A scanning electron microscope study of the internal structure of mature linear mycelial organs of four basidiomycete species

1989 ◽  
Vol 67 (8) ◽  
pp. 2266-2271 ◽  
Author(s):  
J. W. G. Cairney ◽  
D. H. Jennings ◽  
C. J. Veltkamp

The internal structure of mature mycelial cords of Lycoperdon pyriforme, Mutinus caninus, Steccherinum fimbriatum, and Tricholomopsis platyphylla was studied using scanning electron microscopy. Although interspecific differences in the degree of internal differentiation were observed, linear mycelial organ structure in all four species was similar, in that they consisted of a cortex of fine hyphae surrounding a medulla containing large diameter "vessel" hyphae. Based on similarities between the internal structure of rhizomorphs of Armillaria mellea and the mycelial cords of the species considered in this study, the exclusive use of the term "rhizomorph," qualified by adjectives describing development at the growing front and the degree of internal differentiation, is proposed in describing all linear mycelial aggregates.

1983 ◽  
Vol 115 (11) ◽  
pp. 1503-1512 ◽  
Author(s):  
Robert M. K. W. Lee ◽  
D. A. Craig

AbstractMandibles of females of 10 species of mosquitoes from five genera; hypopharynx of females of 26 species from 11 genera; and laciniae of females of 31 species from 14 genera, were examined using scanning electron microscopy. Mandibular teeth are present in Anopheles and Armigeres females, but absent in Aedes, Culiseta, and Culex. Interdigitating cuticular projections are present at the tip of the hypopharynx in all females examined. The salivary canal is open both at the tip as well as dorsally along a longitudinal slit. The average number of lateral teeth on the maxillary stylets varies according to species. Mesial and vestigial teeth are present in some species. There is no correlation between number of maxillary teeth and specific hosts of mosquito species. The function of stylet structure in feeding is discussed.


Author(s):  
A. S. Frost ◽  
J. S. Gardner ◽  
M. Nielson

Brochosomes are minute granules secreted by specialized cells lining the lumen of Malphigian tubules in homopteran insects. They have been reported on two different homopteran families, the Cicadellidae (leaf-hoppers) and Membracidae (tree-hoppers), but they have never been reported on members of the family Cercopidae (froghoppers), although they have been suspected to be produced by other homopteran families. These three families all belong to the subgroup Auchenorryncha, and often coexist in the same habitat. Many theories have been proposed regarding brochosome function, but no conclusive results have ever been reported.Scanning electron microscopy was used to study legs of five species of Cercopidae. Brochosomes were observed on legs of Lepyronid batrachoidea (Fig. 1), Clastoptera brunnea (Fig. 2), Philaronia bilineata (Fig. 3), and Aphozphoza media (Fig. 4). None was found on Clastoptera juniperina. The shape of the brochosomes remained fairly consistent on all species except Clastoptera brunnea. Normally the structure was a polyhedron consisting of 12 pentagons and 20 hexagons, appearing hollow and nearly spherical. However, on Clastoptera brunnea, the brochosomes were larger and appeared to be more faceted.


Author(s):  
A. Julio Martinez ◽  
E. Clifford Nelson ◽  
Doris G. Fultz ◽  
Ragnit Geeraets

Scanning electron microscopy (SEM) can serve as a valuable supplement to transmission electron microscopy (TEM) in the study of pathogenic protozoa. Details of overall form and structure of surface and organelles which may have a role in pathogenicity may be revealed. TEM studies on Naegleria have contributed much to understanding the extraordinary virulence of this ameba, but some remaining questions may be resolved by SEM. This report describes a technique which has proven useful in preparing SEM specimens. Naegleria ameba trophozoites adhere strongly to the surface on which they are growing. In culture tubes, amebae will multiply on the wall. Naegleria tends to grow from the top of the fluid downward and may multiply until a solid monolayer develops. If a strip of plastic film is introduced, the growth on the strip can be observed by direct microscope viewing through the wall of the tube.


1987 ◽  
Vol 65 (7) ◽  
pp. 1703-1712 ◽  
Author(s):  
T. A. Bakke ◽  
R. E. Bailey

Specimens of Phyllodistomum umblae (Fabricius, 1780) from Oncorhynchus nerka (Walbaum) from the Nautley River, British Columbia, and Salmo gairdneri Richardson from the Stuart River, British Columbia, are described and figured using light microscopy and scanning electron microscopy. Particular emphasis is placed on describing the numbers, types, and arrangement of papillae as seen with scanning electron microscopy. No significant differences were observed between the present Canadian material from O. nerka and S. gairdneri and specimens of P. umblae described from Norway, Sweden, and the U.S.S.R. Thus, P. umblae has a holarctic distribution in salmonids. Phyllodistomum limnosa Sandeman and Pippy, 1967, described from Salmo salar L. and Salvelinus fontinalis (Mitchill) from Newfoundland, is regarded as a synonym of P. umblae. Phyllodistomum lachancei Choquztte, 1947, described from S. fontinalis in Quebec, probably is also a synonym of P. umblae, but a more detailed scanning electron microscope study of the papillae in P. lachancei is required for confirmation.


Author(s):  
David Joy ◽  
James Pawley

The scanning electron microscope (SEM) builds up an image by sampling contiguous sub-volumes near the surface of the specimen. A fine electron beam selectively excites each sub-volume and then the intensity of some resulting signal is measured. The spatial resolution of images made using such a process is limited by at least three factors. Two of these determine the size of the interaction volume: the size of the electron probe and the extent to which detectable signal is excited from locations remote from the beam impact point. A third limitation emerges from the fact that the probing beam is composed of a finite number of discrete particles and therefore that the accuracy with which any detectable signal can be measured is limited by Poisson statistics applied to this number (or to the number of events actually detected if this is smaller).


1987 ◽  
Vol 41 (6) ◽  
pp. 1238-1243
Author(s):  
Yohichiroh Soh ◽  
Junroh Tahara ◽  
Takashi Hayashikawa ◽  
Masatoshi Hitaka ◽  
Kohzoh Kubota ◽  
...  

Author(s):  
Mamaeva S.N. ◽  
Vinokurov R.R. ◽  
Munkhalova Ya.A. ◽  
Dyakonova D.P. ◽  
Platonova V.A. ◽  
...  

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.


Author(s):  
J R Santos-Mallet ◽  
T D Balthazar ◽  
A A Oliveira ◽  
W A Marques ◽  
A Q Bastos ◽  
...  

Abstract The aim of the present study was to describe the morphology of the eggs of Culex (Culex) saltanensis Dyar that occurs in the Neotropical region. Eggs of the Cx. (Cux.) saltanensis were collected at the Mata Atlântica FIOCRUZ campus, fixed in 1% osmium tetroxide, prepared for mounting on metal supports, observed under a scanning electron microscope, and described morphologically. The eggs had a coniform shape with a length of approximately 0.5 mm (505–510 µm) and a width in the median portion of 117 µm (113–123 µm). Upper portion is lined with tubers of irregular shape and varying sizes (0.64–1.31 µm), located on a cross-linked matrix forming bands observed under optical microscopy. The micropyle is encased in a necklace of approximately 6.6-µm plates arranged in a flower-like shape. Comparing Cx. (Cux.) saltanensis eggs with several species of different genera, important divergent characteristics can be observed. However, this study points to the need for new descriptions of eggs of species belonging to the same subgenus in order to analyze if there will be differences between them. Culex (Cux.) saltanensis eggs have particular characteristics not observed in eggs of other Culicidae genera.


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