Fine structures and ion images on fresh frozen dried ultrathin sections by transmission electron and scanning ion microscopy

2003 ◽  
Vol 203-204 ◽  
pp. 684-688 ◽  
Author(s):  
K. Takaya ◽  
M. Okabe ◽  
M. Sawataishi ◽  
H. Takashima ◽  
T. Yoshida
Keyword(s):  
Transmission Electron ◽  
Fresh Frozen ◽  
Ultrathin Sections ◽  
Fine Structures ◽  
Ion Microscopy

Magnesium and sulfur in mast cell and basophil granules of lower vertebrates in relation with histamine

1992 ◽  
Vol 50 (2) ◽  
pp. 1596-1597
Author(s):  
Kenichi Takaya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mast Cell ◽  
Mast Cells ◽  
Tree Frog ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Fresh Frozen ◽  
Ultrathin Sections

Mast cell and basophil granules of the vertebrate contain heparin or related sulfated proteoglycans. Histamine is also present in mammalian mast cells and basophils. However, no histamine is detected in mast cell granules of the amphibian or fish, while it is shown in those of reptiles and birds A quantitative x-ray microanalysis of mast cell granules of fresh frozen dried ultrathin sections of the tongue of Wistar rats and tree frogs disclosed high concentrations of sulfur in rat mast cell granules and those of sulfur and magnesium in the tree frog granules. Their concentrations in tree frog mast cell granules were closely correlated (r=0.94).Fresh frozen dried ultrathin sections and fresh air-dried prints of the tree frog tongue and spleen and young red-eared turtle (ca. 6 g) spleen and heart blood were examined by a quantitative energy-dispersive x-ray microanalysis (X-650, Kevex-7000) for the element constituents of the granules of mast cells and basophils. The specimens were observed by transmission electron microscopy (TEM) (80-200 kV) and followed by scanning transmission electron microscopy (STEM) under an analytical electron microscope (X-650) at an acceleration voltage of 40 kV and a specimen current of 0.2 nA. A spot analysis was performed in a STEM mode for 100 s at a specimen current of 2 nA on the mast cell and basophil granules and other areas of the cells. Histamine was examined by the o-phthalaldehyde method.

Elemental composition of mast cell granules of the rat and tree frog: X-ray Microanalysis on fresh frozen dried ultrathin sections

1990 ◽  
Vol 48 (3) ◽  
pp. 356-357
Author(s):  
Kenichi Takaya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mast Cell ◽  
Mast Cells ◽  
Pancreatic Acinar Cells ◽  
Tree Frog ◽  
X Ray ◽  
Transmission Electron ◽  
Fresh Frozen ◽  
Ultrathin Sections

Electron probe x-ray microanalysis using fresh air-dried spreads revealed electrolyte elements in the granules of platelets, mast cells, pancreatic acinar cells and melanocytes. Mast cell granules of the rat and tree frog are quantitatively compared by an energy dispersive spectrometry (EDS) using fresh frozen dried ultrathin sections.Adult Wistar rats (ca. 250 g) and tree frogs (Hyla arborea japonica) of both sexes were used. Fresh frozen dried smears of rat peritoneal mast cells were prepared on the collodion-membrane covered titanium grid. Fresh frozen dried ultrathin sections of the tongue of the rat and tree frog were made by the metal contact method employing the rapid freezing apparatus (RF-2) cooled with liquid nitrogen. Ultrathin cryosections (60 nmj were cut at 163 K, transferred to the frozen specimen treating apparatus (FD-2) for freeze-drying in high vacuum at 173 K for 74-96 h. The specimens were observed first by 200kV transmission electron microscopy (TEM) and then under the scanning analytical electron microscope (X-650) for scanning transmission electron microscopy (STEM) images at an acceleration voltage of 40 kV and a specimen current of 0.2 nA.

The Ultrastructure of Lymphocytic Hypophysitis

1981 ◽  
Vol 39 ◽  
pp. 466-467
Author(s):  
S.L. Asa ◽  
K. Kovacs ◽  
J. M. Bilbao ◽  
R. G. Josse ◽  
K. Kreines
Keyword(s):  
Electron Microscopy ◽  
Plasma Cells ◽  
Secretory Granules ◽  
Sella Turcica ◽  
Uranyl Acetate ◽  
Lymphocytic Hypophysitis ◽  
Pituitary Cells ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Mass Lesions

Seven cases of lymphocytic hypophysitis in women have been reported previously in association with various degrees of hypopituitarism. We report two pregnant patients who presented with mass lesions of the sella turcica, clinically mimicking pituitary adenoma. However, pathologic examination revealed extensive infiltration of the anterior pituitary by lymphocytes and plasma cells with destruction of the gland. To our knowledge, the ultrastructural features of lymphocytic hypophysitis have not been studied so far.For transmission electron microscopy, tissue from surgical specimens was fixed in glutaraldehyde, postfixed in OsO4, dehydrated and embedded in epoxy-resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Philips 300 electron microscope.Electron microscopy revealed adenohypophysial cells of all types exhibiting varying degrees of injury. In the areas of most dense inflammatory cell infiltration pituitary cells contained large lysosomal bodies fusing with secretory granules (Fig. 1), as well as increased numbers of swollen mitochondria, indicating oncocytic transformation (Fig. 2).

Ultrastructural studies of the relationship between actin filaments and secretory granules

1990 ◽  
Vol 48 (3) ◽  
pp. 458-459
Author(s):  
Ellen Holm Nielsen
Keyword(s):  
Electron Microscopy ◽  
Colloidal Gold ◽  
Actin Filaments ◽  
Secretory Granules ◽  
Secretory Cells ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Granule Membrane ◽  
Ultrathin Sections ◽  
Lowicryl K4m

In secretory cells a dense and complex network of actin filaments is seen in the subplasmalemmal space attached to the cell membrane. During exocytosis this network is undergoing a rearrangement facilitating access of granules to plasma membrane in order that fusion of the membranes can take place. A filamentous network related to secretory granules has been reported, but its structural organization and composition have not been examined, although this network may be important for exocytosis.Samples of peritoneal mast cells were frozen at -70°C and thawed at 4°C in order to rupture the cells in such a gentle way that the granule membrane is still intact. Unruptured and ruptured cells were fixed in 2% paraformaldehyde and 0.075% glutaraldehyde, dehydrated in ethanol. For TEM (transmission electron microscopy) cells were embedded in Lowicryl K4M at -35°C and for SEM (scanning electron microscopy) they were placed on copper blocks, critical point dried and coated. For immunoelectron microscopy ultrathin sections were incubated with monoclonal anti-actin and colloidal gold labelled IgM. Ruptured cells were also placed on cover glasses, prefixed, and incubated with anti-actin and colloidal gold labelled IgM.

Corneal anatomy of marine mammals

1993 ◽  
Vol 71 (11) ◽  
pp. 2282-2290 ◽  
Author(s):  
M. T. Pardue ◽  
J. G. Sivak ◽  
K. M. Kovacs
Keyword(s):  
Marine Mammals ◽  
Equatorial Region ◽  
Balaenoptera Acutorostrata ◽  
Marine Habitat ◽  
Corneal Surface ◽  
Balaenoptera Physalus ◽  
Phoca Groenlandica ◽  
Minke Whales ◽  
Transmission Electron ◽  
Ultrathin Sections

The corneal anatomy of fin whales (Balaenoptera physalus), minke whales (Balaenoptera acutorostrata), harp seals (Phoca groenlandica), ringed seals (Phoca hispida), and bearded seals (Eriganthus barbatus) was examined to determine if marine mammals have evolved specialized corneas for life in a marine habitat. One to seven eyes of each species were analyzed: paraffin sections stained with haematoxylin and eosin for light microscopy; and ultrathin sections for transmission electron microscopy. All corneas contain the five typical mammalian layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The corneas of these marine mammals are thicker than human corneas because of a thicker stromal layer. The other layers are thinner than those found in humans, except for the epithelial layer in the bearded seal and the cetaceans where it may provide extra protection for the eye during feeding behaviour. The epithelial cells in all corneas studied have an abundance of tonofilaments, which may strengthen the cells and distribute force across the corneal surface. No special organization of collagen fibrils was found in the stroma that would offer protection from ultraviolet radiation or glare for pinnipeds when on ice. The thickness of the sclera in the cetaceans may serve to hold the inner globe of the eye in an elliptical shape, while the thinning of the sclera in the equatorial region in pinnipeds may flatten the eye in air to reduce aerial myopia.

Biosynthesis of Gold Nanoparticles with Serratia marcescens Bacteria

2015 ◽  
Vol 1132 ◽  
pp. 19-35
Author(s):  
S.O. Dozie-Nwachukwu ◽  
J.D. Obayemi ◽  
Y. Danyo ◽  
G. Etuk-Udo ◽  
N. Anuku ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Serratia Marcescens ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Color Changes ◽  
Transmission Electron ◽  
Helium Ion ◽  
Ph Conditions ◽  
Uv Visible ◽  
Ion Microscopy

This paper presents the biosynthesis of gold nanoparticles from the bacteria, Serratia marcescens.The intra-and extra-cellular synthesis of gold nanoparticles is shown to occur over a range of pH and incubation times in cell-free exracts and biomass ofserratia marcescensthat were reacted with 2.5mM Tetrachloroauric acid (HAuCl4). The formation of gold nanoparticles was identified initially via color changes from yellow auro-chloride to shades of red or purple in gold nanoparticle solutions. UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDS), Helium Ion Microscopy (HIM) and Dynamic Light Scattering (DLS) were also used to characterize gold nanoparticles produced within a range of pH conditions. The results show clearly that the production of gold nanoparticles from cell-free extracts require shorter times than the production of gold nanoparticles from the biomass.

scholarly journals Putative morphology of Neoehrlichia mikurensis in salivary glands of Ixodes ricinus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jaroslav Ondruš ◽  
Pavel Kulich ◽  
Oldřich Sychra ◽  
Pavel Široký
Keyword(s):  
Salivary Glands ◽  
Ixodes Ricinus ◽  
Mammalian Cells ◽  
Intracellular Pathogen ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
In Vitro Feeding ◽  
Neoehrlichia Mikurensis ◽  
Electron Lucent

Abstract Neoehrlichia mikurensis is an emerging tick-borne intracellular pathogen causing neoehrlichiosis. Its putative morphology was described in mammalian, but not in tick cells. In this study, we aim to show the presumptive morphology of N. mikurensis in salivary glands of engorged females of Ixodes ricinus. To accomplish this, we collected I. ricinus ticks in a locality with a high N. mikurensis prevalence, allowed them to feed in the artificial in vitro feeding system, dissected salivary glands and screened them by PCR for N. mikurensis and related bacteria. Ultrathin sections of salivary glands positive for N. mikurensis but negative for other pathogens were prepared and examined by transmission electron microscopy. We observed two individual organisms strongly resembling N. mikurensis in mammalian cells as described previously. Both bacteria were of ovoid shape between 0.5–0.8 μm surrounded by the inner cytoplasmic and the rippled outer membrane separated by an irregular electron-lucent periplasmic space. Detection of N. mikurensis in salivary glands of I. ricinus suggests that this bacterium uses the “salivary pathway of transmission” to infect mammals.

scholarly journals On the reliability of highly magnified micrographs for structural analysis in materials science

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Martin Wortmann ◽  
Ashley Stephen Layland ◽  
Natalie Frese ◽  
Uwe Kahmann ◽  
Timo Grothe ◽  
...  
Keyword(s):  
Materials Science ◽  
Scientific Literature ◽  
Micromagnetic Simulations ◽  
Transmission Electron ◽  
Helium Ion ◽  
Cherry Picking ◽  
Ion Microscopy ◽  
Embedded Nanoparticles ◽  
Poly Acrylonitrile ◽  
Bare Minimum

Abstract Highly magnified micrographs are part of the majority of publications in materials science and related fields. They are often the basis for discussions and far-reaching conclusions on the nature of the specimen. In many cases, reviewers demand and researchers deliver only the bare minimum of micrographs to substantiate the research hypothesis at hand. In this work, we use heterogeneous poly(acrylonitrile) nanofiber nonwovens with embedded nanoparticles to demonstrate how an insufficient or biased micrograph selection may lead to erroneous conclusions. Different micrographs taken by transmission electron microscopy and helium ion microscopy with sometimes contradictory implications were analyzed and used as a basis for micromagnetic simulations. With this, we try to raise awareness for the possible consequences of cherry-picking for the reliability of scientific literature.

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