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Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are major causes of morbidity and mortality in the intensive care unit, but despite continuing research few effective therapies have been identified. In recent years, inhaled carbon monoxide (CO) has been reported to have cytoprotective effects in several animal models of tissue injury. We therefore evaluated the effects of inhaled CO in three different in vivo mouse models of ALI. Anesthetized C57BL/6 mice were ventilated with oxygen in the presence or absence of CO (500 parts per million) for 1 h before lung injury was induced by lipopolysaccharide (LPS) or oleic acid (OA) administration. Ventilation was then continued with the same gases for a further 2-3 h, with hemodynamic and respiratory parameters monitored throughout. Intratracheal LPS administration induced lung injury with alveolar inflammation (increased lavage fluid neutrophils, total protein, and cytokines). In contrast, intravenous LPS induced a predominantly vascular lung injury, with increased plasma TNF and increased neutrophil activation (surface Mac-1 upregulation and L-selectin shedding) and sequestration within the pulmonary vasculature. Intravenous OA produced deteriorations in lung function, reflected by changes in respiratory mechanics and blood gases and lavage fluid neutrophil accumulation. However, addition of CO to the inspired gas did not produce significant changes in the measured physiological or immunological parameters in the mouse models used in this study. Thus the results do not support the hypothesis that use of inhaled CO is beneficial in the treatment of ALI and ARDS. cytokines; lipopolysaccharide; oleic acid; neutrophil recruitment; pulmonary inflammation ACUTE LUNG INJURY (ALI) and its more severe form acute respiratory distress syndrome (ARDS) are major causes of mortality and morbidity in the intensive care unit. These syndromes are characterized by the development of hypoxemia, alveolar-capillary barrier damage, and pulmonary inflammation, occurring within hours to days of a predisposing insult, which may be of either pulmonary (e.g., pneumonia, aspiration of gut contents) or extrapulmonary (sepsis, acute pancreatitis) nature (32). Despite intense research, few studies have identified therapies that show a beneficial impact on the outcome of ALI, with the exception of the use of lung protective ventilatory strategies (1, 2).Carbon monoxide (CO) has long been known in biology and medicine as a toxic compound, due to its ability to bind hemoglobin with a much higher affinity than oxygen (25). Despite this image as a deadly gas, recent evidence indicates that CO may in fact have a cytoprotective function at low doses. CO is endogenously produced during heme metabolism by the enzyme heme oxygenase, which is one of the major antioxidant cytoprotective enzymes within the body (17,22). Several investigators have reported that exogenously administered CO by inhalation may exert anti-inflammatory effects, providing protection in various animal models of tiss...

BackgroundMacrophage migration inhibitory factor (MIF) was originally described as a cytokine that inhibits migration of macrophages at the site of inflammation. Subsequently it was also identified as a stress-induced hormone released from the anterior pituitary lobe in response to some pro-inflammatory stimuli like endotoxins and tumour necrosis factor (TNF-α).AimTo compare postoperative changes in serum MIF levels of patients undergoing bowel and liver resections. It has clinical relevance to describe the kinetics of this crucial mediator of systemic inflammation in surgery.MethodsA total of 58 patients were studied over 4 years. Group A (28 patients) underwent only hepatic resection without enterotomy. Group B (30 patients) had bowel resection with enterotomy. MIF, IL-1β, IL-8, prealbumin, albumin, α1-glycoprotein, fibrinogen, and C-reactive protein levels were measured preoperatively, immediately following surgery, and postoperatively for three consecutive days. To evaluate organ functions, multiple organ dysfunction score was used.ResultsA significantly higher level of MIF (4,505 pg/mL) was found in group A when compared to that of group B immediately following surgery. Other parameters monitored in this study were not statistically different between the two groups.ConclusionHigher elevations in MIF levels with liver resections, compared to bowel resections, might be attributable to MIF release from damaged liver cells. The presumably minimal endotoxin exposure during bowel surgery was either insufficient or inefficient to induce relevant MIF elevations in our patients. To fully delineate implications of this finding further studies are needed.

We studied changes in platelet aggregation and fibrinogen levels during thrombolysis with massive or submassive pulmonary embolism. Fifteen patients were randomized into ultrahigh-dose streptokinase (UH-SK n = 8) or alteplase (tPA n = 7) groups. Arterial blood samples were taken before and after thrombolysis every 4 h between 4 and 36 h, and once daily between 2 and 30 days. In-vitro platelet aggregation was examined as spontaneous (0.9% NaCl) and induced aggregation with adrenaline 10 micromol/l, collagen 2 microg/ml and ADP 10 micromol/l. D-dimer and fibrinogen were measured every 8 h on first day, and later as above. In the UH-SK group, adrenaline-induced platelet aggregation decreased at 4 and 8 h compared with baseline (P < 0.03). Adrenaline-induced platelet aggregation was significantly lower in the UH-SK group than in the tPA group at 36 h and on day 3 (P < 0.03). Platelet aggregation induced by ADP was lower at 4 h than at baseline in the UH-SK group (P < 0.05). Collagen-induced platelet aggregation was lower at 4 and 8 h than at baseline (P < 0.05) in the UH-SK group. Compared with baseline, fibrinogen levels decreased in both groups after thrombolysis. D-dimer levels were elevated in both groups at 8 h (tPA group, P < 0.0004; UH-SK group, P < 0.05). Spontaneous platelet aggregation, major bleeding or re-embolism was not documented. Platelet aggregation decreased after thrombolysis with UH-SK for 12 h, in comparison tPA caused an insignificant decrease. Fibrinogen level decreased with UH-SK treatment for 5 days but in case of tPA we could not measure significant changes. According to our findings, tPA is a more suitable drug but streptokinase is also effective because of its cost-benefit ratio.

Repeated ischemic preconditioning might improve hemodynamic parameters, whereas we were unable to find any significant differences between the groups regarding N-acetylcysteine.