Experimental model of actinic keratosis due to exposure to ultraviolet A radiation

Las queratosis actínicas son lesiones cutáneas preneoplásicas frecuentes causadas por una exposición crónica a las radiaciones solares. La obtención de modelos animales que contribuyan a comprender los mecanismos implicados en esta patología y a evaluar nuevas terapias farmacológicas resulta de gran interés para la comunidad científica. Se desarrolló un biomodelo de queratosis actínica en ratones Balb/c, empleando como inductor la radiación UVA. Se aplicaron dos esquemas de irradiación: Grupo I, expuesto a tres sesiones diarias de radiación de 2 h y Grupo II, dos sesiones diarias de 4 h, con igual tiempo de receso entre sesiones y durante un período de 14 días. Se evaluaron parámetros macroscópicos y microscópicos, y la frecuencia de aparición de micronúcleos en sangre periférica. Los animales correspondientes al Grupo I no mostraron lesiones mascroscópicas y microscópicamente evidenciaron una leve acantosis con ausencia de displasia; mientras que en los animales del Grupo II se observaron lesiones macroscópicas que se correlacionan histopatológicamente con la presencia de una queratosis actínica. La frecuencia de micronúcleos obtenida en el Grupo II fue significativamente superior a la formación de micronúcleos espontáneos en el Grupo Control. El biomodelo experimental de queratosis actínica obtenido reproduce el efecto de las radiaciones ultravioletas sobre la piel.Actinic keratoses are frequent preneoplastic skin lesions caused by chronic exposure to solar radiation. Obtaining animal models that contribute to understanding the mechanisms involved in this pathology and evaluating new pharmacological therapies is of great interest to the scientific community. A biomodel of actinic keratosis was developed in Balb/c mice, using UVA radiation as an inducer. Two irradiation schemes were applied: Group I, exposed to three daily radiation sessions of 2 h and Group II, two daily sessions of 4 h, with the same break time between sessions and for a period of 14 days. Macroscopic and microscopic parameters were evaluated, as well as the frequency of appearance of micronuclei in peripheral blood. The animals corresponding to Group I did not show mascroscopic lesions and microscopically they showed a slight acanthosis with the absence of dysplasia; while in Group II animals macroscopic lesions were observed that histopathologically correlate with the presence of an actinic keratosis. The frequency of micronuclei obtained in Group II was significantly higher than the formation of spontaneous micronuclei in the Control Group. The experimental biomodel of actinic keratosis obtained reproduces the effect of ultraviolet radiation on the skin.Ciencias Experimentale

Influence of solar and geomagnetic storms on terrestrial photosynthesis

It is reviewed the potential influence of solar and geomagnetic storms on terrestrial photosynthesis. Then it is presented a modification of a physical-mathematical model of photosynthesis published by some of us, which allows quantifying the influence of particulate ionizing radiation on this biological process. Some guidelines to obtain this new model from first principles are mentioned and it is applied to some case studies including atmospheric and geomagnetic perturbation due to solar storms

Influence of solar and geomagnetic storms on terrestrial photosynthesis

It is reviewed the potential influence of solar and geomagnetic storms on terrestrial photosynthesis. Then it is presented a modification of a physical-mathematical model of photosynthesis published by some of us, which allows quantifying the influence of particulate ionizing radiation on this biological process. Some guidelines to obtain this new model from first principles are mentioned and it is applied to some case studies including atmospheric and geomagnetic perturbation due to solar storms