Photobiomodulation with 630-nm LED Inhibits M1 Macrophage Polarization via STAT1 Pathway Against Sepsis-Induced Acute Lung Injury.

Background: Sepsis-induced acute lung injury (ALI) is a clinical syndrome characterized by excessive uncontrolled inflammation. Photobiomodulation such as light-emitting diode (LED) irradiation has been used to attenuate inflammatory disease. Objective: The protective effect of 630 nm LED irradiation on sepsis-induced ALI remains unknown. The purpose of this study was to investigate the role of 630 nm LED irradiation in sepsis-induced ALI and its underlying mechanism. Methods and results: C57BL/6 mice were performed cecal ligation and puncture (CLP) for 12 h to generate experimental sepsis models. Histopathology analysis showed that alveolar injury, inflammatory cells infiltration, and hemorrhage were suppressed in CLP mice after 630 nm LED irradiation. The ratio of wet/dry weigh of lung tissue was significantly inhibited by irradiation. The number of leukocytes was reduced in bronchoalveolar lavage fluid. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results and enzyme-linked immunosorbent assay showed that 630 nm LED irradiation significantly inhibited the mRNA and protein levels of M1 macrophage-related genes in the lung of CLP-induced septic mice. Meanwhile, LED irradiation significantly inhibited signal transducer and activator of transcription 1 (STAT1) phosphorylation in the lung of septic mice. In vitro experiments showed that 630 nm LED irradiation significantly inhibited M1 genes mRNA and protein expression in THP-1-derived M1 macrophages without affecting the cell viability. LED irradiation also significantly inhibited the level of STAT1 phosphorylation in THP-1-derived M1 macrophages. Conclusions: We concluded that 630 nm LED is promising as a treatment against ALI through inhibiting M1 macrophage polarization, which is associated with the downregulation of STAT1 phosphorylation.

Ruscogenin attenuates particulate matter-induced acute lung injury in mice via protecting pulmonary endothelial barrier and inhibiting TLR4 signaling pathway.

The inhalation of particulate matter (PM) is closely related to respiratory damage, including acute lung injury (ALI), characterized by inflammatory fluid edema and disturbed alveolar-capillary permeability. Ruscogenin (RUS), the main active ingredient in the traditional Chinese medicine Ophiopogonis japonicus, has been found to exhibit anti-inflammatory activity and rescue LPS-induced ALI. In this study, we investigated whether and how RUS exerted therapeutic effects on PM-induced ALI. RUS (0.1, 0.3, 1 mg·kg-1·d-1) was orally administered to mice prior to or after intratracheal instillation of PM suspension (50 mg/kg). We showed that RUS administration either prior to or after PM challenge significantly attenuated PM-induced pathological injury, lung edema, vascular leakage and VE-cadherin expression in lung tissue. RUS administration significantly decreased the levels of cytokines IL-6 and IL-1ß, as well as the levels of NO and MPO in both bronchoalveolar lavage fluid (BALF) and serum. RUS administration dose-dependently suppressed the phosphorylation of NF-κB p65 and the expression of TLR4 and MyD88 in lung tissue. Furthermore, TLR4 knockout partly diminished PM-induced lung injury, and abolished the protective effects of RUS in PM-instilled mice. In conclusion, RUS effectively alleviates PM-induced ALI probably by inhibition of vascular leakage and TLR4/MyD88 signaling. TLR4 might be crucial for PM to initiate pulmonary lesion and for RUS to exert efficacy against PM-induced lung injury.

Beneficial effect of low-level laser therapy in acute lung injury after i-I/R is dependent on the secretion of IL-10 and independent of the TLR/MyD88 signaling.

The use of low-level laser for lung inflammation treatment has been evidenced in animal studies as well as clinical trials. The laser action mechanism seems to involve downregulation of neutrophil chemoattractants and transcription factors. Innate immune responses against microorganisms may be mediated by toll-like receptors (TLR). Intestinal ischemia and reperfusion (i-I/R) lead to bacterial product translocation, such as endotoxin, which consequently activates TLRs leading to intestinal and lung inflammation after gut trauma. Thus, the target of this study was to investigate the role of TLR activation in the laser (660 nm, 30 mW, 67.5 J/cm2, 0.375 mW/cm2, 5.4 J, 180 s, and spot size with 0.08 cm2) effect applied in contact with the skin on axillary lymph node in lung inflammation induced by i-I/R through a signaling adaptor protein known as myeloid differentiation factor 88 (MyD88). It is a quantitative, experimental, and laboratory research using the C57Bl/6 and MyD88-/- mice (n = 6 mice for experimental group). Statistical differences were evaluated by ANOVA and the Tukey-Kramer multiple comparisons test to determine differences among groups. In order to understand how the absence of MyD88 can interfere in the laser effect on lung inflammation, MyD88-/- mice were treated or not with laser and subjected to occlusion of the superior mesenteric artery (45 min) followed by intestinal reperfusion (4 h). In summary, the laser decreased the MPO activity and the lung vascular permeability, thickened the alveolar septa, reduced both the edema and the alveolar hemorrhage, as well as significantly decreased neutrophils infiltration in MyD88-deficient mice as well in wild-type mice. It noted a downregulation in chemokine IL-8 production as well as a cytokine IL-10 upregulation in these animals. The results also evidenced that in absence of IL-10, the laser effect is reversed. Based on these results, we suggest that the beneficial effect of laser in acute lung injury after i-I/R is dependent on the secretion of IL-10 and independent of the TLR/MyD88 signaling.

Molecular mechanisms underlying hyperoxia acute lung injury.

The management of acute hypoxemic respiratory failure frequently includes the use of supraphysiological fractions of inspired oxygen (FiO2), which can be beneficial in the short-term but not without risks in the long-term, causing acute lung injury (ALI). Over the last few years, much attention has been devoted to the intracellular signaling transduction pathways that lead to hyperoxia-induced cell damage, particularly MAP kinase cascades. Identification of involved signaling molecules and understanding of the regulation of the main signal transduction pathways might provide the basis for improving the outcome of patients under high FiO2 exposure through more effective therapeutic interventions. This review, which includes studies published from 1987 to 2015, presents an overview on recent progresses in the hyperoxia ALI field with special emphasis on potential therapeutic targets and clinical approaches based on the molecular mechanisms underlying hyperoxia-induced inflammation. Further studies are needed to gain deeper insight into controversial molecular mechanisms underlying hyperoxia-induced cell death, which may play a critical role in future pharmacological interventions, as well as into hyperoxia-induced cell damage, that could monitor and therefore prevent hyperoxia ALI.

Should Immune-Enhancing Formulations Be Used for Patients With Acute Respiratory Distress Syndrome?

The potential for regulating immune function in acute respiratory distress syndrome (ARDS) through enteral-administered anti-inflammatory lipids has generated much interest over the past 20 years. Yet recommendations remain inconclusive regarding the utilization of ω-3 fatty acids in patients with ARDS and acute lung injury (ALI). Studies are limited in number, with differing methods, small sample sizes, and conflicting results, making recommendations difficult to interpret.

The mechanism underlying alpinetin-mediated alleviation of pancreatitis-associated lung injury through upregulating aquaporin-1.

Characterized by its acute onset, critical condition, poor prognosis, and high mortality rate, severe acute pancreatitis (SAP) can cause multiple organ failure at its early stage, particularly acute lung injury (ALI). The pathogenesis of ALI is diffuse alveolar damage, including an increase in pulmonary microvascular permeability, a decrease in compliance, and invasion of many inflammatory cells. Corticosteroids are the main treatment method for ALI; however, the associated high toxicity and side effects induce pain in patients. Recent studies show that the effective components in many traditional Chinese medicines can effectively inhibit inflammation with few side effects, which can decrease the complications caused by steroid consumption. Based on these observations, the main objective of the current study is to investigate the effect of alpinetin, which is a flavonoid extracted from Alpinia katsumadai Hayata, on treating lung injury induced by SAP and to explore the mechanism underlying the alpinetin-mediated decrease in the extent of ALI. In this study, we have shown through in vitro experiments that a therapeutic dose of alpinetin can promote human pulmonary microvascular endothelial cell proliferation. We have also shown via in vitro and in vivo experiments that alpinetin upregulates aquaporin-1 and, thereby, inhibits tumor necrosis factor-α expression as well as reduces the degree of lung injury. Overall, our study shows that alpinetin alleviates SAP-induced ALI. The likely molecular mechanism includes upregulated aquaporin expression, which inhibits tumor necrosis factor-α and, thus, alleviates SAP-induced ALI.

The protective effect of Trillin LPS-induced acute lung injury by the regulations of inflammation and oxidative state.

Inflammation response and oxidative stress have been reported to be involved in the pathogenesis of acute lung injury (ALI). Accordingly, anti-inflammatory treatment is proposed to be a possible efficient therapeutic strategy for ALI. The purpose of our present study was to evaluate the anti-inflammatory efficacy of trillin (Tr) on ALI induced by lipopolysaccharide (LPS) in mice and explore the underlying mechanism. BALB/c mice received Tr (50, 100 mg/kg) intraperitoneally 1 h prior to the intratracheal instillation of lipopolysaccharide (LPS) challenge. Pretreatment with Tr at the dose of 50, 100 mg/kg markedly ameliorated lung wet-to-dry weight (W/D) ratio, myeloperoxidase (MPO) activity and pulmonary histopathological conditions. In addition, the protective efficacy of Tr might be attributed to the down-regulations of neutrophil infiltration, malondialdehyde (MDA), inflammatory cytokines and the up-regulations of super-oxide dismutase (SOD), catalase(CAT), glutathione(GSH), Glutathione Peroxidase(GSH-Px) in bronchoalveolar lavage fluid (BALF). Meanwhile, our study revealed some correlations between (NF-E2-related factor 2) Nrf2/heme oxygenase (HO)-1/nuclear factor-kappa B (NF-κB) pathways and the beneficial effect of Tr, as evidenced by the significant up-regulations of HO-1 and Nrf2 protein expressions as well as the down-regulations of p-NF-κB and p-inhibitor of NF-κB (IκB) in lung tissues. Taken together, our results indicated that Tr exhibited protective effect on LPS-induced ALI by the regulations of related inflammatory events via the activations of Nrf2, HO-1 and NF-κB pathway. The current study indicated that Tr could be a potentially effective candidate medicine for the treatment of ALI.

[Effects of sivelestat on acute lung injury in dogs with severe burn-blast combined injury].

OBJECTIVE: To observe and study the effects of sivelestat on acute lung injury in dogs with severe burn-blast combined injury. METHODS: Thirty-two male beagle dogs of clean grade were divided into 4 groups: uninjured group (U), combined injury control group (CIC), combined injury+low dose of sivelestat group (CI+LS), combined injury+high dose of sivelestat group (CI+HS), with 8 dogs in each group. Except for the dogs in group U which were not injured, the dogs in the other 3 groups were inflicted with severe burn-blast combined injury. According to the Parkland formula, the dogs in groups U and CIC were infused with physiological saline, and the dogs in groups CI+LS and CI+HS received sivelestat with the dosage of 0.5 and 2.0 mg·kg(-1)·h(-1) respectively in addition. The 24 h continuous intravenous infusion was carried out for 2 days. At post injury hour (PIH) 6, CT scanning was conducted to observe the lung damage. At PIH 2, 6, 12, 24, and 48, mean arterial pressure (MAP), respiratory rate (RR), extra vascular lung water (EVLW), pulmonary vascular permeability index (PVPI), PaO2, and PaCO2 were measured; the contents of neutrophil elastase (NE), IL-8, and TNF-α were determined by ELISA. At PIH 48, all the dogs were sacrificed, and the lung tissues were harvested to measure the wet to dry lung weight ratio. The same examination was carried out in the dogs of the group U at the same time points. Data were processed with analysis of variance of repeated measurement and LSD test. RESULTS: (1) CT images showed some exudative lesions in the dogs of groups CIC and CI+LS but not in the dogs of groups U and CI+HS. (2) No statistically significant differences were observed in MAP at each time point between every two groups (with P values above 0.05). The RR values in group U were significantly different from those of the other 3 groups at all time points (with P values below 0.05). The values of EVLW and PVPI in 3 combined injury groups were significantly different from those in group U at PIH 6, 12, 24, and 48 (with P values below 0.05). The values of RR and EVLW in group CI+LS were significantly different from those in group CI+HS at PIH 12, 24, and 48 (with P values below 0.05). The values of PVPI in group CI+LS were significantly different from those in group CI+HS at PIH 24 and 48 (with P values below 0.05). (3) The levels of PaO2 and PaCO2 showed significant differences between group U and the other 3 groups at each time point (with P values below 0.05). The levels of PaO2 in group CI+LS were significantly different from those in CI+HS group at PIH 12, 24, and 48 (with P values below 0.05). The level of PaCO2 showed significant differences between group CI+LS and group CI+HS at PIH 24 and 48 (with P values below 0.05). (4) The contents of NE (except for PIH 2), TNF-α, and IL-8 showed significant differences between group U and the other 3 groups at each time point (P < 0.05 or P < 0.01). At PIH 2, 6, 12, 24, and 48, the contents of NE in groups U, CIC, CI+LS, and CI+HS were respectively (69 ± 21), (83 ± 24), (80 ± 20), (75 ± 17), (72 ± 27) pg/mL; (66 ± 24), (196 ± 20), (231 ± 26), (252 ± 25), (266 ± 22) pg/mL ; (71 ± 22), (180 ± 27), (214 ± 21), (194 ± 24), (218 ± 20) pg/mL; (68 ± 22), (136 ± 24), (153 ± 22), (146 ± 26), (150 ± 28) pg/mL. NE values in group CI+HS were statistically different from those in groups CIC and CI+LS at PIH 6, 12, 24, and 48 (with P values below 0.05). The contents of TNF-α in group CI+LS were statistically different from those in groups CIC and CI+HS at PIH 24 and 48 (with P values below 0.05). The contents of IL-8 in group CI+LS were statistically different from those in group CI+HS at PIH 24 and 48 (with P values below 0.05). (5) At PIH 48, the wet to dry lung weight ratio of group CIC was statistically different from that in group CI+LS or group CI+HS (with P values below 0.05); there was also difference between group CI+LS and group CI+HS (P < 0.05). CONCLUSIONS: Sivelestat, especially in a high dose, exerts a protective effect in acute lung injury after burn-blast combined injury through improving the index of blood gas analysis, ameliorating pulmonary edema, and lowering the production of pro-inflammatory mediators.

H2S protecting against lung injury following limb ischemia-reperfusion by alleviating inflammation and water transport abnormality in rats.

OBJECTIVE: To investigate the effect of H2S on lower limb ischemia-reperfusion (LIR) induced lung injury and explore the underlying mechanism. METHODS: Wistar rats were randomly divided into control group, IR group, IR+ Sodium Hydrosulphide (NaHS) group and IR+ DL-propargylglycine (PPG) group. IR group as lung injury model induced by LIR were given 4 h reperfusion following 4 h ischemia of bilateral hindlimbs with rubber bands. NaHS (0.78 mg/kg) as exogenous H2S donor and PPG (60 mg/kg) which can suppress endogenous H2S production were administrated before LIR, respectively. The lungs were removed for histologic analysis, the determination of wet-to-dry weight ratios and the measurement of mRNA and protein levels of aquaporin-1 (AQP1), aquaporin-5 (AQP5) as indexes of water transport abnormality, and mRNA and protein levels of Toll-like receptor 4 (TLR4), myeloid differentiation primary-response gene 88 (MyD88) and p-NF-κB as indexes of inflammation. RESULTS: LIR induced lung injury was accompanied with upregulation of TLR4-Myd88-NF-κB pathway and downregulation of AQP1/AQP5. NaHS pre-treatment reduced lung injury with increasing AQP1/AQP5 expression and inhibition of TLR4-Myd88-NF-κB pathway, but PPG adjusted AQP1/AQP5 and TLR4 pathway to the opposite side and exacerbated lung injury. CONCLUSION: Endogenous H2S, TLR4-Myd88-NF-κB pathway and AQP1/AQP5 were involved in LIR induced lung injury. Increased H2S would alleviate lung injury and the effect is at least partially depend on the adjustment of TLR4-Myd88-NF-κB pathway and AQP1/AQP5 expression to reduce inflammatory reaction and lessen pulmonary edema.

[Effect of acupuncture on serum MIP-2 and MIP-2 mRNA expressions in isolated Fei and Dachang of severe acute pancreatitis induced acute lung injury rats in the acute phase].

OBJECTIVE: To observe effect of acupuncture on serum macrophage inflammatory protein-2 (MIP-2) and MIP-2 mRNA expressions in isolated Fei and Dachang of severe acute pancreatitis (SAP) induced acute lung injury (ALI) rats in the acute phase. METHODS: Forty male Wistar rats were randomly divided into four groups, i.e., the sham-operation group, the SAP group, the acupuncture treatment group, and the acupuncture control group, 10 in each group. The SAP model was induced by retrograde infusion of 3.5% sodium taurocholate into the pancreatobiliary duct. Under the guidance of "Fei and Dachang exterior-inferiorly related", points were acupunctured along Fei, Dachang, and Pi channels, as well as those points on the back of rats in the acupuncture treatment group 0.5 h after modeling. Besides, points were acupunctured along Fei and Pi channels, as well as those points on the back of rats in the acupuncture control group 0.5 h after modeling. Serum levels of tumor necrosis factor alpha (TNF-alpha) and nitric oxide (NO), and MIP-2 expressions were examined 6 h after modeling. Expressions of MIP-2 mRNA in isolated lung and large intestine tissues were detected by reverse transcription PCR. RESULTS: Compared with the sham-operation group, serum levels of TNF-alpha and NO, and expressions of MIP-2 and MIP-2 mRNA in isolated lung and large intestine tissues were significantly higher in the SAP group (P < 0.05). Each index was lower in the acupuncture treatment group than in the SAP group and the acupuncture control group (P < 0.05). Besides, the serum level of MIP-2 and the MIP-2 mRNA expression in isolated lung and large intestine tissues were positively correlated in all groups except the sham-operation group (P < 0.05). CONCLUSIONS: Under the guidance of "Fei and Dachang exterior-inferiorly related", acupuncture could remarkably reduce the severity of SAP induced ALI rats in the acute phase. Its mechanism might be related to suppressing over-expressions of MIP-2 mRNA in isolated lung and large intestine tissues, and lowering the serum MIP-2 expression level.

Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus SEMICYUC-SENPE: Respiratory failure / Recomendaciones para el soporte nutricional y metabólico especializado del paciente crítico. Actualización. Consenso SEMICYUC-SENPE: Insuficiencia respiratoria

Severe acute respiratory failure requiring mechanical ventilation is one of the most frequent reasons for admission to the intensive care unit. Among the most frequent causes for admission are exacerbation of chronic obstructive pulmonary disease and acute respiratory failure with acute lung injury (ALI) or with criteria of acute respiratory distress syndrome (ARDS). These patients have a high risk of malnutrition due to the underlying disease, their altered catabolism and the use of mechanical ventilation. Consequently, nutritional evaluation and the use of specialized nutritional support are required. This support should alleviate the catabolic effects of the disease, avoid calorie overload and, in selected patients, to use omega-3 fatty acid and antioxidant-enriched diets, which could improve outcome (AU)

La insuficiencia respiratoria aguda grave que precisa ventilación mecánica es una de las causas mas frecuentes de ingreso de los pacientes en UCI. Entre las etiologías mas frecuentes se encuentran la reagudización de la enfermedad pulmonar obstructiva crónica y la insuficiencia respiratoria aguda con lesion pulmonar aguda o con criterios de síndrome de distrés respiratorio agudo. Estos pacientes presentan un riesgo elevado de desnutrición por su enfermedad de base, por la situación catabólica en la que se encuentran y por el empleo de la ventilación mecánica. Ello justifica que estos pacientes deban ser valorados desde el punto de vista nutricional y que el uso de soporte nutricional especializado sea necesario. El soporte nutricional especializado debe paliar los efectos catabólicos de la enfermedad, evitar la sobrecarga de calorías y utilizar, en casos seleccionados, dietas especificas enriquecidas con ácidos grasos ω-3 y antioxidantes que podrían mejorar el pronostico (AU)

Recomendaciones para el soporte nutricional y metabólico especializado del paciente crítico. Actualización. Consenso SEMICYUC-SENPE: Insuficiencia respiratoria / Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): Respiratory failure

La insuficiencia respiratoria aguda grave que precisa ventilación mecánica es una de las causas más frecuentes de ingreso de los pacientes en UCI. Entre las etiologías más frecuentes se encuentran la reagudización de la enfermedad pulmonar obstructiva crónica y la insuficiencia respiratoria aguda con lesión pulmonar aguda o con criterios de síndrome de distrés respiratorio agudo. Estos pacientes presentan un riesgo elevado de desnutrición por su enfermedad de base, por la situación catabólica en la que se encuentran y por el empleo de la ventilación mecánica. Ello justifica que estos pacientes deban ser valorados desde el punto de vista nutricional y que el uso de soporte nutricional especializado sea necesario. El soporte nutricional especializado debe paliar los efectos catabólicos de la enfermedad, evitar la sobrecarga de calorías y utilizar, en casos seleccionados, dietas específicas enriquecidas con ácidos grasos w-3 y antioxidantes que podrían mejorar el pronóstico (AU)

Severe acute respiratory failure requiring mechanical ventilation is one of the most frequent reasons for admission to the intensive care unit. Among the most frequent causes for admission are exacerbation of chronic obstructive pulmonary disease and acute respiratory failure with acute lung injury (ALI) or with criteria of acute respiratory distress syndrome (ARDS). These patient s have a high risk of malnutrition due to the under lying disease, their altered catabolism and the use of mechanical ventilation. Consequently, nutritional evaluation and the use of specialized nutritional support are required. This support should alleviate the catabolic effects of the disease, avoid calorie overload and, in selected patients, to use omega-3 fatty acid- and antioxidant-enriched diets, which could improve outcome (AU)

Enteral omega-3 fatty acid, gamma-linolenic acid, and antioxidant supplementation in acute lung injury.

CONTEXT: The omega-3 (n-3) fatty acids docosahexaenoic acid and eicosapentaenoic acid, along with γ-linolenic acid and antioxidants, may modulate systemic inflammatory response and improve oxygenation and outcomes in patients with acute lung injury. OBJECTIVE: To determine if dietary supplementation of these substances to patients with acute lung injury would increase ventilator-free days to study day 28. DESIGN, SETTING, AND PARTICIPANTS: The OMEGA study, a randomized, double-blind, placebo-controlled, multicenter trial conducted from January 2, 2008, through February 21, 2009. Participants were 272 adults within 48 hours of developing acute lung injury requiring mechanical ventilation whose physicians intended to start enteral nutrition at 44 hospitals in the National Heart, Lung, and Blood Institute ARDS Clinical Trials Network. All participants had complete follow-up. INTERVENTIONS: Twice-daily enteral supplementation of n-3 fatty acids, γ-linolenic acid, and antioxidants compared with an isocaloric control. Enteral nutrition, directed by a protocol, was delivered separately from the study supplement. MAIN OUTCOME MEASURE: Ventilator-free days to study day 28. RESULTS: The study was stopped early for futility after 143 and 129 patients were enrolled in the n-3 and control groups. Despite an 8-fold increase in plasma eicosapentaenoic acid levels, patients receiving the n-3 supplement had fewer ventilator-free days (14.0 vs 17.2; P = .02) (difference, -3.2 [95% CI, -5.8 to -0.7]) and intensive care unit-free days (14.0 vs 16.7; P = .04). Patients in the n-3 group also had fewer nonpulmonary organ failure-free days (12.3 vs 15.5; P = .02). Sixty-day hospital mortality was 26.6% in the n-3 group vs 16.3% in the control group (P = .054), and adjusted 60-day mortality was 25.1% and 17.6% in the n-3 and control groups, respectively (P = .11). Use of the n-3 supplement resulted in more days with diarrhea (29% vs 21%; P = .001). CONCLUSIONS: Twice-daily enteral supplementation of n-3 fatty acids, γ-linolenic acid, and antioxidants did not improve the primary end point of ventilator-free days or other clinical outcomes in patients with acute lung injury and may be harmful. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00609180.

Acute respiratory distress syndrome and acute lung injury.

Acute respiratory distress syndrome (ARDS) is a life threatening respiratory failure due to lung injury from a variety of precipitants. Pathologically ARDS is characterised by diffuse alveolar damage, alveolar capillary leakage, and protein rich pulmonary oedema leading to the clinical manifestation of poor lung compliance, severe hypoxaemia, and bilateral infiltrates on chest radiograph. Several aetiological factors associated with the development of ARDS are identified with sepsis, pneumonia, and trauma with multiple transfusions accounting for most cases. Despite the absence of a robust diagnostic definition, extensive epidemiological investigations suggest ARDS remains a significant health burden with substantial morbidity and mortality. Improvements in outcome following ARDS over the past decade are in part due to improved strategies of mechanical ventilation and advanced support of other failing organs. Optimal treatment involves judicious fluid management, protective lung ventilation with low tidal volumes and moderate positive end expiratory pressure, multi-organ support, and treatment where possible of the underlying cause. Moreover, advances in general supportive measures such as appropriate antimicrobial therapy, early enteral nutrition, prophylaxis against venous thromboembolism and gastrointestinal ulceration are likely contributory reasons for the improved outcomes. Although therapies such as corticosteroids, nitric oxide, prostacyclins, exogenous surfactants, ketoconazole and antioxidants have shown promising clinical effects in animal models, these have failed to translate positively in human studies. Most recently, clinical trials with ß2 agonists aiding alveolar fluid clearance and immunonutrition with omega-3 fatty acids have also provided disappointing results. Despite these negative studies, mortality seems to be in decline due to advances in overall patient care. Future directions of research are likely to concentrate on identifying potential biomarkers or genetic markers to facilitate diagnosis, with phenotyping of patients to predict outcome and treatment response. Pharmacotherapies remain experimental and recent advances in the modulation of inflammation and novel cellular based therapies, such as mesenchymal stem cells, may reduce lung injury and facilitate repair.

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): respiratory failure]. / Recomendaciones para el soporte nutricional y metabólico especializado del paciente crítico. Actualización. Consenso SEMICYUC-SENPE: insuficiencia respiratoria.

Severe acute respiratory failure requiring mechanical ventilation is one of the most frequent reasons for admission to the intensive care unit. Among the most frequent causes for admission are exacerbation of chronic obstructive pulmonary disease and acute respiratory failure with acute lung injury (ALI) or with criteria of acute respiratory distress syndrome (ARDS). These patients have a high risk of malnutrition due to the underlying disease, their altered catabolism and the use of mechanical ventilation. Consequently, nutritional evaluation and the use of specialized nutritional support are required. This support should alleviate the catabolic effects of the disease, avoid calorie overload and, in selected patients, to use omega-3 fatty acid- and antioxidant-enriched diets, which could improve outcome.

[Expression of Cav-1, AQP1 and AQP5 in lung of acute pancreatitis-associated lung injury rats and the therapeutic role of Qingyitang].

OBJECTIVE: to investigate the expression and location of caveolin-1 (Cav-1), aquaporin 1 (AQP1) and AQP5 in the lung of acute pancreatitis-associated lung injury rats and to determine the role of these molecules in the pathologic progress and the potential therapeutic mechanisms of Qingyitang. METHODS: forty Wistar rats were randomly divided into sham operation (SHAM) group, acute lung injury (ALI) group, dexamethasone (DEX) group and Qingyitang (QYT) group. ALI was induced by reverse injection of deoxycholate into biliopancreatic duct of rats. Blood and lung tissues were collected after 24 h. Serum amylase, lung wet/dry (W/D) ratio and pathological section were detected to evaluate the degree of lung injury. reverse transcription-polymerase chain reaction was taken to detect the mRNA levels of Cav-1, AQP1 and AQP5. Lipid rafts were prepared for detection of the distribution and expression level of Cav-1, AQP1 and AQP5 proteins by Western blot. RESULTS: the concentration of serum amylase, the value of W/D and the degree of pathological lung injury obviously increased in ALI rats. Cav-1, AQP1 and AQP5 were present in the lung while the mRNA level decreased in ALI rats. Cav-1 appeared mainly in lipid rafts and less in non-lipid rafts. AQP1 was localized to lipid rafts while AQP5 to non-lipid rafts. The localization of these three molecules in the lung of ALI rats did not change compared with SHAM rats while their protein levels decreased. Compared with ALI rats, the concentration of serum amylase, the value of W/D and the degree of pathological lung injury obviously decreased in DEX and QYT rats. The mRNA and the protein expression of Cav-1, AQP1 and AQP5 increased in various degrees by DEX or QYT treatment. CONCLUSION: Cav-1 and AQP1 are enriched in lipid rafts while AQP5 in non-lipid rafts. The down-regulated expression of these three molecules may play important role in acute pancreatitis-associated lung injury. DEX and QYT may relieve lung injury effectively by up-regulating the expressions of Cav-1, AQP1 and AQP5.