scholarly journals TRICOMPLEX FIXATION OF PHOSPHOLIPIDS

1965 ◽  
Vol 24 (1) ◽  
pp. 23-30 ◽  
Author(s):  
P. F. Elbers ◽  
P. H. J. T. Ververgaert ◽  
R. Demel
Keyword(s):  
Electron Microscope ◽  
Cell Membrane ◽  
Mode Of Action ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Osmium Tetroxide ◽  
Fixation Method ◽  
Brain Phospholipids ◽  
Tricomplex Flocculation ◽  
Colloid Systems

A basis for the interpretation of the structure of the cell membrane is often looked for in electron microscope investigations on the structure of lipid models. A difficulty in these investigations is our lack of knowledge of the effect of the preparative treatment on the structure studied. This applies especially to the strongly oxidizing fixatives: osmium tetroxide and potassium permanganate. These agents have, moreover, the drawback that they cannot be used to fix fully saturated lipids. On the basis of existing theories concerning complex colloid systems, a fixation method was developed that allows the electron microscope study of the structure of phospholipid models, irrespective of whether they consist of saturated or unsaturated compounds. With this fixation, namely tricomplex flocculation by means of suitable ions, the structure of the lipid molecules is not altered. Moreover, the site and mode of action of this fixation are well known. The first application of this method to the study of isolated beef brain phospholipids is described.

An Electron Microscope study of a Small Free-living Amoeba (Hartmanella astronyxis)

1959 ◽  
Vol s3-100 (49) ◽  
pp. 13-15
Author(s):  
K. DEUTSCH ◽  
M. M. SWANN
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Cell Membrane ◽  
Nuclear Membrane ◽  
Layered Structure ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Honeycomb Structure ◽  
Free Living ◽  
Free Living Amoeba

The fine structure of a species of small free-living amoeba, Hartmanella astronyxis, has been investigated. The mitochondria resemble those of other species of amoeba. Structureless bodies of about the same size as mitochondria are sometimes found in association with them. Double membranes are common in the cytoplasm, and may show granules along their outer borders. The nuclear membrane is a double-layered structure, with a honeycomb structure evident in tangential sections. The cell membrane is also double-layered, or occasionally multi-layered.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF CALF THYMUS NUCLEAR PREPARATIONS ISOLATED IN SUCROSE SOLUTIONS

1963 ◽  
Vol 18 (3) ◽  
pp. 541-553 ◽  
Author(s):  
Robert M. Kodama ◽  
Henry Tedeschi
Keyword(s):  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Osmium Tetroxide ◽  
Microscope Examination ◽  
Intact Cells ◽  
Embedding Technique ◽  
Random Samples ◽  
Sucrose Solutions ◽  
Calf Thymus

This work was carried out with the intent of developing a method capable of routinely evaluating calf thymus nuclear preparations with the electron microscope. Examination of small random samples, pre-embedded in agar after fixation with permanganate, were found to give results comparable to those obtained with much larger samples withdrawn randomly from pellets and embedded and sectioned conventionally. Results obtained by this pre-embedding technique with acrolein, osmium tetroxide, or permanganate fixations were equivalent. Calf thymus nuclear preparations isolated in sucrose by the method prevalently used (see 1) are contaminated only slightly with intact cells, to a degree which varies with each preparation. However, intact cells, damaged cells, or nuclei with some cytoplasm constitute together about 30 per cent of the preparation. Particles other than intact cells are not readily distinguishable from one another by light or phase microscope techniques. These preparations can be purified further by centrifuging through a dense sucrose layer. In our hands, however, contamination with some cytoplasm still remains in approximately 10 per cent of the particles. Incubation of the particles prepared without purification procedures, under conditions frequently used, results in the extensive breakdown of particles. Under at least one set of conditions, nuclei are selectively disrupted, leaving primarily damaged cells in the preparation.

AN ELECTRON MICROSCOPE STUDY OF INTRAVACUOLAR BODIES IN THE UREDIA OF WHEAT STEM RUST AND IN HYPHAE OF OTHER FUNGI

1967 ◽  
Vol 45 (9) ◽  
pp. 1473-1478 ◽  
Author(s):  
P. L. Thomas ◽  
P. K. Isaac
Keyword(s):  
Electron Microscope ◽  
Internal Structure ◽  
Stem Rust ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Osmium Tetroxide ◽  
Wheat Stem Rust ◽  
Wheat Leaves

An electron microscope study of plant and fungal specimens fixed in a mixture of glutaraldehyde and acrolein followed by osmium tetroxide showed intravacuolar bodies with an intricate internal structure ranging from myelin-like membranes to a system of tubules. The bodies were commonly found in the developing uredia of stem rust infected wheat leaves and in the hyphae of several species of fungi. The origin and nature of the bodies is discussed.

scholarly journals The Fine Structure of Some Retinal Photoreceptors

1960 ◽  
Vol 7 (1) ◽  
pp. 87-92 ◽  
Author(s):  
M. F. Moody ◽  
J. D. Robertson
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Cell Membrane ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Double Membrane ◽  
Double Structure ◽  
Rods And Cones ◽  
Retinal Photoreceptors ◽  
Bounding Surfaces

An electron microscope study has been made of octopus and amphibian photoreceptors, after fixing with KMnO4 and embedding in araldite. What has previously been seen as a single dense stratum bounding the tubular compartments (octopus) or the double membrane discs (rods and cones), now shows a double structure. We interpret this as showing that these tubules and discs have similar bounding surfaces, which are probably directly related to the cell membrane. This is confirmed by the finding that the tubules and discs are (at least occasionally) continuous with the cell membrane.

Ultrastructure of Plant Leaf Tissue Infected with Mite-Borne Viral-Like Pathogens

1970 ◽  
Vol 28 ◽  
pp. 178-179 ◽  
Author(s):  
O. E. Bradfute ◽  
R. E. Whitmoyer ◽  
L. R. Nault
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Electron Microscope ◽  
Hordeum Vulgare ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Leaf Tissue ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Aceria Tulipae

A pathogen transmitted by the eriophyid mite, Aceria tulipae, infects a number of Gramineae producing symptoms similar to wheat spot mosaic virus (1). An electron microscope study of leaf ultrastructure from systemically infected Zea mays, Hordeum vulgare, and Triticum aestivum showed the presence of ovoid, double membrane bodies (0.1 - 0.2 microns) in the cytoplasm of parenchyma, phloem and epidermis cells (Fig. 1 ).

Electron microscope study of the microgranules in human vaginal epithelium

1978 ◽  
Vol 36 (2) ◽  
pp. 568-569
Author(s):  
A. Campos ◽  
J. Vilches ◽  
J. Gomez
Keyword(s):  
Electron Microscope ◽  
Microscope Study ◽  
Intercellular Space ◽  
Electron Microscope Study ◽  
Vaginal Epithelium ◽  
Vaginal Mucosa ◽  
Secretory Phase ◽  
Cervical Epithelium ◽  
Keratinized Epithelium ◽  
Fertile Women

Microgranules have been described with different names in keratinized and in nonkeratinized epithelium. In keratinized epithelium it seems clear that the microgranules are lamellated bodies bounded by a membrane which empty their contents into the intercellular space. Their existence in nonkeratinized epithelium is more debatable. Until now the so-called microgranules have been described in nonkeratinized bucal, lingual and cervical epithelium. In the present work we describe the morphology and nature of such structures in human vaginal epithelium.Biopsies from the midlevel of the vaginal mucosa were taken from voluntary fertile women. The specimens were divided into three groups with four vaginal specimens. The first group was obtained in the folicular phase; those of the second in the postovulatory phase and, finally, the last group corresponded to the secretory phase.

Structure of Fibrinogen and its Derivatives: An Electron Microscope Study

1979 ◽  
Vol 41 (04) ◽  
pp. 655-661 ◽  
Author(s):  
L Tranqui ◽  
M H Prandini ◽  
M Suscillon
Keyword(s):  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study
Sign in / Sign up

Export Citation Format

Share Document