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Zemanick ET, Emerman I, McCreary M, Mayer-Hamblett N, Warden MN, Odem-Davis K, VanDevanter DR, Ren CL, Young J, Konstan MW. Heterogeneity of CFTR modulator-induced sweat chloride concentrations in people with cystic fibrosis. J Cyst Fibros 2024:S1569-1993(24)00015-8. [PMID: 38360461 DOI: 10.1016/j.jcf.2024.02.001] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/03/2024] [Accepted: 02/04/2024] [Indexed: 02/17/2024]
Abstract
BACKGROUND Sweat chloride (SC) concentrations in people with cystic fibrosis (PwCF) reflect relative CF transmembrane conductance regulator (CFTR) protein function, the primary CF defect. Populations with greater SC concentrations tend to have lesser CFTR function and more severe disease courses. CFTR modulator treatment can improve CFTR function within specific CF genotypes and is commonly associated with reduced SC concentration. However, SC concentrations do not necessarily fall to concentrations seen in the unaffected population, suggesting potential for better CFTR treatment outcomes. We characterized post-modulator SC concentration variability among CHEC-SC study participants by genotype and modulator. METHODS PwCF receiving commercially approved modulators for ≥90 days were enrolled for a single SC measurement. Clinical data were obtained from chart review and the CF Foundation Patient Registry (CFFPR). Variability of post-modulator SC concentrations was assessed by cumulative SC concentration frequencies. RESULTS Post-modulator SC concentrations (n = 3787) were collected from 3131 PwCF; most (n = 1769, 47 %) were collected after elexacaftor/tezacaftor/ivacaftor (ETI) treatment. Modulator use was associated with lower SC distributions, with post-ETI concentrations the lowest on average. Most post-ETI SC concentrations were <60 mmol/L (79 %); 26 % were <30 mmol/L. Post-ETI distributions varied by genotype. All genotypes containing at least one F508del allele had individuals with post-ETI SC ≥60 mmol/L, with the largest proportion being F508del/minimal function (31 %). CONCLUSIONS Post-modulator SC concentration heterogeneity was observed among all genotypes and modulators, including ETI. The presence of PwCF with post-modulator SC concentrations within the CF diagnostic range suggests room for additional treatment-associated CFTR restoration in this population.
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Affiliation(s)
- E T Zemanick
- University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
| | - I Emerman
- Seattle Children's Hospital, Seattle, WA, United States
| | - M McCreary
- Seattle Children's Hospital, Seattle, WA, United States
| | - N Mayer-Hamblett
- Seattle Children's Hospital, Seattle, WA, United States; University of Washington, Seattle, WA, United States
| | - M N Warden
- Seattle Children's Hospital, Seattle, WA, United States
| | - K Odem-Davis
- Seattle Children's Hospital, Seattle, WA, United States
| | - D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - C L Ren
- Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - J Young
- Seattle Children's Hospital, Seattle, WA, United States
| | - M W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH, United States; Rainbow Babies and Children's Hospital, Cleveland, OH, United States
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VanDevanter DR, LiPuma JJ, Konstan MW. Longitudinal bacterial prevalence in cystic fibrosis airways: Fact and artifact. J Cyst Fibros 2024; 23:58-64. [PMID: 37783605 PMCID: PMC10949087 DOI: 10.1016/j.jcf.2023.09.011] [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: 08/01/2023] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 10/04/2023]
Abstract
BACKGROUND Opportunistic bacterial infection is a hallmark of cystic fibrosis (CF) lung disease and early mortality. Poorly characterized prevalence changes have accompanied two decades of health improvements, with CFTR modulators likely to further affect infection epidemiology. METHODS Bacterial prevalence change trends across birth cohorts were assessed with linear regression using 2001-2019 US CF Foundation Patient Registry data. Informative missingness was assessed, as was age-to-age infection status. RESULTS Bacterial prevalence constantly changed from 2001 to 2019, with changes differing across birth cohorts. Informative censoring affected prevalence change for some organisms. Age-to-age infection status changes were greater than net changes in bacterial prevalence and varied by age. CONCLUSIONS CF infection epidemiology changed over two decades and will continue to do so. Understanding how modulators affect infection epidemiology will require creative designs for longitudinal prevalence change studies emphasizing prevalence changes independent of effects on lung biology.
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Affiliation(s)
- D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland OH USA.
| | - J J LiPuma
- University of Michigan, Ann Arbor, MI USA
| | - M W Konstan
- Case Western Reserve University School of Medicine, Cleveland OH USA; Rainbow Babies and Children's Hospital, Cleveland OH USA
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VanDevanter DR, Zemanick ET, Konstan MW, Ren CL, Odem-Davis K, Emerman I, Young J, Mayer-Hamblett N. Willingness of people with cystic fibrosis receiving elexacaftor/tezacaftor/ivacaftor (ETI) to participate in randomized modulator and inhaled antimicrobial clinical trials. J Cyst Fibros 2023; 22:652-655. [PMID: 37100705 PMCID: PMC10523954 DOI: 10.1016/j.jcf.2023.04.007] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/31/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023]
Abstract
OBJECTIVE To assess the feasibility of enrolling people with CF (pwCF) taking the CFTR modulator elexacaftor/tezacaftor/ivacaftor (ETI) in clinical trials of a new modulator. METHODS PwCF receiving ETI at CHEC-SC study (NCT03350828) enrollment were surveyed for interest in 2-week to 6-month placebo- (PC) and active-comparator (AC) modulator studies. Those taking inhaled antimicrobials (inhABX) were surveyed for interest in PC inhABX studies. RESULTS Of 1791 respondents, 75% [95% CI 73, 77] would enroll in a 2-week PC modulator study versus 51% [49, 54] for a 6-month study; 82% [81, 84] and 63% [61, 65] would enroll in 2-week and 6 month AC studies; 77% [74, 80] of 551 taking inhABX would enroll in a 2-week PC inhABX study versus 59% [55, 63] for a 6-month study. Previous clinical trial experience increased willingness. CONCLUSIONS Study designs will affect feasibility of future clinical trials of new modulators and inhABX in people receiving ETI.
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Affiliation(s)
- D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH United States.
| | - E T Zemanick
- University of Colorado, Anschutz Medical Campus, Aurora CO United States
| | - M W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH United States; Rainbow Babies and Children's Hospital, Cleveland, OH United States
| | - C L Ren
- Children's Hospital of Philadelphia, Philadelphia, PA United States
| | - K Odem-Davis
- Seattle Children's Hospital, Seattle, WA United States
| | - I Emerman
- Seattle Children's Hospital, Seattle, WA United States
| | - J Young
- Seattle Children's Hospital, Seattle, WA United States
| | - N Mayer-Hamblett
- Seattle Children's Hospital, Seattle, WA United States; University of Washington, Seattle, WA United States
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VanDevanter DR, West NE, Sanders DB, Skalland M, Goss CH, Flume PA, Heltshe SL. Antipseudomonal treatment decisions during CF exacerbation management. J Cyst Fibros 2022; 21:753-758. [PMID: 35466039 PMCID: PMC9509480 DOI: 10.1016/j.jcf.2022.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Received: 12/20/2021] [Revised: 03/01/2022] [Accepted: 04/04/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cystic fibrosis (CF) pulmonary exacerbation (PEx) treatment guidelines suggest that Pseudomonas aeruginosa (Pa) airway infection be treated with two antipseudomonal agents. METHODS We retrospectively studied treatment responses for STOP2 PEx treatment trial (NCT02781610) participants with a history of Pa infection. Mean lung function and symptom changes from intravenous (IV) antimicrobial treatment start to Visit 2 (7 to 10 days later) were compared between those receiving one, two, and three+ antipseudomonal classes before Visit 2 by ANCOVA. Odds of PEx retreatment with IV antimicrobials within 30 days and future IV-treated PEx hazard were modeled by logistic and Cox proportional hazards regression, respectively. Sensitivity analyses limited to the most common one-, two-, and three-class regimens, to only IV/oral antipseudomonal treatments, and with more stringent Pa infection definitions were conducted. RESULTS Among 751 participants, 50 (6.7%) were treated with one antipseudomonal class before Visit 2, while 552 (73.5%) and 149 (19.8%) were treated with two and with three+ classes, respectively. Females and participants with a negative Pa culture in the prior month were more likely to be treated with a single class. The most common single, double, and triple class regimens were beta-lactam (BL; n = 42), BL/aminoglycoside (AG; n = 459), and BL/AG/fluoroquinolone (FQ; n = 73). No lung function or symptom response, odds of retreatment, or future PEx hazard differences were observed by number of antipseudomonal classes administered in primary or sensitivity analyses. CONCLUSIONS We were unable to identify additional benefit when multiple antipseudomonal classes are used to treat PEx in people with CF and Pa.
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Affiliation(s)
- D R VanDevanter
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, OH, United States.
| | - N E West
- Department of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - D B Sanders
- Department of Pediatrics, Indiana University, Indianapolis, IN, United States
| | - M Skalland
- CF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA, United States
| | - C H Goss
- CF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA, United States; Department of Medicine, University of Washington, Seattle, WA, United States; Department of Pediatrics, University of Washington, Seattle, WA, United States
| | - P A Flume
- Departments of Medicine and Pediatrics, Medical University of South Carolina, Charleston, SC, United States
| | - S L Heltshe
- CF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA, United States; Department of Pediatrics, University of Washington, Seattle, WA, United States
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VanDevanter DR, Heltshe SL, Skalland M, West NE, Sanders DB, Goss CH, Flume PA. C-reactive protein (CRP) as a biomarker of pulmonary exacerbation presentation and treatment response. J Cyst Fibros 2021; 21:588-593. [PMID: 34933824 DOI: 10.1016/j.jcf.2021.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 08/19/2021] [Revised: 11/09/2021] [Accepted: 12/05/2021] [Indexed: 01/05/2023]
Abstract
BACKGROUND C-reactive protein (CRP) has been proposed as a biomarker for pulmonary exacerbation (PEx) diagnosis and treatment response. CRP >75mg/L has been associated with increased risk of PEx treatment failure. We have analyzed CRP measures as biomarkers for clinical response during the STOP2 PEx study (NCT02781610). METHODS CRP measures were collected at antimicrobial treatment start (V1), seven to 10 days later (V2), and two weeks after treatment end (V3). V1 log10CRP concentrations and log10CRP change from V1 to V3 correlations with clinical responses (changes in lung function and symptom score) were assessed by least squares regression. Odds of intravenous (IV) antimicrobial retreatment within 30 days and future PEx hazard associated with V1 and V3 CRP concentrations and V1 CRP >75 mg/L were studied by adjusted logistic regression and proportional hazards modeling, respectively. RESULTS In all, 951 of 982 STOP2 subjects (92.7%) had CRP measures at V1. V1 log10CRP varied significantly by V1 lung function subgroup, symptom score quartile, and sex, but not by age subgroup. V1 log10CRP correlated moderately with log10CRP change at V3 (r2=0.255) but less so with lung function (r2=0.016) or symptom (r2=0.031) changes at V3. Higher V1 CRP was associated with greater response. CRP changes from V1 to V3 only weakly correlated with lung function (r2=0.061) and symptom (r2=0.066) changes. However, V3 log10CRP was associated with increased odds of retreatment (P = .0081) and future PEx hazard (P = .0114). DISCUSSION Despite consistent trends, log10CRP change was highly variable with only limited utility as a biomarker of PEx treatment response.
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Affiliation(s)
- D R VanDevanter
- Case Western Reserve Univ. School of Medicine, Cleveland OH, USA.
| | - S L Heltshe
- Univ. of Washington, Seattle WA, USA; CFF TDNCC, Seattle Children's Hospital, Seattle WA, USA
| | - M Skalland
- CFF TDNCC, Seattle Children's Hospital, Seattle WA, USA
| | - N E West
- Johns Hopkins University, Baltimore MD, USA
| | - D B Sanders
- Indiana Univ. School of Medicine, Indianapolis IN, USA
| | - C H Goss
- Univ. of Washington, Seattle WA, USA
| | - P A Flume
- Medical Univ. of South Carolina, Charleston SC, USA
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Konstan MW, VanDevanter DR, Rowe SM, Wilschanski M, Kerem E, Sermet-Gaudelus I, DiMango E, Melotti P, McIntosh J, De Boeck K. Efficacy and safety of ataluren in patients with nonsense-mutation cystic fibrosis not receiving chronic inhaled aminoglycosides: The international, randomized, double-blind, placebo-controlled Ataluren Confirmatory Trial in Cystic Fibrosis (ACT CF). J Cyst Fibros 2020; 19:595-601. [PMID: 31983658 PMCID: PMC9167581 DOI: 10.1016/j.jcf.2020.01.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [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] [Received: 01/15/2020] [Accepted: 01/17/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Ataluren was developed for potential treatment of nonsense-mutation cystic fibrosis (CF). A previous phase 3 ataluren study failed to meet its primary efficacy endpoint, but post-hoc analyses suggested that aminoglycosides may have interfered with ataluren's action. Thus, this subsequent trial (NCT02139306) was designed to assess the efficacy and safety of ataluren in patients with nonsense-mutation CF not receiving aminoglycosides. METHODS Eligible subjects with nonsense-mutation CF (aged ≥6 years; percent predicted (pp) FEV1 ≥40 and ≤90) from 75 sites in 16 countries were randomly assigned in double-blinded fashion to receive oral ataluren or matching placebo thrice daily for 48 weeks. The primary endpoint was absolute change in average ppFEV1 from baseline to the average of Weeks 40 and 48. FINDINGS 279 subjects were enrolled; 138 subjects in the ataluren arm and 136 in the placebo arm were evaluable for efficacy. Absolute ppFEV1 change from baseline did not differ significantly between the ataluren and placebo groups at Week 40 (-0.8 vs -1.8) or Week 48 (-1.7 vs -2.4). Average ppFEV1 treatment difference from baseline to Weeks 40 and 48 was 0.6 (95% CI -1.3, 2.5; p = 0.54). Pulmonary exacerbation rate per 48 weeks was not significantly different (ataluren 0.95 vs placebo 1.13; rate ratio p = 0.40). Safety was similar between groups. No life-threatening adverse events or deaths were reported. INTERPRETATION Neither ppFEV1 change nor pulmonary exacerbation rate over 48 weeks were statistically different between ataluren and placebo groups. Development of a nonsense-mutation CF therapy remains elusive.
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Affiliation(s)
- M W Konstan
- Rainbow Babies and Children's Hospital, Cleveland, OH 44106 USA; Case Western Reserve University School of Medicine, Cleveland, OH 44106 USA.
| | - D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH 44106 USA
| | - S M Rowe
- Pulmonary and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL 35249 USA
| | - M Wilschanski
- Center for Cystic Fibrosis, Hadassah Hebrew University Medical Center, Jerusalem, 91240, Israel
| | - E Kerem
- Center for Cystic Fibrosis, Hadassah Hebrew University Medical Center, Jerusalem, 91240, Israel
| | - I Sermet-Gaudelus
- Centre de Ressource et de Competence de la Mucoviscidose, Service de Pediatrie Generale, Service de Pneumologie Pediatrique, Service de Radiologie Pediatrique, Centre d'Investigation Clinique Hôpital Necker - Enfants Malades, 75015 Paris, France
| | - E DiMango
- Pulmonary, Allergy, and Critical Care Medicine, Columbia University, Department of Medicine, New York, NY 10032 USA
| | - P Melotti
- Centro Fibrosi Cistica, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - J McIntosh
- PTC Therapeutics, South Plainfield, NJ 07080 USA
| | - K De Boeck
- Pediatric Pulmonology and Infectious Diseases, University Hospital of Leuven, University of Leuven, Belgium
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Mayer-Hamblett N, van Koningsbruggen-Rietschel S, Nichols DP, VanDevanter DR, Davies JC, Lee T, Durmowicz AG, Ratjen F, Konstan MW, Pearson K, Bell SC, Clancy JP, Taylor-Cousar JL, De Boeck K, Donaldson SH, Downey DG, Flume PA, Drevinek P, Goss CH, Fajac I, Magaret AS, Quon BS, Singleton SM, VanDalfsen JM, Retsch-Bogart GZ. Building global development strategies for cf therapeutics during a transitional cftr modulator era. J Cyst Fibros 2020; 19:677-687. [PMID: 32522463 DOI: 10.1016/j.jcf.2020.05.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [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: 02/07/2020] [Revised: 05/18/2020] [Accepted: 05/27/2020] [Indexed: 12/30/2022]
Abstract
As CFTR modulator therapy transforms the landscape of cystic fibrosis (CF) care, its lack of uniform access across the globe combined with the shift towards a new standard of care creates unique challenges for the development of future CF therapies. The advancement of a full and promising CF therapeutics pipeline remains a necessary priority to ensure maximal clinical benefits for all people with CF. It is through collaboration across the global CF community that we can optimize the evaluation and approval process of new therapies. To this end, we must identify areas for which harmonization is lacking and for which efficiencies can be gained to promote ethical, feasible, and credible study designs amidst the changing CF care landscape. This article summarizes the counsel from core advisors across multiple international regions and clinical trial networks, developed during a one-day workshop in October 2019. The goal of the workshop was to identify, in consideration of the highly transitional era of CFTR modulator availability, the drug development areas for which global alignment is currently uncertain, and paths forward that will enable advancement of CF therapeutic development.
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Affiliation(s)
- N Mayer-Hamblett
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA.
| | - S van Koningsbruggen-Rietschel
- Cystic Fibrosis Center, Children's Hospital, University of Cologne; Faculty of Medicine and University Hospital Cologne, Cologne Germany
| | - D P Nichols
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA
| | - D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH
| | - J C Davies
- National Heart & Lung Institute, Imperial College London, London, UK; Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - T Lee
- Leeds Regional Paediatric Cystic Fibrosis Centre, Leeds, UK
| | | | - F Ratjen
- University of Toronto, Toronto, Canada
| | - M W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH; Rainbow Babies and Children's Hospital, Cleveland, OH
| | - K Pearson
- Seattle Children's Hospital, Seattle, WA
| | - S C Bell
- Children's Health Research Centre, The University of Queensland, Brisbane, Australia
| | - J P Clancy
- Cystic Fibrosis Foundation, Bethesda, MD
| | | | | | - S H Donaldson
- University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - D G Downey
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland
| | - P A Flume
- Medical University of South Carolina, Charleston, SC
| | - P Drevinek
- Charles University, Prague, Czechia, Motol University Hospital, Prague, Czechia
| | - C H Goss
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA
| | - I Fajac
- Université de Paris, Paris, France
| | - A S Magaret
- University of Washington, Seattle, WA; Seattle Children's Hospital, Seattle, WA
| | - B S Quon
- University of British Columbia, Vancouver, British Columbia
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VanDevanter DR, Mayer-Hamblett N. Important steps in the journey to highly effective CFTR modulator access for people with CF. J Cyst Fibros 2019; 18:577-578. [PMID: 31500809 DOI: 10.1016/j.jcf.2019.06.013] [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: 11/16/2022]
Affiliation(s)
- D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - N Mayer-Hamblett
- University of Washington and Seattle Children's Hospital, Seattle, WA, USA
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VanDevanter DR, Gonda I, Dahms J, Cipolla D, Davis AM, Chalmers JD, Froehlich J. Microbiological changes observed over 48 weeks of treatment with inhaled liposomal ciprofloxacin in individuals with non-cystic fibrosis bronchiectasis and chronic Pseudomonas aeruginosa lung infection. Clin Microbiol Infect 2019; 25:1532-1538. [PMID: 31035017 DOI: 10.1016/j.cmi.2019.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/09/2019] [Accepted: 04/18/2019] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Non-cystic fibrosis bronchiectasis (NCFBE) with Pseudomonas aeruginosa has been associated with increased pulmonary exacerbation (PEx) and mortality risk. European Respiratory Society guidelines conditionally recommend inhaled antimicrobials for persons with NCFBE, P aeruginosa and three or more PEx/year. We report microbiological results of two randomized, 48-week placebo-controlled trials of ARD-3150 (inhaled liposomal ciprofloxacin) in individuals with NCFBE with P aeruginosa and PEx history [Lancet Respir Med 2019;7:213-26]. METHODS Respiratory secretions from 582 participants receiving up to six 28-day on/off treatment cycles were analysed for sputum P. aeruginosa, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Escherichia coli densities, P. aeruginosa susceptibilities to ciprofloxacin and nine other antimicrobials, and prevalence of other bacterial opportunists. Associations between PEx risk and sputum density, antimicrobial susceptibility and opportunist prevalence changes were studied. RESULTS Sputum P. aeruginosa density reductions from baseline after ARD-3150 treatments ranged from 1.77 (95% CI 2.13-1.40) versus 0.54 (95% CI 0.89-0.19) log10 CFU/g for placebo (second period) to 2.07 (95% CI 2.45-1.69) versus 0.70 (95% CI 1.11-0.29) log10 CFU/g for placebo (fourth period) with only modest correlation between density reduction magnitude and PEx benefit. ARD-3150 (but not placebo) treatment was associated with increased P. aeruginosa ciprofloxacin MIC but not emergence of other bacterial opportunists across the study; ciprofloxacin MIC50 increased from 0.5 to 1 mg/L, MIC90 increased from 4 to 16 mg/L. Other antimicrobial MIC were mostly unaffected. CONCLUSION Microbiological changes over 48 weeks of ARD-3150 treatment appear modest. Ciprofloxacin susceptibility (but not other antimicrobial susceptibility) decreases were observed that did not appear to preclude PEx risk reduction benefit.
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Affiliation(s)
- D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - I Gonda
- Respidex LLC, San Francisco, CA, USA
| | - J Dahms
- Aradigm Corporation, Hayward, CA, USA
| | | | - A M Davis
- Grifols, Research Triangle Park, NC, USA
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VanDevanter DR, Heltshe SL, Spahr J, Beckett VV, Daines CL, Dasenbrook EC, Gibson RL, Raksha J, Sanders DB, Goss CH, Flume PA. Rationalizing endpoints for prospective studies of pulmonary exacerbation treatment response in cystic fibrosis. J Cyst Fibros 2017; 16:607-615. [PMID: 28438499 DOI: 10.1016/j.jcf.2017.04.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [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: 09/30/2016] [Revised: 03/08/2017] [Accepted: 04/04/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND Given the variability in pulmonary exacerbation (PEx) management within and between Cystic Fibrosis (CF) Care Centers, it is possible that some approaches may be superior to others. A challenge with comparing different PEx management approaches is lack of a community consensus with respect to treatment-response metrics. In this analysis, we assess the feasibility of using different response metrics in prospective randomized studies comparing PEx treatment protocols. METHODS Response parameters were compiled from the recent STOP (Standardized Treatment of PEx) feasibility study. Pulmonary function responses (recovery of best prior 6-month and 12-month FEV1% predicted and absolute and relative FEV1% predicted improvement from treatment initiation) and sign and symptom recovery from treatment initiation (measured by the Chronic Respiratory Infection Symptom Score [CRISS]) were studied as categorical and continuous variables. The proportion of patients retreated within 30days after the end of initial treatment was studied as a categorical variable. Sample sizes required to adequately power prospective 1:1 randomized superiority and non-inferiority studies employing candidate endpoints were explored. RESULTS The most sensitive endpoint was mean change in CRISS from treatment initiation, followed by mean absolute FEV1% predicted change from initiation, with the two responses only modestly correlated (R2=.157; P<0.0001). Recovery of previous best FEV1 was a problematic endpoint due to missing data and a substantial proportion of patients beginning PEx treatment with FEV1 exceeding their previous best measures (12.1% >12-month best, 19.6% >6-month best). Although mean outcome measures deteriorated approximately 2-weeks post-treatment follow-up, the effect was non-uniform: 62.7% of patients experienced an FEV1 worsening versus 49.0% who experienced a CRISS worsening. CONCLUSIONS Results from randomized prospective superiority and non-inferiority studies employing mean CRISS and FEV1 change from treatment initiation should prove compelling to the community. They will need to be large, but appear feasible.
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Affiliation(s)
- D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| | - S L Heltshe
- University of Washington, Seattle, WA 98121, USA; CFF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA 98105, USA
| | - J Spahr
- Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA 15224, USA
| | - V V Beckett
- CFF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA 98105, USA
| | - C L Daines
- University of Arizona, Tucson, AZ 85724, USA
| | - E C Dasenbrook
- Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - R L Gibson
- CFF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA 98105, USA
| | - Jain Raksha
- University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - D B Sanders
- University of Wisconsin, Madison, WI 53792, USA
| | - C H Goss
- University of Washington, Seattle, WA 98121, USA; CFF Therapeutics Development Network Coordinating Center, Seattle Children's Research Institute, Seattle, WA 98105, USA
| | - P A Flume
- Medical University of South Carolina, Charleston, SC 29425, USA
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VanDevanter DR, Flume PA, Morris N, Konstan MW. Probability of IV antibiotic retreatment within thirty days is associated with duration and location of IV antibiotic treatment for pulmonary exacerbation in cystic fibrosis. J Cyst Fibros 2016; 15:783-790. [PMID: 27139161 DOI: 10.1016/j.jcf.2016.04.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [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: 02/04/2016] [Revised: 03/26/2016] [Accepted: 04/15/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND There are few objective data to guide management of cystic fibrosis (CF) pulmonary exacerbations. We studied intravenous (IV) antibiotic treatment failure as defined by a need to retreat patients with IV antibiotics within 30days of completion of a prior IV antibiotic treatment for pulmonary exacerbation. METHODS The first IV-treated exacerbation on or after Jan. 1, 2010 among US CF Foundation Patient Registry patients was studied, combining treatments separated by <7days into single treatments. IV treatment duration categories were: 1-4, 5-8, 9-12, 13-16, 17-22, and ≥23days (inclusive). Logistic regressions for IV retreatment in ≤30days were adjusted with 12 categorical covariates, including age, sex, lung function, prior-year exacerbations, CF complications, CF Care Program, and ever/never treated in hospital. RESULTS 777 of 13,579 patients (5.7%) were retreated within 30days, with incidence varying by treatment duration: 1-4days, 8.7%; 5-8days; 6.6%; 9-12days, 3.2%; 13-16days, 4.5%; 17-22days, 6.2%; ≥23days, 10.3% and hospitalization: ever, 5.0%; never 8.5%. Adjusted odds ratios (OR) for retreatment (compared to 13-16days treatment) were: 1-4days, 1.94 [95%CI 1.49, 2.54] P<.001; 5-8days, 1.55 [1.18, 2.04] P=.002; 9-12days, 0.78 [0.58, 1.04] P=.09; 17-22days, 1.12 [0.88, 1.42] P=.37; ≥23days, 1.46 [1.12, 1.91] P=.005. Adjusted retreatment OR for never/ever hospitalized was 1.57 [1.29, 1.90] P<.001. Prior-year exacerbation number, oxygen therapy, non-invasive ventilation, and female sex were significantly associated with retreatment. Modeling hazard rate time-dependence showed that treatment duration and location-associated hazard rates attenuated within a few months after treatment. CONCLUSION After adjustment for covariates known to be associated with increased risk of IV treatment for exacerbation, IV antibiotic treatments of <9 and ≥23days and those without hospitalization were significant risk factors for IV retreatment within 30days of completion of an exacerbation treatment.
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Affiliation(s)
- D R VanDevanter
- Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - P A Flume
- Medical University of South Carolina, Charleston, SC, USA
| | - N Morris
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - M W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH, USA; Rainbow Babies and Children's Hospital, Cleveland, OH, USA
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12
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Konstan MW, Wagener JS, Yegin A, Millar SJ, Pasta DJ, VanDevanter DR. Design and powering of cystic fibrosis clinical trials using rate of FEV(1) decline as an efficacy endpoint. J Cyst Fibros 2010; 9:332-8. [PMID: 20646968 DOI: 10.1016/j.jcf.2010.05.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 05/24/2010] [Accepted: 05/26/2010] [Indexed: 11/26/2022]
Abstract
BACKGROUND Rate of lung function decline (RLFD) (as FEV(1) percent predicted/yr) is a robust measure of CF therapeutic efficacy rarely used as a study endpoint, in part due to uncertainty of sample size requirements. METHODS Sample size requirements for 1:1 randomizations to detect RLFD treatment effects from 20% to 80% were assessed in Epidemiologic Study of CF (ESCF) patients. Effects of measuring FEV(1) 1-4 times per year in studies of 1- to 4-year durations were assessed in 399 patients age ≥ 6 years with FEV(1) ≥ 70%. Impacts of inclusion/exclusion based on risk factors in 2369 ESCF patients were assessed over 1.5 years using semi-annual FEV(1) measures. RESULTS Increasing study duration and exclusion of lower risk patients (e.g., no P. aeruginosa infection) both substantially reduced requirements. CONCLUSIONS CF RLFD studies of 1.5 years in duration appear feasible provided that investigators account for the beneficial effects of subject inclusion/exclusion based on risk factors in power estimates.
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Affiliation(s)
- M W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
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13
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Erwin AL, VanDevanter DR. The Pseudomonas aeruginosa genome: how do we use it to develop strategies for the treatment of patients with cystic fibrosis and Pseudomonas infections? Curr Opin Pulm Med 2002; 8:547-51. [PMID: 12394165 DOI: 10.1097/00063198-200211000-00011] [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] [Indexed: 11/26/2022]
Abstract
In the 2 years since the complete sequence of Pseudomonas aeruginosa strain PAO1 was published, at least 200 papers have been published describing research that made use of the PAO1 genome sequence. Some of this research included genome-wide studies of gene expression or the effect of mutation on bacterial functions such as biofilm formation; this type of global analysis would not have been possible without the availability of the sequence. As a result of these and other, more traditional, research studies, there is a wealth of new knowledge about the physiology of this pathogen. This raises the possibility of new strategies for the treatment of patients with P. aeruginosa infection, either by novel antibiotics or by drugs targeting bacterial functions essential for survival and virulence in the human host.
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Affiliation(s)
- A L Erwin
- Chiron Corperation, Seattle, Washington 98119, USA.
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14
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Stover CK, Warrener P, VanDevanter DR, Sherman DR, Arain TM, Langhorne MH, Anderson SW, Towell JA, Yuan Y, McMurray DN, Kreiswirth BN, Barry CE, Baker WR. A small-molecule nitroimidazopyran drug candidate for the treatment of tuberculosis. Nature 2000; 405:962-6. [PMID: 10879539 DOI: 10.1038/35016103] [Citation(s) in RCA: 722] [Impact Index Per Article: 30.1] [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: 11/09/2022]
Abstract
Mycobacterium tuberculosis, which causes tuberculosis, is the greatest single infectious cause of mortality worldwide, killing roughly two million people annually. Estimates indicate that one-third of the world population is infected with latent M. tuberculosis. The synergy between tuberculosis and the AIDS epidemic, and the surge of multidrug-resistant clinical isolates of M. tuberculosis have reaffirmed tuberculosis as a primary public health threat. However, new antitubercular drugs with new mechanisms of action have not been developed in over thirty years. Here we report a series of compounds containing a nitroimidazopyran nucleus that possess antitubercular activity. After activation by a mechanism dependent on M. tuberculosis F420 cofactor, nitroimidazopyrans inhibited the synthesis of protein and cell wall lipid. In contrast to current antitubercular drugs, nitroimidazopyrans exhibited bactericidal activity against both replicating and static M. tuberculosis. Lead compound PA-824 showed potent bactericidal activity against multidrugresistant M. tuberculosis and promising oral activity in animal infection models. We conclude that nitroimidazopyrans offer the practical qualities of a small molecule with the potential for the treatment of tuberculosis.
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Affiliation(s)
- C K Stover
- PathoGenesis Corporation, Seattle, Washington 98119, USA.
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15
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VanDevanter DR, Warrener P, Bennett L, Schultz ER, Coulter S, Garber RL, Rose TM. Detection and analysis of diverse herpesviral species by consensus primer PCR. J Clin Microbiol 1996; 34:1666-71. [PMID: 8784566 PMCID: PMC229091 DOI: 10.1128/jcm.34.7.1666-1671.1996] [Citation(s) in RCA: 561] [Impact Index Per Article: 20.0] [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: 02/02/2023] Open
Abstract
A consensus primer PCR method which amplifies a region of herpesviral DNA-directed DNA polymerase (EC 2.7.7.7) and which uses degenerate primers in a nested format was developed. Primers were designed to target sequences coding for highly conserved amino acid motifs covering a region of approximately 800 bp. The assay was applied to 22 species of herpesviruses (8 human and 14 animal viruses), with PCR products obtained for 21 of 22 viruses. In the process, 14 previously unreported amino acid-coding sequences from herpesviral DNA polymerases were obtained, including regions of human herpesviruses 7 and 8. The 50 to 60 amino acid-coding sequences recovered in the present study were determined to be unique to each viral species studied, with very little sequence variation between strains of a single species when studied. Template dilution studies in the presence of human carrier DNA demonstrated that six human herpesviruses (herpesviruses 1, 2, 3, 4, 5, and 6B) could be detected at levels at or below 100 genome equivalents per 100 ng of carrier DNA. These data suggest that consensus primer PCR targeted to herpesviral DNA polymerase may prove to be useful in the detection and identification of known herpesviruses in clinical samples and the initial characterization of new herpesviral genomes.
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16
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Kirk JA, Radich J, Edmands S, Lee A, VanDevanter DR, Reems JA, Bryant EM. Unusual expression of mRNA typical of Philadelphia positive acute lymphoblastic leukemia detected in chronic myeloid leukemia. Am J Hematol 1996; 52:129-34. [PMID: 8756076 DOI: 10.1002/(sici)1096-8652(199607)52:3<129::aid-ajh1>3.0.co;2-v] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The Philadelphia chromosome (Ph) is found in both chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL). The Ph translocation, t(9;22)(q34;q11), can disrupt the BCR gene on chromosome 22 in one to two areas called the major (Mbcr1) and minor (mbcr1) breakpoint cluster regions. In CML the breakpoint has been mapped almost exclusively to Mbcr1, whereas in Ph positive ALL both Mbcr1 and the upstream mbcr1 breakpoints have been described. In this communication we describe an unusual patient with typical chronic phase Ph positive CML and evidence of the uncharacteristic mbcr1 breakpoint, predicting expression of the ALL-type p190 fusion protein. Fluorescence in situ hybridization demonstrated BCR gene rearrangement, the reverse transcription polymerase chain reaction detected the BCR-ABL fusion mRNA characteristic of the mbcr1 breakpoint, and failed to detect BCR-ABL mRNA characteristic of the Mbcr1 breakpoint. Southern blot analysis revealed no rearrangement in Mbcr1, and direct sequencing of the PCR product confirmed it to be the ALL-type mbcr1 fusion mRNA with the first exon of the BCR gene fused to ABL exon a2. This case differs from the previously reported cases of "p190" CML in that the patient presented without abnormal hematopoietic features other than those found in typical CML and provides further evidence that the p190 mRNA is not sufficient to cause an acute rather than chronic leukemia.
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Affiliation(s)
- J A Kirk
- Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA
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17
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VanDevanter DR, Tseng JC, Yirdaw G. Electrophoretic isolation of extrachromosomal DNA from tumor cells. Genes Chromosomes Cancer 1995; 12:262-71. [PMID: 7539280 DOI: 10.1002/gcc.2870120405] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Gene amplification allows transformed cells to overexpress specific genes and gain a survival advantage. For this reason, cloning and characterization of amplified genes can improve our understanding of the biology of transformed cells. The techniques of in-gel renaturation and chromosome microdissection can enrich for amplified DNA sequences, but both are labor intensive and have other drawbacks. We have developed an alternative strategy of enriching for amplified DNA sequences that involves two-directional agarose gel electrophoresis of extrachromosomal circular DNA. Extrachromosomal circles can be detected with repetitive DNA probes and can be used to produce DNA probes suitable for fluorescence in situ hybridization for location of genomic origin. The ability to enrich for amplified DNA without specialized equipment or transformed cell metaphases should prove useful in the search for new genes which are important in tumor cell progression.
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Affiliation(s)
- D R VanDevanter
- Tumor Institute, Swedish Medical Center, Seattle, Washington, USA
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18
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Kirk JA, VanDevanter DR, Biberman J, Bryant EM. Y chromosome loss in chronic myeloid leukemia detected in both normal and malignant cells by interphase fluorescence in situ hybridization. Genes Chromosomes Cancer 1994; 11:141-5. [PMID: 7530482 DOI: 10.1002/gcc.2870110302] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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: 01/25/2023] Open
Abstract
Loss of the Y chromosome in bone marrow (BM) cells is a normal age-associated event. Y chromosome loss is also observed in the Philadelphia chromosome (Ph) positive BM cells of some patients with chronic myeloid leukemia (CML) in chronic phase, but at a younger age than in normal individuals. While the significance of loss of the sex chromosome in normal males is uncertain, -Y marrow cells are not believed to be of clonal origin. However, because CML is a clonal disease, CML sub-populations with Y loss may constitute a disease-related sub-clone. We used a PCR-amplified yeast artificial chromosome containing the BCR gene region for single color interphase analysis of BCR rearrangement by fluorescence in situ hybridization (FISH). Then, using two color FISH, with one fluorochrome detecting the BCR gene region and the other detecting Y chromosome repeat sequences, we surveyed peripheral and BM Y loss in both normal Ph- (BCR not disrupted) and CML Ph+ (BCR rearranged) interphase nuclei of two patients with Y loss in Ph positive cells observed by metaphase analysis. -Y was seen in a proportion of Ph+ cells in both cases, and the proportion matched that seen in Ph- cells, indicating that Y loss is probably sporadic in both normal and CML populations, and that the propensity for Y loss in normal BM cells may be a phenotype that can be retained by malignant cells in CML.
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Affiliation(s)
- J A Kirk
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98104
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19
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Ryan MC, Tizard R, VanDevanter DR, Carter WG. Cloning of the LamA3 gene encoding the alpha 3 chain of the adhesive ligand epiligrin. Expression in wound repair. J Biol Chem 1994; 269:22779-87. [PMID: 8077230] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have isolated cDNA clones encoding the entire 170-kDa chain of epiligrin (alpha 3Ep) and a genomic clone encoding the alpha 3Ep gene (LamA3). Analysis of multiple cDNA clones revealed two distinct transcripts (alpha 3EpA and alpha 3EpB). Sequencing of the alpha 3EpA transcript indicated sequence and structural homology to laminin alpha 1 and alpha 2 chains that extend from domain IIIa through the carboxyl-terminal G domain. The alpha 3EpB transcript encodes a larger amino-terminal domain and contains additional epidermal growth factor repeats and sequences corresponding to domain IV of alpha 1 laminin. Fluorescence in situ hybridization indicated that the LamA3 gene is located on chromosome 18q11.2, a locus distinct from the LamA1 gene (18p11.3). The G domain of the epiligrin alpha 3 chain contains five subdomains that are individually related to the G subdomains reported for Drosophila and vertebrate laminin alpha chains. Sequence divergence within the G domain of alpha 3 epiligrin suggests that it is functionally distinct from laminin, consistent with our previous report showing that epiligrin interacts with different integrin adhesion receptors. Analysis of RNA from human foreskin keratinocytes (HFKs) identified multiple epiligrin transcripts that were down-regulated by viral transformation and differentiation. In contrast, epiligrin expression was up-regulated in wound sites of human skin.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Cell Adhesion Molecules/biosynthesis
- Cell Adhesion Molecules/chemistry
- Cell Adhesion Molecules/genetics
- Chromosome Mapping
- Chromosomes, Human, Pair 8
- Cloning, Molecular
- DNA Primers
- DNA, Complementary/isolation & purification
- DNA, Complementary/metabolism
- Drosophila/genetics
- Gene Expression
- Humans
- In Situ Hybridization, Fluorescence
- Keratinocytes/metabolism
- Laminin/chemistry
- Laminin/genetics
- Macromolecular Substances
- Molecular Sequence Data
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- Sequence Homology, Amino Acid
- Transcription, Genetic
- Vertebrates
- Wound Healing
- Wounds and Injuries/metabolism
- Wounds and Injuries/pathology
- Kalinin
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Affiliation(s)
- M C Ryan
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98104
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20
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VanDevanter DR, Choongkittaworn NM, Dyer KA, Aten J, Otto P, Behler C, Bryant EM, Rabinovitch PS. Pure chromosome-specific PCR libraries from single sorted chromosomes. Proc Natl Acad Sci U S A 1994; 91:5858-62. [PMID: 8016078 PMCID: PMC44096 DOI: 10.1073/pnas.91.13.5858] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [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: 01/28/2023] Open
Abstract
Chromosome-specific DNA libraries can be very useful in molecular and cytogenetic genome mapping studies. We have developed a rapid and simple method for the generation of chromosome-specific DNA sequences that relies on polymerase chain reaction (PCR) amplification of a single flow-sorted chromosome or chromosome fragment. Previously reported methods for the development of chromosome libraries require larger numbers of chromosomes, with preparation of pure chromosomes sorted by flow cytometry, generation of somatic cell hybrids containing targeted chromosomes, or a combination of both procedures. These procedures are labor intensive, especially when hybrid cell lines are not already available, and this has limited the generation of chromosome-specific DNA libraries from nonhuman species. In contrast, a single sorted chromosome is a pure source of DNA for library production even when flow cytometric resolution of chromosome populations is poor. Furthermore, any sorting cytometer may be used with this technique. Using this approach, we demonstrate the generation of PCR libraries suitable for both molecular and fluorescence in situ hybridization studies from individual baboon and canine chromosomes, separate human homologues, and a rearranged marker chromosome from a transformed cell line. PCR libraries specific to subchromosomal regions have also been produced by sorting a small chromosome fragment. This simple and rapid technique will allow generation of nonhuman linkage maps and probes for fluorescence in situ hybridization and the characterization of marker chromosomes from solid tumors. In addition, allele-specific libraries generated by this strategy may also be useful for mapping genetic diseases.
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21
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Abstract
Cytogenetically visible gene amplification structures can consist of arrays of amplicons presumably formed by secondary "rearrangements" following amplicon formation. The structural evolution of gene amplification sites in tumor cells suggests that complex secondary structures may have some selective advantage in the tumor cell environment. Although secondary amplicon rearrangements are a hallmark of the gene amplification process, little is known about the mechanics of this process. COLO320 neuroendocrine tumor cells carry two different types of amplified MYC oncogene sequences, one type with an intact MYC gene and the other with a rearranged "chimeric" MYC gene. We have studied various clonal subpopulations of COLO320 cells and identified regions within and downstream of the MYC locus that are unique to each amplicon type. Using double-label fluorescence in situ hybridization with DNA probes unique to each amplicon type, we have observed that both chromosomal and extrachromosomal MYC amplicon arrays in COLO320 cells frequently consist of heterogeneous mixtures of each MYC amplicon type. Our results suggest that the two MYC amplicon types of COLO320 cells were formed simultaneously but independently, and that double minute chromosomes observed in COLO320 cells were formed by intermolecular homologous recombination secondary to amplicon formation.
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22
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VanDevanter DR, Yirdaw G, Do C, Tysseling KA, Drescher CA, Forseth BJ, Von Hoff DD, McNutt MA. Preparation of uniform, intact DNA samples from resected tumor tissues for pulsed-field gel electrophoretic analyses. Biotechniques 1992; 13:884-7. [PMID: 1335736] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Preparation of high molecular weight DNA from resected tumor tissues suitable for pulsed-field gel electrophoresis (PFGE) can be complicated by the presence of nonviable cells and lymphocytes. We have developed a simple procedure to reduce the level of degraded DNA in PFGE DNA samples prepared from resected tumor tissues. The procedure employs a single, three component Percoll step gradient centrifugation and can be performed on several tumor samples simultaneously. Analyses of DNAs from 15 tumor specimens (7 solid tumors and 8 aspirated fluids) demonstrate that the technique enriches the integrity of PFGE DNA samples. Morphologic evaluation of 9 specimens suggested that both cellular debris and contaminating normal lymphocytes are removed from starting cell populations during the enrichment procedure. Fractionation of cells also reduced cell clumping, allowing for the formation of more uniform PFGE DNA samples.
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Affiliation(s)
- D R VanDevanter
- Tumor Institute, Swedish Hospital Medical Center, Seattle, WA 98104
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23
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Affiliation(s)
- D R VanDevanter
- Tumor Institute, Swedish Hospital Medical Center, Seattle, WA 98104
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24
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Abstract
Esthesioneuroblastoma is a rare malignancy believed to be derived from neuroectodermal stem cells within the olfactory epithelium. We have obtained the karyotype of a primary esthesioneuroblastoma following brief (7-day) in vitro culture, and have determined that the only observable cytogenetic anomaly is the presence of an additional chromosome 8. Previously, the karyotypes of two cell lines established from metastatic esthesioneuroblastomas have been reported to contain the equivalent of three copies of chromosome 8, in addition to other chromosomal aberrations, including the reciprocal translocation, t(11;22)(q24;q12). Examination of the cytogenetic literature suggests that an extra copy of chromosome 8 is a common occurrence in undifferentiated small round cell tumors frequently observed to carry the t(11;22), including esthesioneuroblastoma, Ewing's sarcoma, peripheral neuroepithelioma, Askin's tumor, and rhabdomyosarcoma. These data, combined with our report of a small round cell tumor with the karyotype 47,XY, +8, indicate that trisomy 8 may be a common phenomenon in these tumors, and may also provide some sort of selective advantage to these tumor types.
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Affiliation(s)
- D R VanDevanter
- Clinical Research Division, Swedish Hospital Medical Center, Seattle, WA 98104
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25
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VanDevanter DR, Piaskowski VD, Casper JT, Douglass EC, Von Hoff DD. Ability of circular extrachromosomal DNA molecules to carry amplified MYCN proto-oncogenes in human neuroblastomas in vivo. J Natl Cancer Inst 1990; 82:1815-21. [PMID: 2250296 DOI: 10.1093/jnci/82.23.1815] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [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: 12/31/2022] Open
Abstract
Amplification of the proto-oncogene MYCN (also known as N-myc) in neuroblastomas has been shown to correlate with both disease stage and prognosis, yet little is known about the DNA structures that carry amplified MYCN genes in neuroblastomas in vivo. We have used DNA irradiation and pulsed-field gel electrophoresis to analyze MYCN amplification structures in eight neuroblastomas from separate patients (four primary tumors and four metastatic lesions exhibiting MYCN amplification). Six of the eight neuroblastomas (three primary tumors and three metastatic lesions) exhibited MYCN DNA irradiation profiles consistent with the presence of circular extrachromosomal DNA amplification structures. Five neuroblastomas possessed amplification structures within the size range of double minute chromosomes, and one contained smaller DNA circles. Two neuroblastomas exhibited MYCN DNA irradiation patterns consistent with larger (presumably chromosomal) amplification structures. Multiple sizes of DNA circles were observed in the neuroblastomas of four different patients, implying in vivo multimerization of amplification structures. The presence of circular MYCN amplification structures in six of eight neuroblastomas examined suggests that circular DNA molecules are important structures in in vivo gene amplification.
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Affiliation(s)
- D R VanDevanter
- Tumor Institute, Swedish Hospital Medical Center, Seattle, Wash
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26
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Rosen H, Orman J, Rakita RM, Michel BR, VanDevanter DR. Loss of DNA-membrane interactions and cessation of DNA synthesis in myeloperoxidase-treated Escherichia coli. Proc Natl Acad Sci U S A 1990; 87:10048-52. [PMID: 2175901 PMCID: PMC55312 DOI: 10.1073/pnas.87.24.10048] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [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: 12/30/2022] Open
Abstract
Neutrophils and monocytes employ a diverse array of antimicrobial effector systems to support their host defense functions. The mechanisms of action of most of these systems are incompletely understood. The present report indicates that microbicidal activity by a neutrophil-derived antimicrobial system, consisting of myeloperoxidase, enzymatically generated hydrogen peroxide, and chloride ion, is accompanied by prompt cessation of DNA synthesis in Escherichia coli, as determined by markedly reduced incorporation of [3H]thymidine into trichloracetic acid-precipitable material. Simultaneously, the myeloperoxidase system mediates a decline in the ability of E. coli membranes to bind hemimethylated DNA sequences containing the E. coli chromosomal origin of replication (oriC). Binding of oriC to the E. coli membrane is an essential element of orderly chromosomal DNA replication. Comparable early changes in DNA synthesis and DNA-membrane interactions were not observed with alternative oxidant or antibiotic-mediated microbicidal systems. It is proposed that oxidants generated by the myeloperoxidase system modify the E. coli membrane in such a fashion that oriC binding is markedly impaired. As a consequence chromosomal DNA replication is impaired and organisms can no longer replicate.
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Affiliation(s)
- H Rosen
- Department of Medicine, University of Washington, Seattle
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