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Biomedical subjects

A A Fowler

Publications and source records attributed to A A Fowler.

At least 19 recordsLinked to original sources
PubMed2003

Linoleic acid, but not oleic acid, upregulates the production of interleukin-8 by human intestinal smooth muscle cells isolated from patients with Crohn's disease.

BACKGROUND & AIMS: Crohn's disease is a chronic inflammatory bowel disease (IBD) of unknown etiology. In this study, we investigated the hypothesis that dietary fatty acids, linoleic acid (LA) and oleic acid (OA), could be involved in the inflammatory response through stimulation of the neutrophil chemokine, IL-8. METHODS: Human intestinal smooth muscle (HISM) cells were isolated from normal patients and patients with Crohn's disease and cultured for 24h with LA or OA in the presence or absence of oxidative stress. The concentrations of IL-8 were measured in the media and cellular oxidative stress was quantitated by measurement of thiobarbituric acid reactive substances (TBARSs). RESULTS: Spontaneous production of IL-8 was significantly higher in HISM cells isolated from Crohn's bowel compared to control bowel. LA caused a marked, nine-fold, increase in IL-8 secretion by Crohn's cells, an effect that could be simulated in normal HISM cells by co-incubation of LA with an oxidizing solution (Ox) composed of hypoxanthine+xanthine oxidase+FeSO(4) (OxLA). These effects were inhibited by vitamins C and E. Treatment of Crohn's cells with OxLA did not further increase IL-8 over that of LA alone. The effect of LA alone was not associated with an increase in cellular oxidative stress as quantitated by TBARSs. In contrast to the results with LA, treatment with OA or OxOA did not increase IL-8 in either normal or Crohn's cells. In addition, OA protected Crohn's cells from the increase in TBARSs induced by Ox. In contrast to IL-8, spontaneous production of monocyte chemotactic protein (MCP-1) was significantly lower in Crohn's HISM cells as compared to normal cells and exposure to OxLA did not increase its production. CONCLUSIONS: LA, but not OA, increased the production of IL-8 by HISM cells. These results suggest that replacement of LA by OA in the diet of Crohn's patients and increased intake of a diet rich in antioxidants could be beneficial in decreasing inflammatory activity in Crohn's disease.

Analysis of Variance↗
PubMed2001

Nitric oxide suppresses IL-8 transcription by inhibiting c-Jun N-terminal kinase-induced AP-1 activation.

The role of activator protein-1 (AP-1) in tumor necrosis factor-alpha (TNF-alpha)-induced interleukin-8 (IL-8) gene expression was evaluated. We showed that TNF-alpha activates AP-1 in the transformed endothelial cell line ECV304 by transient transfections of IL-8 promoter construct pGL-3BF(2). Mutation of either the AP-1 site or the NF-IL-6 site on the IL-8 promoter suppressed the TNF-alpha-induced activation, suggesting cooperation between these transcription factors and transcription factor NF-kappaB. Overexpression of dominant negative mutants of c-Jun suppressed AP-1-driven transcription of the IL-8 promoter following stimulation by TNF-alpha, suggesting that cooperative interaction between AP-1 and NF-kappaB is essential for IL-8 transcription in the presence of TNF-alpha. We also showed that nitric oxide (NO), in the form of an exogenous NO donor, suppressed the level of activation of the AP-1 subunit, c-Jun, by down-regulation of c-Jun NH2 terminal kinase. This down-regulation could be the putative mechanism of action for NO-mediated inhibition of IL-8 secretion in activated endothelium. These observations suggest for the first time that NO has broad suppressive activities on various proinflammatory effectors in activated endothelium.

CCAAT-Enhancer-Binding Protein-beta↗
PubMed2001

Redox imbalance in Crohn's disease intestinal smooth muscle cells causes NF-kappaB-mediated spontaneous interleukin-8 secretion.

Interleukin-8 (IL-8), a chemokine secreted by cells at injury sites, has recently been recognized as involved in the pathogenesis of Crohn's disease. However, the pathogenesis of enhanced spontaneous transcription of IL-8 by the bowel in patients with Crohn's disease is undefined. Although IL-8 is secreted primarily by neutrophils, macrophages, and endothelial and epithelial cells, we observed the involvement of mesenchymal cells in the inflammatory process. A smooth muscle cell line isolated from the ileum of a patient with Crohn's disease (CDISM) and maintained in culture exhibited spontaneous transcription and secretion of IL-8 when compared with intestinal smooth muscle cells obtained from a normal subject (NHISM). Furthermore, IL-8 transcription from CDISM cells was associated with remarkable spontaneous activation of the oxidant-sensitive transcription factor NF-kappaB, as assessed by transient transfection assays with an IL-8 promoter reporter construct, Western blot analysis, and electrophoretic mobility shift assays (EMSA). Finally, we report here that CDISM cells exhibit significantly altered redox balance. The antioxidant pyrrolidine dithiocarbamate (PDTC) restored the redox equilibrium by mechanisms that inhibit binding of NF-kappaB to its cognate site on the IL-8 promoter. These findings suggest that restoration of the redox balance could hold promise for therapeutic intervention in Crohn's disease.

Antioxidants↗
PubMed2001

Obstructive granulomatous bronchiolitis due to Mycobacterium avium complex in an immunocompetent man.

While the development of pulmonary disease due to Mycobacterium avium complex (MAC) infection is most commonly associated with underlying predisposing factors, this organism occasionally causes symptomatic disease in otherwise normal individuals. Patients with MAC pulmonary disease most often present with cavitating granulomas, but a spectrum of pathologic changes has been described. The authors present a case of MAC pulmonary disease in an immunocompetent, middle-aged man with no identified predisposing factors. The diagnostic biopsy disclosed the unusual finding of noncaseating granulomas with predominant involvement of bronchioles, corresponding to the patient's obstructive and restrictive pulmonary dysfunction.

Adult↗
PubMed1999

Nitric oxide regulates interleukin-8 gene expression in activated endothelium by inhibiting NF-kappaB binding to DNA: effects on endothelial function.

Nuclear factor-kappaB (NF-kappaB) binds to nucleotide sequences between -80 and -70 bp upstream of the transcriptional start site in the interleukin-8 (IL-8) promoter and is crucial for transcription of the IL-8 gene. We showed that exogenous nitric oxide in the form of a nitric oxide donor significantly reduced IL-8 mRNA in cytokine-activated ECV304. Similarly, nitric oxide significantly reduced migration of polymorphonuclear neutrophils through cytokine-activated ECV304 monolayers, an IL-8-dependent process. Using a luciferase reporter construct containing the NF-kappaB site of the IL-8 gene, we showed that exposing cytokine-activated ECV304 to exogenous nitric oxide resulted in significant reduction of NF-kappaB binding. Follow-up studies using a luciferase reporter construct possessing a mutated NF-kappaB site confirmed that the luciferase activity observed in the NF-kappaB reporter resulted from NF-kappaB binding. These studies demonstrate that nitric oxide, supplied exogenously into reactions containing activated endothelium, down-regulates pro-inflammatory activity, such as the secretion of chemokines, and functional activity, such as transendothelial migration of neutrophils.

Base Sequence↗
PubMed1998

Heat shock provides delayed protection against oxidative injury in cultured human umbilical vein endothelial cells.

During both mild and severe ischemia, vascular endothelial cells lining large and small vessels of the ischemic organ are exposed to oxygen-derived free radicals resulting in oxidative damage to the organ. Heat shock has been shown to induce thermotolerance and also protect against ischemic injury, possibly via increased synthesis of heat shock proteins (HSPs). We hypothesized that heat shock preconditioning may protect human endothelial cells against oxidative damage. Cultured human umbilical vein endothelial cells (HUVEC) were subjected to heat shock (42 degrees C, 1 h) and allowed to recover for 2 or 20 h, at which times the cells were oxidatively stressed for 1 h by exposing them to 100-200 mumol/l of hydrogen peroxide (H2O2). Cellular damage was assessed immediately and 18 h later by morphology and release of lactate dehydrogenase (LDH). No protection of HUVEC was seen using the 2-hour recovery interval, but a significant protection (P < 0.05) was observed after the 20-hour delay. Northern blot analysis at 1 and 2 h after heating showed induction of HSP-70 mRNA. Western blot analysis demonstrated a significant increase in HSP-72 protein after 2 as well as 20 h of recovery from heat shock, although the amounts of protein at the two times were not significantly different. Furthermore, no differences in the activity of the antioxidant enzyme catalase were observed between heated and unheated HUVEC at 2 and 20 h after heat preconditioning. Thus, heat shock preconditioning induces delayed protection against oxidative injury in HUVEC, and the mechanism of protection appears to involve more than the expression of HSP-72 or activity of catalase.

Blotting, Northern↗
PubMed1998

Prolonged weakness after cisatracurium infusion: a case report.

OBJECTIVE: To present the first documented case report of myopathy persisting for >48 hrs in a patient treated with cisatracurium and concomitant high-dose corticosteroids. DESIGN: Anecdotal observations in one patient. SETTING: Medical-respiratory intensive care unit (ICU) at a tertiary care, university teaching hospital. PATIENT: A 45-yr-old female admitted status for post-bilateral total knee replacement complicated by aspiration pneumonitis and acute respiratory distress syndrome (ARDS). INTERVENTIONS: The patient required pressure control ventilation and sedation with midazolam and fentanyl infusions. On ICU day 2, the patient was placed on inverse ratio ventilation and paralyzed with cisatracurium. On ICU day 6, methylprednisolone 125 mg i.v. every 6 hrs was initiated for fibroproliferative ARDS. On ICU day 11, methylprednisolone was reduced to 60 mg i.v. every 6 hrs and tapered over several weeks. Cisatracurium infusion rates ranged from 6.3 to 10.5 microg/kg/min, with an average of 8.0 microg/kg/min. MEASUREMENTS AND MAIN RESULTS: Train-of-Four was assessed before initiation of therapy and every 4 hrs, thereafter. Train-of-Four values were maintained from 1 to 4 throughout therapy and a value of 4 was recorded when therapy was discontinued. On day 13, neuromuscular blocking agent therapy was discontinued, but severe proximal and distal muscle weakness was observed bilaterally. Creatinine kinase concentrations on 3 and 13 days after discontinuation of the paralytic agent were 181 and 96 units/L, respectively. On day 24, the patient moved her fingertips. On ICU day 30, the patient was weaned from the mechanical ventilator. The patient was transferred to the ward on day 33. Extensive rehabilitation with physical and occupational therapy was required for several months. CONCLUSION: Clinicians should remember that irrespective of chemical structural, neuromuscular blocking agents might produce prolonged paralysis in predisposed patients.

Atracurium↗
PubMed1998

Histamine receptor antagonists, cyclooxygenase blockade, and tumor necrosis factor during acute septic insult.

Tumor necrosis factor (TNF) may be a major endogenous mediator of sepsis-induced acute organ injury. We proposed that treatment of septic pigs with the combined agents ibuprofen, a cyclooxygenase inhibitor, and histamine receptor antagonists, cimetidine (H2 antagonist) and diphenhydramine (H1 antagonist) would result in lower circulating levels of TNF and decreased parameters of sepsis-induced injury in these animals. To test this, plasma TNF activity, cardiac index, systemic and pulmonary arterial pressures, arterial PO2 and bronchoalveolar lavage protein content were monitored for 300 min in four groups of anesthetized pigs: saline-infused control pigs (n = 4); pigs infused for 60 min with Pseudomonas aeruginosa (5 x 10(8) organisms/mL, .3 mL/20 kg/min) (n = 5) and pigs infused for 60 min with P. aeruginosa plus ibuprofen (12.5 mg/kg) alone (n = 4) or ibuprofen plus cimetidine (150 mg) and diphenhydramine (30 mg/kg) at 0 and 120 min (CID, n = 4). Within 60 min, pigs infused with P. aeruginosa exhibited increased plasma TNF activity (>8-fold increase in ng/mL TNF; L929 cytolysis assay) and showed alterations in all hemodynamic and pulmonary parameters. Ibuprofen or CID administration in the septic pigs decreased peak TNF activity by 4.6 and 10.2 ng/mL, respectively, and CID treatment was correlated with better attenuation of certain sepsis-induced alterations. These results show that CID treatment attenuates sepsis-induced injury and that this is correlated with reduced plasma TNF activity in a porcine model of sepsis-induced acute organ injury.

Animals↗
PubMed1997

Delayed administration of inhaled nitric oxide preserves alveolar-capillary membrane integrity in porcine gram-negative sepsis.

OBJECTIVE: To determine the effect of delayed administration of inhaled nitric oxide (NO) on acute lung injury after the onset of gram-negative sepsis. DESIGN: Nonrandomized controlled study. SETTING: University medical center laboratory. SUBJECTS: Yorkshire swine. INTERVENTIONS: Five groups of swine were anesthetized, mechanically ventilated, and studied for 5 hours. After surgical preparation, control (n = 10) and NO-treated control (n = 6) animals received a 1-hour infusion of sterile saline solution. Sepsis was induced with a 1-hour intravenous infusion of live Pseudomonas aeruginosa. Untreated animals with sepsis (n = 10) received no treatment. Inhaled NO at 20 ppm was administered to NO30-treated animals with sepsis (n = 7) and NO60-treated animals with sepsis (n = 8) beginning at 30 and 60 minutes after bacterial infusion was begun, respectively. MAIN OUTCOME MEASURES: Systemic and pulmonary hemodynamics, arterial blood gas determination, bronchoalveolar lavage protein and neutrophil content, neutrophil oxidant burst, lung myeloperoxidase content, and scanning electron micrographic studies. RESULTS: A progressive, significant (P < .05) decline in PaO2 developed in untreated animals with sepsis, which was prevented in NO30- and NO60-treated animals with sepsis. A significant (P < .05) increase in bronchoalveolar lavage protein and neutrophil counts compared with baseline values was observed in untreated animals with sepsis, indicating acute lung injury. These variables exhibited no notable increase in NO30- and NO60-treated animals with sepsis and were significantly (P < .05) reduced compared with untreated animals with sepsis. The lung myeloperoxidase content was significantly (P < .05) elevated at 5 hours in all groups with sepsis compared with baseline values and the control and NO-treated control groups. The total phorbol myristate acetate-induced polymorphonuclear leukocyte oxidant burst at 5 hours was significantly (P < .05) decreased in the NO30- and NO60-treated animals with sepsis compared with untreated animals with sepsis. Untreated and NO30- and NO60-treated animals with sepsis showed a significant (P < .05) increase in pulmonary artery pressure at 30 minutes, followed by a progressive decline. These changes were significant (P < .05) compared with baseline values and the control groups. No significant (P < .05) difference in pulmonary artery pressure or systemic arterial pressure was found at any time between untreated and NO30- and NO60-treated animals with sepsis. CONCLUSIONS: The delayed administration of inhaled NO preserves alveolar-capillary membrane integrity in this porcine model of gram-negative sepsis. The inhibition of neutrophil transendothelial migration, rather than neutrophil rolling or tight adhesion, may be a critical mechanism by which inhaled NO produces this effect. Decreased oxidant production by activated neutrophils may be a secondary mechanism by which inhaled NO reduces acute lung injury.

Animals↗
PubMed1997

OPC-6535, a superoxide anion production inhibitor, attenuates acute lung injury.

A large body of evidence has demonstrated that inhibition of the neutrophil's oxidant burst attenuates sepsis-induced acute lung injury. The present study sought to evaluate the ability of OPC-6535, a superoxide anion production inhibitor, to attenuate sepsis-induced acute lung injury. Four groups of swine were anesthetized, ventilated, and studied for 5 hr. Following surgical preparation, control (n = 10) and OPC-control (n = 2) animals received a 1-hr infusion of sterile saline. Sepsis was induced with a 1-hr intravenous infusion of live Pseudomonas aeruginosa. Untreated septic animals (n = 10) received no treatment. Animals treated with OPC-6535 (n = 6) received a 1 mg/kg bolus of OPC-6535 15 min prior to initiation of the bacterial infusion. Changes in systemic and pulmonary hemodynamics, arterial oxygen tension, bronchoalveolar lavage protein and neutrophil content, neutrophil integrin expression, neutrophil oxidant burst, and lung myeloperoxidase content were used as outcome measures. Treatment with OPC-6535 significantly reduced acute lung injury, as indicated by improved bronchoalveolar lavage protein and neutrophil content, resulting in a significant improvement in arterial oxygenation. Treatment with OPC-6535 failed to prevent the development of pulmonary hypertension and systemic hypotension. Neutrophils from animals with both treated and untreated sepsis exhibited significant up-regulation of CD18 and production of increased levels of oxidants, indicating significant activation when compared to neutrophils from control animals. Although animals treated with OPC-6535 produced 25% less superoxide anion than untreated septic animals, this decrease was not statistically significant. Treatment of animals with OPC-6535 prior to the onset of sepsis produced significant protection against acute lung injury but failed to attenuate hemodynamic derangements associated with sepsis.

Administration, Inhalation↗
PubMed1997

Pretreatment with inhaled nitric oxide inhibits neutrophil migration and oxidative activity resulting in attenuated sepsis-induced acute lung injury.

OBJECTIVE: To determine if, and by what mechanisms, inhaled nitric oxide attenuates acute lung injury in a porcine model of adult respiratory distress syndrome induced by Gram-negative sepsis. DESIGN: Nonrandomized, controlled study. SETTING: Laboratory at a university medical center. SUBJECTS: Thirty pathogen-free Yorkshire swine (15 to 20 kg). INTERVENTIONS: Four groups of swine were anesthetized, mechanically ventilated, and studied for 5 hrs. Both control-nitric oxide and septic-nitric oxide animals received inhaled nitric oxide at 20 parts per million throughout the study. Control (n = 10) and control-nitric oxide (n = 5) animals received a 1-hr infusion of sterile saline. Sepsis was induced in septic (n = 10) and septic-nitric oxide (n = 5) animals with a 1-hr intravenous infusion of live Pseudomonas aeruginosa. MEASUREMENTS AND MAIN RESULTS: Untreated septic animals developed a progressive decrease in Pao2 that was prevented in septic-nitric oxide animals (73 +/- 4 vs. 214 +/- 23 torr [9.7 +/- 0.5 vs. 28.5 +/- 3.1 kPa], respectively, at 5 hrs, p < .05). Untreated septic animals showed a significant increase in bronchoalveolar lavage protein and neutrophil count at 5 hrs, compared with the baseline value, indicating acute lung injury. Septic-nitric oxide animals showed no significant increase in these parameters. Peripheral blood neutrophils from untreated septic animals and septic-nitric oxide animals exhibited significant (p < .05) up-regulation of CD18 receptor expression and oxidant activity (10.5 +/- 0.9 and 5.0 +/- 0.9 nmol of superoxide anion/10(6) neutrophils/10 mins, respectively) compared with both control and control-nitric oxide animals (3.0 +/- 0.6 and 2.6 +/- 0.2 nmol of superoxide anion/10(6) neutrophils/10 mins, respectively). Also, priming for the oxidant burst at 5 hrs was decreased by 50% in septic-nitric oxide animals compared with untreated septic animals. Both untreated septic and septic-nitric oxide animals showed a significant increase in pulmonary arterial pressure at 30 mins (47.5 +/- 2.4 and 51.0 +/- 3.0 mm Hg, respectively), followed by a progressive decrease (32.8 +/- 2.6 and 31.3 +/- 5.4 mm Hg, respectively, at 5 hrs). Both of these changes were significant (p < .05) compared with baseline values and compared with the control groups. There was no significant difference in pulmonary arterial pressure or systemic arterial pressure at any time between untreated septic and septic-nitric oxide animals. CONCLUSIONS: These results demonstrate that inhaled nitric oxide attenuates alveolar-capillary membrane injury in this porcine model of Gram-negative sepsis but does not adversely affect systemic hemodynamics. The data suggest that inhaled nitric oxide preserves alveolar-capillary membrane integrity by the following means: a) inhibiting transendothelial migration of activated, tightly adherent neutrophils; and b) possibly by attenuating the neutrophil oxidant burst.

Administration, Inhalation↗
PubMed1997

Protective role of synthetic sialylated oligosaccharide in sepsis-induced acute lung injury.

Proper engagement of leukocyte and endothelial cell selectins with their counterreceptors is an initial step in neutrophil trafficking to sites of inflammation. Certain fucosylated carbohydrate determinants such as sialyl Lewis-x are proposed to act as these counterreceptors. We studied the effects of a synthetic sialyl Lewis-x analog, CY-1503, on the course of hemodynamic derangements and acute lung injury during experimental gram-negative sepsis. Anesthetized ventilated swine were made septic with an infusion of live Pseudomonas aeruginosa. A treatment group received an initial bolus of CY-1503 (60 mg/kg) before sepsis, followed by continuous infusion of CY-1503 (15 mg.kg-1.h-1). Treatment with CY-1503 did not prevent the development of pulmonary hypertension, systemic hypotension, decline in cardiac output, or severe neutropenia. However, CY-1503 significantly attenuated lung injury, demonstrated by decreased bronchoalveolar lavage protein content and neutrophil influx, lowered lung myeloperoxidase activity, and improved arterial oxygenation. Neutrophils from septic and CY-1503 animals showed significant activation, reflected by upregulated CD18 expression and priming for oxidant burst compared with control animals. This study suggests blockade of selectin interactions as a potential therapeutic intervention in sepsis-induced lung injury.

Animals↗
PubMed1997

Soluble E-selectin levels in sepsis and critical illness. Correlation with infection and hemodynamic dysfunction.

E-selectin, an early mediator of leukocyte-endothelial adhesion, is expressed on activated endothelium. Soluble E-selectin is present in the supernatant of cytokine-activated endothelial cells and elevated serum levels are found in a variety of inflammatory conditions. We documented elevated E-selectin serum levels in 119 critically ill medical ICU patients (log transformed mean E-selectin level, measured by ELISA, was 5.28 ng/ml) compared to normal volunteers (1 ng/ml). Forty-three patients with culture-positive sepsis had higher (p < 0.05) E-selectin levels (15.39 ng/ml) than 24 patients with culture-negative sepsis (4.87 ng/ml), 44 with noninfectious SIRS (2.33 ng/ml), and eight without SIRS (1.97 ng/ml). E-selectin levels related strongly to the degree of hemodynamic compromise (p < 0.0001). Further analysis demonstrated microbiological status and hemodynamic status to be independent variables related to E-selectin level. Day 1 E-selectin levels correlated positively with peak organ failure score over the course of ICU hospitalization (r = 0.30, p = 0.001) and were higher (p < 0.05) for nonsurvivor (10.61 ng/ml, n = 26) than survivors (4.35 ng/ml, n = 93). We conclude that soluble E-selectin levels are higher in serum of patients with microbiologically documented sepsis than in other critically ill medical ICU patients. Day 1 E-selectin levels correlate highly with hemodynamic compromise and modestly with subsequent organ dysfunction and survival.

APACHE↗
PubMed1996

Current concepts of sepsis and acute lung injury.

Acute respiratory distress syndrome continues to be a vexing clinical problem with no specific therapy. Epidemiologic and basic sciences have advanced our understanding of the clinical syndrome and have brought us to the brink of effective intervention strategies. This article carefully examines the current state of knowledge, with reference to acute lung injury and current efforts, to arrive at effective pharmacologic approaches.

Cytokines↗
PubMed1996

Sarcoidosis: a clinical overview.

Sarcoidosis is a granulomatous disease of unknown etiology that occurs most often in the 20 to 40-year age group. It will affect the lungs in 90% of patients and may be multiorgan disease. It will usually present with bilateral hilar adenopathy, with or without parenchymal abnormalities. Many cases are asymptomatic and are discovered on routine chest radiographs. Elevated ACE levels and immunoglobulins are associated with active sarcoid lesions. Gallium scans will "light up" in areas of disease activity. Noncaseating granulomas on histology in a patient with the appropriate history are diagnostic of the disease. Tuberculosis and fungal infections must be ruled out in all cases where a tissue diagnosis is obtained. Corticosteroids are considered the firstline treatment for sarcoid symptoms. Asymptomatic disease will often spontaneously resolve without steroids, whereas a few patients will go on to have a chronic, unremitting course of deteriorating lung function despite steroids and will eventually succumb to their lung disease.

Acute Disease↗
PubMed1995

Sepsis-induced acute lung injury is attenuated by selectin blockade following the onset of sepsis.

OBJECTIVE: To determine the effect of infusion with a dual-binding antibody to E- and L-selectin, EL-246, in a postonset model of sepsis. DESIGN: Nonrandomized controlled study. STUDY SUBJECTS: Young Yorkshire swine. INTERVENTIONS: Three groups were studied. Controls (n = 8) received saline solution only. Untreated animals with sepsis (n = 8) received a 1-hour intravenous infusion of live Pseudomonas aeruginosa. Animals treated with EL-246 (n = 6) received the same bacterial infusion and a 2-mg/kg bolus of EL-246 at 30 minutes. OUTCOME MEASURES: Systemic and pulmonary hemodynamics, arterial blood gas determination, bronchoalveolar lavage protein and neutrophil content, neutrophil integrin and selectin expression, neutrophil oxidant burst, and organ myeloperoxidase content. RESULTS: Treatment with EL-246 significantly reduced lung injury, as indicated by improved bronchoalveolar lavage protein and neutrophil content, resulting in a significant improvement in arterial oxygenation. This reduction in lung injury was produced by a reduction in lung myeloperoxidase content. Treatment with EL-246 failed to prevent the development of pulmonary hypertension and systemic hypotension. Neutrophils from animals with sepsis exhibited significant activation and upregulation of CD18, shedding of L-selectin, and production of increased levels of oxidants compared with controls. CONCLUSION: Treatment of animals with EL-246 soon the onset of sepsis produced significant protection against acute lung injury but failed to attenuate hemodynamic derangements associated with sepsis.

Animals↗
PubMed1995

Tumor necrosis factor-alpha and interleukin-6 selectively regulate neutrophil function in vitro.

The neutrophil is an important effector cell of the host response to sepsis. Tumor necrosis factor-alpha (TNF-alpha), a cytokine mediator of the septic response, is rapidly released following endotoxemia or gram-negative bacteremia. Interleukin-6 (IL-6) is another cytokine mediator of the host response to sepsis whose role is less well understood than that of TNF-alpha. It is known to be elevated in gram-negative sepsis, where peak levels have been correlated with mortality. This study examined the effect of IL-6 alone and in combination with TNF-alpha on three neutrophil functions--CD18 adhesion receptor expression, phagocytosis, and superoxide anion generation. Neutrophils from human volunteers were incubated with amounts of IL-6 ranging from 10 to 1000 ng/ml. At a concentration of 1000 ng/ml, IL-6 increased neutrophil phagocytosis of opsonized bacteria (826 +/- 255 x 10(3) MESF vs 552 +/- 103 MESF, P < 0.05) and also increased neutrophil superoxide anion generation (18.41 +/- 1.86 vs 12.6 nmol O2-/10(6) PMN/10 min, P < 0.05). Lesser amounts of IL-6 had no effect on phagocytosis or superoxide generation. IL-6 did not increase neutrophil CD18 adhesion receptor expression. Combining IL-6 with TNF-alpha at doses of 100 ng/ml and 100 U/ml, respectively, neutrophil phagocytosis (221 +/- 455 MESF vs 552 +/- 103 MESF) and superoxide generation (23.18 +/- 1.86 vs 12.6 nmol O2-/10(6) PMN/10 min) were significantly (P < 0.05) increased above control by an amount similar to that seen with 1000 U/ml TNF-alpha alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗