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Pan Z, Dahman B, Bono RS, Sabik LM, Belgrave FZ, Yerkes L, Nixon DE, Kimmel AD. Brief Report: Physician Reimbursement and Retention in HIV Care: Racial Disparities in the US South. J Acquir Immune Defic Syndr 2023; 92:1-5. [PMID: 36184773 PMCID: PMC9742342 DOI: 10.1097/qai.0000000000003105] [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: 04/07/2022] [Accepted: 08/17/2022] [Indexed: 02/04/2023]
Abstract
BACKGROUND Retention in HIV care remains a national challenge. Addressing structural barriers to care may improve retention. We examined the association between physician reimbursement and retention in HIV care, including racial differences. METHODS We integrated person-level administrative claims (Medicaid Analytic eXtract, 2008-2012), state Medicaid-to-Medicare physician fee ratios (Urban Institute, 2008, 2012), and county characteristics for 15 Southern states plus District of Columbia. The fee ratio is a standardized measure of physician reimbursement capturing Medicaid relative to Medicare physician reimbursement across states. Generalized estimating equations assessed the association between the fee ratio and retention (≥2 care markers ≥90 days apart in a calendar year). Stratified analyses assessed racial differences. We varied definitions of retention, subsamples, and definitions of the fee ratio, including the fee ratio at parity. RESULTS The sample included 55,237 adult Medicaid enrollees with HIV (179,002 enrollee years). Enrollees were retained in HIV care for 76.6% of their enrollment years, with retention lower among non-Hispanic Black (76.1%) versus non-Hispanic White enrollees (81.3%, P < 0.001). A 10-percentage point increase in physician reimbursement was associated with 4% increased odds of retention (adjusted odds ratio 1.04, 95% confidence interval: 1.01 to 1.07). In stratified analyses, the positive, significant association occurred among non-Hispanic Black (1.08, 1.05-1.12) but not non-Hispanic White enrollees (0.87, 0.74-1.02). Findings were robust across sensitivity analyses. When the fee ratio reached parity, predicted retention increased significantly overall and for non-Hispanic Black enrollees. CONCLUSION Higher physician reimbursement may improve retention in HIV care, particularly among non-Hispanic Black individuals, and could be a mechanism to promote health equity.
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Affiliation(s)
- Zhongzhe Pan
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Bassam Dahman
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Rose S. Bono
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Lindsay M. Sabik
- Department of Health Policy and Management, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Faye Z. Belgrave
- Department of Psychology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Lauren Yerkes
- Virginia Department of Health, Richmond, Virginia, USA
| | - Daniel E. Nixon
- Department of Internal Medicine, Division of Infectious Diseases, Virginia Commonwealth University, Richmond, Virginia, USA
| | - April D. Kimmel
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
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Bono RS, Dahman B, Sabik LM, Yerkes LE, Deng Y, Belgrave FZ, Nixon DE, Rhodes AG, Kimmel AD. Human Immunodeficiency Virus-Experienced Clinician Workforce Capacity: Urban-Rural Disparities in the Southern United States. Clin Infect Dis 2021; 72:1615-1622. [PMID: 32211757 DOI: 10.1093/cid/ciaa300] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/23/2020] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV)-experienced clinicians are critical for positive outcomes along the HIV care continuum. However, access to HIV-experienced clinicians may be limited, particularly in nonmetropolitan areas, where HIV is increasing. We examined HIV clinician workforce capacity, focusing on HIV experience and urban-rural differences, in the Southern United States. METHODS We used Medicaid claims and clinician characteristics (Medicaid Analytic eXtract [MAX] and MAX Provider Characteristics, 2009-2011), county-level rurality (National Center for Health Statistics, 2013), and diagnosed HIV cases (AIDSVu, 2014) to assess HIV clinician capacity in 14 states. We assumed that clinicians accepting Medicaid approximated the region's HIV workforce, since three-quarters of clinicians accept Medicaid insurance. HIV-experienced clinicians were defined as those providing care to ≥ 10 Medicaid enrollees over 3 years. We assessed HIV workforce capacity with county-level clinician-to-population ratios, using Wilcoxon-Mann-Whitney tests to compare urban-rural differences. RESULTS We identified 5012 clinicians providing routine HIV management, of whom 28% were HIV-experienced. HIV-experienced clinicians were more likely to specialize in infectious diseases (48% vs 6%, P < .001) and practice in urban areas (96% vs 83%, P < .001) compared to non-HIV-experienced clinicians. The median clinician-to-population ratio for all HIV clinicians was 13.3 (interquartile range, 38.0), with no significant urban-rural differences. When considering HIV experience, 81% of counties had no HIV-experienced clinicians, and rural counties generally had fewer HIV-experienced clinicians per 1000 diagnosed HIV cases (P < .001). CONCLUSIONS Significant urban-rural disparities exist in HIV-experienced workforce capacity for communities in the Southern United States. Policies to improve equity in access to HIV-experienced clinical care for both urban and rural communities are urgently needed.
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Affiliation(s)
- Rose S Bono
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Bassam Dahman
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Lindsay M Sabik
- Department of Health Policy and Management, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lauren E Yerkes
- Division of Population Health Data, Virginia Department of Health, Richmond, Virginia, USA.,Division of Disease Prevention, Virginia Department of Health, Richmond, Virginia, USA
| | - Yangyang Deng
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Faye Z Belgrave
- Department of Psychology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Daniel E Nixon
- Department of Internal Medicine, Division of Infectious Diseases, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Anne G Rhodes
- Division of Disease Prevention, Virginia Department of Health, Richmond, Virginia, USA
| | - April D Kimmel
- Department of Health Behavior and Policy, Virginia Commonwealth University, Richmond, Virginia, USA
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MacDonald DM, Zanotto AD, Collins G, Baker JV, Czarnecki M, Loiza E, Nixon DE, Papastamopoulos V, Wendt CH, Wood R, Kunisaki KM. Associations between baseline biomarkers and lung function in HIV-positive individuals. AIDS 2019; 33:655-664. [PMID: 30601153 DOI: 10.1097/qad.0000000000002101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The aim of this study was to analyse the association of baseline biomarker data with cross-sectional lung function and subsequent decline in lung function in HIV-positive persons. DESIGN Lung function was modelled in all START pulmonary substudy participants who had baseline biomarker data and good-quality spirometry. In longitudinal analyses, we restricted to those participants with at least one good-quality follow-up spirometry test. METHODS We performed linear regression of baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC and their longitudinal slopes on log2-transformed baseline biomarkers with adjustment for age, sex, race, region, smoking status, baseline CD4+ T-cell counts and baseline HIV-RNA. Biomarkers included D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-27, serum amyloid A, soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule (sVCAM)-1, albumin and total bilirubin. RESULTS Among 903 included participants, baseline median age was 36 years, CD4+ cell count was 647 cells/μl, and 28.5% were current smokers. In adjusted analyses, elevated markers of systemic inflammation (hsCRP, IL-6 and serum amyloid A) were associated with lower baseline FEV1 and FVC. Elevated D-dimer and IL-6 were associated with worse airflow obstruction (lower FEV1/FVC). Despite these cross-sectional associations at baseline, no associations were found between baseline biomarkers and subsequent longitudinal lung function decline over a median follow-up time of 3.9 years (3293 spirometry-years of follow-up). CONCLUSION Commonly available biomarkers, in particular markers of systemic inflammation, are associated with worse cross-sectional lung function, but do not associate with subsequent lung function decline among HIV-positive persons with early HIV infection and baseline CD4 T-cell counts more than 500 cells/μl.
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Hall CE, Koparde VN, Jameson-Lee M, Elnasseh AG, Scalora AF, Kobulnicky DJ, Serrano MG, Roberts CH, Buck GA, Neale MC, Nixon DE, Toor AA. Sequence homology between HLA-bound cytomegalovirus and human peptides: A potential trigger for alloreactivity. PLoS One 2017; 12:e0178763. [PMID: 28800601 PMCID: PMC5553991 DOI: 10.1371/journal.pone.0178763] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 05/18/2017] [Indexed: 11/18/2022] Open
Abstract
Human cytomegalovirus (hCMV) reactivation may often coincide with the development of graft-versus-host-disease (GVHD) in stem cell transplantation (SCT). Seventy seven SCT donor-recipient pairs (DRP) (HLA matched unrelated donor (MUD), n = 50; matched related donor (MRD), n = 27) underwent whole exome sequencing to identify single nucleotide polymorphisms (SNPs) generating alloreactive peptide libraries for each DRP (9-mer peptide-HLA complexes); Human CMV CROSS (Cross-Reactive Open Source Sequence) database was compiled from NCBI; HLA class I binding affinity for each DRPs HLA was calculated by NetMHCpan 2.8 and hCMV- derived 9-mers algorithmically compared to the alloreactive peptide-HLA complex libraries. Short consecutive (≥6) amino acid (AA) sequence homology matching hCMV to recipient peptides was considered for HLA-bound-peptide (IC50<500nM) cross reactivity. Of the 70,686 hCMV 9-mers contained within the hCMV CROSS database, an average of 29,658 matched the MRD DRP alloreactive peptides and 52,910 matched MUD DRP peptides (p<0.001). In silico analysis revealed multiple high affinity, immunogenic CMV-Human peptide matches (IC50<500 nM) expressed in GVHD-affected tissue-specific manner. hCMV+GVHD was found in 18 patients, 13 developing hCMV viremia before GVHD onset. Analysis of patients with GVHD identified potential cross reactive peptide expression within affected organs. We propose that hCMV peptide sequence homology with human alloreactive peptides may contribute to the pathophysiology of GVHD.
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Affiliation(s)
- Charles E. Hall
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Vishal N. Koparde
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Maximilian Jameson-Lee
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Abdelrhman G. Elnasseh
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Allison F. Scalora
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - David J. Kobulnicky
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Myrna G. Serrano
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Catherine H. Roberts
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Gregory A. Buck
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Michael C. Neale
- Departments of Psychiatry and Human & Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Daniel E. Nixon
- Division of Infectious Diseases, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Amir A. Toor
- Bone Marrow Transplant Program, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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Hall CE, Koparde VN, Jameson-Lee M, Elnasseh A, Scalora AF, Kobulnicky DJ, Serrano MG, Roberts CH, McCarty JM, Chung HM, Clark WB, Wiedl CM, Buck GA, Neale MC, Nixon DE, Toor AA. Cytomegalovirus Antigenic Mimicry of Human Alloreactive Peptides: Exploring Cross-Reactivity As a Potential Trigger for Graft Versus Host Disease. Biol Blood Marrow Transplant 2017. [DOI: 10.1016/j.bbmt.2016.12.649] [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]
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Kunisaki KM, Niewoehner DE, Collins G, Aagaard B, Atako NB, Bakowska E, Clarke A, Corbelli GM, Ekong E, Emery S, Finley EB, Florence E, Infante RM, Kityo CM, Madero JS, Nixon DE, Tedaldi E, Vestbo J, Wood R, Connett JE. Pulmonary effects of immediate versus deferred antiretroviral therapy in HIV-positive individuals: a nested substudy within the multicentre, international, randomised, controlled Strategic Timing of Antiretroviral Treatment (START) trial. Lancet Respir Med 2016; 4:980-989. [PMID: 27773665 DOI: 10.1016/s2213-2600(16)30319-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/31/2016] [Accepted: 09/01/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND Observational data have been conflicted regarding the potential role of HIV antiretroviral therapy (ART) as a causative factor for, or protective factor against, COPD. We therefore aimed to investigate the effect of immediate versus deferred ART on decline in lung function in HIV-positive individuals. METHODS We did a nested substudy within the randomised, controlled Strategic Timing of Antiretroviral Treatment (START) trial at 80 sites in multiple settings in 20 high-income and low-to-middle-income countries. Participants were HIV-1 infected individuals aged at least 25 years, naive to ART, with CD4 T-cell counts of more than 500 per μL, not receiving treatment for asthma, and without recent respiratory infections (baseline COPD was not an exclusion criterion). Participants were randomly assigned to receive ART (an approved drug combination derived from US Department of Health and Human Services guidelines) either immediately, or deferred until CD4 T-cell counts decreased to 350 per μL or AIDS developed. The randomisation was determined by participation in the parent START study, and was not specific to the substudy. Because of the nature of our study, site investigators and participants were not masked to the treatment group assignment; however, the assessors who reviewed the outcomes were masked to the treatment group. The primary outcome was the annual rate of decline in lung function, expressed as the FEV1 slope in mL/year; spirometry was done annually during follow-up for up to 5 years. We analysed data on an intention-to-treat basis, and planned separate analyses in smokers and non-smokers because of the known effects of smoking on FEV1 decline. The substudy was registered at ClinicalTrials.gov number NCT01797367. FINDINGS Between March 11, 2010, and Aug 23, 2013, we enrolled 1026 participants to our substudy, who were then randomly assigned to either immediate (n=518) or deferred (n=508) ART. Median baseline characteristics included age 36 years (IQR 30-44), CD4 T-cell count 648 per μL (583-767), and HIV plasma viral load 4·2 log10 copies per mL (3·5-4·7). 29% were female and 28% were current smokers. Median follow-up time was 2·0 years (IQR 1·9-3·0). We noted no differences in FEV1 slopes between the immediate and deferred ART groups either in smokers (difference of -3·3 mL/year, 95% CI -38·8 to 32·2; p=0·86) or in non-smokers (difference of -5·6 mL/year, -29·4 to 18·3; p=0·65) or in pooled analyses adjusted for smoking status at each study visit (difference of -5·2 mL/year, -25·1 to 14·6; p=0·61). INTERPRETATION The timing of ART initiation has no major short-term effect on rate of lung function decline in HIV-positive individuals who are naive to ART, with CD4 T-cell counts of more than 500 per μL. In light of updated WHO recommendations that all HIV-positive individuals should be treated with ART, regardless of their CD4 T-cell count, our results suggest an absence of significant pulmonary harm with such an approach. FUNDING US National Heart Lung and Blood Institute, US National Institute of Allergy and Infectious Diseases, Division of AIDS, Agence Nationale de Recherches sur le SIDA et les Hipatites Virales (France), Australian National Health and Medical Research Council, Danish National Research Foundation, European AIDS Treatment Network, German Ministry of Education and Research, UK Medical Research Council and National Institute for Health Research, and US Veterans Health Administration Office of Research and Development.
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Affiliation(s)
- Ken M Kunisaki
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, USA; University of Minnesota, Minneapolis, MN, USA.
| | - Dennis E Niewoehner
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, USA; University of Minnesota, Minneapolis, MN, USA
| | | | - Bitten Aagaard
- Copenhagen HIV Programme, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Nafisah B Atako
- Medical Research Council Clinical Trials Unit at University College London, London, UK
| | | | | | | | - Ernest Ekong
- Institute of Human Virology-Nigeria, Abuja, Nigeria
| | - Sean Emery
- Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | | | | | - Rosa M Infante
- Asociación Civil Impacta Salud y Educación, Barranco, Lima, Perú
| | | | - Juan Sierra Madero
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Infectious Diseases Department, Mexico City, Mexico
| | | | - Ellen Tedaldi
- Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | | | - Robin Wood
- Desmond Tutu HIV Foundation, Cape Town, South Africa
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Bajaj JS, Sterling RK, Betrapally NS, Nixon DE, Fuchs M, Daita K, Heuman DM, Sikaroodi M, Hylemon PB, White MB, Ganapathy D, Gillevet PM. HCV eradication does not impact gut dysbiosis or systemic inflammation in cirrhotic patients. Aliment Pharmacol Ther 2016; 44:638-43. [PMID: 27417456 DOI: 10.1111/apt.13732] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 05/27/2016] [Accepted: 06/24/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Eradication of hepatitis C virus (HCV) is increasing but its residual impact on the pro-inflammatory milieu in cirrhosis, which is associated with gut dysbiosis, is unclear. AIM To define the impact of sustained virological response (SVR) on gut dysbiosis and systemic inflammation in HCV cirrhosis patients. METHODS Cirrhotic out-patients with HCV with/without SVR (achieved >1 year prior) and age-matched healthy controls underwent serum and stool collection. Serum was analysed for IL-6, TNF-α and endotoxin while stool microbiota analysis was performed using multitagged pyrosequencing. Microbial comparisons were made using UNIFRAC and cirrhosis dysbiosis ratio (lower score indicates dysbiosis). Comparisons were performed between cirrhotics with/without SVR and controls vs. cirrhotic patients. RESULTS A total of 105 HCV cirrhotics and 45 age-matched healthy controls were enrolled. Twenty-one patients had achieved SVR using pegylated interferon + ribavrin a median of 15 months prior. No significant differences on demographics, cirrhosis severity, concomitant medications or diabetes were seen between cirrhotics with/without SVR. There was no significant difference in overall microbiota composition (UNIFRAC P = 0.3) overall or within specific microbial families (cirrhosis dysbiosis ratio median 1.3 vs. 1.0, P = 0.45) between groups with/without SVR. This also extended towards IL-6, TNF-α and endotoxin levels. Both cirrhosis groups, however, had significant dysbiosis compared to healthy controls [UNIFRAC P = 0.01, cirrhosis dysbiosis ratio (1.1 vs. 2.9, P < 0.001)] along with higher levels of endotoxin, IL-6 and TNF-α. CONCLUSIONS Gut dysbiosis and a pro-inflammatory systemic milieu, are found in HCV cirrhosis regardless of SVR. This persistent dysbiosis could contribute towards varying rates of improvement after HCV eradication in cirrhosis.
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Affiliation(s)
- J S Bajaj
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - R K Sterling
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - N S Betrapally
- Microbiome Analysis Center, George Mason University, Manassas, VA, USA
| | - D E Nixon
- Division of Infectious Diseases, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - M Fuchs
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - K Daita
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - D M Heuman
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - M Sikaroodi
- Department of Microbiology, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - P B Hylemon
- Department of Microbiology, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - M B White
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - D Ganapathy
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - P M Gillevet
- Department of Microbiology, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
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Adler SP, Manganello AM, Lee R, McVoy MA, Nixon DE, Plotkin S, Mocarski E, Cox JH, Fast PE, Nesterenko PA, Murray SE, Hill AB, Kemble G. A Phase 1 Study of 4 Live, Recombinant Human Cytomegalovirus Towne/Toledo Chimera Vaccines in Cytomegalovirus-Seronegative Men. J Infect Dis 2016; 214:1341-1348. [PMID: 27521362 DOI: 10.1093/infdis/jiw365] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [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: 05/25/2016] [Accepted: 06/28/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Human cytomegalovirus (HCMV) infection causes disease in newborns and transplant recipients. A HCMV vaccine (Towne) protects transplant recipients. METHODS The genomes of Towne and the nonattenuated Toledo strain were recombined, yielding 4 Towne/Toledo chimera vaccines. Each of 36 HCMV-seronegative men received 1 subcutaneous dose of 10, 100, or 1000 plaque-forming units (PFU) in cohorts of 3. Safety and immunogenicity were evaluated over 12 weeks after immunization and for 52 weeks for those who seroconverted. RESULTS There were no serious local or systemic reactions. No subject had HCMV in urine or saliva. For chimera 3, none of 9 subjects seroconverted. For chimera 1, 1 of 9 seroconverted (the seroconverter received 100 PFU). For chimera 2, 3 subjects seroconverted (1 received 100 PFU, and 2 received 1000 PFU). For chimera 4, 7 subjects seroconverted (1 received 10 PFU, 3 received 100 PFU, and 3 received 1000 PFU). All 11 seroconverters developed low but detectable levels of neutralizing activity. CD4+ T-cell responses were detectable in 1 subject (who received 100 PFU of chimera 4). Seven subjects receiving chimera 2 or 4 had detectable CD8+ T-cell responses to IE1; 3 responded to 1-2 additional antigens. CONCLUSIONS The Towne/Toledo chimera vaccine candidates were well tolerated and were not excreted. Additional human trials of chimeras 2 and 4 are appropriate. CLINICAL TRIALS REGISTRATION NCT01195571.
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Affiliation(s)
| | | | | | | | - Daniel E Nixon
- Department of Internal Medicine, Virginia Commonwealth University, Richmond
| | - Stanley Plotkin
- University of Pennsylvania.,Wistar Institute, Philadelphia, Pennsylvania
| | - Edward Mocarski
- Department of Microbiology and Immunology, Emory Vaccine Center, Emory University, Atlanta, Georgia
| | | | | | - Pavlo A Nesterenko
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University
| | - Susan E Murray
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University.,Department of Biology, University of Portland, Oregon
| | - Ann B Hill
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University
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Kunisaki KM, Niewoehner DE, Collins G, Nixon DE, Tedaldi E, Akolo C, Kityo C, Klinker H, La Rosa A, Connett JE. Pulmonary function in an international sample of HIV-positive, treatment-naïve adults with CD4 counts > 500 cells/μL: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial. HIV Med 2015; 16 Suppl 1:119-28. [PMID: 25711330 DOI: 10.1111/hiv.12240] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2014] [Indexed: 02/03/2023]
Abstract
OBJECTIVES The aim of the study was to describe the prevalence and correlates of chronic obstructive pulmonary disease (COPD) in a multicentre international cohort of persons living with HIV (PLWH). METHODS We performed a cross-sectional analysis of adult PLWH, naïve to HIV treatment, with baseline CD4 cell count > 500 cells/μL enrolled in the Pulmonary Substudy of the Strategic Timing of AntiRetroviral Treatment (START) trial. We collected standardized, quality-controlled spirometry. COPD was defined as forced expiratory volume in 1 s:forced vital capacity (FEV1 :FVC) ratio less than the lower limit of normal. RESULTS Among 1026 participants from 80 sites and 20 countries, the median age was 36 [interquartile range (IQR) 30, 44] years, 29% were female, and the median time since HIV diagnosis was 1.2 (IQR 0.4, 3.5) years. Baseline median CD4 cell count was 648 (IQR 583, 767) cells/μL, median viral load was 4.2 (IQR 3.5, 4.7) log10 HIV-1 RNA copies/mL, and 10% had a viral load ≤ 400 copies/mL despite lack of HIV treatment. Current/former/never smokers comprised 28%/11%/61% of the cohort, respectively. COPD was present in 6.8% of participants, and varied by age, smoking status and region. Forty-eight per cent of those with COPD reported lifelong nonsmoking. In multivariable regression, age and pack-years of smoking had the strongest associations with FEV1 :FVC ratio (P < 0.0001). There was a significant effect of region on FEV1 :FVC ratio (P = 0.010). CONCLUSIONS Our data suggest that, among PLWH who were naïve to HIV treatment and had CD4 cell counts > 500 cells/μL, smoking and age were important factors related to COPD. Smoking cessation should remain a high global priority for clinical care and research in PLWH.
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Affiliation(s)
- K M Kunisaki
- Minneapolis VA Health Care System, Minneapolis, MN, USA; University of Minnesota, Minneapolis, MN, USA
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Sandler NG, Wand H, Roque A, Law M, Nason MC, Nixon DE, Pedersen C, Ruxrungtham K, Lewin SR, Emery S, Neaton JD, Brenchley JM, Deeks SG, Sereti I, Douek DC. Plasma levels of soluble CD14 independently predict mortality in HIV infection. J Infect Dis 2011; 203:780-90. [PMID: 21252259 DOI: 10.1093/infdis/jiq118] [Citation(s) in RCA: 870] [Impact Index Per Article: 66.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Chronic human immunodeficiency virus (HIV) infection is associated with intestinal permeability and microbial translocation that contributes to systemic immune activation, which is an independent predictor of HIV disease progression. The association of microbial translocation with clinical outcome remains unknown. METHODS This nested case-control study included 74 subjects who died, 120 of whom developed cardiovascular disease and 81 of whom developed AIDS during the Strategies for Management of Anti-Retroviral Therapy (SMART) study with matched control subjects. Intestinal fatty acid binding protein (I-FABP), lipopolysaccharide (LPS), soluble CD14 (sCD14), endotoxin core antibody (EndoCAb), and 16S ribosomal DNA (rDNA) were measured in baseline plasma samples. RESULTS Subjects with the highest quartile of sCD14 levels had a 6-fold higher risk of death than did those in the lowest quartile (95% confidence interval, 2.2-16.1; P<.001), with minimal change after adjustment for inflammatory markers, CD4(+) T cell count, and HIV RNA level. No other marker was significantly associated with clinical outcomes. I-FABP, LPS, and sCD14 were increased and EndoCAb was decreased in study subjects, compared with healthy volunteers. sCD14 level correlated with levels of IL-6, C-reactive protein, serum amyloid A and D-dimer. CONCLUSIONS sCD14, a marker of monocyte response to LPS, is an independent predictor of mortality in HIV infection. Therapeutic attenuation of innate immune activation may improve survival in patients with HIV infection.
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Lifson AR, Belloso WH, Carey C, Davey RT, Duprez D, El-Sadr WM, Gatell JM, Gey DC, Hoy JF, Krum EA, Nelson R, Nixon DE, Paton N, Pedersen C, Perez G, Price RW, Prineas RJ, Rhame FS, Sampson J, Worley J. Determination of the underlying cause of death in three multicenter international HIV clinical trials. HIV Clin Trials 2008; 9:177-85. [PMID: 18547904 DOI: 10.1310/hct0903-177] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE Describe processes and challenges for an Endpoint Review Committee (ERC) in determining and adjudicating underlying causes of death in HIV clinical trials. METHOD Three randomized HIV trials (two evaluating interleukin-2 and one treatment interruption) enrolled 11,593 persons from 36 countries during 1999-2008. Three ERC members independently reviewed each death report and supporting source documentation to assign underlying cause of death; differences of opinion were adjudicated. RESULTS Of 453 deaths reported through January 14, 2008, underlying causes were as follows: 10% AIDS-defining diseases, 21% non-AIDS malignancies, 9% cardiac diseases, 9% liver disease, 8% non-AIDS-defining infections, 5% suicides, 5% other traumatic events/accidents, 4% drug overdoses/acute intoxications, 11% other causes, and 18% unknown. Major reasons for unknown classification were inadequate clinical information or supporting documentation to determine cause of death. Half (51%) of deaths reviewed by the ERC required follow-up adjudication; consensus was eventually always reached. CONCLUSION ERCs can successfully provide blinded, independent, and systematic determinations of underlying cause of death in HIV clinical trials. Committees should include those familiar with AIDS and non-AIDS-defining diseases and have processes for adjudicating differences of opinion. Training for local investigators and procedure manuals should emphasize obtaining maximum possible documentation and follow-up information on all trial deaths.
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Affiliation(s)
- Alan R Lifson
- University of Minnesota, Minneapolis, Minnesota 55454-1015, USA.
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Masho SW, Wang CL, Nixon DE. Review of tenofovir-emtricitabine. Ther Clin Risk Manag 2007; 3:1097-104. [PMID: 18516268 PMCID: PMC2387297] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Highly active antiretroviral therapy has significantly reduced HIV-related morbidity and mortality. Increasingly, fixed-dose antiretroviral combinations with equal or greater potency than traditional antiretrovirals, along with fewer side effects, reduced toxicity, and simplified dosing convenience are being utilized. Tenofovir-emtricitabine (TDF-FTC) represents one of the more recent fixed-dose combinations. In combination with either a ritonavir-boosted protease inhibitor or a non-nucleoside reverse transcriptase inhibitor, TDF-FTC is a preferred choice in recent treatment guidelines on the basis of demonstrated potency in randomized clinical trials, one-pill-a-day dosing convenience, and relatively low toxicity. In addition, the drug is active against hepatitis B virus. Caution must be exercised in patients with renal insufficiency, or when the drug is used with certain other drugs. This manuscript reviews the use of TDF-FTC in the treatment of HIV.
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Affiliation(s)
- Saba Woldemichael Masho
- Department of Epidemiology and Community Health, School of Medicine, Virginia Commonwealth UniversityRichmond, Virginia, USA
| | - Cun-Lin Wang
- Federal Drug AdministrationBethesda, Maryland, USA
| | - Daniel E Nixon
- Virginia Commonwealth University HIV/AIDS Center, Department of Internal Medicine, School of Medicine, Virginia Commonwealth UniversityRichmond, Virginia, USA
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Abstract
The current literature is controversial in providing evidence to determine the optimal time to initiate therapy among patients with HIV. However, there is evidence that initiating early treatment might provide benefits by treating primary HIV infection, preserving normal immune function, suppressing HIV viral replication, deferring clinical progression, and reducing HIV transmission. The biggest challenges in initiating treatment early are issues related with long-term management, including toxicities, adherence, and drug resistance. However, the availability of superior new antiretroviral drugs and simplified regimens, the development of effective treatment strategy, and further improvement of adherence through directly observed treatment are addressing the issues and changing the balance towards earlier treatment.
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Affiliation(s)
- Cunlin Wang
- Medical College of Virginia Campus, Virginia Commonwealth University, 1000 East Clay Street, Richmond, VA 23298, USA.
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McVoy MA, Nixon DE. Impact of 2-bromo-5,6-dichloro-1-beta-D-ribofuranosyl benzimidazole riboside and inhibitors of DNA, RNA, and protein synthesis on human cytomegalovirus genome maturation. J Virol 2005; 79:11115-27. [PMID: 16103162 PMCID: PMC1193602 DOI: 10.1128/jvi.79.17.11115-11127.2005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [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
Herpesvirus genome maturation is a complex process in which concatemeric DNA molecules are translocated into capsids and cleaved at specific sequences to produce encapsidated-unit genomes. Bacteriophage studies further suggest that important ancillary processes, such as RNA transcription and DNA synthesis, concerned with repeat duplication, recombination, branch resolution, or damage repair may also be involved with the genome maturation process. To gain insight into the biochemical activities needed for herpesvirus genome maturation, 2-bromo-5,6-dichloro-1-beta-d-ribofuranosyl benzimidazole riboside (BDCRB) was used to allow the accumulation of human cytomegalovirus concatemeric DNA while the formation of new genomes was being blocked. Genome formation was restored upon BDCRB removal, and addition of various inhibitors during this time window permitted evaluation of their effects on genome maturation. Inhibitors of protein synthesis, RNA transcription, and the viral DNA polymerase only modestly reduced genome formation, demonstrating that these activities are not required for genome maturation. In contrast, drugs that inhibit both viral and host DNA polymerases potently blocked genome formation. Radioisotope incorporation in the presence of a viral DNA polymerase inhibitor further suggested that significant host-mediated DNA synthesis occurs throughout the viral genome. These results indicate a role for host DNA polymerases in genome maturation and are consistent with a need for terminal repeat duplication, debranching, or damage repair concomitant with DNA packaging or cleavage. Similarities to previously reported effects of BDCRB on guinea pig cytomegalovirus were also noted; however, BDCRB induced low-level formation of a supergenomic species called monomer+ DNA that is unique to human cytomegalovirus. Analysis of monomer+ DNA suggested a model for its formation in which BDCRB permits limited packaging of concatemeric DNA but induces skipping of cleavage sites.
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Affiliation(s)
- Michael A McVoy
- Department of Pediatrics, Virginia Commonwealth University School of Medicine, Richmond, 23298-0163, USA.
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Nixon DE, McVoy MA. Dramatic effects of 2-bromo-5,6-dichloro-1-beta-D-ribofuranosyl benzimidazole riboside on the genome structure, packaging, and egress of guinea pig cytomegalovirus. J Virol 2004; 78:1623-35. [PMID: 14747528 PMCID: PMC369448 DOI: 10.1128/jvi.78.4.1623-1635.2004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [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 halogenated benzimidazoles BDCRB (2-bromo-5,6-dichloro-1-beta-D-riborfuranosyl benzimidazole riboside) and TCRB (2,5,6-trichloro-1-beta-D-riborfuranosyl benzimidazole riboside) were the first compounds shown to inhibit cleavage and packaging of herpesvirus genomes. Both inhibit the formation of unit length human cytomegalovirus (HCMV) genomes by a poorly understood mechanism (M. R. Underwood et al., J. Virol. 72:717-715, 1998; P. M. Krosky et al., J. Virol. 72:4721-4728, 1998). Because the simple genome structure of guinea pig cytomegalovirus (GPCMV) provides a useful model for the study of herpesvirus DNA packaging, we investigated the effects of BDCRB on GPCMV. GPCMV proved to be sensitive to BDCRB (50% inhibitory concentration = 4.7 microM), although somewhat less so than HCMV. In striking contrast to HCMV, however, a dose of BDCRB sufficient to reduce GPCMV titers by 3 logs (50 microM) had no effect on the quantity of GPCMV genomic DNA that was formed in infected cells. Electron microscopy revealed that this DNA was in fact packaged within intranuclear capsids, but these capsids failed to egress from the nucleus and failed to protect the DNA from nuclease digestion. The terminal structure of genomes formed in the presence of BDCRB was also altered. Genomes with ends lacking a terminal repeat at the right end, which normally exist in an equimolar ratio with those having one copy of the repeat at the right end, were selectively eliminated by BDCRB treatment. At the left end, BDCRB treatment appeared to induce heterogeneous truncations such that 2.7 to 4.9 kb of left-end-terminal sequences were missing. These findings suggest that BDCRB induces premature cleavage events that result in truncated genomes packaged within capsids that are permeable to nuclease. Based on these and other observations, we propose a model for duplication of herpesvirus terminal repeats during the cleavage and packaging process that is similar to one proposed for bacteriophage T7 (Y. B. Chung, C. Nardone, and D. C. Hinkle, J. Mol. Biol. 216:939-948, 1990).
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Affiliation(s)
- Daniel E Nixon
- Department of Medicine, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond, Virginia 23298-0163, USA
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Nixon DE, McVoy MA. Terminally repeated sequences on a herpesvirus genome are deleted following circularization but are reconstituted by duplication during cleavage and packaging of concatemeric DNA. J Virol 2002; 76:2009-13. [PMID: 11799198 PMCID: PMC135902 DOI: 10.1128/jvi.76.4.2009-2013.2002] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The mechanisms underlying cleavage of herpesvirus genomes from replicative concatemers are unknown. Evidence from herpes simplex virus type 1 suggests that cleavage occurs by a nonduplicative process; however, additional evidence suggests that terminal repeats may also be duplicated during the cleavage process. This issue has been difficult to resolve due to the variable numbers of reiterated terminal repeats that the herpes simplex virus type 1 genome can contain. Guinea pig cytomegalovirus is a herpesvirus with a simple terminal repeat arrangement that defines two genome types. Type II genomes have a single copy of a 1-kb terminal repeat at both their left and right termini, whereas type I genomes have only one copy at their left termini and lack the repeat at their right termini. In a previous study, we constructed a recombinant guinea pig cytomegalovirus in which certain cis elements were disrupted such that only type II genomes were produced. Here we show that double repeats that are formed by circularization of infecting genomes are rapidly converted to single repeats, such that the junctions between genomes within replicative concatemers formed late in infection almost exclusively contain single copies of the terminal repeat. Therefore, for the recombinant virus, each cleavage event begins with a single repeat within a concatemer yet produces two repeats, one at each of the resulting termini, demonstrating that terminal repeat duplication occurs in conjunction with cleavage. For wild-type guinea pig cytomegalovirus, the formation of type I genomes further suggests that cleavage can also occur by a nonduplicative process and that duplicative and nonduplicative cleavage can occur concurrently. Other herpesviruses having terminal repeats, such as the herpes simplex viruses and human cytomegalovirus, may also utilize repeat duplication and deletion; however, the biological importance of these events remains unknown.
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Affiliation(s)
- Daniel E Nixon
- Department of Medicine, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond, Virginia 23298-0163, USA
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Abstract
Zinc modulates the structure and binding of the DNA binding domain of the 1alpha,25-dihydroxyvitamin D(3) receptor to specific vitamin D response element DNA (Nature Biotechnology 16, 262-266, 1998). To determine whether zinc alters 1alpha,25-dihydroxyvitamin D(3)-regulated genes in cells, we permanently transfected rat osteoblasts with two vitamin D-dependent promoter-reporter systems and examined their responses to 1alpha,25-dihydroxyvitamin D(3) in the presence of increasing amounts of extracellular zinc. When extracellular zinc concentrations were increased in the presence of 1alpha,25-dihydroxyvitamin D(3), there was an increase in the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent promoters with increasing concentrations of zinc. The effect was specific for zinc since metals such as copper failed to increase the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent promoters. The concentration of the vitamin D receptor within the cell and the affinity of 1alpha,25-dihydroxyvitamin D(3) for its receptor remained unchanged with added zinc. Our results show that zinc increases the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent promoters in osteoblasts.
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Affiliation(s)
- W Lutz
- Nephrology Research Unit, Mayo Clinic and Foundation, 200 First Street SW, Rochester, Minnesota, 55905, USA
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McVoy MA, Nixon DE, Hur JK, Adler SP. The ends on herpesvirus DNA replicative concatemers contain pac2 cis cleavage/packaging elements and their formation is controlled by terminal cis sequences. J Virol 2000; 74:1587-92. [PMID: 10627574 PMCID: PMC111498 DOI: 10.1128/jvi.74.3.1587-1592.2000] [Citation(s) in RCA: 30] [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] [Received: 08/13/1999] [Accepted: 10/25/1999] [Indexed: 11/20/2022] Open
Abstract
Herpesviruses have large double-stranded linear DNA genomes that are formed by site-specific cleavage from complex concatemeric intermediates. In this process, only one of the two genomic ends are formed on the concatemer. Although the mechanism underlying this asymmetry is not known, one explanation is that single genomes are cleaved off of concatemer ends in a preferred direction. This implies that cis elements control the direction of packaging. Two highly conserved cis elements named pac1 and pac2 lie near opposite ends of herpesvirus genomes and are important for cleavage and packaging. By comparison of published reports and by analysis of two additional herpesviruses, we found that pac2 elements lie near the ends formed on replicative concatemers of four herpesviruses: herpes simplex virus type 1, equine herpesvirus 1, guinea pig cytomegalovirus, and murine cytomegalovirus. Formation of pac2 ends on concatemers depended on terminal cis sequences, since ectopic cleavage sites engineered into the murine cytomegalovirus genome mediated formation of pac2 ends on concatemers regardless of the orientation of their insertion. These findings are consistent with a model in which pac2 elements at concatemer ends impart a directionality to concatemer packaging by binding proteins that initiate insertion of concatemer ends into empty capsids.
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Affiliation(s)
- M A McVoy
- Department of Pediatrics, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond, Virginia 23298-0163, USA.
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McVoy MA, Nixon DE, Adler SP, Mocarski ES. Sequences within the herpesvirus-conserved pac1 and pac2 motifs are required for cleavage and packaging of the murine cytomegalovirus genome. J Virol 1998; 72:48-56. [PMID: 9420199 PMCID: PMC109348 DOI: 10.1128/jvi.72.1.48-56.1998] [Citation(s) in RCA: 33] [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: 02/05/2023] Open
Abstract
The DNA sequence motifs pac1 [an A-rich region flanked by poly(C) runs] and pac2 (CGCGGCG near an A-rich region) are conserved near herpesvirus genomic termini and are believed to mediate cleavage of genomes from replicative concatemers. To determine their importance in the cleavage process, we constructed a number of recombinant murine cytomegaloviruses with a second cleavage site inserted at an ectopic location within the viral genome. Cleavage at a wild-type ectopic site occurred as frequently as at the natural cleavage site, whereas mutation of this ectopic site revealed that some of the conserved motifs of pac1 and pac2 were essential for cleavage whereas others were not. Within pac1, the left poly(C) region was very important for cleavage and packaging but the A-rich region was not. Within pac2, the A-rich region and adjacent sequences were essential for cleavage and packaging and the CGCGGCG region contributed to, but was not strictly essential for, efficient cleavage and packaging. A second A-rich region was not important at all. Furthermore, mutations that prevented cleavage also blocked duplication and deletion of the murine cytomegalovirus 30-bp terminal repeat at the ectopic site, suggesting that repeat duplication and deletion are consequences of cleavage. Given that the processes of genome cleavage and packaging appear to be highly conserved among herpesviruses, these findings should be relevant to other members of this family.
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Affiliation(s)
- M A McVoy
- Department of Pediatrics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0163, USA.
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22
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Abstract
The mechanisms by which herpesvirus genome ends are fused to form circles after infection and are re-formed by cleavage from concatemeric DNA are unknown. We used the simple structure of guinea pig cytomegalovirus genomes, which have either one repeated DNA sequence at each end or one repeat at one end and no repeat at the other, to study these mechanisms. In circular DNA, two restriction fragments contained fused terminal sequences and had sizes consistent with the presence of single or double terminal repeats. This result implies a simple ligation of genomic ends and shows that circularization does not occur by annealing of single-stranded terminal repeats formed by exonuclease digestion. Cleavage to form the two genome types occurred at two sites, and homologies between these sites identified two potential cis elements that may be necessary for cleavage. One element coincided with the A-rich region of a pac2 sequence and had 9 of 11 bases identical between the two sites. The second element had six bases identical at both sites, in each case 7 bp from the termini. To confirm the presence of cis cleavage elements, a recombinant virus in which foreign sequences displaced the 6- and 11-bp elements 1 kb from the cleavage point was constructed. Cleavage at the disrupted site did not occur. In a second recombinant virus, restoration of 64 bases containing the 6- and 11-bp elements to the disrupted cleavage site restored cleavage. Therefore, cis cleavage elements exist within this 64-base region, and sequence conservation suggests that they are the 6- and 11-bp elements.
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Affiliation(s)
- M A McVoy
- Department of Pediatrics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0163, USA.
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McConnell JP, Moyer TP, Nixon DE, Schnur PL, Salomao DR, Crotty TB, Weinzweig J, Harris JB, Petty PM. Determination of silicon in breast and capsular tissue from patients with breast implants performed by inductively coupled plasma emission spectroscopy. Comparison with tissue histology. Am J Clin Pathol 1997; 107:236-46. [PMID: 9024074 DOI: 10.1093/ajcp/107.2.236] [Citation(s) in RCA: 15] [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] [Indexed: 02/03/2023] Open
Abstract
A method for analysis of silicon in tissue was developed to determine silicon content in breast parenchymal and periprosthetic capsular tissues of patients with silicone or saline implants and to compare levels in tissues from normal (nonaugmented) breasts. It is of interest to determine whether increased silicon content in tissues can be associated with morbidity in patients who have received silicone implants. This manuscript addresses the issues involved in analysis of breast tissue samples for silicon and compares silicon levels with tissue histologic findings and patient morbidity. One hundred sixty tissue samples were obtained for silicon analysis from 72 patients during augmentation, capsulectomy with or without replacement mammoplasty, mastectomy, or biopsy procedures and were frozen in acid-washed polystyrene tubes at 220 degrees C until analysis. Samples were thawed, sectioned to approximately 0.1 g (dry weight), and digested in nitric acid before analysis by inductively coupled plasma emission spectroscopy, monitoring emission intensity at 251.6 nm. Tissue silicon levels (breast parenchymal and periprosthetic capsular tissue) in patients with silicone gel implants were much higher (mean, 9,287 micrograms/g, n = 106) than in patients with saline implants (mean, 196 micrograms/g, n = 37) or nonaugmented breasts (mean, 64 micrograms/g, n = 17). Histologic examination was performed on 54 tissue samples stained with hematoxylin-eosin. Tissue samples were rated as to degree of inflammation and calcification, and amount of giant cells, foamy histiocytes, and vacuoles containing a colorless refractory material. Vacuolization and foamy histiocyte ratings correlated significantly with tissue silicon concentration. No correlations were found between tissue silicon concentration and inflammation, calcification, or giant cell rating. Implant age (number of years an implant was in place before sampling) correlated with capsular tissue silicon concentration in patients with intact implants but not in those with ruptured implants. No difference in tissue silicon concentration was found between patients with or without signs or symptoms of morbidity. Using 0.1 g of tissue, the method was linear to 1,000 micrograms/g, and sensitivity was 3.7 micrograms/g. Precision between runs (mean, 5.1 micrograms/g; coefficient of variance, 13.7%; n = 13) was calculated from multiple analyses of a bovine liver standard (National Bureau of Standards, reference material 1577a). Significant biologic variability (21.4% to 52.5%) was seen in tissues with high silicon levels. Paraffin-embedded, formalin-fixed tissues are not amenable to silicon analysis by this method, because of leaching of silicone from the tissues during preparation. Thus only fresh frozen tissue samples were used.
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Affiliation(s)
- J P McConnell
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905, USA
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Nixon DE, Mussmann GV, Moyer TP. Inorganic, organic, and total mercury in blood and urine: cold vapor analysis with automated flow injection sample delivery. J Anal Toxicol 1996; 20:17-22. [PMID: 8837946 DOI: 10.1093/jat/20.1.17] [Citation(s) in RCA: 20] [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: 02/02/2023] Open
Abstract
A cold vapor atomic absorption technique for blood or urine mercury analysis that uses persulfate oxidation to prepare samples for total mercury analysis and acid permanganate oxidation to prepare samples for inorganic mercury analysis is described. The linearity of the procedures ranged from 0.5 to 25 micrograms/L. Precision ranged from 20% at 1 microgram/L to 7% at 20 micrograms/L. Documentation of accuracy is based on analysis of samples prepared by an international proficiency survey program. The development of a two-step digestion procedure followed by automated flow-injection mercury analysis was a necessary precursor to the assessment of inorganic and alkylmercury exposure in a large unexposed human population. Application of this technique to 902 blood and 902 urine samples collected from a normal human population who had no extraordinary mercury exposure generated mean plus two standard deviation skewed confidence-limit ranges of results as follows: blood total mercury, 0-8.4 micrograms/L; blood inorganic mercury, 0-1.7 micrograms/L; blood organic mercury, 0-7.5 micrograms/L; urine total mercury, 0-9.9 micrograms/L; urine inorganic mercury, 0-8.6 micrograms/L; and urine organic mercury, 0-1.8 micrograms/L.
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Affiliation(s)
- D E Nixon
- Division of Clinical Biochemistry, Mayo Clinic, Rochester, MN 55905, USA
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Abstract
Abstract
We describe the rapid separation of inorganic arsenic plus metabolites from arsenobetaine or seafood arsenic in urine. Traditional, high-pressure liquid chromatography is replaced by disposable silica-based cation-exchange cartridges for this separation. Both fractions are quickly separated and collected for analysis by atomic absorption spectrophotometry. Analytical recovery of both fractions is > or = 95%, with an overall precision (CV) ranging from 1.6% to 6.4%. Using this method, we correctly identified the sources of arsenic exposure, whether of inorganic or seafood origin, in 11 urine specimens supplied by the Centre de Toxicologie du Quebec.
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Affiliation(s)
- D E Nixon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
| | - T P Moyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
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Nixon DE, Moyer TP. Arsenic analysis II: rapid separation and quantification of inorganic arsenic plus metabolites and arsenobetaine from urine. Clin Chem 1992; 38:2479-83. [PMID: 1458588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We describe the rapid separation of inorganic arsenic plus metabolites from arsenobetaine or seafood arsenic in urine. Traditional, high-pressure liquid chromatography is replaced by disposable silica-based cation-exchange cartridges for this separation. Both fractions are quickly separated and collected for analysis by atomic absorption spectrophotometry. Analytical recovery of both fractions is > or = 95%, with an overall precision (CV) ranging from 1.6% to 6.4%. Using this method, we correctly identified the sources of arsenic exposure, whether of inorganic or seafood origin, in 11 urine specimens supplied by the Centre de Toxicologie du Quebec.
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Affiliation(s)
- D E Nixon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
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Kershisnik MM, Kalamegham R, Ash KO, Nixon DE, Ashwood ER. Using 16O35Cl to correct for chloride interference improves accuracy of urine arsenic determinations by inductively coupled plasma mass spectrometry. Clin Chem 1992; 38:2197-202. [PMID: 1424111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have observed inaccurate urine arsenic values with the method of isobaric fractionation, which was designed to correct for the 40Ar35Cl interference with 75As quantitation by inductively coupled plasma mass spectrometry. Isobaric fractionation, which is based on ion intensities at m/z 77 and 82, consistently underestimates the 40Ar35Cl interference and overestimates urine arsenic. We present an improved method for identifying the argon-chloride interference. We observed that signal intensities for the species 16O35Cl and 40Ar35Cl are proportional (I75 = 0.0295 x I51 - 14.7, r2 = 0.998; where Ix is the normalized ion intensity at m/z X) in water and urine, over a broad range of chloride concentrations (0-800 mmol/L). The proportionality constant is remarkably stable within a run (mean and SD, 0.0295 +/- 0.0023, based on 10 replicates of five chloride calibrators, 0, 100, 200, 400, and 800 mmol/L). Increased sensitivity (50-fold) for detecting the 40Ar35Cl interference provides improved accuracy for urine arsenic quantitation as demonstrated by a split-sample comparison with graphite-furnace atomic absorption spectrophotometry.
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Affiliation(s)
- M M Kershisnik
- Department of Pathology, University of Utah Medical Center, Salt Lake City 84132
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Kershisnik MM, Kalamegham R, Ash KO, Nixon DE, Ashwood ER. Using 16O35CL to Correct for Chloride Interference Improves Accuracy of Urine Arsenic Determinations by Inductively Coupled Plasma Mass Spectrometry. Clin Chem 1992. [DOI: 10.1093/clinchem/38.11.2197] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
We have observed inaccurate urine arsenic values with the method of isobaric fractionation, which was designed to correct for the 40Ar35Cl interference with 75As quantitation by inductively coupled plasma mass spectrometry. Isobaric fractionation, which is based on ion intensities at m/z 77 and 82, consistently underestimates the 40Ar35Cl interference and overestimates urine arsenic. We present an improved method for identifying the argon-chloride interference. We observed that signal intensities for the species 16O35Cl and 40Ar35Cl are proportional (I75 = 0.0295 x I51 - 14.7, r2 = 0.998; where Ix is the normalized ion intensity at m/z X) in water and urine, over a broad range of chloride concentrations (0-800 mmol/L). The proportionality constant is remarkably stable within a run (mean and SD, 0.0295 +/- 0.0023, based on 10 replicates of five chloride calibrators, 0, 100, 200, 400, and 800 mmol/L). Increased sensitivity (50-fold) for detecting the 40Ar35Cl interference provides improved accuracy for urine arsenic quantitation as demonstrated by a split-sample comparison with graphite-furnace atomic absorption spectrophotometry.
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Affiliation(s)
- M M Kershisnik
- Department of Pathology, University of Utah Medical Center, Salt Lake City 84132
| | - R Kalamegham
- Department of Pathology, University of Utah Medical Center, Salt Lake City 84132
| | - K O Ash
- Department of Pathology, University of Utah Medical Center, Salt Lake City 84132
| | - D E Nixon
- Department of Pathology, University of Utah Medical Center, Salt Lake City 84132
| | - E R Ashwood
- Department of Pathology, University of Utah Medical Center, Salt Lake City 84132
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Nixon DE, Mussmann GV, Eckdahl SJ, Moyer TP. Total arsenic in urine: palladium-persulfate vs nickel as a matrix modifier for graphite furnace atomic absorption spectrophotometry. Clin Chem 1991; 37:1575-9. [PMID: 1893592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We evaluated the effectiveness of nickel and palladium with or without added potassium persulfate as matrix modifiers for the determination of total arsenic in urine. Complete recovery of pure aqueous solutions of As(III), As(V), cacodylic acid (DMA), monomethylarsinic acid (MMA), and o-arsanilic acid was attained by using both nickel and palladium modifiers. Combined arsenobetaine and arsenocholine (so-called fish arsenic), extracted from a certified control material of dogfish muscle (DORM-1), were completely recovered with Pd-S2O8 matrix modification, but not with nickel. Excellent agreement with target values for arsenic in urines from the Centre de Toxicologie du Quebec, supplied by the Interlaboratory Comparison Program, was attained irrespective of the arsenic source when we used Pd-S2O8 as the matrix modifier.
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Affiliation(s)
- D E Nixon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
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30
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Nixon DE, Mussmann GV, Eckdahl SJ, Moyer TP. Total arsenic in urine: palladium-persulfate vs nickel as a matrix modifier for graphite furnace atomic absorption spectrophotometry. Clin Chem 1991. [DOI: 10.1093/clinchem/37.9.1575] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.4] [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]
Abstract
Abstract
We evaluated the effectiveness of nickel and palladium with or without added potassium persulfate as matrix modifiers for the determination of total arsenic in urine. Complete recovery of pure aqueous solutions of As(III), As(V), cacodylic acid (DMA), monomethylarsinic acid (MMA), and o-arsanilic acid was attained by using both nickel and palladium modifiers. Combined arsenobetaine and arsenocholine (so-called fish arsenic), extracted from a certified control material of dogfish muscle (DORM-1), were completely recovered with Pd-S2O8 matrix modification, but not with nickel. Excellent agreement with target values for arsenic in urines from the Centre de Toxicologie du Quebec, supplied by the Interlaboratory Comparison Program, was attained irrespective of the arsenic source when we used Pd-S2O8 as the matrix modifier.
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Affiliation(s)
- D E Nixon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
| | - G V Mussmann
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
| | - S J Eckdahl
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
| | - T P Moyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
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31
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Moyer TP, Mussmann GV, Nixon DE. Blood-collection device for trace and ultra-trace metal specimens evaluated. Clin Chem 1991; 37:709-14. [PMID: 2032325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We evaluated the evacuated phlebotomy tube designed specifically for trace metal analysis by Sherwood Medical Co. Pools of human serum containing known concentrations of aluminum, arsenic, calcium, cadmium, copper, chromium, iron, lead, magnesium, manganese, mercury, selenium, and zinc were exposed to the tube and rubber stopper for defined periods ranging from 5 min to 24 h. Analysis for each element was performed in a randomized fashion under rigidly controlled conditions by use of standard electrothermal atomization atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, and cold vapor atomic absorption spectrometry. In addition, for comparative purposes, we collected blood samples from normal volunteers by use of ultra-clean polystyrene phlebotomy syringes as well as standard evacuated phlebotomy tubes. We conclude that, except for lead, there was no significant contribution of any trace element studied from the evaluated tube and stopper to the serum. Because whole blood is the usual specimen for lead testing, the observation of a trace amount of lead in this tube designed for serum collection is trivial.
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Affiliation(s)
- T P Moyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
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32
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Abstract
Abstract
We evaluated the evacuated phlebotomy tube designed specifically for trace metal analysis by Sherwood Medical Co. Pools of human serum containing known concentrations of aluminum, arsenic, calcium, cadmium, copper, chromium, iron, lead, magnesium, manganese, mercury, selenium, and zinc were exposed to the tube and rubber stopper for defined periods ranging from 5 min to 24 h. Analysis for each element was performed in a randomized fashion under rigidly controlled conditions by use of standard electrothermal atomization atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, and cold vapor atomic absorption spectrometry. In addition, for comparative purposes, we collected blood samples from normal volunteers by use of ultra-clean polystyrene phlebotomy syringes as well as standard evacuated phlebotomy tubes. We conclude that, except for lead, there was no significant contribution of any trace element studied from the evaluated tube and stopper to the serum. Because whole blood is the usual specimen for lead testing, the observation of a trace amount of lead in this tube designed for serum collection is trivial.
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Affiliation(s)
- T P Moyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
| | - G V Mussmann
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
| | - D E Nixon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905
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Marco-Franco JE, Torres VE, Nixon DE, Wilson DM, James EM, Bergstralh EJ, McCarthy JT. Oxalate, silicon and vanadium in acquired cystic kidney disease. Clin Nephrol 1991; 35:52-8. [PMID: 2019015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have investigated the importance of several clinical and laboratory parameters on the development of acquired cystic kidney disease (ACKD) as detected by ultrasonography in 19 patients who had received dialysis therapy for at least three years. We were particularly interested on the possible effect of the serum levels of oxalate and silicon, which can produce tubular obstruction, and that of vanadium, which can affect cell proliferation. The severity of ACKD increased with the duration of dialysis and was greater in men than in women. Positive correlations were observed between the grades of ACKD and the levels of hemoglobin, hematocrit, and parathyroid hormone, while there was a negative correlation between ACKD and serum ferritin levels. The serum levels of oxalate, silicon, and vanadium, pre- and postdialysis, were markedly and significantly higher than those in normal controls, but there was no significant correlation between these levels and the duration of dialysis therapy or severity of ACKD. The pre- and postdialysis levels of vanadium were not significantly different, while the levels of oxalate and silicon were significantly lower in the postdialysis samples. No significant correlations were detected between ACKD and age of the patients, blood pressure, protein catabolic rate, efficiency of dialysis index, or the serum levels of iron, sodium, potassium, calcium, phosphorus, aluminum, and beta 2-microglobulin.
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Affiliation(s)
- J E Marco-Franco
- Department of Laboratory Medicine, Mayo Clinic, Rochester, MN 55905
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Nixon DE, Moyer TP, Squillace DP, McCarthy JT. Determination of serum nickel by graphite furnace atomic absorption spectrometry with Zeeman-effect background correction: values in a normal population and a population undergoing dialysis. Analyst 1989; 114:1671-4. [PMID: 2633657 DOI: 10.1039/an9891401671] [Citation(s) in RCA: 24] [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: 01/01/2023]
Abstract
An atomic absorption spectrometric method with Zeeman-effect background correction for the determination of nickel, which requires only serum dilution with an aqueous surfactant, is described. The average nickel concentration in sera collected from 38 healthy adult volunteers was 0.14 +/- 0.09 micrograms l-1 of Ni, which is approximately four times lower than normals reported previously (0.65 +/- 0.35 or 0.46 +/- 0.26 microgram l-1 of Ni). The procedure yielded accurate results for the analysis of three different reference serum pools. A comparison of the average nickel concentrations from a patient population undergoing regular haemodialysis with our normal population showed that the average concentration of serum nickel in the dialysis patient group (n = 27 patients) was 46 times higher than normal (6.38 +/- 3.36 micrograms l-1 of Ni; n = 40 specimens).
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McCarthy JT, Johnson WJ, Nixon DE, Jenson BM, Moyer TP. Transfusional iron overload in patients undergoing dialysis: treatment with erythropoietin and phlebotomy. J Lab Clin Med 1989; 114:193-9. [PMID: 2754306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Five patients undergoing long-term hemodialysis with transfusional iron overload received treatment for 18 weeks with a regimen of recombinant human erythropoietin (150 U/kg) and regular phlebotomy to maintain the hematocrit value at 25% and reduce the total body iron burden. In the 149 phlebotomy sessions performed in these patients, a mean of 228 +/- 8 ml (mean +/- SEM) of whole blood was removed; it had a hematocrit value of 27.7% +/- 0.2%. The iron content of the erythrocytes removed (erythrocyte iron concentration, 787 +/- 11 micrograms/ml in 133 samples) accounted for more than 99% of the total iron removal by phlebotomy. Serum iron (serum iron concentration, 1.57 +/- 0.09 micrograms/ml in 65 samples) accounted for an insignificant fraction of the total iron removed. The iron removed at each phlebotomy session averaged 49.1 +/- 2.0 mg, similar to the amount of iron removed with deferoxamine administration in patients undergoing dialysis who had iron overload, but without the potential for adverse side effects reported with long-term deferoxamine therapy. Total iron removal during the 18 weeks of this study ranged from 732 to 2797 mg. Mean serum ferritin level decreased from 3189 +/- 1076 micrograms/L to 1676 +/- 342 micrograms/L (p less than 0.02, Wilcoxon signed rank test). When compared with a group of five patients without transfusional iron overload who received recombinant human erythropoietin and did not undergo therapeutic phlebotomy, the patients with iron overload had much greater iron losses and a larger decrease in serum ferritin levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J T McCarthy
- Division of Nephrology and Internal Medicine, Mayo Clinic, Rochester, MN 55905
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Nixon DE, Smith GA. Comparison of Jarrell-Ash, Perkin-Elmer, and modified Perkin-Elmer nebulizers for inductively coupled plasma analysis. Anal Chem 1986; 58:2886-8. [PMID: 3813022 DOI: 10.1021/ac00126a069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Nixon DE, Moyer TP, Johnson P, McCall JT, Ness AB, Fjerstad WH, Wehde MB. Routine measurement of calcium, magnesium, copper, zinc, and iron in urine and serum by inductively coupled plasma emission spectroscopy. Clin Chem 1986; 32:1660-5. [PMID: 3742794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We describe an inductively coupled plasma atomic emission spectrometer that has been adapted to perform routine, simultaneous, direct analyses of calcium, magnesium, copper, zinc, and iron in serum or urine without sample digestion or pretreatment. The system, constructed with inexpensive, readily available components, can analyze 1-mL or smaller samples. Results correlate nearly perfectly with those derived by standard atomic absorption techniques (r = 0.98 to 0.997). Using certified serum and urine samples from various sources, we demonstrate that the instrument yields accurate results with a precision better than certified values. The instrument is sensitive to one order of magnitude less than the lower limit of the normal range in serum or urine for all elements tested, and responds linearly to concentrations two orders of magnitude higher than the upper limit of the normal range. With the system described here, these five elements can be assayed with the same or less technical effort than needed for a single element by atomic absorption.
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Nixon DE, Moyer TP, Johnson P, McCall JT, Ness AB, Fjerstad WH, Wehde MB. Routine measurement of calcium, magnesium, copper, zinc, and iron in urine and serum by inductively coupled plasma emission spectroscopy. Clin Chem 1986. [DOI: 10.1093/clinchem/32.9.1660] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
We describe an inductively coupled plasma atomic emission spectrometer that has been adapted to perform routine, simultaneous, direct analyses of calcium, magnesium, copper, zinc, and iron in serum or urine without sample digestion or pretreatment. The system, constructed with inexpensive, readily available components, can analyze 1-mL or smaller samples. Results correlate nearly perfectly with those derived by standard atomic absorption techniques (r = 0.98 to 0.997). Using certified serum and urine samples from various sources, we demonstrate that the instrument yields accurate results with a precision better than certified values. The instrument is sensitive to one order of magnitude less than the lower limit of the normal range in serum or urine for all elements tested, and responds linearly to concentrations two orders of magnitude higher than the upper limit of the normal range. With the system described here, these five elements can be assayed with the same or less technical effort than needed for a single element by atomic absorption.
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