Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Eur J Vasc Endovasc Surg ; 67(6): 923-932, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38447693

RESUMEN

OBJECTIVE: There is a need for improved outcomes in the endovascular treatment of patients suffering from chronic limb threatening ischaemia (CLTI), highly calcified lesions, and chronic total occlusions (CTOs). The helical centreline self expanding BioMimics 3D stent might be particularly useful in these high risk subsets, combining flexibility and fracture resistance with radial strength. Herein, the performance of the BioMimics 3D stent was assessed in these high risk subsets. METHODS: MIMICS-3D is a prospective, multicentre, European real world registry. This was a post hoc analysis, comparing patients with CLTI vs. intermittent claudication (IC), lesions with bilateral calcification vs. those without (peripheral arterial calcium scoring system [PACSS] 3,4 vs. PACSS 0 - 2), and CTO vs. no CTO. Propensity score matching was performed to reduce the impact of baseline variables. The 36 month endpoints were clinically driven target lesion revascularisation (CD-TLR), death, major target limb amputation, and stent patency. RESULTS: A total of 507 patients were enrolled. At 36 months, patients with CLTI had lower freedom from major amputation than patients with IC (92.6% vs. 100%, p < .001). In terms of primary patency, patients with CTO had lower patency rates than those without (63.9% vs. 77.8%, p = .003), but the difference reduced after propensity score matching (70.5% vs. 76.8%, p = .43). Primary patency was not impaired for patients with PACSS 3,4 or patients with CLTI. Freedom from CD-TLR was not significantly different among the groups and was 73.8% for CLTI vs. 78.9% for IC (p = .15), 77.6% for PACSS 3,4 vs. 78.7% for PACSS 0 - 2 (p = .55), and 75.6% for CTO vs. 81.0% for no CTO (p = .11). CONCLUSIONS: The outcome of the MIMICS-3D registry suggests that the BioMimics 3D stent is effective in the endovascular treatment of complex femoropopliteal lesions and in CLTI. Future randomised controlled trials should confirm its non-inferiority or superiority compared with existing alternatives.


Asunto(s)
Aleaciones , Sistema de Registros , Humanos , Masculino , Femenino , Anciano , Estudios Prospectivos , Persona de Mediana Edad , Amputación Quirúrgica , Resultado del Tratamiento , Isquemia Crónica que Amenaza las Extremidades/cirugía , Enfermedad Arterial Periférica/fisiopatología , Enfermedad Arterial Periférica/terapia , Enfermedad Arterial Periférica/diagnóstico por imagen , Diseño de Prótesis , Procedimientos Endovasculares/instrumentación , Procedimientos Endovasculares/efectos adversos , Grado de Desobstrucción Vascular , Recuperación del Miembro , Factores de Tiempo , Anciano de 80 o más Años , Stents , Europa (Continente) , Factores de Riesgo , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/terapia
2.
J Cardiovasc Dev Dis ; 10(3)2023 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-36975890

RESUMEN

BACKGROUND: Through its helical centreline geometry, the BioMimics 3D vascular stent system is designed for the mobile femoropopliteal region, aiming to improve long-term patency and the risk of stent fractures. METHODS: MIMICS 3D is a prospective, European, multi-centre, observational registry to evaluate the BioMimics 3D stent in a real-world population through 3 years. A propensity-matched comparison was performed to investigate the effect of the additional use of drug-coated balloons (DCB). RESULTS: The MIMICS 3D registry enrolled 507 patients (518 lesion, length 125.9 ± 91.0 mm). At 3 years, the overall survival was 85.2%, freedom from major amputation 98.5%, freedom from clinically driven target lesion revascularisation 78.0%, and primary patency 70.2%. The propensity-matched cohort included 195 patients in each cohort. At 3-year follow-up, there was no statistically significant difference in clinical outcomes, such as overall survival (87.9% in the DCB vs. 85.1% in the no DCB group), freedom from major amputation (99.4% vs. 97.2%), clinically driven TLR (76.4% vs. 80.3%), and primary patency (68.5% vs. 74.4%). CONCLUSION: The MIMICS 3D registry showed good 3-year outcomes of the BioMimics 3D stent in femoropopliteal lesions, demonstrating the safety and performance of this device under real-world conditions, whether used alone or in combination with a DCB.

3.
Eur J Heart Fail ; 25(5): 754-763, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36891760

RESUMEN

AIMS: The management of congestion is one of the key treatment targets in heart failure. Assessing congestion is, however, difficult. The purpose of this study was to investigate the safety and dynamic response of a novel, passive, inferior vena cava (IVC) sensor in a chronic ovine model. METHODS AND RESULTS: A total of 20 sheep divided into three groups were studied in acute and chronic in vivo settings. Group I and Group II included 14 sheep in total with 12 sheep receiving the sensor and two sheep receiving a control device (IVC filter). Group III included an additional six animals for studying responses to volume challenges via infusion of blood and saline solutions. Deployment was 100% successful with all devices implanted; performing as expected with no device-related complications and signals were received at all observations. At similar volume states no significant differences in IVC area normalized to absolute area range were measured (55 ± 17% on day 0 and 62 ± 12% on day 120, p = 0.51). Chronically, the sensors were completely integrated with a thin, reendothelialized neointima with no loss of sensitivity to infused volume. Normalized IVC area changed significantly from 25 ± 17% to 43 ± 11% (p = 0.007) with 300 ml infused. In contrast, right atrial pressure required 1200 ml of infused volume prior to a statistically significant change from 3.1 ± 2.6 mmHg to 7.5 ± 2.0 mmHg (p = 0.02). CONCLUSION: In conclusion, IVC area can be measured remotely in real-time using a safe, accurate, wireless, and chronic implantable sensor promising to detect congestion with higher sensitivity than filling pressures.


Asunto(s)
Insuficiencia Cardíaca , Vena Cava Inferior , Animales , Ovinos , Vena Cava Inferior/diagnóstico por imagen , Insuficiencia Cardíaca/terapia
4.
Biomedicines ; 11(2)2023 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-36831016

RESUMEN

Neutrophils act as critical mediators of innate immunity, which depends on their rapid responses to chemokines followed by their migration towards sites of infection during chemotaxis. Chemokine receptors expressed on the surface of neutrophils mediate chemotaxis by activating contractile machinery as the cells escape from capillary beds and then attack pathogens. Neutrophils also contribute to inflammatory responses, which support pathogen destruction but can lead to acute and chronic inflammatory disorders. CXCR2, a G-protein-coupled chemokine receptor expressed on both myeloid and epithelial cells, is well-characterized for its capacities to bind multiple chemokines, including interleukin-8 and growth-related oncogene alpha in humans or keratinocyte chemokine (KC) in mice. Here we show that a small molecule CXCR2 antagonist termed RIST4721 can effectively inhibit KC-stimulated chemotaxis by neutrophils derived from ex vivo-cultured mouse bone marrow in a potent and dose-dependent manner. Antagonistic properties of RIST4721 are thoroughly characterized, including the maximal, half-maximal and minimum concentrations required to inhibit chemotaxis. Importantly, RIST4721-treated neutrophils exhibit robust phagocytosis and reactive oxygen species production, confirming drug specificity to chemotaxis inhibition. Together our data indicate that RIST4721 acts to inhibit inflammation mediated and potentiated by neutrophils and therefore promises to facilitate treatment of a host of inflammatory conditions.

5.
Methods Mol Biol ; 2614: 47-70, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36587118

RESUMEN

The respiratory burst is a rapid cellular consumption of oxygen resulting in abundant production of reactive oxygen species (ROS), most often associated with primary mediators of innate immunity, neutrophils and macrophages. These myeloid cells convert ROS into potent antimicrobial oxidants that efficiently kill pathogens. The respiratory burst also can have destructive consequences, as ROS are well known to support chronic inflammation and aberrant autoimmune responses. Interestingly, ROS perform conflicting roles in the tumor microenvironment; ROS and derived cytotoxic products can destroy cancer cells but also suppress important tumor-fighting functions of T cells or natural killer cells, or yield mutagenized proteins that can promote tumorigenesis or support tumor cell growth. Moreover, high numbers of neutrophils or macrophages in tumors are associated with poor prognosis. Therefore, accurate and quantitative assays to assess the respiratory burst are an important tool for measuring ROS production by neutrophils or cells of the monocyte/macrophage system, each recently identified in the tumor microenvironment. Described are methods to derive mouse or human models of neutrophils or macrophages, which are then used in a detailed assay to quantitatively measure ROS produced by either cell type using luminescence-enhanced reagents and a multi-well platform along with different stimulants that cause rapid ROS production.


Asunto(s)
Neutrófilos , Estallido Respiratorio , Ratones , Humanos , Animales , Especies Reactivas de Oxígeno/metabolismo , Neutrófilos/metabolismo , Macrófagos/metabolismo , Inmunidad Innata
6.
Immunohorizons ; 6(1): 16-35, 2022 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-35039433

RESUMEN

Neutrophils mediate critical innate immune responses by migrating to sites of infection or inflammation, phagocytosing microorganisms, and releasing an arsenal of antimicrobial agents, including reactive oxygen species. These functions are shared by other innate immune cell types, but an interesting feature of neutrophils is their hallmark lobulated nuclei. Although why this bizarre nuclear shape forms is still being elucidated, studies of two intermediate filament proteins that associate with the nuclear envelope, lamin A and C, indicate that expression levels of these proteins govern nuclear maturation. These A-type lamins also modulate nuclear stiffness, the loss of which may be critical to the migration of not only neutrophils but also cancer cells that become prone to metastasis. We investigated whether increased expression of either lamin A or C affects neutrophil nuclear morphologic maturation, but more importantly we tested whether overexpression of either lamin also affects neutrophil functional responses, using two mouse myeloid progenitor models that can be induced toward functionally responsive neutrophil-like cells. Collectively, our results demonstrate that overexpression of either lamin A or C not only disrupts nuclear lobulation but also causes aberrant functional responses critical to innate immunity, including chemotaxis, phagocytosis, and reactive oxygen species production. Moreover, the lamin A-overexpressing cells exhibit decreased expression of a critical NADPH oxidase complex factor, gp91phox, and transcriptomic profiling demonstrated differential expression of a number of myeloid differentiation and functional pathway components. Taken together, these data demonstrate that A-type lamin expression levels modulate not only nuclear morphologic features but also gene expression changes as neutrophils mature.


Asunto(s)
Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Neutrófilos/metabolismo , Transcriptoma , Animales , Diferenciación Celular/genética , Línea Celular , Núcleo Celular/genética , Quimiotaxis/genética , Inmunidad Innata , Ratones , NADPH Oxidasa 2/metabolismo , Fagocitosis/genética
7.
Vasa ; 51(1): 5-12, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34878313

RESUMEN

Background: The MIMICS-3D study aimed to assess the safety and effectiveness of the BioMimics 3D Vascular Stent System for the treatment of symptomatic femoropopliteal artery disease in a real-world patient population. Patients and methods: Consecutive participants who were scheduled for implantation of the BioMimics 3D stent were enrolled in the prospective, observational, multicenter study. The primary effectiveness outcome was freedom from clinically driven target lesion revascularization at 12 months and the primary safety outcome was a composite of major adverse events comprising death, major target limb amputation, or clinically driven target lesion revascularization at 30 days. Outcomes through 24 months are reported. Results: A total of 507 patients (70±10 years, 65.5% male sex) were enrolled and treated with the study stent. 24.0% had critical limb-threatening ischemia, lesion length was 127±92 mm, and 56.8% of lesions were totally occluded. The Kaplan-Meier (KM) estimate of freedom from clinically driven target lesion revascularization at twelve-months was 90.6% (95% CI: 87.9%-93.3%) and the 30-day primary safety outcome occurred in 1.2% (95% CI: 0.5%-2.7%) of participants. At 24 months, clinical improvement was achieved in 86.6% and the KM estimate of freedom from clinically driven target lesion revascularization was 82.8% (95% CI: 79.4%-86.4%). The KM estimate of freedom from loss of primary patency according to PSVR >2.4 was 78.6% (95% CI: 74.7%-82.4%). Survival distribution functions regarding primary patency were lower with long lesions (>150 mm; log-rank p<0.001) but did not differ significantly between participants with or without critical limb-threatening ischemia (log-rank p=0.07). Conclusions: Endovascular treatment of atherosclerotic femoropopliteal lesions with the BioMimics 3D Vascular Stent System is efficacious and safe in a real-world setting.


Asunto(s)
Enfermedad Arterial Periférica , Arteria Poplítea , Femenino , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/cirugía , Humanos , Recuperación del Miembro , Masculino , Enfermedad Arterial Periférica/diagnóstico por imagen , Enfermedad Arterial Periférica/cirugía , Arteria Poplítea/diagnóstico por imagen , Arteria Poplítea/cirugía , Estudios Prospectivos , Diseño de Prótesis , Stents , Resultado del Tratamiento , Grado de Desobstrucción Vascular
8.
J Endovasc Ther ; 28(2): 236-245, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33331207

RESUMEN

PURPOSE: To report the safety and effectiveness outcomes through 2 years of the BioMimics 3D Vascular Stent System in the treatment of symptomatic patients with atherosclerotic femoropopliteal disease. MATERIALS AND METHODS: The tubular, nitinol BioMimics 3D stent, which was designed to impart a helical shape to the arterial segment, was implanted in 271 patients (mean age 68.4±9.5 years; 180 men) with de novo femoropopliteal lesions enrolled at 43 investigational sites [31 US (n=162), 6 German (n=78), and 6 Japanese (n=31)] in the prospective, single-arm MIMICS-2 investigational device exemption trial (ClinicalTrials.gov identifier NCT02400905) between June 2015 and October 2016. Mean lesion length was 81.2±38.4 mm, 30.0% of patients had total occlusions, and 45.9% had moderate to severe calcification. Primary safety and effectiveness endpoints were compared at 1 year with prespecified objective performance goals (OPGs) set by the VIVA Physicians organization. Outcomes through 2 years are reported. RESULTS: The primary effectiveness endpoint of 12-month primary stent patency was met by 182 of 249 patients (73.1%, 95% CI 67.3% to 78.2%), exceeding the OPG of 66%. The primary safety endpoint of 30-day freedom from major adverse events (MAEs) was met in 268 of 269 patients (99.6%, 95% CI 97.7% to 100%), exceeding the OPG of 88%. Kaplan-Meier estimates of freedom from loss of primary patency were 83.1% at 12 months and 70.2% at 24 months, freedom from MAEs estimates were 86.9% at 12 months and 79.2% at 24 months, and freedom from clinically-driven target lesion revascularization estimates were 88.0% at 12 months and 83.0% at 24 months. At 24 months, 88.2% of patients showed improvement of ≥1 Rutherford category; the ankle-brachial index was >0.9 for 64.4% vs 11.3% at baseline. There were no cases of stent fracture. CONCLUSION: Through 24 months, the BioMimics 3D Vascular Stent System provided safe and effective treatment for femoropopliteal lesions in patients with symptomatic peripheral artery disease.


Asunto(s)
Procedimientos Endovasculares , Enfermedad Arterial Periférica , Anciano , Procedimientos Endovasculares/efectos adversos , Arteria Femoral/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/diagnóstico por imagen , Enfermedad Arterial Periférica/terapia , Arteria Poplítea/diagnóstico por imagen , Estudios Prospectivos , Diseño de Prótesis , Stents , Resultado del Tratamiento , Grado de Desobstrucción Vascular
9.
Methods Mol Biol ; 2087: 93-106, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31728985

RESUMEN

Two critical functional responses of neutrophils are chemotaxis, a response driven by concentration gradients of chemokines released by infected or inflamed tissues, and production of reactive oxygen species (ROS), molecules essential to their capacity to kill pathogens. Assays to accurately test each response have been important to assess efficacies of pharmaceuticals predicted to block recruitment of neutrophils or attenuate their ROS production. Identified antagonists to neutrophil functions may help to reduce tissue damage following inflammation. Described are detailed assays to test these functions, along with steps to generate neutrophils from ex vivo-cultured murine bone marrow that produce robust responses in either assay. The first function protocol details a quantitative assay for chemotaxis that involves culture plates with dual chamber wells that separate cells from a chemokine with small pore-sized membranes. Quantitative measurements of cell numbers in the chemokine-containing chamber are performed with either fluorescence or luminescence detection reagents, which provide signals directly proportional to the numbers of migrated cells. Multiwell plates are used for rapidly testing a variety of conditions and/or chemoattractants. Described in the second function protocol is an assay to measure ROS produced by stimulated neutrophils, again using a multiwell platform for rapid, quantitative measurements of several conditions simultaneously.


Asunto(s)
Quimiotaxis de Leucocito/inmunología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Estallido Respiratorio/inmunología , Animales , Biomarcadores , Células Cultivadas , Quimiocinas/metabolismo , Quimiotaxis/inmunología , Quimiotaxis de Leucocito/genética , Queratinocitos/metabolismo , Ratones , Activación Neutrófila/inmunología , Especies Reactivas de Oxígeno/metabolismo
10.
Colloids Surf B Biointerfaces ; 182: 110348, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31301579

RESUMEN

Bioimaging probes incorporating quantum dots (QDs) are important for identifying organelles and monitoring their movement/location in living cells. Organelle specificity can be accomplished by functionalizing probe surfaces with chemical groups that can react with antibodies capable of targeting specific organelle-protein epitopes. Here, such a bioprobe is generated by encapsulating ZnS-capped CdSe QDs within polystyrene (PS) nanocolloids via Pickering miniemulsion using laponite nanoclay platelets as solid-stabilizers. The surfaces of these platelets are modified with aminopropyltriethoxysilane (APTES), and biotinylated by reacting sulfo-NHS-Biotin via the APTES amine group. Surface functionalization and bioconjugation are confirmed using X-ray photoelectron spectroscopy. The number of sites available on Streptavidin for Biotin binding is determined using a competitive HABA assay to optimize the bioconjugation protocol. The PS-encapsulated QDs (PS-QDs) nanocolloids are 50-200 nm in diameter and colloidally stable, as evidenced by transmission electron microscopy and ζ-potential measurements, respectively. Spherical particle shape is confirmed by scanning electron microscopy. Transmission electron microscopy also showed the nanoclay platelets on the surface of QD-encapsulating latex particles. The PS-QDs particles are easily dispersed in water and exhibit long-term photostability over various conditions. Cell viability of >95% is observed for NIH-3T3 cells after 72-h exposure to PS-QDs nanocolloids, with no cytotoxicity to living cells, even at 0.1 mg mL-1. NIH-3T3 cellular uptake and internalization are confirmed by confocal microscopy, with PS-QDs fluorescence within cells remaining high even after 24-h exposure, demonstrating the applicability of PS-QDs nanocolloids as long-lived fluorescent bioprobes for in vitro intracellular imaging.


Asunto(s)
Colorantes Fluorescentes/química , Imagen Molecular/métodos , Imagen Óptica/métodos , Puntos Cuánticos/química , Compuestos de Selenio/química , Silicatos/química , Compuestos de Zinc/química , Animales , Biotina/química , Biotinilación , Supervivencia Celular/efectos de los fármacos , Coloides , Composición de Medicamentos/métodos , Humanos , Ratones , Células 3T3 NIH , Poliestirenos/química , Propilaminas/química , Puntos Cuánticos/ultraestructura , Silanos/química , Estreptavidina/química
11.
Int J Vasc Med ; 2018: 6981505, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30112213

RESUMEN

The Sentry inferior vena cava (IVC) filter is designed to provide temporary protection from pulmonary embolism (PE) and then bioconvert to become incorporated in the vessel wall, leaving a patent IVC lumen. Objective. To evaluate the performance and stages of incorporation of the Sentry IVC filter in an ovine model. Methods. Twenty-four bioconvertible devices and 1 control retrievable filter were implanted in the infrarenal IVC of 25 sheep, with extensive daily monitoring and intensive imaging. Vessels and devices were analyzed at early (≤98 days, n = 10) and late (180 ± 30 days, n = 14 study devices, 1 control) termination and necropsy time-points. Results. Deployment success was 100% with all devices confirmed in filtering configuration, there were no filter-related complications, and bioconversion was 100% at termination with vessels widely patent. By 98 days for all early-incorporation analysis animals, the stabilizing cylindrical part of the Sentry frame was incorporated in the vessel wall, and the filter arms were retracted. By 180 days for all late-incorporation analysis animals, the filter arms as well as frames were stably incorporated. Conclusions. Through 180 days, there were no filter-related complications, and the study devices were all bioconverted and stably incorporated, leaving all IVCs patent.

12.
Part Fibre Toxicol ; 15(1): 29, 2018 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-29970114

RESUMEN

BACKGROUND: Engineered nanomaterials (ENM) are used extensively in food products to fulfill a number of roles, including enhancement of color and texture, for nutritional fortification, enhanced bioavailability, improved barrier properties of packaging, and enhanced food preservation. Safety assessment of ingested engineered nanomaterials (iENM) has gained interest in the nanotoxicology community in recent years. A variety of test systems and approaches have been used for such evaluations, with in vitro monoculture cell models being the most common test systems, owing to their low cost and ease-of-use. The goal of this review is to systematically assess the current state of science in toxicological testing of iENM, with particular emphasis on model test systems, their physiological relevance, methodological strengths and challenges, realistic doses (ranges and rates), and then to identify future research needs and priorities based on these assessments. METHODS: Extensive searches were conducted in Google Scholar, PubMed and Web of Science to identify peer-reviewed literature on safety assessment of iENM over the last decade, using keywords such as "nanoparticle", "food", "toxicity", and combinations thereof. Relevant literature was assessed based on a set of criteria that included the relevance of nanomaterials tested; ENM physicochemical and morphological characterization; dispersion and dosimetry in an in vitro system; dose ranges employed, the rationale and dose realism; dissolution behavior of iENM; endpoints tested, and the main findings of each study. Observations were entered into an excel spreadsheet, transferred to Origin, from where summary statistics were calculated to assess patterns, trends, and research gaps. RESULTS: A total of 650 peer-reviewed publications were identified from 2007 to 2017, of which 39 were deemed relevant. Only 21% of the studies used food grade nanomaterials for testing; adequate physicochemical and morphological characterization was performed in 53% of the studies. All in vitro studies lacked dosimetry and 60% of them did not provide a rationale for the doses tested and their relevance. Only 12% of the studies attempted to consider the dissolution kinetics of nanomaterials. Moreover, only 1 study attempted to prepare and characterize standardized nanoparticle dispersions. CONCLUSION: We identified 5 clusters of factors deemed relevant to nanotoxicology of food-grade iENM: (i) using food-grade nanomaterials for toxicity testing; (ii) performing comprehensive physicochemical and morphological characterization of iENM in the dry state, (iii) establishing standard NP dispersions and their characterization in cell culture medium, (iv) employing realistic dose ranges and standardized in vitro dosimetry models, and (v) investigating dissolution kinetics and biotransformation behavior of iENM in synthetic media representative of the gastrointestinal (GI) tract fluids, including analyses in a fasted state and in the presence of a food matrix. We discussed how these factors, when not considered thoughtfully, could influence the results and generalizability of in vitro and in vivo testing. We conclude with a set of recommendations to guide future iENM toxicity studies and to develop/adopt more relevant in vitro model systems representative of in vivo animal and human iENM exposure scenarios.


Asunto(s)
Aditivos Alimentarios/toxicidad , Nanoestructuras/toxicidad , Pruebas de Toxicidad/métodos , Animales , Disponibilidad Biológica , Aditivos Alimentarios/química , Aditivos Alimentarios/farmacocinética , Inocuidad de los Alimentos , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/metabolismo , Humanos , Nanoestructuras/química , Tamaño de la Partícula , Propiedades de Superficie
13.
ACS Nano ; 12(8): 8115-8128, 2018 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-30021067

RESUMEN

Engineered nanomaterials (ENM) are extensively used as food additives in numerous food products, and at present, little is known about the fate of ingested ENM (iENM) in the gastrointestinal (GI) environment. Here, we investigated the dissolution behavior, biodurability, and persistence of four major iENM (TiO2, SiO2, ZnO, and two Fe2O3) in individual simulated GI fluids (saliva, gastric, and intestinal) and a physiologically relevant digestion cascade (saliva → gastric → intestinal) in the fasted state over physiologically relevant time frames. TiO2 was found to be the most biodurable and persistent iENM in simulated GI fluids with a maximum of only 0.42% (4 µM Ti4+ ion release) dissolution in cascade digestion, followed by iron oxides, of which the rod-like morphology was more biodurable and persistent (0.7% maximum dissolution, 8.7 µM Fe3+) than the acicular one (2.27% maximum dissolution, 16.7 µM Fe3+) in the cascade digestion, respectively. SiO2 and ZnO were less biodurable than Fe2O3, with 65.5% (416 µM Si4+) and 100% (1718.1 µM Zn2+) dissolution in the gastric phase, respectively. In the intestinal phase, however, Si4+ ions reprecipitated, possibly due to sudden pH changes, while ZnO remained completely dissolved. These observations were also confirmed using high-resolution particle size and concentration, and electron microscopy, time-dependent analysis. In terms of decreasing biodurability and persistence in the simulated GI environment, the tested nanomaterials can be ranked as follows: TiO2 ≫ rod-like Fe2O3 > acicular Fe2O3 ≫ SiO2 > ZnO, which is in agreement with limited animal biokinetics data. Chronic uptake of these iENM as particles or ions by the GI tract, especially in the presence of a food matrix and authentic digestive media, and associated implications for human health warrants further investigation.


Asunto(s)
Jugo Gástrico/química , Tracto Gastrointestinal/química , Nanoestructuras/química , Compuestos Férricos/química , Compuestos Férricos/metabolismo , Jugo Gástrico/metabolismo , Tracto Gastrointestinal/metabolismo , Humanos , Dióxido de Silicio/química , Dióxido de Silicio/metabolismo , Titanio/química , Titanio/metabolismo , Óxido de Zinc/química , Óxido de Zinc/metabolismo
14.
Blood ; 129(23): 3046-3047, 2017 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-28596437
15.
Methods ; 112: 124-146, 2017 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-27663441

RESUMEN

Neutrophils and macrophages differentiate from common myeloid progenitors in the bone marrow, where they undergo nuclear morphologic changes during maturation. During this process, both cell types acquire critical innate immune functions that include phagocytosis of pathogens, and for neutrophils the release of nuclear material called nuclear extracellular traps (NETs). Primary cells used to study these functions are typically purified from mature mouse tissues, but bone marrow-derived ex vivo cultures provide more abundant numbers of progenitors and functionally mature cells. Routine analyses of these cells use conventional microscopy and flow cytometry, which present limitations; microscopy is laborious and subjective, whereas flow cytometry lacks spatial resolution. Here we describe methods to generate enriched populations of neutrophils or macrophages from cryopreserved mouse bone marrow cultured ex vivo, and to use imaging flow cytometry that combines the resolution of microscopy with flow cytometry to analyze cells for morphologic features, phagocytosis, and NETosis.


Asunto(s)
Células de la Médula Ósea/inmunología , Trampas Extracelulares/diagnóstico por imagen , Citometría de Flujo/métodos , Citometría de Imagen/métodos , Macrófagos/inmunología , Neutrófilos/inmunología , Animales , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/ultraestructura , Calcimicina/farmacología , Diferenciación Celular/efectos de los fármacos , Criopreservación , Trampas Extracelulares/inmunología , Citometría de Flujo/instrumentación , Colorantes Fluorescentes/química , Citometría de Imagen/instrumentación , Inmunidad Innata , Macrófagos/efectos de los fármacos , Macrófagos/ultraestructura , Masculino , Ratones , Ratones Endogámicos C57BL , Neutrófilos/efectos de los fármacos , Neutrófilos/ultraestructura , Fagocitosis , Cultivo Primario de Células , Coloración y Etiquetado/métodos , Acetato de Tetradecanoilforbol/farmacología
16.
Carbohydr Polym ; 155: 432-439, 2017 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-27702532

RESUMEN

Microwave-assisted synthesis of a new class of polymeric surfactants based on polygalacturonic acid (PGA) is presented. PGA is water-insoluble and not surface-active under normal conditions. Single-step hydrophilic modification of PGA with taurine (2-aminoethane sulfonic acid) renders it surface-active. The modification can be carried out either using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDCl) as a coupling agent or using microwave irradiation without a catalyst. Microwave irradiation significantly shortens reaction times and eliminates the need for a coupling agent. In all cases, functionalization was confirmed using 1H NMR, FTIR spectroscopy and elemental analysis. PGA-SO3 exhibits surface-active properties comparable to commercial surfactants, Triton X-100 and sodium lauryl sulfate. Detailed cytotoxicity evaluation performed using human dermal fibroblast (HDF) and human leukemic (HL-60) cell lines indicate that PGA-SO3 is not toxic even at 20 fold higher concentrations. These polymeric surfactants synthesized from PGA with no demonstrable cytotoxicity have the potential for serving as 'greener' alternatives to common petrochemical-based surfactants.

18.
J Immunol ; 197(3): 910-22, 2016 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-27342846

RESUMEN

Nuclear segmentation is a hallmark feature of mammalian neutrophil differentiation, but the mechanisms that control this process are poorly understood. Gene expression in maturing neutrophils requires combinatorial actions of lineage-restricted and more widely expressed transcriptional regulators. Examples include interactions of the widely expressed ETS transcription factor, GA-binding protein (GABP), with the relatively lineage-restricted E-twenty-six (ETS) factor, PU.1, and with CCAAT enhancer binding proteins, C/EBPα and C/EBPε. Whether such cooperative interactions between these transcription factors also regulate the expression of genes encoding proteins that control nuclear segmentation is unclear. We investigated the roles of ETS and C/EBP family transcription factors in regulating the gene encoding the lamin B receptor (LBR), an inner nuclear membrane protein whose expression is required for neutrophil nuclear segmentation. Although C/EBPε was previously shown to bind the Lbr promoter, surprisingly, we found that neutrophils derived from Cebpe null mice exhibited normal Lbr gene and protein expression. Instead, GABP provided transcriptional activation through the Lbr promoter in the absence of C/EBPε, and activities supported by GABP were greatly enhanced by either C/EBPε or PU.1. Both GABP and PU.1 bound Ets sites in the Lbr promoter in vitro, and in vivo within both early myeloid progenitors and differentiating neutrophils. These findings demonstrate that GABP, PU.1, and C/EBPε cooperate to control transcription of the gene encoding LBR, a nuclear envelope protein that is required for the characteristic lobulated morphology of mature neutrophils.


Asunto(s)
Diferenciación Celular/fisiología , Regulación de la Expresión Génica/fisiología , Granulocitos/citología , Receptores Citoplasmáticos y Nucleares/biosíntesis , Animales , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Núcleo Celular , Inmunoprecipitación de Cromatina , Ensayo de Cambio de Movilidad Electroforética , Factor de Transcripción de la Proteína de Unión a GA/metabolismo , Células HEK293 , Células Madre Hematopoyéticas/citología , Humanos , Immunoblotting , Ratones , Ratones Endogámicos C57BL , Mutagénesis Sitio-Dirigida , Proteínas Proto-Oncogénicas/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/fisiología , Transactivadores/metabolismo , Receptor de Lamina B
19.
Artículo en Inglés | MEDLINE | ID: mdl-27208046

RESUMEN

BACKGROUND: Reintervention in the femoropopliteal artery is frequent and a major driver of cost-effectiveness. High wall shear generated by swirling blood flow is associated with reduced occurrence of atherosclerosis and restenosis. This trial investigated the clinical and hemodynamic outcomes of the BioMimics 3D self-expanding tubular nitinol stent with helical centerline geometry compared with a straight stent in the femoropopliteal artery. METHODS AND RESULTS: In a prospective, multicenter, randomized controlled trial, 76 patients with symptomatic peripheral arterial disease were randomized 2:1 to receive a helical or a straight stent. An independent core laboratory adjudicated angiographic and ultrasound parameters. The primary safety end point was freedom from a composite of all death, target limb amputation, and target lesion revascularization at 30 days. The primary effectiveness end point was freedom from clinically driven target lesion revascularization at 6 months. Patency was a secondary end point. Subjects were followed up for 2 years from intervention. The primary safety (1-sided P<0.01) and efficacy (1-sided P<0.001) end points for the helical stent were met. The proportion of patients treated with the helical stent who maintained patency at 12 and 24 months was 80% and 72%, respectively, compared with 71% and 55% for the control group. The difference was significant through 24 months (P=0.05). Freedom from clinically driven target lesion revascularization for the helical compared with straight stent was 91% versus 92% at 12 months and 91% versus 76% at 24 months. CONCLUSIONS: Both groups had similar safety outcomes and clinically driven target lesion revascularization to 2 years. However, after placement of a BioMimics 3D helical stent, there was improved patency to 2 years. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02163863.


Asunto(s)
Procedimientos Endovasculares/instrumentación , Arteria Femoral , Enfermedad Arterial Periférica/terapia , Arteria Poplítea , Stents , Grado de Desobstrucción Vascular , Anciano , Aleaciones , Amputación Quirúrgica , Supervivencia sin Enfermedad , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/mortalidad , Femenino , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/fisiopatología , Alemania , Oclusión de Injerto Vascular/etiología , Oclusión de Injerto Vascular/fisiopatología , Humanos , Estimación de Kaplan-Meier , Recuperación del Miembro , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/diagnóstico por imagen , Enfermedad Arterial Periférica/mortalidad , Enfermedad Arterial Periférica/fisiopatología , Arteria Poplítea/diagnóstico por imagen , Arteria Poplítea/fisiopatología , Estudios Prospectivos , Diseño de Prótesis , Recurrencia , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
20.
J Vasc Interv Radiol ; 26(5): 642-50.e1, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25770373

RESUMEN

PURPOSE: To determine whether equivalent-quality images can be obtained from digital subtraction angiography (DSA) of the iliac artery after implementation of a novel imaging technology that reduces patient and scatter x-ray dose. MATERIALS AND METHODS: Imaging using two randomly ordered DSA runs was performed in 51 adults scheduled for iliac artery angiography or intervention or both. One DSA run used standard acquisition chain and image processing algorithms (referred to as " reference DSA"), and the other DSA run used dose-reduction and real-time advanced image noise reduction technology (referred to as "study DSA"). The quality of each pair of runs, consecutively performed without changes in working projection or injection parameters, was independently rated by five radiologists blinded to the imaging technology used. Patient radiation dose was evaluated using air kerma and dose area product, and scatter dose was evaluated using three dosimeters (DoseAware, Philips Healthcare, Best, The Netherlands), located at fixed positions. RESULTS: Comparable image pairs were available in 48 patients. There were 44 patients undergoing treatment involving the common (n = 33) or external (n = 29) iliac arteries. Study DSA images were rated as equal to or better than reference DSA images for 96% of comparisons, with an average overall agreement among raters of 0.93 (95% confidence interval, 0.65-0.96). Mean patient radiation dose (n = 48) and scatter dose rate for the three dosimeters (n = 50) was 83% ± 5 and 69% ± 10 lower, respectively, using the study technology (P < .001). CONCLUSIONS: Iliac artery DSA performed using a dose-reduction and real-time advanced image noise reduction technology results in image quality that is noninferior to conventional DSA but with significantly lower patient and scatter radiation exposure (P < .001).


Asunto(s)
Angiografía de Substracción Digital/métodos , Arteria Ilíaca/diagnóstico por imagen , Dispersión de Radiación , Anciano , Femenino , Humanos , Masculino , Dosis de Radiación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...