Studies on the interactions of immunostimulated macrophages andYersinia enterocoliticaO:8

2000 ◽  
Vol 46 (3) ◽  
pp. 218-228 ◽  
Author(s):  
E Ivanova ◽  
I Yanchev ◽  
H Najdenski ◽  
R Toshkova ◽  
P Dimitrova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Yersinia Enterocolitica ◽  
Peritoneal Macrophages ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Bacterial Cells ◽  
Electron Microscopic ◽  
Serotype O

Immunological and electron microscopy investigations of the phagocytic and killing activities of peritoneal macrophages from rats and mice against Yersinia enterocolitica serotype O:8 cells were performed. The effect of in vivo application of cytoplasmic membranes (CM) from the stable Escherichia coli WF+ L-form on macrophage activity was also studied. It was established that rat macrophages more actively phagocytosed the plasmidless pYV(-) Y. enterocolitica cells, compared to the plasmid-bearing pYV(+) Y. enterocolitica cells. The killing ability against both variants of the Y. enterocolitica strain was significantly enhanced in macrophages from CM-treated rats after 2 h, 4 h, and 24 h incubation. The CM treatment enhanced the phagocytic activity of the macrophages. The in vitro interaction of normal and immunostimulated rat macrophages with both pYV(+) and pYV(-) variants of Y. enterocolitica did not lead to any additional apoptotic and necrotic changes in macrophages compared to control macrophages, which were cultivated without Y. enterocolitica. Electron-microscopic investigation showed that mouse macrophages eliminated Y. enterocolitica pYV(+) cells in vivo after 24 h. No engulfed or digested bacterial cells were observed. Activation of cell surfaces and vacuolization of macrophage cytoplasm, both of CM-treated non-infected and infected mice, were observed. The experimental results showed that Y. enterocolitica pYV(+) cells could be eliminated by peritoneal macrophages.Key words: Yersinia enterocolitica, immunostimulation, electron microscopy, bacterial L-forms, macrophages.

Morphometrical Ultrastructural Studies of the Rat's Hepatocytes Under Cooling

1997 ◽  
Vol 3 (S2) ◽  
pp. 245-246
Author(s):  
A.S. Kaprelyants ◽  
A.A. Kaprelyants ◽  
A.N. Reylan ◽  
R.K. Migunova
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscopic ◽  
Rat Hepatocyte ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Morphometric Methods

The aim of given investigation is to study the effect of cooling upon rat hepatocyte structure using transmission electron microscopic and computer morphometric methods. Ultrastructural and morphometrical characteristics of hepatocytes under liver cooling for various levels under in vivo and in vitro conditions were investigated. Vistar rats of 180-250 g were used in the experiment. Liver cooling (in vivo) was performed by means of original cryoapplicator with different probe temperature (1,2). Liver tissue for transmission electron microscopy was fixed in glutaraldehyde fixator on cocadylate buffer and OsO4. Dehydration was completed on acetone (3). Tissue embedding was done into the mixture of Epon/Araldite epoxy rasin. Ultrathin slices were contrasted by the method of Reinolds. Cell viewing and imaging were accomplished by electron microscope at accelerating power of 75kV.Morphometrical and stereometrical analysis was performed using the “Morpho-Tools” original computer system (c) 1994-1996 A.S. Kaprelyants, A.A. Kaprelyants, A.N. Reylan .

Electron microscopic investigation of the structure and morphology of syndiotactic polypropylene

1989 ◽  
Vol 47 ◽  
pp. 358-359
Author(s):  
Andrew J. Lovinger ◽  
Bernard Lotz ◽  
Don D. Davis
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Dark Field ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Dilute Solution ◽  
Electron Microscopic ◽  
Syndiotactic Polypropylene ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

In contrast to its isotactic isomer, syndiotactic polypropylene has received only little attention. Our main source of understanding of its structure is the X-ray study by Conradini et al., who found the chains to have a (t2g2)2 conformation (corresponding to a 4∗2/1 helix with molecular repeat 0.74 nm), and to be packed in a C-centered unit cell as shown in the left side of Fig. 1. We have recently begun a study of the structure, crystallization, and morphology of syndiotactic polypropylene using electron microscopy and diffraction. Here we concentrate specifically on the electron-diffraction evidence as a function of temperature, in order to obtain an understanding of the evolution and variation of structure in this polymer.Thin films of syndiotactic polypropylene (synthesized by Dr. R. E. Cais as reported previously) were prepared by casting from dilute solution in xylenes at ca. 140°c onto freshly cleaved mica substrates. Following evaporation of the solvent, they were melted and then isothermally crystallized at a variety of temperatures. After shadowing with Pt/C and coating with carbon, they were floated off their substrates for examination by transmission electron microscopy (bright- and dark-field) and selected-area electron diffraction at 100-200 keV.

Electron microscopy of barley root infection by the fungal pathogen Bipolaris sorokiniana

1991 ◽  
Vol 69 (12) ◽  
pp. 2724-2731 ◽  
Author(s):  
H. Carlson ◽  
U. Stenram ◽  
M. Gustafsson ◽  
H.-B. Jansson
Keyword(s):  
Cell Wall ◽  
Bipolaris Sorokiniana ◽  
Root Surface ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Barley Root ◽  
Outer Cortex ◽  
Electron Microscopic ◽  
Helminthosporium Sativum

An electron microscopic investigation of barley roots infected in vitro by Bipolaris sorokiniana showed the existence of an extracellular sheath on germ tubes and appressoria attached to the root surface. Growth of the fungus in the epidermis and outer cortex was predominantly intracellular, whereas in the inner cortex the hyphae observed were mainly intercellular. Hyphae could not be detected in the stele 24 or 72 h after inoculation. Enzymatic activity in the apex of penetration hyphae is a possible explanation of the electron-dense areas seen in host cell walls 72 h after inoculation. Separation of plasmalemma from cell wall and degeneration of host nuclei and mitochondria were other infection-induced changes commonly seen. A host response to fungal infection involved the development of papillae between the plasma membrane and cell wall of the plant as well as around fungal hyphae. Key words: Bipolaris sorokiniana, Cochliobolus sativus, Helminthosporium sativum, Hordeum vulgare, barley, root, microscopy.

scholarly journals Electron-Microscopic Investigation of the Flora of Sheep Alimentary Tract

1970 ◽  
Vol 23 (4) ◽  
pp. 793 ◽  
Author(s):  
NJ Hoogenraad ◽  
FJR Hird
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Alimentary Tract ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Large Numbers

Digesta from different regions of the sheep alimentary tract have been examined using electron microscopy. Direct examination of digesta from the rumen has revealed the presence of a number of phages and of a large variety of bacteria differing considerably in their morphology. An atlas of electron micrographs of these bacteria has been presented. The presence of large numbers of bacterial cell walls ;n the rumen indicates that the breakdown of bacteria commences in this organ. The major sites of digestion of bacteria are in the abomasum and small intestine where there is a substantial removal and modification of bacteria.

A high resolution electron microscopic investigation of bacterial magnetite. Implications for crystal growth

1984 ◽  
Vol 221 (1225) ◽  
pp. 385-393 ◽  
Keyword(s):  
Crystal Growth ◽  
High Resolution ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Regular Growth ◽  
Crystal Formation ◽  
Hexagonal Prism ◽  
Bacterial Cells ◽  
Electron Microscopic ◽  
Domain Structures

Magnetite particles isolated from magnetococcoid bacterial cells have been studied by high resolution transmission electron microscopy (h.r.t.e.m.). The particles show lattice images consistent with the magnetite structure and have a hexagonal prism habit truncated by {011} and {100} planes. The particles have a high degree of crystal perfection and are single domain structures. Some crystals showed a superimposed ‘graininess’ and ill-defined edges. In some crystals regular growth points on the crystal edge could be observed while in other crystals the material at the crystal edge appeared to be amorphous. These results suggest that the crystals are often surrounded by an amorphous phase. These observations are consistent with a model of crystal formation which involves nucleation of the magnetite phase at one primary site followed by slow crystal growth. It is proposed that crystal growth proceeds by dissolution of kinetically favoured precursor iron oxide phases aggregated or precipitated at the magnetite surface of the primary crystal followed by incorporation of soluble ferric-ferrous hydroxo-complexes into the magnetite lattice. The possible roles of the surrounding membrane in magnetite synthesis are discussed.

scholarly journals Cytological, Biochemical, and Transcriptomic Analyses of a Novel Yellow Leaf Variation in a Paphiopedilum (Orchidaceae) SCBG COP15

Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 71
Author(s):  
Ji Li ◽  
Kunlin Wu ◽  
Lin Li ◽  
Meina Wang ◽  
Lin Fang ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Chloroplast Ultrastructure ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Color Variation ◽  
Yellow Leaf ◽  
Electron Microscopic ◽  
Chl A ◽  
Leaf Variation

The genus Paphiopedilum, belonging to the Orchidaceae, has high ornamental value. Leaf variations can considerably improve the economic and horticultural value of the orchids. In the study, a yellow leaf mutant of a Paphiopedilum hybrid named P. SCBG COP15 was identified during the in vitro plant culture process; however, little is known about their molecular mechanisms. For this, RNA-seq libraries were created and used for the transcriptomic profiling of P. SCBG COP15 and the yellow mutant. The Chl a, Chl b, and carotenoid contents in the yellow leaves decreased by approximately 75.99%, 76.92%, and 56.83%, respectively, relative to the green leaves. Decreased chloroplasts per cell and abnormal chloroplast ultrastructure were observed by electron microscopic investigation in yellowing leaves; photosynthetic characteristics and Chl fluorescence parameters were also decreased in the mutant. Altogether, 34,492 unigenes were annotated by BLASTX; 1,835 DEGs were identified, consisting of 697 upregulated and 1138 downregulated DEGs. HEMA, CRD, CAO, and CHLE, involved in Chl biosynthesis, were predicted to be key genes responsible for leaf yellow coloration. Our findings provide an essential genetic resource for understanding the molecular mechanism of leaf color variation and breeding new varieties of Paphiopedilum with increased horticultural value.

Observations on healing tissue: A combined light and electron microscopic investigation

1963 ◽  
Vol 246 (733) ◽  
pp. 305-325 ◽  
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Light Microscopy ◽  
Secretory Activity ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Foreign Body Giant Cell ◽  
Electron Microscopic ◽  
Adventitial Cells

1. The process of healing in the rabbit ear chamber has been investigated in detail by correlating light microscopy, mainly in vivo , and electron microscopy. 2. During healing new vessels are formed from existing vessels by a process of sprouting and anastomosis, with subsequent remodelling of the loops so formed. 3. The fundamental process in the formation of vessels by sprouting is the mitotic division of existing endothelium, during which it retains its characteristic properties. 4. Blood vessel sprouts are composed of strands of tightly apposed cells formed in continuity with the walls of existing vessels. The subsequent canalization of such strands takes place extra-cellularly by a series of events largely as described by Billroth (1856). 5. The endothelium of recently formed vessels has a fine structure which distinguishes it clearly from that of more mature vessels. Certain features of this structure are compatible with a secretory activity by the endothelium during the formation of new vessels. 6. Evidence was obtained that in the course of differentiation of recently formed vessels fibroblast-like cells are incorporated into vessel walls to become adventitial cells, and that adventitial cells may undergo conversion to vascular smooth muscle cells. 7. Lymphatic endothelium exhibits properties during regeneration that confirm the specificity of this form of endothelium. 8. Cells with the characteristic fine structure of fibroblasts were frequently found in mitosis. The fibroblasts in the regions of active fibrogenesis had a highly developed cisternal form of endoplasmic reticulum. Vesicles and corresponding caveolae identifiable in such fibroblasts may provide a communication between the endoplasmic reticulum and the sites of fibrogenesis at the external surfaces of the cells. 9. Cells sharing characteristic features of fine structure formed a series which grouped together the monocyte, macrophage and foreign body giant cell. 10. Highly fibrillary intracytoplasmic tracts were found in both fibroblasts and macrophages. These tracts were equated with the fibroglial fibres of light microscopy. 11. ‘ Clear spaces ’ in advance of the growing fringe of blood vessels were temporary structures lined by a pavement of mesothelium-like cells. 12. No evidence was found of the formation of primitive mesenchymal tissue during healing in the mammal.

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