• 한국건축시공학회지
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• 제17권1호
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• pp.15-21
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• 2017

라돈은 토양이나 암석, 지하수 안에서 우라늄(U-238)이 핵분열 할 때 발생하는 무색, 무취, 무미의 반응성이 거의 없는 비활성 단원자 분자 기체로 반감기 동안 연쇄적으로 붕괴하는데 이때 방사성 핵종(Bi, Po, Pb)이 만들어 지며 이를 자손핵종이라 한다. 이는 공기 중의 먼지 등에 흡착하여 사람이 호흡할시 폐에 흡착하여 붕괴하는데 여기서 발생하는 알파선에 장기간 피폭하면 폐암을 유발하는 것으로 밝혀졌다. 이에 따라 실내공기질에 관한 기준과 연구가 지속적으로 시행되고 있는 실정이다. 본 연구는 실내 라돈가스를 최소화 하고 저감하기 위한 무시멘트계 흡착재를 연구개발 하기위한 기초실험으로 흡착재의 첨가량에 따라 유동성 및 강도는 저하되는 경향을 보였지만, 이는 흡착재의 밀도 및 공극에 의한 것으로 판단되며, 라돈가스 농도의 경우 첨가량 증가에 따라 감소하는 경향을 보였다. 향후 가장 적합한 흡착재를 활용하여 보다 세밀하고 다양한 실험이 이루어져야 할 것으로 판단되며, 경화체상의 기초실험을 통해 추후 건축 마감재에 관한 실험도 이루어져야 할 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제19권1호
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• pp.51-57
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• 2015

The etiology of periodontal disease is multifactorial. Exogenous stimuli such as bacterial pathogens can interact with toll-like receptors to activate intracellular calcium signaling in gingival epithelium and other tissues. The triggering of calcium signaling induces the secretion of pro-inflammatory cytokines such as interleukin-8 as part of the inflammatory response; however, the exact mechanism of calcium signaling induced by bacterial toxins when gingival epithelial cells are exposed to pathogens is unclear. Here, we investigate calcium signaling induced by bacteria and expression of inflammatory cytokines in human gingival epithelial cells. We found that peptidoglycan, a constituent of grampositive bacteria and an agonist of toll-like receptor 2, increases intracellular calcium in a concentration-dependent manner. Peptidoglycan-induced calcium signaling was abolished by treatment with blockers of phospholipase C (U73122), inositol 1,4,5-trisphosphate receptors, indicating the release of calcium from intracellular calcium stores. Peptidoglycan-mediated interleukin-8 expression was blocked by U73122 and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxymethyl ester). Moreover, interleukin-8 expression was induced by thapsigargin, a selective inhibitor of the sarco/endoplasmic reticulum calcium ATPase, when thapsigargin was treated alone or co-treated with peptidoglycan. These results suggest that the gram-positive bacterial toxin peptidoglycan induces calcium signaling via the phospholipase C/inositol 1,4,5-trisphosphate pathway, and that increased interleukin-8 expression is mediated by intracellular calcium levels in human gingival epithelial cells.

• 상하수도학회지
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• 제25권1호
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• pp.85-93
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• 2011

The structural components of microorganism are quite related to the toxin and environmental conditions. The vegetative and dormant cells are quite affected by the physical and chemical environments to survive and they will be dormant when they are in the extreme environment. The mechanism to activate the microorganisms however, is not well defined yet in the area of activation state and sporulation state through the analysis of EPS. Other than that even the main mechanism of prior to acquisition of analysis values is not well understood. Therefore, what kind of specific environment to affect the activation and sporulation will be discussed through the analysis of the extracellular polymeric substances(EPS). EPS are a high molecular weight mixture of polymers presenting both outside of cells and interior of microbial aggregates. They are a major complex materials in microbial aggregation for sustaining them together in a three dimensional matrix. Three commonly used extraction methods were applied to this study their effectiveness and quantification in extracting EPS from several Bacillus microorganisms and activated sludge. Three extraction methods used for this study are regular centrifugation with formaldehyde (RCF), Steaming, and EDTA extraction. The results of EPS contents such as the quantitative proteins, carbohydrates and the ratio of protein versus carbohydrate from the several species with the several specific methods showed in this research. This study aims to get comparable results of the quantitative production of EPS and the effectiveness of sedimentation for Bacillus microorganisms and activated sludge from several wastewater treatment plans. The results revealed that the protein amount extracted was the highest by the Steaming method of three extraction methods before sporulation and the carbohydrate amount extracted was the highest by the RCA method of three extraction methods after sporulation. The higher amount of protein compared with carbohydrate from Bacillus microorganisms affected higher sedimentation efficiency, however it could not be found the relation between the EPS production and sedimentation efficiency for the activated sludge.

• Experimental and Molecular Medicine
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• 제51권2호
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• pp.9.1-9.10
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• 2019

Mesangial cell proliferation has been identified as a major factor contributing to glomerulosclerosis, which is a typical symptom of diabetic nephropathy (DN). Lysophosphatidic acid (LPA) levels are increased in the glomerulus of the kidney in diabetic mice. LPA is a critical regulator that induces mesangial cell proliferation; however, its effect and molecular mechanisms remain unknown. The proportion of ${\alpha}-SMA^+/PCNA^+$ cells was increased in the kidney cortex of db/db mice compared with control mice. Treatment with LPA concomitantly increased the proliferation of mouse mesangial cells (SV40 MES13) and the expression of cyclin D1 and CDK4. On the other hand, the expression of $p27^{Kip1}$ was decreased. The expression of $Kr{\ddot{u}}ppel$-like factor 5 (KLF5) was upregulated in the kidney cortex of db/db mice and LPA-treated SV40 MES13 cells. RNAi-mediated silencing of KLF5 reversed these effects and inhibited the proliferation of LPA-treated cells. Mitogen-activated protein kinases (MAPKs) were activated, and the expression of early growth response 1 (Egr1) was subsequently increased in LPA-treated SV40 MES13 cells and the kidney cortex of db/db mice. Moreover, LPA significantly increased the activity of the Ras-related C3 botulinum toxin substrate (Rac1) GTPase in SV40 MES13 cells, and the dominant-negative form of Rac1 partially inhibited the phosphorylation of p38 and upregulation of Egr1 and KLF5 induced by LPA. LPA-induced hyperproliferation was attenuated by the inhibition of Rac1 activity. Based on these results, the Rac1/MAPK/KLF5 signaling pathway was one of the mechanisms by which LPA induced mesangial cell proliferation in DN models.

• Journal of Ginseng Research
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• 제30권2호
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• pp.70-77
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• 2006

Ginseng has an anti-cancer effect in several cancer models. As a mechanism study of ginsenoside-induced growth inhibition in cancer cells, we measured change of membrane potential in prostate cancer and glioma cells by ginsenosides, active constituents of ginseng. Membrane potential was estimated by measuring fluorescence change of DiBAC-Ioaded cells. Among 11 ginsenosides tested, ginsenosides $Rb_2$, $Rg_3$, and $Rh_2$ increased significantly and robustly the membrane potential in a concentration-dependent manner in prostate cancer and glioma cells. Ginsenosides Rc, Ro, and $Rb_1$ slightly increased membrane potential. The ginsenoside-induced membrane potential increase was not affected by treatment with pertussis toxin or U73122. The ginsenoside-induced membrane potential increase was not diminished in $Na^+$-free or $HCO_3^-$-free media. Furthermore, the ginsenoside-induced increase of membrane potential was not changed by EIPA (5-(N-ethyl-N-isopropyl)-amiloride), SITS (4-acetoamido-4'-isothiocyanostilbene-2,2'-disulfonic acid), and omeprazole. In summary, ginsenosides $Rb_2$, $Rg_3$, and $Rh_2$ increased membrane potential in prostate cancer and glioma cells in a GPCR-independent and $Na^+$ independent manner.

• 미생물학회지
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• 제55권1호
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• pp.77-79
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• 2019

본 논문에서는 한국인 만성 치주염 환자의 치은연하치태에서 분리된 Veillonella atypica KHUD-V1의 유전체 서열을 보고한다. 다른 V. atypica 균주와 달리, KHUD-V1에서는 프로 파지 및 이와 관련된 것으로 추정되는 여러 병독성 인자가 확인되었다. V. atypica KHUD-V1 균주 및 이 균주의 유전체 서열정보는 Veillonella의 유전체 다양성을 진화론적 관점에서 이해하고, V. atypica의 병독성 및 유전적 다양성에 기여하는 프로파지의 역할을 연구하는데 유용할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1903-1912
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• 2018

Objective: To evaluate the effect of lactic acid bacteria and storage temperature on the microbial, chemical and mycotoxin composition of corn silage. Methods: Corn was harvested at 32.8% dry matter, and chopped to 1 to 2 cm. The chopped material was subjected to three treatments: i) control (distilled water); ii) $1{\times}10^6$ colony forming units (cfu)/g of Lactobacillus plantarum; iii) $1{\times}10^6cfu/g$ of Pediococcus pentosaceus. Treatments in triplicate were ensiled for 55 d at $20^{\circ}C$, $28^{\circ}C$, and $37^{\circ}C$ in 1-L polythene jars following packing to a density of approximately $800kg/m^3$ of fresh matter, respectively. At silo opening, microbial populations, fermentation characteristics, nutritive value and mycotoxins of corn silage were determined. Results: L. plantarum significantly increased yeast number, water soluble carbohydrates, nitrate and deoxynivalenol content, and significantly decreased the ammonia N value in corn silage compared with the control (p<0.05). P. pentosaceus significantly increased lactic acid bacteria and yeast number and content of deoxynivalenol, nivalenol, T-2 toxin and zearalenone, while decreasing mold population and content of nitrate and 3-acetyl-deoxynivalneol in corn silage when stored at $20^{\circ}C$ compared to the control (p<0.05). Storage temperature had a significant effect on deoxynivalenol, nivalenol, ochratoxin A, and zearalenone level in corn silage (p<0.05). Conclusion: Lactobacillus plantarum and Pediococcus pentosaceus did not decrease the contents of mycotoxins or nitrate in corn silage stored at three temperatures.

• Nutrition Research and Practice
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• 제16권4호
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• pp.464-475
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• 2022

BACKGROUND/OBJECTIVES: Increased levels of uremic toxins and decreased antioxidant capacity have a significant impact on the progression of chronic kidney disease (CKD). However, it remains unclear whether they interact with each other to mediate the damage of kidney function. The purpose of this study was to investigate whether uremic toxins (i.e., homocysteine and indoxyl sulfate [IS]), as well as glutathione-dependent antioxidant enzyme activities are dependently or independently associated with kidney function during different stages of CKD patients. SUBJECTS/METHODS: One hundred thirty-two patients diagnosed with CKD at stages 1 to 5 participated in this cross-sectional study. RESULTS: Patients who had reached an advanced CKD stage experienced an increase in plasma uremic toxin levels, along with decreased glutathione peroxidase (GSH-Px) activity. Plasma homocysteine, cysteine, and IS concentrations were all positively associated with each other, but negatively correlated to GSH-Px activity levels after adjusting for potential confounders in all CKD patients. Although plasma homocysteine, cysteine, IS, and GSH-Px levels were significantly associated with kidney function, only plasma IS levels still had a significant association with kidney function after these parameters were simultaneously adjusted. In addition, plasma IS could interact with GSH-Px activity to be associated with kidney function. CONCLUSIONS: IS plays a more dominant role than homocysteine and GSH-Px activity in relation to kidney function.

• 대한임상독성학회지
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• 제21권2호
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• pp.81-91
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• 2023

Purpose: Edible insect extracts have been used as an alternative source for medicinal supplements due to their significant antioxidative and anti-inflammatory activity. Recent studies have reported that anti-microbial peptides from insects have neuroprotective effects on dopamine toxins. The purpose of this study was to investigate the protective functions of mealworm (Tenebrio molitor) extract (MWE) on N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced cellular toxicity in SH-SY5Y neuroblastoma cells. Methods: Cellular toxicity induced by the MPTP toxin and the impact of MWE on cell survival were analyzed using MTT assays. DAPI staining was performed to observe apoptotic phenomena caused by MPTP. Changes in caspase-3 activity and protein expression were observed using enzyme activity assays and western blot assays, respectively. Results: MWE exerted significant antioxidant activity, which was measured by both DPPH and ABTS radical assays, with a dose-dependent relationship. Furthermore, MWE resulted in cellular proliferation in SHSY5Y cells in a dose-dependent manner. Furthermore, MWE pretreatment significantly inhibited MPTP-induced cytotoxicity, with a dose-dependent relationship. The morphological characteristics of apoptosis and increased reactive oxygen species induced by MPTP were also significantly reduced by MWE pretreatment. Conclusion: MWE treatment significantly attenuated MPTP-induced changes in the levels of proteins associated with apoptosis, such as caspase-3 and PARP. These findings suggest that MWE exerts neuroprotective effects on human neuroblastoma SH-SY5Y cells subject to MPTP-induced dopaminergic neurodegeneration.

• 한국식품영양과학회지
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• 제44권12호
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• pp.1895-1904
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• 2015

본 연구에서는 건당 환자수가 높아 식품안전관리 우선순위가 높은 단체급식소의 식품, 조리도구 및 환경에서 식중독균을 분석하고 이들 미생물의 병원성 인자 및 항생제 내성을 확인하여 미생물 위험분석을 위한 기본정보를 제공하고자 하였다. 경기도 소재 총 8개(농촌 3, 도시 4 및 벽지 1) 학교급식소에서 식품 시료(n=66), 조리도구(n=44) 및 환경 시료(n=56) 등 총 179점의 시료를 채취하여 지표세균 및 식중독균을 분석하였다. 식품 시료에서 총균수는 평균 4.7 log CFU/g, 최대 8.1 log CFU/g으로 대장균군의 평균 오염도 3.1 log CFU/g, 최대 오염도 4.0 log CFU/g으로 높았다. 선반 및 개수대 등 환경 시료의 총균수는 평균 2.7 log CFU/g, 최대 4.1 log CFU/g으로 식품 시료보다 낮은 수준으로 분석되었으나 대장균의 경우 평균 4.0 log CFU/g, 최대 5.4 log CFU/g으로 식품 시료보다 오염 수준이 높아 환경으로 부터의 교차오염 가능성을 배제할 수 없었다. 병원성 미생물 중 Bacillus cereus의 정량분석 결과 식품(원료, 조리단계 및 조리식품 포함) 시료에서 평균 2.1 log CFU/g, 최대 4.1 log CFU/g으로 분석되었으나, 이 중 조리된 식품의 오염도는 10,000 CFU/g 이하로 식품공전의 기준 이하로 오염되어 있었다. Escherichia coli는 식품 중 조리 전 시료(n=14)에서만 검출율 35.7%로 분석되었으며 조리단계의 식품, 조리도구 및 환경 시료에서는 검출되지 않았다. Staphylococcus aureus의 경우 조리 전 식품 원료(n=14)의 21.4%에서 검출되었으며 환경 시료(냉장고 손잡이)에서 1건 양성으로 검출되었고, 조리단계의 식품, 조리도구 및 환경 시료에서는 검출되지 않았다. 그 외 Clostridium perfringens, Listeria monocytogenes, Salmonella spp., Vibrio parahaemolyticus는 분석된 모든 시료에서 모두 음성이었다. 분리된 B. cereus의 독소유전자(hblACD, nheABC, entFM, cytK enterotoxin gene)를 분석한 결과 구토 유발 독소인 ces는 모두 음성이었으나 분석된 86주 모두 적어도 1종 이상의 설사 유발 독소유전자가 검출되었으며 66.2%의 균주는 설사 유발 독소유전자를 모두 보유하고 있었다. 식품과 환경에서 분리한 S. aureus(n=16)의 장독소 생성 유전자를 분석한 결과 모두 1종 이상의 독소유전자가 검출되었다. 전형적인 장독소유전자 중에서는 sea만 검출되었으며, 독소충격증후군 toxin(tst) 유전자는 모든 분리주에서 검출되지 않았다. 집단 식중독 발생 시 초기 진료에 결정적 영향을 주는 항생제 내성 여부를 분석한 결과 E. coli(n=41)의 92.7%는 분석한 항생제 16종에 대해 내성을 보이지 않았고 cefazolin에 대한 내성률이 4.9%로 가장 높았으며, 1개 균주에서만 2개 항생제에 대해 다제내성을 보여 국내외 항생제 내성률보다 낮았다. S. aureus(n=16)는 시험한 19종 항생제 중 gentamicin에 대한 내성률이 62.5%로 가장 높았으며 일부 균주에서 2주 항생제에 대해 다제내성이 관찰되었다. 한편 단체 급식소 2개소의 조리도구와 환경 중 미생물 군집을 분석한 결과 특정균이 도구와 환경에서 중복 검출되어 도구와 환경 중 교차오염 가능성을 간접적으로 시사하였다. 이와 같이 본 연구에서 단체급식소 식품, 조리도구 및 환경 중 위생지표균과 병원성 미생물의 오염패턴을 분석하고 분리된 균주의 독성인자와 항생제 내성 정보를 분석하였다. 관련 정보는 단체급식소 미생물 위험분석과 이를 바탕으로 사전적, 정량적 안전관리 기술 개발에 활용 가능할 것으로 사료된다. 한편 식중독 유발의 다른 원인인 바이러스류와 기타 원인에 대한 연구는 진행되지 않아 추가 연구가 필요하다.