title: Comparative late effects of X-rays and negative pimesons on the mouse kidney.
abstract: A system is described for comparing various modalities and fractionation schedules of radiation by means of their long-term morphologic effects upon the mouse kidney. The comparison system utilizes a grading scale for histopathologic changes in which a given histologic grade depends upon meeting defined threshold criteria, rather than quantitation of a particular measurement. Renal tubular alterations served as the basis for comparison, since they appeared more reliably defined than glomerular changes. The radiation dose that induced a specific threshold effect in kidneys from 50% of the animals at 6 months was defined as the effective dose-50%, or ED50.ED50 was found for x-rays and negative pimesons administered in 1, 2, or 5 fractions. From these data, the relative biologic effectiveness (RBE) of negative pi-mesons with respect to x-rays was determined for each fractionation schedule.
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D004601:Elementary Particles; D005260:Female; D007668:Kidney / Q000473:pathology / Q000528:radiation effects*; D007678:Kidney Glomerulus / Q000528:radiation effects; D007685:Kidney Tubules, Collecting / Q000528:radiation effects; D007686:Kidney Tubules, Distal / Q000528:radiation effects; D007687:Kidney Tubules, Proximal / Q000528:radiation effects; D008297:Male; D051379:Mice; D012062:Relative Biological Effectiveness; D013997:Time Factors; D014965:X-Rays