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1.
Cell ; 162(4): 701-3, 2015 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-26276624

RESUMO

DNA transposition plays key roles in genome diversity, pathogenesis, and evolution. Yet, structural and mechanistic information on transposition targeting and regulation is limited. Arias-Palomo and Berger now define the decameric organization of the AAA+ ATPase IstB, unveiling key insights into its targeting and regulation of IstA transposase activity.


Assuntos
Bactérias/genética , Bactérias/metabolismo , Elementos de DNA Transponíveis
2.
Nature ; 621(7979): 536-542, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37558870

RESUMO

Coral reef ecosystems are being fundamentally restructured by local human impacts and climate-driven marine heatwaves that trigger mass coral bleaching and mortality1. Reducing local impacts can increase reef resistance to and recovery from bleaching2. However, resource managers lack clear advice on targeted actions that best support coral reefs under climate change3 and sector-based governance means most land- and sea-based management efforts remain siloed4. Here we combine surveys of reef change with a unique 20-year time series of land-sea human impacts that encompassed an unprecedented marine heatwave in Hawai'i. Reefs with increased herbivorous fish populations and reduced land-based impacts, such as wastewater pollution and urban runoff, had positive coral cover trajectories predisturbance. These reefs also experienced a modest reduction in coral mortality following severe heat stress compared to reefs with reduced fish populations and enhanced land-based impacts. Scenario modelling indicated that simultaneously reducing land-sea human impacts results in a three- to sixfold greater probability of a reef having high reef-builder cover four years postdisturbance than if either occurred in isolation. International efforts to protect 30% of Earth's land and ocean ecosystems by 2030 are underway5. Our results reveal that integrated land-sea management could help achieve coastal ocean conservation goals and provide coral reefs with the best opportunity to persist in our changing climate.


Assuntos
Antozoários , Conservação dos Recursos Naturais , Recifes de Corais , Calor Extremo , Aquecimento Global , Oceanos e Mares , Água do Mar , Animais , Conservação dos Recursos Naturais/métodos , Calor Extremo/efeitos adversos , Peixes , Aquecimento Global/estatística & dados numéricos , Objetivos , Havaí , Atividades Humanas , Cooperação Internacional , Água do Mar/análise , Água do Mar/química , Águas Residuárias/análise , Fatores de Tempo
3.
Nucleic Acids Res ; 51(13): 6770-6783, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37309889

RESUMO

Ataxia-telangiectasia mutated (ATM) drives the DNA damage response via modulation of multiple signal transduction and DNA repair pathways. Previously, ATM activity was implicated in promoting the non-homologous end joining (NHEJ) pathway to repair a subset of DNA double-stranded breaks (DSBs), but how ATM performs this function is still unclear. In this study, we identified that ATM phosphorylates the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a core NHEJ factor, at its extreme C-terminus at threonine 4102 (T4102) in response to DSBs. Ablating phosphorylation at T4102 attenuates DNA-PKcs kinase activity and this destabilizes the interaction between DNA-PKcs and the Ku-DNA complex, resulting in decreased assembly and stabilization of the NHEJ machinery at DSBs. Phosphorylation at T4102 promotes NHEJ, radioresistance, and increases genomic stability following DSB induction. Collectively, these findings establish a key role for ATM in NHEJ-dependent repair of DSBs through positive regulation of DNA-PKcs.


Assuntos
Ataxia Telangiectasia , Proteína Quinase Ativada por DNA , Humanos , Proteína Quinase Ativada por DNA/genética , Reparo do DNA , Treonina/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Reparo do DNA por Junção de Extremidades , DNA/genética
4.
Biol Lett ; 20(5): 20240035, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38807544

RESUMO

Interspecific interactions are fundamental drivers of animal space use. Yet while non-consumptive effects of predation risk on prey space use are well-known, the risk of aggressive interactions on space use of competitors is largely unknown. We apply the landscape of risk framework to competition-driven space use for the first time, with the hypothesis that less aggressive competitors may alter their behaviour to avoid areas of high competitor density. Specifically, we test how aggressive risk from territorial algal-farming damselfishes can shape the spatial distribution of herbivore fish competitors. We found that only the most aggressive damselfish had fewer competitors in their surrounding area, demonstrating that individual-level behavioural variation can shape spatial distributions. In contradiction to the landscape of risk framework, abundances of farming damselfish and other fishes were positively associated. Our results suggest that reef fishes do not simply avoid areas of high damselfish abundance, but that spatial variation in aggressive behaviour, rather than of individuals, created a competitive landscape of risk. We emphasize the importance of individual-level behaviour in identifying patterns of space use and propose expanding the landscape of risk framework to non-predatory interactions to explore cascading behavioural responses to aggressive risk.


Assuntos
Recifes de Corais , Animais , Comportamento Competitivo , Agressão , Perciformes/fisiologia , Comportamento Animal/fisiologia , Peixes/fisiologia
5.
Int J Geriatr Psychiatry ; 39(2): e6061, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38281509

RESUMO

BACKGROUND: The accumulation of age-associated cognitive deficits can lead to Mild Cognitive Impairment (MCI) and dementia. This is a major public health issue for the modern ageing population, as it impairs health, independence and overall quality of life. Keeping the brain active during life has been associated with an increased cognitive reserve, therefore reducing the risk of cognitive impairment in older age. Previous research has identified a potential relationship between musicality and cognition. OBJECTIVES: Explore the relationship between musicality and cognitive function in a large cohort of older adults. METHODS: This was a nested study within the PROTECT-UK cohort, which collects longitudinal computerised assessments of cognitive function in adults over 40. Participants were invited to complete the validated Edinburgh Lifetime Musical Experience Questionnaire (ELMEQ) to assess their musical experience and lifetime exposure to music. Linear regression analysis was performed using cognitive data from PROTECT-UK. RESULTS: Analysis identified an association between musicality and cognition in this cohort. Playing a musical instrument was associated with significantly better performance in working memory and executive function. Significant associations were also found between singing and executive function, and between overall musical ability and working memory. CONCLUSIONS: Our findings confirm previous literature, highlighting the potential value of education and engagement in musical activities throughout life as a means of harnessing cognitive reserve as part of a protective lifestyle for brain health.


Assuntos
Disfunção Cognitiva , Qualidade de Vida , Humanos , Idoso , Qualidade de Vida/psicologia , Envelhecimento/psicologia , Cognição , Reino Unido
6.
J Nanobiotechnology ; 22(1): 317, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38849886

RESUMO

Sonodynamic therapy (SDT), a promising strategy for cancer treatment with the ability for deep tissue penetration, has received widespread attention in recent years. Sonosensitizers with intrinsic characteristics for tumor-specific curative effects, tumor microenvironment (TME) regulation and tumor diagnosis are in high demand. Herein, amorphous CoBiMn-layered double hydroxide (a-CoBiMn-LDH) nanoparticles are presented as multifunctional sonosensitizers to trigger reactive oxygen species (ROS) generation for ultrasound (US) imaging-guided SDT. Hydrothermal-synthesized CoBiMn-LDH nanoparticles are etched via a simple acid treatment to obtain a-CoBiMn-LDH nanoparticles with abundant defects. The a-CoBiMn-LDH nanoparticles give greater ROS generation upon US irradiation, reaching levels ~ 3.3 times and ~ 8.2 times those of the crystalline CoBiMn-LDH nanoparticles and commercial TiO2 sonosensitizer, respectively. This excellent US-triggered ROS generation performance can be attributed to the defect-induced narrow band gap and promoted electrons and holes (e-/h+) separation. More importantly, the presence of Mn4+ enables the a-CoBiMn-LDH nanoparticles to regulate the TME by decomposing H2O2 into O2 for hypoxia relief and US imaging, and consuming glutathione (GSH) for protection against ROS clearance. Biological mechanism analysis shows that a-CoBiMn-LDH nanoparticles modified with polyethylene glycol can serve as a multifunctional sonosensitizer to effectively kill cancer cells in vitro and eliminate tumors in vivo under US irradiation by activating p53, apoptosis, and oxidative phosphorylation-related signaling pathways.


Assuntos
Hidróxidos , Nanopartículas , Espécies Reativas de Oxigênio , Microambiente Tumoral , Terapia por Ultrassom , Microambiente Tumoral/efeitos dos fármacos , Animais , Espécies Reativas de Oxigênio/metabolismo , Humanos , Terapia por Ultrassom/métodos , Hidróxidos/química , Hidróxidos/farmacologia , Camundongos , Nanopartículas/química , Linhagem Celular Tumoral , Cobalto/química , Ultrassonografia/métodos , Camundongos Endogâmicos BALB C , Neoplasias/terapia , Neoplasias/diagnóstico por imagem , Apoptose/efeitos dos fármacos , Feminino , Camundongos Nus
7.
Handb Exp Pharmacol ; 284: 69-91, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37059912

RESUMO

Proteins and peptides are highly desirable as therapeutic agents, being highly potent and specific. However, there are myriad challenges with processing them into patient-friendly formulations: they are often unstable and have a tendency to aggregate or degrade upon storage. As a result, the vast majority of protein actives are delivered parenterally as solutions, which has a number of disadvantages in terms of cost, accessibility, and patient experience. Much work has been undertaken to develop new delivery systems for biologics, but to date this has led to relatively few products on the market. In this chapter, we review the challenges faced when developing biologic formulations, discuss the technologies that have been explored to try to overcome these, and consider the different delivery routes that can be applied. We further present an overview of the currently marketed products and assess the likely direction of travel in the next decade.


Assuntos
Sistemas de Liberação de Medicamentos , Proteínas , Humanos
8.
Handb Exp Pharmacol ; 284: 343-365, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37733107

RESUMO

In addition to proteins, discussed in the Chapter "Advances in Vaccine Adjuvants: Nanomaterials and Small Molecules", there are a wide range of alternatives to small molecule active ingredients. Cells, extracellular vesicles, and nucleic acids in particular have attracted increasing research attention in recent years. There are now a number of products on the market based on these emerging technologies, the most famous of which are the mRNA-based vaccines against SARS-COV-2. These advanced therapeutic moieties are challenging to formulate however, and there remain significant challenges for their more widespread use. In this chapter, we consider the potential and bottlenecks for developing further medical products based on these systems. Cells, extracellular vesicles, and nucleic acids will be discussed in terms of their mechanism of action, the key requirements for translation, and how advanced formulation approaches can aid their future development. These points will be presented with selected examples from the literature, and with a focus on the formulations which have made the transition to clinical trials and clinical products.


Assuntos
Vacinas contra COVID-19 , Ácidos Nucleicos , Humanos , Sistemas de Liberação de Medicamentos , Ácidos Nucleicos/uso terapêutico
9.
Alzheimers Dement ; 20(3): 1797-1806, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38116916

RESUMO

INTRODUCTION: iWHELD is a digital person-centered care program for people with dementia in nursing homes adapted for remote delivery during the COVID-19 pandemic. METHODS: A 16-week two-arm cluster-randomized controlled trial in 149 UK nursing homes compared iWHELD with treatment as usual (TAU). Primary outcome was the overall quality of life with secondary outcomes of agitation and psychotropic use. RESULTS: iWHELD conferred benefit to quality of life on the primary (F = 4.3, p = 0.04) and secondary measures of quality of life (F = 6.45, p = 0.01) and reduced psychotropic medication use (χ2  = 4.08, p = 0.04) with no worsening of agitation. Benefit was seen in participants who contracted COVID-19, those with agitation at baseline, and those taking psychotropic medications. DISCUSSION: iWHELD confers benefits to quality of life and key measures of well-being, can be delivered during the challenging conditions of a pandemic, and should be considered for use alongside any emerging pharmacological treatment for neuropsychiatric symptoms. HIGHLIGHTS: iWHELD is the only remote, digital delivery nursing home training programme for dementia care iWHELD improved quality of life in people with dementia and reduced antipsychotic use without worsening of agitation Residents who contracted Covid-19 during the study also experienced benefits from iWHELD iWHELD offers a valuable, pandemic-safe tool for improving dementia care.


Assuntos
COVID-19 , Demência , Humanos , Idoso , Pandemias , Instituição de Longa Permanência para Idosos , Qualidade de Vida , Demência/diagnóstico , COVID-19/complicações , Casas de Saúde , Assistência Centrada no Paciente , Agitação Psicomotora/tratamento farmacológico , Agitação Psicomotora/diagnóstico
10.
Proc Biol Sci ; 290(1995): 20230023, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36946114

RESUMO

Highly competitive coral reef benthic communities are acutely sensitive to changes in environmental parameters such as temperature and nutrient concentrations. Physical oceanographic processes that induce upwelling therefore act as drivers of community structure on tropical reefs. How upwelling impacts coral communities, however, is not fully understood; upwelling may provide a natural buffer against climate impacts and could potentially enhance the efficacy of spatial management and reef conservation efforts. This study employed a systematic review to assess existing literature linking upwelling with reef community structure, and a meta-analysis to quantify upwelling impact on the percentage cover of coral reef benthic groups. We show that upwelling has context-dependant effects on the cover of hard coral and fleshy macroalgae, with effect size and direction varying with depth, region and remoteness. Fleshy macroalgae were found to increase by 110% on inhabited reefs yet decrease by 56% around one well-studied remote island in response to upwelling. Hard coral cover was not significantly impacted by upwelling on inhabited reefs but increased by 150% when direct local human pressures were absent. By synthesizing existing evidence, this review facilitates adaptive and nuanced reef management which considers the influence of upwelling on reef assemblages.


Assuntos
Antozoários , Alga Marinha , Animais , Humanos , Recifes de Corais , Antozoários/fisiologia , Clima , Nutrientes
11.
Mod Pathol ; 36(9): 100220, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37230414

RESUMO

Programmed cell death ligand-1 (PD-L1) expression levels in patients' tumors have demonstrated clinical utility across many cancer types and are used to determine treatment eligibility. Several independently developed PD-L1 immunohistochemical (IHC) predictive assays are commercially available and have demonstrated different levels of staining between assays, generating interest in understanding the similarities and differences between assays. Previously, we identified epitopes in the internal and external domains of PD-L1, bound by antibodies in routine clinical use (SP263, SP142, 22C3, and 28-8). Variance in performance of assays utilizing these antibodies, observed following exposure to preanalytical factors such as decalcification, cold ischemia, and duration of fixation, encouraged additional investigation of antibody-binding sites, to understand whether binding site structures/conformations contribute to differential PD-L1 IHC assay staining. We proceeded to further investigate the epitopes on PD-L1 bound by these antibodies, alongside the major clones utilized in laboratory-developed tests (E1L3N, QR1, and 73-10). Characterization of QR1 and 73-10 clones demonstrated that both bind the PD-L1 C-terminal internal domain, similar to SP263/SP142. Our results also demonstrate that under suboptimal decalcification or fixation conditions, the performance of internal domain antibodies is less detrimentally affected than that of external domain antibodies 22C3/28-8. Furthermore, we show that the binding sites of external domain antibodies are susceptible to deglycosylation and conformational structural changes, which directly result in IHC staining reduction or loss. The binding sites of internal domain antibodies were unaffected by deglycosylation or conformational structural change. This study demonstrates that the location and conformation of binding sites, recognized by antibodies employed in PD-L1 diagnostic assays, differ significantly and exhibit differing degrees of robustness. These findings should reinforce the need for vigilance when performing clinical testing with different PD-L1 IHC assays, particularly in the control of cold ischemia and the selection of fixation and decalcification conditions.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Imuno-Histoquímica , Epitopos/uso terapêutico , Antígeno B7-H1/metabolismo , Isquemia Fria , Ligantes , Anticorpos , Células Clonais/patologia , Apoptose , Biomarcadores Tumorais/metabolismo
12.
PLoS Pathog ; 17(11): e1010090, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34793581

RESUMO

Natural Killer (NK) cells contribute to HIV control in adults, but HLA-B-mediated T-cell activity has a more substantial impact on disease outcome. However, the HLA-B molecules influencing immune control in adults have less impact on paediatric infection. To investigate the contribution NK cells make to immune control, we studied >300 children living with HIV followed over two decades in South Africa. In children, HLA-B alleles associated with adult protection or disease-susceptibility did not have significant effects, whereas Bw4 (p = 0.003) and low HLA-A expression (p = 0.002) alleles were strongly associated with immunological and viral control. In a comparator adult cohort, Bw4 and HLA-A expression contributions to HIV disease outcome were dwarfed by those of protective and disease-susceptible HLA-B molecules. We next investigated the immunophenotype and effector functions of NK cells in a subset of these children using flow cytometry. Slow progression and better plasma viraemic control were also associated with high frequencies of less terminally differentiated NKG2A+NKp46+CD56dim NK cells strongly responsive to cytokine stimulation and linked with the immunogenetic signature identified. Future studies are indicated to determine whether this signature associated with immune control in early life directly facilitates functional cure in children.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Antígenos HLA-B/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Células Matadoras Naturais/imunologia , Receptores KIR3DL1/metabolismo , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Infecções por HIV/metabolismo , Infecções por HIV/virologia , Humanos , Ativação Linfocitária
13.
Glob Chang Biol ; 29(12): 3318-3330, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37020174

RESUMO

Scientists and managers rely on indicator taxa such as coral and macroalgal cover to evaluate the effects of human disturbance on coral reefs, often assuming a universally positive relationship between local human disturbance and macroalgae. Despite evidence that macroalgae respond to local stressors in diverse ways, there have been few efforts to evaluate relationships between specific macroalgae taxa and local human-driven disturbance. Using genus-level monitoring data from 1205 sites in the Indian and Pacific Oceans, we assess whether macroalgae percent cover correlates with local human disturbance while accounting for factors that could obscure or confound relationships. Assessing macroalgae at genus level revealed that no genera were positively correlated with all human disturbance metrics. Instead, we found relationships between the division or genera of algae and specific human disturbances that were not detectable when pooling taxa into a single functional category, which is common to many analyses. The convention to use percent cover of macroalgae as an indication of local human disturbance therefore likely obscures signatures of local anthropogenic threats to reefs. Our limited understanding of relationships between human disturbance, macroalgae taxa, and their responses to human disturbances impedes the ability to diagnose and respond appropriately to these threats.


Assuntos
Antozoários , Alga Marinha , Animais , Humanos , Recifes de Corais , Ecossistema , Alga Marinha/fisiologia , Antozoários/fisiologia , Oceano Pacífico
14.
Cell ; 135(7): 1169-71, 2008 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-19109888

RESUMO

Packaging of viral genomes into virus capsids requires powerful motors to overcome the repulsive force that builds as the nucleic acids are compressed. Through structural analyses of the T4 bacteriophage packaging motor gp17, Sun et al. (2008) now propose a packaging mechanism in which electrostatic forces cause the motor to alternate between tensed and relaxed conformational states.


Assuntos
Bacteriófago T4/metabolismo , Empacotamento do DNA , Proteínas Virais/química , Proteínas Virais/metabolismo , Montagem de Vírus
15.
BMC Cardiovasc Disord ; 23(1): 246, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-37170253

RESUMO

OBJECTIVE: To investigate whether left atrial (LA) volume and left ventricular filling pressure (LVFP) assessed by cardiovascular magnetic resonance (CMR) change during adenosine delivered myocardial hyperaemia as part of a first-pass stress perfusion study. METHODS AND RESULTS: We enrolled 33 patients who had stress CMR. These patients had a baseline four-chamber cine and stress four-chamber cine, which was done at peak myocardial hyperaemic state after administering adenosine. The left and right atria were segmented in the end ventricular diastolic and systolic phases. Short-axis cine stack was segmented for ventricular functional assessment. At peak hyperaemic state, left atrial end ventricular systolic volume just before mitral valve opening increased significantly from baseline in all (91 ± 35ml vs. 81 ± 33ml, P = 0.0002), in males only (99 ± 35ml vs. 88 ± 33ml, P = 0.002) and females only (70 ± 26ml vs. 62 ± 22ml, P = 0.02). The right atrial end ventricular systolic volume increased less significantly from baseline (68 ± 21ml vs. 63 ± 20ml, P = 0.0448). CMR-derived LVFP (equivalent to pulmonary capillary wedge pressure) increased significantly at the peak hyperaemic state in all (15.1 ± 2.9mmHg vs. 14.4 ± 2.8mmHg, P = 0.0002), females only (12.9 ± 2.1mmHg vs. 12.3 ± 1.9mmHg, P = 0.029) and males only (15.9 ± 2.8mmHg vs. 15.2 ± 2.7mmHg, P = 0.002) cohorts. CONCLUSION: Left atrial volume assessment by CMR can measure acute and dynamic changes in preloading conditions on the left ventricle. During adenosine administered first-pass perfusion CMR, left atrial volume and LVFP rise significantly.


Assuntos
Fibrilação Atrial , Hiperemia , Masculino , Feminino , Humanos , Átrios do Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética , Perfusão , Volume Sistólico , Imagem Cinética por Ressonância Magnética/métodos , Função Ventricular Esquerda
16.
Chem Soc Rev ; 51(14): 6126-6176, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35792076

RESUMO

Against the backdrop of increased public health awareness, inorganic nanomaterials have been widely explored as promising nanoagents for various kinds of biomedical applications. Layered double hydroxides (LDHs), with versatile physicochemical advantages including excellent biocompatibility, pH-sensitive biodegradability, highly tunable chemical composition and structure, and ease of composite formation with other materials, have shown great promise in biomedical applications. In this review, we comprehensively summarize the recent advances in LDH-based nanomaterials for biomedical applications. Firstly, the material categories and advantages of LDH-based nanomaterials are discussed. The preparation and surface modification of LDH-based nanomaterials, including pristine LDHs, LDH-based nanocomposites and LDH-derived nanomaterials, are then described. Thereafter, we systematically describe the great potential of LDHs in biomedical applications including drug/gene delivery, bioimaging diagnosis, cancer therapy, biosensing, tissue engineering, and anti-bacteria. Finally, on the basis of the current state of the art, we conclude with insights on the remaining challenges and future prospects in this rapidly emerging field.


Assuntos
Hidróxidos , Nanocompostos , Sistemas de Liberação de Medicamentos , Técnicas de Transferência de Genes , Hidróxidos/química , Nanocompostos/química , Engenharia Tecidual
17.
Int J Mol Sci ; 24(13)2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37446396

RESUMO

The pan Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor fasudil acts as a vasodilator and has been used as a medication for post-cerebral stroke for the past 29 years in Japan and China. More recently, based on the involvement of ROCK inhibition in synaptic function, neuronal survival, and processes associated with neuroinflammation, it has been suggested that the drug may be repurposed for neurodegenerative diseases. Indeed, fasudil has demonstrated preclinical efficacy in many neurodegenerative disease models. To facilitate an understanding of the wider biological processes at play due to ROCK inhibition in the context of neurodegeneration, we performed a global gene expression analysis on the brains of Alzheimer's disease model mice treated with fasudil via peripheral IP injection. We then performed a comparative analysis of the fasudil-driven transcriptional profile with profiles generated from a meta-analysis of multiple neurodegenerative diseases. Our results show that fasudil tends to drive gene expression in a reverse sense to that seen in brains with post-mortem neurodegenerative disease. The results are most striking in terms of pathway enrichment analysis, where pathways perturbed in Alzheimer's and Parkinson's diseases are overwhelmingly driven in the opposite direction by fasudil treatment. Thus, our results bolster the repurposing potential of fasudil by demonstrating an anti-neurodegenerative phenotype in a disease context and highlight the potential of in vivo transcriptional profiling of drug activity.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Animais , Camundongos , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Encéfalo/metabolismo , Camundongos Transgênicos , Doenças Neurodegenerativas/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Quinases Associadas a rho/metabolismo
18.
Anal Chem ; 94(5): 2465-2475, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35072456

RESUMO

The biomolecular contents of extracellular vesicles, such as exosomes, have been shown to be crucial in intercellular communication and disease propagation. As a result, there has been a recent surge in the exploration of novel biosensing platforms that can sensitively and specifically detect exosomal content such as proteins and nucleic acids, with a view toward application in diagnostic assays. Here, we demonstrate dual-mode and label-free detection of plasma exosomes using an electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D). The platform adopts a direct immunosensing approach to effectively capture exosomes via their surface protein expression of CD63. By combining QCM-D with a tandem in situ electrochemical impedance spectroscopy measurement, we are able to demonstrate relationships between mass, viscoelasticity and impedance inducing properties of each functional layer and analyte. In addition to lowering the limit of detection (by a factor of 2-4) to 6.71 × 107 exosome-sized particles (ESP) per mL in 25% v/v serum, the synergy between dissipation and impedance response introduces improved sensing specificity by offering further distinction between soft and rigid analytes, thereby promoting EQCM-D as an important technique for exosome analysis.


Assuntos
Técnicas Biossensoriais , Exossomos , Ácidos Nucleicos , Técnicas Biossensoriais/métodos , Impedância Elétrica , Quartzo , Técnicas de Microbalança de Cristal de Quartzo/métodos
19.
Mol Pharm ; 19(5): 1477-1487, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35347993

RESUMO

Flufenamic acid (FFA) is a highly polymorphic drug molecule with nine crystal structures reported in the Cambridge Structural Database. This study explores the use of synchrotron X-ray powder diffraction combined with differential scanning calorimetry to study crystallization and polymorphic phase transitions upon heating FFA-polymer amorphous solid dispersions (ASDs). Ethyl cellulose (EC, 4 cp) and hydroxypropylmethylcellulose (HPMC) grades with different viscosities and substitution patterns were used to prepare dispersions with FFA at 5:1, 2:1, 1:1, and 1:5 w/w drug/polymer ratios by quench cooling. We employed a 6 cp HPMC 2910 material and two HPMC 2208 samples at 4000 and 100 000 cp. Hyphenated X-ray diffraction (XRD)-differential scanning calorimetry (DSC) studies show that the 6 and 100 000 cp HPMCs and 4 cp EC polymers can stabilize FFA form IV by inhibiting the transition to form I during heating. It appears that the polymers stabilize FFA in both amorphous and metastable forms via a combination of intermolecular interactions and viscosity effects. Increasing the polymer content of the ASD also inhibits polymorphic transitions, with drug/polymer ratios of 1:5 w/w resulting in FFA remaining amorphous during heating. The comparison of FFA ASDs prepared with different samples of HPMCs and ECs suggests that the chemical substitution of the polymer (HPMC 2208 has 19-24% methoxy groups and 4-12% hydroxypropyl groups, while HPMC 2910 has 28-30% methoxy groups and 7-12% hydroxypropyl groups) plays a more significant role in directing polymorphic transitions than the viscosity. A previously unreported polymorph of FFA was also noted during heating but its structure could not be determined.


Assuntos
Ácido Flufenâmico , Polímeros , Varredura Diferencial de Calorimetria , Derivados da Hipromelose/química , Polímeros/química , Solubilidade , Difração de Raios X
20.
BMC Med Res Methodol ; 22(1): 49, 2022 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-35184739

RESUMO

BACKGROUND: Clinical trial investigators may need to evaluate treatment effects in a specific subgroup (or subgroups) of participants in addition to reporting results of the entire study population. Such subgroups lack power to detect a treatment effect, but there may be strong justification for borrowing information from a larger patient group within the same trial, while allowing for differences between populations. Our aim was to develop methods for eliciting expert opinions about differences in treatment effect between patient populations, and to incorporate these opinions into a Bayesian analysis. METHODS: We used an interaction parameter to model the relationship between underlying treatment effects in two subgroups. Elicitation was used to obtain clinical opinions on the likely values of the interaction parameter, since this parameter is poorly informed by the data. Feedback was provided to experts to communicate how uncertainty about the interaction parameter corresponds with relative weights allocated to subgroups in the Bayesian analysis. The impact on the planned analysis was then determined. RESULTS: The methods were applied to an ongoing non-inferiority trial designed to compare antiretroviral therapy regimens in 707 children living with HIV and weighing ≥ 14 kg, with an additional group of 85 younger children weighing < 14 kg in whom the treatment effect will be estimated separately. Expert clinical opinion was elicited and demonstrated that substantial borrowing is supported. Clinical experts chose on average to allocate a relative weight of 78% (reduced from 90% based on sample size) to data from children weighing ≥ 14 kg in a Bayesian analysis of the children weighing < 14 kg. The total effective sample size in the Bayesian analysis was 386 children, providing 84% predictive power to exclude a difference of more than 10% between arms, whereas the 85 younger children weighing < 14 kg provided only 20% power in a standalone frequentist analysis. CONCLUSIONS: Borrowing information from a larger subgroup or subgroups can facilitate estimation of treatment effects in small subgroups within a clinical trial, leading to improved power and precision. Informative prior distributions for interaction parameters are required to inform the degree of borrowing and can be informed by expert opinion. We demonstrated accessible methods for obtaining opinions.


Assuntos
Prova Pericial , Teorema de Bayes , Criança , Ensaios Clínicos como Assunto , Humanos , Tamanho da Amostra , Incerteza
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