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1.
Connect Tissue Res ; 65(2): 89-101, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38375562

RESUMO

OBJECTIVE: The aim of this study was to comprehensively examine and summarize the available in vitro evidence regarding the relationship between mechanical stimulation and biomarkers of collagen synthesis in human-derived tendon cells. METHODS: Systematic review with narrative analyses and risk of bias assessment guided by the Health Assessment and Translation tool. The electronic databases MEDLINE (Ovid), EMBASE (Ovid), CENTRAL (Ovid) and COMPENDEX (Engineering Village) were systematically searched from inception to 3 August 2023. Inclusion criteria encompassed English language, original experimental, or quasi-experimental in vitro publications that subjected human tendon cells to mechanical stimulation, with collagen synthesis (total collagen, type I, III, V, XI, XII, and XIV) and related biomarkers (matrix metalloproteinases, transforming growth factor ß, scleraxis, basic fibroblast growth factor) as outcomes. RESULTS: Twenty-one publications were included. A pervasive definite high risk of bias was evident in all included studies. Owing to incomplete outcome reporting and heterogeneity in mechanical stimulation protocols, planned meta-analyses were unfeasible. Reviewed data suggested that human tendon cells respond to mechanical stimulation with increased synthesis of collagen (e.g., COL1A1, procollagen, total soluble collagen, etc.), scleraxis and several matrix metalloproteinases. Results also indicate that mechanical stimulation dose magnitude may influence synthesis in several biomarkers. CONCLUSIONS: A limited number of studies, unfortunately characterized by a definite high risk of bias, suggest that in vitro mechanical stimulation primarily increases type I collagen synthesis by human tendon cells. Findings from this systematic review provide researchers and clinicians with biological evidence concerning the possible beneficial influence of exercise and loading on cellular-level tendon adaptation.


Assuntos
Colágeno , Tendões , Humanos , Colágeno/metabolismo , Tendões/metabolismo , Colágeno Tipo I/metabolismo , Biomarcadores/metabolismo , Metaloproteinases da Matriz/metabolismo
2.
J Appl Clin Med Phys ; 25(4): e14167, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37812733

RESUMO

PURPOSE: Optimizing CT protocols is challenging in the presence of automatic dose modulation because the CT dose index (CTDIvol) at different patient sizes is unknown to the operator. The task is more difficult when both the image quality index and iterative reconstruction prospectively affect the dose determination. It is of interest in practice to be informed of the CTDIvol during the protocol initialization and evaluation. It was our objective to obtain a predictive relationship between CTDIvol, the image quality index, and iterative reconstruction strength at various patient sizes. METHODS: Dose modulation data were collected on a GE Revolution 256-slice scanner utilizing a Mercury phantom and selections of the noise index (NI) from 8 to 17, the third generation iterative reconstruction (ASIR-V) from 0% to 80%, and phantom diameters from 16 to 36 cm. The fixed parameters were 120 kVp, a pitch of .984, and a collimation of 40 mm with a primary slice width of 2.5 mm. The CTDIvol per diameter was based on the average tube current over three adjacent slices (same or similar diameter) multiplied by a conversion factor between the average mA of the series and the reported CTDIvol. The relationship between CTDIvol, NI, and ASIR-V for each diameter was fitted with a 2nd order polynomial of ASIR-V multiplied by a power law of NI. RESULTS: The ASIR-V fit parameters versus diameter followed a Lorentz function while the NI exponent versus diameter followed an exponential growth function. The CTDIvol predictions were accurate within 15% compared to phantom results on a separate GE Revolution. For clinical relevance, the phantom diameter was converted to an abdomen or chest equivalent diameter and was well matched to patient data. CONCLUSION: The fitted relationship for CTDIvol. for given values of NI and ASIR-V blending for a range of phantom sizes was a good match to phantom and patient data. The results can be of direct help for selecting adequate parameters in CT protocol development.


Assuntos
Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada por Raios X , Humanos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Imagens de Fantasmas , Algoritmos
3.
J Appl Biomech ; 40(4): 270-277, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38834183

RESUMO

Imbalanced joint load distribution across the tibiofemoral surface is a risk factor for osteoarthritic changes to this joint. Lateral wedge insoles, with and without arch support, are a form of biomechanical intervention that can redistribute tibiofemoral joint load, as estimated by external measures of knee load. The objective of this study was to examine the effect of these insoles on the internal joint contact characteristics of osteoarthritic knees during weightbearing. Fifteen adults with tibiofemoral osteoarthritis underwent magnetic resonance imaging of the affected knee, while standing under 3 insole conditions: flat control, lateral wedge alone, and lateral wedge with arch support. Images were processed, and the surface area and centroid location of joint contact were quantified separately for the medial and lateral tibiofemoral compartments. Medial contact surface area was increased with the 2 lateral wedge conditions compared with the control (P ≤ .012). A more anterior contact centroid was observed in the medial compartment in the lateral wedge with arch support compared with the lateral wedge alone (P = .009). Significant changes in lateral compartment joint contact outcomes were not observed. These findings represent early insights into how loading at the tibiofemoral interface may be altered by lateral wedge insoles as a potential intervention for knee osteoarthritis.


Assuntos
Órtoses do Pé , Osteoartrite do Joelho , Suporte de Carga , Humanos , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/diagnóstico por imagem , Feminino , Masculino , Pessoa de Meia-Idade , Articulação do Joelho/fisiopatologia , Articulação do Joelho/diagnóstico por imagem , Idoso , Imageamento por Ressonância Magnética , Fenômenos Biomecânicos , Articulação Tibiofemoral
4.
J Child Psychol Psychiatry ; 64(1): 39-49, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35915056

RESUMO

BACKGROUND: 5%-10% children and young people (CYP) experience specific phobias that impact daily functioning. Cognitive Behaviour Therapy (CBT) is recommended but has limitations. One Session Treatment (OST), a briefer alternative incorporating CBT principles, has demonstrated efficacy. The Alleviating Specific Phobias Experienced by Children Trial (ASPECT) investigated the non-inferiority of OST compared to multi-session CBT for treating specific phobias in CYP. METHODS: ASPECT was a pragmatic, multi-center, non-inferiority randomized controlled trial in 26 CAMHS sites, three voluntary agency services, and one university-based CYP well-being service. CYP aged 7-16 years with specific phobia were randomized to receive OST or CBT. Clinical non-inferiority and a nested cost-effectiveness evaluation was assessed 6-months post-randomization using the Behavioural Avoidance Task (BAT). Secondary outcome measures included the Anxiety Disorder Interview Schedule, Child Anxiety Impact Scale, Revised Children's Anxiety Depression Scale, goal-based outcome measure, and EQ-5DY and CHU-9D, collected blind at baseline and six-months. RESULTS: 268 CYPs were randomized to OST (n = 134) or CBT (n = 134). Mean BAT scores at 6 months were similar across groups in both intention-to-treat (ITT) and per-protocol (PP) populations (CBT: 7.1 (ITT, n = 76), 7.4 (PP, n = 57), OST: 7.4 (ITT, n = 73), 7.6 (PP, n = 56), on the standardized scale-adjusted mean difference for CBT compared to OST -0.123, 95% CI -0.449 to 0.202 (ITT), mean difference -0.204, 95% CI -0.579 to 0.171 (PP)). These findings were wholly below the standardized non-inferiority limit of 0.4, suggesting that OST is non-inferior to CBT. No between-group differences were found on secondary outcomes. OST marginally decreased mean service use costs and maintained similar mean Quality Adjusted Life Years compared to CBT. CONCLUSIONS: One Session Treatment has similar clinical effectiveness to CBT for specific phobias in CYP and may be a cost-saving alternative.


Assuntos
Terapia Cognitivo-Comportamental , Transtornos Fóbicos , Criança , Humanos , Adolescente , Análise Custo-Benefício , Terapia Cognitivo-Comportamental/métodos , Transtornos Fóbicos/terapia , Resultado do Tratamento
5.
BMC Musculoskelet Disord ; 24(1): 282, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37046262

RESUMO

BACKGROUND: Hypercholesterolemia is associated with tendon pathology, but the reasons underpinning this relationship are not well understood. Cholesterol can accumulate in the tendon non-collagenous matrix which may affect both global and local tissue mechanics. Changes to the local strain environment within tendon may have significant implications for mechanosensitive tenocytes. Here, we investigated the association between elevated blood cholesterol and presence of tendon lipids in the Achilles tendon. We expected lipids to be localised in the proteoglycan-rich inter-sub-tendon matrix (ISTM), therefore we also sought to examine the impact of this on the biomechanical and viscoelastic properties of the ISTM. METHODS: The Achilles tendons of 32 young wild-type (SD) and 32 apolipoprotein E knock-out rats (ApoE-/-) were harvested at 15.6 ± 2.3 weeks of age. 32 specimens underwent histological examination to assess the distribution of lipids throughout sub-tendons and ISTM. The remaining specimens were prepared for biomechanical testing, where the ISTM between the gastrocnemius and soleus sub-tendons was subjected to shear load mechanical testing. A sub-set of tests were video recorded to enable a strain analysis. RESULTS: ApoE-/- serum cholesterol was double that of SD rats (mean 2.25 vs. 1.10 mg/ml, p < 0.001) indicating a relatively mild hypercholesterolemia phenotype. Nonetheless, we found histological evidence of esterified lipids in the ISTM and unesterified lipids in the sub-tendons, although the location or intensity of staining was not appreciably different between rat strains. Despite a lack of observable histological differences in lipid content between groups, there were significant differences in the mechanical and viscoelastic behaviour of the Achilles sub-tendon matrix. CONCLUSION: Even slightly elevated cholesterol may result in subtle changes to tendon biomechanical properties and hence injury risk. The young age of our cohort and the mild phenotype of our ApoE-/- rats are likely to have limited our findings and so we also conclude that the ApoE-/- rat model is not well suited for investigating the biomechanical impact of tendon xanthomas on Achilles sub-tendon function.


Assuntos
Tendão do Calcâneo , Hipercolesterolemia , Ratos , Animais , Tendão do Calcâneo/lesões , Ratos Sprague-Dawley , Hipercolesterolemia/etiologia , Hipercolesterolemia/patologia , Fenômenos Biomecânicos , Colesterol
6.
Anal Chem ; 94(16): 6146-6155, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35410467

RESUMO

Global deployment of vaccines poses significant challenges in the distribution and use of the accompanying immunoassays, one of the standard methods for quality control of vaccines, particularly when establishing assays in countries worldwide to support testing/release upon importation. This work describes our effort toward developing an integrated, portable device to carry out affinity assays for viral particles quantification in viral vaccines by incorporating (i) aptamers, (ii) microfluidic devices, and (iii) electrochemical detection. We generated and characterized more than eight aptamers against multiple membrane proteins of cytomegalovirus (CMV), which we used as a model system and designed and fabricated electrochemical microfluidic devices to measure CMV concentrations in a candidate vaccine under development. The aptamer-based assays provided a half maximal effective concentration, EC50, of 12 U/mL, comparable to that of an ELISA using a pair of antibodies (EC50 60 U/mL). The device measured relative CMV concentrations accurately (within ±10% bias) and precisely (11%, percent relative standard deviation). This work represents the critical first steps toward developing simple, affordable, and robust affinity assays for global deployment without the need for sensitive equipment and extensive analyst training.


Assuntos
Aptâmeros de Nucleotídeos , Infecções por Citomegalovirus , Vacinas Virais , Aptâmeros de Nucleotídeos/química , Bioensaio , Humanos , Dispositivos Lab-On-A-Chip
7.
Heart Fail Rev ; 27(3): 915-925, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33655387

RESUMO

Despite advances in the overall management of acute myocardial infarction (AMI), cardiogenic shock in the setting of AMI (CS-AMI) continues to be associated with poor patient outcomes. There are multiple devices that can be used in CS-AMI to support the failing circulation, although their utility in improving outcomes as compared with conventional pharmacotherapy of vasopressors and inotropes remains to be established. This contemporary review provides an update on the evidence base for each of these techniques. In CS-AMI, acute thrombotic occlusion of a major epicardial artery leads to hypoxia and myocardial ischaemia in the territory subtended by that vessel. The resultant regional dysfunction in myocardial contractility can severely compromise stroke volume and result in acute circulatory failure, systemic hypoperfusion, lactic acidosis, multi-organ failure and ultimately death.


Assuntos
Coração Auxiliar , Infarto do Miocárdio , Humanos , Balão Intra-Aórtico , Infarto do Miocárdio/complicações , Choque Cardiogênico/etiologia , Choque Cardiogênico/terapia , Volume Sistólico , Resultado do Tratamento
8.
Curr Psychiatry Rep ; 24(10): 503-508, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36048322

RESUMO

PURPOSE OF REVIEW: The goal of this paper is to summarize the evidence for the use of botanical medicines for the treatment of anxiety disorders. We sought to make this review practical for psychiatrists and psychiatric prescribers. RECENT FINDINGS: In 2018, the Natural Medicines database produced a Clinical Management of Anxiety guide that summarized the conventional and natural treatments of anxiety disorders. Based on this guide, four herbal supplements (also referred to as botanicals) were selected for deeper study including kava, lavender, lemon balm and passionflower. All four were considered possibly safe and possibly effective according to the Natural Medicines database. There is scientific evidence supporting the use of kava, lavender, lemon balm and passionflower in anxiety disorders. Lavender appears to have the best available evidence including comparable efficacy to conventional first line treatments and is available in a patented form that was used in the cited studies (Silexan).


Assuntos
Lavandula , Fitoterapia , Ansiedade/tratamento farmacológico , Transtornos de Ansiedade/tratamento farmacológico , Humanos
9.
BMC Psychiatry ; 22(1): 547, 2022 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-35962334

RESUMO

BACKGROUND: In the UK, around 93,000 (0.8%) children and young people (CYP) are experiencing specific phobias that have a substantial impact on daily life. The current gold-standard treatment-multi-session cognitive behavioural therapy (CBT) - is effective at reducing specific phobia severity; however, CBT is time consuming, requires specialist CBT therapists, and is often at great cost and limited availability. A briefer variant of CBT called one session treatment (OST) has been found to offer similar clinical effectiveness for specific phobia as multi-session CBT. The aim of this study was to assess the cost-effectiveness of OST compared to multi-session CBT for CYP with specific phobias through the Alleviating Specific Phobias Experienced by Children Trial (ASPECT), a two-arm, pragmatic, multi-centre, non-inferiority randomised controlled trial. METHODS: CYP aged seven to 16 years with specific phobias were recruited nationally via Health and Social Care pathways, remotely randomised to the intervention group (OST) or the control group (CBT-based therapies) and analysed (n = 267). Resource use based on NHS and personal social services perspective and quality adjusted life years (QALYs) measured by EQ-5D-Y were collected at baseline and at six-month follow-up. Incremental cost-effectiveness ratio (ICER) was calculated, and non-parametric bootstrapping was conducted to capture the uncertainty around the ICER estimates. The results were presented on a cost-effectiveness acceptability curve (CEAC). A set of sensitivity analyses (including taking a societal perspective) were conducted to assess the robustness of the primary findings. RESULTS: After adjustment and bootstrapping, on average CYP in the OST group incurred less costs (incremental cost was -£302.96 (95% CI -£598.86 to -£28.61)) and maintained similar improvement in QALYs (QALYs gained 0.002 (95% CI - 0.004 to 0.008)). The CEAC shows that the probability of OST being cost-effective was over 95% across all the WTP thresholds. Results of a set of sensitivity analyses were consistent with the primary outcomes. CONCLUSION: Compared to CBT, OST produced a reduction in costs and maintained similar improvement in QALYs. Results from both primary and sensitivity analyses suggested that OST was highly likely to be cost saving. TRIAL REGISTRATION: ISRCTN19883421 (30/11/2016).


Assuntos
Terapia Cognitivo-Comportamental , Transtornos Fóbicos , Adolescente , Criança , Terapia Cognitivo-Comportamental/métodos , Análise Custo-Benefício , Humanos , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida
10.
Proc Natl Acad Sci U S A ; 116(52): 26389-26393, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31826951

RESUMO

The lowermost portion of Earth's mantle (D″) above the core-mantle boundary shows anomalous seismic features, such as strong seismic anisotropy, related to the properties of the main mineral MgSiO3 postperovskite. But, after over a decade of investigations, the seismic observations still cannot be explained simply by flow models which assume dislocation creep in postperovskite. We have investigated the chemical diffusivity of perovskite and postperovskite phases by experiment and ab initio simulation, and derive equations for the observed anisotropic diffusion creep. There is excellent agreement between experiments and simulations for both phases in all of the chemical systems studied. Single-crystal diffusivity in postperovskite displays at least 3 orders of magnitude of anisotropy by experiment and simulation (Da = 1,000 Db; Db ≈ Dc) in zinc fluoride, and an even more extreme anisotropy is predicted (Da = 10,000 Dc; Dc = 10,000 Db) in the natural MgSiO3 system. Anisotropic chemical diffusivity results in anisotropic diffusion creep, texture generation, and a strain-weakening rheology. The results for MgSiO3 postperovskite strongly imply that regions within the D″ region of Earth dominated by postperovskite will 1) be substantially weaker than regions dominated by perovskite and 2) develop a strain-induced crystallographic-preferred orientation with strain-weakening rheology. This leads to strain localization and the possibility to bring regions with significantly varying textures into close proximity by strain on narrow shear zones. Anisotropic diffusion creep therefore provides an attractive alternative explanation for the complexity in observed seismic anisotropy and the rapid lateral changes in seismic velocities in D″.

11.
Clin Endocrinol (Oxf) ; 95(4): 576-586, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34042196

RESUMO

OBJECTIVE: Hypertension cure following adrenalectomy in unilateral primary aldosteronism is not guaranteed. Its likelihood is associated with pre-operative parameters, which have been variably combined in six different predictive scoring systems. The relative performance of these systems is currently unknown. The objective of this work was to identify the best performing scoring system for predicting hypertension cure following adrenalectomy for primary aldosteronism. DESIGN: Retrospective analysis in a single tertiary referral centre. PATIENTS: Eighty-seven adult patients with unilateral primary aldosteronism who had undergone adrenalectomy between 2004 and 2018 for whom complete data sets were available to calculate all scoring systems. MEASUREMENTS: Prediction of hypertension cure by each of the six scoring systems. RESULTS: Hypertension cure was achieved in 36/87 (41.4%) patients within the first post-operative year, which fell to 18/71 (25.4%) patients at final follow-up (median 53 months, P = .002). Analysis of receiver operating characteristic area under the curves for the different scoring systems identified a difference in performance at early, but not late, follow-up. For all systems, the area under the curve was lower at early compared with late follow-up and compared to performance in the cohorts in which they were originally defined. CONCLUSIONS: No single scoring system performed significantly better than all others when applied in our cohort, although two did display particular advantages. It remains to be determined how best such scoring systems can be incorporated into the routine clinical care of patients with PA.


Assuntos
Hiperaldosteronismo , Hipertensão , Adrenalectomia , Adulto , Humanos , Hiperaldosteronismo/cirurgia , Hipertensão/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
12.
Postgrad Med J ; 97(1148): 345-348, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33177209

RESUMO

AIM: Human factors, surgery and aviation are intimately tied together by the common threads of error, risk and interpersonal relationships. A plethora of research abounds in all disciplines individually. The lessons learnt in one domain however are not unique and can be shared between all to promote best practice, further research and a greater understanding at a fundamental level. METHODS: A structured, thematic, literature review was performed. PubMed, EMBASE and Ovid MEDLINE databases were interrogated directly. The Health Foundation, National Health Service and Department of Health online databases were used through querying intrinsic search functions. RESULTS: With expanding use of technologies such as checklists, there is a gap left to better address and understand the nuances and roles of stress, communication and emotion on both learning and clinical practice. These can be prominent in the high-pressure environments shared between aviation and surgery. CONCLUSIONS: The authors explore lessons learnt from aviation, the human factors applicable to both and how they can be extrapolated to improve patient safety outcomes and promote the use of the 'Software, Hardware, Environment, Liveware' tool to aid practice.


Assuntos
Aviação/educação , Cirurgia Geral/educação , Lista de Checagem , Difusão de Inovações , Ergonomia , Humanos , Segurança do Paciente
13.
J Appl Clin Med Phys ; 22(5): 117-127, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33773008

RESUMO

The performance of three digital detectors was measured at two exposure index (EI) levels in terms of the effect on features at the borderline of detectability. The null hypothesis was that there would be no statistically significant difference in the CNR of marginally visible features of a baseline- (2.2 µGy) and reduced dose (1.4 µGy) images. The experiment used three digital detectors and a phantom composed of an aluminum contrast-recovery plate, with features of varying diameters and hole depths, which was placed between the detector/grid and 5-20 cm Lucite. Exposures were made using a kVp between 55 and 110 corresponding to the Lucite thickness and a mAs producing an EI of approximately 220 or 140. Images were acquired for all detectors, EI values, and all Lucite thicknesses, then scored by a team of physicists and technologists in terms of feature visibility for each feature size. Contrast-to-noise ratio (CNR) was calculated for each feature using an ROI over the feature and a local background annulus. The uncertainty in the CNR was determined by sampling the background at each feature size, finding residuals from an overall background fit, and then calculating a standard deviation in the noise for each size. The marginal feature pair for each feature size bracketed the reader score. The difference between the CNR values of corresponding marginal features in EI-paired images was significant (P < 0.05) for one detector and not significant (P > 0.05) for marginal features of the other two. Based on both reader scoring and CNR measurements of phantoms, patient doses can be lowered by 30% for those two detectors without a statistically significant difference in lesion perceptibility of the marginally visible feature, while for the other detector there was a statistically significant change in marginal feature detectability and dose reduction was not recommended.


Assuntos
Redução da Medicação , Intensificação de Imagem Radiográfica , Humanos , Imagens de Fantasmas , Doses de Radiação
14.
Anal Chem ; 92(11): 7845-7851, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32437125

RESUMO

We report a dual-readout, AuNP-based sandwich immunoassay for the device-free colorimetric and sensitive scanometric detection of disease biomarkers. An AuNP-antibody conjugate serves as a signal transduction and amplification agent by promoting the reduction and deposition of either platinum or gold onto its surface, generating corresponding colorimetric or light scattering (scanometric) signals, respectively. We apply the Pt-based colorimetric readout of this assay to the discovery of a novel monoclonal antibody (mAb) sandwich pair for the detection of an anthrax protective antigen (PA83). The identified antibody pair detects PA83 down to 1 nM in phosphate-buffered saline and 5 nM in human serum, which are physiologically relevant concentrations. Reducing gold rather than platinum onto the mAb-AuNP sandwich enables scanometric detection of subpicomolar PA83 concentrations, over 3 orders of magnitude more sensitive than the colorimetric readout.


Assuntos
Antraz/diagnóstico , Antígenos de Bactérias/análise , Toxinas Bacterianas/análise , Imunoensaio , Anticorpos Monoclonais/química , Biomarcadores/análise , Colorimetria , Ouro/química , Nanopartículas Metálicas/química
15.
Macromol Rapid Commun ; 41(21): e2000275, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32815257

RESUMO

Transplantation of microencapsulated islet cells holds great potential for the treatment of type 1 diabetes mellitus. However, its clinical translation is hampered by the peri-transplantation loss of islet viability and functionality in the microcapsules. In this work, a novel islet cells biomimetic microencapsulant material that is based on the interpenetrating networks of alginate and extracellular matrix (ECM) hydrogel composite (AEC) is presented. The ECM component is derived from human lipoaspirate. In situ encapsulation of pancreatic ß islet cells (MIN6 ß-cells) can be achieved via ionotropic gelation of the alginate matrix and thermal-induced gelation of the pepsin-solubilized ECM pre-gel. Due to the enhanced cell-matrix interaction, islets encapsulated within the AEC microcapsules (≈640 µm) display sevenfold increase in cell growth over 1 week of culture and characteristic glucose-stimulated insulin response in vitro. The results show that the AEC microcapsule is a potent platform to bioaugment the performance of islet cells.


Assuntos
Alginatos , Ilhotas Pancreáticas , Matriz Extracelular/metabolismo , Humanos , Hidrogéis/metabolismo , Insulina , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo
16.
Gen Comp Endocrinol ; 285: 113226, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374286

RESUMO

A "reproducibility crisis" is widespread across scientific disciplines, where results and conclusions of studies are not supported by subsequent investigation. Here we provide a steroid immunoassay example where human errors generated unreproducible results and conclusions. Our study was triggered by a scientific report citing abnormally high concentrations (means of 4-79 ng L-1) of three natural sex steroids [11-ketotestosterone (11-KT), testosterone (T) and oestradiol (E2)] in water samples collected from two UK rivers over 4 years (2002-6). Furthermore, the data suggested that trout farms were a major source because reported steroid concentrations were 1.3-6 times higher downstream than upstream. We hypothesised that the reported levels were erroneous due to substances co-extracted from the water causing matrix effects (i.e. "false positives") during measurement by enzyme-linked immunoassay (EIA). Thus, in collaboration with three other groups (including the one that had conducted the 2002-6 study), we carried out field sampling and assaying to examine this hypothesis. Water samples were collected in 2010 from the same sites and prepared for assay using an analogous method [C18 solid phase extraction (SPE) followed by extract clean-up with aminopropyl SPE]. Additional quality control ("spiked" and "blank") samples were processed. Water extracts were assayed for steroids using radioimmunoassay (RIA) as well as EIA. Although there were statistically significant differences between EIA and RIA (and laboratories), there was no indication of matrix effects in the EIAs. Both the EIAs and RIAs (uncorrected for recovery) measured all three natural steroids at <0.6 ng L-1 in all river water samples, indicating that the trout farms were not a significant source of natural steroids. The differences between the two studies were considerable: E2 and T concentrations were ca. 100-fold lower and 11-KT ca. 1000-fold lower than those reported in the 2002-6 study. In the absence of evidence for any marked changes in husbandry practice (e.g. stock, diet) or environmental conditions (e.g. water flow rate) between the study periods, we concluded that calculation errors were probably made in the first (2002-6) study associated with confusion between extract and water sample concentrations. The second (2010) study also had several identified examples of calculation error (use of an incorrect standard curve; extrapolation below the minimum standard; confusion of assay dilutions during result work-up; failure to correct for loss during extraction) and an example of sample contamination. Similar and further errors have been noted in other studies. It must be recognised that assays do not provide absolute measurements and are prone to a variety of errors, so published steroid levels should be viewed with caution until independently confirmed.


Assuntos
Aquicultura , Água Doce , Imunoensaio/métodos , Esteroides/análise , Truta/imunologia , Animais , Ensaio de Imunoadsorção Enzimática , Radioimunoensaio , Padrões de Referência , Reprodutibilidade dos Testes , Rios , Água/química
17.
J Med Internet Res ; 22(10): e16782, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32697197

RESUMO

BACKGROUND: Adherence to nebulizer treatments in adults with cystic fibrosis (CF) is often low. A new complex intervention to help adults with CF increase their adherence to nebulizer treatments was tested in a pilot randomized controlled trial (RCT) in 2 UK CF centers. Patients used a nebulizer with electronic monitoring capabilities that transferred data automatically to a digital platform (CFHealthHub) to monitor adherence over time and to a tailored website to display graphs of adherence data and educational and problem-solving information about adherence. A trained interventionist helped patients identify ways to increase their adherence. OBJECTIVE: This study aims to explore the mechanisms of action underpinning the intervention. METHODS: A qualitative interview study was conducted concurrently with a pilot RCT. In total, 25 semistructured interviews were conducted with 3 interventionists at 2 time points, 14 patients in the intervention arm of the trial, and 5 members of the multidisciplinary teams offering wider care to patients. A framework approach was used for the analysis. RESULTS: The intervention was informed by a theoretical framework of behavior change. There was evidence of the expected behavior change mechanisms of action. There was also evidence of additional mechanisms of action associated with effective telehealth interventions for self-management support: relationships, visibility, and fit. Patients described how building a relationship with the interventionist through face-to-face visits with someone who cared about them and their progress helped them to consider ways of increasing adherence to medication. Rather than seeing the visibility of adherence data to clinicians as problematic, patients found this motivating, particularly if they received praise about progress made. The intervention was tailored to individuals, but there were challenges in how the intervention fitted into some patients' busy lives when delivered through a desktop computer. CONCLUSIONS: The mechanisms of action associated with effective telehealth interventions for self-management operated within this new intervention. The intervention was modified to strengthen mechanisms of action based on these findings, for example, delivery through an app accessed via mobile phones and then tested in an RCT in 19 UK CF centers. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number 13076797; http://www.isrctn.com/ISRCTN13076797.


Assuntos
Fibrose Cística/tratamento farmacológico , Intervenção Baseada em Internet/tendências , Adesão à Medicação/estatística & dados numéricos , Nebulizadores e Vaporizadores/estatística & dados numéricos , Telemedicina/métodos , Adolescente , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pesquisa Qualitativa , Adulto Jovem
18.
Psychol Health Med ; 25(8): 958-968, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31899953

RESUMO

Inflammatory Bowel Disease (IBD) is commonly associated with poor global sleep quality, and has been posited as a modifiable determinant of IBD related outcomes. However, there is little evidence on the specific types of problems sleeping (e.g., sleep apnea, insomnia etc.) that might characterize the poor sleep quality experienced by those with IBD. The present research aimed to investigate the severity of seven specific types of problems sleeping in those with IBD vs. a healthy control group. This cross sectional comparison study recruited N = 409 with IBD, and N = 377 healthy controls. The Sleep-50 questionnaire was used to assess the presence of seven type of problems sleeping. Multivariate Analysis of Covariance (MANCOVA) was used to compare the severity of sleep disturbances between the IBD and control groups. Those in the IBD group reported significantly more severe experiences of five of the seven domains of the sleep-50, including increased; sleep apnea, insomnia, narcolepsy, restless-legs, and nightmares. More research is needed to; (i) improve the identification and treatment of problems sleeping in routine care; (ii) understand the mechamism(s) of action that links problems sleeping to IBD realted outcomes; and (iii) develop adapted interventions to improve sleep in those with IBD.


Assuntos
Doenças Inflamatórias Intestinais/epidemiologia , Transtornos do Sono-Vigília/epidemiologia , Transtornos do Sono-Vigília/fisiopatologia , Adulto , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
J Appl Biomed ; 18(1): 1-7, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34907706

RESUMO

Health status is determined by the balance of oxidants and antioxidants which protects healthy cells against the threat of internal and external risk factors. Antioxidants such as ascorbate (vitamin C, ascorbic acid) are of fundamental importance in this respect. Ascorbate neutralizes potential damage caused by cellular oxidative stress which may be the greatest risk of damage to healthy tissue. Cellular oxidative stress is mediated by external factors (e.g. psychological stress, physical exertion, drugs, various diseases, environmental pollution, preservatives, smoking, and alcohol) and internal factors (products of cellular metabolism including reactive oxygen species). When the products of oxidative stress are not sufficiently neutralized, healthy cells are at risk for both mitochondrial and DNA damage. In the short term, cell function may deteriorate, while an increased production of proinflammatory cytokines over time may lead to the development of chronic inflammatory changes and diseases, including cancer. Although pharmaceutical research continues to bring effective chemotherapeutic agents to the market, a limiting factor is often the normal tissue and organ toxicity of these substances, which leads to oxidative stress on healthy tissue. There is increasing interest and imperative to protect healthy tissues from the negative effects of radio-chemotherapeutic treatment. The action of ascorbate against the development of oxidative stress may justify its use not only in the prevention of carcinogenesis, but as a part of supportive or complementary therapy during treatment. Ascorbate (particularly when administered parentally at high doses) may have antioxidant effects that work to protect healthy cells and improve patient tolerability to some toxic radio-chemotherapy regimens. Additionally, ascorbate has demonstrated an immunomodulatory effect by supporting mechanisms essential to anti-tumor immunity. Intravenous administration of gram doses of vitamin C produce high plasma levels immediately, but the levels drop rapidly. Following oral vitamin C administration, plasma levels increase slowly to relatively low values, and then gradually decay. With an oral liposomal formulation, significantly higher levels are attainable than with standard oral formulations. Therefore, oral administration of liposomal vitamin C appears to be an optimal adjunct to intravenous administration. In this review, the basic mechanisms and clinical benefits of ascorbate as an antioxidant that may be useful as complementary therapy to chemotherapeutic regimens will be discussed.

20.
BMC Pulm Med ; 19(1): 77, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975206

RESUMO

BACKGROUND: Preventative medication reduces hospitalisations in people with cystic fibrosis (PWCF) but adherence is poor. We assessed the feasibility of a randomised controlled trial of a complex intervention, which combines display of real time adherence data and behaviour change techniques. METHODS: Design: Pilot, open-label, parallel-group RCT with concurrent semi-structured interviews. PARTICIPANTS: PWCF at two Cystic Fibrosis (CF) units. Eligible: aged 16 or older; on the CF registry. Ineligible: post-lung transplant or on the active list; unable to consent; using dry powder inhalers. INTERVENTIONS: Central randomisation on a 1:1 allocation to: (1) intervention, linking nebuliser use with data recording and transfer capability to a software platform, and behavioural strategies to support self-management delivered by trained interventionists (n = 32); or, (2) control, typically face-to-face meetings every 3 months with CF team (n = 32). OUTCOMES: RCT feasibility defined as: recruitment of ≥ 48 participants (75% of target) in four months (pilot primary outcome); valid exacerbation data available for ≥ 85% of those randomised (future RCT primary outcome); change in % medication adherence; FEV1 percent predicted (key secondaries in future RCT); and perceptions of trial procedures, in semi-structured interviews with intervention (n = 14) and control (n = 5) participants, interventionists (n = 3) and CF team members (n = 5). RESULTS: The pilot trial recruited to target, randomising 33 to intervention and 31 to control in the four-month period, June-September 2016. At study completion (30th April 2017), 60 (94%; Intervention = 32, Control =28) participants contributed good quality exacerbation data (intervention: 35 exacerbations; control: 25 exacerbation). The mean change in adherence and baseline-adjusted FEV1 percent predicted were higher in the intervention arm by 10% (95% CI: -5.2 to 25.2) and 5% (95% CI -2 to 12%) respectively. Five serious adverse events occurred, none related to the intervention. The mean change in adherence was 10% (95% CI: -5.2 to 25.2), greater in the intervention arm. Interventionists delivered insufficient numbers of review sessions due to concentration on participant recruitment. This left interventionists insufficient time for key intervention procedures. A total of 10 key changes that were made to RCT procedures are summarised. CONCLUSIONS: With improved research processes and lower monthly participant recruitment targets, a full-scale trial is feasible. TRIAL REGISTRATION: ISRCTN13076797 . Prospectively registered on 07/06/2016.


Assuntos
Fibrose Cística/tratamento farmacológico , Adesão à Medicação/psicologia , Educação de Pacientes como Assunto/métodos , Autogestão/métodos , Adulto , Atitude Frente a Saúde , Fibrose Cística/psicologia , Progressão da Doença , Estudos de Viabilidade , Feminino , Humanos , Masculino , Projetos Piloto , Qualidade de Vida , Estresse Psicológico , Adulto Jovem
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