Role of interleukin 8 in the genesis of acute respiratory distress syndrome through an effect on neutrophil apoptosis

OBJECTIVE: To evaluate the role of interleukin 8 (IL-8) in the regulation of neutrophil (PMN) apoptosis in normal plasma and plasma from patients with early, fulminant acute respiratory distress syndrome (ARDS). DESIGN: Experimental study using cultured human PMNs. SETTING: University hospital, level I trauma center. PARTICIPANTS: Plasma was obtained from 6 patients with early, fulminant posttraumatic ARDS (mean Injury Severity Score, 26). All samples were drawn within 24 hours after injury. Plasma was also taken from 13 healthy control subjects. These controls were also used as sources of PMNs. MAIN OUTCOME MEASURES: Effect of early, fulminant ARDS and normal plasma on spontaneous apoptosis, CD16, and CD11-b expression in PMNs in vitro; levels of IL-8 in plasma; correlation of extracellular IL-8 concentration with rate of PMN apoptosis; and effect of IL-8 blockade on PMN apoptosis, CD16, and CD11-b expression in ARDS and normal plasma. RESULTS: Plasma from patients with early, fulminant ARDS inhibited spontaneous PMN apoptosis at 24 hours (35%+/-5% vs 54%+/-5%; P=.01). Neither CD16 nor CD1l-b differed significantly between the 2 groups. The mean plasma level of IL-8 in patients with early, fulminant ARDS was 359+/-161 pg/mL vs 3.0+/-0.4 pg/mL in healthy controls (P<.05). Interleukin 8 inhibited apoptosis in plasma-free medium at low doses (1-50 pg/mL) but had no significant effect at higher doses (100-5000 pg/mL) (P<.05). Interleukin 8 blockade with monoclonal antibody suppressed apoptosis in normal plasma (28%+/-5% with monoclonal antibody vs 51%+/-5% without monoclonal antibody; P=.008) but not in plasma from patients with early, fulminant ARDS (29%+/-5% with monoclonal antibody vs 34%+/-6% without monoclonal antibody; P=.67). It had no effect on CD16 or CD11-b expression in either plasma. CONCLUSIONS: Plasma from patients with early, fulminant ARDS contains soluble factors that inhibit PMN apoptosis in vitro. Low levels of IL-8 inhibit PMN apoptosis in normal plasma. Although plasma levels of IL-8 are markedly elevated in early, fulminant ARDS, IL-8 is not directly responsible for the antiapoptotic effect of plasma from patients with early, fulminant ARDS.     

Elevated levels of expired breath hydrogen peroxide in bronchiectasis

Airway inflammation is important in the development and progression of many lung diseases, including bronchiectasis. Activation of inflammatory cells such as neutrophils, eosinophils, and macrophages induces a respiratory burst resulting in the production of reactive oxygen species such as hydrogen peroxide (H2O2). We have measured exhaled H2O2 in patients with documented bronchiectasis and investigated whether the concentration of H2O2 is related to the disease severity, as defined by lung function. We also investigated whether the concentrations of expired H2O2 were different in bronchiectatic patients who received inhaled corticosteroids compared with steroid-na?ve patients. In 37 patients with bronchiectasis (mean age, 45 +/- 2.5 yr; FEV1, 59 +/- 3% pred), mean H2O2 concentration in exhaled breath condensate was significantly elevated as compared with the values in 25 age-matched (mean age, 42 +/- 2 yr) normal subjects (0.87 +/- 0.01 versus 0.26 +/- 0.04 microM, p < 0.001). There was a significant negative correlation between H2O2 and FEV1 (r = -0.76, p < 0.0001). Patients treated with inhaled corticosteroids had values of H2O2 similar to those of steroid-na?ve patients (0.8 +/- 0.1 versus 0.9 +/- 0.1, p > 0.05). We conclude that H2O2 is elevated in exhaled air condensate of patients with bronchiectasis and is correlated with disease severity. Measurement of H2O2 may be used as a simple noninvasive method to monitor airway inflammation and oxidative stress.     

Localization of distinct F2-isoprostanes in human atherosclerotic lesions

F2-Isoprostanes are prostaglandin (PG) isomers formed in situ in cell membranes by peroxidation of arachidonic acid. 8-epi PGF2alpha and IPF2alpha-I are F2-isoprostanes produced in humans which circulate in plasma and are excreted in urine. Measurement of F2-isoprostanes may offer a sensitive, specific, and noninvasive method for measuring oxidant stress in clinical settings where reactive oxygen species are putatively involved. We determined whether isoprostanes were present in human atherosclerotic lesions, where lipid peroxidation is thought to occur in vivo. 8-epi PGF2alpha ranged from 1.310-3.450 pmol/micromol phospholipid in atherectomy specimens compared with 0.045-0.115 pmol/micromol phospholipid (P < 0.001) in vascular tissue devoid of atherosclerosis. Corresponding values of IPF2alpha-I were 5.6-13.8 vs. 0.16-0.44 pmol/micromol phospholipid (P < 0.001). Levels of the two isoprostanes in vascular tissue were highly correlated (r = 0.80, P < 0.0001). Immunohistochemical studies confirmed that foam cells adjacent to the lipid necrotic core of the plaque were markedly positive for 8-epi PGF2alpha. These cells were also reactive with anti-CD68, an epitope specific for human monocyte/macrophages. 8-epi PGF2alpha immunoreactivity was also detected in cells positive for anti-alpha-smooth muscle actin antibody, which specifically recognizes vascular smooth muscle cells. Our results indicate that 8-epi PGF2alpha and IPF2alpha-I, two distinct F2-isoprostanes and markers of oxidative stress in vivo, are present in human atherosclerotic plaque. Quantitation of these chemically stable products of lipid peroxidation in target tissues, as well as in biological fluids, may aid in the rational development of antioxidant drugs in humans.     

The clinical relevance of circulating tumor necrosis factor-alpha in acute decompensated chronic heart failure without cachexia

STUDY OBJECTIVE: To evaluate the clinical relevance of circulating tumor necrosis factor-alpha (TNF alpha) in subjects with advanced acutely decompensated congestive heart failure (CHF) and to determine the modulatory effect of clinical interventions on short-term elaboration of this cytokine. DESIGN: Prospective, case-controlled study. SETTING: Inpatient and outpatient (hospital and clinic), at regional academic medical center. PATIENT INTERVENTIONS: Plasma concentrations of TNF alpha were determined in 25 healthy, normal control subjects and in 29 noncachectic patients with advanced CHF (mean ejection fraction = 16 +/- 6%) who required hospitalization for i.v. diuretic and/or inotropic therapy despite optimization of oral medical regimens. CHF patients were divided into two groups: diuretic responsive (group A; n = 6) and diuretic resistant requiring inotropic support (group B; n = 23). Group B was randomly allocated to receive either i.v. dobutamine (n = 13) or milrinone (n = 10) for 72 h. TNF alpha levels in CHF patients were measured serially at baseline, at 6 h, at 48 h, at 72 h, and at 1-week follow-up after hospital discharge. RESULTS: Plasma TNF alpha levels at baseline in CHF patients were 4.0 +/- 1.1 pg/mL (range, 0.5 to 6.5 pg/ mL) and 2.5 +/- 0.6 pg/mL (range, 0.5 to 6.8 pg/mL) in groups A and B, respectively, which were significantly different (p < 0.002) from normal subjects (0.89 +/- 0.40 pg/mL; range, 0.5 to 9.7 pg/mL). Despite clinically successful therapy with i.v. diuretics, dobutamine, or milrinone, plasma levels of this cytokine remained unchanged. Plasma TNF alpha in CHF patients measured in recovery (1 week after hospital discharge) was 5.1 +/- 1.2 pg/mL (range, 1.0 to 9.9 pg/mL) and 3.9 +/- 0.8 pg/mL (range, 0.5 to 8.7 pg/mL) in groups A and B, respectively. CONCLUSION: These findings suggest that although noncachectic patients with chronic heart failure who suffer acute decompensation elaborate significantly higher circulating levels of TNF alpha compared with healthy control subjects, no significant reduction or alteration in circulating TNF alpha is noted in the short-term follow-up despite clinical improvement.     

Estrogen receptor alpha and beta expression in upper gastrointestinal tract with regulation of trefoil factor family 2 mRNA levels in ovariectomized rats

STUDY OBJECTIVE: To investigate the effect of short-term inhalation of nitric oxide (NO) on transpulmonary angiotensin II formation in patients with severe ARDS. DESIGN: Prospective, clinical study. SETTING: Anesthesiology ICU of a university hospital. PATIENTS: Ten ARDS patients who responded to inhalation of 100 ppm NO by decreasing their pulmonary vascular resistance (PVR) by at least 20 dyne x s x cm(-5) were included in the study. INTERVENTIONS AND MEASUREMENTS: In addition to standard treatment, the patients inhaled 0, 1, and 100 ppm NO in 20-min intervals. Fraction of inspired oxygen was 1.0. Hemodynamics were measured and recorded online. Mixed venous (pulmonary arterial catheter) and arterial (arterial catheter) blood samples were taken simultaneously for hormonal analyses at the end of each inhalation period. RESULTS: Pulmonary arterial pressure decreased from 33+/-2 mm Hg (0 ppm NO, mean+/-SEM) to 29+/-2 mm Hg (1 ppm NO, p<0.05), and to 27+/-2 mm Hg (100 ppm NO, p<0.05, vs 0 ppm). PVR decreased from 298+/-56 (0 ppm NO) to 243+/-45 dyne x s x cm(-5) (1 ppm NO, not significant [NS]), and to 197+/-34 dyne x s x cm(-5) (100 ppm NO, p<0.05, vs 0 ppm). Arterial oxygen pressure increased from 174+/-23 mm Hg (0 ppm NO) to 205+/-26 mm Hg (1 ppm NO, NS), and to 245+/-25 mm Hg (100 ppm NO, p <0.05, vs 0 ppm). Mean plasma angiotensin II concentrations were 85+/-20 (arterial) and 57+/-13 pg/mL (mixed venous) during 0 ppm NO and did not change during inhalation of 1 and 100 ppm NO. Mean transpulmonary plasma angiotensin II concentration gradient (=difference between arterial and mixed venous blood values) was 28+/-8 pg/mL (range, 0 to 69) during 0 ppm NO and did not change during inhalation of 1 and 100 ppm NO. Mean transpulmonary angiotensin II formation (transpulmonary angiotensin II gradient multiplied with the cardiac index) was 117+/-39 ng/min/m2 (range, 0 to 414) during 0 ppm NO and did not change during inhalation of 1 and 100 ppm NO. Mean arterial plasma cyclic guanosine monophosphate concentration was 11+/-2 pmol/mL (0 ppm NO), did not change during 1 ppm NO, and increased to 58+/-8 pmol/mL (100 ppm NO, p<0.05). Arterial plasma concentrations of aldosterone (142+/-47 pg/mL), atrial natriuretic peptide (114+/-34 pg/mL), angiotensin-converting enzyme (30+/-5 U/L), and plasma renin activity (94+/-26 ng/mL/h of angiotensin I) did not change. CONCLUSION: The decrease of PVR by short-term NO inhalation in ARDS patients was not accompanied by changes in transpulmonary angiotensin II formation. Our results do not support any relationship between transpulmonary angiotensin II formation and the decrease in PVR induced by inhaled NO.     

Functional characterization of the ocular prostaglandin f2alpha (PGF2alpha) receptor. Activation by the isoprostane, 12-iso-PGF2alpha

Prostaglandin F2alpha (PGF2alpha) is a product of cyclooxygenase-catalyzed metabolism of arachidonic acid. Recently, PGF2alpha analogs have been hypothesized to reduce intraocular pressure via relaxation of the ciliary muscle. To investigate the molecular basis of PGF2alpha receptor (FP) activation in the eye, we cloned the FP from a human ciliary body (hcb) cDNA library. The open reading frame of the hcb-FP cDNA was identical to the uterine FP cDNA. The hcb-FP appeared to be predominantly membrane-localized, as visualized by an FP-specific peptide antibody, and coupled to inositol phosphate formation when stably expressed in HEK 293 cells. Interestingly, the hcb-FP could also be activated by the F2 isoprostane, 12-iso-PGF2alpha, in addition to its cognate ligand, PGF2alpha. 12-iso-PGF2alpha was less potent (EC50 = 5 microM) than PGF2alpha (EC50 = 10 nM) in generating inositol phosphates via the hcb-FP in HEK 293 cells. Both ligands also stimulated mitogenesis in NIH 3T3 cells. Although 12-iso-PGF2alpha caused a dose-dependent activation of the FP, it failed to activate the recombinant human prostacyclin receptor and caused only minimal activation of the thromboxane receptor isoforms stably expressed in HEK 293 cells. Four additional F2 isoprostanes, 8-iso-PGF2alpha, IPF2alpha-I, IPF2alpha-III, and 9beta,11beta-PGF2, caused trivial, or no, activation of the FP. Consistent with these observations, only PGF2alpha and 12-iso-PGF2alpha caused rapid homologous desensitization of FP and also exhibited cross-desensitization, with PGF2alpha resulting in a maximum of approximately 60% desensitization. The human FP may thus be activated specifically, by the free radical-catalyzed F2 isoprostane, 12-iso-PGF2alpha, in addition to the cyclooxygenase product, PGF2alpha. Incidental receptor activation by isoprostanes may complement the actions of PGF2alpha in clinical syndromes where oxidant stress and augmented prostaglandin biosynthesis coincide.     

Prediction and prevention of malaria epidemics in the valley of the Senegal River

The metabolism of PGF2alpha in human and other species results initially in the formation of 15-keto-dihydro-PGF2alpha and later to several beta-oxidized metabolites, which are species-specific. Since the discovery of cyclooxygenase-2 (COX-2), the importance of measuring various arachidonic acid metabolites during inflammatory conditions is on focus. This study presents the development and validation of a new radioimmunoassay of 15-keto-dihydro-PGF2alpha as an index of lipid peroxidation via cyclooxygenase (COX-1 and COX-2) pathway. Furthermore, its application in endotoxin-induced acute inflammation in pigs is presented. An antibody was raised in rabbits by immunization with 15-keto-dihydro-PGF2alpha coupled to BSA at the carboxylic acid by 1,1'-carbonyldiimidazole method. The cross-reactivity of the antibody with PGF2alpha, 15-keto-PGF2alpha, PGE2, 15-keto-13,14-dihydro-PGE2, 8-iso-15-keto-13,14-dihydro-PGF2alpha, 11beta-PGF2alpha, 9beta-PGF2alpha, TXB2 and 8-iso-PGF3alpha was 0.02, 0.43, < 0.001, 0.5, 1.7, < 0.001, < 0.001, < 0.001, 0.01%, respectively. The intra-assay precision was 12.2% (CV) at the level of 64 pg/0.1 ml and 14.0% with 512 pg/0.1 ml in the human plasma. Similarly, intra-assay accuracy was 108.6% and 103.3% for the low and the high standards, respectively. The detection limit was about 45 pmol/L. 15-keto-dihydro-PGF2alpha levels in plasma from normal human volunteers were evaluated and found to correlate with the obtained values by GC-MS methods from other studies. The levels of 15-keto-dihydro-PGF2alpha in the plasma increased several-fold after endotoxin infusion (10 microg/kg/h over 6 h) to the pigs. Thus, this 1 5-keto-dihydro-PGF2alpha radioimmunoassay method is relevant to apply in inflammatory injury, and other physiological and pathophysiological studies, as an index of in vivo enzymatic lipid peroxidation.     

Portal levels of the isoprostane F2 alpha-III, a marker of lipid peroxidation, do not correlate with increased portal pressure in cirrhotic patients

BACKGROUND: Isoprostane F2 alpha-III (iPF2 alpha-III), a recently described member of a family of prostaglandin F2 alpha isomers and a biologically active end-product of lipid peroxidation, has been reported to increase portal pressure in cirrhotic rats. We found that its urinary levels were elevated in cirrhotic patients. METHODS: To investigate whether portal levels of iPF2 alpha-III were elevated in cirrhotic patients and whether there was a relationship between these levels and the portal pressure in the same patients, peripheral and portal plasma from cirrhotic patients (n = 18) undergoing elective transjugular intrahepatic portosystemic shunt and appropriate controls (n = 18) were assayed for iPF2 alpha-III levels by using a gas chromatography/mass spectrometry assay. Portal pressure was measured in all cirrhotic patients. RESULTS: Cirrhotic patients had higher peripheral plasma levels of iPF2 alpha-III [78 (27-150) pg/mL] than controls [18(10-30)pg/mL] (P < 0.001). Portal iPF2 alpha-III levels were higher than plasma peripheral levels [129(50-375) pg/mL; P < 0.0001]. No correlation was found between peripheral and portal levels of iPF2 alpha-III (Rho = 0.17, P = 0.5). Portal levels of iPF2 alpha-III and portal pressure did not correlate (Rho = 0.17, P = 0.49). CONCLUSIONS: This study shows that peripheral and portal levels of iPF2 alpha-III, marker of in vivo lipid peroxidation, are elevated in liver cirrhosis. There is no correlation between iPF2 alpha-III portal levels and the portal pressure observed in these patients. These findings suggest that this biologically active isoprostane does not directly contribute to the portal hypertension observed in hepatic cirrhosis.     

Hydrogen peroxide in exhaled air is increased in stable asthmatic children

Exhaled air condensate provides a noninvasive means of obtaining samples from the lower respiratory tract. Hydrogen peroxide (H2O2) in exhaled air has been proposed as a marker of airway inflammation. We hypothesized that in stable asthmatic children the H2O2 concentration in exhaled air condensate may be elevated as a result of airway inflammation. In a cross-sectional study, 66 allergic asthmatic children (of whom, 41 were treated with inhaled steroids) and 21 healthy controls exhaled through a cold trap. The resulting condensate was examined fluorimetrically for the presence of H2O2. All subjects were clinically stable, nonsmokers, without infection. The median H2O2 level in the exhaled air condensate of the asthmatic patients was significantly higher than in healthy controls (0.60 and 0.15 micromol, respectively; p<0.05), largely because of high values in the stable asthmatic children who did not use anti-inflammatory treatment (0.8 micromol; p<0.01 compared to controls). We conclude that hydrogen peroxide is elevated in exhaled air condensate of children with stable asthma, and may reflect airway inflammation.     

The isoprostanes: a perspective

The isoprostanes are a new class of natural products produced in vivo by a non-enzymatic free-radical-induced peroxidation of polyunsaturated fatty acid. In the case of arachidonic acid, for example, four classes of isoprostanes can be produced. Because of the specific structural features distinguishing them from other free-radical-generated products, e.g., HETEs, etc., the isoprostanes can provide an exclusive and selective index for the oxidant component of several inflammatory and degenerative diseases. The possible mechanisms of formation of the individual isoprostanes is discussed in detail. Class III products, such as 8-iso-PGF2 alpha and 8-iso-PGE2 have been shown to be vasoconstrictors and modulate platelet function. Several synthetic representatives from the four classes of arachidonic-acid-derived isoprostanes have already been prepared by total synthesis. These synthetic standards have been used for the identification and quantitation of these isoprostanes in biological fluids using gas chromatography/mass spectrometry methodology.     

Nitrite levels in breath condensate of patients with cystic fibrosis is elevated in contrast to exhaled nitric oxide

BACKGROUND: Nitric oxide (NO) is released by activated macrophages, neutrophils, and stimulated bronchial epithelial cells. Exhaled NO has been shown to be increased in patients with asthma and has been put forward as a marker of airways inflammation. However, we have found that exhaled NO is not raised in patients with cystic fibrosis, even during infective pulmonary exacerbation. One reason for this may be that excess airway secretions may prevent diffusion of gaseous NO into the airway lumen. We hypothesised that exhaled NO may not reflect total NO production in chronically suppurative airways and investigated nitrite as another marker of NO production. METHODS: Breath condensate nitrite concentration and exhaled NO levels were measured in 21 clinically stable patients with cystic fibrosis of mean age 26 years and mean FEV1 57% and 12 healthy normal volunteers of mean age 31 years. Breath condensate was collected with a validated method which excluded saliva and nasal air contamination and nitrite levels were measured using the Griess reaction. Exhaled NO was measured using a sensitive chemiluminescence analyser (LR2000) at an exhalation rate of 250 ml/s. Fourteen patients with cystic fibrosis had circulating plasma leucocyte levels and differential analysis performed on the day of breath collection. RESULTS: Nitrite levels were significantly higher in patients with cystic fibrosis than in normal subjects (median 1.93 microM compared with 0.33 microM). This correlated positively with circulating plasma leucocytes and neutrophils (r = 0.6). In contrast, exhaled NO values were not significantly different from the normal range (median 3.8 ppb vs 4.4 ppb). There was no correlation between breath condensate nitrite and lung function and between breath condensate nitrite and exhaled NO. CONCLUSIONS: Nitrite levels in breath condensate were raised in stable patients with cystic fibrosis in contrast to exhaled NO. This suggests that nitrite levels may be a more useful measure of NO production and possibly airways inflammation in suppurative airways and that exhaled NO may not reflect total NO production.     

Oxidative injury induced cyclooxygenase activation in experimental hepatotoxicity

This report investigates the plasma and/or urinary levels of 8-iso-PGF2alpha, a nonenzymatic, and 15-keto-dihydro-PGF2alpha, a cyclooxygenase catalyzed oxidation product of arachidonic acid in experimental hepatotoxicity in rats. The study was undertaken to evaluate oxidative injury-induced inflammation as a consequence of cyclooxygenase induction. A significant and immediate increase of 8-iso-PGF2alpha in both plasma and urine after CCl4 administration indicates an oxidative injury during acute hepatotoxicity in rats. The inflammatory response index was determined by measuring 15-keto-dihydro-PGF2alpha levels in plasma which increased significantly 9-fold at 4 h after the administration of CCl4. The oxidative injury index, 8-iso-PGF2alpha, in both plasma and urine increased 17- and 53-fold, respectively. Six hours later the levels of 15-keto-dihydro-PGF2alpha in plasma remained high (5-fold increase) when 8-iso-PGF2alpha levels in plasma and urine elevated to 7- and 87-fold, respectively. Thus, cyclooxygenase and free radical-catalyzed oxidation of arachidonic acid are well involved during CCl4-induced hepatotoxicity. Cyclooxygenase-dependent inflammatory response through PGF2alpha formation in CCl4-induced hepatotoxicity may possibly be a secondary effect to oxidative injury and a conceivable link between inflammatory response and oxidative injury.     

Platelet activating factor and tumor necrosis factor-alpha in bronchoalveolar lavage fluid of patients with ARDS

Platelet activating factor (PAF) and tumor necrosis factor alpha (TNF-alpha) were examined in the bronchoalveolar lavage fluid (BALF) of 21 ARDS patients to clarify the role of these factors in ARDS. Neutrophil percentages and albumin concentrations in the BALF of the ARDS group were markedly elevated compared with those in the control group (p < 0.01), showing a significant correlation (r = 0.596, p < 0.01). PAF was detected in 14 of 19 ARDS patients (237.5 +/- 86.0 pg/ml) and TNF-alpha was detected in 7 of 16 ARDS patients (24.9 +/- 13.6 pg/ml), whereas these factors were not detected in control subjects. Neither PAF nor TNF-alpha showed a significant correlation with neutrophil percentage, neutrophil number or albumin concentration. They do not seem to be contributing factors to the prognosis of ARDS patients. However the existence of PAF and TNF-alpha in the BALF of some ARDS patients suggests that they might play a role in the pathogenesis of ARDS.     

Soluble interleukin-1 receptor antagonist serum levels in smokers and nonsmokers with Graves' ophthalmopathy undergoing orbital radiotherapy

Interleukin-1 (IL-1) plays an important role in the pathogenesis of Graves' ophthalmopathy (GO). Impaired antagonism of the proinflammatory cytokine IL-1 by the naturally occurring IL-1 receptor antagonist (IL-1RA) has been implicated in the initiation and perpetuation of various autoimmune diseases and may play a role in the evolution of GO. Cigarette smoking appears to adversely affect the course of GO. We have evaluated the course of IL-1 alpha, IL-1 beta, and soluble IL-1RA (sIL-1RA) serum levels in smokers and nonsmokers with GO undergoing orbital radiotherapy (OR). We prospectively studied the eye status of 27 randomly selected patients (mean age 47.3 +/- 11.0 yr; 20 females; 18 smokers) with active, moderately severe GO before and 3 and 6 months following OR, respectively. None had received any previous treatment for GO, and all patients were kept euthyroid on carbimazole. Serum concentrations of IL-1 alpha, IL-1 beta, and sIL-1RA were measured using highly sensitive enzyme linked immunosorbent assay systems. Baseline sIL-1RA levels were negatively correlated with the number of cigarettes smoked before and following OR (P < 0.0001). Patients with no or minor therapeutic response to OR (n = 8), all of whom were smokers, revealed mean baseline sIL-1RA levels of 114 +/- 85 pg/mL, which increased to 172 +/- 103 pg/mL at 3 months and 149 +/- 96 pg/mL at 6 months after initiation of OR, respectively. By contrast, patients with a good clinical response (n = 19, 9 nonsmokers), revealed significantly higher baseline sIL-1RA levels at 294 +/- 148 pg/mL (P = 0.004), which increased to 845 +/- 668 pg/mL at 3 months (P = 0.01) and 634 +/- 337 pg/mL at 6 months (P < 0.001), respectively, following initiation of OR. Serum concentrations of IL-1 alpha IL-1 beta were below 3.9 pg/mL in all patients with GO who were studied, and were not correlated with gender, age, smoking status, clinical course, or outcome. Low baseline levels and impaired surge of sIL-1RA serum levels following OR were strongly correlated with smoking status and a less favorable therapeutic outcome in patients with active, moderately severe GO. Measurement of sIL-1RA may contribute to predict the therapeutic response to OR in patients with active, moderately severe GO. Strategies designed to raise local or systemic concentrations of sIL-1RA may be of benefit to patients with GO.     

Application of a new method for analysis of exhaled gas in critically ill patients

OBJECTIVE: Application of a new method for analysis of exhaled gas in critically ill patients. DESIGN: Open study. SETTING: Surgical intensive care unit of an university hospital. PATIENTS: Thirty-seven consecutive, critically ill, mechanically ventilated patients. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Chemical analysis of the patient's exhaled gas was based upon substance adsorption and concentration onto activated charcoal, microwave desorption and gas chromatographic separation. Patients with acute respiratory distress syndrome (ARDS) exhaled less isoprene than those without ARDS [9.8 (8.2-21.6) vs 21.8 (13.9-41.4) nmol/m2 per min [median (95% confidence interval)], p = 0.04]. In patients who developed pulmonary infection, pentane elimination increased from 0.4 (0.0-5.4) to 2.7 (0.6-6.1, p = 0.05) nmol/m2 per min and isoprene elimination decreased from 5.2 (0-33) to 5.0 (0-17, p = 0.05) nmol/m2 per min, resulting in a significant increase in pentane/isoprene ratio from 0.1 (0-0.3) to 0.4 (0-15, p = 0.007) when compared to patients without pulmonary infection. CONCLUSIONS: The new method allows quantitative analysis of human gas samples with low substance concentrations and is well suited for clinical studies which involve the investigation of metabolic processes in the lung and the body.     

Identification of specific nuclear protein kinase C isozymes and accelerated protein kinase C-dependent nuclear protein phosphorylation during myocardial ischemia

Tritium labelled (x=1.1 MBq/17.7 microg/kg) and unlabelled 8-iso-PGF2alpha (43 microg/kg) were administered intravenously to female rabbits and frequent blood and continuous urinary samples were collected up to 4 h. The total radioactivity was lost rapidly from the circulation. About 80% of the total radioactivity was found in urine within 4 h. The plasma half-life of 8-iso-PGF2alpha is found to be 1 min at the distribution phase. The terminal elimination phase half-life was about 4 min. At 1.5 min after administration 64%, 19% and 13% of the plasma radioactivity represented 8-iso-PGF2alpha, 15-keto-8-iso-PGF2alpha and beta-oxidised products, respectively. The values for 20-min plasma were 5%, 2%, and 88%. The radiochromatograms from 10 min-4 h urinary samples were dominated by more polar beta-oxidised products. Alpha-Tetranor-15-keto-13,14-dihydro-8-iso-PGF2alpha was identified as a major urinary metabolite.Thus, 8-iso-PGF2alpha metabolises in the rabbit mainly to several degraded polar metabolites through dehydrogenation at C-15, reduction of delta13-double bond and beta-oxidation, and excretes efficiently into the urine.     

Soluble cytokine receptors and receptor antagonists are sequentially released after trauma

Cytokine receptors and receptor antagonists (RAs) have been identified in trauma patients. We hypothesized that after traumatic injury, a sequential release of soluble cytokine receptors and RAs may exist that mirrors the release of the primary cytokines themselves. Twenty-two patients were included in the study: 14 males and 8 females. The mean age was 30.1 +/- 12.5 (range, 19 to 71), and the mean Injury Severity Score was 28.7 +/- 12.6 (range, 4 to 57). There were 15 survivors and 7 nonsurvivors. Samples were collected on arrival to the emergency department and at serial intervals for up to 7 days. Monoclonal antibody enzyme-linked immunosorbent assay kits to tumor necrosis factor (TNF), soluble TNF-receptor (sTNF-R) 55 kd and 75 kd, interleukin (IL)-1 and IL-1 RA, and IL-2 and IL-2r were used. Sera from 22 healthy individuals were used as normal controls. No TNF, IL-1, or IL-2 could be detected in any patient sera after injury. Control levels for the soluble cytokine receptors and RAs were as follows: sTNF-R 55 kd, 607 +/- 89 pg/mL; sTNF-R 75 kd, 2,141 +/- 169 pg/mL; IL-1 RA, 291 +/- 35 pg/mL; and IL-2r, 426 +/- 53 U/mL. In trauma patients, both 55 kd and 75 kd sTNF-R were significantly elevated on arrival to the emergency department, with values of 2,441 +/- 506 pg/mL (p < 0.001) and 4,736 +/- 537 pg/mL (p < 0.001), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct activation of human peritoneal mesothelial cells by heat-killed microorganisms

OBJECTIVE: The aim of the study was to determine if human peritoneal mesothelial cells (HPMCs) can be activated directly by bacterial products contained in preparations of heat-killed Escherichia coli and staphylococci. SUMMARY BACKGROUND DATA: It has been shown recently that cytokine-activated HPMCs produce the inflammatory mediators, interleukin-1, interleukin-6, interleukin-8, and macrophage chemotactic protein-1. Studies concerning the effects of bacterial products on HPMCs are scarce and have not yielded conclusive results. METHODS: Growth-arrested HPMC monolayers were prepared from cell suspensions obtained by enzymatic disaggregation of small pieces of omentum. They were incubated for 24 hours with heat-killed E. coli (ATCC 25922), heat-killed staphylococci (ATCC 25933), or E. coli lipopolysaccharide, and the release of various cytokines in the culture media was measured by radioimmunoassays or enzyme-linked immunosorbent assays. Results were expressed as mean +/- standard error of the mean in picograms per milliliter of supernatant and analyzed with the Wilcoxon test; p values of less than 0.05 were considered significant. RESULTS: Baseline production of interleukin-6, interleukin-8, the chemokine "regulated upon activation, normal T cell expressed and secreted" (RANTES), and macrophage chemotactic protein-1 varied widely from one omental preparation to the other. E. coli increased the release of these mediators: from 1206 +/- 316 pg/mL to 8480 +/- 2189 pg/mL for interleukin-6, from 285 +/- 58 pg/mL to 3164 +/- 1053 pg/mL for interleukin-8, from 7 +/- 5 pg/mL to 684 +/- 264 pg/mL for RANTES, and from 2212 +/- 346 pg/mL to 7726 +/- 1473 pg/mL for macrophage chemotactic protein-1. Heat-killed staphylococci did not alter significantly the production of RANTES or macrophage chemotactic protein-1 but increased the production of the two other cytokines from 1325 +/- 389 pg/mL to 2206 +/- 523 pg/mL for interleukin-6 and from 318 +/- 70 pg/mL to 819 +/- 265 pg/mL for interleukin-8. CONCLUSIONS: The authors' results show that HPMCs are able to react to a direct stimulation with heat-killed microbes. They suggest that HPMCs, as well as resident macrophages, participate actively in the initiation and possibly in the modulation of intraperitonen inflammatory reactions.     

Serum levels of interleukin 1 and tumor necrosis factor alpha correlate with peritoneal adhesion grades in humans after major abdominal surgery

Peritoneal adhesions are a leading cause of potential morbidity and mortality. We undertook this prospective study to determine the clinical relevance of interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF-alpha) levels as biological markers for peritoneal adhesion formation in humans. Fifteen patients who had previous colectomies and were undergoing re-exploration for an elective vascular procedure were studied. Blood samples were collected from each patient preoperatively and 30 minutes after the abdominal incision was made. Serum levels of IL-1 and TNF-alpha were determined using enzyme-linked immunosorbent assay kits. Adhesions were graded using an adhesion scale of 0 (none), 1 (mild), 2 (moderate), and 3 (extensive, dense). Preoperative levels of IL-1 and TNF-alpha did not differ significantly among all patients (IL-1 level was 60 +/- 14 pg/mL, and TNF-alpha level was 45 +/- 11 pg/mL; mean +/- standard deviation). Significant correlation was observed between grades of adhesions and early intraoperative levels of IL-1 [101 +/- 36 pg/mL for grade 1 (n = 8) vs 298 +/- 73 pg/mL for grade 3 (n = 6); P < 0.01] and TNF-alpha (88 +/- 23 pg/mL for grade 1 vs 261 +/- 88 mL for grade 3; P < 0.02). We conclude that early elevations of IL-1 and TNF-alpha are reliable biological markers for postoperative adhesions in humans. Studies utilizing cytokines antibodies to these markers may further elucidate the efficacy of this method for prevention of peritoneal adhesions.     

In vivo formation of 8-Epi-prostaglandin F2 alpha is increased in hypercholesterolemia

F2-isoprostanes are bioactive prostaglandin (PG)-like compounds that are produced from arachidonic acid through a nonenzymatic process of lipid peroxidation catalyzed by oxygen free-radicals. 8-Epi-PGF2 alpha may amplify the platelet response to agonists, circulates in plasma, and is excreted in urine. We examined the hypothesis that the formation of 8-epi-PGF2 alpha is altered in patients with hypercholesterolemia and contributes to platelet activation in this setting. Urine samples were obtained from 40 hypercholesterolemic patients and 40 age- and sex-matched control subjects for measurement of immunoreactive 8-epi-PGF2 alpha. Urinary excretion of 11-dehydro-thromboxane (TX) B2, a major metabolite of TXA2, was measured as an in vivo index of platelet activation. Low-dose aspirin, indobufen, and vitamin E were used to investigate the mechanism of formation and effects of 8-epi-PGF2 alpha on platelet activation. Urinary 8-epi-PGF2 alpha was significantly (P = .0001) higher in hypercholesterolemic patients than in control subjects: 473 +/- 305 versus 205 +/- 95 pg/mg creatinine. Its rate of excretion was inversely related to the vitamin E content of LDL and showed a positive correlation with urinary 11-dehydro-TXB2. Urinary 8-epi-PGF2 alpha was unchanged after 2-week dosing with aspirin and indobufen despite complete suppression of TX metabolite excretion. Vitamin E supplementation was associated with dose-dependent reductions in both urinary 8-epi-PGF2 alpha and 11-dehydro-TXB2 by 34% to 36% and 47% to 58% at 100 and 600 mg daily, respectively. We conclude that the in vivo formation of the F2-isoprostane 8-epi-PGF2 alpha is enhanced in the vast majority of patients with hypercholesterolemia. This provides an aspirin-insensitive mechanism possibly linking lipid peroxidation to amplification of platelet activation in the setting of hypercholesterolemia. Dose-dependent suppression of enhanced 8-epi-PGF2 alpha formation by vitamin E supplementation may contribute to the beneficial effects of antioxidant treatment.