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1.
J Surg Res ; 101(2): 232-7, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11735280

ABSTRACT

BACKGROUND: Tumor necrosis factor (TNF)-alpha is a critical effector of lipopolysaccharide (LPS)-induced acute lung injury, and its effects are mediated by two structurally related receptors, RI and RII. Cellular adhesion molecules and C-X-C chemokines (Keratinocyte chemoattractant (KC) and macrophage inflammatory protein [MIP]-2) regulate tissue neutrophil polymorphonuclear neutrophil (PMN) accumulation in a multitude of inflammatory states. We hypothesized that TNFRI signaling dictates PMN accumulation in the lung via regulation of chemokine molecule production. Therefore, the purposes of this study were to (1) delineate LPS-induced lung TNF-alpha production and (2) characterize the contribution of both TNF receptors to lung chemokine production and neutrophil influx following systemic LPS. METHODS: Wild-type or TNFRI and TNFRII knockout (KO) mice were injected with vehicle (saline) or LPS (Escherichia coli 0.5 mg/kg intraperitoneally). After 2, 4, 6, or 24 h, lungs were analyzed for TNF-alpha and chemokine (KC and MIP-2) protein expression (enzyme-linked immunosorbent assay) and PMN accumulation (myeloperoxidase assay). RESULTS: There was an increase in total lung TNF-alpha (vehicle, 5.0 +/- 1.2 pg/mg total protein vs LPS, 950 +/- 318; P < 0.05) after LPS. Lung chemokine production and PMN accumulation were also increased compared to vehicle-injected mice. Lung chemokine production and PMN accumulation were significantly lower in TNFRI KO, but not TNFRII KO, mice, despite no difference in TNF-alpha production (TNFRI KO, 925 +/- 301 vs TNFRII KO, 837 +/- 267, P = 0.82). CONCLUSIONS: Acute lung injury following systemic LPS administration is characterized by increased lung (1) TNF-alpha production, (2) C-X-C chemokine production, and (3) neutrophil accumulation. The maximal effect of LPS-induced lung neutrophil accumulation appears to be dependent upon the TNFRI receptor but not the TNFRII receptor. .


Subject(s)
Antigens, CD/physiology , Chemokines/biosynthesis , Lipopolysaccharides/toxicity , Lung/drug effects , Neutrophils/physiology , Receptors, Tumor Necrosis Factor/physiology , Animals , Cell Movement/drug effects , Lung/metabolism , Male , Mice , Receptors, Tumor Necrosis Factor, Type I , Receptors, Tumor Necrosis Factor, Type II , Tumor Necrosis Factor-alpha/biosynthesis
2.
J Surg Res ; 99(2): 187-93, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11469886

ABSTRACT

BACKGROUND: Elevation of cellular cAMP inhibits lipopolysaccharide(LPS)-stimulated tumor necrosis factor alpha (TNF-alpha) production and increases the expression of interleukin (IL)-10 in mononuclear cells. TNF-alpha gene expression obligates activation of the transcription factor nuclear factor kappaB (NF-kappaB). Exogenous IL-10 inhibits NF-kappaB in monocytes and thus attenuates TNF-alpha production. We examined the role of endogenous IL-10 in the regulation of NF-kappaB activation and TNF-alpha production in human monocytes by cAMP. METHODS: Human monocytes were stimulated with Escherichia coli LPS (100 ng/ml) with and without forskolin (FSK, 50 microM) or dibutyryl cyclic AMP (dbcAMP, 100 microM). Cytokine (TNF-alpha and IL-10) release was measured by immunoassay. TNF-alpha mRNA was measured by reverse transcription polymerase chain reaction, and NF-kappaB DNA binding activity was assessed by gel mobility shift assay. RESULTS: cAMP-elevating agents inhibited LPS-stimulated TNF-alpha release (0.77 +/- 0.13 ng/10(6) cells in LPS + dbcAMP and 0.68 +/- 0.19 ng/10(6) cells in LPS + FSK, both P < 0.05 vs 1.61 +/- 0.34 ng/10(6) cells in LPS alone). Conversely, cAMP enhanced LPS-stimulated IL-10 release (100 +/- 21.5 pg/10(6) cells in LPS + dbcAMP and 110 +/- 25.2 pg/10(6) cells in LPS + FSK, both P < 0.05 vs 53.3 +/- 12.8 pg/10(6) cells in LPS alone). Neither TNF-alpha mRNA expression nor NF-kappaB activation stimulated by LPS was inhibited by the cAMP-elevating agents. Neutralization of IL-10 with a specific antibody did not attenuate the effect of cAMP-elevating agents on TNF-alpha production. CONCLUSION: The results indicate that cAMP inhibits LPS-stimulated TNF-alpha production through a posttranscriptional mechanism that is independent of endogenous IL-10.


Subject(s)
Cyclic AMP/metabolism , Interleukin-10/genetics , Monocytes/physiology , Tumor Necrosis Factor-alpha/genetics , Antibodies/pharmacology , Bucladesine/pharmacology , Colforsin/pharmacology , Gene Expression/drug effects , Gene Expression/immunology , Humans , Interleukin-10/immunology , Lipopolysaccharides/pharmacology , NF-kappa B/metabolism , RNA, Messenger/analysis
3.
Am J Physiol Lung Cell Mol Physiol ; 280(3): L400-8, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11159022

ABSTRACT

Chemokines stimulate the influx of leukocytes into tissues. Their production is regulated by nuclear factor-kappaB (NF-kappaB), an inducible transcription factor under the control of inhibitory factor kappaB-alpha (IkappaB-alpha). We have previously demonstrated that L-arginine (L-Arg) attenuates neutrophil accumulation and pulmonary vascular injury after administration of lipopolysaccharide (LPS). We hypothesized that L-Arg would attenuate the production of lung chemokines by stabilizing IkappaB-alpha and preventing NF-kappaB DNA binding. We examined the effect of L-Arg on chemokine production, IkappaB-alpha degradation, and NF-kappaB DNA binding in the lung after systemic LPS. To block nitric oxide (NO) production, a NO synthase inhibitor was given before L-Arg. LPS induced the production of chemokine protein and mRNA. L-Arg attenuated the production of chemokine protein and mRNA, prevented the decrease in IkappaB-alpha levels, and inhibited NF-kappaB DNA binding. NO synthase inhibition abolished the effects of L-Arg on all measured parameters. Our results suggest that L-Arg abrogates chemokine protein and mRNA production in rat lung after LPS. This effect is dependent on NO and is mediated by stabilization of IkappaB-alpha levels and inhibition of NF-kappaB DNA binding.


Subject(s)
Arginine/pharmacology , Chemokines, CXC , Chemokines/antagonists & inhibitors , Chemokines/biosynthesis , Intercellular Signaling Peptides and Proteins , Lipopolysaccharides/pharmacology , Lung/metabolism , Animals , Arginine/blood , Chemokine CXCL1 , Chemokine CXCL2 , Chemokines/genetics , Chemokines/metabolism , Chemotactic Factors/genetics , Chemotactic Factors/metabolism , DNA/metabolism , Growth Substances/genetics , Growth Substances/metabolism , I-kappa B Proteins/metabolism , Male , NF-kappa B/metabolism , Nitrates/metabolism , Nitrites/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley
4.
Surg Clin North Am ; 80(5): 1427-41, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11059712

ABSTRACT

Laparoscopic adrenalectomy quickly has become the procedure of choice for benign adrenal lesions because it results in less pain, shorter hospital stay, comparable safety, and more patient satisfaction overall. The laparoscopic approach requires advanced laparoscopic surgical skills. Surgeons should be familiar with these techniques and the open approaches before attempting this procedure. When first learning the technique, small left-sided lesions are likely the easiest, and a more experienced surgeon should be present for the initial few cases; however, at this point, the laparoscopic approach to pancreatic endocrine tumors does not have a clear benefit, and it should be considered primarily investigational without clearly established benefits.


Subject(s)
Adrenal Gland Neoplasms/surgery , Adrenalectomy/methods , Islets of Langerhans/surgery , Pancreatectomy/methods , Pancreatic Neoplasms/surgery , Adrenal Gland Neoplasms/diagnosis , Humans , Laparoscopy , Pancreatic Neoplasms/diagnosis , Preoperative Care , Treatment Outcome
5.
Crit Care Med ; 28(9): 3314-31, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11008997

ABSTRACT

OBJECTIVE: To systematically review clinical trials in acute respiratory distress syndrome (ARDS). DATA SOURCES: Computerized bibliographic search of published research and citation review of relevant articles. STUDY SELECTION: All clinical trials of therapies for ARDS were reviewed. Therapies that have been compared in prospective, randomized trials were the focus of this analysis. DATA EXTRACTION: Data on population, interventions, and outcomes were obtained by review. Studies were graded for quality of scientific evidence. MAIN RESULTS: Lung protective ventilator strategy is supported by improved outcome in a single large, prospective trial and a second smaller trial. Other therapies for ARDS, including noninvasive positive pressure ventilation, inverse ratio ventilation, fluid restriction, inhaled nitric oxide, almitrine, prostacyclin, liquid ventilation, surfactant, and immune-modulating therapies, cannot be recommended at this time. Results of small trials using corticosteroids in late ARDS support the need for confirmatory large clinical trials. CONCLUSIONS: Lung protective ventilator strategy is the first therapy found to improve outcome in ARDS. Trials of prone ventilation and fluid restriction in ARDS and corticosteroids in late ARDS support the need for large, prospective, randomized trials.


Subject(s)
Respiratory Distress Syndrome/therapy , Clinical Trials as Topic , Humans , Prospective Studies , Respiration, Artificial , Treatment Outcome
6.
Shock ; 14(1): 1-7, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10909885

ABSTRACT

Chemokines are important mediators of inflammation. Animal studies suggest that inhibition of chemokine action results in a decrease in inflammation. Novel anti-inflammatory agents directed against chemokines are now available. Surgeons are uniquely positioned to treat multiple chemokine-mediated diseases. In this article, we review the biology and nomenclature of chemokines as well as their role in neutrophil migration. Further, the potential role of chemokines in various diseases related to surgical conditions, including adult respiratory distress syndrome, atherosclerosis, inflammatory bowel disease, and solid organ rejection, is reviewed. Finally, the idea that chemokines could be targets for novel therapeutic agents is discussed.


Subject(s)
Chemokines/physiology , Neutrophil Infiltration/physiology , Postoperative Complications/physiopathology , Receptors, Chemokine/physiology , Animals , Arteriosclerosis/etiology , Arteriosclerosis/physiopathology , Chemokines/biosynthesis , Chemokines/classification , Chemokines/genetics , Gene Expression Regulation/drug effects , Graft Rejection/etiology , Graft Rejection/physiopathology , Humans , I-kappa B Kinase , Inflammatory Bowel Diseases/etiology , Inflammatory Bowel Diseases/physiopathology , Mice , Mice, Knockout , NF-kappa B/antagonists & inhibitors , NF-kappa B/physiology , Postoperative Complications/etiology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Receptors, Chemokine/antagonists & inhibitors , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/physiopathology
7.
Am J Physiol Regul Integr Comp Physiol ; 278(5): R1232-9, 2000 May.
Article in English | MEDLINE | ID: mdl-10801292

ABSTRACT

Inducible nitric oxide synthase (iNOS) is associated with vascular hypocontractility in systemic vessels after endotoxin lipopolysaccharide (LPS) administration. Although lung iNOS is increased after LPS, its role in the pulmonary circulation is unclear. We hypothesized that whereas iNOS upregulation is responsible for LPS-induced vascular dysfunction in systemic vessels, iNOS does not play a significant role in the pulmonary artery (PA). Using isolated aorta (AO) and PA rings, we examined the effect of nonselective NOS inhibition [N(G)-monomethyl-L-arginine (L-NMMA); 100 micromol/l] and selective iNOS inhibition (aminoguanidine, AG; 100 micromol/l) on alpha(1)-adrenergic-mediated vasoconstriction (phenylephrine; 10(-9) to 10(-3) M) after LPS (Salmonella typhimurium, 20 mg/kg ip). We also determined the presence of iNOS using Western blot and immunohistochemistry. LPS markedly impaired AO contractility (maximal control tension 1,076 +/- 33 mg vs. LPS 412 +/- 39 mg, P < 0.05), but PA contractility was unchanged (control 466 +/- 29 mg vs. LPS 455 +/- 27 mg, P > 0.05). Selective iNOS inhibition restored the AO's response to vasoconstriction (LPS + AG 1,135 +/- 54 mg, P > 0.05 vs. control and P < 0.05 vs. LPS), but had no effect on the PA (LPS + AG 422 +/- 38 mg, P > 0.05 vs. control and LPS). Western blot and immunohistochemistry revealed increased iNOS expression in the AO after LPS, but iNOS was not detected in the PA. Our results suggest that differential iNOS expression after LPS in systemic and pulmonary vessels contributes to the phenomenon of sepsis/endotoxemia-induced systemic hypotension and pulmonary hypertension.


Subject(s)
Aorta/enzymology , Lipopolysaccharides/pharmacology , Nitric Oxide Synthase/analysis , Nitric Oxide Synthase/physiology , Pulmonary Artery/enzymology , Animals , Aorta/drug effects , Aorta/physiology , Enzyme Inhibitors , Fluorescent Antibody Technique , Guanidines/pharmacology , Immunoblotting , Male , Muscle Contraction/drug effects , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase Type II , Pulmonary Artery/drug effects , Pulmonary Artery/physiology , Rats , Rats, Sprague-Dawley , Receptors, Adrenergic, alpha/drug effects , Receptors, Adrenergic, alpha/physiology , Salmonella typhimurium , Tissue Distribution , omega-N-Methylarginine/pharmacology
8.
J Trauma ; 48(4): 673-82; discussion 682-3, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10780601

ABSTRACT

BACKGROUND: Thoracic aortic injury (TAI) is a devastating condition in which prompt recognition can obviate morbidity and mortality. It is a long-held belief that TAI is more likely when there is a "major mechanism of injury." The purposes of this prospective study were to determine mechanism characteristics that are predictive of TAI and to evaluate chest computed tomography (CT) as a screening tool for TAI. METHODS: Over a 5 1/2 year period, blunt chest trauma patients at two Level I trauma centers were evaluated for potential TAI. Patients were assigned mechanism and radiograph scores from 1 (low suspicion for TAI) to 5 (very high suspicion for TAI). Immediate aortography was obtained when suspicion for TAI was very high. The remaining patients were evaluated with contrast-enhanced chest CT. Confirmatory aortography was obtained on all positive chest CT scans and on all patients with mechanism scores of 4 or 5 even if the CT was negative. Mechanism and radiographic data were correlated with the results of aortic imaging. RESULTS: Of the 1,561 patients evaluated for TAI, 30 aortic injuries were found. The assessment of mechanism was imperfect with a reliance on often incomplete and subjective data. The subjective mechanism score proved to be the most useful predictor of TAI. Radiographic scores were useful but insensitive for intimal injuries. Computed tomography was found to have 100% and 100% NPV for TAI. CONCLUSION: Considering the inherent difficulties in identifying patients at risk for TAI and the effectiveness of chest CT as a screening tool for aortic injury, we recommend liberal use of chest CT in blunt chest trauma. Guidelines for determining the need for aortic imaging are outlined.


Subject(s)
Aorta, Thoracic/diagnostic imaging , Aorta, Thoracic/injuries , Tomography, X-Ray Computed , Wounds, Nonpenetrating/diagnostic imaging , Wounds, Nonpenetrating/etiology , Accidental Falls , Accidents, Traffic , Aortography , Female , Humans , Male , Prospective Studies , Radiography, Thoracic
9.
J Immunol ; 164(5): 2644-9, 2000 Mar 01.
Article in English | MEDLINE | ID: mdl-10679104

ABSTRACT

In addition to stimulating IFN-gamma synthesis, IL-18 also possesses inflammatory effects by inducing synthesis of the proinflammatory cytokines TNF and IL-1beta and the chemokines IL-8 and macrophage inflammatory protein-1alpha. We hypothesized that neutralization of IL-18 would have a beneficial effect in lethal endotoxemia in mice. IL-1beta converting enzyme (ICE)-deficient mice, lacking the ability to process mature IL-18 and IL-1beta, were completely resistant to lethal endotoxemia induced by LPS derived from either Escherichia coli or Salmonella typhimurium. In contrast, both wild-type and IL-1beta-/- mice were equally susceptible to the lethal effects of LPS, implicating that absence of mature IL-18 or IFN-gamma but not IL-1beta in ICE-/- mice is responsible for this resistance. However, IFN-gamma-deficient mice were not resistant to S. typhimurium LPS, suggesting an IFN-gamma-independent role for IL-18. Anti-IL-18 Abs protected mice against a lethal injection of either LPS. Anti-IL-18 treatment also reduced neutrophil accumulation in liver and lungs. The increased survival was accompanied by decreased levels of IFN-gamma and macrophage inflammatory protein-2 in anti-IL-18-treated animals challenged with E. coli LPS, whereas IFN-gamma and TNF concentrations were decreased in treated mice challenged with S. typhimurium. In conclusion, neutralization of IL-18 during lethal endotoxemia protects mice against lethal effects of LPS. This protection is partly mediated through inhibition of IFN-gamma production, but mechanisms involving decreased neutrophil-mediated tissue damage due to the reduction of either chemokines (E. coli LPS) or TNF (S. typhimurium LPS) synthesis by anti-IL-18 treatment may also be involved.


Subject(s)
Cell Movement/immunology , Endotoxemia/immunology , Escherichia coli Infections/immunology , Immune Sera/pharmacology , Interleukin-18/immunology , Neutrophils/immunology , Salmonella Infections, Animal/immunology , Salmonella typhimurium/immunology , Animals , Chemokines/biosynthesis , Endotoxemia/mortality , Endotoxemia/pathology , Endotoxemia/prevention & control , Escherichia coli Infections/mortality , Escherichia coli Infections/pathology , Escherichia coli Infections/prevention & control , Injections, Intraperitoneal , Interferon-gamma/antagonists & inhibitors , Interferon-gamma/biosynthesis , Interleukin-18/antagonists & inhibitors , Interleukin-18/biosynthesis , Lipopolysaccharides/administration & dosage , Liver/enzymology , Liver/immunology , Liver/metabolism , Lung/enzymology , Lung/immunology , Lung/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Neutrophils/pathology , Peroxidase/metabolism , Salmonella Infections, Animal/mortality , Salmonella Infections, Animal/pathology , Salmonella Infections, Animal/prevention & control , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/biosynthesis
10.
Radiology ; 213(1): 195-202, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10540662

ABSTRACT

PURPOSE: To determine whether chest computed tomography (CT) can be used to exclude aortic injury. MATERIALS AND METHODS: Patients in whom there was very high suspicion of traumatic aortic injury were examined with aortography only. Other patients were examined with contrast material-enhanced CT. Follow-up aortography was performed in all patients with moderate to high suspicion of traumatic aortic injury and in all patients with CT scans that were positive for traumatic aortic injury. CT scans were regarded as positive when they showed mediastinal hematoma or direct findings of aortic injury. During a 4 1/2-year period, 1,009 patients (263 female, 746 male; age range, 3-90 years) were evaluated for possible traumatic aortic injury. RESULTS: Of the 207 patients who underwent aortography directly without CT, 10 had traumatic aortic injury. Of the 802 patients who were examined with CT, 382 underwent follow-up aortography. In this group, there were 10 true-positive and no false-negative CT scans. CT had 100% sensitivity and a 100% negative predictive value for the detection of traumatic aortic injury.


Subject(s)
Aorta/injuries , Aortography , Radiography, Thoracic , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aged, 80 and over , Aortography/economics , Child , Child, Preschool , Contrast Media , Costs and Cost Analysis , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Radiography, Thoracic/economics , Sensitivity and Specificity , Tomography, X-Ray Computed/economics
11.
Am J Physiol ; 277(5): L861-7, 1999 11.
Article in English | MEDLINE | ID: mdl-10564168

ABSTRACT

Interleukin (IL)-11, like other members of the gp130 receptor class, possesses anti-inflammatory properties. We hypothesized that IL-11 pretreatment would attenuate endotoxin [lipopolysaccharide (LPS)]-induced lung inflammation and diminish injury to endothelium-dependent and -independent mechanisms of pulmonary vasorelaxation that require cGMP in Sprague-Dawley rats. LPS (20 mg/kg ip) increased lung tumor necrosis factor (TNF)-alpha compared with the saline control (0.7 +/- 0.15 ng/g lung wet wt for control vs. 3.5 +/- 0.09 ng/g lung wet wt for LPS; P < 0.05). IL-11 (200 mg/kg ip) injected 10 min before LPS administration attenuated the LPS-induced lung TNF-alpha levels (1.6 +/- 0.91 ng/g lung wet wt; P < 0.05 vs. LPS). IL-11 also diminished LPS-induced lung neutrophil sequestration as assessed by myeloperoxidase units (2.1 +/- 0.25 U/g lung wet wt for saline and 15.6 +/- 2.02 U/g lung wet wt for LPS vs. 7.07 +/- 1.65 U/g lung wet wt for LPS plus IL-11; P < 0.05). Similarly, TNF-alpha binding protein (175 mg/kg) attenuated LPS-induced myeloperoxidase activity (6.04 +/- 0.14 U/g lung wet wt; P < 0.05). Both IL-11 and TNF-alpha binding protein similarly attenuated LPS-induced endothelium-dependent vasomotor dysfunction with improved relaxation responses to 10(-7) and 10(-6) M acetylcholine and A-23187 in phenylephrine-preconstricted isolated pulmonary artery rings (P < 0.05 vs. LPS). Endothelium-independent relaxation responses to sodium nitroprusside were also improved after LPS at 10(-6) M (P < 0.05 vs. LPS). Moreover, IL-11 decreased endotoxin-induced mortality in CF1 mice from 90 to 50% (P

Subject(s)
Interleukin-11/pharmacology , Pneumonia/drug therapy , Pulmonary Circulation/immunology , Acetylcholine/pharmacology , Animals , Antigens, CD/physiology , Calcimycin/pharmacology , Cyclic GMP/metabolism , Cytokine Receptor gp130 , Ionophores/pharmacology , Lipopolysaccharides , Lung/chemistry , Lung/cytology , Lung/immunology , Male , Membrane Glycoproteins/physiology , Neutrophils/enzymology , Neutrophils/immunology , Nitroprusside/pharmacology , Peroxidase/metabolism , Pneumonia/chemically induced , Pneumonia/immunology , Pulmonary Circulation/drug effects , Rats , Rats, Sprague-Dawley , Receptors, Tumor Necrosis Factor/metabolism , Receptors, Tumor Necrosis Factor, Type I , Survival Analysis , Tumor Necrosis Factor Decoy Receptors , Tumor Necrosis Factor-alpha/analysis , Tumor Necrosis Factor-alpha/immunology , Vasodilator Agents/pharmacology
12.
Am J Physiol ; 277(4): L769-76, 1999 10.
Article in English | MEDLINE | ID: mdl-10516218

ABSTRACT

Endotoxin (Etx) causes excessive activation of the nuclear repair enzyme poly(ADP-ribose) synthase (PARS), which depletes cellular energy stores and leads to vascular dysfunction. We hypothesized that PARS inhibition would attenuate injury to mechanisms of pulmonary vasorelaxation in acute lung injury. The purpose of this study was to determine the effect of in vivo PARS inhibition on Etx-induced dysfunction of pulmonary vasorelaxation. Rats received intraperitoneal saline or Etx (Salmonella typhimurium; 20 mg/kg) and one of the PARS inhibitors, 3-aminobenzamide (3-AB; 10 mg/kg) or nicotinamide (Nic; 200 mg/kg), 90 min later. After 6 h, concentration-response curves were determined in isolated pulmonary arterial rings. Etx impaired endothelium-dependent (response to ACh and calcium ionophore) and -independent (sodium nitroprusside) cGMP-mediated vasorelaxation. 3-AB and Nic attenuated Etx-induced impairment of endothelium-dependent and -independent pulmonary vasorelaxation. 3-AB and Nic had no effect on Etx-induced increases in lung myeloperoxidase activity and edema. Lung ATP decreased after Etx but was maintained by 3-AB and Nic. Pulmonary arterial PARS activity increased fivefold after Etx, which 3-AB and Nic prevented. The beneficial effects were not observed with benzoic acid, a structural analog of 3-AB that does not inhibit PARS. Our results suggest that PARS inhibition with 3-AB or Nic improves pulmonary vasorelaxation and preserves lung ATP levels in acute lung injury.


Subject(s)
Endotoxins/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors , Pulmonary Circulation/drug effects , Vasodilation/drug effects , Adenosine Triphosphate/metabolism , Animals , Benzamides/pharmacology , Cyclic GMP/physiology , Endotoxemia/enzymology , Endotoxemia/metabolism , Enzyme Inhibitors/pharmacology , Lung/enzymology , Lung/metabolism , Male , Niacinamide/pharmacology , Peroxidase/metabolism , Pulmonary Edema/metabolism , Rats , Rats, Sprague-Dawley , Vasodilation/physiology
13.
Ann Thorac Surg ; 67(5): 1227-31; discussion 1231-2, 1999 May.
Article in English | MEDLINE | ID: mdl-10355388

ABSTRACT

BACKGROUND: Vessel injury results in an inflammatory response characterized by the elaboration of cytokines and growth factors, which ultimately influence vascular smooth muscle cell (VSMC) growth and contribute to atherogenesis. Nuclear factor-kappa B (NFkappaB) is a central transcription factor important in mediating stress and inflammatory-induced signals. We hypothesized that strategies aimed at inhibiting NFkappaB would abrogate mitogen-induced human VSMC proliferation. METHODS: Human aortic VSMC were stimulated with basic fibroblast growth factor (FGF) and tumor necrosis factor-alpha (TNF), and proliferation was quantified by a colormetric assay. The influence of NFkappaB on VSMC proliferation was examined by both nonspecific NFkappaB blockade with calpain inhibitor-1 (CI-1) and dexamethasone (Dex) and specific NFkappaB blockade with liposomal delivery of the NFkappaB inhibitory peptide, IkappaBalpha. RESULTS: FGF and TNF induced concentration-dependent VSMC proliferation (p < 0.002). Neither CI-1, Dex, nor liposomal IkappaBalpha influenced proliferation of unstimulated VSMC. However, both FGF- and TNF-stimulated VSMC proliferation was inhibited to the level of control with CI-1, Dex, and liposomal IkappaBalpha (p < 0.001). CONCLUSION: The mitogenic effect of FGF and TNF on human arterial VSMC may be prevented by inhibiting NFkappaB. Furthermore, liposomal delivery of endogenous inhibitory proteins such as IkappaBalpha may represent a novel, therapeutically accessible method for selective transcriptional suppression in the response to vascular injury.


Subject(s)
Aorta/metabolism , DNA-Binding Proteins/pharmacology , DNA-Binding Proteins/physiology , I-kappa B Proteins , Muscle, Smooth, Vascular/cytology , NF-kappa B , Calpain/antagonists & inhibitors , Cell Division/drug effects , Cells, Cultured , Dexamethasone/pharmacology , Fibroblast Growth Factors/pharmacology , Humans , Liposomes , Mitogens/pharmacology , Muscle, Smooth, Vascular/metabolism , NF-KappaB Inhibitor alpha , NF-kappa B/antagonists & inhibitors , NF-kappa B/pharmacology , Signal Transduction/physiology , Tumor Necrosis Factor-alpha/pharmacology
14.
J Surg Res ; 84(2): 240-6, 1999 Jun 15.
Article in English | MEDLINE | ID: mdl-10357926

ABSTRACT

Cardiotrophin-1 (CT-1) is a recently discovered member of the gp130 cytokine family, which includes IL-6, IL-11, leukemia inhibitory factor, ciliary neurotrophic factor, and oncostatin M. Recent evidence suggests that, like other members of this family, CT-1 may possess anti-inflammatory properties. We hypothesized that in vivo CT-1 administration would attenuate endotoxin (ETX)-induced acute lung injury. We studied the effects of CT-1 (100 microgram/kg ip, 10 min prior to ETX) in a rat model of ETX-induced acute lung injury (Salmonella typhimurium lipopolysaccharide, 20 mg/kg ip). Six hours after ETX, lungs were harvested for determination of neutrophil accumulation (myeloperoxidase, MPO, assay) and lung edema (wet-to-dry weight ratio). Mechanisms of pulmonary vasorelaxation were examined in isolated pulmonary artery rings at 6 h by interrogating endothelium-dependent (response to acetylcholine) and endothelium-independent (response to sodium nitroprusside) relaxation following alpha-adrenergic (phenylephrine)-stimulated preconstriction. CT-1 abrogated the endotoxin-induced lung neutrophil accumulation: 2.3 +/- 0.2 units MPO/g wet lung (gwl) vs 6. 3 +/- 0.3 units MPO/gwl in the ETX group (P < 0.05 vs ETX, P > 0.05 vs control). Similarly, CT-1 prevented ETX-induced lung edema: wet-to-dry-weight ratio, 4.473 +/- 0.039 vs 4.747 +/- 0.039 in the ETX group (P < 0.05 vs ETX, P > 0.05 vs control). Endotoxin caused significant impairment of both endothelium-dependent and -independent pulmonary vasorelaxation, and CT-1 attenuated this injury. Thus, cardiotrophin-1 possesses significant anti-inflammatory properties in a model of endotoxin-induced acute lung injury.


Subject(s)
Cytokines/pharmacology , Edema/chemically induced , Edema/prevention & control , Endotoxins , Lung Diseases/chemically induced , Lung Diseases/prevention & control , Acute Disease , Animals , Cyclic GMP/physiology , Endotoxemia/pathology , Lung/pathology , Lung Diseases/pathology , Lung Diseases/physiopathology , Male , Neutrophils/pathology , Pulmonary Circulation/drug effects , Pulmonary Circulation/physiology , Rats , Rats, Sprague-Dawley , Vasodilation/drug effects , Vasodilation/physiology
15.
16.
J Surg Res ; 83(1): 69-74, 1999 May 01.
Article in English | MEDLINE | ID: mdl-10210645

ABSTRACT

BACKGROUND: Tumor necrosis factor alpha (TNF-alpha) is an important mediator of septic shock. Endotoxin (LPS) signal transduction in human monocytes leads to activation of nuclear factor-kappa B (NF-kappaB) and TNF-alpha release. Previous studies have implicated activation of both protein kinase C (PKC) and protein tyrosine kinases (PTK) in LPS-induced NF-kappaB activation and TNF-alpha production. We hypothesized that inhibition of either PKC or PTK would decrease LPS-induced NF-kappaB DNA binding and TNF-alpha release in human monocytes. MATERIALS AND METHODS: Human monocytes were stimulated with PMA (50 ng/ml) alone or LPS (100 ng/ml) with and without a nonspecific serine/threonine protein kinase inhibitor staurosporine (Stauro), a specific pan-PKC inhibitor bisindolylmaleimide (Bis), or an inhibitor of PTK genistein (Gen). TNF-alpha release in culture supernatants was measured by an ELISA. NF-kappaB DNA binding was evaluated by electrophoretic mobility shift assay. RESULTS: LPS increased NF-kappaB DNA binding and TNF-alpha release in human monocytes. Nonspecific protein kinase inhibition inhibited NF-kappaB activation and TNF-alpha release, while specific PKC inhibition with Bis had no effect on LPS-induced NF-kappaB DNA binding or TNF-alpha release. PTK inhibition with Gen attenuated both LPS-induced NF-kappaB DNA binding and TNF-alpha production in human monocytes. Direct activation of PKC with PMA induced both NF-kappaB activation and TNF-alpha production by human monocytes. CONCLUSIONS: These results suggest that LPS-induced NF-kappaB activation and TNF-alpha release in human monocytes are independent of PKC activity. Furthermore, our results provide evidence that PTK plays a role in LPS-induced NF-kappaB activation and TNF-alpha release in human monocytes and thus could be a potential therapeutic target in inflammatory states.


Subject(s)
Lipopolysaccharides/pharmacology , Monocytes/metabolism , NF-kappa B/metabolism , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , Tumor Necrosis Factor-alpha/metabolism , Cells, Cultured , DNA/metabolism , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Genistein/pharmacology , Humans , Indoles/pharmacology , Maleimides/pharmacology , Monocytes/drug effects , Protein Kinase C/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Staurosporine/pharmacology , Tetradecanoylphorbol Acetate/pharmacology
17.
Surgery ; 125(1): 33-40, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9889795

ABSTRACT

BACKGROUND: Pulmonary vasorelaxation to endothelium-dependent and independent agonists is dysfunctional in endotoxin-induced acute lung injury. L-arginine is the precursor to endothelial production of nitric oxide (NO), suggesting that arginine and NO are intimately linked. We hypothesized that L-arginine would attenuate endotoxin-induced dysfunction of guanosine 3',5'-cyclic monophosphate-mediated pulmonary vasorelaxation. METHODS: Concentration-response curves were generated for acetylcholine, calcium ionophore A23187, and sodium nitroprusside (SNP) in isolated phenylepherine-preconstricted pulmonary artery rings (10(-9) to 10(-6) mol/L) 4 hours after endotoxin (500 mg/kg intraperitoneal) or saline injection. The effect of L-arginine in vitro was determined with L- or D-arginine (50 mmol/L) 30 minutes before dose response. RESULTS: Endothelium-dependent pulmonary vasorelaxation was dysfunctional after endotoxin injection as demonstrated by impaired responses to acetylcholine and A23187 (P < .05 vs control). Endotoxin-induced dysfunction of these endothelium-dependent responses was attenuated by L-arginine (P < .05 vs endotoxin). Endothelium-independent vasorelaxation (SNP) was also dysfunctional after endotoxin treatment (P < .05 vs control). L-arginine failed to attenuate the endotoxin-induced dysfunction of the response to SNP. The concentration responses for endothelium-dependent and independent vasorelaxing agonists in endotoxin-treated rats were not influenced by D-arginine. CONCLUSION: L-arginine supplementation attenuates endotoxin-induced dysfunction of endothelium-dependent pulmonary vasorelaxation.


Subject(s)
Arginine/pharmacology , Endothelium, Vascular/physiopathology , Endotoxins/toxicity , Lung Injury , Pulmonary Artery/physiology , Acetylcholine/pharmacology , Animals , Calcimycin/pharmacology , Cyclic GMP/physiology , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiology , In Vitro Techniques , Lung/blood supply , Lung/drug effects , Male , Nitric Oxide/biosynthesis , Nitroprusside/pharmacology , Phenylephrine/pharmacology , Pulmonary Artery/drug effects , Pulmonary Artery/physiopathology , Rats , Rats, Sprague-Dawley , Salmonella typhimurium , Stereoisomerism , Vasoconstriction/drug effects , Vasoconstriction/physiology , Vasodilation/drug effects , Vasodilation/physiology
18.
Shock ; 10(5): 309-18, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9840644

ABSTRACT

Pharmacological therapy of surgical disease often involves manipulating the physiologic balance between pro- and anti-inflammatory responses. Many agents target only one aspect of the inflammatory cascade. Originally identified as a protein elaborated by T-lymphocytes, IL-10 appears to globally inhibit cytokine production. The purpose of this manuscript is to examine the immunomodulatory and anti-inflammatory effects of interleukin-10 (IL-10) in an attempt to define the clinical utility of IL-10, both as a marker of and as a therapeutic strategy for intervention in inflammatory and immune-mediated diseases. IL-10 is elaborated from multiple sources and has diverse cellular effects to regulate immune and inflammatory responses. Accumulating evidence suggests that the anti-inflammatory influence of IL-10 observed at the cellular level may be manipulated to impact the immune and inflammatory-mediated responses associated with injury and sepsis, gastrointestinal and cardiovascular disease, and transplantation. In conclusion, IL-10 is an important mediator of immune and anti-inflammatory responses in surgical disease and, as such, has therapeutic promise as an immunomodulator and as an anti-inflammatory agent.


Subject(s)
Interleukin-10/pharmacology , Interleukin-10/physiology , Sepsis/drug therapy , Transplantation , Wounds and Injuries/metabolism , Animals , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/metabolism , Cytokines/metabolism , DNA-Binding Proteins/metabolism , Humans , Inflammation/drug therapy , Inflammation/metabolism , Pancreatitis/drug therapy , Pancreatitis/metabolism , Protein-Tyrosine Kinases/metabolism , STAT3 Transcription Factor , Sepsis/immunology , Sepsis/metabolism , Trans-Activators/metabolism , Transcription, Genetic , Wounds and Injuries/drug therapy , Wounds and Injuries/immunology
19.
J Trauma ; 45(5): 862-7, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9820693

ABSTRACT

PURPOSE: The purpose of this study was to determine the effect of endotoxin on vasorelaxation in the pulmonary and systemic circulations in response to the following agonists that require generation of cyclic adenosine monophosphate: (1) beta-adrenergic receptor stimulation with isoproterenol; (2) H2 receptor stimulation with dimaprit; and (3) adenylate cyclase stimulation with forskolin. METHODS: Male Sprague-Dawley rats weighing 250 to 350 g were injected with endotoxin (20 mg/kg intraperitoneal) or saline. Six hours later, the cumulative dose response to beta-adrenergic receptor stimulation (isoproterenol), H2 receptor stimulation (dimaprit), and adenylate cyclase stimulation (forskolin) was determined in isolated rat pulmonary artery and thoracic aortic rings preconstricted with phenylephrine. RESULTS: Endotoxin caused significant impairment of relaxation to isoproterenol in the pulmonary artery, but the response in the aorta was not different from the control response. In the pulmonary circulation, endotoxin converted the response to dimaprit from vasorelaxation to vasoconstriction. On the other hand, dimaprit resulted in vasorelaxation in the thoracic aorta after endotoxin; however, the response was impaired compared with the control response. Endotoxin did not affect the dose response to forskolin in either the pulmonary artery or the thoracic aorta. CONCLUSION: From these data, we conclude that endotoxin causes regional specific changes in vascular reactivity. These changes in vascular reactivity result in preserved vasorelaxation in the systemic circulation and impairment of vasorelaxation in the pulmonary circulation in response to endotoxin.


Subject(s)
Aorta, Thoracic/drug effects , Endotoxins/pharmacology , Pulmonary Artery/drug effects , Salmonella typhi , Vasodilation/drug effects , Adrenergic beta-Agonists/pharmacology , Animals , Blood Circulation/drug effects , Blood Pressure/drug effects , Colforsin/pharmacology , Dimaprit/pharmacology , Dose-Response Relationship, Drug , Histamine Agonists/pharmacology , Isoproterenol/pharmacology , Male , Rats , Rats, Sprague-Dawley , Vascular Resistance/drug effects
20.
Ann Thorac Surg ; 66(2): 313-7, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9725362

ABSTRACT

BACKGROUND: Inflammatory cytokine production contributes to lung injury after lung ischemia reperfusion and during lung transplant rejection. Although nitric oxide has been demonstrated to reduce lung injury associated with the adult respiratory distress syndrome, it remains unknown whether the mechanism of nitric oxide's beneficial effects involves reducing lung macrophage inflammatory cytokine production. The purpose of this study was to determine whether nitric oxide downregulates lung macrophage inflammatory cytokine production. METHODS: Lung macrophages were harvested by bronchoalveolar lavage (10(6) macrophage per milliliter from normal Sprague-Dawley rats, 6 animals per group) and treated under ex vivo tissue culture conditions with the nitric oxide releasing compound S-nitoso-N-acetyl-D, L-penicillamine (0, 10(-5) 10(-4), 10(-3), 10(-2) mol/L) before induction of inflammatory cytokines with endotoxin, (50 ng/mL for 24 hours). Supernatants were assayed for inflammatory cytokine production (tumor necrosis factor alpha, interleukin-1beta) by enzyme-linked immunosorbent assay. RESULTS: Continuous nitric oxide release by S-nitoso-N-acetyl-D, L-penicillamine decreased lung macrophage tumor necrosis factor-alpha and interleukin-1beta production in a dose-dependent fashion (6 rats per group; data were analyzed for significance [p < 0.05] using two-way analysis of variance with Tukey's post-hoc correction). CONCLUSIONS: Nitric oxide decreases inflammatory cytokine production by lung macrophage. The mechanism of nitric oxide's beneficial effects may be partially attributable to decreased production of inflammatory cytokines. Nitric oxide may serve an expanded role for reducing inflammatory cytokine production during acute lung injury, ischemia-reperfusion-induced inflammation, or lung transplant rejection.


Subject(s)
Interleukin-1/biosynthesis , Macrophages, Alveolar/metabolism , Nitric Oxide/physiology , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Cells, Cultured , Dimercaprol , Down-Regulation , Enzyme-Linked Immunosorbent Assay , Male , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , Rats , Rats, Sprague-Dawley
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