66 results on '"Rehal S"'
Search Results
2. Handling intercurrent events and missing data in non-inferiority trials using the estimand framework: a tuberculosis case study
- Author
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Rehal, S, Cro, S, Phillips, P, Fielding, K, and Carpenter, J
- Abstract
Introduction The ICH E9 addendum outlining the estimand framework for clinical trials was published in 2019 but provides limited guidance around how to handle intercurrent events for non-inferiority studies. Once an estimand is defined, it is also unclear how to deal with missing values using principled analyses for non-inferiority studies. Methods Using a tuberculosis clinical trial as a case study, we propose a primary estimand, and an additional estimand suitable for non-inferiority studies. For estimation, multiple imputation methods that align with the estimands for both primary and sensitivity analysis are proposed. We demonstrate estimation methods using the twofold fully conditional specification multiple imputation algorithm and then extend and use reference-based multiple imputation for a binary outcome to target the relevant estimands, proposing sensitivity analyses under each. We compare the results from using these multiple imputation methods with those from the original study. Results Consistent with the ICH E9 addendum, estimands can be constructed for a non-inferiority trial which improves on the per-protocol/intention-to-treat-type analysis population previously advocated, involving respectively a hypothetical or treatment policy strategy to handle relevant intercurrent events. Results from using the ‘twofold’ multiple imputation approach to estimate the primary hypothetical estimand, and using reference-based methods for an additional treatment policy estimand, including sensitivity analyses to handle the missing data, were consistent with the original study’s reported per-protocol and intention-to-treat analysis in failing to demonstrate non-inferiority. Conclusions Using carefully constructed estimands and appropriate primary and sensitivity estimators, using all the information available, results in a more principled and statistically rigorous approach to analysis. Doing so provides an accurate interpretation of the estimand.
- Published
- 2023
3. Evaluating the clarity of the questions being addressed in randomised trials: a systematic review of estimands
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Cro, S, Kahan, BC, Rehal, S, Chis Ster, A, Carpenter, JR, White, IR, Cornelius, VR, and National Institute for Health Research
- Subjects
General & Internal Medicine ,1103 Clinical Sciences ,1117 Public Health and Health Services - Abstract
Objective: To evaluate how often the precise question being addressed about an intervention (the estimand) is stated or can be worked out from reported methods, and to identify what types of questions are addressed in phase II-IV randomised trials. Design: A systematic review of the clarity of research questions addressed in randomised trials in 2020 in six leading general medical journals. Eligibility criteria: Phase II-IV randomised trials, with no restrictions on medical conditions or interventions. Cluster randomised, cross-over, non-inferiority, and equivalence trials were excluded. Data source: A search of PubMed was performed in February 2021. Main outcome measures: The number of trials which stated the precise primary question being addressed about an intervention (the primary estimand) or for which this could be unambiguously worked out from the reported methods using statistical knowledge. The strategies being used to handle post-randomisation events that affect the interpretation or existence of patient outcomes, such as intervention discontinuations or uses of additional medications (termed intercurrent events), and the corresponding types of questions being addressed. Results: A total of 255 eligible randomised trials were identified. No trials clearly stated all the attributes of the estimand. In 117/255 (46%) trials the primary question addressed could be worked out from the reported methods. Intercurrent events occurred in 95% of trials; but the handling of these could only be determined in 125/255 (49%) trials. Most trials which provided this information considered the occurrence of intercurrent events as irrelevant in the calculation of the treatment effect and addressed the effect of the intervention regardless (96/125, 76%) i.e. as if introduced into routine practice (treatment policy strategy). 4/99 (4%) trials with treatment non-adherence due to adverse events estimated the treatment effect in a hypothetical setting (the effect as if participants continued treatment despite adverse events) and 19/24 (79%) trials where some patients died estimated the treatment effect in a hypothetical setting (the effect as if participants did not die). Conclusions: It is unclear in most trials what precise research question is being addressed. The main driver for this is lack of clarity on the approach to handling intercurrent events. Clear reporting of estimands is necessary in trial reports so all stakeholders, including clinicians, patients and policy makers, can make fully informed decisions about medical interventions.
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- 2022
4. THE DIRECT AMPK-β1 SELECTIVE ACTIVATOR PF-06409577 TARGETS MACROPHAGES TO REDUCE ATHEROSCLEROSIS IN MICE
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Day, E., Townsend, L., Rehal, S., Batchuluun, B., Wang, D., Morrow, M., Lu, R., Lundenberg, L., Lu, J., Desjardins, E., Raphenya, A., McArthur, A., Fullerton, M., and Steinberg, G.
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- 2023
- Full Text
- View/download PDF
5. High-dose rifampicin, Moxifloxacin, and SQ109 for Treating Tuberculosis: A Multi-arm, Multi-stage Randomised Controlled Trial
- Author
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Boeree, M.J., Heinrich, N., Aarnoutse, R.E., Diacon, A.H., Dawson, R., Rehal, S., Kibiki, G.S., Churchyard, G., Sanne, I., Ntinginya, N.E., Minja, L.T., Hunt, R.D., Charalambous, S., Hanekom, M., Semvua, H.H., Mpagama, S.G., Manyama, C., Mtafya, B., Reither, K., Wallis, R.S., Venter, A., Narunsky, K., Mekota, A., Henne, S., Colbers, A., Balen, G.P. van, Gillespie, S.H., Phillips, P.P., and Hoelscher, M.
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Adult ,Male ,Moxifloxacin ,Antitubercular Agents ,Adamantane ,Ethylenediamines ,bacterial infections and mycoses ,Pyrazinamide ,Tanzania ,Drug Administration Schedule ,Treatment ,South Africa ,lnfectious Diseases and Global Health Radboud Institute for Health Sciences [Radboudumc 4] ,Infectious Diseases ,Isoniazid ,Humans ,Drug Therapy, Combination ,Female ,Rifampin ,Tuberculosis, Pulmonary ,Ethambutol ,Fluoroquinolones - Abstract
Contains fulltext : 169689.pdf (Publisher’s version ) (Open Access) BACKGROUND: Tuberculosis is the world's leading infectious disease killer. We aimed to identify shorter, safer drug regimens for the treatment of tuberculosis. METHODS: We did a randomised controlled, open-label trial with a multi-arm, multi-stage design. The trial was done in seven sites in South Africa and Tanzania, including hospitals, health centres, and clinical trial centres. Patients with newly diagnosed, rifampicin-sensitive, previously untreated pulmonary tuberculosis were randomly assigned in a 1:1:1:1:2 ratio to receive (all orally) either 35 mg/kg rifampicin per day with 15-20 mg/kg ethambutol, 20 mg/kg rifampicin per day with 400 mg moxifloxacin, 20 mg/kg rifampicin per day with 300 mg SQ109, 10 mg/kg rifampicin per day with 300 mg SQ109, or a daily standard control regimen (10 mg/kg rifampicin, 5 mg/kg isoniazid, 25 mg/kg pyrazinamide, and 15-20 mg/kg ethambutol). Experimental treatments were given with oral 5 mg/kg isoniazid and 25 mg/kg pyrazinamide per day for 12 weeks, followed by 14 weeks of 5 mg/kg isoniazid and 10 mg/kg rifampicin per day. Because of the orange discoloration of body fluids with higher doses of rifampicin it was not possible to mask patients and clinicians to treatment allocation. The primary endpoint was time to culture conversion in liquid media within 12 weeks. Patients without evidence of rifampicin resistance on phenotypic test who took at least one dose of study treatment and had one positive culture on liquid or solid media before or within the first 2 weeks of treatment were included in the primary analysis (modified intention to treat). Time-to-event data were analysed using a Cox proportional-hazards regression model and adjusted for minimisation variables. The proportional hazard assumption was tested using Schoelfeld residuals, with threshold p
- Published
- 2017
6. Reducing bias in open-label trials where blinded outcome assessment is not feasible: strategies from two randomised trials
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Kahan, BC, Cro, S, Dore, CJ, Bratton, DJ, Rehal, S, Maskell, NA, Rahman, N, and Jairath, V
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Time Factors ,OBSERVER BIAS ,IMPACT ,Endpoint Determination ,Medicine (miscellaneous) ,Research & Experimental Medicine ,1102 Cardiovascular Medicine And Haematology ,TRANSFUSION ,Bias ,Recurrence ,General & Internal Medicine ,Humans ,Pharmacology (medical) ,Open-label ,Subjective outcome ,Referral and Consultation ,Pleurodesis ,Randomised controlled trial ,Science & Technology ,Unmasked ,Research ,EMPIRICAL-EVIDENCE ,1103 Clinical Sciences ,MULTIPLE-SCLEROSIS ,Unblinded outcome assessment ,Pleural Effusion, Malignant ,ASSESSORS ,Treatment Outcome ,Medicine, Research & Experimental ,Cardiovascular System & Hematology ,Research Design ,Drainage ,Erythrocyte Transfusion ,Gastrointestinal Hemorrhage ,Life Sciences & Biomedicine ,CLINICAL-TRIALS ,FEASIBILITY TRIAL - Abstract
Background Blinded outcome assessment is recommended in open-label trials to reduce bias, however it is not always feasible. It is therefore important to find other means of reducing bias in these scenarios. Methods We describe two randomised trials where blinded outcome assessment was not possible, and discuss the strategies used to reduce the possibility of bias. Results TRIGGER was an open-label cluster randomised trial whose primary outcome was further bleeding. Because of the cluster randomisation, all researchers in a hospital were aware of treatment allocation and so could not perform a blinded assessment. A blinded adjudication committee was also not feasible as it was impossible to compile relevant information to send to the committee in a blinded manner. Therefore, the definition of further bleeding was modified to exclude subjective aspects (such as whether symptoms like vomiting blood were severe enough to indicate the outcome had been met), leaving only objective aspects (the presence versus absence of active bleeding in the upper gastrointestinal tract confirmed by an internal examination). TAPPS was an open-label trial whose primary outcome was whether the patient was referred for a pleural drainage procedure. Allowing a blinded assessor to decide whether to refer the patient for a procedure was not feasible as many clinicians may be reluctant to enrol patients into the trial if they cannot be involved in their care during follow-up. Assessment by an adjudication committee was not possible, as the outcome either occurred or did not. Therefore, the decision pathway for procedure referral was modified. If a chest x-ray indicated that more than a third of the pleural space filled with fluid, the patient could be referred for a procedure; otherwise, the unblinded clinician was required to reach a consensus on referral with a blinded assessor. This process allowed the unblinded clinician to be involved in the patient’s care, while reducing the potential for bias. Conclusions When blinded outcome assessment is not possible, it may be useful to modify the outcome definition or method of assessment to reduce the risk of bias. Trial registration TRIGGER: ISRCTN85757829. Registered 26 July 2012. TAPPS: ISRCTN47845793. Registered 28 May 2012.
- Published
- 2014
7. S115 Hot-hmv uk trial secondary outcome analysis: early readmission is reduced by the addition of home mechanical ventilation to home oxygen therapy in copd patients with chronic respiratory failure following a life-threatening exacerbation
- Author
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Murphy, PB, primary, Arbane, G, additional, Bourke, S, additional, Calverley, P, additional, Crooks, A, additional, Dowson, L, additional, Duffy, N, additional, Gibson, GJ, additional, Hughes, P, additional, Hurst, JR, additional, Lewis, K, additional, Mukherjee, R, additional, Nickol, A, additional, Oscroft, N, additional, Pepperell, J, additional, Rehal, S, additional, Smith, I, additional, Stradling, J, additional, Wedizcha, W, additional, Polkey, MI, additional, Elliott, M, additional, and Hart, N, additional
- Published
- 2016
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8. A dose-ranging trial to optimize the dose of rifampin in the treatment of tuberculosis
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Boeree, M.J., Diacon, A.H., Dawson, R., Narunsky, K., Bois, J. du, Venter, A., Phillips, P.P., Gillespie, S.H., McHugh, T.D., Hoelscher, M., Heinrich, N., Rehal, S., Soolingen, D. van, Ingen, J. van, Magis-Escurra Ibanez, C., Burger, D.M., Plemper van Balen, G., Aarnoutse, R.E., Boeree, M.J., Diacon, A.H., Dawson, R., Narunsky, K., Bois, J. du, Venter, A., Phillips, P.P., Gillespie, S.H., McHugh, T.D., Hoelscher, M., Heinrich, N., Rehal, S., Soolingen, D. van, Ingen, J. van, Magis-Escurra Ibanez, C., Burger, D.M., Plemper van Balen, G., and Aarnoutse, R.E.
- Abstract
Item does not contain fulltext, RATIONALE: Rifampin at a dose of 10 mg/kg was introduced in 1971 based on pharmacokinetic, toxicity, and cost considerations. Available data in mice and humans showed that an increase in dose may shorten the duration of tuberculosis treatment. OBJECTIVES: To evaluate the safety and tolerability, the pharmacokinetics, and the extended early bactericidal activity of increasing doses of rifampin. METHODS: Patients with drug-susceptible tuberculosis were enrolled into a control group of eight patients receiving the standard dose of 10 mg/kg rifampin, followed by consecutive experimental groups with 15 patients each receiving rifampin 20, 25, 30, and 35 mg/kg, respectively, for 14 days. In all patients isoniazid, pyrazinamide, and ethambutol were added in standard doses for the second 7 days of treatment. Safety, pharmacokinetics of rifampin, and fall in bacterial load were assessed. MEASUREMENTS AND MAIN RESULTS: Grade 1 and 2 adverse events were equally distributed between the five dose groups; there were five grade 3 events of which one was a possibly related hepatotoxicity. Areas under the time-concentration curves and peak serum concentrations of rifampin showed a more than proportional increase with dose. The daily fall in bacterial load over 14 days was 0.176, 0.168, 0.167, 0.265, and 0.261 log10 colony-forming units/ml sputum in the 10, 20, 25, 30, and 35 mg/kg groups, respectively. CONCLUSIONS: Two weeks of rifampin up to 35 mg/kg was safe and well tolerated. There was a nonlinear increase in exposure to rifampin without an apparent ceiling effect and a greater estimated fall in bacterial load in the higher dosing groups. Clinical trial registered with www.clinicaltrials.gov (NCT 01392911).
- Published
- 2015
9. A Step toward an Optimized Rifampin Dose Completed.
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Boeree, M.J., Diacon, A.H., Dawson, R., Narunsky, K., Bois, J. du, Venter, A., Phillips, P.P., Gillespie, S.H., McHugh, T.D., Hoelscher, M., Heinrich, N., Rehal, S., Soolingen, D. van, Ingen, J. van, Magis-Escurra Ibanez, C., Burger, D.M., Plemper van Balen, G., Aarnoutse, R.E., Boeree, M.J., Diacon, A.H., Dawson, R., Narunsky, K., Bois, J. du, Venter, A., Phillips, P.P., Gillespie, S.H., McHugh, T.D., Hoelscher, M., Heinrich, N., Rehal, S., Soolingen, D. van, Ingen, J. van, Magis-Escurra Ibanez, C., Burger, D.M., Plemper van Balen, G., and Aarnoutse, R.E.
- Abstract
Item does not contain fulltext
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- 2015
10. Relationship between the location of primary head & neck malignancy and lymph node ratio (LNR) in a contemporary series of patients with suspected nodal metastasis
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Farook, S., primary, Rehal, S., additional, Puri, S., additional, Patel, C., additional, Ahmed, A., additional, Gilhooly, M., additional, and Visavadia, B., additional
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- 2015
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11. S20 Primary Result of the 1st Therapeutic Interventions in Malignant Effusion (TIME1) Trial: A 2 × 2 factorial, randomised trial of chest tube size and analgesic strategy for pleurodesis in malignant pleural effusion
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Rahman, NM, primary, Pepperell, J, additional, Rehal, S, additional, Saba, T, additional, Tang, A, additional, Ali, N, additional, West, A, additional, Hettiarachchi, G, additional, Mukherjee, D, additional, Samuel, J, additional, Bentley, A, additional, Dowson, L, additional, Miles, J, additional, Ryan, F, additional, Yoneda, K, additional, Chauhan, A, additional, Corcoran, J, additional, Psallidas, I, additional, Wrightson, JM, additional, Hallifax, R, additional, Davies, HE, additional, Lee, YCG, additional, Hedley, EL, additional, Seaton, D, additional, Russell, N, additional, Chapman, M, additional, McFadyen, BM, additional, Shaw, RA, additional, Davies, RJO, additional, Maskell, NA, additional, Nunn, AJ, additional, and Miller, RF, additional
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- 2015
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12. Risk of selection bias in randomised trials
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Kahan, BC, Rehal, S, and Cro, S
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Randomised controlled trial ,Selection bias ,MULTICENTER TRIALS ,OUTCOMES ,Science & Technology ,Patient Selection ,Medicine (miscellaneous) ,1103 Clinical Sciences ,Research & Experimental Medicine ,ALLOCATION ,Clinical trial ,Medicine, Research & Experimental ,Clinical Trials, Phase III as Topic ,Cardiovascular System & Hematology ,Sample Size ,General & Internal Medicine ,Humans ,Pharmacology (medical) ,Randomisation procedure ,MINIMIZATION ,Life Sciences & Biomedicine ,1102 Cardiorespiratory Medicine and Haematology ,Randomized Controlled Trials as Topic - Abstract
Background Selection bias occurs when recruiters selectively enrol patients into the trial based on what the next treatment allocation is likely to be. This can occur even if appropriate allocation concealment is used if recruiters can guess the next treatment assignment with some degree of accuracy. This typically occurs in unblinded trials when restricted randomisation is implemented to force the number of patients in each arm or within each centre to be the same. Several methods to reduce the risk of selection bias have been suggested; however, it is unclear how often these techniques are used in practice. Methods We performed a review of published trials which were not blinded to assess whether they utilised methods for reducing the risk of selection bias. We assessed the following techniques: (a) blinding of recruiters; (b) use of simple randomisation; (c) avoidance of stratification by site when restricted randomisation is used; (d) avoidance of permuted blocks if stratification by site is used; and (e) incorporation of prognostic covariates into the randomisation procedure when restricted randomisation is used. We included parallel group, individually randomised phase III trials published in four general medical journals (BMJ, Journal of the American Medical Association, The Lancet, and New England Journal of Medicine) in 2010. Results We identified 152 eligible trials. Most trials (98 %) provided no information on whether recruiters were blind to previous treatment allocations. Only 3 % of trials used simple randomisation; 63 % used some form of restricted randomisation, and 35 % did not state the method of randomisation. Overall, 44 % of trials were stratified by site of recruitment; 27 % were not, and 29 % did not report this information. Most trials that did stratify by site of recruitment used permuted blocks (58 %), and only 15 % reported using random block sizes. Many trials that used restricted randomisation also included prognostic covariates in the randomisation procedure (56 %). Conclusions The risk of selection bias could not be ascertained for most trials due to poor reporting. Many trials which did provide details on the randomisation procedure were at risk of selection bias due to a poorly chosen randomisation methods. Techniques to reduce the risk of selection bias should be more widely implemented.
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13. Applying the Estimand Framework to Non‐Inferiority Trials.
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Lynggaard H, Keene ON, Mütze T, and Rehal S
- Abstract
Most published applications of the estimand framework have focused on superiority trials. However, non-inferiority trials present specific challenges compared to superiority trials. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use notes in their addendum on estimands and sensitivity analysis in clinical trials that there may be special considerations to the implementation of estimands in clinical trials with a non-inferiority objective yet provides little guidance. This paper discusses considerations that trial teams should make when defining estimands for a clinical trial with a non-inferiority objective. We discuss how the pre-addendum way of establishing non-inferiority can be embraced by the estimand framework including a discussion of the role of the Per Protocol analysis set. We examine what clinical questions of interest can be formulated in the context of non-inferiority trials and outline why we do not think it is sensible to describe an estimand as 'conservative'. The impact of the estimand framework on key considerations in non-inferiority trials such as whether trials should have more than one primary estimand, the choice of non-inferiority margin, assay sensitivity, switching from non-inferiority to superiority and estimation are discussed. We conclude by providing a list of recommendations, and important considerations for defining estimands for trials with a non-inferiority objective., (© 2024 The Author(s). Pharmaceutical Statistics published by John Wiley & Sons Ltd.)
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- 2024
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14. Comments on "Emerging insights and commentaries - MMRM vs LOCF by Naitee Ting".
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Wright D, Bratton DJ, Drury T, Keene ON, Rehal S, and White IR
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- Humans, Data Interpretation, Statistical, Treatment Outcome, Tolnaftate, Models, Statistical
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- 2024
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15. Macrophage AMPK β1 activation by PF-06409577 reduces the inflammatory response, cholesterol synthesis, and atherosclerosis in mice.
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Day EA, Townsend LK, Rehal S, Batchuluun B, Wang D, Morrow MR, Lu R, Lundenberg L, Lu JH, Desjardins EM, Smith TKT, Raphenya AR, McArthur AG, Fullerton MD, and Steinberg GR
- Abstract
Atherosclerotic cardiovascular disease is characterized by both chronic low-grade inflammation and dyslipidemia. The AMP-activated protein kinase (AMPK) inhibits cholesterol synthesis and dampens inflammation but whether pharmacological activation reduces atherosclerosis is equivocal. In the current study, we found that the orally bioavailable and highly selective activator of AMPKβ1 complexes, PF-06409577, reduced atherosclerosis in two mouse models in a myeloid-derived AMPKβ1 dependent manner, suggesting a critical role for macrophages. In bone marrow-derived macrophages (BMDMs), PF-06409577 dose dependently activated AMPK as indicated by increased phosphorylation of downstream substrates ULK1 and acetyl-CoA carboxylase (ACC), which are important for autophagy and fatty acid oxidation/ de novo lipogenesis, respectively. Treatment of BMDMs with PF-06409577 suppressed fatty acid and cholesterol synthesis and transcripts related to the inflammatory response while increasing transcripts important for autophagy through AMPKβ1. These data indicate that pharmacologically targeting macrophage AMPKβ1 may be a promising strategy for reducing atherosclerosis., Competing Interests: G.R.S. has received research funding from Esperion Therapeutics, Espervita Therapeutics, Poxel Pharmaceuticals and Novo Nordisk, honoraria and/or consulting fees from Astra Zeneca, Eli-Lilly, Esperion Therapeutics, Poxel Pharmaceuticals, Merck and is a founder and shareholder of Espervita Therapeutics., (© 2023 The Author(s).)
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- 2023
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16. Handling intercurrent events and missing data in non-inferiority trials using the estimand framework: A tuberculosis case study.
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Rehal S, Cro S, Phillips PP, Fielding K, and Carpenter JR
- Subjects
- Humans, Algorithms, Data Interpretation, Statistical, Equivalence Trials as Topic, Models, Statistical, Research Design
- Abstract
Introduction: The ICH E9 addendum outlining the estimand framework for clinical trials was published in 2019 but provides limited guidance around how to handle intercurrent events for non-inferiority studies. Once an estimand is defined, it is also unclear how to deal with missing values using principled analyses for non-inferiority studies., Methods: Using a tuberculosis clinical trial as a case study, we propose a primary estimand, and an additional estimand suitable for non-inferiority studies. For estimation, multiple imputation methods that align with the estimands for both primary and sensitivity analysis are proposed. We demonstrate estimation methods using the twofold fully conditional specification multiple imputation algorithm and then extend and use reference-based multiple imputation for a binary outcome to target the relevant estimands, proposing sensitivity analyses under each. We compare the results from using these multiple imputation methods with those from the original study., Results: Consistent with the ICH E9 addendum, estimands can be constructed for a non-inferiority trial which improves on the per-protocol/intention-to-treat-type analysis population previously advocated, involving respectively a hypothetical or treatment policy strategy to handle relevant intercurrent events. Results from using the 'twofold' multiple imputation approach to estimate the primary hypothetical estimand, and using reference-based methods for an additional treatment policy estimand, including sensitivity analyses to handle the missing data, were consistent with the original study's reported per-protocol and intention-to-treat analysis in failing to demonstrate non-inferiority., Conclusions: Using carefully constructed estimands and appropriate primary and sensitivity estimators, using all the information available, results in a more principled and statistically rigorous approach to analysis. Doing so provides an accurate interpretation of the estimand.
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- 2023
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17. GDF15 promotes weight loss by enhancing energy expenditure in muscle.
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Wang D, Townsend LK, DesOrmeaux GJ, Frangos SM, Batchuluun B, Dumont L, Kuhre RE, Ahmadi E, Hu S, Rebalka IA, Gautam J, Jabile MJT, Pileggi CA, Rehal S, Desjardins EM, Tsakiridis EE, Lally JSV, Juracic ES, Tupling AR, Gerstein HC, Paré G, Tsakiridis T, Harper ME, Hawke TJ, Speakman JR, Blondin DP, Holloway GP, Jørgensen SB, and Steinberg GR
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- Animals, Humans, Mice, Appetite Depressants metabolism, Appetite Depressants pharmacology, Appetite Depressants therapeutic use, Caloric Restriction, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 metabolism, Diet, High-Fat, Eating drug effects, Non-alcoholic Fatty Liver Disease complications, Non-alcoholic Fatty Liver Disease metabolism, Non-alcoholic Fatty Liver Disease therapy, Receptors, Adrenergic, beta metabolism, Energy Metabolism drug effects, Growth Differentiation Factor 15 metabolism, Growth Differentiation Factor 15 pharmacology, Growth Differentiation Factor 15 therapeutic use, Muscle, Skeletal drug effects, Muscle, Skeletal metabolism, Weight Loss drug effects
- Abstract
Caloric restriction that promotes weight loss is an effective strategy for treating non-alcoholic fatty liver disease and improving insulin sensitivity in people with type 2 diabetes
1 . Despite its effectiveness, in most individuals, weight loss is usually not maintained partly due to physiological adaptations that suppress energy expenditure, a process known as adaptive thermogenesis, the mechanistic underpinnings of which are unclear2,3 . Treatment of rodents fed a high-fat diet with recombinant growth differentiating factor 15 (GDF15) reduces obesity and improves glycaemic control through glial-cell-derived neurotrophic factor family receptor α-like (GFRAL)-dependent suppression of food intake4-7 . Here we find that, in addition to suppressing appetite, GDF15 counteracts compensatory reductions in energy expenditure, eliciting greater weight loss and reductions in non-alcoholic fatty liver disease (NAFLD) compared to caloric restriction alone. This effect of GDF15 to maintain energy expenditure during calorie restriction requires a GFRAL-β-adrenergic-dependent signalling axis that increases fatty acid oxidation and calcium futile cycling in the skeletal muscle of mice. These data indicate that therapeutic targeting of the GDF15-GFRAL pathway may be useful for maintaining energy expenditure in skeletal muscle during caloric restriction., (© 2023. The Author(s).)- Published
- 2023
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18. Exploring the Knowledge, Attitude, and Practices of Healthy Pregnant Women Towards Gestational Diabetes Mellitus in Nigeria.
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Offomiyor FA and Rehal S
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- Pregnancy, Female, Humans, Pregnant Women, Prenatal Care, Health Knowledge, Attitudes, Practice, Nigeria, Diabetes, Gestational, Diabetes Mellitus, Type 2
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Gestational Diabetes Mellitus (GDM) is a major public health issue and a threat to the well-being of a mother and her offspring. As a growing concern in sub-Saharan Africa, this paper explores the knowledge, attitude, and practices of healthy expectant mothers towards GDM, and the content of GDM information delivered by prenatal nurses during Antenatal Clinic (ANC) in Warri, Delta State, Nigeria. Semi-structured telephone interviews were employed with 22 participants comprising 20 pregnant women and 2 antenatal nurses. The results reveal that majority of the pregnant women were unaware of GDM as a particular health condition during pregnancy that poses a risk to both maternal and infant health and could lead to a long-term risk of developing the chronic condition of Type 2 Diabetes Mellitus (T2DM). This low level of awareness was attributed to a lack of adequate information during prenatal clinic sessions. The findings from this study emphasize the need to enhance the quality of public health education offered to pregnant women during pre and antenatal clinical services emphasizing GDM as part of the overall global agenda on promoting maternal and infant health.
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- 2023
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19. A randomized, cross-over study comparing critical and overall errors, learning time, and preference of the ELLIPTA versus BREEZHALER dry powder inhalers in patients with asthma.
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van der Palen J, Slade D, Rehal S, Verma M, and Plank M
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- Humans, Female, Adolescent, Adult, Middle Aged, Male, Cross-Over Studies, Administration, Inhalation, Equipment Design, Dry Powder Inhalers, Asthma drug therapy, Pulmonary Disease, Chronic Obstructive
- Abstract
Background: Many patients with asthma make errors using inhalers, affecting the amount of medication received. Previous evidence demonstrated that patients with asthma or chronic obstructive pulmonary disease make fewer critical errors with the ELLIPTA inhaler after reading the patient information leaflet (PIL) versus other dry powder inhalers. We assessed errors made by patients with asthma using placebo ELLIPTA or BREEZHALER inhalers., Methods: This randomized, multicenter, open-label placebo inhaler-handling study (ClinicalTrials.gov: NCT04813354) with 2x2 complete block crossover design was conducted at three centers in the Netherlands and enrolled patients aged ≥18 years with mild-to-moderate asthma. Inclusion criteria were inhaler use for ≥12 weeks prior to enrollment and naivety to ELLIPTA and BREEZHALER inhalers. Patients were randomized to ELLIPTA or BREEZHALER inhaler first and were assessed for errors in use of both inhalers after 1) reading PIL instructions, 2) receiving further instruction from a healthcare professional (HCP) if they made an error., Results: 114 patients with asthma (57% female; mean age of 55.3 years) were assessed. After reading the PIL, 6% of patients made ≥1 critical error with ELLIPTA versus 26% with BREEZHALER (odds ratio [OR]: 0.11 [95% confidence interval (CI): 0.01-0.40]; p < 0.001). With ELLIPTA, 27% of patients made ≥1 overall error after reading the PIL versus 41% with BREEZHALER (OR: 0.25 [95% CI: 0.03-0.74]; p = 0.005). Fewer patients required HCP instruction with ELLIPTA than BREEZHALER (25% versus 32%)., Conclusions: Fewer patients made critical and overall errors using the ELLIPTA inhaler versus BREEZHALER after reading the PIL., Competing Interests: Declaration of competing interest JvdP has no conflicts to report. DS is an employee of and holds shares in GSK. SR is an employee of GSK. MP is an employee of and holds shares in GSK. MV is an employee of and holds shares in GSK. Some of the data included in this manuscript have previously been presented at the American Thoracic Society (ATS) meeting 2022; van der Palen et al. (2022) “A Randomized, Cross-Over Study Comparing Critical and Overall Errors, Teaching Time, and Preference of the ELLIPTA versus BREEZHALER Dry Powder Inhalers in Patients with Asthma”., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2022
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20. Evaluating how clear the questions being investigated in randomised trials are: systematic review of estimands.
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Cro S, Kahan BC, Rehal S, Chis Ster A, Carpenter JR, White IR, and Cornelius VR
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- Humans, Randomized Controlled Trials as Topic
- Abstract
Objectives: To evaluate how often the precise research question being addressed about an intervention (the estimand) is stated or can be determined from reported methods, and to identify what types of questions are being investigated in phase 2-4 randomised trials., Design: Systematic review of the clarity of research questions being investigated in randomised trials in 2020 in six leading general medical journals., Data Source: PubMed search in February 2021., Eligibility Criteria for Selecting Studies: Phase 2-4 randomised trials, with no restrictions on medical conditions or interventions. Cluster randomised, crossover, non-inferiority, and equivalence trials were excluded., Main Outcome Measures: Number of trials that stated the precise primary question being addressed about an intervention (ie, the primary estimand), or for which the primary estimand could be determined unambiguously from the reported methods using statistical knowledge. Strategies used to handle post-randomisation events that affect the interpretation or existence of patient outcomes, such as intervention discontinuations or uses of additional drug treatments (known as intercurrent events), and the corresponding types of questions being investigated., Results: 255 eligible randomised trials were identified. No trials clearly stated all the attributes of the estimand. In 117 (46%) of 255 trials, the primary estimand could be determined from the reported methods. Intercurrent events were reported in 242 (95%) of 255 trials; but the handling of these could only be determined in 125 (49%) of 255 trials. Most trials that provided this information considered the occurrence of intercurrent events as irrelevant in the calculation of the treatment effect and assessed the effect of the intervention regardless (96/125, 77%)-that is, they used a treatment policy strategy. Four (4%) of 99 trials with treatment non-adherence owing to adverse events estimated the treatment effect in a hypothetical setting (ie, the effect as if participants continued treatment despite adverse events), and 19 (79%) of 24 trials where some patients died estimated the treatment effect in a hypothetical setting (ie, the effect as if participants did not die)., Conclusions: The precise research question being investigated in most trials is unclear, mainly because of a lack of clarity on the approach to handling intercurrent events. Clear reporting of estimands is necessary in trial reports so that all stakeholders, including clinicians, patients and policy makers, can make fully informed decisions about medical interventions., Systematic Review Registration: PROSPERO CRD42021238053., Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form at https://www.icmje.org/disclosure-of-interest/ and declare: SC had financial support from the NIHR for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2022
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21. Lack of Vesicular Zinc Does Not Affect the Behavioral Phenotype of Polyinosinic:Polycytidylic Acid-Induced Maternal Immune Activation Mice.
- Author
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Sandoval KC, Thackray SE, Wong A, Niewinski N, Chipak C, Rehal S, and Dyck RH
- Abstract
Zinc is important in neural and synaptic development and neuronal transmission. Within the brain, zinc transporter 3 (ZnT3) is essential for zinc uptake into vesicles. Loss of vesicular zinc has been shown to produce neurodevelopmental disorder (NDD)-like behavior, such as decreased social interaction and increased anxiety- and repetitive-like behavior. Maternal immune activation (MIA) has been identified as an environmental factor for NDDs, such as autism spectrum disorders (ASDs) and schizophrenia (SZ), in offspring, which occurs during pregnancy when the mother's immune system reacts to the exposure to viruses or infectious diseases. In this study, we investigated the interaction effect of a genetic factor [ZnT3 knockout (KO) mice] and an environmental factor (MIA). We induced MIA in pregnant female (dams) mice during mid-gestation, using polyinosinic:polycytidylic acid (polyI:C), which mimics a viral infection. Male and female ZnT3 KO and wild-type (WT) offspring were tested in five behavioral paradigms: Ultrasonic Vocalizations (USVs) at postnatal day 9 (P9), Open Field Test, Marble Burying Test, three-Chamber Social Test, and Pre-pulse Inhibition (PPI) in adulthood (P60-75). Our results indicate that loss of vesicular zinc does not result in enhanced ASD- and SZ-like phenotype compared to WT, nor does it show a more pronounced phenotype in male ZnT3 KO compared to female ZnT3 KO. Finally, MIA offspring demonstrated an ASD- and SZ-like phenotype only in specific behavioral tests: increased calls emitted in USVs and fewer marbles buried. Our results suggest that there is no interaction between the loss of vesicular zinc and MIA induction in the susceptibility to developing an ASD- and SZ-like phenotype., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sandoval, Thackray, Wong, Niewinski, Chipak, Rehal and Dyck.)
- Published
- 2022
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22. Macrophage Jak2 deficiency accelerates atherosclerosis through defects in cholesterol efflux.
- Author
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Dotan I, Yang J, Ikeda J, Roth Z, Pollock-Tahiri E, Desai H, Sivasubramaniyam T, Rehal S, Rapps J, Li YZ, Le H, Farber G, Alchami E, Xiao C, Karim S, Gronda M, Saikali MF, Tirosh A, Wagner KU, Genest J, Schimmer AD, Gupta V, Minden MD, Cummins CL, Lewis GF, Robbins C, Jongstra-Bilen J, Cybulsky M, and Woo M
- Subjects
- Animals, Macrophages metabolism, Mice, Mice, Inbred C57BL, Atherosclerosis enzymology, Atherosclerosis genetics, Atherosclerosis metabolism, Cholesterol metabolism, Janus Kinase 2 deficiency, Janus Kinase 2 genetics, Janus Kinase 2 metabolism
- Abstract
Atherosclerosis is a chronic inflammatory condition in which macrophages play a major role. Janus kinase 2 (JAK2) is a pivotal molecule in inflammatory and metabolic signaling, and Jak2
V617F activating mutation has recently been implicated with enhancing clonal hematopoiesis and atherosclerosis. To determine the essential in vivo role of macrophage (M)-Jak2 in atherosclerosis, we generate atherosclerosis-prone ApoE-null mice deficient in M-Jak2. Contrary to our expectation, these mice exhibit increased plaque burden with no differences in macrophage proliferation, recruitment or bone marrow clonal expansion. Notably, M-Jak2-deficient bone marrow derived macrophages show a significant defect in cholesterol efflux. Pharmacologic JAK2 inhibition with ruxolitinib also leads to defects in cholesterol efflux and accelerates atherosclerosis. Liver X receptor agonist abolishes the efflux defect and attenuates the accelerated atherosclerosis that occurs with M-Jak2 deficiency. Macrophages of individuals with the Jak2V617F mutation show increased efflux which is normalized when treated with a JAK2 inhibitor. Together, M-Jak2-deficiency leads to accelerated atherosclerosis primarily through defects in cholesterol efflux from macrophages., (© 2022. The Author(s).)- Published
- 2022
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23. Salsalate reduces atherosclerosis through AMPKβ1 in mice.
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Day EA, Ford RJ, Smith BK, Houde VP, Stypa S, Rehal S, Lhotak S, Kemp BE, Trigatti BL, Werstuck GH, Austin RC, Fullerton MD, and Steinberg GR
- Subjects
- AMP-Activated Protein Kinases deficiency, Animals, Cells, Cultured, Mice, Mice, Knockout, AMP-Activated Protein Kinases metabolism, Atherosclerosis metabolism, Salicylates metabolism
- Abstract
Objective: Salsalate is a prodrug of salicylate that lowers blood glucose in people with type 2 diabetes. AMP-activated protein kinase (AMPK) is an αβγ heterotrimer which inhibits macrophage inflammation and the synthesis of fatty acids and cholesterol in the liver through phosphorylation of acetyl-CoA carboxylase (ACC) and HMG-CoA reductase (HMGCR), respectively. Salicylate binds to and activates AMPKβ1-containing heterotrimers that are highly expressed in both macrophages and liver, but the potential importance of AMPK and ability of salsalate to reduce atherosclerosis have not been evaluated., Methods: ApoE
-/- and LDLr-/- mice with or without (-/-) germline or bone marrow AMPKβ1, respectively, were treated with salsalate, and atherosclerotic plaque size was evaluated in serial sections of the aortic root. Studies examining the effects of salicylate on markers of inflammation, fatty acid and cholesterol synthesis and proliferation were conducted in bone marrow-derived macrophages (BMDMs) from wild-type mice or mice lacking AMPKβ1 or the key AMPK-inhibitory phosphorylation sites on ACC (ACC knock-in (KI)-ACC KI) or HMGCR (HMGCR-KI)., Results: Salsalate reduced atherosclerotic plaques in the aortic roots of ApoE-/- mice, but not ApoE-/- AMPKβ1-/- mice. Similarly, salsalate reduced atherosclerosis in LDLr-/- mice receiving wild-type but not AMPKβ1-/- bone marrow. Reductions in atherosclerosis by salsalate were associated with reduced macrophage proliferation, reduced plaque lipid content and reduced serum cholesterol. In BMDMs, this suppression of proliferation by salicylate required phosphorylation of HMGCR and the suppression of cholesterol synthesis., Conclusions: These data indicate that salsalate suppresses macrophage proliferation and atherosclerosis through an AMPKβ1-dependent pathway, which may involve HMGCR phosphorylation and cholesterol synthesis. Since rapidly-proliferating macrophages are a hallmark of atherosclerosis, these data indicate further evaluation of salsalate as a potential therapeutic agent for treating atherosclerotic cardiovascular disease., (Copyright © 2021 The Author(s). Published by Elsevier GmbH.. All rights reserved.)- Published
- 2021
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24. Public health practitioners' perspective on the sustainability of the tuberculosis control programme at primary health care level in Pakistan.
- Author
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Ali SM and Rehal S
- Subjects
- Delivery of Health Care, Humans, Pakistan, Primary Health Care, Public Health, Tuberculosis prevention & control
- Abstract
Background: In resource-limited settings, national tuberculosis (TB) control programmes are highly dependent on external funds, which may pose a challenge to programme sustainability. There is a recognized need for developing guidance around sustainable programming of current TB control initiatives., Aims: The aim of this study was to explore public health practitioners' perspectives on the sustainability of TB control initiatives in Pakistan at the primary health care (PHC) level., Methods: Guided by an interpretive epistemology, online in-depth interviews were conducted with 10 public health practitioners who had experience as resource planners in the TB control programme in Pakistan. Thematic content analysis was employed to the textual data as the analytical approach., Results: Three themes were inductively derived from the thematic analysis: community involvement, stakeholder engagement and efficient use of the PHC system. Community involvement was a determinant in sustaining TB control initiatives. This was attributed to the nature of the disease and prevalent health seeking behaviour. Stakeholder engagement was associated with funding arrangements between public and private partners and considered important in how new initiatives can be made part of the routine structure. Overall, having an efficient PHC system was deemed critical in sustaining current TB control initiatives at the PHC level in Pakistan., Conclusion: Fostering an enabling operational environment through regulations, supporting the utilization of existing resources, expanding the network of providers, inclusive planning, increasing spending on research and cost-effective testing are pivotal for sustaining the TB control initiatives., (Copyright © World Health Organization (WHO) 2021. Open Access. Some rights reserved. This work is available under the CC BY-NC-SA 3.0 IGO license (https://creativecommons.org/licenses/by-nc-sa/3.0/igo).)
- Published
- 2021
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25. Nr4A1 modulates inflammation-associated intestinal fibrosis and dampens fibrogenic signaling in myofibroblasts.
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Pulakazhi Venu VK, Alston L, Iftinca M, Tsai YC, Stephens M, Warriyar K V V, Rehal S, Hudson G, Szczepanski H, von der Weid PY, Altier C, and Hirota SA
- Subjects
- Animals, Cells, Cultured, Humans, Intestines pathology, Mice, Signal Transduction physiology, Fibrosis metabolism, Inflammation metabolism, Myofibroblasts metabolism, Nuclear Receptor Subfamily 4, Group A, Member 1 metabolism
- Abstract
Intestinal fibrosis is a common complication of the inflammatory bowel diseases (IBDs), contributing to tissue stiffening and luminal narrowing. Human nuclear receptor 4A 1 (NR4A1) was previously reported to regulate mesenchymal cell function and dampen fibrogenic signaling. NR4A1 gene variants are associated with IBD risk, and it has been shown to regulate intestinal inflammation. Here, we tested the hypothesis that NR4A1 acts as a negative regulator of intestinal fibrosis through regulating myofibroblast function. Using the SAMP1/YitFc mouse, we tested whether two pharmacological agents known to enhance NR4A1 signaling, cytosporone B (Csn-B) or 6-mercaptopurine (6-MP), could reduce fibrosis. We also used the dextran sulfate sodium (DSS) model of colitis and assessed the magnitude of colonic fibrosis in mouse nuclear receptor 4A 1 ( Nr4a1
-/- ) and their wild-type littermates ( Nr4a1+/+ ). Lastly, intestinal myofibroblasts isolated from Nr4a1-/- and Nr4a1+/+ mice or primary human intestinal myofibroblasts were stimulated with transforming growth factor-β1 (TGF-β1), in the presence or absence of Csn-B or 6-MP, and proliferation and ECM gene expression assessed. Csn-B or 6-MP treatment significantly reduced ileal thickness, collagen, and overall ECM content in SAMP1/YitFc mice. This was associated with a reduction in proliferative markers within the mesenchymal compartment. Nr4a1-/- mice exposed to DSS exhibited increased colonic thickening and ECM content. Nr4a1-/- myofibroblasts displayed enhanced TGF-β1-induced proliferation. Furthermore, Csn-B or 6-MP treatment was antiproliferative in Nr4a1+/+ but not Nr4a1-/- cells. Lastly, activating NR4A1 in human myofibroblasts reduced TGF-β1-induced collagen deposition and fibrosis-related gene expression. Our data suggest that NR4A1 can attenuate fibrotic processes in intestinal myofibroblasts and could provide a valuable clinical target to treat inflammation-associated intestinal fibrosis. NEW & NOTEWORTHY Fibrosis and increased muscle thickening contribute to stricture formation and intestinal obstruction, a complication that occurs in 30%-50% of patients with CD within 10 yr of disease onset. More than 50% of those who undergo surgery to remove the obstructed bowel will experience stricture recurrence. To date, there are no drug-based approaches approved to treat intestinal strictures. In the current submission, we identify NR4A1 as a novel target to treat inflammation-associated intestinal fibrosis.- Published
- 2021
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26. Knowledge, Practice and Attitude towards Foot Ulcers and Foot Care among Adults Living with Diabetes in Tobago: A Qualitative Study.
- Author
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Adeyemi TM, Olatunji TL, Adetunji AE, and Rehal S
- Subjects
- Adult, Health Knowledge, Attitudes, Practice, Humans, Quality of Life, Trinidad and Tobago, Walking, Diabetes Mellitus, Diabetic Foot epidemiology, Diabetic Foot prevention & control
- Abstract
Globally, the prevalence of diabetes has risen significantly by 62% over the last ten years. A complication of unmanaged diabetes is diabetic foot ulcer (DFU), which adversely affects the quality of life of individuals with diabetes and inflicts a huge economic burden on the family, government, and health care services. However, this complication is preventable with adequate patient knowledge and practice regarding DFU and foot care. The present study was aimed at assessing the knowledge, attitude, and practice of adults with diabetes on foot ulcers and foot care in Tobago using a qualitative exploratory design. Purposeful sampling technique was used to recruit 20 participants from the lifestyle and diabetes foot clinics of Scarborough Health Centre, Tobago. Telephone interviews were conducted with the use of a semi-structured interview guide. The data obtained from participants were analyzed using thematic content analysis. Four major themes, namely foot ulcer problems, participants' knowledge on DFU, knowledge on foot care, and practice and attitude of foot care, emerged from the study. The findings from the study revealed that the majority of participants had poor knowledge regarding DFU but exhibited awareness about foot care, especially on foot cleaning and inspection, preventing irritation after washing, appropriate footwear, and not walking barefooted. The participants had good attitudes and practices of foot care despite their poor knowledge of DFU. However, participants reported inadequate health education on DFU and foot care from healthcare personnel. There should be improved health education, information, and communication on DFU and foot care centred and tailored to the understanding of people living with diabetes. This will prevent DFU and reduce the mortality arising from this complication, which is a major target of the sustainable development goals (SDG) in mitigating the burden of non-communicable diseases (NCD) such as diabetes.
- Published
- 2021
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27. Regulation of lymphatic function and injury by nitrosative stress in obese mice.
- Author
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Rehal S, Kataru RP, Hespe GE, Baik JE, Park HJ, Ly C, Shin J, and Mehrara BJ
- Subjects
- Adipose Tissue metabolism, Animals, Diet, High-Fat, Endothelial Cells metabolism, Glucose, Inflammation metabolism, Insulin metabolism, Insulin Resistance physiology, Lipid Metabolism physiology, Lymph Nodes metabolism, Lymph Nodes physiology, Lymphatic Vessels injuries, Lymphatic Vessels metabolism, Lymphatic Vessels physiology, Male, Mice, Mice, Inbred C57BL, Mice, Obese, Nitric Oxide Synthase Type II genetics, Nitrosative Stress physiology, Obesity metabolism, Obesity physiopathology, Endothelial Cells physiology, Nitric Oxide Synthase Type II metabolism, Nitrosative Stress immunology
- Abstract
Objective: Obesity results in lymphatic dysfunction, but the cellular mechanisms that mediate this effect remain largely unknown. Previous studies in obese mice have shown that inducible nitric oxide synthase-expressing (iNOS
+ ) inflammatory cells accumulate around lymphatic vessels. In the current study, we therefore tested the hypothesis that increased expression of iNOS results in nitrosative stress and injury to the lymphatic endothelial cells (LECs). In addition, we tested the hypothesis that lymphatic injury, independent of obesity, can modulate glucose and lipid metabolism., Methods: We compared the metabolic changes and lymphatic function of wild-type and iNOS knockout mice fed a normal chow or high-fat diet for 16 weeks. To corroborate our in vivo findings, we analyzed the effects of reactive nitrogen species on isolated LECs. Finally, using a genetically engineered mouse model that allows partial ablation of the lymphatic system, we studied the effects of acute lymphatic injury on glucose and lipid metabolism in lean mice., Results: The mesenteric lymphatic vessels of obese wild-type animals were dilated, leaky, and surrounded by iNOS+ inflammatory cells with resulting increased accumulation of reactive nitrogen species when compared with lean wild-type or obese iNOS knockout animals. These changes in obese wild-type mice were associated with systemic glucose and lipid abnormalities, as well as decreased mesenteric LEC expression of lymphatic-specific genes, including vascular endothelial growth factor receptor 3 (VEGFR-3) and antioxidant genes as compared with lean wild-type or obese iNOS knockout animals. In vitro experiments demonstrated that isolated LECs were more sensitive to reactive nitrogen species than blood endothelial cells, and that this sensitivity was ameliorated by antioxidant therapies. Finally, using mice in which the lymphatics were specifically ablated using diphtheria toxin, we found that the interaction between metabolic abnormalities caused by obesity and lymphatic dysfunction is bidirectional. Targeted partial ablation of mesenteric lymphatic channels of lean mice resulted in increased accumulation of iNOS+ inflammatory cells and increased reactive nitrogen species. Lymphatic ablation also caused marked abnormalities in insulin sensitivity, serum glucose and insulin concentrations, expression of insulin-sensitive genes, lipid metabolism, and significantly increased systemic and mesenteric white adipose tissue (M-WAT) inflammatory responses., Conclusions: Our studies suggest that increased iNOS production in obese animals plays a key role in regulating lymphatic injury by increasing nitrosative stress. In addition, our studies suggest that obesity-induced lymphatic injury may amplify metabolic abnormalities by increasing systemic and local inflammatory responses and regulating insulin sensitivity. These findings suggest that manipulation of the lymphatic system may represent a novel means of treating metabolic abnormalities associated with obesity., (Copyright © 2020 The Authors. Published by Elsevier GmbH.. All rights reserved.)- Published
- 2020
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28. Effects of enriched housing on the neuronal morphology of mice that lack zinc transporter 3 (ZnT3) and vesicular zinc.
- Author
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McAllister BB, Thackray SE, de la Orta BKG, Gosse E, Tak P, Chipak C, Rehal S, Valverde Rascón A, and Dyck RH
- Subjects
- Animals, Basolateral Nuclear Complex cytology, Basolateral Nuclear Complex metabolism, CA1 Region, Hippocampal cytology, CA1 Region, Hippocampal metabolism, Cation Transport Proteins deficiency, Environment, Female, Housing, Animal, Mice, Inbred C57BL, Mice, Knockout, Cation Transport Proteins physiology, Corpus Striatum cytology, Corpus Striatum metabolism, Dendritic Spines ultrastructure, Somatosensory Cortex cytology, Somatosensory Cortex metabolism, Synaptic Vesicles metabolism, Zinc metabolism
- Abstract
In the central nervous system, certain neurons store zinc within the synaptic vesicles of their axon terminals. This vesicular zinc can then be released in an activity-dependent fashion as an intercellular signal. The functions of vesicular zinc are not entirely understood, but evidence suggests that it is important for some forms of experience-dependent plasticity in the brain. The ability of neurons to store and release vesicular zinc is dependent on expression of the vesicular zinc transporter, ZnT3. Here, we examined the neuronal morphology of mice that lack ZnT3. Brains were collected from mice housed under standard laboratory conditions and from mice housed in enriched environments - large, multilevel enclosures with running wheels, numerous objects and tunnels, and a greater number of cage mates. Golgi-Cox staining was used to visualize neurons for analysis of dendritic length and dendritic spine density. Neurons were analyzed from the barrel cortex, striatum, basolateral amygdala, and hippocampus (CA1). ZnT3 knockout mice, relative to wild type mice, exhibited increased basal dendritic length in the layer 2/3 pyramidal neurons of barrel cortex, independently of housing condition. Environmental enrichment decreased apical dendritic length in these same neurons and increased dendritic spine density on striatal medium spiny neurons. Elimination of ZnT3 did not modulate any of the effects of enrichment. Our results provide no evidence that vesicular zinc is required for the experience-dependent changes that occur in response to environmental enrichment. They are consistent, however, with recent reports suggesting increased cortical volume in ZnT3 knockout mice., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
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29. Gantenerumab reduces amyloid-β plaques in patients with prodromal to moderate Alzheimer's disease: a PET substudy interim analysis.
- Author
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Klein G, Delmar P, Voyle N, Rehal S, Hofmann C, Abi-Saab D, Andjelkovic M, Ristic S, Wang G, Bateman R, Kerchner GA, Baudler M, Fontoura P, and Doody R
- Subjects
- Aged, Aged, 80 and over, Alzheimer Disease diagnostic imaging, Antibodies, Monoclonal, Humanized pharmacology, Double-Blind Method, Female, Humans, Male, Middle Aged, Plaque, Amyloid diagnostic imaging, Positron-Emission Tomography, Treatment Outcome, Alzheimer Disease drug therapy, Antibodies, Monoclonal, Humanized therapeutic use, Brain diagnostic imaging, Plaque, Amyloid drug therapy
- Abstract
Background: We previously investigated low doses (105 or 225 mg) of gantenerumab, a fully human monoclonal antibody that binds and removes aggregated amyloid-β by Fc receptor-mediated phagocytosis, in the SCarlet RoAD (SR) and Marguerite RoAD (MR) phase 3 trials. Several lines of evidence suggested that higher doses may be necessary to achieve clinical efficacy. We therefore designed a positron emission tomography (PET) substudy to evaluate the effect of gantenerumab uptitrated to 1200 mg every 4 weeks on amyloid-β plaques as measured using florbetapir PET in patients with prodromal to moderate Alzheimer's disease (AD)., Methods: A subset of patients enrolled in the SR and MR studies who subsequently entered the open-label extensions (OLEs) were included in this substudy. Patients were aged 50 to 90 years with a clinical diagnosis of probable prodromal to moderate AD and were included based on a visual read of the original screening scan in the double-blind phase. Patients were assigned to 1 of 5 titration schedules (ranging from 2 to 10 months) with a target gantenerumab dose of 1200 mg every 4 weeks. The main endpoint of this substudy was change in amyloid-β plaque burden from OLE baseline to week 52 and week 104, assessed using florbetapir PET. Florbetapir global cortical signal was calculated using a prespecified standard uptake value ratio method converted to the Centiloid scale., Results: Sixty-seven of the 89 patients initially enrolled had ≥ 1 follow-up scan by August 15, 2018. Mean amyloid levels were reduced by 39 Centiloids by the first year and 59 Centiloids by year 2, a 3.5-times greater reduction than was seen after 2 years at 225 mg in SR. At years 1 and 2, 37% and 51% of patients, respectively, had amyloid-β plaque levels below the amyloid-β positivity threshold., Conclusion: Results from this exploratory interim analysis of the PET substudy suggest that gantenerumab doses up to 1200 mg resulted in robust amyloid-β plaque removal at 2 years. PET amyloid levels were consistent with sparse-to-no neuritic amyloid-β plaques in 51% of patients after 2 years of therapy. Amyloid reductions were similar to those observed in other placebo-controlled studies that have suggested potential clinical benefit., Trial Registration: ClinicalTrials.gov, NCT01224106 (SCarlet RoAD) and NCT02051608 (Marguerite RoAD).
- Published
- 2019
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30. Tumor Lymphatic Function Regulates Tumor Inflammatory and Immunosuppressive Microenvironments.
- Author
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Kataru RP, Ly CL, Shin J, Park HJ, Baik JE, Rehal S, Ortega S, Lyden D, and Mehrara BJ
- Subjects
- Animals, Biomarkers, Tumor, Breast Neoplasms immunology, Breast Neoplasms metabolism, Breast Neoplasms pathology, Cytokines metabolism, Disease Models, Animal, Disease Progression, Edema, Female, Inflammation, Lymphatic System, Lymphatic Vessels, Lymphocytes, Tumor-Infiltrating immunology, Lymphocytes, Tumor-Infiltrating metabolism, Lymphocytes, Tumor-Infiltrating pathology, Male, Melanoma, Experimental, Mice, Immunomodulation, Neoplasms immunology, Neoplasms pathology, Tumor Microenvironment immunology
- Abstract
Proliferation of aberrant, dysfunctional lymphatic vessels around solid tumors is a common histologic finding. Studies have shown that abnormalities in lymphatic function result in accumulation of inflammatory cells with an immunosuppressive profile. We tested the hypothesis that dysfunctional lymphatic vessels surrounding solid tumors regulate changes in the tumor microenvironment and tumor-specific immune responses. Using subcutaneously implanted mouse melanoma and breast cancer tumors in a lymphatic endothelial cell-specific diphtheria toxin receptor transgenic mouse, we found that local ablation of lymphatic vessels increased peritumoral edema, as compared with controls. Comparative analysis of the peritumoral fluid demonstrated increases in the number of macrophages, CD4
+ inflammatory cells, F4/80+ /Gr-1+ (myeloid-derived suppressor cells), CD4+ /Foxp3+ (Tregs) immunosuppressive cells, and expression of inflammatory cytokines such as TNFα, IFNγ, and IL1β following lymphatic ablation. Tumors grown in lymphatic ablated mice exhibited reduced intratumoral accumulation of cytotoxic T cells and increased tumor PD-L1 expression, causing rapid tumor growth, compared with tumors grown in nonlymphatic-ablated mice. Our study suggests that lymphatic dysfunction plays a role in regulating tumor microenvironments and may be therapeutically targeted in combination with immunotherapy to prevent tumor growth and progression., (©2019 American Association for Cancer Research.)- Published
- 2019
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31. Fibrosis and secondary lymphedema: chicken or egg?
- Author
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Kataru RP, Wiser I, Baik JE, Park HJ, Rehal S, Shin JY, and Mehrara BJ
- Subjects
- Fibrosis, Humans, Lymphatic Vessels injuries, Lymphedema immunology, Lymphocyte Activation immunology, Models, Biological, T-Lymphocytes immunology, Lymphatic Vessels pathology, Lymphedema pathology
- Abstract
Secondary lymphedema is a common complication of cancer treatment resulting in progressive fibroadipose tissue deposition, increased risk of infections, and, in rare cases, secondary malignancies. Until recently, the pathophysiology of secondary lymphedema was thought to be related to impaired collateral lymphatic formation after surgical injury. However, more recent studies have shown that chronic inflammation-induced fibrosis plays a key role in the pathophysiology of this disease. In this review, we will discuss the evidence supporting this hypothesis and summarize recent publications demonstrating that lymphatic injury activates chronic immune responses that promote fibrosis and lymphatic leakiness, decrease collecting lymphatic pumping, and impair collateral lymphatic formation. We will review how chronic mixed T-helper cell inflammatory reactions regulate this process and how this response may be used to design novel therapies for lymphedema., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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32. Most noninferiority trials were not designed to preserve active comparator treatment effects.
- Author
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Tsui M, Rehal S, Jairath V, and Kahan BC
- Subjects
- Female, Humans, Male, Sensitivity and Specificity, Equivalence Trials as Topic, Publications statistics & numerical data, Quality Improvement, Research Design
- Abstract
Objectives: To evaluate whether noninferiority trials are designed to adequately preserve the historical treatment effect of their active comparators., Study Design and Setting: We reviewed 162 noninferiority trials published in high-impact medical journals. We assessed whether trials were designed to ensure that interventions could only be declared noninferior if they preserved at least 50% of the active comparator's historical treatment effect., Results: Only 25 of 162 trials (15%) were designed so that interventions could only be declared noninferior if they preserved at least 50% of the active comparator's historical treatment effect. Most trials did not provide evidence that the active comparator was effective (n = 101), provided inadequate evidence (n = 18), or used a noninferiority margin that was too wide (n = 18). In a subset of 61 noninferiority trials which referenced a prior randomized trial or meta-analysis evaluating the active comparator, only 25 (41%) used a noninferiority margin small enough to preserve at least 50% of the active comparator's treatment effect. Overall, 14 of 162 noninferiority trials (9%) would have allowed the intervention to be declared noninferior even if it was worse than either placebo or another historical control., Conclusion: Most noninferiority trials published in major medical journals could allow erroneous declarations of noninferiority., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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33. Regulation of Immune Function by the Lymphatic System in Lymphedema.
- Author
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Kataru RP, Baik JE, Park HJ, Wiser I, Rehal S, Shin JY, and Mehrara BJ
- Subjects
- Alarmins biosynthesis, Alarmins genetics, Alarmins immunology, Animals, Cell Movement, Dendritic Cells physiology, Disease Models, Animal, Fibrosis, Humans, Inflammation, Lymph Node Excision adverse effects, Lymph Nodes immunology, Lymphatic Metastasis, Lymphatic Vessels immunology, Lymphatic Vessels physiopathology, Lymphedema epidemiology, Lymphedema etiology, Lymphocyte Activation, Macrophage Activation, Mice, Postoperative Complications etiology, Postoperative Complications immunology, Receptors, Pattern Recognition immunology, T-Lymphocytes, Helper-Inducer immunology, T-Lymphocytes, Regulatory immunology, Lymphatic System immunology, Lymphedema immunology, T-Lymphocyte Subsets immunology
- Abstract
The lymphatic vasculature has traditionally been thought to play a passive role in the regulation of immune responses by transporting antigen presenting cells and soluble antigens to regional lymph nodes. However, more recent studies have shown that lymphatic endothelial cells regulate immune responses more directly by modulating entry of immune cells into lymphatic capillaries, presenting antigens on major histocompatibility complex proteins, and modulating antigen presenting cells. Secondary lymphedema is a disease that develops when the lymphatic system is injured during surgical treatment of cancers or is damaged by infections. We have used mouse models of lymphedema in order to understand the effects of chronic lymphatic injury on immune responses and have shown that lymphedema results in a mixed T helper cell and T regulatory cell (Treg) inflammatory response. Prolonged T helper 2 biased immune responses in lymphedema regulate the pathology of this disease by promoting tissue fibrosis, inhibiting formation of collateral lymphatics, decreasing lymphatic vessel pumping capacity, and increasing lymphatic leakiness. Treg infiltration following lymphatic injury results from proliferation of natural Tregs and suppresses innate and adaptive immune responses. These studies have broad clinical relevance since understanding how lymphatic injury in lymphedema can modulate immune responses may provide a template with which we can study more subtle forms of lymphatic injury that may occur in physiologic conditions such as aging, obesity, metabolic tumors, and in the tumor microenvironment.
- Published
- 2019
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34. CD4 + T cells are activated in regional lymph nodes and migrate to skin to initiate lymphedema.
- Author
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García Nores GD, Ly CL, Cuzzone DA, Kataru RP, Hespe GE, Torrisi JS, Huang JJ, Gardenier JC, Savetsky IL, Nitti MD, Yu JZ, Rehal S, and Mehrara BJ
- Subjects
- Adoptive Transfer, Animals, CD4 Antigens genetics, CD4 Antigens metabolism, CD4-Positive T-Lymphocytes drug effects, Cell Differentiation immunology, Dendritic Cells immunology, Disease Models, Animal, Female, Fingolimod Hydrochloride pharmacology, Fingolimod Hydrochloride therapeutic use, Humans, Immunosuppressive Agents pharmacology, Lymph Nodes cytology, Lymph Nodes pathology, Lymphangiogenesis immunology, Lymphatic Vessels cytology, Lymphatic Vessels immunology, Lymphatic Vessels pathology, Lymphedema drug therapy, Lymphedema pathology, Lymphocyte Activation drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Receptors, Lysosphingolipid immunology, Receptors, Lysosphingolipid metabolism, Skin cytology, Skin immunology, CD4-Positive T-Lymphocytes immunology, Immunosuppressive Agents therapeutic use, Lymphedema immunology, Lymphocyte Activation immunology
- Abstract
T cell-mediated responses have been implicated in the development of fibrosis, impaired lymphangiogenesis, and lymphatic dysfunction in secondary lymphedema. Here we show that CD4
+ T cells are necessary for lymphedema pathogenesis by utilizing adoptive transfer techniques in CD4 knockout mice that have undergone tail skin and lymphatic excision or popliteal lymph node dissection. We also demonstrate that T cell activation following lymphatic injury occurs in regional skin-draining lymph nodes after interaction with antigen-presenting cells such as dendritic cells. CD4+ T cell activation is associated with differentiation into a mixed T helper type 1 and 2 phenotype, as well as upregulation of adhesion molecules and chemokines that promote migration to the skin. Most importantly, we find that blocking T cell release from lymph nodes using a sphingosine-1-phosphate receptor modulator prevents lymphedema, suggesting that this approach may have clinical utility.- Published
- 2018
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35. Acute small intestinal inflammation results in persistent lymphatic alterations.
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Rehal S, Stephens M, Roizes S, Liao S, and von der Weid PY
- Subjects
- Animals, Antigens, CD metabolism, Cell Movement, Dendritic Cells metabolism, Dendritic Cells pathology, Dextran Sulfate, Disease Models, Animal, Ileitis chemically induced, Ileitis metabolism, Ileum metabolism, Integrin alpha Chains metabolism, Intestinal Mucosa metabolism, Lymph Nodes metabolism, Lymphangiectasis, Intestinal chemically induced, Lymphangiectasis, Intestinal metabolism, Lymphatic Vessels metabolism, Male, Mice, Inbred C57BL, Time Factors, Ileitis pathology, Ileum pathology, Intestinal Mucosa pathology, Lymph Nodes pathology, Lymphangiectasis, Intestinal pathology, Lymphangiogenesis, Lymphatic Vessels pathology
- Abstract
Inflammatory bowel disease (IBD) has a complex pathophysiology with limited treatments. Structural and functional changes in the intestinal lymphatic system have been associated with the disease, with increased risk of IBD occurrence linked to a history of acute intestinal injury. To examine the potential role of the lymphatic system in inflammation recurrence, we evaluated morphological and functional changes in mouse mucosal and mesenteric lymphatic vessels, and within the mesenteric lymph nodes during acute ileitis caused by a 7-day treatment with dextran sodium sulfate (DSS). We monitored whether the changes persisted during a 14-day recovery period and determined their potential consequences on dendritic cell (DC) trafficking between the mucosa and lymphoid tissues. DSS administration was associated with marked lymphatic abnormalities and dysfunctions exemplified by lymphangiectasia and lymphangiogenesis in the ileal mucosa and mesentery, increased mesenteric lymphatic vessel leakage, and lymphadenopathy. Lymphangiogenesis and lymphadenopathy were still evident after recovery from intestinal inflammation and correlated with higher numbers of DCs in mucosal and lymphatic tissues. Specifically, a deficit in CD103
+ DCs observed during acute DSS in the lamina propria was reversed and further enhanced during recovery. We concluded that an acute intestinal insult caused alterations of the mesenteric lymphatic system, including lymphangiogenesis, which persisted after resolution of inflammation. These morphological and functional changes could compromise DC function and movement, increasing susceptibility to further gastrointestinal disease. Elucidation of the changes in mesenteric and intestinal lymphatic function should offer key insights for new therapeutic strategies in gastrointestinal disorders such as IBD. NEW & NOTEWORTHY Lymphatic integrity plays a critical role in small intestinal homeostasis. Acute intestinal insult in a mouse model of acute ileitis causes morphological and functional changes in mesenteric and intestinal lymphatic vessels. While some of the changes significantly regressed during inflammation resolution, others persisted, including lymphangiogenesis and altered dendritic cell function and movement, potentially increasing susceptibility to the recurrence of gastrointestinal inflammation.- Published
- 2018
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36. Randomized Controlled Trial of Urokinase versus Placebo for Nondraining Malignant Pleural Effusion.
- Author
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Mishra EK, Clive AO, Wills GH, Davies HE, Stanton AE, Al-Aloul M, Hart-Thomas A, Pepperell J, Evison M, Saba T, Harrison RN, Guhan A, Callister ME, Sathyamurthy R, Rehal S, Corcoran JP, Hallifax R, Psallidas I, Russell N, Shaw R, Dobson M, Wrightson JM, West A, Lee YCG, Nunn AJ, Miller RF, Maskell NA, and Rahman NM
- Subjects
- Aged, Double-Blind Method, Female, Humans, Length of Stay statistics & numerical data, Male, Palliative Care methods, Pleural Effusion, Malignant enzymology, Pleurodesis methods, Prospective Studies, Pleural Effusion, Malignant therapy, Urokinase-Type Plasminogen Activator therapeutic use
- Abstract
Rationale: Patients with malignant pleural effusion experience breathlessness, which is treated by drainage and pleurodesis. Incomplete drainage results in residual dyspnea and pleurodesis failure. Intrapleural fibrinolytics lyse septations within pleural fluid, improving drainage., Objectives: To assess the effects of intrapleural urokinase on dyspnea and pleurodesis success in patients with nondraining malignant effusion., Methods: We conducted a prospective, double-blind, randomized trial. Patients with nondraining effusion were randomly allocated in a 1:1 ratio to intrapleural urokinase (100,000 IU, three doses, 12-hourly) or matched placebo., Measurements and Main Results: Co-primary outcome measures were dyspnea (average daily 100-mm visual analog scale scores over 28 d) and time to pleurodesis failure to 12 months. Secondary outcomes were survival, hospital length of stay, and radiographic change. A total of 71 subjects were randomized (36 received urokinase, 35 placebo) from 12 U.K. centers. The baseline characteristics were similar between the groups. There was no difference in mean dyspnea between groups (mean difference, 3.8 mm; 95% confidence interval [CI], -12 to 4.4 mm; P = 0.36). Pleurodesis failure rates were similar (urokinase, 13 of 35 [37%]; placebo, 11 of 34 [32%]; adjusted hazard ratio, 1.2; P = 0.65). Urokinase was associated with decreased effusion size visualized by chest radiography (adjusted relative improvement, -19%; 95% CI, -28 to -11%; P < 0.001), reduced hospital stay (1.6 d; 95% CI, 1.0 to 2.6; P = 0.049), and improved survival (69 vs. 48 d; P = 0.026)., Conclusions: Use of intrapleural urokinase does not reduce dyspnea or improve pleurodesis success compared with placebo and cannot be recommended as an adjunct to pleurodesis. Other palliative treatments should be used. Improvements in hospital stay, radiographic appearance, and survival associated with urokinase require further evaluation. Clinical trial registered with ISRCTN (12852177) and EudraCT (2008-000586-26).
- Published
- 2018
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37. Effect of Home Noninvasive Ventilation With Oxygen Therapy vs Oxygen Therapy Alone on Hospital Readmission or Death After an Acute COPD Exacerbation: A Randomized Clinical Trial.
- Author
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Murphy PB, Rehal S, Arbane G, Bourke S, Calverley PMA, Crook AM, Dowson L, Duffy N, Gibson GJ, Hughes PD, Hurst JR, Lewis KE, Mukherjee R, Nickol A, Oscroft N, Patout M, Pepperell J, Smith I, Stradling JR, Wedzicha JA, Polkey MI, Elliott MW, and Hart N
- Subjects
- Aged, Combined Modality Therapy, Female, Forced Expiratory Volume, Home Care Services, Humans, Hypercapnia etiology, Hypercapnia therapy, Male, Middle Aged, Pulmonary Disease, Chronic Obstructive complications, Pulmonary Disease, Chronic Obstructive mortality, Quality of Life, Respiratory Insufficiency etiology, Respiratory Insufficiency therapy, Risk, Time Factors, Noninvasive Ventilation, Oxygen Inhalation Therapy, Patient Readmission statistics & numerical data, Pulmonary Disease, Chronic Obstructive therapy
- Abstract
Importance: Outcomes after exacerbations of chronic obstructive pulmonary disease (COPD) requiring acute noninvasive ventilation (NIV) are poor and there are few treatments to prevent hospital readmission and death., Objective: To investigate the effect of home NIV plus oxygen on time to readmission or death in patients with persistent hypercapnia after an acute COPD exacerbation., Design, Setting, and Participants: A randomized clinical trial of patients with persistent hypercapnia (Paco2 >53 mm Hg) 2 weeks to 4 weeks after resolution of respiratory acidemia, who were recruited from 13 UK centers between 2010 and 2015. Exclusion criteria included obesity (body mass index [BMI] >35), obstructive sleep apnea syndrome, or other causes of respiratory failure. Of 2021 patients screened, 124 were eligible., Interventions: There were 59 patients randomized to home oxygen alone (median oxygen flow rate, 1.0 L/min [interquartile range {IQR}, 0.5-2.0 L/min]) and 57 patients to home oxygen plus home NIV (median oxygen flow rate, 1.0 L/min [IQR, 0.5-1.5 L/min]). The median home ventilator settings were an inspiratory positive airway pressure of 24 (IQR, 22-26) cm H2O, an expiratory positive airway pressure of 4 (IQR, 4-5) cm H2O, and a backup rate of 14 (IQR, 14-16) breaths/minute., Main Outcomes and Measures: Time to readmission or death within 12 months adjusted for the number of previous COPD admissions, previous use of long-term oxygen, age, and BMI., Results: A total of 116 patients (mean [SD] age of 67 [10] years, 53% female, mean BMI of 21.6 [IQR, 18.2-26.1], mean [SD] forced expiratory volume in the first second of expiration of 0.6 L [0.2 L], and mean [SD] Paco2 while breathing room air of 59 [7] mm Hg) were randomized. Sixty-four patients (28 in home oxygen alone and 36 in home oxygen plus home NIV) completed the 12-month study period. The median time to readmission or death was 4.3 months (IQR, 1.3-13.8 months) in the home oxygen plus home NIV group vs 1.4 months (IQR, 0.5-3.9 months) in the home oxygen alone group, adjusted hazard ratio of 0.49 (95% CI, 0.31-0.77; P = .002). The 12-month risk of readmission or death was 63.4% in the home oxygen plus home NIV group vs 80.4% in the home oxygen alone group, absolute risk reduction of 17.0% (95% CI, 0.1%-34.0%). At 12 months, 16 patients had died in the home oxygen plus home NIV group vs 19 in the home oxygen alone group., Conclusions and Relevance: Among patients with persistent hypercapnia following an acute exacerbation of COPD, adding home noninvasive ventilation to home oxygen therapy prolonged the time to readmission or death within 12 months., Trial Registration: clinicaltrials.gov Identifier: NCT00990132.
- Published
- 2017
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38. TNFΔARE Mice Display Abnormal Lymphatics and Develop Tertiary Lymphoid Organs in the Mesentery.
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Rehal S and von der Weid PY
- Subjects
- Animals, Biological Transport, CX3C Chemokine Receptor 1, Chronic Disease, Dendritic Cells metabolism, Ileitis pathology, Ileum pathology, Lipid Metabolism, Lymphadenopathy pathology, Lymphangiogenesis, Mice, Transgenic, Receptors, CCR7 metabolism, Receptors, Chemokine metabolism, Lymph Nodes pathology, Lymphatic System abnormalities, Lymphatic System pathology, Mesentery pathology
- Abstract
Chronic inflammatory diseases are associated with a persistent and enhanced response to environmental antigens. As an adaptive response to this exaggerated immune state, affected tissue typically develops tertiary lymphoid organs. Studies of Crohn disease (CD), a chronic inflammatory disease of the intestinal tract, report tertiary lymphoid organs present within the mucosal wall, along with other lymphatic diseases, such as lymphangiogenesis and obstructed lymphatic vessels. These observations suggest that downstream mesenteric lymphatic vessels and lymph drainage into mesenteric lymph nodes may be compromised. However, information is lacking on the morphologic features and functional status of mesenteric lymphatics in CD. Using confocal imaging, PCR, flow cytometry, and functional strategies, we addressed these questions in the established TNFΔARE mouse model of CD and found that this mouse model had many lymphatic abnormalities reminiscent of human CD. These abnormalities include intestinal lymphangiectasia, mesenteric lymph node lymphadenopathy, and lymphangiogenesis in both the mesentery and mucosa. Critically, TNFΔARE mice also present mesenteric tertiary lymphoid organs and have altered lymphatic transport of dendritic cells to mesenteric lymph nodes, two features likely to actively modulate immunity. Our findings provide key insights into lymphatic remodeling in the TNFΔARE mouse model. They shed light on the involvement of these lymphatic changes in immune dysfunctions observed in CD and suggest the lymphatic system as new target for therapeutic options., (Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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39. The pro-inflammatory cytokine TNF-α inhibits lymphatic pumping via activation of the NF-κB-iNOS signaling pathway.
- Author
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Chen Y, Rehal S, Roizes S, Zhu HL, Cole WC, and von der Weid PY
- Subjects
- Animals, Inflammation metabolism, Mesentery blood supply, Muscle Contraction drug effects, Rats, Lymphatic Vessels physiopathology, NF-kappa B metabolism, Nitric Oxide Synthase Type II metabolism, Signal Transduction, Tumor Necrosis Factor-alpha pharmacology
- Abstract
Objective: Mesenteric lymphatic vessel pumping, important to propel lymph and immune cells from the intestinal interstitium to the mesenteric lymph nodes, is compromised during intestinal inflammation. The objective of this study was to test the hypothesis that the pro-inflammatory cytokine TNF-α, is a significant contributor to the inflammation-induced lymphatic contractile dysfunction, and to determine its mode of action., Methods: Contractile parameters were obtained from isolated rat mesenteric lymphatic vessels mounted on a pressure myograph after 24-hours incubation with or without TNF-α. Various inhibitors were administered, and quantitative real-time PCR, Western blotting, and immunofluorescence confocal imaging were applied to characterize the mechanisms involved in TNF-α actions., Results: Vessel contraction frequency was significantly decreased after TNF-α treatment and could be restored by selective inhibition of NF-кB, iNOS, guanylate cyclase, and ATP-sensitive K
+ channels. We further demonstrated that NF-кB inhibition also suppressed the significant increase in iNOS mRNA observed in TNF-α-treated lymphatic vessels and that TNF-α treatment favored the nuclear translocation of the p65 NF-κB subunit., Conclusions: These findings suggest that TNF-α decreases mesenteric lymphatic contractility by activating the NF-κB-iNOS signaling pathway. This mechanism could contribute to the alteration of lymphatic pumping reported in intestinal inflammation., (© 2017 John Wiley & Sons Ltd.)- Published
- 2017
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40. High-dose rifampicin, moxifloxacin, and SQ109 for treating tuberculosis: a multi-arm, multi-stage randomised controlled trial.
- Author
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Boeree MJ, Heinrich N, Aarnoutse R, Diacon AH, Dawson R, Rehal S, Kibiki GS, Churchyard G, Sanne I, Ntinginya NE, Minja LT, Hunt RD, Charalambous S, Hanekom M, Semvua HH, Mpagama SG, Manyama C, Mtafya B, Reither K, Wallis RS, Venter A, Narunsky K, Mekota A, Henne S, Colbers A, van Balen GP, Gillespie SH, Phillips PPJ, and Hoelscher M
- Subjects
- Adamantane therapeutic use, Adult, Drug Administration Schedule, Ethambutol therapeutic use, Female, Humans, Isoniazid therapeutic use, Male, Moxifloxacin, Pyrazinamide therapeutic use, South Africa, Tanzania, Tuberculosis, Pulmonary diagnosis, Adamantane analogs & derivatives, Antitubercular Agents therapeutic use, Drug Therapy, Combination, Ethylenediamines therapeutic use, Fluoroquinolones therapeutic use, Rifampin therapeutic use, Tuberculosis, Pulmonary drug therapy
- Abstract
Background: Tuberculosis is the world's leading infectious disease killer. We aimed to identify shorter, safer drug regimens for the treatment of tuberculosis., Methods: We did a randomised controlled, open-label trial with a multi-arm, multi-stage design. The trial was done in seven sites in South Africa and Tanzania, including hospitals, health centres, and clinical trial centres. Patients with newly diagnosed, rifampicin-sensitive, previously untreated pulmonary tuberculosis were randomly assigned in a 1:1:1:1:2 ratio to receive (all orally) either 35 mg/kg rifampicin per day with 15-20 mg/kg ethambutol, 20 mg/kg rifampicin per day with 400 mg moxifloxacin, 20 mg/kg rifampicin per day with 300 mg SQ109, 10 mg/kg rifampicin per day with 300 mg SQ109, or a daily standard control regimen (10 mg/kg rifampicin, 5 mg/kg isoniazid, 25 mg/kg pyrazinamide, and 15-20 mg/kg ethambutol). Experimental treatments were given with oral 5 mg/kg isoniazid and 25 mg/kg pyrazinamide per day for 12 weeks, followed by 14 weeks of 5 mg/kg isoniazid and 10 mg/kg rifampicin per day. Because of the orange discoloration of body fluids with higher doses of rifampicin it was not possible to mask patients and clinicians to treatment allocation. The primary endpoint was time to culture conversion in liquid media within 12 weeks. Patients without evidence of rifampicin resistance on phenotypic test who took at least one dose of study treatment and had one positive culture on liquid or solid media before or within the first 2 weeks of treatment were included in the primary analysis (modified intention to treat). Time-to-event data were analysed using a Cox proportional-hazards regression model and adjusted for minimisation variables. The proportional hazard assumption was tested using Schoelfeld residuals, with threshold p<0·05 for non-proportionality. The trial is registered with ClinicalTrials.gov (NCT01785186)., Findings: Between May 7, 2013, and March 25, 2014, we enrolled and randomly assigned 365 patients to different treatment arms (63 to rifampicin 35 mg/kg, isoniazid, pyrazinamide, and ethambutol; 59 to rifampicin 10 mg/kg, isoniazid, pyrazinamide, SQ109; 57 to rifampicin 20 mg/kg, isoniazid, pyrazinamide, and SQ109; 63 to rifampicin 10 mg/kg, isoniazid, pyrazinamide, and moxifloxacin; and 123 to the control arm). Recruitment was stopped early in the arms containing SQ109 since prespecified efficacy thresholds were not met at the planned interim analysis. Time to stable culture conversion in liquid media was faster in the 35 mg/kg rifampicin group than in the control group (median 48 days vs 62 days, adjusted hazard ratio 1·78; 95% CI 1·22-2·58, p=0·003), but not in other experimental arms. There was no difference in any of the groups in time to culture conversion on solid media. 11 patients had treatment failure or recurrent disease during post-treatment follow-up: one in the 35 mg/kg rifampicin arm and none in the moxifloxacin arm. 45 (12%) of 365 patients reported grade 3-5 adverse events, with similar proportions in each arm., Interpretation: A dose of 35 mg/kg rifampicin was safe, reduced the time to culture conversion in liquid media, and could be a promising component of future, shorter regimens. Our adaptive trial design was successfully implemented in a multi-centre, high tuberculosis burden setting, and could speed regimen development at reduced cost., Funding: The study was funded by the European and Developing Countries Clinical Trials partnership (EDCTP), the German Ministry for Education and Research (BmBF), and the Medical Research Council UK (MRC)., (Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2017
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41. Non-inferiority trials: are they inferior? A systematic review of reporting in major medical journals.
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Rehal S, Morris TP, Fielding K, Carpenter JR, and Phillips PP
- Subjects
- Bias, Biomedical Research standards, Guidelines as Topic, Humans, Journal Impact Factor, Patient Selection, Periodicals as Topic, Sample Size, Statistics as Topic, Biomedical Research methods, Publishing, Research Design
- Abstract
Objective: To assess the adequacy of reporting of non-inferiority trials alongside the consistency and utility of current recommended analyses and guidelines., Design: Review of randomised clinical trials that used a non-inferiority design published between January 2010 and May 2015 in medical journals that had an impact factor >10 (JAMA Internal Medicine, Archives Internal Medicine, PLOS Medicine, Annals of Internal Medicine, BMJ, JAMA, Lancet and New England Journal of Medicine)., Data Sources: Ovid (MEDLINE)., Methods: We searched for non-inferiority trials and assessed the following: choice of non-inferiority margin and justification of margin; power and significance level for sample size; patient population used and how this was defined; any missing data methods used and assumptions declared and any sensitivity analyses used., Results: A total of 168 trial publications were included. Most trials concluded non-inferiority (132; 79%). The non-inferiority margin was reported for 98% (164), but less than half reported any justification for the margin (77; 46%). While most chose two different analyses (91; 54%) the most common being intention-to-treat (ITT) or modified ITT and per-protocol, a large number of articles only chose to conduct and report one analysis (65; 39%), most commonly the ITT analysis. There was lack of clarity or inconsistency between the type I error rate and corresponding CIs for 73 (43%) articles. Missing data were rarely considered with (99; 59%) not declaring whether imputation techniques were used., Conclusions: Reporting and conduct of non-inferiority trials is inconsistent and does not follow the recommendations in available statistical guidelines, which are not wholly consistent themselves. Authors should clearly describe the methods used and provide clear descriptions of and justifications for their design and primary analysis. Failure to do this risks misleading conclusions being drawn, with consequent effects on clinical practice., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)
- Published
- 2016
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42. Effect of Opioids vs NSAIDs and Larger vs Smaller Chest Tube Size on Pain Control and Pleurodesis Efficacy Among Patients With Malignant Pleural Effusion: The TIME1 Randomized Clinical Trial.
- Author
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Rahman NM, Pepperell J, Rehal S, Saba T, Tang A, Ali N, West A, Hettiarachchi G, Mukherjee D, Samuel J, Bentley A, Dowson L, Miles J, Ryan CF, Yoneda KY, Chauhan A, Corcoran JP, Psallidas I, Wrightson JM, Hallifax R, Davies HE, Lee YC, Dobson M, Hedley EL, Seaton D, Russell N, Chapman M, McFadyen BM, Shaw RA, Davies RJ, Maskell NA, Nunn AJ, and Miller RF
- Subjects
- Aged, Algorithms, Analgesia methods, Analgesics, Opioid adverse effects, Anti-Inflammatory Agents, Non-Steroidal adverse effects, Confidence Intervals, Equipment Design, Female, Humans, Male, Pain Measurement methods, Pleural Effusion, Malignant complications, Salvage Therapy methods, Salvage Therapy statistics & numerical data, Thoracoscopy instrumentation, Treatment Failure, Analgesics, Opioid therapeutic use, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Chest Tubes adverse effects, Pain Management methods, Pleural Effusion, Malignant therapy, Pleurodesis methods
- Abstract
Importance: For treatment of malignant pleural effusion, nonsteroidal anti-inflammatory drugs (NSAIDs) are avoided because they may reduce pleurodesis efficacy. Smaller chest tubes may be less painful than larger tubes, but efficacy in pleurodesis has not been proven., Objective: To assess the effect of chest tube size and analgesia (NSAIDs vs opiates) on pain and clinical efficacy related to pleurodesis in patients with malignant pleural effusion., Design, Setting, and Participants: A 2×2 factorial phase 3 randomized clinical trial among 320 patients requiring pleurodesis in 16 UK hospitals from 2007 to 2013., Interventions: Patients undergoing thoracoscopy (n = 206; clinical decision if biopsy was required) received a 24F chest tube and were randomized to receive opiates (n = 103) vs NSAIDs (n = 103), and those not undergoing thoracoscopy (n = 114) were randomized to 1 of 4 groups (24F chest tube and opioids [n = 28]; 24F chest tube and NSAIDs [n = 29]; 12F chest tube and opioids [n = 29]; or 12F chest tube and NSAIDs [n = 28])., Main Outcomes and Measures: Pain while chest tube was in place (0- to 100-mm visual analog scale [VAS] 4 times/d; superiority comparison) and pleurodesis efficacy at 3 months (failure defined as need for further pleural intervention; noninferiority comparison; margin, 15%)., Results: Pain scores in the opiate group (n = 150) vs the NSAID group (n = 144) were not significantly different (mean VAS score, 23.8 mm vs 22.1 mm; adjusted difference, -1.5 mm; 95% CI, -5.0 to 2.0 mm; P = .40), but the NSAID group required more rescue analgesia (26.3% vs 38.1%; rate ratio, 2.1; 95% CI, 1.3-3.4; P = .003). Pleurodesis failure occurred in 30 patients (20%) in the opiate group and 33 (23%) in the NSAID group, meeting criteria for noninferiority (difference, -3%; 1-sided 95% CI, -10% to ∞; P = .004 for noninferiority). Pain scores were lower among patients in the 12F chest tube group (n = 54) vs the 24F group (n = 56) (mean VAS score, 22.0 mm vs 26.8 mm; adjusted difference, -6.0 mm; 95% CI, -11.7 to -0.2 mm; P = .04) and 12F chest tubes vs 24F chest tubes were associated with higher pleurodesis failure (30% vs 24%), failing to meet noninferiority criteria (difference, -6%; 1-sided 95% CI, -20% to ∞; P = .14 for noninferiority). Complications during chest tube insertion occurred more commonly with 12F tubes (14% vs 24%; odds ratio, 1.91; P = .20)., Conclusions and Relevance: Use of NSAIDs vs opiates resulted in no significant difference in pain scores but was associated with more rescue medication. NSAID use resulted in noninferior rates of pleurodesis efficacy at 3 months. Placement of 12F chest tubes vs 24F chest tubes was associated with a statistically significant but clinically modest reduction in pain but failed to meet noninferiority criteria for pleurodesis efficacy., Trial Registration: isrctn.org Identifier: ISRCTN33288337.
- Published
- 2015
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43. Risk of selection bias in randomised trials.
- Author
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Kahan BC, Rehal S, and Cro S
- Subjects
- Humans, Sample Size, Selection Bias, Clinical Trials, Phase III as Topic methods, Patient Selection, Randomized Controlled Trials as Topic methods
- Abstract
Background: Selection bias occurs when recruiters selectively enrol patients into the trial based on what the next treatment allocation is likely to be. This can occur even if appropriate allocation concealment is used if recruiters can guess the next treatment assignment with some degree of accuracy. This typically occurs in unblinded trials when restricted randomisation is implemented to force the number of patients in each arm or within each centre to be the same. Several methods to reduce the risk of selection bias have been suggested; however, it is unclear how often these techniques are used in practice., Methods: We performed a review of published trials which were not blinded to assess whether they utilised methods for reducing the risk of selection bias. We assessed the following techniques: (a) blinding of recruiters; (b) use of simple randomisation; (c) avoidance of stratification by site when restricted randomisation is used; (d) avoidance of permuted blocks if stratification by site is used; and (e) incorporation of prognostic covariates into the randomisation procedure when restricted randomisation is used. We included parallel group, individually randomised phase III trials published in four general medical journals (BMJ, Journal of the American Medical Association, The Lancet, and New England Journal of Medicine) in 2010., Results: We identified 152 eligible trials. Most trials (98%) provided no information on whether recruiters were blind to previous treatment allocations. Only 3% of trials used simple randomisation; 63% used some form of restricted randomisation, and 35% did not state the method of randomisation. Overall, 44% of trials were stratified by site of recruitment; 27% were not, and 29% did not report this information. Most trials that did stratify by site of recruitment used permuted blocks (58%), and only 15% reported using random block sizes. Many trials that used restricted randomisation also included prognostic covariates in the randomisation procedure (56%)., Conclusions: The risk of selection bias could not be ascertained for most trials due to poor reporting. Many trials which did provide details on the randomisation procedure were at risk of selection bias due to a poorly chosen randomisation methods. Techniques to reduce the risk of selection bias should be more widely implemented.
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- 2015
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44. A Step toward an Optimized Rifampin Dose Completed.
- Author
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Boeree MJ, Diacon AH, Dawson R, Narunsky K, du Bois J, Venter A, Phillips PP, Gillespie SH, McHugh TD, Hoelscher M, Heinrich N, Rehal S, van Soolingen D, van Ingen J, Magis-Escurra C, Burger D, Plemper van Balen G, and Aarnoutse RE
- Subjects
- Female, Humans, Male, Antibiotics, Antitubercular administration & dosage, Drug Dosage Calculations, Rifampin administration & dosage, Tuberculosis, Pulmonary drug therapy
- Published
- 2015
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45. Blinded Outcome Assessment Was Infrequently Used and Poorly Reported in Open Trials.
- Author
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Kahan BC, Rehal S, and Cro S
- Subjects
- Double-Blind Method, Humans, Clinical Trials as Topic, Outcome Assessment, Health Care methods
- Abstract
Objective: Unblinded outcome assessment can lead to biased estimates of treatment effect in randomised trials. We reviewed published trials to assess how often blinded assessment is used, and whether its use varies according to the type of outcome or assessor., Design and Setting: A review of parallel group, individually randomised phase III trials published in four general medical journals (BMJ, Journal of the American Medical Association, The Lancet, and New England Journal of Medicine) in 2010., Main Outcome Measures: Whether assessment of the primary outcome was blinded, and whether this differed according to outcome or assessor type., Results: We identified 258 eligible trials. Of these, 106 (41%) were reported as double-blind, and 152 (59%) as partially or fully open-label (that is, they included some groups who were unblinded, such as patients, those delivering the intervention, or those in charge of medical care). Of the 152 open trials, 125 required outcome assessment. Of these 125 trials, only 26% stated that outcome assessment was blinded; 51% gave no information on whether assessment was blinded or not. Furthermore, 18% of trials did not state who performed the assessment. The choice of outcome type (e.g. instrument measured, rated, or naturally occurring event) did not appear to influence whether blinded assessment was performed (range 24-32% for the most common outcome types). However, the choice of outcome assessor did influence blinding; independent assessors were blinded much more frequently (71%) than participant (5%) or physician (24%) assessors. Despite this, open trials did not use independent assessors any more frequently than double-blind trials (17% vs. 18% respectively)., Conclusions: Blinding of outcome assessors is infrequently used and poorly reported. Increased use of independent assessors could increase the frequency of blinded assessment.
- Published
- 2015
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46. A dose-ranging trial to optimize the dose of rifampin in the treatment of tuberculosis.
- Author
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Boeree MJ, Diacon AH, Dawson R, Narunsky K, du Bois J, Venter A, Phillips PP, Gillespie SH, McHugh TD, Hoelscher M, Heinrich N, Rehal S, van Soolingen D, van Ingen J, Magis-Escurra C, Burger D, Plemper van Balen G, and Aarnoutse RE
- Subjects
- Adolescent, Adult, Antibiotics, Antitubercular pharmacokinetics, Bacterial Load drug effects, Drug Therapy, Combination, Ethambutol administration & dosage, Female, Humans, Isoniazid administration & dosage, Male, Middle Aged, Pyrazinamide administration & dosage, Rifampin pharmacokinetics, Tuberculosis, Pulmonary microbiology, Young Adult, Antibiotics, Antitubercular administration & dosage, Drug Dosage Calculations, Rifampin administration & dosage, Tuberculosis, Pulmonary drug therapy
- Abstract
Rationale: Rifampin at a dose of 10 mg/kg was introduced in 1971 based on pharmacokinetic, toxicity, and cost considerations. Available data in mice and humans showed that an increase in dose may shorten the duration of tuberculosis treatment., Objectives: To evaluate the safety and tolerability, the pharmacokinetics, and the extended early bactericidal activity of increasing doses of rifampin., Methods: Patients with drug-susceptible tuberculosis were enrolled into a control group of eight patients receiving the standard dose of 10 mg/kg rifampin, followed by consecutive experimental groups with 15 patients each receiving rifampin 20, 25, 30, and 35 mg/kg, respectively, for 14 days. In all patients isoniazid, pyrazinamide, and ethambutol were added in standard doses for the second 7 days of treatment. Safety, pharmacokinetics of rifampin, and fall in bacterial load were assessed., Measurements and Main Results: Grade 1 and 2 adverse events were equally distributed between the five dose groups; there were five grade 3 events of which one was a possibly related hepatotoxicity. Areas under the time-concentration curves and peak serum concentrations of rifampin showed a more than proportional increase with dose. The daily fall in bacterial load over 14 days was 0.176, 0.168, 0.167, 0.265, and 0.261 log10 colony-forming units/ml sputum in the 10, 20, 25, 30, and 35 mg/kg groups, respectively., Conclusions: Two weeks of rifampin up to 35 mg/kg was safe and well tolerated. There was a nonlinear increase in exposure to rifampin without an apparent ceiling effect and a greater estimated fall in bacterial load in the higher dosing groups. Clinical trial registered with www.clinicaltrials.gov (NCT 01392911).
- Published
- 2015
- Full Text
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47. Experimental ileitis alters prostaglandin biosynthesis in mesenteric lymphatic and blood vessels.
- Author
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Rehal S and von der Weid PY
- Subjects
- Animals, Guinea Pigs, Ileitis chemically induced, Ileitis pathology, Intestine, Small pathology, Lymphatic Vessels pathology, Rats, Splanchnic Circulation, Dinoprostone metabolism, Epoprostenol metabolism, Ileitis metabolism, Intestine, Small metabolism, Lymphatic Vessels metabolism, Mesentery metabolism, Mesentery pathology
- Abstract
Prostaglandins are important mediators responsible for many changes that occur during the inflammatory response. Specifically, in inflammatory bowel disease (IBD), prostaglandins are key players in maintenance of blood flow and mucosal defense. In blood vessels, prostaglandins modulate and inhibit transmigration. In lymphatic vessels, on the other hand, prostaglandin E2 (PGE2) and prostacyclin (PGI2) have been shown to potently inhibit lymphatic contractility. Inhibition of lymphatic contractility could impair proper tissue fluid drainage during inflammation, consequently leading to the submucosal oedema observed in IBD. Alterations in production of PGE2 and PGI2 during inflammation could have severe implications on lymphatic and vascular functions within the small intestine. Using the 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced ileitis guinea pig and rat models, we assessed by quantitative PCR changes in mRNA transcript of enzymes and receptors involved in the production and actions of prostaglandins in mesenteric lymphatic and blood vessels as well as in the affected ileum. Furthermore, we also assessed lymphatic tissue levels of PGE2 and PGI2 during inflammation. We observed significant changes in lymphatic mRNA expression of COX-1, COX-2, MPGES-1, PGIS, EP4 and IP and increases in PGE2 and PGI2 in tissues of TNBS-treated animals. Changes in mRNA in blood vessels from TNBS-treated animals included differences in COX-1, COX-2, MPGES-1, PGIS, EP1, EP2 and IP expression. Prostaglandin metabolites are differentially regulated in both lymphatic and blood vessels during intestinal inflammation., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
48. Acute variceal haemorrhage in the United Kingdom: patient characteristics, management and outcomes in a nationwide audit.
- Author
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Jairath V, Rehal S, Logan R, Kahan B, Hearnshaw S, Stanworth S, Travis S, Murphy M, Palmer K, and Burroughs A
- Subjects
- Adult, Aged, Anti-Bacterial Agents therapeutic use, Area Under Curve, End Stage Liver Disease complications, Erythrocyte Transfusion, Female, Gastrointestinal Hemorrhage etiology, Hemostasis, Endoscopic statistics & numerical data, Humans, Male, Medical Audit, Middle Aged, Platelet Transfusion, Proton Pump Inhibitors therapeutic use, ROC Curve, Recurrence, Risk Assessment, Time-to-Treatment, Treatment Outcome, United Kingdom epidemiology, Vasoconstrictor Agents therapeutic use, Esophageal and Gastric Varices etiology, Gastrointestinal Hemorrhage mortality, Gastrointestinal Hemorrhage therapy, Liver Cirrhosis complications, Severity of Illness Index
- Abstract
Background: Despite advances in treatment, acute variceal haemorrhage remains life-threatening., Aim: To describe contemporary characteristics, management and outcomes of patients with cirrhosis and acute variceal haemorrhage and risk factors for rebleeding and mortality., Methods: Multi-centre clinical audit conducted in 212 UK hospitals., Results: In 526 cases of acute variceal haemorrhage, 66% underwent endoscopy within 24h with 64% (n=339) receiving endoscopic therapy. Prior to endoscopy, 57% (n=299) received proton pump inhibitors, 44% (n=232) vasopressors and 27% (n=144) antibiotics. 73% (n=386) received red cell transfusion, 35% (n=184) fresh frozen plasma and 14% (n=76) platelets, with widely varying transfusion thresholds. 26% (n=135) experienced further bleeding and 15% (n=80) died by day 30. The Model for End Stage Liver Disease score was the best predictor of mortality (area under the receiver operating curve=0.74, P<0.001). Neither the clinical nor full Rockall scores were useful predictors of outcome. Coagulopathy was strongly associated with rebleeding (odds ratio 2.23, 95% CI 1.22-4.07, P=0.01, up to day 30) and mortality (odds ratio 3.06, 95% CI 1.29-7.26, P=0.01)., Conclusions: Although mortality has improved following acute variceal haemorrhage, rebleeding rates remain appreciably high. There are notable deficiencies in the use of vasopressors and endoscopic therapy. More work is needed to understand the optimum transfusion strategies. Better risk stratification tools are required to identify patients needing more intensive support., (Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2014
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49. Mechanisms of VIP-induced inhibition of the lymphatic vessel pump.
- Author
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von der Weid PY, Rehal S, Dyrda P, Lee S, Mathias R, Rahman M, Roizes S, and Imtiaz MS
- Subjects
- Animals, Guinea Pigs, In Vitro Techniques, Membrane Potentials, Lymphatic Vessels physiology, Vasoactive Intestinal Peptide physiology
- Abstract
Lymphatic vessels serve as a route by which interstitial fluid, protein and other macromolecules are returned to the blood circulation and immune cells and antigens gain access to lymph nodes. Lymph flow is an active process promoted by rhythmical contraction-relaxation events occurring in the collecting lymphatic vessels. This lymphatic pumping is an intrinsic property of the lymphatic muscles in the vessel wall and consequent to action potentials. Compromised lymphatic pumping may affect lymph and immune cell transport, an action which could be particularly detrimental during inflammation. Importantly, many inflammatory mediators alter lymphatic pumping. Vasoactive intestinal peptide (VIP) is a neuro- and immuno-modulator thought to be released by nerve terminals and immune cells in close proximity to lymphatic vessels. We demonstrated the presence of the peptide in lymphatic vessels and in the lymph and examined the effects of VIP on mesenteric collecting lymphatic vessels of the guinea pig using pharmacological bioassays, intracellular microelectrode electrophysiology, immunofluorescence and quantitative real-time PCR. We showed that VIP alters lymphatic pumping by decreasing the frequency of lymphatic contractions and hyperpolarizing the lymphatic muscle membrane potential in a concentration-dependent manner. Our data further suggest that these effects are mainly mediated by stimulation of the VIP receptor VPAC2 located on the lymphatic muscle and the downstream involvement of protein kinase A (PKA) and ATP-sensitive K⁺ (KATP) channels. Inhibition of lymphatic pumping by VIP may compromise lymph drainage, oedema resolution and immune cell trafficking to the draining lymph nodes.
- Published
- 2012
- Full Text
- View/download PDF
50. Role of the lymphatic system in the pathogenesis of Crohn's disease.
- Author
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von der Weid PY, Rehal S, and Ferraz JG
- Subjects
- Humans, Lymphangiogenesis physiology, Lymphatic System immunology, Lymphatic System microbiology, Crohn Disease immunology, Lymphangitis complications, Lymphatic System physiopathology
- Abstract
Purpose of Review: Intestinal lymph containing interstitial fluid, proteins, immune cells, and digested lipids is actively transported back to the blood stream thanks to rhythmical contractions of the mesenteric lymphatic vessels. During this process, lymph flows through several lymph nodes, allowing antigens to be sampled by the immune system. Abnormalities in lymphatic drainage have been noted in the original descriptions of Crohn's disease, but essentially ignored since. The lymphatic system is re-emerging as a critical player in inflammatory and immune processes and the purpose of this review is to present and discuss new concepts related to the involvement of the lymphatic system in the development of inflammatory bowel diseases (IBDs) and more specifically Crohn's disease., Recent Findings: Recent studies reporting lymphangitis, lymphangiogenesis, bacterial infiltration and lymph node infection, immune cell trafficking, and fat-wrapping in Crohn's disease suggest altered lymph drainage and lymphatic pumping, implicating the lymphatic system as a likely player in inflammatory disorders and IBDs., Summary: Improved knowledge and appreciation of the roles that the lymphatic system plays in immune cell trafficking, infection, fat transport, distribution and metabolism and, of course, edema resolution is necessary to better understand the pathogenesis of chronic inflammatory conditions such as Crohn's disease and may provide the basis for new therapeutic strategies.
- Published
- 2011
- Full Text
- View/download PDF
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