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Casaban J, Zhang Y, Pacheco R, Coney C, Holmes C, Sutherland E, Hamill C, Breen J, James SL, Tufano D, Wong D, Stavrakakis E, Annath H, Moore A. Towards MOFs' mass market adoption: MOF Technologies' efficient and versatile one-step extrusion of shaped MOFs directly from raw materials. Faraday Discuss 2021; 231:312-325. [PMID: 34225354 DOI: 10.1039/d1fd00025j] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Metal Organic Frameworks (MOFs) offer unparalleled physical and sorption properties due to their chemical tunability and unmatched porosity. MOFs are consequently envisaged to play a key role in commercial gas storage and separation applications. However, it is essential to tackle their current market entry barriers, if mainstream adoption is to be realised. MOF Technologies is a pioneer in MOF commercialisation and has developed innovative solutions with unprecedented efficiency to bring these materials to market. A continuous, versatile and sustainable one-step production method of MOFs in shaped form is demonstrated for the first time. Its advantages for large-scale production and mass customisation are exemplified and validated with performance evaluation under realistic operating conditions.
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Sim N, Lee S, Yap HY, Tan QY, Tan J, Wong D, Chau A, Mak M, Chong TT, Tay HT. A review of the Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe (TOPHAT) flap for wound coverage during ray amputations of the toes. Foot (Edinb) 2021; 47:101803. [PMID: 33964533 DOI: 10.1016/j.foot.2021.101803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/07/2021] [Accepted: 04/11/2021] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Exposure of the adjacent Metatarsal-Phalangeal Joint (MTPJ) commonly occurs after application of Topical Negative Pressure Wound Therapy (TNPWT) for a ray amputation wound. This is due to mechanical soft tissue erosion or trauma to the adjacent digital artery from direct pressure effect. This results in toe gangrene requiring a ray amputation and ultimately a larger wound bed. We describe the use of the Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe (TOPHAT) flap - a filleted toe flap to protect the adjacent MTPJ capsule combined with a novel Negative Pressure Wound Therapy with instillation and dwell-time (NPWTi-d) dressing technique. The flap protects the adjacent joint capsule and reduces the wound burden whilst allowing the wound to benefit from TNPWT, thereby accelerating wound healing. MATERIAL AND METHODS A retrospective review was conducted of patients with toe gangrene requiring ray amputation that underwent the TOPHAT flap on in our institution from 2019 and 2020. Complications such as wound dehiscence, hematoma, flap necrosis and secondary infection were recorded. Other outcomes recorded were time taken to final skin grafting and time taken for complete wound epithelialization. RESULTS 9 patients underwent treatment with the TOPHAT flap. 2 patients had flap necrosis. 7 patients progressed to definitive skin coverage with skin grafting. One patient subsequently had progressive arterial disease despite successful skin grafting and required above knee amputation. The mean time to final skin grafting and complete wound epithelialization was 49.5 days and 107.5 days respectively. All patients were satisfied with the outcomes and were able to return to their pre-morbid function. CONCLUSIONS The TOPHAT flap has a consistent vascular supply that provides durable soft tissue coverage. It is a robust and easily reproducible technique to accelerate wound healing after ray amputations even in patients with peripheral vascular disease.
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Boone N, Ramiro S, Moes DJ, Mostard R, Magro Checa C, Van Dongen C, Gronenschild M, Van Haren E, Buijs J, Peeters R, Wong D, Landewé RBM. POS1256 SINGLE DOSE TOCILIZUMAB PHARMACOKINETICS IN GLUCOCORTICOID PRE-TREATED COVID-19 PATIENTS DURING CYTOKINE STORM SYNDROME HYPERINFLAMMATORY EPISODE: LESS IS MORE. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.3836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Background:The cytokine storm syndrome (CSS) associated with COVID-19 pneumonia occurs in up to 20% of the admitted patients causing high morbidity and mortality [1]. In the COVID High-intensity Immunosuppression in Cytokine storm syndrome (CHIC) study [1] we reported that CSS patients, who despite high-dose methylprednisolone (MP) treatment still showed severe respiratory deterioration, received subsequent single dose tocilizumab (TCZ) treatment. Our clinical experience with TCZ, every 4 weeks in RA, where a pre-dose serum concentration of > 1 µg/ml is sufficient to block all interleukin (IL)-6 receptors and thereby induce and maintain clinical remission, prompted further investigation of TCZ pharmacokinetics in patients with COVID-19 CSS [1,2].Objectives:In this pharmacokinetic study we investigated the clinical-pharmacokinetic rationale for a single TCZ dose in a subset of COVID19 induced CSS patients.Methods:Patients with COVID-19-associated CSS, defined as rapid respiratory deterioration plus at least two biomarker elevations (C-reactive protein (CRP) >100 mg/L; ferritin >900 μg/L; D-dimers >1500 μg/L), received per protocol high-dose intravenous MP for 5 consecutive days. If the respiratory condition had not improved sufficiently, TCZ (8 mg/kg, max. 800 mg) single infusion was added on or after day 2[1]. TCZ serum samples were drawn at TCZ day 1, 3 and 10 to assess TCZ serum concentrations with a validated ELISA-method. A nonlinear-mixed effects model was developed based on all concentration time data to characterise TCZ pharmacokinetics (NONMEM). Subsequently individual pharmacokinetic parameters (AUC0-inf, Cmax, time above 1 µg/ml) were estimated and TCZ concentration-time observations were plotted against the individual predicted concentrations to visualize the complete TCZ concentration-time curve.Results:In total, 34 patients with COVID19 induced CSS still showing clinical deterioration upon MP treatment received TCZ per protocol [mean (SD) age: 62 (12) years, 22% female, baseline mean (SD) bodyweight: 87 (17) kg, CRP: 108 (833) mmol/L, ferritin: 1653 (911) µg/L, D-dimers 4462 (7272) µg/L]. TCZ clearance was described by a homogeneous population-kinetics model yielding 87 serum samples. TCZ serum concentrations followed a biphasic course [Distribution volume 5.0 L (3.3-7.3), Area Under the Curve0-∞1st dose (682 (397-913) mg/L*days), Cmax 137 mg/L (88 – 199), half-life (linear) 3.5 days (2.3-4.1)]. In all patients, TCZ serum concentrations remained above the theoretical maximum IL-6 receptor occupancy concentration of 1 µg/ml for at least 12 days, depicted in Figure 1.Figure 1.Predicted concentration-time profiles after single dose tocilizumab in 34 methylpred-nisolone pretreated patients with COVID-19 induced cytokine storm syndrome. Dashed line: maximum IL-6 receptor occupancy concentration 1 µg/mlConclusion:Based on our study results on the pharmacokinetics of TCZ in patients with severe COVID-19 induced CSS we conclude that the clearance of TCZ is faster compared to RA-patients at steady state. However, our observations indicate that a single dose of tocilizumab in CSS-patients is enough to cover IL-6 mediated hyperinflammation. Restricting TCZ to a single dosage can prevent overtreatment, drug shortage and saves costs, while still maintaining efficacy, as most patients will have overcome their hyperinflammatory period of the CSS after 10-14 days.References:[1]Ramiro S. Mostard R.L.M. et al. Historically controlled comparison of glucocorticoids with or without tocilizumab versus supportive care only in patients with COVID-19-associated cytokine storm syndrome: results of the CHIC study. Ann Rheum Dis 2020;79(9):1143-1151.[2]Nishimoto N, Terao K et al. Mechanisms and pathologic significances in increase in serum interleukin-6 (IL-6) and soluble IL-6 receptor after administration of an anti IL-6 receptor antibody, tocilizumab, in patients with rheumatoid arthritis and Castleman disease. Blood. 2008;112:3959-3964.Acknowledgements:The authors are grateful to all patients, nurses and physicians who participated in this study.Disclosure of Interests:None declared
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Zargarnezhad H, Asselin E, Wong D, Lam CNC. A Critical Review of the Time-Dependent Performance of Polymeric Pipeline Coatings: Focus on Hydration of Epoxy-Based Coatings. Polymers (Basel) 2021; 13:1517. [PMID: 34065062 PMCID: PMC8125940 DOI: 10.3390/polym13091517] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 11/16/2022] Open
Abstract
The barrier performance of organic coatings is a direct function of mass transport and long-term stability of the polymeric structure. A predictive assessment of the protective coating cannot be conducted a priori of degradation effects on transport. Epoxy-based powder coatings are an attractive class of coatings for pipelines and other structures because application processing times are low and residual stresses between polymer layers are reduced. However, water ingress into the polymeric network of these coatings is of particular interest due to associated competitive sorption and plasticization effects. This review examines common analytical techniques for identifying parameters involved in transport in wet environments and underscores the gaps in the literature for the evaluation of the long-term performance of such coating systems. Studies have shown that the extent of polymer hydration has a major impact on gas and ion permeability/selectivity. Thus, transport analyses based only on micropore filling (i.e., adsorption) by water molecules are inadequate. Combinatorial entropy of the glassy epoxy and water vapor mixture not only affects the mechanism of membrane plasticization, but also changes the sorption kinetics of gas permeation and causes a partial gas immobility in the system. However, diffusivity, defined as the product of a kinetic mobility parameter and a concentration-dependent thermodynamic parameter, can eventually become favorable for gas transport at elevated temperatures, meaning that increasing gas pressure can decrease selectivity of the membrane for gas permeation. On the other hand, reverse osmosis membranes have shown that salt permeation is sensitive to, among other variables, water content in the polymer and a fundamental attribute in ionic diffusion is the effective size of hydrated ions. In addition, external electron sources-e.g., cathodic protection potentials for pipeline structures-can alter the kinetics of this transport as the tendency of ions to dissociate increases due to electrostatic forces. Focusing primarily on epoxy-based powder coatings, this review demonstrates that service parameters such as humidity, temperature, and concentration of aggressive species can dynamically develop different transport mechanisms, each at the expense of others. Although multilayered coating systems decrease moisture ingress and the consequences of environmental exposure, this survey shows that demands for extreme operating conditions can pose new challenges for coating materials and sparse data on transport properties would limit analysis of the remaining life of the system. This knowledge gap impedes the prediction of the likelihood of coating and, consequently, infrastructure failures.
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Milosevic V, Linkens A, Winkens B, Hurkens KPGM, Wong D, van Oijen BPC, van der Kuy HM, Mestres-Gonzalvo C. Fall incidents in nursing home residents: development of a predictive clinical rule (FINDER). BMJ Open 2021; 11:e042941. [PMID: 33941626 PMCID: PMC8098923 DOI: 10.1136/bmjopen-2020-042941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVES To develop (part I) and validate (part II) an electronic fall risk clinical rule (CR) to identify nursing home residents (NH-residents) at risk for a fall incident. DESIGN Observational, retrospective case-control study. SETTING Nursing homes. PARTICIPANTS A total of 1668 (824 in part I, 844 in part II) NH-residents from the Netherlands were included. Data of participants from part I were excluded in part II. PRIMARY AND SECONDARY OUTCOME MEASURES Development and validation of a fall risk CR in NH-residents. Logistic regression analysis was conducted to identify the fall risk-variables in part I. With these, three CRs were developed (ie, at the day of the fall incident and 3 days and 5 days prior to the fall incident). The overall prediction quality of the CRs were assessed using the area under the receiver operating characteristics (AUROC), and a cut-off value was determined for the predicted risk ensuring a sensitivity ≥0.85. Finally, one CR was chosen and validated in part II using a new retrospective data set. RESULTS Eleven fall risk-variables were identified in part I. The AUROCs of the three CRs form part I were similar: the AUROC for models I, II and III were 0.714 (95% CI: 0.679 to 0.748), 0.715 (95% CI: 0.680 to 0.750) and 0.709 (95% CI: 0.674 to 0.744), respectively. Model III (ie, 5 days prior to the fall incident) was chosen for validation in part II. The validated AUROC of the CR, obtained in part II, was 0.603 (95% CI: 0.565 to 0.641) with a sensitivity of 83.41% (95% CI: 79.44% to 86.76%) and a specificity of 27.25% (95% CI 23.11% to 31.81%). CONCLUSION Medication data and resident characteristics alone are not sufficient enough to develop a successful CR with a high sensitivity and specificity to predict fall risk in NH-residents. TRIAL REGISTRATION NUMBER Not available.
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Lee W, Kwan K, Wong D, Lee V. PO-0223 Ir-192 position measurement for pre-treatment QA using a fluorescent screen-based optical detector. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06382-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lin A, Kolossváry M, Cadet S, McElhinney P, Yuvaraj J, Nerlekar N, Nicholls S, Slomka P, Maurovich-Horvat P, Wong D, Dey D. RADIOMICS-BASED PRECISION PHENOTYPING DISTINGUISHES CULPRIT AND NONCULPRIT LESIONS IN MYOCARDIAL INFARCTION AND LESIONS IN STABLE CORONARY ARTERY DISEASE. J Am Coll Cardiol 2021. [DOI: 10.1016/s0735-1097(21)02638-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schneider J, Davies S, Howarth A, GARCIA SANCHEZ J, Rao N, Grandy S, Bhatt P, Parackal A, Wong D, Briggs A. POS-321 TRANSLATING THE FINDINGS OF THE ROXADUSTAT NDD GLOBAL PHASE 3 PROGRAM INTO COST OFFSETS FROM A CANADIAN HEALTHCARE PERSPECTIVE. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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GARCIA SANCHEZ J, Fifer S, West B, Wittbrodt E, Bhatt P, Grandy S, Rao N, Wong D, Karamy R, Parackal A, Khan F, Tennankore K, Johnson D. POS-318 PATIENT PREFERENCES FOR RISKS AND BENEFITS OF MEDICATIONS TO MANAGE ANEMIA OF CHRONIC KIDNEY DISEASE: A DISCRETE CHOICE EXPERIMENT. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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GARCIA SANCHEZ J, Retat L, Webber L, Cabrera C, Grandy S, Rao N, Bhatt P, Parackal A, Wong D, Wish J, Tangri N. POS-320 INSIDE ANEMIA OF CKD: QUANTIFYING THE EPIDEMIOLOGICAL BURDEN OF ANEMIA OF CKD IN CANADA VIA MICROSIMULATION MODELLING. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Tigges A, Wong D, Blanchard D. Right Atrial Function Index in Chronic Thromboembolic Pulmonary Hypertension before and after Pulmonary Thromboendarterectomy. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.1281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Leung K, Jaberi A, Kachura J, Duan K, Wong D. A228 WHEN ASCITES & VARICEAL BLEEDING ARE NOT FROM CIRRHOSIS: A CASE OF MUTIPLE ARTERIOPORTAL FISTULAE CAUSING PORTAL HYPERTENSION. J Can Assoc Gastroenterol 2021. [DOI: 10.1093/jcag/gwab002.226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Portal hypertension is usually due to increased resistance from cirrhosis. However, pressures can also be elevated due to increased flow.
Aims
To describe a peculiar case of non-cirrhotic portal hypertension.
Methods
A case report and literature review was performed.
Results
A 47-year-old previously well man presented with a 6 month history of rapidly progressive weight loss, ascites and variceal bleed. Workup ruled out common causes of primary liver disease. Initial imaging demonstrated a heterogenous liver, splenomegaly, ascites, patent hepatic/portal veins and multiple poorly defined low-density hepatic lesions with the largest measuring 2.1 cm. Transient elastography was 7.3 kPa (F1-mild fibrosis). At transjugular liver biopsy, hepatic venogram ruled out Budd-Chiari and hepatic vein pressure gradient was normal at 3–4 mmHg. Histology unfortunately showed hemangioma. A percutaneous liver biopsy suggested nodular regenerative hyperplasia, minimal fibrosis and mild cholestasis. Given worsening ascites, hyponatremia and 7 months of rapidly progressive decline, transjugular intrahepatic portosystemic shunt (TIPSS) was inserted. Intra-procedure, portal vein pressure was noted to be 51 mmHg, with a portosystemic gradient of 42 mmHg. Although numerous abdominal CT and MRI did not show AV shunting, ultrasound post-TIPSS showed hepatic pseudoaneurysms & arterioportal fistulae (APF). Direct angiogram showed numerous hepatic pseudoaneurysms and intrahepatic fistulae making embolization impossible. CT showed no evidence of pseudoaneurysms or fistulae outside of the liver. Workup for autoimmune rheumatological diseases and congenital telangiectatic syndromes were negative. Given the high pressures being directed through the new TIPSS, right heart failure is an ongoing concern.
APF are rarely encountered causes of presinusoidal portal hypertension, with communications most commonly arising from the hepatic (65%) & splenic arteries (11%) & the portal vein. Causes include traumatic (28%), iatrogenic (16%), vascular/telangiectatic malformations (15%), tumors (15%), aneurysms (14%) & congenital disease. Endovascular embolization can be used to treat single lesions. In complex cases with mulitple APF, surgery and/or liver transplantation may be required.
Conclusions
We report a rare case of non-cirrhotic portal hypertension due to increased flow rather than increased resistance secondary to APF.
Funding Agencies
None
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Lewis J, Li J, Gray R, Carlyle A, Wong D. Cardiac Sarcoidosis Mimicking Hypertrophic Cardiomyopathy: The Utility of Multimodality Imaging. Heart Lung Circ 2021. [DOI: 10.1016/j.hlc.2021.06.192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Yuvaraj J, Cameron W, Andrews J, Lin A, Nerlekar N, Nicholls S, Hamilton G, Wong D, Issa M, Che Z, Lim E. Association of Coronary Inflammation With Obstructive Sleep Apnoea and Coronary Artery Disease: Insights From Computed Tomography Coronary Angiography (CTCA). Heart Lung Circ 2021. [DOI: 10.1016/j.hlc.2021.06.183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Tan S, Chan J, Thakur U, Thein P, Muthalaly R, Talman A, Dey D, Brown A, Wu A, Seneviratne S, Cameron J, Wong D, Nerlekar N. Inter-Software and Inter-Scan Variability Amongst Post-Processing Software Platforms in Measurement of Epicardial Adipose Tissue. Heart Lung Circ 2021. [DOI: 10.1016/j.hlc.2021.06.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Cheung KW, Seto MTY, Kan ASY, Wong D, Kou TKO, So PL, Lau WL, Wong RMS, Lee CP, Ng EHY. Maternal and obstetric factors of hepatitis B immunisation failure in Hong Kong: a multicentre prospective study: abridged secondary publication. Hong Kong Med J 2020; 26 Suppl 6:24-25. [PMID: 33229599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023] Open
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Bouchareychas L, Duong P, Covarrubias S, Alsop E, Q Phu T, Chung A, Gomes M, Wong D, Meechoovet B, Capili A, Yamamoto R, Nakauchi H, Mcmanus M, Carpenter S, Van Keuren-Jensen K, Raffai R. M2 macrophage exosomes regulate hematopoiesis & resolve inflammation in atherosclerosis via microrna cargo. Atherosclerosis 2020. [DOI: 10.1016/j.atherosclerosis.2020.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Filippou V, Redmond AC, Bennion J, Backhouse MR, Wong D. Capturing accelerometer outputs in healthy volunteers under normal and simulated-pathological conditions using ML classifiers .. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:4604-4607. [PMID: 33019019 DOI: 10.1109/embc44109.2020.9176201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Wearable devices offer a possible solution for acquiring objective measurements of physical activity. Most current algorithms are derived using data from healthy volunteers. It is unclear whether such algorithms are suitable in specific clinical scenarios, such as when an individual has altered gait. We hypothesized that algorithms trained on healthy population will result in less accurate results when tested in individuals with altered gait. We further hypothesized that algorithms trained on simulated-pathological gait would prove better at classifying abnormal activity. We studied healthy volunteers to assess whether activity classification accuracy differed for those with healthy and simulated-pathological conditions. Healthy participants (n=30) were recruited from the University of Leeds to perform nine predefined activities under healthy and simulated-pathological conditions. Activities were captured using a wrist-worn MOX accelerometer (Maastricht Instruments, NL). Data were analyzed based on the Activity-Recognition-Chain process. We trained a Neural-Network, Random-Forests, k-Nearest-Neighbors (k-NN), Support-Vector-Machines (SVM) and Naive Bayes models to classify activity. Algorithms were trained four times; once with `healthy' data, and once with `simulated-pathological data' for each of activity-type and activity-task classification. In activity-type instances, the SVM provided the best results; the accuracy was 98.4% when the algorithm was trained and then tested with unseen data from the same group of healthy individuals. Accuracy dropped to 52.8% when tested on simulated-pathological data. When the model was retrained with simulated-pathological data, prediction accuracy for the corresponding test set was 96.7%. Algorithms developed on healthy data are less accurate for pathological conditions. When evaluating pathological conditions, classifier algorithms developed using data from a target sub-population can restore accuracy to above 95%.
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Trieu PDY, Puslednik L, Colley B, Brennan A, Rodriguez VC, Cook N, Dean K, Dryburgh S, Lowe H, Mahon C, McGowan S, O'Brien J, Moog W, Whale J, Wong D, Li T, Brennan PC. Interpretative characteristics and case features associated with the performances of radiologists in reading mammograms: A study from a non-screening population in Asia. Asia Pac J Clin Oncol 2020; 17:139-148. [PMID: 32894814 DOI: 10.1111/ajco.13429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 06/20/2020] [Indexed: 11/30/2022]
Abstract
AIMS To explore radiologist characteristics and case features associated with diagnostic performances in cancer detection on mammograms in a South East Asian population. METHODS Fifty-three radiologists reported 60 mammographic examinations which consisted of 40 normal and 20 cancer-containing cases at the BREAST workshops. Radiologists were asked to examine each mammogram using the BIRADS on diagnostic monitors. Differences in reader characteristics and case features between correct and incorrect decisions were assessed separately for cancer and normal cases. Univariate and multivariate logistic regressions were applied to generate odds ratios (OR) for significant factors related to correct decisions. RESULTS Radiologists who spent ≥10 hours/week reporting mammograms had a higher possibility of detecting cancer lesions (OR = 1.6; P = 0.01). A higher rate of accuracy in reporting negative cases was associated with female radiologists (OR = 1.4; P = 0.002), radiologists who read ≤20 mammograms per week (OR = 1.5; P < 0.0001), had completed training course (OR = 1.7; P < 0.0001) or wore eyeglasses (OR = 1.4; P = 0.01). Cancer cases with breast density >50% (OR = 2.1; P < 0.0001), having abnormal lesions ≥9 mm (OR = 1.8; P < 0.0001), or displaying calcifications, a discrete mass or nonspecific density (OR = 1.6; P < 0.0001) were recorded with a higher detection rate by radiologists than other cases. Lesions located on the right breasts (OR = 1.8; P < 0.0001) or found in the lower inner, upper outer or mixed locations (OR = 2.7; P < 0.0001) were also recorded with a better diagnostic possibility compared with other lesions. CONCLUSION This work identified key features related to diagnostic accuracy of breast cancer on mammograms in a nonscreening population, which is helpful for developing appropriate strategies to improve breast cancer detectability of radiologists.
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Murphy O, Hoy K, Wong D, Bailey N, Fitzgerald P, Segrave R. Transcranial random noise stimulation is more effective than transcranial direct current stimulation for enhancing working memory in healthy individuals: Behavioural and electrophysiological evidence. Brain Stimul 2020; 13:1370-1380. [DOI: 10.1016/j.brs.2020.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/16/2020] [Accepted: 07/01/2020] [Indexed: 01/22/2023] Open
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Lin A, Wong N, Razipour A, McElhinney P, Commandeur F, Cadet S, Gransar H, Chen X, Cantu S, Miller R, Nerlekar N, Wong D, Slomka P, Rozanski A, Tamarappoo B, Berman D, Dey D. Metabolic Syndrome, Fatty Liver, And Artificial Intelligence-based Epicardial Adipose Tissue Measures Predict Long-term Risk Of Cardiac Events. J Cardiovasc Comput Tomogr 2020. [DOI: 10.1016/j.jcct.2020.06.127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lin A, Kolossváry M, Yuvaraj J, Cadet S, McElhinney P, Jiang C, Nerlekar N, Nicholls S, Slomka P, Maurovich-Horvat P, Wong D, Dey D. Myocardial Infarction Is Associated With A Distinct Pericoronary Adipose Tissue Radiomic Phenotype: A Prospective Case-Control Study. J Cardiovasc Comput Tomogr 2020. [DOI: 10.1016/j.jcct.2020.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yuvaraj J, Lin A, Nerlekar N, Munnur R, Cameron J, Nicholls S, Wong D. 402 Role of Coronary Inflammation in High-Risk Plaque and Acute Coronary Syndrome in Patients With Stable Coronary Artery Disease: Insights from Pericoronary Adipose Tissue Attenuation (PCAT) on CTCA. Heart Lung Circ 2020. [DOI: 10.1016/j.hlc.2020.09.409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Murphy O, Hoy K, Wong D, Bailey N, Fitzgerald P, Segrave R. Individuals with depression display abnormal modulation of neural oscillatory activity during working memory encoding and maintenance. Biol Psychol 2019; 148:107766. [DOI: 10.1016/j.biopsycho.2019.107766] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 07/12/2019] [Accepted: 09/05/2019] [Indexed: 12/19/2022]
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Linz B, Hohl M, Nickel A, Lang L, Boor P, Wong D, Sanders P, Boehm M, Jespersen T, Linz D. P2561Withdrawal of simulated obstructive sleep apnea partially reverses atrial arrhythmogenic substrate in rats. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Obstructive sleep apnea (OSA) is associated with structural alterations of the left atria (LA) and increased occurrence of atrial fibrillation (AF). Obstructive respiratory events lead to intermittent hypoxia (IH) and ineffective inspiration against the occluded upper airways, which result in intrathoracic and cardiac transmural pressure changes. Data on reversibility of LA-structural remodeling processes after withdrawal of OSA are still missing.
Objectives
Aim of the study was to develop a novel AF animal model mimicking intrathoracic pressure changes in addition to IH and to analyze the effect of OSA-withdrawal on atrial remodeling reversibility.
Method
In sedated rats (2% isoflurane), IH (n=9) was applied by intermittent increase in the respiratory dead volume. Standardized obstructive respiratory events were induced by defined intermittent negative upper airway pressure (INAP = inverse CPAP) applied via a customized mask connected to a negative pressure device (n=9). One minute of IH or INAP was followed by a rest period of nine minutes for four hours every second day. Rats with comparable anesthesia were used as controls (CTR). After three weeks, the animals were sacrificed. To analyze atrial structural remodeling reversibility, additional INAP-rats (n=5) were sacrificed after INAP-withdrawal of three weeks and compared to respective CTR (n=7).
Result
Blood pressure was not affected by IH or INAP. Intermittent desaturation and post-apneic hyperventilation were comparable in INAP- and IH-rats, but INAP-rats showed significantly higher breathing efforts during apneas compared to IH-rats. LA connexin43 (Cx43) protein expression assessed by quantitative immunofluorescence was reduced in both groups compared to CTR (0.77±0.07% in CTR vs. 0.45±0.06% in IH, p=0.02; CTR vs. 0.39±0.06% in INAP, p=0.005). However, LA interstitial fibrosis content (7.03±0.58% vs. CTR, p=0.01) and LA myocyte diameters (13.23±0.34μm vs. CTR, p=0.03) were increased in INAP-rats, but not in IH-rats. This was associated with longer inducible AF-durations in INAP-rats (11.65±4.43s vs. 0.72±0.33s in CTR, p=0.03) but not in IH-rats (1.28±0.33s vs. CTR, p=0.31). Three weeks of INAP-withdrawal (INAP-W) normalized interstitial fibrosis content (INAP-W vs. CTR, p=0.50) and LA-myocyte diameter (INAP-W vs. CTR, p=0.31). However, LA Cx43 protein expression remained low after three weeks of INAP withdrawal and inducible AF-episodes were still prolonged compared to respective CTR.
Conclusion
Application of INAP in rats mimics important components of OSA beyond IH and allows the study of an arrhythmogenic substrate in the atrium independent of the development of risk factors. In our model, withdrawal of INAP resulted in partial reversibility of structural LA remodeling but was not sufficient to abolish inducible AF-episodes completely. Future clinical studies are warranted to determine the anti-arrhythmic effect of isolated sleep apnea treatment in AF-patients.
Acknowledgement/Funding
Else Kröner-Fresenius-Stiftung, SFB-TRR219-M02/S-02
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