1
|
Forman CJ, Olson SW, Gordon SM, Hughes JB, Stitt RS, Bailey WT, Edison JD, Nee R. Association of Race and Risk of Future Scleroderma Renal Crisis at Systemic Sclerosis Diagnosis. Arthritis Care Res (Hoboken) 2021; 75:801-807. [PMID: 34738330 DOI: 10.1002/acr.24807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 06/25/2021] [Revised: 10/10/2021] [Accepted: 10/14/2021] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Scleroderma renal crisis (SRC) is a rare and severe manifestation of systemic sclerosis (SSc). Although it is well documented that Blacks with SSc have worse morbidity and mortality than non-Blacks, racial predilection for SRC is underreported. We examine the association of race and future development of SRC in an SSc cohort. METHODS Using the electronic health record of the United States Military Health System, we conducted a comprehensive chart review of each patient with SSc from 2005 to 2016. The final study cohort was comprised of 31 SRC cases and 322 SSc without SRC controls. We conducted logistic regression of SRC as the outcome variable and race (Black vs. non-Black) as the primary predictor variable, adjusted for age, estimated glomerular filtration rate, hypertension and proteinuria at SSc diagnosis. RESULTS Out of 353 patients, 294 had identifiable race (79 Black, 215 non-Black). Thirteen out of 79 Blacks (16.5%) vs. 16/215 (7.4%) non-Blacks developed SRC (p=0.02). On adjusted analysis, Blacks had a significantly higher risk of developing SRC than non-Blacks (odds ratio 6.4, 95% CI 1.3-31.2, p=0.02). Anti-Ro antibody was present in a higher proportion of Black SRC patients vs. Blacks without SRC [45% vs. 14%, p=0.01]. Conversely, older age, thrombocytopenia, and anti-RNA polymerase III antibody at SSc diagnosis were significantly associated with future SRC in the non-Black cohort. CONCLUSION Black race was independently associated with a higher risk of future SRC. Further studies are needed to elucidate the mechanisms that underlie this important association. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Crystal J Forman
- Department of Medicine, San Antonio Uniformed Services Health Education Consortium, Brooke Army Medical Center, Fort Sam Houston, Texas
| | - Stephen W Olson
- Nephrology Service, Walter Reed National Military Medical Center, Bethesda, Maryland.,Uniformed Services University, Bethesda, Maryland
| | - Sarah M Gordon
- Nephrology Service, Walter Reed National Military Medical Center, Bethesda, Maryland.,Uniformed Services University, Bethesda, Maryland
| | - James B Hughes
- Department of Medicine, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Rodger S Stitt
- Rheumatology Service, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Wayne T Bailey
- Rheumatology Service, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Jess D Edison
- Rheumatology Service, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Robert Nee
- Nephrology Service, Walter Reed National Military Medical Center, Bethesda, Maryland.,Uniformed Services University, Bethesda, Maryland
| |
Collapse
|
2
|
Forster BM, Nee R, Little DJ, Greasley PJ, Hughes JB, Gordon SM, Olson SW. Focal Segmental Glomerulosclerosis, Risk Factors for End Stage Kidney Disease, and Response to Immunosuppression. Kidney360 2020; 2:105-113. [PMID: 35368810 PMCID: PMC8785735 DOI: 10.34067/kid.0006172020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/30/2020] [Indexed: 02/04/2023]
Abstract
Background FSGS is a heterogeneic glomerular disease. Risk factors for kidney disease ESKD and the effect of immunosuppression treatment (IST) has varied in previously published cohorts. These cohorts were limited by relatively small case numbers, short follow-up, lack of racial/ethnic diversity, a mix of adult and pediatric patients, lack of renin-angiotensin-aldosterone system (RAAS) inhibition, or lack of subgroup analysis of IST. Methods We compared demographics, clinical characteristics, histopathology, and IST to long-term renal survival in a large, ethnically diverse, adult cohort of 338 patients with biopsy-proven FSGS with long-term follow-up in the era of RAAS inhibition using data from the US Department of Defense health care network. Results Multivariate analysis showed that nephrotic-range proteinuria (NRP), eGFR <60 ml/min per 1.73 m2, hypoalbuminemia, interstitial fibrosis and tubular atrophy, and interstitial inflammation at diagnosis and the absence of remission were all associated with worse long-term renal survival. IgM, C3, and a combination of IgM/C3 immunofluorescence staining were not associated with reduced renal survival. IST was not associated with improved renal survival in the whole cohort, or in a subgroup with NRP. However, IST was associated with better renal survival in a subgroup of patients with FSGS with both NRP and hypoalbuminemia and hypoalbuminemia alone. Conclusions Our study suggests that IST should be reserved for patients with FSGS and nephrotic syndrome. It also introduces interstitial inflammation as a potential risk factor for ESKD and does not support the proposed pathogenicity of IgM and complement activation.
Collapse
Affiliation(s)
- Benjamin M. Forster
- Walter Reed National Military Medical Center, Nephrology Department, Bethesda, Maryland
| | - Robert Nee
- Walter Reed National Military Medical Center, Nephrology Department, Bethesda, Maryland
| | - Dustin J. Little
- Walter Reed National Military Medical Center, Nephrology Department and Late Development, Cardiovascular, Renal and Metabolism BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | - Peter J. Greasley
- Early Clinical Development, Research and Early Development, Cardiovascular, Renal and Metabolism BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - James B. Hughes
- Walter Reed National Military Medical Center, Nephrology Department, Bethesda, Maryland
| | - Sarah M. Gordon
- Tripler Army Medical Center, Nephrology Department, Honolulu, Hawaii
| | - Stephen W. Olson
- Walter Reed National Military Medical Center, Nephrology Department, Bethesda, Maryland
| |
Collapse
|
3
|
Gordon SM, Hughes JB, Nee R, Stitt RS, Bailey WT, Little DJ, Edison JD, Olson SW. Systemic sclerosis medications and risk of scleroderma renal crisis. BMC Nephrol 2019; 20:279. [PMID: 31345158 PMCID: PMC6659266 DOI: 10.1186/s12882-019-1467-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/17/2019] [Indexed: 01/13/2023] Open
Abstract
Background Scleroderma Renal Crisis (SRC) is associated with significant morbidity and mortality. While prednisone is strongly associated with SRC, there are no previous large cohort studies that have evaluated ace inhibitor (ACEi) calcium channel blocker (CCB), angiotensin receptor blocker (ARB), endothelin receptor blocker (ERB), non-steroidal anti-inflammatory drug (NSAID), fluticasone, or mycophenolate mofetil (MMF) use in systemic sclerosis (SSc) and the risk of SRC. Methods In this retrospective cohort study of the entire military electronic medical record between 2005 and 2016, we compared the use of ACEi, ARB, CCB, NSAID, ERB, fluticasone, and MMF after SSc diagnosis for 31 cases who subsequently developed SRC to 322 SSc without SRC disease controls. Results ACEi was associated with an increased risk for SRC adjusted for age, race, and prednisone use [odds ratio (OR) 4.1, 95% confidence interval (CI) 1.6–10.2, P = 0.003]. On stratified analyses, ACEi was only associated with SRC in the presence [OR 5.3, 95% CI 1.1–29.2, p = 0.03], and not the absence of proteinuria. In addition, a doubling of ACEi dose [61% vs. 12%, p < 0.001) and achieving maximum ACEi dose [45% vs. 4%, p < 0.001] after SSc diagnosis was associated with future SRC. CCB, ARB, NSAIDs, ERB, fluticasone, and MMF use were not significantly associated with SRC. Conclusion ACEi use at SSC diagnosis was associated with an increased risk for SRC. Results suggest that it may be a passive marker of known SRC risk factors, such as proteinuria, or evolving disease. SSC patients that require ACEi should be more closely monitored for SRC.
Collapse
Affiliation(s)
- S M Gordon
- Nephrology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - J B Hughes
- Department of Medicine, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, USA
| | - R Nee
- Nephrology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - R S Stitt
- Rheumatology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, USA
| | - W T Bailey
- Rheumatology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, USA
| | - D J Little
- Nephrology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA
| | - J D Edison
- Rheumatology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, USA
| | - S W Olson
- Nephrology Department, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD, 20889, USA.
| |
Collapse
|
4
|
Burbelo PD, Gordon SM, Waldman M, Edison JD, Little DJ, Stitt RS, Bailey WT, Hughes JB, Olson SW. Autoantibodies are present before the clinical diagnosis of systemic sclerosis. PLoS One 2019; 14:e0214202. [PMID: 30913258 PMCID: PMC6435159 DOI: 10.1371/journal.pone.0214202] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [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: 05/30/2018] [Accepted: 03/08/2019] [Indexed: 02/02/2023] Open
Abstract
Systemic sclerosis (SSc) is a heterogeneous autoimmune disorder associated with vascular dysfunction and fibrotic changes in the skin, vasculature and internal organs. Although serologic abnormalities are an important diagnostic tool for SSc, little is known about whether autoantibodies precede clinical diagnosis. Here we investigated the presence of autoantibodies before SSc diagnosis and assessed whether certain autoantibodies might associate with the future onset of scleroderma renal crisis (SRC), a potentially fatal complication of the disease. Using the Department of Defense Serum Repository, autoantibodies were analyzed from archived, prospectively collected, longitudinal serum samples from sixteen individuals with SRC (SSc/SRC) and thirty cases of SSc without SRC (SSc/no SRC), matched for age, sex, and race. Seventy five percent (12/16) of the SSc/SRC and 40% (12/30) of the SSc/no SRC were seropositive for at least one autoantibody prior to clinical diagnosis (up to 27.1 years earlier, mean = -7.4 years). Although both disease groups demonstrated a heterogeneous immunoreactivity profile against the autoantigen panel, the SSc/SRC subjects showed two enriched clusters with one featuring elevated levels of autoantibodies against Ro52 and/or Ro60 and another with high levels of immunoreactivity against the RNA polymerase complex. Consistent with larger spectrum of immunoreactivity and the elevated levels of autoantibodies in SSc/SRC, the total response against the autoantigen panel from the last time point of the seropositive subjects revealed that the SSc/SRC cohort harbored higher antibody levels (p = 0.02) compared to SSc/no SRC. Overall, our findings demonstrate that relevant seropositive autoantibodies often precede the clinical diagnosis of SSc/no SRC and SSc/SRC.
Collapse
Affiliation(s)
- Peter D. Burbelo
- Dental Clinical Research Core, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, United States of America
| | - Sarah M. Gordon
- Nephrology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| | - Meryl Waldman
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, and, National Institutes of Health, Bethesda, MD, United States of America
| | - Jess D. Edison
- Rheumatology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| | - Dustin J. Little
- Nephrology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| | - Rodger S. Stitt
- Rheumatology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| | - Wayne T. Bailey
- Rheumatology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| | - James B. Hughes
- Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Stephen W. Olson
- Nephrology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| |
Collapse
|
5
|
Gordon SM, Stitt RS, Nee R, Bailey WT, Little DJ, Knight KR, Hughes JB, Edison JD, Olson SW. Risk Factors for Future Scleroderma Renal Crisis at Systemic Sclerosis Diagnosis. J Rheumatol 2018; 46:85-92. [PMID: 30008456 DOI: 10.3899/jrheum.171186] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2018] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Systemic sclerosis (SSc) is a disease of autoimmunity, fibrosis, and vasculopathy. Scleroderma renal crisis (SRC) is one of the most severe complications. Corticosteroid exposure, presence of anti-RNA polymerase III antibodies (ARA), skin thickness, and significant tendon friction rubs are among the known risk factors at SSc diagnosis for developing future SRC. Identification of additional clinical characteristics and laboratory findings could expand and improve the risk profile for future SRC at SSc diagnosis. METHODS In this retrospective cohort study of the entire military electronic medical record between 2005 and 2016, we compared the demographics, clinical characteristics, and laboratory results at SSc diagnosis for 31 cases who developed SRC after SSc diagnosis to 322 SSc without SRC disease controls. RESULTS After adjustment for potential confounding variables, at SSc diagnosis these conditions were all associated with future SRC: proteinuria (p < 0.001; OR 183, 95% CI 19.1-1750), anemia (p = 0.001; OR 9.9, 95% CI 2.7-36.2), hypertension (p < 0.001; OR 13.1, 95% CI 4.7-36.6), chronic kidney disease (p = 0.008; OR 20.7, 95% CI 2.2-190.7), elevated erythrocyte sedimentation rate (p < 0.001; OR 14.3, 95% CI 4.8-43.0), thrombocytopenia (p = 0.03; OR 7.0, 95% CI 1.2-42.7), hypothyroidism (p = 0.01; OR 2.8, 95% CI 1.2-6.7), Anti-Ro antibody seropositivity (p = 0.003; OR 3.9, 95% CI 1.6-9.8), and ARA (p = 0.02; OR 4.1, 95% CI 1.2-13.8). Three or more of these risk factors present at SSc diagnosis was sensitive (77%) and highly specific (97%) for future SRC. No SSc without SRC disease controls had ≥ 4 risk factors. CONCLUSION In this SSc cohort, we present a panel of risk factors for future SRC. These patients may benefit from close observation of blood pressure, proteinuria, and estimated glomerular filtration rate, for earlier SRC identification and intervention. Future prospective therapeutic studies could focus specifically on this high-risk population.
Collapse
Affiliation(s)
- Sarah M Gordon
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Rodger S Stitt
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Robert Nee
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Wayne T Bailey
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Dustin J Little
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Kendral R Knight
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - James B Hughes
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Jess D Edison
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center
| | - Stephen W Olson
- From the Nephrology Department, and the Rheumatology Department, Walter Reed National Military Medical Center; the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA. .,S.W. Olson, MD, Nephrology Department, Walter Reed National Military Medical Center; S.M. Gordon, MD, Nephrology Department, Walter Reed National Military Medical Center; R. Nee, MD, Nephrology Department, Walter Reed National Military Medical Center; R.S. Stitt, MD, Rheumatology Department, Walter Reed National Military Medical Center; W.T. Bailey, MD, Rheumatology Department, Walter Reed National Military Medical Center; D.J. Little, MD, Nephrology Department, Walter Reed National Military Medical Center; K.R. Knight, MD, Nephrology Department, Walter Reed National Military Medical Center; J.B. Hughes, Medical Student, Uniformed Services University of the Health Sciences; J.D. Edison, MD, Rheumatology Department, Walter Reed National Military Medical Center.
| |
Collapse
|
6
|
Dow ER, Hughes JB, Stephens SM, Narayan VA, Bishop RW. Integrating scientific data for drug discovery and development using the Life Sciences Grid. Expert Opin Drug Discov 2009; 4:687-99. [DOI: 10.1517/17460440902991500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
7
|
Tront JM, Fortner JD, Plötze M, Hughes JB, Puzrin AM. Microbial fuel cell biosensor for in situ assessment of microbial activity. Biosens Bioelectron 2008; 24:586-90. [PMID: 18621521 DOI: 10.1016/j.bios.2008.06.006] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 04/24/2008] [Accepted: 06/04/2008] [Indexed: 11/16/2022]
Abstract
Microbial fuel cell (MFC)-based sensing was explored to provide useful information for the development of an approach to in situ monitoring of substrate concentration and microbial respiration rate. The ability of a MFC to provide meaningful information about in situ microbial respiration and analyte concentration was examined in column systems, where Geobacter sulfurreducens used an external electron acceptor (an electrode) to metabolize acetate. Column systems inoculated with G. sulfurreducens were operated with influent media at varying concentrations of acetate and monitored for current generation. Current generation was mirrored by bulk phase acetate concentration, and a correlation (R(2)=0.92) was developed between current values (0-0.30 mA) and acetate concentrations (0-2.3 mM). The MFC-system was also exposed to shock loading (pulses of oxygen), after which electricity production resumed immediately after media flow recommenced, underlining the resilience of the system and allowing for additional sensing capacity. Thus, the electrical signal produced by the MFC-system provided real-time data for electron donor availability and biological activity. These results have practical implications for development of a biosensor for inexpensive real-time monitoring of in situ bioremediation processes, where MFC technology provides information on the rate and nature of biodegradation processes.
Collapse
Affiliation(s)
- J M Tront
- Institute for Geotechnical Engineering, ETH Zurich, Wolfgang-Pauli Strasse 15, 8093 Zurich, Switzerland
| | | | | | | | | |
Collapse
|
8
|
Da Silva MLB, Daprato RC, Gomez DE, Hughes JB, Ward CH, Alvarez PJJ. Comparison of bioaugmentation and biostimulation for the enhancement of dense nonaqueous phase liquid source zone bioremediation. Water Environ Res 2006; 78:2456-65. [PMID: 17243245 DOI: 10.2175/106143006x123111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Two 11.7-m(3) experimental controlled release systems (ECRS), packed with sandy model aquifer material and amended with tetrachloroethene (PCE) dense nonaqueous phase liquid (DNAPL) source zone, were operated in parallel with identical flow regimes and electron donor amendments. Hydrogen Releasing Compound (Regenesis Bioremediation Products, Inc., San Clemente, California), and later dissolved lactate, served as electron donors to promote dechlorination. One ECRS was bioaugmented with an anaerobic dechlorinating consortium directly into the source zone, and the other served as a control (biostimulated only) to determine the benefits of bioaugmentation. The presence of halorespiring bacteria in the aquifer matrix before bioaugmentation, shown by nested polymerase chain reaction with phylogenetic primers, suggests that dechlorinating catabolic potential may be somewhat widespread. Results obtained corroborate that source zone reductive dechlorination of PCE is possible at near field scale and that a system bioaugmented with a competent halorespiring consortium can enhance DNAPL dissolution and dechlorination processes at significantly greater rates than in a system that is biostimulated only.
Collapse
Affiliation(s)
- M L B Da Silva
- Department of Civil and Environmental Engineering (CEE), Rice Univeristy, Houston, Texas 77005, USA
| | | | | | | | | | | |
Collapse
|
9
|
Silva AMM, Silva AR, Pinheiro AM, Freitas SRVB, Silva VDA, Souza CS, Hughes JB, El-Bachá RS, Costa MFD, Velozo ES, Tardy M, Costa SL. Alkaloids from Prosopis juliflora leaves induce glial activation, cytotoxicity and stimulate NO production. Toxicon 2006; 49:601-14. [PMID: 17241650 DOI: 10.1016/j.toxicon.2006.07.037] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 07/21/2006] [Accepted: 07/25/2006] [Indexed: 11/19/2022]
Abstract
Prosopis juliflora is used for feeding cattle and humans. Intoxication with the plant has been reported, and is characterized by neuromuscular alterations and gliosis. Total alkaloidal extract (TAE) was obtained using acid/basic-modified extraction and was fractionated. TAE and seven alkaloidal fractions, at concentrations ranging 0.03-30 microg/ml, were tested for 24h on astrocyte primary cultures derived from the cortex of newborn Wistar rats. The MTT test and the measure of LDH activity on the culture medium, revealed that TAE and fractions F29/30, F31/33, F32 and F34/35 were cytotoxic to astrocytes. The EC(50) values for the most toxic compounds, TAE, F31/33 and F32 were 2.87 2.82 and 3.01 microg/ml, respectively. Morphological changes and glial cells activation were investigated through Rosenfeld's staining, by immunocytochemistry for the protein OX-42, specific of activated microglia, by immunocytochemistry and western immunoblot for GFAP, the marker of reactive and mature astrocytes, and by the production of nitric oxide (NO). We observed that astrocytes exposed to 3 microg/ml TAE, F29/30 or F31/33 developed compact cell body with many processes overexpressing GFAP. Treatment with 30 microg/ml TAE and fractions, induced cytotoxicity characterized by a strong cell body contraction, very thin and long processes and condensed chromatin. We also observed that when compared with the control (+/-1.34%), the proportion of OX-42 positive cells was increased in cultures treated with 30 microg/ml TAE or F29/30, F31/33, F32 and F34/35, with values raging from 7.27% to 28.74%. Moreover, incubation with 3 microg/ml F32, 30 microg/ml TAE, F29/30, F31/33 or F34/35 induced accumulation of nitrite in culture medium indicating induction of NO production. Taken together these results show that TAE and fractionated alkaloids from P. juliflora act directly on glial cells, inducing activation and/or cytotoxicity, stimulating NO production, and may have an impact on neuronal damages observed on intoxicated animals.
Collapse
Affiliation(s)
- A M M Silva
- Laboratório de Neuroquímica e Biologia Celular, Departamento de Biofunção, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, BA, 40.110-100, Brazil
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Wilson GA, Bertrand N, Patel Y, Hughes JB, Feil EJ, Field D. Orphans as taxonomically restricted and ecologically important genes. Microbiology (Reading) 2005; 151:2499-2501. [PMID: 16079329 DOI: 10.1099/mic.0.28146-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- G A Wilson
- Molecular Evolution and Bioinformatics Section, CEH-Oxford, Mansfield Road, Oxford, OX1 3SR, UK
| | - N Bertrand
- Molecular Evolution and Bioinformatics Section, CEH-Oxford, Mansfield Road, Oxford, OX1 3SR, UK
| | - Y Patel
- Molecular Evolution and Bioinformatics Section, CEH-Oxford, Mansfield Road, Oxford, OX1 3SR, UK
| | - J B Hughes
- Department of Ecology and Evolutionary Biology, Brown University, USA
| | - E J Feil
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - D Field
- Molecular Evolution and Bioinformatics Section, CEH-Oxford, Mansfield Road, Oxford, OX1 3SR, UK
| |
Collapse
|
11
|
Fortner JD, Lyon DY, Sayes CM, Boyd AM, Falkner JC, Hotze EM, Alemany LB, Tao YJ, Guo W, Ausman KD, Colvin VL, Hughes JB. C60 in water: nanocrystal formation and microbial response. Environ Sci Technol 2005; 39:4307-16. [PMID: 15984814 DOI: 10.1021/es048099n] [Citation(s) in RCA: 372] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Upon contact with water, under a variety of conditions, C60 spontaneously forms a stable aggregate with nanoscale dimensions (d = 25-500 nm), termed here "nano-C60". The color, hydrophobicity, and reactivity of individual C60 are substantially altered in this aggregate form. Herein, we provide conclusive lines of evidence demonstrating that in solution these aggregates are crystalline in order and remain as underivatized C60 throughout the formation/stabilization process that can later be chemically reversed. Particle size can be affected by formation parameters such as rates and the pH of the water addition. Once formed, nano-C60 remains stable in solution at or below ionic strengths of 0.05 I for months. In addition to demonstrating aggregate formation and stability over a wide range of conditions, results suggest that prokaryotic exposure to nano-C60 at relatively low concentrations is inhibitory, indicated by lack of growth (> or = 0.4 ppm) and decreased aerobic respiration rates (4 ppm). This work demonstrates the fact that the environmental fate, distribution, and biological risk associated with this important class of engineered nanomaterials will require a model that addresses not only the properties of bulk C60 but also that of the aggregate form generated in aqueous media.
Collapse
Affiliation(s)
- J D Fortner
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Zhang C, Daprato RC, Nishino SF, Spain JC, Hughes JB. Remediation of dinitrotoluene contaminated soils from former ammunition plants: soil washing efficiency and effective process monitoring in bioslurry reactors. J Hazard Mater 2001; 87:139-154. [PMID: 11566406 DOI: 10.1016/s0304-3894(01)00240-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A pilot-scale bioslurry system was used to test the treatment of soils highly contaminated with 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT). The treatment scheme involved a soil-washing process followed by two sequential aerobic slurry reactors augmented with 2,4-DNT- and 2,6-DNT-mineralizing bacteria. Test soils were obtained from two former army ammunition plants, the Volunteer Army Ammunition Plant (VAAP, Chattanooga, TN) and the Badger Army Ammunition Plant (BAAP, Baraboo, WI). Soil washing was used to minimize operational problems in slurry reactors associated with large particulates. The Eimco slurry reactors were operated in a draw-and-fill mode for 3 months and were monitored for the biodegradation of 2,4-DNT and 2,6-DNT, nitrite production, NaOH consumption, and oxygen uptake rate. Results show that soil washing was very effective for the removal of sands and the recovery of soil fines containing 2,4-DNT and 2,6-DNT. Bioslurry reactors offered rapid and nearly complete degradation of both DNT isomers, but require real time monitoring to avoid long lag periods upon refeeding. Results found a significant discrepancy between the measured DNT concentrations and calculated DNT concentrations in the slurry reactors because of solids profiles in the slurry reactors and the presence of floating crystal of DNTs. Based on the actual amount of dinitrotoluene degradation, nitrite release, NaOH consumption, and oxygen uptake were close to the theoretical stoichiometric coefficients of complete DNT mineralization. Such stoichiometric relationships were not achieved if the calculation was based on the measured DNT concentrations due to the heterogeneity of DNT in the reactor. Results indicate that nitrite release, NaOH consumption, and oxygen uptake rates provide a fast assessment of 2,4-DNT degradation and microbial activity in a slurry reactor, but could not be extended to a second reactor in series where the degradation of a much lower concentration of 2,6-DNT degradation was achieved.
Collapse
Affiliation(s)
- C Zhang
- School of Natural and Applied Sciences, University of Houston-Clear Lake, Houston, TX 77058, USA
| | | | | | | | | |
Collapse
|
13
|
Affiliation(s)
- J B Hughes
- Department of Biological Sciences, Stanford University, Stanford, California 94305-5020, USA.
| | | | | | | |
Collapse
|
14
|
Bhadra R, Wayment DG, Williams RK, Barman SN, Stone MB, Hughes JB, Shanks JV. Studies on plant-mediated fate of the explosives RDX and HMX. Chemosphere 2001; 44:1259-64. [PMID: 11513416 DOI: 10.1016/s0045-6535(00)00272-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The fate of the explosives RDX and HMX on exposure to plants was investigated in 'natural' aquatic systems of Myriophyllum aquaticum for 16 days, and in axenic hairy root cultures of Catharanthus roseus for > or = 9 weeks. Exposure levels were: HMX, 5 mg/l; and RDX, approximately 8 mg/l. Exposure outcomes observed include: HMX, no transformation by aquatic plants, and minimal biological activity by axenic roots; and RDX, removal by both plant systems. In the case of RDX exposure to axenic roots, since 14C-RDX was included, removal was confirmed by the accumulation of 14C-label in the biomass. The intracellular 14C-label in these RDX studies was detected in two forms: intact RDX and bound unknown(s).
Collapse
Affiliation(s)
- R Bhadra
- Department of Bioengineering, Rice University, Houston, TX 77005-1892, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
The influence of dechlorinating microorganisms on PCE and its reduction products in a residual nonaqueous phase liquid (NAPL) source zone was investigated. Experiments were conducted in upflow columns containing glass beads (diameters 500-750 microns) contaminated with a residual NAPL consisting of tridecane and labeled 14C-PCE. Three columns were inoculated with a mixed PCE-dechlorinating culture, that was fed electron donor (pyruvate) at concentrations of 25, 100, and 250 mM. Pyruvate was fermented in all columns with essentially no methanogenic activity. Comparisons between actively dechlorinating columns and abiotic-PCE columns demonstrated that dechlorination resulted in an increase in total PCE removal, up to a factor of 16 over dissolution. PCE was sequentially reduced to trichloroethene, cis-dichloroethene, and vinyl chloride without ethene formation over the experimental period in the two columns operated at the lower electron donor levels. Total chlorinated ethenes removal for the columns that retained dechlorinating populations was enhanced from 5.0 to 6.5 times over the removal that would have resulted from dissolution alone. The system fed the highest pyruvate levels, interestingly, lost dechlorinating activity early in the experiment.
Collapse
Affiliation(s)
- N Cope
- Department of Environmental Science and Engineering, Rice University, 6100 Main Street, Houston, Texas 77005-1892, USA
| | | |
Collapse
|
16
|
Huang S, Lindahl PA, Wang C, Bennett GN, Rudolph FB, Hughes JB. 2,4,6-trinitrotoluene reduction by carbon monoxide dehydrogenase from Clostridium thermoaceticum. Appl Environ Microbiol 2000; 66:1474-8. [PMID: 10742229 PMCID: PMC92010 DOI: 10.1128/aem.66.4.1474-1478.2000] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purified CO dehydrogenase (CODH) from Clostridium thermoaceticum catalyzed the transformation of 2,4,6-trinitrotoluene (TNT). The intermediates and reduced products of TNT transformation were separated and appear to be identical to the compounds formed by C. acetobutylicum, namely, 2-hydroxylamino-4,6-dinitrotoluene (2HA46DNT), 4-hydroxylamino-2,6-dinitrotoluene (4HA26DNT), 2, 4-dihydroxylamino-6-nitrotoluene (24DHANT), and the Bamberger rearrangement product of 2,4-dihydroxylamino-6-nitrotoluene. In the presence of saturating CO, CODH catalyzed the conversion of TNT to two monohydroxylamino derivatives (2HA46DNT and 4HA26DNT), with 4HA26DNT as the dominant isomer. These derivatives were then converted to 24DHANT, which slowly converted to the Bamberger rearrangement product. Apparent K(m) and k(cat) values of TNT reduction were 165 +/- 43 microM for TNT and 400 +/- 94 s(-1), respectively. Cyanide, an inhibitor for the CO/CO(2) oxidation/reduction activity of CODH, inhibited the TNT degradation activity of CODH.
Collapse
Affiliation(s)
- S Huang
- Department of Biochemistry and Cell Biology and the Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005-1892, USA
| | | | | | | | | | | |
Collapse
|
17
|
Tadros MG, Crawford A, Mateo-Sullivan A, Zhang C, Hughes JB. Toxic effects of hydroxylamino intermediates from microbial transformation of trinitrotoluene and dinitrotoluenes on algae Selenastrum capricornutum. Bull Environ Contam Toxicol 2000; 64:579-585. [PMID: 10754056 DOI: 10.1007/s001280000042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- M G Tadros
- Department of Biology, Alabama A&M University, Post Office Box 13, Normal, AL 35762, USA
| | | | | | | | | |
Collapse
|
18
|
Abstract
Although humanity depends on the continued, aggregate functioning of natural ecosystems, few studies have explored the impact of community structure on the stability of aggregate community properties. Here we derive the stability of the aggregate property of community biomass as a function of species' competition coefficients for a two-species model. The model predicts that the stability of community biomass is relatively independent of the magnitude of the interaction strengths. Instead, the degree of asymmetry of the interactions appears to be key to community stability.
Collapse
Affiliation(s)
- J B Hughes
- Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA
| | | |
Collapse
|
19
|
|
20
|
Abstract
Genetically distinct populations are an important component of biodiversity. This work estimates the number of populations per area of a sample of species from literature on population differentiation and the average range area of a species from a sample of distribution maps. This yields an estimate of about 220 populations per species, or 1.1 to 6.6 billion populations globally. Assuming that population extinction is a linear function of habitat loss, approximately 1800 populations per hour (16 million annually) are being destroyed in tropical forests alone.
Collapse
Affiliation(s)
- J B Hughes
- Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA
| | | | | |
Collapse
|
21
|
Hughes JB, Beckles DM, Chandra SD, Ward CH. Utilization of bioremediation processes for the treatment of PAH-contaminated sediments. J Ind Microbiol Biotechnol 1997; 18:152-60. [PMID: 9134762 DOI: 10.1038/sj.jim.2900308] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.0] [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: 02/04/2023]
Abstract
The widespread contamination of aquatic sediments by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective remediation processes. Many common PAHs are biodegradable, leading to studies investigating the potential of sediment bioremediation. This article reviews several factors that currently complicate the implementation of sediment bioremediation processes: the effect of complex mixtures of contaminants on the rate and extent of degradation observed, the bioavailability of PAHs in sorbed- and nonaqueous-phase, and methods being evaluated to enhance degradation/availability (surfactant-enhanced solubility, nutrient addition, and bioaugmentation).
Collapse
Affiliation(s)
- J B Hughes
- Department of Environmental Science and Engineering, George R Brown School of Engineering, Rice University, Houston, TX 77005-1892, USA
| | | | | | | |
Collapse
|
22
|
Abstract
This paper reports the results of a study to determine whether pulsed electromagnetic stimulation, applied over the mastoid bone, caused an improvement in the level of tinnitus in long-standing tinnitus sufferers. Fifty-eight patients from the Liverpool Tinnitus Association volunteered to take part in a double-blind placebo controlled trial. Active and placebo devices were randomly allocated to these patients on their first visit. At the end of one week of treatment, each patient noted whether their tinnitus had completely disappeared, was improved, unchanged or made worse by the treatment Forty-five per cent of the patients who completed the trial were improved by the active device, but only 9% by placebo (P = 0.0013, Mann-Whitney test). We suggest that electromagnetic stimulation may be an effective treatment in some tinnitus sufferers.
Collapse
Affiliation(s)
- N J Roland
- Department of Otolaryngology, Royal Liverpool University Hospital, UK
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
The magnitude and origin of audiometric air-bone gaps in the range 3 kHz to 8 kHz was investigated in 20 normal subjects. The average gap ranged from a minimum of about 3 dB at 3 kHz to a maximum of about 19 dB at 6 kHz. Approximately 5 dB of the gap at high frequencies is caused by excess air-radiated sound from the bone vibrator. A larger error appears to result from discrepancies between the air and bone conduction standards to which audiometers are calibrated. These errors may influence diagnosis and we recommend that bone conduction tests at frequencies greater than 4 kHz are avoided. These findings have implications for medico-legal work where small air-bone gaps have diagnostic significance.
Collapse
Affiliation(s)
- G R Lightfoot
- Department of Clinical Engineering, Royal Liverpool University Hospital
| | | |
Collapse
|
24
|
Balon TW, Treadway JL, Hughes JB, Young JC, Ruderman NB. Effect of prior exercise and insulin on potential thermogenic systems in rat skeletal muscle. J Appl Physiol (1985) 1992; 72:2203-9. [PMID: 1629074 DOI: 10.1152/jappl.1992.72.6.2203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 12/28/2022] Open
Abstract
We previously reported that insulin stimulates oxygen consumption by the perfused rat hindquarter after high-intensity exercise. The purpose of the present study was to examine whether fructose 6-phosphate-fructose 1,6-bisphosphate cycling or an uncoupling of mitochondrial respiration contributes to this phenomenon. Hindquarter skeletal muscle was analyzed after perfusion in the absence or presence of insulin (150-200 microU/ml) for high-energy phosphate content, fructose 6-phosphate-fructose 1,6-bisphosphate cycling of glucose before incorporation into glycogen, and mitochondrial respiratory control. Muscle from exercised rats perfused with insulin did not display greater rates of glucose cycling or mitochondrial uncoupling; in fact, insulin decreased the rate of fructose 6-phosphate cycling and tended to increase respiratory control in skeletal muscle mitochondria. In addition, the concentrations of ATP and creatine phosphate and the calculated free ADP level in muscle of previously exercised rats perfused with insulin were similar to those of control rats. The results do not exclude the possibility that localized subcellular changes in ADP occurred, however. In conclusion, the results suggest that insulin-induced increases in other substrate cycles, ion transport systems, and/or as yet unidentified energy-requiring processes account for the 25-30% increase in hindquarter oxygen consumption after intense exercise.
Collapse
Affiliation(s)
- T W Balon
- Department of Exercise Science, University of Iowa, Iowa City 52242
| | | | | | | | | |
Collapse
|
25
|
Mohareb EW, Hughes JB, Bruce JI. Sensitive resolution of Giardia lamblia membrane antigens. J Chromatogr A 1989; 480:421-6. [PMID: 2592491 DOI: 10.1016/s0021-9673(01)84311-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- E W Mohareb
- Center for Tropical Disease, University of Lowell, MA 01854
| | | | | |
Collapse
|
26
|
Abstract
Mitochondrial H+ -ATPase complex, purified by the lysolecithin extraction procedure, has been resolved into a "membrane" (NaBr-F0) and a "soluble" fraction by treatment with 3.5 M sodium bromide. The NaBr-F0 fraction is completely devoid of beta, delta, and epsilon subunits of the F, ATPase and largely devoid of alpha and gamma subunits of F1, where F0 is used to denote the membrane fraction and F1, coupling factor 1. This is confirmed by complete loss of ATPase and Pi-ATP exchange activities. The addition of F1 (400 micrograms X mg-1 F0) results in complete restoration of oligomycin sensitivity without any reduction in the F1-ATPase activity. Presumably, this is due to release of ATPase inhibitor protein from the F1-F0 complex consequent to sodium bromide extraction. Restoration of Pi-ATP exchange and H+ -pumping activities require coupling factor B in addition to F1-ATPase. The oligomycin-sensitive ATPase and 32Pi-ATP exchange activities in reconstituted F1-F0 have the same sensitivity to uncouplers and energy transfer inhibitors as in starting submitochondrial particles from the heavy layer of mitochondria and F1-F0 complex. The data suggest that the altered properties of NaBr-F0 observed in other laboratories are probably inherent to their F1-F0 preparations rather than to sodium bromide treatment itself. The H+ -ATPase (F1-F0) complex of all known prokaryotic (3, 8, 9, 10, 21, 32, 34) and eukaryotic (11, 26, 30, 33, 35-37) phosphorylating membranes contain two functionally and structurally distinct entities. The hydrophilic component F1, composed of five unlike subunits, shows ATPase activity that is cold labile as well as uncoupler- and oligomycin-insensitive. The membrane-bound hydrophobic component F0, having no energy-linked catalytic activity of its own, is indirectly assayed by its ability to regain oligomycin sensitive ATPase and Pi-ATP exchange activities on binding to F1-ATPase (33). The purest preparations of bovine heart mitochondrial F0 show seven or eight major components in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate or SDS-PAGE (1, 2, 12, 14), ranging from 6 to 54 ku in molecular weight (12). The precise structure and polypeptide composition of mitochondrial F0 is not known. The F0 preparations from bovine heart reported so far have been derived from H+ -ATPase preparations isolated in the presence of cholate and deoxycholate (11, 33, 36, 37).(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
|
27
|
Griffiths DG, Pringle MJ, Hughes JB, Sanadi DR. Environment of the sulfhydryl groups in bovine heart mitochondrial H+-ATPase. J Bioenerg Biomembr 1984; 16:465-75. [PMID: 6100375 DOI: 10.1007/bf00743239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Electron transport particles and purified H+-ATPase (F1-F0) vesicles from beef heart mitochondria have been treated with two classes of thiol reagent, viz. membrane-impermeable organomercurials and a homologous series of N-polymethylene carboxymaleimides (Mal-(CH2)x-COOH or AMx). The effect of such treatment on ATP-driven reactions (ATP-Pi exchange and proton translocation) has been examined and compared to the effects on rates of ATP hydrolysis. The organomercurials inhibited ATP-Pi exchange and one of them (p-chloromercuribenzoate) inhibited ATPase activity. Of the maleimide series (AMx), AM10 and AM11 inhibited both ATP-Pi exchange and ATP-driven membrane potential, but not ATPase activity. The other members of the series were essentially inactive. N-Ethylmaleimide was intermediate in its efficacy. Passive H+ conductance through the membrane sector F0 was 50% blocked by AM10, slightly blocked by AM2 and N-ethylmaleimide, and unaffected by the other members of the AMx series. The data imply that one -SH near the membrane surface and one -SH about 12 A from the surface are functional in proton translocation through the H+-ATPase.
Collapse
|
28
|
Kantham BC, Hughes JB, Pringle MJ, Sanadi DR. On the functional role of coupling factor B in the mitochondrial H+ -ATPase. J Biol Chem 1984; 259:10627-32. [PMID: 6147346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Evidence for the presence of a functionally important vicinal dithiol in mitochondrial coupling factor B (FB) has been presented earlier (Sanadi, D. R. (1982) Biochim. Biophys. Acta 683, 39-56). FB was completely inactivated by 38 micron of copper o-phenanthroline or 0.63 mM iodosobenzoate, and the kinetics were consistent with intramolecular disulfide formation as were polyacrylamide gel patterns which showed that FB which had been treated with copper o-phenanthroline had a different mobility from that of untreated FB. ATP-Pi exchange activity and ATP-induced binding of bis[3-propyl-5-oxoisoxazol-4-yl]pentamethine oxonol (oxonol VI) to H+ -ATPase were also inhibited by the thiol oxidizing reagents, although oligomycin-sensitive ATPase activity was unaffected. F0 isolated from H+ -ATPase rebinds purified F1 with the restoration of ATP-induced oxonol-binding activity. Prior treatment of F0 (but not of F1) with copper o-phenanthroline abolished the oxonol-binding activity of reconstituted F0-F1. 115Cd binds tightly to H+ -ATPase and the bound protein can be recovered by gel electrophoresis in phosphate buffer in the presence of sodium dodecyl sulfate at a position corresponding to FB. Prior treatment of the H+ -ATPase with copper o-phenanthroline abolished 115Cd binding. The results indicate that the major effect of these inhibitors is on FB dithiol and leave little doubt that Cd2+ is indeed bound to a vicinal dithiol group.
Collapse
|
29
|
|
30
|
Sanadi DR, Pringle M, Kantham L, Hughes JB, Srivastava A. Evidence for the involvement of coupling factor B in the H+ channel of the mitochondrial H+-ATPase. Proc Natl Acad Sci U S A 1984; 81:1371-4. [PMID: 6143319 PMCID: PMC344835 DOI: 10.1073/pnas.81.5.1371] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Membrane energization by ATP has been measured in vesicles containing purified bovine heart mitochondrial H+-ATPase (ATP synthase) with the voltage-sensitive dye oxonol VI. The dithiol chelator, Cd2+, and the thiol oxidant, copper o-phenanthroline, produced discharge of the membrane potential when added at the steady state and inhibited its establishment when added prior to energization by ATP. These effects, which were reversed by dithiothreitol, were not accompanied by an increase in the nonspecific H+ permeability of the membrane. Passive H+ conduction in proteoliposomes containing F0 (hydrophobic segment of ATP synthase) was assayed by the quenching of 9-aminoacridine fluorescence after establishing a K+ diffusion potential. This conductance was blocked by Cd2+, an inhibitor of coupling factor B (FB). Labeling of F0 with 115Cd2+ at the concentrations that inhibited the F0 conductance followed by gel electrophoresis yielded a single radioactive band with a molecular weight corresponding to FB, the presence of which in the F0 preparation was confirmed by immunoblot staining. The data offer strong evidence that FB is an essential component of the H+ channel of F0, because H+ conduction through the channel is inhibited by chemical modification of FB.
Collapse
|
31
|
Hughes JB, Joshi S, Sanadi DR. On the role of factor B and oligomycin on generation and discharge of the proton gradient. J Biol Chem 1982; 257:6697-701. [PMID: 7085595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Bovine mitochondrial coupling factor B (FB) stimulates oxidative phosphorylation as well as other energy-linked reactions which are supported by ATP hydrolysis. Extraction of FB from submitochondrial particles results in a decrease in ATP-dependent proton translocation (delta pH) and binding of the voltage-sensitive dye, oxonol VI. Reconstitution of deficient particles with FB restores ATP-dependent proton translocation and oxonol binding but has little effect on oxonol binding supported by respiratory substrates.l In contrast, low levels of oligomycin stimulate oxonol binding supported by either ATP or NADH. In the case of oligomycin, the stimulatory effect is associated with a decrease in the rate of discharge of the proton gradient, but the depletion of FB or its restoration has no detectable effect on the discharge rate. The data indicate that the primary effect of FB is upon the rate of H+ translocation coupled to ATP hydrolysis, while that of low oligomycin is on the H+ permeability of the membrane.
Collapse
|
32
|
|
33
|
Sanadi DR, Hughes JB, Joshi S. Activation of potassium-dependent H+ efflux from mitochondria by cadmium and phenylarsine oxide. J Bioenerg Biomembr 1981; 13:425-31. [PMID: 7334025 DOI: 10.1007/bf00743214] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Addition of Cd2+ or phenylarsine oxide (PhAsO) to respiring rat liver mitochondria results first in acidification of the medium (H+ efflux) followed by disappearance of H+ (discharge of the pH gradient or uncoupling). The first phase of H+ efflux is dependent upon the presence of K+ in the medium, and is not seen in the presence of valinomycin, which is consistent with the conclusion that H+ efflux is linked to membrane potential-dependent uptake of K+. These effects are abolished by low levels of 2,3-dimercaptopropanol but potentiated by excess of 2-mercaptoethanol, showing involvement of a dithiol type of group in the response. Mersalyl produces only the H+ efflux, and subsequent addition of Cd2+ of PhAsO produces collapse of the delta pH.
Collapse
|
34
|
Joshi S, Hughes JB. Inhibition of coupling factor B activity by cadmium ion, arsenite-2,3-dimercaptopropanol, and phenylarsine oxide, and preferential reactivation by dithiols. J Biol Chem 1981; 256:11112-6. [PMID: 6116711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Coupling factor B activity was measured by the stimulation of the ATP-driven NAD+ reduction by succinate or the 32Pi-ATP exchange activity of Factor B-depleted submitochondrial particles. Half-maximal coupling activity was inhibited by 30 microM cadmium, 5 microM phenylarsine oxide, or 0.3 mM arsenite-2,3-dimercaptopropanol. The inhibition was relieved by slight excess of dithiol but not by a 10-fold molar excess of 2-mercaptoethanol. Inhibition of coupling activity by phenylarsine oxide or cadmium was not due to interference in binding of Factor B to depleted particles. Isolated Factor B binds phenylarsine oxide resulting in loss of ability to stimulate depleted submitochondrial particles. The inhibition was largely overcome by dithiol but not by monothiols. The residual coupling activity of depleted submitochondrial particles was highly resistant to cadmium or arsenical. Moreover, binding of arsenical to the depleted particles per se, did not result in inhibition of Factor B-stimulated activity. Furthermore, the addition of phenylarsine oxide to H+-ATPase resulted in loss of Pi-ATP exchange and stimulation of oligomycin-sensitive ATPase activities. Both effects were further potentiated by 2-mercaptoethanol and reversed by dithiols. These effects parallel uncoupling of oxidative phosphorylation in mitochondria by these inhibitors and point to Factor B as the probable component sensitive to these inhibitors.
Collapse
|
35
|
Joshi S, Hughes JB, Houghton RL, Sanadi DR. Occurrence of proteins immunoreactive with anti-coupling factor B in phosphorylating membrane preparations. Biochim Biophys Acta 1981; 637:504-11. [PMID: 7284357 DOI: 10.1016/0005-2728(81)90057-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Coupling factor B has been isolated from beef heart mitochondria, apparently in multiple forms which differ in molecular weight and specific activity. Since it has no known intrinsic catalytic activity, detection and quantitation have been based upon the factor B-dependent stimulation of ATP-linked activities in factor B-deficient sub-mitochondrial particles. This communication reports the development of a reliable and more universally applicable enzyme-linked immunosorbent assay (ELISA) for detection and quantitation of factor B in soluble or membranous preparations. The assay requires nanoliter volumes of rabbit antiserum raised against purified factor B and will detect nanogram amounts of the coupling factor. Analysis of beef heart submitochondrial particles using a competitive binding ELISA indicated a factor B content of 0.27 nmol/mg protein, making factor B stoichiometric with F1 (0.3--0.6 nmol/mg). Furthermore, application of the factor B ELISA has indicated the presence of material cross-reacting with the beef heart factor B-antiserum in phosphorylating membranes from chloroplasts, Escherichia coli, Paracoccus denitrificans and the thermophilic bacterium, PS3. Negative results were obtained with mitochondria and microsomes from rat liver, purple membranes from Halobium halobacterium and sarcoplasmic reticulum from rabbit skeletal muscle.
Collapse
|
36
|
Joshi S, Hughes JB, Shaikh F, Sanadi DR. On the role of coupling factor B in the mitochondrial Pi-ATP exchange reaction. J Biol Chem 1979; 254:10145-52. [PMID: 158592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
37
|
Hughes JB. Metoclopramide in migrane treatment. Med J Aust 1977; 2:580. [PMID: 600183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
38
|
Abstract
The therapeutic effectiveness of parenterally administered rabbit antigastrin antibody was evaluated in a patient with the Zollinger-Ellison syndrome who had a fasting serum gastrin level of 3020 pg/ml and a basal gastric acid secretion of 48.9 mEq/hr. Control globulin reduced gastric secretion to 32 mEq/hr. Gastrin antibody reduced it futher to 8.7 mEq/hr. Betazole hydrochloride which was given 75 min after administration of gastrin antibody stimulated acid secretion to 57.2 mEq/hr. One day later basal acid secretion was uninhibited although some antibody activity was present in the patient's serum. The results suggested that gastrin antibody acutely inhibited basal but not betazole-stimulated secretion.
Collapse
|
39
|
|
40
|
|
41
|
Horton D, Hughes JB, Jewell JS, Philips KD, Turner WN. Anomeric equilibria in derivatives of amino sugars. Nuclear magnetic resonance studies on acetylated amino sugars and specifically deuterated analogs. J Org Chem 1967; 32:1073-80. [PMID: 6042145 DOI: 10.1021/jo01279a048] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|