tokens: The degree of vacuolar degeneration of myocardial cells was analyzed in relation to the duration of adriamycin treatment ( 2 mg / kg , once a week ). There were no abnormalities or only isolated degeneration in the 1 - or 2 - wk treatment groups , isolated or scattered degeneration in half of the 3 - wk group , frequent scattered degeneration in the 4 - wk group , scattered or focal degeneration in the 5 - wk group , and extensive degeneration in the 8 - wk group .