AN ELECTRON MICROSCOPE STUDY OF THIN SECTIONS OF HAEMOPHILUS VAGINALIS (GARDNER AND DUKES) AND SOME POSSIBLY RELATED SPECIES

1966 ◽  
Vol 12 (6) ◽  
pp. 1125-1136 ◽  
Author(s):  
Alice Reyn ◽  
A. Birch-Andersen ◽  
S. P. Lapage
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Lactobacillus Acidophilus ◽  
Related Species ◽  
Electron Microscope Study ◽  
Similar Degree ◽  
Gram Positive ◽  
Thin Sections

The line structure of Haemophilus vaginalis (Gardner and Dukes 1955) was compared with that of four, possibly related species (Butyribacterium rettgeri, Corynebacterium diphtheriae var. mitis, Lactobacillus acidophilus, Haemophilus influenzae) and an unrelated species, Neisseria haemolysans, which had shown a similar degree of Gram-variability as that of H. vaginalis. Although H. vaginalis was first described as a Gram-negative rod, its fine structure, particularly that of cell wall and septa, was more like that of Gram-positive organisms. Also N. haemolysans had a fine structure close to that of Gram-positive organisms, and its typical Gram-positive cell wall varied in. thickness from one cell to another.The study did not solve the problem of the classification of the so-called H. vaginalis, but the appearance of the few strains studied in the electron microscope suggests that it: should be included in Corynebacterium or Butyribacterium rather than in Lactobacillus.

scholarly journals THE CYTOPLASMIC FINE STRUCTURE OF THE DIATOM, NITZSCHIA PALEA

1963 ◽  
Vol 18 (2) ◽  
pp. 429-440 ◽  
Author(s):  
Ryan W. Drum
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Hydrofluoric Acid ◽  
Oil Bodies ◽  
Oil Droplets ◽  
Pennate Diatom ◽  
Thin Sections ◽  
Nitzschia Palea ◽  
Peripheral Cytoplasm

The cytoplasmic fine structure of the motile, pennate diatom, Nitzschia palea was studied in thin sections viewed in the electron microscope. The cells were fixed in OsO4, embedded in methacrylate, and immersed in 10 per cent hydrofluoric acid (HF) for 36 to 40 hours to remove the siliceous cell wall prior to sectioning. The HF treatment did not cause any obvious cytoplasmic damage. The dictyosome complex is perinuclear, and located only in the central cytoplasm. Mitochondria are sparse in the central cytoplasm, but abundant in the peripheral cytoplasm, and fill many of the transvacuolar cytoplasmic strands. Characteristic, amorphous oil bodies fill certain cytoplasmic strands and probably are not leucosin. The pyrenoid appears to be membrane limited, and oil droplets are found adjacent to the pyrenoid. The pyrenoid of another diatom, Cymbella affinis, is also membrane-limited. The membrane limiting the pyrenoid may be a composite of the terminal portions of chloroplast discs, facilitating rapid movement of photosynthate into the pyrenoid matrix, where the characteristic oil droplets may be formed. Carinal fibrils are found singly in each carinal pore, and may be involved in the locomotion of Nitzschia palea.

The fine structure and development of chlamydospores of Fusarium oxysporum

1972 ◽  
Vol 18 (7) ◽  
pp. 997-1002 ◽  
Author(s):  
I. L. Stevenson ◽  
S. A. W. E. Becker
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cell Surface ◽  
Outer Layer ◽  
Outer Wall ◽  
Wall Layer ◽  
Thin Sections ◽  
Hyphal Wall

Methods have been developed for the rapid, reproducible induction of high-density populations of F. oxysporum chlamydospores. On transferring washed pregerminated conidia to a simple two-salts medium, chlamydospore morphogenesis was evident by 12 h and masses of mature spores could be harvested at the end of 4 days. Electron-microscope studies of thin sections of mature chlamydospores reveal a thick triple-layered cell wall. The cytoplasm contains, in addition to large lipid deposits, a nucleus, mitochondria, and endoplasmic reticulum all typical of fungal cells. Chlamydospores of F. oxysporum exhibit two distinct types of cell surface in thin section. The outer wall layer of two of the isolates studied was smooth-surfaced while the outer layer of the two other isolates was distinctly fibrillose. Some evidence is presented suggesting that the fibrillose material arises through the partial breakdown of the original hyphal wall.

scholarly journals THE FINE STRUCTURE OF CHONDROCOCCUS COLUMNARIS

1967 ◽  
Vol 35 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Jack L. Pate ◽  
Erling J. Ordal
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Electron Microscope ◽  
Outer Membrane ◽  
Electron Microscope Study ◽  
Ruthenium Red ◽  
Gliding Motility ◽  
Dense Layer ◽  
Adhesive Properties

An electron microscope study of the myxobacterium Chondrococcus columnaris has revealed the following structures in the peripheral layers of the cells: (1) a plasma membrane, (2) a single dense layer (probably the mucopeptide component of the cell wall), (3) peripheral fibrils, (4) an outer membrane, and (5) a material coating the surfaces of the cells which could be stained with the dye ruthenium red.The ruthenium red-positive material is probably an acid mucopolysaccharide and may be involved in the adhesive properties of the cells. The outer membrane and plasma membrane both have the appearance of unit membranes: an electron-translucent layer sandwiched between two electron-opaque layers. The peripheral fibrils span the gap between the outer membrane and the mucopeptide layer, a distance of about 100 A, and run parallel to each other along the length of the cell. The fibrils appear to be continuous across the ends of the cells. The location of these fibrillar structures suggests that they may play a role in the gliding motility of these bacteria.

The fine structure of Rhodopseudomonas acidophila

1974 ◽  
Vol 20 (1) ◽  
pp. 13-17 ◽  
Author(s):  
H.-D. Tauschel ◽  
Judith F. M. Hoeniger
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Outer Layer ◽  
Photosynthetic Bacterium ◽  
Thin Sections ◽  
Rhodopseudomonas Acidophila ◽  
Motile Cells ◽  
Similarities And Differences ◽  
Mother Cells

The morphology of the photosynthetic bacterium Rhodopseudomonas acidophila strain P18aF1 1.2 has been investigated with the electron microscope. The cells grow by budding, the sessile buds eventually separating from the mother cells by constriction. In some dividing stages a belt-like structure was observed in the zone of division. Motile cells possess a subpolar tuft of unsheathed flagella. At the site of insertion of the flagella, the cell wall bears 12- to 14-nm wide holes or annuli through which the flagella probably pass. Motile cells readily lose their flagella.The structure of the surface revealed two distinct types: cells with a hexagonally patterned outer layer composed of ring-shaped elements and cells possessing a thick, fibrous capsule. Thin sections showed a well-developed thylakoid system arranged in piles and similar to that of other budding photosynthetic bacteria.The morphology of R. acidophila has been compared with that of R. palustris to show similarities and differences between the two species.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

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 Electron Microscope Study of the Normal Rat Aorta

1960 ◽  
Vol 7 (3) ◽  
pp. 533-537 ◽  
Author(s):  
M. K. Keech
Keyword(s):  
Smooth Muscle ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cross Section ◽  
Electron Microscope Study ◽  
Rat Aorta ◽  
Endothelial Layer ◽  
Signet Ring ◽  
Normal Rat ◽  
Elastic Laminae

The fine structure of the normal rat aorta is described. The presence of a sub-endothelial layer, the oblique orientation of the smooth muscle cells with respect to the aortic axis, and the occurrence of desmosomes between these cells and adjacent elastic laminae, are emphasized. Lead-stained collagen presented a characteristic signet-ring appearance on cross-section. The rats examined were the pair-fed controls for the lathyritic series described in a separate communication.

scholarly journals FINE STRUCTURE OF MEMBRANOUS AND MICROFIBRILLAR SYSTEMS IN THE CORTEX OF PARAMECIUM CAUDATUM

1971 ◽  
Vol 49 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Richard D. Allen
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Three Dimensional ◽  
Paramecium Caudatum ◽  
Fibrillar Material ◽  
Muscular Function ◽  
Branching System

An electron microscope study of the cortex of Paramecium caudatum has revealed new details pertinent to several unresolved problems. The lateral boundaries of the alveoli do not regularly follow the crests of the polygonal ridges and thus their staining with silver cannot account for the external lattice seen by light microscopists. A granulo-fibrillar material is present, however, within the peaks of the ridges, which would account for the external lattice if so stained. Perforations are present between adjacent alveoli which make the whole mosaic of alveolar sacs within the cell's cortex continuous—both the membranes and the lumen. A microfibrillar system exhibiting a cross-striated pattern lies in the superficial cortex. These bands are inserted at their ends in the epiplasm and have a fine structure and arrangement suggesting a muscular function. The infraciliary lattice is a branching system of fibers with electron-opaque posts at the center of each branching locus. This system is distinct from the striated bands in morphology and in space. The epiplasm is discontinuous along the crests of the ridges, which may account for the pellicles' disposition to tear along these lines. A three-dimensional drawing is presented to show the interrelationships between the above membranous and microfibrillar systems.

Radioautographic visualization of β-glucans formed by pea membranes from UDP-glucose

1983 ◽  
Vol 61 (4) ◽  
pp. 1266-1275 ◽  
Author(s):  
Susette C. Mueller ◽  
Gordon A. Maclachlan
Keyword(s):  
Stem Cells ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Electron Microscope ◽  
Hot Water ◽  
Thin Sections ◽  
Fibrillar Material ◽  
Close Physical Proximity ◽  
Glucose Incorporation ◽  
Stem Slices

Radioautographic experiments were carried out using pea stem slices to determine the site of glucose incorporation from UDP-glucose. Cut or damaged pea stem cells were the only cells to incorporate [3H]glucose from UDP-[3H]glucose. The product formed at 20 μM UDP-glucose was observed in electron microscope thin sections in patches on the plasma membrane and the cell wall. The product formed at 5 mM UDP-glucose occurred in fibrillar bundles that stretched between the plasma membrane and the cell wall. This periplasmic material fluoresced when stained with aniline blue. Experiments in which slices were subjected to sequential incubations in radioactive 5 mM UDP-glucose followed by unlabelled 5 mM UDP-glucose, or incubations in the reverse order, indicated that incorporation of [3H]glucose into products insoluble in chloroform:methanol:water or hot water occurs at the plasma membrane, and radioactivity is displaced from the membrane by subsequent incubations. A similar experiment, in which slices were first incubated in radioactive 20 μM UDP-glucose followed by unlabelled 5 mM UDP-glucose, indicated that the synthesis of fibrillar material from 5 mM UDP-glucose displaces the labelled product that had been formed from 20 μM UDP-glucose. It is concluded that only cut or damaged pea stem cells utilize UDP-glucose and the plasma membrane enzymes that incorporate [3H]glucose from 20 μM or 5 mM UDP-[3H]glucose are in close physical proximity.

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