scholarly journals Alteration in Oxidative Stress Biomarkers and Cytoarchitecture of Hepatic Tissues in Freshwater Fish Clarias batrachus (Linn.) under Sub lethal Butachlor Stress: Spectrophotometric and TEM Study

2021 ◽  
Vol 21 (2) ◽  
pp. 56
Author(s):  
Gyanendra Bahadur Chand ◽  
Prakriti Verma ◽  
Prakash Singh
Keyword(s):  
Oxidative Stress ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Prolonged Exposure ◽  
Reduced Glutathione ◽  
Clarias Batrachus ◽  
Control Fish ◽  
Hepatic Cells ◽  
Transmission Electron ◽  
Eosinophilic Inclusion

<p>The present study addresses the deleterious impact of sub lethal exposure of butachlor 2-chloro-N-(2-6-diphenyl) acetamide on hepatic cells of air breathing fish <em>Clarias batrachus</em> (Linn.) based on light and transmission electron microscopy and estimation of oxidative stress biomarker enzymes <em>viz.</em> reduced glutathione and lipidperoxidase. Fishes were exposed to 1.0µl/L butachlor for 5, 10 and 15 days respectively. After schedule exposure, blood sample were collected and extracted serum were analyzed for quantitative estimation of serum reduced glutathione and lipid peroxidase activity by spectrophotometer. The liver tissues were processed for light and electron microscope. Light photomicrographs of hepatic cells reveal dose related abnormalities which increases with the duration of exposure. Major changes attributed to the hepatic cell were parenchyma degeneration, necrosis along with fibrosis, widening of sinusoids, vacuolation, and infiltration of eosinophilic inclusion, karyolysis, pyknosis and perivenular congestion. Transmission electron microscopy of hepatic cells also revealed degenerated hepatic parenchyma, accumulation of lipid and electron dense material, degenerated mitochondria, nuclear shrinkage and enlarged lysosomes engulfing cytoplasmic particles in contrast to control fish. On prolonged exposure, the most frequent pathological modifications were mitochondrial swelling with regression of cristae and giant lysosome with myelinated phospholipid membrane pointing towards phospholipidosis. The activities of all the marker enzymes showed high fluctuation indicating significant imbalance in comparison to control. The study highlights the oxidative stress caused by butachlor correlated with histopathological anomalies of hepatic cells. It can be used as sensitive index for assessing the magnitude of oxidative damage and physiological dysfunction of experimental fish under laboratory condition.</p>

Angiotensin II-mediated oxidative stress promotes myocardial tissue remodeling in the transgenic (mRen2) 27 Ren2 rat

2007 ◽  
Vol 293 (1) ◽  
pp. E355-E363 ◽  
Author(s):  
Adam Whaley-Connell ◽  
Gurushankar Govindarajan ◽  
Javad Habibi ◽  
Melvin R. Hayden ◽  
Shawna A. Cooper ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Angiotensin Ii ◽  
Nadph Oxidase ◽  
Heart Tissue ◽  
Left Ventricular ◽  
Cine Mri ◽  
Ang Ii ◽  
Transmission Electron

Angiotensin II (ANG II) contributes to cardiac remodeling, hypertrophy, and left ventricular dysfunction. ANG II stimulation of the ANG type 1 receptor (AT1R) generates reactive oxygen species via NADPH oxidase, which facilitates this hypertrophy and remodeling. This investigation sought to determine whether cardiac oxidative stress and cellular remodeling could be attenuated by in vivo AT1R blockade (AT1B) (valsartan) or superoxide dismutase/catalase mimetic (tempol) treatment in a rodent model of chronically elevated tissue levels of ANG II, the transgenic (mRen2) 27 rat (Ren2). Ren2 rats overexpress the mouse renin transgene with resultant hypertension, insulin resistance, proteinuria, and cardiovascular damage. Young (6–7 wk old) male Ren2 and age-matched Sprague-Dawley rats were treated with valsartan (30 mg/kg), tempol (1 mmol/l), or placebo for 3 wk. Heart tissue NADPH oxidase (NOX) activity and immunohistochemical analysis of subunits NOX2, Rac1, and p22phox, heart tissue malondialdehyde, and insulin-stimulated protein kinase B (Akt) activation were measured. Structural changes were assessed with cine MRI, transmission electron microscopy, and light microscopy. Increases in septal wall thickness and altered systolic function (cine MRI) were associated with perivascular fibrosis and increased mitochondria in Ren2 on light and transmission electron microscopy ( P < 0.05). AT1B, but not tempol, reduced blood pressure ( P < 0.05); significant improvements were seen with both AT1B and tempol on NOX activity, subunit expression, malondialdehyde, and insulin-mediated activation/phosphorylation of Akt (each P < 0.05). Collectively, these data suggest cardiac oxidative stress-induced structural and functional changes are driven, in part, by AT1R-mediated increases in NADPH oxidase activity.

scholarly journals Autophagy attenuates high glucose-induced oxidative injury to lens epithelial cells

2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Xiaomin Liu ◽  
Xiaowen Zhao ◽  
Rong Cheng ◽  
Yusen Huang
Keyword(s):  
Oxidative Stress ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Epithelial Cells ◽  
High Glucose ◽  
Lens Epithelial Cells ◽  
Ros Generation ◽  
Diabetic Mice ◽  
Transmission Electron ◽  
And Oxidative Stress

Abstract Purpose: Autophagic dysfunction and abnormal oxidative stress are associated with cataract. The purpose of the present study was to investigate the changes of cellular autophagy and oxidative stress and their association in lens epithelial cells (LECs) upon exposure to high glucose. Methods: Autophagy and oxidative stress-related changes were detected in streptozotocin-induced Type 1 diabetic mice and normal mouse LECs incubated in high glucose conditions. Rapamycin at a concentration of 100 nm/l or 50 μM chloroquine was combined for analysis of the relationship between autophagy and oxidative stress. The morphology of LECs during autophagy was observed by transmission electron microscopy. The expressions of autophagy markers (LC3B and p62) were identified, as well as the key factors of oxidative stress (SOD2 and CAT) and mitochondrial reactive oxygen species (ROS) generation. Results: Transmission electron microscopy indicated an altered autophagy activity in diabetic mouse lens tissues with larger autophagosomes and multiple mitochondria. Regarding the expressions, LC3B was elevated, p62 was decreased first and then increased, and SOD2 and CAT were increased before a decrease during 4 months of follow-up in diabetic mice and 72 h of culture under high glucose for mouse LECs. Furthermore, rapamycin promoted the expressions of autophagy markers but alleviated those of oxidative stress markers, whereas chloroquine antagonized autophagy but enhanced oxidative stress by elevating ROS generation in LECs exposed to high glucose. Conclusions: The changes in autophagy and oxidative stress were fluctuating in the mouse LECs under constant high glucose conditions. Autophagy might attenuate high glucose-induced oxidative injury to LECs.

scholarly journals Cardiomyocyte mitochondrial oxidative stress and cytoskeletal breakdown in the heart with a primary volume overload

2015 ◽  
Vol 308 (6) ◽  
pp. H651-H663 ◽  
Author(s):  
Danielle M. Yancey ◽  
Jason L. Guichard ◽  
Mustafa I. Ahmed ◽  
Lufang Zhou ◽  
Michael P. Murphy ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mitochondrial Membrane ◽  
Volume Overload ◽  
Ros Production ◽  
Isolated Cardiomyocytes ◽  
Transmission Electron ◽  
Cyclical Stretch

Left ventricular (LV) volume overload (VO) results in cardiomyocyte oxidative stress and mitochondrial dysfunction. Because mitochondria are both a source and target of ROS, we hypothesized that the mitochondrially targeted antioxidant mitoubiquinone (MitoQ) will improve cardiomyocyte damage and LV dysfunction in VO. Isolated cardiomyocytes from Sprague-Dawley rats were exposed to stretch in vitro and VO of aortocaval fistula (ACF) in vivo. ACF rats were treated with and without MitoQ. Isolated cardiomyocytes were analyzed after 3 h of cyclical stretch or 8 wk of ACF with MitoSox red or 5-(and-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate to measure ROS and with tetramethylrhodamine to measure mitochondrial membrane potential. Transmission electron microscopy and immunohistochemistry were used for cardiomyocyte structural assessment. In vitro cyclical stretch and 8-wk ACF resulted in increased cardiomyocyte mitochondrial ROS production and decreased mitochondrial membrane potential, which were significantly improved by MitoQ. ACF had extensive loss of desmin and β2-tubulin that was paralleled by mitochondrial disorganization, loss of cristae, swelling, and clustering identified by mitochondria complex IV staining and transmission electron microscopy. MitoQ improved mitochondrial structural damage and attenuated desmin loss/degradation evidenced by immunohistochemistry and protein expression. However, LV dilatation and fractional shortening were unaffected by MitoQ treatment in 8-wk ACF. In conclusion, although MitoQ did not affect LV dilatation or function in ACF, these experiments suggest a connection of cardiomyocyte mitochondria-derived ROS production with cytoskeletal disruption and mitochondrial damage in the VO of ACF.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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).

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