• The Korean Journal of Physiology and Pharmacology
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• 제1권1호
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• pp.71-78
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• 1997

In an attempt to investigate the role of phospholipase $A_2$($PLA_2$) in interleukin-l (IL-l) induced acute lung injury, mepacrine was tried to inhibit $PLA_2$ in IL-l induced ARDS rats. For confirmation of acute lung injury by IL-l, and to know the role of neutrophils in this injury, lung leak index, lung myeloperoxidase(MPO), number of neutrophils and protein content in the bronchoalveolar lavage (BAL) and wet lung weight were measured. At the same time lung $PLA_2$ was measured to know the effect of IL-l on $PLA_2$ activity. Pulmonary surfactant was also measured for an investigation of type II alveolar cell function. Neutrophil adhesion assay was performed to know the effect of $PLA_2$ inhibition in vitro with human umbilical vein endothelial cells (HUVEC). For precise location of injury by IL-l, morpholgical study was performed by electron microscopy. Five hours after instillation of IL-l (50 ng/rat), lung leak index, protein content, number of neutrophils, lung MPO and wet lung weight were increased significantly. Five hours after IL-l instillation lung $PLA_2$ activity was increased significantly, and increased surfactant release was observed in IL-l induced ARDS rats' BAL. In contrast, in rats given mepacrine and IL-l, there was decrease of acute lung injury i.e. decrease of lung leak index, wet lung weight, protein content, number of neutrophils in BAL and decreased lung MPO activity. Mepacrine decreased surfactant release also. Interestingly, inhibition of $PLA_2$ decreased adhesion of human neutrophils to HUVEC in vitro. Morphologically, IL-l caused diffuse necrosis of endothelial cells, type I and II epithelial cells and increased the infiltration of neutrophils in the interstitium of the lung but after mepacrine treatment these pathological findings were lessened. On the basis of these experimental results it is suggested that $PLA_2$ has a major role in the pathogenesis of acute lung injury mediated by neutrophil dependent manner in IL-l induced acute lung injury.

• Archives of Plastic Surgery
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• 제45권5호
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• pp.403-410
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• 2018

Background Radiation-induced skin injury is a dose-limiting complication of radiotherapy. To investigate this problem and to develop a framework for making decisions on treatment and dose prescription, a murine model of radiation-induced skin injury was developed. Methods The dorsal skin of the mice was isolated, and irradiation was applied at single doses of 15, 30, and 50 Gy. The mice were followed for 12 weeks with serial photography and laser Doppler analysis. Sequential skin biopsy samples were obtained and subjected to a histological analysis, immunostaining against transforming growth factor beta (TGF-${\beta}$), and Western blotting with Wnt-3 and ${\beta}$-catenin. Increases in the levels of TGF-${\beta}$, Wnt, and ${\beta}$-catenin were detected after irradiation. Results All tested radiation doses caused progressive dermal thickening and fibrosis. The cause of this process, however, may not be radiation alone, as the natural course of wound healing may elicit a similar response. The latent appearance of molecular and histological markers that induce fibrosis in the 15 Gy group without causing apparent gross skin injuries indicates that 15 Gy is an appropriate dose for characterizing the effects of chronic irradiation alone. Thus, this model best mimics the patterns of injury that occur in human subjects. Conclusions This animal model can be used to elucidate the gross and molecular changes that occur in radiation-induced skin injury and provides an effective platform for studying this adverse effect without complicating the process of wound healing.

• Advances in Traditional Medicine
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• 제9권4호
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• pp.292-302
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• 2009

Ischemia/reperfusion injury, which is commonly seen in the field of renal surgery or transplantation, is a major cause of acute renal failure. Previous studies showed that antioxidant treatments attenuated renal ischemia/reperfusion injury. The objective of this study was to examine the role of hesperidin in modulating reactive oxygen species induced inflammation and apoptosis after renal ischemia/reperfusion injury. Rats were subjected to right nephrectomy, 15 days later 45 min of renal ischemia and 24 h reperfusion with or without treatment with hesperidin. Renal function, inflammation and apoptosis were compared at 24 h after reperfusion injury. Hesperidin improved the renal dysfunction and reduced inflammation and apoptosis after ischemia/reperfusion injury. In conclusion, hesperidin shows potent anti-apoptotic and antiinflammatory properties due to antioxidant property. These findings may have major implications in the treatment of human ischemic acute renal failure.

• Journal of Microbiology
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• 제39권2호
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• pp.142-145
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• 2001

Changes in the Activities of several antioxidant enzymes in transformed human dermal microvascular endothelial Cells (HMEC-1) by infection with the obligate intracellular bacterium Orientia tsutsugamushi, the causative agent of scrub typhus, were investigated. The activities of glucose-6-phosphate dehydrogenase, catalase, and glutathione peroxidase were significantly decreased in HMEC-1 cells infected with Ο. tsutsugamushi. However, the level of superoxide dismutase increased slightly. Furthermore, Increased levels of intracellular peroxide was observed in HMEC-1 during infection. These results support the hypothesis that cells infected by this intracellular bacterium experience oxidant-mediated injury that may eventually contribute to cell death.

• 대한기계학회논문집A
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• 제33권6호
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• pp.590-599
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• 2009

In this paper, a method of modeling seat belts on crew seat during dynamic seat testing was studied. The body segments of the occupant were modeled with joints. The joints consisted with various stiffnesses, dampings, and frictions. Three types of seat belt restraint systems were investigated. The analysis for on the injury assessment of helicopter's crew under drop impact was conducted. The effectiveness of the seat belt system for crashworthiness and safety was evaluated. As the results of impact analysis, head, neck and spine of the crew can be easily damaged in the vertical direction more than the longitudinal direction. Based on the verified model, behavior of human body was studied with three-point restraint systems. The displacement and injury level of the 12-point restraint system was the smallest.

• Journal of Preventive Medicine and Public Health
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• 제23권1호
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• pp.98-105
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• 1990

교통사고와 기상요소와의 관련성을 보기 위하여 대구지방에서 1988년도 1월 1일부터 12월 31일까지 1년간 교통사고를 일으킨 총 운전자중 약 1/10인 2,562명을 대상으로 하여 대구측후소에서 측정한 기상요소를 중심으로 그 관련성을 관찰하였다. 사고양상은 사고당시 인적피해와 물적피해로 구분하고 인적피해와 물적피해가 중복된 경우는 인적피해로 간주하였다. 인적피해는 다시 사망, 중상, 경상 등으로 구분하였으며 두가지 이상에 해당될 때는 피해가 큰 쪽으로 결정하였다. 계절별로 보면 겨울철이 1일평균 사고건수도 적고 인적피해 사고의 비율도 가장 낮았으며 계절에 따른 사고양상은 통계학적으로도 유익한 차이가 있었다. 기온에 다른 시간당 사고건수는 $25.1-30.0^{\circ}C$에서 가장 많았고 인적피해 사고의 비율은 41-50%일 때 가장 높았으나 습도에 따른 사고양상은 통계학적으로 유의하지 않았다. 풍속에 따른 시간당 사고건수는 풍속이 강할수록 많아지는 경향을 보였고 인적피해 사고의 비율은 6.1-7.0m/sec일 때 가장 높은 비율을 보였으나 풍속에 따른 사고양상은 통계학적으로 유의하지 않았다. 강수에 따른 시간당 사고건수는 5.1-10.0mm일 때 5.4건으로 가장 많았고 인적피해 사고이 비율은 강수량이 많을수록 높아지는 경향을 보였으며 강수량과 사고양상 간에는 통계학적으로도 유의한 관련성이 있었다. 시정에 따른 시간당 사고건수는 시정 6 Km미만일 때 가장 많았고 인적피해사고의 비율은 6 Km미만일 때 가장 낮았으며 시정과 사고양상 사이에는 통계학적으로 유의한 관련성이 있었다. 적설이 있을 때 시간당 사고건수는 적설이 없을 때보다 많았고 인적피해사고의 비율은 비교적 적었으나 적설유무와 사고양상과는 통계학적으로 유의하지 않았다. 이상의 결과로 보아 자동차 사고는 기온, 습도, 풍속 등 몇가지 기상조건에 따라 서로 그 발생양상에 크고 작은 차이를 보이고 있는데 계절, 강수량 빛 시정에 따른 사고발생 분포의 차이는 통계적으로도 유의했다.

• Archives of Pharmacal Research
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• 제19권2호
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• pp.85-90
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• 1996

It has been suggested that oxygen-derived free radicals play an important role in the pathophysiology of acute gastric ulceration induced by NSAIDs and ischemia-reperfusion. Taurine is hypothetized to exert its protective effect on NSAIDs-induced gastric injury by its antioxidant properties. Protective effect of taurine on indomethacin-induced gastric mucosal lesion and its protection mechanism were investigated. Intragastric administration of 25 mg/kg of indomethacin induced hemorrhagic lesions on the glandular stomach in rats. Pretreatment with 0.25 or 0.5 g/kg of taurine one day before or for 3 days significantly reduced the gastric lesion formation and inhibited the elevation of lipid peroxide level in gastric mucosa. The luminol-dependent chemiluminescence of rat peritoneal neutrophils increased immediately after treatment of FMLP or indomethacin. Taurine (5-20 mM) inhibited chemiluminescence of neutrophils activated by FMLP. Human neutrophils (polymorphonuclear leukocytes) significantly adhered to the confluent monolayer of human umbilical vein endothelial cells (HUVEC) after coincubation with indomethacin. This neutrophil adhesion induced by indomethacin to HUVEC was prevented by taurine in a dose-dependent manner. These results indicate that the protective effect of taurine against NSAIDs-induced gastric mucosal injury is due to its antioxidant effect, which inhibits lipid peroxidation and neutrophil activation.

• The Korean Journal of Physiology and Pharmacology
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• 제27권6호
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• pp.533-540
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• 2023

Sweroside is a natural monoterpene derived from Swertia pseudochinensis Hara. Recently, studies have shown that sweroside exhibits a variety of biological activities, such as anti-inflammatory, antioxidant, and hypoglycemic effects. However, its role and mechanisms in high glucose (HG)-induced renal injury remain unclear. Herein, we established a renal injury model in vitro by inducing human renal tubular epithelial cell (HK-2 cells) injury by HG. Then, the effects of sweroside on HK-2 cell activity, inflammation, reactive oxygen species (ROS) production, and epithelial mesenchymal transition (EMT) were observed. As a result, sweroside treatment ameliorated the viability, inhibited the secretion of inflammatory cytokines (TNF-α, IL-1β, and VCAM-1), reduced the generation of ROS, and inhibited EMT in HK-2 cells. Moreover, the protein expression of SIRT1 was increased and the acetylation of p65 NF-kB was decreased in HK-2 cells with sweroside treatment. More importantly, EX527, an inhibitor of SIRT1, that inactivated SIRT1, abolished the improvement effects of sweroside on HK-2 cells. Our findings suggested that sweroside may mitigate HG-caused injury in HK-2 cells by promoting SIRT1-mediated deacetylation of p65 NF-kB.

• Human Ecology Research
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• 제60권4호
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• pp.535-547
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• 2022

This study aimed to examine the effect of parental psychological control on adolescents' non-suicidal self-injury and verify whether this effect is mediated by depression. In the first survey of 647 middle and high school students, only those who had experiences of non-suicidal self-injury were selected (136 adolescents). For data analysis purposes, descriptive statistics for each measured variable and Pearson's correlation coefficients among research variables were calculated. In addition, Process Macro - Model 4 by Hayes (2013) was used to investigate the mediating model. Finally, the bootstrapping method was applied to confirm the significance of the mediating effect. The results of this study were as follows. First, parental psychological control and depression directly affected the frequency of non-suicidal self-injury among adolescents. Second, depression mediated the relationship between parental psychological control and non-suicidal self-injury. In conclusion, the more parents controlled their children's psychological factors, the higher the level of depression among adolescents, and as a result, the higher the frequency of non-suicidal self-injury. These findings suggest that educational intervention on parental psychological control is important to prevent and reduce non-suicidal self-injury; however, psychotherapy intervention that reduces the levels of depression should also be required.

• International Journal of Safety
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• 제5권2호
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• pp.12-17
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• 2006

Operations of human-centered robot, in general, facilitates the creation of new process that may potentially harm the human operators. Design of safety-guaranteed operation of human-centered robots is, therefore, important since it determines the ultimate outcomes of operations involving safety of human operators. This study discusses the application of information-theoretic measures to safety assessment of human-centered robotic operations. Some examples are given.