Mis casos clínicos de especialidades odontológicas

Libro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasLibro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasUniversidad Autónoma de Campeche Universidad Autónoma del Estado de Hidalgo Universidad Autónoma del Estado de Méxic

Efecto de la exposición a campos magnéticos de extrema baja frecuencia en un modelo de hemiparkinson en ratas

Parkinson’s disease (PD) is a neurodegenerative illness which affects dopaminergic neurons in the substance nigra pars compacta (SNc) at the mesencephalic area. It is characterized by abnormal movements with progressive loss of motor and cognitive skills. Up to date there is no completely effective treatment. This is why it is very important to establish therapeutic tools to alleviate or at least retard the expression of the PD symptoms. One of the most novel strategies is electromagnetic stimulation of extremely low frequency, whose effects on PD have not been well studied. Objective: The main purpose of this study was to evaluate behavioral effects of extremely low frequency magnetic fields (MF) on a rat model of hemiparkinsonism. Material and methods: In this study we injected 6- hidroxidopamine into the SNc to lesion the nigrostriatal pathway of the right side of Wistar rat’s brain. After the lesion, the animals were stimulated with MF (60 Hz, 2.4 mT) daily during 2 hours for 2 months. Changes in posture, locomotion and equilibrium were every 15 days measured. Results: The main results showed that daily stimulation improved equilibrium and reduced anxiety parameters, measured by open field test. Conclusion: Based in these results we propose that the ELF MF stimulation parameters are useful to ameliorate some of the motor symptoms the PD and could be an alternative in the treatment for PD patients.La Enfermedad de Parkinson (EP) es un padecimiento degenerativo, el cual afecta las neuronas dopaminérgicas de la sustancia negra pars compacta del mesencéfalo (SNc). Se manifiesta por movimientos anormales con pérdida progresiva de habilidades motoras y cognoscitivas. Actualmente no existe un tratamiento completamente eficaz, por tal motivo es muy importante establecer herramientas terapéuticas para aliviar o al menos retardar la expresión de los síntomas de la enfermedad. Una de las más novedosas estrategias es la estimulación magnética de extrema baja frecuencia, cuyos efectos en la EP no han sido estudiados. Objetivo: El propósito de este estudio fue evaluar los efectos conductuales en ratas en un modelo de hemiparkinsonismo, inducidos por la exposición a campos magnéticos de extrema baja frecuencia (CM). Material y métodos: En este estudio inyectamos 6-hidroxidopamina en la SNc para lesionar la vía nigroestriatal derecha de ratas Wistar. Después de la lesión, los animales fueron estimulados con CM (60 Hz, 2.4 mT) 2 horas diarias durante 2 meses. Los cambios en postura, locomoción y equilibrio se evaluaron cada 15 días. Resultados: Los principales resultados obtenidos mostraron que la estimulación diaria mejoró el equilibrio y redujo algunos parámetros relacionados con la ansiedad, medidos estos últimos con la prueba de campo abierto. Conclusión: Basados en estos resultados, proponemos que los parámetros de estimulación con CM en el modelo animal de la EP son adecuados para mejorar algunos síntomas motores de EP y que podrían ser una alternativa en el tratamiento de los pacientes con este padecimiento

Extremely low frequency electromagnetic field exposure and restraint stress induce changes on the brain lipid profile of Wistar rats

Abstract Background Exposure to electromagnetic fields can affect human health, damaging tissues and cell homeostasis. Stress modulates neuronal responses and composition of brain lipids. The aim of this study was to evaluate the effects of chronic extremely low frequency electromagnetic field (ELF-EMF) exposure, restraint stress (RS) or both (RS + ELF-EMF) on lipid profile and lipid peroxidation in Wistar rat brain. Methods Twenty-four young male Wistar rats were allocated into four groups: control, RS, ELF-EMF exposure, and RS + ELF-EMF for 21 days. After treatment, rats were euthanized, the blood was obtained for quantitate plasma corticosterone concentration and their brains were dissected in cortex, cerebellum and subcortical structures for cholesterol, triacylglycerols, total free fatty acids, and thiobarbituric acid reactive substances (TBARS) analysis. In addition, fatty acid methyl esters (FAMEs) were identified by gas chromatography. Results Increased values of plasma corticosterone were found in RS and ELF-EMF exposed groups (p < 0.05), this effect was higher in RS + ELF-EMF group (p < 0.05, vs. control group). Chronic ELF-EMF exposure increased total lipids in cerebellum, and total cholesterol in cortex, but decreased polar lipids in cortex. In subcortical structures, increased concentrations of non-esterified fatty acids were observed in RS + ELF-EMF group. FAMEs analysis revealed a decrease of polyunsaturated fatty acids of cerebellum and increases of subcortical structures in the ELF-EMF exposed rats. TBARS concentration in lipids was increased in all treated groups compared to control group, particularly in cortex and cerebellum regions. Conclusions These findings suggest that chronic exposure to ELF-EMF is similar to physiological stress, and induce changes on brain lipid profile

Tratamiento a largo plazo con campos electromagnéticos en un modelo animal de la enfermedad de Parkinson

Parkinson’s disease (PD) is a neurodegenerative disease that causes motor and non-motor alterations induced by the loss of neurons of substance nigra pars compacta (SNc) In clinical therapy, the use of pharmacological treatments to improve symptoms is commonly used. Recently, non-pharmacological techniques are being developed. Such is the case for Electromagnetic Field Stimulation (EMF). Although this treatment has already been used in PD patients, its underlying therapeutic mechanism remains unclear. Studies in animal models of PD have been performed but only for short periods of stimulation with EMF. This study aimed to investigate motor behavior in hemiparkinsonian Wistar rats treated with EMF of 60 Hz (2.4 mT) 2 hours daily for six months. Behavioral evaluations such as apomorphine-induced rotation, open field test, elevated cross maze, and balance beam were performed monthly. Also, immunoreactive dopaminergic neurons were counted, and their degree of loss was estimated. The main results showed that lesioned animals treated with EMF, did not differ in weight gain compared to control animals. Furthermore, magnetic treatment reduced turning behavior and improved balance, without significant changes in the survival of SNc dopaminergic neurons. These results support the use of EMF as an alternative therapy that could help to improve the motor symptoms of PD. La enfermedad de Parkinson (EP) es un padecimiento neurodegenerativo que afecta las neuronas de la sustancia negra pars compacta (SNc), provocando alteraciones motoras y no motoras. En la actualidad para el tratamiento de pacientes con EP se aplica la Estimulación con Campos Electromagnéticos (CEM), observándose cierta mejoría clínica. Sin embargo, su mecanismo terapéutico subyacente sigue sin ser dilucidado. Los estudios en modelos animales de la EP se han realizado por periodos cortos de estimulación con CEM. Por lo tanto, el objetivo del presente estudio fue investigar los cambios en el comportamiento motor de ratas Wistar con hemiparkinson, tratadas con CEM de 60 Hz, 2 horas diariamente durante 6 meses. Mensualmente se realizaron evaluaciones de conducta: rotación inducida por apomorfina, campo abierto, laberinto elevado en cruz y barra de equilibrio. Al finalizar el tratamiento se contó el número de neuronas dopaminérgicas en la SNc y se estimó su grado de pérdida. Los animales lesionados que recibieron CEM tuvieron una ganancia de peso similar a los animales control. El tratamiento redujo la conducta de giro y mejoró el equilibrio, sin cambios significativos en la sobrevida de las neuronas dopaminérgicas de la SNc. Estos resultados apoyan el uso de los CEM de 60 Hz como una terapia complementaria que puedan ayudar a mejorar los síntomas motores de la enfermedad

Human Embryonic Stem Cell-Derived Immature Midbrain Dopaminergic Neurons Transplanted in Parkinsonian Monkeys

Human embryonic stem cells (hESCs) differentiate into specialized cells, including midbrain dopaminergic neurons (DANs), and Non-human primates (NHPs) injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine develop some alterations observed in Parkinson’s disease (PD) patients. Here, we obtained well-characterized DANs from hESCs and transplanted them into two parkinsonian monkeys to assess their behavioral and imaging changes. DANs from hESCs expressed dopaminergic markers, generated action potentials, and released dopamine (DA) in vitro. These neurons were transplanted bilaterally into the putamen of parkinsonian NHPs, and using magnetic resonance imaging techniques, we calculated the fractional anisotropy (FA) and mean diffusivity (MD), both employed for the first time for these purposes, to detect in vivo axonal and cellular density changes in the brain. Likewise, positron-emission tomography scans were performed to evaluate grafted DANs. Histological analyses identified grafted DANs, which were quantified stereologically. After grafting, animals showed signs of partially improved motor behavior in some of the HALLWAY motor tasks. Improvement in motor evaluations was inversely correlated with increases in bilateral FA. MD did not correlate with behavior but presented a negative correlation with FA. We also found higher 11C-DTBZ binding in positron-emission tomography scans associated with grafts. Higher DA levels measured by microdialysis after stimulation with a high-potassium solution or amphetamine were present in grafted animals after ten months, which has not been previously reported. Postmortem analysis of NHP brains showed that transplanted DANs survived in the putamen long-term, without developing tumors, in immunosuppressed animals. Although these results need to be confirmed with larger groups of NHPs, our molecular, behavioral, biochemical, and imaging findings support the integration and survival of human DANs in this pre-clinical PD model