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Hur J, Abousleiman YN, Hull KL, Qomi MJA. A ReaxFF Potential for Modeling Organic Matter Degradation with Oxybromine Oxidants. Chemphyschem 2024; 25:e202300860. [PMID: 38263476 DOI: 10.1002/cphc.202300860] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 01/25/2024]
Abstract
Oxidation of organic matter with oxybromine oxidants is ushering in a new era of enhanced hydrocarbon recovery. While these potent reagents are being tested in laboratory and field experiments, there is a pressing demand to delineate the molecular processes governing oxidation reactions at geological depth. Here, we parameterize a ReaxFF potential to model the oxidative decompositions of aliphatic and aromatic hydrocarbons in the presence of water-NaBr solutions that contain oxybromine (BrOn)- oxidizers. Our parameterization results in a reliable empirical bond-order potential that accurately calculates bond energies, exhibiting an RMSE of ∼1.18 eV, corresponding to 1.36 % average error. Reproducing bond dissociation and binding energies from Density Functional Theory (DFT), our parameterization proves transferable to aqueous environments. This H/C/O/Na/Br ReaxFF potential accurately reproduces the oxidation pathways of small hydrocarbons with oxybromine oxidizers. This force field captures proton and oxygen transfer, C-C bond tautomerization, and cleavage, leading to ring-opening and chain fragmentation. Molecular dynamic simulations demonstrate the oxidative degradation of aromatic and aliphatic kerogen-like moieties in bulk solutions. We envision that such reactive force fields will be useful to understand better the oxidation reactions of organic matter formed in geological reservoirs for enhanced shale gas recovery and improved carbon dioxide treatments.
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Affiliation(s)
- Jaewoong Hur
- Department of Civil and Environmental Engineering, Henry Samueli School of Engineering, University of California Irvine, E4130 Engineering Gateway, Irvine, CA 92697-2175, United States
| | - Younane N Abousleiman
- Integrated PoroMechanics Institute, The University of Oklahoma, 100 East Boyd Street, RM 710, Norman, Oklahoma, 73019, United States
| | - Katherine L Hull
- Aramco Research Center-Houston Aramco Americas, 16300 Park Row, Houston, Texas, 77084, United States
| | - Mohammad Javad Abdolhosseini Qomi
- Department of Civil and Environmental Engineering, Henry Samueli School of Engineering, University of California Irvine, E4130 Engineering Gateway, Irvine, CA 92697-2175, United States
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2
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Cluley V, Burton JO, Hull KL, Eborall H. The paradox of haemodialysis: the lived experience of the clocked treatment of chronic illness. Health Sociol Rev 2024; 33:24-42. [PMID: 38471040 DOI: 10.1080/14461242.2024.2319189] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 02/11/2024] [Indexed: 03/14/2024]
Abstract
Studies exploring the relationship between time and chronic illness have generally focused on measurable aspects of time, also known as linear time. Linear time follows a predictable, sequential order of past, present and future; measured using a clock and predicated on normative assumptions. Sociological concepts addressing lifecourse disruption following diagnosis of chronic illness have served to enhance the understanding of lived experience. To understand the nuanced relationship between time and chronic illness, however, requires further exploration. Here, we show how the implicit assumptions of linear time meet in tension with the lived experience of chronic illness. We draw on interviews and photovoice work with people with end-stage kidney disease in receipt of in-centre-daytime haemodialysis to show how the clocked treatment of chronic illness disrupts experiences of time. Drawing on concepts of 'crip' and 'chronic' time we argue that clocked treatment and the lived experience of chronic illness converge at a paradox whereby clocked treatment allows for the continuation of linear time yet limits freedom. We use the concept of 'crip time' to challenge the normative assumptions implicit within linear concepts of time and argue that the understanding of chronic illness and its treatment would benefit from a 'cripped' starting point.
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Affiliation(s)
- Victoria Cluley
- School of Sociology and Social Policy, University of Nottingham, England
| | - James O Burton
- Department of Cardiovascular Sciences, College of Life Sciences, University of Leicester and John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, England
| | - Katherine L Hull
- Department of Cardiovascular Sciences, College of Life Sciences, University of Leicester and John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, England
| | - Helen Eborall
- Critical Public Health, The University of Edinburgh, Scotland
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3
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Hull KL, McIntyre C, Burton JO. Does cooled dialysate still have a role in reducing intradialytic stress? Implications of the MyTEMP trial. Curr Opin Nephrol Hypertens 2023; 32:537-543. [PMID: 37753645 DOI: 10.1097/mnh.0000000000000917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
PURPOSE OF REVIEW There is an excess of cardiovascular morbidity and mortality in the maintenance haemodialysis population. Targeting traditional risk factors (e.g. hypercholesterolaemia) do not improve cardiovascular outcomes. Repeated myocardial stunning during haemodialysis is an important nontraditional risk, resulting in pathological cardiac remodelling and fibrosis. This review explores dialysate cooling as a management strategy to promote haemodynamic stability, reduce myocardial injury, and improve cardiovascular disease outcomes for individuals receiving maintenance haemodialysis. RECENT FINDINGS Observational data and small interventional studies demonstrate dialysate cooling has the potential to reduce end-organ damage and provide cardioprotection, renal protection and neuroprotection compared with standard care. These data are limited by the small sample sizes, short follow-up times and lack of long-term patient important outcomes. The MyTEMP study, a multicentre pragmatic randomized controlled trial, demonstrated cooled dialysate (0.5°C below body temperature) vs. standard care did not improve cardiovascular outcomes for prevalent haemodialysis patients. SUMMARY Dialysate cooling has been widely adopted into routine clinical practice; the MyTEMP study challenges the unit-level approach to implementing dialysate cooling. Due to methodological limitations, the absence of other important patient outcome measures, and lack of granularity of patient-level data, dialysate cooling should not be hastily removed from all dialysis care and warrants further research.
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Affiliation(s)
- Katherine L Hull
- Department of Cardiovascular Sciences, University of Leicester
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Chris McIntyre
- Lilibeth Caberto Kidney Clinical Research Unit, Lawson Health Research Institute
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - James O Burton
- Department of Cardiovascular Sciences, University of Leicester
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
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4
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Hull KL, Bramham K, Brookes CL, Cluley V, Conefrey C, Cooper NJ, Eborall H, Fotheringham J, Graham-Brown MPM, Gray LJ, Mark PB, Mitra S, Murphy GJ, Quann N, Rooshenas L, Warren M, Burton JO. The NightLife study - the clinical and cost-effectiveness of thrice-weekly, extended, in-centre nocturnal haemodialysis versus daytime haemodialysis using a mixed methods approach: study protocol for a randomised controlled trial. Trials 2023; 24:522. [PMID: 37573352 PMCID: PMC10422763 DOI: 10.1186/s13063-023-07565-w] [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: 05/18/2023] [Accepted: 08/03/2023] [Indexed: 08/14/2023] Open
Abstract
BACKGROUND In-centre nocturnal haemodialysis (INHD) offers extended-hours haemodialysis, 6 to 8 h thrice-weekly overnight, with the support of dialysis specialist nurses. There is increasing observational data demonstrating potential benefits of INHD on health-related quality of life (HRQoL). There is a lack of randomised controlled trial (RCT) data to confirm these benefits and assess safety. METHODS The NightLife study is a pragmatic, two-arm, multicentre RCT comparing the impact of 6 months INHD to conventional haemodialysis (thrice-weekly daytime in-centre haemodialysis, 3.5-5 h per session). The primary outcome is the total score from the Kidney Disease Quality of Life tool at 6 months. Secondary outcomes include sleep and cognitive function, measures of safety, adherence to dialysis and impact on clinical parameters. There is an embedded Process Evaluation to assess implementation, health economic modelling and a QuinteT Recruitment Intervention to understand factors that influence recruitment and retention. Adults (≥ 18 years old) who have been established on haemodialysis for > 3 months are eligible to participate. DISCUSSION There are 68,000 adults in the UK that need kidney replacement therapy (KRT), with in-centre haemodialysis the treatment modality for over a third of cases. HRQoL is an independent predictor of hospitalisation and mortality in individuals on maintenance dialysis. Haemodialysis is associated with poor HRQoL in comparison to the general population. INHD has the potential to improve HRQoL. Vigorous RCT evidence of effectiveness is lacking. The NightLife study is an essential step in the understanding of dialysis therapies and will guide patient-centred decisions regarding KRT in the future. TRIAL REGISTRATION Trial registration number: ISRCTN87042063. Registered: 14/07/2020.
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Affiliation(s)
- Katherine L Hull
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK.
| | - Kate Bramham
- King's Kidney Care, King's College Hospital, London, UK
- Department of Women and Children's Health, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | | | - Victoria Cluley
- School of Sociology and Social Policy, University of Nottingham, Nottingham, UK
| | - Carmel Conefrey
- Bristol Population Health Science Institute, University of Bristol Medical School, Bristol, UK
| | - Nicola J Cooper
- Department of Population Health Sciences, University of Leicester, Leicester, UK
| | - Helen Eborall
- College of Medicine and Veterinary Medicine, Usher Institute, University of Edinburgh, Edinburgh, UK
| | - James Fotheringham
- Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, Sheffield, UK
- Sheffield Kidney Institute, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Matthew P M Graham-Brown
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Laura J Gray
- Department of Population Health Sciences, University of Leicester, Leicester, UK
| | - Patrick B Mark
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Sandip Mitra
- Manchester Institute of Nephrology and Transplantation, Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
| | - Gavin J Murphy
- Leicester Clinical Trials Unit, University of Leicester, Leicester, UK
- Cardiovascular Research Centre, University of Leicester, Leicester, UK
| | - Niamh Quann
- Leicester Clinical Trials Unit, University of Leicester, Leicester, UK
| | - Leila Rooshenas
- Bristol Population Health Science Institute, University of Bristol Medical School, Bristol, UK
| | | | - James O Burton
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
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Singh S, Hull KL, Abousleiman YN. Understanding the Impact of Chlorite Oxidizer on Organic Matter of Source Rocks Using Nanoindentation (NI) and Scanning Electron Microscopy (SEM). Microsc Microanal 2023; 29:1232-1233. [PMID: 37613659 DOI: 10.1093/micmic/ozad067.633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Simrat Singh
- Aramco Research Center-Houston, Aramco Americas, Houston, TX, United States
| | - Katherine L Hull
- Aramco Research Center-Houston, Aramco Americas, Houston, TX, United States
| | - Younane N Abousleiman
- School of Geosciences, Integrated PoroMechanics Institute, The University of Oklahoma, Norman, OK, United States
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Quann N, Burns S, Hull KL, Cluley V, Richardson C, MacConaill K, Conefrey C, Rooshenas L, Eborall H, Burton JO. Reducing the carbon footprint of research: experience from the NightLife study. BMJ Open 2023; 13:e070200. [PMID: 37094890 PMCID: PMC10151866 DOI: 10.1136/bmjopen-2022-070200] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND As set out in the Climate Change Act (2008), the UK National Health Service (NHS) has made a commitment to halve greenhouse gas emissions by 2025 and reach net zero by 2050. Research forms a core part of NHS activity and reducing the carbon footprint of clinical trials is a core element of the National Institute for Health and Care Research Carbon Reduction Strategy (2019). KEY ARGUMENTS However, support from funding organisations on how to achieve these targets is lacking. This brief communication article reports the reduction in the carbon footprint of the NightLife study, an ongoing multicentre randomised controlled trial assessing the impact of in-centre nocturnal haemodialysis on quality of life. CONCLUSION By using remote conferencing software and innovative data collection methods, we demonstrated a total saving of 136 tonnes of carbon dioxide equivalent over three workstreams during the first 18 months of the study, following grant activation on 1 January 2020. In addition to the environmental impact, there were additional benefits seen to cost as well as increased participant diversity and inclusion. This work highlights ways in which trials could be made less carbon intensive, more environmentally sustainable and better value for money.
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Affiliation(s)
- Niamh Quann
- Leicester Clinical Trials Unit, College of Life Sciences, University of Leicester, Leicester, UK
| | - Steph Burns
- John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Katherine L Hull
- John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, College of Life Sciences, University of Leicester, Leicester, UK
| | - Victoria Cluley
- School of Sociology and Social Policy, University of Nottingham, Nottingham, UK
| | - Carla Richardson
- Leicester Clinical Trials Unit, College of Life Sciences, University of Leicester, Leicester, UK
| | - Kateryna MacConaill
- John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Carmel Conefrey
- Bristol Population Health Science Institute, University of Bristol Medical School, Bristol, UK
| | - Leila Rooshenas
- Bristol Population Health Science Institute, University of Bristol Medical School, Bristol, UK
| | - Helen Eborall
- Usher Institute, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - James O Burton
- John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, College of Life Sciences, University of Leicester, Leicester, UK
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7
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Cluley V, Burton JO, Quann N, Hull KL, Eborall H. Biographical dialectics: The ongoing and creative problem solving required to negotiate the biographical disruption of chronic illness. Soc Sci Med 2023; 325:115900. [PMID: 37084703 DOI: 10.1016/j.socscimed.2023.115900] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/03/2023] [Accepted: 04/08/2023] [Indexed: 04/23/2023]
Abstract
Here we propose the term 'biographical dialectics' as a sister term to 'biographical disruption' to capture the ongoing problem solving that characterises the lives of many people living with life limiting chronic illnesses. The paper is based on the experiences of 35 adults with end-stage kidney disease (ESKD) in receipt of haemodialysis. Photovoice and semi-structured interviews showed that ESKD and the use of haemodialysis was widely agreed to be biographically disruptive. In talking about and showing disruption through photographs the participants' ongoing problem solving was universal across their diverse experiences. 'Biographical disruption' and Hegalian dialectical logic, are drawn on to make sense of these actions and to further understand the personal and disruptive experience of chronic illness. Based on this, 'biographical dialectics' captures the work that is required to account for and manage the enduring and biographical impact of chronic illness that follows the initial disruption of diagnosis and continues as life progresses.
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Affiliation(s)
- Victoria Cluley
- School of Sociology and Social Policy, University of Nottingham, University Park, Nottingham, UK.
| | - James O Burton
- Department of Cardiovascular Sciences, College of Life Sciences, University of Leicester, Leicester, UK; John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Niamh Quann
- Leicester Clinical Trials Unit, College of Life Sciences, University of Leicester, Leicester, UK; John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Katherine L Hull
- Department of Cardiovascular Sciences, College of Life Sciences, University of Leicester, Leicester, UK; John Walls Renal Unit, Leicester General Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Helen Eborall
- Usher Institute, College of Medicine and Veterinary Medicine, University of Edinburgh, UK
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8
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Selvaskandan H, Hull KL, Adenwalla S, Ahmed S, Cusu MC, Graham-Brown M, Gray L, Hall M, Hamer R, Kanbar A, Kanji H, Lambie M, Lee HS, Mahdi K, Major R, Medcalf JF, Natarajan S, Oseya B, Stringer S, Tabinor M, Burton J. Risk factors associated with COVID-19 severity among patients on maintenance haemodialysis: a retrospective multicentre cross-sectional study in the UK. BMJ Open 2022; 12:e054869. [PMID: 35636784 PMCID: PMC9152624 DOI: 10.1136/bmjopen-2021-054869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES To assess the applicability of risk factors for severe COVID-19 defined in the general population for patients on haemodialysis. SETTING A retrospective cross-sectional study performed across thirty four haemodialysis units in midlands of the UK. PARTICIPANTS All 274 patients on maintenance haemodialysis who tested positive for SARS-CoV-2 on PCR testing between March and August 2020, in participating haemodialysis centres. EXPOSURE The utility of obesity, diabetes status, ethnicity, Charlson Comorbidity Index (CCI) and socioeconomic deprivation scores were investigated as risk factors for severe COVID-19. MAIN OUTCOMES AND MEASURES Severe COVID-19, defined as requiring supplemental oxygen or respiratory support, or a C reactive protein of ≥75 mg/dL (RECOVERY trial definitions), and its association with obesity, diabetes status, ethnicity, CCI, and socioeconomic deprivation. RESULTS 63.5% (174/274 patients) developed severe disease. Socioeconomic deprivation associated with severity, being most pronounced between the most and least deprived quartiles (OR 2.81, 95% CI 1.22 to 6.47, p=0.015), after adjusting for age, sex and ethnicity. There was no association between obesity, diabetes status, ethnicity or CCI with COVID-19 severity. We found no evidence of temporal evolution of cases (p=0.209) or clustering that would impact our findings. CONCLUSION The incidence of severe COVID-19 is high among patients on haemodialysis; this cohort should be considered high risk. There was strong evidence of an association between socioeconomic deprivation and COVID-19 severity. Other risk factors that apply to the general population may not apply to this cohort.
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Affiliation(s)
- Haresh Selvaskandan
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Katherine L Hull
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Sherna Adenwalla
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Safa Ahmed
- Department of Renal Transplantation and Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - Maria-Cristina Cusu
- Department of Renal Medicine, Northampton General Hospital NHS Trust, Northampton, UK
| | - Matthew Graham-Brown
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Laura Gray
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - Matt Hall
- Nottingham Renal and Transplant Unit, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Rizwan Hamer
- Department of Renal Transplantation and Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - Ammar Kanbar
- Department of Renal Medicine, Royal Stoke University Hospital, Stoke-on-Trent, UK
| | - Hemali Kanji
- Department of Renal Transplantation and Nephrology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - Mark Lambie
- School of Medicine, Keele University, Keele, UK
| | - Han Sean Lee
- Nottingham Renal and Transplant Unit, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Khalid Mahdi
- Department of Renal Medicine, Lincoln County Hospital, Lincoln, UK
| | - Rupert Major
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Health Sciences, University Hospital of Leicester, Leicester, UK
| | - James F Medcalf
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | | | - Boavojuvie Oseya
- Department of Renal Medicine, Northampton General Hospital NHS Trust, Northampton, UK
| | - Stephanie Stringer
- Department of Renal Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Matthew Tabinor
- Department of Renal Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - James Burton
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
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Cairns AJ, Hull KL, Althaus SM. Specific-Ion Effects Unveil a Route for Modulating Oxidatively Triggered Acid Systems for Reservoir Applications. Inorg Chem 2022; 61:7720-7728. [PMID: 35533339 DOI: 10.1021/acs.inorgchem.1c03804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
On-demand in situ preparation of industrially relevant organic acids, namely, methanesulfonic acid, triflic acid, and trifluoroacetic acid, is demonstrated in this study. Sodium and potassium bromate were found to selectively oxidize a series of ammonium salts NH4X, where X = OMs, OTf, or OTFAc, with characteristic clock reaction behavior. The redox system undergoes rapid acid formation following an extended induction time at 150 °C and is identified as a potential candidate for high-temperature oil field chemistry applications where on-demand acid placement is required. Although the reaction kinetics for acid formation from NH4X salts where X = Cl, Br, F, or SO42- follows a pKa trend, the rates of formation of the organic acids are much slower and deviate from this trend. Furthermore, we demonstrate that the rate of acid formation can be modulated by the addition of alkali metal salts, with the strongest effect observed from LiBr. Spectroscopic studies implicate the formation of lithium bromate ion pairs that slow or altogether inhibit the oxidation of NH4+. Additionally, the presence of Br- alters the reaction path, eliminating the clock behavior and creating a pathway for Li+ to strongly inhibit the redox reaction. From these studies, a method for slowing ammonium oxidation under reservoir conditions to sufficiently delay acid formation until the precursors are placed in the zone of interest is identified.
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Affiliation(s)
- Amy J Cairns
- Aramco Americas: Aramco Research Center-Houston, 16300 Park Row, Houston, Texas 77084, United States
| | - Katherine L Hull
- Aramco Americas: Aramco Research Center-Houston, 16300 Park Row, Houston, Texas 77084, United States
| | - Stacey M Althaus
- Aramco Americas: Aramco Research Center-Houston, 16300 Park Row, Houston, Texas 77084, United States
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10
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Asad A, Thomas A, Dungey M, Hull KL, March DS, Burton JO. Associations between physical activity levels and renal recovery following acute kidney injury stage 3: a feasibility study. BMC Nephrol 2022; 23:140. [PMID: 35410183 PMCID: PMC9004179 DOI: 10.1186/s12882-022-02759-x] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Acute kidney injury (AKI) can lead to chronic kidney disease, which results in poor long-term outcomes. There is plausibility that increased levels of physical activity may promote renal recovery post-AKI. This study aimed to investigate associations between physical activity levels and renal recovery following stage 3 AKI, and to assess the feasibility of measuring physical activity levels in this population. METHODS Forty One hospitalised patients with AKI stage 3 were enrolled. Serum creatinine and estimated glomerular filtration rate (eGFR) were collected at 12 months prior to the development of AKI, during the hospital admission when the episode of AKI stage 3 occurred, and at 1-, 3- and 6-months post discharge. All participants completed the General Practice Activity Questionnaire (GPPAQ) to assess physical activity levels. A pedometer was also worn for 7 days immediately following discharge and at 6-months post discharge to ascertain an average daily step count. Feasibility outcomes including eligibility, recruitment and retention rates, and losses to follow up were also assessed. RESULTS The average (± SD) baseline eGFR and median (IQR) serum creatinine was 71 ± 20 mL/min/1.73m2 and 85 (49) μmol/L respectively. A threefold increase in creatinine occurred during hospitalisation 436 (265) μmol/L. Greatest renal recovery occurred prior to discharge, with recovery continuing for a further three months. Inactive individuals (low GPPAQ scores) had consistently higher serum creatinine values compared to those who were active: 1 months 122 (111) μmol/L vs 70 (0) μmol/L, 6 months 112 (57) μmol/L vs 68 (0) μmol/L. Individuals with higher step counts also displayed better renal recovery 6-months post discharge (r = -0.600, p = 0.208). CONCLUSIONS Higher levels of physical activity are associated with improved renal recovery after 6- months following an episode of stage 3 AKI. A future randomised controlled trial is feasible and would be required to confirm these initial findings.
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Affiliation(s)
- Anam Asad
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Amal Thomas
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Maurice Dungey
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Katherine L Hull
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.,John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - Daniel S March
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.,York Trials Unit, Department of Health Sciences, University of York, York, UK
| | - James O Burton
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK. .,John Walls Renal Unit, Leicester General Hospital, Leicester, UK. .,NIHR Leicester Biomedical Research Centre, Leicester, UK. .,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
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11
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Hull KL, Adenwalla SF, Topham P, Graham-Brown MP. Indications and considerations for kidney biopsy: an overview of clinical considerations for the non-specialist. Clin Med (Lond) 2022; 22:34-40. [PMID: 38589098 DOI: 10.7861/clinmed.2021-0472] [Citation(s) in RCA: 8] [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] [Indexed: 11/27/2022]
Abstract
Around 3 million people in the UK have chronic kidney disease and 20% of hospital admissions are complicated by acute kidney injury. Decline in kidney function is not a diagnosis; it is essential to identify and treat underlying causes of acute and chronic kidney disease to either achieve recovery or slow the decline of kidney function. Thorough clinical assessment and simple investigations help determine the category of kidney injury (pre-renal, intrinsic or post-renal) and inform the need for kidney biopsy, which can provide significant information in the evaluation of suspected intrinsic kidney disease, supporting diagnosis, guiding prognosis and management, and identifying disease relapse. The procedure is invasive and not without risk, which although small has the potential to be both organ- and life-threatening. This review outlines roles of kidney biopsy for the non-specialist, with focus of its role in patients with diabetes, lupus, myeloma and in the older patient.
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Affiliation(s)
- Katherine L Hull
- University Hospitals of Leicester NHS Trust, Leicester, UK and University of Leicester, Leicester, UK; *joint first authors
| | - Sherna F Adenwalla
- University Hospitals of Leicester NHS Trust, Leicester, UK and University of Leicester, Leicester, UK; *joint first authors
| | - Peter Topham
- University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Matthew P Graham-Brown
- University Hospitals of Leicester NHS Trust, Leicester, UK and University of Leicester, Leicester, UK.
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12
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Hull KL, Quann N, Glover S, Wimbury C, Churchward DR, Pickering WP, Preston R, Baines R, Graham-Brown MPM, Burton JO. Evaluating the clinical experience of a regional in-center nocturnal hemodialysis program: The patient and staff perspective. Hemodial Int 2021; 25:447-456. [PMID: 34133061 DOI: 10.1111/hdi.12953] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/10/2021] [Accepted: 05/23/2021] [Indexed: 11/30/2022]
Abstract
INTRODUCTION End-stage kidney disease causes significant morbidity, mortality, and reduced quality of life. Despite improvements in conventional hemodialysis, these problems persist. In-center nocturnal hemodialysis (INHD) has been shown to be beneficial in observational studies. This report outlines a 4-year renal network experience of INHD from the patient and frontline staff perspective. METHODS Staff and patients' experiences of INHD were evaluated through two work streams. Work stream one: 12 patients who chose to stop INHD and 24 patients who chose to continue with INHD completed an anonymous survey. Work stream two: one-to-one interviews with 20 patients receiving INHD and seven staff working INHD shifts were conducted. Clinical incident reporting for conventional hemodialysis and INHD from April 2014 to December 2018 was reviewed. FINDINGS Work stream one: Five themes were identified; facilities, time, health and well-being, sleep, and transport. A patient "starter pack" was developed and improvements to the dialysis unit were completed. Work stream two: Patient interviews demonstrated starter packs to aid sleep were well received; sleep itself was not a single reason to discontinue INHD. Staff indicated that their greatest concern was staffing levels; although staff-to-patient ratio remains unchanged, total numbers on INHD shifts were fewer, causing concern around less colleague availability for support during an emergency. SAFETY 363 clinical incidents were reported across all dialysis shifts; for conventional hemodialysis, a larger proportion were due to medical interventions, infection control, and transport; for INHD, most incidents centered around communication with patients and relatives, delays in patient transfer, and issues with medical equipment or facilities. DISCUSSION Patients continue with INHD due to increased social time and perceived health benefits. Patient starter packs and adjustments to the dialysis unit may enhance sleep. This experience has optimized the design of the NightLife study; a randomized controlled trial evaluated the effect of INHD on quality of life.
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Affiliation(s)
- Katherine L Hull
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - Niamh Quann
- Leicester Clinical Trials Unit, College of Life Sciences, University of Leicester, Leicester, UK
| | - Suzanne Glover
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - Coral Wimbury
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - Darren R Churchward
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | | | - Rob Preston
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - Richard Baines
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - Matthew P M Graham-Brown
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
| | - James O Burton
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, Leicester General Hospital, Leicester, UK
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
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13
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Hur J, Abousleiman YN, Hull KL, Abdolhosseini Qomi MJ. Reactive force fields for modeling oxidative degradation of organic matter in geological formations. RSC Adv 2021; 11:29298-29307. [PMID: 35479567 PMCID: PMC9040638 DOI: 10.1039/d1ra04397h] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/25/2021] [Indexed: 11/21/2022] Open
Abstract
In an attempt to better explore organic matter reaction and properties, at depth, to oxidative fluid additives, we have developed a new ReaxFF potential to model and describe the oxidative decompositions of aliphatic and aromatic hydrocarbons in the presence of the oxychlorine ClO n - oxidizers. By carefully adjusting the new H/C/O/Cl parameters, we show that the potential energies in both training and validation sets correlate well with calculated density functional theory (DFT) energies. Our parametrization yields a reliable empirical reactive force field with an RMS error of ∼1.57 eV, corresponding to a 1.70% average error. At this accuracy level, the reactive force field provides a reliable atomic-level picture of thermodynamically favorable reaction pathways governing oxidative degradation of H/C/O/Cl compounds. We demonstrate this capability by studying the structural degradation of small aromatic and aliphatic hydrocarbons in the presence of oxychlorine oxidizers in aqueous environments. We envision that such reactive force fields will be critical in understanding the oxidation processes of organic matter in geological reservoirs and the design of the next generation of reactive fluids for enhanced shale gas recovery and improved carbon dioxide adsorption and sequestration.
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Affiliation(s)
- Jaewoong Hur
- Department of Civil and Environmental Engineering, Henry Samueli School of Engineering, University of California E4130 Engineering Gateway Irvine CA 92697-2175 USA
| | - Younane N Abousleiman
- Integrated PoroMechanics Institute, School of Geosciences, The University of Oklahoma Norman Oklahoma 73019 USA
| | - Katherine L Hull
- Aramco Services Company, Aramco Research Center - Houston 16300 Park Row Houston Texas 77084 USA
| | - Mohammad Javad Abdolhosseini Qomi
- Department of Civil and Environmental Engineering, Henry Samueli School of Engineering, University of California E4130 Engineering Gateway Irvine CA 92697-2175 USA
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14
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Affiliation(s)
- Katherine L. Hull
- Aramco Services Company: Aramco Research Center – Houston Houston Texas USA
| | - Younane N. Abousleiman
- Integrated PoroMechanics Institute, School of Geosciences The University of Oklahoma Norman Oklahoma USA
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15
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Wilkinson TJ, Clarke AL, Nixon DGD, Hull KL, Song Y, Burton JO, Yates T, Smith AC. Prevalence and correlates of physical activity across kidney disease stages: an observational multicentre study. Nephrol Dial Transplant 2021; 36:641-649. [PMID: 31725147 DOI: 10.1093/ndt/gfz235] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [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: 08/23/2019] [Accepted: 10/14/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND People with chronic kidney disease (CKD) report high levels of physical inactivity, a major modifiable risk factor for morbidity and mortality. Understanding the biological, psychosocial and demographic causes of physical activity behaviour is essential for the development and improvement of potential health interventions and promotional initiatives. This study investigated the prevalence of physical inactivity and determined individual correlates of this behaviour in a large sample of patients across the spectrum of kidney disease. METHODS A total of 5656 people across all stages of CKD (1-2, 3, 4-5, haemodialysis, peritoneal dialysis and renal transplant recipients) were recruited from 17 sites in England from July 2012 to October 2018. Physical activity was evaluated using the General Practice Physical Activity Questionnaire. Self-reported cardiorespiratory fitness, self-efficacy and stage of change were also assessed. Binominal generalized linear mutually adjusted models were conducted to explore the associations between physical activity and correlate variables. This cross-sectional observational multi-centre study was registered retrospectively as ISRCTN87066351 (October 2015). RESULTS The prevalence of physical activity (6-34%) was low and worsened with disease progression. Being older, female and having a greater number of comorbidities were associated with greater odds of being physically inactive. Higher haemoglobin, cardiorespiratory fitness and self-efficacy levels were associated with increased odds of being active. Neither ethnicity nor smoking history had any effect on physical activity. CONCLUSIONS Levels of physical inactivity are high across all stages of CKD. The identification of stage-specific correlates of physical activity may help to prioritize factors in target groups of kidney patients and improve the development and improvement of public health interventions.
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Affiliation(s)
- Thomas J Wilkinson
- Department of Health Sciences, Leicester Kidney Lifestyle Team, University of Leicester, Leicester, UK.,NIHR Leicester Biomedical Research Centre, Leicester, UK
| | - Amy L Clarke
- Department of Health Sciences, Leicester Kidney Lifestyle Team, University of Leicester, Leicester, UK
| | - Daniel G D Nixon
- Department of Health Sciences, Leicester Kidney Lifestyle Team, University of Leicester, Leicester, UK.,NIHR Leicester Biomedical Research Centre, Leicester, UK
| | - Katherine L Hull
- Department of Health Sciences, Leicester Kidney Lifestyle Team, University of Leicester, Leicester, UK.,University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Yan Song
- Department of Health Sciences, Leicester Kidney Lifestyle Team, University of Leicester, Leicester, UK.,School of Nursing, Nantong University Medical School, Nantong University, Nantong, PR China
| | - James O Burton
- NIHR Leicester Biomedical Research Centre, Leicester, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Thomas Yates
- NIHR Leicester Biomedical Research Centre, Leicester, UK.,Diabetes Research Centre, Leicester General Hospital, University of Leicester, Leicester, UK
| | - Alice C Smith
- Department of Health Sciences, Leicester Kidney Lifestyle Team, University of Leicester, Leicester, UK.,NIHR Leicester Biomedical Research Centre, Leicester, UK
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16
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Hull KL, Schipper DE, Oliver AG. Correction: Synthesis and structural characterization of CO 2-soluble oxidizers [Bu 4N]BrO 3 and [Bu 4N]ClO 3 and their dissolution in cosolvent-modified CO 2 for reservoir applications. RSC Adv 2021; 11:3476. [PMID: 35426998 PMCID: PMC8694196 DOI: 10.1039/d1ra90002a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 01/08/2021] [Indexed: 11/21/2022] Open
Abstract
Correction for ‘Synthesis and structural characterization of CO2-soluble oxidizers [Bu4N]BrO3 and [Bu4N]ClO3 and their dissolution in cosolvent-modified CO2 for reservoir applications’ by Katherine L. Hull et al., RSC Adv., 2020, 10, 44973–44980, DOI: 10.1039/D0RA09563J.
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Affiliation(s)
| | | | - Allen G. Oliver
- The Department of Chemistry and Biochemistry
- University of Notre Dame
- Notre Dame
- USA
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17
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Rhode C, Badenhorst R, Hull KL, Greenwood MP, Bester-van der Merwe AE, Andere AA, Picard CJ, Richards C. Genetic and phenotypic consequences of early domestication in black soldier flies (Hermetia illucens). Anim Genet 2020; 51:752-762. [PMID: 32524667 DOI: 10.1111/age.12961] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2020] [Indexed: 01/18/2023]
Abstract
The black soldier fly, Hermetia illucens, is an emerging biotechnological agent with its larvae being effective converters of organic waste into usable bio-products including protein and lipids. To date, most operations use unimproved commercial populations produced by mass rearing, without cognisance of specific breeding strategies. The genetic and phenotypic consequences of these commercial practices remain unknown and could have a significant impact on long-term population viability and productivity. The aim of this study was thus to assess the genetic and phenotypic changes during the early phases of colony establishment and domestication in the black soldier fly. An experimental colony was established from wild founder flies and a new microsatellite marker panel was developed to assess population genetic parameters along with the phenotypic characteristics of each generational cohort under captive breeding. The experimental colony was characterised by a small effective population size, subsequent loss of genetic diversity and rapid genetic and phenotypic differentiation between the generational cohorts. Ultimately, the population collapsed by the fifth generation, most likely owing to the adverse effect of inbreeding depression following the fixation of deleterious alleles. Species with r-selected life history characteristics (e.g. short life-span, high fecundity and low larval survival) are known to pose particular challenges for genetic management. The current study suggests that sufficient genetic and phenotypic variations exist in the wild population and that domestication and strain development could be achieved with careful population augmentation and selection during the early stages of colony establishment.
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Affiliation(s)
- C Rhode
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - R Badenhorst
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.,AgriProtein Holdings Ltd, 1 Farnham Road, Guildford, Surrey, GU2 4RG, UK
| | - K L Hull
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - M P Greenwood
- Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | | | - A A Andere
- Department of Biology, Purdue School of Science, Indiana University - University of Purdue Indianapolis, SL 306, 723 W Michigan Street, Indianapolis, IN, 46202, USA
| | - C J Picard
- Department of Biology, Purdue School of Science, Indiana University - University of Purdue Indianapolis, SL 306, 723 W Michigan Street, Indianapolis, IN, 46202, USA
| | - C Richards
- AgriProtein Holdings Ltd, 1 Farnham Road, Guildford, Surrey, GU2 4RG, UK
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18
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Hull KL, March DS, Churchward DR, Graham‐Brown MP, Burton JO. The effect of extended‐hours hemodialysis on outcomes: A systematic review and meta‐analysis. Hemodial Int 2020; 24:133-147. [DOI: 10.1111/hdi.12828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/05/2020] [Accepted: 02/17/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Katherine L. Hull
- Department of Cardiovascular SciencesUniversity of Leicester Leicester UK
- John Walls Renal UnitLeicester General Hospital Leicester UK
| | - Daniel S. March
- Department of Cardiovascular SciencesUniversity of Leicester Leicester UK
- John Walls Renal UnitLeicester General Hospital Leicester UK
| | - Darren R. Churchward
- Department of Cardiovascular SciencesUniversity of Leicester Leicester UK
- John Walls Renal UnitLeicester General Hospital Leicester UK
| | - Matthew P.M. Graham‐Brown
- Department of Cardiovascular SciencesUniversity of Leicester Leicester UK
- John Walls Renal UnitLeicester General Hospital Leicester UK
| | - James O. Burton
- Department of Cardiovascular SciencesUniversity of Leicester Leicester UK
- John Walls Renal UnitLeicester General Hospital Leicester UK
- School of Sport, Exercise and Health SciencesLoughborough University Loughborough UK
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19
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Grantham CE, Hull KL, Graham-Brown MP, March DS, Burton JO. The Potential Cardiovascular Benefits of Low-Glucose Degradation Product, Biocompatible Peritoneal Dialysis Fluids: A Review of the Literature. Perit Dial Int 2020; 37:375-383. [DOI: 10.3747/pdi.2016.00228] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 02/06/2017] [Indexed: 01/08/2023] Open
Abstract
Cardiovascular mortality in the end-stage renal disease (ESRD) population remains the leading cause of death. Targeting traditional cardiovascular risk factors has proven unsuccessful in this patient population, and therefore attention has turned to risk factors related to chronic kidney disease (CKD). The toxicity of high-glucose peritoneal dialysis (PD) solutions has been well documented. The breakdown of glucose into glucose degradation products (GDP) and advanced glycation end-products (AGE) has the ability to alter cell viability and cause premature apoptosis and is strongly correlated with interstitial fibrosis and microvascular sclerosis. Biocompatible solutions have been introduced to combat the hostile milieu to which PD patients are exposed.Given the considerable cardiovascular burden for PD patients, little is known about the cardiovascular impact the new biocompatible solutions may have. This review analyzes the existing literature regarding the mechanisms through which low-GDP solutions may modulate cardiovascular risk. Interventions using low-GDP solutions have provided encouraging changes in structural cardiovascular measures such as left ventricular mass (LVM), although metabolic changes from reduced GDP and AGE exposure yield inconclusive results on vascular remodelling. It is thought that the local effects of reduced glucose exposure may improve membrane integrity and therefore fluid status. Further research in the form of a robust randomized controlled trial should be carried out to assess the true extent of the cardiovascular benefits these biocompatible solutions may hold.
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Affiliation(s)
- Charlotte E. Grantham
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- University of Leicester, Leicester, UK; John Walls Renal Unit, University of Leicester, Leicester, UK
| | - Katherine L. Hull
- University of Leicester, Leicester, UK; John Walls Renal Unit, University of Leicester, Leicester, UK
| | - Matthew P.M. Graham-Brown
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- University of Leicester, Leicester, UK; John Walls Renal Unit, University of Leicester, Leicester, UK
- Leicester General Hospital, Leicester, UK; National College of Sport and Exercise Medicine, University of Leicester, Leicester, UK
| | - Daniel S. March
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- University of Leicester, Leicester, UK; John Walls Renal Unit, University of Leicester, Leicester, UK
| | - James O. Burton
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- University of Leicester, Leicester, UK; John Walls Renal Unit, University of Leicester, Leicester, UK
- University of Loughborough, Loughborough, UK; and Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
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20
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Hull KL, Schipper DE, Oliver AG. Synthesis and structural characterization of CO 2-soluble oxidizers [Bu 4N]BrO 3 and [Bu 4N]ClO 3 and their dissolution in cosolvent-modified CO 2 for reservoir applications. RSC Adv 2020; 10:44973-44980. [PMID: 35516229 PMCID: PMC9058644 DOI: 10.1039/d0ra09563j] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/25/2021] [Accepted: 12/01/2020] [Indexed: 12/15/2022] Open
Abstract
CO2 utilization in upsteam oil and gas applications requires CO2-soluble additives such as polymers, surfactants, and other components. Here we report the facile synthesis of CO2-soluble oxidizers composed of judiciously selected organic cations paired with oxidizing anions. [Bu4N]BrO3 and [Bu4N]ClO3 are prepared using a double displacement synthetic strategy, whereby the crystalline product is readily obtained in high yield and structurally characterized using single-crystal X-ray diffraction. The facility of the approach is demonstrated through the preparation of several additional alkylammonium bromate compounds. Static solubility studies using a high-pressure cell with viewing windows showed that tetrabutylammonium compounds could be solubilized using cosolvent-modified CO2. Using 4 mol% ethanol as cosolvent, >3 mM [Bu4N]BrO3 could be dissolved in CO2, while ∼0.75 mM [Bu4N]ClO3 could be dissolved in the same solvent system. The solubility properties of [Bu4N]BrO3 along with its thermal stability up to ∼200 °C suggest that it is a promising oilfield oxidizer that can be utilized in subterranean CO2 applications. Bromate and chlorate salts were hydrophobically modified with tetrabutylammonium to yield oxidizers that are soluble in CO2-cosolvent mixtures.![]()
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Affiliation(s)
| | | | - Allen G. Oliver
- The Department of Chemistry and Biochemistry
- University of Notre Dame
- USA
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21
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Hull KL, Churchward DR, Graham-Brown MPM, Glover S, Jesus-Silva J, Baines R, Burton JO. SP679EXPLORING THE EXPERIENCES AND CONCERNS OF STAFF AND PATIENTS ON AN IN-CENTRE NOCTURNAL HAEMODIALYSIS PROGRAMME. Nephrol Dial Transplant 2019. [DOI: 10.1093/ndt/gfz103.sp679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | | | - Suzanne Glover
- University Hospitals of Leicester, Leicester, United Kingdom
| | | | - Richard Baines
- University Hospitals of Leicester, Leicester, United Kingdom
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22
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Abstract
A redox chemistry approach has been employed to synthesize an assortment of acids in the subterranean environment for the purpose of enhancing productivity from hydrocarbon-bearing rock formations. Experimental studies revealed that bromate selectively oxidizes a series of ammonium salts NH4X where X = F-, Cl-, Br-, SO42-, and CF3CO2- to produce 5-17 wt % HX. Importantly, the in situ method allows strategic placement of the acid in the zone of interest where the fluid is heated, and the reaction is triggered. Ammonium counteranions are shown to influence the kinetics of the bromate-ammonium reaction, and the conditions are tailored to promote oxidation of ammonium at reservoir temperatures. The reaction is observed to be acid-catalyzed, where the formation of bromous acid (HBrO2) is involved in the rate-limiting step. As a result, an induction period that scales with the p Ka of the acid being formed is followed by rapid formation of the reaction products.
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Affiliation(s)
- Katherine L Hull
- Aramco Services Company: Aramco Research Center - Houston, 16300 Park Row , Houston , Texas 77084 , United States
| | - Amy J Cairns
- Aramco Services Company: Aramco Research Center - Houston, 16300 Park Row , Houston , Texas 77084 , United States
| | - Marium Haq
- Aramco Services Company: Aramco Research Center - Houston, 16300 Park Row , Houston , Texas 77084 , United States
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23
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Clarke AL, Zaccardi F, Gould DW, Hull KL, Smith AC, Burton JO, Yates T. Association of self-reported physical function with survival in patients with chronic kidney disease. Clin Kidney J 2018; 12:122-128. [PMID: 30746139 PMCID: PMC6366129 DOI: 10.1093/ckj/sfy080] [Citation(s) in RCA: 12] [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: 10/24/2017] [Indexed: 12/27/2022] Open
Abstract
Background Reduced physical function is associated with an increased risk of mortality among patients with chronic kidney disease (CKD) not requiring renal replacement therapy (RRT). Assessments of physical performance can help to identify those at risk for adverse events. However, objective measures are not always feasible and self-reported measures may provide a suitable surrogate. Methods We performed a cohort study examining associations between self-reported physical function and walking behaviour with survival in patients with CKD not requiring RRT. Data were analysed from the QCKD study (Physical activity opinions in kidney disease) (ISRCTN 87066351), a prospective observational mixed methods study of physical activity in patients with CKD. A total of 450 patients with CKD not requiring RRT, ages 17–93 years, were followed up for a median of 43 months. Upon enrolment, participants completed two questionnaires: Duke Activity Status Index (DASI) (physical function) and General Practice Physical Activity Questionnaire (GPPAQ) (habitual activity). Mortality data were collected from electronic records in September 2016; RRT was considered a competing event. Results A total of 74 deaths occurred during follow-up and 101 participants were started on RRT. The adjusted subdistribution hazard ratio (SHR) of mortality in participants scoring >19.2 on the DASI was 0.51 [95% confidence interval (CI) 0.30–0.88] while a one-unit increase in the DASI was associated with an SHR of 0.97 (95% CI 0.95–0.99). The adjusted SHRs of mortality were 0.48 (95% CI 0.26–0.90), 0.25 (0.11–0.57) and 0.48 (0.23–0.80) for participants walking <1, 1–3 and ≥3 h/week, respectively, compared with no walking. A walking pace >3 mph was associated with a reduced risk of mortality [SHR 0.37 (95% CI 0.20–0.71)] compared with a walking pace <3 mph. Conclusions Physical function and walking behaviours were independently associated with survival in CKD and may help to identify patients at risk for adverse events.
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Affiliation(s)
- Amy L Clarke
- Department of Infection Immunity and Inflammation, College of Life Sciences, University of Leicester, Leicester, UK
- Correspondence and offprint requests to: Amy L. Clarke; E-mail: ; Twitter handle: @aimes89
| | - Francesco Zaccardi
- Diabetes Research Centre, College of Life Sciences and Psychology, University of Leicester, Leicester, UK
| | - Douglas W Gould
- Department of Infection Immunity and Inflammation, College of Life Sciences, University of Leicester, Leicester, UK
| | - Katherine L Hull
- Department of Infection Immunity and Inflammation, College of Life Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals Leicester NHS Trust, Leicester, UK
| | - Alice C Smith
- Department of Infection Immunity and Inflammation, College of Life Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals Leicester NHS Trust, Leicester, UK
| | - James O Burton
- Department of Infection Immunity and Inflammation, College of Life Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals Leicester NHS Trust, Leicester, UK
- Department of Cardiovascular Sciences, University of Leicester, UK
- NIHR Leicester Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Thomas Yates
- Diabetes Research Centre, College of Life Sciences and Psychology, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, University of Leicester, Leicester, UK
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24
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Campana L, Starkey Lewis PJ, Pellicoro A, Aucott RL, Man J, O'Duibhir E, Mok SE, Ferreira-Gonzalez S, Livingstone E, Greenhalgh SN, Hull KL, Kendall TJ, Vernimmen D, Henderson NC, Boulter L, Gregory CD, Feng Y, Anderton SM, Forbes SJ, Iredale JP. The STAT3-IL-10-IL-6 Pathway Is a Novel Regulator of Macrophage Efferocytosis and Phenotypic Conversion in Sterile Liver Injury. J Immunol 2018; 200:1169-1187. [PMID: 29263216 PMCID: PMC5784823 DOI: 10.4049/jimmunol.1701247] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/25/2017] [Indexed: 12/20/2022]
Abstract
The disposal of apoptotic bodies by professional phagocytes is crucial to effective inflammation resolution. Our ability to improve the disposal of apoptotic bodies by professional phagocytes is impaired by a limited understanding of the molecular mechanisms that regulate the engulfment and digestion of the efferocytic cargo. Macrophages are professional phagocytes necessary for liver inflammation, fibrosis, and resolution, switching their phenotype from proinflammatory to restorative. Using sterile liver injury models, we show that the STAT3-IL-10-IL-6 axis is a positive regulator of macrophage efferocytosis, survival, and phenotypic conversion, directly linking debris engulfment to tissue repair.
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Affiliation(s)
- Lara Campana
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom;
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Philip J Starkey Lewis
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Antonella Pellicoro
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Rebecca L Aucott
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Janet Man
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Eoghan O'Duibhir
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Sarah E Mok
- University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Sofia Ferreira-Gonzalez
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Eilidh Livingstone
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Stephen N Greenhalgh
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Katherine L Hull
- University Hospitals of Leicester, Leicester LE3 9QP, United Kingdom
| | - Timothy J Kendall
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
- Division of Pathology, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Douglas Vernimmen
- Developmental Biology Division, The Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, United Kingdom
| | - Neil C Henderson
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Luke Boulter
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom; and
| | - Christopher D Gregory
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Yi Feng
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Stephen M Anderton
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Stuart J Forbes
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - John P Iredale
- Medical Research Council Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
- Senate House, University of Bristol, Bristol BS8 1TH, United Kingdom
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Graham-Brown MPM, Churchward DR, Hull KL, Preston R, Pickering WP, Eborall HC, McCann GP, Burton JO. Cardiac Remodelling in Patients Undergoing in-Centre Nocturnal Haemodialysis: Results from the MIDNIGHT Study, a Non-Randomized Controlled Trial. Blood Purif 2017; 44:301-310. [PMID: 29084397 DOI: 10.1159/000481248] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 09/04/2017] [Indexed: 01/01/2023]
Abstract
Evidence suggests extended-hours haemodialysis (HD) may improve cardiovascular, medical and quality-of-life outcomes. In-centre nocturnal haemodialysis (INHD) is an established but underutilized method of providing extended-hours treatment. This 6-month, non-randomized controlled trial (ISRCTN16672784) recruited 13 INHD patients and 12 control patients on conventional HD. The effects of treatment on left ventricular (LV) structure, function and myocardial fibrosis were assessed using cardiac magnetic resonance imaging and native T1 mapping. Quality-of-life and clinical measures were also collected. INHD led to significant reductions in LV mass (-14.75 vs. +6.54 g; p = 0.02), global T1 (-30.62 vs. 0.4 ms; p = 0.05) and non-septal native T1 values (-30.93 vs. 8.96 ms; p = 0.02) over time. There were also significant improvements in serum phosphate (-0.39 vs. +0.02 mmol/L; p = 0.03) and reductions in ultrafiltration rates (-2.32 vs. +0.70 mL/h/kg p = 0.05) between INHD and controls. Six-months of INHD was associated with favourable LV remodelling and reduced myocardial fibrosis compared to patients on conventional haemodialysis.
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MacKinnon HJ, Clarke AL, Young HL, Hull KL, Burton JO, Smith AC. Creating a SPARK: Investigating exercise behaviour and preferences in patients with chronic kidney disease to aid the design of exercise programmes. International Journal of Therapy and Rehabilitation 2015. [DOI: 10.12968/ijtr.2015.22.sup8.s2] [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: 11/11/2022]
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Clarke AL, Young HML, Hull KL, Hudson N, Burton JO, Smith AC. Motivations and barriers to exercise in chronic kidney disease: a qualitative study. Nephrol Dial Transplant 2015; 30:1885-92. [DOI: 10.1093/ndt/gfv208] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/15/2015] [Indexed: 02/02/2023] Open
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Dungey M, Hull KL, Smith AC, Burton JO, Bishop NC. Inflammatory factors and exercise in chronic kidney disease. Int J Endocrinol 2013; 2013:569831. [PMID: 23737775 PMCID: PMC3666228 DOI: 10.1155/2013/569831] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 04/19/2013] [Accepted: 04/19/2013] [Indexed: 01/03/2023] Open
Abstract
Patients with chronic kidney disease frequently present with chronic elevations in markers of inflammation, a condition that appears to be exacerbated by disease progression and onset of haemodialysis. Systemic inflammation is interlinked with malnutrition and muscle protein wasting and is implicated in a number of morbidities including cardiovascular disease: the most common cause of mortality in this population. Research in the general population and other chronic disease cohorts suggests that an increase in habitual activity levels over a prolonged period may help redress basal increases in systemic inflammation. Furthermore, those populations with the highest baseline levels of systemic inflammation appear to have the greatest improvements from training. On the whole, the activity levels of the chronic kidney disease population reflect a sedentary lifestyle, indicating the potential for increasing physical activity and observing health benefits. This review explores the current literature investigating exercise and inflammatory factors in the chronic kidney disease population and then attempts to explain the contradictory findings and suggests where future research is required.
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Affiliation(s)
- Maurice Dungey
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK
- Leicester Kidney Exercise Team, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - Katherine L. Hull
- Leicester Kidney Exercise Team, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
- Department of Infection, Immunity and Inflammation, Maurice Shock Medical Sciences Building, University Road, Leicester LE1 9HN, UK
| | - Alice C. Smith
- Leicester Kidney Exercise Team, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
- Department of Infection, Immunity and Inflammation, Maurice Shock Medical Sciences Building, University Road, Leicester LE1 9HN, UK
| | - James O. Burton
- Leicester Kidney Exercise Team, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
- Department of Infection, Immunity and Inflammation, Maurice Shock Medical Sciences Building, University Road, Leicester LE1 9HN, UK
| | - Nicolette C. Bishop
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK
- Leicester Kidney Exercise Team, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
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Hull KL, Carmichael I, Noll BC, Henderson KW. Homo- and Heterodimetallic Geminal Dianions Derived from the Bis(phosphinimine) {Ph2P(NSiMe3)}2CH2 and the Alkali Metals Li, Na, and K. Chemistry 2008; 14:3939-53. [DOI: 10.1002/chem.200701976] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hull KL, Cockrem JF, Bridges JP, Candy EJ, Davidson CM. Effects of corticosterone treatment on growth, development, and the corticosterone response to handling in young Japanese quail (Coturnix coturnix japonica). Comp Biochem Physiol A Mol Integr Physiol 2007; 148:531-43. [PMID: 17681843 DOI: 10.1016/j.cbpa.2007.06.423] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2007] [Revised: 06/28/2007] [Accepted: 06/30/2007] [Indexed: 10/23/2022]
Abstract
Corticosterone, a glucocorticoid secreted during stress responses, has a range of actions that help birds respond to stressors. Although effects of corticosterone treatment have been described in several avian species, the impacts of defined increases in plasma corticosterone on early development and on corticosterone stress responses are little known. These issues were addressed by providing quail with different doses of corticosterone in drinking water from days 8 to 38 post-hatch. The corticosterone dose consumed by each bird during treatment days 15-30 was calculated by measuring water intake. The corticosterone dose was inversely, but weakly, correlated with weights of the bursa, thymus, spleen, liver, testes, oviduct, muscle, and body, and positively correlated with peritoneal fat deposition. When birds were divided into groups based on their corticosterone intake, weights of the spleen, thymus, bursa, muscle, testes, and oviduct were significantly reduced in birds receiving the highest doses; with the exception of muscle, similar reductions were also observed in birds receiving medium doses, and thymic growth was inhibited in birds receiving low doses. The acute corticosterone stress response was measured by handling birds for 15 min. Plasma corticosterone was transiently increased at 15 min in control birds in response to the handling stressor. Some birds consuming low doses of corticosterone had corticosterone responses similar to control birds. Initial corticosterone concentrations were elevated in birds consuming higher doses of corticosterone. Plasma corticosterone in these birds decreased from 0 to 15 min, then increased from 15 to 30 min. The initial decrease could be due to corticosterone clearance, whilst the increase could indicate that the birds had a greater response than control birds to isolation as a stressor. Corticosterone treatment may have reduced the strength of corticosterone negative feedback within the hypothalamo-pituitary-adrenal axis. The results indicate that individuals and organs differ in their sensitivity to corticosterone. Moreover, elevated plasma corticosterone may disrupt the acute corticosterone stress response, and may thus reduce the ability of birds to cope with stressors.
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Affiliation(s)
- K L Hull
- Department of Biology, Bishop's University, Sherbrooke, Quebec, Canada.
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Hull KL, Noll BC, Henderson KW. Structural Characterization and Dynamic Solution Behavior of the Disodio and Lithio−Sodio Geminal Organodimetallics [{{Ph2P(Me3Si)N}2CNa2}2] and [{{Ph2P(Me3Si)N}2CLiNa}2]. Organometallics 2006. [DOI: 10.1021/om0605635] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine L. Hull
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| | - Bruce C. Noll
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| | - Kenneth W. Henderson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
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Harvey S, Baudet ML, Murphy A, Luna M, Hull KL, Aramburo C. Testicular growth hormone (GH): GH expression in spermatogonia and primary spermatocytes. Gen Comp Endocrinol 2004; 139:158-67. [PMID: 15504394 DOI: 10.1016/j.ygcen.2004.08.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Revised: 07/30/2004] [Accepted: 08/25/2004] [Indexed: 11/22/2022]
Abstract
Growth hormone (GH) gene expression is not restricted to pituitary somatotrophs and has recently been demonstrated in a variety of extrapituitary sites in mammals and the domestic chicken. The possibility that GH gene expression occurs in the male reproductive system of chickens was therefore examined, since GH has established roles in male reproductive function and GH immunoreactivity is present in the chicken testis. Using RT-PCR and oligonucleotide primers for pituitary GH cDNA, GH mRNA was shown to be present in the testes and vas deferens of adult cockerels. Although testicular GH mRNA was of low abundance (not detectable by Northern blotting), a 690 bp fragment of the amplified testicular GH cDNA was cloned and had a nucleotide sequence 99.6% homologous with pituitary GH cDNA. GH mRNA was localized by in situ hybridization in spermatogonia and primary spermatocytes of the seminiferous tubules, but unlike testicular GH-immunoreactivity, GH mRNA was not present in secondary spermatocytes, spermatids or spermatozoa. The presence of Pit-1 mRNA in the male reproductive tract may indicate Pit-1 involvement in GH expression in these tissues. The presence of GH receptor mRNA in the testis and vas deferens also suggests they are target sites for GH action. These results demonstrate, for the first time, expression of the pituitary GH gene in the testis, in which GH mRNA was discretely localized in primary spermatocytes. The local expression of the GH gene in these cells suggests autocrine or paracrine actions of GH during spermatogenesis.
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Affiliation(s)
- S Harvey
- Department of Physiology, University of Alberta, Edmonton, Alta., Canada T6G 2H7.
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Abstract
The actions of growth hormone (GH) are not restricted to growth: GH modulates metabolic pathways as well as neural, reproductive, immune, cardiovascular, and pulmonary physiology. The importance of GH in most physiological systems suggests that GH deficiency at any age would be associated with significant morbidity. However, prior to the advent of recombinant GH, cadaver-derived GH was only used therapeutically to correct the height deficit, and thereby hypothetically improve quality of life (QoL), in GH-deficient children. Physicians now have access to unlimited, albeit expensive, supplies of recombinant GH, and are considering the advisability of GH replacement or supplementation in other patient populations. This paper analyses studies investigating the relationship between GH and QoL in GH-deficient children or adults, in GH-replete short children suffering from idiopathic short stature, Turner syndrome, or intrauterine growth retardation and in GH-deficient or replete elderly adults. Possible mechanisms by which GH might improve QoL at neural and somatic sites are also proposed.
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Affiliation(s)
- K L Hull
- Department of Biology, Bishop's University, Lennoxville, Canada, J1M 1Z7.
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Abstract
It is now well established that exogenous GH promotes sexual maturation and reproductive function. The possibility that this may reflect physiological actions of endogenous GH has, however, rarely been considered. Correlative changes in GH secretion and reproductive state (puberty, pregnancy, lactation, menopause and ovarian cycles) are thus the primary focus of this review. GH secretion is, for instance, elevated during major transitions in reproductive status such as puberty and pregnancy. In some cases, augmented circulating GH levels are paired with hepatic GH resistance. This interaction may permit selective activation of gonadal responses to GH without activating IGF-I-mediated systemic responses. This selective activation may also be mediated by autocrine, paracrine or intracrine GH actions, since GH is also synthesized in reproductive tissues. Correlative changes in GH secretion and reproductive state may be mediated by events at the hypothalamic, pituitary and gonadal level. In addition to direct effects on gonadal function, GH may influence reproductive activity by increasing gonadotropin secretion at the hypothalamic and pituitary level and by enhancing gonadotropin responsiveness at the gonadal level. The close association between reproductive status and the somatotrophic axis supports the physiological importance of GH in reproductive function.
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Affiliation(s)
- K L Hull
- Bishop's University, Lennoxville, Quebec J1M 1Z7, Canada
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35
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Abstract
GH, as its name suggests, is obligatory for growth and development. It is, however, also involved in the processes of sexual differentiation and pubertal maturation and it participates in gonadal steroidogenesis, gametogenesis and ovulation. It also has additional roles in pregnancy and lactation. These actions may reflect direct endocrine actions of pituitary GH or be mediated by its induction of hepatic or local IGF-I production. However, as GH is also produced in gonadal, placental and mammary tissues, it may act in paracrine or autocrine ways to regulate local processes that are strategically regulated by pituitary GH. The concept that GH is an important modulator of female reproduction is the focus of this review.
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Affiliation(s)
- K L Hull
- Bishop's University, Lennoxville, Quebec J1M 1Z7, Canada
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Abstract
Growth hormone (GH) is primarily produced in pituitary somatotrophs. The synthesis of this hormone is thought to be dependent upon a pituitary-specific transcription factor (Pit-1). However, many extrapituitary tissues are now known to express GH genes. The extrapituitary production of GH may therefore indicate an extrapituitary distribution of the Pit-1 gene. The extrapituitary production of GH may, alternatively, indicate that GH expression occurs independently of Pit-1 in extrapituitary tissues. These possibilities are considered in this brief review.Key words: growth hormone, pituitary, pituitary transcription factor 1.
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Harvey S, Azumaya Y, Hull KL. Pituitary and extrapituitary growth hormone: Pit-1 dependence? Can J Physiol Pharmacol 2000; 78:1013-28. [PMID: 11149379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Growth hormone (GH) is primarily produced in pituitary somatotrophs. The synthesis of this hormone is thought to be dependent upon a pituitary-specific transcription factor (Pit-1). However, many extrapituitary tissues are now known to express GH genes. The extrapituitary production of GH may therefore indicate an extrapituitary distribution of the Pit-1 gene. The extrapituitary production of GH may, alternatively, indicate that GH expression occurs independently of Pit-1 in extrapituitary tissues. These possibilities are considered in this brief review.
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Affiliation(s)
- S Harvey
- Department of Physiology, University of Alberta, Edmonton, Canada.
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Abstract
Growth hormone (GH) is primarily synthesized, stored, and released by pituitary somatotrophs. These cells comprise a highly labile population that continuously undergoes proliferation, differentiation, and morphogenesis in response to changing physiological stimuli. They are also functionally and morphologically heterogeneous with distinct spatial and temporal distribution within the pituitary gland. The characteristics of these cells are discussed in this brief review.Key words: somatotroph, aves, growth hormone, adenohypophysis.
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Abstract
Growth hormone (GH), as its name suggests, is obligatory for growth and development. It is, however, also required for sexual differentiation and pubertal maturation and participates in gonadal steroidogenesis and gametogenesis. These roles are likely to reflect the endocrine actions of pituitary GH, directly at gonadal sites and indirectly via hepatic insulin-like growth factor-1. However, because GH is also produced in gonadal tissues, it may act in paracrine or autocrine ways to regulate local processes that are strategically regulated by pituitary GH. The concept that GH is a major regulator of male reproduction is the focus of this review.
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Affiliation(s)
- K L Hull
- Bishop's University, Lennoxville, Quebec, Canada
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Hull KL, Murphy A, Harvey S. Avian somatotrophs: differentiation, morphology, distribution, and regulation. Can J Physiol Pharmacol 2000; 78:994-1002. [PMID: 11149388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Growth hormone (GH) is primarily synthesized, stored, and released by pituitary somatotrophs. These cells comprise a highly labile population that continuously undergoes proliferation, differentiation, and morphogenesis in response to changing physiological stimuli. They are also functionally and morphologically heterogeneous with distinct spatial and temporal distribution within the pituitary gland. The characteristics of these cells are discussed in this brief review.
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Affiliation(s)
- K L Hull
- Department of Biology, Bishops University, Lennoxville, QC, Canada.
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Hull KL, Harvey S. GH secretion in TRH-refractory and TRH-responsive chickens is independent of somatotroph abundance and morphometry. Gen Comp Endocrinol 2000; 120:137-45. [PMID: 11078625 DOI: 10.1006/gcen.2000.7531] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chicken pituitary glands chronically exposed (for 2-4 h) to growth hormone (GH) secretagogues in vitro have increased GH secretion and increased numbers of GH-secreting cells. In contrast, thyrotropin-releasing hormone (TRH)-induced GH release in chickens in vivo is only transitory and cannot be maintained by constant infusion or repeated serial iv administration. The possibility that this reflects changes in somatotroph abundance, morphology, and GH content was therefore examined in chickens responsive or refractory to TRH in vivo. TRH-induced GH release was immediately (within 10-30 min) followed by a reduction in the size and number of immunoreactive pituitary somatotrophs and in the size of somatotroph clusters, resulting in a reduction in somatotroph area. The number and area of the immunoreactive GH-secreting cells was further reduced 60 min after the bolus administration of TRH, although control values were restored after 120 min. The decline in immunoreactive somatotroph number and size was attenuated by serial TRH injections, but this did not restore plasma GH responsiveness in TRH-refractory birds. These results demonstrate that somatotroph responses to GH secretagogues in vivo differ from those in vitro.
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Affiliation(s)
- K L Hull
- Department of Biology, Bishop's University, Lennoxville, Quebec, J1M 1Z7, Canada
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Abstract
Growth hormone (GH) is not classically considered as a reproductive hormone, although a vast literature indicates that it has roles in reproductive function. It is required for sexual differentiation and pubertal maturation and it participates in gonadal steroidogenesis, gametogenesis and ovulation. GH is also required for fetal nutrition and growth during pregnancy and for mammary development and lactation. Although some of these roles reflect the action of GH on the secretion and action of LH and FSH (Chandrashekar and Bartke, 1998), they also reflect direct actions of GH and indirect actions mediated through the local production of insulin-like growth factor I. Moreover, as GH is produced in gonadal and mammary tissues, these actions may reflect local autocrine or paracrine actions of extrapituitary GH, as well as the endocrine actions of pituitary GH. The roles of GH in reproductive function are considered in this review.
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Affiliation(s)
- K L Hull
- Department of Biology, Bishop's University, Lennoxville, Quebec, J1M 1Z7, Canada
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Abstract
GH exerts pleiotropic effects on growth and metabolism through the GH receptor. A deficiency in the GH receptor gene is thus associated with GH resistance and dwarfism. Complete GH resistance in humans, or Laron syndrome, has been associated with numerous inherited defects in the GH receptor, including point mutations, complete or partial gene deletions, and splice site alterations. Analysis of the GH receptor genes of these patients has provided considerable insight into structure-function relationships of the GH receptor. However, the relative rarity of this disease and the obvious difficulties involved in human research have prompted a search for an animal model of GH resistance. Numerous models have been proposed, including the sex-linked dwarf chicken, the guinea pig, and the Laron mouse. In this review, the characteristics and etiology of Laron syndrome and these animal models will be discussed. The insight provided by these disorders into the roles and mechanism of action of GH will also be reviewed.
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Affiliation(s)
- K L Hull
- Bishop's University, Lennoxville, Québec, Canada J1M 1Z7
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Abstract
Sex-linked dwarfism (SLD) in chickens is characterized by impaired growth despite normal or supranormal plasma growth hormone (GH) levels. This resistance to GH action is thought to be due to mutations of the GH receptor (GHR) gene that reduce or prevent GH binding to target sites. The genetic lesion causing GH resistance in Cornell SLD chickens is, however, not known. Previous studies have shown that hepatic GH-binding activity is abnormally low in these birds, yet the GHR gene is transcribed into a transcript of appropriate size and abundance. Point mutations or defects in translation could therefore account for the impaired GHR activity in this strain. These possibilities were addressed in the present study. A missense mutation resulting in the substitution of serine for the conserved phenylalanine was identified in the region of the GHR cDNA encoding the extracellular domain. Translation of this mutant transcript was indicated by the presence of GHR/GH-binding protein (GHBP)-immunoreactive proteins in liver (55, 70 and 100 kDa) and serum (70 kDa) of normal (K) and SLD birds. Radiolabelled GH did not, however, bind to the hepatic membranes of most SLD chickens. Serum GH-binding activity, in contrast, was readily detectable, although at significantly lower levels than in normal birds. The missense mutation in the SLD GHR gene may thus affect targeting of GHRs to hepatic plasma membranes.
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Affiliation(s)
- K L Hull
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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Harvey S, Johnson CD, Sharma P, Sanders EJ, Hull KL. Growth hormone: a paracrine growth factor in embryonic development? Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 1998; 119:305-15. [PMID: 9827003 DOI: 10.1016/s0742-8413(98)00019-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Although pituitary growth hormone is obligatory for normal postnatal growth and development, early embryonic and fetal growth is generally considered to be independent of pituitary GH. Indeed, in chickens, somatotrophs and serum GH are not detectable until late in embryogenesis, and neither partial decapitation nor pre-hatch GH administration greatly affects embryonic growth. However, since it is now known that GH can be produced and act in many extra-pituitary tissues, early embryonic growth may be independent of pituitary GH but dependent upon the paracrine actions of extra-pituitary GH. The possibility that growth hormone may be a paracrine growth factor during early development will therefore be considered in this brief review, which is based on the embryogenesis of the domestic fowl.
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Affiliation(s)
- S Harvey
- Department of Physiology, University of Alberta, Edmonton, Canada
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Abstract
In mammals and higher vertebrates, calcitropic peptides are produced by peripheral endocrine glands: the parathyroid gland (PTH), thyroid or ultimobranchial gland (calcitonin) and the anterior pituitary gland (growth hormone and prolactin). These hormones are, however, also found in the neural tissues of lower vertebrates and invertebrates that lack these endocrine organs, suggesting that neural tissue may be an ancestral site of calcitropic peptide synthesis. Indeed, the demonstration of CNS receptors for these calcitropic peptides and their induction of neurological actions suggest that these hormones arose as neuropeptides. Neural and neuroendocrine roles of some of these calcitropic hormones (calcitonin and parathyroid hormone) and related peptides (calcitonin gene related peptide, stanniocalcin and parathyroid hormone related peptide) are thus the focus of this review.
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Affiliation(s)
- K L Hull
- Department of Physiology, University of Alberta, Edmonton, Canada
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Abstract
Growth hormone (GH) differs from other pituitary hormones in that it can affect a wide spectrum of cellular activities in many different tissues. These disparate actions are, however, mediated by a common receptor, suggesting tissue-specific differences in the post-receptor mechanisms and/or tissue sensitivities to GH stimulation may confer specificity. Tissue sensitivity depends upon the abundance of GH receptors (GHRs) and may be modulated by the amplitude and pulsatility of GH secretion. It may also be dependent upon the presence of non-signal transducing GH-binding proteins (GHBPs), which result from the alternate splicing of GHR gene transcripts. Tissue-specific autoregulation of GHRs and GHBPs could, therefore, contribute to differential tissue responsiveness to GH action. The autoregulation of GHR and GHBP gene transcription in novel central (hypothalamus, brainstem, and cortex/neocortex) and peripheral (spleen) tissues was therefore examined in adult, male Sprague-Dawley rats. For comparative purposes, GHR/GHBP gene expression was also examined in the liver, which has traditionally been considered the major GH-target site. Chronic hyposomatotropism, induced by hypophysectomy, exerted tissue-specific effects on the abundance of GHR gene products 10 days post-hypophysectomy. Both GHR and GHBP transcripts were reduced in the hypothalamus of hypophysectomized rats by 20% (P < 0.001), although neither transcript was affected in the liver, spleen, cortex/neocortex or brainstem. In contrast, 2 h after a single bolus GH injection that was designed to simulate a pulsatile increase in circulating GH concentrations, GHR and GHBP mRNA content was significantly increased by 25-30% (P < 0.001) in all brain regions and in the spleen of hypophysectomized or sham-hypophysectomized rats. Production of the two transcripts was differentially regulated, however, as GHBP, but not GHR, transcripts were increased in the liver (P < 0.001), whereas the GHR:GHBP ratio was decreased in the hypothalamus of GH-treated rats (P < 0.001). These results suggest that GHR gene transcription and splicing are acutely autoregulated in a tissue-specific way.
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Affiliation(s)
- K L Hull
- Department of Physiology, University of Alberta, Edmonton, Canada
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Abstract
Growth hormone (GH) regulates numerous cellular functions in many different tissues. A common receptor is believed to mediate these tissue-specific effects, suggesting that post-receptor signalling molecules or tissue sensitivity to GH may differ between tissues. Tissue sensitivity depends upon the abundance of GH receptors (GHRs), thus tissue-specific GHR regulation could enable tissue-specific GH actions. The comparative autoregulation of GHR gene transcription in central (whole brain or hypothalami) and peripheral (liver, bursa, spleen and thymus) tissues was therefore examined in domestic fowl. In all tissues, a 4.4 kb GHR gene transcript that encodes the full-length GHR was identified. The abundance of this transcript was inversely related to endogenous GH status; it was lower in males with high circulating concentrations of GH and higher in females with lower basal concentrations of plasma GH. The abundance of this transcript was also rapidly downregulated in response to a bolus systemic injection of recombinant chicken GH, designed to mimic an episodic burst of endogenous GH release. This autoregulatory response was observed within 2 h of GH administration and was of greater magnitude in the brain than in peripheral tissues. Intracerebroventricular injections of GH also downregulated GHR gene expression in the brain, although hepatic GHR transcripts were unaffected 24 h after central administration of GH. In contrast, the induction of hyposomatotropism by passive GH immunoneutralization increased the abundance of the GHR transcript in the thymus, but not in other central (brain) or peripheral (bursa, liver) tissues. GH is not the sole regulator of GHR abundance, however; hypersomatropism induced by hypothyroidism was associated with an increase in GHR mRNA. The expression of the GHR gene in the domestic fowl would thus appear to be autoregulated by GH in a tissue-specific way.
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Affiliation(s)
- K L Hull
- Department of Physiology, University of Alberta, Edmonton, Canada
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49
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Abstract
A number of tissues, including the brain, pituitary, immune system, placenta, mammary gland, and testis, may be self-contained units of GH regulation, production, and action. The production of GH and GH-releasing factors outside the hypothalamo-pituitary axis complements, rather than replaces, the traditional endocrine interactions between GH-releasing factors, GH, and its target tissues.
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Affiliation(s)
- S Harvey
- Department of Physiology, University of Alberta, Edmonton, Canada.
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50
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Abstract
It is well established that the activity and proliferation of lymphoid cells and lymphoid organs are stimulated by growth hormone. These actions on lymphoid cells may be direct or mediated by actions on the epithelial and non-immune tissue cells that regulate immune function. The occurrence and cellular localization of growth hormone receptors in immune tissues has therefore been investigated to determine the target-sites of growth hormone action. Growth hormone receptor mRNA was first detected by Northern blotting in the spleen, bursa of Fabricius, and thymus of domestic fowl. In addition to the 4.4-kb transcript thought to encode the full-length growth hormone receptor, smaller transcripts of 2.8 kb and 1.0 kb, which may encode growth hormone-binding proteins, were also occasionally observed. Further analysis using the polymerase chain reaction revealed that mRNA sequences encoding the extracellular and intracellular domains of the growth hormone receptor were present in all tissues and highly homologous with hepatic transcripts. Translation of these transcripts also occurs in immune tissues, since immunoreactive growth hormone-binding proteins or growth hormone receptors of approximately 56 kDa were detected in hepatic, splenic, thymic, and bursal extracts. Immunocytochemistry of these tissues subsequently revealed that macrophages probably contain the bulk of this immunoreactivity, although some thymic medullary epithelial cells (including Hassall's corpuscles) and splenic ellipsoids and interdigitating cells were also immunoreactive. This immunoreactivity is present in immune tissues of newly hatched and adult chickens. Importantly, B-lymphocytes were rarely, if ever, immunoreactive, and T-lymphocytes containing growth hormone receptors or binding proteins were not observed. These results suggest that a number of primary (thymus and bursa) and secondary (spleen) lymphoid tissues in the chicken contain growth hormone receptors and are thus target-sites for growth hormone action. The distribution of growth hormone receptor/growth hormone-binding protein immunoreactivity in these tissues would further suggest that growth hormone plays a major role in macrophage proliferation and/or activity and may indirectly affect lymphocyte maturation and storage via effects on thymic and splenic stromal cells.
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Affiliation(s)
- K L Hull
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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