Lena Perez Font | Universiteit Hasselt (original) (raw)

Papers by Lena Perez Font

Revista Ingeniería Electrónica, Automática y Comunicaciones ISSN: 1815-5928, Sep 4, 2021

La angiogénesis, que conduce a la formación de redes capilares, tiene un rol importante en un ele... more La angiogénesis, que conduce a la formación de redes capilares, tiene un rol importante en un elevado número de eventos fisiológicos y patológicos, entre los cuales figuran el desarrollo embrionario, la cicatrización de heridas, la artritis, el crecimiento tumoral, la metástasis y los procesos isquémicos, como uno de los mecanismos de la protección endógena y exógena. A tales efectos se analizan los métodos más utilizados actualmente tanto in vivo como in vitro para los estudios de angiogénesis; también se destacan las ventajas y desventajas de cada uno y se enfatiza en la combinación de ambos. Palabras clave: angiogénesis, ensayo in vivo, ensayo in vitro.

International Journal of Molecular Sciences, Jul 5, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

DOAJ (DOAJ: Directory of Open Access Journals), Oct 1, 2021

$Research paper thumbnail of Factores asociados al fracaso de las terapias neuroprotectoras en fase clínica en modelos animales con isquemia cerebral$

La alteración del suministro de sangre al cerebro es la principal causa de la enfermedad cerebrov... more La alteración del suministro de sangre al cerebro es la principal causa de la enfermedad cerebrovascular. Esta alteración puede deberse a una isquemia (trombosis, embolismo arterial) o a una hemorragia. En este estudio se analizó la viabilidad y las potencialidades de la técnica de bioimpedancia eléctrica para monitorear el daño cerebral unilateral utilizando un modelo computacional. Las simulaciones se realizaron en un modelo numérico hemisférico de la cabeza humana. Los potenciales eléctricos se obtuvieron mediante la solución de la ecuación de Laplace en el dominio de la frecuencia. Se introdujo un índice de asimetría eléctrica hemisférica que permite determinar la localización aproximada de la región dañada dentro del hemisferio dañado, el cual fue evaluado para varias conductividades y volúmenes de lesión. Se obtuvo un valor negativo para la isquemia (amplitud del potencial en el hemisferio isquémico mayor que en el hemisferio intacto), mientras que para la hemorragia se obtuvo un valor positivo. Las simulaciones evidenciaron que las variaciones en la conductividad eléctrica y el volumen del tejido dañado tienen un efecto sobre la asimetría hemisférica del potencial eléctrico en la superficie. Palabras claves: Bioimpedancia, Daño cerebral, Modelo numérico de cabeza humana Disturbance of the blood supply to the brain is the main cause of cerebrovascular disease. This disturbance may be due to ischemia (thrombosis, arterial embolism) or to hemorrhage. In this study, the feasibility and potentialities of the electrical bioimpedance technique for monitoring unilateral brain damage was analyzed using a computerized model. The simulations were performed on a hemispheric numerical model of the human head. The electric potentials were obtained by solving Laplace's equation in the frequency domain. A hemispheric electrical asymmetry index was introduced that allows determining the approximate location of the damaged region within the damaged hemisphere, and its evaluation was performed for several conductivities and lesion volumes. A negative value was obtained for ischemia (potential amplitude in the ischemic hemisphere greater than in the intact hemisphere), whereas for hemorrhage a positive value was found. The simulations revealed that variations in electrical conductivity and the volume of damaged tissue have an effect on the hemispheric asymmetry of electrical potential at the surface.

DOAJ (DOAJ: Directory of Open Access Journals), 2016

Journal of Cerebral Blood Flow and Metabolism, Feb 25, 2022

The efficacy of the very low frequency electromagnetic field in cancer treatment remains elusive ... more The efficacy of the very low frequency electromagnetic field in cancer treatment remains elusive due to a lack of explanatory mechanisms for its effect. We developed a novel thermodynamic model that calculates for every cell type the frequency capable of inhibiting proliferation. When this frequency was applied to two human cancer cell lines, it reduced their growth while not affecting healthy cells. The effect was abolished by the inhibition of calcium fluxes. We found evidences of an enhanced respiratory activity due to the increased expression of the elements of the respiratory chain and oxidative phosphorylation, both at the mRNA and protein level. The respiratory burst potentiated the production of reactive oxygen species but was not associated to increased levels of ATP, leading to the conclusion that the energy was readily spent in the adaptive response to the electromagnetic field. Taken together, our data demonstrate that, regardless of individual molecular defects, it is possible to control cancer cells with a specific irradiation that imposes a mitochondrial metabolic switch, regulating calcium fluxes and deleterious to cancer growth. This approach lays the foundations for a personalized cancer medicine.

DOAJ (DOAJ: Directory of Open Access Journals), May 1, 2019

Palabras clave: campo magnético de frecuencia extremadamente baja; seguridad; estudio toxicológic... more Palabras clave: campo magnético de frecuencia extremadamente baja; seguridad; estudio toxicológico; sistema nervioso central, encéfalo.

Frontiers in Neuroscience, 2019

Despite the high prevalence and devastating outcome, only a few treatment options for cerebral is... more Despite the high prevalence and devastating outcome, only a few treatment options for cerebral ischemic stroke exist. Based on the nitric oxide (NO)-stimulating capacity of Non-pulsed Sinusoidal Electromagnetic Field (NP-SEMF) and the possible neuroprotective role of NO in ischemic stroke, we hypothesized that NP-SEMF is able to enhance survival and neurological outcome in a rat model of cerebral ischemia. The animals, in which ischemic injury was induced by occlusion of both common carotid arteries, received 20 min of NP-SEMF of either 10 or 60 Hz daily for 4 days. NP-SEMF dramatically increased survival, reduced the size of the infarcted brain area and significantly improved the neurological score of the surviving rats. Corresponding to previous reports, NP-SEMF was able to induce NO production in vitro. The importance of NO as a key signaling molecule was highlighted by inhibition of the NP-SEMF beneficial effects in the rat stroke model after blocking NO synthase (NOS). Our results indicate for the first time that NP-SEMF exposure (13.5 mT at 60 and 10 Hz) improves the survival and neurological outcome of rats subjected to cerebral ischemia and that this effect is mediated by NO, underlining the great therapeutic potential of NP-SEMF as a therapy for ischemic stroke.

IFMBE Proceedings, 2013

Magnetic fields have been used as neuronal stimulator, specifically in rehabilitation of patients... more Magnetic fields have been used as neuronal stimulator, specifically in rehabilitation of patients after an ischemic episode, but not in the acute phase of the illness. The objectives of this work are focused in evaluate the neuroprotector effect of Extremely Low Frequency Magnetic Field (ELFMF) when applied in the acute phase of the illness, two elements were evaluated: viability (survival after 7 days) and neurological state. The improvement of both indicators were observed, concluding the possibility of a neuroprotector effect of ELFMF and outlining a possible hypothesis of the mechanisms that intervene in this phenomenon, recommending the extension of the experimental study in order to prove the outlined hypotheses.

Frontiers in Molecular Biosciences, Sep 7, 2021

Cerebral stroke is a leading cause of death and adult-acquired disability worldwide. To this date... more Cerebral stroke is a leading cause of death and adult-acquired disability worldwide. To this date, treatment options are limited; hence, the search for new therapeutic approaches continues. Electromagnetic fields (EMFs) affect a wide variety of biological processes and accumulating evidence shows their potential as a treatment for ischemic stroke. Based on their characteristics, they can be divided into stationary, pulsed, and sinusoidal EMF. The aim of this review is to provide an extensive literature overview ranging from in vitro to even clinical studies within the field of ischemic stroke of all EMF types. A thorough comparison between EMF types and their effects is provided, as well as an overview of the signal pathways activated in cell types relevant for ischemic stroke such as neurons, microglia, astrocytes, and endothelial cells. We also discuss which steps have to be taken to improve their therapeutic efficacy in the frame of the clinical translation of this promising therapy.

Frontiers in Neuroscience, 2018

Investigacion Y Saberes, Apr 3, 2014

Las enfermedades cerebro vasculares (ECV) comprenden un conjunto de trastornos causados por la di... more Las enfermedades cerebro vasculares (ECV) comprenden un conjunto de trastornos causados por la disminucion del flujo sanguineo en el cerebro. En la actualidad es la tercera causa de muerte a nivel mundial, incluyendose dentro de las prioridades de los programas sanitarios de la Organizacion Mundial de la Salud (OMS) y de la Organizacion Panamericana de la Salud (OPS), por constituir un problema de salud y una urgencia medica. En Cuba son tambien la tercera causa de muerte con una tendencia creciente. En esta revision se discuten los aspectos moleculares del estres oxidativo y la inflamacion en el ictus isquemico y el potencial de las estrategias terapeuticas en la neuroinflamacion y el sistema inmune innato con enfasis en el uso del campo magnetico de frecuencia extremadamente baja y baja intensidad (CMFEB). Estudios recientes demuestran que la orientacion de la respuesta inmune adaptativa endogena puede ofrecernuevas y prometedoras terapias neuroprotectoras, accion que ha sido atribuida a los cambios en los estilos y expectativas de vida. Los campos magneticos de referenciase utilizan con fines terapeuticos y varias evidencias sugieren su posible aplicacion en el tratamiento de la Enfermedad Cerebro Vascular Isquemica.