• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.223-232
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• 2023

Oxidative stress plays a significant role in the pathogenesis of various skin conditions, resulting in cellular and tissue damage that can contribute to the development of skin tone unevenness, roughness and wrinkles. In this study, we found that Trifolium pratense L. extract (TE) attenuated oxidative-induced damage in HaCaT cells and elucidated the underlying molecular mechanism. Our finding demonstrated that TE effectively protected HaCaT cells against H₂O₂-induced cell death by inhibiting caspase-3 activation, downregulating Bax and upregulating Bcl-2, and attenuating the activation of three mitogen-activated protein kinases (MAPKs). Our results suggest that TE has remarkable cytoprotective properties against oxidative damage in HaCaT cells and could serve as a complementary or alternative approach to prevent and treat skin damage.

• Journal of Yeungnam Medical Science
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• v.33 no.2
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• pp.85-89
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• 2016

Background: Formaldehyde is used to preserve cadaver in medical schools, and students are exposed to formaldehyde during cadaver dissection classes. When humans are exposed to formaldehyde, it induces mucosal inflammation, skin inflammation, and declining of neurobehavioral function including attention and memory executive functions. The purpose of this study is to identify the effects of formaldehyde exposure on student's neurobehavioral performance during cadaver dissection classes. Methods: The level of formaldehyde was measured in a cadaver dissection class. A total of 16 students were randomly divided into two groups. One group wore respiratory protection masks, while the other group did not. Among many subtests in Korean Computerized Neurobehavioral test, backward digit span was tested on all subjects before and after the class. Results: The length of memorized digit span between the two groups was not significant; however there was a greater decrease in neurobehavioral function after formaldehyde exposure in the non-mask group than the mask group. Conclusion: Formaldehyde exposure during cadaver dissection may likely decrease neurobehavioral performance of students. Therefore, proper ventilation system and respiratory protective equipment are necessary to protect medical school students from adverse effects of formaldehyde exposure.

• Applied Microscopy
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• v.40 no.1
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• pp.29-35
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• 2010

The present study was carried out to investigate the hepatoprotective effect of water extract of Lithospermum erythrorhizon on acute hepatotoxicity induced in Sprague-Dawley (SD) rats by a single dose of galactosamine (400 mg/kg, i.p). The animals were divided into four groups. The animals in the Con group were fed basal diet. GalN group were administered with galactosamine. LE200 and LE500 groups treated with water extract of Lithospermum erythrorhizon (such as 200 and 500 mg/kg/day, p.o) for 7 days before galactosamine injection. In the change of AST, ALT, ALP, GGT and LDH contents, as compared with GalN group, LE200 group were significantly decreased. According to the electron microscopical observation, liver cells were increased the lipid droplet, change of mitochondria in the GalN compared with LE200. These results suggest that administration of water extract of Lithospermum erythrorhizon suppress or retard galactosamine induced acute liver injury.

• Food Science of Animal Resources
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• v.35 no.2
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• pp.164-170
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• 2015

The objective of this study was to evaluated the photoprotective effects of porcine placenta extract (PPE) on ultraviolet B (UVB)-induced oxidative stress in human keratinocytes (HaCaT) to evaluate its functional activities as a skin food ingredient. PPE prepared by subcritical water extraction was termed SPE, and subsequently digested by enzymes to prepare E-SPE. Increased intracellular reactive oxygen species (ROS) levels (192.0%) induced by UVB were decreased by SPE and E-SPE. SPE had more effective ROS scavenging activity than E-SPE treatment. UVB treatment increased expression of tissue inhibitor of metalloproteinase 1 (TIMP-1), and this elevated expression was decreased by E-SPE treatment. High-dose treatment with E-SPE (50 and 100 µg/mL) reduced TIMP-1 expression levels of UVB-C (control) to 33.5 and 34.6%, respectively. In contrast, at low SPE doses (1 and 10 µg/mL), the treatment slightly decreased TIMP- 1 expression levels to 73.3% and 71.3% of UVB-C, respectively. In conclusion, the present study demonstrated the protective effect of SPE and E-SPE against UVB damage in keratinocytes via ROS scavenging, down-regulating MMP-2 expression and up-regulating TIMP- 1 expression. This highlights the potential for SPE as an ingredient in the preparation of functional food against photoaging.

• Archives of Reconstructive Microsurgery
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• v.2 no.1
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• pp.46-52
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• 1993

Soft-tissue deficits over the plantar forefoot, plantar heel, Achilles tendon, and distal parts of lower leg are often troublesome to cover with a simple graft or local flap due to limited mobility of surrounding skin and poor circulation in these area. Soft-tissue reconstruction in these regions should provide tissue components similar to the original lost tissue, supply durability and minimal protective pressure sensation and result in a donor site that is well tolerated and treated. We analysed 7 cases that were treated with the Instep flap due to soft-tissue defects over these regions from July of 1990 to July of 1993. All flaps were viable and successful at follow-up. 1. The age ranged from 9 years to 60 years, and 6 cases were male and 1 case female. 2. The sites of soft-tissue loss were the plantar forefoot(1 case), plantar heel(3 cases), Achilles tendon(2 cases), and distal parts of lower leg(1 case). 3. The causes of soft-tissue loss were simple soft-tissue crushing injury(1 case), crushing injury of the 1st toe(1 case) and posttraumatic infection and necrosis(5 cases). 4. The associated injury were open distal tibio-fibula, fracture(2 cases), medial malleolar fracture of the ankle(1 case), Achilles tendon rupture(2 case) and 1st metatarso-phalangeal disarticulation(1 case). 5. The size of flap was from $3{\times}4cm$ to $5{\times}10cm$(average $4{\times}5.6cm)$. 6. In 7 cases, we were not to find post-operative necrosis and infection, non-viability, limitation of ankle joint, and gait disturbance caused by the Instep flap surgery. 7. This study demonstrates that the Instep flap should be considered as another valuable technique in reconstruction of these regions.

• The Korean Journal of Community Living Science
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• v.17 no.4
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• pp.49-56
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• 2006

The purpose of this study was to evaluate the thermal and subjective comfort of various pesticide-proof clothes made from different material. Seven male adults took part in the study, conducted in a climate-chamber controlled with an ambient temperature of $30^{\circ}C$ and a relative humidity of 60%RH. The thermal and subjective responses of subjects wearing pesticide-proof clothing made of Goretex(coating treatment), polyester (water-repellent treatment), non-woven(coating) and nylon(coating) were measured. The main results were summarized as follows: (1) Change of rectal temperature and clothing microclimate were inhibited more effectively in pesticide-proof clothing made of Goretex, polyester and non-woven than nylon materials. (2) Mean skin temperature at the end of the experiment was significantly higher in subjects who wore nylon than non-woven and Goretex, and was lowest in those with pesticide-proof clothing made of polyester. (3) Change of heart rate was significantly lower in subjects with Goretex and polyester clothiing than those with non-woven, and in those with nylon, it was highest. (4) Subjective comfort was greater in subjects with Goretex, polyester and nonwoven clothing than nylon, except for thermal sensation. Thermal sensation was greater in order of polyester, Goretex, non-woven and nylon. Thus, it was concluded that pesticide-proof clothing made of Goretex, polyester and non-woven material could reduce thermal stress during the spraying of pesticides in summer.

• Biomolecules & Therapeutics
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• v.26 no.3
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• pp.282-289
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• 2018

Melanin is a pigment produced from tyrosine in melanocytes. Although melanin has a protective role against UVB radiation-induced damage, it is also associated with the development of melanoma and darker skin tone. Tyrosinase is a key enzyme in melanin synthesis, which regulates the rate-limiting step during conversion of tyrosine into DOPA and dopaquinone. To develop effective RNA interference therapeutics, we designed a melanin siRNA pool by applying multiple prediction programs to reduce human tyrosinase levels. First, 272 siRNAs passed the target accessibility evaluation using the RNAxs program. Then we selected 34 siRNA sequences with ${\Delta}G{\geq}-34.6kcal/mol$, i-Score value ${\geq}65$, and siRNA scales score ${\leq}30$. siRNAs were designed as 19-bp RNA duplexes with an asymmetric 3' overhang at the 3' end of the antisense strand. We tested if these siRNAs effectively reduced tyrosinase gene expression using qRT-PCR and found that 17 siRNA sequences were more effective than commercially available siRNA. Three siRNAs further tested showed an effective visual color change in MNT-1 human cells without cytotoxic effects, indicating these sequences are anti-melanogenic. Our study revealed that human tyrosinase siRNAs could be efficiently designed using multiple prediction algorithms.

• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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• pp.245-251
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• 2002

Flavonoid seems to have various biological effects. Quercetin is a kind of natural plant flavonoids and has multiple biological effects such as antioxidant, antimutagenic and anticarcinogenec agent. Melanogenesis is a physiological process resulting in the synthesis of melanin pigments, which play a crucial protective role against skin photocarcinogenesis. This present study was designed to investigate effect of quercetin on proliferation and melanogenesis in Melan-a melanocyte cells. After 48h treatment of cells with quercetin, the cells exhibited a dose-dependent inhibition in their proliferation without apoptosis. Therefore, thε growth retardation by the extract may be due to the cell arrest or cell differentiation. We also investigated the effect of quercetin on melanogenesis of this cells. Melan-a melanocyte cells were grown for 48h in the presence of $0.01-60\;{\mu}g/ml$ quercetin and the total melanin content and activity of tyrosinase were measured. Quercetin stimulated melanization of the cells in low concentrations $(0.01-1.0\;{\mu}g/ml)$, whereas it inhibited melanization in high concentrations $(5.0-30\;{\mu}g/ml)$. It was observed that quercetin differently regulates melanogenesis of Melan-a melanocyte cells dependent on Its concentrations.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7561-7566
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• 2015

Ziziphus jujuba (ZJ) fruit is rich in bioactive functional components such as polysaccharides, triterpenoid acid, flavonoids and oleamide. It has been commonly used in the treatment of various diseases including diabetes, digestive disorders, diarrhea, skin infections, liver and urinary diseases. However, its dietary effect on chemoprevention of colon cancer has never been studied. The present study was to evaluate the protective effects of dietary ZJ on colitis-associated colon carcinogenesis in azoxymethane (AOM)-dextran sodium sulphate (DSS)-treated mice. AOM was injected (10 mg/kg b.wt., i.p.) and three cycles of 2% DSS in drinking water for 7 days with 14 days of normal drinking water in-between was administered to induce colitis-associated colon cancer. ZJ fruit was supplemented in feed as 5 and 10%. Dietary ZJ significantly attenuated aberrant crypt foci (ACF) formation thereby decreasing the progression of hyperplasia to dysplasia. In addition, it significantly reduced circulating white blood cells, lymphocytes, neutrophils, monocytes, eosinophils, basophils and platelets compared to colon cancer mice. We conclude that ZJ supplementation delayed the progression of colon cancer from hyperplasia to dysplasia and ultimately adenocarcinoma and cancer. In addition, it decreased circulating tumor-related leucocytes, main regulators of cancer inflammation. Therefore, dietary consumption of ZJ fruit attenuated the formation of ACF and delayed the progression of colon cancer.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.1
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• pp.63-76
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• 2015

This study conducted a survey to gauge the buying and wearing propensities of wearers of leg guards made for baseball catchers, as well as product characteristics of preferred leg guards. Data from the survey were analyzed to obtain basic data for the development of an advanced leg guard design. Degree of compression, horizontal distance, cross section view and outline 3D sketch were also analyzed from the 3D data of leg guards; in addition, mobility and kinematic analysis were conducted through a wearing test. The survey indicated that imported products dominate the current retail market because they are appreciated by customers in terms of fit, price, brand, and protection. Representative complaints of products were discomfort, pressure, and the heavy-weight of the leg guards in general attributed to overall structure and 3D shape. When the pressure was lower on the front area of knee, it feels better to wear and the average knee angular velocity during the up and down motion increased, which suggests a better design from a kinematic point of view. The knee is the primary part of the body responsible for any movement of the lower limbs; consequently, the degree of compression and support stability of the leg guards near the knee area are important factors to evaluate the performance of leg guards. The results of our study indicate significant opportunities for improvement in product design and the development of baseball leg guards along with an ergonomic design that considers the mobility of the knee, skin deformations is necessary to improve performance. The process followed in this study will be applicable to studies on other personal protective equipment for sports.