• International Journal of Oral Biology
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• 제44권4호
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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.

• 한국안전학회지
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• 제26권2호
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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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• 제31권2호
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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.

• 미생물학회지
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• 제40권4호
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• pp.364-366
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• 2004

본 연구는 차 카테킨인 EGCG (epigallocatechin gallate)에 의한 구강세균의 살균효과를 조사하기 위하여 수행되었다. 초기 세포밀도 $10^{7}$ cell/ml의 대상 세균에 대한 항세균 활성은 EGCG 1ml당 5mg에서 조사하였다. 선택 또는 복합배지상에서 집락생성단위(colony-forming unit, CFU)에 근거하여 EGCG의 항세균 활성은 농도에 비례하는 것을 확인하였다. Streptococcus mutans와 Streptococcus sobrinus는 5mg/ml의 EGCG에서 8시간 이내에 완전히 살균되었다. Lactobacillus acidophilus와 Lactobacillus plantarum도 동일한 조건에서 각각 2시간과 4시간 이내에 살균되었다. 2.5 mg/ml의 EGCG로 처리한 사람의 타액에서 유래하는 총 구강세균의 생존율을 BHI 고체배지상에서 조사하였으며, 총 구강세균은 10시간 이내에 완전히 살균되었다. MS 고체배지상에서 S. mitis and S. salivarius의 집락은 감소되었으며 배양 12시간 이내에서는 집락은 관찰되지 않았다. 그 결과, EGCG는 입냄새와 치석의 원인이 되는 구강세균을 살균시키고 충치를 예방하는 자연적이며 효과적인 물질임이 입증되었다.

• 대한본초학회지
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• 제20권3호
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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.

• 한국임상약학회지
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• 제20권1호
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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.

• 대한의생명과학회지
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• 제15권4호
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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).

• 한국지하수토양환경학회지:지하수토양환경
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• 제9권1호
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• pp.12-27
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• 2004

본 연구에서는 벤젠을 대상으로 오염된 지하수를 생활용수로 사용했을 때 발생하는 실내오염도를 모사하고 실내에서 가능한 흡입, 섭취, 피부흡수와 같은 노출경로를 고려하여 노출시나리오를 자성하였다. 인체에 유입된 벤젠에 대하여 PBPK 모델을 이용하여 인체의 각 장기에 어떻게 분포하는지를 분석하였다. 결과에서 흡입과 섭취가 주요노출 경로였으며 남성이 여성보다 많은 호흡량으로 인해 보다 높은 노출속도를 유지하였다. 노출속도에 대한 피부흡수의 공헌도는 상대적으로 매우 작았다. 단기노출의 결과 오염물 노출에 대하여 SPT, RPT,간의 정맥혈 중 벤젠농도는 빠르게 증감하는 반면 지방의 경우는 느리게 반응하였고 많은 벤젠이 지방세포에 축적되어 정맥혈에는 적은 농도로 존재하였다. 장기간 노출에서 여성은 남성보다 전체적으로 2.1배 많은 벤젠을 체내에 축적하고 있는 것으로 나타났다. 장기간 노출에서 총유입벤젠의 98%가 호흡과 대사분해에 의해 제거되었다. 흡입경로는 벤젠이 호흡배출에 의해 69.8% 제거되었으며 섭취경로는 48.4%로 오염물이 유입되는 위치에 따라 각각의 제거기작의 공헌도가 다르게 나타났다. 본 연구의 결과는 실내오염에 따라 오염물이 체내에 흡수되고 분포ㆍ제거되는 현상을 이해하고 노출저감대책을 마련하는데 필요한 자료를 제공하고자 하였다.

• 한국콘텐츠학회논문지
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• 제8권12호
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• pp.176-189
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• 2008

본 연구는 공연 시 배우의 심박수의 각성변화와 유발된 각성상태에 대한 심리적 자기조절을 분석하는데 그 목적이 있다. 연구대상자는 연극 전문극단에 소속되어 있는 배우 5명을 목적적 표본추출하였다. 각성변화를 측정하기 위해서 심박수 측정기를 활용하였고, 자기조절 행동을 관찰 및 기록할 수 있는 행동 관찰지를 사용하였으며, 공연종료 후 개인별 심층상담을 실시하였다. 심박수 변화에 대한 평균과 표준편차를 산출하여, 공연 시간대별 변화 추이를 그래프화 하였으며, 자기조절 행동을 분석하기 위해 질적 연구방법을 실시하였다. 도출된 연구결과는 다음과 같다. 첫째, 배우들은 공연이 시작되기 전부터 심박수의 각성수준이 높아지는 변화를 나타냈으며, 공연 시작 20분 전부터 5분 전까지 가장 높은 각성상태를 보였다. 둘째, 공연 시작 전 심호흡, 호흡 가다듬기, 자기대화, 배우들과의 대화, 대본연습에 집중, 화장실 가기, 흡연, 복장점검 등의 자기조절적 행동을 나타냈다. 셋째, 공연 시 높아진 각성상태를 조절하기 위해서 이완기법, 자기집중화, 자신감강화, 상황대처 및 적응 등과 같은 심리적 자기조절 방법을 사용하는 것으로 나타났다.

• 한국안광학회지
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• 제15권2호
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• pp.195-199
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• 2010

목적: 알코올 섭취 후 발생하는 일시적인 눈의 근시성 굴절변화와 동반되어 나타나는 해부학적 변화가 갖는 상호 관련성을 알아보고자 하였다. 방법: 평균 $24.5{\pm}1.5$세의 남자 8명(16 안)을 대상으로 0.42 g/kg의 알코올을 30분간에 걸쳐 섭취토록 한 다음, 알코올 섭취 1시간, 4시간, 24시간 후의 교정굴절력, 각막곡률반경과 두께, 동공직경, 안압, 그리고 안구축의 길이 변화를 측정하여 알코올 섭취 전과 비교하였다. 결과: 알코올 섭취 1시간 후에 알코올 섭취전과 비교하여 호흡 중 알코올 농도가 가장 높았고(p<0.001), 교정굴절력의 구면 (-)굴절력 증가(p<0.05), 동공 크기의 감소(p<0.05), 안압의 하강(p<0.001), 그리고 안구축의 길이 증가가 나타났다. 알코올 섭취 4시간 후에도 모든 측정값들이 섭취 1시간 후와 동일한 경향이었다. 그러나 알코올 섭취 24시간 후에는 알코올 섭취 전과 비교하여 의의 있는 변화를 보이지 않았다. 결론: 알코올 섭취로 인한 일시적인 근시성 굴절변화는 안압하강과 안구축의 길이 변화와 관련성이 있을 것으로 판단된다.