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Moore T, Atkinson S, Maurizi E, Schiroli D, Mairs L, Christie K, McLean I, Allen E, Pedrioli D, Moore J, Nesbit A. Regulating gene expression towards solving ocular surface diseases. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0170] [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]
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Daupin J, Rosseaux G, Lebel D, Atkinson S, Bedard P, Bussieres JF. Comparison of Information Available in the Medication Profile of an Electronic Health Record and the Inpatient Best Possible Medication History in a Mother and Child Teaching Hospital Center. JOURNAL OF POPULATION THERAPEUTICS AND CLINICAL PHARMACOLOGY = JOURNAL DE LA THERAPEUTIQUE DES POPULATIONS ET DE LA PHARMACOLOGIE CLINIQUE 2016; 23:e131-e141. [PMID: 27462999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BackgroundMedication reconciliation (MedRec) can improve patient safety. In Canada, most provinces are implementing electronic health records (EHR). The Quebec Health Record (QHR) can theoretically be used for medication reconciliation. However, the quantity and the quality of information available in this EHR have not been studied. ObjectivesThe main objective was to compare the quantity and quality of the information collected between the inpatient best possible medication history (BPMH) and the QHR. MethodsThis is a descriptive prospective study conducted at CHU Sainte-Justine, a 500-bed tertiary mother-and-child university hospital center. All inpatients from May 19-26, 2015 were considered for inclusion. Every prescription line in the BPMH and QHR were compared. ResultsThe study included 344 patients and 1,039 prescription lines were analyzed. The medications' name and dosing were more often available in the QHR (95%) than in the BPMH (61%). Concordance between the medication names between QHR and BPMH was found in 48% of the prescription lines; this rate fell to 29% when also factoring daily dosage. ConclusionsThis study suggests that the QHR can provide high-quality information to support the MedRec hospital process. However, it should be used as a second source to optimize the BPMH obtained from a thorough interview with the patient and/or his or her family. More studies are required to confirm the most optimal way to integrate the QHR to the MedRec process in hospitals.
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Dubois S, Barbier A, Thibault M, Atkinson S, Bussières JF. [Selection and optimal sequence of critical elements for medication review: A simulation with hospital pharmacy residents]. ANNALES PHARMACEUTIQUES FRANÇAISES 2016; 75:131-143. [PMID: 27423187 DOI: 10.1016/j.pharma.2016.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/03/2016] [Accepted: 06/14/2016] [Indexed: 12/30/2022]
Abstract
OBJECTIVES The main objective of this study was to compare the responses of pharmacy residents regarding critical steps for medication order review, in the presence or absence of clinical pharmacists on patient care units, to describe the sequence of these steps and to compare them to an optimal sequence. The secondary objectives were to test this sequence in a simulation and to assess the residents' level of agreement on medication order review. METHODS Twenty-two validation steps were selected from guidelines. A simulation on order review was organized in three steps: selecting elements judged to be necessary or not for the order review critical path, then organizing this sequence in chronological order, implementation of this critical path on two simulated practical cases, resident perceptions about order review in their training. RESULTS Forty-one residents participated in the activity. Responses were heterogeneous regarding the elements' sequence and the time required for the review of a simulated case (3-13minutes). A majority of residents considered that their training was insufficient (29/41), that pharmacists validated differently (27/41), and that it was impossible to review the 22 proposed items for each prescription (30/41). CONCLUSIONS This article highlights heterogeneous medication order review practices among pharmacy residents, due to a lack of training in their curriculum according to them. It is essential to acquire medication order review standard both locally and nationally.
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Young JB, Perkins P, Atkinson S, Chamberlain MA. Initial experience with a telemeterized gait analysis system. Clin Rehabil 2016. [DOI: 10.1177/026921558900300304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The M I E gait analysis system has been developed to allow a range of objective gait measurements to be readily obtained in a clinical setting. The equipment and its use are described together with a series of repeatability studies. The results suggest that the system is easy to operate and sufficiently reliable for use in clinical departments.
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Abstract
The human pathogens
Yersinia pseudotuberculosis and
Yersinia enterocolitica cause enterocolitis, while
Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.
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Condori S, Atkinson S, Leys N, Wattiez R, Mastroleo F. Construction and phenotypic characterization of M68, an RruI quorum sensing knockout mutant of the photosynthetic alphaproteobacterium Rhodospirillum rubrum. Res Microbiol 2016; 167:380-92. [PMID: 26993754 DOI: 10.1016/j.resmic.2016.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 02/19/2016] [Accepted: 02/25/2016] [Indexed: 01/08/2023]
Abstract
Many bacterial species communicate using a complex system known as quorum sensing (QS) in which gene expression is controlled in response to cell density. In this study an N-acylhomoserine lactone (AHL) synthase (Rru_A3396) knockout mutant (M68) of Rhodospirillum rubrum S1H (WT) was constructed and characterized phenotypically under light anaerobic conditions. Results showed that R. rubrum WT produces unsubstituted, 3-OH and 3-oxo-substituted AHLs with acyl chains ranging from 4 to 14 carbons, with 3-OH-C8 being the most abundant. Growth, pigment content and swimming motility were found to be under the control of this LuxI-type QS system. In addition, cultivation in a low shear environment put forward the aggregative phenotype of M68 and linked biofilm formation to QS in R. rubrum S1H. Interestingly, QS-mutant M68 continued to produce decreased levels of 3-OH-C8-HSL, probably due to the presence of an extra HdtS-type AHL synthase.
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Drancourt P, Atkinson S, Lebel D, Bussières JF. [Assessment of perception about medication reconciliation among healthcare professionals at Saint-Justine hospital]. ANNALES PHARMACEUTIQUES FRANÇAISES 2016; 74:304-16. [PMID: 26739918 DOI: 10.1016/j.pharma.2015.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Our main objective is to assess nurses and doctors perception about medication reconciliation. METHODS This is a descriptive and cross-sectional study. We have created three surveys, one for each health worker (nurses, doctors, resident, pharmacists). Each survey consists of single or multi-choice closed questions. A four-point Likert scale was used to collect the perception. Descriptive statistics have been calculated. RESULTS A total of 114 nurses, 98 doctors and residents and 26 pharmacists from all care services, replied to the survey. The majority of doctors (58%), pharmacists (60%) and nurses (52%) recognized the relevance and utility of medication reconciliation in healthcare safety. However, few healthcare professionals (6% of doctors, 13% of nurses et 46% of pharmacists) know that medication reconciliation is a required organizational practice. Only 25% of doctors always consult the best possible medication history after a patient admission while the majority do not use it because of unreliability issues. So, there have been some major changes to optimize medication reconciliation process in our hospital. CONCLUSION This study shows a increasing interest to medication reconciliation by healthcare professionals. However, the use of medication reconciliation remains marginal.
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Atkinson S, Way M, McQuillin A, Morgan M, Thursz M. A Genome-Wide Association Study Identifies PNPLA3 and SLC38A4 as Risk Loci for Alcoholic Hepatitis. J Hepatol 2016. [DOI: 10.1016/s0168-8278(16)01634-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Berruyer M, Atkinson S, Lebel D, Bussières JF. [Failure mode and effects analysis (FMEA) of insulin in a mother-child university-affiliated health center]. Arch Pediatr 2015; 23:1-8. [PMID: 26552621 DOI: 10.1016/j.arcped.2015.09.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/20/2015] [Accepted: 09/30/2015] [Indexed: 10/22/2022]
Abstract
CONTEXT AND OBJECTIVES Insulin is a high-alert drug. The main objective of this descriptive cross-sectional study was to evaluate the risks associated with insulin use in healthcare centers. The secondary objective was to propose corrective measures to reduce the main risks associated with the most critical failure modes in the analysis. METHODS We conducted a failure mode and effects analysis (FMEA) in obstetrics-gynecology, neonatology and pediatrics. RESULTS Five multidisciplinary meetings occurred in August 2013. A total of 44 out of 49 failure modes were analyzed. Nine out of 44 (20%) failure modes were deemed critical, with a criticality score ranging from 540 to 720. DISCUSSION Following the multidisciplinary meetings, everybody agreed that an FMEA was a useful tool to identify failure modes and their relative importance. This approach identified many corrective measures. CONCLUSION This shared experience increased awareness of safety issues with insulin in our mother-child center. This study identified the main failure modes and associated corrective measures.
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Atkinson S. Pain management in veterinary practice. 1st edn. Edited by CMEgger, LLove and TJDoherty. Wiley Blackwell, West Sussex, 2014. 447 pages. Price A$101.99. ISBN 9780813812243. Aust Vet J 2015. [DOI: 10.1111/avj.12245] [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]
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Moore T, Courtney D, Atkinson S, Maurizi E, Allen E, McLean I, Leslie Pedrioli D, Moore J, Nesbit A. Genetic modification possibilities in treating corneal diseases. Acta Ophthalmol 2015. [DOI: 10.1111/j.1755-3768.2015.0145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sohani Z, Anand S, Robiou-du-Pont S, Morrison K, McDonald S, Atkinson S, Teo K, Meyre D. 137: Genes Increasing Glucose Levels in Early Childhood Provide Support for the Fetal Insulin Hypothesis: Results from the Family Study. Paediatr Child Health 2015. [DOI: 10.1093/pch/20.5.e84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Storey S, FitzGerald G, Moore G, Knights E, Atkinson S, Smith S, Freeman O, Cryer P, Wilson A. Effect of a contact monitoring system with immediate visual feedback on hand hygiene compliance. J Hosp Infect 2014; 88:84-8. [DOI: 10.1016/j.jhin.2014.06.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 06/28/2014] [Indexed: 10/25/2022]
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Hook AL, Chang CY, Yang J, Luckett J, Cockayne A, Atkinson S, Mei Y, Bayston R, Irvine DJ, Langer R, Anderson DG, Williams P, Davies MC, Alexander MR. Erratum: Corrigendum: Combinatorial discovery of polymers resistant to bacterial attachment. Nat Biotechnol 2014. [DOI: 10.1038/nbt0614-592c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Twigg MS, Tait K, Williams P, Atkinson S, Cámara M. Interference with the germination and growth of Ulva zoospores by quorum-sensing molecules from Ulva-associated epiphytic bacteria. Environ Microbiol 2014; 16. [PMID: 23879807 PMCID: PMC4304359 DOI: 10.1111/emi.12203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ulva zoospores preferentially settle on N-acylhomoserine lactone (AHL) producing marine bacterial biofilms. To investigate whether AHL signal molecules also affect the success and rate of zoospore germination in addition to zoospore attraction, the epiphytic bacteria associated with mature Ulva linza were characterized and bacterial isolates representative of this community tested for the ability to produce AHLs. Two of these AHL-producing isolates, Sulfitobacter spp. 376 and Shewanella spp. 79, were transformed with plasmids expressing the Bacillus spp. AHL lactonase gene aiiA to generate AHL-deficient variants. The germination and growth of U. linza zoospores was studied in the presence of these AHL-deficient strains and their AHL-producing counterparts. This revealed that the AHLs produced by Sulfitobacter spp. and Shewanella spp. or the bacterial products they regulate have a negative impact on both zoospore germination and the early growth of the Ulva germling. Further experiments with Escherichia coli biofilms expressing recombinant AHL synthases and synthetic AHLs provide data to demonstrate that zoospores germinated and grown in the absence of AHLs were significantly longer than those germinated in the presence of AHLs. These results reveal an additional role for AHLs per se in the interactive relationships between marine bacteria and Ulva zoospores.
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Phan V, Blydt-Hansen T, Feber J, Alos N, Arora S, Atkinson S, Bell L, Clarson C, Couch R, Cummings EA, Filler G, Grant RM, Grimmer J, Hebert D, Lentle B, Ma J, Matzinger M, Midgley J, Pinsk M, Rodd C, Shenouda N, Stein R, Stephure D, Taback S, Williams K, Rauch F, Siminoski K, Ward LM. Skeletal findings in the first 12 months following initiation of glucocorticoid therapy for pediatric nephrotic syndrome. Osteoporos Int 2014; 25:627-37. [PMID: 23948876 PMCID: PMC4100956 DOI: 10.1007/s00198-013-2466-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 07/16/2013] [Indexed: 02/08/2023]
Abstract
UNLABELLED Incident vertebral fractures and lumbar spine bone mineral density (BMD) were assessed in the 12 months following glucocorticoid initiation in 65 children with nephrotic syndrome. The incidence of vertebral fractures was low at 12 months (6 %) and most patients demonstrated recovery in BMD Z-scores by this time point. INTRODUCTION Vertebral fracture (VF) incidence following glucocorticoid (GC) initiation has not been previously reported in pediatric nephrotic syndrome. METHODS VF was assessed on radiographs (Genant method); lumbar spine bone mineral density (LS BMD) was evaluated by dual-energy X-ray absorptiometry. RESULTS Sixty-five children were followed to 12 months post-GC initiation (median age, 5.4 years; range, 2.3-17.9). Three of 54 children with radiographs (6 %; 95 % confidence interval (CI), 2-15 %) had incident VF at 1 year. The mean LS BMD Z-score was below the healthy average at baseline (mean ± standard deviation (SD), -0.5 ± 1.1; p = 0.001) and at 3 months (-0.6 ± 1.1; p < 0.001), but not at 6 months (-0.3 ± 1.3; p = 0.066) or 12 months (-0.3 ± 1.2; p = 0.066). Mixed effect modeling showed a significant increase in LS BMD Z-scores between 3 and 12 months (0.22 SD; 95 % CI, 0.08 to 0.36; p = 0.003). A subgroup (N = 16; 25 %) had LS BMD Z-scores that were ≤-1.0 at 12 months. In these children, each additional 1,000 mg/m(2) of GC received in the first 3 months was associated with a decrease in LS BMD Z-score by 0.39 at 12 months (95 % CI, -0.71 to -0.07; p = 0.017). CONCLUSIONS The incidence of VF at 1 year was low and LS BMD Z-scores improved by 12 months in the majority. Twenty-five percent of children had LS BMD Z-scores ≤-1.0 at 12 months. In these children, LS BMD Z-scores were inversely associated with early GC exposure, despite similar GC exposure compared to the rest of the cohort.
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Mastroleo F, Van Houdt R, Atkinson S, Mergeay M, Hendrickx L, Wattiez R, Leys N. Modelled microgravity cultivation modulates N-acylhomoserine lactone production in Rhodospirillum rubrum S1H independently of cell density. Microbiology (Reading) 2013; 159:2456-2466. [DOI: 10.1099/mic.0.066415-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Atkinson S, Velarde A, Algers B. Assessment of stun quality at commercial slaughter in cattle shot with captive bolt. Anim Welf 2013. [DOI: 10.7120/09627286.22.4.473] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Harper C, Corlett C, Macdonald G, Worthington G, Porter D, Kelly D, Segal S, Pollard AJ, Atkinson S. PW03-032 – Periodic fevers in children. Pediatr Rheumatol Online J 2013. [PMCID: PMC3952387 DOI: 10.1186/1546-0096-11-s1-a258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Twigg MS, Tait K, Williams P, Atkinson S, Cámara M. Interference with the germination and growth of
U
lva
zoospores by quorum‐sensing molecules from
U
lva
‐associated epiphytic bacteria. Environ Microbiol 2013; 16:445-53. [DOI: 10.1111/1462-2920.12203] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 06/22/2013] [Indexed: 11/30/2022]
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Hook AL, Chang CY, Yang J, Atkinson S, Langer R, Anderson DG, Davies MC, Williams P, Alexander MR. Discovery of novel materials with broad resistance to bacterial attachment using combinatorial polymer microarrays. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:2542-7. [PMID: 23417823 PMCID: PMC3736217 DOI: 10.1002/adma.201204936] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Indexed: 05/24/2023]
Abstract
A new class of bacteria-attachment-resistant materials is discovered using a multi-generation polymer microarray methodology that reduces bacterial attachment by up to 99.3% compared with a leading commercially available silver hydrogel anti-bacterial material. The coverage of three bacterial species, Pseudomonas aeruginosa, Staphylococcus aureus, and uropathogenic Escherichia coli is assessed.
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Hargreaves CE, Grasso M, Hampe CS, Stenkova A, Atkinson S, Joshua GWP, Wren BW, Buckle AM, Dunn-Walters D, Banga JP. Yersinia enterocolitica provides the link between thyroid-stimulating antibodies and their germline counterparts in Graves' disease. THE JOURNAL OF IMMUNOLOGY 2013; 190:5373-81. [PMID: 23630351 DOI: 10.4049/jimmunol.1203412] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Graves' disease results from thyroid-stimulating Abs (TSAbs) activating the thyrotropin receptor (TSHR). How TSAbs arise from early precursor B cells has not been established. Genetic and environmental factors may contribute to pathogenesis, including the bacterium Yersinia enterocolitica. We developed two pathogenic monoclonal TSAbs from a single experimental mouse undergoing Graves' disease, which shared the same H and L chain germline gene rearrangements and then diversified by numerous somatic hypermutations. To address the Ag specificity of the shared germline precursor of the monoclonal TSAbs, we prepared rFab germline, which showed negligible binding to TSHR, indicating importance of somatic hypermutation in acquiring TSAb activity. Using rFab chimeras, we demonstrate the dominant role of the H chain V region in TSHR recognition. The role of microbial Ags was tested with Y. enterocolitica proteins. The monoclonal TSAbs recognize 37-kDa envelope proteins, also recognized by rFab germline. MALDI-TOF identified the proteins as outer membrane porin (Omp) A and OmpC. Using recombinant OmpA, OmpC, and related OmpF, we demonstrate cross-reactivity of monoclonal TSAbs with the heterogeneous porins. Importantly, rFab germline binds recombinant OmpA, OmpC, and OmpF confirming reactivity with Y. enterocolitica. A human monoclonal TSAb, M22 with similar properties to murine TSAbs, also binds recombinant porins, showing cross-reactivity of a spontaneously arising pathogenic Ab with Y. enterocolitica. The data provide a mechanistic framework for molecular mimicry in Graves' disease, where early precursor B cells are expanded by Y. enterocolitica porins to undergo somatic hypermutation to acquire a cross-reactive pathogenic response to TSHR.
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Gillman A, Matouš K, Atkinson S. Microstructure-statistics-property relations of anisotropic polydisperse particulate composites using tomography. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:022208. [PMID: 23496506 DOI: 10.1103/physreve.87.022208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Indexed: 06/01/2023]
Abstract
In this paper, a systematic method is presented for developing microstructure-statistics-property relations of anisotropic polydisperse particulate composites using microcomputer tomography (micro-CT). Micro-CT is used to obtain a detailed three-dimensional representation of polydisperse microstructures, and an image processing pipeline is developed for identifying particles. In this work, particles are modeled as idealized shapes in order to guide the image processing steps and to provide a description of the discrete micro-CT data set in continuous Euclidean space. n-point probability functions used to describe the morphology of mixtures are calculated directly from real microstructures. The statistical descriptors are employed in the Hashin-Shtrikman variational principle to compute overall anisotropic bounds and self-consistent estimates of the thermal-conductivity tensor. We make no assumptions of statistical isotropy nor ellipsoidal symmetry, and the statistical description is obtained directly from micro-CT data. Various mixtures consisting of polydisperse ellipsoidal and spherical particles are prepared and studied to show how the morphology impacts the overall anisotropic thermal-conductivity tensor.
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Atkinson S, Velarde A, Llonch P, Algers B. Assessing pig welfare at stunning in Swedish commercial abattoirs using CO 2 group-stun methods. Anim Welf 2012. [DOI: 10.7120/09627286.21.4.487] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Hook AL, Chang CY, Yang J, Scurr DJ, Langer R, Anderson DG, Atkinson S, Williams P, Davies MC, Alexander MR. Polymer microarrays for high throughput discovery of biomaterials. J Vis Exp 2012:e3636. [PMID: 22314927 PMCID: PMC3462568 DOI: 10.3791/3636] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The discovery of novel biomaterials that are optimized for a specific biological application is readily achieved using polymer microarrays, which allows a combinatorial library of materials to be screened in a parallel, high throughput format1. Herein is described the formation and characterization of a polymer microarray using an on-chip photopolymerization technique 2. This involves mixing monomers at varied ratios to produce a library of monomer solutions, transferring the solution to a glass slide format using a robotic printing device and curing with UV irradiation. This format is readily amenable to many biological assays, including stem cell attachment and proliferation, cell sorting and low bacterial adhesion, allowing the ready identification of 'hit' materials that fulfill a specific biological criterion3-5. Furthermore, the use of high throughput surface characterization (HTSC) allows the biological performance to be correlated with physio-chemical properties, hence elucidating the biological-material interaction6. HTSC makes use of water contact angle (WCA) measurements, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). In particular, ToF-SIMS provides a chemically rich analysis of the sample that can be used to correlate the cell response with a molecular moiety. In some cases, the biological performance can be predicted from the ToF-SIMS spectra, demonstrating the chemical dependence of a biological-material interaction, and informing the development of hit materials5,3.
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