Ultrastructural localization of endogenous peroxidase in the lower respiratory tract of the guinea pig.

Endogenous peroxidase activity was demonstrated by cytochemistry in mucous cells of the submucosal glands and tracheobronchial epithelium of guinea pigs. It is localized in the nuclear envelope, in cisternae of rough endoplasmic reticulum, and in secretory granules. It was not seen in Golgi saccules or in the airway lumen.

Whipple's disease with minimal intestinal involvement.

An uncharacteristic case of Whipple's disease is reported, in which, although overt intestinal involvement was absent, and there was only a patchy histological lesion, the diagnosis was confirmed by electron-microscopic examination of peroral intestinal biopsies.