Ultrastructural Changes in the Hydropic Cochlea of the Guinea-pig

Transmission electron microscopy of the cochlear organ of Corti in experimental endolymphatic hydrops revealed two principal features. Starting 1 month after induction of hydrops, osmiophilic inclusions thought to represent lipofuscin accumulation were frequently observed in the subcuticular cytoplasm of the outer hair cells along the length of the cochlea. Starting 3 months after induction of hydrops the efferent terminals on the outer hair cells appeared to be vacuolated. These data suggest that oxidative insult is likely to contribute to the pathology associated with endolymphatic hydrops and thus that free radical scavengers might be useful in the treatment of Menière's disease patients. In addition the early modification of the efferent innervation of the hydropic cochlea might underlie the known hypersensitivity to various insults, including noise stimulation, glycerol administration and hypoxia.     

Lacteal zinc and copper in relation to volume, total ash and energy during the first three months of lactation of Brazilian women

The concentrations of zinc and copper were longitudinally studied during the first three months of self-determined lactation periods of nine Brazilian women. Both elements were studied in relation to volume, energy and total ash of milk. During the six bi-weekly intervals, zinc showed a significant difference between the high initial value (as mass/volume), mass/g of ash and mass/kcal) and later values toward the end of the third month, but no significant difference was observed for copper. With respect to all three of those parameters, regression analysis of zinc against length of lactation (six bi-weekly intervals) showed a significant and inverse correlation. Only when expressed as mass/g of ash was copper significantly and directly correlated with length of lactation. The data indicate that zinc secretion into human milk occurs independently of copper and mineral mass and also follows a previously identified physiological pattern.