Ultrastructural studies of cartilage in genetic disorders of skeletal growth

Author(s):  
D. O. Sillence ◽  
D. L. Rimoin ◽  
Ruth Silberberg

The human skeletal dysplasias are an heterogeneous group of heritable connective tissue disorders associated with abnormalities in the size and shape of the limbs, trunk and/or skull which frequently result in disproportionate short stature. In recent years it has become apparent that these comprise over 50 distinct conditions with a variety of subtypes distinguished on clinical and radiological grounds. We have investigated the pathogenesis of these conditions in over 100 patients by direct transmission electron microscopic examination of chondro-osseous tissue. Some of the ultrastructural studies have been previously reported.Small biopsies of chondro-osseous junction were collected for electron microscopy from the rib or iliac crest of patients with skeletal dysplasias or from normal controls at the time of surgery. These were cut into small blocks and fixed for one hour in either 5% glutaraldehyde in white's buffer or directly in 1% osmic acid in White's buffer or a modified Karnovsky's fixative, (2. 5% paraformaldehyde, 2. 5% glutaraldehyde, 2. 5mM calcium in cacodylate buffer). Subsequent processing included osmium fixation, block staining with uranyl acetate and embedding in Araldite or Spurr's low viscosity resin (firm composition). Sections were cut with glass knives or diamond knives. The latter produced sections which were much more even in thickness, permitting more consistent appraisal of matrix features.

Author(s):  
R. V. W. Dimlich

Neural mechanisms are important in the regulation of numerous hepatic functions including hepatic blood flow, carbohydrate metabolism and biliary flow. The innervation of the liver is species specific and in the rat, light microscopic data indicated that catecholamine and cholinergic nerves were present in portal areas. (1,2) Electron microscopic studies described the presence of nerve endings in the connective tissue adjacent to blood vessels and bile ducts as well as limiting plate hepatocytes. (2) A previous study in this laboratory reported unmyelinated nerve processes near mast cells. (3) The present study was undertaken to quantify the appearance of nerves and their relationship to mast cells in hepatic portal areas in rats.Hepatic tissue from 8 rats was removed and fixed in 2% glutaraldehyde and 2% paraformaldehyde in a 0.1M Na cacodylate buffer (pH 7.3), postfixed in 1% osmium tetroxide, and embedded in Epon. Sections stained with uranyl acetate and lead citrate were viewed on a Philips 301 electron microscope. A minimum of 3 sections per rat and a total of 30 portal areas were analyzed.


Author(s):  
Kosuke Ueda ◽  
Hiroto Washida ◽  
Nakazo Watari

IntroductionHemoglobin crystals in the red blood cells were electronmicroscopically reported by Fawcett in the cat myocardium. In the human, Lessin revealed crystal-containing cells in the periphral blood of hemoglobin C disease patients. We found the hemoglobin crystals and its agglutination in the erythrocytes in the renal cortex of the human renal lithiasis, and these patients had no hematological abnormalities or other diseases out of the renal lithiasis. Hemoglobin crystals in the human erythrocytes were confirmed to be the first case in the kidney.Material and MethodsTen cases of the human renal biopsies were performed on the operations of the seven pyelolithotomies and three ureterolithotomies. The each specimens were primarily fixed in cacodylate buffered 3. 0% glutaraldehyde and post fixed in osmic acid, dehydrated in graded concentrations of ethanol, and then embedded in Epon 812. Ultrathin sections, cut on LKB microtome, were doubly stained with uranyl acetate and lead citrate.


Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.


Author(s):  
S. Shirahama ◽  
G. C. Engle ◽  
R. M. Dutcher

A transplantable carcinoma was established in North West Sprague Dawley (NWSD) rats by use of X-irradiation by Engle and Spencer. The tumor was passaged through 63 generations over a period of 32 months. The original tumor, an adenocarcinoma, changed into an undifferentiated carcinoma following the 19th transplant. The tumor grew well in NWSD rats of either sex at various ages. It was invariably fatal, causing death of the host within 15 to 35 days following transplantation.Tumor, thymus, spleen, and plasma from 7 rats receiving transplants of tumor at 3 to 9 weeks of age were examined with an electron microscope at intervals of 8, 15, 22 and 30 days after transplantation. Four normal control rats of the same age were also examined. The tissues were fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in Epon. The plasma was separated from heparanized blood and processed as previously described for the tissue specimens. Sections were stained with uranyl acetate followed by lead citrate and examined with an RCA EMU-3G electron microscope.


Author(s):  
J. W. Horn ◽  
B. J. Dovey-Hartman ◽  
V. P. Meador

Osmium tetroxide (OsO4) is a universally used secondary fixative for routine transmission electron microscopic evaluation of biological specimens. Use of OsO4 results in good ultrastructural preservation and electron density but several factors, such as concentration, length of exposure, and temperature, impact overall results. Potassium ferricyanide, an additive used primarily in combination with OsO4, has mainly been used to enhance the contrast of lipids, glycogen, cell membranes, and membranous organelles. The purpose of this project was to compare the secondary fixative solutions, OsO4 vs. OsO4 with potassium ferricyanide, and secondary fixative temperature for determining which combination gives optimal ultrastructural fixation and enhanced organelle staining/contrast.Fresh rat liver samples were diced to ∼1 mm3 blocks, placed into porous processing capsules/baskets, preserved in buffered 2% formaldehyde/2.5% glutaraldehyde solution, and rinsed with 0.12 M cacodylate buffer (pH 7.2). Tissue processing capsules were separated (3 capsules/secondary fixative.solution) and secondarily fixed (table) for 90 minutes. Tissues were buffer rinsed, dehydrated with ascending concentrations of ethanol solutions, infiltrated, and embedded in epoxy resin.


Author(s):  
J. L. Stites

A Nocardia sp.was found during an initial transmission electron microscopic (TEM) examination to have unusual intracellular bodies (ICB's) which do not appear to have been described previously in the literature. Most intracellular structures within bacteria have been classified as storage granules, a product of membrane invagination (i.e. mesosomes), or vacuoles. In bacteria there are no known intracellular membrane-bound organelles, and all internal membranes are invaginations of the unit membrane. Several microscopic-level examinations of the Nocardia sp. ICB's were initiated in order to determine their overall structure, classification, and internal constitution.Different TEM staining procedures were performed to determine possible molecular components of the ICB. In all of the staining protocols the ICB's showed a lack of electron density similar to the cell wall. Because the ICB's showed no affinity to any stain, it appeared they do not have strong positive charge (phosphotungstic acid), are not protein rich (en bloc uranyl acetate), lack glycogen and are not phosphate or sulphur rich (lead citrate), nor do they contain lipids or ribonucleic acids (osmium tetroxide).


1973 ◽  
Vol 19 (8) ◽  
pp. 887-894
Author(s):  
Linda Poffenroth ◽  
J. W. Costerton ◽  
Nonna Kordová ◽  
John C. Wilt

Electron microscopic examination of a semipurified Chlamydia psittaci 6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.


1978 ◽  
Vol 56 (17) ◽  
pp. 2006-2012 ◽  
Author(s):  
Gerald L. Benny ◽  
Don A. Samuelson ◽  
James W. Kimbrough

Transmission electron microscopic observations made on the ascus tip of Orbilia luteorubella showed that it is truncate and that the outer ascus wall is relatively thicker at the shoulders than on the top or sides. There is no demonstrable discharge mechanism in the ascal apex of this fungus comparable with that found in the ascus tip of other supposedly related inoperculate Discomycetes, including Mollisia cinerea.Ascospores of O. luteorubella contain a single, electron-opaque spore body that appears to evolve from a mitochondrion that is attached, at one end, to the inner wall of the spore apiculus. The function of the spore body is unknown.A blue-green alga, probably of the genus Anacystis, is associated with this and at least one other Orbilia species. Since these Orbilia species are here shown to be lichenized and they do not have an ascal pore discharge mechanism, the transfer of these fungi from the Helotiales is proposed. They can probably best be treated as lichens of uncertain affinities, perhaps related to those members of Lecanorales with iodine-negative asci.


2002 ◽  
Vol 2 ◽  
pp. 972-977 ◽  
Author(s):  
M.A. Mondaca ◽  
V. Campos ◽  
R. Moraga ◽  
C.A. Zaror

Pollution of aquatic systems by heavy metals has resulted in increasing environmental concern because they cannot be biodegraded. One metal that gives reason for concern due to its toxicity is chromium. Cr(VI) and Cr(III) are the principal forms of chromium found in natural waters. A chromate-resistant strain of the bacterium S. marcescens was isolated from tannery effluent. The strain was able to reduce Cr(VI) to Cr(III), and about 80% of chromate was removed from the medium. The reduction seems to occur on the cell surface. Transmission electron microscopic examination of cells revealed that particles were deposited on the outside of bacterial cells. A stable biofilm was formed in less than 10 h, reaching around 1010cfu attached per milligram of activated carbon. These findings demonstrate that immobilizedS. marcescensmight be used in industrial waste treatment processes.


1982 ◽  
Vol 60 (4) ◽  
pp. 550-559 ◽  
Author(s):  
William P. Eshleman ◽  
Jerrel L. Wilkens ◽  
Michael J. Cavey

The proteins of the striated adductor muscles, smooth adductor muscles, and diductor muscles of the articulate brachiopod Terebratalia transversa have been examined by sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Electrophoretic patterns indicate the presence of paramyosin in all of these valve muscles. Tentative identification has also been made of the proteins responsible for actin and for myosin regulation of contraction (troponin–tropomyosin and myosin light chains, respectively). The myofilaments of the striated adductor cells, smooth adductor cells, and diductor cells have been characterized by transmission electron microscopy. The smooth adductor cells and the diductor cells exhibit very thick myofilaments which are fusiform in shape, exceptionally long, and axially banded. Morphological features of these thick myofilaments are consistent with those of paramyosin filaments found in other muscles and myoepithelia. Although the striated adductor cells contain paramyosin, it is not manifest in the thick myofilaments.


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