collectively, the data in this report demonstrate that the Virochip can successfully detect pathogenic viruses frequently found in swine in a variety of solid and liquid specimens, such as turbinate tissue homogenate and lung lavage fluid, as well as antemortem samples, such as serum.

The effect of Nigella sativa extract on tracheal responsiveness and lung inflammation in ovalbumin-sensitized guinea pigs

OBJECTIVE:To examine the preventive effect of a hydro-ethanolic extract of Nigella sativa on the tracheal responsiveness and white blood cell count in the lung lavage fluid of sensitized guinea pigs.METHODS:Three groups of guinea pigs sensitized to intraperitoneally injected and inhaled ovalbumin were given drinking water alone (group S), drinking water containing a low concentration of N. sativa extract (group S+LNS) or drinking water containing a high concentration of N. sativa extract (group S+HNS). The tracheal responses of control animals (group C) and the three groups of sensitized guinea pigs (n = 7 for all groups) to methacholine were measured by the assessment of the tracheal smooth muscle response to increasing concentrations of methacholine, and the effective concentration causing 50% of the maximum response (EC50) was determined. Tracheal responses to 0.1% ovalbumin and white blood cell counts in the lung lavage fluid were also examined.RESULTS:The tracheal response of the group S guinea pigs to both methacholine and ovalbumin was significantly higher than the response of the controls (p<0.01 for both cases). The tracheal responses of the S+LNS and S+HNS groups to both methacholine and ovalbumin were significantly decreased compared to those of the S group (p<0.05 to p<0.01). The total white blood cell and eosinophil counts in the lung lavage fluid of group S were significantly higher than those of group C (p<0.01). The white blood cell counts in both treated groups showed significant improvements (p<0.01 for both cases).CONCLUSIONS:These results demonstrate the preventive effect of the N. sativa extract on the tracheal response and lung inflammation in sensitized guinea pigs.

Alpha-1 Antitrypsin is Markedly Decreased Following Pulmonary F. tularensis Challenge

Neutrophils form the first line of defense during infection and are indispensable in this function. The neutrophil elastase is a key effector molecule of the innate immune system with potent antimicrobial activity against Gram-negative bacteria, spirochaetes, and fungi. However, the release of neutrophil elastase during bacterial infection must be checked otherwise its release in the extracellular milieu will result in damage to surrounding tissues. Alpha-1 antitrypsin is a small glycoprotein clade A serpine serine protease inhibitor and has been shown to increase in humans following bacterial and viral infection. Francisella tularensis is a Gram-negative facultative intracellular bacterium and the causative agent of tularemia. Type A strains are the most virulent with an infectious dose as low as 10 colony forming units and a mortality rate of 30–60% among untreated cases of pneumonic tularemia. We report here significant reduction of this major inhibitor of the neutrophil elastase in plasma of F. tularensis LVS and F. tularensis (type A) SCHU S4 infected animals following pulmonary challenge. Associated with an imbalance of protease–antiprotease function at the alveolar level in lungs of infected animals, increased elastase activity was observed in lung lavage fluids accompanied by decrease lung function, i.e., loss of lung elastance with concomitant increase of pulmonary hysteresivity. Consistent with a competent acute phase response following F. tularensis LVS and F. tularensis (type A) SCHU S4 pulmonary challenge and proposed up-regulation of plasma haptoglobin during the course of the acute phase reaction, haptoglobin was observed significantly increased. These data suggest that unchecked neutrophil serine protease activity may arise from F. tularensis targeted reduction of plasma α1-antitrysin promoting lung tissue damage facilitating increased dissemination of this bacterium in infected animals.

Soluble urokinase-type plasminogen activator receptor levels in patients with burn injuries and inhalation trauma requiring mechanical ventilation: an observational cohort study

IntroductionSoluble urokinase-type plasminogen activator receptor (suPAR) has been proposed as a biologic marker of fibrinolysis and inflammation. The aim of this study was to investigate the diagnostic and prognostic value of systemic and pulmonary levels of suPAR in burn patients with inhalation trauma who need mechanical ventilation.MethodssuPAR was measured in plasma and nondirected lung-lavage fluid of mechanically ventilated burn patients with inhalation trauma. The samples were obtained on the day of inhalation trauma and on alternate days thereafter until patients were completely weaned from the mechanical ventilator. Mechanically ventilated patients without burns and without pulmonary disease served as controls.ResultsSystemic levels of suPAR in burn patients with inhalation trauma were not different from those in control patients. On admission and follow up, pulmonary levels of suPAR in patients with inhalation trauma were significantly higher compared with controls. Pulmonary levels of suPAR highly correlated with pulmonary levels of interleukin 6, a marker of inflammation, and thrombin-antithrombin complexes, markers of coagulation, but not plasminogen activator activity, a marker of fibrinolysis. Systemic levels of suPAR were predictive of the duration of mechanical ventilation and length of intensive care unit (ICU) stay. Duration of mechanical ventilation and length of ICU stay were significantly longer in burn-injury patients with systemic suPAR levels > 9.5 ng/ml.ConclusionsPulmonary levels of suPAR are elevated in burn patients with inhalation trauma, and they correlate with pulmonary inflammation and coagulation. Although pulmonary levels of suPAR may have diagnostic value in burn-injury patients, systemic levels of suPAR have prognostic value.

Immune responses to the oral administration of recombinant Bacillus subtilis expressing multi-epitopes of foot-and-mouth disease virus and a cholera toxin B subunit

Bacillus subtilis has been engineered successfully to express heterologous antigens for use as a vaccine vehicle that can elicit mucosal and systemic immunity response. In this study, a recombinant B. subtilis expressing the B subunit of cholera toxin (CT-B) and an epitope box constituted with antigen sites from foot-and-mouth disease virus (FMDV) type Asia 1 was constructed and named 1A751/CTB-TEpiAs. Its capability to induce mucosal, humoral, and cellular responses in mice and guinea pigs was evaluated after oral administration with vegetative cells of 1A751/CTB-TEpiAs. In addition, its capability to protect guinea pigs against homologous virus challenge was examined. All animals were given booster vaccination at day 21 after initial inoculation and guinea pigs were challenged 3 weeks after booster vaccination. The control groups were inoculated with a commercial vaccine or administered orally with 1A751/pBC38C or an oral buffer. All animals vaccinated with 1A751/CTB-TEpiAs developed specific anti-FMDV IgA in lung and gut lavage fluid, serum ELISA antibody, neutralizing antibody as well as T lymphocyte proliferation, and IFN-γ secretory responses. Three of the five guinea pigs vaccinated with 1A751/CTB-TEpiAs were protected completely from the viral challenge. The results demonstrate the potential viability of a B. subtilis-based recombinant vaccine for the control and prevention of FMDV infections.

Assessment of Surfactant Protein A (SP-A) dependent agglutination

BackgroundMonomers of the collectin surfactant associated protein-A (SP-A) are arranged in trimers and higher oligomers. The state of oligomerization differs between individuals and likely affects SP-A's functional properties. SP-A can form aggregates together with other SP-A molecules. Here we report and assess a test system for the aggregate forming properties of SP-A in serum and broncho-alveolar lavage samples.MethodsAnti-SP-A antibodies fixed to latex beads bound SP-A at its N-terminal end and allowed the interaction with other SP-A molecules in a given sample by their C-terminal carbohydrate recognition domain (CRD) to agglutinate the beads to aggregates, which were quantified by light microscopy.ResultsSP-A aggregation was dependent on its concentration, the presence of calcium, and was dose-dependently inhibited by mannose. Unaffected by the presence of SP-D no aggregation was observed in absence of SP-A. The more complex the oligomeric structure of SP-A present in a particular sample, the better was its capability to induce aggregation at a given total concentration of SP-A. SP-A in serum agglutinated independently of the pulmonary disease; in contrast SP-A in lung lavage fluid was clearly inferior in patients with chronic bronchitis and particularly with cystic fibrosis compared to controls.ConclusionsThe functional status of SP-A with respect to its aggregating properties in serum and lavage samples can be easily assessed. SP-A in lung lavage fluid in patients with severe neutrophilic bronchitis was inferior.

Asymmetric dimethylarginine potentiates lung inflammation in a mouse model of allergic asthma.

Nitric oxide (NO), formed by nitric oxide synthase (NOS), is an important mediator of lung inflammation in allergic asthma. Asymmetric dimethylarginine (ADMA), a competitive endogenous inhibitor of NOS, is metabolized by the enzyme dimethylarginine dimethylaminohydrolase (DDAH). Elevated ADMA has been shown to affect lung function in mice, and by inhibiting NOS it alters NO and reactive oxygen species production in mouse lung epithelial cells. However, the effects of altered ADMA levels during lung inflammation have not been explored. A model of allergen-induced airway inflammation was utilized in combination with the modulation of endogenous circulating ADMA levels in mice. Airway inflammation was assessed by quantifying inflammatory cell infiltrates in lung lavage and by histology. Lung DDAH expression was assessed by quantitative PCR and immunohistochemistry. Nitrite levels were determined in lung lavage fluid as a measure of NO production. iNOS expression was determined by immunohistochemistry, immunofluorescence, Western blot, and quantitative PCR. NF-κB binding activity was assessed by a transcription factor binding assay. Allergen-induced lung inflammation was potentiated in mice with elevated circulating ADMA and was reduced in mice overexpressing DDAH. Elevated ADMA reduced nitrite levels in lung lavage fluid in both allergen-challenged and control animals. ADMA increased iNOS expression in airway epithelial cells in vivo following allergen challenge and in vitro in stimulated mouse lung epithelial cells. ADMA also increased NF-κB binding activity in airway epithelial cells in vitro. These data support that ADMA may play a role in inflammatory airway diseases such as asthma through modulation of iNOS expression in lung epithelial cells.

Novel findings from the second wave of adult pH1N1 in the United States*

To describe the impact of novel pH1N1 virus in Atlanta, GA, for inpatient and intensive care services, including lung lavage data and determinants of disease outcome, from the earliest group of infected US population after initial cases. An observational review of all patients with laboratory-confirmed pH1N1 disease hospitalized in four Atlanta hospitals from August 1 through October 31, 2009. Data reviewed included demographics, anthropometrics, clinical laboratory, and respiratory physiology. Four hospitals in urban Atlanta, Georgia. Consecutively admitted patients between August 1 and October 31, 2009 with laboratory confirmed pH1N1 infection. None. A total of 109 patients were admitted during the surveillance period and intensive care unit care was required in 23 patients (21%) among which there were six deaths (26%). Only eight of the 109 (7%) patients were without medical comorbidity; 34% of the 65 female patients were pregnant and none died or required intensive care unit care. Patients with respiratory failure undergoing bronchoalveolar lavage exhibited neutrophilic predominance (average 64%) and negative bacterial cultures. Body mass index was > 30 kg/m in 35 of 81 (43%) of patients with anthropometric data and 16 of 23 (70%) patients requiring intensive care unit care (p = .03). The 16 patients who required mechanical ventilation (70% of intensive care unit patients) were characterized by severe hypoxemia (requiring high levels of inspired oxygen and positive end-expiratory pressures), reduced lung compliance, and high lung injury scores. This first report of the second wave of US pH1N1 disease from Atlanta, GA, shares epidemiologic characteristics of earlier cohorts but differs by having an even greater prevalence of obesity and fewer patients who were free from chronic medical conditions. Importantly, lung lavage fluid in severe pH1N1 disease is predominantly neutrophilic and culture-negative. Further reports are needed to validate these new findings regarding pH1N1 disease in the United States.

Airborne Asian sand dust enhances murine lung eosinophilia

There is no experimental study demonstrating the effects of airborne Asian sand dust (AASD) on allergic lung eosinophilia. The organic substances adsorbed onto AASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360°C for 30 min. The effects of AASD or heated-AASD (H-AASD) towards allergic lung inflammation were compared in murine lungs to investigate the role of organic substances. ICR mice were administrated with the two kinds of AASD and/or ovalbumin (OVA) intratracheally four times at 2-week intervals. AASD and H-AASD enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. AASD and H-AASD synergistically increased Th2 cytokines—interleukin-13 (IL-13), eosinophil-relevant cytokine and chemokine, such as IL-5, and monocyte chemotactic protein-3 (MCP-3) induced by OVA in whole lung lavage fluid. The enhancing effects were much greater in AASD than in H-AASD. AASD induced adjuvant effects on OVA-specific immunoglobulin E (IgE) and IgG1 production. In an in vitro study using RAW264.7 cells, AASD increased the expression of Toll-like receptors 2 (TLR2) mRNA, but not TLR4 mRNA. AASD increased mRNA expression of NALP3, ASC, and IL-1β compared with the control. H-AASD caused no expression of either mRNA. These results suggest that the aggravated lung eosinophilia in AASD is due to activation of a Th2-associated immune response and that the activation of TLR2 and NALP3 inflammasome by microbial materials could be participating in this phenomenon.

Efficacy of an inactivated recombinant vaccine encoding a fimbrial protein of Pasteurella multocida B:2 against hemorrhagic septicemia in goats

This study was carried out to determine the antibody responses and protective capacity of an inactivated recombinant vaccine expressing the fimbrial protein of Pasteurella multocida B:2 following intranasal vaccination against hemorrhagic septicemia in goats. Goats were vaccinated intranasal with 10(6)CFU/mL of the recombinant vaccine (vaccinated group) and 10(6)CFU/mL of pET32/LIC vector without fimbrial protein (control group). All three groups were kept separated before all goats in the three groups were challenged with 10(9)CFU/mL of live pathogenic P. multocida B:2. During the course of study, both serum and lung lavage fluid were collected to evaluate the antibody levels via enzyme-linked immunosorbent assay. It was found that goats immunized with the inactivated recombinant vaccine developed a strong and significantly (p < 0.05) higher specific IgA and IgG responses in both serum and lung lavage fluid samples compared to the control and unvaccinated groups. Following intratracheal challenge, the rate of isolation was 17% for the vaccinated group, 67% for the control group and 100% for the unvaccinated group. However, none of the goat from the vaccinated group had P. multocida B:2 in the liver, tonsil and heart. Therefore, the study revealed that an inactivated recombinant vaccine significantly provides significant protection against high dose challenge and enhances the stimulation of the local and systemic immunities.

Small-Sized Titanium Dioxide Nanoparticles Mediate Immune Toxicity in Rat Pulmonary Alveolar Macrophages &lt;I&gt;In Vivo&lt;/I&gt;

Small-sized titanium dioxide (TiO2) nanoparticles (< 10 nm) are widely used in both industry and daily life due to their enhanced thermomagnetic and photocatalytic properties and surface activity. However, their increasing use increases the health risk of people exposed to these particles, either occupationally or environmentally. This study was performed to evaluate the effect of small-sized TiO2 nanoparticles on the immune function of rat pulmonary alveolar macrophages in vivo. Forty-two rats were intra-tracheally instilled with 0.5, 5 or 50 mg/kg of NP-1 and F-1 TiO2 primary particles with a median size of 5 nm and 200 nm, respectively. Rat pulmonary alveolar macrophages were obtained from lung lavage fluids using a closed chest technique. Cells were assessed for morphology, phagocytic ability and chemotactic ability, Fc receptor expression, MHC-class II molecule expression, and expression of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha). The result showed that the inhalation of NP-1 TiO2 particles induced the membrane and ultrastructure damage of PAMs. The phagocytic ability of the macrophages increased when they were exposed to low dose of NP-1 TiO2 and decreased when they were exposed to high dose of NP-1 TiO2. Exposure to NP-1 TiO2 also decreased the chemotactic ability of the macrophages as well as decreasing the expression of Fc receptors and MHC-class II on the cell surface. The mechanism responsible for these changes was mediated via altering NO and TNF-alpha expression by the PAMs. The amount of NO and TNF-alpha secreted by macrophages gradually increased as the dosage of TiO2 nanoparticles increased. Small-sized TiO2 nanoparticles (but not the fine counterpart) elicited stronger NO and TNF-alpha production. The present study suggests that both damage to the cell structure and pulmonary alveolar macrophage dysfunction may occur, leading to a reduction in both non-specific and specific immune responses in individuals exposed to small-sized TiO2 nanoparticles.

Effects of positive end expiratory pressure on pulmonary surfactant in patients undergoing one-lung ventilation

To evaluate the effect of positive end expiratory pressure on the bronchoalveolar lavage fluid (BALF) in pulmonary surfactant (PS) of patient during one lung ventilation anesthesia. Patients undergoing Bullae resection were anesthetized with treatment (n = 12) or control (n = 12) combined anesthesia. Total phospholipid (TPL), saturated phosphatidylcholine (SatPC) and total protein (TP) in the bronchoalveolar lavage fluid (BALF) were measure. The ratio of SatPC/TPL% and SatPC/TP% represented the activity of PS. The thoracic surgery pulmonary surfactant significantly reduced, PEEP can prevent the decrease, but with decreased cardiac output. The end-expiratory pressure breathing can maintain the level of pulmonary surfactant to protect lung function.