Scanning Electron Microscopy of Trophozoites of Naegleria Species

1985 ◽  
Vol 43 ◽  
pp. 642-643
Author(s):  
M. Lattyak ◽  
G. Cabral ◽  
F. Marciano-Cabral
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Membrane Surface ◽  
Opportunistic Pathogens ◽  
Environmental Isolates ◽  
Free Living ◽  
Naegleria Lovaniensis ◽  
Primary Amebic Meningoencephalitis ◽  
Scanning Electron ◽  
Naegleria Gruberi

The genus, Naegleria, includes four species of amebae which are either free-living or opportunistic pathogens. Naegleria fowleri, is the causative agent of Primary Amebic Meningoencephalitis, a rare but almost always fatal disease in man. Naegleria australiensis is an environmental isolate which is moderately pathogenic in mice. Naegleria lovaniensis and Naegleria gruberi are nonpathogenic environmental isolates. The four species were examined by scanning electron microscopy in order to determine whether membrane surface extensions, called food cups, could be correlated to pathogenicity. Food cups have been previously identified on the surface of Entamoeba histolytica and N. fowleri. It has been suggested that the food cups or stomas, are associated with internationalization of liquid and particulate components.

scholarly journals Membrane Surface Features of Blastocystis Subtypes

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 417 ◽  
Author(s):  
John Yason ◽  
Kevin Tan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Death ◽  
Species Complex ◽  
Membrane Surface ◽  
Surface Coat ◽  
Pathogenic Potential ◽  
Morphological Differences ◽  
Carbohydrate Components ◽  
Scanning Electron

Blastocystis is a common intestinal protistan parasite with global distribution. Blastocystis is a species complex composed of several isolates with biological and morphological differences. The surface coats of Blastocystis from three different isolates representing three subtypes were analyzed using scanning electron microscopy. This structure contains carbohydrate components that are also present in surface glycoconjugates in other parasitic protozoa. Electron micrographs show variations in the surface coats from the three Blastocystis isolates. These differences could be associated with the differences in the pathogenic potential of Blastocystis subtypes. Apart from the surface coat, a plasma membrane-associated surface antigen has been described for Blastocystis ST7 and is associated with programmed cell death features of the parasite.

Free-living marine planktonic unarmoured dinoflagellates from the Gulf of Mexico and the Mexican Pacific

2015 ◽  
Vol 58 (1) ◽  
Author(s):  
Sergio Escobar-Morales ◽  
David U. Hernández-Becerril
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gulf Of Mexico ◽  
Species Composition ◽  
New Records ◽  
Morphological Characters ◽  
Phylogenetic Group ◽  
Free Living ◽  
Mexican Pacific ◽  
Scanning Electron

AbstractThe so-called unarmoured dinoflagellates are not a “natural” (phylogenetic) group but they lack thecal plates, share fragility and possess relatively few morphological characters that can be positively identified. This study depicts the species composition of unarmoured dinoflagellates collected from sites along the coasts of the Gulf of Mexico and the Mexican Pacific and includes their descriptions and illustrations. We identified a total of 25 species belonging to 13 genera and six families that were studied through various techniques using light and scanning electron microscopy. Seven new records for the Mexican Pacific are annotated here that include

scholarly journals Comparison of techniques for counting prokaryotes in marine planktonic and biofilm samples

2021 ◽  
Vol 85 (3) ◽  
pp. 211-220
Author(s):  
Vanessa Ochi Agostini ◽  
Letícia Terres Rodrigues ◽  
Alexandre José Macedo ◽  
Erik Muxagata
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Damage ◽  
High Variability ◽  
Epifluorescence Microscopy ◽  
Free Living ◽  
Marine Biofilm ◽  
Comparison Of Techniques ◽  
Green Fluorescent ◽  
Scanning Electron

Though a large number of techniques are available for the study of aquatic bacteria, the aim of this study was to establish a technique for analysing free-living and biofilm prokaryotic cells through laboratory assays. In particular, we wished to analyse the efficiency of ultrasound to detach and disrupt biofilm, to obtain an efficient stain treatment for quantifying free-living and biofilm prokaryotes in flow cytometry (FC), and to compare epifluorescence microscopy (EFM), scanning electron microscopy (SEM) and FC for quantifying free-living and biofilm prokaryotes#. Marine-grade plywood substrates were immersed in natural marine water that was conditioned for 12 days. At 6 and 12 days, water aliquots and substrates were removed to estimate free-living and biofilm prokaryote density. Ultrasound efficiently removed marine biofilm from substrates (up to 94%) without cell damage. FC analysis (unstained) reliably quantified marine plankton and young or mature biofilm prokaryotes compared with other staining (acridine orange, 4′,6-diamidino-2-phenylindole, propidium iodide and green fluorescent nucleic acid), EFM or SEM techniques. FC and SEM achieved similar results, while a high variability was observed in the EFM technique. FC was faster and more precise than SEM because the count is not dependent on the observer.

The postfire recovery of rock-inhabiting algae, microfungi, and lichens

1992 ◽  
Vol 70 (2) ◽  
pp. 301-312 ◽  
Author(s):  
Jacob Garty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Green Algae ◽  
Water Holding Capacity ◽  
Rock Surface ◽  
Fruiting Bodies ◽  
Free Living ◽  
Mountain Area ◽  
Water Holding ◽  
Scanning Electron

Despite numerous investigations on the re-establishment of epiphytic cryptogams, especially lichens, after forest fires, very little is known about the recolonization of burnt rocks by lithobiontic microorganisms after fire in the Mediterranean region. Reported herein are the results of a combined field observation and scanning electron microscopy study focusing on the connection between the microrelief of the rocks that was shaped during prefire periods and the recolonization of pioneer lithobiontic microorganisms after the fire. Scanning electron microscopy revealed that the burnt rock surfaces exhibit 10 kinds of weathering elements that include 9 kinds of cryptogamic imprints corroded by saxicolous (rock-inhabiting) unicellular green algae, free-living microfungi, and fruiting bodies or microgrooves of endolithic lichens during prefire periods. The total volume of several selected structural weathering elements formed by lithobiontic microorganisms during the prefire period was estimated relative to the possible contribution of these lithobionts to local pedogenesis. Considering that the specific weight of chalk is 2.6 g/cm3, the estimated amount of the rock material removed by small pits with a diameter of 0.01 mm formed by unicellular green algae during the prefire period can reach 3.06 kg/ha mountain area with 10% rock coverage, while the estimated amount of chalk rock material removed by pinhead holes with a diameter of 0.8 mm formed by fruiting bodies of endolithic lichens can reach 174 kg/ha with the same rock coverage. Water-holding capacity of empty pinhead holes and small pits on the rock surface in burnt areas was also estimated, and it is suggested that the water-holding capacity of empty small pits (d = 0.01 mm) formed by unicellular green algae on rock surface per hectare mountain area with 10% rock coverage can reach 1.18 L, whereas in case of pinhead holes (d = 0.8 mm) formed by fruiting bodies of endolithic lichens the water-holding capacity can reach 66.9 L/ha with the same rock coverage. Scanning electron microscopy revealed the presence of three different kinds of unicellular green algae, one free-living microfungus, two different species of endolithic lichens, two epilithic lichen species, and great numbers of lichen ascospores, fungal spores, and hyphae established postfire in pinhead holes and small pits produced by former microlithobionts inhabiting rocks during prefire periods. These microorganisms and diaspores were also present in ruts, shallow rock depressions, and microcrevices produced by abiotic factors. Key words: lithobiontic microorganisms, wildfire, algae, microfungi, lichens.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

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