• International Journal of Oral Biology
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• v.44 no.4
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• pp.152-159
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• 2019

The oral care probiotic strain Weissella cibaria CMU (oraCMU) inhibits volatile sulphur compounds associated with halitosis, presumably by inhibiting the growth of associated oral pathogens. In the present study, we investigated whether oraCMU inhibits the production of these compounds by suppressing the expression of mgl. This gene encodes L-methionine-α-deamino-γ-mercaptomethane-lyase (METase) and is involved in the production of methyl mercaptan (CH₃SH) by Porphyromonas gingivalis. Therefore, we specifically investigated the effects of oraCMU on the growth, CH₃SH production, METase activity, and mgl expression of P. gingivalis. The minimum inhibitory concentrations of cell-free supernatant and secreted proteins from oraCMU were 125 mg/mL and 800 ㎍/mL, respectively. At sub-minimum inhibitory concentration levels, these metabolites inhibited CH₃SH production, but they also reduced P. gingivalis viability. Only heat-killed oraCMU decreased CH₃SH production without affecting P. gingivalis viability. Heat-killed oraCMU also inhibited METase activity toward L-methionine and mgl mRNA expression (p < 0.05). In summary, we demonstrated the inhibition of volatile sulphur compounds via the antimicrobial action of oraCMU and, for the first time, the inhibition of such compounds by heat-killed oraCMU, which occurred at the molecular level.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.42-47
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• 2011

Going underwater is supposed to begin with the history of human beings. At first it was confined to relatively shallow level, less than several meters by holding breath. Recently, deep level diving has been necessary for such purpose as construction, maritime salvage, military operations, research and sports by using SCUBA(self-contained underwater breathing apparatus) equipment. As one goes down into water, the pressure on the diver is increased due to water pressure with depth, usually 1 atm for each 10 m water level. In deep water, mixed gas or nitrox(EAN, enriched air nitrox) could be applied for the divers lest they should get disease due to high pressure. Of these, the former is usually composed of oxygen and inert gas like helium or hydrogen, the latter contains higher oxygen content than that in normal air in which the oxygen concentration is designated by the character "EAN" followed by vol. % of oxygen, for example, "EAN 40" contains 40% of oxygen. In this case, a victim was found at the 39 m below the sea surface breathing air and nitrox in cylinder wrongly marked as EAN 36, which was analyzed to contain 63% of oxygen by GC/TCD. The cause of death could not be exactly related with the oxygen content in the nitrox cylinder, because the accurate depth for the victim to dive was not known, even though the victim was just found at the depth of 39 m. However, the wrongly marked nitrox could be believed to be the main cause of the death at the depth unless there happened any other accident except that during diving.

• Toxicological Research
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• v.31 no.2
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• pp.203-211
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• 2015

Trichloroacetonitrile is used as an intermediate in insecticides, pesticides, and dyes. In Korea alone, over 10 tons are used annually. Its oral and dermal toxicity is classified as category 3 according to the globally harmonized system of classification and labelling of chemicals, and it is designated a toxic substance by the Ministry of Environment in Korea. There are no available inhalation toxicity data on trichloroacetonitrile. Thus, the present study performed inhalation tests to provide data for hazard and risk assessments. Sprague-Dawley rats were exposed to trichloroacetonitrile at concentrations of 4, 16, or 64 ppm for 6 hour per day 5 days per week for 13 weeks in a repeated study. As a result, salivation, shortness of breath, and wheezing were observed, and their body weights decreased significantly (p < 0.05) in the 16 and 64 ppm groups. All the rats in 64 ppm group were dead or moribund within 4 weeks of the exposure. Some significant changes were observed in blood hematology and serum biochemistry (e.g., prothrombin time, ratio of albumin and globulin, blood urea nitrogen, and triglycerides), but the values were within normal physiological ranges. The major target organs of trichloroacetonitrile were the nasal cavity, trachea, and lungs. The rats exposed to 16 ppm showed moderate histopathological changes in the transitional epithelium and olfactory epithelium of the nasal cavity. Nasal-associated lymphoid tissue (NALT) and respiratory epithelium were also changed. Respiratory lesions were common in the dead rats that had been exposed to the 64 ppm concentration. The dead animals also showed loss of cilia in the trachea, pneumonitis in the lung, and epithelial hyperplasia in the bronchi and bronchioles. In conclusion, the no-observed-adverse-effect level (NOAEL) was estimated to be 4 ppm. The main target organs of trichloroacetonitrile were the nasal cavity, trachea, and lungs.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.364-366
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• 2004

The purpose of this work was to investigate the effect oftea catechin, epigallocatechin gallate (EGCG) on killing of oral bacteria. The antibacterial activity of 2.5 mg/ml and 5.0 mg/ml EGCG was investigated for target bacteria of which initial cell number was approximately adjusted to $10^{7}ml$. The antibacterial activity of EGCG was proportional to the concentration according to colony-forming unit(CFU) of target bacteria enumerating on selective and complex media. Streptococcus mutans and Streptococcus sobrinus at 5mg/ml EGCG were completely killed within 8 hrs. Lactobacillus plantarum and Lactobacillus acidophilus were also killed within 2 hrs and 4 hrs under the same conditions, respectively. Oral bacteria at 2.5 mg/ml EGCG were completely killed within 10 hr. Colony numvers of S. mitis and S. salivarius treated with 2.5 mg/ml EGCG were decreased on MS solid media and no colony was observed on the media within 12 hrs. In consequence, EGCG would be a natural and effective compound that kill oral bacteria being caused of bad breath, plaque and gingivitis, and for preventing and treating dental caries.

• The Korea Journal of Herbology
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• v.20 no.3
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• pp.43-49
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• 2005

Objectives : The present study was carried out to determine if Glycyrrhizae Radix extract exerts beneficial effect against the ischemia-induced acute renal failure in rabbits. Glycyrrhizae Radix was known to reinforce the function of the spleen and replenish Qi, remove heat and counteract toxicity, dispel phlegm and relieve cough, alleviate spasmodic pain, and to moderate drug actions. It's indications are weakness of the spleen and the stomach marked by lassitude and weakness; cardiac palpitation and shortness of breath; cough with much phlegm: spasmodic pain in the epigastrium, abdomen and limbs: carbuncles and sores. It is often used for reducing the toxic or drastic actions of other drugs. Methods : Antioxidative effect of 3% concentration of Glycyrrhizae Radix extract was measured. Rabbits were treated with Glycyrrhizae Radix extract via i.v., followed by renal ischemia/reperfusion, and the changes of urine volume, serum creatinine levels, glomerular filtration rate(GFR), fractional Na+ excretion$(FE\;Na^+)\;and\;K^+\;excretion(FE\;K^+)$ in ischemia/reperfusion induced acute renal failure were measured. Results : Renal ischemia/reperfusion caused increase of serum creatinine level, which was accompanied by a reduction in glomerular filtration rate(GFR). The fractional excretion of $Na^+\;and\;K^+$ increased in ischemia-induced animals, which was partially prevented by Glycyrrhizae Radix extract treatment. Conclusions : These results indicate that lipid peroxidation plays a critical role in ischemia-induced acute renal failure. Glycyrrhizae Radix extract exerts the protective effect against acute renal failure induced by renal ischemia/reperfusion, and its effect may be attributed to an antioxidant action.

• Korean Journal of Clinical Pharmacy
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• v.20 no.1
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• pp.1-8
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• 2010

We conducted a single blind, randomized and crossover clinical trial in order to test the effect of curcuma longa herbal mixture on blood alcohol level and alcohol hangover in 19 healthy volunteers. The herbal mixture did not show a statistical significance in $C_{max}$, $T_{max}$ and AUC in alcohol disposition. The herbal mixture did not also ameliorate blood laboratory result after alcohol consumption. In contrast, the herbal mixture is shown effective on alcohol hangover. In behavior tests, the fewer subjects in the herbal mixture group were impaired with alcohol than in reference group. Moreover, the symptom severity score in the herbal mixture was lower than that in reference group. The symptom severity score was statistically especially in stomach pain, diarrhea, concentration disorder, memory and bad breath at drinking day and one day after drinking. These results indicate that the general symptoms seemed to be recovered as time goes on. From these results, it was suggested that the herbal mixture have a beneficial effect on modulating alcohol hangover.

• Biomedical Science Letters
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• v.15 no.4
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• pp.309-317
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• 2009

Occupational exposure to inorganic dusts such as coal and silica has been identified as a chronic obstructive pulmonary disease (COPD) risk factor. This risk factor causes lung inflammation and protease-antiprotease imbalance. This abnormal inflammatory response of the lung induces parenchymal tissue destruction and leads to progressive airflow limitation that is characteristics of COPD. The aim of this study was to determine the relationship of proteases such as neutrophil elastase (NE) and matrix metalloproteinase (MMP)-9 and antiproteases such as alpha-1 antitrypsin (AAT) and tissue inhibitors of metalloproteinase (TIMP)-1 with lung function. The study population contained 223 retired workers exposed to inorganic dusts. We performed lung function test, including percent of forced expiratory volume in one second ($%FEV_1$) predicted and $%FEV_1$/forced vital capacity (FVC). We analyzed serum MMP-9, AAT, TIMP-1 and plasma NE concentrations by sandwich enzyme immunoassay. NE, AAT, and TIMP-1 concentrations in workers, who had $%FEV_1$<80% predicted, were higher than those of workers who had $%FEV_1{\geq}80%$ (P<0.05). Both AAT and TIMP-1 concentrations in workers with airflow limitation were higher than those of workers with normal airflow (P<0.05). $%FEV_1$ predicted showed significant negative correlation with AAT (r=-0.255, P<0.0l), TIMP-1 (r=-0.232, P<0.01), and NE (r=-0.196, P<0.01). $%FEV_1$/FVC predicted showed significant negative correlation with NE (r=-0.172, P<0.05). From the results of stepwise multiple regression analysis about $%FEV_1$ and $%FEV_1$/FVC, significant independents were NE (r=-0.135, P=0.001) and AAT (r=-0.100, P=0.013) in $%FEV_1$, and NE (r=-0.160, P=0.014) in $%FEV_1$/FVC. In the present study, there were significant correlations between airflow limitation and protease concentration and between airflow limitation and antiprotease concentration. Serum protease and antiprotease concentrations, however, may be affected by the biological and inflammatory responses. It is necessary to evaluate specimens more reflected the effects of proteases and antiproteases in the lung such as lung tissue, bronchoalveolar lavage fluid, and exhaled breath condensate (EBC).

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.12-27
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• 2004

The contamination pattern of indoor air was simulated when groundwater dissolving benzene was used for household activities. Indoor exposure scenario consisted of inhalation, ingestion, and dermal absorption. Physiologically based pharmacokinetic (PBPK) model was used to analyze how benzene exposed to human body was distributed in internal organs. Main exposure pathways contributing total internal dose were inhalation and ingestion while the contribution of dermal absorption was very small. Man showed higher exposure rate than woman due to his higher breath rate. For a short-term exposure, benzene concentration in venous blood of SPT, RPT and liver changed rapidly while slowly did in venous blood of adipose tissue at a low concentration. For a long-term exposure, woman accumulated about 2.1 times higher than man. Most of benzene exposed to human body was removed by exhalation and metabolism at lung and liver, respectively. For inhalation and ingestion, the benzene removals by exhalation were 69.8 and 48.4%, respectively. Relative importance of removal mechanism was different according to the inflow displacement of benzene. The results obtained from this study would help understand exposure, distribution, and removal phenomena and make plans for the reduction of the health risk associated with the contaminated groundwater by various organic compounds.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.176-189
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• 2008

The purpose of this study was to analyze self-regulation about changing heart rate and perceived arousal variation when actors start their performance. Object of this study were 5 actors who belong to the theater selected using the purposive sampling method. This study used a measuring instrument of heart rate to measure arousal status, used behavior observation paper to observe and record self-regulation behavior and executed personal consultation after ending performance. There was graph mad by variation transition which calculated average and standard deviation about variation of heart rate each time of performance. The results of this study were as follows. First, there were high variation of awake level that actor's heart rates were rising before starting performance and the most high level of arousal was from 20minutes to 5minutes before starting performance. Second, there were self-regulation behaviors appeared such as deep breathing, breath controling, self talking, talking with other actors, concentrating an script, going to toilet, smoking, checking closes before starting performance. Third, when performance start, actors used psychological self-regulational method such as relaxation, self concentration, confidence reinforcement, coping with state or accommodation for controling raised arousal status.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.195-199
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• 2010

Purpose: This study was to investigate the relevance between refractive and anatomical changes temporarily on the eyes after alcohol ingestion. Methods: Eight subjects (16 eyes) which were $24.5{\pm}1.5$ aged males drunk the alcohol of 0.42 g per kg of body weight within 30 minutes. Refractive errors, the radius of corneal curvature, corneal thickness, pupillary size, intraocular pressure, and the length of the ocular axis at 1 h, 4 h, and 24 h after alcohol ingestion were compared with them of non-alcoholic state. Results: At 1 h after alcohol ingestion, breath alcohol concentration was the highest (p<0.001), more negative spherical power was needed (p<0.05) for correction, pupillary diameter was decreased (p<0.05), intraocular pressure was decreased (p<0.001), and the length of the ocular axis was increased compared with each one of non-alcoholic state. At 4 h after alcohol ingestion, all anatomical changes were the same tendency as at 1 h after alcohol ingestion. But at 24 h after alcohol ingestion, both refractive changes and anatomical changes were not significant compared with them of non-alcoholic state. Conclusions: Temporary changes of refractive error after alcohol ingestion may be related with decrease of intraocular pressure and increase of the length of ocular axis.