35 results on '"Kelleher DP"'
Search Results
2. Passive Immunisation of Hamsters against Clostridium Difficile Infection using Antibodies against Surface Layer Proteins
- Author
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O'Brien, JB, primary, McCabe, MS, additional, Ní Eidhin, DB, additional, and Kelleher, DP, additional
- Published
- 2004
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3. The yield of colonoscopy in average-risk patients with non-specific colonic symptoms.
- Author
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Ang YS, Macaleenan N, Mahmud N, Keeling PWN, Kelleher DP, Weir DG, Ang, Yeng S, Macaleenan, Niall, Mahmud, Nasir, Keeling, Paul W N, Kelleher, Dermot P, and Weir, Donald G
- Published
- 2002
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4. Patient knowledge and educational needs in irritable bowel syndrome.
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O'Sullivan MA, Mahmud N, Kelleher DP, Lovett E, O'Morain CA, O'Sullivan, M A, Mahmud, N, Kelleher, D P, Lovett, E, and O'Morain, C A
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- 2000
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5. Identifying pragmatic solutions to reduce cigarette smoking prevalence in Indigenous North Americans: A sequential exploratory mixed-methods study protocol.
- Author
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Rusk AM, Paul M, Kelleher DP, Tilburt J, Northfelt D, Rank M, Cartin-Ceba R, Capossela G, Jackson T, Sabaque C, Chamberlain AM, Ortega VE, Benzo R, and Kennedy C
- Subjects
- Adult, Female, Humans, Male, Pregnancy, Minnesota epidemiology, Prevalence, American Indian or Alaska Native, Cigarette Smoking epidemiology, Smoking Cessation methods
- Abstract
Background: American Indians and Alaska Natives (AI/AN) have the highest prevalence of cigarette smoking of any race or ethnicity in the United States. Efforts to address smoking prevalence in this population have not historically targeted maintenance of smoking cessation, or behaviors associated with pregnancy. Recent longitudinal cohort studies have identified maintenance of cessation and pregnancy as potential opportunities to address smoking in AI/AN people., Methods: To promote success in achieving sustained smoking cessation in AI/AN people, we propose a community engaged sequential exploratory mixed-methods study focused on identifying pragmatic elements of cessation interventions. A discovery sample of 45 AI/AN people will be included in the qualitative study in one of two arms consisting of small groups or one-on-one interviews to develop elements of cessation interventions for evaluation in a discrete choice experiment survey. These one-on-one interviews will characterize the key drivers of smoking relapse and unique experiences of smoking during pregnancy. An additional, independent small group will consist of counselors who engage in smoking cessation counseling. A larger-scale survey will be administered to an AI/AN cohort from Olmsted County, Minnesota (n = 898). Elements of successful interventions will be used to inform a smoking cessation intervention pilot study. Community stakeholders have informed the methods outlined in this protocol, and there is a longitudinal engagement plan for the duration of study., Discussion: We outline the methods to understand optimal strategies to promote sustained cigarette smoking cessation and cessation during pregnancy in AI/AN people. This study is critical to inform a pilot intervention aimed at reducing smoking prevalence in AI/AN people., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Rusk et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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6. Examining the association between professional language interpreter services and intensive care unit utilization among patients with non-English language preference: Evidence from a large U.S. hospital.
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Kelleher DP, Barwise AK, Robbins KA, and Borah BJ
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- Humans, Female, Male, Middle Aged, Adult, Language, Aged, Length of Stay statistics & numerical data, United States, Cohort Studies, Limited English Proficiency, Intensive Care Units, Communication Barriers, Translating
- Abstract
Objective: To examine the healthcare utilization of patients with non-English language preference (NELP) who utilized a professional language interpreter (PLI) in the intensive care unit (ICU) compared to similar patients with NELP who did not utilize a PLI in the ICU., Methods: Single center cohort study of patients with NELP with at least one ICU admission a large academic medical center in the U.S. Midwest (1/1/2008-12/31/2022). The first model examined ICU length-of-stay (LOS) using a negative binomial and the second model examined whether a patient was readmitted to the ICU using a logistic regression with each model controlling for PLI utilization and covariates., Results: Patients with NELP who utilized a PLI in the ICU had 0.87-days longer in the ICU (p < 0.01) and had a 46 % decreased odds of being readmitted to the ICU (p < 0.01) than a comparable patient with NELP who did not utilize a PLI in the ICU., Conclusion: Providing patients with NELP with access to a PLI in the ICU can improve patient outcomes and reduce language barriers., Practice Implications: These results can provide the justification to potentially increase PLI staffing levels or increase the access to existing PLIs for more patients with NELP in ICUs., Competing Interests: Declaration of Competing Interest No funding supported this research. Dr Kelleher, Dr Barwise and Kellie Robbins have no conflicts of interest whatsoever to report of. Dr. Borah is a consultant to Boehringer Ingelheim and Exact Sciences Corporation on studies unrelated to this work., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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7. Deoxycholic acid promotes development of gastroesophageal reflux disease and Barrett's oesophagus by modulating integrin-αv trafficking.
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Prichard DO, Byrne AM, Murphy JO, Reynolds JV, O'Sullivan J, Feighery R, Doyle B, Eldin OS, Finn SP, Maguire A, Duff D, Kelleher DP, and Long A
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- Animals, Barrett Esophagus genetics, Barrett Esophagus pathology, Cell Adhesion, Cell Line, Collagen chemistry, Disease Models, Animal, Epithelial Cells metabolism, Epithelial Cells pathology, Esophagitis genetics, Esophagitis pathology, Fibronectins chemistry, Gastroesophageal Reflux genetics, Gastroesophageal Reflux pathology, Gene Expression Profiling, Gene Expression Regulation, Humans, Integrin alphaV metabolism, Integrins genetics, Integrins metabolism, Laminin chemistry, Permeability drug effects, Protein Transport, Rats, Tissue Array Analysis, Vitronectin chemistry, Barrett Esophagus metabolism, Deoxycholic Acid pharmacology, Epithelial Cells drug effects, Esophagitis metabolism, Gastroesophageal Reflux metabolism, Integrin alphaV genetics
- Abstract
The fundamental mechanisms underlying erosive oesophagitis and subsequent development of Barrett's oesophagus (BO) are poorly understood. Here, we investigated the contribution of specific components of the gastric refluxate on adhesion molecules involved in epithelial barrier maintenance. Cell line models of squamous epithelium (HET-1A) and BO (QH) were used to examine the effects of bile acids on cell adhesion to extracellular matrix proteins (Collagen, laminin, vitronectin, fibronectin) and expression of integrin ligands (α
3 , α4, α5 , α6 and αν ). Experimental findings were validated in human explant oesophageal biopsies, a rat model of gastroesophageal reflux disease (GORD) and in patient tissue microarrays. The bile acid deoxycholic acid (DCA) specifically reduced adhesion of HET-1A cells to vitronectin and reduced cell-surface expression of integrin-αν via effects on endocytic recycling processes. Increased expression of integrin-αv was observed in ulcerated tissue in a rat model of GORD and in oesophagitis and Barrett's intestinal metaplasia patient tissue compared to normal squamous epithelium. Increased expression of integrin-αν was observed in QH BO cells compared to HET-1A cells. QH cells were resistant to DCA-mediated loss of adhesion and reduction in cell-surface expression of integrin-αν . We demonstrated that a specific component of the gastric refluxate, DCA, affects the epithelial barrier through modulation of integrin αν expression, providing a novel mechanism for bile acid-mediated erosion of oesophageal squamous epithelium and promotion of BO. Strategies aimed at preventing bile acid-mediated erosion should be considered in the clinical management of patients with GORD., (© 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)- Published
- 2017
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8. Differential modulation of Helicobacter pylori lipopolysaccharide-mediated TLR2 signaling by individual Pellino proteins.
- Author
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Smith SM, Freeley M, Moynagh PN, and Kelleher DP
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- Cells, Cultured, Cytokines metabolism, Epithelial Cells immunology, Gastric Mucosa immunology, Humans, Nuclear Proteins genetics, Organ Culture Techniques, Receptor-Interacting Protein Serine-Threonine Kinases metabolism, Ubiquitin-Protein Ligases genetics, Immunity, Innate, Lipopolysaccharides immunology, Nuclear Proteins metabolism, Receptor-Interacting Protein Serine-Threonine Kinases genetics, Signal Transduction, Toll-Like Receptor 2 metabolism, Ubiquitin-Protein Ligases metabolism
- Abstract
Background: Eradication rates for current H. pylori therapies have fallen in recent years, in line with the emergence of antibiotic resistant infections. The development of therapeutic alternatives to antibiotics, such as immunomodulatory therapy and vaccines, requires a more lucid understanding of host-pathogen interactions, including the relationships between the organism and the innate immune response. Pellino proteins are emerging as key regulators of immune signaling, including the Toll-like receptor pathways known to be regulated by H. pylori. The aim of this study was to characterize the role of Pellino proteins in the innate immune response to H. pylori lipopolysaccharide., Materials and Methods: Gain-of-function and loss-of-function approaches were utilized to elucidate the role of individual Pellino proteins in the Toll-like receptor 2-mediated response to H. pylori LPS by monitoring NF-ĸB activation and the induction of proinflammatory chemokines. Expression of Pellino family members was investigated in gastric epithelial cells and gastric tissue biopsy material., Results: Pellino1 and Pellino2 positively regulated Toll-like receptor 2-driven responses to H. pylori LPS, whereas Pellino3 exerted a negative modulatory role. Expression of Pellino1 was significantly higher than Pellino3 in gastric epithelial cells and gastric tissue. Furthermore, Pellino1 expression was further augmented in gastric epithelial cells in response to infection with H. pylori or stimulation with H. pylori LPS., Conclusions: The combination of low Pellino3 levels together with high and inducible Pellino1 expression may be an important determinant of the degree of inflammation triggered upon Toll-like receptor 2 engagement by H. pylori and/or its components, contributing to H. pylori-associated pathogenesis by directing the incoming signal toward an NF-kB-mediated proinflammatory response., (© 2016 John Wiley & Sons Ltd.)
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- 2017
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9. A nitrophenyl-based prodrug type for colorectal targeting of prednisolone, budesonide and celecoxib.
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Marquez Ruiz JF, Kedziora K, Pigott M, Keogh B, Windle H, Gavin J, Kelleher DP, and Gilmer JF
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- Antineoplastic Agents therapeutic use, Antineoplastic Agents toxicity, Budesonide therapeutic use, Budesonide toxicity, Caco-2 Cells, Celecoxib, Cell Membrane Permeability drug effects, Clostridium perfringens drug effects, Colorectal Neoplasms drug therapy, Cyclooxygenase 2 Inhibitors chemistry, Cyclooxygenase 2 Inhibitors therapeutic use, Cyclooxygenase 2 Inhibitors toxicity, Humans, Lactones chemistry, Nitroreductases metabolism, Prednisolone therapeutic use, Prednisolone toxicity, Prodrugs therapeutic use, Prodrugs toxicity, Pyrazoles therapeutic use, Pyrazoles toxicity, Sulfonamides therapeutic use, Sulfonamides toxicity, Antineoplastic Agents chemistry, Budesonide chemistry, Nitrobenzenes chemistry, Prednisolone chemistry, Prodrugs chemistry, Pyrazoles chemistry, Sulfonamides chemistry
- Abstract
Celecoxib is a COX-2 inhibitor drug that can be used to reduce the risk of colorectal adenocarcinoma. Glucocorticoids are used in the treatment of inflammatory bowel disease. A limitation to the use of both drug types is that they undergo absorption from the intestinal tract with serious side effects. The prodrug systems introduced here involve forming a nitro-substituted acylsulfonamide group in the case of celecoxib and a nitro-substituted 21-ester for the glucocorticoids. Drug release is triggered by the nitro reductase action of the colonic microflora, liberating a cyclization competent species. The release of the active parent drugs was evaluated in vitro using Clostridium perfringens and epithelial transport through Caco-2 monolayer evaluation was carried out to estimate the absorption properties of the prodrugs compared to the parental drugs., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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10. Structure requirements for anaerobe processing of azo compounds: implications for prodrug design.
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Gavin J, Ruiz JF, Kedziora K, Windle H, Kelleher DP, and Gilmer JF
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- Anaerobiosis, Azo Compounds chemistry, Clostridium perfringens metabolism, Humans, Molecular Structure, Prodrugs chemistry, Prodrugs metabolism, Azo Compounds metabolism, Clostridium perfringens chemistry, Drug Design, Prodrugs chemical synthesis
- Abstract
This Letter generalizes the metabolism of the azo class of compounds by Clostridium perfringens, an anaerobe found in the human colon. A recently reported 5-aminosalicylic acid-based prednisolone prodrug was shown to release the drug when incubated with the bacteria, while the para-aminobenzoic acid (PABA) based analogue did not. Instead, it showed a new HPLC peak with a relatively close retention time to the parent which was identified by LCMS as the partially reduced hydrazine product. This Letter investigates azoreduction across a panel of substrates with varying degrees of electronic and steric similarity to the PABA-based compound. Azo compounds with an electron donating group on the azo-containing aromatic ring showed immediate disproportionation to their parent amines without any detection of hydrazine intermediates by HPLC. Compounds containing only electron withdrawing groups are partially and reversibly reduced to produce a stable detectable hydrazine. They do not disproportionate to their parent amines, but regenerate the parent azo compound. This incomplete reduction is relevant to the design of azo-based prodrugs and the toxicology of azo-based dyes., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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11. Azo-reductase activated budesodine prodrugs for colon targeting.
- Author
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Marquez Ruiz JF, Kedziora K, O'Reilly M, Maguire J, Keogh B, Windle H, Kelleher DP, and Gilmer JF
- Subjects
- Budesonide chemistry, Clostridium perfringens, Colitis, Ulcerative drug therapy, Colitis, Ulcerative metabolism, Colon microbiology, Cyclization, Drug Delivery Systems, Humans, Molecular Structure, Nitroreductases, Organ Specificity, Prodrugs chemistry, Budesonide analogs & derivatives, Budesonide metabolism, Colon metabolism, NADH, NADPH Oxidoreductases metabolism, Prodrugs metabolism, Prodrugs pharmacokinetics
- Abstract
Budesodine is a synthetic glurocorticoid that undergoes substantial first pass metabolism, limiting systemic exposure. Its use in treatment of inflammatory bowel disease would benefit from a targeting strategy that could lead to a local topical effect, improving safety and increasing anti-inflammatory efficacy. A two-step prodrug strategy involving azoreduction/cyclization that we developed previously for prednisolone is here applied with some variations to budesonide. The budesodine prodrugs were tested using an in vitro azoreductase assay simulating human colonic microflora. The kinetics of amino steroid ester cyclization and its pH dependence was also evaluated. The stability of the prodrugs systems in simulated human duodenal and gastric fluid was evaluated to determine the likelihood of intact intestinal transit. The propionic acid derived prodrug 3 undergoes rapid activation by Clostridium perfingens and its putative reduction product cyclizes with acceptable rapidity when synthesized independently. These properties of 3 suggest that it has potential in management of ulcerative colitis., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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12. Common variants at the MHC locus and at chromosome 16q24.1 predispose to Barrett's esophagus.
- Author
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Su Z, Gay LJ, Strange A, Palles C, Band G, Whiteman DC, Lescai F, Langford C, Nanji M, Edkins S, van der Winkel A, Levine D, Sasieni P, Bellenguez C, Howarth K, Freeman C, Trudgill N, Tucker AT, Pirinen M, Peppelenbosch MP, van der Laan LJ, Kuipers EJ, Drenth JP, Peters WH, Reynolds JV, Kelleher DP, McManus R, Grabsch H, Prenen H, Bisschops R, Krishnadath K, Siersema PD, van Baal JW, Middleton M, Petty R, Gillies R, Burch N, Bhandari P, Paterson S, Edwards C, Penman I, Vaidya K, Ang Y, Murray I, Patel P, Ye W, Mullins P, Wu AH, Bird NC, Dallal H, Shaheen NJ, Murray LJ, Koss K, Bernstein L, Romero Y, Hardie LJ, Zhang R, Winter H, Corley DA, Panter S, Risch HA, Reid BJ, Sargeant I, Gammon MD, Smart H, Dhar A, McMurtry H, Ali H, Liu G, Casson AG, Chow WH, Rutter M, Tawil A, Morris D, Nwokolo C, Isaacs P, Rodgers C, Ragunath K, MacDonald C, Haigh C, Monk D, Davies G, Wajed S, Johnston D, Gibbons M, Cullen S, Church N, Langley R, Griffin M, Alderson D, Deloukas P, Hunt SE, Gray E, Dronov S, Potter SC, Tashakkori-Ghanbaria A, Anderson M, Brooks C, Blackwell JM, Bramon E, Brown MA, Casas JP, Corvin A, Duncanson A, Markus HS, Mathew CG, Palmer CN, Plomin R, Rautanen A, Sawcer SJ, Trembath RC, Viswanathan AC, Wood N, Trynka G, Wijmenga C, Cazier JB, Atherfold P, Nicholson AM, Gellatly NL, Glancy D, Cooper SC, Cunningham D, Lind T, Hapeshi J, Ferry D, Rathbone B, Brown J, Love S, Attwood S, MacGregor S, Watson P, Sanders S, Ek W, Harrison RF, Moayyedi P, de Caestecker J, Barr H, Stupka E, Vaughan TL, Peltonen L, Spencer CC, Tomlinson I, Donnelly P, and Jankowski JA
- Subjects
- Adult, Aged, Case-Control Studies, Female, Gene Frequency, Genetic Loci, Genome-Wide Association Study, Humans, Linkage Disequilibrium, Male, Middle Aged, Models, Genetic, Barrett Esophagus genetics, Chromosomes, Human, Pair 16, Genetic Predisposition to Disease, Major Histocompatibility Complex, Polymorphism, Single Nucleotide
- Abstract
Barrett's esophagus is an increasingly common disease that is strongly associated with reflux of stomach acid and usually a hiatus hernia, and it strongly predisposes to esophageal adenocarcinoma (EAC), a tumor with a very poor prognosis. We report the first genome-wide association study on Barrett's esophagus, comprising 1,852 UK cases and 5,172 UK controls in the discovery stage and 5,986 cases and 12,825 controls in the replication stage. Variants at two loci were associated with disease risk: chromosome 6p21, rs9257809 (Pcombined=4.09×10(-9); odds ratio (OR)=1.21, 95% confidence interval (CI)=1.13-1.28), within the major histocompatibility complex locus, and chromosome 16q24, rs9936833 (Pcombined=2.74×10(-10); OR=1.14, 95% CI=1.10-1.19), for which the closest protein-coding gene is FOXF1, which is implicated in esophageal development and structure. We found evidence that many common variants of small effect contribute to genetic susceptibility to Barrett's esophagus and that SNP alleles predisposing to obesity also increase risk for Barrett's esophagus.
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- 2012
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13. Alkyl hydroperoxide reductase: a candidate Helicobacter pylori vaccine.
- Author
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O'Riordan AA, Morales VA, Mulligan L, Faheem N, Windle HJ, and Kelleher DP
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- Adjuvants, Immunologic administration & dosage, Alum Compounds administration & dosage, Animals, Antibodies, Bacterial blood, Bacterial Vaccines administration & dosage, Disease Models, Animal, Female, Gene Expression, Glycoproteins immunology, Helicobacter Infections immunology, Humans, Immunoglobulin G blood, Mice, Mice, Inbred C57BL, Pichia genetics, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Vaccines, Subunit administration & dosage, Vaccines, Subunit immunology, Vaccines, Synthetic administration & dosage, Vaccines, Synthetic immunology, Bacterial Vaccines immunology, Helicobacter Infections prevention & control, Helicobacter pylori enzymology, Helicobacter pylori immunology, Peroxiredoxins immunology
- Abstract
Helicobacter pylori (H. pylori) is the most important etiological agent of chronic active gastritis, peptic ulcer disease and gastric cancer. The aim of this study was to evaluate the efficacy of alkyl hydroperoxide reductase (AhpC) and mannosylated AhpC (mAhpC) as candidate vaccines in the C57BL/6J mouse model of H. pylori infection. Recombinant AhpC was cloned, over-expressed and purified in an unmodified form and was also engineered to incorporate N and C-terminal mannose residues when expressed in the yeast Pichia pastoris. Mice were immunized systemically and mucosally with AhpC and systemically with mAhpC prior to challenge with H. pylori. Serum IgG responses to AhpC were determined and quantitative culture was used to determine the efficacy of vaccination strategies. Systemic prophylactic immunization with AhpC/alum and mAhpC/alum conferred protection against infection in 55% and 77.3% of mice, respectively. Mucosal immunization with AhpC/cholera toxin did not protect against infection and elicited low levels of serum IgG in comparison with systemic immunization. These data support the use of AhpC as a potential vaccine candidate against H. pylori infection., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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14. A double prodrug system for colon targeting of benzenesulfonamide COX-2 inhibitors.
- Author
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Ruiz JF, Kedziora K, Keogh B, Maguire J, Reilly M, Windle H, Kelleher DP, and Gilmer JF
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- Animals, Caco-2 Cells, Celecoxib, Clostridium perfringens enzymology, Colon microbiology, Colonic Neoplasms drug therapy, Cyclization, Cyclooxygenase 2 metabolism, Cyclooxygenase 2 Inhibitors chemistry, Cyclooxygenase 2 Inhibitors metabolism, Humans, NADH, NADPH Oxidoreductases metabolism, Nitroreductases, Prodrugs chemistry, Prodrugs metabolism, Pyrazoles chemistry, Pyrazoles metabolism, Rats, Sulfonamides chemistry, Sulfonamides metabolism, Benzenesulfonamides, Colon metabolism, Cyclooxygenase 2 Inhibitors pharmacokinetics, Drug Design, Prodrugs pharmacokinetics, Pyrazoles pharmacokinetics, Sulfonamides pharmacokinetics
- Abstract
The design, synthesis and delivery potential of a new type of benzenesulfonamide cyclo-oxygenase-2 (COX-2) inhibitor prodrug is investigated using celecoxib. The approach involves a double prodrug that is activated first by azoreductases and then by cyclization triggering drug release. We studied the intramolecular aminolysis of the acylsulfonamide. The cyclization was surprisingly rapid at physiological pH and very fast at pH 5. The prodrug is activated specifically under conditions found in the colon but highly stable in the presence of human and rodent intestinal extracts. Finally, the prototype with celecoxib was transported much more slowly in the Caco-2 transepithelial model than the parent. The design therefore shows significant promise for the site specific delivery of benzenesulfonamide COX-2 inhibitors to the colon., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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15. The prevalence of alpha-1 antitrypsin deficiency in Ireland.
- Author
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Carroll TP, O'Connor CA, Floyd O, McPartlin J, Kelleher DP, O'Brien G, Dimitrov BD, Morris VB, Taggart CC, and McElvaney NG
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- Chi-Square Distribution, DNA Mutational Analysis, Gene Frequency, Genetic Predisposition to Disease, Genetic Testing, Health Surveys, Humans, Ireland epidemiology, Mass Screening methods, Mutation, Odds Ratio, Phenotype, Prevalence, Risk Assessment, Risk Factors, alpha 1-Antitrypsin genetics, alpha 1-Antitrypsin Deficiency diagnosis, alpha 1-Antitrypsin Deficiency genetics, alpha 1-Antitrypsin Deficiency epidemiology
- Abstract
Background: Alpha-1 antitrypsin deficiency (AATD) results from mutations in the SERPINA1 gene and classically presents with early-onset emphysema and liver disease. The most common mutation presenting with clinical evidence is the Z mutation, while the S mutation is associated with a milder plasma deficiency. AATD is an under-diagnosed condition and the World Health Organisation recommends targeted detection programmes for AATD in patients with chronic obstructive pulmonary disease (COPD), non-responsive asthma, cryptogenic liver disease and first degree relatives of known AATD patients., Methods: We present data from the first 3,000 individuals screened following ATS/ERS guidelines as part of the Irish National Targeted Detection Programme (INTDP). We also investigated a DNA collection of 1,100 individuals randomly sampled from the general population. Serum and DNA was collected from both groups and mutations in the SERPINA1 gene detected by phenotyping or genotyping., Results: The Irish National Targeted Detection Programme identified 42 ZZ, 44 SZ, 14 SS, 430 MZ, 263 MS, 20 IX and 2 rare mutations. Analysis of 1,100 randomly selected individuals identified 113 MS, 46 MZ, 2 SS and 2 SZ genotypes., Conclusion: Our findings demonstrate that AATD in Ireland is more prevalent than previously estimated with Z and S allele frequencies among the highest in the world. Furthermore, our targeted detection programme enriched the population of those carrying the Z but not the S allele, suggesting the Z allele is more important in the pathogenesis of those conditions targeted by the detection programme.
- Published
- 2011
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16. Post-operative infection and sepsis in humans is associated with deficient gene expression of γc cytokines and their apoptosis mediators.
- Author
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White M, Mahon V, Grealy R, Doherty DG, Stordeur P, Kelleher DP, McManus R, and Ryan T
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- Aged, Aged, 80 and over, Apoptosis Regulatory Proteins genetics, Bacteremia genetics, Bacteremia metabolism, CD3 Complex immunology, Cells, Cultured, Chemokines, C genetics, Cohort Studies, Female, Gene Expression Regulation, Bacterial, Humans, Interferon-gamma biosynthesis, Interferon-gamma deficiency, Interleukin-2 deficiency, Interleukin-2 genetics, Interleukin-7 deficiency, Interleukin-7 genetics, Lipopolysaccharides pharmacology, Male, Postoperative Complications microbiology, Prospective Studies, Sepsis genetics, Apoptosis Regulatory Proteins deficiency, Chemokines, C deficiency, Postoperative Complications genetics, Sepsis metabolism
- Abstract
Introduction: Lymphocyte homeostasis is dependent on the γc cytokines. We hypothesised that sepsis in humans is associated with differential gene expression of the γc cytokines and their associated apoptosis mediators., Methods: The study population consisted of a total of 60 patients with severe sepsis, 15 with gram negative bacteraemia, 10 healthy controls and 60 patients undergoing elective lung resection surgery. Pneumonia was diagnosed by CDC NNIC criteria. Gene expression in peripheral blood leukocytes (PBLs) of interleukin (IL)-2, 7, 15 and interferon (IFN)-γ, Bax, Bim, Bcl-2 was determined by qRT-PCR and IL-2 and IL-7 serum protein levels by ELISA. Gene expression of IL-2, 7 and IFN-γ was measured in peripheral blood leukocytes (PBL), cultured in the presence of lipopolysaccharide (LPS) and CD3 binding antibody (CD3ab), Results: IL-2 gene expression was lower in the bacteraemia group compared with controls, and lower still in the sepsis group (P < 0.0001). IL-7 gene expression was similar in controls and bacteraemia, but lower in sepsis (P < 0.0001). IL-15 gene expression was similar in the three groups. Bcl-2 gene expression was less (P < 0.0001) and Bim gene expression was greater (P = 0.0003) in severe sepsis compared to bacteraemic and healthy controls. Bax gene expression was similar in the three groups.In lung resection surgery patients, post-operative pneumonia was associated with a perioperative decrease in IL-2 mRNA (P < 0.0001) and IL-7 mRNA (P = 0.003). IL-2 protein levels were reduced in sepsis and bacteraemia compared to controls (P = 0.02) but similar in pneumonia and non-pneumonia groups. IL-7 protein levels were similar in all groups.In cultured PBLs, IFN-γ gene expression was decreased in response to LPS and increased in response to CD3ab with sepsis: IL-7 gene expression increased in response to LPS in controls and to CD3ab with sepsis; Bcl-2 gene expression decreased in response to combined CD3ab and IL-2 with sepsis., Conclusions: Patients with infection and sepsis have deficient IL-2 and IL-7 gene expression in PBLs. Aberrant cytokine gene expression may precede the onset of infection.
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- 2011
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17. George Ryerson Fowler: Brooklyn's surgical pioneer: a biographical sketch based on historical documents.
- Author
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Kelleher ME, Swan KG, and Kelleher DP
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- Appendectomy education, Appendicitis surgery, History, 19th Century, Posture, Appendectomy history, Appendicitis history, General Surgery history
- Abstract
The Fowler position, widely used in surgery and obstetrics for patient placement, marks a fraction of 19th-century Brooklyn surgeon George Ryerson Fowler's prodigious accomplishments. Fowler was a pioneer who refined the appendectomy, performed the first lung decortication, advocated for sterile techniques, introduced first aid in the US Army, and helped start a precursor to Annals of Surgery. His publications include the first US textbook on appendicitis--ironically, the disease that killed him.
- Published
- 2011
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18. Investigation into drug release from colon-specific azoreductase-activated steroid prodrugs using in-vitro models.
- Author
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Ruiz JF, Kedziora K, Windle H, Kelleher DP, and Gilmer JF
- Subjects
- Amino Acids chemistry, Animals, Humans, Hydrogen-Ion Concentration, Inflammatory Bowel Diseases drug therapy, Mice, Mice, Inbred BALB C, Nitroreductases, Colon metabolism, Drug Delivery Systems methods, NADH, NADPH Oxidoreductases metabolism, Prednisolone administration & dosage, Prodrugs administration & dosage
- Abstract
Objectives: The aim of this study was to investigate drug release from a double steroid prodrug, OPN501, which incorporates a phenylpropionate linker, and its phenylacetate analogue. The prodrugs, which were designed to deliver prednisolone to the colon for the treatment of inflammatory bowel disease, are based on a novel design that requires sequential azoreductase activity and cyclization of an amino ester to trigger drug release. We sought to explain the divergent effects of the two compounds in anti-inflammatory models and to justify the selection of OPN-501 for clinical development., Methods: The compounds were incubated in mouse colonic contents (10%) fermented in brain heart infusion under anaerobic conditions. The disappearance of the prodrugs and release of prednisolone was monitored by HPLC. We then developed a method for assessment of prodrug activation using suspensions of Clostridium perfringens, an anaerobe from the human colon. The cyclization of the compounds was studied in various media, assessing the influence of pH and bulk solvent polarity on cyclization rate using HPLC and NMR., Key Findings: The prodrugs were activated via multiple pathways releasing prednisolone in mouse colonic ferment. The compounds released prednisolone by reduction-cyclization in C perfringens suspension. The active OPN-501 generated a stoichiometric amount of prednisolone following azoreductase activation, whereas its analogue did not. The pH rate profile for the cyclization of the amino intermediates of the two compounds revealed significant differences in rate at pH values relevant to the inflamed colon, which explain in part the different amounts of drug produced., Conclusions: The steroid prodrug OPN-501 has optimal drug release characteristics for colon targeting because of a kinetic advantage of a six-membered ring formation in the aminolysis reactions of anilides. The results are relevant to the development of OPN-501 but also to cyclization strategies in prodrug design especially for colon targeting., (© 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.)
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- 2011
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19. Nanodrug applications in photodynamic therapy.
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Paszko E, Ehrhardt C, Senge MO, Kelleher DP, and Reynolds JV
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- Animals, Humans, Drug Compounding trends, Nanocapsules chemistry, Nanocapsules therapeutic use, Nanomedicine trends, Photochemotherapy trends
- Abstract
Photodynamic therapy (PDT) has developed over last century and is now becoming a more widely used medical tool having gained regulatory approval for the treatment of various diseases such as cancer and macular degeneration. It is a two-step technique in which the delivery of a photosensitizing drug is followed by the irradiation of light. Activated photosensitizers transfer energy to molecular oxygen which results in the generation of reactive oxygen species which in turn cause cells apoptosis or necrosis. Although this modality has significantly improved the quality of life and survival time for many cancer patients it still offers significant potential for further improvement. In addition to the development of new PDT drugs, the use of nanosized carriers for photosensitizers is a promising approach which might improve the efficiency of photodynamic activity and which can overcome many side effects associated with classic photodynamic therapy. This review aims at highlighting the different types of nanomedical approaches currently used in PDT and outlines future trends and limitations of nanodelivery of photosensitizers., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
20. Tribbles 3: a novel regulator of TLR2-mediated signaling in response to Helicobacter pylori lipopolysaccharide.
- Author
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Smith SM, Moran AP, Duggan SP, Ahmed SE, Mohamed AS, Windle HJ, O'Neill LA, and Kelleher DP
- Subjects
- Cell Cycle Proteins antagonists & inhibitors, Cell Cycle Proteins biosynthesis, Cell Line, Cell Line, Tumor, Chemokines biosynthesis, Colorectal Neoplasms immunology, Colorectal Neoplasms metabolism, Down-Regulation genetics, Down-Regulation immunology, Epithelial Cells immunology, Epithelial Cells metabolism, Epithelial Cells microbiology, HEK293 Cells, Humans, Immunity, Innate genetics, Interleukin-8 biosynthesis, Interleukin-8 genetics, Lipopolysaccharides isolation & purification, NF-kappa B metabolism, Promoter Regions, Genetic immunology, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein Serine-Threonine Kinases biosynthesis, Repressor Proteins antagonists & inhibitors, Repressor Proteins biosynthesis, Signal Transduction genetics, Toll-Like Receptor 2 physiology, Up-Regulation genetics, Up-Regulation immunology, Cell Cycle Proteins physiology, Helicobacter pylori immunology, Lipopolysaccharides physiology, Protein Serine-Threonine Kinases physiology, Repressor Proteins physiology, Signal Transduction immunology, Toll-Like Receptor 2 metabolism
- Abstract
Helicobacter pylori causes chronic gastritis, peptic ulcers, and gastric carcinoma. Gastric epithelial cells provide the first point of contact between H. pylori and the host. TLRs present on these cells recognize various microbial products, resulting in the initiation of innate immunity. Although previous reports investigated TLR signaling in response to intact H. pylori, the specific contribution of H. pylori LPS with regard to functional genomics and cell-signaling events has not been defined. This study set out to define downstream signaling components and altered gene expression triggered by H. pylori LPS and to investigate the role of the signaling protein tribbles 3 (TRIB3) during the TLR-mediated response to H. pylori LPS. Cotransfections using small interfering RNA and dominant-negative constructs demonstrated that H. pylori LPS functions as a classic TLR2 ligand by signaling through pathways involving the key TLR signaling components MyD88 adaptor-like, MyD88, IRAK1, IRAK4, TNFR-associated factor 6, IκB kinase β, and IκBα. Microarray analysis, real-time PCR, and ELISA revealed the induction of a discrete pattern of chemokines as a direct effect of LPS:TLR2 signaling. H. pylori infection was associated with decreased expression of TRIB3 in human gastric epithelial cell lines and tissue samples. Additionally, H. pylori decreased expression of C/EBP homologous protein and activating transcription factor 4, the transcription factors involved in the induction of TRIB3 expression. Furthermore, knockdown of TRIB3 and C/EBP homologous protein enhanced TLR2-mediated NF-κB activation and chemokine induction in response to H. pylori LPS. Thus, modulation of TRIB3 by H. pylori and/or its products may be an important mechanism during H. pylori-associated pathogenesis.
- Published
- 2011
- Full Text
- View/download PDF
21. Proteomics of bacterial pathogenicity: therapeutic implications.
- Author
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Windle HJ, Brown PA, and Kelleher DP
- Subjects
- Animals, Bacterial Proteins metabolism, Biofilms, Host-Pathogen Interactions, Humans, Bacteria metabolism, Bacteria pathogenicity, Bacterial Infections therapy, Proteomics methods
- Abstract
Identification of the molecular mechanisms of host-pathogen interaction is becoming a key focus of proteomics. Analysis of these interactions holds promise for significant developments in the identification of new therapeutic strategies to combat infectious diseases, a process that will also benefit parallel improvements in molecular diagnostics, biomarker identification and drug discovery. This review highlights recent advances in functional proteomics initiatives in infectious disease with emphasis on studies undertaken within physiologically relevant parameters that enable identification of the infectious proteome rather than that of the vegetative state. Deciphering the molecular details of what constitutes physiologically relevant host-pathogen interactions remains an underdeveloped aspect of research into infectious disease. The magnitude of this deficit will be largely influenced by the ease with which model systems can be established to investigate such interactions. As the selective pressures exerted by the host on an infecting pathogen are numerous, the adequacy of certain model systems should be considered carefully., (Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2010
- Full Text
- View/download PDF
22. Proteomic and functional characterization of the outer membrane vesicles from the gastric pathogen Helicobacter pylori.
- Author
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Mullaney E, Brown PA, Smith SM, Botting CH, Yamaoka YY, Terres AM, Kelleher DP, and Windle HJ
- Abstract
The gastric pathogen Helicobacter pylori causes a spectrum of gastro-duodenal diseases, which may be mediated in part by the outer membrane vesicles (OMVs) constitutively shed by the pathogen. We aimed to determine the proteome of H. pylori OMV to help evaluate the mechanisms whereby these structures confer their known immuno-modulatory and cytotoxic activities to host cells, as such disease-associated activities are also conferred by the bacterium from which the vesicles are derived. We also evaluated the effect of the OMV on gastric/colonic epithelial cells, duodenal explants and neutrophils. A proteomic analysis of the OMV proteins separated by SDS-PAGE from two strains of H. pylori (J99 and NCTC 11637) was undertaken and 162 OMV-associated proteins were identified in J99 and 91 in NCTC 11637 by LC-MS/MS. The vesicles are rich in membrane proteins, porins, adhesins and several molecules known to modulate chemokine secretion, cell proliferation and other host cellular processes. Further, the OMVs are also vehicles for the carriage of the cytotoxin-associated gene A cytotoxin in addition to the previously documented toxin, vacuolating cytotoxin. Taken together, it is evident from the proteome of H. pylori OMV that these structures are equipped with the molecules required to interact with host cells in a manner not dissimilar from the intact pathogen., (Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2009
- Full Text
- View/download PDF
23. Interleukin 17: an unlikely marker of acute coronary syndrome?
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Patel KD, Murphy RT, White M, Gasparro D, Kelleher DP, Ryan T, McManus R, and Ryan AW
- Subjects
- Acute Coronary Syndrome metabolism, Aged, Angina, Unstable blood, Biomarkers blood, Female, Humans, Inflammation, Male, Middle Aged, Myocardial Infarction blood, Acute Coronary Syndrome blood, Interleukin-17 blood, Interleukin-17 physiology
- Published
- 2009
- Full Text
- View/download PDF
24. Design, synthesis, and pharmacological effects of a cyclization-activated steroid prodrug for colon targeting in inflammatory bowel disease.
- Author
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Ruiz JF, Radics G, Windle H, Serra HO, Simplício AL, Kedziora K, Fallon PG, Kelleher DP, and Gilmer JF
- Subjects
- Animals, Bacteria metabolism, Colon microbiology, Cyclization, Drug Delivery Systems, Esters, Intestinal Absorption drug effects, Mice, Prodrugs chemistry, Prodrugs metabolism, Adrenal Cortex Hormones administration & dosage, Colon metabolism, Drug Carriers chemical synthesis, Inflammatory Bowel Diseases drug therapy, Prodrugs chemical synthesis
- Abstract
Glucocorticoids are used in the treatment of inflammatory bowel disease. A limitation to their use is that they undergo absorption from the GIT before reaching the colon causing severe systemic side effects. We report here on a novel prodrug approach to targeting corticosteroids to the colon. The design involves attaching a 21-ester group that suppresses absorption during transit to the colon. The prodrug is designed to be primed by colonic microflora liberating an amino ester that cyclizes releasing the steroid. One of the prodrugs 5b was as efficacious as prednisolone in the murine DSS model but did not cause thymic atrophy, a marker for systemic steroid effects.
- Published
- 2009
- Full Text
- View/download PDF
25. Natural selection and the molecular basis of electrophoretic variation at the coagulation F13B locus.
- Author
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Ryan AW, Hughes DA, Tang K, Kelleher DP, Ryan T, McManus R, and Stoneking M
- Subjects
- Electrophoresis, Genetic Drift, Genetics, Population, Factor XIII chemistry, Factor XIII genetics, Polymorphism, Genetic, Selection, Genetic
- Abstract
Electrophoretic analysis of protein variation at the coagulation F13B locus has previously revealed three alleles, with alleles 1, 2, and 3 each being at high frequency in European, African, and Asian populations, respectively. To determine if this unusual pattern of interpopulation differentiation reflects local natural selection or neutral genetic drift, we re-sequenced 4.6 kb of the gene, encompassing all exons, splice junctions, and 1.4 kb of the promoter, in African, European, and Asian samples. These analyses revealed three major lineages, which correspond to the common protein alleles and differ from each other at a non-synonymous substitution in exon 3 and a novel splice acceptor in intron K. There is previous evidence that these lineages are not functionally equivalent; we therefore carried out case-control analyses and confirmed that variability at F13B modulates susceptibility and/or survivorship in coronary artery disease (P<0.05) and type II diabetes within the coronary artery disease cohort (P<0.01). Tajima's D and Fu and Li's tests did not indicate significant departures from neutral expectations. However, publicly available data from SeattleSNPs and HapMap do indicate highly unusual levels of population differentiation (P=0.003) and an excess of allele-specific, extended haplotype homozygosity within the African population (P=0.0125). Possible causes of this putative signal of selection include hematophagous organisms, infection by pathogens that cause disseminated intravascular coagulation, and metabolic or dietary factors.
- Published
- 2009
- Full Text
- View/download PDF
26. The human response to infection is associated with distinct patterns of interleukin 23 and interleukin 27 expression.
- Author
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O'Dwyer MJ, Mankan AK, White M, Lawless MW, Stordeur P, O'Connell B, Kelleher DP, McManus R, and Ryan T
- Subjects
- Adult, Aged, Aged, 80 and over, Bacteremia immunology, Case-Control Studies, Disease Progression, Female, Gene Expression Regulation, Humans, Interferon-gamma genetics, Interferon-gamma immunology, Interleukin-17 genetics, Interleukin-18 genetics, Interleukin-23 genetics, Male, Middle Aged, Prospective Studies, RNA, Messenger blood, Reverse Transcriptase Polymerase Chain Reaction, Survival Analysis, Interferon-gamma deficiency, Interleukin-17 blood, Interleukin-18 blood, Interleukin-23 blood, Systemic Inflammatory Response Syndrome immunology
- Abstract
Objective: The development and progression of severe sepsis is related to a deficiency in pro-inflammatory cytokine production, characterised by lesser IFNgamma levels, which are not explained by variations in levels of the main putative regulator of IFNgamma, namely IL-12. As alternative regulators of IFNgamma may be of greater importance in human sepsis, we investigated the hypothesis that the development of severe sepsis is related to variations in IL-18, IL-23 and IL-27 gene expression., Design and Setting: A prospective observational trial in a mixed intensive care unit (ICU) and hospital wards in a university teaching hospital., Patients and Participants: Sixty-two ICU patients with severe sepsis, 13 bacteraemic patients with no acute critical illness, and 10 healthy controls., Measurements and Results: All subjects were assayed for IL-18, IL-23 and IL-27 mRNA levels in peripheral blood. IL-27 mRNA levels distinguished between the three groups, with levels highest in the ICU group, intermediate in the bacteraemic group and lowest in the control group. IL-23 distinguished between the groups, with levels lowest in the ICU group. In late sepsis IL-23 and TNFalpha mRNA levels were directly related. IL-18 mRNA levels did not distinguish between the patient groups., Conclusions: We conclude that the deficient pro-inflammatory response in patients with sepsis is expansive and includes deficient IL-23 and excessive IL-27 gene expression. This provides further evidence that upregulation of a cytokine-based immune response is beneficial in sepsis.
- Published
- 2008
- Full Text
- View/download PDF
27. Active immunization of hamsters against Clostridium difficile infection using surface-layer protein.
- Author
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Ní Eidhin DB, O'Brien JB, McCabe MS, Athié-Morales V, and Kelleher DP
- Subjects
- Adjuvants, Immunologic administration & dosage, Animals, Antibodies, Bacterial blood, Cell Wall Skeleton administration & dosage, Cholera Toxin administration & dosage, Cholera Toxin immunology, Cord Factors administration & dosage, Cricetinae, Enterocolitis, Pseudomembranous immunology, Female, Immunoglobulin A blood, Immunoglobulin G blood, Lipid A administration & dosage, Lipid A analogs & derivatives, Mesocricetus, Mice, Mice, Inbred BALB C, Survival Analysis, Bacterial Vaccines immunology, Clostridioides difficile immunology, Enterocolitis, Pseudomembranous prevention & control, Membrane Glycoproteins immunology
- Abstract
Clostridium difficile is the leading cause of infectious antibiotic-associated diarrhoea, particularly among the elderly. Its surface-layer protein (SLP) was tested as a vaccine component in a series of immunization and challenge experiments with Golden Syrian hamsters, combined with different systemic and mucosal adjuvants. Some regimens were also tested in a nonchallenge BALB/c mouse model, enabling closer monitoring of the immune response. None of the regimens conferred complete protection in the hamster model, and antibody stimulation was variable within regimens, and generally modest or poor. Mice displayed stronger antibody responses to SLP compared with hamsters. Two hamsters of five given SLP with Ribi (monophosphoryl lipid A and synthetic trehalose dicorynomycolate) survived the challenge, as did two of three given SLP with Ribi and cholera toxin. This modest trend to protection is interpreted with caution, because the survivors had low anti-SLP serum antibody titres. The hamsters were an outbred line, and subject to more genetic variability than inbred animals; however, BALB/c mice also showed strongly variable antibody responses. There is a clear need for better adjuvants for single-component vaccines, particularly for mucosal delivery. The hamster challenge model may need to be modified to be useful in active immunization experiments with SLP.
- Published
- 2008
- Full Text
- View/download PDF
28. The occurrence of severe sepsis and septic shock are related to distinct patterns of cytokine gene expression.
- Author
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O'Dwyer MJ, Mankan AK, Stordeur P, O'Connell B, Duggan E, White M, Kelleher DP, McManus R, and Ryan T
- Subjects
- Adult, Aged, Aged, 80 and over, Cohort Studies, Female, Humans, Interferon-gamma biosynthesis, Interleukin-10 biosynthesis, Male, Middle Aged, Reverse Transcriptase Polymerase Chain Reaction, Tumor Necrosis Factor-alpha biosynthesis, Gene Expression Regulation, Sepsis diagnosis, Sepsis metabolism, Shock diagnosis, Shock metabolism
- Abstract
Patient response to acute bacterial infection is highly variable. Differing outcomes in this setting may be related to variations in the immune response to an infectious insult. Using quantitative real-time polymerase chain reaction, we quantified gene expression of the tumor necrosis factor alpha(TNFalpha), interferon gamma (IFNgamma), and interleukin 10 (IL10), IL12p35, and IL4 genes in 3 patient groups. These groups consisted of an intensive care unit (ICU) cohort who presented with severe sepsis or septic shock, a group of noncritically ill ward patients with documented Gram-negative bacteremia, and a group of healthy controls. Greater interleukin 10 messenger RNA (mRNA) levels were detected in the ICU group in comparison with both the bacteremic and control groups (P < 0.0001). More TNF-alpha mRNA was detected in the ICU group when compared with the control group (P < 0.0001). However, TNF-alpha mRNA was most abundant in the bacteremic group (P = 0.0007). Lesser IFN-gamma mRNA levels were detected in the ICU group when compared with both the bacteremic and control groups (P < 0.0003). Cytokine mRNA levels were not associated with the occurrence of shock upon admission to ICU. On the seventh day of ICU stay, the presence of shock was associated with lesser IFN-gamma mRNA (P = 0.0004) and lesser TNF-alpha mRNA (P = 0.001). Survivors had greater TNF-alpha mRNA copy numbers on day 7 of ICU stay than nonsurvivors (P = 0.002). We conclude that a proinflammatory response is the appropriate response in the setting of infection and is associated with lesser requirements for inotropes and lesser mortality. Quantitative real-time polymerase chain reaction can be used to predict infection outcome in clinically relevant situations where enzyme-linked immunosorbent assay testing has proved disappointing.
- Published
- 2006
- Full Text
- View/download PDF
29. Septic shock is correlated with asymmetrical dimethyl arginine levels, which may be influenced by a polymorphism in the dimethylarginine dimethylaminohydrolase II gene: a prospective observational study.
- Author
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O'Dwyer MJ, Dempsey F, Crowley V, Kelleher DP, McManus R, and Ryan T
- Subjects
- Alleles, Arginine blood, Arginine genetics, Female, Genetic Variation, Humans, Male, Prospective Studies, Shock, Septic blood, Amidohydrolases blood, Amidohydrolases genetics, Arginine analogs & derivatives, Polymorphism, Genetic genetics, Shock, Septic genetics
- Abstract
Introduction: Asymmetrical dimethyl arginine (ADMA) is an endogenous non-selective inhibitor of nitric oxide synthase that may influence the severity of organ failure and the occurrence of shock secondary to an infectious insult. Levels may be genetically determined by a promoter polymorphism in a regulatory gene encoding dimethylarginine dimethylaminohydrolase II (DDAH II), which functions by metabolising ADMA to citrulline. The aim of this study was to examine the association between ADMA levels and the severity of organ failure and shock in severe sepsis and also to assess the influence of a promoter polymorphism in DDAH II on ADMA levels., Methods: A prospective observational study was designed, and 47 intensive care unit (ICU) patients with severe sepsis and 10 healthy controls were enrolled. Serum ADMA and IL-6 were assayed on admission to the ICU and seven days later. Allelic variation for a polymorphism at position -449 in the DDAH II gene was assessed in each patient. Clinical and demographic details were also collected., Results: On day 1 more ADMA was detectable in the ICU group than in the control group (p = 0.005). Levels subsequently increased during the first week in ICU (p = 0.001). ADMA levels were associated with vasopressor requirements on day one (p = 0.001). ADMA levels and Sequential Organ Failure Assessment scores were directly associated on day one (p = 0.0001) and day seven (p = 0.002). The degree of acidaemia and lactaemia was directly correlated with ADMA levels at both time points (p < 0.01). On day seven, IL-6 was directly correlated with ADMA levels (p = 0.006). The variant allele with G at position -449 in the DDAH II gene was associated with increased ADMA concentrations at both time points (p < 0.05)., Conclusion: Severity of organ failure, inflammation and presence of early shock in severe sepsis are associated with increased ADMA levels. ADMA concentrations may be influenced by a polymorphism in the DDAH II gene.
- Published
- 2006
- Full Text
- View/download PDF
30. Passive immunisation of hamsters against Clostridium difficile infection using antibodies to surface layer proteins.
- Author
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O'Brien JB, McCabe MS, Athié-Morales V, McDonald GS, Ní Eidhin DB, and Kelleher DP
- Subjects
- Animals, Antibodies, Bacterial immunology, Cell Line, Cricetinae, Disease Models, Animal, Female, Humans, Mesocricetus, Monocytes, Phagocytosis, Antibodies, Bacterial therapeutic use, Bacterial Proteins immunology, Clostridioides difficile immunology, Enterocolitis, Pseudomembranous prevention & control, Immunization, Passive, Membrane Glycoproteins immunology
- Abstract
Clostridium difficile is a major cause of antibiotic-associated diarrhoea and the primary cause of pseudomembraneous colitis in hospitalised patients. We assessed the protective effect of anti-surface layer protein (SLP) antibodies on C. difficile infection in a lethal hamster challenge model. Post-challenge survival was significantly prolonged in the anti-SLP treated group compared with control groups (P=0.0281 and P=0.0283). The potential mechanism of action of the antiserum was shown to be through enhancement of C. difficile phagocytosis. This report indicates that anti-SLP antibodies can modulate the course of C. difficile infection and may therefore merit closer investigation for use as constituents of multi-component vaccines against C. difficile associated diarrhoea.
- Published
- 2005
- Full Text
- View/download PDF
31. Detection of a tyrosine phosphatase LAR on intestinal epithelial cells and intraepithelial lymphocytes in the human duodenum.
- Author
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Murphy AM, Sheils OM, McDonald GS, and Kelleher DP
- Subjects
- CD3 Complex metabolism, Cells, Cultured, Endothelium, Vascular enzymology, Epithelial Cells cytology, Epithelial Cells enzymology, Flow Cytometry methods, Humans, Nerve Tissue Proteins analysis, Protein Tyrosine Phosphatases analysis, Receptor-Like Protein Tyrosine Phosphatases, Class 2, Receptors, Cell Surface analysis, Duodenum cytology, Duodenum enzymology, Lymphocytes enzymology, Nerve Tissue Proteins metabolism, Protein Tyrosine Phosphatases metabolism, Receptors, Cell Surface metabolism
- Abstract
Studies of tyrosine phosphorylation in the human duodenum have indicated that proliferating cells in the middle portion of the duodenal crypt were devoid of this feature, suggesting that tyrosine kinase activation is not a dominant factor in crypt cell proliferation, and that consequently tyrosine phosphatase activity may be a more critical factor in crypt cell development. We investigated the expression of the leukocyte common antigen-related receptor (LAR) family of tyrosine phosphatases. A flow cytometry system was used to examine cells from the surface, mid-portion, and lower part of the crypt. Individual cell populations were immunostained with anti-LAR antibodies using phycoerythrin-conjugated anti-CD3 to discriminate between epithelial cells (CD3-) and intraepithelial lymphocytes (CD3+). Epithelial cells expressed LAR throughout the crypt. Expression of LAR was maximal in the mid-portion of the crypt with lower expression at the top of the villi. Intraepithelial lymphocytes expressed low levels of LAR at the tips of the villi with stronger expression extending towards the base of the crypt. These findings were confirmed by immunohistochemistry on paraffin-fixed sections. Of note, peripheral blood lymphocytes expressed less LAR than IEL. These observations suggest the possibility that tyrosine phosphatase LAR may be of importance in the regulation of crypt cell proliferation. Moreover, as the extracellular domain of LAR has homology with adhesion molecules, the finding of this molecule on IEL could suggest a possible functional role in homing of this unique lymphocyte.
- Published
- 2005
- Full Text
- View/download PDF
32. Soluble extracts from Helicobacter pylori induce dome formation in polarized intestinal epithelial monolayers in a laminin-dependent manner.
- Author
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Terrés AM, Windle HJ, Ardini E, and Kelleher DP
- Subjects
- Animals, Apoptosis, Benzoquinones, Cell Line, Cell Polarity, Chlorides metabolism, Cycloheximide pharmacology, Cytoskeleton physiology, Humans, Integrin alpha6 physiology, Integrin beta4 physiology, Intestinal Mucosa cytology, Lactams, Macrocyclic, Microscopy, Electron, Quinones pharmacology, Rifabutin analogs & derivatives, Staurosporine pharmacology, Helicobacter pylori pathogenicity, Intestinal Mucosa microbiology, Intestinal Mucosa ultrastructure, Laminin physiology
- Abstract
Helicobacter pylori colonizes the stomach at the interface between the mucus layer and the apical pole of gastric epithelial cells. A number of secreted and shed products from the bacteria, such as proteins and lipopolysaccharide, are likely to have a role in the pathogenesis at the epithelial level. To determine the physiological response of transporting polarized epithelia to released soluble factors from the bacterium, we used the T84 cell line. Monolayers of T84 cells were exposed to soluble extracts from H. pylori. The extracts induced rapid "dome" formation as well as an immediate decrease in transepithelial electrical resistance. Domes are fluid-filled blister-like structures unique to polarized epithelia. Their formation has been linked to sodium-transporting events as well as to diminished adherence of the cells to the substrate. H. pylori-induced dome formation in T84 monolayers was exacerbated by amiloride and inhibited by ouabain. Furthermore, it was associated with changes in the expression of the laminin binding alpha 6 beta 4 integrin and the 67-kDa laminin receptor. Domes formed primarily on laminin-coated filters, rather than on fibronectin or collagen matrices, and their formation was inhibited by preincubating the bacterial extract with soluble laminin. This effect was specific to H. pylori and independent of the urease, vacA, cagA, and Lewis phenotype of the strains. These data indicate that released elements from H. pylori can alter the physiological balance and integrity of the epithelium in the absence of an underlying immune response.
- Published
- 2003
- Full Text
- View/download PDF
33. Transvenous liver biopsy via the femoral vein.
- Author
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Khosa F, McNulty JG, Hickey N, O'Brien P, Tobin A, Noonan N, Ryan B, Keeling PW, Kelleher DP, and McDonald GS
- Subjects
- Adult, Aged, Biopsy adverse effects, Blood Loss, Surgical, Blood Pressure, Catheterization, Peripheral, Female, Hepatic Veins diagnostic imaging, Humans, Liver injuries, Male, Middle Aged, Pain etiology, Phlebography, Surgical Instruments, Biopsy methods, Femoral Vein, Liver pathology
- Abstract
Aim: To study the safety, effectiveness and diagnostic value of transvenous forceps biopsy of the liver in 54 patients with coagulopathy, gross ascites or morbid obesity and suspected liver disease in whom percutaneous liver biopsy was contraindicated., Material and Methods: Forceps biopsy of the liver via the femoral vein was attempted in 54 adult patients with advanced liver disease of unknown aetiology who had coagulation disorders (41 cases), gross ascites (11 cases) or morbid obesity (two cases). In each patient two to six biopsies (average four) were taken using a radial jaw forceps inserted via the right or left femoral vein., Results: The procedure was successful in 53 cases. Hepatic vein catheterization failed in one patient. Adequate liver tissue for diagnosis was obtained in 84% of cases. One patient developed delayed haemorrhage at 12 h from a capsular leak that was undetected during the biopsy procedure. This patient required blood transfusions and laparotomy to control bleeding. There were no deaths in the 53 patients studied. Transient minor chest and shoulder pain was encountered during sheath insertion into a hepatic vein in 23 patients. Three patients developed a femoral vein haematoma, which resolved with conservative treatment., Conclusion: Transvenous liver biopsy via the femoral vein is another safe, effective, simple alternative technique of biopsy when the percutaneous route is contraindicated.
- Published
- 2003
- Full Text
- View/download PDF
34. Carcinoma of the ampulla of Vater: a tumour with a poor prognosis?
- Author
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Farrell RJ, Noonan N, Khan IM, Goggins M, Kelleher DP, and Keeling PW
- Subjects
- Aged, Cholangiopancreatography, Endoscopic Retrograde, Common Bile Duct Neoplasms pathology, Common Bile Duct Neoplasms surgery, Female, Humans, Male, Middle Aged, Prognosis, Reoperation, Sex Factors, Stents, Survival Rate, Ampulla of Vater, Common Bile Duct Neoplasms mortality
- Abstract
Objective: To assess the overall prognosis of patients with ampullary carcinomas and evaluate the presentation, diagnosis, pathology and management of these potentially highly curable tumours, attempting to relate these factors to overall survival., Patients and Methods: Forty patients with ampullary carcinoma were reviewed. Age, Sex, nature and duration of history, laboratory information at admission, results of diagnostic radiology, endoscopic retrograde cholangiopancreatograms and pathological findings were considered. Both curative and palliative management strategies were reviewed., Results: The overall median survival was 19 months. The median duration of history was 5.9 +/- 5.4. weeks, with no significant difference in survival between patients with short and those with long histories (P = 0.46). Twenty nine (73%) patients were potentially resectable, but only 15 (37%) underwent potentially curative surgery. The difference in survival between the Whipple's (13) and the endoscopically stented (20 ) groups was not significant (p = 0.08). The Whipple's group were significantly younger than the stented group (P = 0.001) and had a significant operative morbidity, re-operation rate (38%) and post-operative mortality (15%). Only five of 13 patients were alive following Whipple's treatment after a mean follow-up of 18.9 months. Sphincterotomy before Whipple's treatment improved survival significantly (P = 0.04); absence of jaundice, exophytic macroscopic appearance, well-differentiated tumours and early stage were also associated with good survival. Endoscopic retrograde cholangiopancreatography has a high diagnostic yield and a low associated morbidity and mortality, with endoscopic papillectomy aiding cannulation while effective palliation was provided through stenting, endoscopic papillectomy and laser debulking of obstructing tumours. Little benefit was obtained from chemoradiotherapy., Conclusion: Despite the potential for curative resection in patients with ampullary carcinoma, the majority of such patients are unsuitable for curative surgery on grounds of age, general health status or advanced disease; since only 37% of patients undergo potentially curative surgery the condition has a poor prognosis.
- Published
- 1996
- Full Text
- View/download PDF
35. A metastatic neuroendocrine anaplastic small cell tumor in a patient with multiple endocrine neoplasia type 1 syndrome. Assessment of disease status and response to doxorubicin, cyclophosphamide, etoposide chemotherapy through scintigraphic imaging with 111In-pentetreotide.
- Author
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O'Byrne KJ, Goggins MG, McDonald GS, Daly PA, Kelleher DP, and Weir DG
- Subjects
- Antineoplastic Combined Chemotherapy Protocols therapeutic use, Carcinoma, Small Cell secondary, Cyclophosphamide administration & dosage, Disease Progression, Doxorubicin administration & dosage, Etoposide administration & dosage, Fatal Outcome, Female, Humans, Indium Radioisotopes, Middle Aged, Multiple Endocrine Neoplasia Type 1 secondary, Radionuclide Imaging, Salvage Therapy, Somatostatin analogs & derivatives, Carcinoma, Small Cell diagnostic imaging, Carcinoma, Small Cell drug therapy, Multiple Endocrine Neoplasia Type 1 diagnostic imaging, Multiple Endocrine Neoplasia Type 1 drug therapy
- Abstract
Extrapulmonary small cell and small cell neuroendocrine tumors of unknown primary site are, in general, aggressive neoplasms with a short median survival. Like small cell lung cancer (SCLC), they often are responsive to chemotherapy and radiotherapy. Small cell lung cancer and well differentiated neuroendocrine carcinomas of the gastrointestinal tract and pancreas tend to express somatostatin receptors. These tumors may be localized in patients by scintigraphic imaging using radiolabeled somatostatin analogues. A patient with anaplastic neuroendocrine small cell tumor arising on a background of multiple endocrine neoplasia type 1 syndrome is reported. The patient had a known large pancreatic gastrinoma and previously treated parathyroid adenopathy. At presentation, there was small cell cancer throughout the liver and skeleton. Imaging with a radiolabeled somatostatin analogue, 111In-pentetreotide (Mallinckrodt Medical B. V., Petten, Holland), revealed all sites of disease detected by routine biochemical and radiologic methods. After six cycles of chemotherapy with doxorubicin, cyclophosphamide, and etoposide, there was almost complete clearance of the metastatic disease. 111In-pentetreotide scintigraphy revealed uptake consistent with small areas of residual disease in the liver, the abdomen (in mesenteric lymph nodes), and posterior thorax (in a rib). The primary gastrinoma present before the onset of the anaplastic small cell cancer showed no evidence of response to the treatment. The patient remained well for 1 year and then relapsed with brain, lung, liver, and skeletal metastases. Despite an initial response to salvage radiotherapy and chemotherapy with carboplatin and dacarbazine, the patient died 6 months later.
- Published
- 1994
- Full Text
- View/download PDF
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