A histological and electron-microscopic study of the cell types involved in rejection of skin allografts in ammocoetes

1983 ◽  
Vol 231 (2) ◽  
Author(s):  
Tamotsu Fujii ◽  
Izumi Hayakawa
Keyword(s):  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Cell Types ◽  
Electron Microscopic ◽  
Skin Allografts

Selective staining of secretory granules of adrenal medullary cells by silver methenamine: A light and electron microscopic study

1968 ◽  
Vol 46 (5) ◽  
pp. 745-747 ◽  
Author(s):  
William W. L. Chang ◽  
Sergio A. Bencosme
Keyword(s):  
Microscopic Study ◽  
Adrenal Medulla ◽  
Electron Microscopic Study ◽  
Secretory Granules ◽  
Cell Types ◽  
Cell Type ◽  
Glutaraldehyde Fixation ◽  
Electron Microscopic ◽  
Selective Staining ◽  
The Third

A reevaluation of the silver methenamine reaction as an electron stain has ensued from recent use of glutaraldehyde fixation alone. By this technique, three cell types of rat adrenal medulla were found: (i) the norepinephrine-containing cells showed selectively stained, irregular, black granules; (ii) the epinephrine-containing cells showed round, light-grey granules; and (iii) the third cell type showed round granules like those of epinephrine-containing cells, but black in color, similar to those of the norepinephrine-containing cells.

An electron microscopic study of the formation and structure of the periostracum in Astarte (Bivalvia)

1974 ◽  
Vol 52 (12) ◽  
pp. 1463-1471 ◽  
Author(s):  
A. S. M. Saleuddin
Keyword(s):  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Cell Types ◽  
Homogeneous Layer ◽  
Fibrous Layer ◽  
Electron Microscopic ◽  
The Third ◽  
Thin Sectioning ◽  
Structural Details ◽  
Different Cell Types

An electron microscopic study of the outer and middle folds of the mantle edge of Astarte castanea reveals the fine-structural details of the cells which are involved in the formation of the periostracum. There are four types of cells in the outer fold whereas there is only one type in the middle fold. The role of different cell types in the formation of the periostracum has been discussed. The periostracum originates in the intercellular space between the basal cell of the outer fold and the first cell of the middle fold. Even at the point of origin it consists of two outer membranous layers and the inner dark homogeneous layer. The fibrous translucent layer, which is the third layer of the fully mature periostracum, does not appear until the young periostracum has moved down the periostracal groove at the level of the third cell. As the periostracum matures, the two membranous layers remain remarkably constant in width, whereas the two inner layers, dark homogeneous and fibrous translucent, increase in thickness. Scanning electron microscopy and thin sectioning reveal that the fully mature periostraca of A. castanea and A. elliptica appear uniformly pitted, but the nature of the pits between the two species is different. The fibrils of the fibrous layer show either uniform or random arrangements, depending on the region. It is the innermost part of the fibrous layer of the periostracum that provides the nuclei for calcification.

scholarly journals Electron microscopic study of Saccharomyces cerevisiae rDNA chromatin replication.

1986 ◽  
Vol 6 (4) ◽  
pp. 1148-1157 ◽  
Author(s):  
L D Saffer ◽  
O L Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Cell Types ◽  
S Phase ◽  
Restrictive Temperature ◽  
Electron Microscopic ◽  
Autonomously Replicating Sequence ◽  
The Mean ◽  
Mating Factor

An electron microscopic study was made of the replication of rDNA chromatin of Saccharomyces cerevisiae. Two different methods were used to synchronize cells. cdc7-1 cells were raised to a restrictive temperature, whereas A364a cells were blocked with mating factor. Replication bubbles typically opened in the nontranscribed spacers of rDNA repeats in both cell types. The mean position of the center of these bubbles corresponds closely to a position where an autonomously replicating sequence previously has been mapped in an rDNA repeat. Clusters of replication bubbles containing up to four bubbles spaced one to three genes apart were seen opening in early S phase.

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