Analysis of Stomatogenesis by Scanning Electron Microscopy in Tetrahymena pyriformis Strain W during Synchronous Cell Division

1973 ◽  
Vol 92 (1) ◽  
pp. 95 ◽  
Author(s):  
Howard E. Buhse ◽  
Susan J. Stamler ◽  
John O. Corliss
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Division ◽  
Tetrahymena Pyriformis ◽  
Synchronous Cell ◽  
Scanning Electron

scholarly journals Morphological evidence by scanning electron microscopy of excretion of metacyclic forms of Trypanosoma cruzi in vector's urine

1988 ◽  
Vol 83 (3) ◽  
pp. 361-365 ◽  
Author(s):  
Rodrigo Zeledon ◽  
Rodolfo Bolaños ◽  
M. R. Espejo Navarro ◽  
Miguel Rojas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Division ◽  
Trypanosoma Cruzi ◽  
Urine Flow ◽  
The Other ◽  
Rectal Gland ◽  
Morphological Evidence ◽  
Different Levels ◽  
Scanning Electron

Comparision by scanning electron microscopy (SEM) of Trypanosoma cruzi flagellates attached to the cuticle of the rectal gland of infected Dipetalogaster maxima nymphs, showed marked differences before amd after feeding. Before feeding numerous metacyclic trypomastigotes were observed among the abundant epimastigotes that formed the carpet of flagellates. On the other hand, in insects that were allowed to urinate for 24 hours after a meal, the metacyclics were scarce,indicating that they had been detached by the urine flow. An asymetric type of cell division, probably originating both an epi-and a trypomastigote, was occasionally observed. The occurrence of swellings at different levels of the flagella of epimastigotes suggests that secondary sites of attachment may be common.

Morphology and morphogenesis of Strongylidium pseudocrassum Wang and Nie, 1935, with redefinition of Strongylidium Sterki, 1878  (Protista: Ciliophora: Stichotrichia)

Zootaxa ◽  
2007 ◽  
Vol 1559 (1) ◽  
pp. 31-57 ◽  
Author(s):  
THIAGO DA SILVA PAIVA ◽  
INÁCIO DOMINGOS DA SILVA-NETO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Division ◽  
Rare Species ◽  
De Novo ◽  
Current Knowledge ◽  
Northern Region ◽  
First Time ◽  
Scanning Electron

A population of the rare species Strongylidium pseudocrassum Wang and Nie, 1935, was discovered from a lagoon in the northern region of Rio de Janeiro, Brazil, and its morphology was investigated through protargol-impregnation, scanning electron microscopy and in vivo observations. Morphogenetic events of cell division and physiological reorganization were described for the first time to this species. It was found that S. pseudocrassum has the ventral cirral rows organized in the same manner as Pseudouroleptus caudatus Hemberger, 1985. However two independent primordia VI, one for the proter and other for the opisthe, are generated intrakinetally from the rightmost ventral cirral row. In addition, dorsal kineties replicate entirely “de novo” and do not fragment. Based on the data obtained, the genus Strongylidium was redefined and the species currently assigned to it were classified into five groups according to current knowledge on their ciliature and the combination S. lentum (Biernacka, 1963) nov. comb. is proposed.

scholarly journals STRAWBERRY GROWTH FOLLOWING A SUB-LETHAL FREEZE

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 654f-654
Author(s):  
Michele R. Warmund
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Division ◽  
Vascular System ◽  
Tissue Growth ◽  
Fragaria Ananassa ◽  
Anatomical Studies ◽  
Crown Tissue ◽  
Scanning Electron

`Earliglow' strawberry (Fragaria × ananassa Duch.) plants were frozen to -5C to examine the distribution of ice in the crowns. Anatomical studies were also performed to characterize tissue growth in a greenhouse at 4, 8, and 16 weeks after freezing to -5C. Ice masses observed in fresh crown tissue corresponded to the presence of extracellular tissue voids in specimens fixed for scanning electron microscopy (SEM). Voids were present near the peduncle and adjacent to the vascular system in crown tissue. After plants were grown in the greenhouse, cell division and enlargement were observed near the voids in crowns subjected to -5C. By 15 weeks after freezing, a few small extracellular voids remained in the crowns.

scholarly journals Ice Distribution in `Earliglow' Strawberry Crowns and Tissue Recovery following Extracellular Freezing

1993 ◽  
Vol 118 (5) ◽  
pp. 644-648 ◽  
Author(s):  
Michele R. Warmund
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Division ◽  
Vascular System ◽  
Tissue Growth ◽  
Lethal Temperature ◽  
Anatomical Studies ◽  
Crown Tissue ◽  
Tissue Recovery ◽  
Scanning Electron

`Earliglow' strawberry (Fragaria xananassa Duchesne) plants were frozen to -5 or -50C to examine the distribution of ice in the crowns. Anatomical studies were also performed to characterize tissue growth in a greenhouse at 4, 8, and 15 weeks after freezing to -5C. Ice masses observed in fresh crown tissue corresponded to the presence of extracellular tissue voids in specimens fixed for scanning electron microscopy (SEM). Voids were present near the peduncle and adjacent to the vascular system in crown tissue. After plants were grown in the greenhouse, cell division and enlargement were observed near the voids in crowns subjected to -5C. By 15 weeks after freezing, a few small extracellular voids remained in the crowns. Tissue voids were also present in crowns of plants frozen rapidly to -50C and subsequently thawed. Cells in the crown of these plants were intact and did not appear collapsed after exposure to -50C, a lethal temperature.

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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