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2018 ◽  
Author(s):  
Daniel Bell
Keyword(s):  
Author(s):  
Raoul Fresco ◽  
Mary Chang-Lo

Confusion surrounds the nature of the “adenomatoid tumor” of the testis, as evidenced by the large number of synonyms which have been ascribed to it. Various authors have considered the tumor to be of endothelial, mesothelial or epithelial origin. There appears to be no controversy as to the stromal elements of the tumor, which consists mainly of smooth muscle and fibrous tissue. It is the irregular gland-like spaces which have given rise to the numerous theories as to its histogenesis, and even recent ultrastructural studies fail to agree on the origin of these structures.Electron microscopy of a typical intrascrotal adenomatoid tumor showed the gland-like spaces to be lined by epithelial cells (Fig. 1), rich in cytoplasmic tonofibrils and united to each other by numerous desmosomes (Fig. 2). The most salient feature of these epithelial cells was the presence on their luminal surface of numerous long and repeatedly branching microvillous structures of the type known as stereocilia (Fig. 3). These are extremely long slender cell processes which are as much as three to four times the length of those in brush borders.


Author(s):  
John H. L. Watson ◽  
C. N. Sun

That the etiology of Whipple's disease could be bacterial was first suggested from electron micrographs in 1960. Evidence for binary fission of the bacteria, their phagocytosis by histiocytes in the lamina propria, their occurrence between and within the cells of the epithelium and on the brush border of the lumen were reported later. Scanning electron microscopy has been applied by us in an attempt to confirm the earlier observations by the new technique and to describe the bacterium further. Both transmission and scanning electron microscopy have been used concurrently to study the same biopsy specimens, and transmission observations have been used to confirm those made by scanning.The locations of the brush borders, the columnar epithelial cells, the basement membrane and the lamina propria beneath it were each easily identified by scanning electron microscopy. The lamina propria was completely filled with the wiener-shaped bacteria, Fig. 1.


1976 ◽  
Vol 21 (3) ◽  
pp. 449-463
Author(s):  
A.G. Booth ◽  
J. Kenny

The vesiculation of kidney proximal tubule microvilli has been examined in tissue slices, isolated brush borders and isolated microvilli. Vesiculation could be induced in tissue slices by 2,4-dinitrophenol and anoxia. Cycloheximide and fluoride had no effect. In brush borders and microvilli, the vesiculation was found to be essentially temperature-dependent. Whilst an osmotic swelling could be produced by hypo-osmolar media, the temperature-dependent vesiculation could not be prevented in hyper-osmolar media. Of a wide variety of reagents tested, only glutaraldehyde, mercuric chloride and mersalyl were effective in arresting the vesiculation. Electron micrographs show that vesiculation involves a collapse of the internal structure of the microvillus. However, the collapse was not associated with depolymerization of the microvillus actin filaments. Rather it appeared to be due to the parting of cross-bridges between the membrane and the actin filaments. The nature of these cross-bridges is discussed: it is suggested that alpha-actinin possesses the characteristics for the cross-bridging protein and that vesiculation might be explained by the displacement of alpha-actinin by tropomyosin.


1984 ◽  
Vol 12 (6) ◽  
pp. 1116-1117 ◽  
Author(s):  
GORDON BRUCE ◽  
JOHN F. WOODLEY

Microbiology ◽  
1981 ◽  
Vol 125 (1) ◽  
pp. 167-172 ◽  
Author(s):  
P. N. LEVETT ◽  
R. R. DANIEL
Keyword(s):  

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