Ultrastructural Findings in Adrenal Cortical Adenomas Clinically Mimicking Pheochromocytoma: A Comparison with Other Adrenal Tumors and Tissue Preparation Techniques

Localization of amylase,chymotrypsinogen and trypsinogen in pancreas was demonstrated by Yasuda and Coons (1966), by using fluorescent antibody method. These enzymes were naturally found in the zymogen granules. Among them, amylase showed a diffuse localization around the nucleus, in addition to the zymogen granules. Using ferritin antibody method, scattered ferritin granules were also found around the Golgi area (Yasuda et al.,1967). The recent advance in the tissue preparation enables the antigen to be localized in the ultrathin frozen sections, by applying the labeled antibodies onto the sections instead of staining the tissue en bloc.The present study deals with the comparison of the localization of amylase and lipase demonstrated by applying the bismuth-labeled, peroxidase-labeled and ferritin-labeled antibody methods on the ultrathin frozen sections of pancreas, and on the blocks of the same tissue.

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A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079097 ◽

1977 ◽

Vol 35 ◽

pp. 314-315

Author(s):

Earl R. Walter ◽

Glen H. Bryant

Keyword(s):

Sample Preparation ◽

High Vacuum ◽

Vacuum System ◽

Latex Particles ◽

New Methods ◽

Diffusion Pump ◽

Film Forming ◽

Routine Basis ◽

Distribution Studies ◽

Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

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The ionic strength dependence of chromatin folding

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081966 ◽

1978 ◽

Vol 36 (2) ◽

pp. 220-221

Author(s):

F. Thoma ◽

TH. Koller

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Ionic Strength ◽

Specimen Preparation ◽

Preparation Technique ◽

Carbon Supports ◽

Ionic Strength Dependence ◽

Chromatin Folding ◽

Strength Dependence ◽

Preparation Techniques

Under a variety of electron microscope specimen preparation techniques different forms of chromatin appearance can be distinguished: beads-on-a-string, a 100 Å nucleofilament, a 250 Å fiber and a compact 300 to 500 Å fiber.Using a standardized specimen preparation technique we wanted to find out whether there is any relation between these different forms of chromatin or not. We show that with increasing ionic strength a chromatin fiber consisting of a row of nucleo- somes progressively folds up into a solenoid-like structure with a diameter of about 300 Å.For the preparation of chromatin for electron microscopy the avoidance of stretching artifacts during adsorption to the carbon supports is of utmost importance. The samples are fixed with 0.1% glutaraldehyde at 4°C for at least 12 hrs. The material was usually examined between 24 and 48 hrs after the onset of fixation.

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Electron Microscopic Observation of Biological Specimens in Their Native State by Employing Cryogenic Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100095315 ◽

1972 ◽

Vol 30 ◽

pp. 410-411 ◽

Cited By ~ 1

Author(s):

Tokio Nei ◽

Haruo Yotsumoto ◽

Yoichi Hasegawa ◽

Yuji Nagasawa

Keyword(s):

Electron Microscopic Observation ◽

Surface Structures ◽

Specimen Preparation ◽

Native State ◽

Electron Microscopic ◽

Biological Specimen ◽

Specimen Holder ◽

Cold Stage ◽

Preparation Techniques ◽

Scanning Electron

In order to observe biological specimens in their native state, that is, still containing their water content, various methods of specimen preparation have been used, the principal two of which are the chamber method and the freeze method.Using its recently developed cold stage for installation in the pre-evacuation chamber of a scanning electron microscope, we have succeeded in directly observing a biological specimen in its frozen state without the need for such conventional specimen preparation techniques as drying and metallic vacuum evaporation. (Echlin, too, has reported on the observation of surface structures using the same freeze method.)In the experiment referred to herein, a small sliced specimen was place in the specimen holder. After it was rapidly frozen by freon cooled with liquid nitrogen, it was inserted into the cold stage of the specimen chamber.

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High-Resolution Scanning Electron Microscopy of Biological Specimens

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103012 ◽

1988 ◽

Vol 46 ◽

pp. 186-187

Author(s):

M. Müller ◽

R. Hermann

Keyword(s):

High Resolution ◽

Freeze Drying ◽

Room Temperature ◽

Structural Information ◽

Freeze Substitution ◽

Critical Point Drying ◽

Sem Study ◽

Major Factors ◽

Structural Preservation ◽

Preparation Techniques

Three major factors must be concomitantly assessed in order to extract relevant structural information from the surface of biological material at high resolution (2-3nm).Procedures based on chemical fixation and dehydration in graded solvent series seem inappropriate when aiming for TEM-like resolution. Cells inevitably shrink up to 30-70% of their initial volume during gehydration; important surface components e.g. glycoproteins may be lost. These problems may be circumvented by preparation techniques based on cryofixation. Freezedrying and freeze-substitution followed by critical point drying yields improved structural preservation in TEM. An appropriate preservation of dimensional integrity may be achieved by freeze-drying at - 85° C. The sample shrinks and may partially collapse as it is warmed to room temperature for subsequent SEM study. Observations at low temperatures are therefore a necessary prerequisite for high fidelity SEM. Compromises however have been unavoidable up until now. Aldehyde prefixation is frequently needed prior to freeze drying, rendering the sample resistant to treatment with distilled water.

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Bronchial stereocilia in the immotile cilia syndrome: A case report

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110635 ◽

1984 ◽

Vol 42 ◽

pp. 52-53

Author(s):

George Price ◽

Lizardo Cerezo

Keyword(s):

Surface Modifications ◽

Respiratory Epithelium ◽

Immotile Cilia ◽

Kartagener's Syndrome ◽

Membrane Blebs ◽

Radial Spokes ◽

Males And Females ◽

Dynein Arms ◽

Ultrastructural Finding ◽

Ultrastructural Findings

Ultrastructural defects of ciliary structure have been known to cause recurrent sino-respiratory infection concurrent with Kartagener's syndrome. (1,2,3) These defects are also known to cause infertility in both males and females. (4) Overall, the defects are defined as the Immotile, or Dyskinetic Cilia Syndrome (DCS). Several ultrastructural findings have been described, including decreased number of cilia, multidirection orientation, fused and compound cilia, membrane blebs, excess matrix in the axoneme, missing outer tubular doublets, translocated doublets, defective radial spokes and dynein arms. A rare but noteworthy ultrastructural finding in DCS is the predominance of microvilli-like structures on the luminal surface of the respiratory epithelium. (5,6) These permanent surface modifications of the apical respiratory epithelium no longer resemble cilia but reflect the ultrastructure of stereocilia, similar to that found in the epidydimal epithelium. Like microvilli, stereocilia are devoid of microtubular ultrastructure in comparison with true cilia.

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