Life Sciences Commons^™

The Role Of Scanning Electron Microscopy In Periodontal Research, A. Carrassi, S. Abati, G. Santarelli

Scanning Microscopy

During recent years a great amount of research has led to a better understanding of the etiology, pathogenesis and pattern of progression of periodontal diseases. Scanning electron microscopy (SEM) has contributed to this improvement, mainly with respect to histology of periodontal tissues, the description of the morphology and distribution of bacteria on the exposed root surface, analysis of the host-parasite interactions on the gingival pocket wall, and morphological evaluation of root treatment. This review deals with all these topics. Unusual types of SEM research are also described and discussed. Uncommon sample preparation techniques for SEM in periodontal research are described. …

Sertoli Cell Death By Apoptosis In The Immature Rat Testis Following X-Irradiation, David J. Allan, Glenda C. Gobé, Brian V. Harmon

Scanning Microscopy

The importance of the morphological study of cell death has recently been emphasized by the recognition that the ultrastructural features of dying cells allow categorization of the death as either apoptosis or necrosis. This classification enables inferences to be drawn about the mechanism and biological significance of the death occurring in a particular set of circumstances.

In this study, Sertoli cell death induced in the immature testis of three and four day old rats by 5 Gy (500 rads) x-irradiation was described by light and transmission electron microscopy with the objective of categorizing the death as apoptosis or necrosis. The …

X-Ray-Induced Cell Death By Apoptosis In The Immature Rat Cerebellum, Brian V. Harmon, David J. Allan

Scanning Microscopy

The cells of the external granular layer (EGL) of the developing cerebellum are known to be particularly sensitive to radiation. In the past, changes induced in this layer by irradiation have been referred to by non-specific terms such as "pyknotic cells" and the mode of cell death has been assumed to be necrosis. However, in published light micrographs of these dying cells, the appearance is suggestive of apoptosis, a distinctive mode of cell death which occurs spontaneously in normal adult and embryonic tissues and can also be triggered by certain pathological stimuli.

This light and transmission electron microscopic study of …

Response Of Mouse Lung Air-Blood Barrier To X-Irradiation: Ultrastructural And Stereological Analysis, L. De Saint-Georges, U. Van Gorp, J. R. Maisin

Scanning Microscopy

Male mice of the Balb/c strain were exposed, at an age of three months, to a single dose of 10 or 20 Gy on the right hemithorax. At 3, 4, 6, 9 and 12 months after exposure, lungs were processed for electron microscopy following a standardized procedure in order to allow stereological analysis. By this method, the arithmetical mean thickness and, the air-blood barrier mean thickness in the lung parenchyma was shown to increase quickly with time by oedemization and fibrinization of the septal space. The ratio endothelium/epithelium surfaces (Sr/SF) gradually decreased by reduction of both surfaces but this was …

Ultrastructural Analysis Of Dynamic Cellular Processes: A Survey Of Current Problems, Pitfalls And Perspectives, Helmut Plattner, Gerd Knoll

Scanning Microscopy

Dynamic phenomena in cells that can be analyzed on the ultrastructural level comprise so different aspects as ion shifts, conformational changes of macromolecules, membrane particle rearrangements, lipid phase transitions, protein--protein interactions (notably ligand-receptor interactions, including their sorting and sequestration), reversible membrane-to-membrane contacts, membrane fusions, transcellular transport phenomena, restructuring of cytoskeletal elements, ciliary and flagellar beat, cell shape changes, etc. Only some of these phenomena can be analyzed under stationary conditions, while others are unidirectional and sometimes very rapid. Therefore, the methodical approaches to be used (primary methods and follow-up procedures) might be widely different. Quite different methods are available, such …