A small amount of the myotube-like structures (chained nuclei) are present in skeletal muscle independently of disease. These experiments show that the incidence of the myotube-like structure increases with the advance of age in mice. Moreover, it is shown that the DNA in the myotube-like structure is not fragmented. That is, the myotube-like structures were TUNEL (Terminal deoxynuc-leotidyl transferase (TdT) -mediated dUTP-biotin Nick-End labeling) negative. Moreover, we detected the polyadenylated mRNA around the myotube-like structure by using an in situ hybridization technique. This suggests that the myotube-like structure has transcription activity.
This report indicates that the myotube-like structure is a useful indicator of aging in skeletal muscle.

OBJECTIVESTo investigate the effect of snack eating on salivary cortisol and chromogranin A (CgA).

METHODSFrom 14∶00 to 18∶00, starting two hours after consumption of a midday meal, saliva samples were collected every 30 minutes from 15 healthy males, 7 of whom (snack group) ate a snack immediately after the sampling at 15∶00. Salivary cortisol and CgA levels were determined by ELISA. Samples were controlled according to salivary flow rates.

RESULTSFor the snack group, after snack consumption, salivary cortisol increased to exceed significance (p<0.05) at 15∶30 and rose even higher at 16∶00. In the control group, there was no such change. There was no significant change in salivary CgA in either the snack group or the control groups during the sampling period.

CONCLUSIONSThese findings suggest that no food should be consumed for at least 90 mins before saliva sampling for cortisol determination and that salivary CgA is probably not affected by snack eating.