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1.
ACS Cent Sci ; 10(3): 514-516, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38559309
2.
Drug Deliv Transl Res ; 14(4): 970-983, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37824040

RESUMO

Novel tumor-on-a-chip approaches are increasingly used to investigate tumor progression and potential treatment options. To improve the effect of any cancer treatment it is important to have an in depth understanding of drug diffusion, penetration through the tumor extracellular matrix and cellular uptake. In this study, we have developed a miniaturized chip where drug diffusion and cellular uptake in different hydrogel environments can be quantified at high resolution using live imaging. Diffusion of doxorubicin was reduced in a biomimetic hydrogel mimicking tissue properties of cirrhotic liver and early stage hepatocellular carcinoma (373 ± 108 µm2/s) as compared to an agarose gel (501 ± 77 µm2/s, p = 0.019). The diffusion was further lowered to 256 ± 30 µm2/s (p = 0.028) by preparing the biomimetic gel in cell media instead of phosphate buffered saline. The addition of liver tumor cells (Huh7 or HepG2) to the gel, at two different densities, did not significantly influence drug diffusion. Clinically relevant and quantifiable doxorubicin concentration gradients (1-20 µM) were established in the chip within one hour. Intracellular increases in doxorubicin fluorescence correlated with decreasing fluorescence of the DNA-binding stain Hoechst 33342 and based on the quantified intracellular uptake of doxorubicin an apparent cell permeability (9.00 ± 0.74 × 10-4 µm/s for HepG2) was determined. Finally, the data derived from the in vitro model were applied to a spatio-temporal tissue concentration model to evaluate the potential clinical impact of a cirrhotic extracellular matrix on doxorubicin diffusion and tumor cell uptake.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Biomimética , Doxorrubicina , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/tratamento farmacológico , Cirrose Hepática , Hidrogéis/uso terapêutico
3.
Biomater Sci ; 11(9): 3144-3158, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-36919682

RESUMO

Silicon nitride (SiN) coatings may reduce unwanted release of metal ions from metallic implants. However, as SiN slowly dissolves in aqueous solutions, additives that reduce this dissolution rate would likely increase the lifetime and functionality of implants. Adding iron (Fe) and carbon (C) permits tuning of the SiN coatings' mechanical properties, but their effect on SiN dissolution rates, and their capacity to reduce metal ion release from metallic implant substrates, have yet to be investigated. Such coatings have recently been proposed for use in spinal implants; therefore, it is relevant to assess their impact on the viability of cells expected at the implant site, such as microglia, the resident macrophages of the central nervous system (CNS). To study the effects of Fe and C on the dissolution rate of SiN coatings, compositional gradients of Si, Fe and C in combination with N were generated by physical vapor deposition onto CoCrMo discs. Differences in composition did not affect the surface roughness or the release of Si, Fe or Co ions (the latter from the CoCrMo substrate). Adding Fe and C reduced ion release compared to a SiN reference coating, which was attributed to altered reactivity due to an increase in the fraction of stabilizing Si-C or Fe-C bonds. Extracts from the SiN coatings containing Fe and C were compatible with microglial viability in 2D cultures and 3D collagen hydrogels, to a similar degree as CoCrMo and SiN coated CoCrMo reference extracts. As Fe and C reduced the dissolution rate of SiN-coatings and did not compromise microglial viability, the capacity of these additives to extend the lifetime and functionality of SiN-coated metallic implants warrants further investigation.


Assuntos
Materiais Revestidos Biocompatíveis , Microglia , Materiais Revestidos Biocompatíveis/química , Solubilidade , Colágeno , Íons , Propriedades de Superfície , Teste de Materiais
4.
Vet Radiol Ultrasound ; 64(3): 484-491, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36853616

RESUMO

The prevention of musculoskeletal injuries and their related welfare and economic impacts represent an immediate priority for the horse racing industry. This prospective pilot study aimed to evaluate a method to quantitatively analyze scintigraphic features of specific anatomical regions of the horse's appendicular skeleton in combination with secondary measures of musculoskeletal metabolism in blood. Twelve horses referred for scintigraphic assessment of lameness were enrolled. Blood samples were collected immediately prior to the administration of radiotracer. Serum concentrations associated with bone turnover were determined for the following biomarkers: C-terminal telopeptides of type I collagen, proteoglycans and sulfated glycosaminoglycans, collagen type II, osteocalcin, and procollagen II C-terminal propeptide. Scintigraphic images underwent radiomic analysis of discrete regions of the distal limbs and these data were correlated to bone turnover markers. Three lame horses demonstrated asymmetrical radiomic abnormalities. The concentration of osteocalcin in the lame horses was significantly higher when compared to the control group, while no significant changes were observed for the other screened serum biomarkers. Findings from the current study provided evidence that radiomic analysis of equine scintigraphy is feasible. This method has the potential to interrogate which serum markers are associated with musculoskeletal injuries.


Assuntos
Osso e Ossos , Cavalos , Animais , Projetos Piloto , Osteocalcina , Estudos Prospectivos , Osso e Ossos/diagnóstico por imagem , Biomarcadores/metabolismo
5.
J Cell Biol ; 222(1)2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36350286

RESUMO

The primary cilium is an organelle present in most adult mammalian cells that is considered as an antenna for sensing the local microenvironment. Here, we use intact mouse pancreatic islets of Langerhans to investigate signaling properties of the primary cilium in insulin-secreting ß-cells. We find that GABAB1 receptors are strongly enriched at the base of the cilium, but are mobilized to more distal locations upon agonist binding. Using cilia-targeted Ca2+ indicators, we find that activation of GABAB1 receptors induces selective Ca2+ influx into primary cilia through a mechanism that requires voltage-dependent Ca2+ channel activation. Islet ß-cells utilize cytosolic Ca2+ increases as the main trigger for insulin secretion, yet we find that increases in cytosolic Ca2+ fail to propagate into the cilium, and that this isolation is largely due to enhanced Ca2+ extrusion in the cilium. Our work reveals local GABA action on primary cilia that involves Ca2+ influx and depends on restricted Ca2+ diffusion between the cilium and cytosol.


Assuntos
Cálcio , Cílios , Ilhotas Pancreáticas , Receptores de GABA-B , Ácido gama-Aminobutírico , Animais , Camundongos , Cálcio/metabolismo , Células Cultivadas , Cílios/metabolismo , Ácido gama-Aminobutírico/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Receptores de GABA-B/metabolismo , Citosol
6.
Sci Rep ; 12(1): 21479, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-36509864

RESUMO

The blood-brain barrier (BBB) greatly limits the delivery of protein-based drugs into the brain and is a major obstacle for the treatment of brain disorders. Targeting the transferrin receptor (TfR) is a strategy for transporting protein-based drugs into the brain, which can be utilized by using TfR-binding BBB transporters, such as the TfR-binding antibody 8D3. In this current study, we investigated if binding to heparan sulfate (HS) contributes to the brain uptake of a single chain fragment variable of 8D3 (scFv8D3). We designed and produced a scFv8D3 mutant, engineered with additional HS binding sites, HS(+)scFv8D3, to assess whether increased HS binding would improve brain uptake. Additionally, a mutant with a reduced number of HS binding sites, HS(-)scFv8D3, was also engineered to see if reducing the HS binding sites could also affect brain uptake. Heparin column chromatography showed that only the HS(+)scFv8D3 mutant bound HS in the experimental conditions. Ex vivo results showed that the brain uptake was unaffected by the introduction or removal of HS binding sites, which indicates that scFv8D3 is not dependent on the HS binding sites for brain uptake. Conversely, introducing HS binding sites to scFv8D3 decreased its renal excretion while removing them had the opposite effect.


Assuntos
Barreira Hematoencefálica , Encéfalo , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Anticorpos/metabolismo , Heparitina Sulfato/metabolismo , Sítios de Ligação
7.
J Cell Sci ; 135(7)2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35274124

RESUMO

Cancer cells exploit a variety of migration modes to leave primary tumors and establish metastases, including amoeboid cell migration, which is typically reliant on bleb formation. Here we demonstrate that thrombin induces dynamic blebbing in the MDA-MB-231 breast cancer cell line and confirm that protease-activated receptor 1 (PAR1) activation is sufficient to induce this effect. Cell confinement has been implicated as a driving force in bleb-based migration. Unexpectedly, we found that gentle contact compression, exerted using a custom built 'cell press' to mechanically stimulate cells, reduced thrombin-induced blebbing. Thrombin-induced blebbing was similarly attenuated using the small molecule Yoda1, an agonist of the mechanosensitive Ca2+ channel Piezo1, and this attenuation was impaired in Piezo1-depleted cells. Additionally, Piezo1 activation suppressed thrombin-induced phosphorylation of ezrin, radixin and moesin (ERM) proteins, which are implicated in the blebbing process. Our results provide mechanistic insights into Piezo1 activation as a suppressor of dynamic blebbing, specifically that which is induced by thrombin.


Assuntos
Neoplasias da Mama , Canais Iônicos , Movimento Celular , Feminino , Humanos , Canais Iônicos/metabolismo , Fosforilação , Trombina/metabolismo , Trombina/farmacologia
8.
Sci Rep ; 11(1): 21547, 2021 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-34732783

RESUMO

Bioprinting is increasingly used to create complex tissue constructs for an array of research applications, and there are also increasing efforts to print tissues for transplantation. Bioprinting may also prove valuable in the context of drug screening for personalized medicine for treatment of diseases such as cancer. However, the rapidly expanding bioprinting research field is currently limited by access to bioprinters. To increase the availability of bioprinting technologies we present here an open source extrusion bioprinter based on the E3D motion system and tool changer to enable high-resolution multimaterial bioprinting. As proof of concept, the bioprinter is used to create collagen constructs using freeform reversible embedding of suspended hydrogels (FRESH) methodology, as well as multimaterial constructs composed of distinct sections of laminin and collagen. Data is presented demonstrating that the bioprinted constructs support growth of cells either seeded onto printed constructs or included in the bioink prior to bioprinting. This open source bioprinter is easily adapted for different bioprinting applications, and additional tools can be incorporated to increase the capabilities of the system.


Assuntos
Bioimpressão/instrumentação , Bioimpressão/métodos , Neoplasias/fisiopatologia , Impressão Tridimensional , Engenharia Tecidual/métodos , Neoplasias da Mama/fisiopatologia , Calibragem , Linhagem Celular Tumoral , Sobrevivência Celular , Colágeno/química , Desenho de Equipamento , Humanos , Hidrogéis/química , Laminina/química , Temperatura , Alicerces Teciduais
9.
J Neuroinflammation ; 18(1): 124, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34082772

RESUMO

BACKGROUND: Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by brain accumulation of aggregated amyloid-beta (Aß) and alpha-synuclein (αSYN), respectively. In order to develop effective therapies, it is crucial to understand how the Aß/αSYN aggregates can be cleared. Compelling data indicate that neuroinflammatory cells, including astrocytes and microglia, play a central role in the pathogenesis of AD and PD. However, how the interplay between the two cell types affects their clearing capacity and consequently the disease progression remains unclear. METHODS: The aim of the present study was to investigate in which way glial crosstalk influences αSYN and Aß pathology, focusing on accumulation and degradation. For this purpose, human-induced pluripotent cell (hiPSC)-derived astrocytes and microglia were exposed to sonicated fibrils of αSYN or Aß and analyzed over time. The capacity of the two cell types to clear extracellular and intracellular protein aggregates when either cultured separately or in co-culture was studied using immunocytochemistry and ELISA. Moreover, the capacity of cells to interact with and process protein aggregates was tracked using time-lapse microscopy and a customized "close-culture" chamber, in which the apical surfaces of astrocyte and microglia monocultures were separated by a <1 mm space. RESULTS: Our data show that intracellular deposits of αSYN and Aß are significantly reduced in co-cultures of astrocytes and microglia, compared to monocultures of either cell type. Analysis of conditioned medium and imaging data from the "close-culture" chamber experiments indicate that astrocytes secrete a high proportion of their internalized protein aggregates, while microglia do not. Moreover, co-cultured astrocytes and microglia are in constant contact with each other via tunneling nanotubes and other membrane structures. Notably, our live cell imaging data demonstrate that microglia, when attached to the cell membrane of an astrocyte, can attract and clear intracellular protein deposits from the astrocyte. CONCLUSIONS: Taken together, our data demonstrate the importance of astrocyte and microglia interactions in Aß/αSYN clearance, highlighting the relevance of glial cellular crosstalk in the progression of AD- and PD-related brain pathology.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Astrócitos/metabolismo , Astrócitos/patologia , Microglia/metabolismo , Microglia/patologia , Agregados Proteicos , Agregação Patológica de Proteínas , alfa-Sinucleína/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Encéfalo/metabolismo , Estruturas da Membrana Celular/fisiologia , Células Cultivadas , Técnicas de Cocultura , Humanos , Células-Tronco Pluripotentes Induzidas , Microscopia Confocal , Nanotubos , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Proteólise
10.
Acta Neuropathol Commun ; 9(1): 84, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33971986

RESUMO

Defective amyloid-ß (Aß) clearance from the brain is a major contributing factor to the pathophysiology of Alzheimer's disease (AD). Aß clearance is mediated by macrophages, enzymatic degradation, perivascular drainage along the vascular basement membrane (VBM) and transcytosis across the blood-brain barrier (BBB). AD pathology is typically associated with cerebral amyloid angiopathy due to perivascular accumulation of Aß. Heparan sulfate (HS) is an important component of the VBM, thought to fulfill multiple roles in AD pathology. We previously showed that macrophage-mediated clearance of intracortically injected Aß was impaired in the brains of transgenic mice overexpressing heparanase (Hpa-tg). This study revealed that perivascular drainage was impeded in the Hpa-tg brain, evidenced by perivascular accumulation of the injected Aß in the thalamus of Hpa-tg mice. Furthermore, endogenous Aß accumulated at the perivasculature of Hpa-tg thalamus, but not in control thalamus. This perivascular clearance defect was confirmed following intracortical injection of dextran that was largely retained in the perivasculature of Hpa-tg brains, compared to control brains. Hpa-tg brains presented with thicker VBMs and swollen perivascular astrocyte endfeet, as well as elevated expression of the BBB-associated water-pump protein aquaporin 4 (AQP4). Elevated levels of both heparanase and AQP4 were also detected in human AD brain. These findings indicate that elevated heparanase levels alter the organization and composition of the BBB, likely through increased fragmentation of BBB-associated HS, resulting in defective perivascular drainage. This defect contributes to perivascular accumulation of Aß in the Hpa-tg brain, highlighting a potential role for heparanase in the pathogenesis of AD.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Regulação Enzimológica da Expressão Gênica , Glucuronidase/biossíntese , Sistema Glinfático/metabolismo , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/administração & dosagem , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/toxicidade , Animais , Encéfalo/patologia , Feminino , Glucuronidase/genética , Sistema Glinfático/patologia , Humanos , Injeções Intraventriculares , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/toxicidade
11.
Transl Neurodegener ; 9(1): 37, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32951598

RESUMO

BACKGROUND: Alzheimer's disease (AD) immunotherapy with antibodies targeting amyloid-ß (Aß) has been extensively explored in clinical trials. The aim of this study was to study the long-term brain distribution of two radiolabeled monoclonal Aß antibody variants - RmAb158, the recombinant murine version of BAN2401, which has recently demonstrated amyloid removal and reduced cognitive decline in AD patients, and the bispecific RmAb158-scFv8D3, which has been engineered for enhanced brain uptake via transferrin receptor-mediated transcytosis. METHODS: A single intravenous injection of iodine-125 (125I)-labeled RmAb158-scFv8D3 or RmAb158 was administered to AD transgenic mice (tg-ArcSwe). In vivo single-photon emission computed tomography was used to investigate brain retention and intrabrain distribution of the antibodies over a period of 4 weeks. Activity in blood and brain tissue was measured ex vivo and autoradiography was performed in combination with Aß and CD31 immunostaining to investigate the intrabrain distribution of the antibodies and their interactions with Aß. RESULTS: Despite faster blood clearance, [125I]RmAb158-scFv8D3 displayed higher brain exposure than [125I]RmAb158 throughout the study. The brain distribution of [125I]RmAb158-scFv8D3 was more uniform and coincided with parenchymal Aß pathology, while [125I]RmAb158 displayed a more scattered distribution pattern and accumulated in central parts of the brain at later times. Ex vivo autoradiography indicated greater vascular escape and parenchymal Aß interactions for [125I]RmAb158-scFv8D3, whereas [125I]RmAb158 displayed retention and Aß interactions in lateral ventricles. CONCLUSIONS: The high brain uptake and uniform intrabrain distribution of RmAb158-scFv8D3 highlight the benefits of receptor-mediated transcytosis for antibody-based brain imaging. Moreover, it suggests that the alternative transport route of the bispecific antibody contributes to improved efficacy of brain-directed immunotherapy.


Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Anticorpos Biespecíficos/metabolismo , Anticorpos Monoclonais/metabolismo , Encéfalo/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Anticorpos Biespecíficos/genética , Anticorpos Monoclonais/genética , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Humanos , Radioisótopos do Iodo/administração & dosagem , Radioisótopos do Iodo/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/fisiologia
12.
J Child Psychol Psychiatry ; 61(5): 584-593, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31701533

RESUMO

BACKGROUND: Research on psychosocial interventions has been focused on the effectiveness of psychosocial interventions on mental health outcomes, without exploring how interventions achieve beneficial effects. Identifying the potential pathways through which interventions work would potentially allow further strengthening of interventions by emphasizing specific components connected with such pathways. METHODS: We conducted a preplanned mediation analysis using individual participant data from a dataset of 11 randomized controlled trials (RCTs) which compared focused psychosocial support interventions versus control conditions for children living in low- and middle-income countries (LMICs) affected by humanitarian crises. Based on an ecological resilience framework, we hypothesized that (a) coping, (b) hope, (c) social support, and (d) functional impairment mediate the relationship between intervention and outcome PTSD symptoms. A systematic search on the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed, PyscARTICLES, Web of Science, and the main local LMICs databases was conducted up to August 2018. The hypotheses were tested by using individual participant data obtained from study authors of all the studies included in the systematic review. RESULTS: We included 3,143 children from 11 studies (100% of data from included studies), of which 1,877 from six studies contributed to the mediation analysis. Functional impairment was the strongest mediator for focused psychosocial interventions on PTSD (mediation coefficient -0.087, standard error 0.040). The estimated proportion of effect mediated by functional impairment, and adjusted for confounders, was 31%. CONCLUSIONS: Findings did not support the proposed mediation hypotheses for coping, hope, and social support. The mediation through functional impairment may represent unmeasured proxy measures or point to a broader mechanism that impacts self-efficacy and agency.


Assuntos
Conjuntos de Dados como Assunto , Intervenção Psicossocial , Sistemas de Apoio Psicossocial , Adaptação Psicológica , Criança , Esperança , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Apoio Social
13.
Sci Rep ; 9(1): 11321, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31383888

RESUMO

Microfluidic systems are very useful for in vitro studies of interactions between blood cells and vascular endothelial cells under flow, and several commercial solutions exist. However, the availability of customizable, user-designed devices is largely restricted to researchers with expertise in photolithography and access to clean room facilities. Here we describe a strategy for producing tailor-made modular microfluidic systems, cast in PDMS from 3D-printed molds, to facilitate studies of leukocyte adherence to endothelial cells. A dual-chamber barrier module was optimized for culturing two endothelial cell populations, separated by a 250 µm wide dividing wall, on a glass slide. In proof-of-principle experiments one endothelial population was activated by TNFα, while the other served as an internal control. The barrier module was thereafter replaced with a microfluidic flow module, enclosing both endothelial populations in a common channel. A suspension of fluorescently-labeled leukocytes was then perfused through the flow module and leukocyte interactions with control and TNFα-treated endothelial populations were monitored in the same field of view. Time-lapse microscopy analysis confirmed the preferential attachment of leukocytes to the TNFα-activated endothelial cells. We conclude that the functionality of these modular microfluidic systems makes it possible to seed and differentially activate adherent cell types, and conduct controlled side-by-side analysis of their capacity to interact with cells in suspension under flow. Furthermore, we outline a number of practical considerations and solutions associated with connecting and switching between the microfluidic modules, and the advantages of simultaneously and symmetrically analyzing control and experimental conditions in such a microfluidic system.


Assuntos
Técnicas de Cultura de Células/instrumentação , Células Endoteliais/citologia , Leucócitos/citologia , Técnicas Analíticas Microfluídicas/instrumentação , Adesão Celular , Células Cultivadas , Dimetilpolisiloxanos/química , Desenho de Equipamento , Células Endoteliais da Veia Umbilical Humana , Humanos , Impressão Tridimensional
14.
J Environ Qual ; 48(2): 340-351, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30951116

RESUMO

The degradation of freshwater resources and loss of freshwater biodiversity by anthropogenic activities, including agriculture, are of major global concern. Together with diffuse pollutants, point sources, such as where cattle have direct access to riparian margins and watercourses, can potentially present significant environmental challenges. These can include impacts on stream morphology, increased sedimentation, nutrient additions, microbial contamination, and impacts on aquatic biota. Mitigation measures aimed at reducing these frequently include reducing the amount of time cattle spend in riparian margins and watercourses. This is often accomplished through the provision of an alternative water supply and grazing management, or even cattle exclusion measures. Although a number of studies refer to potential negative impacts, there has been little attempt to review previous research on this topic. The key aim of this paper is to collate and review these disparate studies, as well as those relating to the effectiveness of mitigation measures. Although it is difficult to draw generalizations from studies due to the inherent variability between and within catchments, evidence pertaining to impacts in relation to sedimentation, pathogens, and riparian margin vegetation were strong. Conclusions in relation to impacts on stream morphology and nutrient parameters were less clear, whereas studies on responses of macroinvertebrate communities were particularly variable, with differences due to cattle access difficult to separate from catchment scale effects. A greater understanding of the impact of cattle access on watercourses under varying conditions will help inform policymakers on the cost effectiveness of existing management criteria and will help in revising existing measures.


Assuntos
Criação de Animais Domésticos , Conservação dos Recursos Naturais , Monitoramento Ambiental , Rios , Agricultura , Animais , Bovinos , Ecossistema , Abastecimento de Água
15.
Water Environ Res ; 91(2): 144-156, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30735298

RESUMO

This paper analyzes six case studies of new water technology innovations in the last three decades and investigates the differences in timelines for moving through the various stages of water technology commercialization. The concept of two different types of innovation was explored: Crisis/Needs Driven and Value Driven. It was found that the case studies that mapped to the Crisis/Needs Driven innovation moved relatively quickly compared to Value Driven innovations and in most cases involved new entrants. New entrants refer to new companies or start-ups that have recently entered the water technology market. The case studies, which could be mapped to Value Driven innovation, had a slower rate of technology diffusion, and they involved a combination of existing companies as well as new entrants. PRACTITIONER POINTS: The paper identifies two key types of innovation: Crisis/Needs Driven and Value Driven. Legislation was observed to be a key driver for the adoption of new technology innovation in the water sector. The Crisis/Needs driven innovations studied were observed to diffuse through the Water Technology Diffusion model at up to twice the pace of Value driven innovation. Crisis/Needs driven innovation typically involves disruptive innovation offered by new entrants, whereas with Value driven innovation, the solutions are provided by both existing companies as well as new entrants. It is also observed that in most cases a technology that is adopted in order to meet a crisis or need in the market is more expensive at the outset compared with incumbent solutions. While value driven adoption has a slower cycle for adoption, it presents a lower risk as it is less dependent on external factors and timing of implementation of regulations or the occurrence of some public health related or environmental crisis.


Assuntos
Invenções , Purificação da Água , Desinfecção , Água Potável/química , Água Potável/microbiologia , Hidrólise , Fósforo/isolamento & purificação , Esgotos , Temperatura , Raios Ultravioleta
16.
Lab Chip ; 19(6): 1071-1081, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30783638

RESUMO

The function and behaviour of any given cell in a healthy tissue, or in a tumor, is affected by interactions with its neighboring cells. It is therefore important to create methods that allow for reconstruction of tissue niches in vitro for studies of cell-cell signaling and associated cell behaviour. To this end we created the cell assembly generator (CAGE), a microfluidic device which enables the organization of different cell types into precise cell clusters in a flow chamber compatible with high-resolution microscopy. In proof-of-concept paracrine signalling experiments, 4-cell clusters consisting of one pancreatic ß-cell and three breast cancer cells were formed. It has previously been established that extracellular ATP induces calcium (Ca2+) release from the endoplasmic reticulum (ER) to the cytosol before it is cleared back into the ER via sarcoplasmic/ER Ca2+ ATPase (SERCA) pumps. Here, ATP release from the ß-cell was stimulated by depolarization, and dynamic changes in Ca2+ levels in the adjacent cancer cells measured using imaging of the calcium indicator Fluo-4. We established that changes in the concentration of cytosolic Ca2+ in the cancer cells were proportional to the distance from the ATP-releasing ß-cell. Additionally, we established that the relationship between distance and cytosolic calcium changes were dependent on Ca2+-release from the ER using 5-cell clusters composed of one ß-cell, two untreated cancer cells and two cancer cells pretreated with Thapsigargin (to deplete the ER of Ca2+). These experiments show that the CAGE can be used to create exact cell clusters, which affords precise control for reductionist studies of cell-cell signalling and permits the formation of heterogenous cell models of specific tissue niches.


Assuntos
Trifosfato de Adenosina/farmacologia , Cálcio/metabolismo , Microfluídica/métodos , Comunicação Parácrina/efeitos dos fármacos , Compostos de Anilina/química , Animais , Cálcio/química , Linhagem Celular , Citosol/metabolismo , Retículo Endoplasmático/metabolismo , Humanos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Células MCF-7 , Camundongos , Microfluídica/instrumentação , Impressão Tridimensional , Xantenos/química
17.
PLoS One ; 13(8): e0201557, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30086153

RESUMO

The exocyst is a molecular tether that retains secretory vesicles at the plasma membrane prior to SNARE-mediated docking and fusion. However, individual exocyst complex components (EXOCs) may also function independently of exocyst assembly. Alternative splice variants of EXOC mRNA and paralogs of EXOC genes have been described and several have been attributed functions that may be independent of the exocyst complex. Here we describe a novel splice variant of murine Exoc3l2, which we term Exoc3l2a. We discuss possible functional implications of the resulting domain excision from this isoform of EXOC3L2 based on structural similarities with its paralog M-Sec (EXOC3L3), which is implicated in tunneling nanotube formation. The identification of this Exoc3l2 splice variant expands the potential for subunit diversity within the exocyst and for alternative functionality of this component independently of the exocyst.


Assuntos
Processamento Alternativo , Fatores de Necrose Tumoral/química , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética , Animais , Camundongos , Modelos Moleculares , Conformação Proteica , RNA/metabolismo , Análise de Sequência de RNA , Fatores de Necrose Tumoral/genética
18.
Lancet Glob Health ; 6(4): e390-e400, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29530422

RESUMO

BACKGROUND: Results from studies evaluating the effectiveness of focused psychosocial support interventions in children exposed to traumatic events in humanitarian settings in low-income and middle-income countries have been inconsistent, showing varying results by setting and subgroup (eg, age or gender). We aimed to assess the effectiveness of these interventions, and to explore which children are likely to benefit most. METHODS: We did a systematic review and meta-analysis of individual participant data (IPD) from 3143 children recruited to 11 randomised controlled trials of focused psychosocial support interventions versus waiting list. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, PsycArticles, Web of Science, and the main local low-income and middle-income countries (LMICs) databases according to the list of databases relevant to LMIC developed collaboratively by Cochrane and WHO Library, up to November, 2016. We included randomised controlled trials that assessed the effectiveness of focused psychosocial support interventions in children exposed to traumatic events in LMICs, compared with waiting lists (eg, inactive controls). We excluded quasi-randomised trials, studies that did not focus on psychosocial support interventions, and studies that compared two active interventions without control conditions. We requested anonymised data from each trial for each of the prespecified variables for each child who was randomly assigned. The main outcomes considered were continuous scores in post-traumatic stress disorder (PTSD) symptoms, depressive symptoms, and anxiety symptoms assessed with rating scales administered immediately (0-4 weeks) after the intervention. We harmonised all individual items from rating scales using item response theory methods. This study is registered with PROSPERO, number CRD42013006960. FINDINGS: We identified a beneficial effect of focused psychosocial support interventions on PTSD symptoms (standardised mean difference [SMD] -0·33, 95% CI -0·52 to -0·14) that was maintained at follow-up (-0·21, -0·42 to -0·01). We also identified benefits at the endpoint for functional impairment (-0·29, -0·43 to -0·15) and for strengths: coping (-0·22, -0·43 to -0·02), hope (-0·29, -0·48 to -0·09), and social support (-0·27, -0·52 to -0·02). In IPD meta-analyses focused on age, gender, displacement status, region, and household size we found a stronger improvement in PTSD symptoms in children aged 15-18 years (-0·43, -0·63 to -0·23), in non-displaced children (-0·40, -0·52 to -0·27), and in children living in smaller households (<6 members; -0·27, -0·42 to -0·11). INTERPRETATION: Overall, focused psychosocial interventions are effective in reducing PTSD and functional impairment, and in increasing hope, coping, and social support. Future studies should focus on strengthening interventions for younger children, displaced children, and children living in larger households. FUNDING: European Commission FP7th Framework Programme for Research (Marie Curie International Outgoing Fellowship) and the National Institute on Aging.


Assuntos
Altruísmo , Países em Desenvolvimento , Psicoterapia/métodos , Transtornos de Estresse Pós-Traumáticos/prevenção & controle , Criança , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
19.
Dyslexia ; 24(1): 3-16, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29314436

RESUMO

This paper considers two major concerns centring on the Joint Council for Qualifications (JCQ) regulations for access arrangement and reasonable adjustments and qualifications for teachers who take on the role of Level 7 access arrangements assessor. Thus, the paper is divided into two parts. First, the JCQ 2017-2018 regulations are critically evaluated highlighting the areas of need for which greater clarity and more extensive detail is required in these regulations. The second part of the paper discusses the findings of research on teacher competence in test administration, scoring, and reporting. Drawing on evidence from the first stage of this research, McMurray, O'Callaghan, and McVeigh highlight the extensive formative process required to build a high-level skill set required for competent assessment involving the use of high level tests and also the specialist knowledge required to analyse and accurately report assessment findings to make recommendations for students with specific literacy difficulties. Recommendations are provided both at policy and practice levels regarding the content of courses and the assessment involving the use of high level tests and also the specialist knowledge required to analyse and accurately report assessment findings to make recommendations for students with specific literacy difficulties. The authors provide recommendations for test publishers, course providers, and assessors.


Assuntos
Dislexia/diagnóstico , Avaliação Educacional/normas , Competência Profissional , Garantia da Qualidade dos Cuidados de Saúde/normas , Professores Escolares/psicologia , Avaliação Educacional/métodos , Humanos , Alfabetização/psicologia , Estudantes/psicologia
20.
J Histochem Cytochem ; 66(4): 305-319, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29290138

RESUMO

Heparan sulfate proteoglycans (HSPGs) are implicated as inflammatory mediators in a variety of settings, including chemokine activation, which is required to recruit circulating leukocytes to infection sites. Heparan sulfate (HS) polysaccharide chains are highly interactive and serve co-receptor roles in multiple ligand:receptor interactions. HS may also serve as a storage depot, sequestering ligands such as cytokines and restricting their access to binding partners. Heparanase, through its ability to fragment HS chains, is a key regulator of HS function and has featured prominently in studies of HS's involvement in inflammatory processes. This review focuses on recent discoveries regarding the role of HSPGs, HS, and heparanase during inflammation, with particular focus on the brain. HS chains emerge as critical go-betweens in multiple aspects of the inflammatory response-relaying signals between receptors and cells. The molecular interactions proposed to occur between HSPGs and the pathogen receptor toll-like receptor 4 (TLR4) are discussed, and we summarize some of the contrasting roles that HS and heparanase have been assigned in diseases associated with chronic inflammatory states, including Alzheimer's disease (AD). We conclude by briefly discussing how current knowledge could potentially be applied to augment HS-mediated events during sustained neuroinflammation, which contributes to neurodegeneration in AD.


Assuntos
Doença de Alzheimer/imunologia , Encéfalo/imunologia , Proteoglicanas de Heparan Sulfato/imunologia , Imunidade Inata , Inflamação/imunologia , Neuroglia/imunologia , Doença de Alzheimer/patologia , Animais , Encéfalo/patologia , Citocinas/imunologia , Glucuronidase/imunologia , Heparitina Sulfato/imunologia , Humanos , Inflamação/patologia , Neuroglia/patologia , Neuroimunomodulação , Receptor 4 Toll-Like/imunologia
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