Ultrastructure of the tegument of Saccocoelioides godoyi

2001 ◽  
Vol 75 (1) ◽  
pp. 15-21 ◽  
Author(s):  
S.C. Cohen ◽  
A. Kohn ◽  
M. de Fatima Diniz Baptista-Farias

The tegument of adultSaccocoelioides godoyiKohn & Froes, 1986 (Digenea: Haploporidae), specimens of which were collected from the intestine of the freshwater fish,Leporinus friderici(Bloch, 1794) (Anostomidae) from the reservoir of Itaipu Hydroelectric Power Station, Parana State, Brazil, was studied by transmission electron microscopy. The tegument comprises an external anucleate layer, covered by a surface plasma membrane and associated glycocalyx. The surface layer is bound by the basal plasma membrane and contains spines, two types of inclusion bodies and mitochondria. Tegumental cell bodies are located beneath the surface musculature and contain a single nucleus, cytoplasm with rough endoplasmic reticulum, mitochondria, ribosomes, and inclusion bodies similar to those found in the external layer. Cytoplasmic strands connect the cell bodies to the external surface layer, suggesting that the inclusion bodies are produced in these cells and pass up into the syncytium, as is known for other digeneans from experimental evidence.

2013 ◽  
Vol 58 (4) ◽  
Author(s):  
Zdzisław Świderski ◽  
Isabel Montoliu ◽  
Carlos Feliu ◽  
David Gibson ◽  
Jordi Miquel

AbstractThe tegument of the microphallid digenean Maritrema feliui, examined by means of TEM, is described as a syncytial epithelium organised into two layers. The outer layer is an external anucleate, cytoplasmic region connected to a second region composed of nucleate perikarya (cytons) deeply embedded in the surrounding cortical parenchyma. The surface layer of the tegument is covered by a plasma membrane with many deep invaginations, which are apparently pinocytotic. This layer also bears numerous large, electron-dense spines of two types, which are intracellular and attached to the basal plasma membrane. Its cytoplasm is rich in free ribosomes, contains numerous mitochondria, disc-shaped granules frequently arranged in a rouleau, and several large, moderately electron-dense, membranous bodies. The subtegumentary perikarya and their nuclei, which are both flattened, are described in detail, as are their connections with the surface tegument. These perikarya appear to be the source of the disc-shaped granules and some of the other inclusions present in the surface layer. The main characteristics of the tegumental structure of M. feliui are commented upon in relation to the findings of previous publications and their suggested functions.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

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).


Author(s):  
T. L. Benning ◽  
P. Ingram ◽  
J. D. Shelburne

Two benzofuran derivatives, chlorpromazine and amiodarone, are known to produce inclusion bodies in human tissues. Prolonged high dose chlorpromazine therapy causes hyperpigmentation of the skin with electron-dense inclusion bodies present in dermal histiocytes and endothelial cells ultrastructurally. The nature of the deposits is not known although a drug-melanin complex has been hypothesized. Amiodarone may also cause cutaneous hyperpigmentation and lamellar lysosomal inclusion bodies have been demonstrated within the cells of multiple organ systems. These lamellar bodies are believed to be the product of an amiodarone-induced phospholipid storage disorder. We performed transmission electron microscopy (TEM) and energy dispersive x-ray microanalysis (EDXA) on tissue samples from patients treated with these drugs, attempting to detect the sulfur atom of chlorpromazine and the iodine atom of amiodarone within their respective inclusion bodies.A skin biopsy from a patient with hyperpigmentation due to prolonged chlorpromazine therapy was fixed in 4% glutaraldehyde and processed without osmium tetroxide or en bloc uranyl acetate for Epon embedding.


2018 ◽  
Vol 245 ◽  
pp. 15002 ◽  
Author(s):  
Roman Davydov ◽  
Valery Antonov ◽  
Dmitry Molodtsov ◽  
Alexey Cheremisin ◽  
Vadim Korablev

The rapid spread of storm floods over large areas requires flood management throughout the river basin by the creation an innovative system of flood control facilities of various functional purposes distributed in the area. The central part of the system is the hydro system with hydro power plant. In addition, the flood control facilities on the side tributaries with self-regulating reservoir are included in the system. To assess the effect of controlling extreme water discharges by flood control facilities, it is necessary to develop special mathematical models reflecting the specifics of their operation. Unified mathematical models of the operation modes of a hydro complex with hydroelectric power station and flood control facility are created. They are implemented in a computer program that provides the ability to determine the main parameters and operating characteristics of hydro systems when performing multivariate calculations in a wide range of initial data. This makes possible specifying the parameters and operation modes of each hydro system with the current economic and environmental requirements, to assess the energy-economic and environmental consequences in the operation of the system of flood control facilities distributed in the area. The article analyses the results of the extreme water discharge’s regulation by the hydro system on the main river and flood control facilities on the side tributaries, considering environmental requirements.


1974 ◽  
Vol 8 (10) ◽  
pp. 914-916
Author(s):  
I. S. Ronzhin ◽  
A. D. Osipov ◽  
V. Kh. Gol'tsman ◽  
A. B. Yumatov

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 562
Author(s):  
Alexey Panin ◽  
Andrey Dmitriev ◽  
Anton Nikonov ◽  
Marina Kazachenok ◽  
Olga Perevalova ◽  
...  

Experimental and theoretical studies helped to reveal patterns of surface roughening and the microstructure refinement in the surface layer of commercial pure titanium during ultrasonic impact treatment. Applying transmission electron microscopy technique, a gradient microstructure in the surface layer of the ultrasonically treated sample, where the grain size is varied from nano- to micrometers was revealed. It was shown that the surface plastic strains of the titanium sample proceeded according to the plastic ploughing mechanism, which was accompanied by dislocation sliding, twinning, and the transformations of the microstructure and phase composition. The molecular dynamics method was applied to demonstrate the mechanism of the phase transformations associated with the formation of stacking faults, as well as the reversible displacement of atoms from their sites in the hcp lattice, causing a change in coordination numbers. The role of the electronic subsystem in the development of the strain-induced phase transformations during ultrasonic impact treatment was discussed.


2021 ◽  
Vol 18 (3) ◽  
pp. 410-420
Author(s):  
Vladimir N. KAVKAZKY ◽  
◽  
Yana V. MEL’NIK ◽  
Alexey P. LEIKIN ◽  
Andrey V. BENIN ◽  
...  

Objective: Chirkeyskaya HPP is by far the most powerful hydroelectric power plant in the North Caucasus with the highest arched dam in Russia and the second highest dam in the country after the Sayano-Shushenskaya HPP. This explains why it is called the pearl of the Caucasus. Methods: For the operation and maintenance of this unique structure, a large-scale complex of underground structures for various purposes was built, the technical condition of which must be constantly monitored. To carry out work on the survey of underground structures, the management of the design and survey institute of JSC “Lengidroproekt” decided to attract specialists from the Department of Tunnels and Subways and the Test Center “Strength” of Emperor Alexander I Petersburg State Transport University. The work was successfully carried out at the end of 2015. Results: The safety of underground structures was objectively assessed. Recommendations for the repair and further comprehensive reconstruction of the Chirkeyskaya HPP have been developed. Practical importance: Carry out work on the survey of underground structures of Chirkeyskaya HPP is allowes elaborate of complex measures on safety from Chirkeyskaya HPP.


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