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1.
Immunology ; 169(4): 467-486, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37055914

RESUMO

Citrullination and homocitrullination are stress induced post-translational modifications (siPTMs) which can be recognized by T cells. Peripheral blood mononuclear cells isolated from healthy donors and rheumatoid arthritis (RA) patients were stimulated with nine siPTM-peptides. CD45RA/CD45RO depletion was employed to determine if peptide-specific responses are naïve or memory. Human leucocyte antigen (HLA)-DP4 and HLA-DR4 transgenic mice were immunized with siPTM-peptides and immune responses were determined with ex vivo ELISpot assays. The majority (24 out of 25) of healthy donors showed CD4 T cell-specific proliferation to at least 1 siPTM-peptide, 19 to 2 siPTM-peptides, 14 to 3 siPTM-peptides, 9 to 4 siPTM-peptides, 6 to 5 siPTM-peptides and 4 to 6 siPTM-peptides. More donors responded to Vim28-49cit (68%) and Bip189-208cit (75%) compared with Vim415-433cit (33%). In RA patients, the presentation of citrullinated epitopes is associated with HLA-SE alleles; however, we witnessed responses in healthy donors who did not express the SE allele. The majority of responding T cells were effector memory cells with a Th1/cytotoxic phenotype. Responses to Vim28-49cit and Eno241-260cit originated in the memory pool, while the response to Vim415-433cit was naïve. In the HLA-DP4 and HLA-DR4 transgenic models, Vim28cit generated a memory response. Peptide-specific T cells were capable of Epstein-Barr virus transformed lymphoblastoid cell line recognition suggesting a link with stress due to infection. These results suggest siPTM-peptides are presented under conditions of cellular stress and inflammation and drive cytotoxic CD4 T cell responses that aid in the removal of stressed cells. The presentation of such siPTM-peptides is not restricted to HLA-SE in both humans and animal models.


Assuntos
Artrite Reumatoide , Infecções por Vírus Epstein-Barr , Camundongos , Animais , Humanos , Alelos , Antígeno HLA-DR4/genética , Infecções por Vírus Epstein-Barr/genética , Leucócitos Mononucleares , Herpesvirus Humano 4/genética , Peptídeos , Antígenos de Histocompatibilidade Classe II/genética , Artrite Reumatoide/genética , Antígenos HLA , Camundongos Transgênicos , Imunidade
2.
J Urol ; 208(2): 277-283, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35394343

RESUMO

PURPOSE: Research priorities are often set by expert clinicians and researchers. We sought to apply an established process in patient-centered research to engage survivors and their caregivers in prioritizing research topics in prostate cancer. MATERIALS AND METHODS: A prostate cancer patient survey network, formed in partnership with Us TOO and the National Alliance of State Prostate Cancer Coalitions, engaged in a series of mixed-methods studies to prioritize comparative effectiveness research questions. This was accomplished through an iterative process that included 2 survey rounds and multidisciplinary working groups. RESULTS: There were 591 and 706 survey respondents in the first and second rounds, respectively, with most having had localized prostate cancer (58.1%). Survey participants represented 45 states in the U.S. Five of the top 11 prioritized research questions related to treatment decision making and/or survivorship care. The following had the highest overall importance ratings: What is the comparative effectiveness of different 1) strategies to improve counseling regarding the side effects of prostate cancer treatment, 2) tools for decision making in localized prostate cancer and 3) sequences of treatments for metastatic prostate cancer? CONCLUSIONS: We present a unique, patient-centered list of prioritized research questions among prostate cancer patients and their caregivers. These research questions may inform funding decisions for organizations that support research, and should be considered as priorities for clinicians, researchers and institutions conducting prostate cancer research. Prostate cancer is a common disease that affects 1 in 9 men over their lifetime. Researchers usually identify questions to study without asking men with prostate cancer. We asked survivors of prostate cancer and their caregivers to help us. They identified research questions and topics that are important to them. Researchers can focus on this list of questions to help men with prostate cancer. Groups who pay for research studies can make these questions their priority.


Assuntos
Cuidadores , Neoplasias da Próstata , Cuidadores/psicologia , Pesquisa Comparativa da Efetividade , Humanos , Masculino , Assistência Centrada no Paciente , Neoplasias da Próstata/terapia , Inquéritos e Questionários
3.
J Microsc ; 266(3): 273-287, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28252807

RESUMO

Knowledge of the collagen structure of an Achilles tendon is critical to comprehend the physiology, biomechanics, homeostasis and remodelling of the tissue. Despite intensive studies, there are still uncertainties regarding the microstructure. The majority of studies have examined the longitudinally arranged collagen fibrils as they are primarily attributed to the principal tensile strength of the tendon. Few studies have considered the structural integrity of the entire three-dimensional (3D) collagen meshwork, and how the longitudinal collagen fibrils are integrated as a strong unit in a 3D domain to provide the tendons with the essential tensile properties. Using second harmonic generation imaging, a 3D imaging technique was developed and used to study the 3D collagen matrix in the midportion of Achilles tendons without tissue labelling and dehydration. Therefore, the 3D collagen structure is presented in a condition closely representative of the in vivo status. Atomic force microscopy studies have confirmed that second harmonic generation reveals the internal collagen matrix of tendons in 3D at a fibril level. Achilles tendons primarily contain longitudinal collagen fibrils that braid spatially into a dense rope-like collagen meshwork and are encapsulated or wound tightly by the oblique collagen fibrils emanating from the epitenon region. The arrangement of the collagen fibrils provides the longitudinal fibrils with essential structural integrity and endows the tendon with the unique mechanical function for withstanding tensile stresses. A novel 3D microscopic method has been developed to examine the 3D collagen microstructure of tendons without tissue dehydrating and labelling. The study also provides new knowledge about the collagen microstructure in an Achilles tendon, which enables understanding of the function of the tissue. The knowledge may be important for applying surgical and tissue engineering techniques to tendon reconstruction.


Assuntos
Tendão do Calcâneo/ultraestrutura , Colágeno/ultraestrutura , Imageamento Tridimensional/métodos , Microscopia de Geração do Segundo Harmônico/métodos , Animais , Microscopia de Força Atômica , Coelhos
4.
Front Vet Sci ; 11: 1290705, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39144085

RESUMO

Livestock provide meat, milk, draught labour, are used for breeding, and act as a store of value for smallholder farmers. High young stock mortality (YSM) has the potential to cause significant financial loss. The Young Stock Mortality Reduction Consortium collaborated on a project to deliver a package of basic health and husbandry interventions to reduce YSM for cattle and small ruminants in mixed and pastoral production systems in Ethiopia. Prior to the intervention, YSM rates ranged from 9.8% for calves in mixed systems, to 35.6% for small ruminants in pastoral systems. Proportional reductions YSM from the intervention ranged from 60% for calves and for small ruminants in mixed systems, to 72% for calves in pastoral systems. This brief research report assesses the costs and benefits of the intervention ex-poste to determine its efficiency. NPVs for the intervention (per household) were calculated for a range of benefit periods (from 1 to 20 years), based on the cost of training enumerators and farmers and the net annual household benefits realised within each benefit period. We found in both pastoral and mixed systems the net annual household benefit for the intervention was positive. For pastoral households the intervention achieves a positive NPV after 2 years. For mixed households the intervention achieves a positive NPV after 11 years. Overall, we found the benefits of the intervention exceed the costs, by a very large amount in pastoral systems, and that benefits were larger for households that kept larger numbers of breeding females.

5.
Biotechnol Bioeng ; 110(5): 1495-507, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23242991

RESUMO

Identification of functional programmable mechanical stimulation (PMS) on tendon not only provides the insight of the tendon homeostasis under physical/pathological condition, but also guides a better engineering strategy for tendon regeneration. The aims of the study are to design a bioreactor system with PMS to mimic the in vivo loading conditions, and to define the impact of different cyclic tensile strain on tendon. Rabbit Achilles tendons were loaded in the bioreactor with/without cyclic tensile loading (0.25 Hz for 8 h/day, 0-9% for 6 days). Tendons without loading lost its structure integrity as evidenced by disorientated collagen fiber, increased type III collagen expression, and increased cell apoptosis. Tendons with 3% of cyclic tensile loading had moderate matrix deterioration and elevated expression levels of MMP-1, 3, and 12, whilst exceeded loading regime of 9% caused massive rupture of collagen bundle. However, 6% of cyclic tensile strain was able to maintain the structural integrity and cellular function. Our data indicated that an optimal PMS is required to maintain the tendon homeostasis and there is only a narrow range of tensile strain that can induce the anabolic action. The clinical impact of this study is that optimized eccentric training program is needed to achieve maximum beneficial effects on chronic tendinopathy management.


Assuntos
Tendão do Calcâneo/fisiologia , Reatores Biológicos , Resistência à Tração/fisiologia , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Tendão do Calcâneo/química , Tendão do Calcâneo/citologia , Análise de Variância , Animais , Apoptose/fisiologia , Fenômenos Biomecânicos/fisiologia , Contagem de Células , Forma Celular , Colágeno Tipo III/química , Matriz Extracelular , Feminino , Histocitoquímica , Humanos , Coelhos , Estresse Mecânico
7.
NPJ Digit Med ; 5(1): 182, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36526692

RESUMO

During the United Kingdom's Covid-19 vaccination campaign, general practitioners (GPs) have held responsibility for vaccinating housebound patients. This presented them with a large, complex and unfamiliar logistical challenge, namely determining the most time-efficient route to visit multiple patients at their home address. In response to a lack of existing solutions tailored specifically to vaccination, and in light of overwhelming demand, Vaximap ( https://www.vaximap.org ) was created in January 2021 to automate the process of route planning. It is free of charge for all users and has been used to-date to plan vaccinations for over 470,000 patients. This article analyses usage data to estimate the time savings (3 work years) and financial savings (£110,000) the service has yielded for GP surgeries, thus demonstrating that it helped to accelerate the UK's Covid-19 vaccination campaign at critical moments.

8.
Microsc Res Tech ; 85(2): 728-737, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34632676

RESUMO

The nanostructural response of New Zealand white rabbit Achilles tendons to a fatigue damage model was assessed quantitatively and qualitatively using the endpoint of dose assessments of each tendon from our previous study. The change in mechanical properties was assessed concurrently with nanostructural change in the same non-viable intact tendon. Atomic force microscopy was used to study the elongation of D-periodicities, and the changes were compared both within the same fibril bundle and between fibril bundles. D-periodicities increased due to both increased strain and increasing numbers of fatigue cycles. Although no significant difference in D-periodicity lengthening was found between fibril bundles, the lengthening of D-periodicity correlated strongly with the overall tendon mechanical changes. The accurate quantification of fibril elongation in response to macroscopic applied strain assisted in assessing the complex structure-function relationship in Achilles tendons.


Assuntos
Tendão do Calcâneo , Nanoestruturas , Animais , Fenômenos Biomecânicos , Citoesqueleto , Microscopia de Força Atômica , Coelhos
9.
Microsc Res Tech ; 85(1): 233-243, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34390286

RESUMO

This study investigates the nanostructural mechanisms that lie behind load transmission in tendons and the role of glycosaminoglycans (GAGs) in the transmission of force in the tendon extracellular matrix. The GAGs in white New Zealand rabbit Achilles tendons were enzymatically depleted, and the tendons subjected to cyclic loading at 6% strain for up to 2 hr. A nanoscale morphometric assessment of fibril deformation under strain was linked with the decline in the tendon macroscale mechanical properties. An atomic force microscope (AFM) was employed to characterize the D-periodicity within and between fibril bundles (WFB and BFB, respectively). By the end of the second hour of the applied strain, the WFB and BFB D-periodicities had significantly increased in the GAG-depleted group (29% increase compared with 15% for the control, p < .0001). No statistically significant differences were found between WFB and BFB D-periodicities in either the control or GAG-depleted groups, suggesting that mechanical load in Achilles tendons is uniformly distributed and fairly homogenous among the WFB and BFB networks. The results of this study have provided evidence of a cycle-dependent mechanism of damage accumulation. The accurate quantification of fibril elongation (measured as the WFB and BFB D-periodicity lengths) in response to macroscopic applied strain has assisted in assessing the complex structure-function relationship in Achilles tendon.


Assuntos
Tendão do Calcâneo , Glicosaminoglicanos , Animais , Fenômenos Biomecânicos , Proteoglicanas , Coelhos
10.
Sci Data ; 9(1): 543, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36068231

RESUMO

Arterial spin labeling (ASL) is a non-invasive MRI technique that allows for quantitative measurement of cerebral perfusion. Incomplete or inaccurate reporting of acquisition parameters complicates quantification, analysis, and sharing of ASL data, particularly for studies across multiple sites, platforms, and ASL methods. There is a strong need for standardization of ASL data storage, including acquisition metadata. Recently, ASL-BIDS, the BIDS extension for ASL, was developed and released in BIDS 1.5.0. This manuscript provides an overview of the development and design choices of this first ASL-BIDS extension, which is mainly aimed at clinical ASL applications. Discussed are the structure of the ASL data, focussing on storage order of the ASL time series and implementation of calibration approaches, unit scaling, ASL-related BIDS fields, and storage of the labeling plane information. Additionally, an overview of ASL-BIDS compatible conversion and ASL analysis software and ASL example datasets in BIDS format is provided. We anticipate that large-scale adoption of ASL-BIDS will improve the reproducibility of ASL research.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Neuroimagem , Humanos , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/normas , Neuroimagem/métodos , Reprodutibilidade dos Testes , Marcadores de Spin
11.
EBioMedicine ; 76: 103868, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35172957

RESUMO

BACKGROUND: The manufacturing of any standard mechanical ventilator cannot rapidly be upscaled to several thousand units per week, largely due to supply chain limitations. The aim of this study was to design, verify and perform a pre-clinical evaluation of a mechanical ventilator based on components not required for standard ventilators, and that met the specifications provided by the Medicines and Healthcare Products Regulatory Agency (MHRA) for rapidly-manufactured ventilator systems (RMVS). METHODS: The design utilises closed-loop negative feedback control, with real-time monitoring and alarms. Using a standard test lung, we determined the difference between delivered and target tidal volume (VT) at respiratory rates between 20 and 29 breaths per minute, and the ventilator's ability to deliver consistent VT during continuous operation for >14 days (RMVS specification). Additionally, four anaesthetised domestic pigs (3 male-1 female) were studied before and after lung injury to provide evidence of the ventilator's functionality, and ability to support spontaneous breathing. FINDINGS: Continuous operation lasted 23 days, when the greatest difference between delivered and target VT was 10% at inspiratory flow rates >825 mL/s. In the pre-clinical evaluation, the VT difference was -1 (-90 to 88) mL [mean (LoA)], and positive end-expiratory pressure (PEEP) difference was -2 (-8 to 4) cmH2O. VT delivery being triggered by pressures below PEEP demonstrated spontaneous ventilation support. INTERPRETATION: The mechanical ventilator presented meets the MHRA therapy standards for RMVS and, being based on largely available components, can be manufactured at scale. FUNDING: Work supported by Wellcome/EPSRC Centre for Medical Engineering,King's Together Fund and Oxford University.


Assuntos
Desenho de Equipamento , Respiração Artificial/instrumentação , Animais , COVID-19/patologia , COVID-19/prevenção & controle , COVID-19/virologia , Feminino , Masculino , Taxa Respiratória , SARS-CoV-2/isolamento & purificação , Suínos , Volume de Ventilação Pulmonar
12.
Cells ; 10(11)2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34831065

RESUMO

Fibroblasts are the major cell population in the connective tissue of most organs, where they are essential for their structural integrity. They are best known for their role in remodelling the extracellular matrix, however more recently they have been recognised as a functionally highly diverse cell population that constantly responds and adapts to their environment. Biological memory is the process of a sustained altered cellular state and functions in response to a transient or persistent environmental stimulus. While it is well established that fibroblasts retain a memory of their anatomical location, how other environmental stimuli influence fibroblast behaviour and function is less clear. The ability of fibroblasts to respond and memorise different environmental stimuli is essential for tissue development and homeostasis and may become dysregulated in chronic disease conditions such as fibrosis and cancer. Here we summarise the four emerging key areas of fibroblast adaptation: positional, mechanical, inflammatory, and metabolic memory and highlight the underlying mechanisms and their implications in tissue homeostasis and disease.


Assuntos
Doença , Desenvolvimento Embrionário , Fibroblastos/patologia , Homeostase , Fibroblastos/metabolismo , Humanos , Inflamação/patologia , Modelos Biológicos
13.
J Biomech ; 128: 110790, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34634539

RESUMO

The response of white New Zealand rabbit Achilles tendons to load was assessed using mechanical measures and confocal arthroscopy (CA). The progression of fatigue-loading-induced damage of the macro- (tenocyte morphology, fiber anisotropy and waviness), as well as the mechanical profile, were assessed within the same non-viable intact tendon in response to prolonged cyclic and static loading (up to four hours) at different strain levels (3%, 6% and 9%). Strain-mediated repeated loading induced a significant decline in mechanical function (p < 0.05) with increased strain and cycles. Mechanical and structural resilience was lost with repeated loading (p < 0.05) at macroscales. The lengthening of D-periodicity correlated strongly with the overall tendon mechanical changes and loss of spindle shape in tenocytes. This is the first study to provide a clear concurrent assessment of form (morphology) and function (mechanics) of tendons undergoing different strain-mediated repeated loading at multiple-scale assessments. This study identifies a variety of multiscale properties that may contribute to the understanding of mechanisms of tendon pathology.


Assuntos
Tendão do Calcâneo , Animais , Coelhos , Estresse Mecânico
14.
J Biomech ; 128: 110796, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34649066

RESUMO

Tendinopathy of the Achilles tendon contributes to a large range of disorders, including mechanical damage and degenerative diseases. Glycosaminoglycans (GAGs), are thought to play a role in the mechanical strength of tendons by forming cross-links between collagen molecules and allowing the transmission of forces between fibrils. This study assessed the response of GAG-depleted tendons to damage induced by fatigue loading, investigating the mechanical damage (stiffness, hysteresis and maximum load), macrostructural changes (tenocyte morphology, fiber anisotropy and waviness) assessed by confocal imaging and nanostructural changes (fibril D-periodicity length) within the same non-viable intact tendons. Changes in fiber waviness and tenocyte shape are strongly correlated to mechanical and nano-structural (D-periodicity elongation) properties in both Control and GAG-depleted tendons. This study supports firstly, the vital role GAGs play as mechanical connectors facilitating the load transfer between the fibrils and their hydrophilic role in facilitating fibril sliding. Secondly, that observed changes in tenocyte shape and fiber waviness correlate with tendon stiffness and other mechanical profiles.


Assuntos
Tendão do Calcâneo , Tendinopatia , Fenômenos Biomecânicos , Colágeno , Glicosaminoglicanos , Humanos
15.
ACS Appl Mater Interfaces ; 13(51): 61638-61652, 2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-34908393

RESUMO

Injection of a hydrogel loaded with drugs with simultaneous anti-inflammatory and tissue regenerating properties can be an effective treatment for promoting periodontal regeneration in periodontitis. Nevertheless, the design and preparation of an injectable hydrogel with self-healing properties for tunable sustained drug release is still highly desired. In this work, polysaccharide-based hydrogels were formed by a dynamic cross-linked network of dynamic Schiff base bonds and dynamic coordination bonds. The hydrogels showed a quick gelation process, injectability, and excellent self-healing properties. In particular, the hydrogels formed by a double-dynamic network would undergo a gel-sol transition process without external stimuli. And the gel-sol transition time could be tuned by the double-dynamic network structure for in situ stimuli involving a change in its own molecular structure. Moreover, the drug delivery properties were also tunable owing to the gel-sol transition process. Sustained drug release characteristics, which were ascribed to a diffusion process, were observed during the first stage of drug release, and complete drug release owing to the gel-sol transition process was achieved. The sustained drug release time could be tuned according to the double-dynamic bonds in the hydrogel. The CCK-8 assay was used to evaluate the cytotoxicity, and the result showed no cytotoxicity, indicating that the injectable and self-healing hydrogels with double-dynamic bond tunable gel-sol transition could be safely used in controlled drug delivery for periodontal disease therapy. Finally, the promotion of periodontal regeneration in periodontitis in vivo was investigated using hydrogels loaded with ginsenoside Rg1 and amelogenin. Micro-CT and histological analyses indicated that the hydrogels were promising candidates for addressing the practical needs of a tunable drug delivery method for promoting periodontal regeneration in periodontitis.


Assuntos
Amelogenina/química , Materiais Biocompatíveis/química , Fármacos do Sistema Nervoso Central/farmacologia , Ginsenosídeos/farmacologia , Hidrogéis/química , Periodontite/tratamento farmacológico , Periodonto/efeitos dos fármacos , Materiais Biocompatíveis/síntese química , Fármacos do Sistema Nervoso Central/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Ginsenosídeos/química , Hidrogéis/síntese química , Teste de Materiais
16.
Elife ; 102021 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-34939928

RESUMO

Solar ultraviolet radiation (UVR) is a major source of skin damage, resulting in inflammation, premature ageing, and cancer. While several UVR-induced changes, including extracellular matrix reorganisation and epidermal DNA damage, have been documented, the role of different fibroblast lineages and their communication with immune cells has not been explored. We show that acute and chronic UVR exposure led to selective loss of fibroblasts from the upper dermis in human and mouse skin. Lineage tracing and in vivo live imaging revealed that repair following acute UVR is predominantly mediated by papillary fibroblast proliferation and fibroblast reorganisation occurs with minimal migration. In contrast, chronic UVR exposure led to a permanent loss of papillary fibroblasts, with expansion of fibroblast membrane protrusions partially compensating for the reduction in cell number. Although UVR strongly activated Wnt signalling in skin, stimulation of fibroblast proliferation by epidermal ß-catenin stabilisation did not enhance papillary dermis repair. Acute UVR triggered an infiltrate of neutrophils and T cell subpopulations and increased pro-inflammatory prostaglandin signalling in skin. Depletion of CD4- and CD8-positive cells resulted in increased papillary fibroblast depletion, which correlated with an increase in DNA damage, pro-inflammatory prostaglandins, and reduction in fibroblast proliferation. Conversely, topical COX-2 inhibition prevented fibroblast depletion and neutrophil infiltration after UVR. We conclude that loss of papillary fibroblasts is primarily induced by a deregulated inflammatory response, with infiltrating T cells supporting fibroblast survival upon UVR-induced environmental stress.


Assuntos
Linhagem da Célula/efeitos da radiação , Fibroblastos/efeitos da radiação , Regeneração/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Adulto , Feminino , Fibroblastos/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade
17.
IEEE Trans Med Imaging ; 39(5): 1501-1510, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31714217

RESUMO

Partial volume effects (PVE) present a source of confound for the analysis of functional imaging data. Correction for PVE requires estimates of the partial volumes (PVs) present in an image. These estimates are conventionally obtained via volumetric segmentation, but such an approach may not be accurate for complex structures such as the cortex. An alternative is to use surface-based segmentation, which is well-established within the literature. Toblerone is a new method for estimating PVs using such surfaces. It uses a purely geometric approach that considers the intersection between a surface and the voxels of an image. In contrast to existing surface-based techniques, Toblerone is not restricted to use with any particular structure or modality. Evaluation in a neuroimaging context has been performed on simulated surfaces, simulated T1-weighted MRI images and finally a Human Connectome Project test-retest dataset. A comparison has been made to two existing surface-based methods; in all analyses Toblerone's performance either matched or surpassed the comparator methods. Evaluation results also show that compared to an existing volumetric method (FSL FAST), a surface-based approach with Toblerone offers improved robustness to scanner noise and field non-uniformity, and better inter-session repeatability in brain volume. In contrast to volumetric methods, a surface-based approach negates the need to perform resampling which is advantageous at the resolutions typically used for neuroimaging.


Assuntos
Conectoma , Processamento de Imagem Assistida por Computador , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Neuroimagem
18.
Cancer Res ; 80(16): 3399-3412, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32532823

RESUMO

Murine IgG3 glycan-targeting mAb often induces direct cell killing in the absence of immune effector cells or complement via a proinflammatory mechanism resembling oncotic necrosis. This cancer cell killing is due to noncovalent association between Fc regions of neighboring antibodies, resulting in enhanced avidity. Human isotypes do not contain the residues underlying this cooperative binding mode; consequently, the direct cell killing of mouse IgG3 mAb is lost upon chimerization or humanization. Using the Lewisa/c/x -targeting 88mAb, we identified the murine IgG3 residues underlying the direct cell killing and increased avidity via a series of constant region shuffling and subdomain swapping approaches to create improved ("i") chimeric mAb with enhanced tumor killing in vitro and in vivo. Constant region shuffling identified a major CH3 and a minor CH2 contribution, which was further mapped to discontinuous regions among residues 286-306 and 339-378 that, when introduced in 88hIgG1, recapitulated the direct cell killing and avidity of 88mIgG3. Of greater interest was the creation of a sialyl-di-Lewisa-targeting i129G1 mAb via introduction of these selected residues into 129hIgG1, converting it into a direct cell killing mAb with enhanced avidity and significant in vivo tumor control. The human iG1 mAb, termed Avidimabs, retained effector functions, paving the way for the proinflammatory direct cell killing to promote antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity through relief of immunosuppression. Ultimately, Fc engineering of human glycan-targeting IgG1 mAb confers proinflammatory direct cell killing and enhanced avidity, an approach that could be used to improve the avidity of other mAb with therapeutic potential. SIGNIFICANCE: Fc engineering enhances avidity and direct cell killing of cancer-targeting anti-glycan antibodies to create superior clinical candidates for cancer immunotherapy.


Assuntos
Anticorpos Monoclonais/imunologia , Afinidade de Anticorpos/imunologia , Morte Celular/imunologia , Neoplasias Colorretais/terapia , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/imunologia , Polissacarídeos/imunologia , Animais , Citotoxicidade Celular Dependente de Anticorpos , Linhagem Celular Tumoral , Neoplasias Colorretais/imunologia , Proteínas do Sistema Complemento , Feminino , Engenharia Genética , Humanos , Imunoterapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Distribuição Aleatória
19.
J Orthop Surg Res ; 14(1): 18, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30636623

RESUMO

Tendons are soft tissues of the musculoskeletal system that are designed to facilitate joint movement. Tendons exhibit a wide range of mechanical properties matched to their functions and, as a result, have been of interest to researchers for many decades. Dimensions are an important aspect of tendon properties.Change in the dimensions of tissues is often seen as a sign of injury and degeneration, as it may suggest inflammation or general disorder of the tissue. Dimensions are also important for determining the mechanical properties and behaviours of materials, particularly the stress, strain, and elastic modulus. This makes the dimensions significant in the context of a mechanical study of degenerated tendons. Additionally, tendon dimensions are useful in planning harvesting for tendon transfer and joint reconstruction purposes.Historically, many methods have been used in an attempt to accurately measure the dimensions of soft tissue, since improper measurement can lead to large errors in the calculated properties. These methods can be categorised as destructive (by approximation), contact, and non-contact and can be considered in terms of in vivo and ex vivo.


Assuntos
Tendinopatia/diagnóstico , Tendões/diagnóstico por imagem , Tendões/patologia , Antropometria/métodos , Humanos , Imageamento por Ressonância Magnética , Tendinopatia/patologia , Tomografia Computadorizada por Raios X , Ultrassonografia
20.
Arthroscopy ; 24(4): 423-9, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18375274

RESUMO

PURPOSE: This study aimed to assess the ability of the laser scanning confocal arthroscope (LSCA) to evaluate cartilage microstructure, particularly in differentiating stages of human osteoarthritis (OA) as classified by the International Cartilage Repair Society (ICRS) OA grade definitions. METHODS: Ten tibial plateaus from total knee arthroplasty patients were obtained at the time of surgery. Cartilage areas were visually graded based on the ICRS classification, imaged by use of a 7-mm-diameter LSCA (488-nm excitation with 0.5% [wt/vol] fluorescein, 20-minute staining period), and then removed with underlying bone for histologic examination with H&E staining. The 2 imaging techniques were then compared for each ICRS grade to ascertain similarity between the methods and thus gauge the techniques' diagnostic resolution. Cartilage surface degeneration was readily imaged and OA severity accurately gauged by the LSCA and confirmed by histology. RESULTS: LSCA and histologic images of specimens in the late stages of OA were seen to be mutually related even though they were imaged in planes that were orthogonal to each other. Useful and comparable diagnostic resolution was obtained in all imaged specimens from subjects with various stages of OA. CONCLUSIONS: This study showed the LSCA's ability to image detailed cartilage surface morphologic features that identify grade 1 through 4 of the ICRS OA grading system. The LSCA's imaging potential was best shown by its ability to resolve the fine collagen network present under the lamina splendens. The incorporation of high-magnification confocal technology within the confines of an arthroscopic probe has proved to provide the imaging requirements necessary to perform detailed cartilage condition assessment. CLINICAL RELEVANCE: In comparison to video arthroscopy, LSCA provides increased magnification along with improved contrast and resolution.


Assuntos
Meniscos Tibiais/patologia , Meniscos Tibiais/ultraestrutura , Microscopia Confocal , Osteoartrite do Joelho/patologia , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/métodos , Artroscópios , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Osteoartrite do Joelho/cirurgia , Estudos de Amostragem , Sensibilidade e Especificidade , Índice de Gravidade de Doença
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