Use of Autometallography in Studies of Nanosilver Distribution and Toxicity

With the increasing use of and interest in nanoparticles in medicine and technology, the tissue and cell-specific localization of the particles are important considerations when the nanomaterials find their way into biological systems. This brief communication shows the utility of autometallography in determining the location of metal deposition at the light microscopic level. Although primarily focusing on studies of the toxicity and deposition of silver nanoparticles, use of autometallography to localize zinc and other metals at the tissue and subcellular localization is also recognized.

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An approach to postembedding staining of protein (immunoglobulin) antigen embedded in plastic: prerequisites and limitations.

Journal of Histochemistry & Cytochemistry ◽

10.1177/28.10.6158534 ◽

1980 ◽

Vol 28 (10) ◽

pp. 1041-1049 ◽

Cited By ~ 49

Author(s):

H Takamiya ◽

S Batsford ◽

A Vogt

Keyword(s):

Biopsy Specimen ◽

Picric Acid ◽

Renal Tissue ◽

Microscopic Level ◽

Tissue Structure ◽

Electron Microscopic Level ◽

Light Microscopic Level ◽

Electron Microscopic ◽

Specific Localization ◽

Ultrathin Sections

A method is described for performing postembedding staining of protein (immunoglobulin) antigen embedded in styrene-methacrylate resin. Fixation of specimens in a combination of 4% paraformaldehyde and 0.2% picric acid and washing in buffer containing 7% sucrose, followed by abrupt dehydration with absolute acetone in the cold preserved the antigenicity, although in a masked form. The masked antigenicity could be reexposed by treatment with nonspecific protease. Staining with fluorescent-, peroxidase-, or ferritin-labeled antibodies on semi- and ultrathin sections resulted in specific localization of the antigen. We applied this technique to the localization of rabbit immunoglobulin in specimens of renal tissue obtained from rats with anti-glomerular basement membrane nephritis; we also localized human IgG in a renal biopsy specimen. The prerequisites for recovery of antigenicity are such that preservation of tissue structure at the light microscopic level is good, but relatively poor at the electron microscopic level.

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Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053747 ◽

1982 ◽

Vol 40 ◽

pp. 216-217

Author(s):

D. J. McComb ◽

J. Beri ◽

F. Zak ◽

K. Kovacs

Keyword(s):

Microscopic Study ◽

Pituitary Adenomas ◽

Wistar Rats ◽

Microscopic Level ◽

Sprague Dawley ◽

Prolactin Cells ◽

Light Microscopic Level ◽

Ultrastructural Investigation ◽

Sprague Dawley Rats ◽

Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

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The Fine Structure of Irradiated Mouse Heart

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090907 ◽

1976 ◽

Vol 34 ◽

pp. 184-185

Author(s):

Vivian V. Yang ◽

S. Phyllis Stearner

Keyword(s):

Microscopic Level ◽

Ultrastructural Changes ◽

Mouse Heart ◽

Blood Vessel Wall ◽

Histopathological Changes ◽

Light Microscopic Level ◽

Γ Rays ◽

Fission Neutrons ◽

Total Body

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.

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Liquid crystalline ordering of paired helical filaments in neurofibrillary tangles of Alzheimer's disease

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143365 ◽

1986 ◽

Vol 44 ◽

pp. 348-349

Author(s):

D.F. Clapin ◽

V.J.A. Montpetit

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurofibrillary Tangles ◽

Liquid Crystalline ◽

Amyloid Fibrils ◽

Geometric Analysis ◽

Paired Helical Filaments ◽

Microscopic Level ◽

Light Microscopic Level ◽

Regular Spacing

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.

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ultrastructural process of intestinal wound healing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141494 ◽

1995 ◽

Vol 53 ◽

pp. 1024-1025

Author(s):

Rick L. Vaughn ◽

Shailendra K. Saxena ◽

John G. Sharp

Keyword(s):

Wound Healing ◽

Epithelial Cells ◽

Smooth Muscles ◽

Microscopic Level ◽

Light Microscopic Level ◽

Ileal Mucosa ◽

Wound Model ◽

Serosal Surface ◽

Complex Process ◽

Orderly Fashion

We have developed an intestinal wound model that includes surgical construction of an ileo-cecal patch to study the complex process of intestinal wound healing. This allows approximation of ileal mucosa to the cecal serosa and facilitates regeneration of ileal mucosa onto the serosal surface of the cecum. The regeneration of ileal mucosa can then be evaluated at different times. The wound model also allows us to determine the rate of intestinal regeneration for a known size of intestinal wound and can be compared in different situations (e.g. with and without EGF and Peyer’s patches).At the light microscopic level it appeared that epithelial cells involved in regeneration of ileal mucosa originated from the enlarged crypts adjacent to the intestinal wound and migrated in an orderly fashion onto the serosal surface of the cecum. The migrating epithelial cells later formed crypts and villi by the process of invagination and evagination respectively. There were also signs of proliferation of smooth muscles underneath the migratory epithelial cells.

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Ultrastorcture of Cerebellar Purkinje Cells in Rats Subjected To Partial Global Cerebral Ischemia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100120060 ◽

1985 ◽

Vol 43 ◽

pp. 674-675

Author(s):

R.V.W. Dimlich ◽

M.H. Biros

Keyword(s):

Cerebral Ischemia ◽

Purkinje Cells ◽

Cell Types ◽

Microscopic Level ◽

Global Cerebral Ischemia ◽

Light Microscopic Level ◽

Cerebellar Damage ◽

Cerebellar Injury ◽

Cerebellar Purkinje Cells ◽

Cell Changes

In severe cerebral ischemia, Purkinje cells of the cerebellum are one of the cell types most vulnerable to anoxic damage. In the partial (forebrain) global ischemic (PGI) model of the rat, Paljärvi noted at the light microscopic level that cerebellar damage is inconsistant and when present, milder than in the telencephalon, diencephalon and rostral brain stem. Cerebellar injury was observed in 3 of 4 PGI rats following 5 minutes of reperfusion but in none of the rats after 90 min of reperfusion. To evaluate a time between these two extremes (5 and 90 min), the present investigation used the PGI model to study the effects of ischemia on the ultrastructure of cerebellar Purkinje cells in rats that were sacrificed after 30 min of reperfusion. This time also was chosen because lactic acid that is thought to contribute to ischemic cell changes in PGI is at a maximum after 30 min of reperfusion.

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An ultrastructural study on the shark liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016011x ◽

1990 ◽

Vol 48 (3) ◽

pp. 512-513

Author(s):

Masako Yamada ◽

Yutaka Tanuma

Keyword(s):

Portal Vein ◽

Kupffer Cells ◽

Ultrastructural Study ◽

Lipid Droplets ◽

Microscopic Level ◽

The Other ◽

Fish Stock ◽

Structural Studies ◽

Light Microscopic Level ◽

Perfusion Fixation

Although many fine structural studies on the vertebrate liver have been reported on mammals, avians, reptiles, amphibians, teleosts and cyclostomes, there are no studies on elasmobranchii liver except one by T. Ito etal. (1962) who studied it on light microscopic level. The purpose of the present study was to as certain the ultrastructural details and cytochemical characteristics of normal elasmobranchii liver and was to compare with the other higher vertebrate ones.Seventeen Scyliorhinus torazame, one kind of elasmobranchii, were obtained from the fish stock of the Ueno Zoo aquarium, Ueno, Tokyo. The sharks weighing about 300-600g were anesthetized with MS-222 (Sigma), and the livers were fixed by perfusion fixation via the portal vein according to the procedure of Y. Saito et al. (1980) for 10 min. Then the liver tissues were immersed in the same fixative for 2 hours and postfixed with 1% OsO4-solution in 0.1 Mc acodylate buffer for one hour. In order to make sure a phagocytic activity of Kupffer cells, latex particles (0.8 μm in diameter, 0.05mg/100 g b.w.) were injected through the portal vein for one min before fixation. For preservation of lipid droplets in the cytoplasm, a series of these procedure were performed under ice cold temperature until the end of dehydration.

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Further studies on the melanophores of periodic albino mutant of Xenopus laevis

Development ◽

10.1242/dev.91.1.65 ◽

1986 ◽

Vol 91 (1) ◽

pp. 65-78

Author(s):

T. Fukuzawa ◽

H. Ide

Keyword(s):

Xenopus Laevis ◽

Microscopic Level ◽

Wild Type ◽

Light Microscopic Level ◽

In Vitro Proliferation ◽

Albino Mutant ◽

Site Of Action ◽

Periodic Albino

It is still unknown why dermal melanophores disappear during larval development, and why no or very few epidermal melanophores appear during and after metamorphosis, in Xenopus laevis showing periodic albinism (ap). To elucidate these points, we investigated (1) the occurrence of depigmentation in mutant (ap/ap) melanophores during in vitro proliferation and (2) the incidence of melanophore differentiation from mutant melanoblasts in the skin in vitro. During in vitro proliferation of mutant melanophores, ap-type melanosomes decreased in number gradually and instead the number of premelanosomes increased in the cells, which caused depigmentation at the light microscopic level in the culture. Depigmentation was observed only in mutant melanophores, and not in wild-type (+/+) melanophores. These results suggest that autonomous depigmentation of mutant dermal melanophores is the cause of the disappearance of these cells in vivo. Dopa-positive melanoblasts were demonstrated in both wild-type and mutant skins. However, the melanoblasts of metamorphosed mutant froglets did not differentiate in vitro, while those of wild-type froglets did. These results suggest that mutant melanoblasts in the skin of froglets lose the potency to differentiate into melanophores, and that this causes the lack of mutant melanophores in the froglets. The site of action of the ap gene is also discussed.

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Synthesis of metal nanoparticles using yeast strains Saccharomyces Cerevisae and Saccharomyces Boulardi

10.33920/med-13-2102-03 ◽

2021 ◽

pp. 44-49

Author(s):

Ekaterina A. Pukhovskaya ◽

Egor V. Kalinin ◽

Ya. M. Stanishevskiy

Keyword(s):

Antimicrobial Activity ◽

Silver Nanoparticles ◽

Metal Nanoparticles ◽

Extracellular Enzymes ◽

Biological Systems ◽

Environmentally Friendly ◽

Synthesis Of Nanoparticles ◽

Yeast Strains ◽

Environmentally Friendly Process

The development of an environmentally friendly process for the synthesis of metal nanoparticles is an important step in the field of nanotechnology. One way to achieve this goal is to use biological systems. In this study, silver nanoparticles were obtained using extracellular enzymes of organisms of the Saccharomyces boulardi strain. The effect of the pH of the medium on the synthesis of nanoparticles was studied. The antimicrobial activity of the obtained nanoparticles was investigated.

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