scholarly journals Contrasting effects of accumulation and tolerance characteristics in Arabidopsis thaliana under Cr(III) and Cr(VI) stress

2021 ◽  
Author(s):  
Yonghong Han ◽  
Guotao Ding ◽  
Peng Sun ◽  
Giuiying Li ◽  
Weihao Li
Keyword(s):  
Oxidative Stress ◽  
Arabidopsis Thaliana ◽  
Root Length ◽  
Morphological Changes ◽  
Antioxidant Systems ◽  
Inhibition Of Growth ◽  
Transmission Electron ◽  
Chromium Accumulation ◽  
First Time ◽  
Physiological And Biochemical

In this study, for the first time we investigated Cr(III) and Cr(VI) stress-induced physiological and biochemical responses in Arabidopsis thaliana . The capacity of A. thalian to accumulate Cr is closely related to the valence of chromium. Cr(VI) was more toxic than Cr(III) as indicated by chromium accumulation and growth inhibition. When the concentration of chromium is greater than 200μM, the root length and biomass of A. thaliana are reduced. But interestingly, Cr(III) at 200μM increased the root length and biomass of A. thaliana compared to the control. The transmission electron microscope shows that Cr(VI) can cause the chloroplasts damaged and the chlorophyll reduced more than Cr(III). The chloroplasts were filled the starch grains. An increase of lipid peroxidation in A. thaliana roots caused by Cr was measured, and this effect increases as the increasing Cr. It indicated that A. thaliana suffers from Cr-induced oxidative stress which resulted cell death in roots. To fight against oxidative stress, Ascorbate peroxidase and Glutathione reductase were activated by Cr in antioxidant defense. The inhibition of growth, the accumulation of chromium, the responses of antioxidant systems, and the ultra-morphological changes indicate that Cr(VI) was more toxic than Cr(III) .

scholarly journals Theβ-SiC Nanowires (~100 nm) Induce Apoptosis via Oxidative Stress in Mouse Osteoblastic Cell Line MC3T3-E1

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Weili Xie ◽  
Qi Xie ◽  
Meishan Jin ◽  
Xiaoxiao Huang ◽  
Xiaodong Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Dna Damage ◽  
Morphological Changes ◽  
Osteoblastic Cell ◽  
Osteoblastic Cell Line ◽  
Sic Nanowires ◽  
Tissue Replacement ◽  
Transmission Electron ◽  
First Time

Silicon carbide (SiC), a compound of silicon and carbon, with chemical formula SiC, the beta modification (β-SiC), with a zinc blende crystal structure (similar to diamond), is formed at temperature below1700∘C.β-SiC will be the most suitable ceramic material for the future hard tissue replacement, such as bone and tooth. Thein vitrocytotoxicity ofβ-SiC nanowires was investigated for the first time. Our results indicated that 100 nm long SiC nanowires could significantly induce the apoptosis in MC3T3-E1 cells, compared with 100 μm long SiC nanowires. And 100 nm long SiC nanowires increased oxidative stress in MC3T3-E1 cells, as determined by the concentrations of MDA (as a marker of lipid peroxidation) and 8-OHdG (indicator of oxidative DNA damage). Moreover, transmission electron microscopy (TEM) was performed to evaluate the morphological changes of MC3T3-E1 cells. After treatment with 100 nm long SiC nanowires, the mitochondria were swelled and disintegrated, and the production of ATP and the total oxygen uptake were also decreased significantly. Therefore,β-SiC nanowires may have limitations as medical material.

scholarly journals Morphological and Biochemical Study of Bidens pilosa on the Effects of Extract of Urochloa ruziziensis

2019 ◽  
Vol 11 (15) ◽  
pp. 217 ◽  
Author(s):  
Érica Marusa Pergo Coelho ◽  
Patrícia Aparecida Galletti ◽  
Elizandra Aparecida Britta ◽  
Andréia Cristina Peres Rodrigues da Costa ◽  
Valdir Zucareli
Keyword(s):  
Oxidative Stress ◽  
Dry Matter ◽  
Biochemical Study ◽  
Morphological Changes ◽  
High Capacity ◽  
Initial Growth ◽  
Energetic Metabolism ◽  
Bidens Pilosa ◽  
Growth And Survival ◽  
Transmission Electron

Bidens pilosa is an aggressive species that competes with crops and, in addition, has a high capacity to acquire resistance or tolerance to herbicides. Thus, the objective of the present study was to investigate the allelopathic effects of aqueous extract of Urochloa ruziziensis on germination, development, respiration, antioxidant enzymes and cells morphology of B. pilosa seedlings during initial growth at laboratory.The seeds were sown with water or U. ruziziensis extract at concentrations of 250, 500 and 900 ppm, and after four days the percentage of germinated seeds, root and hypocotyl development, as well as respiration, peroxidase and catalase activity by seedlings, were analysed. The results were submitted to analysis of variance (ANOVA) and the means compared by the Tukey test and regression analysis. The cellular structures of the root with U. ruziziensis extract treatment (0, 500 and 900 ppm) were also analysed by transmission electron microscopy. The application of the extract reduced the germination of the seeds. The root growth increased, however, there was a reduction in the dry matter mass at 500 ppm. Mitochondrial respiration decreased and there was an increase in the activity of the peroxidase and catalase enzymes at 500 ppm. Morphological changes in the cells were also found, mainly with this concentration. Thus, it is possible can be concluded that allelochemicals present in extract from U. ruziziensis have the potential to provoke oxidative stress in B. pilosa seedlings in laboratory, mainly at a concentration of 500 ppm. This oxidative stress caused alterations mainly in the energetic metabolism of this plant, being this a primordial factor for its growth and survival.

Nickel Oxide Nanoparticles Induce Oxidative Stress and Morphological Changes on Marine Chlorella vulgaris

2014 ◽  
Vol 955-959 ◽  
pp. 956-960 ◽  
Author(s):  
Ning Gong ◽  
Kui Shuang Shao ◽  
Guang Yao Li ◽  
Ye Qing Sun
Keyword(s):  
Oxidative Stress ◽  
Chlorella Vulgaris ◽  
Antioxidant Defense ◽  
Morphological Changes ◽  
Antioxidant Defense System ◽  
Ros Generation ◽  
Nickel Oxide Nanoparticles ◽  
Sod Activity ◽  
Transmission Electron ◽  
The Status

The status of oxidative stress of marineChlorella vulgariswas investigated via measuring the content of H2O2, MDA, SOD and CAT in cells after 72h NiO nanoparticles (nNiO) exposure. Morphological changes of algal cells were also determined by transmission electron microscopy (TEM). The results showed that nNiO induced the ROS generation and stimulated the antioxidant defense system of algae. Significant increases (p < 0.01) in MDA level and SOD activity were found after 72h 10 mg L-1nNiO treatment. H2O2content and CAT activity also increased under higher concentration treatments although non-significant. The disruption of plasma membrane and the disordered thylakoid lamella of algal cells were found under nNiO exposure, which indicated cell morphological changes. Our results implied that oxidative damage was one of toxic causes of nanoparticles on algae. It also indicates the potential impacts on aquatic biota by nanomaterials.

scholarly journals CBS-derived H2S facilitates host colonization of Vibrio cholerae by promoting the iron-dependent catalase activity of KatB

2021 ◽  
Vol 17 (7) ◽  
pp. e1009763
Author(s):  
Yao Ma ◽  
Xiaoman Yang ◽  
Hongou Wang ◽  
Zixin Qin ◽  
Chunrong Yi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vibrio Cholerae ◽  
Catalase Activity ◽  
Proteome Analysis ◽  
Antioxidant Systems ◽  
Enzymatic Antioxidants ◽  
Adult Mice ◽  
First Time

Sensing and resisting oxidative stress is critical for Vibrio cholerae to survive in either the aquatic environment or the gastrointestinal tract. Previous studies mainly focused on the mechanisms of oxidative stress response regulation that rely on enzymatic antioxidant systems, while functions of non-enzymatic antioxidants are rarely discussed in V. cholerae. For the first time, we investigated the role of hydrogen sulfide (H2S), the simplest thiol compound, in protecting V. cholerae against oxidative stress. We found that degradation of L-cysteine by putative cystathionine β-synthase (CBS) is the major source of endogenous H2S in V. cholerae. Our results indicate that intracellular H2S level has a positive correlation with cbs expression, while the enhanced H2S production can render V. cholerae cells less susceptible to H2O2 in vitro. Using proteome analysis and real-time qPCR assay, we found that cbs expression could stimulate the expression of several enzymatic antioxidants, including reactive oxygen species (ROS) detoxifying enzymes SodB, KatG and AhpC, the DNA protective protein DPS and the protein redox regulator Trx1. Assays of ROS detoxification capacities revealed that CBS-derived H2S could promote catalase activity at the post-translational level, especially for KatB, which serves as an important way that endogenous H2S participates in H2O2 detoxification. The enhancement of catalase activity by H2S is achieved through facilitating the uptake of iron. Adult mice experiments showed that cbs mutant has colonization defect, while either complementation of cbs or exogenous supplement of N-Acetyl-L-Cysteine restores its fitness in the host environment. Herein, we proposed that V. cholerae regulates CBS-dependent H2S production for better survival and proliferation under ROS stress.

A Novel TEM Technique for Characterizing As-Grown CVD Diamond Films

1991 ◽  
Vol 49 ◽  
pp. 956-957 ◽  
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton
Keyword(s):  
Diamond Films ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Dark Field ◽  
Growth Surface ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
First Time ◽  
Microstructural Studies

Microstructural studies by transmission electron microscopy (TEM) of diamond films grown by chemical vapor deposition (CVD) usually involve tedious specimen preparation. This process has been avoided with a technique that is described in this paper. For the first time, thick as-grown diamond films have been examined directly in a conventional TEM without thinning. With this technique, the important microstructures near the growth surface have been characterized. An as-grown diamond film was fractured on a plane containing the growth direction. It took about 5 min to prepare a sample. For TEM examination, the film was tilted about 30-45° (see Fig. 1). Microstructures of the diamond grains on the top edge of the growth face can be characterized directly by transmitted electron bright-field (BF) and dark-field (DF) images and diffraction patterns.

Ultrastructural Study of Rat Colon Following Psyllium Ingestion

1985 ◽  
Vol 43 ◽  
pp. 580-581
Author(s):  
F.G. Lightfoot ◽  
L.E. Grau ◽  
M.M. Cassidy ◽  
G.R. Tadvalkar ◽  
G.V. Vahouny
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Large Population ◽  
Rat Colon ◽  
Gastrointestinal Disorders ◽  
Luminal Surface ◽  
Fecal Material ◽  
Transmission Electron ◽  
Morphologic Analysis ◽  
Irritable Bowel

Psyllium hydrophillic mucilloid is a natural gelling fiber consumed by a large population of our society. It is used as a bulk-producing laxative and in the treatment of gastrointestinal disorders such as “Irritable Bowel Syndrome”. The literature pertaining to the ultrastructural effects of this agent is sparse.This study documents morphological changes induced by psyllium. Animals fed a diet containing 2% psyllium for four weeks were subsequently sacrificed and processed for scanning and transmission electron microscopy. The colon contained fecal material combined with psyllium which conformed to the contour of the luminal surface. This mixture formed surface replicas of the intestinal mucosa. These replicas and their related colonic sites were processed for morphologic analysis.

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

1975 ◽  
Vol 33 ◽  
pp. 600-601
Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo
Keyword(s):  
Electron Microscopy ◽  
Cellular Proliferation ◽  
Morphological Changes ◽  
Culture Fluid ◽  
Cellular Functions ◽  
Human Trophoblast ◽  
Transmission Electron ◽  
Marked Activity ◽  
Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

Oxidative Stress, Ocular Disease and Diabetes Retinopathy

2019 ◽  
Vol 24 (40) ◽  
pp. 4726-4741 ◽  
Author(s):  
Orathai Tangvarasittichai ◽  
Surapon Tangvarasittichai
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Cell Death ◽  
Protein Modification ◽  
Morphological Changes ◽  
Corneal Dystrophy ◽  
Age Related Macular Degeneration ◽  
Ocular Diseases ◽  
Retinal Light Damage ◽  
Age Related

Background: Oxidative stress is caused by free radicals or oxidant productions, including lipid peroxidation, protein modification, DNA damage and apoptosis or cell death and results in cellular degeneration and neurodegeneration from damage to macromolecules. Results: Accumulation of the DNA damage (8HOdG) products and the end products of LPO (including aldehyde, diene, triene conjugates and Schiff’s bases) were noted in the research studies. Significantly higher levels of these products in comparison with the controls were observed. Oxidative stress induced changes to ocular cells and tissues. Typical changes include ECM accumulation, cell dysfunction, cell death, advanced senescence, disarrangement or rearrangement of the cytoskeleton and released inflammatory cytokines. It is involved in ocular diseases, including keratoconus, Fuchs endothelial corneal dystrophy, and granular corneal dystrophy type 2, cataract, age-related macular degeneration, primary open-angle glaucoma, retinal light damage, and retinopathy of prematurity. These ocular diseases are the cause of irreversible blindness worldwide. Conclusions: Oxidative stress, inflammation and autophagy are implicated in biochemical and morphological changes in these ocular tissues. The development of therapy is a major target for the management care of these ocular diseases.

Liver Toxicity in Rats Fed A Mixture of Pcb Congeners and 2,3,7,8-Tcdd

1997 ◽  
Vol 3 (S2) ◽  
pp. 51-52
Author(s):  
B.J. Cornell ◽  
A. Singh ◽  
I. Chu
Keyword(s):  
Aromatic Compounds ◽  
Liver Toxicity ◽  
Corn Oil ◽  
Morphological Changes ◽  
Test Substance ◽  
Sprague Dawley ◽  
Morphological Alterations ◽  
Pcb Congeners ◽  
Transmission Electron ◽  
Sprague Dawley Rats

Polyhalogenated aromatic compounds such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDDs) continue to be environmental contaminants because of their bioaccumulation in the food chain and high resistance to biodegradation. The current study was undertaken to determine if a mixture of PCB congeners (WHO-IPCS) were interactive with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in producing morphological changes in the rat liver. Both compounds are known to produce a broad range of biochemical and morphological alterations including enzyme induction.Groups (N=5) of female Sprague-Dawley rats were administered TCDD (0, 2.5, 25, 250, 1000 ng/kg bw/day) or PCB (0, 2, 20 μg/kg bw/day) alone, or in combination with each concentration of both compounds. Incorrect concentrations were published in a previous abstract. The test substance was mixed with corn oil and given by gavage at 2 ml/kg daily for 28 days. At the end of the experiment, the rats were killed and liver samples were prepared for transmission electron microscopy.

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