Modelo de fotocarcinogénesis cutánea en ratones SKH-1 por radiación ultravioleta / An experimental model of ultraviolet radiation-induced cutaneous photocarcinogenesis in SKH-1 mice

Antecedentes. La exposición crónica a las radiaciones solares provoca el envejecimiento patológico de la piel (fotoenvejecimiento) y es uno de los principales factores etiológicos implicados en el desarrollo del cáncer cutáneo. Métodos. Para el presente experimento, hemos expuesto 20 ratones SKH-1 a radiaciones ultravioleta, que se aplicaban tres veces a la semana durante 60min (80 sesiones). Las zonas expuestas a las radiaciones han sido estudiadas macro y microscópicamente. Resultados. El 100% de los animales tratados desarrollaron neoplasias malignas, así como los signos típicos del fotoenvejecimiento. Conclusiones. Debido a la gran similitud de las lesiones desarrolladas por los animales, con las que tienen lugar en la piel humana tras la exposición crónica a las radiaciones ultravioleta, consideramos este modelo, idóneo para el estudio del fotoenvejecimiento y la fotocarcinogénesis, así como para el ensayo de sustancias antioxidantes y fotoprotectoras(AU)

Introduction. Chronic exposure to solar radiation leads to pathological aging of the skin (photoaging) and is one of the principal etiological factors of skin cancer. Methods. For the present experiment, twenty SKH-1 mice were exposed to ultraviolet radiation three times a week for 60min (a total of 80 sessions). The areas exposed to radiation were subsequently examined macroscopically and microscopically. Results. All the experimental animals developed malignant neoplasias (skin carcinomas) as well as signs typical of photoaging. Conclusions. Given the great similarity between the lesions found in the experimental animals and those appearing in human skin following extensive exposure to ultraviolet radiation, we consider this model suitable for the study of photoaging and photocarcinogenesis and for the assessment of antioxidants and photoprotectors(AU)

Should saphenous vein grafts be the conduits of last resort for coronary artery bypass surgery?

There is overwhelming evidence that internal mammary artery grafts improve survival and clinical outcomes after coronary artery bypass graft surgery. It has therefore become standard practice to use the left internal mammary artery as the graft of first choice. Given the overwhelming evidence for the superiority of internal mammary artery grafts, the question that naturally follows is whether the conduit of second choice should be the contralateral internal mammary artery, rather than a saphenous venous graft. This article reviews the evidence supporting the superiority of internal mammary artery grafts over other available conduits and addresses the selection of the second conduit after the left internal mammary artery. The current body of evidence, encompassing multiple clinical studies and employing different methodologies consistently, demonstrates that bilateral internal mammary artery grafting improves survival and long-term clinical outcome. The increasing longevity of postcoronary bypass patients with modern advances in medical and electrical therapies would augment the benefit of this procedure and argue for its greater utilization. Higher patency of arterial grafts may translate to a decreased need for repeat target vessel revascularization and may increase the cost-effectiveness of bilateral internal mammary artery use. However, in 2003, only 3% to 4% of patients undergoing surgical coronary revascularization received bilateral internal mammary artery grafts. There appears to be a potential to increase utilization of this procedure above the current rate. Increased utilization of this procedure would need a concerted effort by the cardiology and cardiac surgery community.