1
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Schmidt DR, Gramatikov IMT, Sheen A, Williams CL, Hurwitz M, Dodge LE, Holupka E, Kiger WS, Cornwall-Brady MR, Huang W, Mak HH, Cormier KS, Condon C, Dane Wittrup K, Yilmaz ÖH, Stevenson MA, Down JD, Floyd SR, Roper J, Vander Heiden MG. Ablative radiotherapy improves survival but does not cure autochthonous mouse models of prostate and colorectal cancer. Commun Med (Lond) 2023; 3:108. [PMID: 37558833 PMCID: PMC10412558 DOI: 10.1038/s43856-023-00336-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 07/24/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND Genetically engineered mouse models (GEMMs) of cancer are powerful tools to study mechanisms of disease progression and therapy response, yet little is known about how these models respond to multimodality therapy used in patients. Radiation therapy (RT) is frequently used to treat localized cancers with curative intent, delay progression of oligometastases, and palliate symptoms of metastatic disease. METHODS Here we report the development, testing, and validation of a platform to immobilize and target tumors in mice with stereotactic ablative RT (SART). Xenograft and autochthonous tumor models were treated with hypofractionated ablative doses of radiotherapy. RESULTS We demonstrate that hypofractionated regimens used in clinical practice can be effectively delivered in mouse models. SART alters tumor stroma and the immune environment, improves survival in GEMMs of primary prostate and colorectal cancer, and synergizes with androgen deprivation in prostate cancer. Complete pathologic responses were achieved in xenograft models, but not in GEMMs. CONCLUSIONS While SART is capable of fully ablating xenografts, it is unable to completely eradicate disease in GEMMs, arguing that resistance to potentially curative therapy can be modeled in GEMMs.
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Affiliation(s)
- Daniel R Schmidt
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, USA.
- Harvard Medical School, Boston, MA, USA.
| | - Iva Monique T Gramatikov
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Allison Sheen
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christopher L Williams
- Harvard Medical School, Boston, MA, USA
- Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Radiation Oncology, Brigham and Women's Hospital, Boston, MA, USA
| | - Martina Hurwitz
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Laura E Dodge
- Harvard Medical School, Boston, MA, USA
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Edward Holupka
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - W S Kiger
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Milton R Cornwall-Brady
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Wei Huang
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Howard H Mak
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kathleen S Cormier
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Charlene Condon
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - K Dane Wittrup
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ömer H Yilmaz
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, USA
| | - Mary Ann Stevenson
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Julian D Down
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Scott R Floyd
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC, USA
| | - Jatin Roper
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Medicine, Division of Gastroenterology, and Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Dana-Farber Cancer Institute, Boston, MA, USA.
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2
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Isler JR, Pini N, Lucchini M, Shuffrey LC, Morales S, Bowers ME, Leach SC, Sania A, Wang L, Condon C, Nugent JD, Elliott AJ, Friedrich C, Andrew R, Fox NA, Myers MM, Fifer WP. Longitudinal characterization of EEG power spectra during eyes open and eyes closed conditions in children. Psychophysiology 2023; 60:e14158. [PMID: 35968705 PMCID: PMC9729391 DOI: 10.1111/psyp.14158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 07/27/2021] [Revised: 05/18/2022] [Accepted: 07/11/2022] [Indexed: 11/28/2022]
Abstract
This study is the first to examine spectrum-wide (1 to 250 Hz) differences in electroencephalogram (EEG) power between eyes open (EO) and eyes closed (EC) resting state conditions in 486 children. The results extend the findings of previous studies by characterizing EEG power differences from 30 to 250 Hz between EO and EC across childhood. Developmental changes in EEG power showed spatial and frequency band differences as a function of age and EO/EC condition. A 64-electrode system was used to record EEG at 4, 5, 7, 9, and 11 years of age. Specific findings were: (1) the alpha peak shifts from 8 Hz at 4 years to 9 Hz at 11 years, (2) EC results in increased EEG power (compared to EO) at lower frequencies but decreased EEG power at higher frequencies for all ages, (3) the EEG power difference between EO and EC changes from positive to negative within a narrow frequency band which shifts toward higher frequencies with age, from 9 to 12 Hz at 4 years to 32 Hz at 11 years, (4) at all ages EC is characterized by an increase in lower frequency EEG power most prominently over posterior regions, (5) at all ages, during EC, decreases in EEG power above 30 Hz are mostly over anterior regions of the scalp. This report demonstrates that the simple challenge of opening and closing the eyes offers the potential to provide quantitative biomarkers of phenotypic variation in brain maturation by employing a brief, minimally invasive protocol throughout childhood.
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Affiliation(s)
- J. R. Isler
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032 USA
| | - N. Pini
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032 USA
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | - M. Lucchini
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032 USA
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | - L. C. Shuffrey
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032 USA
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | - S. Morales
- Department of Psychology, University of Southern California, Los Angeles, CA 90089 USA
| | - M. E. Bowers
- Department of Human Development and Quantitative Methodology, University of Maryland, College Park, MD 20742 USA
| | - S. C. Leach
- Department of Human Development and Quantitative Methodology, University of Maryland, College Park, MD 20742 USA
| | - A. Sania
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032 USA
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | - L. Wang
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
- Data Science Institute, Columbia University, New York, NY 10027 USA
| | - C. Condon
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | - J. D. Nugent
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | | | - C. Friedrich
- Avera Research Institute, Sioux Falls, SD 57108 USA
| | - R. Andrew
- Avera Research Institute, Sioux Falls, SD 57108 USA
| | - N. A. Fox
- Department of Human Development and Quantitative Methodology, University of Maryland, College Park, MD 20742 USA
| | - M. M. Myers
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032 USA
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032 USA
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
| | - W. P. Fifer
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032 USA
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032 USA
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY 10032 USA
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3
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Condon C, Connaughton R, Keady N, Martin M. 59 IMPROVING DELIRIUM AWARENESS AMONGST JUNIOR DOCTORS IN A REGIONAL HOSPITAL. Age Ageing 2022. [DOI: 10.1093/ageing/afac218.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Delirium is a common medical emergency which is well known to be associated with adverse outcomes but often remains under recognised and inappropriately managed in the acute care setting. This audit aimed to assess Non-Consultant Hospital Doctors (NCHDs) approach to diagnosing, managing and prescribing in patients with delirium.
Methods
Data was collected via an anonymous questionnaire and distributed to NCHDs in April 2021 and repeated again in March 2022 following several education sessions on delirium and the inclusion of the 4AT screening tool in the medical admission pro-forma. A point prevalence survey on 20 randomised patient charts was completed in April 2022 to establish if a 4AT score was documented by NCHDs in the medical admission pro-forma.
Results
Two audits were completed over a one-year period between April 2021 and March 2022 including NCHDs, n=25 and n=26 respectively. The results showed that 56% vs 70% considered delirium as a medical emergency, 40% vs 77% stated that they used the 4AT tool when assessing cognition in patients aged over 65 years of age and 72% vs 76% stated that they did not use any guideline when prescribing a medication for a patient with delirium. However, on review of 20 medical charts, 0% of patients had a documented 4AT score completed on admission in April 2022.
Conclusion
Although there was a positive improvement in NCHD’s knowledge of delirium diagnosis and management on paper, it was evident that this did not transpire into clinical practice. We will address this by delivering further education sessions on delirium, with a plan to re-audit. We have also made the National Delirium Algorithms visible in the emergency department and on the wards to act as visual prompts for our NCHDs.
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Affiliation(s)
- C Condon
- Naas General Hospital, Naas , Ireland
| | | | - N Keady
- Naas General Hospital, Naas , Ireland
| | - M Martin
- Naas General Hospital, Naas , Ireland
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4
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Rickelt S, Neyaz A, Condon C, Whittaker CA, Zaidi AH, Taylor MS, Abbruzzese G, Mattia AR, Zukerberg L, Shroff SG, Yilmaz OH, Yılmaz O, Wu EY, Choi WT, Jobe BA, Odze RD, Patil DT, Deshpande V, Hynes RO. Agrin loss in Barrett's esophagus-related neoplasia and its utility as a diagnostic and predictive biomarker. Clin Cancer Res 2021; 28:1167-1179. [PMID: 34785582 DOI: 10.1158/1078-0432.ccr-21-2822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/29/2021] [Accepted: 11/10/2021] [Indexed: 11/16/2022]
Abstract
PURPOSE There is an unmet need for identifying novel biomarkers in Barrett's esophagus (BE) that could stratify patients with regards to neoplastic progression. We investigate the expression patterns of extracellular matrix (ECM) molecules in BE and BE-related neoplasia, and assess their value as biomarkers for the diagnosis of BE-related neoplasia and to predict neoplastic progression. EXPERIMENTAL DESIGN Gene expression analyses of ECM matrisome gene sets were performed using publicly available data on human BE, BE-related dysplasia, esophageal ADCA and normal esophagus. Immunohistochemical expression of basement membrane (BM) marker agrin (AGRN) and p53 was analyzed in biopsies of BE-related neoplasia from 321 patients in three independent cohorts. RESULTS Differential gene expression analysis revealed significant enrichment of ECM matrisome gene sets in dysplastic BE and ADCA compared with controls. Loss of BM AGRN expression was observed in both BE-related dysplasia and ADCA. The mean AGRN loss in BE glands was significantly higher in BErelated dysplasia and ADCA compared to non-dysplastic BE (NDBE; p<0.001; specificity=82.2% and sensitivity=96.4%). Loss of AGRN was significantly higher in NDBE samples from progressors compared to non-progressors (p<0.001) and identified patients who progressed to advanced neoplasia with a specificity of 80.2% and sensitivity of 54.8%. Moreover, the combination of AGRN loss and abnormal p53 staining identified progression to BE-related advanced neoplasia with a specificity and sensitivity of 86.5% and 58.7%. CONCLUSIONS We highlight ECM changes during BE progression to neoplasia. BM AGRN loss is a novel diagnostic biomarker that can identify NDBE patients at increased risk of developing advanced neoplasia.
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Affiliation(s)
- Steffen Rickelt
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | - Azfar Neyaz
- Department of Pathology, Massachusetts General Hospital
| | - Charlene Condon
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | - Charles A Whittaker
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | - Ali H Zaidi
- Esophageal and Lung Institute, Allegheny Health Network
| | | | - Genevieve Abbruzzese
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | | | | | - Omer H Yilmaz
- The David H. Koch Institute for Integrative Cancer Research at MIT, Massachusetts Institute of Technology
| | - Osman Yılmaz
- Pathology & Laboratory Medicine, Boston University School of Medicine
| | | | - Won-Tak Choi
- Department of Pathology, University of California, San Francisco
| | | | | | - Deepa T Patil
- Department of Pathology, Brigham and Women's Hospital
| | - Vikram Deshpande
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School
| | - Richard O Hynes
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
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5
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Norton S, Condon C, O’Kelly P, Cooney A, O’Connor E, Power R, Forde J, Ferede A, Robertson I, Smyth G, Little D, Mohan P. The Paediatric Renal Transplant Recipient: A retrospective review of the changing trends of transplantation in Ireland. EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00201-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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6
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Condon C, Norton S, O’Kelly P, Cooney A, McDermott A, Power R, Forde J, Ferede A, Robertson I, Smyth G, Little D, Mohan P. A cross sectional sample study of pregnancy and renal outcomes after renal transplant at the National Kidney Transplant Service. EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00200-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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7
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Rickelt S, Condon C, Mana M, Whittaker C, Pfirschke C, Roper J, Patil DT, Brown I, Mattia AR, Zukerberg L, Zhao Q, Chetty R, Lauwers GY, Neyaz A, Leijssen LGJ, Boylan K, Yilmaz OH, Deshpande V, Hynes RO. Agrin in the Muscularis Mucosa Serves as a Biomarker Distinguishing Hyperplastic Polyps from Sessile Serrated Lesions. Clin Cancer Res 2020; 26:1277-1287. [PMID: 31852835 PMCID: PMC7073301 DOI: 10.1158/1078-0432.ccr-19-2898] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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] [Received: 09/05/2019] [Revised: 10/25/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE Sessile serrated lesions (SSL) are precursors to colon carcinoma, and their distinction from other polyps, in particular hyperplastic polyps (HP), presents significant diagnostic challenges. We evaluated expression patterns in colonic polyps of previously identified colon carcinoma-associated extracellular matrix (ECM) proteins to identify markers distinguishing SSLs from other polyps. EXPERIMENTAL DESIGN Gene-expression analyses of ECM proteins were performed using publicly available data on preneoplastic colonic polyps. In parallel, we evaluated by IHC the expression of agrin (AGRN) in over 400 colonic polyps, including HP, SSL with and without dysplasia, traditional serrated adenomas (TSA), and tubular adenomas (TA), and compared the consistency of standard histologic diagnosis of SSLs by experienced gastrointestinal pathologists with that of AGRN IHC. RESULTS Differential gene expression analysis and IHC identified AGRN, serine peptidase inhibitor (SERPINE2), and TIMP metallopeptidase inhibitor 1 (TIMP1) elevated in SSLs and HPs but decreased in TAs and absent in normal colon. AGRN-positive basal laminae were noted in all TA, TSA, HP, and SSL in distinguishable patterns, whereas other polyps and normal mucosa were negative. SSL with or without dysplasia consistently showed IHC staining for AGRN in the muscularis mucosae, which was absent in HP, TSA, TA, and other polyps. In contrast, histologic evaluation showed only weak interobserver agreement (kappa value = 0.493) in distinguishing SSLs. CONCLUSIONS Muscularis mucosae-based AGRN immunostaining is a novel biomarker to distinguish SSL from HP, TSA, and TA, with a specificity of 97.1% and sensitivity of 98.9% and can assist in diagnosis of morphologically challenging colonic polyps.
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Affiliation(s)
- Steffen Rickelt
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.
| | - Charlene Condon
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Swanson Biotechnology Center, David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Miyeko Mana
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Charlie Whittaker
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Swanson Biotechnology Center, David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Christina Pfirschke
- Center for Systems Biology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, Massachusetts
| | - Jatin Roper
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Deepa T Patil
- Cleveland Clinic, Department of Pathology, Cleveland, Ohio
| | - Ian Brown
- Envoi Pathology, Kelvin Grove, Queensland, Australia
| | - Anthony R Mattia
- Department of Pathology, North Shore Medical Center, Salem, Massachusetts
| | - Lawrence Zukerberg
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Qing Zhao
- Department of Pathology and Laboratory Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Runjan Chetty
- Department of Pathology, Toronto General Hospital, Toronto, Ontario, Canada
| | | | - Azfar Neyaz
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Lieve G J Leijssen
- Department of General and Gastrointestinal Surgery, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Katherine Boylan
- Department of Pathology, University of Utah, Huntsman Cancer Institute, Salt Lake City, Utah
| | - Omer H Yilmaz
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Vikram Deshpande
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
| | - Richard O Hynes
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.
- Howard Hughes Medical Institute, Chevy Chase, Maryland
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
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8
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Brett T, Arnold-Reed D, She Ping-Delfos WC, Condon C, Watts G. Familial Hypercholesterolaemia - Time For A Greater Role For Primary Care. Atherosclerosis 2019. [DOI: 10.1016/j.atherosclerosis.2019.06.637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Condon C, McGrane N, Mockler D, Stokes E. Ability of physiotherapists to undertake evidence-based practice steps: a scoping review. Physiotherapy 2015; 102:10-9. [PMID: 26404896 DOI: 10.1016/j.physio.2015.06.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 06/12/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND Evidence-based practice (EBP) is promoted to ensure quality of care. However, analysis of the skill of physiotherapists in undertaking the steps of EBP, or the impact of EBP on the work of physiotherapists is limited. OBJECTIVES To conduct a scoping review into physiotherapists performing the steps of EBP. DATA SOURCE Literature concerning the skill of physiotherapists in EBP between 1990 and June 2013 was searched using AMED, Academic Search Complete, CINAHL, PubMed, ERIC, PEDRO and EMBASE databases. STUDY SELECTION Twenty-five studies (six qualitative, one mixed methods and 18 quantitative) were selected. DATA EXTRACTION AND SYNTHESIS Quantitative and qualitative data were extracted using two appraisal tools to analyse each of the five steps of EBP. RESULTS Limited evidence exists to show that physiotherapists undertake the full EBP process. Despite formulating clinical questions and acquiring literature-based evidence, the drivers for conducting literature or evidence searches have not been clarified. The critical appraisal step was mainly assessed in the form of recognition of statistical terms. Only examples of guideline usage support the reflective final assessment step. Physiotherapists report using their peers and other trusted sources in preference to literature, primarily due to time but also due to divergence between the literature-based evidence and other evidence that they use and value (tacit knowledge). A positive impact of EBP on patient outcomes is lacking. CONCLUSIONS Understanding the information needs of physiotherapists may be necessary before adoption of the EBP process. The use of professional networks may offer a better means to identify knowledge gaps and translate acquired knowledge into practice, rather than focusing on individual skills in EBP.
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Affiliation(s)
- C Condon
- Physiotherapy Discipline, Trinity Centre for Health Sciences, Dublin, Ireland.
| | - N McGrane
- Physiotherapy Discipline, Trinity Centre for Health Sciences, Dublin, Ireland
| | - D Mockler
- Library Services, Trinity Centre for Health Sciences, Dublin, Ireland
| | - E Stokes
- Physiotherapy Discipline, Trinity Centre for Health Sciences, Dublin, Ireland
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10
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Condon C, Moloney E, Lane S, Stokes E. Pulmonary rehabilitation for patients with chronic obstructive pulmonary disease: An audit of referral and uptake. ACTA ACUST UNITED AC 2015. [DOI: 10.3233/ppr-150058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- C. Condon
- Discipline of Physiotherapy, Trinity Centre for Health Sciences, Trinity College Dublin, Dublin, Ireland
| | - E. Moloney
- Department of Respiratory Medicine, Tallaght Hospital, Dublin, Ireland
| | - S. Lane
- Department of Respiratory Medicine, Tallaght Hospital, Dublin, Ireland
| | - E. Stokes
- Discipline of Physiotherapy, Trinity Centre for Health Sciences, Trinity College Dublin, Dublin, Ireland
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11
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Condon C, Jackson SHD, Whitney J. 49 * CAN CARE HOME RESIDENTS ACHIEVE THE RECOMMENDED DOSE AND INTENSITY OF FALLS PREVENTION EXERCISE? - ANALYSIS FROM THE PREVENTION OF FALLS IN COGNITIVELY IMPAIRED OLDER ADULTS LIVING IN RESIDENTIAL CARE (PROF-COG) STUDY. Age Ageing 2015. [DOI: 10.1093/ageing/afv032.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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12
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McNamara D, Qasim A, Lee N, Condon C, O'Morain C. Round one of the Adelaide and Meath Hospital/Trinity College Colorectal Cancer Screening Programme: programme report and analysis based on established international key performance indices. Ir J Med Sci 2011; 180:549-52. [PMID: 21264524 DOI: 10.1007/s11845-010-0650-8] [Citation(s) in RCA: 14] [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] [Received: 11/02/2010] [Accepted: 11/21/2010] [Indexed: 02/07/2023]
Abstract
BACKGROUND In Ireland, colorectal cancer (CRC) is the second most frequently diagnosed cancer in men, after prostate cancer, and the second most frequently diagnosed cancer in women, after breast cancer. By 2020, the number of new cases diagnosed annually in Ireland is projected to have increased by 79% in men and 56% in women. Organised screening for CRC is already underway or is in the process of being rolled out in several European countries, either at a regional or national level. The Adelaide and Meath Hospital/ Trinity College Dublin Colorectal Cancer Screening Programme (TTC-CRC-SP) is Ireland's first pilot population based bowel screening programme. METHOD Based on a biennial test model the pilot aimed to assess the accuracy of FIT and to evaluate the whole programme based on established international key performance indices. RESULTS To date 9,993 individuals aged 50-74 years have been invited to participate in the TTC-CRC-SP with over 5,000 FIT's analysed. Overall uptake was 51% and FIT positivity was 10%. The programme has undertaken over 400 screening colonoscopies and detected 154 precancerous adenomas and 38 cancerous lesions. CONCLUSIONS The first round of The Adelaide and Meath Hospital Tallaght/Trinity College Dublin Colorectal Cancer Screening Programme has been highly successful and confirmed that there is an advantage for FIT based two stage bowel cancer screening programmes.
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Affiliation(s)
- D McNamara
- Department of Clinical Medicine, Trinity Centre, The Adelaide and Meath Hospital, Trinity College Dublin, Tallaght, Dublin 24, Ireland.
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13
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Condon C, O'leary A, Deasy A, Collender V, Walsh E, Doherty C. 152 Poster Moderated is Self Efficacy a Predictor of Weight Loss in Obese Adults Diagnosed with Cardiac Disease? Eur J Cardiovasc Nurs 2010. [DOI: 10.1016/s1474-5151(10)60113-2] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- C. Condon
- University College Cork, Cork, Ireland
| | | | - A. Deasy
- Mercy University Hospital, Cork, Ireland
| | - V. Collender
- South Infirmary/Victoria University Hospital, Cork, Ireland
| | - E. Walsh
- University College Cork, Cork, Ireland
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14
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Condon C, Gormley J, Hussey J. A review of the physical activity levels of children with juvenile arthritis. Physical Therapy Reviews 2009. [DOI: 10.1179/108331909x12540993898215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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15
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Purcell E, Condon C. Intense pulsed light therapy in the management of hereditary benign telangiectasia. ACTA ACUST UNITED AC 2004; 57:453-5. [PMID: 15191828 DOI: 10.1016/j.bjps.2003.11.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2002] [Accepted: 11/17/2003] [Indexed: 11/29/2022]
Abstract
Hereditary benign telangiectasia is an idiopathic condition that causes considerable cosmetic embarrassment but has eluded successful treatment due to its extensive nature. We report a case of hereditary benign telangiectasia of the lower limbs in which the challenge of treating an extensive vascular lesion is met by using an Intense pulsed light (IPL) source.
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Affiliation(s)
- E Purcell
- Department of Plastic and Reconstructive Surgery, University College Hospital, Galway, Ireland.
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16
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Condon C, Brechemier-Baey D, Beltchev B, Grunberg-Manago M, Putzer H. Identification of the gene encoding the 5S ribosomal RNA maturase in Bacillus subtilis: mature 5S rRNA is dispensable for ribosome function. RNA 2001; 7:242-253. [PMID: 11233981 PMCID: PMC1370082 DOI: 10.1017/s1355838201002163] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Over 25 years ago, Pace and coworkers described an activity called RNase M5 in Bacillus subtilis cell extracts responsible for 5S ribosomal RNA maturation (Sogin & Pace, Nature, 1974, 252:598-600). Here we show that RNase M5 is encoded by a gene of previously unknown function that is highly conserved among the low G + C gram-positive bacteria. We propose that the gene be named rnmV. The rnmV gene is nonessential. B. subtilis strains lacking RNase M5 do not make mature 5S rRNA, indicating that this process is not necessary for ribosome function. 5S rRNA precursors can, however, be found in both free and translating ribosomes. In contrast to RNase E, which cleaves the Escherichia coli 5S precursor in a single-stranded region, which is then trimmed to yield mature 5S RNA, RNase M5 cleaves the B. subtilis equivalent in a double-stranded region to yield mature 5S rRNA in one step. For the most part, eubacteria contain one or the other system for 5S rRNA production, with an imperfect division along gram-negative and gram-positive lines. A potential correlation between the presence of RNase E or RNase M5 and the single- or double-stranded nature of the predicted cleavage sites is explored.
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Affiliation(s)
- C Condon
- Unité Propre de Recherche 9073, Institut de Biologie Physico-Chimique, Paris, France.
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17
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Condon C, Hourihane SL, Dang-Lawson M, Escribano J, Matsuuchi L. Aberrant trafficking of the B cell receptor Ig-alpha beta subunit in a B lymphoma cell line. J Immunol 2000; 165:1427-37. [PMID: 10903747 DOI: 10.4049/jimmunol.165.3.1427] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The B cell Ag receptor (BCR) has two important functions: first, it binds and takes up Ag for presentation to T lymphocytes; and second, it transmits signals that regulate B cell development. Normal expression of the BCR requires the association of the Ag binding subunit, membrane IgM (mIgM), with the signaling component, the Ig-alpha beta heterodimer. After assembly in the endoplasmic reticulum, the intact BCR travels through the secretory pathway to the cell surface. In this paper, we report two variants of the B lymphoma cell lines, WEHI 279 and WEHI 231, that have both lost the ability to express mu heavy chain and consequently do not express mIgM. However, these variants do express the Ig-alpha beta heterodimer. In one variant, WEHI 279*, the Ig-alpha beta remained trapped intracellularly in the absence of mIgM. The other variant, 303.1.5.LM, expressed an aberrantly glycosylated Ig-alpha beta on the cell surface that was capable of signaling after cross-linking with anti-Ig-beta Abs. Further characterization uncovered a point mutation in the 303.1.5.LM mb1 gene that would change a proline for a leucine in the extracellular domain of Ig-alpha. The 303.1.5.LM Ig-alpha beta could not associate with a wild-type mIgM after mu heavy chain was reconstituted by DNA transfection. Thus, this mutation could define a region of the Ig-alpha polypeptide that is important for recognition by the endoplasmic reticulum quality control system, for association with glycosylating enzymes, and for the association of Ig-alpha beta subunits with mIgM subunits to create a complete BCR complex.
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MESH Headings
- Animals
- Antigens, CD/analysis
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Biological Transport/genetics
- Biological Transport/immunology
- CD79 Antigens
- Cell Membrane/immunology
- Cell Membrane/metabolism
- Cricetinae
- Hexosaminidases/metabolism
- Hybridomas
- Immunoglobulin Heavy Chains/biosynthesis
- Immunoglobulin Light Chains/biosynthesis
- Immunoglobulin M/metabolism
- Immunoglobulin mu-Chains/biosynthesis
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/metabolism
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/metabolism
- Mice
- Mutation
- Receptors, Antigen, B-Cell/analysis
- Receptors, Antigen, B-Cell/biosynthesis
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Sequence Analysis, DNA
- Tumor Cells, Cultured
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Affiliation(s)
- C Condon
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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18
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Clarke S, Harrington P, Condon C, Kelleher D, Smith OP, Mulcahy F. Late onset hepatitis and prolonged deterioration in hepatic function associated with nevirapine therapy. Int J STD AIDS 2000; 11:336-7. [PMID: 10824944 DOI: 10.1177/095646240001100511] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [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: 11/15/2022]
Abstract
The aetiology of hepatic dysfunction in patients with HIV infection is multifactorial. Re-activation of hepatitis C infection, drug toxicity, and opportunistic infections are all potential causes. Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor used as part of combination antiretroviral therapy for the treatment of HIV infection. It is associated with a significant incidence of hepatotoxicity, usually occurring in the initial month of therapy. We report the case of a 49-year-old man who developed NVP-induced prolonged hepatotoxicity 5 months after commencing antiretroviral therapy.
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Affiliation(s)
- S Clarke
- Department of Genito-Urinary Medicine, St James's Hospital, Dublin, Ireland
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19
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Clarke S, Harrington P, Condon C, Kelleher D, Smith OP, Mulcahy F. Late onset hepatitis and prolonged deterioration in hepatic function associated with nevirapine therapy. Int J STD AIDS 2000. [DOI: 10.1258/0956462001915831] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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20
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Asai T, Condon C, Voulgaris J, Zaporojets D, Shen B, Al-Omar M, Squires C, Squires CL. Construction and initial characterization of Escherichia coli strains with few or no intact chromosomal rRNA operons. J Bacteriol 1999; 181:3803-9. [PMID: 10368156 PMCID: PMC93859 DOI: 10.1128/jb.181.12.3803-3809.1999] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Escherichia coli genome carries seven rRNA (rrn) operons, each containing three rRNA genes. The presence of multiple operons has been an obstacle to many studies of rRNA because the effect of mutations in one operon is diluted by the six remaining wild-type copies. To create a tool useful for manipulating rRNA, we sequentially inactivated from one to all seven of these operons with deletions spanning the 16S and 23S rRNA genes. In the final strain, carrying no intact rRNA operon on the chromosome, rRNA molecules were expressed from a multicopy plasmid containing a single rRNA operon (prrn). Characterization of these rrn deletion strains revealed that deletion of two operons was required to observe a reduction in the growth rate and rRNA/protein ratio. When the number of deletions was extended from three to six, the decrease in the growth rate was slightly more than the decrease in the rRNA/protein ratio, suggesting that ribosome efficiency was reduced. This reduction was most pronounced in the Delta7 prrn strain, in which the growth rate, unlike the rRNA/protein ratio, was not completely restored to wild-type levels by a cloned rRNA operon. The decreases in growth rate and rRNA/protein ratio were surprisingly moderate in the rrn deletion strains; the presence of even a single operon on the chromosome was able to produce as much as 56% of wild-type levels of rRNA. We discuss possible applications of these strains in rRNA studies.
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Affiliation(s)
- T Asai
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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21
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Luo D, Condon C, Grunberg-Manago M, Putzer H. In vitro and in vivo secondary structure probing of the thrS leader in Bacillus subtilis. Nucleic Acids Res 1998; 26:5379-87. [PMID: 9826762 PMCID: PMC148014 DOI: 10.1093/nar/26.23.5379] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [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: 11/12/2022] Open
Abstract
The Bacillus subtilis thrS gene is a member of the T-box gene family in Gram-positive organisms whose expression is regulated by a tRNA-mediated transcriptional antitermination mechanism involving a direct tRNA:mRNA interaction. The complex leader sequences of these genes share only short stretches of primary sequence homology, but a common secondary structure has been proposed by comparing the leaders of many genes of this family. The proposed mechanism forthe tRNA:mRNA interaction depends heavily on the secondary structure model, but is so far only supported by genetic evidence. We have studied the structure of the B.subtilis thrS leader in solution, in protection experiments using both chemical and enzymatic probes. The thrS leader structure was also probed in vivo using dimethylsulphate and the in vitro and in vivo data are in good accordance. We have organized the thrS leader into three major domains comprising six separate stem-loops. All but one of the short sequences conserved in this gene family are present in loop structures. The ACC specifier codon proposed to interact with the tRNAThrGGUisoacceptor is present in a bulge and probably exists in a stacking conformation. The proposed antiterminator structure is not visible in transcripts containing the terminator, but was probed using a transcript with the 3'-half of the terminator deleted and its folding appears consistent with the regulatory model. The leader sequences, and in particular the specifier domains, of the other genes of this family can be folded similarly to the experimentally solved thrS structure.
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Affiliation(s)
- D Luo
- UPR 9073, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
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22
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Abstract
We have recently reported that processing occurs in the untranslated leader region of several members of a family of Gram-positive genes regulated by tRNA-mediated antitermination. We showed that cleavage at this site plays an important role in the induction of Bacillus subtilis thrS gene expression, following threonine starvation, by stabilising the downstream mRNA. Here we show that, when transferred on a plasmid, processing of the B. subtilis thrS leader can occur at the same site in Escherichia coli. Cleavage at this site is dependent on the E. coli endoribonuclease E, both in vivo and in vitro, suggesting that a functional homologue of RNase E is responsible for thrS processing in B. subtilis.
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Affiliation(s)
- C Condon
- UPR 9073, Institut de Biologie Physico-Chimique, Paris, France
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23
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24
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Condon C. Long term effects of smoking cessation program for cardiac patients ... (continuing education credit). Kans Nurse 1997; 72:1-2. [PMID: 9069878] [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: 02/03/2023]
Abstract
Twenty-eight cardiac rehabilitation patients who were smokers were followed for three years to measure smoking outcomes after an inpatient smoking cessation intervention. Participants were interviewed at three weeks, six months, one, two, and three year intervals to determine their smoking practice. Thirty-six percent (N = 10) of the smokers were not smoking at three years post education. The results suggest that smoking intervention can have a positive impact on long term smoking cessation outcomes.
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25
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Abstract
Delivery of antigen in a manner that induces effective, antigen-specific immunity is a critical challenge in vaccine design. Optimal antigen presentation is mediated by professional antigen-presenting cells (APCs) capable of taking up, processing and presenting antigen to T cells in the context of costimulatory signals required for T-cell activation. Developing immunization strategies to optimize antigen presentation by dendritic cells, the most potent APCs, is a rational approach to vaccine design. Here we show that cutaneous genetic immunization with naked DNA results in potent, antigen-specific, cytotoxic T lymphocyte-mediated protective tumor immunity. This method of immunization results in the transfection of skin-derived dendritic cells, which localize in the draining lymph nodes. These observations provide a basis for further development of DNA-based vaccines and demonstrate the feasibility of genetically engineering dendritic cells in vivo.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigen Presentation
- Biolistics
- Cell Movement
- Dendritic Cells/immunology
- Epitopes/genetics
- Epitopes/immunology
- Feasibility Studies
- Female
- H-2 Antigens/immunology
- Immunization/methods
- Lymph Nodes/immunology
- Lymphoma, T-Cell/pathology
- Melanoma, Experimental/genetics
- Melanoma, Experimental/immunology
- Melanoma, Experimental/pathology
- Melanoma, Experimental/prevention & control
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Neoplasm Transplantation
- Ovalbumin/genetics
- Ovalbumin/immunology
- T-Lymphocytes, Cytotoxic/immunology
- Tumor Cells, Cultured
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
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Affiliation(s)
- C Condon
- Department of Dermatology, University of Pittsburgh School of Medicine, Pennsylvania 15213, USA
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26
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Condon C, Putzer H, Grunberg-Manago M. Processing of the leader mRNA plays a major role in the induction of thrS expression following threonine starvation in Bacillus subtilis. Proc Natl Acad Sci U S A 1996; 93:6992-7. [PMID: 8692931 PMCID: PMC38922 DOI: 10.1073/pnas.93.14.6992] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [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: 02/01/2023] Open
Abstract
The threonyl-tRNA synthetase gene, thrS, is a member of a family of Gram-positive genes that are induced following starvation for the corresponding amino acid by a transcriptional antitermination mechanism involving the cognate uncharged tRNA. Here we show that an additional level of complexity exists in the control of the thrS gene with the mapping of an mRNA processing site just upstream of the transcription terminator in the thrS leader region. The processed RNA is significantly more stable than the full-length transcript. Under nonstarvation conditions, or following starvation for an amino acid other than threonine, the full-length thrS mRNA is more abundant than the processed transcript. However, following starvation for threonine, the thrS mRNA exists primarily in its cleaved form. This can partly be attributed to an increased processing efficiency following threonine starvation, and partly to a further, nonspecific increase in the stability of the processed transcript under starvation conditions. The increased stability of the processed RNA contributes significantly to the levels of functional RNA observed under threonine starvation conditions, previously attributed solely to antitermination. Finally, we show that processing is likely to occur upstream of the terminator in the leader regions of at least four other genes of this family, suggesting a widespread conservation of this phenomenon in their control.
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Affiliation(s)
- C Condon
- Unité Propre de Recherche 9073, Institut de Biologie Physic-Chimique, Paris, France
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27
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Abstract
In this review, we summarize progress on the regulation of the aminoacyl-tRNA synthetase genes in Bacillus subtilis. Most of the genes encoding this set of enzymes in B subtilis are members of a large family of Gram-positive genes and operons controlled by a novel antitermination mechanism that uses their cognate uncharged tRNA as the effector. A subset of these genes is, in addition, likely to be controlled at the level of mRNA processing and degradation. We describe the key experiments leading to these conclusions.
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Affiliation(s)
- C Condon
- UPR 9073, Institut de Biologie Physico-Chimique, Paris, France
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28
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Abstract
The control of rRNA synthesis in response to both extra- and intracellular signals has been a subject of interest to microbial physiologists for nearly four decades, beginning with the observations that Salmonella typhimurium cells grown on rich medium are larger and contain more RNA than those grown on poor medium. This was followed shortly by the discovery of the stringent response in Escherichia coli, which has continued to be the organism of choice for the study of rRNA synthesis. In this review, we summarize four general areas of E. coli rRNA transcription control: stringent control, growth rate regulation, upstream activation, and anti-termination. We also cite similar mechanisms in other bacteria and eukaryotes. The separation of growth rate-dependent control of rRNA synthesis from stringent control continues to be a subject of controversy. One model holds that the nucleotide ppGpp is the key effector for both mechanisms, while another school holds that it is unlikely that ppGpp or any other single effector is solely responsible for growth rate-dependent control. Recent studies on activation of rRNA synthesis by cis-acting upstream sequences has led to the discovery of a new class of promoters that make contact with RNA polymerase at a third position, called the UP element, in addition to the well-known -10 and -35 regions. Lastly, clues as to the role of antitermination in rRNA operons have begun to appear. Transcription complexes modified at the antiterminator site appear to elongate faster and are resistant to the inhibitory effects of ppGpp during the stringent response.
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Affiliation(s)
- C Condon
- Department of Molecular Biology and Microbiology, Tufts University Health Sciences Campus, Boston, Massachusetts 02111, USA
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29
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Heinrich T, Condon C, Pfeiffer T, Hartmann RK. Point mutations in the leader boxA of a plasmid-encoded Escherichia coli rrnB operon cause defective antitermination in vivo. J Bacteriol 1995; 177:3793-800. [PMID: 7601845 PMCID: PMC177098 DOI: 10.1128/jb.177.13.3793-3800.1995] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We have introduced point mutations into the leader boxA of a plasmid-encoded Escherichia coli rrnB operon to study the in vivo role of this regulatory element in the natural context of rRNA synthesis. The same mutations were previously shown to cause severe antitermination defects in vitro and in the context of a reporter gene assay. The plasmid-encoded rrnB mutant constructs studied here also contained point mutations in the 16S and 23S rRNA genes, which were used to distinguish rRNAs derived from plasmid and chromosomal rrn operons by primer extension analysis. Point mutations in boxA reduced the fraction of plasmid-derived rRNA in the cell from 75% to about 50%. The reduction was similar for both 30S and 50S subunits as well as 70S ribosomes, suggesting that no transcriptional polarity occurred between the expression of the 16S and 23S rRNA genes in plasmid rrnB operons carrying a mutant boxA. The boxA mutations do not affect the amount of transcription initiation, suggesting that a suboptimal leader boxA causes premature transcription termination at an early stage of transcription. Our results are consistent with a role for antitermination in the completion of full-length rrn transcripts but give no indications of posttranscriptional boxA functions.
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MESH Headings
- Base Sequence
- DNA, Ribosomal/genetics
- Escherichia coli/genetics
- Molecular Sequence Data
- Operon/genetics
- Plasmids/genetics
- Point Mutation
- RNA, Ribosomal/biosynthesis
- RNA, Ribosomal/genetics
- RNA, Ribosomal, 16S/biosynthesis
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/biosynthesis
- RNA, Ribosomal, 23S/genetics
- Regulatory Sequences, Nucleic Acid/genetics
- Ribosomes/genetics
- Ribosomes/metabolism
- Terminator Regions, Genetic
- Transcription, Genetic
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Affiliation(s)
- T Heinrich
- Institut für Biochemie, Freie Universität Berlin, Germany
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30
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Condon C, Liveris D, Squires C, Schwartz I, Squires CL. rRNA operon multiplicity in Escherichia coli and the physiological implications of rrn inactivation. J Bacteriol 1995; 177:4152-6. [PMID: 7608093 PMCID: PMC177152 DOI: 10.1128/jb.177.14.4152-4156.1995] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.5] [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: 01/26/2023] Open
Abstract
Here we present evidence that only five of the seven rRNA operons present in Escherichia coli are necessary to support near-optimal growth on complex media. Seven rrn operons are necessary, however, for rapid adaptation to nutrient and temperature changes, suggesting it is the ability to adapt quickly to changing environmental conditions that has provided the selective pressure for the persistence of seven rrn operons in E. coli. We have also found that one consequence of rrn operon inactivation is a miscoordination of the concentrations of initiation factor IF3 and ribosomes.
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Affiliation(s)
- C Condon
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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31
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Putzer H, Laalami S, Brakhage AA, Condon C, Grunberg-Manago M. Aminoacyl-tRNA synthetase gene regulation in Bacillus subtilis: induction, repression and growth-rate regulation. Mol Microbiol 1995; 16:709-18. [PMID: 7476165 DOI: 10.1111/j.1365-2958.1995.tb02432.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [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: 01/25/2023]
Abstract
The thrS gene in Bacillus subtilis is specifically induced by starvation for threonine and is, in addition, autorepressed by the overproduction of its own gene product, the threonyl-tRNA synthetase. Both methods of regulation employ an antitermination mechanism at a factor-independent transcription terminator that occurs just upstream of the start codon. The effector of the induction mechanism is thought to be the uncharged tRNA(Thr), which has been proposed to base pair in two places with the leader mRNA to induce antitermination. Here we show that the autoregulation by synthetase overproduction is likely to utilize a mechanism similar to that characterized for induction by amino acid starvation, that is by altering the levels of tRNA charging in the cell. We also demonstrate that the base pairing interaction at the two proposed contact points between the tRNA and the leader are necessary but not always sufficient for either form of regulation. Finally, we present evidence that the thrS gene is expressed in direct proportion to the growth rate. This method of regulation is also at the level of antitermination but is independent of the interaction of the tRNA with the leader region.
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Affiliation(s)
- H Putzer
- Institut de Biologie Physico-Chimique, Paris, France
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32
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Carson KD, Grimes SB, McGinley JM, Thornton MT, Mulhall J, Bourke AM, McCrory C, Marsh B, Hone R, Phelan D, White M, Fabry J, Hughes D, Carson K, Donnelly M, Shanahan E, Fitzpatrick GJ, Bourke M, Warde D, Buggy D, Hughes N, Taylor A, Dowd N, Markham T, Blunnie W, Nicholson G, O’Leary E, Cunningham AJ, Dwyer R, McMechan S, Cullen C, Dempsey G, Wright G, MacKenzie G, Anderson J, Adgey J, Walsh M, O’Callaghan P, Graham I, O’Hare JA, Geoghegan M, Iman N, Shah P, Chander R, Lavin F, Daly K, Johnston PW, Imam Z, Adgey AAJ, Rusk RA, Richardson SG, Hale A, Kinsella BM, FitzGerald GA, King G, Crean P, Gearty G, Cawley T, Docherty JR, Geraghty J, Osborne H, Upton J, D’Arcy G, Stinson J, Cooke T, Colgan MP, Hall M, Tyrrell J, Gaffney K, Grouden M, Moore DJ, Shanik G, Feely J, Delanty N, Reilly M, Lawson JA, Fitzgerald DJ, Reilly MP, McAdam BF, Bergin C, Walshe MJ, Herity NA, Allen JD, Silke B, Singh HP, O’Neill S, Hargrove M, Coleman E, Shorten E, Aherne T, Kelly BE, Hill DH, McIlrath E, Morrow BC, Lavery GG, Blackwood B, Fee JPH, Kevin L, Doran M, Tansey D, Boylan I, McShane AJ, O’Reilly G, Tuohy B, Grainger P, Larkin T, Mahady J, Malone J, Condon C, Donoghue T, O’Leary J, Lyons JF, Tay YK, Tham SN, Khoo Tan HS, Gibson G, O’Grady A, Leader M, Walshe J, Carmody M, Donohoe J, Murphy GM, O’Connor W, Barnes L, Watson R, Darby C, O’Moore R, Mulcahy F, O’Toole E, O’Briain DS, Young MM, Buckley D, Healy E, Rogers S, Ni Scannlain N, McKenna MJ, McBrinn Y, Murray B, Freaney R, Barrett E, Razza Q, Abuaisha F, Powell D, Murray TM, Powell AM, O’Mongain E, O’Neill J, Kernan RP, O’Connor P, Clarke D, Fearon U, Cunningham SK, McKenna TJ, Hayes F, Heffernan A, Sheahan K, Harper R, Johnston GD, Atkinson AB, Sheridan B, Bell PM, Heaney AP, Loughrey G, McCance DR, Hadden DR, Kennedy AL, McNamara P, O’Shaughnessy C, Loughrey HC, Reid I, Teahan S, Caldwell M, Walsh TN, McSweeney J, Hennessy TP, Caldwell MTP, Byrne PJ, Hennessy TPJ, El-Magbri AA, Stevens FM, O’Sullivan R, McCarthy CF, Laundon J, Heneghan MA, Kearns M, Goulding J, Egan EL, McMahon BP, Hegarty F, Malone JF, Merriman R, MacMathuna P, Crowe J, Lennon J, White P, Clarke E, Prabhakar MC, Ryan E, Graham D, Yeoh PL, Kelly P, McKeogh D, O’Keane C, Kitching A, Mulligan E, Gorey TF, Mahmud N, O’Connell M, Goggins M, Keeling PWN, Weir DG, Kelleher D, McDonald GSA, Maguire D, O’Sullivan G, Harvey B, Cherukuri A, McGrath JP, Timon C, Lawlor P, O’Shea J, Buckley M, English L, Walsh T, O’Morain C, Lavelle SM, Kanagaratnam B, Harding B, Murphy B, Kavanagh J, Kerr D, Lavelle E, O’Gorman T, Liston S, Fitzpatrick C, Fitzpatrick P, Turner M, Murphy AW, Cafferty D, Dowling J, Bury G, Kaf Al-Ghazal S, Zimmermann E, O’Donoghue J, McCann J, Sheehan C, Boissel L, Lynch M, Cryan B, Fanning S, O’Meara D, Fennell J, Byrne PM, Lyons D, Mulcahy R, Pooransingh A, Walsh JB, Coakley D, O’Neill D, Ryall N, Connolly P, Namushi R, Lawler M, Locasciulli A, Bacigalupo A, Humphries P, McCann SR, Pamphilon D, Reidy M, Madden M, Finch T, Borton M, Barnes CA, Lawlor SE, Gardiner N, Egan LJ, Orren A, Doherty J, Curran C, O’Hanlon D, Kent P, Kerin M, Maher D, Given HF, Lynch S, McManus R, O’Farrelly C, Madrigal L, Feighery C, O’Donoghue D, Whelan CA, Rea IM, Stewart M, Campbell P, Alexander HD, Crockard AD, Morris TCM, Maguire H, Davidson F, Kaminski GZ, Butler K, Hillary IB, Parfrey NA, Crowley B, McCreary C, Keane C, O’Reilly M, Goh J, Kennedy M, Fitzgerald M, Scott T, Murphy S, Hildebrand J, Holliman R, Smith C, Kengasu K, Riain UN, Cormican M, Flynn J, Glennon M, Smith T, Whyte D, Keane CT, Barry T, Noone D, Maher M, Dawson M, Gilmartin JJ, Gannon F, Eljamel MS, Allcut D, Pidgeon CN, Phillips J, Rawluk D, Young S, Toland J, Deveney AM, Waddington JL, O’Brien DP, Hickey A, Maguire E, Phillips JP, Al-Ansari N, Cunney R, Smyth E, Sharif S, Eljamel M, Pidgeon C, Maguire EA, Burke ET, Staunton H, O’Riordan JI, Hutchinson M, Norton M, McGeeney B, O’Connor M, Redmond JMT, Feely S, Boyle G, McAuliffe F, Foley M, Kelehan P, Murphy J, Greene RA, Higgins J, Darling M, Byrne P, Kondaveeti U, Gordon AC, Hennelly B, Woods T, Harrison RF, Geary M, Sutherst JR, Turner MJ, DeLancey JOL, Donnelly VS, O’Connell PR, O’Herlihy C, Barry-Kinsella C, Sharma SC, Drury L, Lewis S, Stratton J, Ni Scanaill S, Stuart B, Hickey K, Coulter-Smith S, Moloney A, Robson MS, Murphy M, Keane D, Stronge J, Boylan P, Gonsalves R, Blankson S, McGuinness E, Sheppard B, Bonnar J, MacDonagh-White CM, Kelleher CC, Newell J, White O, Young Y, Hallahan C, Carroll K, Tipton K, McDermott EW, Reynolds JV, Nolan N, McCann A, Rafferty R, Sweeney P, Carney D, O’Higgins NJ, Duffy MJ, Grimes H, Gallagher S, O’Hanlon DM, Strattan J, Lenehan P, Robson M, Cusack YA, O’Riordain D, Mercer PM, Smyth PPA, Gallagher HJ, Moule B, Cooke TG, McArdle CS, Burke C, Vance A, Saidtéar C, Early A, Eustace P, Maguire L, Cullinane ABP, Prosser ES, Coca-Prados M, Harvey BJ, Saidléar C, Orwa S, Fitzsimons RB, Bradley O, Hogan M, Zimmerman L, Wang J, Kuliszewski M, Liu J, Post M, Premkumar, Conran MJ, Nolan G, Duff D, Oslizlok P, Denham B, O’Connell PA, Birthistle K, Hitchcock R, Carrington D, Calvert S, Holmes K, Smith DF, Hetherton AM, Mott MG, Oakhill A, Foreman N, Foot A, Dixon J, Walsh S, Mortimer G, O’Sullivan C, Kilgallen CM, Sweeney EC, Brayden DJ, Kelly JG, McCormack PME, Hayes C, Johnson Z, Dack P, Hosseini J, O’Connell T, Hemeryck L, Condren L, McCormack P, McAdam B, Lawson J, Keimowitz R, O’Leary A, Pilkington R, Adebayo GI, Gaffney P, McGettigan P, McManus J, O’Shea B, Wen Y, Killalea S, Golden J, Swanwick G, Clare AW, Mulvany F, Byrne M, O’Callaghan E, Byrne H, Cannon N, Kinsella T, Cassidy B, Shepard N, Horgan R, Larkin C, Cotter D, Coffey VP, Sham PC, Murray LH, Lane A, Kinsella A, Murphy P, Colgan K, Sloan D, Gilligan P, McEnri J, Ennis JT, Stack J, Corcoran E, Walsh D, Thornton L, Temperley I, Lawlor E, Tobin A, Hillary I, Nelson HG, Martin M, Ryan FM, Christie MA, Murray D, Keane E, Holmes E, Hollyer J, Strangeways J, Foster P, Stanwell-Smith R, Griffin E, Conlon T, Hayes E, Clarke T, Fogarty J, Moloney AC, Killeen P, Farrell S, Clancy L, Hynes M, Conlon C, Foley-Nolan C, Shelley E, Collins C, McNamara E, Hayes B, Creamer E, LaFoy M, Costigan P, Al fnAnsari N, Cunney RJ, Smyth EG, Johnson H, McQuoid G, Gilmer B, Browne G, Keogh JAB, Jefferson A, Smith M, Hennessy S, Burke CM, Sreenan S, Power CK, Pathmakanthan S, Poulter LW, Chan A, Sheehan M, Maguire M, O’Connor CM, FitzGerald MX, Southey A, Costello CM, McQuaid K, Urbach V, Thomas S, Horwitz ER, Mulherin D, FitzGerald O, Bresnihan B, Kirk G, Veale DJ, Belch JJF, Mofidi A, Mofidi R, Quigley C, McLaren M, Veale D, D’Arrigo C, Couto JC, Woof J, Greer M, Cree I, Belch J, Hone S, Fenton J, Hamilton S, McShane D. National Scientific Medical Meeting 1994 Abstracts. Ir J Med Sci 1994. [DOI: 10.1007/bf02943102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Over a 5 year period, from January 1988 to January 1993, 23 patients were admitted with extensive unstable psoriasis, 21 of whom had full case notes available. Over the study period these 21 patients required 45 admissions, the mean duration of each admission being 30.54 days. Those patients living more than 30 miles from our unit required almost twice as many admissions as the city group. In 77% of cases, a precipitating factor for the acute flare was identified, and in 53% of these the precipitating factor was iatrogenic related. These patients are prone to develop complications of which infection is the most common. The complexity of medical management was reflected in the number of cross consultations requested. These findings have implications for the optimal delivery of care to this important sub-group of psoriatics.
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Affiliation(s)
- C Condon
- Department of Dermatology, Victoria Hospital Ltd., Cork, Ireland
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Condon C, French S, Squires C, Squires CL. Depletion of functional ribosomal RNA operons in Escherichia coli causes increased expression of the remaining intact copies. EMBO J 1993; 12:4305-15. [PMID: 8223440 PMCID: PMC413727 DOI: 10.1002/j.1460-2075.1993.tb06115.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The synthesis of ribosomal RNA is a complex and highly regulated process. To study this process, we have used deletion-insertions to disrupt sequentially from one to four of the seven rRNA (rrn) operons on the Escherichia coli genome. Inactivation of four rrn operons caused a 2.3-fold increase in the expression of a chloramphenicol acetyl transferase reporter gene fused to the tandem promoters of rrnA and a similar increase in the expression of the trp tRNA gene at the end of rrnC. This reflected enhanced expression of the remaining operons to compensate for having only three intact copies. The elevated expression was caused by an increase in both transcription initiation and RNA polymerase elongation rates specifically on rrn operons and occurred in the absence of changes in the intracellular concentration of ppGpp, suggesting that ppGpp is not involved in the regulation of this phenomenon. We discuss these results in relation to the ribosome feedback inhibition model described by Nomura and coworkers.
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Affiliation(s)
- C Condon
- Department of Biological Sciences, Columbia University, New York, NY 10027
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Compston CA, Condon C, Hanna HR, Mazid MA. Rapid production of a panel of blood group A-active oligosaccharides using chemically synthesized di- and tri-saccharide primers and an easily prepared porcine (1-->3)-alpha-N-acetyl-D-galactosaminyltransferase. Carbohydr Res 1993; 239:167-76. [PMID: 8457994 DOI: 10.1016/0008-6215(93)84212-o] [Citation(s) in RCA: 11] [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: 01/30/2023]
Abstract
A porcine (1-->3)-alpha-N-acetyl-D-galactosaminyltransferase was obtained in a state suitable for preparative-scale (mg-scale) synthesis using simple procedures requiring only three days of effort. The enzyme thus prepared transferred GalNAc efficiently from UDP-GalNAc to six different chemically synthesized di- and tri-saccharide H-active structures to yield blood-group A-active oligosaccharides that were characterized by 1H NMR spectroscopy and mass spectrometry. This work further demonstrates the efficiency and attractiveness of using glycosyltransferases in a combined chemoenzymatic approach for the rapid production of biologically active oligosaccharides.
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Squires CL, Greenblatt J, Li J, Condon C, Squires CL. Ribosomal RNA antitermination in vitro: requirement for Nus factors and one or more unidentified cellular components. Proc Natl Acad Sci U S A 1993; 90:970-4. [PMID: 8430111 PMCID: PMC45792 DOI: 10.1073/pnas.90.3.970] [Citation(s) in RCA: 98] [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: 01/30/2023] Open
Abstract
Using an in vitro transcription assay, we have successfully demonstrated read through of a Rho-dependent terminator by the ribosomal RNA antitermination system. The assay used a DNA template containing a promoter-antiterminator-terminator arrangement, RNA polymerase, termination factor Rho, antitermination factors NusA, NusB, NusE, and NusG, and a cellular extract depleted of NusB. Terminator read-through was highly efficient only in the presence of the extract and Nus factors, suggesting that an as yet uncharacterized cellular component is required for ribosomal antitermination. The NusB-depleted extract had no activity in the absence of NusB, confirming an absolute requirement for this protein in ribosomal RNA antitermination. The DNA template requirements were the same as those previously established in vivo; transcription of a wild-type boxA sequence is both necessary and sufficient to promote RNA polymerase modification into a terminator-resistant form.
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Affiliation(s)
- C L Squires
- Department of Biological Sciences, Columbia University, New York, NY 10027
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Abstract
We have compared the expression of the seven ribosomal RNA operons (rrn) of Escherichia coli and their responses to a variety of physiological and genetic perturbations. We used a set of rrn promoter fusion constructs in their native chromosomal positions to examine effects of chromosomal location on rrn operon expression and the same set of fusions on lambda lysogens to assay intrinsic promoter strengths independent of chromosome context. In its native chromosomal location, expression of the rrnH operon was significantly lower than expected. This effect was not attributable to weak promoter activity and was dependent on the growth medium. The rrnE operon had reduced promoter activity relative to the other ribosomal operons in minimal medium and thus appears to have abnormal growth rate regulation. The ribosomal RNA operons showed varied responses to amino acid starvation; expression of rrnD was inhibited most. There was only a slight increase in rrn transcription in response to a temperature shift (30 degrees C to 42 degrees C) and the differences between individual operons was very small. The rrnG operon showed a significantly lower response than the other ribosomal RNA operons to a depletion of the rrn transcription activator, Fis, and thus appears to have decreased Fis-mediated transactivation. Finally, the chromosomal fusion strains were used to study the effect on growth rate of inactivating each rrn operon. In fast growth conditions, loss of certain rrn operons caused subtle decreases in growth rate on complex medium.
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Affiliation(s)
- C Condon
- Department of Biological Sciences, Columbia University, New York, NY 10027
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Coffin JW, Condon C, Compston CA, Potter KN, Lamontagne LR, Shafiq J, Kunimoto DY. Use of restriction fragment length polymorphisms resolved by pulsed-field gel electrophoresis for subspecies identification of mycobacteria in the Mycobacterium avium complex and for isolation of DNA probes. J Clin Microbiol 1992; 30:1829-36. [PMID: 1352787 PMCID: PMC265389 DOI: 10.1128/jcm.30.7.1829-1836.1992] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [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] Open
Abstract
Mycobacterial strains from the Mycobacterium avium complex were compared with each other and with Mycobacterium phlei isolates by restriction endonuclease digestion of chromosomal DNA with SspI and analysis by pulsed-field gel electrophoresis. Characteristic profiles were observed for known typed strains, and five groups were identified. Primary bovine isolates identified as Mycobacterium paratuberculosis by classical methods were shown to fall into both the M. paratuberculosis- and M. avium-like groups. M. paratuberculosis 18 was in the latter category. Two Mycobacterium intracellulare strains of different Schaefer serotypes had different digestion profiles. In addition, this system was exploited for the preparation of DNA probes by the isolation, digestion, and subcloning of DNA fragments separated by pulsed-field gel electrophoresis. Probe JC12 hybridized only to M. avium complex strains, but not to M. phlei, showing characteristic hybridization profiles for each of the groups previously identified by pulsed-field gel electrophoresis. The approach taken in the study lends itself to the comparative analysis of members of the M. avium complex and to the isolation and characterization of DNA probes with specificity for these mycobacteria.
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Affiliation(s)
- J W Coffin
- Chembiomed Ltd., Edmonton, Alberta, Canada
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Mulkerrin EC, Dewar R, Condon C, Curran J, Bayer AJ, Laher MS. A retrospective study of myocardial infarction occurring in elderly patients in a coronary care unit. Ir J Med Sci 1991; 160:257-8. [PMID: 1938315 DOI: 10.1007/bf02973401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 12/29/2022]
Abstract
Myocardial infarction is a major cause of morbidity and mortality particularly in the elderly. Coronary Care Unit monitoring has resulted in the improvement in prognosis in all age groups. In this study, the clinical course and outcome of 204 consecutive patients with acute myocardial infarction aged over 65 years is retrospectively analysed. All patients were managed in a Coronary Care Unit operating a needs related policy. Those under 75 years (120 patients) were compared to those over that age (84 patients). The groups differed in terms of clinical presentation, cardiac enzymatic rise and response to drug therapy. However they had similar complication rates, morbidity and mortality.
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Affiliation(s)
- E C Mulkerrin
- Department of General Medicine, James Connolly Memorial Hospital, Blanchardstown, Dublin
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Abstract
Recombinant plasmids which carried portions of the Escherichia coli frd operon were constructed and their expression examined by in vivo complementation of E. coli MI1443. This strain lacked a chromosomal frd operon and was unable to grow anaerobically on glycerol and fumarate. Introduction of all four fumarate reductase subunits into E. coli MI1443 was essential for the restoration of growth. The FRD A, FRD B dimer (but neither subunit alone) was active in the benzyl viologen oxidase assay. Both FRD C and FRD D were required for membrane association of fumarate reductase and for the oxidation of reduced quinone analogues. Introduction into E. coli MI1443 of the frdABC and frdD genes on two separate plasmid vectors failed to restore anaerobic growth on glycerol and fumarate. Thus separation of the DNA coding for the FRD C and FRD D proteins affected the ability of fumarate reductase to assemble into a functional complex.
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Affiliation(s)
- C Condon
- Department of Biochemistry, University of Alberta, Edmonton, Canada
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Kuwahara A, Bowen S, Wang J, Condon C, Cooke HJ. Epithelial responses evoked by stimulation of submucosal neurons in guinea pig distal colon. Am J Physiol 1987; 252:G667-74. [PMID: 3578525 DOI: 10.1152/ajpgi.1987.252.5.g667] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The influence of submucosal neurons on ion transport in the guinea pig distal colon was examined in muscle-stripped sheets of submucosa-mucosa set up in Ussing flux chambers. Spontaneous variations in potential differences (PD) and short-circuit current occurred ranging from positive currents associated with luminal negative PDs to negative currents with luminal positive PDs. Basal current in both groups was reduced by mucosal amiloride. In tissues with positive or negative short-circuit currents, unidirectional mucosal-to-serosal sodium fluxes were greater than serosal-to-mucosal fluxes and small net absorptive fluxes were present. Little or no chloride secretory flux was present. Electrical stimulation of submucosal neurons evoked a tetrodotoxin-sensitive increase in short-circuit current in tissues with positive or negative short-circuit currents. This was due to an increase in net chloride flux and little change in net sodium flux or residual flux. The increase in net chloride flux was due almost entirely to an increase in serosal-to-mucosal chloride flux and was associated with an increase in total tissue conductance. The stimulus-evoked response was reduced by atropine. These results suggest that stimulation of submucosal neurons that innervate the distal colonic epithelium evokes a large chloride secretory response that is due in part to release of acetylcholine at neuro-enterocyte junctions.
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Weiner JH, Cammack R, Cole ST, Condon C, Honoré N, Lemire BD, Shaw G. A mutant of Escherichia coli fumarate reductase decoupled from electron transport. Proc Natl Acad Sci U S A 1986; 83:2056-60. [PMID: 3008149 PMCID: PMC323229 DOI: 10.1073/pnas.83.7.2056] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The terminal electron-transfer enzyme fumarate reductase of Escherichia coli is a complex iron-sulfur flavoenzyme composed of four nonidentical subunits organized into two domains: FrdA and -B (a membrane-extrinsic catalytic domain) and FrdC and -D (a transmembrane anchor domain). We have identified a mutation within the membrane-intrinsic domain that alters the electron transfer properties of the iron-sulfur and flavin redox centers of the catalytic domain. Functional electron flow from the quinone analog 2,3-dimethyl-1,4-naphthoquinone or from the electron transport chain is impaired. However, the mutant enzyme can be reduced normally by single-electron donors such as the dye benzyl viologen. The mutant phenotype results from a single A----G transition changing His-82, within the second transmembrane alpha-helix of the FrdC anchor sequence, to an arginine. The mutation, physically located within the anchor domain, is manifested by altered catalytic properties, indicating that the intrinsic and extrinsic domains are conformationally connected. These results confirm the important role of the anchor subunits in functional electron transport and have implications for communication between intrinsic and extrinsic domains of membrane proteins.
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Cole ST, Condon C, Lemire BD, Weiner JH. Molecular biology, biochemistry and bioenergetics of fumarate reductase, a complex membrane-bound iron-sulfur flavoenzyme of Escherichia coli. Biochim Biophys Acta 1985; 811:381-403. [PMID: 3910107 DOI: 10.1016/0304-4173(85)90008-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Condon C, Cammack R, Patil DS, Owen P. The succinate dehydrogenase of Escherichia coli. Immunochemical resolution and biophysical characterization of a 4-subunit enzyme complex. J Biol Chem 1985; 260:9427-34. [PMID: 2991245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Using EPR spectroscopy to monitor the integrity of the enzyme, conditions have been established which allow specific immunoprecipitation of the succinate dehydrogenase complex of Escherichia coli. The enzyme complex precipitated from Lubrol PX-solubilized membranes by monospecific antiserum in the presence of a cocktail of protease inhibitors contains four polypeptides of apparent MrS 71,000, 26,000, 17,000, and 15,000. The 71-kDa flavopeptide is readily susceptible to proteolysis, and the enzyme complex shows unusual facile dissociation. Spectroscopic measurements indicate the presence of a [2Fe-2S] cluster (Center 1), a [3Fe-xS] cluster (Center 3), and a b-type cytochrome. In addition, a change in relaxation of Center 1 at low potentials is indicative of Center 2. Midpoint redox potentials of Centers 1-3 for both the membrane-bound and detergent-solubilized enzyme were estimated to be +10 mV, -175 mV, and +65 mV, respectively.
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Condon C, Cammack R, Patil DS, Owen P. The succinate dehydrogenase of Escherichia coli. Immunochemical resolution and biophysical characterization of a 4-subunit enzyme complex. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)39384-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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