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Kleinstreuer NC, Karmaus A, Mansouri K, Allen DG, Fitzpatrick JM, Patlewicz G. Predictive Models for Acute Oral Systemic Toxicity: A Workshop to Bridge the Gap from Research to Regulation. ACTA ACUST UNITED AC 2018; 8:21-24. [PMID: 30320239 DOI: 10.1016/j.comtox.2018.08.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In early 2018, the Interagency Coordinating Committee for the Validation of Alternative Methods (ICCVAM) published the "Strategic Roadmap for Establishing New Approaches to Evaluate the Safety of Chemicals and Medical Products in the United States" (ICCVAM 2018). Cross-agency federal workgroups have been established to implement this roadmap for various toxicological testing endpoints, with an initial focus on acute toxicity testing. The ICCVAM acute toxicity workgroup (ATWG) helped organize a global collaboration to build predictive in silico models for acute oral systemic toxicity, based on a large dataset of rodent studies and targeted towards regulatory needs identified across federal agencies. Thirty-two international groups across government, industry, and academia participated in the project, culminating in a workshop in April 2018 held at the National Institutes of Health (NIH). At the workshop, computational modelers and regulatory decision makers met to discuss the feasibility of using predictive model outputs for regulatory use in lieu of acute oral systemic toxicity testing. The models were combined to yield consensus predictions which demonstrated excellent performance when compared to the animal data, and workshop outcomes and follow-up activities to make these tools available and put them into practice are discussed here.
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Affiliation(s)
- Nicole C Kleinstreuer
- National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Agnes Karmaus
- Integrated Laboratory Systems, Inc., Research Triangle Park, North Carolina 27560, United States
| | - Kamel Mansouri
- Integrated Laboratory Systems, Inc., Research Triangle Park, North Carolina 27560, United States
| | - David G Allen
- Integrated Laboratory Systems, Inc., Research Triangle Park, North Carolina 27560, United States
| | - Jeremy M Fitzpatrick
- National Center for Computational Toxicology (NCCT), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park (RTP), NC 27711, USA
| | - Grace Patlewicz
- National Center for Computational Toxicology (NCCT), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park (RTP), NC 27711, USA
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Fitzpatrick JM, Roberts DW, Patlewicz G. An evaluation of selected (Q)SARs/expert systems for predicting skin sensitisation potential. SAR QSAR Environ Res 2018; 29:439-468. [PMID: 29676182 PMCID: PMC6077848 DOI: 10.1080/1062936x.2018.1455223] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 03/17/2018] [Indexed: 06/08/2023]
Abstract
Predictive testing to characterise substances for their skin sensitisation potential has historically been based on animal models such as the Local Lymph Node Assay (LLNA) and the Guinea Pig Maximisation Test (GPMT). In recent years, EU regulations, have provided a strong incentive to develop non-animal alternatives, such as expert systems software. Here we selected three different types of expert systems: VEGA (statistical), Derek Nexus (knowledge-based) and TIMES-SS (hybrid), and evaluated their performance using two large sets of animal data: one set of 1249 substances from eChemportal and a second set of 515 substances from NICEATM. A model was considered successful at predicting skin sensitisation potential if it had at least the same balanced accuracy as the LLNA and the GPMT had in predicting the other outcomes, which ranged from 79% to 86%. We found that the highest balanced accuracy of any of the expert systems evaluated was 65% when making global predictions. For substances within the domain of TIMES-SS, however, balanced accuracies for the two datasets were found to be 79% and 82%. In those cases where a chemical was within the TIMES-SS domain, the TIMES-SS skin sensitisation hazard prediction had the same confidence as the result from LLNA or GPMT.
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Affiliation(s)
- Jeremy M Fitzpatrick
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), 109 T W Alexander Dr, Research Triangle Park (RTP), NC 27711, USA
| | - David W Roberts
- School of Pharmacy, Liverpool John Moores University, Byrom Street, Liverpool, UK
| | - Grace Patlewicz
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), 109 T W Alexander Dr, Research Triangle Park (RTP), NC 27711, USA
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Fitzpatrick JM, Patlewicz G. Application of IATA - A case study in evaluating the global and local performance of a Bayesian network model for skin sensitization. SAR QSAR Environ Res 2017; 28:297-310. [PMID: 28423913 PMCID: PMC6284231 DOI: 10.1080/1062936x.2017.1311941] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/23/2017] [Indexed: 06/07/2023]
Abstract
The information characterizing key events in an Adverse Outcome Pathway (AOP) can be generated from in silico, in chemico, in vitro and in vivo approaches. Integration of this information and interpretation for decision making are known as integrated approaches to testing and assessment (IATA). One such IATA was published by Jaworska et al., which describes a Bayesian network model known as ITS-2. The current work evaluated the performance of ITS-2 using a stratified cross-validation approach. We also characterized the impact of replacing the most significant component of the network, output from the expert system TIMES-SS, with structural alert information from the OECD Toolbox and Toxtree. Lack of structural alerts or TIMES-SS predictions yielded a sensitization potential prediction of 79%. If the TIMES-SS prediction was replaced by a structural alert indicator, the network predictivity increased up to 87%. The original network's predictivity was 89%. The local applicability domain of the original ITS-2 network was also evaluated using reaction mechanistic domains to understand what types of chemicals ITS-2 was able to make the best predictions for. We found that the original network was successful at predicting which chemicals would be sensitizers, but not at predicting their potency.
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Affiliation(s)
- J M Fitzpatrick
- a National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA) , Durham , USA
| | - G Patlewicz
- a National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA) , Durham , USA
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Lundon DJ, Boland A, Prencipe M, Hurley G, O'Neill A, Kay E, Aherne ST, Doolan P, Madden SF, Clynes M, Morrissey C, Fitzpatrick JM, Watson RW. The prognostic utility of the transcription factor SRF in docetaxel-resistant prostate cancer: in-vitro discovery and in-vivo validation. BMC Cancer 2017; 17:163. [PMID: 28249598 PMCID: PMC5333466 DOI: 10.1186/s12885-017-3100-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 02/01/2017] [Indexed: 02/06/2023] Open
Abstract
Background Docetaxel based therapy is one of the first line chemotherapeutic agents for the treatment of metastatic castrate-resistant prostate cancer. However, one of the major obstacles in the treatment of these patients is docetaxel-resistance. Defining the mechanisms of resistance so as to inform subsequent treatment options and combinations represents a challenge for clinicians and scientists. Previous work by our group has shown complex changes in pro and anti-apoptotic proteins in the development of resistance to docetaxel. Targeting these changes individually does not significantly impact on the resistant phenotype but understanding the central signalling pathways and transcription factors (TFs) which control these could represent a more appropriate therapeutic targeting approach. Methods Using a number of docetaxel-resistant sublines of PC-3 cells, we have undertaken a transcriptomic analysis by expression microarray using the Affymetrix Human Gene 1.0 ST Array and in conjunction with bioinformatic analyses undertook to predict dysregulated TFs in docetaxel resistant prostate cancer. The clinical significance of this prediction was ascertained by performing immunohistochemical (IHC) analysis of an identified TF (SRF) in the metastatic sites from men who died of advanced CRPC. Investigation of the functional role of SRF was examined by manipulating SRF using SiRNA in a docetaxel-resistant PC-3 cell line model. Results The transcription factors identified include serum response factor (SRF), nuclear factor kappa-B (NFκB), heat shock factor protein 1 (HSF1), testicular receptor 2 & 4 (TR2 &4), vitamin-D and retinoid x receptor (VDR-RXR) and oestrogen-receptor 1 (ESR1), which are predicted to be responsible for the differential gene expression observed in docetaxel-resistance. IHC analysis to quantify nuclear expression of the identified TF SRF correlates with both survival from date of bone metastasis (p = 0.003), survival from androgen independence (p = 0.00002), and overall survival from prostate cancer (p = 0.0044). Functional knockdown of SRF by siRNA demonstrated a reversal of apoptotic resistance to docetaxel treatment in the docetaxel-resistant PC-3 cell line model. Conclusions Our results suggest that SRF could aid in treatment stratification of prostate cancer, and may also represent a therapeutic target in the treatment of men afflicted with advanced prostate cancer. Electronic supplementary material The online version of this article (doi:10.1186/s12885-017-3100-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- D J Lundon
- UCD School of Medicine, Conway Institute of Biomedical and Biomolecular Sciences, University College Dublin, Belfield, Dublin, Dublin 4, Ireland.
| | - A Boland
- UCD School of Mathematical Sciences and Insight, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
| | - M Prencipe
- UCD School of Medicine, Conway Institute of Biomedical and Biomolecular Sciences, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
| | - G Hurley
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
| | - A O'Neill
- UCD School of Medicine, Conway Institute of Biomedical and Biomolecular Sciences, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
| | - E Kay
- Department of Pathology, Beaumont Hospital & Royal College of Surgeons in Ireland, Dublin, Ireland
| | - S T Aherne
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland Non-US/Non-Canadian, Ireland
| | - P Doolan
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland Non-US/Non-Canadian, Ireland
| | - S F Madden
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
| | - M Clynes
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland Non-US/Non-Canadian, Ireland
| | - C Morrissey
- Department of Urology, University of Washington, Seattle, WA, USA
| | - J M Fitzpatrick
- UCD School of Medicine, Conway Institute of Biomedical and Biomolecular Sciences, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
| | - R W Watson
- UCD School of Medicine, Conway Institute of Biomedical and Biomolecular Sciences, University College Dublin, Belfield, Dublin, Dublin 4, Ireland
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Fitzpatrick JM, Roberts DW, Patlewicz G. Is skin penetration a determining factor in skin sensitization potential and potency? Refuting the notion of a LogKow threshold for skin sensitization. J Appl Toxicol 2016; 37:117-127. [PMID: 27357739 DOI: 10.1002/jat.3354] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 04/21/2016] [Accepted: 05/09/2016] [Indexed: 11/09/2022]
Abstract
It is widely accepted that substances that cannot penetrate through the skin will not be sensitizers. LogKow and molecular weight (MW) have been used to set thresholds for sensitization potential. Highly hydrophilic substances e.g. LogKow ≤ 1 are expected not to penetrate effectively to induce sensitization. To investigate whether LogKow >1 is a true requirement for sensitization, a large dataset of substances that had been evaluated for their skin sensitization potential under Registration, Evaluation, Authorisation and restriction of CHemicals (REACH), together with available measured LogKow values was compiled using the OECD eChemPortal. The incidence of sensitizers relative to non-sensitizers above and below a LogKow of 1 was explored. Reaction chemistry principles were used to explain the sensitization observed for the subset of substances with a LogKow ≤0. 1482 substances were identified with skin sensitization data and measured LogKow values. 525 substances had a measured LogKow ≤ 1, 100 of those were sensitizers. There was no significant difference in the incidence of sensitizers above and below a LogKow of 1. Reaction chemistry principles that had been established for lower MW and more hydrophobic substances were found to be still valid in rationalizing the skin sensitizers with a LogKow ≤ 0. The LogKow threshold arises from the widespread misconception that the ability to efficiently penetrate the stratum corneum is a key determinant of sensitization potential and potency. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jeremy M Fitzpatrick
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), USA
| | - David W Roberts
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Grace Patlewicz
- National Center for Computational Toxicology (NCCT), US Environmental Protection Agency (US EPA), USA
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Patlewicz G, Fitzpatrick JM. Current and Future Perspectives on the Development, Evaluation, and Application of in Silico Approaches for Predicting Toxicity. Chem Res Toxicol 2016; 29:438-51. [PMID: 26686752 DOI: 10.1021/acs.chemrestox.5b00388] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Exploiting non-testing approaches to predict toxicity early in the drug discovery development cycle is a helpful component in minimizing expensive drug failures due to toxicity being identified in late development or even during clinical trials. Changes in regulations in the industrial chemicals and cosmetics sectors in recent years have prompted a significant number of advances in the development, application, and assessment of non-testing approaches, such as (Q)SARs. Many efforts have also been undertaken to establish guiding principles for performing read-across within category and analogue approaches. This review offers a perspective, as taken from these sectors, of the current status of non-testing approaches, their evolution in light of the advances in high-throughput approaches and constructs such as adverse outcome pathways, and their potential relevance for drug discovery. It also proposes a workflow for how non-testing approaches could be practically integrated within testing and assessment strategies.
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Affiliation(s)
- Grace Patlewicz
- National Center for Computational Toxicology (NCCT), U.S. Environmental Protection Agency , Research Triangle Park, North Carolina 27711, United States
| | - Jeremy M Fitzpatrick
- National Center for Computational Toxicology (NCCT), U.S. Environmental Protection Agency , Research Triangle Park, North Carolina 27711, United States
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Fitzpatrick JM, Biswas JS, Edgeworth JD, Islam J, Jenkins N, Judge R, Lavery AJ, Melzer M, Morris-Jones S, Nsutebu EF, Peters J, Pillay DG, Pink F, Price JR, Scarborough M, Thwaites GE, Tilley R, Walker AS, Llewelyn MJ. Gram-negative bacteraemia; a multi-centre prospective evaluation of empiric antibiotic therapy and outcome in English acute hospitals. Clin Microbiol Infect 2015; 22:244-51. [PMID: 26577143 DOI: 10.1016/j.cmi.2015.10.034] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 10/23/2015] [Accepted: 10/31/2015] [Indexed: 10/22/2022]
Abstract
Increasing antibiotic resistance makes choosing antibiotics for suspected Gram-negative infection challenging. This study set out to identify key determinants of mortality among patients with Gram-negative bacteraemia, focusing particularly on the importance of appropriate empiric antibiotic treatment. We conducted a prospective observational study of 679 unselected adults with Gram-negative bacteraemia at ten acute english hospitals between October 2013 and March 2014. Appropriate empiric antibiotic treatment was defined as intravenous treatment on the day of blood culture collection with an antibiotic to which the cultured organism was sensitive in vitro. Mortality analyses were adjusted for patient demographics, co-morbidities and illness severity. The majority of bacteraemias were community-onset (70%); most were caused by Escherichia coli (65%), Klebsiella spp. (15%) or Pseudomonas spp. (7%). Main foci of infection were urinary tract (51%), abdomen/biliary tract (20%) and lower respiratory tract (14%). The main antibiotics used were co-amoxiclav (32%) and piperacillin-tazobactam (30%) with 34% receiving combination therapy (predominantly aminoglycosides). Empiric treatment was inappropriate in 34%. All-cause mortality was 8% at 7 days and 15% at 30 days. Independent predictors of mortality (p <0.05) included older age, greater burden of co-morbid disease, severity of illness at presentation and inflammatory response. Inappropriate empiric antibiotic therapy was not associated with mortality at either time-point (adjusted OR 0.82; 95% CI 0.35-1.94 and adjusted OR 0.92; 95% CI 0.50-1.66, respectively). Although our study does not exclude an impact of empiric antibiotic choice on survival in Gram-negative bacteraemia, outcome is determined primarily by patient and disease factors.
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Affiliation(s)
- J M Fitzpatrick
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton, UK
| | - J S Biswas
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, Kings College London and Guy's and St Thomas' Hospitals NHS Foundation Trust, London, UK
| | - J D Edgeworth
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, Kings College London and Guy's and St Thomas' Hospitals NHS Foundation Trust, London, UK
| | - J Islam
- Department of Microbiology, Surrey and Sussex Healthcare NHS Trust, Redhill, UK
| | - N Jenkins
- Department of Microbiology, Infection and Tropical Medicine, Heart of England NHS Trust, Birmingham, UK
| | - R Judge
- Department of Microbiology, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - A J Lavery
- Department of Clinical Microbiology and Virology, UCLH NHS Foundation Trust, London, UK
| | - M Melzer
- Department of Infection, Barts Health NHS Trust, London, UK
| | - S Morris-Jones
- Department of Clinical Microbiology and Virology, UCLH NHS Foundation Trust, London, UK
| | - E F Nsutebu
- Tropical and Infectious Disease Unit Royal Liverpool University Hospital, Liverpool, UK
| | - J Peters
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton, UK
| | - D G Pillay
- Department of Microbiology, Infection and Tropical Medicine, Heart of England NHS Trust, Birmingham, UK
| | - F Pink
- Department of Infection, Barts Health NHS Trust, London, UK
| | - J R Price
- Department of Microbiology, Western Sussex Hospitals NHS Foundation Trust, Chichester, UK
| | - M Scarborough
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK
| | - G E Thwaites
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - R Tilley
- Department of Microbiology, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - A S Walker
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK; Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - M J Llewelyn
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton, UK; Division of Medicine, Brighton and Sussex Medical School, Falmer, UK.
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Song GJ, Leslie KL, Barrick S, Mamonova T, Fitzpatrick JM, Drombosky KW, Peyser N, Wang B, Pellegrini M, Bauer PM, Friedman PA, Mierke DF, Bisello A. Phosphorylation of ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) by Akt promotes stability and mitogenic function of S-phase kinase-associated protein-2 (Skp2). J Biol Chem 2014; 290:2879-87. [PMID: 25492869 DOI: 10.1074/jbc.m114.609768] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The regulation of the cell cycle by the ubiquitin-proteasome system is dependent on the activity of E3 ligases. Skp2 (S-phase kinase associated protein-2) is the substrate recognition subunit of the E3 ligase that ubiquitylates the cell cycle inhibitors p21(cip1) and p27(kip1) thus promoting cell cycle progression. Increased expression of Skp2 is frequently observed in diseases characterized by excessive cell proliferation, such as cancer and neointima hyperplasia. The stability and cellular localization of Skp2 are regulated by Akt, but the molecular mechanisms underlying these effects remain only partly understood. The scaffolding protein Ezrin-Binding Phosphoprotein of 50 kDa (EBP50) contains two PDZ domains and plays a critical role in the development of neointimal hyperplasia. Here we report that EBP50 directly binds Skp2 via its first PDZ domain. Moreover, EBP50 is phosphorylated by Akt on Thr-156 within the second PDZ domain, an event that allosterically promotes binding to Skp2. The interaction with EBP50 causes cytoplasmic localization of Skp2, increases Skp2 stability and promotes proliferation of primary vascular smooth muscle cells. Collectively, these studies define a novel regulatory mechanism contributing to aberrant cell growth and highlight the importance of scaffolding function of EBP50 in Akt-dependent cell proliferation.
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Affiliation(s)
- Gyun Jee Song
- From the Department of Pharmacology and Chemical Biology, Department of Pharmacology, Brain Science and Engineering Institute, School of Medicine, Kungpook National University, Daegu 702-701, Korea, and
| | | | - Stacey Barrick
- From the Department of Pharmacology and Chemical Biology
| | | | | | | | - Noah Peyser
- From the Department of Pharmacology and Chemical Biology
| | - Bin Wang
- From the Department of Pharmacology and Chemical Biology
| | - Maria Pellegrini
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Philip M Bauer
- Vascular Medicine Institute, and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | | | - Dale F Mierke
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Alessandro Bisello
- From the Department of Pharmacology and Chemical Biology, Vascular Medicine Institute, and
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Fitzpatrick JM, Pellegrini M, Cushing PR, Mierke DF. Small molecule inhibition of the Na(+)/H(+) exchange regulatory factor 1 and parathyroid hormone 1 receptor interaction. Biochemistry 2014; 53:5916-22. [PMID: 25171053 PMCID: PMC4172209 DOI: 10.1021/bi500368k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have identified a series of small molecules that bind to the canonical peptide binding groove of the PDZ1 domain of NHERF1 and effectively compete with the association of the C-terminus of the parathyroid hormone 1 receptor (PTH1R). Employing nuclear magnetic resonance and molecular modeling, we characterize the mode of binding that involves the GYGF loop important for the association of the C-terminus of PTH1R. We demonstrate that the common core of the small molecules binds to the PDZ1 domain of NHERF1 and displaces a (15)N-labeled peptide corresponding to the C-terminus of PTH1R. The small size (molecular weight of 192) of this core scaffold makes it an excellent candidate for further elaboration in the development of an inhibitor for this important protein-protein interaction.
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Affiliation(s)
- Jeremy M Fitzpatrick
- Department of Chemistry and Department of Molecular and Cellular Biology, Dartmouth College , Hanover, New Hampshire 03755, United States
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10
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Burgner J, Simpson AL, Fitzpatrick JM, Lathrop RA, Herrell SD, Miga MI, Webster RJ. A study on the theoretical and practical accuracy of conoscopic holography-based surface measurements: toward image registration in minimally invasive surgery. Int J Med Robot 2013; 9:190-203. [PMID: 22761086 PMCID: PMC3819208 DOI: 10.1002/rcs.1446] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2012] [Indexed: 11/10/2022]
Abstract
BACKGROUND Registered medical images can assist with surgical navigation and enable image-guided therapy delivery. In soft tissues, surface-based registration is often used and can be facilitated by laser surface scanning. Tracked conoscopic holography (which provides distance measurements) has been recently proposed as a minimally invasive way to obtain surface scans. Moving this technique from concept to clinical use requires a rigorous accuracy evaluation, which is the purpose of our paper. METHODS We adapt recent non-homogeneous and anisotropic point-based registration results to provide a theoretical framework for predicting the accuracy of tracked distance measurement systems. Experiments are conducted a complex objects of defined geometry, an anthropomorphic kidney phantom and a human cadaver kidney. RESULTS Experiments agree with model predictions, producing point RMS errors consistently < 1 mm, surface-based registration with mean closest point error < 1 mm in the phantom and a RMS target registration error of 0.8 mm in the human cadaver kidney. CONCLUSIONS Tracked conoscopic holography is clinically viable; it enables minimally invasive surface scan accuracy comparable to current clinical methods that require open surgery.
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Affiliation(s)
- J Burgner
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, USA.
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Girard FP, Byrne J, Downes M, Fanning D, Desgrandchamps F, Fitzpatrick JM, Watson RW. Detecting soluble clusterin in in-vitro and in-vivo models of prostate cancer. Neoplasma 2010; 57:488-93. [PMID: 20568904 DOI: 10.4149/neo_2010_05_488] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
PSA, the only relevant marker for prostate cancer, has a low predictive value; moreover its low threshold leads to unnecessary biopsies with associated complications. Identification of prognostic factors is an important goal in prostate cancer. In the search for new markers, clusterin, has some potential as it is closely linked with cancer progression and resistance to apoptosis. We looked at the expression of secreted clusterin (sCLU) in prostate cells to determine correlations with progression and drug resistance. The plasmatic expression of sCLU was also investigated in order to use it as a potential marker for prostate cancer. sCLU expression was studied using Western blotting on cultured prostate cells, PWR-1E, PC3 and PC3 Docetaxel resistant cells in the cytosol and culture medium. An inhouse ELISA test was developed to determine sCLU expression in culture media and plasma samples. A patient cohort was identified from the Prostate Cancer Research Consortium Bio-Resource and plasmatic expression of sCLU was studied using western blotting and the inhouse ELISA test. Only the fully processed form of sCLU was identified in the medium of cells with increased expression associated with increased progression of disease and resistance to docetaxel. Plasmatic expression of sCLU was significantly higher in the plasma of patients with high grade prostate cancer with extracapsular extension than in the plasma of prostate cancer patients without extracapsular extension. Plasmatic sCLU may be an effective prognostic marker of prostate cancer and needs to be tested in a multimarker approach.
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Affiliation(s)
- F P Girard
- UCD School of Medicine and Medical Science, University College Dublin, Ireland.
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Fitzpatrick JM, Carlon DB, Lippe C, Robertson DR. The West Pacific diversity hotspot as a source or sink for new species? Population genetic insights from the Indo-Pacific parrotfish Scarus rubroviolaceus. Mol Ecol 2010; 20:219-34. [PMID: 21143329 DOI: 10.1111/j.1365-294x.2010.04942.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We used a population genetic approach to quantify major population subdivisions and patterns of migration within a broadly distributed Indo-Pacific parrotfish. We genotyped 15 microsatellite loci in Scarus rubroviolaceus collected from 20 localities between Africa and the Americas. A STRUCTURE model indicates the presence of four major populations: Eastern Pacific, Hawaii, Central-West Pacific and a less well-differentiated Indian Ocean. We used the isolation and migration model to estimate splitting times, population sizes and migration patterns between sister population pairs. To eliminate loci under selection, we used BayeScan to select loci for three isolation and migration models: Eastern Pacific and Central-West Pacific, Hawaii and the Central-West Pacific, and Indian Ocean and the Central-West Pacific. To test the assumption of a stepwise mutation model (SMM), we used likelihood to test the SMM against a two-phase model that allowed mutational complexity. A posteriori, minor departures from SMM were estimated to affect ≤2% of the alleles in the data. The data were informative about the contemporary and ancestral population sizes, migration rates and the splitting time in the eastern Pacific/Central-West Pacific comparison. The model revealed a splitting time ∼17,000 BP, a larger contemporary N(e) in the Central-West Pacific than in the eastern Pacific and a strong bias of east to west migration. These characteristics support the Center of Accumulation model of peripatric diversification in low-diversity peripheral sites and perhaps migration from those sites to the western Pacific diversity hotspot.
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Affiliation(s)
- J M Fitzpatrick
- Department of Zoology, University of Hawaii, Honolulu, HI 96822, USA
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13
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Abstract
Registration is presented as the central issue of surgical guidance. The focus is on the accuracy of approaches employed today, all of which use pre-operative images to guide surgery on rigid anatomy. The three most well-established approaches to guidance, namely the stereotactic frame, point fiducials, and surface matching, are examined in detail, together with two new approaches based on microstereotactic frames. It is shown that each method relies on the registration of points in the image to corresponding points in the operating room, and therefore that the error patterns associated with point registration are similar for all of them. Three types of registration error, namely fiducial localization error (FLE), fiducial registration error (FRE), and target registration error (TRE), are highlighted, as well as two additional guidance errors, namely target localization error and total targeting error, the latter of which is the overall error of the guidance system. Statistical relationships between TRE and FLE, between FRE and FLE, and between TRE, TLE, and TTE are given. Finally some myths concerning fiducial registration are highlighted.
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Affiliation(s)
- J M Fitzpatrick
- Department of Electrical Engineering and Computer Science, Vanderbilt University, VU Station B #351679, 2301 Vanderbilt Place, Nashville, TN 37235-1679, USA.
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14
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Geoghegan S, Fitzpatrick JM, McGuire B, O'Malley KJ, Shaw C, Fabre A. A rare benign renal tumour presenting as polycythaemia in a teenage girl. Ir Med J 2010; 103:122-123. [PMID: 20486320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We present the case of a 15-year-old girl who presented with polycythemia. CT abdomen revealed an enhancing mass in the upper pole of her left kidney with features suggestive of renal cell carcinoma. She underwent a laparoscopic radical nephrectomy. Histology demonstrated a well circumscribed, focally encapsulated, round blue cell tumour showing areas of microcalcifications and numerous psammoma bodies. Imunostaining showed diffuse positive staining for CD 57. This was consistent with a diagnosis of metanephric adenoma a rare benign epithelial renal tumour.
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Affiliation(s)
- S Geoghegan
- Department of Urology, Mater Misericordiae University Hospital, Eccles St, Dublin 7
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15
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Fanning DM, Fan Y, Fitzpatrick JM, Watson RWG. External validation of the 2007 and 2001 Partin tables in Irish prostate cancer patients. Urol Int 2010; 84:174-9. [PMID: 20215821 DOI: 10.1159/000277594] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 06/29/2009] [Indexed: 11/19/2022]
Abstract
INTRODUCTION External validation of predictive prostate cancer nomograms is of critical importance within distinct geographical locations, prior to their institution into routine clinical practice. We performed external validation of the 2007 and 2001 Partin tables in a cohort of Irish prostate cancer patients. PATIENTS AND METHODS Men enrolled in the Irish Prostate Cancer Research Consortium (n = 175) and who had undergone radical prostatectomy between 2004 and 2008 were used to externally validate the 2007 and 2001 Partin tables. A comparative analysis of the clinical and pathological parameters of the Irish and Partin patient cohorts was performed. The reported receiver operating characteristic (ROC) curve derived area under the curve (AUC) values were used to assess for variations in predictive accuracy. Statistical analyses were calculated with R software. RESULTS AUC values assigned to the differentiation of extra-prostatic extension and seminal vesicle invasion using the 2007 tables are 22 and 3%, respectively. The 2007 Partin tables showed superior accuracy for all parameters, excluding seminal vesicle invasion. CONCLUSION Cumulatively the Partin tables showed poor discriminate ability for prediction of post-radical prostatectomy pathological outcomes in Irish men, necessitating caution in their clinical utilisation.
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Affiliation(s)
- D M Fanning
- UCD School of Medicine and Medical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland. deirdre.fanning @ ucd.ie
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16
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Smyth LG, O'Hurley G, O'Grady A, Fitzpatrick JM, Kay E, Watson RWG. Carbonic anhydrase IX expression in prostate cancer. Prostate Cancer Prostatic Dis 2009; 13:178-81. [PMID: 20038959 DOI: 10.1038/pcan.2009.58] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tumour hypoxia is associated with over 70% of solid tumours including prostate and colorectal cancer. Hypoxia promotes tumour progression and resistance to treatment. Carbonic anhydrase IX (CA IX) is an endogenous marker of hypoxia. It is expressed in lung and renal cell carcinomas and is associated with a poor prognosis. CA IX has an important role in maintaining pH levels in the highly metabolically active cancer cell. The expression of CA IX in prostate cancer has not previously been investigated. Immunohistochemistry was used to examine CA IX expression in 59 patients, using tissue microarrays (TMAs) and full sections of BPH, surrounding stroma and prostate adenocarcinoma. Cores reviewed included 189 BPH, 130 Gleason grade 3, 93 Gleason grade 4, 40 Gleason grade 5. CA IX expression in colorectal cancer and HIF 1alpha in prostate cancer acted as positive controls. There was only occasional cell staining for CA IX expression. Although prostate cancer is a hypoxic tumour it does not express CA IX. This implies it relies on alternative pathways for maintaining pH balance in cancer. These studies would indicate that CA IX is not a suitable marker of hypoxia in prostate cancer.
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Affiliation(s)
- L G Smyth
- University College Dublin School of Medicine and Medical Science, Dublin, Ireland.
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17
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McGuire BB, O'Brien MF, McLoughlin S, O'Malley KJ, Fitzpatrick JM. Should patients with symptomatic BPH have a trial of medical therapy by their general practitioner prior to referral for urological assessment? Ir Med J 2007; 100:428-9. [PMID: 17566476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The British Association of Urological Surgeons (BAUS) has recently recommended guidelines for the management of Lower Urinary Tract Sypmtoms by GPs outlining the indications for urological referral. We wished to assess the prescription of medical therapy by GPs in the referrals to our LUTS pre-assessment clinic. 115 consecutive patients were reviewed prospectively, over a three month period. Each patient was assessed for International Prostatic Symptom Score (IPSS) and Bother Score, uroflowometry with post void residual and whether medical therapy had been commenced (D-Blocker or 5-D-Reductase inhibitor). The majority of patients (75%) were classified with moderate symptoms. Only 10% of those with moderate symptoms and 5% of those with severe symptoms were commenced on medical therapy by their GP as recommended by the BAUS guidelines. Only 30 patients (26%) had completed an IPSS form with their GP. The majority of patients referred to our service for assessment of LUTS have at least moderate symptom severity and are not prescribed medical therapy by their GP. Further primary care education with greater emphasis on the BAUS LUTS algorithm prior to referral to an urologist should be encouraged.
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Affiliation(s)
- B B McGuire
- Department of Urology, Mater Misericordiae University Hospital, Eccles St., Dublin
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18
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Abstract
The focus of research in allograft rejection has targeted the lymphocyte, with little attention given to the neutrophil. Recent data indicate that a perioperative neutrophil influx into the cardiac allograft influences early rejection. Factors that influence neutrophil transendothelial migration might offer predictive markers of rejection. We explored the relationship between the number of circulating neutrophils in heart transplant recipients and the development of rejection. Differential white cell counts were obtained prior to transplantation and concurrently with subsequent endomyocardial rejection surveillance biopsies for 53 heart transplant recipients undergoing 410 biopsies. Preoperative differential white cell counts had no relationship with rejection. In the first 3 months after transplantation, no relationship was found between contemporary differential white cell counts and rejection. However, more than 3 months following surgery, rejection grade positively correlated on univariate analysis with neutrophil counts and the usage of cyclosporine, prednisolone, and mycophenolate. There was no relationship with eosinophils or lymphocytes. Multivariate analysis demonstrated a persistent relationship among rejection severity, neutrophil count, and prednisolone usage. A significant positive association of higher steroid usage with higher rejection grades must reflect efforts to treat patients with rejection. The significant association of higher neutrophil counts with higher rejection severity might suggest a pathological contribution to rejection. However, given the neutrophilia response to acute steroid administration, we must conclude that the neutrophil association was related to steroid administration. The absence of a relationship between white cell counts and rejection suggests that functional rather than antiproliferative strategies may offer the greatest therapeutic potential.
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Affiliation(s)
- D G Healy
- Prof Eoin O'Malley National Centre for Cardiothoracic Surgery, Mater Misericordiae University Hospital, Eccles St, Dublin, Ireland.
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19
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Downes MR, Byrne JC, Dunn MJ, Fitzpatrick JM, Watson RWG, Pennington SR. Application of proteomic strategies to the identification of urinary biomarkers for prostate cancer: a review. Biomarkers 2006; 11:406-16. [PMID: 16966158 DOI: 10.1080/13547500600799821] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In the post-genomic era, genes and proteins are now studied on a more comprehensive scale. Studying disease processes at only the genetic or transcriptomic level will give an incomplete amount of information. A proteomic approach potentially allows for a more global overview of how disease processes affect the proteins present in cells, tissues and organisms. The challenge arises in determining which proteins are affected in specific diseases and establishing which of these changes are unique to a particular disease. Existing and emerging proteomic technologies allow for high throughput analysis of proteins in a variety of sample types. Prostate cancer is a significant male health problem in the Western world. It is widely accepted that more specific prognostic and diagnostic markers of prostate cancer are urgently required. The present paper suggests that urine may be an attractive biofluid in which to pursue the identification of novel biomarkers of prostate cancer. This review introduces some proteomic techniques including mass spectrometry and the newer, quantitative proteomic strategies. It focuses on the potential application of these platforms to novel urinary biomarker identification in prostate malignancy. It also includes a synopsis of the current literature on urinary proteomics.
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Affiliation(s)
- M R Downes
- Proteome Research Centre, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin, Ireland.
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20
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Beddy D, Mulsow J, Watson RWG, Fitzpatrick JM, O'Connell PR. Expression and regulation of connective tissue growth factor by transforming growth factor beta and tumour necrosis factor alpha in fibroblasts isolated from strictures in patients with Crohn's disease. Br J Surg 2006; 93:1290-6. [PMID: 16838391 DOI: 10.1002/bjs.5431] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Connective tissue growth factor (CTGF) stimulates fibroblast proliferation and extracellular matrix production. Fibroblasts may initiate stricture formation in Crohn's disease through overexpression of CTGF. Stricturing that occurs in patients with Crohn's disease after treatment with anti-tumour necrosis factor (TNF) alpha may be due to dysregulation of CTGF homeostasis. The aim of this study was to examine CTGF expression and regulation in fibroblasts isolated from patients with Crohn's disease. METHODS Fibroblasts were isolated by a primary explant technique from serosal biopsies of strictured segments of bowel in eight patients undergoing resection for Crohn's disease and from normal colon in seven patients having resection for benign or malignant colorectal disease. Cells were stimulated with transforming growth factor (TGF) beta and TNF-alpha. CTGF protein and mRNA expression were measured by western blotting and real-time polymerase chain reaction respectively. RESULTS Mean(s.d.) CTGF protein expression in strictured Crohn's fibroblasts was higher than that in normal fibroblasts (56.5(9.7) versus 17.0(10.0) respectively; P = 0.011). In normal and strictured Crohn's fibroblasts, culture with TGF-beta increased CTGF protein and mRNA expression. Co-culture of normal fibroblasts with TNF-alpha suppressed TGF-beta-stimulated CTGF expression. CONCLUSION : Increased expression of CTGF in strictured Crohn's fibroblasts underlies its role in fibrosis. TNF-alpha suppresses fibrosis by downregulating fibroblast CTGF expression, an effect that may be lost following anti-TNF-alpha treatment, thereby promoting stricture formation.
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Affiliation(s)
- D Beddy
- Department of Surgery, Mater Misericordiae University Hospital and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
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21
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O'Connor K, Gill C, Tacke M, Rehmann FJK, Strohfeldt K, Sweeney N, Fitzpatrick JM, Watson RWG. Novel titanocene anti-cancer drugs and their effect on apoptosis and the apoptotic pathway in prostate cancer cells. Apoptosis 2006; 11:1205-14. [PMID: 16699961 DOI: 10.1007/s10495-006-6796-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Advanced prostate cancer is not curable by current treatment strategies indicating a significant need for new chemotherapeutic options. Highly substituted ansa-titanocene compounds have shown promising cytotoxic activity in a range of cancers. The objectives of this study are to examine the effects of these titanocene compounds on prostate cancer cells. Prostate cell lines were treated with three novel titanocene compounds and compared to titanocene dichloride and cisplatin. Percent apoptosis, viability and cell cycle were assessed using propidium iodide DNA incorporation with flow cytometry. Cytochrome C was assessed by western blotting of mitochondrial and cytoplasmic fractions. Apoptosis Inducing Factor was assessed by confocal microscopy. These novel compounds induced more apoptosis compared to cisplatin in a dose dependent manner. Compound Y had the most significant effect on cell cycle and apoptosis. Despite the release of cytochrome C from the mitochondrial fraction there was no inhibition of apoptosis with the pan caspase inhibitor, ZVAD-FMK. AIF was shown to translocate from the cytosol to the nucleus mediating a caspase independent cell death. Bcl-2 over expressing PC-3 cells, which were resistant to cisplatin induced apoptosis, underwent apoptosis following treatment with all the titanocene compounds. This study demonstrates possible mechanisms by which these novel titanocene compounds can mediate their apoptotic effect in vitro. The fact that they can induce more apoptosis than cisplatin in advanced cancer cell lines would confer an advantage over cisplatin. They represent exciting new agents with future potential for the treatment of advanced prostate cancer.
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Affiliation(s)
- K O'Connor
- UCD School of Medicine and Medical Sciences, Mater Misericordiae University Hospital, University College Dublin, Belfield, Dublin 4, Ireland
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22
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Quinlan JF, Watson RWG, Kelly G, Kelly PM, O'Byrne JM, Fitzpatrick JM. Transforming growth factor-beta (TGF-β) in acute injuries of the spinal cord. ACTA ACUST UNITED AC 2006; 88:406-10. [PMID: 16498024 DOI: 10.1302/0301-620x.88b3.16400] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Injuries to the spinal cord may be associated with increased healing of fractures. This can be of benefit, but excessive bone growth can also cause considerable adverse effects. We evaluated two groups of patients with fractures of the spinal column, those with neurological compromise (n = 10) and those without (n = 15), and also a control group with an isolated fracture of a long bone (n = 12). The level of transforming growth factor-beta (TGF-β), was measured at five time points after injury (days 1, 5, 10, 42 and 84). The peak level of 142.79 ng/ml was found at day 84 in the neurology group (p < 0.001 vs other time points). The other groups peaked at day 42 and had a decrease at day 84 after injury (p ≤ 0.001). Our findings suggest that TGF-β may have a role in the increased bone turnover and attendant complications seen in patients with acute injuries to the spinal cord.
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Affiliation(s)
- J F Quinlan
- School of Medicine and Medical Science, Mater Misericordiae University Hospital, Eccles Street, Dublin 7, Republic of Ireland
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23
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McGuire BB, O'Brien MF, Akhtar M, Fitzpatrick JM. Testicular vasculitis mimicking a testicular neoplasm. Ir Med J 2006; 99:27-8. [PMID: 16506690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Vasculitis of the testis generally presents as a manifestation of systemic vasculitis which is well documented. In isolation, it has only been described on few occasions previously, and hitherto it has been in the young. It often mimics a neoplasm of the testis resulting in radical orchidectomy, only for it to be diagnosed when the specimen is examined under the microscope. In our case, an elderly man presented to us with a presumed testicular neoplasm, however, despite strong clinical and radiological suspicion a testicular vasculitis in isolation was revealed. Following our experience, we performed a literature review and examined all of the cases of testicular vasculitis reported so far and present our findings. We report the general clinical presentation, methods of investigation and subsequent management. This is the first time it has been described in the elderly population.
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24
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Galvin DJ, Watson RWG, O'Neill A, Coffey RNT, Taylor C, Gillespie JI, Fitzpatrick JM. Hypoxia inhibits human bladder smooth muscle cell proliferation: a potential mechanism of bladder dysfunction. Neurourol Urodyn 2004; 23:342-8. [PMID: 15227652 DOI: 10.1002/nau.20035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIMS Recent animal studies have suggested that bladder outflow obstruction causes bladder wall hypoxia during both the filling and the voiding phases of the micturition cycle. We have previously demonstrated that mechanical deformation of human detrusor leads to smooth muscle (SM) cell hypertrophy and hyperplasia, which may then contribute to hypoxia in the dysfunctional bladder. We hypothesise that the detrusor's response to a hypoxic environment contributes to bladder dysfunction. The aim of this study was to evaluate the effect of hypoxia on detrusor cell survival and growth. METHODS Normal human detrusor muscle was obtained at radical cystectomy and primary cultures were established. Cells were then cultured in the presence of 1% oxygen in a hypoxic chamber for different times. Apoptosis was assessed by propidium iodide DNA staining and flow cytometry. Proliferation was assessed by radiolabelled thymidine incorporation. Cell supernatants were retained for growth factor estimation by enzyme linked immuno-sorbent assay (ELISA), and total cell and nuclear extracts were isolated for Western blotting. RESULTS SM cells responded to the presence of hypoxia through significant upregulation of survival factors hypoxia inducible factor (HIF 1alpha) and vascular endothelial growth factor (VEGF) in a time-dependent manner. Hypoxia did not induce cell death, but significantly reduced the rate of proliferation over time, associated with an increase in the cell cycle inhibitor p27kip1. CONCLUSIONS In an in vitro human detrusor cell culture model, cells demonstrate a resistance to hypoxia-induced apoptosis but proliferation is inhibited. We suggest that the anti-proliferative effects of hypoxia may limit the ability of detrusor cells to respond to, and compensate for, alterations in their environment contributing to bladder dysfunction.
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Affiliation(s)
- D J Galvin
- Department of Surgery, Mater Misericordiae University Hospital, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
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25
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Fitzpatrick JM. 'Urology: Today's Advances, Tomorrow's Clinical Practice', Cannes, November 2003. Current thinking in prostatic diseases: insights into dual 5alpha-reductase inhibitor therapy in BPH and prostate cancer. Prostate Cancer Prostatic Dis 2004; 7:91-2. [PMID: 15175660 DOI: 10.1038/sj.pcan.4500724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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O'Neill A, Greenan MC, Doyle B, Fitzpatrick JM, Watson RWG. Gene profiling of in vitro and in vivo models of delayed neutrophil apoptosis: a common pathway? Biochem Soc Trans 2004; 32:470-3. [PMID: 15157163 DOI: 10.1042/bst0320470] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mechanisms responsible for the termination of an inflammatory response include the activation of a genetic programme of cellular suicide termed apoptosis, which leads to the elimination of the cellular effectors of acute inflammation, particularly the neutrophil. However, delays in this response result in the persistence of inflammation and the development of inflammatory disorders. Understanding the mechanism that inhibits the process of cell death may be helpful in the treatment of inflammatory disorders. Inflammatory cytokines have been shown to inhibit apoptosis through stabilization of the mitochondria and inhibition of the caspase cascade. To date, how these processes are inhibited remains the central question. We hypothesize that the decision for the delay in neutrophil apoptosis is made through signals delivered on the cell surface, which activate combinations of specific genes that inhibit the cell death pathway. Gene chip microarray experiments were performed in in vivo and in vitro models of delayed neutrophil apoptosis. Analysis has yielded changes in a large number of genes involved in inflammation, metabolism, signalling, mitochondrial function and apoptosis. A number of genes have been identified as suitable targets responsible for the regulation of neutrophil apoptosis and their expression was confirmed by real-time PCR and explored at the level of the protein. Their functional role in the apoptotic response is now being determined. One significant finding is that the gene patterns of delay in vitro and in vivo appear to be different, indicating the possibility for different pathways regulating the delay in neutrophil apoptosis.
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Affiliation(s)
- A O'Neill
- Department of Surgery, Conway Institute, University College Dublin, Mater Misericordiae University Hospital, Belfield, Dublin 7, Ireland
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Bartsch G, Fitzpatrick JM, Schalken JA, Isaacs J, Nordling J, Roehrborn CG. Consensus statement: the role of prostate-specific antigen in managing the patient with benign prostatic hyperplasia. BJU Int 2004; 93 Suppl 1:27-9. [PMID: 15009083 DOI: 10.1111/j.1464-410x.2004.04646.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- G Bartsch
- Department of Urology, University of Innsbruck, Austria.
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Fitzpatrick JM, Kirby RS. Two-drug therapy is best for symptomatic prostate enlargement: could a combination of doxazosin and finasteride change clinical practice? BJU Int 2004; 93:914-5. [PMID: 15142134 DOI: 10.1111/j.1464-410x.2004.04799.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Abstract
HL-60 cell differentiation into neutrophil like cells is associated with their induction of apoptosis. We investigated the cellular events that occur pre and post mitochondrial permeability transition to determine the role of the mitochondria in the induction of differentiation induced apoptosis. Pro-apoptotic Bax was translocated to and cleaved at the mitochondrial membrane in addition to t-Bid activation. These processes contributed to mitochondrial membrane disruption and the release of cytochrome c and Smac/DIABLO. The release of cytochrome c was caspase independent, as the caspase inhibitor Z-VAD.fmk, which inhibited apoptosis, did not block the release of cytochrome c. In contrast, the release of Smac/DIABLO was partially inhibited by caspase inhibition indicating differential release pathways for these mitochondrial pro-apoptotic factors. In addition to caspase inhibition we assessed the effects of the Bcl-2 anti-apoptotic family on differentiation induced apoptosis. BH4-Bcl-xl-TAT recombinant protein did not delay apoptosis, but did block the release of cytochrome c and Smac/DIABLO. Bcl-2 over-expression also inhibited differentiation induced apoptosis but was associated with the inhibition of the differentiation process. Differentiation mediated mitochondrial release of cytochrome c and Smac/DIABLO, may not trigger the induction of apoptosis, as BH4-Bclxl-TAT blocks the release of pro-apoptotic factors from the mitochondria, but does not prevent apoptosis.
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Affiliation(s)
- B T Doyle
- Department of Surgery, Mater Misericordiae University Hospital, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
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30
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Beddy D, Watson RWG, Fitzpatrick JM, O'Connell PR. Author's reply: Increased vascular endothelial growth factor production in fibroblasts isolated from strictures in patients with Crohn's disease ( Br J Surg 2004; 91: 72–77). Br J Surg 2004. [DOI: 10.1002/bjs.4656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- D Beddy
- Department of Surgery, Mater Misericordiae Hospital and Conway Institute of Biomolecular and Biomedical Research, University College, Dublin, Ireland
| | - R W G Watson
- Department of Surgery, Mater Misericordiae Hospital and Conway Institute of Biomolecular and Biomedical Research, University College, Dublin, Ireland
| | - J M Fitzpatrick
- Department of Surgery, Mater Misericordiae Hospital and Conway Institute of Biomolecular and Biomedical Research, University College, Dublin, Ireland
| | - P R O'Connell
- Department of Surgery, Mater Misericordiae Hospital and Conway Institute of Biomolecular and Biomedical Research, University College, Dublin, Ireland
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31
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Affiliation(s)
- J M Fitzpatrick
- University College Dublin, Mater Hospital, 47 Eccles Street, Dublin 7, Ireland.
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32
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Beddy D, Watson RWG, Fitzpatrick JM, O'Connell PR. Increased vascular endothelial growth factor production in fibroblasts isolated from strictures in patients with Crohn's disease. Br J Surg 2004; 91:72-7. [PMID: 14716797 DOI: 10.1002/bjs.4453] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that is implicated in early wound healing and fibrosis. Fibroblasts may initiate stricture formation in Crohn's disease through overexpression of VEGF. The aim of this study was to examine VEGF expression and regulation in fibroblasts isolated from patients with Crohn's disease. METHODS Fibroblasts were isolated by a primary explant technique from serosal biopsies of non-strictured and strictured segments of bowel from eight patients undergoing resection for Crohn's disease, and normal colon from six patients undergoing resection for benign and malignant colorectal disease. Fibroblasts were cultured with transforming growth factor (TGF) beta and corticosteroids. After 24 h the culture supernatant was collected for VEGF assay by enzyme-linked immunosorbent assay. RESULTS VEGF production was significantly higher in fibroblasts isolated from strictures (mean(s.e.m.) 1980(260) pg/ml) than from non-strictured segments (1116(165) pg/ml) in patients with Crohn's disease or control fibroblasts (898(93) pg/ml). TGF-beta increased VEGF production in normal and non-strictured Crohn's fibroblasts. Corticosteroids suppressed unstimulated VEGF production in all groups. CONCLUSION Enhanced serosal fibroblast VEGF production might play a role in initiating stricture formation in Crohn's disease. VEGF production in serosal fibroblasts is sensitive to stimulation with TGF-beta. Corticosteroids may reduce stricturing through suppression of VEGF.
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Affiliation(s)
- D Beddy
- Department of Surgery, Mater Misericordiae Hospital and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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Abstract
STUDY DESIGN Disc tissue obtained from patients undergoing surgery for scoliosis, lumbar radiculopathy, and discogenic pain was cultured under basal and lipopolysaccharide-stimulated conditions and the medium analyzed for production of a range of pro-inflammatory mediators. OBJECTIVES This study was conducted to confirm that the human intervertebral disc is capable of responding to a pro-inflammatory stimulus and to identify the principal mediators involved in any response. SUMMARY OF BACKGROUND DATA Degenerate human disc tissue has been shown to spontaneously secrete a number of pro-inflammatory mediators. The importance of these molecules in the pathophysiology of symptomatic disc degeneration is increasingly recognized. Human nucleus pulposus has been shown to synthesize increased amounts of interleukin (IL)-6, prostaglandin E2 (PGE2), and nitric oxide in response to stimulation with IL-1beta. Murine nucleus pulposus synthesizes increased amounts of IL-1beta, IL-6, IL-10, and granulocyte-macrophage colony-stimulating factor in response to lipopolysaccharide stimulation. Lipopolysaccharide is a potent inducer of tumor necrosis factor-alpha (TNF-alpha), which is thought to play an important role in the pathophysiology of sciatica. To date, human nucleus pulposus has not been shown to secrete TNF-alpha in response to a pro-inflammatory stimulus. METHODS Human disc tissue obtained from patients undergoing surgery for scoliosis, lumbar radiculopathy, and discogenic pain was cultured under basal and lipopolysaccharide-stimulated conditions and the medium subsequently analyzed for a range of pro-inflammatory mediators. RESULTS None of the specimens produced any TNF-alpha, IL-1beta, granulocyte-macrophage colony-stimulating factor, or leukotriene B4. Measurable quantities of IL-6, IL-8, PGE2, MCP-1, basic fibroblast growth factor, and trans forming growth factor-beta1 were produced by a number of specimens. Lipopolysaccharide significantly increased IL-6, IL-8, and PGE2 production in both control and degenerate disc tissue. Degenerate disc specimens responded more vigorously to lipopolysaccharide stimulation than scoliotic specimens. CONCLUSIONS We conclude that both scoliotic and degenerate human nucleus pulposus can respond to an exogenous pro-inflammatory stimulus by secreting increased amounts of IL-6, IL-8, and PGE2 but not TNF-alpha and that degenerate disc tissue is more sensitive to a pro-inflammatory stimulus than its scoliotic counterpart.
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Affiliation(s)
- J G Burke
- Department of Orthopaedic Surgery and Surgical Professorial Unit, Mater Misericordiae Hospital Dublin and University College Dublin, Ireland.
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O'Connell MJ, Smith CS, Fitzpatrick PE, Keane CO, Fitzpatrick JM, Behan M, Fenlon HF, Murray JG. Transrectal ultrasound-guided biopsy of the prostate gland: value of 12 versus 6 cores. ACTA ACUST UNITED AC 2003; 29:132-6. [PMID: 15160768 DOI: 10.1007/s00261-003-0089-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the effect on prostate carcinoma detection of 12 versus 6 core biopsies at transrectal ultrasound (TRUS), when all biopsies are taken from the lateral peripheral zone. This was a prospective study of 202 consecutive men, ages 51 to 81 years, referred for TRUS-guided biopsy of the prostate gland. All patients had prostate serum antigen levels higher than 4.0 ng/mL and/or abnormal digital rectal examination. In each case three biopsies were taken from the peripheral zones of the right and left lobes of the prostate. Biopsies were taken at the apex, midway between the apex and the base, and at the base. A second set of biopsies was taken from the same regions and analyzed separately. In total, twelve biopsies were taken. Note was subsequently made of additional carcinoma diagnosis increase in Gleason grade, and new diagnoses of carcinoma in the opposite side of the gland diagnosed on the second set of biopsies alone. Seventy-eight of the 202 men (38.6%) had prostatic carcinoma diagnosed on TRUS-guided biopsy. Of these 78 patients, six were diagnosed with malignancy based on the second set of biopsies alone, a 2.9% increase in the 202 patients, representing an increased yield of 8.3% (95% confidence interval, 5.3-28.6%). In nine cases (12.5%; 95% confidence interval, 6.2-22.9%), the Gleason tumor grade was increased on the second set of sextant biopsies; in an additional nine cases, carcinoma was detected in the opposite side of the gland. There were two complications (1%). A 12- versus six-core biopsy strategy for TRUS-guided biopsy of the prostate gland improves detection and histologic grading of prostate carcinoma. The added benefit of additional biopsies was lower in this series than in some prior studies using extensive biopsy protocols.
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Affiliation(s)
- M J O'Connell
- Department of Radiology, Mater Misericordiae Hospital, Eccles Street, Dublin 7, Ireland.
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Affiliation(s)
- P Boyle
- Surgical Professorial Unit, Mater Misericordiae Hospital, Dublin, Republic of Ireland
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Affiliation(s)
- J M Fitzpatrick
- Mater Misericordiae Hospital and University College, Dublin, Ireland
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Affiliation(s)
- J M Fitzpatrick
- Mater Misericordiae Hospital and University College, Dublin, Ireland
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Fitzpatrick JM, Watson RWG. Apoptosis in the prostate. Can J Urol 2003; 10:1796-8. [PMID: 12773229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The prostate requires androgens for development and glandular maintenance, dying by the process of apoptosis following their removal. Anti-androgen therapy is targeted to induce this process but eventually fails with the emergence of an androgen independent cancer. These cells have development mechanisms to survive with out androgen impart due to the expression of anti-apoptotic factors.
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Affiliation(s)
- J M Fitzpatrick
- Department of Surgery, University College Dublin, Dublin, Ireland
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Fitzpatrick JM. Introduction. Prostate Cancer Prostatic Dis 2002; 4:S1. [PMID: 12497051 DOI: 10.1038/sj.pcan.4500538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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McEleny KR, Watson RWG, Fitzpatrick JM. Defining a role for the inhibitors of apoptosis proteins in prostate cancer. Prostate Cancer Prostatic Dis 2002; 4:28-32. [PMID: 12497060 DOI: 10.1038/sj.pcan.4500502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2000] [Revised: 09/22/2000] [Accepted: 11/07/2000] [Indexed: 11/09/2022]
Abstract
The aim of this paper is to review the inhibitors of apoptosis proteins, a recently discovered group of caspase inhibitors. We will briefly review the relevance of apoptosis in prostate cancer and some of the control mechanisms, before describing the structure, function and regulation of these molecules. Lastly, we will consider the evidence for the role that IAPs may have in cancer and the implications for prostate cancer in particular. Prostate Cancer and Prostatic Diseases (2001) 4, 28-32
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Affiliation(s)
- K R McEleny
- Department of Surgery, Mater Misericordiae Hospital, University College Dublin, Ireland
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Fitzpatrick JM. Urology: A Handbook for Medical Students S. Brewster, D. Cranston, J. Noble and J. Reynard 245 × 190 mm. Pp. 153. Illustrated. 2001. Oxford: BIOS Scientific Publishers. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2002.02239_1.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- J M Fitzpatrick
- Surgical Professorial Unit, Mater Misericordiae Hospital, 47 Eccles Street, Dublin 7, Ireland
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Fitzpatrick JM. Operative pediatric urology. 2nd ed. J. D. Frank, J. P. Gearhart and H. M. Synder III (eds) 280 × 220 mm. Pp. 292. Illustrated. 2001. Edinburgh: Churchill Livingstone. £94·95. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.2002.02093_5.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- J M Fitzpatrick
- Surgical Professorial Unit, Mater Misericordiae Hospital and University College Dublin, 47 Eccles Street, Dublin 7, Ireland
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Wagner G, Claes H, Costa P, Cricelli C, De Boer J, Debruyne FMJ, Dean J, Dinsmore WW, Fitzpatrick JM, Ralph DJ, Hackett GI, Heaton JP, Hatzichristou DG, Mendive J, Meuleman EJ, Mirone V, Montorsi F, Raineri F, Schulman CC, Stief CG, Von Keitz AT, Wright PJ. A shared care approach to the management of erectile dysfunction in the community. Int J Impot Res 2002; 14:189-94. [PMID: 12058246 DOI: 10.1038/sj.ijir.3900882] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2002] [Revised: 04/02/2002] [Accepted: 04/15/2002] [Indexed: 11/09/2022]
Abstract
Erectile dysfunction (ED) affects men of all ages and results in considerable distress and impact on quality of life for those who suffer from it. As ED is associated with a wide variety of under-lying conditions and cardiovascular co-morbidities, there is a requirement for diversity of treatment options and several factors must be considered to customise and optimise therapy. In the ideal holistic approach to management of the ED patient, both primary care and specialist physicians have an important role to play. This article reports on a sequential approach for the diagnosis and treatment of ED, with an emphasis on 'shared care'. The deliberations are based on a pan-European inter-disciplinary group that met at the Lygon Arms, UK on 22 February 2002.
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Affiliation(s)
- G Wagner
- Department of Medical Physiology, University of Copenhagen, Denmark
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Burke JG, Watson RWG, McCormack D, Dowling FE, Walsh MG, Fitzpatrick JM. Intervertebral discs which cause low back pain secrete high levels of proinflammatory mediators. J Bone Joint Surg Br 2002; 84:196-201. [PMID: 11924650 DOI: 10.1302/0301-620x.84b2.12511] [Citation(s) in RCA: 422] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Herniated intervertebral disc tissue has been shown to produce a number of proinflammatory mediators and cytokines, but there have been no similar studies using discs from patients with discogenic low back pain. We have compared the levels of production of interleukin-6 (IL-6), interleukin-8 (IL-8) and prostaglandin E2 (PGE2) in disc tissue from patients undergoing discectomy for sciatica (63) with that from patients undergoing fusion for discogenic low back pain (20) using an enzyme-linked immunoabsorbent assay. There was a statistically significant difference between levels of production of IL-6 and IL-8 in the sciatica and low back pain groups (p < 0.006 and p < 0.003, respectively). The high levels of proinflammatory mediator found in disc tissue from patients undergoing fusion suggest that production of proinflammatory mediators within the nucleus pulposus may be a major factor in the genesis of a painful lumbar disc.
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Affiliation(s)
- J G Burke
- University College Dublin, the Mater Misericordiae Hospital, Ireland
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Doyle BT, O'Neill AJ, Newsholme P, Fitzpatrick JM, Watson RWG. The loss of IAP expression during HL-60 cell differentiation is caspase-independent. J Leukoc Biol 2002; 71:247-54. [PMID: 11818445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Human promyelocytic leukaemia cells (HL-60) differentiate into neutrophil-like cells that die spontaneously by apoptosis when treated with retinoic acid (RA). Inhibitors of apoptosis proteins (IAP) bind to and inhibit caspases 3, 7, and 9 activity and the induction of apoptosis. In this study, we demonstrate that undifferentiated HL-60 cells express IAP. During their differentiation, IAP expression is decreased at the mRNA and protein levels. In addition, we show that there is a corresponding increase in the expression and functional activity of active caspases 3 and 9. This activity was associated with the cleavage of XIAP, NAIP, and cIAP-2. Most importantly, we demonstrate that blocking caspase activity does not alter the decrease in IAP protein expression during differentiation but prevents caspase activation, IAP cleavage, and the induction of apoptosis. This result shows that the loss of IAP expression is independent of the induction of apoptosis and is solely related to the differentiation process. However, IAP cleavage is caspase-dependent. Terminal differentiation results in an altered apoptotic phenotype that is associated with the induction of HL-60 cell apoptosis.
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Affiliation(s)
- B T Doyle
- Department of Surgery, Mater Misericordiae Hospital, University College Dublin, Ireland
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Narula J, Acio ER, Narula N, Samuels LE, Fyfe B, Wood D, Fitzpatrick JM, Raghunath PN, Tomaszewski JE, Kelly C, Steinmetz N, Green A, Tait JF, Leppo J, Blankenberg FG, Jain D, Strauss HW. Annexin-V imaging for noninvasive detection of cardiac allograft rejection. Nat Med 2001; 7:1347-52. [PMID: 11726976 DOI: 10.1038/nm1201-1347] [Citation(s) in RCA: 252] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Heart transplant rejection is characterized pathologically by myocyte necrosis and apoptosis associated with interstitial mononuclear cell infiltration. Any one of these components can be targeted for noninvasive detection of transplant rejection. During apoptotic cell death, phosphatidylserine, a phospholipid that is normally confined to the inner leaflet of cell membrane bilayer, gets exteriorized. Technetium-99m-labeled annexin-V, an endogenous protein that has high affinity for binding to phosphatidylserine, has been administered intravenously for noninvasive identification of apoptotic cell death. In the present study of 18 cardiac allograft recipients, 13 patients had negative and five had positive myocardial uptake of annexin. These latter five demonstrated at least moderate transplant rejection and caspase-3 staining, suggesting apoptosis in their biopsy specimens. This study reveals the clinical feasibility and safety of annexin-V imaging for noninvasive detection of transplant rejection by targeting cell membrane phospholipid alterations that are commonly associated with the process of apoptosis.
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Affiliation(s)
- J Narula
- Hahnemann University Hospital, Philadelphia, Pennsylvania, USA.
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Coffey RN, Watson RW, Hegarty PK, Watson CL, Wolohan L, Brady HR, O'Keane C, Fitzpatrick JM. Priming prostate carcinoma cells for increased apoptosis is associated with up-regulation of the caspases. Cancer 2001; 92:2297-308. [PMID: 11745284 DOI: 10.1002/1097-0142(20011101)92:9<2297::aid-cncr1576>3.0.co;2-b] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The potential to prime prostatic carcinoma cell lines for apoptosis represents an exciting strategy for the treatment of patients with this disease. The ability and the underlying molecular mechanisms involved in sensitizing both androgen-sensitive and androgen-insensitive cell types to a range of apoptotic-inducing agents are investigated by the authors. METHODS Primary and secondary cell lines were pretreated with diethyl-maleate (DEM) prior to the induction of apoptosis by Fas antibody (1 microg/mL), cycloheximide (1 microg/mL), etoposide (62.5 microM), and radiation (5 grays). It was demonstrated previously that DEM (50 microM) increases the sensitivity to apoptosis induced by these agents. The effects of DEM on both protein and RNA expression was determined by Western blot analysis and a ribonuclease protection assay, respectively. The effects of DEM on intracellular glutathione (GSH) levels and its intracellular distribution also were assessed. RESULTS DEM did not affect the expression of the caspases at the transcriptional level but was associated with increased procaspase-3 and caspase-8 protein levels. DEM preincubation restored sensitivity to Fas antibody and radiation-induced apoptosis in cells from the LNCaP-bcl-2 transfectant cell line that, normally, are resistant to these apoptotic stimuli. It is that DEM chemically depletes intracellular thiol levels. Although no depletion in total intracellular thiol GSH was observed at these concentrations of DEM, trafficking of GSH from the nucleus to the cytosol was demonstrated. CONCLUSIONS Identification of the caspases as a potential target for chemical manipulation may serve as an effective, adjuvant-based approach in the treatment of patients with prostate carcinoma and, in particular, for immunotherapy and radiation-based strategies that rely on the activation of these death-effector proteases.
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Affiliation(s)
- R N Coffey
- Department of Surgery, Mater Misericordiae Hospital, University College Dublin, 47 Eccles Street, Dublin 7, Ireland.
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Abstract
Guidance systems designed for neurosurgery, hip surgery, spine surgery and for approaches to other anatomy that is relatively rigid can use rigid-body transformations to accomplish image registration. These systems often rely on point-based registration to determine the transformation and many such systems use attached fiducial markers to establish accurate fiducial points for the registration, the points being established by some fiducial localization process. Accuracy is important to these systems, as is knowledge of the level of that accuracy. An advantage of marker-based systems, particularly those in which the markers are bone-implanted, is that registration error depends only on the fiducial localization and is, thus, to a large extent independent of the particular object being registered. Thus, it should be possible to predict the clinical accuracy of marker-based systems on the basis of experimental measurements made with phantoms or previous patients. For most registration tasks, the most important error measure is target registration error (TRE), which is the distance after registration between corresponding points not used in calculating the registration transform. In this paper, we derive an approximation to the distribution of TRE; this is an extension of previous work that gave the expected squared value of TRE. We show the distribution of the squared magnitude of TRE and that of the component of TRE in an arbitrary direction. Using numerical simulations, we show that our theoretical results are a close match to the simulated ones.
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Affiliation(s)
- J M Fitzpatrick
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN 37235, USA.
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Sweeney P, Young LS, Fitzpatrick JM. An autoradiographic study of regional blood flow distribution in the rat kidney during ureteric obstruction--the role of vasoactive compounds. BJU Int 2001; 88:268-72. [PMID: 11488744 DOI: 10.1046/j.1464-410x.2001.02272.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the changes in regional renal blood flow during ureteric obstruction and to examine the role of vasoactive mediators in effecting these changes. MATERIALS AND METHODS Renal blood flow in Sprague-Dawley rats was assessed after periods of ureteric obstruction using a quantitative autoradiographic technique based on Kety's theory of diffusion of an inert tracer (14C-iodoantipyrine). Prostaglandins, thromboxanes and renin-angiotensin were inhibited pharmacologically using diclofenac sodium and enalapril. RESULTS Baseline blood flow to the outer cortex, inner cortex and medulla was 807, 258 and 105 mL/100 g/min, respectively. There was an increase in outer cortical blood flow after 10 min of ureteric obstruction which became significant at 30 min (P < 0.05). There was a significant decrease in inner cortical and medullary blood flow at 30 min, to 210 and 68 mL/100 g/min, respectively (P < 0.05). Diclofenac sodium abolished the increase in outer cortical blood flow. After 24 h of unilateral ureteric obstruction, outer cortical blood flow decreased to 492 mL/100 g/min; inner cortical blood flow also decreased but to a lesser extent, to 190 mL/100 g/min. Inhibition of prostaglandins, thromboxanes and the renin-angiotensin system reduced the degree of renal vasoconstriction but there was still a significant decrease in outer cortical perfusion despite the presence of these blocking agents. CONCLUSIONS The control of the renal vasculature involves a complex interplay between a variety of vasoactive mediators. Quantitative autoradiography offers the opportunity to evaluate changes in regional renal perfusion with high resolution and will allow a greater understanding of the pathophysiology of renal diseases.
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Affiliation(s)
- P Sweeney
- Department of Urology/Surgery, Mater Misericordiae Hospital and University College, Dublin, Ireland
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