In vivo 3D analysis of systemic effects after local heavy-ion beam irradiation in an animal model.

Radiotherapy is widely used in cancer treatment. In addition to inducing effects in the irradiated area, irradiation may induce effects on tissues close to and distant from the irradiated area. Japanese medaka, Oryzias latipes, is a small teleost fish and a model organism for evaluating the environmental effects of radiation. In this study, we applied low-energy carbon-ion (26.7 MeV/u) irradiation to adult medaka to a depth of approximately 2.2 mm from the body surface using an irradiation system at the National Institutes for Quantum and Radiological Science and Technology. We histologically evaluated the systemic alterations induced by irradiation using serial sections of the whole body, and conducted a heart rate analysis. Tissues from the irradiated side showed signs of serious injury that corresponded with the radiation dose. A 3D reconstruction analysis of the kidney sections showed reductions in the kidney volume and blood cell mass along the irradiated area, reflecting the precise localization of the injuries caused by carbon-beam irradiation. Capillary aneurysms were observed in the gill in both ventrally and dorsally irradiated fish, suggesting systemic irradiation effects. The present study provides an in vivo model for further investigation of the effects of irradiation beyond the locally irradiated area.

Naturally grown rucola, Eruca sativa, contains more α-linolenic acid than conventionally grown rucola.

The ratio of dietary n-6/n-3 polyunsaturated fatty acids is higher in the modern Western meal when compared with that of the Paleolithic era. Evidences have been accumulating that the extremely high ratio of dietary n-6/n-3 polyunsaturated fatty acids increases the risk of disease and the deterioration of physical conditions among humans. In this study, the ratio of linoleic acid (C18:2, n-6) and α-linolenic acid (C18:3, n-3) of rucola, Eruca sativa, was compared between naturally grown samples and conventional farming products (n=3 for each). We found that the naturally grown rucola contained significantly higher amount of α-linolenic acid (p=0.026), resulting in the lower ratio of linoleic acid and α-linolenic acid than the conventional (p=0.016). This finding suggests that vegetables cultured in conventional farming method could decrease the health promotion effects that the vegetables originally possess in natural environment.