• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.470-473
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• 2004

In the yeast Saccharomyces cerevisiae, iron can be toxic. Because of this phenomenon, its metabolism of iron is strictly regulated. We have constructed a model system in which cell growth is defected during periods of iron over-load. When $Aft1-1^{up}$ protein was overexpressed with Ga110 promoter, a galactose inducible promoter, cell growth was defected and levels of CLN2 transcript decreased. However transcript levels of AFT1 and FET3 genes increased over time in a consistent manner throughout the course of $AFT1-1^{up}$ overexpression. We have screened to find genes to suppress cell growth defect by iron overload with YEp-derived high copy yeast genomic DNA library and found that high copy of Rmelp suppressed cell growth defects. Rme1p has been known as an activator protein of CLN2 gene expression. Taking these results together, we suggest that the yeast cell cycle is arrested at the $G_1$, phase by iron overload via Cln2p.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.1
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• pp.15-23
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• 2001

In regulation of IGC code 12.1 mechanical ventilation should be arranged to ensure sufficient air movement through the space to avoid the accumulation of flammable or toxic vapours and ensure a safe working environment, but in no case should the ventilation system have a capacity of less than 30 changes of air per hour baed upon the total volume of the space. In this study, a scaled mode chamber was constructed to investigate the ventilation characteristics and stagnation area in the hood room of LNG carrier and pump room in tanker. An experimental study was performed on the model by using visualization equipment with a laser apparatus and an image intensifier CCD camera. Twelve different kinds of measuring areas were selected as the experimental condition. Instant simultaneous velocity vectors in the whole fields were measured by a 2-D PIV system A three-dimensional numerical simulation was also carried out for three different Reynolds numbers. Then the CFD predictions were discussed with the experimental results. The results show the spiral L-shape flow that moves from the opening on the left wall diagonally to the upper right part dominates the ventilation structure. The stationary area of hood room in the velcoity distributions was located in the upper left stern part.

• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.1-8
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• 1994

Nerve conduction impairment in lead neuropathy has been empirically linked to altered nerve myo-inositol metabolism. In most cases of neuropathy, abnormal myo-inositol metabolism is associated with abnormal $Na^+/K^+$ATPase provides a potential mechanism to relate defects of the myo-inositol metabolism in the peripheral nerve treated with lead. Therefore, the effect of lead on the rat sciatic nerve $Na^+/K^+$ATPase and other ATPase of sciatic nerve was studied. ATPase activity was measured enzymatically in sciatic nerve homogenates from 2-wk lead treated neuropathy rats and age-mached controls administered myo-inositol. $Na^+/K^+$ATPase components were assessed by ouabain inhibition or the omission of sodium and potassium ions. Lead reduced 50% reduction in the $Na^+/K^+$ATPase activity in homogenates of sciatic nerve. The 50% reduction in the $Na^+/K^+$ ATPase activity was selectively prevented by myo-inositol treatment. This study suggests that the toxic mechanism of the lead on peripheral nerve may be through reduction in $Na^+/K^+$ATPase activity which has been linked to axonal transport slowing in the rat model of lead neuropathy, via direct changes by the perturbation of the intracelluar sodium or potasium level.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8119-8126
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• 2016

Cancer is a leading cause of death worldwide. Due to the toxic side effects of the commonly used chemotherapeutic drug cyclophosphamide (CTX), the use of herbal medicines with fewer side effects but having potential use as inducing anti-cancer outcomes in situ has become increasingly popular. The present study sought to investigate the effects of a methanolic extract of Bauhinia tomentosa against Dalton's ascites lymphoma (DAL) induced ascites as well as solid tumors in BALB/c mice. Specifically, B. tomentosa extract was administered intraperitonealy (IP) at 10 mg/kg. BW body weight starting just after tumor cell implantation and thereafter for 10 consecutive days. In the ascites tumor model hosts, administration of extract resulted in a 52% increase in the life span. In solid tumor models, co-administration of extract and CTX significantly reduced tumor volume (relative to in untreated hosts) by 73% compared to just by 52% when the extract alone was provided. Co-administration of the extract also mitigated CTX-induced toxicity, including decreases in WBC count, and in bone marrow cellularity and ${\alpha}$-esterase activity. Extract treatment also attenuated any increases in serum levels of $TNF{\alpha}$, iNOS, IL-$1{\beta}$, IL-6, GM-CSF, and VEGF seen in tumor-bearing hosts. This study confirmed that, the potent antitumor activity of B.tomentosa extract may be associated with immune modulatory effects by regulating anti-oxidants and cytokine levels.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.6
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• pp.307-312
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• 2015

The sandwich panel is commonly used domestically because it's less costly and easier to handle. But fires have frequently occurred in buildings employing sandwich panels, such as the fires in Eecheon cold storage and in Gwangju Pyungdong industrial zone. Sandwich panels with steel plates on their surface prevent fire water from penetrating to the fire source, which makes it difficult to extinguish a fire in a timely manner. Toxic gas generated from some insulation material leads to serious loss of life and property. This study is intended to develop an extinguishing system for sandwich panels, thereby reducing the fire risk. Fire water and volume were determined in the wake of the study on the structure of a sandwich panel extinguishing system, and improvement and testing of the fire characteristics of the sandwich panel. Based on such study and test, a fire model test was conducted. Consequently, the sandwich panel with extinguishing system was proven to have a reduced fire risk, compared to traditional or fire retardant panels.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.98-102
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• 1993

The therapeutic effectiveness of adenine arabinoside(tora-A) and its conjugate of prednisone(BR-8702-AP) was compared in Herpes simplex Virus Type 1 (HSV-1) infected BALB/C mice. The BALB/C mouse was infected with HSV-1(700 PFU/mouse) intranasally. Among mice infected intranasally with virus, a mortality rate of 100% was observed. On the oral administration of non-toxic doses of ara-A or BR-8702-AP(125 mg /kg/day) for 5 consecutive days 2 hours after virus infection, the tora-A was highly effective in reducing mortality to 0% (P<0.001) and BR-8702-AP was also effective in reducing mortality to 15% (P<0.01). In this model infection, the virus was first replicated in the lung and transmitted to the brain. Both arts-A and BR-8702-AP did not inhibit the viral replication in the lung, but they inhibited the viral transmission to the brain. However, the BR-8702-AP was less effective than the aria-A to prevent transmission of virus to brain. Therefore, the reduced mortality due to tora-A or BR-8702-AP therapy was associated with inhibition of viral transmission to brain.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1050-1053
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• 2000

Biological evaluation of residual malathion after 168 hrs of single dipping exposure of White Leghorn hens to different concentrations (0, 0.5, 1.0 and 1.5%) of pesticides was investigated. Thirty-two male albino rats divided into four groups of eight each were kept on 20% isoproteinous diet prepared from the meat of these malathion dipped hens. After 30 days feeding trial, the rats were killed by decapitation. No significant change was found in erythrocytes. However, the triglyceride concentration in brain tissue was increased significantly (p<0.05) when dose level of pesticide was 1% in dipping solution. Similarly, malathion exposed poultry meat failed in altering any significant change in the pancreatic amylase and lipase activities of rats. This study concludes the virtual absence of toxic accumulation of pesticide in the meat of birds after 168 hrs of exposure in usual concentration range upto 1.5%.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.121-125
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• 2002

Rhodococcus rhodochrous IGTSS (ATCC 5396S) can break organo sulfur compounds such as dibenzothiophene. Since the environment for biodesulfurization process is invariably hydrophobic, parameters in hydrophobic systems should be examined. For the model oil, hexadecane-containing 5.43mM dibenzothiophene, the volumetric desulfurization rate was decreased with the oil-to-aqueous phase ratio up to 50%. The rate declined sharply after 48h because the cell activity, which is refreshed by medium exchange, was lost. To supply the exhausted nutrients, medium exchange was performed. At 30% oil phase, most of DBT was removed by medium exchange on 48h, and the rate was 2.03mg $DBT_{removed}/L_{dispersion}-hr.$ At 50% oil phase, medium exchange on 60h was performed and the rate was 1.79mg $DBT_{removed}/L_{dispersion}-hr.$ The 300mL flask system was scaled up to a 5-L bioreactor system. On 60 h, a medium exchange was performed and the rate was 5.28mg $DBT_{removed}/L_{dispersion}-hr.$ and all of DBT was removed. It means that we can use the biodesulfurization process even 10 the high oil-to-water phase by some appropriate methods such as controlled feeding of key nutrients and the dilution or removal of some toxic metabolites by continuous reactor.

• Toxicological Research
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• v.13 no.4
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• pp.385-391
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• 1997

Inductive effects of cytochrome P450 2B1 by $\alpha$- and $\beta$-ionone were characterized in individual liver lobes of male Sprague Dawley rats. When rats were administered ionones orally at 100, 300, and 600 mg/kg for 24 hr, cytochrome P450 2B1 was induced dose-dependently in liver S-9 fractions as measured by P450 2B-specific monooxygenases and Western immunoblotting. The activity of P450 1A- and P450 2B-specific monooxygenases was differentially expressed in each lobe of normal liver. In addition, the monooxygenase activity was induced by $\alpha$- and $\beta$-ionone with different potency in each lobe of the liver. Our present results indicate that the different induction of P450s by $\alpha$- and $\beta$-ionone in each lobe may explain different susceptibilities of rat liver lobes to certain hepatotoxicants which require metabolic activation for their toxicity and that $\alpha$- and $\beta$-ionone may be useful model inducers of P450 2B1 in studying the toxic mechanism of certain toxicants which may require the metabolic activation by P450.

• Toxicological Research
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• v.29 no.4
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• pp.221-227
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• 2013

Embryonic stem (ES) cells have potential for use in evaluation of developmental toxicity because they are generated in large numbers and differentiate into three germ layers following formation of embryoid bodies (EBs). In earlier study, embryonic stem cell test (EST) was established for assessment of the embryotoxic potential of compounds. Using EBs indicating the onset of differentiation of mouse ES cells, many toxicologists have refined the developmental toxicity of a variety of compounds. However, due to some limitation of the EST method resulting from species-specific differences between humans and mouse, it is an incomplete approach. In this regard, we examined the effects of several developmental toxic chemicals on formation of EBs using human ES cells. Although human ES cells are fastidious in culture and differentiation, we concluded that the relevancy of our experimental method is more accurate than that of EST using mouse ES cells. These types of studies could extend our understanding of how human ES cells could be used for monitoring developmental toxicity and its relevance in relation to its differentiation progress. In addition, this concept will be used as a model system for screening for developmental toxicity of various chemicals. This article might update new information about the usage of embryonic stem cells in the context of their possible ability in the toxicological fields.