Isolation and characterization of mitochondria-rich cell types from the gill of freshwater rainbow trout

2002 ◽  
Vol 282 (3) ◽  
pp. R658-R668 ◽  
Author(s):  
Fernando Galvez ◽  
Scott D. Reid ◽  
Guy Hawkings ◽  
Greg G. Goss
Keyword(s):  
Rainbow Trout ◽  
Iron Particle ◽  
Cell Types ◽  
Chloride Cells ◽  
Transmission Electron Microscopy Analysis ◽  
Pavement Cells ◽  
Isolation And Characterization ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Magnetic Cell Separation

A magnetic cell separation technique (MACS) was developed for isolating and characterizing peanut lectin agglutinin positive (PNA+) cells from rainbow trout gills. Percoll density separated mitochondria-rich (MR) cells were serially labeled with PNA-FITC and an anti-FITC antibody covalently coupled to a 50-nm iron particle and then applied to a magnetic column. PNA+ MR cells were enriched to >95% purity. Transmission electron microscopy analysis of both the PNA+ and PNA negative (PNA−) fraction showed that PNA binds to MR chloride cells while the PNA− cell fraction is comprised of MR cells with features characteristic of pavement cells. Western blotting demonstrated that both PNA+ and PNA− fractions had high levels of Na+-K+-ATPase and Sco1 expression; however, relative expression of H+-ATPase in PNA+ and PNA− cells demonstrated that untreated fish had twofold higher H+-ATPase levels in PNA− cells relative to the PNA+ cells. Furthermore, hypercapnic acidosis significantly increased the relative H+-ATPase expression on PNA− cells only, whereas metabolic alkalosis had no significant effect.

Peanut lectin binds to a subpopulation of mitochondria-rich cells in the rainbow trout gill epithelium

2001 ◽  
Vol 281 (5) ◽  
pp. R1718-R1725 ◽  
Author(s):  
Greg G. Goss ◽  
Sophia Adamia ◽  
Fernando Galvez
Keyword(s):  
Electron Microscopy ◽  
Rainbow Trout ◽  
Chloride Cells ◽  
Isolated Cells ◽  
Peanut Lectin ◽  
Pavement Cells ◽  
Transmission Electron ◽  
Percoll Density Gradient ◽  
Trout Gill

Fluorescently labeled peanut lectin agglutinin (PNA-FITC) was used to identify a subtype of mitochondria-rich (MR) cells in the gills of freshwater rainbow trout. In situ binding of PNA-FITC was visualized by inverted fluorescence microscopy and found to bind to cells on the trailing edge of the filament epithelium as demonstrated by differential interference contrast optics. The amount of PNA-FITC binding on the filament epithelium increased with cortisol pretreatment concomitant with an increased chloride cell fractional area as demonstrated by scanning electron microscopy. Dispersed gill cells were isolated by trypsinization and separated using a discontinuous Percoll density gradient. Cells migrating to the 1.06–1.09 g/ml interface were found to be MR as demonstrated by staining with the vital mitochondrial dye 4-(4-(dimethylamino)styryl)- N-methylpyridinium iodide and transmission electron microscopy (TEM). However, only ∼40% of the MR cells were found to bind PNA-FITC. Cortisol pretreatment increased the relative numbers of MR cells isolated from the dispersed gill cell population, but the relative proportions of PNA binding cells remained unchanged. Ultrastructural analysis of isolated cells in the TEM demonstrated that the MR cell fraction was comprised of a mixed population of chloride cells and pavement cells.

CHARACTERIZATION AND ELECTRICAL PROPERTIES OF ALIGNED CARBON NANOTUBES WITH HIGH ASPECT RATIO

2011 ◽  
Vol 10 (01n02) ◽  
pp. 23-28
Author(s):  
RAVI BHATIA ◽  
V. PRASAD ◽  
M. REGHU
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Multiwall Carbon Nanotubes ◽  
High Quality ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
High Degree

High-quality multiwall carbon nanotubes (MWNTs) were produced by a simple one-step technique. The production of MWNTs was based on thermal decomposition of the mixture of a liquid phase organic compound and ferrocene. High degree of alignment was noticed by scanning electron microscopy. The aspect ratio of as-synthesized MWNTs was quite high (more than 4500). Transmission electron microscopy analysis showed the presence of the catalytic iron nanorods at various lengths of MWNTs. Raman spectroscopy was used to know the quality of MWNTs. The ratio of intensity of the G-peak to the D-peak was very high which revealed high quality of MWNTs. Magnetotransport studies were carried out at low temperature and a negative MR was noticed.

scholarly journals Thermodynamic Modelling and Microstructural Study of Z-Phase Formation in a Ta-Alloyed Martensitic Steel

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1332
Author(s):  
Florian Riedlsperger ◽  
Bernadette Gsellmann ◽  
Erwin Povoden-Karadeniz ◽  
Oriana Tassa ◽  
Susanna Matera ◽  
...  
Keyword(s):  
Special Focus ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Computational Framework ◽  
Mobility Data ◽  
Interfacial Energies ◽  
Transmission Electron ◽  
Size Number ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

A thermokinetic computational framework for precipitate transformation simulations in Ta-containing martensitic Z-steels was developed, including Calphad thermodynamics, diffusion mobility data from the literature, and a kinetic parameter setup that considered precipitation sites, interfacial energies and dislocation density evolution. The thermodynamics of Ta-containing subsystems were assessed by atomic solubility data and enthalpies from the literature as well as from the experimental dissolution temperature of Ta-based Z-phase CrTaN obtained from differential scanning calorimetry. Accompanied by a comprehensive transmission electron microscopy analysis of the microstructure, thermokinetic precipitation simulations with a wide-ranging and well-documented set of input parameters were carried out in MatCalc for one sample alloy. A special focus was placed on modelling the transformation of MX into the Z-phase, which was driven by Cr diffusion. The simulation results showed excellent agreement with experimental data in regard to size, number density and chemical composition of the precipitates, showing the usability of the developed thermokinetic simulation framework.

Transport properties of cultured branchial epithelia from freshwater rainbow trout: a novel preparation with mitochondria-rich cells

2000 ◽  
Vol 203 (10) ◽  
pp. 1523-1537 ◽  
Author(s):  
M. Fletcher ◽  
S.P. Kelly ◽  
P. Part ◽  
M.J. O'Donnell ◽  
C.M. Wood
Keyword(s):  
Rainbow Trout ◽  
Flux Ratio ◽  
Culture Conditions ◽  
Chloride Cells ◽  
Pavement Cells ◽  
Ratio Criterion ◽  
Peg 4000 ◽  
Tight Epithelia ◽  
Gill Filaments

A new double-seeded insert (DSI) technique is described for culture of branchial epithelial preparations from freshwater rainbow trout on filter supports. DSI epithelia contain both pavement cells and mitochondria-rich (MR) cells (15.7+/−2.5 % of total cell numbers). MR cells occur singly or in clusters, are voluminous, open apically to the ‘external environment’ and exhibit ultrastructural characteristics similar to those found in the ‘chloride cells’ of freshwater fish gills. After 6–9 days in culture with Leibovitz's L-15 medium on both surfaces (symmetrical conditions), transepithelial resistance (TER) stabilized at values as high as 34 k capomega cm(2), indicative of electrically ‘tight’ epithelia. The density of MR cells, the surface area of their clusters and transepithelial potential (TEP; up to +8 mV basolateral positive, mean +1.9+/−0.2 mV) were all positively correlated with TER. In contrast, preparations cultured using an earlier single-seeded insert (SSI) technique contained only pavement cells and exhibited a negligible TEP under symmetrical conditions. Na(+)/K(+)-ATPase activities of DSI preparations were comparable with those in gill filaments, but did not differ from those of SSI epithelia. Replacement of the apical medium with fresh water to mimic the in vivo situation (asymmetrical conditions) induced a negative TEP (−6 to −15 mV) and increased permeability to the paracellular marker PEG-4000. Under symmetrical conditions, unidirectional Na(+) and Cl(−) fluxes were in balance, and there was no active transport by the Ussing flux ratio criterion. Under asymmetrical conditions, there were large effluxes, small influxes and evidence for active Cl(−) uptake and Na(+) extrusion. Unidirectional Ca(2+) fluxes were only 0.5-1.0 % of Na(+) and Cl(−) fluxes; active net Ca(2+) uptake occurred under symmetrical conditions and active net extrusion under asymmetrical conditions. Thus, DSI epithelia exhibit some of the features of the intact gill, but improvements in culture conditions are needed before the MR cells will function as true freshwater ‘chloride cells’.

scholarly journals Morphological changes and bioaccumulation in response to cadmium exposure in Morchella spongiola, a fungus with potential for detoxification

2021 ◽  
Author(s):  
Hongyan Xu ◽  
Jing Guo ◽  
Qing Meng ◽  
Zhanling Xie
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Intracellular Accumulation ◽  
Tolerance Mechanism ◽  
Edible Fungi ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Micro Morphology

<i>Morchella</i> is a genus of edible fungi with strong resistance to Cd and the ability to accumulate it in the mycelium. However, the mechanisms conferring Cd resistance in <i>Morchella</i> are unknown. In the present study, morphological and physiological responses to Cd were evaluated in the mycelia of <i>Morchella spongiola</i>. Variations in hyphal micro-morphology including twisting, folding and kinking in mycelia exposed to different Cd concentrations (0.15, 0.9, 1.5, 2.4, 5.0 mg/L) were observed using scanning electron microscopy. Deposition of Cd precipitates on cell surfaces (at Cd concentrations > 2.4 mg/L) was shown by SEM-EDS. Transmission electron microscopy analysis of cells exposed to different concentrations of Cd revealed the loss of intracellular structures and the localization of Cd depositions inside/outside the cell. FTIR analysis showed that functional groups such as C=O, -OH, -NH and -CH could be responsible for Cd binding on the cell surface of <i>M. spongiola</i>. In addition, intracellular accumulation was observed in cultures at low Cd concentrations (< 0.9 mg/L), while extracellular adsorption occurred at higher concentrations. These results provide valuable information on the Cd tolerance mechanism in <i>M. spongiola</i> and constitute a robust foundation for further studies on fungal bioremediation strategies.

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