• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.34-43
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• 1992

To investigate the effect of hyperoxia on EKG findings and to evaluate the applicability of EKG as noninvasive monitoring index of oxygen toxicity, 38 rabbits were continuously exposed to 6 different conditions-3 hyperbaric oxygenations (HBO-2.5, 3.5 and 5ATA, 100% $O_2$), normobaric oxygenation (NBO,100% $O_2$), hyperbaric aeration (HBA-5ATA, 21% $O_2$) and normobaric aeration (NBA, 21% $O_2$)-for 120 minutes and their EKG and time to dyspnea and convulsion were recorded. Dyspnea and death were observed in exposure conditions of HBO-3.5 and HBO-5 (Positive rate of dyspnea 10%, 100%, death : 10%, 25%, respectively) only, and convulsion in 4 oxygenation groups (NBO;20%, HBO-2.5;20%, HBO-3.5;20%, HBO-5;88%). Abnormal EKG findings included arrhythmia and ST-T changes and the incidences was increasing with doses(partial pressure of oxygen). In addition to EKG change, findings observed during exposure were dyspnea and convulsion in the order of appearance and when non specific ST-T change was accepted as positive(abnormal) finding, the frequency of abnormal EKG was statistically significant(p<0.01), but when it was excluded from positive results, the frequency of EKG change was not significant(p>0.05). These results suggest that the effect of hyperoxia on heart is myocardial ischemia and arrhythmia, that oxygenation more than 3.5ATA causes myocardial damage in 120 minutes exposure, and that EKG is valuable as monitoring index of oxygen toxicity.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.259-267
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• 1995

This study was conducted to evaluate the effects of pressure and dissolved oxygen concentration on the activated slut비e and to determine the optimum depth of deep shaft process. Some results from this study were summarized as follows. 1. It is considered that low sludge product in the activated sludge system maintaining high dissolved oxygen concentration is attributed to the increase of endogeneous respiration rate caused by the increase of aerobic zone in the sludge floe. 2. The increase of dissolved oxygen concentration does not affect to the increase of organic removal efficiency greatly and therefore the limiting factor is the substrate transfer into the inner part of floe. 3. The yield coefficient, Y is decreased in proportion to the increase of oxygen concentration. In this study, Y values arre ranged from 0.70 to 0.41 according to the variation of dissolved oxygen concentration from 18.0mg/$\ell$ to 258 mg/$\ell$. 4. The optimum depth of deep shaft process should be determined within the limits of non-toxicity to the microorganism and it is about loom in this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.874-881
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• 1997

In order to estimate toxicity of copper, radmium and chromium on survival, growth and oxygen consumption of the estuarine mysid, Neomysis awatschensis, adult and juvenile, the experiments were conducted by renewal bioassay method at $20{\pm}1^{\circ}C\;and\;20{\pm}1\%_{\circ}$ salinity. The $96hr-LC_{50}$ of the mysid exposed to cadmium, copper and chromium was 20.2, 11.3 and $670.4\;{\mu}g/\ell$ in adut and 3.4, 1.9 and $49.4\;{\mu}g/\ell$ in juvenile, respectively, and were ranked in order of toxicity : copper >cadmium >chromium. Survival rates of the mysid exposed to the sublethal concentrations of heavy metals for 40 days were significantly affected by cadmium $\geq1.0\;{\mu}g/\ell$ and copper $\geq0.6\;{\mu}g/\ell$ concentrations. The growth rate of the mysid exposed to $cadmium\geq2.0\;{\mu}g\ell$ and copper $\geq1.2\;{\mu}g/\ell$ concentrations were significantly reduced than that exposed to normal condition, but there was no affect on intermoult period. Oxygen consumption rate of the mysid exposed to heavy metals was significantly reduced with increasing heavy metals concentrations. The results of the present study led us to conclude that concentrations levels cadmium$\geq1.0\;{\mu}g\ell$ and copper $\geq0.6\;{\mu}g\ell$ of the estuarine could markedly affect the distribution and population of the mysid by reduced survival, growth and oxygen consumption rate.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.548-557
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• 2015

This study investigated environmental assessments of leachate containing formaldehyde from medium density fiberboard (MDF) disposed in laboratory-scale simulated landfills. Environmental impact assessment of leachate was conducted by measuring formaldehyde, toxicity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), bacterial enumeration, and pH. Amount of formaldehyde in leachate from MDF in soil decreased to the level of soil only treatment by 28 days, and toxicity decreased as the amount of formaldehyde decreased. BOD and COD levels in leachate from the treatments containing MDF exceeded permissible discharge levels of BOD or COD throughout the experimental period. The pH levels of all treatment were within permissible discharge range except on day 0. Fewer bacteria were observed in leachate from MDF in soil treatment than other treatments (MDF only, cured UF resin in soil, and soil only). Consequently, the leachate from disposal of MDF in soil detrimentally affect on environment. However, soil buffered formaldehyde leaching and pH on leachate in this study. Waste MDF may be required the pre-water soaking treatment for leaching formaldehyde to reclaim on land.

• Toxicological Research
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• v.30 no.3
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• pp.193-198
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• 2014

Degradation of glucose is aberrantly increased in hyperglycemia, which causes various harmful effects on the liver. Methylglyoxal is produced during glucose degradation and the levels of methylglyoxal are increased in diabetes patients. In this study we investigated whether methylglyoxal induces mitochondrial impairment and apoptosis in HepG2 cells and induces liver toxicity in vivo. Methylglyoxal caused apoptotic cell death in HepG2 cells. Moreover, methylglyoxal significantly promoted the production of reactive oxygen species (ROS) and depleted glutathione (GSH) content. Pretreatment with antioxidants caused a marked decrease in methylglyoxal-induced apoptosis, indicating that oxidant species are involved in the apoptotic process. Methylglyoxal treatment induced mitochondrial permeability transition, which represents mitochondrial impairment. However, pretreatment with cyclosporin A, an inhibitor of the formation of the permeability transition pore, partially inhibited methylglyoxal-induced cell death. Furthermore, acute treatment of mice with methylglyoxal increased the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating liver toxicity. Collectively, our results showed that methylglyoxal increases cell death and induces liver toxicity, which results from ROS-mediated mitochondrial dysfunction and oxidative stress.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.2-8
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• 2021

Dimethachlor is a synthetic herbicide, belonging to the chloroacetanilide group, that inhibits the undesirable growth of weeds via the suppression of very long-chain fatty acid synthesis. Although dimethachlor has been shown to run off from agricultural fields into aquatic ecosystems, the toxicity of dimethachlor on aquatic invertebrates and vertebrates is unknown. In our study, we assessed the toxicity of dimethachlor on developing zebrafish embryos by analyzing viability, hatching ability, and phenotypic changes. Embryonic viability decreased from 48 h post-fertilization (hpf) at the highest concentration of dimethachlor. Decreased hatching ratio, shortened body length, and pathological changes in the eye, heart, and yolk sac were observed at sub-lethal concentrations. Additionally, dimethachlor increased the number of apoptotic cells and level of reactive oxygen species 120 hpf. Our results indicate that dimethachlor may act as an anti-developmental toxicant when accumulated in an aquatic environment.

• Journal of Life Science
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• v.26 no.12
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• pp.1458-1465
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• 2016

We investigated the neuroprotective effect of an ethanol extract from Asparagus cochinchinensis (AC) against glutamate-induced toxicity in the HT22 hippocampal cell, which is an ideal in vitro model for oxidative stress. The neuroprotective effects of AC in HT22 cells were evaluated by analyzing cell viability, lactate dehydrogenase (LDH), flow cytometry for cell death types, reactive oxygen species (ROS), mitochondria membrane potential (MMP), and Western blot assays. In the cell death analysis, AC treatment resulted in significantly attenuated glutamate-induced loss of cell viability with a decrease in LDH release. AC treatment also reduced glutamate-induced apoptotic cell death. In the ROS and MMP analysis, AC treatment inhibited the elevation of intracellular ROS induced by glutamate exposure and the disruption of MMP. In oxidative stress-related proteins analysis, AC treatment inhibited the expression of poly ADP ribose polymerase and heme oxygenase-1 by glutamate. These results indicate that AC exerts a significant neuroprotective effect against glutamate-induced hippocampal damage by decreasing ROS production and stabilizing MMP. Thus, AC potentially provides a new strategy for the treatment of oxidative stress-related diseases.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.71-80
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• 2002

To evaluate the skin toxicity of topical cyclohexane application (25mg/$\textrm{cm}^2$) was sequentially applied to the rat skin for four days. On the histopathological findings in the light micrographs, neutrophils and engulfed neutrophils are seen, and many cytoplasmic processes were appeared in proliferated layer whereas in the dermis area, increased numbers of fibroblast, accumulation of neutrophil and lipid droplets are demonstrated. On the other hand, applying the cyclohexane to the rat skin led to the remarkable rise of cutaneous xanthine oxidase activity and similar activities of superoxide dismutase and glutathione peroxidase and glutathione content and declined activity of glutathione S-transferase compared with control group. Especially the remarkably decreased activity of aniline hydroxylase (AH) was appeared in skin as little as scarcely determined. Furthermore, the applying the cyclohexane to skin led to the significantly increased activity of hepatic AH and alcohol dehydrogenase. These results indicate that oxygen free radical and intermediate metabolite of cyclohexane may be responsible for structural changes in skin by cyclohexane application to rat skin.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.1016-1022
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• 2012

In order to investigate the effects of 70% EtOH extract obtained from Hovenia dulcis Thunberg on enzymes relating reactive oxygen intermediate, cancer-stricken animals induced by DEN (N,N-diethylnitrosamine) were recovered by administering the extract of Hovenia dulcis Thunberg. It showed that there was no effect on the generation of superoxide radical by the extract of Hovenia dulcis Thunberg. However, considering the increase of the activity of Cu, Zn-SOD and Mn-SOD in the tested animal class, the extract of Hovenia dulcis Thunberg could participate directly in removing of superoxides. The experimented-animals treated with the extract of Hovenia dulcis Thunberg showed an increase in the activity of the enzymes, catalase and glutathione peroxidase, which can eliminate hydrogen peroxide pertained in liver tissue. The extract of Hovenia dulcis Thunberg seemed to have some factors that accelerate the oxidation. Also, the extract of Hovenia dulcis Thunberg showed effects on the enzymes relating to the active oxygen toxicity which could be an indicator of aging and body toxicity.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.142.1-142.1
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• 2003

Excessive accumulation of beta-amyloid (A$\beta$) peptides is one of the leading hypotheses to explain neurodegenerative processes in Alzheimer's disease (AD). It has been suggested that $A\beta$ toxicity is associated with increases in reactive oxygen species. whose overproduction may in turn initiate neurotoxic events. (omitted)