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Hardman J, Jamdar S, Shields C, McMahon R, Redmond HP, Siriwardena AK. Intravenous selenium modulates L-arginine-induced experimental acute pancreatitis. JOP : JOURNAL OF THE PANCREAS 2005; 6:431-7. [PMID: 16186664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
CONTEXT Oxidative stress is understood to have a critical role in the development of acinar injury in experimental acute pancreatitis. We have previously demonstrated that compound multiple antioxidant therapy ameliorates end-organ damage in the intra-peritoneal L-arginine rat model. As the principal co-factor for glutathione, selenium is a key constituent of multiple antioxidant preparations. OBJECTIVE The intention of this study was to investigate the effect of selenium on pancreatic and remote organ injury in a well-validated experimental model of acute pancreatitis. METHODS Male Sprague-Dawley rats were randomly allocated to one of 3 groups (n=5/group) and sacrificed at 72 hours. Acute pancreatitis was induced by 250 mg per 100 g body weight of 20% L-arginine hydrochloride in 0.15 mol/L sodium chloride. Group allocations were: Group 1, control; Group 2, acute pancreatitis; Group 3, selenium. MAIN OUTCOME MEASURES Serum amylase, anti-oxidant levels, bronchoalveolar lavage protein, lung myeloperoxidase activity, and histological assessment of pancreatic injury. RESULTS L-arginine induced acute pancreatitis characterised by oedema, neutrophil infiltration, acinar cell degranulation and elevated serum amylase. Selenium treatment was associated with reduced pancreatic oedema and inflammatory cell infiltration. Acinar degranulation and dilatation were completely absent. A reduction in bronchoalveolar lavage protein content was also demonstrated. CONCLUSION Intravenous selenium given 24 hours after induction of experimental acute pancreatitis was associated with a reduction in the histological stigmata of pancreatic injury and a dramatic reduction in broncho-alveolar lavage protein content. Serum selenium fell during the course of experimental acute pancreatitis and this effect was not reversed by exogenous selenium supplementation.
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O'Connor OJ, Cahill RA, Kirwan WO, Redmond HP. The impact of bone marrow micrometastases on metastatic disease-free survival in patients with colorectal carcinoma. Colorectal Dis 2005; 7:406-9. [PMID: 15932568 DOI: 10.1111/j.1463-1318.2005.00792.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
AIMS The biological relevance of bone marrow micrometastases (BMM) in colorectal cancer remains unknown. Here, we investigate their nature by examining the impact of the presence of BMM on metastatic disease-free survival in a cohort of patients with this disease. METHODS Sixty-three consecutive patients undergoing surgery for colorectal cancer of any stage were studied after approval of the study protocol by the local ethics committee and with full individual informed consent. All had bilateral iliac crest bone marrow aspirates prior to operation. Aspirates were then examined for the presence of aberrant cytokeratin-18-positive cells by a blinded observer using both flow cytometric and APAAP immunohistochemical techniques. RESULTS Mean follow-up after surgery was 4.6 years (range 1.9-6.9) for those without hepatic metastases at diagnosis. Seven of 34 patients with Dukes' stage A or B developed metastatic disease after a mean interval of 4.7 years (range 3.8-6.8). However, only 2 of these patients demonstrated BMM at the time of surgery. Nine of 15 patients with Dukes' C carcinoma at the time of surgery subsequently developed metastases after a mean interval of 4.4 years (range 1.9-6.9). Again, only two of these patients had BMM detectable initially. In only three of the 14 patients known to have metastases at the time of operation (i.e. Dukes''D' disease) were BMM found. CONCLUSION The presence of BMM as detected by this methodology was not predictive of tumour recurrence or metastasis. This study does not support the consideration of adjuvant therapy based on the presence of BMM at a single pre-operative time point in patients with colorectal cancer.
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Hardman J, Shields C, Schofield D, McMahon R, Redmond HP, Siriwardena AK. Intravenous antioxidant modulation of end-organ damage in L-arginine-induced experimental acute pancreatitis. Pancreatology 2005; 5:380-6. [PMID: 15980666 DOI: 10.1159/000086538] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Accepted: 09/16/2004] [Indexed: 12/11/2022]
Abstract
BACKGROUND Oxidative stress mediates acinar injury in experimental acute pancreatitis (AP) and antioxidants are depleted in human AP. This study tests the hypothesis that exogenous antioxidant supplementation ameliorates experimental AP. METHODS Male Sprague-Dawley rats were randomly allocated to 1 of 4 groups (n = 5/group) and sacrificed at 72 h. AP was induced by 250 mg per 100 g body weight of 20% L-arginine hydrochloride in 0.15 mol/l sodium chloride. Group allocations were: group 1 (control) no intervention; group 2 AP; group 3 early multiple antioxidant (MAOX) intervention comprising 15 microg/kg selenium, 30 microg/kg ascorbate and 300 mg/kg N-acetylcysteine given at 6 and 30 h and group 4 the MAOX combination above given at 24 and 48 h. Endpoints were: serum amylase, antioxidant levels, bronchoalveolar lavage (BAL) protein and lung myeloperoxidase (MPO) activity and histological assessment of pancreatic injury. RESULTS L-arginine induced AP characterised by oedema, neutrophil infiltration, acinar cell degranulation and elevated serum amylase. Early MAOX reduced pulmonary MPO and BAL protein and reduced acinar swelling, degranulation and pancreatic parenchymal infiltration by inflammatory cells. These features were absent when intervention was delayed. CONCLUSION In this model, early but not late antioxidant intervention ameliorates pancreatic and pulmonary injury.
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Smith FM, O'Brien N, Redmond HP, Bourantas NE. Continuous crossover femoropopliteal bypass in a 68-year-old gentleman with rest pain. INT ANGIOL 2005; 24:199-201. [PMID: 15997225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Patients who have had multiple previous attempts at limb salvaging surgery frequently go on to have an amputation. This, however, results both in psychological perturbation for the patient and high rehabilitation costs for the community. Successful limb salvage surgery therefore has an important role in vascular surgery. We describe the management of a patient with critical limb ischemia that had previously undergone multiple limb salvage procedures and whose limb was saved by the use of a continuous femoropopliteal crossover bypass graft. The patient, who may have been deemed by some as a candidate for amputation, has full use of his limb 6 months after surgery with ankle brachial pressure index readings of 0.6. Continuous femoropopliteal crossover bypass grafting is a poorly described surgical technique that may be appropriate in a subgroup of patients and may allow salvage of a limb that otherwise may have been deemed fit for amputation.
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Choileain NN, Chaudhry MZ, McSwiney E, Redmond HP. An unusual case of an arteriobiliary fistula. IRISH MEDICAL JOURNAL 2005; 98:187-8. [PMID: 16097514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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106
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Smith FM, Coffey JC, Khasri NM, Walsh MF, Parfrey N, Gaffney E, Stephens R, Kennedy MJ, Kirwan W, Redmond HP. Sentinel nodes are identifiable in formalin-fixed specimens after surgeon-performed ex vivo sentinel lymph node mapping in colorectal cancer. Ann Surg Oncol 2005; 12:504-9. [PMID: 15886906 DOI: 10.1245/aso.2005.08.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Accepted: 02/07/2005] [Indexed: 11/18/2022]
Abstract
BACKGROUND In recent years, the technique of sentinel lymph node (SLN) mapping has been applied to colorectal cancer. One aim was to ultrastage patients who were deemed node negative by routine pathologic processing but who went on to develop systemic disease. Such a group may benefit from adjuvant chemotherapy. METHODS With fully informed consent and ethical approval, 37 patients with primary colorectal cancer and 3 patients with large adenomas were prospectively mapped. Isosulfan blue dye (1 to 2 mL) was injected around tumors within 5 to 10 minutes of resection. After gentle massage to recreate in vivo lymph flow, specimens were placed directly into formalin. During routine pathologic analysis, all nodes were bivalved, and blue-staining nodes were noted. These later underwent multilevel step sectioning with hematoxylin and eosin and cytokeratin staining. RESULTS SLNs were found in 39 of 40 patients (98% sensitivity), with an average of 4.1 SLNs per patient (range, 1-8). In 14 of 16 (88% specificity) patients with nodal metastases on routine reporting, SLN status was in accordance. Focused examination of SLNs identified occult tumor deposits in 6 (29%) of 21 node-negative patients. No metastatic cells were found in SLNs draining the three adenomas. CONCLUSIONS The ability to identify SLNs after formalin fixation increases the ease and applicability of SLN mapping in colorectal cancer. Furthermore, the sensitivity and specificity of this simple ex vivo method for establishing regional lymph node status were directly comparable to those in previously published reports.
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Cahill RA, McGreal GT, Crowe BH, Ryan DA, Manning BJ, Cahill MR, Redmond HP. Duration of increased bleeding tendency after cessation of aspirin therapy. J Am Coll Surg 2005; 200:564-73; quiz A59-61. [PMID: 15804471 DOI: 10.1016/j.jamcollsurg.2004.11.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2004] [Revised: 11/02/2004] [Accepted: 11/02/2004] [Indexed: 10/25/2022]
Abstract
BACKGROUND Aspirin has a significant effect on hemostasis, so it is often recommended that patients taking aspirin discontinue treatment before elective surgery. While off aspirin, these patients may be at risk of thrombosis. The optimum period of time that aspirin should be withheld is controversial. The aim of this study was to establish the duration of the antihemostatic effect of prolonged aspirin therapy. STUDY DESIGN In a prospective study, 51 healthy volunteers were randomly assigned into 3 groups, each receiving an identical tablet for 14 days. One group received a placebo tablet; individuals in the other two groups received either 75 mg or 300 mg of aspirin once a day. Template bleeding times and specific platelet function testing (using the PFA-100; Dade Behring) were carried out on subjects before therapy and again after its completion until they returned to baseline. RESULTS Thirty-eight volunteers complied sufficiently with the protocol to provide useful results. All bleeding times normalized within 96 hours and all platelet function tests within 144 hours after stopping aspirin. There was no demonstrable hemostatic defect in any volunteer persisting by or beyond the sixth day after treatment cessation. There was no apparent difference in duration of effect between those taking either 75 mg or 300 mg of aspirin. CONCLUSIONS This study uses sensitive measures of platelet function to demonstrate the duration of increased bleeding tendency after withdrawal of aspirin therapy. It supports discontinuation of aspirin therapy 5 days before elective surgery (with the operation being performed on the sixth day).
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Killeen SD, O'Sullivan MJ, Coffey JC, Kirwan WO, Redmond HP. Provider volume and outcomes for oncological procedures. Br J Surg 2005; 92:389-402. [PMID: 15786424 DOI: 10.1002/bjs.4954] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Abstract
Background
Oncological procedures may have better outcomes if performed by high-volume providers.
Methods
A review of the English language literature incorporating searches of the Medline, Embase and Cochrane collaboration databases was performed. Studies were included if they involved a patient cohort from 1984 onwards, were community or population based, and assessed health outcome as a dependent variable and volume as an independent variable. The studies were also scored quantifiably to assess generalizability with respect to any observed volume–outcome relationship and analysed according to organ system; numbers needed to treat were estimated where possible.
Results
Sixty-eight relevant studies were identified and a total of 41 were included, of which 13 were based on clinical data. All showed either an inverse relationship, of variable magnitude, between provider volume and mortality, or no volume–outcome effect. All but two clinical reports revealed a statistically significant positive relationship between volume and outcome; none demonstrated the opposite.
Conclusion
High-volume providers have a significantly better outcome for complex cancer surgery, specifically for pancreatectomy, oesphagectomy, gastrectomy and rectal resection.
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Doyle DJ, Relihan N, Redmond HP, Barry JE. Metastatic manifestations of invasive lobular breast carcinoma. Clin Radiol 2005; 60:271-4. [PMID: 15664584 DOI: 10.1016/j.crad.2004.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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O'Brien GC, Wang JH, Redmond HP. Bacterial lipoprotein induces resistance to Gram-negative sepsis in TLR4-deficient mice via enhanced bacterial clearance. THE JOURNAL OF IMMUNOLOGY 2005; 174:1020-6. [PMID: 15634926 DOI: 10.4049/jimmunol.174.2.1020] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TLRs are highly conserved pathogen recognition receptors. As a result, TLR4-deficient C3H/HeJ mice are highly susceptible to Gram-negative sepsis. We have previously demonstrated that tolerance induced by bacterial lipoprotein (BLP) protects wild-type mice against polymicrobial sepsis-induced lethality. In this study, we assessed whether pretreatment of C3H/HeJ mice with BLP could induce resistance to a subsequent Gram-negative Salmonella typhimurium infection. Pretreatment with BLP resulted in a significant survival benefit in TLR4-deficient C3H/HeJ mice (p < 0.0002 vs control C3H/HeJ) after challenge with live S. typhimurium (0.25 x 10(6) CFU/mouse). This survival benefit was associated with enhanced bacterial clearance from the circulation and in the visceral organs (p < 0.05 vs control C3H/HeJ). Furthermore, pretreatment with BLP resulted in significant increases in complement receptor type 3 (CR3) and FcgammaIII/IIR expression on polymorphonuclear neutrophils (PMNs) and macrophages (p < 0.05 vs control C3H/HeJ). There was impaired bacterial recognition and phagocytosis in TLR4-deficient mice compared with wild-type mice. However, a significant augmented uptake, ingestion, and intracellular killing of S. typhimurium by PMNs and peritoneal macrophages was evident in BLP-pretreated C3H/HeJ mice (p < 0.05 vs control C3H/HeJ). An up-regulation of inducible NO synthase and increased production of intracellular NO were observed in peritoneal macrophages from BLP-pretreated C3H/HeJ mice (p < 0.05 vs control C3H/HeJ). Depletion of PMNs did not diminish the beneficial effects of BLP with regard to both animal survival and bacterial clearance. These results indicate that BLP, a TLR2 ligand, protects highly susceptible TLR4-deficient mice from Gram-negative sepsis via enhanced bacterial clearance.
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MESH Headings
- Animals
- Bacterial Proteins/administration & dosage
- Blood Bactericidal Activity/genetics
- Blood Bactericidal Activity/immunology
- Cell Wall/immunology
- Immune Tolerance/genetics
- Immunity, Innate/genetics
- Injections, Intraperitoneal
- Lipoproteins/administration & dosage
- Macrophage Activation/genetics
- Macrophage Activation/immunology
- Male
- Membrane Glycoproteins/antagonists & inhibitors
- Membrane Glycoproteins/deficiency
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C3H
- Neutrophil Activation/genetics
- Neutrophil Activation/immunology
- Receptors, Cell Surface/antagonists & inhibitors
- Receptors, Cell Surface/deficiency
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/physiology
- Salmonella Infections, Animal/genetics
- Salmonella Infections, Animal/immunology
- Salmonella Infections, Animal/microbiology
- Salmonella Infections, Animal/prevention & control
- Salmonella typhimurium/growth & development
- Salmonella typhimurium/immunology
- Sepsis/genetics
- Sepsis/microbiology
- Sepsis/mortality
- Sepsis/prevention & control
- Staphylococcal Infections/genetics
- Staphylococcal Infections/microbiology
- Staphylococcal Infections/mortality
- Staphylococcal Infections/prevention & control
- Toll-Like Receptor 2
- Toll-Like Receptor 4
- Toll-Like Receptors
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Coffey JC, Wang JH, Smith MJF, Laing A, Bouchier-Hayes D, Cotter TG, Redmond HP. Phosphoinositide 3-kinase accelerates postoperative tumor growth by inhibiting apoptosis and enhancing resistance to chemotherapy-induced apoptosis. Novel role for an old enemy. J Biol Chem 2005; 280:20968-77. [PMID: 15741161 DOI: 10.1074/jbc.m414696200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Tumor removal remains the principal treatment modality in the management of solid tumors. The process of tumor removal may potentiate the resurgent growth of residual neoplastic tissue. Herein, we describe a novel murine model in which flank tumor cytoreduction is followed by accelerated local tumor recurrence. This model held for primary and recurrent tumors generated using a panel of human and murine (LS174T, DU145, SW480, SW640, and 3LL) cell lines and replicated accelerated tumor growth following excisional surgery. In investigating this further, epithelial cells were purified from LS174T primary and corresponding recurrent tumors for comparison. Baseline as well as tumor necrosis factor apoptosis-inducing ligand (TRAIL)-induced apoptosis were significantly reduced in recurrent tumor epithelia. Primary and recurrent tumor gene expression profiles were then compared. This identified an increase and reduction in the expression of p110gamma and p85alpha class Ia phosphoinositide 3-kinase (PI3K) subunits in recurrent tumor epithelia. These changes were further confirmed at the protein level. The targeting of PI3K ex vivo, using LY294002, restored sensitivity to TRAIL in recurrent tumor epithelia. In vivo, adjuvant LY294002 prolonged survival and significantly attenuated recurrent tumor growth by greatly enhancing apoptosis levels. Hence, PI3K plays a role in generating the antiapoptotic and chemoresistant phenotype associated with accelerated local tumor recurrence.
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O'Brien G, Shields CJ, Winter DC, Dillon JP, Kirwan WO, Redmond HP. Cyclooxygenase-2 plays a central role in the genesis of pancreatitis and associated lung injury. Hepatobiliary Pancreat Dis Int 2005; 4:126-9. [PMID: 15730936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The exact mechanism by which cyclooxygenase-2 (COX-2) promotes inflammation in pancreatitis in obscure. This study was undertaken to investigate the role of COX-2 inhibition in an animal model of pancreatitis, a disease process characterized by a systemic inflammatory response and ensuing neutrophil-mediated lung injury. METHODS Pancreatitis was induced in 24 Sprague-Dawley rats by intraperitoneal injection of 20% L-arginine (500 mg/100 g body weight). The animals were randomized into 3 groups (8 rats in each group): controls and rats with pancreatitis intravenously resuscitated with either normal saline (0.9% NaCl 3 ml/kg)at 24 and 48 hours or COX-2 inhibitor (parecoxib 1 mg/kg). Pancreatic and lung injuries were assessed histologically. Lung injury was assessed utilizing wet:dry ratio and myeloperoxidase activity to indicate pulmonary neutrophil infiltration. A Western blot was used to determine COX-2 protein expression in pancreatic tissue. RESULTS The animals treated with COX-2 inhibitors displayed significantly less pancreatic and lung injuries than their normal saline counterparts. Histological pancreatic and lung injury scores were significantly reduced (P<0.05) in the COX-2 treated group. Lung wet:dry ratios were significantly improved and pulmonary neutrophil infiltration was attenuated in the COX-2 group (P<0.05). Western blot analysis confirmed attenuated COX-2 protein expression. CONCLUSION This study shows, for the first time in a rat model, that adjuvant COX-2 inhibition significantly attenuates the severity of both pancreatitis and its associated systemic inflammatory response and end-organ injury.
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Cahill RA, Sheehan KM, Scanlon RW, Murray FE, Kay EW, Redmond HP. Effects of a selective cyclo-oxygenase 2 inhibitor on colonic anastomotic and skin wound integrity. Br J Surg 2004; 91:1613-8. [PMID: 15505871 DOI: 10.1002/bjs.4722] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Selective inhibitors of inducible cyclo-oxygenase (COX-2) are of potential benefit in the perioperative period for both their analgesic and, perhaps, antineoplastic actions. However, their effects on laparotomy and intestinal wound healing are unknown. METHODS Forty adult Sprague-Dawley rats underwent laparotomy, descending colonic transection and handsewn reanastomosis. The animals were randomized to receive either a selective COX-2 inhibitor (rofecoxib, 10 mg/kg) or an equal volume of water by gavage before operation and then daily after surgery. Animals were killed after 3 or 7 days, and their wounds were evaluated by means of tensiometry (skin and colonic wounds) and bursting pressure measurement (colonic anastomoses). In addition, haematoxylin and eosin-stained intestinal sections were examined and scored by a blinded independent observer. RESULTS Five animals that received rofecoxib had anastomotic leaks by day 7 compared with none in the control group (P = 0.048). Intact colonic suture lines were also significantly weaker in this group (tensile strength at day 3, P = 0.043; bursting pressure on days 3 and 7, both P = 0.019). Skin wound strengths were similar in the two groups at both time points. CONCLUSION Although beneficial in the treatment of pathological inflammation, selective COX-2 inhibitors may adversely affect colonic anastomotic healing.
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Power CP, Wang JH, Manning B, Kell MR, Aherne NJ, Aherne NF, Wu QD, Redmond HP. Bacterial lipoprotein delays apoptosis in human neutrophils through inhibition of caspase-3 activity: regulatory roles for CD14 and TLR-2. THE JOURNAL OF IMMUNOLOGY 2004; 173:5229-37. [PMID: 15470068 DOI: 10.4049/jimmunol.173.8.5229] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The human sepsis syndrome resulting from bacterial infection continues to account for a significant proportion of hospital mortality. Neutralizing strategies aimed at individual bacterial wall products (such as LPS) have enjoyed limited success in this arena. Bacterial lipoprotein (BLP) is a major constituent of the wall of diverse bacterial forms and profoundly influences cellular function in vivo and in vitro, and has been implicated in the etiology of human sepsis. Delayed polymorphonuclear cell (PMN) apoptosis is a characteristic feature of human sepsis arising from Gram-negative or Gram-positive bacterial infection. Bacterial wall product ligation and subsequent receptor-mediated events upstream of caspase inhibition in neutrophils remain incompletely understood. BLP has been shown to exert its cellular effects primarily through TLR-2, and it is now widely accepted that lateral associations with the TLRs represent the means by which CD14 communicates intracellular messages. In this study, we demonstrate that BLP inhibits neutrophil mitochondrial membrane depolarization with a subsequent reduction in caspase-3 processing, ultimately leading to a significant delay in PMN apoptosis. Pretreatment of PMNs with an anti-TLR-2 mAb or anti-CD14 mAb prevented BLP from delaying PMN apoptosis to such a marked degree. Combination blockade using both mAbs completely prevented the effects of BLP (in 1 and 10 ng/ml concentrations) on PMN apoptosis. At higher concentrations of BLP, the antiapoptotic effects were observed, but were not as pronounced. Our findings therefore provide the first evidence of a crucial role for both CD14 and TLR-2 in delayed PMN apoptosis arising from bacterial infection.
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Shields CJ, Winter DC, Wang JH, Andrews E, Laug WE, Redmond HP. Hypertonic saline impedes tumor cell–endothelial cell interaction by reducing adhesion molecule and laminin expression. Surgery 2004; 136:76-83. [PMID: 15232542 DOI: 10.1016/j.surg.2003.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Hypertonic saline infusion dampens inflammatory responses and suppresses neutrophil-endothelial interaction by reducing adhesion molecule expression. This study tested the hypothesis that hypertonic saline attenuates tumor cell adhesion to the endothelium through a similar mechanism. METHODS Human colon cancer cells (LS174T) were transfected with green fluorescent protein and exposed to lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-6 under hypertonic and isotonic conditions for 1 and 4 hours. Confluent human umbilical vein endothelial cells were similarly exposed. Cellular apoptosis and expression of adhesion molecules and laminin were measured by flow cytometry. Tumor cell adhesion to endothelium and laminin was assessed with fluorescence microscopy. Data are represented as mean +/- standard error of mean, and an ANOVA test was performed to gauge statistical significance, with P <.05 considered significant. RESULTS Hypertonic exposure significantly reduced tumor cell adhesion despite the presence of the perioperative cell stressors (42 +/- 2.9 vs 172.5 +/- 12.4, P <.05), attenuated tumor cell beta-1 integrin (14.43 vs 23.84, P <.05), and endothelial cell laminin expression (22.78 +/- 2.2 vs 33.74 +/- 2.4, P <.05), but did not significantly alter cell viability. CONCLUSION Hypertonic saline significantly attenuates tumor cell adhesion to endothelium by inhibiting adhesion molecule and laminin expression. This may halt the metastatic behavior of tumor cells shed at surgery.
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Abstract
Abstract
Background
Clinical guidelines are increasingly used in patient management but few clinicians are familiar with their origin or appropriate application.
Methods
A Medline search using the terms ‘clinical guidelines’ and ‘practice guidelines’ was conducted. Additional references were sourced by manual searching from the bibliographies of articles located.
Results and conclusion
Clinical guidelines originated in the USA in the early 1980s, initially as a cost containment exercise. Significant improvements in the process and outcomes of care have been demonstrated following their introduction, although the extent of improvement varies considerably. The principles for the development of guidelines are well established but many published guidelines fall short of these basic quality criteria. Guidelines are only one aspect of improving quality and should be used within a wider framework of promoting clinical effectiveness. Understanding their limitations as well as their potential benefits should enable clinicians to have a clearer view of their place in everyday practice.
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Condon ET, Wang JH, Redmond HP. Surgical injury induces the mobilization of endothelial progenitor cells. Surgery 2004; 135:657-61. [PMID: 15179372 DOI: 10.1016/j.surg.2003.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Endothelial progenitor cells (EPCs) are derived from the bone marrow and incorporate into the foci of tumor neovascularization to increase tumor growth. We hypothesized that surgery induces the mobilization of EPCs. METHODS C57BL/6 mice were assigned randomly to standardized laparotomy or anesthesia-only treatment groups (n=102 mice). Animals were killed at 6, 24, 48, and 72 hours. Bone marrow EPCs were detected by blood flow cytometric dual staining for stem cell antigen-1/cKit. Circulating EPCs were characterized in blood by vascular endothelial growth factor receptor 2(+)/macrophage activating complement-1(-) staining. EPCs were detected in splenic homogenates by dual staining for lectin and acetylated low-density lipoprotein uptake. Plasma vascular endothelial growth factor was determined by enzyme-linked immunosorbent assay. RESULTS Surgery induced increases in bone marrow and splenic EPC levels (0.2% +/- 0.01% vs 2.9% +/- 0.3%) at 24 hours and in circulating EPC levels (2.5% +/- 0.01% vs 35.2% +/- 6%) at 48 hours compared with control subjects (P <.001). Surgical injury also caused an increase in vascular endothelial growth factor release (81 +/- 8 vs 14 +/- 2 pg; P>.02). CONCLUSIONS EPCs were mobilized by surgical injury, which may have implications for residual and metastatic tumor growth during the perioperative period.
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Sheehan KM, Cahill RA, McGreal G, Steele C, Byrne MF, Kirwan WO, Kay EW, Fitzgerald DJ, Redmond HP, Murray FE. Cyclooxygenase-2 expression in primary human colorectal cancers and bone marrow micrometastases. Dig Liver Dis 2004; 36:392-7. [PMID: 15248379 DOI: 10.1016/j.dld.2004.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Both the expressions of the inducible form of cyclooxygenase-2 and the presence of bone marrow micrometastases are poor prognostic markers in patients with colorectal carcinoma. AIMS As cyclooxygenase-2 expression in these tumours is associated with increased metastatic potential in vitro, our objectives were to determine the relationship between cyclooxygenase-2 and haematogenous spread to bone marrow. PATIENTS AND METHODS Thirty-two patients with resection of colorectal carcinoma were evaluated (median age: 69.5 years). Bone marrow was obtained from all patients from both iliac crests before manipulation of the primary tumour. The tumours were of varying stages at diagnosis (5 Dukes' A, 14 Dukes' B, 11 Dukes' C and 2 Dukes' D). Tumour sections were stained for cyclooxygenase-2 using the avidin-biotin immunohistochemical technique. Extent of staining was graded depending on the percentage of epithelial cells staining positive for cyclooxygenase-2. Micrometastases were detected by staining contaminant cytokeratin-18 positive cells in the bone marrow aspirates by either immunohistochemical (ARAAP) or immunological (flow cytometry) methods. Fisher's exact probability test was used to calculate statistical significance. RESULTS Cyclooxygenase-2 expression in the primary tumour was detected in 72% of the patients. Twelve (38%) patients had bone marrow micrometastases detected by either immunohistochemistry or flow cytometry. Of the 12 patients who had bone marrow micrometastases, 8 tumours demonstrated increased expression of cyclooxygenase-2 protein (66.6%). In contrast, 9 out of the 20 (45%) patients in whom micrometastases were not detected expressed increased levels of cyclooxygenase-2 (P = 0.29). When dividing the patients into subgroups of localised (Dukes' A and B) versus disseminated (Dukes' C and D) disease, there was no further association between cyclooxygenase-2 expression and bone marrow micrometastases (P = 0.179 and 1.0). CONCLUSION In this pilot study, there was no association between cyclooxygenase-2 expression and bone marrow micrometastases in patients with otherwise localised or disseminated disease.
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Winter DC, Murphy A, Kell MR, Shields CJ, Redmond HP, Kirwan WO. Perioperative topical nitrate and sphincter function in patients undergoing transanal stapled anastomosis: a randomized, placebo-controlled, double-blinded trial. Dis Colon Rectum 2004; 47:697-703. [PMID: 15037937 DOI: 10.1007/s10350-003-0120-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE The use of transanal stapling devices may impair continence because of digital dilatation and/or instrumentation. This study assessed the effect of pharmacological dilatation of the sphincter prior to stapler insertion. METHODS A randomized, placebo-controlled, double-blinded study of 60 patients undergoing transanal stapled anastomosis was undertaken. Consenting patients were randomly assigned to receive a single intraoperative dose of topical 0.2 percent nitroglycerin (glyceryl trinitrate) ointment or nitroglycerin-free placebo. All patients were assessed preoperatively and postoperatively by clinical methods (Wexner incontinence scores and examination), anorectal manometry by a station pull-through technique, and endoanal ultrasonography. RESULTS Intraoperative mean (+/-SEM) resting pressures (mmHg) were significantly reduced by nitroglycerin compared with prenitroglycerin levels (9.9 +/- 0.9 vs. 50.5 +/- 2.7; P = 0.002) or controls (56.0 +/- 3.2; P = 0.001). Twenty-one of the 28 controls (75 percent) but only 4 of the 32 patients in the nitroglycerin group (12.5 percent) required digital dilatation to insert the stapling instrument ( P = 0.003). Squeeze pressures were unaltered by the intervention but mean resting pressures were higher in the nitroglycerin group postoperatively (52.9 +/- 3.2 - 31.6 +/- 1.3 = 21.3 mmHg; 95 percent confidence interval, 14-27). Incontinence scores were lower in the nitroglycerin group at the 3-month (1.1 +/- 0.2 vs. 4.6 +/- 0.3; P = 0.003) and 12-month (0.9 +/- 0.1 vs. 4.4 +/- 0.3; P = 0.002) clinic visits. CONCLUSION Preoperative nitroglycerin dilatation protects sphincter function in patients undergoing transanal stapled anastomoses.
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Manning BJ, O'Brien N, Aravindan S, Cahill RA, McGreal G, Redmond HP. The effect of aspirin on blood loss and transfusion requirements in patients with femoral neck fractures. Injury 2004; 35:121-4. [PMID: 14736467 DOI: 10.1016/s0020-1383(03)00073-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Although it is widely accepted that aspirin will increase the risk of intra- and post-operative bleeding, clinical studies have not consistently supported this assumption. We aimed to assess the effect of pre-operative aspirin on blood loss and transfusion requirements in patients undergoing emergency fixation of femoral neck fractures. A prospective case-control study was undertaken in patients presenting with femoral neck fractures. Parameters recorded included intra-operative blood loss, post-operative blood loss, transfusion requirements and peri-operative reduction in haemoglobin concentration. Of 89 patients presenting with femoral neck fractures 32 were on long-term aspirin therapy. Pre-operative aspirin ingestion did not significantly affect peri-operative blood loss, or change in haemoglobin concentration or haematocrit. However those patients taking aspirin pre-operatively had a significantly lower haemoglobin concentration and haematocrit and were more likely to be anaemic at presentation than those who were not receiving aspirin. Patients taking aspirin were also more likely to receive blood transfusion post-operatively.
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Coffey JC, Wang JH, Smith MJF, Bouchier-Hayes D, Cotter TG, Redmond HP. Excisional surgery for cancer cure: therapy at a cost. Lancet Oncol 2003; 4:760-8. [PMID: 14662433 DOI: 10.1016/s1470-2045(03)01282-8] [Citation(s) in RCA: 252] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Excisional surgery is one of the primary treatment modalities for cancer. Minimal residual disease (MRD) is the occult neoplastic disease that remains in situ after curative surgery. There is increasing evidence that tumour removal alters the growth of MRD, leading to perioperative tumour growth. Because neoplasia is a systemic disease, this phenomenon may be relevant to all patients undergoing surgery for cancer. In this review we discuss the published work that addresses the effects of tumour removal on subsequent tumour growth and the mechanisms by which tumour excision may alter residual tumour growth. In addition, we describe therapeutic approaches that may protect patients against any oncologically adverse effects of tumour removal. On the basis of the evidence presented, we propose a novel therapeutic paradigm; that the postoperative period represents a window of opportunity during which the patient may be further protected against the oncological effects of tumour removal.
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Andrews E, Ramesh BC, Nölke L, Redmond HP, Aherne T, O'Donnell A. A new specifically designed forceps for chest drain insertion. Injury 2003; 34:957-9. [PMID: 14636747 DOI: 10.1016/s0020-1383(03)00065-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Insertion of a chest drain can be associated with serious complications. It is recommended that the drain is inserted with blunt dissection through the chest wall but there is no specific instrument to aid this task. We describe a new reusable forceps that has been designed specifically to facilitate the insertion of chest drains.A feasibility study of its use in patients who required a chest drain as part of elective cardiothoracic operations was undertaken. The primary end-point was successful and accurate placement of the drain. The operators also completed a questionnaire rating defined aspects of the procedure. The new instrument was used to insert the chest drain in 30 patients (19 male, 11 female; median age 61.5 years (range 16-81 years)). The drain was inserted successfully without the trocar in all cases and there were no complications. Use of the instrument rated as significantly easier relative to experience of previous techniques in all specified aspects. The new device can be used to insert intercostal chest drains safely and efficiently without using the trocar or any other instrument.
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Goto Y, O'Malley C, Fanning NF, Wang J, Redmond HP, Shorten GD. Benzodiazepines inhibit the rate of neutrophil apoptosis. Ir J Med Sci 2003; 172:191-4. [PMID: 15029988 DOI: 10.1007/bf02915288] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Benzodiazepines, which are commonly administered perioperatively, can depress immune function. Neutrophil apoptosis plays a central role in the regulation of inflammation. This is particularly important during and after surgery. AIM To examine the effects of benzodiazepines (midazolam and diazepam) on neutrophil apoptosis. METHODS Venous blood samples were withdrawn from patients scheduled to undergo elective surgery, (a) immediately prior to, and 10 minutes after administration of midazolam 0.2 mg/kg intravenously (n=11) and (b) immediately prior to, and 60 minutes after administration of diazepam 10 mg p.o. (n=10). Neutrophil apoptosis was measured by Annexin V-FITC after 1 and 12 hours in culture. RESULTS The percentage of apoptotic cells was significantly less after midazolam at 12% (11.9) hours in culture compared to pre-midazolam 29.7% (13.3) (p<0.05). After diazepam, the rates of neutrophil apoptosis were also significantly less after 12 hours in culture (p<0.05). CONCLUSION Administration of benzodiazepines in clinically relevant doses inhibits neutrophil apoptosis. In the perioperative period, this may influence the inflammatory response to surgery.
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Smith FM, Coffey JC, El Sayeed A, O'Sullivan F, Kirwan WO, Redmond HP. Sentinel lymph node mapping in colorectal cancer (Br J Surg 2003; 90: 659-67 [corrected]). Br J Surg 2003; 90:1166. [PMID: 12945094 DOI: 10.1002/bjs.4381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Shields CJ, O'Sullivan AW, Wang JH, Winter DC, Kirwan WO, Redmond HP. Hypertonic saline enhances host response to bacterial challenge by augmenting receptor-independent neutrophil intracellular superoxide formation. Ann Surg 2003; 238:249-57. [PMID: 12894019 PMCID: PMC1422699 DOI: 10.1097/01.sla.0000080827.77985.fc] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE This study sought to determine whether hypertonic saline (HTS) infusion modulates the host response to bacterial challenge. METHODS Sepsis was induced in 30 Balb-C mice by intraperitoneal injection of Escherichia coli (5 x 107 organisms per animal). In 10 mice, resuscitation was performed at 0 and 24 hours with a 4 mL/kg bolus of HTS (7.5% NaCl), 10 animals received 4 mL/kg of normal saline (0.9% NaCl), and the remaining animals received 30 mL/kg of normal saline. Samples of blood, spleen, and lung were cultured at 8 and 36 hours. Polymorphonucleocytes were incubated in isotonic or hypertonic medium before culture with E. coli. Phagocytosis was assessed by flow cytometry, whereas intracellular bacterial killing was measured after inhibition of phagocytosis with cytochalasin B. Intracellular formation of free radicals was assessed by the molecular probe CM-H(2)DCFDA. Mitogen-activated protein (MAP) kinase p38 and ERK-1 phosphorylation, and nuclear factor kappa B (NFkappaB) activation were determined. Data are represented as means (SEM), and an analysis of variance test was performed to gauge statistical significance. RESULTS Significantly reduced bacterial culture was observed in the animals resuscitated with HTS when compared with their NS counterparts, in blood (51.8 +/- 4.3 vs. 82.0 +/- 3.3 and 78.4 +/- 4.8, P = 0.005), lung (40.0 +/- 4.1 vs. 93.2 +/- 2.1 and 80.9 +/- 4.7, P = 0.002), and spleen (56.4 +/- 3.8 vs. 85.4 +/- 4.2 and 90.1 +/- 5.9, P = 0.05). Intracellular killing of bacteria increased markedly (P = 0.026) and superoxide generation was enhanced upon exposure to HTS (775.78 +/- 23.6 vs. 696.57 +/- 42.2, P = 0.017) despite inhibition of MAP kinase and NFkappaB activation. CONCLUSIONS HTS significantly enhances intracellular killing of bacteria while attenuating receptor-mediated activation of proinflammatory cascades.
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Redmond HP. Systemic inflammatory response predicts survival following curative resection of colorectal cancer (Br J Surg 2003; 90: 215-219). Br J Surg 2003; 90:889; author reply 889. [PMID: 12854120 DOI: 10.1002/bjs.4333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Shields CJ, Sookhai S, Winter DC, Dowdall JF, Kingston G, Parfrey N, Wang JH, Kirwan WO, Redmond HP. Attenuation of pancreatitis-induced pulmonary injury by aerosolized hypertonic saline. Surg Infect (Larchmt) 2003; 2:215-23; discussion 223-4. [PMID: 12593711 DOI: 10.1089/109629601317202696] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The immunomodulatory effects of hypertonic saline (HTS) provide potential strategies to attenuate inappropriate inflammatory reactions. This study tested the hypothesis that administration of intratracheal aerosolized HTS modulates the development of lung injury in pancreatitis. METHODS Pancreatitis was induced in 24 male Sprague-Dawley rats by intraperitoneal injection of 20% L-arginine (500 mg/100 g body weight). At 24 and 48 h, intratracheal aerosolized HTS (7.5% NaCl, 0.5 mL) was administered to 8 rats, while a further 8 received 0.5 mL of aerosolized normal saline (NS). At 72 hours, pulmonary neutrophil infiltration (myeloperoxidase activity) and endothelial permeability (bronchoalveolar lavage and wet:dry weight ratios) were assessed. In addition, histological assessment of representative lung tissue was performed by a blinded assessor. In a separate experiment, polymorphonucleocytes (PMN) were isolated from human donors, and exposed to increments of HTS. Neutrophil transmigration across an endothelial cell layer, VEGF release, and apoptosis at 1, 6, 12, 18, and 24 h were assessed. RESULTS Histopathological lung injury scores were significantly reduced in the HTS group (4.78 +/- 1.43 vs. 8.64 +/- 0.86); p < 0.001). Pulmonary neutrophil sequestration (1.40 +/- 0.2) and increased endothelial permeability (6.77 +/- 1.14) were evident in the animals resuscitated with normal saline when compared with HTS (0.70 +/- 0.1 and 3.57 +/- 1.32), respectively; p < 0.04). HTS significantly reduced PMN transmigration (by 97.1, p = 0.002, and induced PMN apoptosis (p < 0.03). HTS did not impact significantly upon neutrophil VEGF release (p > 0.05). CONCLUSIONS Intratracheal aerosolized HTS attenuates the neutrophil-mediated pulmonary insult subsequent to pancreatitis. This may represent a novel therapeutic strategy.
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Kell MR, Power K, Winter DC, Power C, Shields C, Kirwan WO, Redmond HP. Predicting outcome after appendicectomy. Ir J Med Sci 2003; 172:63-5. [PMID: 12930054 DOI: 10.1007/bf02915248] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIM To validate an intraoperative appendicitis severity score (IASS) and examine outcome following emergency appendectomy. METHODS A prospective study was undertaken, enrolling consecutive patients undergoing emergency appendicectomy. Data were obtained independently on preoperative Alvarado scores, IASS (0-3: 0 no inflammation, 1 engorged appendix/no peritonitis, 2 peritoneal reaction/exudate or 3 evidence of perforation/abscess) and postoperative outcome parameters. RESULTS There were 149 patients identified with a mean age of 20.7 years. There was no association between Alvarado score and length of hospital stay, septic complication, patient sex or duration of symptoms (p>0.05). IASS was found to be an independent risk factor for septic complication, wound infection (p<0.05) and length of hospital stay (p<0.001). There was no correlation between preoperative duration of symptoms or time until surgery and intraoperative score. CONCLUSIONS This simple scoring system can identify patients more likely to suffer morbidity following emergency appendicectomy. Specifically, this system identifies patients who have a high risk of sepsis and therefore could be of use when comparing healthcare performance.
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Aherne NJ, Kavanagh EG, Condon ET, Coffey JC, El Sayed A, Redmond HP. Duodenal perforation after a blunt abdominal sporting injury: the importance of early diagnosis. THE JOURNAL OF TRAUMA 2003; 54:791-4. [PMID: 12707547 DOI: 10.1097/01.ta.0000061514.05103.7b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Higgins GT, Wang JH, Dockery P, Cleary PE, Redmond HP. Induction of angiogenic cytokine expression in cultured RPE by ingestion of oxidized photoreceptor outer segments. Invest Ophthalmol Vis Sci 2003; 44:1775-82. [PMID: 12657621 DOI: 10.1167/iovs.02-0742] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Normal aging is associated with accumulation of lipofuscin pigment in the retinal pigment epithelium (RPE). This may occur as a result of phagocytosis and incomplete degradation of oxidized photoreceptor outer segments (POS). This study was undertaken to determine whether phagocytosis of UV-irradiated POS (artificial lipofuscin) would increase expression in the RPE of various chemotactic and angiogenic cytokines. METHODS ARPE-19 cells were exposed to latex beads (0.76 micro m), naïve bovine POS, and UV-irradiated POS (Ox-POS; 2 x 10(7)/mL), and supernatants were collected at 18 and 36 hours. The supernatants were assayed for IL-8, monocyte chemotactic protein-(MCP)-1, and TNF-alpha by ELISA. Protein synthesis and NFkappaB activity were inhibited by actinomycin D and SN50, respectively. Phagocytosis and generation of intracellular reactive oxygen species were assessed by flow cytometry. Confocal and electron microscopy studies were also performed to verify phagocytosis and cellular integrity. RESULTS IL-8 and MCP-1 levels were decreased in the naïve POS group (IL-8: 473.76 +/- 66.9 pg/mL, P = 0.0005; MCP-1: 550.1 +/- 21.8 pg/mL, P = 0.0001), but were increased in the Ox-POS group (IL-8: 1348.8 +/- 164.9 pg/mL; MCP-1: 1772.28 +/- 65.19 pg/mL) compared with the control (IL-8: 741.09 +/- 39.8 pg/mL; MCP-1: 1413.47 +/- 38.4 pg/mL) and latex bead groups (data not shown). TNF-alpha levels were not affected. At 12 hours (but not at 6 hours), ROS were increased in the Ox-POS group. The cytokine increases observed were dependent on de novo protein synthesis and were NF-kappaB dependent. CONCLUSIONS Ingestion by RPE of oxidized bovine POS stimulates expression of the chemotactic and angiogenic factors IL-8 and MCP-1 that have the capability to promote angiogenesis directly, or indirectly through the accumulation of immune cells such as macrophages, which themselves may release angiogenic promoters and degrade Bruch's membrane. This may be of significance in the development of exudative AMD.
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Leonard SA, Redmond HP. Effects of volatile and intravenous anesthetic agents on neutrophil function. Int Anesthesiol Clin 2003; 41:21-9. [PMID: 12544417 DOI: 10.1097/00004311-200341010-00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Tyther R, O'Brien J, Wang J, Redmond HP, Shorten G. Effect of sevoflurane on human neutrophil apoptosis. Eur J Anaesthesiol 2003; 20:111-5. [PMID: 12622493 DOI: 10.1017/s0265021503000206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE Both chronic occupational exposure to volatile anaesthetic agents and acute in vitro exposure of neutrophils to isoflurane have been shown to inhibit the rate of apoptosis of human neutrophils. It is possible that inhibition of neutrophil apoptosis arises through delaying mitochondrial membrane potential collapse. We assessed mitochondrial depolarization and apoptosis in unexposed neutrophils and neutrophils exposed to sevoflurane in vivo. METHODS A total of 20 mL venous blood was withdrawn pre- and postinduction of anaesthesia, the neutrophils isolated and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide. Mitochondrial depolarization was measured using the dual emission styryl dye JC-1. RESULTS Apoptosis was significantly inhibited in neutrophils exposed to sevoflurane in vivo at 24 (exposed: 38 (12)% versus control: 28 (11)%, P = 0.001), but not at 1 or 12 h, in culture. Mitochondrial depolarization was not delayed in neutrophils exposed to sevoflurane. CONCLUSIONS The most important findings are that sevoflurane inhibits neutrophil apoptosis in vivo and that inhibition is not mediated primarily by an effect on mitochondrial depolarization.
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Redmond HP. Immunology for Surgeons. A. P. Zbar, P. J. Guillou, K. I. Bland and K. N. Syrigos (eds). 235 × 155 mm. Pp. 464. 2002. Illustrated. Springer: Heidelberg. £49·50. Br J Surg 2003. [DOI: 10.1002/bjs.4079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wang JH, Manning BJ, Wu QD, Blankson S, Bouchier-Hayes D, Redmond HP. Endotoxin/lipopolysaccharide activates NF-kappa B and enhances tumor cell adhesion and invasion through a beta 1 integrin-dependent mechanism. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:795-804. [PMID: 12517943 DOI: 10.4049/jimmunol.170.2.795] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Beta(1) integrins play a crucial role in supporting tumor cell attachment to and invasion into the extracellular matrix. Endotoxin/LPS introduced by surgery has been shown to enhance tumor metastasis in a murine model. Here we show the direct effect of LPS on tumor cell adhesion and invasion in extracellular matrix proteins through a beta(1) integrin-dependent pathway. The human colorectal tumor cell lines SW480 and SW620 constitutively expressed high levels of the beta(1) subunit, whereas various low levels of alpha(1), alpha(2), alpha(4), and alpha(6) expression were detected. SW480 and SW620 did not express membrane-bound CD14; however, LPS in the presence of soluble CD14 (sCD14) significantly up-regulated beta(1) integrin expression; enhanced tumor cell attachment to fibronectin, collagen I, and laminin; and strongly promoted tumor cell invasion through the Matrigel. Anti-beta(1) blocking mAbs (4B4 and 6S6) abrogated LPS- plus sCD14-induced tumor cell adhesion and invasion. Furthermore, LPS, when combined with sCD14, resulted in NF-kappaB activation in both SW480 and SW620 cells. Inhibition of the NF-kappaB pathway significantly attenuated LPS-induced up-regulation of beta(1) integrin expression and prevented tumor cell adhesion and invasion. These results provide direct evidence that although SW480 and SW620 cells do not express membrane-bound CD14, LPS in the presence of sCD14 can activate NF-kappaB, up-regulate beta(1) integrin expression, and subsequently promote tumor cell adhesion and invasion. Moreover, LPS-induced tumor cell attachment to and invasion through extracellular matrix proteins is beta(1) subunit-dependent.
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Kell MR, Barry BD, Redmond HP. Systemic inflammatory response syndrome: a new direction? Ir J Med Sci 2003; 172:7-8. [PMID: 12760454 DOI: 10.1007/bf02914776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Wang JH, Doyle M, Manning BJ, Blankson S, Wu QD, Power C, Cahill R, Redmond HP. Cutting edge: bacterial lipoprotein induces endotoxin-independent tolerance to septic shock. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:14-8. [PMID: 12496376 DOI: 10.4049/jimmunol.170.1.14] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tolerance to bacterial cell wall components is an adaptive host response. Endotoxin/LPS tolerance is characterized by a survival advantage against subsequent lethal LPS challenge. However, it is uncertain whether LPS tolerance can afford protection against other septic challenges. In this study, we show that tolerance induced by bacterial lipoprotein (BLP) protects mice against not only BLP-induced lethality, but also LPS-, live bacteria-, and polymicrobial sepsis-induced lethality. In contrast, LPS tolerance offers no survival benefit against the latter two challenges. Furthermore, induction of BLP tolerance results in overexpression of complement receptor type 3 and FcgammaIII/IIR on neutrophils (polymorphonuclear neutrophils) and peritoneal macrophages, with increased bacterial recognition and bactericidal activity, whereas LPS-tolerized mice exhibit an impaired ability to ingest and to kill bacteria. These results indicate that BLP tolerance is a novel adaptive host response associated with a unique protective effect during septic shock.
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Shields CJ, Winter DC, Manning BJ, Wang JH, Kirwan WO, Redmond HP. Hypertonic saline infusion for pulmonary injury due to ischemia-reperfusion. ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 2003; 138:9-14. [PMID: 12511143 DOI: 10.1001/archsurg.138.1.9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
HYPOTHESIS Inhibition of neutrophil-endothelial cell interactions by hypertonic saline (HTS) may confer protection against organ injury in states of immunologic disarray. This study tested the hypothesis that infusion of HTS modulates the development of end-organ injury in a model of lower-torso ischemia-reperfusion injury. DESIGN Ischemia-reperfusion injury was induced in 30 male Sprague-Dawley rats by infrarenal aortic cross-clamp for 30 minutes, followed by reperfusion for 2 hours. At 0 and 60 minutes of reperfusion, intravenous HTS (7.5% sodium chloride, 4 mL/kg) was administered to 6 rats each, and another 12 received either 4 or 30 mL/kg of isotonic sodium chloride solution. Six rats received HTS, 4 mL/kg, before ischemia. At 2 hours, we assessed liver function, pulmonary injury, neutrophil infiltration (myeloperoxidase activity), endothelial permeability (bronchoalveolar lavage and wet-dry weight ratios), and proinflammatory cytokine levels (tumor necrosis factor alpha and interleukin 6). RESULTS Infusion with HTS before or after ischemia significantly reduced end-organ injury. Histopathologic pulmonary injury scores were markedly attenuated in the HTS group (5.82 +/- 1.3) and the HTS pretreated group (4.91 +/- 1.6) compared with the isotonic sodium chloride solution groups (8.54 +/- 1.1) (P =.04). Pulmonary neutrophil sequestration (2.07 +/- 0.23) and increased endothelial permeability (4.68 +/- 0.44) were manifest in animals resuscitated with isotonic sodium chloride solution compared with HTS treatment (1.54 +/- 0.19 [P =.04] and 2.06 +/- 0.26 [P =.02]) and pretreatment (1.18 +/- 0.12 [P =.04] and 1.25 +/- 0.07 [P =.002]). In addition, a significant reduction in serum tumor necrosis factor alpha (P =.04) and interleukin 6 (P =.048) levels was observed, whereas HTS resuscitation attenuated the upsurge in aspartate transaminase (P =.03) and alanine transaminase levels (P =.047). CONCLUSIONS Resuscitation with HTS attenuates the pulmonary edema and tissue injury due to lower-torso ischemia-reperfusion and maintains a more benign immunologic profile.
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Doyle M, Wang JH, Wu QD, Blankson S, Redmond HP. Bacterial lipoprotein induces tolerance in human THP-1 monocytes with reduced tumour necrosis factor α production via a CD14-independent pathway. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2000.01544-3.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Endotoxin (lipopolysaccharide; LPS) tolerance is characterized by diminished production of tumour necrosis factor (TNF) α during prolonged exposure to LPS, and therefore represents an essential control mechanism during sepsis. However, it is unknown whether bacterial lipoprotein (BLP), another major component of bacterial walls, can cause tolerance. This study sought to determine whether BLP pretreatment can induce tolerance in human THP-1 monocytes.
Methods
Human THP-1 monocytic cells were pretreated with culture medium alone and medium containing LPS 10 ng ml−1 or BLP 10 ng ml−1 for 24 h. Cells were further stimulated with high doses (0·1–1 mg ml−1) of LPS or BLP for 6 h. TNF-α levels were determined by enzyme-linked immunosorbent assay. CD14 receptor expression on THP-1 monocytes was assessed by flow cytometry.
Results
When THP-1 cells were incubated with culture medium, BLP stimulation resulted in much higher TNF-α levels than LPS stimulation (P < 0·05). Following LPS pretreatment, LPS stimulation-induced TNF-α production was significantly attenuated, whereas BLP stimulation still produced a small amount of TNF-α. However, BLP pretreatment prevented both LPS and BLP stimulation-induced TNF-α production from THP-1 cells. FACScan analysis revealed that THP-1 monocytes do not express CD14 receptor.
Conclusion
These results demonstrate that BLP has a more potent effect than LPS on THP-1 monocyte TNF-α production. Furthermore, BLP pretreatment is capable of inducing both BLP as well as LPS tolerance via a CD14-independent pathway, indicating a unique ability to cause cross-tolerance.
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Sookhai S, Wang J, Austin K, Maguire D, Blankson S, Kirwan WO, Redmond HP. Antivascular endothelial growth factor therapy prevents peritoneal adhesion formation without adversely affecting wound strength or anastomotic integrity. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2000.01544-45.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Postoperative intra-abdominal adhesion formation remains a significant cause of complications in surgical patients. To date, no agent has been shown consistently to block adhesion formation; preliminary evidence has shown that intra-abdominal adhesion formation is angiogenesis dependent. Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis and promotes vascular leakage. This study determined whether a specific VEGF monoclonal antibody (mAb) could prevent postoperative adhesion formation without affecting wound and anastomotic integrity.
Methods
After developing a standardized peritoneal injury which resulted in a reproducible adhesion model, 40 CD-1 mice were randomized and treated intraperitoneally with either VEGF mAb (n = 20) or immunoglobulin (Ig) G isotype control mAb (n = 20) at the time of abdominal closure. Animals (n = 10 per group) were killed on postoperative day 14, and the development of intra-abdominal adhesions was determined and graded blindly using well established criteria. Animals (n = 10 per group) were also killed 10 days after operation, and laparotomy wounds and gastrointestinal anastomoses were assessed by tensiometry. Statistical analyses were performed using the Mann–Whitney and Fisher's exact tests.
Results
Treatment with VEGF mAb resulted in a significantly lower incidence of adhesion formation compared with control animals (P < 0·001). Furthermore, intergroup analysis for the presence of marked adhesions (grade 2 or 3) demonstrated that mice treated with VEGF mAb had a significantly lower incidence of advanced adhesions compared with controls (10 versus 90 per cent). Laparotomy wound and gastrointestinal anastomotic strength were similar between groups.
Conclusion
This study demonstrates that the formation of postoperative intra-abdominal adhesions is attenuated following the administration of VEGF mAb without adversely affecting wound strength or anastomotic integrity.
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Sookhai S, Wang JH, McCourt M, Winter DC, Kirwan WO, Redmond HP. Dopamine attenuates neutrophil–endothelial interaction and is a putative anti-inflammatory cytokine. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2000.01544-31.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Activated neutrophil (PMN) adherence to vascular endothelium comprises a key step for both transendothelial migration and initiation of potentially deleterious release of PMN products. Previous work has shown that the biogenic amine dopamine (DA) functions as an anti-inflammatory cytokine by inducing PMN apoptosis. The effect of DA on PMN transendothelial migration and adhesion receptor expression as well as on the endothelial molecules, E-selectin and intercellular adhesion molecule (ICAM) 1, was evaluated.
Methods
PMNs were isolated from healthy controls, stimulated with lipopolysaccharide (LPS) and tumour necrosis factor (TNF) α and treated with DA. CD11b and CD18 PMN adhesion receptor expression was assessed flow cytometrically. In a separate transwell experiment, the effect of the chemo-attractant peptide interleukin (IL) 8 on PMN migration was assessed. Human umbilical vein endothelial cells were stimulated with LPS/TNF-α, incubated with DA, and ICAM-1 and E-selectin endothelial molecule expression was assessed.
Results
There was a significant increase in transendothelial migration in stimulated PMNs as well as in CD11b/CD18, endothelial E-selectin and ICAM-1 expression compared with normal PMNs. DA attenuated these changes. The chemoattractant effect of IL-8 was also abolished.
Conclusion
These results show that DA attenuates the initial interaction between PMNs and endothelium, providing further evidence that it also functions as an anti-inflammatory cytokine.
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Power C, Wang JH, Street J, Higgins G, Redmond HP. Macrophages that have ingested apoptotic neutrophils release tissue inhibitor of matrix metalloproteinase 1. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2000.01544-65.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Apoptosis of neutrophils (PMNs) in vivo is followed by their rapid uptake into adjacent phagocytic cells, a critical process in tissue remodelling, regulation of the immune response and resolution of inflammation. Tissue inhibitor of matrix metalloproteinase (TIMP) 1 is crucial in regulating the matrix-degrading properties of matrix metalloproteinases released by activated PMNs in inflammatory foci. The aim was to elucidate whether mononuclear-derived phagocytes (MDPs) release TIMP-1 and/or MMP-9 after phagocytosis of apoptotic PMNs.
Methods
MDPs were prepared from peripheral blood monocytes after isolation by culture in well plates for 7–10 days. PMNs were isolated from similarly healthy volunteers. PMN apoptosis was induced by 10 min of ultraviolet irradiation at 254 nm. After a further 6 h of incubation apoptosis was assessed and was routinely greater than 50 per cent. Apoptotic PMNs were then added to MDPs in specific ratios. After 1 h non-phagocytosed PMNs were washed away. RPMI was added to MDPs in well plates and 18 h later the supernatant was collected. Phagocytosis of opsonized zymosan, exposure to tumour necrosis factor (TNF) α and lipopolysaccharide (LPS), and finally MDPs alone were used as controls. TIMP-1 was quantified by enzyme-linked immunosorbent assay.
Results
TIMP-1 was released by MDPs after phagocytosis of apoptotic PMNs and opsonized zymosan. MDPs also produced TIMP-1 after stimulation with TNF-α–LPS. Levels of TIMP-1 from these MDPs were significantly different from those in MDPs alone.
Conclusion
Phagocytosis of apoptotic PMNs is an integral part of the host's attempt to resolve inflammation in altered immune states such as the systemic inflammatory response syndrome in which PMNs persistently release proinflammatory substances damaging the local microenvironment. This study has demonstrated that MDPs release TIMP-1 after phagocytosis of apoptotic PMNs and that this may play a role in the regulation of tissue remodelling and repair in response to inflammation.
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Power C, Wang JH, Blankson S, Kirwan WO, Redmond HP. Bacterial lipoprotein delays neutrophil apoptosis via a CD14-independent pathway. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2000.01544-1.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Lipopolysaccharide (LPS) is considered the most potent exogenous mediator of the systemic inflammatory response syndrome (SIRS) which results, in part, from delayed neutrophil (PMN) apoptosis. The effects of another ubiquitous bacterial component, bacterial lipoprotein (BLP), the most abundant protein in the cell wall of all bacteria, on PMN apoptosis are unknown. The potential role of BLP in the regulation of PMN apoptosis was investigated and these effects were compared with those of LPS.
Methods
PMNs from healthy volunteers were isolated and exposed to identical concentrations of LPS and BLP in the presence or absence of recombinant antihuman CD14 monoclonal antibody. PMN apoptosis was assessed 6 hourly using Annexin V–propidium iodide staining and confirmed on cell morphology. PNM activation was assessed flow cytometrically using expression of functional markers CD11b and CD18.
Results
BLP significantly delayed PMN apoptosis and upregulated PMN adhesion receptor expression compared with control values. The effects seen were markedly similar to those of LPS.
Conclusion
BLP is capable of upregulating PMN adhesion receptor expression and delaying PMN apoptosis in a time- and dose-dependent manner independent of CD14. The potency, and the effects mediated by, BLP are very similar to those of LPS. This identifies BLP as a putative mediator of SIRS and demands that due attention be paid to other bacterial products in the investigation and treatment of septic states.
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145
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Doyle M, Wang JH, Redmond HP. Bacterial lipoprotein induces endotoxin-independent tolerance to the systemic inflammatory response syndrome in vivo and in vitro. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2000.01544-66.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Background
Sublethal doses of endotoxin (lipopolysaccharide; LPS) induce tolerance in vivo and in vitro, and protect against the lethal effects of a further LPS challenge. Tolerance is characterized by diminished production of tumour necrosis factor (TNF) α. Bacterial lipoprotein (BLP), another bacterial wall component, might induce tolerance against its own lethal effects as well as those of endotoxin.
Methods
Ninety male MF-1 mice (mean(s.d.) weight 18(2) g) were randomized into three groups (n = 30 per group). Mice in group 1 received a single BLP-tolerant dose (10 mg kg−1) by intraperitoneal injection, whereas mice in group 2 received a second BLP-tolerant dose (10 mg kg−1) after 24 h. Following induction of tolerance, all mice were challenged with high doses of LPS 45 mg kg−1, BLP 45 mg kg−1 or a combination of LPS 30 mg kg−1 plus BLP 30 mg kg−1. Mice in group 3 were treated with a high dose of the above agents only. Mortality was assessed at 24 and 48 h. Macrophages were isolated from mice and pretreated in vitro with culture medium alone or culture medium containing LPS 10 ng ml−1 or BLP 10 ng ml−1 for 24 h. The cells were then stimulated with high doses (100–1000 ng ml−1) of LPS, BLP or LPS plus BLP for 6 h. The cell culture supernatants were collected and TNF-α levels were determined using enzyme-linked immunosorbent assay.
Results
BLP-induced tolerance significantly improved survival compared with that of mice without tolerance (P < 0·05). In vitro, pretreatment of murine macrophages with BLP significantly attenuated LPS, BLP and LPS plus BLP stimulation-induced TNF-α production.
Conclusion
BLP mimics LPS in the development of the systemic inflammatory response syndrome. Furthermore, BLP is capable of inducing tolerance, both in vivo and in vitro, which subsequently prevents BLP- and LPS plus BLP-induced death.
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Tan B, Wang JH, Wu QD, Kirwan WO, Redmond HP. Authors' reply. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2001.01882-2.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kell MR, Aherne NJ, Coffey C, Power CP, Kirwan WO, Redmond HP. Emergency surgeon-performed hepatobiliary ultrasonography. Br J Surg 2002; 89:1402-4. [PMID: 12390381 DOI: 10.1046/j.1365-2168.2002.02297.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Acute hepatobiliary pathology is a common general surgical emergency referral. Diagnosis requires imaging of the biliary tree by ultrasonography. The accuracy and impact of surgeon-performed ultrasonography (SUS) on the diagnosis of emergent hepatobiliary pathology was examined. METHODS A prospective study, over a 6-month period, enrolled all patients with symptoms or signs of acute hepatobiliary pathology. Patients provided informed consent and underwent both SUS and standard radiology-performed ultrasonography (RUS). SUS was performed using a 2-5-MHz broadband portable ultrasound probe by two surgeons trained in ultrasonography, and RUS using a 2-5-MHz fixed unit. SUS results were correlated with those of RUS and pathological diagnoses. RESULTS Fifty-three consecutive patients underwent 106 ultrasonographic investigations. SUS agreed with RUS in 50 (94.3 per cent) of 53 patients. SUS accurately detected cholelithiasis in all but two cases and no patient was inaccurately diagnosed as having cholelithiasis at SUS (95.2 per cent sensitivity and 100 per cent specificity). As an overall complementary diagnostic tool SUS provided the correct diagnosis in 96.2 per cent of patients. Time to scan was significantly shorter following SUS (3.1 versus 12.0 h, P < 0.05). CONCLUSION SUS provides a rapid and accurate diagnosis of emergency hepatobiliary pathology and may contribute to the emergency management of hepatobiliary disease.
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Fanning NF, Manning BJ, Buckley J, Redmond HP. Iodinated contrast media induce neutrophil apoptosis through a mitochondrial and caspase mediated pathway. Br J Radiol 2002; 75:861-73. [PMID: 12466250 DOI: 10.1259/bjr.75.899.750861] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Iodinated contrast media (ICM) can induce apoptosis (programmed cell death) in renal, myocardial and endothelial cells. Following intravascular injection, circulating immune cells are exposed to high concentrations of ICM. As neutrophils constitutively undergo apoptosis we hypothesized that ICM may adversely affect neutrophil survival. Our aim was to investigate the effect of ICM on neutrophil apoptosis. Neutrophils were isolated from healthy subjects and cultured in vitro with ionic (diatrizoate and ioxaglate) and non-ionic (iohexol and iotrolan) ICM. The effect of ICM on neutrophil apoptosis in both unstimulated and lipopolysaccharide-stimulated neutrophils was determined by annexin V flow cytometry. The influence of physicochemical properties of the different ICM on apoptosis of neutrophils was also studied. We further investigated the effects of ICM on key intracellular signal pathways, including p38 mitogen-activated protein kinase (MAPK) by Western blotting, and mitochondrial depolarization and caspase activity by flow cytometry. Isoiodine concentrations (20 mg ml(-1)) of ionic (diatrizoate 69.6+/-2.9%; ioxaglate 58.9+/-2.0%) and non-ionic (iohexol 57.3+/-2.9%; iotrolan 57.1+/-2.6%) ICM significantly induced neutrophil apoptosis over control levels (47.7+/-1.4%). The apoptotic effect of ICM was influenced by their chemical structure, with ionic ICM having a more significant (p<0.01) apoptotic effect than non-ionic ICM (p<0.05). Furthermore, ICM reversed the anti-apoptotic effect of lipopolysaccharide (1000 ng ml(-1)) treated neutrophils to control levels (23.0+/-3.5% to 61.2+/-5.3%; n=4; p<0.05). These agents induce apoptosis through a p38 MAPK independent pathway that results in mitochondrial depolarization, and is dependent on caspase activation. As neutrophils play a central role in host response to infection and injury, ICM, through induction of neutrophil apoptosis, could have a significant deleterious effect on host immune defence and resolution of an inflammatory response.
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Wang JH, Doyle M, Manning BJ, Di Wu Q, Blankson S, Redmond HP. Induction of bacterial lipoprotein tolerance is associated with suppression of toll-like receptor 2 expression. J Biol Chem 2002; 277:36068-75. [PMID: 12133836 DOI: 10.1074/jbc.m205584200] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tolerance to bacterial cell wall components including lipopolysaccharide (LPS) may represent an essential regulatory mechanism during bacterial infection. Two members of the Toll-like receptor (TLR) family, TLR2 and TLR4, recognize the specific pattern of bacterial cell wall components. TLR4 has been found to be responsible for LPS tolerance. However, the role of TLR2 in bacterial lipoprotein (BLP) tolerance and LPS tolerance is unclear. Pretreatment of human THP-1 monocytic cells with a synthetic bacterial lipopeptide induced tolerance to a second BLP challenge with diminished tumor necrosis factor-alpha and interleukin-6 production, termed BLP tolerance. Furthermore, BLP-tolerized THP-1 cells no longer responded to LPS stimulation, indicating a cross-tolerance to LPS. Induction of BLP tolerance was CD14-independent, as THP-1 cells that lack membrane-bound CD14 developed tolerance both in serum-free conditions and in the presence of a specific CD14 blocking monoclonal antibody (MEM-18). Pre-exposure of THP-1 cells to BLP suppressed mitogen-activated protein kinase phosphorylation and nuclear factor-kappaB activation in response to subsequent BLP and LPS stimulation, which is comparable with that found in LPS-tolerized cells, indicating that BLP tolerance and LPS tolerance may share similar intracellular pathways. However, BLP strongly enhanced TLR2 expression in non-tolerized THP-1 cells, whereas LPS stimulation had no effect. Furthermore, a specific TLR2 blocking monoclonal antibody (2392) attenuated BLP-induced, but not LPS-induced, tumor necrosis factor-alpha and interleukin-6 production, indicating BLP rather than LPS as a ligand for TLR2 engagement and activation. More importantly, pretreatment of THP-1 cells with BLP strongly inhibited TLR2 activation in response to subsequent BLP stimulation. In contrast, LPS tolerance did not prevent BLP-induced TLR2 overexpression. These results demonstrate that BLP tolerance develops through down-regulation of TLR2 expression.
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Dowdall JF, Winter DC, Andrews E, Laug WE, Wang JH, Redmond HP. Soluble interleukin 6 receptor (sIL-6R) mediates colonic tumor cell adherence to the vascular endothelium: a mechanism for metastatic initiation? J Surg Res 2002; 107:1-6. [PMID: 12384057 DOI: 10.1006/jsre.2001.6222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The mechanisms by which surgery increases metastatic proliferation remain poorly characterized, although endotoxin and immunocytes play a role. Recent evidence suggests that endothelial adherence of tumor cells may be important in the formation of metastases. Soluble receptors of interleukin-6 (sIL-6R) shed by activated neutrophils exert IL-6 effects on endothelial cells, which are unresponsive under normal circumstances. This study examined the hypothesis that sIL-6R released by surgical stress increases tumor cell adherence to the endothelium. Neutrophils (PMN) were stimulated with lipopolysaccharide, C-reactive protein (CRP), and tumor necrosis factor-alpha. Soluble IL-6R release was measured by enzyme-linked immunosorbent assay. Colonic tumor cells transfected with green fluorescent protein and endothelial cells were exposed to sIL-6R, and tumor cell adherence and transmigration were measured by fluorescence microscopy. Basal release of sIL-6R from PMN was 44.7 +/- 8.2 pg/ml at 60 min. This was significantly increased by endotoxin and CRP (131 +/- 16.8 and 84.1 +/- 5.3, respectively; both P < 0.05). However, tumor necrosis factor-alpha did not significantly alter sIL-6R release. Endothelial and tumor cell exposure to sIL-6R increased tumor cell adherence by 71.3% within 2 h but did not significantly increase transmigration, even at 6 h. Mediators of surgical stress induce neutrophil release of a soluble receptor for IL-6 that enhances colon cancer cell endothelial adherence. Since adherence to the endothelium is now considered to be a key event in metastatic genesis, these findings have important implications for colon cancer treatment strategies.
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