Immunogenicity and Safety of a Quadrivalent Meningococcal Conjugate Vaccine Versus Nimenrix in Healthy Adolescents: A Randomized Phase IIIb Multicenter Study.

INTRODUCTION: Many immunization programs in Europe recommend quadrivalent meningococcal vaccinations, which are often administered concomitantly with other vaccines. We compared the immune response of a tetanus toxoid conjugated quadrivalent meningococcal vaccine (MenACYW-TT, MenQuadfi®) with another quadrivalent meningococcal conjugate vaccine (MCV4-TT; Nimenrix®) when administered alone or concomitantly with Tdap-IPV and 9vHPV vaccines in adolescents. METHODS: In this phase IIIb trial, healthy adolescents (MenC-naïve or MenC-primed before 2 years of age) from Spain, Italy, Hungary, and Singapore were randomized in a 3:3:2 ratio to receive either MenACYW-TT or MCV4-TT alone, or MenACYW-TT concomitantly with 9vHPV and Tdap-IPV. The primary objective was to demonstrate the non-inferiority of the seroprotection rate (human serum bactericidal assay [hSBA] titer ≥ 1:8) to serogroups A, C, W, and Y 30 days post-vaccination with a single dose of MenACYW-TT or MCV4-TT. Secondary objectives included describing hSBA titers for the four serogroups before and 1 month following vaccination and according to MenC priming status. RESULTS: A total of 463 participants were enrolled (MenACYW-TT, n = 173; MCV4-TT, n = 173; MenACYW-TT/9vHPV/Tdap-IPV n = 117). Non-inferiority based on seroprotection was demonstrated for MenACYW-TT versus MCV4-TT for all serogroups. Immune responses were comparable whether MenACYW-TT was administered alone or concomitantly with Tdap-IPV and 9vHPV. Post-vaccination hSBA GMTs were higher in MenACYW-TT vs. MCV4-TT for serogroups C, Y, and W and comparable for serogroup A. The percentages of participants with an hSBA vaccine seroresponse were higher in MenACYW-TT vs. MCV4-TT for all serogroups. For serogroup C, higher GMTs were observed in both MenC-naïve or -primed participants vaccinated with MenACYW-TT vs. MCV4-TT. Seroprotection and seroresponse were higher in MenC-naïve participants vaccinated with MenACYW-TT vs. MCV4-TT and comparable in MenC-primed. The safety profiles were comparable between groups and no new safety concerns were identified. CONCLUSIONS: These data support the concomitant administration of MenACYW-TT with 9vHPV and Tdap-IPV vaccines in adolescents. TRIAL REGISTRATIONS: Clinicaltrials.gov, NCT04490018; EudraCT: 2020-001665-37; WHO: U1111-1249-2973.

MenACYW conjugate vaccine has been made to protect against meningococcal disease caused by four common types of bacteria (germs) called Neisseria meningitidis (or meningococcus), A, C, W, and Y. Many people, particularly adolescents, have the germs of this disease in their nose or throat, and therefore may develop the disease or transmit the bacteria to other people. Hence, adolescent meningococcal vaccination against serogroups ACWY is increasingly recommended in several countries. This study assessed the immune response to these serogroups in healthy adolescents after one dose of MenACYW conjugate vaccine or Nimenrix^®, a meningococcal licensed vaccine. Moreover, the immune response and safety were assessed when the vaccines were given alone or when given concomitantly with other adolescent vaccines, including the human papillomavirus (9vHPV) and tetanus, diphtheria, pertussis, and poliomyelitis (Tdap-IPV) vaccines. A total of 463 adolescents (aged 10­17 years) participated in this study and received either MenACYW or Nimenrix^® alone, or MenACYW concomitantly with 9vHPV and Tdap-IPV vaccine. The immune response induced by MenACYW was as good as the immune response induced by Nimenrix^®, and when given alone or concomitantly with 9vHPV and Tdap IPV vaccines. None of the participants experienced any serious side effects of any vaccine. The most common non-serious side effects were injection site pain, muscle pain, and headache. These data support the use of MenACYW in adolescents, with or without concomitant administration with 9vHPV and Tdap-IPV, which may help to increase the number of adolescents vaccinated.

Post-Marketing Safety Surveillance of Quadrivalent Influenza Vaccine (VaxigripTetra) in Children Aged 6 to 35 Months in South Korea.

INTRODUCTION: The quadrivalent inactivated split-virion influenza vaccine (QIV; VaxigripTetra®) was initially licensed in South Korea in 2017 for immunization against seasonal influenza in those aged ≥ 3 years, with the indicated age subsequently lowered to include those aged ≥ 6 months in 2018. Here, to comply with South Korean licensure requirements, we undertook a post-marketing surveillance study to assess the safety of QIV in children aged 6-35 months (i.e., extension of the previous age indication to include these young children) in routine clinical practice. METHODS: A multicenter, observational, active safety surveillance of children aged 6-35 months who received a single dose of QIV during a routine healthcare visit was undertaken in South Korea from 15 June 2018 to 14 June 2022. Solicited adverse events (AEs) and unsolicited non-serious AEs were recorded in diary cards, with serious adverse events (SAEs) notified to study investigators. RESULTS: This safety analysis included 676 participants. No AEs led to study termination, and no SAEs were reported. The most frequent solicited injection site reaction was pain in both the ≤ 23-month (12.2% [55/450]) and ≥ 24-month (15.5% [35/226]) age groups. The most frequent solicited systemic reactions were pyrexia and somnolence in the ≤ 23-month age group (6.0% [27/450] each), and malaise (10.6% [24/226]) in the ≥ 24-month age group. Overall, 208 (30.8%) participants experienced 339 unsolicited non-serious AEs, with nasopharyngitis the most common (14.1% [95/676]), and nearly all events (98.8% [335/339]) were considered unrelated to QIV. Grade 3 solicited reactions and unsolicited non-serious AEs were reported in five (0.7%) and three (0.4%) participants, respectively, all of whom recovered by day 7 after vaccination. CONCLUSION: This active safety surveillance study confirms that QIV is well tolerated in children aged 6-35 months in routine clinical practice in South Korea. There were no safety concerns observed in these young children.

Enhanced passive safety surveillance of high-dose and standard-dose quadrivalent inactivated split-virion influenza vaccines in Germany and Finland during the influenza season 2021/22.

BACKGROUND: Enhanced passive safety surveillance (EPSS) was conducted for quadrivalent inactivated split-virion influenza vaccines (IIV4) in Germany (high dose [HD], aged ≥60 years) and in Finland (standard dose [SD], aged ≥6 months) at the beginning of the northern hemisphere 2021/22 influenza season. The primary objective was to assess adverse drug reactions (ADRs) occurring ≤7 days post-vaccination. METHODS: Vaccinees were issued vaccination cards (VC) and were encouraged to report ADRs via an electronic data collection system or by telephone. ADRs were assessed by frequency, time to onset, intensity and by age group. The vaccinee reporting rate (RR) was calculated as the number of vaccinees reporting ≥1 ADR divided by total vaccinees. Reactogenicity was compared with previous experiences with each vaccine. RESULTS: Among 903 HD-IIV4 vaccinees in Germany, 17 reported ≥1 ADR within ≤7 days post-vaccination: RR, 1.88% (95% CI: 1.10, 3.00). Time to onset was known for 53/65 ADRs, all of which occurred ≤7 days post-vaccination. In Germany, seven ADRs were reported that were not listed previously. Among the 1000 SD-IIV4 vaccinees in Finland, 49 reported ≥1 ADR within ≤7 days post-vaccination: RR, 4.90% (95% CI: 3.65, 6.43). Time to onset was known for 126/134 ADRs, of which 125 occurred ≤7 days post-vaccination. In Finland, 21 ADRs were reported that were not listed previously. No ADRs reported during follow-up were serious. CONCLUSIONS: The EPSS for HD-IIV4 and for SD-IIV4 in the 2021/22 influenza season did not suggest any clinically relevant changes in safety beyond what is known/expected for IIV4s.

Immunological non-inferiority and safety of a quadrivalent inactivated influenza vaccine versus two trivalent inactivated influenza vaccines in China: Results from two studies.

WHO UNIVERSAL TRIAL NUMBERS (UTNS): U1111-1174-4615 and U1111-1174-4698. CLINICALTRIALS.GOV: NCT04210349 and NCT03430089.

Post-marketing Surveillance of a Quadrivalent Influenza Vaccine (Vaxigrip Tetra) in South Korea.

INTRODUCTION: In 2017, a quadrivalent inactivated split-virion influenza vaccine (QIV; Vaxigrip Tetra®, Sanofi) was licensed in South Korea for active immunization against influenza A and influenza B viruses in individuals aged 3 years or older, which was subsequently extended to individuals aged 6 months or older in 2018. Post-marketing surveillance trials are mandatory in South Korea to retain drug licensure. Here, we assessed the safety of QIV in routine clinical practice in South Korea. METHODS: This was an open, multicenter, observational, active safety surveillance study conducted between 20 June 2017 and 19 June 2021 at 10 study sites in South Korea in individuals aged 3 years or older who received a single dose of QIV during a routine healthcare visit. The participants or their legally acceptable representatives were instructed to record any adverse reactions (solicited events) and unsolicited non-serious adverse events (AE) in diary cards, and notify study investigators in case of serious adverse events (SAE). RESULTS: Overall, 663 participants were included in this study. There were no AEs leading to study termination, and no SAEs reported. Injection site pain (278 [41.9%]) was the most frequent solicited injection site reaction, with myalgia (250 [37.7%]) and malaise (236 [35.6%]) the most frequent solicited systemic reactions. Grade 3 solicited injection site and systemic reactions were reported by 8 (1.2%) and 13 (2.0%) participants, respectively; most participants with solicited reactions recovered without the need for further action. Overall, 39 (5.9%) participants experienced 49 unsolicited non-serious AEs with the most frequently reported being nasopharyngitis (19 [2.9%]). Grade 3 unsolicited non-serious adverse events were reported in 1 (0.2%) participant. None of the unsolicited non-serious AEs were considered to be related to QIV. CONCLUSION: This post-marketing surveillance study confirms that QIV is well tolerated and has an acceptable safety profile in routine practice in South Korea. No unexpected safety concerns were identified. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT05406180.

Enhanced passive safety surveillance of a quadrivalent inactivated split virion influenza vaccine in Finland during the influenza season 2020/21.

BACKGROUND: The European Medicines Agency (EMA) requires enhanced safety surveillance to be conducted for annual seasonal influenza vaccines with the aim of rapidly detecting any potential new safety concerns before the peak immunisation period of the vaccine in any given year. The aim of this study was to detect any clinically significant change in the frequency or severity of expected reactogenicity of the quadrivalent inactivated split-virion influenza vaccine (IIV4) during routine immunisation in Finland for the 2020/21 season. The primary objective was to investigate the frequency of suspected adverse drug reactions (ADRs) occurring within 7 days following vaccination. METHODS: Enhanced passive safety surveillance of individuals vaccinated with IIV4 was conducted from October 9, 2020 to November 30, 2020 across seven sites in Finland. The vaccinee reporting rate and ADR reporting rate were calculated and compared with known or expected safety data in order to identify any clinically significant changes. RESULTS: Data were collected from 1008 individuals with 29 vaccinees reporting 82 suspected ADRs. Of these, 28 people reported 79 suspected ADRs within 7 days following vaccination, corresponding to a vaccinee reporting rate of 2.78% (95% CI: 1.85, 3.99) (ADR reporting rate, 7.84% [95% CI: 6.25, 9.67%]). The most frequently reported ADRs were injection site reactions (vaccination site pain, vaccination site erythema and vaccination site swelling) (n = 46, 2.28%), myalgia (n = 9, 0.89%) and headache (n = 8, 0.79%). No serious suspected adverse events were reported at any point post-vaccination and ADR reporting rates were in general lower compared to those reported for IIV4 in the 2019/20 surveillance study. CONCLUSION: No clinically significant changes in what is known or expected for IIV4 were reported for the 2020/21 season which supports the safety profile of this vaccine and will help maintain public confidence in influenza vaccination.

Molecular Imaging of Smoke-Induced Changes in Nuclear Factor-Kappa B Expression in Murine Tissues Including the Lung.

Many inflammatory responses are mediated by activation of the transcription factor, nuclear factor-kappa B (NF-κB), and a wide variety of human diseases involve abnormal regulation of its expression. In this investigation, we evaluated the effect of smoke inhalation injury on NF-κB expression in lung using two strains of NF-κB reporter mice. Groups of reporter mice with viral thymidine kinase (TK) or "fire fly" luciferase (Luc) genes under control by the NF-κB promoter (TK/NF-κB mice and Luc/NF-κB mice) were subjected to nonlethal smoke inhalation injury. Sham-treated animals served as controls. Twenty-four hours (each animal was injected intravenously with either 9-(4-18F-fluoro-3-[hydroxymethyl]butyl)guanine (FHBG) (~ 1.0 mCi) or luciferin (1.0 mg). One hour later, the TK/NF-κB mice were studied by micro-positron emission tomography (µ-PET) imaging using a Concord P4 µ-PET camera, and the Luc/NF-κB mice were studied by bioluminescence imaging with a charge-coupled device camera. The µ-PET data demonstrated that smoke injury produced massive increases in NF-κB expression (FHBG-standardized uptake value: 3.1 vs 0.0) 24 hours after smoke inhalation, which was reduced 48 hours after smoke inhalation, but still significantly different than the control. Qualitative analysis of the bioluminescence data revealed a remarkably similar effect of burn NF-κB luciferase expression in vivo. Biodistribution studies of FHBG uptake and luciferase activity in lung tissue demonstrated a similar increase 24 hours after injury, which was reduced 48 hours later, but still significantly higher than the sham. The present data with these models providing longitudinal imaging data on the same mouse may prove useful in the examination of the factors producing lung injury by smoke inhalation, as well as the treatment(s) for the damage produced with and without burn injury.

Heparin reduces overcirculation-induced pulmonary artery remodeling through p38 MAPK in piglet.

BACKGROUND: Artery remodeling is the principal change of pulmonary artery hypertension. Heparin has been shown to inhibit vascular smooth muscle cell proliferation. We hypothesized that heparin may modulate vascular remodeling in pulmonary artery hypertension, and explored the mechanism. METHODS: A localized overcirculation-induced artery remodeling was created in piglets by anastomosing the left lower lobe pulmonary artery (LLLPA) to the thoracic aortic artery. Piglets were treated with heparin or saline for 4 weeks. Hemodynamic data were collected, and histology of the lung was assessed. We investigated the expressions of several candidate genes in lung and further observed the involvement of P38 mitogen-activated protein kinases (MAPK). The effects of heparin on the growth of cultured pulmonary arterial vascular smooth muscle cell and P38 MAPK expression were further determined under various conditions. RESULTS: Four weeks after the shunt setup, overcirculation caused significant LLLPA remodeling, pressure increase, and pulmonary vascular resistance increase, and LLLPA flow reduction compared with that immediately after the shunt setup. Heparin reduced the LLLPA remodeling, pressure, and pulmonary vascular resistance, and increased the LLLPA flow compared with that not heparin treated. Shunt and heparin treatment did not change the piglet's systemic hemodynamics. Shunt increased the expression of P38 MAPK and heparin decreased its expression in the shunted LLLPA. Both heparin and P38 MAPK inhibitor suppressed VSMC growth and P38 MAPK expression in the cultured VSMC, but they did not present additive effects when the two treatments were combined. CONCLUSIONS: Heparin reduces overcirculation-induced pulmonary artery remodeling through a P38 MAPK-dependent pathway.

Remote efficacy for two different forms of hyaluronate-based adhesion barriers.

BACKGROUND: Chemically modified sodium hyaluronate and carboxymethylcellulose (HA/CMC) membrane clinically reduces adhesion formation following surgery but was not designed for laparoscopic use. HA/CMC powder of identical chemical composition has been developed to allow for application laparoscopically. We compared the adhesion reduction efficacy of HA/CMC powder and film when applied directly to or remote from sites of surgical trauma. We also investigated the effect of the powder on wound healing. MATERIALS AND METHODS: Two animal models of adhesion formation were used to evaluate efficacy: a rat peritoneal sidewall defect model and a rabbit cecal abrasion/sidewall defect model. The products were applied directly to the defect or the contralateral sidewall. Adhesions were examined seven days after surgery. In a separate study, the effect of the powder on healing was evaluated at 5, 7, and 28 days using a rat incisional wound strength model. RESULTS: HA/CMC powder and film, when applied directly to the peritoneal defect, significantly reduced adhesions relative to the untreated control in both models. Remote applications of HA/CMC powder also reduced adhesions. In contrast, remote applications of HA/CMC film had no effect. HA/CMC powder did not significantly alter incisional wound strength at any of the timepoints tested. CONCLUSION: In our preclinical models, HA/CMC powder had similar adhesion reduction efficacy to HA/CMC film when applied directly to sites of trauma. In addition, HA/CMC powder reduced adhesions remote from the application site. Importantly, HA/CMC powder did not impair incisional wound healing. On the basis of these results, future investigation of HA/CMC powder is warranted.

JNK activation is responsible for mucus overproduction in smoke inhalation injury.

BACKGROUND: Increased mucus secretion is one of the important characteristics of the response to smoke inhalation injuries. We hypothesized that gel-forming mucins may contribute to the increased mucus production in a smoke inhalation injury. We investigated the role of c-Jun N-terminal kinase (JNK) in modulating smoke-induced mucus secretion. METHODS: We intubated mice and exposed them to smoke from burning cotton for 15 min. Their lungs were then isolated 4 and 24 h after inhalation injury. Three groups of mice were subjected to the smoke inhalation injury: (1) wild-type (WT) mice, (2) mice lacking JNK1 (JNK1-/- mice), and (3) WT mice administered a JNK inhibitor. The JNK inhibitor (SP-600125) was injected into the mice 1 h after injury. RESULTS: Smoke exposure caused an increase in the production of mucus in the airway epithelium of the mice along with an increase in MUC5AC gene and protein expression, while the expression of MUC5B was not increased compared with control. We found increased MUC5AC protein expression in the airway epithelium of the WT mice groups both 4 and 24 h after smoke inhalation injury. However, overproduction of mucus and increased MUC5AC protein expression induced by smoke inhalation was suppressed in the JNK inhibitor-treated mice and the JNK1 knockout mice. Smoke exposure did not alter the expression of MUC1 and MUC4 proteins in all 3 groups compared with control. CONCLUSION: An increase in epithelial MUC5AC protein expression is associated with the overproduction of mucus in smoke inhalation injury, and that its expression is related on JNK1 signaling.

High MW hyaluronan inhibits smoke inhalation-induced lung injury and improves survival.

BACKGROUND AND OBJECTIVE: High MW hyaluronan (HMW HA) as opposed to low MW hyaluronan (LMW HA) has been shown to have anti-inflammatory and anti-apoptotic effects. We hypothesized that treatment with HMW HA would block smoke inhalation lung injury by inhibiting smoke-induced lung inflammation and airway epithelial cell apoptosis. METHODS: Anesthetized, intubated male rats were randomly allocated to either control or smoke inhalation injury groups. Rats were treated with 3-mL subcutaneous normal saline solution (sham) or LMW HA (35 kDa) or HMW HA (1600 kDa) 18 h before exposure to 15 min of cotton smoke (n = 5 each). Rats were also treated post smoke inhalation with 1600 kDa HA by intra-peritoneal injection (3 mL) or intra-tracheal nebulization (200 µL). Lung neutrophil infiltration, airway apoptosis, airway mucous plugging and lung injury were assessed 4 h after smoke inhalation injury. RESULTS: Rats pretreated with 1600 kDa HA had significantly less smoke-induced neutrophil infiltration, lung oedema, airway apoptosis and mucous plugging. Pretreatment with 35 kDa HA, in contrast, increased smoke-induced neutrophil infiltration and lung injury score. Intra-tracheal administration of a single dose 1600 kDa HA, but not intra-peritoneal injection, significantly improved survival post smoke inhalation. CONCLUSIONS: High MW hyaluronan (1600 kDa) may prove to be a beneficial therapy for smoke inhalation through inhibition of smoke-induced inflammation, lung oedema, airway epithelial cell apoptosis and airway mucous plugging.

Interleukin-6 overexpression induces pulmonary hypertension.

Inflammatory cytokine interleukin (IL)-6 is elevated in the serum and lungs of patients with pulmonary artery hypertension (PAH). Several animal models of PAH cite the potential role of inflammatory mediators. We investigated role of IL-6 in the pathogenesis of pulmonary vascular disease. Indices of pulmonary vascular remodeling were measured in lung-specific IL-6-overexpressing transgenic mice (Tg(+)) and compared to wild-type (Tg(-)) controls in both normoxic and chronic hypoxic conditions. The Tg(+) mice exhibited elevated right ventricular systolic pressures and right ventricular hypertrophy with corresponding pulmonary vasculopathic changes, all of which were exacerbated by chronic hypoxia. IL-6 overexpression increased muscularization of the proximal arterial tree, and hypoxia enhanced this effect. It also reproduced the muscularization and proliferative arteriopathy seen in the distal arteriolar vessels of PAH patients. The latter was characterized by the formation of occlusive neointimal angioproliferative lesions that worsened with hypoxia and were composed of endothelial cells and T-lymphocytes. IL-6-induced arteriopathic changes were accompanied by activation of proangiogenic factor, vascular endothelial growth factor, the proproliferative kinase extracellular signal-regulated kinase, proproliferative transcription factors c-MYC and MAX, and the antiapoptotic proteins survivin and Bcl-2 and downregulation of the growth inhibitor transforming growth factor-beta and proapoptotic kinases JNK and p38. These findings suggest that IL-6 promotes the development and progression of pulmonary vascular remodeling and PAH through proproliferative antiapoptotic mechanisms.

High-molecular-weight hyaluronan--a possible new treatment for sepsis-induced lung injury: a preclinical study in mechanically ventilated rats.

INTRODUCTION: Mechanical ventilation with even moderate-sized tidal volumes synergistically increases lung injury in sepsis and has been associated with proinflammatory low-molecular-weight hyaluronan production. High-molecular-weight hyaluronan (HMW HA), in contrast, has been found to be anti-inflammatory. We hypothesized that HMW HA would inhibit lung injury associated with sepsis and mechanical ventilation. METHODS: Sprague-Dawley rats were randomly divided into four groups: nonventilated control rats; mechanical ventilation plus lipopolysaccharide (LPS) infusion as a model of sepsis; mechanical ventilation plus LPS with HMW HA (1,600 kDa) pretreatment; and mechanical ventilation plus LPS with low-molecular-weight hyaluronan (35 kDa) pretreatment. Rats were mechanically ventilated with low (7 ml/kg) tidal volumes. LPS (1 or 3 mg/kg) or normal saline was infused 1 hour prior to mechanical ventilation. Animals received HMW HA or low-molecular-weight hyaluronan via the intraperitoneal route 18 hours prior to the study or received HMW HA (0.025%, 0.05% or 0.1%) intravenously 1 hour after injection of LPS. After 4 hours of ventilation, animals were sacrificed and the lung neutrophil and monocyte infiltration, the cytokine production, and the lung pathology score were measured. RESULTS: LPS induced lung neutrophil infiltration, macrophage inflammatory protein-2 and TNFalpha mRNA and protein, which were decreased in the presence of both 1,600 kDa and 35 kDa hyaluronan pretreatment. Only 1,600 kDa hyaluronan completely blocked both monocyte and neutrophil infiltration and decreased the lung injury. When infused intravenously 1 hour after LPS, 1,600 kDa hyaluronan inhibited lung neutrophil infiltration, macrophage inflammatory protein-2 mRNA expression and lung injury in a dose-dependent manner. The beneficial effects of hyaluronan were partially dependent on the positive charge of the compound. CONCLUSIONS: HMW HA may prove to be an effective treatment strategy for sepsis-induced lung injury with mechanical ventilation.

Oxidant stress mediates inflammation and apoptosis in ventilator-induced lung injury.

BACKGROUND AND OBJECTIVE: Ventilator-induced lung injury (VILI) leads to airway epithelial cell apoptosis and lung inflammation. High tidal volume ventilation in vivo has been shown to induce MIP-2 production, lung neutrophil sequestration and apoptotic airway cell death. This study aimed to determine the effect of N-acetylcysteine (NAC), a scavenger of oxygen radicals, on lung inflammation and apoptosis in an in vivo model of VILI. METHODS: Sprague-Dawley rats (n = 5 per group) were ventilated at low tidal volume (V(T) 7 mL/kg) or high tidal volume (V(T) 20 mL/kg) with or without administration of 140 mg/kg of intravenous NAC. Animals were ventilated for 30 min, 1 or 2 h, then allowed to recover for 2 h, at which time neutrophil infiltration, MIP-2, TNF-alpha and IL-6 in BAL fluid, as well as the percentage of apoptotic airway epithelial cells, were measured. RESULTS: Ventilation at V(T) 20 mL/kg increased oxidant release, as measured by serum isoprostane, and decreased lung glutathione, the major antioxidant in the lung. NAC treatment during ventilation at V(T) 20 mL/kg prevented the decrease in lung glutathione and significantly lowered serum isoprostane levels, neutrophil infiltration, cytokines in the BAL and apoptosis in the airways as compared with animals ventilated at V(T) 20 mL/kg without NAC (P < 0.05). CONCLUSIONS: These data point to an early role of oxidant-induced inflammation and apoptosis in VILI.

Inhibition of JNK activation prolongs survival after smoke inhalation from fires.

Initial injury from smoke inhalation is mainly to the trachea and bronchi and is characterized by mucosal hyperemia and increased microvascular permeability, exfoliation of epithelial lining, mucous secretion, mucous plugging, and an acute inflammatory cell influx. In this study, we explore the role of the c-Jun N-terminal protein kinase (JNK) pathway in smoke inhalation lung injury using a rat model of exposure to smoke from burning cotton. Male Sprague-Dawley rats were exposed to smoke from burning cotton for 15 min, and 1 h after injury a JNK inhibitor (SP-600125) or vehicle was injected. We measured neutrophil influx, cytokine release, percent of apoptotic cells, airway plugging, and survival. Administration of a JNK inhibitor 1 h after smoke inhalation decreased airway apoptosis, mucous plugging, influx of inflammatory cells, and the release of cytokines and significantly prolonged animal survival (P < 0.05). These in vivo data show that the JNK pathway plays a critical role in smoke-induced lung injury and offer an attractive therapeutic approach for this injury.

Oxidant injury mediates TGF-β up-regulation in ventilator induced lung injury / 解放军医学杂志

Objectives To explore ventilation induced cytokine production and the role of oxidant stress in lung stretch. Methods Both in vitro and in vivo models of ventilator-induced lung injury (VILI) were used. Alveolar epithelial cells were stretched in vitro to mimic the lung injury in VILI. Rats were ventilated at large tidal volume to produce ventilator-induced lung injury in vivo. A total of 23 inflammatory cytokines were screened with micro gene array in stretched alveolar epithelial cells. Cytokines found to have up-regulated in cells were measured in serum and lung tissue of rats exposed to large tidal volume ventilation. For investigating the intracellular pathway of cytokine up-regulation in VILI, exogenous TNF-α or H2O2 was added to culture media of alveolar epithelial cells. Cytokines were then measured. To explore the role of oxidant stress in VILI, N-acetylcysteine (NAC), as an anti-oxidant, was used in vitro and in vivo. Results We found that transforming growth factor-β1 (TGF-β1 and transforming growth factor-β2 (TGF β2) were up-regulated in stretched alveolar epithelial cells and also in serum of rats with large tidal volume ventilation. Tumor necrosis factor-α (TNF-α) had no effects on TGF-β production in alveolar epithelial cells. Exogenous H2O2, as an oxidant, increased TGF-β production in alveolar epithelial cells. NAC, an anti-oxidant, decreased stretch induced TGF-β production, along with a down-regulation of oxidant injury. NAC also blocked the up-regulation of TGF-β in in vivo model of VILI. Conclusion TGF-β1 and TGF-β2 were up-regulated in VILI. Oxidant injury mediated up-regulation of TGF-β in VILI. NAC, which attenuated oxidant injury and blocked TGF-β up-regulation in VILI, could be a future therapeutic strategy in VILI.

Systemic microvascular leak in an in vivo rat model of ventilator-induced lung injury.

Positive pressure mechanical ventilation has significant systemic effects, but the systemic effects associated with ventilator-induced lung injury (VILI) are unexplored. We hypothesized that VILI would cause systemic microvascular leak that is dependent on nitric oxide synthase (NOS) expression. Rats were ventilated with room air at 85 breaths/minute for 2 hours with either VT 7 or 20 ml/kg. Kidney microvascular leak, which was assessed by measuring 24-hour urine protein and Evans blue dye, was used as a marker of systemic microvascular leak. A significant microvascular leak occurred in both lung and kidney with large VT (20 ml/kg) ventilation. Injection of 0.9% NaCl corrected the hypotension and the decreased cardiac output related to large VT, but it did not attenuate microvascular leak of lung and kidney. Serum vascular endothelial growth factor was significantly elevated in large VT groups. Endothelial NOS expression significantly increased in the lung and kidney tissue with large VT ventilation but not inducible NOS. The NOS inhibitor, N-nitro-L-arginine methyl ester, attenuated the microvascular leak of lung and kidney and the proteinuria with large VT ventilation. Endothelial NOS may mediate the systemic microvascular leak of the present model of VILI.

Ventilator-induced lung injury: in vivo and in vitro mechanisms.

A lung-protective ventilator strategy significantly reduces mortality in patients with acute lung injury. Substantial progress has been made in understanding how mechanical stress can injure the lung, both in terms of alterations in barrier properties of the pulmonary endothelium and epithelium as well as in stimulating proinflammatory responses of macrophages and neutrophils.

Oxidant injury mediates TGF-? up-regulation in ventilator induced lung injury / 解放军医学杂志

Objectives To explore ventilation induced cytokine production and the role of oxidant stress in lung stretch. Methods Both in vitro and in vivo models of ventilator-induced lung injury (VILI) were used. Alveolar epithelial cells were stretched in vitro to mimic the lung injury in VILI. Rats were ventilated at large tidal volume to produce ventilator-induced lung injury in vivo. A total of 23 inflammatory cytokines were screened with micro gene array in stretched alveolar epithelial cells. Cytokines found to have up-regulated in cells were measured in serum and lung tissue of rats exposed to large tidal volume ventilation. For investigating the intracellular pathway of cytokine up-regulation in VILI, exogenous TNF-? or H_ 2O_ 2 was added to culture media of alveolar epithelial cells. Cytokines were then measured. To explore the role of oxidant stress in VILI, N-acetylcysteine (NAC), as an anti-oxidant, was used in vitro and in vivo. Results We found that transforming growth factor-?_1 (TGF-?_1 and transforming growth factor-?_2 (TGF-?_2) were up-regulated in stretched alveolar epithelial cells and also in serum of rats with large tidal volume ventilation. Tumor necrosis factor-? (TNF-?) had no effects on TGF-? production in alveolar epithelial cells. Exogenous H_ 2O_ 2, as an oxidant, increased TGF-? production in alveolar epithelial cells. NAC, an anti-oxidant, decreased stretch induced TGF-? production, along with a down-regulation of oxidant injury. NAC also blocked the up-regulation of TGF-? in in vivo model of VILI. Conclusion TGF-?_1 and TGF-?_2 were up-regulated in VILI. Oxidant injury mediated up-regulation of TGF-? in VILI. NAC, which attenuated oxidant injury and blocked TGF-? up-regulation in VILI, could be a future therapeutic strategy in VILI.