In Vivo Corrosion of Modular Dual-Mobility Implants: A Retrieval Study

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053425 ◽

1982 ◽

Vol 40 ◽

pp. 142-145

Author(s):

E. J. Kollar

Keyword(s):

Connective Tissue ◽

Oral Mucosa ◽

Basal Lamina ◽

Functional Derivatives ◽

Specific Source ◽

Dental Epithelium ◽

Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

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Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053711 ◽

1982 ◽

Vol 40 ◽

pp. 210-211

Author(s):

M.J. Murphy ◽

R.R. Price ◽

J.C. Sloman

Keyword(s):

Cultured Cells ◽

Human Tumor ◽

Cell Type ◽

Tumor Mass ◽

Initial Cell ◽

Cloning Assay ◽

Human Tumor Cloning ◽

The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

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Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007727x ◽

1983 ◽

Vol 41 ◽

pp. 740-741

Author(s):

H. Engelhardt ◽

R. Guckenberger ◽

W. Baumeister

Keyword(s):

Lattice Structure ◽

Bacterial Species ◽

Hexagonal Lattice ◽

Reaction Centre ◽

Photosynthetic Membrane ◽

Rhodopseudomonas Viridis ◽

Photosynthetic Membranes ◽

Ectothiorhodospira Halochloris ◽

Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

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The Infection of Cells by Bullet-Shaped Viruses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063779 ◽

1969 ◽

Vol 27 ◽

pp. 372-373

Author(s):

Frederick A. Murphy ◽

Alyne K. Harrison ◽

Sylvia G. Whitfield

Keyword(s):

Electron Microscopy ◽

Physical Properties ◽

Host Cell ◽

Thin Section ◽

Cultured Cells ◽

Cell Infection ◽

Thin Section Electron Microscopy ◽

Section Electron ◽

Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

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Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084120 ◽

1978 ◽

Vol 36 (2) ◽

pp. 650-651

Author(s):

Raul I. Garcia ◽

Evelyn A. Flynn ◽

George Szabo

Keyword(s):

Direct Injection ◽

Skin Pigmentation ◽

Freeze Fracture ◽

Pigment Granule ◽

Time Lapse ◽

Ultrastructural Level ◽

Lanthanum Tracer ◽

A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

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