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1.
Proc Natl Acad Sci U S A ; 120(14): e2210745120, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36989307

RESUMO

Cells respond to stress by synthesizing chaperone proteins that seek to correct protein misfolding and maintain function. However, abrogation of protein homeostasis is a hallmark of aging, leading to loss of function and the formation of proteotoxic aggregates characteristic of pathology. Consequently, discovering the underlying molecular causes of this deterioration in proteostasis is key to designing effective interventions to disease or to maintaining cell health in regenerative medicine strategies. Here, we examined primary human mesenchymal stem cells, cultured to a point of replicative senescence and subjected to heat shock, as an in vitro model of the aging stress response. Multi -omics analysis showed how homeostasis components were reduced in senescent cells, caused by dysregulation of a functional network of chaperones, thereby limiting proteostatic competence. Time-resolved analysis of the primary response factors, including those regulating heat shock protein 70 kDa (HSPA1A), revealed that regulatory control is essentially translational. Senescent cells have a reduced capacity for chaperone protein translation and misfolded protein (MFP) turnover, driven by downregulation of ribosomal proteins and loss of the E3 ubiquitin ligase CHIP (C-terminus of HSP70 interacting protein) which marks MFPs for degradation. This limits the cell's stress response and subsequent recovery. A kinetic model recapitulated these reduced capacities and predicted an accumulation of MFP, a hypothesis supported by evidence of systematic changes to the proteomic fold state. These results thus establish a specific loss of regulatory capacity at the protein, rather than transcript, level and uncover underlying systematic links between aging and loss of protein homeostasis.


Assuntos
Células-Tronco Mesenquimais , Proteômica , Humanos , Envelhecimento , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Biossíntese de Proteínas , Células-Tronco Mesenquimais/metabolismo
2.
Biomacromolecules ; 25(6): 3628-3641, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38771115

RESUMO

Peptide-based supramolecular hydrogels are an attractive class of soft materials for biomedical applications when biocompatibility is a key requirement as they exploit the physical self-assembly of short self-assembling peptides avoiding the need for chemical cross-linking. Based on the knowledge developed through our previous work, we designed two novel peptides, E(FKFE)2 and K(FEFK)2, that form transparent hydrogels at pH 7. We characterized the phase behavior of these peptides and showed the clear link that exists between the charge carried by the peptides and the physical state of the samples. We subsequently demonstrate the cytocompatibility of the hydrogel and its suitability for 3D cell culture using 3T3 fibroblasts and human mesenchymal stem cells. We then loaded the hydrogels with two polymers, poly-l-lysine and dextran. When polymer and peptide fibers carry opposite charges, the size of the elemental fibril formed decreases, while the overall level of fiber aggregation and fiber bundle formation increases. This overall network topology change, and increase in cross-link stability and density, leads to an overall increase in the hydrogel mechanical properties and stability, i.e., resistance to swelling when placed in excess media. Finally, we investigate the diffusion of the polymers out of the hydrogels and show how electrostatic interactions can be used to control the release of large molecules. The work clearly shows how polymers can be used to tailor the properties of peptide hydrogels through guided intermolecular interactions and demonstrates the potential of these new soft hydrogels for use in the biomedical field in particular for delivery or large molecular payloads and cells as well as scaffolds for 3D cell culture.


Assuntos
Hidrogéis , Peptídeos , Eletricidade Estática , Hidrogéis/química , Hidrogéis/farmacologia , Humanos , Camundongos , Animais , Peptídeos/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Polilisina/química , Materiais Biocompatíveis/química , Dextranos/química , Células 3T3
3.
Nature ; 560(7716): 84-87, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30068951

RESUMO

Geological pathways for the recycling of Earth's surface materials into the mantle are both driven and obscured by plate tectonics1-3. Gauging the extent of this recycling is difficult because subducted crustal components are often released at relatively shallow depths, below arc volcanoes4-7. The conspicuous existence of blue boron-bearing diamonds (type IIb)8,9 reveals that boron, an element abundant in the continental and oceanic crust, is present in certain diamond-forming fluids at mantle depths. However, both the provenance of the boron and the geological setting of diamond crystallization were unknown. Here we show that boron-bearing diamonds carry previously unrecognized mineral assemblages whose high-pressure precursors were stable in metamorphosed oceanic lithospheric slabs at depths reaching the lower mantle. We propose that some of the boron in seawater-serpentinized oceanic lithosphere is subducted into the deep mantle, where it is released with hydrous fluids that enable diamond growth10. Type IIb diamonds are thus among the deepest diamonds ever found and indicate a viable pathway for the deep-mantle recycling of crustal elements.

4.
J Cardiothorac Vasc Anesth ; 38(6): 1409-1416, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38503625

RESUMO

OBJECTIVE: The aim of this study was to use wearable video-recording technology to measure precisely the timing of discrete events during perioperative central venous catheter (CVC) placements. DESIGN: A single-center, observational, exploratory study on the use of wearable video-recording technology during intraoperative CVC placement. SETTING: The study was conducted at a University Hospital. PARTICIPANTS: Clinical anesthesia residents, cardiothoracic anesthesia fellows, and attending anesthesiologists participated in this study. INTERVENTIONS: Participants were asked to use eye-tracking glasses prior to the placement of a CVC in the cardiac operating rooms. No other instruction was given to the participants. MEASUREMENTS AND MAIN RESULTS: The authors measured the total time to complete the CVC placement, phase-specific time, and specific times of interest. They compared these times across 3 training levels and tested differences with analysis of variance. The authors' findings indicated significant differences in total CVC placement time when the procedure included a pulmonary artery catheter insertion (1,170 ± 364, 923 ± 272, and 596 ± 226 seconds; F2,63 = 12.71, p < 0.0001). Additionally, they found differences in interval times and times of interest. The authors observed a reduction of variability with increasing experience during the CVC placement phase. CONCLUSIONS: In this observational study, the study authors describe their experience using first-person wearable video-recording technology to precisely measure the timing of discrete events during CVC placement by anesthesia residents and anesthesiologists. Future work will leverage the eye-tracking capabilities of the existing hardware to identify areas of inefficiency to develop actionable targets for interventions that could improve trainee performance and patient safety.


Assuntos
Cateterismo Venoso Central , Salas Cirúrgicas , Gravação em Vídeo , Humanos , Gravação em Vídeo/métodos , Cateterismo Venoso Central/métodos , Cateterismo Venoso Central/instrumentação , Dispositivos Eletrônicos Vestíveis , Procedimentos Cirúrgicos Cardíacos/métodos , Cateteres Venosos Centrais , Internato e Residência/métodos , Masculino , Feminino , Anestesiologistas
5.
Mar Drugs ; 21(2)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36827101

RESUMO

Collagen is the most ubiquitous biomacromolecule found in the animal kingdom and is commonly used as a biomaterial in regenerative medicine therapies and biomedical research. The collagens used in these applications are typically derived from mammalian sources which poses sociological issues due to widespread religious constraints, rising ethical concern over animal rights and the continuous risk of zoonotic disease transmission. These issues have led to increasing research into alternative collagen sources, of which marine collagens, in particular from jellyfish, have emerged as a promising resource. This study provides a characterization of the biophysical properties and cell adhesion interactions of collagen derived from the jellyfish Rhizostoma pulmo (JCol). Circular dichroism spectroscopy and atomic force microscopy were used to observe the triple-helical conformation and fibrillar morphology of JCol. Heparin-affinity chromatography was also used to demonstrate the ability of JCol to bind to immobilized heparin. Cell adhesion assays using integrin blocking antibodies and HT-1080 human fibrosarcoma cells revealed that adhesion to JCol is primarily performed via ß1 integrins, with the exception of α2ß1 integrin. It was also shown that heparan sulfate binding plays a much greater role in fibroblast and mesenchymal stromal cell adhesion to JCol than for type I mammalian collagen (rat tail collagen). Overall, this study highlights the similarities and differences between collagens from mammalian and jellyfish origins, which should be considered when utilizing alternative collagen sources for biomedical research.


Assuntos
Cnidários , Colágeno , Cifozoários , Animais , Humanos , Ratos , Adesão Celular , Cnidários/metabolismo , Colágeno/química , Integrinas/metabolismo , Cifozoários/química
6.
Int J Mol Sci ; 25(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38203618

RESUMO

Osteoclastogenesis, one of the dynamic pathways underlying bone remodelling, is a complex process that includes many stages. This complexity, while offering a wealth of therapeutic opportunities, represents a substantial challenge in unravelling the underlying mechanisms. As such, there is a high demand for robust model systems to understand osteoclastogenesis. Hydrogels seeded with osteoclast precursors and decorated with peptides or proteins mimicking bone's extracellular matrix could provide a useful synthetic tool to study pre-osteoclast-matrix interactions and their effect on osteoclastogenesis. For instance, fibrillar collagens have been shown to provide a co-stimulatory pathway for osteoclastogenesis through interaction with the osteoclast-associated receptor (OSCAR), a regulator of osteoclastogenesis expressed on the surface of pre-osteoclast cells. Based on this rationale, here we design two OSCAR-binding peptides and one recombinant OSCAR-binding protein, and we combine them with peptide-based hydrogels to study their effect on osteoclastogenesis. The OSCAR-binding peptides adopt the collagen triple-helical conformation and interact with OSCAR, as shown by circular dichroism spectropolarimetry and surface plasmon resonance. Furthermore, they have a positive effect on osteoclastogenesis, as demonstrated by appropriate gene expression and tartrate-resistant acid phosphatase staining typical of osteoclast formation. Combination of the OSCAR-binding peptides or the OSCAR-binding recombinant protein with peptide-based hydrogels enhances osteoclast differentiation when compared to the non-modified hydrogels, as demonstrated by multi-nucleation and by F-actin staining showing a characteristic osteoclast-like morphology. We envisage that these hydrogels could be used as a platform to study osteoclastogenesis and, in particular, to investigate the effect of costimulatory pathways involving OSCAR.


Assuntos
Osteoclastos , Osteogênese , Hidrogéis/farmacologia , Peptídeos/farmacologia , Citoesqueleto de Actina
7.
Opt Express ; 30(18): 32174-32188, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36242285

RESUMO

Coherent laser arrays compatible with silicon photonics are demonstrated in a waveguide geometry in epitaxially grown semiconductor membrane quantum well lasers transferred on substrates of silicon carbide and oxidised silicon; we record lasing thresholds as low as 60 mW of pump power. We study the emission of single lasers and arrays of lasers in the sub-mm range. We are able to create waveguide laser arrays with modal widths of approximately 5 - 10 µm separated by 10 - 20 µm, using real and reciprocal space imaging we study their emission characteristics and find that they maintain their mutual coherence while operating on either single or multiple longitudinal modes per lasing cavity.

8.
Int J Mol Sci ; 23(13)2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35805921

RESUMO

Back pain is one of the leading causes of disability worldwide and is frequently caused by degeneration of the intervertebral discs. The discs' development, homeostasis, and degeneration are driven by a complex series of biochemical and physical extracellular matrix cues produced by and transmitted to native cells. Thus, understanding the roles of different cues is essential for designing effective cellular and regenerative therapies. Omics technologies have helped identify many new matrix cues; however, comparatively few matrix molecules have thus far been incorporated into tissue engineered models. These include collagen type I and type II, laminins, glycosaminoglycans, and their biomimetic analogues. Modern biofabrication techniques, such as 3D bioprinting, are also enabling the spatial patterning of matrix molecules and growth factors to direct regional effects. These techniques should now be applied to biochemically, physically, and structurally relevant disc models incorporating disc and stem cells to investigate the drivers of healthy cell phenotype and differentiation. Such research will inform the development of efficacious regenerative therapies and improved clinical outcomes.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Diferenciação Celular , Sinais (Psicologia) , Matriz Extracelular/metabolismo , Humanos , Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/metabolismo
9.
Int J Mol Sci ; 23(9)2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35563508

RESUMO

Post-traumatic OA (PTOA) is often triggered by injurious, high-impact loading events which result in rapid, excessive chondrocyte cell death and a phenotypic shift in residual cells toward a more catabolic state. As such, the identification of a disease-modifying OA drug (DMOAD) that can protect chondrocytes from death following impact injury, and thereby prevent cartilage degradation and progression to PTOA, would offer a novel intervention. We have previously shown that urocortin-1 (Ucn) is an essential endogenous pro-survival factor that protects chondrocytes from OA-associated pro-apoptotic stimuli. Here, using a drop tower PTOA-induction model, we demonstrate the extent of Ucn's chondroprotective role in cartilage explants exposed to excessive impact load. Using pathway-specific agonists and antagonists, we show that Ucn acts to block load-induced intracellular calcium accumulation through blockade of the non-selective cation channel Piezo1 rather than TRPV4. This protective effect is mediated primarily through the Ucn receptor CRF-R1 rather than CRF-R2. Crucially, we demonstrate that the chondroprotective effect of Ucn is maintained whether it is applied pre-impact or post-impact, highlighting the potential of Ucn as a novel DMOAD for the prevention of injurious impact overload-induced PTOA.


Assuntos
Cartilagem Articular , Osteoartrite , Cartilagem Articular/metabolismo , Morte Celular , Condrócitos/metabolismo , Humanos , Canais Iônicos/metabolismo , Osteoartrite/etiologia , Osteoartrite/metabolismo , Urocortinas/metabolismo , Urocortinas/farmacologia
10.
Int J Mol Sci ; 22(2)2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33445782

RESUMO

Intervertebral disc (IVD) degeneration is a major risk factor of low back pain. It is defined by a progressive loss of the IVD structure and functionality, leading to severe impairments with restricted treatment options due to the highly demanding mechanical exposure of the IVD. Degenerative changes in the IVD usually increase with age but at an accelerated rate in some individuals. To understand the initiation and progression of this disease, it is crucial to identify key top-down and bottom-up regulations' processes, across the cell, tissue, and organ levels, in health and disease. Owing to unremitting investigation of experimental research, the comprehension of detailed cell signaling pathways and their effect on matrix turnover significantly rose. Likewise, in silico research substantially contributed to a holistic understanding of spatiotemporal effects and complex, multifactorial interactions within the IVD. Together with important achievements in the research of biomaterials, manifold promising approaches for regenerative treatment options were presented over the last years. This review provides an integrative analysis of the current knowledge about (1) the multiscale function and regulation of the IVD in health and disease, (2) the possible regenerative strategies, and (3) the in silico models that shall eventually support the development of advanced therapies.


Assuntos
Degeneração do Disco Intervertebral/fisiopatologia , Disco Intervertebral/fisiopatologia , Animais , Simulação por Computador , Matriz Extracelular/fisiologia , Humanos , Transdução de Sinais/fisiologia , Engenharia Tecidual/métodos
11.
Angew Chem Int Ed Engl ; 60(49): 25856-25864, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34551190

RESUMO

The stereochemistry of polymers has a profound impact on their mechanical properties. While this has been observed in thermoplastics, studies on how stereochemistry affects the bulk properties of swollen networks, such as hydrogels, are limited. Typically, changing the stiffness of a hydrogel is achieved at the cost of changing another parameter, that in turn affects the physical properties of the material and ultimately influences the cellular response. Herein, we report that by manipulating the stereochemistry of a double bond, formed in situ during gelation, materials with diverse mechanical properties but comparable physical properties can be obtained. Click-hydrogels that possess a high % trans content are stiffer than their high % cis analogues by almost a factor of 3. Human mesenchymal stem cells acted as a substrate stiffness cell reporter demonstrating the potential of these platforms to study mechanotransduction without the influence of other external factors.

12.
J Proteome Res ; 19(6): 2167-2184, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32319298

RESUMO

Multivariate regression modelling provides a statistically powerful means of quantifying the effects of a given treatment while compensating for sources of variation and noise, such as variability between human donors and the behavior of different peptides during mass spectrometry. However, methods to quantify endogenous post-translational modifications (PTMs) are typically reliant on summary statistical methods that fail to consider sources of variability such as changes in the levels of the parent protein. Here, we compare three multivariate regression methods, including a novel Bayesian elastic net algorithm (BayesENproteomics) that enables assessment of relative protein abundances while also quantifying identified PTMs for each protein. We tested the ability of these methods to accurately quantify expression of proteins in a mixed-species benchmark experiment and to quantify synthetic PTMs induced by stable isotope labelling. Finally, we extended our regression pipeline to calculate fold changes at the pathway level, providing a complement to commonly used enrichment analysis. Our results show that BayesENproteomics can quantify changes to protein levels across a broad dynamic range while also accurately quantifying PTM and pathway-level fold changes.


Assuntos
Proteômica , Espectrometria de Massas em Tandem , Teorema de Bayes , Humanos , Peptídeos/metabolismo , Processamento de Proteína Pós-Traducional
14.
Int J Mol Sci ; 21(19)2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32992671

RESUMO

Growth differentiation factor (GDF) family members have been implicated in the development and maintenance of healthy nucleus pulposus (NP) tissue, making them promising therapeutic candidates for treatment of intervertebral disc (IVD) degeneration and associated back pain. GDF6 has been shown to promote discogenic differentiation of mesenchymal stem cells, but its effect on NP cells remains largely unknown. Our aim was to investigate GDF6 signalling in adult human NP cells derived from degenerate tissue and determine the signal transduction pathways critical for GDF6-mediated phenotypic changes and tissue homeostatic mechanisms. This study demonstrates maintained expression of GDF6 receptors in human NP and annulus fibrosus (AF) cells across a range of degeneration grades at gene and protein level. We observed an anabolic response in NP cells treated with recombinant GDF6 (increased expression of matrix and NP-phenotypic markers; increased glycosaminoglycan production; no change in catabolic enzyme expression), and identified the signalling pathways involved in these responses (SMAD1/5/8 and ERK1/2 phosphorylation, validated by blocking studies). These findings suggest that GDF6 promotes a healthy disc tissue phenotype in degenerate NP cells through SMAD-dependent and -independent (ERK1/2) mechanisms, which is important for development of GDF6 therapeutic strategies for treatment of degenerate discs.


Assuntos
Fator 6 de Diferenciação de Crescimento/farmacologia , Degeneração do Disco Intervertebral/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Núcleo Pulposo , Regeneração/efeitos dos fármacos , Adulto , Feminino , Humanos , Degeneração do Disco Intervertebral/tratamento farmacológico , Degeneração do Disco Intervertebral/patologia , Núcleo Pulposo/patologia , Núcleo Pulposo/fisiologia , Proteínas Smad/metabolismo
15.
Lab Invest ; 99(1): 85-92, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30353131

RESUMO

Distinct populations of effector memory T cells use different homing receptors to traffic to the skin and gut. Whether tissue-selective T cells are needed for early rejection of a neoplasm growing in these tissues remains an open question. We chose to study an allogeneic tumor model because growth of such a fully mismatched tumor would signify a profound immune deficit. We implanted allogeneic tumor cells in the skin or gut of mice deficient in either α(1,3) fucosyltransferases IV and VII, enzymes critical for generating E-selectin ligands on skin-homing T cells, or ß7 integrin, a component of the α4ß7 integrin ligand for the mucosal adressin MAdCAM. During the first 9 days after tumor implantation, FucTVII-/- mice showed a profoundly impaired capacity to reject tumors growing in the skin, but readily rejected tumors implanted in the gut. Rejection of tumors in the skin was even more impaired in mice deficient in both FucTIV and FucTVII. This impairment was corrected by infusion of T cells from normal mice. By contrast, ß7 integrin-/- mice showed profoundly impaired rejection of tumors in the gut, but no defect in the skin tumor rejection. These differences were unrelated to antigen recognition or effector function of T cells, since all strains of mice were capable of generating tumor-specific CTLs in vitro against the tumor cell line used in vivo. These results demonstrate that T-cell homing defects in vivo impair immune surveillance of peripheral epithelial tissues in a specific and selective fashion.


Assuntos
Neoplasias/imunologia , Linfócitos T/fisiologia , Aloenxertos , Animais , Linhagem Celular Tumoral , Fucosiltransferases/metabolismo , Cadeias beta de Integrinas/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Knockout , Transplante de Neoplasias
16.
Cancer Causes Control ; 30(5): 435-441, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30949885

RESUMO

Many women diagnosed with breast cancer have chronic conditions such as diabetes that may impact other health behaviors. Our purpose was to determine if breast cancer screening and detection differs among women with and without diabetes. We conducted a cross-sectional analysis of a retrospective cohort of women aged 52-74 years diagnosed with incident stages I-III breast cancer enrolled in an integrated health plan between 1999 and 2014 with linkage to the Surveillance, Epidemiology and End Results registry (n = 2040). Screening data were taken from electronic health records. We used multivariable modified Poisson regression models with robust standard errors to estimate relative risks (RR) and 95% confidence intervals (CI) for outcomes of (i) receipt of screening in the 2 years prior to diagnosis; (ii) symptom-detected breast cancer; and (iii) diagnosis of locally advanced stage III breast cancer. Compared to women without diabetes, women with diabetes were similar with respect to receipt of screening mammography (78% and 77%), symptom-detected breast cancer (46% and 49%), and stage III diagnosis (7% and 7%). In multivariable models adjusting for age and year of diagnosis, race, BMI, Charlson comorbidity score and depression diagnosis no differences were observed in the outcomes by presence of diabetes. Further investigation is warranted to determine how diabetes acts as a mediating factor in adverse breast cancer outcomes.


Assuntos
Neoplasias da Mama/epidemiologia , Diabetes Mellitus/epidemiologia , Programas de Rastreamento/métodos , Idoso , Estudos de Coortes , Comorbidade , Estudos Transversais , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Mamografia/métodos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Grupos Raciais , Estudos Retrospectivos
17.
Environ Sci Technol ; 53(19): 11375-11382, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31479249

RESUMO

A pilot-scale plasma reactor installed into an 8 × 20 ft2 mobile trailer was used to rapidly and effectively degrade poly- and perfluoroalkyl substances (PFAS) from liquid investigation-derived waste (IDW; development and purge water from monitoring wells) obtained from 13 different site investigations at Air Force installations. In the raw water, numerous PFAS were detected in a wide concentration range (∼10-105 ng/L; total oxidizable precursors (TOP) ∼102-105 ng/L, total fluorine by combustion ion chromatography ∼102 to 5 × 106 ng F/L). The concentration of total PFAS (12 perfluorocarboxylic acids (PFCAs) and perfluoroalkyl sulfonates (PFSAs)) in the 13 samples ranged between 2.7 and 1440 µg/L and the concentration of perfluorooctane sulfonate (PFOS) plus perfluorooctanoic acid (PFOA) ranged between 365 and 73700 ng/L. Plasma-based water treatment resulted in rapid perfluoroalkyl acids (PFAAs) removal from 4 L individual IDW samples with faster rates for longer-chain PFCAs (C ≥ 8) and PFSAs (C ≥ 6) than for PFCAs and PFSAs of shorter chain length. In 9 of the 13 IDW samples, both PFOS and PFOA were removed to below United States Environmental Protection Agency's (USEPA's) health advisory concentration level (HAL) concentrations in <1 min, whereas longer treatment times (up to 50 min) were required for the remaining four IDW samples due to either extremely high solution electrical conductivity, which decreased the plasma-liquid contact area (one IDW sample) or high concentrations of PFAAs and their precursors; the latter was found to be converted to PFAAs during the treatment. Overall, 36-99% of the TOP concentration present in the IDWs was removed during the treatment. There was no effect of non-PFAS co-contaminants on the degradation efficiency. Overall, the results indicate that plasma-based water treatment is a viable technology for the treatment of PFAS-contaminated IDW.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Poluentes Químicos da Água , Purificação da Água , Monitoramento Ambiental
18.
Adv Exp Med Biol ; 1144: 53-69, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30456642

RESUMO

An extensive number of cell-matrix interaction studies have identified matrix stiffness as a potent regulator of cellular properties and behaviours. Perhaps most notably, matrix stiffness has been demonstrated to regulate mesenchymal stem cell (MSC) phenotype and lineage commitment. Given the therapeutic potential for MSCs in regenerative medicine, significant efforts have been made to understand the molecular mechanisms involved in stiffness regulation. These efforts have predominantly focused on using stiffness-defined polyacrylamide (PA) hydrogels to culture cells in 2D and have enabled elucidation of a number of mechano-sensitive signalling pathways. However, despite proving to be a valuable tool, these stiffness-defined hydrogels do not reflect the dynamic nature of living tissues, which are subject to continuous remodelling during processes such as development, ageing, disease and regeneration. Therefore, in order to study temporal aspects of stiffness regulation, researchers have developed and exploited novel hydrogel substrates with in situ tuneable stiffness. In particular, photoresponsive hydrogels with photoswitchable stiffness are emerging as exciting platforms to study MSC stiffness regulation. This chapter provides an introduction to the use of PA hydrogel substrates, the molecular mechanisms of mechanotransduction currently under investigation and the development of these emerging photoresponsive hydrogel platforms.


Assuntos
Hidrogéis/efeitos da radiação , Mecanotransdução Celular , Células-Tronco Mesenquimais/citologia , Técnicas de Cultura de Células , Diferenciação Celular , Matriz Extracelular , Humanos , Luz
19.
J Environ Manage ; 237: 617-628, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30831431

RESUMO

A field pilot test was conducted using an emulsified vegetable oil (EVO) and colloidal magnesium hydroxide [Mg(OH)2] formulation to enhance reductive dechlorination of dense non-aqueous phase liquid (DNAPL) trichloroethene (TCE) in an acidic (pH < 4), heterogeneous aquifer. The field test consisted of i) a single well injection test to evaluate Mg(OH)2 distribution and ii) installation of two EVO-Mg(OH)2 permeable reactive barriers (PRBs; PRB-1 & PRB-2) at varying distances downgradient of the DNAPL source area. Distribution of Mg(OH)2 was observed up to 2.3 m away from the injection point within a permeable coarse sand layer; however, Mg(OH)2 transport in the overlying clayey-silty sand was minimal. Downgradient of the PRBs, colloidal Mg(OH)2 increased the pH of the coarse sand to levels appropriate for biological reductive dechlorination (pH >∼5); however, some settling of Mg(OH)2 in the injection wells generated persistent high pH (∼9-10) within the PRBs. A redesigned suspension of colloidal Mg(OH)2 was tested and proved to be more effective at raising aquifer pH without an excessive rise in pH within the PRBs. At PRB-1 (located closest to the DNAPL source area), limited TCE biodegradation was observed due to the influx of high TCE concentrations (up to 400 mg/L) and inhibition of dechlorinating bacteria. At PRB-2 (located 25 m downgradient of the DNAPL source area), TCE concentrations were much lower (13-26 mg/L) and production of cis-1,2-dichloroethene (cDCE) and some vinyl chloride (VC) was observed. Subsequent bioaugmentation with a commercial dechlorinating culture at PRB-2 improved conversion of cDCE to VC and ethene at downgradient monitoring wells over the duration of the study. These results emphasize the importance of PRB location (relative to the DNAPL source), base selection for pH adjustment, source strength, and local heterogeneities for the design and long-term performance of ERD in acidic DNAPL-impacted aquifers.


Assuntos
Água Subterrânea , Tricloroetileno , Poluentes Químicos da Água , Biodegradação Ambiental , Halogenação
20.
World J Urol ; 36(5): 801-809, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29380128

RESUMO

PURPOSE: These studies were undertaken to determine if fexapotide triflutate 2.5 mg transrectal injectable (FT) has significant long-term (LT) safety and efficacy for the treatment of benign prostatic hyperplasia (BPH). METHODS: Two placebo controlled double-blind randomized parallel group trials with 995 BPH patients at 72 sites treated 3:2 FT:placebo, with open-label FT crossover (CO) re-injection in 2 trials n = 344 and long-term follow-up (LF) 2-6.75 years (mean 3.58 years, median 3.67 years; FT re-injection CO mean 4.27 years, median 4.42 years) were evaluated. 12 months post-treatment patients elected no further treatment, approved oral medications, FT, or interventional treatment. Primary endpoint variable was change in Symptom Score (IPSS) at 12 months and at LF. CO primary co-endpoints were 3-year incidence of (1) surgery for BPH in FT treated CO patients versus patients crossed over to oral BPH medications and (2) surgery or acute urinary retention in FT-treated CO placebo patients versus placebo patients crossed over to oral BPH medications. 28 CO secondary endpoints assessed surgical and symptomatic outcomes in FT reinjected patients versus conventional BPH medication CO and control subgroups at 2 and 3 years. RESULTS: FT injection had no significant safety differences from placebo. LF IPSS change from baseline was higher in FT treated patients compared to placebo (median FT group improvement - 5.2 versus placebo - 3.0, p < 0.0001). LF incidence of AUR (1.08% p = 0.0058) and prostate cancer (PCa) (1.1% p = 0.0116) were both reduced in FT treated patients. LF incidence of intervention for BPH was reduced in the FT group versus oral BPH medications (8.08% versus 27.85% at 3 years, p < 0.0001). LF incidence of intervention or AUR in placebo CO group with FT versus placebo CO group with oral medications was reduced (6.07% versus 33.3% at 3 years, p < 0.0001). 28/28 secondary efficacy endpoints were reached in LF CO re-injection studies. CONCLUSIONS: FT 2.5 mg is a safe and effective transrectal injectable for LT treatment of BPH. FT treated patients also had reduced need for BPH intervention, and reduced incidence of PCa and AUR.


Assuntos
Fluoracetatos , Peptídeos , Próstata , Hiperplasia Prostática , Prostatismo , Agentes Urológicos , Idoso , Método Duplo-Cego , Monitoramento de Medicamentos/métodos , Fluoracetatos/administração & dosagem , Fluoracetatos/efeitos adversos , Fluoracetatos/farmacocinética , Humanos , Injeções Intralesionais/métodos , Masculino , Pessoa de Meia-Idade , Peptídeos/administração & dosagem , Peptídeos/efeitos adversos , Peptídeos/farmacocinética , Próstata/efeitos dos fármacos , Próstata/patologia , Hiperplasia Prostática/complicações , Hiperplasia Prostática/tratamento farmacológico , Hiperplasia Prostática/patologia , Prostatismo/tratamento farmacológico , Prostatismo/etiologia , Tempo , Resultado do Tratamento , Agentes Urológicos/administração & dosagem , Agentes Urológicos/efeitos adversos , Agentes Urológicos/farmacocinética
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