Electron Microscopic Characterization and Quantitation of Air Borne Particulate Matter with Special Emphasis on Asbestos

1972 ◽  
Vol 30 ◽  
pp. 356-357
Author(s):  
Peter K. Mueller ◽  
Glenn R. Smith ◽  
Leslie M Carpenter ◽  
Ronald L. Stanley
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Ambient Air ◽  
Quality Standard ◽  
Primary Objective ◽  
Cellulose Ester ◽  
Main Concept ◽  
Electron Microscopic ◽  
Air Samples ◽  
Diffraction Patterns

At the present time the primary objective of the electron microscopy group of the Air and Industrial Hygiene Laboratory is the development of a method suitable for use in establishing an air quality standard for asbestos in ambient air and for use in its surveillance. The main concept and thrust of our approach for the development of this method is to obtain a true picture of fiber occurrence as a function of particle size and asbestos type utilizing light and electron microscopy.We have now available an electron micrographic atlas of all asbestos types including selected area diffraction patterns and examples of fibers isolated from air samples. Several alternative approaches for measuring asbestos in ambient air have been developed and/or evaluated. Our experiences in this regard will be described. The most promising method involves: 1) taking air samples on cellulose ester membrane filters with a nominal pore size of 0.8 micron; 2) ashing in a low temperature oxygen plasma for several hours;

mRNA localization by Electron microscopic in situ hybridization

1991 ◽  
Vol 49 ◽  
pp. 430-431
Author(s):  
J. A. Pollock ◽  
M. Martone ◽  
T. Deerinck ◽  
M. H. Ellisman
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Nucleic Acids ◽  
Recombinant Dna ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Functional Sites ◽  
Voltage Electron

Localization of specific proteins in cells by both light and electron microscopy has been facilitate by the availability of antibodies that recognize unique features of these proteins. High resolution localization studies conducted over the last 25 years have allowed biologists to study the synthesis, translocation and ultimate functional sites for many important classes of proteins. Recently, recombinant DNA techniques in molecular biology have allowed the production of specific probes for localization of nucleic acids by “in situ” hybridization. The availability of these probes potentially opens a new set of questions to experimental investigation regarding the subcellular distribution of specific DNA's and RNA's. Nucleic acids have a much lower “copy number” per cell than a typical protein, ranging from one copy to perhaps several thousand. Therefore, sensitive, high resolution techniques are required. There are several reasons why Intermediate Voltage Electron Microscopy (IVEM) and High Voltage Electron Microscopy (HVEM) are most useful for localization of nucleic acids in situ.

Phase-contrast and electron-microscopic observations on a membranous complex in primary spermatocytes of the mouse

1975 ◽  
Vol 18 (1) ◽  
pp. 1-17
Author(s):  
A. Pleshkewych ◽  
L. Levine
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Phase Contrast ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Cytoplasmic Inclusion ◽  
Electron Microscopic ◽  
Secondary Spermatocyte ◽  
Living Mouse ◽  
Circular Contour

A prominent cytoplasmic inclusion present in living mouse primary spermatocytes has been observed by both light and electron microscopy. It began to form at prometaphase and continued to increase in thickness and length as the cells developed. By metaphase it was a distinct sausage-shaped boundary that enclosed a portion of the cytoplasm between the spindle and the cell membrane. At the end of metaphase, the inclusion reached its maximum length. At telophase, it was divided between the daughter secondaries. The inclusion persisted as a circular contour in the interphase secondary spermatocyte. Electron microscopy of the same cultured cells that were previously observed with light microscopy revealed that the inclusion was a distinctive formation of membranes. It consisted of agranular cisternae and vesicles, and was therefore a membranous complex. Many of the smaller vesicles in the membranous complex resembled those found in the spindle. The cisternae in the membranous complex were identical to the cisternal endoplasmic reticulum of interphase primary spermatocytes. Nevertheless, the organization of vesicles and cisternae into the membranous complex was unique for the primaries in division stages, since such an organization was not present in their interphase stages.

Morphological studies of bone and tendon

1992 ◽  
Vol 73 (2) ◽  
pp. S10-S13 ◽  
Author(s):  
S. B. Doty ◽  
E. R. Morey-Holton ◽  
G. N. Durnova ◽  
A. S. Kaplansky
Keyword(s):  
Electron Microscopy ◽  
Bone Cells ◽  
Weight Bearing ◽  
Light And Electron Microscopy ◽  
Cell Activity ◽  
Bone Cell ◽  
Electron Microscopic ◽  
Adult Rats ◽  
Morphological Studies ◽  
Metatarsal Bones

The Soviet biosatellite COSMOS 2044 carried adult rats on a spaceflight that lasted 13.8 days and was intended to repeat animal studies carried out on COSMOS 1887. Skeletal tissue and tendon from animals flown on COSMOS 2044 were studied by light and electron microscopy, histochemistry, and morphometric techniques. Studies were confined to the bone cells and vasculature from the weight-bearing tibias. Results indicated that vascular changes at the periosteal and subperiosteal region of the tibia were not apparent by light microscopy or histochemistry. However, electron microscopy indicated that vascular inclusions were present in bone samples from the flight animals. A unique combination of microscopy and histochemical techniques indicated that the endosteal osteoblasts from this same mid-diaphyseal region demonstrated a slight (but not statistically significant) reduction in bone cell activity. Electron-microscopic studies of the tendons from metatarsal bones showed a collagen fibril disorganization as a result of spaceflight. Thus changes described for COSMOS 1887 were present in COSMOS 2044, but the changes ascribed to spaceflight were not as evident.

Correlated 3D Light and Electron Microscopy of Large, Complex Structures: Analysis of Transverse Tubules in Heart Failure

1998 ◽  
Vol 4 (S2) ◽  
pp. 440-441
Author(s):  
Maryann E. Martone ◽  
Andrea Thor ◽  
Stephen J. Young ◽  
Mark H. Ellisman.
Keyword(s):  
Electron Microscopy ◽  
Electron Tomography ◽  
Light And Electron Microscopy ◽  
Structural Features ◽  
Electron Microscopic Level ◽  
Specimen Preparation ◽  
Large Sample Size ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron

Light microscopic imaging has experienced a renaissance in the past decade or so, as new techniques for high resolution 3D light microscopy have become readily available. Light microscopic (LM) analysis of cellular details is desirable in many cases because of the flexibility of staining protocols, the ease of specimen preparation and the relatively large sample size that can be obtained compared to electron microscopic (EM) analysis. Despite these advantages, many light microscopic investigations require additional analysis at the electron microscopic level to resolve fine structural features.High voltage electron microscopy allows the use of relatively thick sections compared to conventional EM and provides the basis for excellent new methods to bridge the gap between microanatomical details revealed by LM and EM methods. When combined with electron tomography, investigators can derive accurate 3D data from these thicker specimens. Through the use of correlated light and electron microscopy, 3D reconstructions of large cellular or subcellular structures can be obtained with the confocal microscope,

scholarly journals Histochemical localization of trehalase activity in dorsal flight muscle of the flesh fly Sarcophaga bullata with light and electron microscopy.

1975 ◽  
Vol 23 (11) ◽  
pp. 800-807 ◽  
Author(s):  
P L Chang ◽  
P E Morrison
Keyword(s):  
Electron Microscopy ◽  
Incubation Medium ◽  
Mitochondrial Membrane ◽  
Flight Muscle ◽  
Light And Electron Microscopy ◽  
Inner Mitochondrial Membrane ◽  
Electron Microscopic ◽  
Flesh Fly ◽  
Trehalase Activity ◽  
Sarcophaga Bullata

Trehalase activity in flight muscle of the flesh fly Sacrophaga bullata is detected histochemically at light- and electron-microscopic levels by using diaminobenzidine, glucose oxidase and peroxidase in the incubation medium. The association of trehalase activity with the inner mitochondrial membrane is confirmed. Biochemical assay shows that about 50% of the initial total trehalase activity is lost from the tissue during the histochemical processing and about 50% remains for histochemical detection.

scholarly journals THE GLOMERULUS IN EXPERIMENTAL RENAL DISEASE IN RATS AS OBSERVED BY LIGHT AND ELECTRON MICROSCOPY

1955 ◽  
Vol 102 (5) ◽  
pp. 573-580 ◽  
Author(s):  
Carolyn F. Piel ◽  
Luther Dong ◽  
F.W.S. Modern ◽  
Joseph R. Goodman ◽  
Roger Moore
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Basement Membrane ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
Crescent Formation ◽  
Colloidal Iron ◽  
Narrow Channels ◽  
Glomerular Capillary

Nephrotoxic serum disease in rats has been studied by light and electron microscopy from 1 hour to 10 weeks after production of the disease. By light microscopy leucocytic infiltration of the glomerular capillary was observed between the 3rd and 6th hour. At 6 hours an increase in colloidal iron-positive material was observed coating the extraluminal surface of the capillaries. Also at this time swelling of the endothelial cells becomes prominent. By 72 hours, thickening of the basement membrane was observed. Glomerular capillary thrombi were observed in approximately half the tissue examined in the first 2 weeks of disease. 50 per cent of the animals showed severe chronic lesions, exudation into the capsular space, crescent formation, and obliteration of glomeruli. At 1 hour electron microscopic pictures showed that osmophilic material may line the foot processes of the epithelial cells and obliterate all but narrow channels of the space between the feet. By 6 hours thickening of the basement membrane was prominent. This change persisted throughout 10 weeks of observation. The tissue from animals which had severe chronic alterations by light microscopy revealed changes which could not be interpreted at this time.

scholarly journals Inorganic trimetaphosphatase as a histochemical marker for lysosomes in light and electron microscopy.

1977 ◽  
Vol 25 (12) ◽  
pp. 1381-1384 ◽  
Author(s):  
S B Doty ◽  
C E Smith ◽  
A R Hand ◽  
C Oliver
Keyword(s):  
Electron Microscopy ◽  
Incubation Medium ◽  
Soft Tissues ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
Cytochemical Method ◽  
Microscopic Localization ◽  
Histochemical Marker ◽  
Electron Microscopic Localization

A new cytochemical method is presented for the light and electron microscopic localization of lysosomes in mineralized and soft tissues. Inorganic trimetaphosphate is used as substrate in a lead chelate incubation medium at pH 3.9. Lysosomes in several tissues are strongly reactive, and reaction product is frequently present in Golgi saccules and GERL. The reaction can be differentiated from acid glycerophosphatase activity, is relatively insensitive to fixation and demineralization procedures, and the reaction is often complete after short incubation times.

scholarly journals An electron microscopic and optical diffraction analysis of the structure of Limulus telson muscle thick filaments.

1982 ◽  
Vol 92 (2) ◽  
pp. 443-451 ◽  
Author(s):  
R W Kensler ◽  
R J Levine
Keyword(s):  
Electron Microscopy ◽  
Diffraction Analysis ◽  
Electron Micrographs ◽  
Optical Diffraction ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Thick Filaments ◽  
Diffraction Patterns ◽  
Cross Bridges

Long, thick filaments (greater than 4.0 micrometer) rapidly and gently isolated from fresh, unstimulated Limulus muscle by an improved procedure have been examined by electron microscopy and optical diffraction. Images of negatively stained filaments appear highly periodic with a well-preserved myosin cross-bridge array. Optical diffraction patterns of the electron micrographs show a wealth of detail and are consistent with a myosin helical repeat of 43.8 nm, similar to that observed by x-ray diffraction. Analysis of the optical diffraction patterns, in conjunction with the appearance in electron micrographs of the filaments, supports a model for the filament in which the myosin cross-bridges are arranged on a four-stranded helix, with 12 cross-bridges per turn or each helix, thus giving an axial repeat every third level of cross-bridges (43.8 nm).

scholarly journals Effects of radio-frequency electromagnetic radiations (RF-EMR) on cerebral cortex of albino rats-a light and electron microscopic study

2018 ◽  
Vol 5 (3) ◽  
pp. 3662-3668
Author(s):  
Dr.faisal Taufiq ◽  
Dr. Mohit Srivastava
Keyword(s):  
Electron Microscopy ◽  
Cerebral Cortex ◽  
Radio Frequency ◽  
Mobile Phones ◽  
Light And Electron Microscopy ◽  
Albino Rats ◽  
Control Groups ◽  
Electron Microscopic ◽  
Electromagnetic Radiations ◽  
Microscopic Findings

Background: Since the introduction of mobile phones in the late eighties, many studies have raised concerns about the possible adverse effects on health, as a result of the exposure to RF and microwave electromagnetic fields as RF-EMR can penetrate deep into organic tissues and get absorbed producing many biological effects in human body. Brain is involved in very important functions and RF-EMR might have damaging effects on its different parts. The present study was undertaken with an aim to study effects of radio-frequency electromagnetic radiations (RF-EMR) emitted by mobile phones on cerebrum in albino rats under light and electron microscopy and to evaluate such changes after exposure to graded dose of RF-EMR Material and methods: The present study was carried out on twenty four adult albino rats of either sex weighing 180-200 grams each. The animals were divided into four groups: 1 control and 3 experimental and were exposed to RF-EMR via complete missed calls of 45 seconds duration each. Both the experimental and control groups were then sacrificed and cerebral cortex was isolated for tissue processing. The processed tissues were then studied under light microscope (Hematoxylin & Eosin Staining) and Transmission Electron Microscopy (TEM).     Results: Light microscopic findings of the present study showed that cellular size of neuronal cells in pyramidal layer of cerebral cortex, neurons of hippocampus and some granular layers in cerebral cortex of RF-EMR exposed rats decreased in compare to control groups. Individual cells could be seen with condensed cytoplasm and nucleus. Electron microscopic findings revealed individual shrunken cells with condensed cytoplasm and nucleus. Conclusion: From the findings of the present study it appears pertinent that in order to protect the population living around base stations and users of mobile handsets, governments and regulatory bodies adopt safety standards, which translate to limits on exposure levels below a certain value and efforts are underway to harmonize the different standards in existence.

A Light and Electron Microscopic Study in Serial Sections of Skeletal and Extraocular Muscles in Mouse Myotonic Dystrophy

1974 ◽  
Vol 32 ◽  
pp. 6-7
Author(s):  
Bruce R. Pachter ◽  
Jacob Davidowitz ◽  
Goodwin M. Breinin
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Myotonic Dystrophy ◽  
Skeletal Muscles ◽  
Light And Electron Microscopy ◽  
Hereditary Disease ◽  
Serial Sections ◽  
Electron Microscopic ◽  
Suitable Animal Model ◽  
Model Mouse

A suitable animal model (Mouse Strain Re-129 dy2j/dy2j) has been reported for myotonic dystrophy, a hereditary disease in which skeletal muscles degenerate. In the present study, another strain of mouse (Bar Harbor Strain C57BL/6J dy2j/dy2j), carrying this same myotonic gene (dy2j) was studied by light and electron microscopy (EM) in serial sections of epon embedded tissue.

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