Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
J Vasc Surg ; 78(5): 1313-1321, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37524153

RESUMEN

Registry Assessment of Peripheral Interventional Devices (RAPID) initiated the Pathways Program to provide a transparent, collaborative forum in which to pursue insights into multiple unresolved questions on benefit-risk of paclitaxel-coated devices, including understanding the basis of the mortality signal, without a demonstrable potential biological mechanism, and whether the late mortality signal could be artifact intrinsic to multiple independent prospective randomized data sources that did not prespecify death as a long-term end point. In response to the directive, the LEAN-Case Report Form working group focused on enhancements to the RAPID Phase I Minimum Core Data set through the addition of key clinical modifiers that would be more strongly linked to longer-term mortality outcomes after peripheral arterial disease intervention in the drug-eluting device era, with the goal to have future mortality signals more accurately examined.

2.
Cardiovasc Revasc Med ; 52: 67-74, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36870799

RESUMEN

As medical device development becomes increasingly global, the opportunities and potential advantages offered by international clinical trial and regulatory approval strategies are also growing. In particular, medical device clinical trials involving sites in both the United States and Japan and intended to support marketing in both countries may warrant particular consideration, given the similarities in their regulatory systems, patients and clinical practice patterns, and market sizes. Since 2003, the US-Japan Harmonization By Doing (HBD) initiative has been focused on identifying and addressing clinical and regulatory barriers to medical devices access in both countries via collaboration between governmental, academic, and industry stakeholders. Through the efforts of HBD participants, US-Japanese clinical trials have been conducted and the resulting data have supported regulatory approval for marketing in both countries. Based on these experiences, this paper outlines some of the key factors to consider when developing a global clinical trial involving US and Japanese participation. These considerations include the mechanisms for consultation with regulatory authorities on clinical trial strategies, the regulatory framework for clinical trial notification and approval, recruitment and conduct of clinical sites, and lessons learned from specific US-Japanese clinical trial experiences. The goal of this paper is to promote global access to promising medical technologies by assisting potential clinical trial sponsors in understanding when an international strategy may be appropriate and successful.


Asunto(s)
Aprobación de Recursos , Humanos , Estados Unidos , Japón
3.
Eur J Vasc Endovasc Surg ; 65(1): 131-140, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36007713

RESUMEN

OBJECTIVE: This observational cohort study examined outcomes after peripheral vascular intervention (PVI) with paclitaxel coated devices (PCD) and non-PCD, and evaluated heterogeneity of treatment effect in populations of interest. METHODS: The study included patients undergoing percutaneous transluminal angioplasty and or stent placement between 1 October 2015 and 31 December 2018 in the Vascular Quality Initiative Registry linked to Medicare claims. It determined differences in patient mortality and ipsilateral major amputation after PVI with PCD and non-PCD using Kaplan-Meier analyses and Cox regressions with inverse probability weighting in three cohorts: (A) patients treated for femoropopliteal or infrapopliteal occlusive disease with or without any other concurrent treatment (n = 11 452); (B) those treated for isolated superficial femoral or popliteal artery disease (n = 5 519); and (C) patients with inclusion criteria designed to approximate RCT populations (n = 2 278). RESULTS: The mean age of patients was 72.3 (SD = 10.9) years, and 40.6% were female. In cohort A, patients receiving PCD had a lower mortality rate (HR 0.88, 95% CI 0.79 - 0.98) than those receiving non-PCD. There was no significant difference in mortality between groups in cohort B (HR 0.91, 95% CI 0.80 - 1.04) and cohort C (HR 1.10, 95% CI 0.84 - 1.43). Patients receiving PCD did not have a significantly elevated risk of major amputation compared with those receiving non-PCD (cohort A: HR 0.84, 95% CI 0.70 - 1.00; cohort B: HR 0.84, 95% CI 0.67 - 1.06; and cohort C: HR 1.05, 95% CI 0.51 - 2.14). CONCLUSION: No increased patient mortality or major amputation was found at three years after PVI with PCD vs. non-PCD in this large, linked registry claims study, after accounting for heterogeneity of treatment effect by population. The analysis and results from three cohorts intended to mirror the cohorts of previous studies provide robust and niche real world evidence on PCD safety and help to understand and reconcile previously discrepant findings.

4.
Cardiovasc Revasc Med ; 45: 67-73, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35953406

RESUMEN

INTRODUCTION: The COVID-19 pandemic had an unprecedented impact on cardiovascular clinical research. The decision-making and state of study operations in cardiovascular trials 1-year after interruption has not been previously described. METHODS: In the spring of 2020, we created a pandemic impact task force to develop a landscape of use case scenarios from 17 device trials of peripheral artery disease (PAD) and coronary artery disease (CAD) interventions. In conjunction with publicly available (clinictrials.gov) study inclusion criteria, primary endpoints and study design, information was shared for this use-case landscape by trial leadership and data owners. RESULTS: A total of 17 actively enrolling trials (9 CAD and 8 PAD) volunteered to populate the use case landscape. All 17 were multicenter studies (12 in North America and 5 international). Fifteen studies were industry-sponsored, of which 13 were FDA approved IDEs, one was PCORI-sponsored and two were sponsored by the NIH. Enrollment targets ranged from 150 to 9000 pts. At the time of interruption, 5 trials were <20 % enrolled, 9 trials were 50-80 % enrolled and 3 trials were >80 % enrolled. At 1 year, the majority of studies were continuing to enroll in the context of more sporadic but ongoing pandemic activity. CONCLUSIONS: At 1 year from the first surge interruptions, most trials had resumed enrollment. Trials most heavily interrupted were trials early in enrollment and those trials not able to pivot to virtual patient and site visits. Further work is needed to determine the overall impact on vascular intervention trials disrupted during the COVID-19 pandemic.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Pandemias , Proyectos de Investigación
5.
J Cardiovasc Transl Res ; 15(5): 927-943, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35288821

RESUMEN

Successful translation of new and innovative medical products from concept to clinical use is a complex endeavor that requires understanding and overcoming a variety of challenges. In particular, regulatory pathways and processes are often unfamiliar to academic researchers and start-ups, and even larger companies. Growing evidence suggests that the successful translation of ideas to products requires collaboration and cooperation between clinicians, researchers, industry, and regulators. A multi-stakeholder group developed this review to enhance regulatory knowledge and thereby improve translational success for medical devices. Communication between and among stakeholders is identified as a critical factor. Current regulatory programs and processes to facilitate communication and translation of innovative devices are described and discussed. Case studies are used to highlight the importance of flexibility when considering evidence requirements. We provide a review of emerging strategies, opportunities, and best practices to increase the regulatory knowledge base and facilitate medical device translation by all stakeholders. Clinicians, regulators, industry, and researchers require regulatory knowledge and collaboration for successful translation of innovative medical devices.


Asunto(s)
Comunicación
6.
Cardiovasc Revasc Med ; 37: 118-119, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34483075

RESUMEN

Regulatory approval processes for medical devices in Japan and the United States of America (US) often require similar clinical trials to establish safety and effectiveness. The Harmonization by Doing (HBD) program provides a collaborative environment for communication between regulators, academics and industry, facilitating the design and conduct of US/Japanese clinical trials supporting approval in both countries.


Asunto(s)
Aterectomía Coronaria , Enfermedad de la Arteria Coronaria , Intervención Coronaria Percutánea , Calcificación Vascular , Aterectomía , Aterectomía Coronaria/efectos adversos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/cirugía , Humanos , Japón , Intervención Coronaria Percutánea/efectos adversos , Resultado del Tratamiento , Estados Unidos , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/terapia
7.
JACC Cardiovasc Interv ; 14(23): 2598-2609, 2021 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-34887051

RESUMEN

OBJECTIVES: This study sought to determine the safety and efficacy of paclitaxel (PTX) devices in the treatment of peripheral artery disease involving the femoropopliteal artery. BACKGROUND: A meta-analysis of PTX devices for the treatment of femoropopliteal artery disease reported a mortality signal. METHODS: This was a multicenter cohort study using an integrated clinical data surveillance system to conduct a prospective, propensity score-matched survival analysis of 2,456 patients in the Society for Vascular Surgery Vascular Quality Initiative from January 2017 to May 2020. The study compared PTX drug-coated balloon angioplasty versus percutaneous transluminal balloon angioplasty, PTX drug-eluting stents versus bare-metal stents, and any PTX device versus any non-PTX device. The primary outcome was 2-year survival. Secondary endpoints were successful ambulation and interventional success. RESULTS: Treatment with any PTX device versus any non-PTX device was associated with increased 2-year survival (89.5% vs 86.7%; HR: 0.79; 95% CI: 0.72-0.87; P = 0.004), improved interventional success (81.6% vs 77.6%; HR: 0.82; 95% CI: 0.74-0.91; P < 0.001), and higher rates of independent ambulation at 1 year (86.0% vs 83.4%; HR: 0.85; 95% CI: 0.79-0.91; P = 0.008). Treatment with PTX drug-coated balloon angioplasty was associated with improved survival at 2 years (88.9% vs 85.7%; HR: 0.77; 95% CI: 0.70-0.86; P = 0.005), while PTX drug-eluting stent therapy was associated with similar survival compared with bare-metal stent therapy (91.3% vs 89.6%; HR: 0.84; 95% CI: 0.70-1.01; P = 0.36). CONCLUSIONS: In this prospective, active surveillance of a national clinical registry, PTX-containing devices were associated with increased survival at 2 years and improved clinical outcomes at 1 year. (VQI DELTA Paclitaxel Device Safety Analysis [VQI-PTX]; NCT04110288).


Asunto(s)
Angioplastia de Balón , Fármacos Cardiovasculares , Stents Liberadores de Fármacos , Enfermedad Arterial Periférica , Estudios de Cohortes , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/cirugía , Humanos , Estudios Multicéntricos como Asunto , Paclitaxel , Enfermedad Arterial Periférica/tratamiento farmacológico , Enfermedad Arterial Periférica/terapia , Arteria Poplítea/diagnóstico por imagen , Arteria Poplítea/cirugía , Estudios Prospectivos , Resultado del Tratamiento , Grado de Desobstrucción Vascular
9.
J Vasc Surg ; 73(5): 1702-1714.e11, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33080324

RESUMEN

BACKGROUND: The Superficial Femoral Artery-Popliteal EvidencE Development Study Group developed contemporary objective performance goals (OPGs) for peripheral vascular interventions (PVI) for superficial femoral artery (SFA)-popliteal artery disease using the Registry Assessment of Peripheral Interventional Devices. METHODS: The Society for Vascular Surgery Vascular Quality Initiative PVI registry from January 2010 to October 2016 was used to develop OPGs based on SFA-popliteal procedures (n = 21,377) for intermittent claudication and critical limb ischemia (CLI). OPGs included 1-year rates for target lesion revascularization (TLR), major amputation, and 1 and 4-year survival rates. OPGs were calculated for the SFA and popliteal arteries and stratified by four treatments: angioplasty alone (percutaneous transluminal angioplasty [PTA]), self-expanding stenting, atherectomy, and any treatment type. Outcomes were illustrated by unadjusted Kaplan-Meier analyses. RESULTS: Cohorts included PTA (n = 7505), stenting (n = 9217), atherectomy (n = 2510) and any treatment (n = 21,377). The mean age was 69 years, 58% were male, 79% were White, and 52% had CLI. The freedom from TLR OPGs at 1 year in the SFA were 80.3% (PTA), 83.2% (stenting), 83.9% (atherectomy), and 81.9% (any treatments). The freedom from TLR OPGs at 1 year in the popliteal were 81.3% (PTA), 81.3% (stenting), 80.2% (atherectomy), and 81.1% (any treatments). The freedom from major amputation OPGs at 1 year after SFA PVI were 93.4% (PTA), 95.7% (stenting), 95.1% (atherectomy), and 94.8% (any treatments). The freedom from major amputation OPG at 1 year after popliteal PVI were 90.5% (PTA), 93.7% (stenting), 91.8% (atherectomy), and 91.8%, (any treatments). The 4-year survival OPGs after SFA PVI were 76% (PTA), 80% (stenting), 82% (atherectomy), and 79% (any treatments), and for the popliteal artery were 72% (PTA), 77% (stenting), 82% (atherectomy), and 75% (any treatment). On a multivariable analysis, which included patient-level, leg-level, and lesion-level covariates, CLI was the single independent factor associated with increased TLR, amputation, and mortality. CONCLUSIONS: The Superficial Femoral Artery-Popliteal EvidencE Development OPGs define a new, contemporary benchmark for SFA-popliteal interventions using a large subset of real-world evidence to inform more efficient peripheral device clinical trial designs to support regulatory and clinical decision-making. It is appropriate to discuss proposals intended for regulatory approval with the US Food and Drug Administration to refine the OPG to match the specific trial population. The OPGs may be updated using coordinated registry networks to assess long-term real-world device performance.


Asunto(s)
Benchmarking , Procedimientos Endovasculares/instrumentación , Arteria Femoral , Claudicación Intermitente/terapia , Isquemia/terapia , Enfermedad Arterial Periférica/terapia , Arteria Poplítea , Indicadores de Calidad de la Atención de Salud , Anciano , Anciano de 80 o más Años , Amputación Quirúrgica , Benchmarking/normas , Enfermedad Crítica , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/mortalidad , Procedimientos Endovasculares/normas , Femenino , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/fisiopatología , Mortalidad Hospitalaria , Humanos , Claudicación Intermitente/diagnóstico por imagen , Claudicación Intermitente/mortalidad , Claudicación Intermitente/fisiopatología , Isquemia/diagnóstico por imagen , Isquemia/mortalidad , Isquemia/fisiopatología , 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 , Indicadores de Calidad de la Atención de Salud/normas , Sistema de Registros , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos
10.
Am Heart J ; 232: 71-83, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33157067

RESUMEN

The Registry Assessment of Peripheral Devices (RAPID) convened a multidisciplinary group of stakeholders including clinicians, academicians, regulators and industry representatives to conduct an in-depth review of limitations associated with the data available to assess the paclitaxel mortality signal. Available studies were evaluated to identify strengths and limitations in the study design and data quality, which were translated to lessons learned to help guide the design, execution, and analyses of future studies. We suggest numerous actionable responses, such as the development and use of harmonized data points and outcomes in a consensus lean case report form. We advocate for reduction in missing data and efficient means for accrual of larger sample sizes in Peripheral arterial disease studies or use of supplemental datasets. Efforts to share lessons learned and working collaboratively to address such issues may improve future data in this device area and ultimately benefit patients. Condensed Abstract: Data sources evaluating paclitaxel-coated devices were evaluated to identify strengths and limitations in the study design and data quality, which were translated to lessons learned to help guide the design, execution, and analyses of future studies. We suggest numerous actionable responses, which we believe may improve future data in this device area and ultimately benefit patients.


Asunto(s)
Angioplastia , Stents Liberadores de Fármacos , Mortalidad , Paclitaxel/administración & dosificación , Enfermedad Arterial Periférica/cirugía , Moduladores de Tubulina/administración & dosificación , Comités Consultivos , Angioplastia de Balón , Aterectomía , Elementos de Datos Comunes , Exactitud de los Datos , Recolección de Datos , Arteria Femoral/cirugía , Humanos , Metaanálisis como Asunto , Arteria Poplítea , Ensayos Clínicos Controlados Aleatorios como Asunto , Reproducibilidad de los Resultados , Medición de Riesgo , Stents
11.
J Vasc Surg ; 72(6): 2153-2160, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32442604

RESUMEN

The Vascular Implant Surveillance and Interventional Outcomes Network (VISION) is a Coordinated Registry Network (CRN) a member of Medical Device Epidemiology Network, a U.S. Food and Drug Administration (FDA)-supported global public-private partnership that seeks to advance the collection and use of real-world data to improve patient outcomes. The VISION CRN began in September 2015 and held its first strategic meeting on September 10, 2018, at the FDA headquarters in Silver Spring, Maryland. VISION is a collaboration of the Vascular Quality Initiative (VQI), the FDA, and other stakeholders. At this annual meeting, leaders from the FDA, VQI, industry representatives, population health researchers, and regulatory science experts gathered to discuss strategic goals and opportunities for VISION. One of the key focus areas for VISION is linkage of VQI registry data to Medicare, longitudinal data sources maintained by various states, and other relevant data sources, as a model for efficient, cost-saving, and effectual evidence generation and appraisal. This would provide the means to expand data collection, assess long-term procedural outcomes across the carotid, lower extremity, aortic, and venous intervention datasets, and execute registry-based trials through the CRN structure in an efficient, cost-effective manner. Looking forward, VISION strives to validate long-term outcome data in the VQI using industry datasets, in hopes of using CRNs to make device regulatory decisions. With the guidance of a steering committee, VISION will provide vascular surgeons, industry, and regulators the appropriate data to improve care for patients with vascular disease.


Asunto(s)
Procedimientos Endovasculares/instrumentación , Equipos y Suministros , Vigilancia de Productos Comercializados , Asociación entre el Sector Público-Privado , United States Food and Drug Administration , Procedimientos Quirúrgicos Vasculares/instrumentación , Procedimientos Endovasculares/efectos adversos , Diseño de Equipo , Medicina Basada en la Evidencia , Humanos , Cooperación Internacional , Seguridad del Paciente , Vigilancia de la Población , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos , Procedimientos Quirúrgicos Vasculares/efectos adversos
13.
J Vasc Surg ; 67(2): 637-644.e30, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29389426

RESUMEN

OBJECTIVE: The current state of evaluating patients with peripheral artery disease and more specifically of evaluating medical devices used for peripheral vascular intervention (PVI) remains challenging because of the heterogeneity of the disease process, the multiple physician specialties that perform PVI, the multitude of devices available to treat peripheral artery disease, and the lack of consensus about the best treatment approaches. Because PVI core data elements are not standardized across clinical care, clinical trials, and registries, aggregation of data across different data sources and physician specialties is currently not feasible. METHODS: Under the auspices of the U.S. Food and Drug Administration's Medical Device Epidemiology Network initiative-and its PASSION (Predictable and Sustainable Implementation of the National Registries) program, in conjunction with other efforts to align clinical data standards-the Registry Assessment of Peripheral Interventional Devices (RAPID) workgroup was convened. RAPID is a collaborative, multidisciplinary effort to develop a consensus lexicon and to promote interoperability across clinical care, clinical trials, and national and international registries of PVI. RESULTS: The current manuscript presents the initial work from RAPID to standardize clinical data elements and definitions, to establish a framework within electronic health records and health information technology procedural reporting systems, and to implement an informatics-based approach to promote the conduct of pragmatic clinical trials and registry efforts in PVI. CONCLUSIONS: Ultimately, we hope this work will facilitate and improve device evaluation and surveillance for patients, clinicians, health outcomes researchers, industry, policymakers, and regulators.


Asunto(s)
Prótesis Vascular , Aprobación de Recursos/normas , Procedimientos Endovasculares/instrumentación , Enfermedad Arterial Periférica/terapia , Sistema de Registros/normas , Stents , United States Food and Drug Administration/normas , Procedimientos Quirúrgicos Vasculares/instrumentación , Minería de Datos/normas , Registros Electrónicos de Salud/normas , Procedimientos Endovasculares/efectos adversos , Humanos , Cooperación Internacional , Informática Médica/normas , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/fisiopatología , Vigilancia de Productos Comercializados/normas , Diseño de Prótesis , Ensayos Clínicos Controlados Aleatorios como Asunto/normas , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología , Procedimientos Quirúrgicos Vasculares/efectos adversos , Flujo de Trabajo
14.
Circ J ; 82(2): 316-322, 2018 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-29367497

RESUMEN

BACKGROUND: The current state of evaluating patients with peripheral artery disease and more specifically of evaluating medical devices used for peripheral vascular intervention (PVI) remains challenging because of the heterogeneity of the disease process, the multiple physician specialties that perform PVI, the multitude of devices available to treat peripheral artery disease, and the lack of consensus about the best treatment approaches. Because PVI core data elements are not standardized across clinical care, clinical trials, and registries, aggregation of data across different data sources and physician specialties is currently not feasible.Methods and Results:Under the auspices of the U.S. Food and Drug Administration's Medical Device Epidemiology Network initiative-and its PASSION (Predictable and Sustainable Implementation of the National Registries) program, in conjunction with other efforts to align clinical data standards-the Registry Assessment of Peripheral Interventional Devices (RAPID) workgroup was convened. RAPID is a collaborative, multidisciplinary effort to develop a consensus lexicon and to promote interoperability across clinical care, clinical trials, and national and international registries of PVI. The current manuscript presents the initial work from RAPID to standardize clinical data elements and definitions, to establish a framework within electronic health records and health information technology procedural reporting systems, and to implement an informatics-based approach to promote the conduct of pragmatic clinical trials and registry efforts in PVI. CONCLUSIONS: Ultimately, we hope this work will facilitate and improve device evaluation and surveillance for patients, clinicians, health outcomes researchers, industry, policymakers, and regulators.


Asunto(s)
Equipos y Suministros/normas , Enfermedad Arterial Periférica , Sistema de Registros/normas , Monitoreo Epidemiológico , Humanos , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/terapia , Estándares de Referencia
15.
Exp Neurol ; 247: 113-21, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23588220

RESUMEN

CNS damage often results in demyelination of spared axons due to oligodendroglial cell death and dysfunction near the injury site. Although new oligodendroglia are generated following CNS injury and disease, the process of remyelination is typically incomplete resulting in long-term functional deficits. Chondroitin sulfate proteoglycans (CSPGs) are upregulated in CNS grey and white matter following injury and disease and are a major component of the inhibitory scar that suppresses axon regeneration. CSPG inhibition of axonal regeneration is mediated, at least in part, by the protein tyrosine phosphatase sigma (PTPσ) receptor. Recent evidence demonstrates that CSPGs inhibit OL process outgrowth, however, the means by which their effects are mediated remains unclear. Here we investigate the role of PTPσ in CSPG inhibition of OL function. We found that the CSPGs, aggrecan, neurocan and NG2 all imposed an inhibitory effect on OL process outgrowth and myelination. These inhibitory effects were reversed by degradation of CSPGs with Chondroitinase ABC prior to OL exposure. RNAi-mediated down-regulation of PTPσ reversed the inhibitory effect of CSPGs on OL process outgrowth and myelination. Likewise, CSPG inhibition of process outgrowth and myelination was significantly reduced in cultures containing PTPσ(-/-) OLs. Finally, inhibition of Rho-associated kinase (ROCK) increased OL process outgrowth and myelination during exposure to CSPGs. These results suggest that in addition to their inhibitory effects on axon regeneration, CSPGs have multiple inhibitory actions on OLs that result in incomplete remyelination following CNS injury. The identification of PTPσ as a receptor for CSPGs, and the participation of ROCK downstream of CSPG exposure, reveal potential therapeutic targets to enhance white matter repair in the damaged CNS.


Asunto(s)
Proteoglicanos Tipo Condroitín Sulfato/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Vaina de Mielina/efectos de los fármacos , Oligodendroglía/efectos de los fármacos , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/metabolismo , Agrecanos/farmacología , Animales , Animales Recién Nacidos , Antígenos/farmacología , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Condroitina ABC Liasa/farmacología , Ganglios Espinales/citología , Gangliósidos/metabolismo , Proteína Básica de Mielina/metabolismo , Proteínas de Neurofilamentos/metabolismo , Proteoglicanos/farmacología , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Células Madre , Quinasas Asociadas a rho/metabolismo
16.
Glia ; 61(6): 843-54, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23554117

RESUMEN

Neuronal activity promotes myelination in vivo and in vitro. However, the molecular events that mediate activity-dependent myelination are not completely understood. Seven, daily 1 h sessions of patterned electrical stimulation (ESTIM) promoted myelin segment formation in mixed cultures of dorsal root ganglion (DRG) neurons and oligodendrocytes (OLs); the increase in myelination was frequency-dependent. Myelin segment formation was also enhanced following exposure of DRGs to ESTIM prior to OL addition, suggesting that ESTIM promotes myelination in a manner involving neuron-specific signaling. Cyclic adenosine monophosphate (cAMP) levels in DRGs were increased three-fold following ESTIM, and artificially increasing cAMP mimicked the ability of ESTIM to promote myelination. Alternatively, inhibiting the cAMP pathway suppressed ESTIM-induced myelination. We used compartmentalized, microfluidic platforms to isolate DRG soma from OLs and assessed cell-type specific effects of ESTIM on myelination. A selective increase or decrease in DRG cAMP levels resulted in enhanced or suppressed myelination, respectively. This work describes a novel role for the cAMP pathway in neurons that results in enhanced myelination.


Asunto(s)
Potenciales de Acción/fisiología , AMP Cíclico/metabolismo , Vaina de Mielina/metabolismo , Neuronas/fisiología , Oligodendroglía/metabolismo , Transducción de Señal/fisiología , Animales , Axones/metabolismo , Células Cultivadas , Estimulación Eléctrica , Ganglios Espinales/fisiología , Ratas , Ratas Sprague-Dawley
17.
Neuromolecular Med ; 14(2): 112-8, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22527791

RESUMEN

Axon demyelination contributes to the loss of sensory and motor function following injury or disease in the central nervous system. Numerous reports have demonstrated that myelination can be achieved in neuron/oligodendrocyte co-cultures. However, the ability to selectively treat neuron or oligodendrocyte (OL) cell bodies in co-cultures improves the value of these systems when designing mechanism-based therapeutics. We have developed a microfluidic-based compartmentalized culture system to achieve segregation of neuron and OL cell bodies while simultaneously allowing the formation of myelin sheaths. Our microfluidic platform allows for a high replicate number, minimal leakage, and high flexibility. Using a custom built lid, fit with platinum electrodes for electrical stimulation (10-Hz pulses at a constant 3 V with ~190 kΩ impedance), we employed the microfluidic platform to achieve activity-dependent myelin segment formation. Electrical stimulation of dorsal root ganglia resulted in a fivefold increase in the number of myelinated segments/mm² when compared to unstimulated controls (19.6 ± 3.0 vs. 3.6 ± 2.3 MBP+ segments/mm²). This work describes the modification of a microfluidic, multi-chamber system so that electrical stimulation can be used to achieve increased levels of myelination while maintaining control of the cell culture microenvironment.


Asunto(s)
Axones/metabolismo , Técnicas de Cultivo de Célula/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Vaina de Mielina/metabolismo , Animales , Axones/ultraestructura , Técnicas de Cocultivo/instrumentación , Estimulación Eléctrica , Ganglios Espinales/metabolismo , Oligodendroglía/metabolismo , Ratas , Ratas Sprague-Dawley
18.
J Neurosci Res ; 90(1): 72-83, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21932370

RESUMEN

Oligodendrocyte (OLG) death plays a major role in white matter dysfunction and demyelination following injury to the CNS. Axonal contact, communication, and neuronal activity appear to promote OLG survival and function in cell culture and during development. The application of electrical stimulation to mixed neural cultures has been shown to promote OLG differentiation and the formation of myelin in vitro. Here we show that OLG viability can be significantly enhanced in mixed cortical cultures by applying biphasic pulses of electrical stimulation (ESTIM). Enhanced survival via ESTIM requires the presence of neurons and is suppressed by inhibition of voltage-gated sodium channels. Additionally, contact between the axon and OLG is necessary for ESTIM to promote OLG survival. This report suggests that patterned neuronal activity could repress delayed progression of white matter injury and promote CNS repair in neurological conditions that involve white matter damage.


Asunto(s)
Estimulación Eléctrica/métodos , Oligodendroglía/fisiología , Clorometilcetonas de Aminoácidos/farmacología , Análisis de Varianza , Anestésicos Locales/farmacología , Animales , Antígenos/metabolismo , Biofisica , Bromodesoxiuridina/metabolismo , Caspasa 3/metabolismo , Recuento de Células , Diferenciación Celular , Proliferación Celular , Supervivencia Celular/fisiología , Células Cultivadas , Corteza Cerebral/citología , Inhibidores de Cisteína Proteinasa/farmacología , Femenino , Galactosilceramidasa/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Proteína Básica de Mielina/metabolismo , Neuronas/fisiología , Oligodendroglía/efectos de los fármacos , Fosfopiruvato Hidratasa/metabolismo , Embarazo , Proteoglicanos/metabolismo , Ratas , Ratas Sprague-Dawley , Células Madre , Tetrodotoxina/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...