Electron microscope study on the glial filaments of astrocytes in the rat brain

Author(s):  
S. Mori ◽  
K. Furukawa ◽  
H. Abe

With the electron microscope, it was demonstrated that the glial filaments existed in astrocytes and could be impregnated by Cajal's gold chloride sublimate solution. By this conspicuous structure of glial filaments, thus, the astrocytes have long been differentiated from other glial cells from the classical light microscopic studies till the recent electron microscopic observations. Further investigations could add the new knowledge on this important component of glial cells in this laboratory that the actin- like filaments might be contained among the glial filaments. It will be shown in this report that glial filaments of astrocytes are consisted of the heterogenous groups of filaments, and some of them can bind with the heavy meromyosins (HMM).Normal rats (about 120 g body weight) were anesthetized with Nembutal and fixed by perfusion through the heart for 30 minutes with the fixative. This fluid was consisted of 3 % glutaraldehyde, 2 % paraformaldehyde, 4 % sucrose and 0. 5 mM CaCl2 in 0. 1 M phosphate buffer at PH 7. 4.

1975 ◽  
Author(s):  
W. H. Krause ◽  
P. Zimmermann

The present study describes an electron microscopic analysis, using a quantitative morphometric method, of fibrin network obtained by thrombin and reptilase in the presence of dextran. The thickness of the thrombin induced fibrin meshwork show a significant difference compared to fibrin formed by reptilase. The segment length of reptilase fibrin are reduced to 25% and the thickness of the fibers are reduced to 75% in comparison with thrombin fibrin.The thickness of the fibrin meshwork obtained by thrombin and/or reptilase in the presence of dextran ( w 40,000) is significantly diminished compared to saline controls (p < 0.001). Segment length and thickness of fibers in the clots with dextran showed different results when thrombin or reptilase were used as enzyme.The investigation indicates that the fibrin meshwork formed by thrombin and/or reptilase in the presence or absence of dextran result in a significantly different fibrin morphylogy. The results are different to the so far descriptive electron microscopic studies.


Blood ◽  
1960 ◽  
Vol 15 (4) ◽  
pp. 480-490 ◽  
Author(s):  
JAMES C. HAMPTON

Abstract Evidence that erythrocytes are phagocytized and dismantled by hepatic parenchymal cells in the newborn rabbit is presented. It is concluded that in these cells iron is recovered from disintegrating erythrocytes, synthesized into ferritin and released into the hepatic cell cytoplasm and into the biliary passages. These conclusions are based upon observations on the distribution of material giving the Prussian blue reaction in sections of liver as revealed by the light microscope and upon electron microscopic images of particles displaying the size, density and configuration of the ferritin molecule.


1953 ◽  
Vol 2 (13) ◽  
pp. 176-180
Author(s):  
Ukichiro Nakaya

AbstractSnow crystals were received on the collodion film of the holder of an electron microscope, and made to sublimate without melting. These specimens were investigated under an electron microscope. One solid nucleus was always observed in the central portion of a snow crystal. These centre nuclei were of sizes between 0.5 and 8μ. Most of them were presumed to be kaolin, clay or carbon particles; some were considered to be micro-organisms. In the other parts of snow crystals numerous smaller nuclei were observed, whose dimensions were of the order of those of condensation nuclei. These condensation nuclei were found to be of two kinds, the larger ones most frequently having a diameter of about 0.15μ, the smaller ones of about 0.05μ. A new theory was proposed from the data of the electron microscopic studies and those of the conditions of formation of snow crystals. In this theory it is proposed that minute water droplets of 1μor so play an important rôls in the process of snow crystal growth.


1973 ◽  
Vol 40 (1) ◽  
pp. 113-117 ◽  
Author(s):  
M. H. Abd El-Salam ◽  
Safinaz El-Shibiny

SummaryA technique is described for preparing ultrathin sections from cheese for electron-microscopic examination. The internal structure of fresh Domiati cheese was found to be composed of a framework of large, spherical casein aggregates held by bridges and enclosing fat.After pickling, the casein aggregates were partly disintegrated into small spherical particles forming a loose structure.


Author(s):  
Kaiser Jamil ◽  
K.N. Jyothi ◽  
A.L. Prasuna

Sensory mechanisms underlying insect chemical communication have been given considerable attention in recent years. A study on the ultrastructural details of the antennal appendages and the pheromone producing structures of Achoea janata L. and Ophiusa algira were studied with scanning electron microscope in order to understand the mechanisms of olfactory perception and pheromone release.For fixation of pheromone producing glands of A.Janata and O.Algira the posterior region of the abdomen was pressed sufficiently and flooded with carnoys fluid for complete excedation of the 9th abdominal along with the ovipositor. The above specimens as well as the antennal appendages were then fixed in 4% glutaraldehyde in phosphate buffer of 7.2 pH dehydrated in increasing grades of ethylalcohol and critical point dried. The specimens were then coated with gold in vacuum evaporator and observed in a Hitachi S-520 evaporator and observed in a Hitachi S-520 SEM operated at 20KV.


1987 ◽  
Vol 20 (6) ◽  
pp. 505-506 ◽  
Author(s):  
K. Łukaszewicz ◽  
J. Stępién-Damm ◽  
R. Horyń ◽  
Z. Bukowski ◽  
M. Kowalski

Electron microscopic observations of small single-crystal grains of YBa2Cu3O6+δ confirmed the orthorhombic symmetry and revealed very fine domain structure with twin boundaries parallel to (110) crystallographic planes.


Development ◽  
1968 ◽  
Vol 20 (3) ◽  
pp. 343-354
Author(s):  
Katherine M. Lyser

Mature neurons with centrioles were first described at the end of the nineteenth century and have been observed in many animals (see Cajal, 1911; Ariëns Kappers, Huber & Crosby, 1936). As mitosis rarely, if ever, occurs after morphological differentiation of the neuroblast begins, the function of the centrioles in nerve cells posed a problem which has yet to be resolved. Held (1909) described centrosomes in differentiating neuroblasts as being associated with the ‘fibrillogenous zone’, which suggests a role for the centriole in the differentiation of neurofibrils. Recently, electron-microscopic observations have refocused attention on the possibility of morphological and functional association between the centrioles of nerve cells and the fibrillar elements, especially neurotubules, which appear to be similar in fine structure to microtubules of other types of cells and to spindle tubules of the mitotic apparatus.


1953 ◽  
Vol 2 (13) ◽  
pp. 176-180 ◽  
Author(s):  
Ukichiro Nakaya

AbstractSnow crystals were received on the collodion film of the holder of an electron microscope, and made to sublimate without melting. These specimens were investigated under an electron microscope. One solid nucleus was always observed in the central portion of a snow crystal. These centre nuclei were of sizes between 0.5 and 8μ. Most of them were presumed to be kaolin, clay or carbon particles; some were considered to be micro-organisms. In the other parts of snow crystals numerous smaller nuclei were observed, whose dimensions were of the order of those of condensation nuclei. These condensation nuclei were found to be of two kinds, the larger ones most frequently having a diameter of about 0.15μ, the smaller ones of about 0.05μ. A new theory was proposed from the data of the electron microscopic studies and those of the conditions of formation of snow crystals. In this theory it is proposed that minute water droplets of 1μ or so play an important rôls in the process of snow crystal growth.


Author(s):  
O. E. Bradfute ◽  
R. E. Whitmoyer ◽  
L. R. Nault

A pathogen transmitted by the eriophyid mite, Aceria tulipae, infects a number of Gramineae producing symptoms similar to wheat spot mosaic virus (1). An electron microscope study of leaf ultrastructure from systemically infected Zea mays, Hordeum vulgare, and Triticum aestivum showed the presence of ovoid, double membrane bodies (0.1 - 0.2 microns) in the cytoplasm of parenchyma, phloem and epidermis cells (Fig. 1 ).


Author(s):  
A. Campos ◽  
J. Vilches ◽  
J. Gomez

Microgranules have been described with different names in keratinized and in nonkeratinized epithelium. In keratinized epithelium it seems clear that the microgranules are lamellated bodies bounded by a membrane which empty their contents into the intercellular space. Their existence in nonkeratinized epithelium is more debatable. Until now the so-called microgranules have been described in nonkeratinized bucal, lingual and cervical epithelium. In the present work we describe the morphology and nature of such structures in human vaginal epithelium.Biopsies from the midlevel of the vaginal mucosa were taken from voluntary fertile women. The specimens were divided into three groups with four vaginal specimens. The first group was obtained in the folicular phase; those of the second in the postovulatory phase and, finally, the last group corresponded to the secretory phase.


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