RESUMO
Realizing that 60% to 80% of dopaminergic nigrostriatal neurons are nonfunctional at the time of clinical diagnosis, there is an emerging consensus that disease-modifying treatments should be initiated in the earliest stages of Parkinson's disease (PD). To date, clinical trial designs and metrics in PD have been focused on motor symptoms as the core feature of the clinical disease. To identify earlier or "pre-motor" populations in PD, new markers have been proposed. We address the prerequisites needed to use these pre-motor markers in clinical trials for the selection of subjects, definition of populations, and monitoring of disease progression. This may require the development of new diagnostic criteria potentially based on non-motor clinical signs, imaging techniques, or biological features, all requiring discussion in a regulatory framework. Questions addressed include: Which steps must be taken to gain a broad consensus in the field from academic opinion leaders, patient advocacy groups, regulatory bodies, and industry? How do we prevent the selection of subgroups, which may not be representative of the full disease spectrum? Is there a way forward in personalized medicine? How do we balance risk and benefit in an at-risk population? While many tools are available, a concerted effort is required to develop integrated data sets, as well as to achieve the necessary standardization for multicenter clinical trials. To this end, public-private consortia (including academic centers, patient advocacy groups, and industry) will be of crucial importance to prospectively investigate and define the best tools and treatment paradigms.
Assuntos
Ensaios Clínicos como Assunto/normas , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson/prevenção & controle , Projetos de Pesquisa/normas , Biomarcadores/metabolismo , Humanos , Doença de Parkinson/diagnóstico , Doença de Parkinson/metabolismoRESUMO
BACKGROUND: In order to increase understanding of how infused cells work, it becomes important to track their initial movement, localization, and engraftment efficiency following transplantation. However, the available in vivo cell tracking techniques are suboptimal. The study objective was to determine the biodistribution of intravenously administered Indium-111 (In-111) oxine labeled human umbilical tissue-derived cells (hUTC) in a rat model of transient middle cerebral occlusion (tMCAo) using single photon emission computed tomography (SPECT). METHODS: Rats received 3 million In-111 labeled hUTC (i.v.) 48 hrs after tMCAo. Following the administration of either hUTC or equivalent dose of In-111-oxine (18.5 MBq), animals underwent SPECT imaging on days 0, 1, and 3. Radioactivity in various organs as well as in the stroke area and contralateral hemisphere was determined, decay corrected and normalized to the total (whole body including head) radioactivity on day 0. Immunohistochemical analysis was also performed to confirm the beneficial effects of hUTC on vascular and synaptic density, and apoptosis. RESULTS: Most of the radioactivity (43.36±23.07% on day 0) trafficked to the lungs immediately following IV administration of In-111 labeled hUTC (day 0) and decreased drastically to 8.81±7.75 and 4.01±4.52% on days 1 and 3 post-injection, respectively. In contrast, radioactivity measured in the lung of animals that received In-111-oxine alone remained relatively unchanged from day 0 to day 1 (18.38±5.45% at day 0 to 12.59±5.94%) and decreased to 8.34±4.25% on day 3. Significantly higher radioactivity was observed in stroke areas of animals that received In-111 labeled hUTC indicating the presence of cells at the site of injury representing approximately 1% of total administered dose. In addition, there was significant increase in vascular and synaptophysin immunoreactivity in stroke areas of rats that received In-111 labeled hUTC. CONCLUSIONS: The present studies showed the tracking of In-111 labeled hUTC to the sites of stroke in a rat model of tMCAo using SPECT. Animals treated with In-111 labeled hUTC showed histological improvements, with higher vascular and synaptic densities observed in the ischemic boundary zone (IBZ).
Assuntos
Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia , Rastreamento de Células/métodos , Radioisótopos de Índio , Transplante de Células-Tronco/métodos , Cordão Umbilical/diagnóstico por imagem , Cordão Umbilical/transplante , Animais , Células Cultivadas , Humanos , Masculino , Compostos Radiofarmacêuticos , Ratos , Ratos Wistar , Coloração e Rotulagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Resultado do Tratamento , Cordão Umbilical/citologiaRESUMO
In legal physician-hastened death, a physician prescribes medication with the primary intent of causing the death of a willing terminally ill patient. This practice differs radically from palliative sedation, intended to relieve a patient's suffering rather than cause a patient's death. In this position paper, we argue that the practice of physician-hastened death is contrary to the interests of patients, their families, and the sound ethical practice of medicine. Therefore, the American Academy of Neurology should advise its members against this practice, as it had done until 2018.
Assuntos
Cuidados Paliativos , Assistência Terminal , Humanos , Países Baixos , Neurologia/ética , Neurologia/métodos , Cuidados Paliativos/ética , Cuidados Paliativos/métodos , Sociedades Médicas , Assistência Terminal/ética , Assistência Terminal/métodos , Estados UnidosRESUMO
Human umbilical tissue-derived cells (hUTC) represent an attractive cell source and a potential technology for neurorestoration and improvement of functional outcomes following stroke. Male Wistar rats were subjected to a transient middle cerebral artery occlusion (tMCAo) and were intravenously administered hUTC (Nâ=â11) or vehicle (Nâ=â10) 48 hrs after stroke. White matter and vascular reorganization was monitored over a 12-week period using MRI and histopathology. MRI results were correlated with neurological functional and histology outcomes to demonstrate that MRI can be a useful tool to measure structural recovery after stroke. MRI revealed a significant reduction in the ventricular volume expansion and improvement in cerebral blood flow (CBF) in the hUTC treated group compared to vehicle treated group. Treatment with hUTC resulted in histological and functional improvements as evidenced by enhanced expression of vWF and synaptophysin, and improved outcomes on behavioral tests. Significant correlations were detected between MRI ventricular volumes and histological lesion volume as well as number of apoptotic cells. A positive correlation was also observed between MRI CBF or cerebral blood volume (CBV) and histological synaptic density. Neurological functional tests were also significantly correlated with MRI ventricular volume and CBV. Our data demonstrated that MRI measurements can detect the effect of hUTC therapy on the brain reorganization and exhibited positive correlation with histological measurements of brain structural changes and functional behavioral tests after stroke. MRI ventricular volumes provided the most sensitive index in monitoring brain remodeling and treatment effects and highly correlated with histological and functional measurements.
Assuntos
Encéfalo/patologia , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/terapia , Cordão Umbilical/citologia , Animais , Comportamento Animal , Transplante de Células , Ventrículos Cerebrais/patologia , Humanos , Masculino , Ratos , Ratos Wistar , Acidente Vascular Cerebral/fisiopatologia , Fatores de TempoRESUMO
BACKGROUND: Trafermin (basic fibroblast growth factor) has been shown to reduce infarct volume in acute ischemic stroke models, and to promote functional recovery and new synapse formation when given to animals with completed cerebral infarction. A previous study in acute stroke patients suggested that trafermin was safe and well tolerated when given over a 3-hour period over a wide dose range. METHODS AND RESULTS: Double-blind, parallel group, placebo-controlled trial of a single 24-hour intravenous infusion of trafermin. Patients having onset of stroke symptoms within 6 h and a baseline score of >/=7 on the NIH Stroke Scale (>/=2 motor) were randomized to receive 5 or 10 mg of trafermin or placebo intravenously infused over 24 h. The primary efficacy outcome was a categorized combination of the Barthel and Rankin scales assessed at 90 days. A total of 286 patients had been enrolled at 55 sites in 11 countries when the sponsor directed that enrollment be stopped because an interim analysis of efficacy data predicted too small a chance of demonstrating a statistically significant benefit after recruitment of the planned 900 patients. The 5-mg group showed a slight but nonsignificant advantage over placebo (OR 1.2, 95% CI 0.72-2.00, p = 0.48); the 10-mg group showed a nonsignificant disadvantage (OR 0.74, 95% CI 0.44-1.22, p = 0.24). Mortality rates at 90 days were 17% in the 5-mg group, 24% in the 10-mg group and 18% in the placebo group. Treatment with trafermin was associated with an increased leukocytosis and a decrease in blood pressure: mean decrease in systolic blood pressure from baseline was 19 mm Hg in the 5-mg group, 22 mm Hg in the 10-mg group and 8 mm Hg in the placebo group. In a post hoc subgroup analysis, patients in the 5-mg group treated more than 5 h after the onset of symptoms showed an apparent advantage over placebo (OR 2.1, 95% CI 1.00-4.41, p = 0.044; after age adjustment: OR 1.9, 95% CI 0.91-4.13, p = 0.08). CONCLUSIONS: With the proper treatment regimen, trafermin can likely be given safely to stroke patients. The 5-mg dose showed a trend toward a treatment advantage. The ideal time window for this agent may exceed 5 h. This may open new avenues for acute stroke therapy, aiming at enhancing recovery mechanisms rather than immediate neuroprotection.