Netlike Appearance Research Articles

Ultrastructural Studies of Elastotic Material and Elastic Fibers in Aged Skin before and after Autoclaving

Elastotic material and aged elastic fibers of patients with solar elastosis before and after autoclaving was studied using the tannic acid stain as well as the conventional stain. The amorphous matrix of the elastotic material and the elastic fibers stained positive with the tannic acid stain. In the fibrous form of elastotic material and in the elastic fibers both electron-dense inclusions and the amorphous matrix remained unchanged after autoclaving, while microfibrils were removed. In the amorphous form the fine granular component and round bodies were removed after autoclaving, and the moderately electron-dense amorphous component with a reticular or net-like appearance remained. It has been suggested that the elastotic degenerative changes are (1) expansion of the electron-dense inclusions to form a larger part of the fiber; (2) transformation of the inclusions into moderately electron-dense material, composing mainly of a fine granular component and an amorphous one; and (3) disorganization of the moderately electron-dense material.

The Influence of EDTA, Trisodiumcitrate and Heparin on the Ultrastructure of Blood Platelets

SummaryThe differences found in the hyalomere of normal human thrombocytes were: the disperse, fine granular arrangement of the hyalomere in the presence of EDTA, fine netlike appearance in the presence of trisodiumcitrate and the fibrillary arrangement of the hyalomere in thrombocytes of heparinised blood.Differences were also found in the appearance of the granulomere in the presence of heparin, trisodiumcitrate or EDTA. They are evaluated as a result of probable contraction of the granulomere in specimens with heparin.Because of the ability of thrombocytes from heparinised blood to contract, we explain the present results as a picture of isolated retraction of blood platelets, without degranulation occuring during viscous metamorphosis.

A comparison of the radiological and pathological changes in coalworkers' pneumoconiosis

A technique is described for cutting sections of entire lungs. These sections, mounted on paper, were used for studying the pathology of coalworkers' pneumoconiosis and for comparison of the latter with the radiographic changes found during life. The radiographic patterns of ‘reticulation’ and ‘granularity’ seen in coalworkers are due to focal dust lesions (‘coal nodules’). A distinctive form of emphysema (‘focal emphysema’) develops in relation to the coal nodules. The degree of this emphysema could not in general be assessed accurately by radiology, but a sharply defined net-like appearance in radiographs corresponded with severe focal emphysema. Except for occasional confusion with neoplasms, massive fibrosis due to infected pneumoconiosis could be accurately diagnosed radiologically.