RESUMEN
This corrects the article on p. 79 in volume 38(1), PMID 25963461.
RESUMEN
INTRODUCTION: Currently used antiparkinsonian drugs neither stop nor slow-down the progressive nature of the disease. The final phase of PD is characterized by the presence of symptoms and signs resistant to dopaminergic agents, such as depression, dementia, freezing and falls. Therefore, it is urgent to develop therapies able to positively modify this outcome. Despite neuroprotection is a research priority in PD, no effective strategies have been found so far. METHOD: A key informants study was conducted. A group of experts in PD fulfilled a questionnaire of 10 questions to explore the most important topics related to neuroprotection. Afterwards a consensus about the current situation of neuroprotection in PD was established and future directions of development were suggested. RESULTS: Most of the answers emphasized the need of new concepts, the limitations of animal models and the difficulties in the difficulties in demonstrating a neuroprotective effects in humans owing to a lack of biomarkers. Some of the experts believe that we are already exerting a disease modifying effect. CONCLUSIONS: The concept of neuroprotection should be widened. Animal models should be improved. A reliable biomarker to start neuroprotective therapies long before the appearance of motor symptoms and to evaluate the neuroprotective effect of any therapy should be urgently developed.
Asunto(s)
Antiparkinsonianos/uso terapéutico , Consenso , Fármacos Neuroprotectores/uso terapéutico , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/prevención & control , Animales , Biomarcadores/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Humanos , Enfermedad de Parkinson/fisiopatología , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
Introducción. La terapia convencional basada en fármacos dopaminérgicosno frena ni ralentiza de modo significativo el cursoprogresivo de la enfermedad de Parkinson (EP). La fase final de la EPse caracteriza por la presencia de síntomas y signos resistentes a laterapia dopaminérgica (depresión, demencia, disartria, caídas, etc.).Es urgente desarrollar terapias que eviten llegar a estas fases deteniendoo retardando la progresión de la enfermedad. Sin embargo,no se dispone de estrategias neuroprotectoras efectivas.Método. Se realizó un estudio de informadores clave en el queexpertos en EP que cumplimentaron un cuestionario de 10 preguntassobre la problemática más importante en el área de la neuroprotecciónen la EP. Tras ello se estableció un consenso sobre la situaciónactual y se sugirieron nuevas direcciones de investigación.Resultados. La mayoría de respuestas coincidieron en la necesidadde nuevos conceptos, en las limitaciones de los actuales modelosanimales o las dificultades de demostrar un efecto protector en humanospor la falta de biomarcadores. Algunos participantes opinanque ya se está ejerciendo un cierto efecto modificador del curso dela enfermedad.Conclusiones. El concepto de neuroprotección debe ser ampliado,los modelos animales deben mejorarse y urge encontrar un biomarcadorfiable para planificar la terapia en fases más precoces ypara determinar el efecto neuroprotector (AU)
Introduction. Currently used antiparkinsonian drugs neitherstop nor slow-down the progressive nature of the disease. The finalphase of PD is characterized by the presence of symptomsand signs resistant to dopaminergic agents, such as depression,dementia, freezing and falls. Therefore, it is urgent to develop therapies able to positively modify this outcome. Despite neuroprotectionis a research priority in PD, no effective strategieshave been found so far.Method. A key informants study was conducted. A group ofexperts in PD fulfilled a questionnaire of 10 questions to explorethe most important topics related to neuroprotection. Afterwardsa consensus about the cur-rent situation of neuroprotection inPD was established and future directions of development weresuggested.Results. Most of the answers emphasized the need of newconcepts, the limitations of animal models and the difficulties inthe difficulties in demonstrating a neuroprotective effects in humansowing to a lack of biomarkers. Some of the experts believethat we are already exerting a disease modifying effect.Conclusions. The concept of neuroprotection should be widened.Animal models should be improved. A reliable biomarkerto start neuroprotective therapies long before the appearance ofmotor symptoms and to evaluate the neuroprotective effect ofany therapy should be urgently developed (AU)
Asunto(s)
Humanos , Animales , Consenso , Antiparkinsonianos/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/prevención & control , Biomarcadores/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Enfermedad de Parkinson/fisiopatología , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
Independent deletion of the PARK2 gene and hTauVLW over-expression in mice produce mild alterations in the brain. However, the presence of both mutations in a parkin-deficient and hTauVLW double mutant mouse causes a tau neuropathology, reactive astrocytosis, and neuronal loss in the cortex and hippocampus, as well as lesions in nigrostriatal and motor neurons. Moreover, these mutants display some memory and exploratory defects that reflect a functional link between parkin and tau proteins. We have tested the motor activity and coordination of these double mutant mice to determine the effects of parkin deletion in mice over-expressing the hTauVLW transgene. While the loss of parkin alone produces increased exploration and alterations in gait and motor coordination, in hTauVLW transgenic mice the absence of parkin causes less prominent motor impairments. These effects suggest the existence of some compensatory mechanisms that are activated when the hTauVLW transgene is over-expressed in the absence of parkin. This mouse model will hopefully help to study the causes of the motor deficits associated with certain neuropathologies related to the tau and parkin proteins, and to find appropriate treatments.
Asunto(s)
Mutación , Secuencias Repetitivas de Ácidos Nucleicos/genética , Ubiquitina-Proteína Ligasas/deficiencia , Proteínas tau/genética , Análisis de Varianza , Animales , Conducta Animal , Conducta Exploratoria/fisiología , Regulación de la Expresión Génica , Humanos , Ratones , Ratones Transgénicos , Actividad Motora/genética , Desempeño Psicomotor/fisiología , Tiempo de Reacción/genética , Factores de TiempoRESUMEN
One of the fields of medicine that has raised the most expectations in recent years is cell therapy with stem cells. The isolation of human embryo cells, the apparent and unexpected potentiality of adult stem cells and the development of gene therapy lead us to imagine a hopeful future for a significant number of diseases that are at present incurable. In this article we will sketch out the panorama of stem cell research, describing the main achievements in this field as well as some of the questions that await an answer. In spite of the great expectations, it is essential that we maintain a critical and realistic spirit when it comes to analysing the scientific advances in this area.
Asunto(s)
Medicina Regenerativa , Trasplante de Células Madre , Células Madre/fisiología , Células Madre Adultas/citología , Células Madre Adultas/fisiología , Animales , Investigación Biomédica , Trasplante de Médula Ósea , Enfermedades Cardiovasculares/terapia , Ensayos Clínicos como Asunto , Diabetes Mellitus/terapia , Modelos Animales de Enfermedad , Células Madre Embrionarias/citología , Células Madre Embrionarias/fisiología , Oftalmopatías/terapia , Humanos , Enfermedades Renales/terapia , Hepatopatías/terapia , Enfermedades Musculares/terapia , Enfermedades del Sistema Nervioso/terapia , Trasplante de Páncreas , Enfermedades de la Piel/terapia , Células Madre/citologíaRESUMEN
Uno de los campos de la medicina que más expectativas ha levantado en los últimos años es la terapia celular con células madre. El aislamiento de células embrionarias humanas, la aparente e inesperada potencialidad de las células madre adultas y el desarrollo de la terapia génica nos lleva a imaginar un futuro esperanzador para un importante número de enfermedades actualmente incurables. A lo largo de las siguientes páginas vamos a tratar de dibujar el panorama de la investigación con células madre, describiendo los principales logros en este campo así como algunas de las preguntas pendientes de responder. A pesar de las grandes expectativas, es fundamental que mantengamos un espíritu crítico y realista a la hora de analizar los avances científicos en este área
One of the fields of medicine that has raised the most expectations in recent years is cell therapy with stem cells. The isolation of human embryo cells, the apparent and unexpected potentiality of adult stem cells and the development of gene therapy lead us to imagine a hopeful future for a significant number of diseases that are at present incurable. In this article we will sketch out the panorama of stem cell research, describing the main achievements in this field as well as some of the questions that await an answer. In spite of the great expectations, it is essential that we maintain a critical and realistic spirit when it comes to analysing the scientific advances in this area
Asunto(s)
Humanos , Trasplante de Células/métodos , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Trasplante de Células Madre/métodos , Medicina Regenerativa/tendenciasRESUMEN
Entacapone (Comtan) is a potent, selective inhibitor of peripheral catechol-O-methyltransferase (COMT) with therapeutic potential as an adjuvant to levodopa therapy in patients with Parkinson's disease. Entacapone decreases peripheral conversion of levodopa to 3-O-methyldopa increasing central extracellular levodopa and consequently striatal dopamine concentrations. At doses of 200 mg 2 to 10 times daily coadministered with levodopa/carbidopa or levodopa/benserazide entacapone may increase the duration of clinical response both after the first single dose and after repeated dosing in patients with end-of-dose fluctuations. At this dosage, it has a time to peak-plasma concentration of 1.2 hours and an elimination half life of 3.4 hours. In two multicentric, long-term (approximately 6 month), randomized and placebo-controlled studies, the duration of 'on' time was increased and the duration of 'off time' was decreased in patients who received adjunctive entacapone therapy. Moreover, patients randomized to entacapone reduced their levodopa requirements. In these and other phase III studies, entacapone was generally well tolerated, with few reported adverse events, mainly dyskinesias and gastrointestinal disorders. The dyskinesias were generally well controlled by decreasing the mean daily levodopa dose. Entacapone appears as a clinically significant and beneficial adjunct to levodopa therapy in Parkinson's disease patients with end-of-dose fluctuations.
Asunto(s)
Antiparkinsonianos/uso terapéutico , Catecoles/uso terapéutico , Levodopa/uso terapéutico , Enfermedad de Parkinson/tratamiento farmacológico , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Humanos , Nitrilos , EspañaRESUMEN
Hyperactivity of the subthalamic nucleus (STN) is major characteristic of parkinsonism secondary to substantia nigra lesions. Interruption of the STN-internal pallidum (GPi) pathway is a new stereotactic target for Parkinson's disease. We have studied the antiparkinsonian efficacy of STN lesions in MPTP-treated monkeys. Four rhesus monkeys were made parkinsonian by MPTP (i.v. 0.15 +/- 1 mg/kg) administration over 3 months. Unilateral subthalamotomy (kainic acid) was performed by a standard stereotactic method. Severity was rated from 0 (normal) to V by fine manual motor tests. Three monkeys (severity state III/IV) showed marked improvement in spontaneous activity, facial expression and manual dexterity bilaterally but significantly greater in the limb contralateral to the lesion. Mild hemichorea was present in 2 and hemiballism in one. L-Dopa treatment (50 mg b.i.d.) enhanced the hemidyskinesias moderately. The therapeutic effect has persisted for over 8 months postsurgery. Monkey No.4 (severity stage V) showed chorea in the lower limb contralateral to the lesion but no improvement and died a few days later. Subthalamotomy improves parkinsonism in moderately severe parkinsonian monkeys. Dyskinesia might be a persistent complication.
Asunto(s)
Enfermedad de Parkinson Secundaria/cirugía , Núcleos Talámicos/cirugía , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Animales , Macaca mulatta , Enfermedad de Parkinson Secundaria/inducido químicamente , Técnicas Estereotáxicas , Resultado del TratamientoRESUMEN
Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in primates induced a parkinsonian syndrome that could be reversed by levodopa treatment. Animals quickly developed an apparent restlessness ("akathisia") of the lower limbs after as little as five doses. After 4-10 weeks of regular levodopa therapy, animals developed "peak dose" choreiform movements in the lower limbs that spread, with time, to involve the upper limbs and orofacial musculature. With further treatment (5-21 months), animals developed "peak dose" dystonia that variably involved the limbs and orofacial musculature. These conditions represent novel models of levodopa-induced chorea and dystonia in humans. They depend on the same underlying neuropathology and treatment regimen as their human counterparts. It is to be anticipated that these models of dyskinesia will be useful in determining the mechanisms underlying chorea and dystonia in humans and are ideally suited for experimental evaluation of new treatment strategies.
Asunto(s)
Corea/inducido químicamente , Distonía/inducido químicamente , Intoxicación por MPTP , Enfermedad de Parkinson Secundaria/inducido químicamente , Animales , Levodopa/uso terapéutico , Macaca fascicularis , Enfermedad de Parkinson Secundaria/complicaciones , Enfermedad de Parkinson Secundaria/tratamiento farmacológicoRESUMEN
The neural mechanisms that mediate dystonia were investigated in a novel experimental primate model of dopamine agonist-induced dystonia. This condition was produced by long-term (15 months) dopamine agonist therapy of a macaque monkey that had been rendered hemiparkinsonian by unilateral infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into the right common carotid artery. The 2-deoxyglucose (2-DG) metabolic mapping technique was applied to the animal during the expression of active unilateral dystonia, and regional brain uptake of 2-DG was assessed autoradiographically. The results demonstrate that dystonia is associated with marked increases in 2-DG uptake in the constituent nuclei of the basal ganglia (caudate nucleus, putamen, medial and lateral segments of the globus pallidus) and in the subthalamic nucleus, but decreased uptake in the structures that receive output of the basal ganglia (ventral anterior/ventral lateral thalamic complex and lateral habenula). Based on these findings it is suggested that dystonia is characterized by increased activity in the putaminopallidal and pallidosubthalamic pathways, and decreased activity in the subthalamopallidal and pallidothalamic pathways.