• Journal of The Korean Society of Clinical Toxicology
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• v.20 no.2
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• pp.39-44
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• 2022

N-Acetylcysteine (NAC) is the standard antidote treatment for preventing hepatotoxicity caused by acetaminophen (AAP) poisoning. This review summarizes the recent evidence for the treatment of AAP poisoning. Several alternative intravenous regimens of NAC have been suggested to improve patient safety by reducing adverse drug reactions and medication errors. A two-bag NAC infusion regimen (200 mg/kg over 4 h, followed by 100 mg/kg over 16 h) is reported to have similar efficacy with significantly reduced adverse reactions compared to the traditional 3-bag regimen. Massive AAP poisoning due to high concentrations (more than 300-lines in the nomogram) needs to be managed with an increased maintenance dose of NAC. In addition to NAC, the combination therapy of hemodialysis and fomepizole is advocated for severe AAP poisoning cases. In the case of a patient presenting with an altered mental status, metabolic acidosis, elevated lactate, and an AAP concentration greater than 900 mg/L, hemodialysis is recommended even if NAC is used. Fomepizole decreases the generation of toxic metabolites by inhibiting CYP2E1 and may be considered an off-label use by experienced clinicians. Since the nomogram cannot be applied to sustained-release AAP formulations, all potentially toxic sustained-release AAP overdoses should receive a full course of NAC regimen. In case of ingesting less than the toxic dose, the AAP concentration is tested twice at an interval of 4 h or more; NAC should be administered if either value is above the 150-line of the nomogram.

• Journal of Life Science
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• v.32 no.3
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• pp.256-262
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• 2022

Oxysterols are oxygenated metabolites of cholesterol generated by serial enzymatic reactions during bile acid synthesis. Similar to cholesterol, oxysterols move rapidly to the intracellular region and modulate various cellular processes, such as immune cell responses, lipid metabolism, and cholesterol homeostasis. Different nuclear transcription factors, such as glucocorticoid, estrogen, and liver X receptors, can be modulated by oxysterols in multiple tissues. The most abundant oxysterol, 27-hydroxycholesterol (27-OHC), is a well-known selective modulator that can either activate or suppress estrogen receptor activity in a tissue-specific manner. The contribution of 27-OHC in atherosclerosis development is apparent because a large amount of it is found in atherosclerotic plaques, accelerating the transformation of macrophages into foam cells that uptake extracellular modified lipids. According to previous studies, however, there are opposing opinions about how 27-OHC affects lipid and cholesterol metabolism in metabolic organs, including the liver and adipose tissue. In particular, the effects of 27-OHC on lipid metabolism are entirely different between in vitro and in vivo conditions, suggesting that understanding the physiology of this oxysterol requires a sophisticated approach. This review summarizes the potential effects of 27-OHC in atherosclerosis and metabolic syndromes with a special discussion of its role in metabolic tissues.

• Journal of Microbiology
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• v.45 no.2
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• pp.87-97
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• 2007

Medium-chain-length polyhydroxyalkanoates (MCL-PHAs), which have constituents with a typical chain length of $C_{6}-C_{14}$, are polyesters that are synthesized and accumulated in a wide variety of Gram-negative bacteria, mainly pseudomonads. These biopolyesters are promising materials for various applications because they have useful mechanical properties and are biodegradable and biocompatible. The versatile metabolic capacity of some Pseudomonas spp. enables them to synthesize MCL-PHAs that contain various functional substituents; these MCL-PHAs are of great interest because these functional groups can improve the physical properties of the polymers, allowing the creation of tailor-made products. Moreover, some functional substituents can be modified by chemical reactions to obtain more useful groups that can extend the potential applications of MCL-PHAs as environmentally friendly polymers and functional biomaterials for use in biomedical fields. Although MCL-PHAs are water-insoluble, hydrophobic polymers, they can be degraded by microorganisms that produce extracellular MCL-PHA depolymerase. MCL-PHA-degraders are relatively uncommon in natural environments and, to date, only a limited number of MCL-PHA depolymerases have been investigated at the molecular level. All known MCL-PHA depolymerases share a highly significant similarity in amino acid sequences, as well as several enzymatic characteristics. This paper reviews recent advances in our knowledge of MCL-PHAs, with particular emphasis on the findings by our research group.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.664-671
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• 2006

Modeling the growth kinetics of lactic acid bacteria (LAB), one of the most valuable microbial groups in the food industry, has been actively pursued in order to understand, control, and optimize the relevant fermentation processes. Most modeling approaches have focused on the development of single population models. Primary single population models provide fundamental kinetic information on the proliferation of a primary LAB species, the effects of biological factors on cell inhibition, and the metabolic reactions associated with cell growth. Secondary single population models can evaluate the dependence of primary model parameters, such as the maximum specific growth rate of LAB, on the initial external environmental conditions. This review elucidates some of the most important single population models that are conveniently applicable to the LAB fermentation analyses. Also, a well-defined mixed population model is presented as a valuable tool for assessing potential microbial interactions during fermentation with multiple LAB species.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.70-73
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• 2001

Isopentenyl diphosphate (IPP) is the common, five-carbon building block in the biosynthesis of all isoprenoids. IPP in Escherichia coli is synthesized through the non-mevalonate pathway. The first reaction of IPP biosynthesis in E. coli is the formation of 1-deoxy-D-xylulose-5-phosphate(DXP), catalyzed by DXP synthase and encoded by dxs. The second reaction in the pathway is the reduction of DXP to 2-C-methyl-D-erythritol-4-phosphate, catalyzed by DXP reductoismerase and encoded by dxr. To determine if one of more of the reactions in the non-mevalonate pathway controlled flux to IPP, dxs and dxr were placed on several expression vectors under the control of three different promoters and transformed into three E. coli strains ($DH5{\alpha}$, XL1-Blue, and JM101) that had been engineered to produce lycopene, a kind of isoprenoids. Lycopene production was improved significantly in strains transformed with the dex expression vectors. At arabinose concentrations between 0 and 1.33 mM, cells expressiong both dxs and from $P_{BAD}$ on a midium-copy plasmid produced 1.4 -2.0 times more lycopene than cells expressing dxs only. However, at higher arabinose concentrations lycopene production in cell expressing both dxs and dxr was lower than in cells expression dxs only. A comparison of the three E. coli strains trasfomed with the arabinose-inducible dxs on a medium-copy plasmid revealed that lycopene production was highest in XL1-Blue.

• Biomedical Science Letters
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• v.17 no.3
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• pp.203-209
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• 2011

Magnesium (Mg) plays an essential role in physiological and metabolic reactions. Recently, there has been an increased interest in the role of Mg deficiency, particularly the relationship between serum Mg value and inflammatory response. This study was designed to determine the relationship between serum Mg deficiency with inflammatory response, electrolytes and hematological alteration over long-term periods. Sixteen male Sprague-Dawley rats were divided into two groups: control (n=8), and Mg deficiency group (MgD group, n=8). Chow and normal water (tap water) were regularly provided to the control group and Mg-depleted chow and third distilled water were regularly provided for 60 days to the MgD group. Body weights, Serum Mg, $K^+$, inorganic phosphorus (IP) and total iron binding capacity (TIBC) levels in the MgD group were lower than those of the control group (P<0.05). Granulocyte fraction and MCV, RDW and PDW levels were higher, whereas lymphocyte fraction, erythrocyte, hemoglobin and MCHC levels were lower in the MgD group than in the control group (P<0.05). MCP-1 and TNF-${\alpha}$ levels in the MgD group were greater than those of the control group (P<0.05). In conclusion, the results of the present study suggest that Mg deficiency over a long-term period had not altered total leukocyte concentration in the blood, but had detrimental effects, including disturbances of electrolytes balance, disturbance of iron indices, potential anemia and elevation of pro-inflammatory cytokine. However, further studies should be performed to determine the relationship between serum Mg deficiency and major organ damage or alteration.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4745-4751
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• 2014

Oxidative stress is caused by an imbalance in the redox status of the body. In such a state, increase of free radicals in the body can lead to tissue damage. One of the most important species of free radicals is reactive oxygen species (ROS) produced by various metabolic pathways, including aerobic metabolism in the mitochondrial respiratory chain. It plays a critical role in the initiation and progression of various types of cancers. ROS affects different signaling pathways, including growth factors and mitogenic pathways, and controls many cellular processes, including cell proliferation, and thus stimulates the uncontrolled growth of cells which encourages the development of tumors and begins the process of carcinogenesis. Increased oxidative stress caused by reactive species can reduce the body's antioxidant defense against angiogenesis and metastasis in cancer cells. These processes are main factors in the development of cancer. Bimolecular reactions cause free radicals in which create such compounds as malondialdehyde (MDA) and hydroxyguanosine. These substances can be used as indicators of cancer. In this review, free radicals as oxidizing agents, antioxidants as the immune system, and the role of oxidative stress in cancer, particularly breast cancer, have been investigated in the hope that better identification of the factors involved in the occurrence and spread of cancer will improve the identification of treatment goals.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1471-1477
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• 2012

Carotenoids produced by non-photosynthetic bacteria protect organisms against lethal photodynamic reactions and scavenge oxygenic radicals. However, the carotenoid produced by Gordonia alkanivorans SKF120101 is coupled to reducing power generation. SKF120101 selectively produces carotenoid under light conditions. The growth yield of SKF120101 cultivated under light conditions was higher than that under dark condition. In the cyclic voltammetry, both upper and lower voltammograms for neutral red (NR) immobilized in intact cells of SKF120101 were not shifted in the condition without external redox sources but were commonly shifted downward by glucose addition and light. Electric current generation in a biofuel cell system (BFCS) catalyzed by harvested cells of SKF120101 was higher under light than dark condition. The ratio of electricity generation to glucose consumption by SKF120101 cultivated in BFCS was higher under light than dark condition. The carotenoid produced by SKF120101 catalyzes production of reducing power from light energy, first evaluated by the electrochemical technique used in this research.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.4 no.1
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• pp.23-42
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• 1991

This study were done to know the effects of Dangkiyeumja on the in vivo and in vitro immune responses of mice. The recipes of Dangkiyeumja used in this study enhanced such, cellular functions of immunocytes as phagocytic capacity of macrophages, rossett-eforming abilities of splenocytes and metabolic activities of lymphocytes, However, the same recipes decreased the formation of such reactive oxygen intermediates(ROI) as superoxide and hydrogenperoxide from the macrophages. The effects of the same recipes on the in vim immune responses was suppressive on the cellular immune response(CIR)measured by delayed-type hypersensitivity against dinitrofluorobenzene and mildly enhancing for the humoral immune response measured by antibody production against sheep red blood cells. The results of this study could be summarized as follow: 1. Administration of Dangkiyeumja enhanced the phagocytic activity of the murine macrophage. 2. Administration of Dangkiyeumja decreased the formation of ROI in the murine macrophage 3. Administration of Dangkiyeumja increased the number of the splenic rotte forming cells in the mouse. 4. Administration of DangKiyeumja did not effect the antibody production against sheep red blood cells. 5. Administration of Dangkiyeumja depressed the delayed-type hypersenitivity against dinitrofluoro benzene in the mouse. The result of this study suggest that Dangkiyeumja could ameliorate the hypersensitivity reactions by reducing the formation of ROI and decreasing the CIR without affecting the other functions of immunocytes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.561-568
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• 2014

Background: The skin is the largest body organ that regulates excretion of metabolic waste products, temperature, and plays an important role in body protection against environmental physical and chemical, as well as biological factors. These include agents that may act as oxidants or catalysts of reactions producing reactive oxygen species (ROS), reactive nitrogen species (RNS), and other oxidants in skin cells. An increased amount of the oxidants, exceeding the antioxidant defense system capacity is called oxidative stress, leading to chronic inflammation, which, in turn, can cause collagen fragmentation and disorganization of collagen fibers and skin cell functions, and thus contribute to skin diseases including cancer. Moreover, research suggests that oxidative stress participates in all stages of carcinogenesis. We report here a summary of the present state of knowledge on the role of oxidative stress in pathogenesis of dermatologic diseases, defensive systems against ROS/RNS, and discuss how physical activity may modulate skin diseases through effects on oxidative stress. The data show duality of physical activity actions: regular moderate activity protects against ROS/RNS damage, and endurance exercise with a lack of training mediates oxidative stress. These findings indicate that the redox balance should be considered in the development of new antioxidant strategies linked to the prevention and therapy of skin diseases.