scholarly journals THE PARASPORAL BODY OF BACILLUS LATEROSPORUS LAUBACH

1957 ◽  
Vol 3 (6) ◽  
pp. 1001-1010 ◽  
Author(s):  
Christopher L. Hannay
Keyword(s):  
Cross Sections ◽  
Vegetative Cell ◽  
Culture Medium ◽  
Lateral Position ◽  
The Body ◽  
Dense Material ◽  
Spore Coat ◽  
Thin Sections ◽  
Electron Dense Material ◽  
Ultrathin Sections

On sporulation the slender vegetative rods swell and form larger spindle-shaped cells in which the spores are formed. When the spores mature they lie in a lateral position cradled in canoe-shaped parasporal bodies which are highly basophilic and can be differentiated from the surrounding vegetative cell cytoplasm with dilute basic dyes. On completion of sporulation the vegetative cell protoplasm and the cell wall lyse, leaving the spore cradled in its parasporal body. This attachment continues indefinitely on the usual culture medium and even persists after the spores have germinated. In thin sections of sporing cells the bodies are differentiated from the cell protoplasm by differences in structure. Whereas the protoplasm has a granular appearance, in both longitudinal and cross-sections the parasporal body comprises electron-dense lamellae running parallel with the membranes of the spore coat and less electron-dense material in the interstices of the lamellae. The inner surface of the body is contiguous with that of the spore coat as if it were part of the spore, rather than a separate body attached to the spore. The staining reactions of the parasporal body are not consistent with those of any substance described in bacteria. With Giemsa the bodies stain like chromatin, but the Feulgen reaction indicates that they do not contain the requisite nucleic acid. With an aqueous solution of toluidine blue they stain metachromatically, but with an acidified solution the results are variable. Neisser's stain for polyphosphate is negative. The basophilic substance is removed from the body with some organic solvents. This basophilic substance has not been specifically identified with any material seen in ultrathin sections, but it is suggested that it might be the less electron-dense material in the interstices of the lamellar structure. In contrast to the spore coat of B. laterosporus, those of its two relatives B. brevis and B. circulans take up basic stain like the parasporal body. Thin spore sections of these species have shown that the walls are thicker than those surrounding the spores of B. laterosporus, and it is suggested that the outer stainable layer of brevis and circulans spores is an accessory coat which in laterosporus may have been deformed to give a parasporal body.

scholarly journals FOWLER'S BACILLUS AND ITS PARASPORAL BODY

1961 ◽  
Vol 9 (2) ◽  
pp. 285-298 ◽  
Author(s):  
Christopher L. Hannay
Keyword(s):  
Vegetative Cell ◽  
Growth Process ◽  
Amorphous Layer ◽  
The Body ◽  
The Other ◽  
Spore Coat ◽  
Cell Structures ◽  
Ultrathin Sections ◽  
Physiological Tests ◽  
Regular Number

Fowler's bacillus is one of several organisms which form a non-viable inclusion or parasporal body during the process of sporulation. This body is globular and may be as large as or larger than the spore. Its position in the cell is not random; the spore is terminal and the body paracentral, lying between the spore and the remaining vegetative cell chromatin bodies. On completion of sporulation both spore and body are contained within an exosporium. The sequence in the development of the cell structures was followed in ultrathin sections of material fixed in permanganate. When sporulation is well advanced the body begins to grow from a single crystal, then presumably as a result of some disorientation in the growth process it develops as a multicrystalline body with the lattices orientated at different angles. When the body approximates the spore in size, a lamella coat is formed and an exosporium develops which eventually encircles the body and the spore. Other lamella systems microscopically similar to those surrounding the parasporal body develop free in the cytoplasm outside the exosporium. In both of these systems the number of lamellae is variable. The spore coat of Fowler's bacillus, consisting of an outer lamella layer and an inner unresolved amorphous layer has been found microscopically identical to the spore coat of B. cereus. In both organisms the lamella layer of the spore coat consists, in contrast to the other lamella systems, of a regular number of lamellae. Physiological tests would indicate that Fowler's bacillus is a variety of B. cereus.

Bacteriophage ФX 174

1968 ◽  
Vol 26 ◽  
pp. 32-33
Author(s):  
M. E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nutrient Medium ◽  
Structural Changes ◽  
Uranyl Acetate ◽  
Dense Material ◽  
Medium Ph ◽  
Electron Dense Material ◽  
Virus Particles ◽  
Ultrathin Sections

Cultures of Escherichia coli CIA (Bertani) growing logarithmically in nutrient medium were infected with 5 to 200 bacteriophage §X 174 per cell. At various times after infection the cultures were fixed for 1 hour in nutrient medium containing 5% formaldehyde pH 7, then pelleted and resuspended in 1% OSO4 in L-medium pH 7 for 1 hour; the material was pelleted again and resuspended in a mixture of 1% OsO4 and 1% uranyl-acetate in water; in this mixture the cells were fixed for 10 hours at 20° C; after fixation they were dehydrated in acetone and embedded in Vestopal W. In ultrathin sections the first structural changes became visible 15 minutes after infection when some of the cells seemed to swell and round up. In the cells small aggregates of electron dense material were observed in the chromosomal areas, and sometimes virus particles were also seen within the area of the cells’ chromosome.

Electron microscopic localization of concanavalin A receptor sites in pollen surface material after fixation with glutaraldehyde-cetylpyridinium chloride.

1984 ◽  
Vol 32 (8) ◽  
pp. 869-871 ◽  
Author(s):  
M Grote ◽  
H G Fromme
Keyword(s):  
Concanavalin A ◽  
Cetylpyridinium Chloride ◽  
Pollen Grains ◽  
Dense Material ◽  
Con A ◽  
Electron Microscopic ◽  
Electron Dense Material ◽  
Receptor Sites ◽  
Pollen Surface ◽  
Ultrathin Sections

Pollen from birch trees (Betula pendula) was fixed in glutaraldehyde containing 0.5% cetylpyridinium chloride (CPC), incubated with concanavalin A (Con A)-ferritin, postfixed in osmium, dehydrated, and embedded in Epon. On ultrathin sections, ferritin particles were observed closely associated with the electron-dense material precipitated by CPC on the surface of the pollen grains. Controls for CPC, which were fixed in glutaraldehyde alone, showed no electron-dense material on the surface. In controls for Con A, which were incubated in Con A-ferritin in the presence of the inhibitory sugar (alpha-methyl-D-mannopyranoside), no ferritin particles were observed. The above-described procedure thus allows the localization of sugar residues in highly soluble pollen wall glycoproteins.

Ultrastructure of the attachment and feeding sites of Gracilacus latescens Raski, 1976 in timber bamboo roots and selected anatomical details of the female stylet

Nematology ◽  
2003 ◽  
Vol 5 (2) ◽  
pp. 307-312
Author(s):  
Dianne Achor ◽  
Larry Duncan ◽  
Renato Inserra ◽  
Alberto Troccoli
Keyword(s):  
Cell Wall ◽  
Cross Sections ◽  
Cortical Cell ◽  
Root Surface ◽  
Mature Female ◽  
Dense Material ◽  
Anterior Portion ◽  
Electron Dense Material ◽  
Transmission Electron ◽  
Phyllostachys Bambusoides

AbstractMature female Gracilacus latescens are sedentary and remain attached by the stylet to the surface of timber bamboo roots (Phyllostachys bambusoides) for their entire life. Observations by transmission electron microscopy (TEM) of the anatomy of the anterior portion of the female body showed the stylet shaft surrounded by a thick stomatal wall sensu Endo (1983) and by large protractor muscles. Cross sections of the root at the site of nematode attachment showed accumulation of electron-opaque material between the nematode body and the epidermal wall penetrated by the stylet. Electron-dense material enwrapped the stylet from the point of its insertion in an epidermal cell wall until its end in the lumen of a sclerenchymal or cortical cell. Two to three cells are penetrated by the stylet. The electron-dense material appeared to originate from the walls of epidermal, cortical parenchymal and sclerenchymal cells perforated by the stylet. The thickness of this material increased with the number of sclerenchyma cell walls penetrated by the stylet. Cross sections of the enwrapped stylet showed it tightly encased in the electron-dense material, which appeared to anchor the stylet and consequently the nematode body to the root surface. A syncytium originates from the innermost cell reached by the enwrapped stylet and expands into the inner cortex and stele. Cell wall dissolution and pit fields are characteristics of the syncytium.

Correlative light and electron microscopic cytochemical demonstration of biodegradation of polyester implants

1989 ◽  
Vol 47 ◽  
pp. 878-879 ◽  
Author(s):  
J. S. Hanker ◽  
P. Yates ◽  
E. Anderson ◽  
B. Giammara
Keyword(s):  
Cross Sections ◽  
Toluidine Blue ◽  
Glycolic Acid ◽  
Light And Electron Microscopy ◽  
The Body ◽  
Poly Lactic Acid ◽  
Distal Stump ◽  
Electron Microscopic ◽  
Polyglactin 910 ◽  
Thin Sections

There are situations in which an implant material is required only temporarily, e.g., when it is needed as a scaffold to support a nondegradable material until the latter can be incorporated by the body; or when it is required for the uniform release of a therapeutic agent over a long period of time. Biodegradable organic polyesters such as poly(glycolic acid), poly(lactic acid) or their copolymers are of particular interest for such purposes because they undergo hydrolysis (Fig. 1) to form glycolic or lactic acids which are metabolites normal to the body. Recent studies were performed on the use of polyglactin 910 mesh (VicrylR, a lactic-glycolic acid polymer) as a conduit (sleeve) to guide the reconnection of regenerating fibers of the proximal stump of rat sciatic nerve, across an llmm gap, with fibers in the distal stump of the interrupted nerve. For experimental set-up and procedure see reference 3.Gross examination of the repaired sciatic nerves at 1 month showed complete reconnection of the stumps but the VicrylR mesh was not apparent.When cryostat or paraffin sections were made of repaired nerve there was some disruption of structure due to movement of the polyester filaments through the tissue during the sectioning process. This could be avoided by embedding the specimens in epoxy resin and making semi-thin sections with a glass knife. Staining of the sections with either toluidine blue or the PATS reaction (a light and electron microscopy variation of the Keriodic acidSchiff PAS, reaction depositing silver, 5) revealed numerous VicrylR filaments in different degradation stages (Figs. 2-4). The toluidine blue stained filaments were reminiscent of earlier results on methylene blue-stained muscle sections that contained cross-sections of polyglactin 910 braided sutures.

Comparative Morphology of Intercellular Bridges Between Developing Germ Cells of the Ovary

1970 ◽  
Vol 28 ◽  
pp. 328-329
Author(s):  
J. R. Ruby ◽  
R. F. Dyer ◽  
R. G. Skalko ◽  
R. F. Gasser ◽  
E. P. Volpe
Keyword(s):  
Germ Cells ◽  
Rana Pipiens ◽  
Comparative Morphology ◽  
Dense Material ◽  
Individual Species ◽  
Microscope Examination ◽  
Electron Dense Material ◽  
Intercellular Bridges ◽  
Cytoplasmic Side ◽  
Intercellular Connections

An electron microscope examination of fetal ovaries has revealed that developing germ cells are connected by intercellular bridges. In this investigation several species have been studied including human, mouse, chicken, and tadpole (Rana pipiens). These studies demonstrate that intercellular connections are similar in morphology regardless of the species.Basically, all bridges are characterized by a band of electron-dense material on the cytoplasmic side of the tri-laminar membrane surrounding the connection (Fig.l). This membrane is continuous with the plasma membrane of the conjoined cells. The dense material, however, never extends beyond the limits of the bridge. Variations in the configuration of intercellular connections were noted in all ovaries studied. However, the bridges in each individual species usually exhibits one structural characteristic seldom found in the others. For example, bridges in the human ovary very often have large blebs projecting from the lateral borders whereas the sides of the connections in the mouse gonad merely demonstrate a slight convexity.

Ferritin Labeled Antibody Staining of Thin Sections

1969 ◽  
Vol 27 ◽  
pp. 420-421
Author(s):  
J. D. McLean ◽  
S. J. Singer
Keyword(s):  
Biological Material ◽  
Water Soluble ◽  
Thin Sections ◽  
Antibody Staining ◽  
Thin Sectioning ◽  
Ultrathin Sections

The successful application of ferritin labeled antibodies (F-A) to ultrathin sections of biological material has been hampered by two main difficulties. Firstly the normally used procedures for the preparation of material for thin sectioning often result in a loss of antigenicity. Secondly the polymers employed for embedding may non-specifically absorb the F-A. Our earlier use of cross-linked polyampholytes as embedding media partially overcame these problems. However the water-soluble monomers used for this method still extract many lipids from the material.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Video Graphics and High-Voltage Electron Microscopy For Analysis of Microtubule Distributions In Fixed Cells

1990 ◽  
Vol 48 (1) ◽  
pp. 524-525
Author(s):  
Richard Mcintosh ◽  
David Mastronarde ◽  
Kent McDonald ◽  
Rubai Ding
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
Cell Shape ◽  
Video Camera ◽  
Computer Memory ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
Morphogenetic Event ◽  
Set Of Points

Microtubules (MTs) are cytoplasmic polymers whose dynamics have an influence on cell shape and motility. MTs influence cell behavior both through their growth and disassembly and through the binding of enzymes to their surfaces. In either case, the positions of the MTs change over time as cells grow and develop. We are working on methods to determine where MTs are at different times during either the cell cycle or a morphogenetic event, using thin and thick sections for electron microscopy and computer graphics to model MT distributions.One approach is to track MTs through serial thin sections cut transverse to the MT axis. This work uses a video camera to digitize electron micrographs of cross sections through a MT system and create image files in computer memory. These are aligned and corrected for relative distortions by using the positions of 8 - 10 MTs on adjacent sections to define a general linear transformation that will align and warp adjacent images to an optimum fit. Two hundred MT images are then used to calculate an “average MT”, and this is cross-correlated with each micrograph in the serial set to locate points likely to correspond to MT centers. This set of points is refined through a discriminate analysis that explores each cross correlogram in the neighborhood of every point with a high correlation score.

Geological Field Sketches and Illustrations

2019 ◽  
Author(s):  
Matthew J. Genge
Keyword(s):  
Cross Sections ◽  
Earth Science ◽  
Three Dimensional ◽  
Worked Examples ◽  
Scientific Publications ◽  
Thin Sections ◽  
Geological Features ◽  
Different Types ◽  
The Subject

Drawings, illustrations, and field sketches play an important role in Earth Science since they are used to record field observations, develop interpretations, and communicate results in reports and scientific publications. Drawing geology in the field furthermore facilitates observation and maximizes the value of fieldwork. Every geologist, whether a student, academic, professional, or amateur enthusiast, will benefit from the ability to draw geological features accurately. This book describes how and what to draw in geology. Essential drawing techniques, together with practical advice in creating high quality diagrams, are described the opening chapters. How to draw different types of geology, including faults, folds, metamorphic rocks, sedimentary rocks, igneous rocks, and fossils, are the subjects of separate chapters, and include descriptions of what are the important features to draw and describe. Different types of sketch, such as drawings of three-dimensional outcrops, landscapes, thin-sections, and hand-specimens of rocks, crystals, and minerals, are discussed. The methods used to create technical diagrams such as geological maps and cross-sections are also covered. Finally, modern techniques in the acquisition and recording of field data, including photogrammetry and aerial surveys, and digital methods of illustration, are the subject of the final chapter of the book. Throughout, worked examples of field sketches and illustrations are provided as well as descriptions of the common mistakes to be avoided.

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