• 제목/요약/키워드: Irradiation Dose

검색결과 1,996건 처리시간 0.035초

Whitening Effect of Black Tea Water Extract on Brown Guinea Pig Skin

  • Choi, So-Young;Kim, Young-Chul
    • Toxicological Research
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    • 제27권3호
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    • pp.153-160
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    • 2011
  • To evaluate the whitening effect of black tea water extract (BT), BT was topically applied to artificially hyperpigmented spots on the back skins of brown guinea-pigs (weight: 450~500 g) induced by 1,500 mJ/$cm^2$ of ultraviolet B (UVB) irradiation. The test compounds of 30 ${\mu}l$ were applied twice a day, six days a week, for four weeks. The artificially hyperpigmented spots were divided into 5 groups: control (UVB + saline, C), vehicle control [UVB + propylene glycol: ethanol: water (5 : 3 : 2), VC], positive control (UVB + 2% hydroquinone, PC), experimental 1 (UVB + 1% BT), experimental 2 (UVB + 2% BT). After 4-week application, the spots were removed by biopsy punch under anesthetic condition and used as specimens for the histological examination. The total polyphenol and flavonoid contents of BT were 104 and 91 mg/g, respectively. The electron-donating ability of BT revealed a dose-dependent response, showing the excellent capacities of 86% at 800 ${\mu}g$/ml. The artificially hyperpigmented spots treated with the PC and BT were obviously lightened compared to the C and VC groups. At the fourth week, the melanin indices for the PC and BT groups were significantly lower (p < 0.001) than those of the C and VC groups. In histological examination, PC and BT groups were significantly reduced in the melanin pigmentation, the proliferation of melanocytes and the synthesis of melanosomes compared to the C and VC groups. It is found that BT inhibits the proliferation of melanocytes and synthesis of melanosomes in vivo using brown guinea pigs, thereby showing a definite skin whitening effect.

느타리(Pleurotus ostreatus)에서 방사선유기 변이주의 RAPD 양상 (RAPD Pattern of Radiation Induced Variants of Oyster Mushroom(Pleurotus ostreatus))

  • 이영근;장화형;김원록;김진규;김재성
    • 한국환경농학회지
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    • 제17권3호
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    • pp.195-199
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    • 1998
  • 이온화방사선을 이용하여 느타리(Pleurotus ostreatus)의 담자포자(basidiospore)로부터 섬유소 분해능이 뛰어난 변이주를 유도하고자 본 실험을 수행하였다. 담자포자를 감마선조사 후 MUF(4-methylumbelliferyl) 반응기를 이용하여 세포외분비효소의 활성도를 측정하였다. 방사선유기 변이주에서 RAPD(random amplified polymorphic DNA)의 양상을 조사하여 유전유사도를 분석하였다. 검색한 45종의 균주들은 MUF의 기질에 따라 다양한 기질분해도를 보였으며, 이 중에서 섬유소 분해능이 뛰어난 3개의 변이주 2KG-1, 2KG-2와 20KG-1를 선발하였다. RAPD 양상을 통해 조사한 변이주의 유전유사도는 대조군에 대해 $50%{\sim}52%$였고, 변이주간에는 $49%{\sim}57%$로 나타나 방사선조사에 의해 유전적 다양성이 증가되었음을 알 수 있었다. 본 연구에서 방사선조사에 의해 유기된 변이주는 섬유소성 생물폐자원의 재활용에 있어서 매우 유용하게 활용될 수 있을 것으로 기대된다.

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Adenophora remotiflora protects human skin keratinocytes against UVB-induced photo-damage by regulating antioxidative activity and MMP-1 expression

  • Kim, Hye Kyung
    • Nutrition Research and Practice
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    • 제10권4호
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    • pp.371-376
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    • 2016
  • BACKGROUND/OBJECTIVES: Chronic ultraviolet (UV) exposure-induced reactive oxygen species (ROS) are commonly involved in the pathogenesis of skin damage by activating the metalloproteinases (MMP) that break down type I collagen. Adenophora remotiflora (AR) is a perennial wild plant that inhabits Korea, China, and Japan. The present study investigated the protective effects of AR against UVB-induced photo-damage in keratinocytes. MATERIALS/METHODS: An in vitro cell-free system was used to examine the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and nitric oxide (NO). The effect of AR on ROS formation, antioxidant enzymes, elastase, MMP-1 level, and mRNA expression of MMP-1 were determined in UVB-irradiated human keratinocyte HaCaT cells. RESULTS: AR demonstrated strong DPPH free radical and NO scavenging activity in a cell-free system exhibiting $IC_{50}$ values of 1.88 mg/mL and 6.77 mg/mL, respectively. AR pretreatment dose-dependently attenuated the production of UVB-induced intracellular ROS, and antioxidant enzymes (catalase and superoxide dismutase) were enhanced in HaCaT cells. Furthermore, pretreatment of AR prevented UVB-induced elastase and collagen degradation by inhibiting the MMP-1 protein level and mRNA expression. Accordingly, AR treatment elevated collagen content in UVB-irradiated HaCaT cells. CONCLUSION: The present study provides the first evidence of AR inhibiting UVB-induced ROS production and induction of MMP-1 as a result of augmentation of antioxidative activity in HaCaT human keratinocytes. These results suggest that AR might act as an effective inhibitor of UVB-modulated signaling pathways and might serve as a photo-protective agent.

Situation of HPV16 E2 Gene Status During Radiotherapy Treatment of Cervical Carcinoma

  • Kahla, Saloua;Kochbati, Lotfi;Maalej, Mongi;Oueslati, Ridha
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2869-2873
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    • 2014
  • Background: Human papillomavirus (HPV) integration within the E2 gene has been proposed as a critical event in cervical carcinogenesis. This study concerned whether HPV16 status and E2 gene intactness are predictive of radiation response in patients with cervical cancer. Materials and Methods: Biopsies of 44 patients with cervical cancer were collected before or after radiotherapy. The presence of HPV16 was assessed by polymerase chain reaction (PCR) using specific primers for the L1 region. E2 disruption was detected by amplifying the entire E2 gene. Results: HPV16 DNA was found in 54.5% of the clinical samples. Overall, 62.5% of the HPV16 positive tumors had integrated viral genome and 37.5% had episomal genome. There was a tendency of increase of HPV16 E2 negative tumors compared with HPV16 L1 ones in advanced stages (75% versus 20% in stage III respectively). Detection of E2 gene appeared influenced by the radiotherapy treatment, as the percentage of samples containing an intact HPV16 E2 was more frequent in pretreated patients compared to radiotherapy treated patients (66.6% versus 20%). The radiation therapy caused an eight-fold [OR= 8; CI=1.22-52.25; p=0.03] increase in the risk of HPV16 genome disruption. The integration status is influenced by the irradiation modalities, interestingly E2 disruption being found widely after radiotherapy treatment (75%) with a total fractioned dose of 50Gy. Conclusions: This study reveals that the status of the viral DNA may be used as a marker to optimize the radiation treatment.

골반 방사선 치료후의 골 변화와 손상 (Post Pelvic Radiotherapy Bony Changes)

  • 허승재
    • Radiation Oncology Journal
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    • 제27권1호
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    • pp.1-9
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    • 2009
  • 방사선치료후 발생할 수 있는 골 손상은 골반 부전골절, 방사선 골 괴사, 무혈성 괴사, 골 육종 등이다, 특히 최근 방사선치료후의 골탄성도의 변화로 발생하는 골반 부전골절에 관하여 많은 보고가 있었다. 과거 방사선치료 후의 골 손상 특히 골절의 빈도는 선형가속기를 이용한 메가볼트 방사선치료 바뀌면서 현저히 줄어 들어서 매우 낮은 것으로 보고 되었으나 최근에는 $8{\sim}20%$로 보고가 되고 있다. 따라서 골반 부전골절의 임상적 의미와 중요성과 예방 및 치료에 대하여 관심이 증가되고 있다. 저자는 자궁경부암 치료 후 관찰한 골반 부전골절, 골 괴사, 무혈성 괴사, 및 2차성 골육종등 골반골 변화와 손상에 관하여 저자의 경험과 문헌고찰을 통하여 보고 하고자 한다.

Preventive and Therapeutic Effects of Quercetin on Experimental Radiation Induced Lung Injury in Mice

  • Wang, Juan;Zhang, Yuan-Yuan;Cheng, Jian;Zhang, Jing-Ling;Li, Bao-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권7호
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    • pp.2909-2914
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    • 2015
  • Objective: To investigate the protective effect of quercetin on radiation induced lung injury (RILI) and related mechanisms. Materials and Methods: Mice treated with radiation and/or quercetin were sacrificed at 1-8 weeks after irradiation under anesthesia. Lung tissues were collected for histological examination. Immunohistochemistry (IHC) and Western blotting were performed to detect the protein expression of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) and Mitogen-activated protein kinases (MAPK) pathway. Results: Hematoxylin and eosin (HE) staining showed that radiation controls displayed more severe lung damage than quercetin groups, either high or low dose. Results of IHC and Western blotting demonstrated the expression level of $NF-{\kappa}B$ to be decreased and that of an inhibitor of $NF-{\kappa}B$ ($I{\kappa}b-{\alpha}$) to be increased by the quercetin intervention compared with the radiation control group. Numbers of JNK/SAPK, p38 and p44/p42 positive inflammatory cells were decreased in the radiation+quercetin injection group (P<0.05). Conclusions: Quercetin may play a radio-protective role in mice lung via suppression of $NF-{\kappa}B$ and MAPK pathways.

ICR mouse에 있어 UVB조사로 유도된 접촉 과민반응에 대한 EGb 761의 억제 효과 (Prevention of Ultraviolet B Radiation (280-320 nm) Induced Contact Hypersensitivity by EGb 761)

  • 최욱희;안형수;안령미
    • 한국환경보건학회지
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    • 제31권1호
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    • pp.7-14
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    • 2005
  • Exposure of skin to UVB radiation can cause the induction of inflammation and impairment of contact hypersensitivity(CHS) response. Several studies have shown that polyphenolic compounds isolated from EGb 761 afford protection against UVB. In this study, we demonstrated that topical application of EGb 761, before 1MED(1.4 KJ/$m^2$), 1.5MED (2.1 KJ/$m^2$), 2MED (2.8 KJ/$m^2$) of UVB exposure to ICR mice prevented UVB-induced inflammation and inhibition of the contact hypersensitivity response. The skin-fold swelling from 1MED, 1.5MED, 2MED of UVB exposure highly significantly increased after twice irradiation. Topical application of EGb 761(0.1%, 1%, 4%), 5 days prior to UVB exposure reduced skin thickness compared to non-treated mice. Exposure of shaved abdominal skin of mice to 1MED, 1.5MED and 2MED of UVB radiation resulted in suppression of contact sensitization through the skin to 56.23%, 65.12%, 74.02%, compared to normal unirradiated skin. Topical application of EGb 761(0.1%, 1%, 4%), 5 days prior to or 5 days after exposure to 1MED and 2MED of UVB resulted in protection against suppression of contact hypersensitivity in mouse dorsal skin. These protective effects were dependent on the dose of EGb 761 employed. The present study show that EGb 761 protect UVB-induced inflammation and immune suppression. Also, we suggest that EGb 761 can provide protection from photoimmunosuppression.

PCBs의 광화학적 연구: NaOH 및 휴믹산 (humic acid, HA)에 의한 분해특성 (Effects of NaOH and Humic Acid on the UV Photolysis of PCBs)

  • 신혜승;김재현
    • 한국환경보건학회지
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    • 제40권2호
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    • pp.147-156
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    • 2014
  • Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid (HA)] was prompted photodegradation of polychlorinated biphenyl (PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at ${\lambda}_{max}=300nm$. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry (GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB (penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation (using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

감마선 조사 타락죽의 3개월 반복투여 독성평가 (Toxicity Evaluation of Irradiated Tarakjuk for Three Months)

  • 윤성복;전영은;김태근;심재훈;강일준
    • 한국식품영양과학회지
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    • 제41권11호
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    • pp.1534-1539
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    • 2012
  • 본 연구는 타락죽의 안전성을 확보하기 위해서 30 kGy 감마선 조사된 타락죽을 ICR 마우스에 3개월간 섭취시킨 다음 독성평가를 수행하였다. 비조사 타락죽 및 30 kGy 조사 타락죽을 암수 마우스에 투여를 한 결과 시험기간 동안 시험물질에 의한 임상증상이나 폐사 동물을 나타나지 않았으며, 체중변화, 사료섭취량 및 주요 장기 무게도 대조군에 비해 차이를 보이지 않았다. 혈액학적 검사 및 혈청학적 검사 모두 정상범위 내의 수치를 나타내었으며, 병리조직학적 검사 역시 간 및 신장 모두 염증, 괴사 등의 유의할 만한 병적 변화 없는 정상적인 구조를 유지하고 있었다. 따라서 30 kGy로 감마선 조사된 타락죽을 암수 마우스에 3개월간 섭취시켜도 본 시험조건에서는 독성이 없는 것으로 나타났다.

인공피부 개발을 위한 생채 적합성 지지체에 관한 연구

  • 김창환;김천호;박현숙;강현주;한은숙;김윤영;최영주;이수현;최태부;손영숙
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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    • pp.429-432
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    • 2000
  • 생체 적합성, 생분해성, 항균성 등의 특징을 갖는 키토산 지지체는 type I -p collagen과 bFGF 또는 fibronectin을 함께 코팅함으로써 세포적합성을 향상시켜 섬유아세포의 증식과 ECM의 분비를 증가시킬 수 있으며, 인공피부를 위한 적합한 지지체로 사용될 수 있다고 사료된다.

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