24 results on '"Christopher Buckle"'
Search Results
2. Amyloid-PET imaging predicts functional decline in clinically normal individuals
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Lisa Quenon, Lyduine E. Collij, David Vállez Garcia, Isadora Lopes Alves, Thomas Gérard, Vincent Malotaux, Lara Huyghe, Juan Domingo Gispert, Frank Jessen, Pieter Jelle Visser, Anouk den Braber, Craig W. Ritchie, Mercè Boada, Marta Marquié, Rik Vandenberghe, Emma S. Luckett, Michael Schöll, Giovanni B. Frisoni, Christopher Buckley, Andrew Stephens, Daniele Altomare, Lisa Ford, Cindy Birck, Anja Mett, Rossella Gismondi, Robin Wolz, Sylke Grootoonk, Richard Manber, Mahnaz Shekari, Renaud Lhommel, Laurence Dricot, Adrian Ivanoiu, Gill Farrar, Frederik Barkhof, Bernard J. Hanseeuw, and the AMYPAD Consortium
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Amyloid-PET ,Centiloid ,Preclinical Alzheimer ,Functional decline ,Instrumental activities of daily living ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background There is good evidence that elevated amyloid-β (Aβ) positron emission tomography (PET) signal is associated with cognitive decline in clinically normal (CN) individuals. However, it is less well established whether there is an association between the Aβ burden and decline in daily living activities in this population. Moreover, Aβ-PET Centiloids (CL) thresholds that can optimally predict functional decline have not yet been established. Methods Cross-sectional and longitudinal analyses over a mean three-year timeframe were performed on the European amyloid-PET imaging AMYPAD-PNHS dataset that phenotypes 1260 individuals, including 1032 CN individuals and 228 participants with questionable functional impairment. Amyloid-PET was assessed continuously on the Centiloid (CL) scale and using Aβ groups (CL 50 = Aβ+). Functional abilities were longitudinally assessed using the Clinical Dementia Rating (Global-CDR, CDR-SOB) and the Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q). The Global-CDR was available for the 1260 participants at baseline, while baseline CDR-SOB and A-IADL-Q scores and longitudinal functional data were available for different subsamples that had similar characteristics to those of the entire sample. Results Participants included 765 Aβ- (61%, Mdn age = 66.0, IQR age = 61.0–71.0; 59% women), 301 Aβ± (24%; Mdn age = 69.0, IQR age = 64.0–75.0; 53% women) and 194 Aβ+ individuals (15%, Mdn age = 73.0, IQR age = 68.0–78.0; 53% women). Cross-sectionally, CL values were associated with CDR outcomes. Longitudinally, baseline CL values predicted prospective changes in the CDR-SOB (b CL*Time = 0.001/CL/year, 95% CI [0.0005,0.0024], p = .003) and A-IADL-Q (b CL*Time = -0.010/CL/year, 95% CI [-0.016,-0.004], p = .002) scores in initially CN participants. Increased clinical progression (Global-CDR > 0) was mainly observed in Aβ+ CN individuals (HR Aβ+ vs Aβ- = 2.55, 95% CI [1.16,5.60], p = .020). Optimal thresholds for predicting decline were found at 41 CL using the CDR-SOB (b Aβ+ vs Aβ- = 0.137/year, 95% CI [0.069,0.206], p
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- 2024
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3. Repair of a Large Nasal Ala and Medial Cheek Defect: Case Report
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Hannah E. Myers, Ashley A. Kessler, Michael Roberts, and Christopher Buckley
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case report ,mohs surgery ,skin cancer ,dermatologic surgery ,Dermatology ,RL1-803 - Abstract
Introduction: Mohs micrographic surgery is a complex but essential aspect of functional and cosmetic skin cancer removal. It allows for skin cancers to be removed from cosmetically challenging areas in the most efficient and effective possible method; however, closure of these lesions can be difficult. Case: An 80-year-old male presented for Mohs surgery of a basal cell carcinoma on the right nasal sidewall that measured 3.4 cm. The patient underwent seven stages of Mohs surgery, and the final defect measured 6.5 cm × 5.5 cm, resulting in a large area for closure with multiple cosmetic and functional units affected. Discussion: This case discusses options for complex closure of large defects on the nose and the reasoning behind the final choice in closure.
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- 2024
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4. Harmonization of brain PET images in multi-center PET studies using Hoffman phantom scan
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Mahnaz Shekari, Eline E. Verwer, Maqsood Yaqub, Marcel Daamen, Christopher Buckley, Giovanni B. Frisoni, Pieter Jelle Visser, Gill Farrar, Frederik Barkhof, Juan Domingo Gispert, Ronald Boellaard, and the AMYPAD Consortium
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Brain PET ,Harmonization ,Neuroimaging ,Quantification ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Background Image harmonization has been proposed to minimize heterogeneity in brain PET scans acquired in multi-center studies. However, standard validated methods and software tools are lacking. Here, we assessed the performance of a framework for the harmonization of brain PET scans in a multi-center European clinical trial. Method Hoffman 3D brain phantoms were acquired in 28 PET systems and reconstructed using site-specific settings. Full Width at Half Maximum (FWHM) of the Effective Image Resolution (EIR) and harmonization kernels were estimated for each scan. The target EIR was selected as the coarsest EIR in the imaging network. Using “Hoffman 3D brain Analysis tool,” indicators of image quality were calculated before and after the harmonization: The Coefficient of Variance (COV%), Gray Matter Recovery Coefficient (GMRC), Contrast, Cold-Spot RC, and left-to-right GMRC ratio. A COV% ≤ 15% and Contrast ≥ 2.2 were set as acceptance criteria. The procedure was repeated to achieve a 6-mm target EIR in a subset of scans. The method’s robustness against typical dose-calibrator-based errors was assessed. Results The EIR across systems ranged from 3.3 to 8.1 mm, and an EIR of 8 mm was selected as the target resolution. After harmonization, all scans met acceptable image quality criteria, while only 13 (39.4%) did before. The harmonization procedure resulted in lower inter-system variability indicators: Mean ± SD COV% (from 16.97 ± 6.03 to 7.86 ± 1.47%), GMRC Inter-Quartile Range (0.040–0.012), and Contrast SD (0.14–0.05). Similar results were obtained with a 6-mm FWHM target EIR. Errors of ± 10% in the DRO activity resulted in differences below 1 mm in the estimated EIR. Conclusion Harmonizing the EIR of brain PET scans significantly reduced image quality variability while minimally affecting quantitative accuracy. This method can be used prospectively for harmonizing scans to target sharper resolutions and is robust against dose-calibrator errors. Comparable image quality is attainable in brain PET multi-center studies while maintaining quantitative accuracy.
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- 2023
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5. Painful schwannoma of scalp: A case report
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Faraz Yousefian, Michael Roberts, Josh Hammel, and Christopher Buckley
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Medicine (General) ,R5-920 - Abstract
Schwannoma, also known as neurilemmoma, is a benign neoplasm of Schwann cells of the cranial or peripheral nerve sheath. Scalp involvement has been reported in 25% of patients with extracranial head and neck schwannomas, which can be misdiagnosed clinically as epidermal cyst or lipoma. In this article, we report a 32-year-old male presenting with a slow-growing painful subcutaneous mass on the left occipital scalps without any neurological symptoms. Pathological findings confirmed the diagnosis of schwannoma, and surgical removal resulted in the resolution of pain and lack of recurrence.
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- 2023
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6. Software compatibility analysis for quantitative measures of [18F]flutemetamol amyloid PET burden in mild cognitive impairment
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Hugh G. Pemberton, Christopher Buckley, Mark Battle, Ariane Bollack, Vrajesh Patel, Petya Tomova, David Cooke, Will Balhorn, Katherine Hegedorn, Johan Lilja, Christine Brand, and Gill Farrar
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Amyloid PET ,SUVr ,Alzheimer’s ,MCI ,Quantification ,[18F]flutemetamol ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Rationale Amyloid-β (Aβ) pathology is one of the earliest detectable brain changes in Alzheimer’s disease pathogenesis. In clinical practice, trained readers will visually categorise positron emission tomography (PET) scans as either Aβ positive or negative. However, adjunct quantitative analysis is becoming more widely available, where regulatory approved software can currently generate metrics such as standardised uptake value ratios (SUVr) and individual Z-scores. Therefore, it is of direct value to the imaging community to assess the compatibility of commercially available software packages. In this collaborative project, the compatibility of amyloid PET quantification was investigated across four regulatory approved software packages. In doing so, the intention is to increase visibility and understanding of clinically relevant quantitative methods. Methods Composite SUVr using the pons as the reference region was generated from [18F]flutemetamol (GE Healthcare) PET in a retrospective cohort of 80 amnestic mild cognitive impairment (aMCI) patients (40 each male/female; mean age = 73 years, SD = 8.52). Based on previous autopsy validation work, an Aβ positivity threshold of ≥ 0.6 SUVrpons was applied. Quantitative results from MIM Software’s MIMneuro, Syntermed’s NeuroQ, Hermes Medical Solutions’ BRASS and GE Healthcare’s CortexID were analysed using intraclass correlation coefficient (ICC), percentage agreement around the Aβ positivity threshold and kappa scores. Results Using an Aβ positivity threshold of ≥ 0.6 SUVrpons, 95% agreement was achieved across the four software packages. Two patients were narrowly classed as Aβ negative by one software package but positive by the others, and two patients vice versa. All kappa scores around the same Aβ positivity threshold, both combined (Fleiss’) and individual software pairings (Cohen’s), were ≥ 0.9 signifying “almost perfect” inter-rater reliability. Excellent reliability was found between composite SUVr measurements for all four software packages, with an average measure ICC of 0.97 and 95% confidence interval of 0.957–0.979. Correlation coefficient analysis between the two software packages reporting composite z-scores was strong (r 2 = 0.98). Conclusion Using an optimised cortical mask, regulatory approved software packages provided highly correlated and reliable quantification of [18F]flutemetamol amyloid PET with a ≥ 0.6 SUVrpons positivity threshold. In particular, this work could be of interest to physicians performing routine clinical imaging rather than researchers performing more bespoke image analysis. Similar analysis is encouraged using other reference regions as well as the Centiloid scale, when it has been implemented by more software packages.
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- 2023
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7. APOE -ε4 modulates the association between regional amyloid deposition and cognitive performance in cognitively unimpaired middle-aged individuals
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Anna Brugulat-Serrat, Gonzalo Sánchez-Benavides, Raffaele Cacciaglia, Gemma Salvadó, Mahnaz Shekari, Lyduine E. Collij, Christopher Buckley, Bart N. M. van Berckel, Andrés Perissinotti, Aida Niñerola-Baizán, Marta Milà-Alomà, Natàlia Vilor-Tejedor, Grégory Operto, Carles Falcon, Oriol Grau-Rivera, Eider M. Arenaza-Urquijo, Carolina Minguillón, Karine Fauria, José Luis Molinuevo, Marc Suárez-Calvet, Juan Domingo Gispert, and the ALFA Study
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Alzheimer’s disease ,Amyloid PET ,Visual read ,Memory ,Executive function ,APOE-ε4 ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Purpose To determine whether the APOE-ε4 allele modulates the relationship between regional β-amyloid (Aβ) accumulation and cognitive change in middle-aged cognitively unimpaired (CU) participants. Methods The 352 CU participants (mean aged 61.1 [4.7] years) included completed two cognitive assessments (average interval 3.34 years), underwent [18F]flutemetamol Aβ positron emission tomography (PET), T1w magnetic resonance imaging (MRI), as well as APOE genotyping. Global and regional Aβ PET positivity was assessed across five regions-of-interest by visual reading (VR) and regional Centiloids. Linear regression models were developed to examine the interaction between regional and global Aβ PET positivity and APOE-ε4 status on longitudinal cognitive change assessed with the Preclinical Alzheimer’s Cognitive Composite (PACC), episodic memory, and executive function, after controlling for age, sex, education, cognitive baseline scores, and hippocampal volume. Results In total, 57 participants (16.2%) were VR+ of whom 41 (71.9%) were APOE-ε4 carriers. No significant APOE-ε4*global Aβ PET interactions were associated with cognitive change for any cognitive test. However, APOE-ε4 carriers who were VR+ in temporal areas (n = 19 [9.81%], p = 0.04) and in the striatum (n = 8 [4.14%], p = 0.01) exhibited a higher decline in the PACC. The temporal areas findings were replicated when regional PET positivity was determined with Centiloid values. Regionally, VR+ in the striatum was associated with higher memory decline. As for executive function, interactions between APOE-ε4 and regional VR+ were found in temporal and parietal regions, and in the striatum. Conclusion CU APOE-ε4 carriers with a positive Aβ PET VR in regions known to accumulate amyloid at later stages of the Alzheimer’s disease (AD) continuum exhibited a steeper cognitive decline. This work supports the contention that regional VR of Aβ PET might convey prognostic information about future cognitive decline in individuals at higher risk of developing AD. ClinicalTrials.gov Identifier: NCT02485730. Registered 20 June 2015 https://clinicaltrials.gov/ct2/show/NCT02485730 and ClinicalTrials.gov Identifier:NCT02685969. Registered 19 February 2016 https://clinicaltrials.gov/ct2/show/NCT02685969 .
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- 2023
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8. Effects of pharmacological and non-pharmacological interventions on physical activity outcomes in COPD: a systematic review and meta-analysis
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Dimitrios Megaritis, Emily Hume, Nikolaos Chynkiamis, Christopher Buckley, Ashley M. Polhemus, Henrik Watz, Thierry Troosters, and Ioannis Vogiatzis
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Medicine - Abstract
Rationale The effect of pharmacological and non-pharmacological interventions on physical activity (PA) outcomes is not fully elucidated in patients with COPD. The objectives of the present study were to provide estimation of treatment effects of all available interventions on PA outcomes in patients with COPD and to provide recommendations regarding the future role of PA outcomes in pharmacological trials. Materials and methods This review was conducted according to the Cochrane Handbook for Systematic Reviews of Interventions and reported in line with PRISMA. Records were identified through searches of 12 scientific databases; the most updated search was performed in January 2023. Results 74 studies published from 2000 to 2021 were included, with a total of 8140 COPD patients. Forced expiratory volume in 1 s % predicted ranged between 31% and 74%, with a mean of 55%. Steps/day constituted the most frequently assessed PA outcome in interventional studies. Compared to usual care, PA behavioural modification interventions resulted in improvements in the mean (95% CI) steps/day when implemented alone (by 1035 (576–1493); p
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- 2023
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9. Auditory rhythmical cueing to improve gait in community-dwelling stroke survivors (ACTIVATE): a pilot randomised controlled trial
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Lisa Shaw, Patricia McCue, Philip Brown, Christopher Buckley, Silvia Del Din, Richard Francis, Heather Hunter, Allen Lambert, Sue Lord, Christopher I. M. Price, Helen Rodgers, Lynn Rochester, and Sarah A. Moore
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Stroke ,Gait ,Exercise ,Rehabilitation ,Auditory rhythmical cueing ,Pilot randomized controlled trial ,Medicine (General) ,R5-920 - Abstract
Abstract Background Gait impairment limiting mobility and restricting activities is common after stroke. Auditory rhythmical cueing (ARC) uses a metronome beat delivered during exercise to train stepping and early work reports gait improvements. This study aimed to establish the feasibility of a full scale multicentre randomised controlled trial to evaluate an ARC gait and balance training programme for use by stroke survivors in the home and outdoors. Methods A parallel-group observer-blind pilot randomised controlled trial was conducted. Adults within 2 years of stroke with a gait-related mobility impairment were recruited from four NHS stroke services and randomised to an ARC gait and balance training programme (intervention) or the training programme without ARC (control). Both programmes consisted of 3x30 min sessions per week for 6 weeks undertaken at home/nearby outdoor community. One session per week was supervised and the remainder self-managed. Gait and balance performance assessments were undertaken at baseline, 6 and 10 weeks. Key trial outcomes included recruitment and retention rates, programme adherence, assessment data completeness and safety. Results Between November 2018 and February 2020, 59 participants were randomised (intervention n=30, control n=29), mean recruitment rate 4/month. At baseline, 6 weeks and 10 weeks, research assessments were conducted for 59/59 (100%), 47/59 (80%) and 42/59 (71%) participants, respectively. Missing assessments were largely due to discontinuation of data collection from mid-March 2020 because of the UK COVID-19 pandemic lockdown. The proportion of participants with complete data for each individual performance assessment ranged from 100% at baseline to 68% at 10 weeks. In the intervention group, 433/540 (80%) total programme exercise sessions were undertaken, in the control group, 390/522 (75%). Falls were reported by five participants in the intervention group, six in the control group. Three serious adverse events occurred, all unrelated to the study. Conclusion We believe that a definitive multicentre RCT to evaluate the ARC gait and balance training programme is feasible. Recruitment, programme adherence and safety were all acceptable. Although we consider that the retention rate and assessment data completeness were not sufficient for a future trial, this was largely due to the UK COVID-19 pandemic lockdown. Trial registration ISRCTN, ISRCTN10874601 , Registered on 05/03/2018,
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- 2022
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10. The amyloid imaging for the prevention of Alzheimer's disease consortium: A European collaboration with global impact
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Lyduine E. Collij, Gill Farrar, David Valléz García, Ilona Bader, Mahnaz Shekari, Luigi Lorenzini, Hugh Pemberton, Daniele Altomare, Sandra Pla, Mery Loor, Pawel Markiewicz, Maqsood Yaqub, Christopher Buckley, Giovanni B. Frisoni, Agneta Nordberg, Pierre Payoux, Andrew Stephens, Rossella Gismondi, Pieter Jelle Visser, Lisa Ford, Mark Schmidt, Cindy Birck, Jean Georges, Anja Mett, Zuzana Walker, Mercé Boada, Alexander Drzezga, Rik Vandenberghe, Bernard Hanseeuw, Frank Jessen, Michael Schöll, Craig Ritchie, Isadora Lopes Alves, Juan Domingo Gispert, and Frederik Barkhof
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amyloid ,positron emission tomography (PET) ,consortium ,Alzheimer's disease ,diagnosis ,prognosis ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
BackgroundAmyloid-β (Aβ) accumulation is considered the earliest pathological change in Alzheimer's disease (AD). The Amyloid Imaging to Prevent Alzheimer's Disease (AMYPAD) consortium is a collaborative European framework across European Federation of Pharmaceutical Industries Associations (EFPIA), academic, and ‘Small and Medium-sized enterprises’ (SME) partners aiming to provide evidence on the clinical utility and cost-effectiveness of Positron Emission Tomography (PET) imaging in diagnostic work-up of AD and to support clinical trial design by developing optimal quantitative methodology in an early AD population.The AMYPAD studiesIn the Diagnostic and Patient Management Study (DPMS), 844 participants from eight centres across three clinical subgroups (245 subjective cognitive decline, 342 mild cognitive impairment, and 258 dementia) were included. The Prognostic and Natural History Study (PNHS) recruited pre-dementia subjects across 11 European parent cohorts (PCs). Approximately 1600 unique subjects with historical and prospective data were collected within this study. PET acquisition with [18F]flutemetamol or [18F]florbetaben radiotracers was performed and quantified using the Centiloid (CL) method.ResultsAMYPAD has significantly contributed to the AD field by furthering our understanding of amyloid deposition in the brain and the optimal methodology to measure this process. Main contributions so far include the validation of the dual-time window acquisition protocol to derive the fully quantitative non-displaceable binding potential (BPND), assess the value of this metric in the context of clinical trials, improve PET-sensitivity to emerging Aβ burden and utilize its available regional information, establish the quantitative accuracy of the Centiloid method across tracers and support implementation of quantitative amyloid-PET measures in the clinical routine.Future stepsThe AMYPAD consortium has succeeded in recruiting and following a large number of prospective subjects and setting up a collaborative framework to integrate data across European PCs. Efforts are currently ongoing in collaboration with ARIDHIA and ADDI to harmonize, integrate, and curate all available clinical data from the PNHS PCs, which will become openly accessible to the wider scientific community.
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- 2023
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11. Effects of canary seed on two patients with disseminated granuloma annulare
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Lily Park, Claudia Green, Sergey Arutyunyan, Gabriella Vasile, Christopher Buckley, and Eduardo Weiss
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Granuloma annulare ,Canary seed ,Alpiste milk ,disseminated granuloma annulare ,Dermatology ,RL1-803 - Abstract
Treatment of disseminated granuloma annulare (GA) can be challenging and there is no gold standard for treatment. We observed two cases of generalized GA that had been resistant to other treaments successfully treated with canary seed milk. Canary seed milk has antioxidant (contains vitamin E), anti-diabetic (DPP-4 inhibition), and anti-hypertensive (ACE inhibition) properties. Therefore, dermatologists can consider alpiste milk as a sole or supplemental treatment for patients with GA with or without comorbidities such as diabetes and hypertension, in GA patients who prefer alternative therapy or failed other treatments.
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- 2022
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12. Anorectal syphilis presenting at Crohn's disease: A case report
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Hannah E Myers, Kevin Pennycook, and Christopher Buckley
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crohn's disease ,cutaneous syphilis ,dermatology ,irritable bowel disease ,sexually transmitted disease ,Dermatology ,RL1-803 - Abstract
This article reports on a case of anorectal syphilis in a 54-year-old man with a history of Crohn's disease. The patient began experiencing a new onset perianal rash approximately when his medication regimen for Crohn's disease was switched from sulfasalazine to mesalamine. There was no reported history of new sexual partners or sexually transmitted infection exposures. Chief differential at this time included Cutaneous Crohn's disease, Lichen Planus, Extramammary Paget's Disease, and Porokeratosis Ptychotropica; however, shave biopsy results revealed unexpected syphilis. There is only one other reported case of syphilis presenting as Crohn's disease, but the incidence of syphilis has been rapidly increasing within the last decade. A high index of clinical suspicion is needed to properly diagnose syphilis, even with a lack of sexual history, for new onset genital lesions.
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- 2023
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13. Evaluating the effects of an exercise program (Staying UpRight) for older adults in long-term care on rates of falls: study protocol for a randomised controlled trial
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Lynne Taylor, John Parsons, Denise Taylor, Elizabeth Binns, Sue Lord, Richard Edlin, Lynn Rochester, Silvia Del Din, Jochen Klenk, Christopher Buckley, Alana Cavadino, Simon A. Moyes, and Ngaire Kerse
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Falls ,Exercise therapy ,Randomised trials ,Aged care ,Long-term care ,Nursing home ,Medicine (General) ,R5-920 - Abstract
Abstract Background Falls are two to four times more frequent amongst older adults living in long-term care (LTC) than community-dwelling older adults and have deleterious consequences. It is hypothesised that a progressive exercise program targeting balance and strength will reduce fall rates when compared to a seated exercise program and do so cost effectively. Methods/design This is a single blind, parallel-group, randomised controlled trial with blinded assessment of outcome and intention-to-treat analysis. LTC residents (age ≥ 65 years) will be recruited from LTC facilities in New Zealand. Participants (n = 528 total, with a 1:1 allocation ratio) will be randomly assigned to either a novel exercise program (Staying UpRight), comprising strength and balance exercises designed specifically for LTC and acceptable to people with dementia (intervention group), or a seated exercise program (control group). The intervention and control group classes will be delivered for 1 h twice weekly over 1 year. The primary outcome is rate of falls (per 1000 person years) within the intervention period. Secondary outcomes will be risk of falling (the proportion of fallers per group), fall rate relative to activity exposure, hospitalisation for fall-related injury, change in gait variability, volume and patterns of ambulatory activity and change in physical performance assessed at baseline and after 6 and 12 months. Cost-effectiveness will be examined using intervention and health service costs. The trial commenced recruitment on 30 November 2018. Discussion This study evaluates the efficacy and cost-effectiveness of a progressive strength and balance exercise program for aged care residents to reduce falls. The outcomes will aid development of evidenced-based exercise programmes for this vulnerable population. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12618001827224. Registered on 9 November 2018. Universal trial number U1111-1217-7148.
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- 2020
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14. Accelerometry-Based Digital Gait Characteristics for Classification of Parkinson's Disease: What Counts?
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Rana Zia Ur Rehman, Christopher Buckley, Maria Encarna Mico-Amigo, Cameron Kirk, Michael Dunne-Willows, Claudia Mazza, Jian Qing Shi, Lisa Alcock, Lynn Rochester, and Silvia Del Din
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Classification ,Machine Learning ,Digital Gait ,Parkinson's disease ,Partial least square-discriminant analysis (PLS-DA) ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Medical technology ,R855-855.5 - Abstract
Objective: Gait may be a useful biomarker that can be objectively measured with wearable technology to classify Parkinson's disease (PD). This study aims to: (i) comprehensively quantify a battery of commonly utilized gait digital characteristics (spatiotemporal and signal-based), and (ii) identify the best discriminative characteristics for the optimal classification of PD. Methods: Six partial least square discriminant analysis (PLS-DA) models were trained on subsets of 210 characteristics measured in 142 subjects (81 people with PD, 61 controls (CL)). Results: Models accuracy ranged between 70.42-88.73% (AUC: 78.4-94.5%) with a sensitivity of 72.84-90.12% and a specificity of 60.3-86.89%. Signal-based digital gait characteristics independently gave 87.32% accuracy. The most influential characteristics in the classification models were related to root mean square values, power spectral density, step velocity and length, gait regularity and age. Conclusions: This study highlights the importance of signal-based gait characteristics in the development of tools to help classify PD in the early stages of the disease.
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- 2020
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15. Correction to: Different aspects of Alzheimer’s disease-related amyloid β-peptide pathology and their relationship to amyloid positron emission tomography imaging and dementia
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Dietmar Rudolf Thal, Alicja Ronisz, Thomas Tousseyn, Ajeet Rijal Upadhaya, Karthikeyan Balakrishnan, Rik Vandenberghe, Mathieu Vandenbulcke, Christine A. F. von Arnim, Markus Otto, Thomas G. Beach, Johan Lilja, Kerstin Heurling, Aruna Chakrabarty, Azzam Ismail, Christopher Buckley, Adrian P. L. Smith, Sathish Kumar, Gill Farrar, and Jochen Walter
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
An amendment to this paper has been published and can be accessed via the original article.
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- 2020
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16. Different aspects of Alzheimer’s disease-related amyloid β-peptide pathology and their relationship to amyloid positron emission tomography imaging and dementia
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Dietmar Rudolf Thal, Alicja Ronisz, Thomas Tousseyn, Ajeet Rijal Upadhaya, Karthikeyan Balakrishnan, Rik Vandenberghe, Mathieu Vandenbulcke, Christine A. F. von Arnim, Markus Otto, Thomas G. Beach, Johan Lilja, Kerstin Heurling, Aruna Chakrabarty, Azzam Ismail, Christopher Buckley, Adrian P. L. Smith, Sathish Kumar, Gill Farrar, and Jochen Walter
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Alzheimer’s disease ,Amyloid β peptide ,Staging ,Amyloid load ,Soluble amyloid ,Insoluble amyloid ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Alzheimer’s disease (AD)-related amyloid β-peptide (Aβ) pathology in the form of amyloid plaques and cerebral amyloid angiopathy (CAA) spreads in its topographical distribution, increases in quantity, and undergoes qualitative changes in its composition of modified Aβ species throughout the pathogenesis of AD. It is not clear which of these aspects of Aβ pathology contribute to AD progression and to what extent amyloid positron emission tomography (PET) reflects each of these aspects. To address these questions three cohorts of human autopsy cases (in total n = 271) were neuropathologically and biochemically examined for the topographical distribution of Aβ pathology (plaques and CAA), its quantity and its composition. These parameters were compared with neurofibrillary tangle (NFT) and neuritic plaque pathology, the degree of dementia and the results from [18F]flutemetamol amyloid PET imaging in cohort 3. All three aspects of Aβ pathology correlated with one another, the estimation of Aβ pathology by [18F]flutemetamol PET, AD-related NFT pathology, neuritic plaques, and with the degree of dementia. These results show that one aspect of Aβ pathology can be used to predict the other two, and correlates well with the development of dementia, advancing NFT and neuritic plaque pathology. Moreover, amyloid PET estimates all three aspects of Aβ pathology in-vivo. Accordingly, amyloid PET-based estimates for staging of amyloid pathology indicate the progression status of amyloid pathology in general and, in doing so, also of AD pathology. Only 7.75% of our cases deviated from this general association.
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- 2019
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17. Balance Impairments as Differential Markers of Dementia Disease Subtype
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Ríona Mc Ardle, Stephanie Pratt, Christopher Buckley, Silvia Del Din, Brook Galna, Alan Thomas, Lynn Rochester, and Lisa Alcock
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dementia ,Alzheimer’s disease ,Lewy body disease ,Parkinson’s disease ,balance ,accelerometer ,Biotechnology ,TP248.13-248.65 - Abstract
BackgroundAccurately differentiating dementia subtypes, such as Alzheimer’s disease (AD) and Lewy body disease [including dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD)] is important to ensure appropriate management and treatment of the disease. Similarities in clinical presentation create difficulties for differential diagnosis. Simple supportive markers, such as balance assessments, may be useful to the diagnostic toolkit. This study aimed to identify differences in balance impairments between different dementia disease subtypes and normal aging using a single triaxial accelerometer.MethodsNinety-seven participants were recruited, forming four groups: cognitive impairment due to Alzheimer’s disease (AD group; n = 31), dementia with Lewy bodies (DLB group; n = 26), Parkinson’s disease dementia (PDD group; n = 13), and normal aging controls (n = 27). Participants were asked to stand still for 2 minutes in a standardized position with their eyes open while wearing a single triaxial accelerometer on their lower back. Seven balance characteristics were derived, including jerk (combined, mediolateral, and anterior–posterior), root mean square (RMS; combined, mediolateral, and anterior–posterior), and ellipsis. Mann–Whitney U tests identified the balance differences between groups. Receiver operating characteristics and area under the curve (AUC) determined the overall accuracy of the selected balance characteristics.ResultsThe PDD group demonstrated higher RMS [combined (p = 0.001), mediolateral (p = 0.005), and anterior–posterior (p = 0.001)] and ellipsis scores (p < 0.002) than the AD group (AUC = 0.71–0.82). The PDD group also demonstrated significantly impaired balance across all characteristics (p ≤ 0.001) compared to the controls (AUC = 0.79–0.83). Balance differences were not significant between PDD and DLB (AUC = 0.69–0.74), DLB and AD (AUC = 0.50–0.65), DLB and controls (AUC = 0.62–0.68), or AD and controls (AUC = 0.55–0.67) following Bonferroni correction.DiscussionAlthough feasible and quick to conduct, key findings suggest that an accelerometer-based balance during quiet standing does not differentiate dementia disease subtypes accurately. Assessments that challenge balance more, such as gait or standing with eyes closed, may prove more effective to support differential diagnosis.
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- 2021
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18. Partially treated domestic wastewater as a nutrient source for tomatoes (Lycopersicum solanum) grown in a hydroponic system: effect on nutrient absorption and yield
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Shirly Tentile Magwaza, Lembe Samukelo Magwaza, Alfred Oduor Odindo, Asanda Mditshwa, and Christopher Buckley
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Human excreta-derived materials ,Waste disposal ,Nutrient recovery ,Greenhouse technology ,Hydroponic system ,Mineral nutrients ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Using effluent from the anaerobic baffled reactor (ABR) of the decentralised wastewater treatment system (DEWATS) as a sole nutrient source is not sufficient for tomato plants grown in hydroponic system. The study investigated the effects of commercial hydroponic fertilizer mix (CHFM) combined with ABR effluent on tomato growth and yield. A media-based hydroponic technique consisting of three treatments, namely, ABR effluent, CHFM, and ABR effluent combined with CHFM (ABR + CHFM (50:50 v/v) was used. The results showed that plant growth parameters, biomass, fruit yield and shoot nutrient content were significantly higher in tomato plants fed with CHFM and ABR + CHFM than those grown in ABR effluent. Addition of 50 % dose of CHFM in ABR wastewater (ABR + CHFM) increased shoot N, K, Ca and Zn. These results indicated that adding 50% CHFM can alleviate nutrient deficiencies when partially treated wastewater from anaerobic digester is used as a nutrient source for hydroponic tomato cultivation.
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- 2020
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19. Induction of selective cytotoxicity and apoptosis in human T4-lymphoblastoid cell line (CEMss) by boesenbergin a isolated from boesenbergia rotunda rhizomes involves mitochondrial pathway, activation of caspase 3 and G2/M phase cell cycle arrest.
- Author
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Kuan-Beng Ng, Bustamam, Ahmad, Aspollah Sukari, Mohd, Ibrahim Abdelwahab, Siddig, Mohan, Syam, James Christopher Buckle, Michael, Kamalidehghan, Behnam, Muhammad Nadzri, Nabilah, Anasamy, Theebaa, Hadi, A. Hamid A., and Sulaiman Rahman, Heshu
- Subjects
ANALYSIS of variance ,APOPTOSIS ,BIOLOGICAL assay ,CELL culture ,CELL cycle ,ELECTROPHORESIS ,FLOW cytometry ,MICROSCOPY ,MITOCHONDRIA ,MOLECULAR structure ,PROTEOLYTIC enzymes ,RESEARCH funding ,PLANT stems ,T-test (Statistics) ,TOXICITY testing ,WESTERN immunoblotting ,DATA analysis software ,DESCRIPTIVE statistics - Abstract
Background: Boesenbergia rotunda (Roxb.) Schlecht (family zingiberaceae) is a rhizomatous herb that is distributed from north-eastern India to south-east Asia, especially in Indonesia, Thailand and Malaysia. Previous research has shown that the crude extract of this plant has cytotoxic properties. The current study examines the cytotoxic properties of boesenbergin A isolated from Boesenbergia rotunda. Methods: MTT assay was used to check the cytotoxicity of boesenbergin A. The morphological assessment of apoptosis was monitored using normal and fluorescence microscopy. The early and late phase of apoptosis was investigated using annexin V and DNA laddering assays, respectively. The mitochondrial membrane potential (MMP) was assessed by fluorescence microscopy. Human apoptosis proteome profiler assays were performed to investigate the mechanism of cell death. In addition, the protein levels of Bax, Bcl2 and HSP 70 were also analyzed using western blot. Assays of caspase =-3/7, -8 and =-9 were carried out in order to test for induction during treatment. Lastly, cell cycle progression was analyzed using flow cytometry. Results: Boesenbergin A was found to have the highest toxicity towards CEMss cancer cells (IC
50 = 8 µg/ml). The morphology of CEMss cells after treatment showed evidence of apoptosis that included blebbing and chromatin condensation. The annexin V assay revealed that early apoptosis is induced after treatment. The DNA laddering assay confirmed that DNA fragmentation had occurred during late apoptosis. The cell cycle analysis indicated that boesenbergin A was able to induce G2/M phase arrest in CEMss cells. The activity of caspases -3/7, -8 and -9 was increased after treatment which indicates both intrinsic and extrinsic pathways are induced during apoptosis. The involvement of mitochondria was established by increased mitochondrial membrane potential and up and down regulation of Bcl2 and Bax proteins as well as HSP70. Conclusion: In conclusion, the results demonstrated that boesenbergin A induced apoptosis of CEMss cells through Bcl2/Bax signaling pathways with the involvement of caspases and G2/M phase cell cycle arrest. The current findings warrant further research on boesenbergin A as a novel chemotherapeutic agent for leukemia intervention including studies in animal models. [ABSTRACT FROM AUTHOR]- Published
- 2013
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20. TSPO imaging using the novel PET ligand [18F]GE-180: quantification approaches in patients with multiple sclerosis
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Lena Vomacka, Nathalie Lisa Albert, Simon Lindner, Marcus Unterrainer, Christoph Mahler, Matthias Brendel, Larissa Ermoschkin, Astrid Gosewisch, Anika Brunegraf, Christopher Buckley, Tania Kümpfel, Rainer Rupprecht, Sibylle Ziegler, Martin Kerschensteiner, Peter Bartenstein, and Guido Böning
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PET ,[18F]GE-180 ,Multiple sclerosis ,TSPO ,Quantification ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Background PET ligands targeting the translocator protein (TSPO) represent promising tools to visualise neuroinflammation. Here, we analysed parameters obtained in dynamic and static PET images using the novel TSPO ligand [18F]GE-180 in patients with relapsing remitting multiple sclerosis (RRMS) and an approach for semi-quantitative assessment of this disease in clinical routine. Seventeen dynamic [18F]GE-180 PET scans of RRMS patients were evaluated (90 min). A pseudo-reference region (PRR) was defined after identification of the least disease-affected brain area by voxel-based comparison with six healthy controls (HC) and upon exclusion of voxels suspected of being affected in static 60–90 min p.i. images. Standardised uptake value ratios (SUVR) obtained from static images normalised to PRR were correlated to the distribution volume ratios (DVR) derived from dynamic data with Logan reference tissue model. Results Group comparison with HC revealed white matter and thalamus as most affected regions. Fewest differences were found in grey matter, and normalisation to frontal cortex (FC) yielded the greatest reduction in variability of healthy grey and white matter. Hence, FC corrected for affected voxels was chosen as PRR, leading to time-activity curves of FC which were congruent to HC data (SUV60–90 0.37, U test P = 0.42). SUVR showed a very strong correlation with DVR (Pearson ρ > 0.9). Focal MS lesions exhibited a high SUVR (range, 1.3–3.2). Conclusions This comparison with parameters from dynamic data suggests that SUVR normalised to corrected frontal cortex as PRR is suitable for the quantification of [18F]GE-180 uptake in lesions and different brain regions of RRMS patients. This efficient diagnostic protocol based on static [18F]GE-180 PET scans acquired 60–90 min p.i. allows the semi-quantitative assessment of neuroinflammation in RRMS patients in clinical routine.
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- 2017
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21. Quantifying Reliable Walking Activity with a Wearable Device in Aged Residential Care: How Many Days Are Enough?
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Christopher Buckley, Alana Cavadino, Silvia Del Din, Sue Lord, Lynne Taylor, Lynn Rochester, and Ngaire Kerse
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aged residential care ,wearables ,accelerometer ,dementia ,reliability ,physical activity ,Chemical technology ,TP1-1185 - Abstract
Strong associations exist between quality of life and physical activity for those living in aged residential care (ARC). Suitable and reliable tools are required to quantify physical activity for descriptive and evaluative purposes. We calculated the number of days required for reliable walking outcomes indicative of physical activity in an ARC population using a trunk-worn device. ARC participants (n = 257) wore the device for up to 7 days. Reasons for data loss were also recorded. The volume, pattern, and variability of walking was calculated. For 197 participants who wore the device for at least 3 days, linear mixed models determined the impact of week structure and number of days required to achieve reliable outcomes, collectively and then stratified by care level. The average days recorded by the wearable device was 5.2 days. Day of the week did not impact walking activity. Depending on the outcome and level of care, 2–5 days was sufficient for reliable estimates. This study provides informative evidence for future studies aiming to use a wearable device located on the trunk to quantify physical activity walking out in the ARC population.
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- 2020
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22. The Role of Movement Analysis in Diagnosing and Monitoring Neurodegenerative Conditions: Insights from Gait and Postural Control
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Christopher Buckley, Lisa Alcock, Ríona McArdle, Rana Zia Ur Rehman, Silvia Del Din, Claudia Mazzà, Alison J. Yarnall, and Lynn Rochester
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movement science ,Parkinson’s disease ,ataxia ,dementia ,machine learning ,deep learning ,risk prediction ,disease phenotyping ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Quantifying gait and postural control adds valuable information that aids in understanding neurological conditions where motor symptoms predominate and cause considerable functional impairment. Disease-specific clinical scales exist; however, they are often susceptible to subjectivity, and can lack sensitivity when identifying subtle gait and postural impairments in prodromal cohorts and longitudinally to document disease progression. Numerous devices are available to objectively quantify a range of measurement outcomes pertaining to gait and postural control; however, efforts are required to standardise and harmonise approaches that are specific to the neurological condition and clinical assessment. Tools are urgently needed that address a number of unmet needs in neurological practice. Namely, these include timely and accurate diagnosis; disease stratification; risk prediction; tracking disease progression; and decision making for intervention optimisation and maximising therapeutic response (such as medication selection, disease staging, and targeted support). Using some recent examples of research across a range of relevant neurological conditions—including Parkinson’s disease, ataxia, and dementia—we will illustrate evidence that supports progress against these unmet clinical needs. We summarise the novel ‘big data’ approaches that utilise data mining and machine learning techniques to improve disease classification and risk prediction, and conclude with recommendations for future direction.
- Published
- 2019
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23. Stromal fibroblasts in tertiary lymphoid structures: a novel target in chronic inflammation.
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Francesca Barone, David Harry Gardner, Saba Nayar, Nathalie Steinthal, Christopher Buckley, and Sanjiv A Luther
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Chemokines ,Fibroblasts ,Lymphotoxin alpha1, beta2 Heterotrimer ,Tumor Necrosis Factor-alpha ,tertiary lymphoid structures ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Tertiary lymphoid structures (TLS) are organized aggregates of lymphocytes, myeloid and stromal cells that provide ectopic hubs for acquired immune responses. TLS share phenotypical and functional features with secondary lymphoid organs (SLO); however, they require persistent inflammatory signals to arise and are often observed at target sites of autoimmune diseases, chronic infection, cancer and organ transplantation. Over the past 10 years, important progress has been made in our understanding of the role of stromal fibroblasts in SLO development, organization and function. A complex and stereotyped series of events regulates fibroblast differentiation from embryonic life in SLOs, to lymphoid organ architecture observed in adults. In contrast, TLS associated fibroblasts differentiate from post-natal, locally activated mesenchyme, predominantly in settings of inflammation and persistent antigen presentation. Therefore, there are critical differences in the cellular and molecular requirements that regulate SLO versus TLS development that ultimately impact on stromal and hematopoietic cell function. These differences may contribute to the pathogenic nature of TLS in the context of chronic inflammation and malignant transformation and offer a window of opportunity for therapeutic interventions in TLS associated pathologies.
- Published
- 2016
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24. In Silico and In Vitro Analysis of Bacoside A Aglycones and Its Derivatives as the Constituents Responsible for the Cognitive Effects of Bacopa monnieri.
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Seetha Ramasamy, Sek Peng Chin, Sri Devi Sukumaran, Michael James Christopher Buckle, Lik Voon Kiew, and Lip Yong Chung
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Medicine ,Science - Abstract
Bacopa monnieri has been used in Ayurvedic medicine to improve memory and cognition. The active constituent responsible for its pharmacological effects is bacoside A, a mixture of dammarane-type triterpenoid saponins containing sugar chains linked to a steroid aglycone skeleton. Triterpenoid saponins have been reported to be transformed in vivo to metabolites that give better biological activity and pharmacokinetic characteristics. Thus, the activities of the parent compounds (bacosides), aglycones (jujubogenin and pseudojujubogenin) and their derivatives (ebelin lactone and bacogenin A1) were compared using a combination of in silico and in vitro screening methods. The compounds were docked into 5-HT1A, 5-HT2A, D1, D2, M1 receptors and acetylcholinesterase (AChE) using AutoDock and their central nervous system (CNS) drug-like properties were determined using Discovery Studio molecular properties and ADMET descriptors. The compounds were screened in vitro using radioligand receptor binding and AChE inhibition assays. In silico studies showed that the parent bacosides were not able to dock into the chosen CNS targets and had poor molecular properties as a CNS drug. In contrast, the aglycones and their derivatives showed better binding affinity and good CNS drug-like properties, were well absorbed through the intestines and had good blood brain barrier (BBB) penetration. Among the compounds tested in vitro, ebelin lactone showed binding affinity towards M1 (Ki = 0.45 μM) and 5-HT2A (4.21 μM) receptors. Bacoside A and bacopaside X (9.06 μM) showed binding affinity towards the D1 receptor. None of the compounds showed any inhibitory activity against AChE. Since the stimulation of M1 and 5-HT2A receptors has been implicated in memory and cognition and ebelin lactone was shown to have the strongest binding energy, highest BBB penetration and binding affinity towards M1 and 5-HT2A receptors, we suggest that B. monnieri constituents may be transformed in vivo to the active form before exerting their pharmacological activity.
- Published
- 2015
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