scholarly journals Structure of the Rete Mirabile in the Kidney of the Rat as Seen with the Electron Microscope

1960 ◽  
Vol 7 (1) ◽  
pp. 103-106 ◽  
Author(s):  
J. B. Longley ◽  
W. G. Banfield ◽  
D. C. Brindley
Keyword(s):  
Endothelial Cells ◽  
Fine Structure ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Simple Diffusion ◽  
Functional Capabilities ◽  
Rete Mirabile ◽  
Peritubular Capillaries ◽  
Fenestrated Endothelium

Electron micrographs of the rete mirabile in the medulla of the rat have revealed that the endothelium of the afferent and efferent vessels are markedly different in fine structure. The venous capillaries returning blood from the papilla are lined with a fenestrated endothelium much like that in the peritubular capillaries of the kidney. The arterial capillaries delivering blood to the papilla have an unperforated lining of overlapping endothelial cells with extremely irregular tapered margins. It is pointed out that the organization of particularly the latter vessels suggests that the functional capabilities of these retia go beyond those of a simple diffusion countercurrent exchanger.

The Ultra-fine Structure of Lipid Globules in the Neurones of Helix aspersa

1958 ◽  
Vol s3-99 (46) ◽  
pp. 279-284
Author(s):  
J.T. Y. CHOU ◽  
G. A. MEEK
Keyword(s):  
Methylene Blue ◽  
Fine Structure ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Light Microscope ◽  
Helix Aspersa

The three kinds of lipid globules recognizable in the living neurones of Helix aspersa have been examined under the electron microscope. The globules of the kind that can be stained blue with methylene blue during life are seen in electron micrographs as spheres or spheroids, with concentric lamination, after calcium-osmium fixation. After fixation with sucrose-osmium laminated crescentic bodies are seen instead; these appear to be formed by distortion of the ‘blue’ globules. The yellow globules contain electrondense material, and sometimes appear reticular. It is possible that the yellow globules may originate by transformation of some of the ‘blue’ globules. The colourless globules generally appear as crenated objects; this appearance may be a shrinkage artifact. Apart from the mitochondria and the three kinds of lipid globules described, no other object large enough to be identified with the light microscope has been seen in the cytoplasm.

MO087PLASMALEMMAL VESICLE-ASSOCIATED PROTEIN-1 (PLVAP) INDICATES THE FORMATION OF DIAPHRAGM-BRIDGED FENESTRATIONS OF GLOMERULAR ENDOTHELIAL CELLS IN KIDNEY DISEASE

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Björn Tampe ◽  
Laura Schridde ◽  
Samy Hakroush
Keyword(s):  
Endothelial Cells ◽  
Diabetic Nephropathy ◽  
Pore Formation ◽  
Major Protein ◽  
Glomerular Diseases ◽  
Glomerular Endothelial Cells ◽  
Peritubular Capillaries ◽  
Glomerular Endothelium ◽  
Fenestrated Endothelium ◽  
Glomerular Tuft

Abstract Background and Aims Plasmalemmal vesicle-associated protein-1 (PLVAP or PV-1) is a major protein of diaphragm-bridged fenestrated endothelial cells found in capillaries of neuroendocrine glands and peritubular capillaries. In contrast to peritubular capillaries, the glomerulus is known for its unique fenestrated endothelium without any diaphragm formation thereby ensuring free filtration. Here we aimed to investigate whether PLVAP is expressed in glomerular endothelial cells in various glomerular diseases and whether PLVAP expression is associated with the formation of diaphragm-bridged endothelial cells. Method A total number of 114 biopsy samples of glomerular diseases including diabetic nephropathy, FSGS, IgA-Nephritis, ANCA-GN and Lupus–Nephritis were analyzed immunohistochemistically for glomerular PLVAP expression. A fraction of PLVAP positive cases was subsequently investigated ultrastrucurally for the formation of diaphragm-bridged glomerular endothelial cells. Results One third of all cases showed at least one glomerulus with one single circumferential PLVAP staining. Interestingly, the most prominent staining, affecting the entire glomerular tuft, was observed in diabetic nephropathy and ANCA-GN. Ultrastructurally, such cases exhibited injured endothelium with focal detachment from the glomerular basement membrane, loss of pore formation and frequently diaphragm-bridged fenestrations reminiscent of peritubular capillaries. Conclusion Our data show that injured glomerular endothelium is capable of forming true diaphragm-bridged fenestrations, suggesting a possible role in preventing glomerular protein leakage and limiting its detachment from the GBM.

scholarly journals OBSERVATIONS WITH THE ELECTRON MICROSCOPE ON THE FINE STRUCTURE OF THE NUCLEI OF TWO SPHERICAL BACTERIA

1961 ◽  
Vol 9 (1) ◽  
pp. 171-181 ◽  
Author(s):  
Woutera Van Iterson ◽  
C. F. Robinow
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Growth Cycle ◽  
The Other ◽  
Low Density ◽  
Thin Sections ◽  
Dna Molecule

The nuclei of two spherical bacteria have been examined in electron micrographs of thin sections of specimens prepared by the method of Ryter and Kellenberger (1958). The nuclei appear to consist of the same fine fibers in a matrix of low density which have already been seen in many other bacteria prepared by the same procedure. They are worth a separate description because their constituent fibers are arranged in patterns of uncommon orderliness. In the nuclei of one of the two bacteria this is seen at all times, in the nuclei of the other one only at the beginning of the growth cycle. In some places the diameter of the nuclear fibers is close to that of the DNA molecule in the model of Watson and Crick (1953).

scholarly journals STUDIES ON INFLAMMATION

1961 ◽  
Vol 11 (3) ◽  
pp. 571-605 ◽  
Author(s):  
G. Majno ◽  
G. E. Palade
Keyword(s):  
Endothelial Cells ◽  
Electron Microscope ◽  
Basement Membrane ◽  
Blood Vessels ◽  
Electron Micrographs ◽  
Light Microscope ◽  
Intercellular Junctions ◽  
Supporting Evidence ◽  
Electron Microscopic ◽  
Tracer Particles

The mechanism, whereby histamine and serotonin increase the permeability of blood vessels, was studied in the rat by means of the electron microscope. The drugs were injected subcutaneously into the scrotum, whence they diffused into the underlying (striated) cremaster muscle. An intravenous injection of colloidal HgS was also given, in order to facilitate the identification of leaks by means of visible tracer particles. After intervals varying from 1 minute to 57 days the animals were killed; the cremaster was fixed, embedded in methacrylate, and examined with the electron microscope. One to 12 minutes after the injection, the blood vessels of the smallest caliber (3 to 5 micra as measured on electron micrographs) appeared intact. Numerous endothelial openings were present in blood vessels with a diameter of 7 to 8 micra or more. These gaps were 0.1 to 0.8 micra in width; portions of intercellular junctions were often present in one or both of the margins. The underlying basement membrane was morphologically intact. An accumulation of tracer particles and chylomicra against the basement membrane indicated that the latter behaved as a filter, allowing fluid to escape but retaining and concentrating suspended particulate matter of the size used. Uptake of tracer particles by endothelial vesicles was minimal. Phagocytosis by endothelial cells became more prominent at 3 hours, but as a secondary occurrence; the pericytes were actively phagocytic at all stages. At the 3-hour stage no leaks were found. The changes induced by histamine and serotonin were indistinguishable, except that the latter was more potent on a mole-to-mole basis. In control animals only small accumulations of tracer particles were found in the wall of a number of blood vessels. With regard to the pathogenesis of the endothelial leaks, the electron microscopic findings suggested that the endothelial cells become partially disconnected along the intercellular junctions. Supporting evidence was provided at the level of the light microscope, by demonstrating—in the same preparation—the leaks with appropriate tracer particles1, and the intercellular junctions by the silver nitrate method. The lipid nature of the chylomicron deposits observed in electron micrographs was also confirmed at the level of the light microscope, using cremasters fixed in formalin and stained in toto with sudan red.

scholarly journals The Fine Structure of Endothelium of Large Arteries

1958 ◽  
Vol 4 (2) ◽  
pp. 187-190 ◽  
Author(s):  
R. C. Buck
Keyword(s):  
Endothelial Cells ◽  
Fine Structure ◽  
Electron Microscope ◽  
Double Row ◽  
Thorium Dioxide ◽  
Thin Sections ◽  
Large Arteries ◽  
Arterial Lumen ◽  
Characteristic Features ◽  
Silver Granules

Endothelium of large arteries from several species was studied in thin sections with the electron microscope. Before sacrifice, some animals received an intravenous injection of colloidal thorium dioxide which was visualized in the sections. Surface replicas were prepared by carbon evaporation on either frozen-dried endothelium or on endothelium dried by sublimation of naphthalene with which the tissue had been impregnated. Cell boundaries, stained with silver, were observed in sections and also from the surface by stripping off the inner part of the endothelium. In addition to the usual cytoplasmic organelles, the endothelial cells showed certain characteristic features, namely, large invaginated pockets communicating with the arterial lumen, numerous much smaller vesicular structures immediately under the plasma membrane and apparently also communicating with the lumen, and inclusions, into which injected thorium particles were incorporated. Intercellular boundaries appeared as regular double membranes in thin sections, and they were outlined by a double row of silver granules after silver staining. No evidence was obtained of permeation of intracellular spaces by colloidal thorium.

Utilizing Dark Field Electron Microscopy to Produce Lantern Slides

1974 ◽  
Vol 32 ◽  
pp. 116-117
Author(s):  
J. N. Meador ◽  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Electron Microscope ◽  
Electron Micrographs ◽  
Dark Field ◽  
Limiting Factor ◽  
Clinical Laboratories ◽  
Field Electron ◽  
Time Element ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Dark Field Micrographs

The electron microscope is being utilized more and more in clinical laboratories for pathologic diagnosis. One of the major problems in the utilization of the electron microscope for diagnostic purposes is the time element involved. Recent experimentation with rapid embedding has shown that this long phase of the process can be greatly shortened. In rush cases the making of projection slides can be eliminated by taking dark field electron micrographs which show up as a positive ready for use. The major limiting factor for use of dark field micrographs is resolution. However, for conference purposes electron micrographs are usually taken at 2.500X to 8.000X. At these low magnifications the resolution obtained is quite acceptable.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

Fine structure of the retina of the giant scallop, Placopecten magellanicus

1984 ◽  
Vol 42 ◽  
pp. 312-313
Author(s):  
C.V.L. Powell
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Light Intensity ◽  
Scanning Electron Microscope ◽  
Eye Development ◽  
Preliminary Observation ◽  
Columnar Epithelium ◽  
Placopecten Magellanicus ◽  
Environmental Light ◽  
Scanning Electron

The overall fine structure of the eye in Placopecten is similar to that of other scallops. The optic tentacle consists of an outer columnar epithelium which is modified into a pigmented iris and a cornea (Fig. 1). This capsule encloses the cellular lens, retina, reflecting argentea and the pigmented tapetum. The retina is divided into two parts (Fig. 2). The distal retina functions in the detection of movement and the proximal retina monitors environmental light intensity. The purpose of the present study is to describe the ultrastructure of the retina as a preliminary observation on eye development. This is also the first known presentation of scanning electron microscope studies of the eye of the scallop.

Ultrastructure of primary spermatocyte in fish (Tilapia: Oreochromis niloticus): The synaptonemal complex

1986 ◽  
Vol 44 ◽  
pp. 288-289
Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Synaptonemal Complex ◽  
Oreochromis Niloticus ◽  
Short Communication ◽  
Primary Spermatocyte ◽  
Mitotic Division ◽  
Meiotic Cell ◽  
Electron Microscope Level ◽  
Homologous Chromosomes

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.

Sign in / Sign up

Export Citation Format

Share Document