• Title/Summary/Keyword: Irradiation Dose

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The Effect of Perioperative Radiation Therapy on Spinal Bone Fusion Following Spine Tumor Surgery

  • Kim, Tae-Kyum;Cho, Wonik;Youn, Sang Min;Chang, Ung-Kyu
    • Journal of Korean Neurosurgical Society
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    • v.59 no.6
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    • pp.597-603
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    • 2016
  • Introduction : Perioperative irradiation is often combined with spine tumor surgery. Radiation is known to be detrimental to healing process of bone fusion. We tried to investigate bone fusion rate in spine tumor surgery cases with perioperative radiation therapy (RT) and to analyze significant factors affecting successful bone fusion. Methods : Study cohort was 33 patients who underwent spinal tumor resection and bone graft surgery combined with perioperative RT. Their medical records and radiological data were analyzed retrospectively. The analyzed factors were surgical approach, location of bone graft (anterior vs. posterior), kind of graft (autologous graft vs. allograft), timing of RT (preoperative vs. postoperative), interval of RT from operation in cases of postoperative RT (within 1 month vs. after 1 month) radiation dose (above 38 Gy vs. below 38 Gy) and type of radiation therapy (conventional RT vs. stereotactic radiosurgery). The bone fusion was determined on computed tomography images. Result : Bone fusion was identified in 19 cases (57%). The only significant factors to affect bony fusion was the kind of graft (75% in autograft vs. 41 in allograft, p=0.049). Other factors proved to be insignificant relating to postoperative bone fusion. Regarding time interval of RT and operation in cases of postoperative RT, the time interval was not significant (p=0.101). Conclusion : Spinal fusion surgery which was combined with perioperative RT showed relatively low bone fusion rate (57%). For successful bone fusion, the selection of bone graft was the most important.

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

  • Choi, So-Young;Kim, Young-Chul
    • Toxicological Research
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    • v.27 no.3
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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.

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

  • Lee, Young-Keun;Chang, Hwa-Hyoung;Kim, Won-Rok;Kim, Jin-Kyu;Kim, Jae-Sung
    • Korean Journal of Environmental Agriculture
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    • v.17 no.3
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    • pp.195-199
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    • 1998
  • To induce the cellulolytic variants of oyster mushroom (Pleurotus ostreatus), basidiospores were irradiated at the dose of $1kGy{\sim}20kGy$ of gamma-ray. After irradiation, activities of extracellular enzymes were determined by the method of MUF residue and genetic similarity was observed by RAPD analysis of variants. Three variants of 2KG-1, 2KG-2 and 20KG-1 were clarified as highly cellulolytic isolates. It seemed that the difference of genetic similarity among variants have derived from gamma-ray radiation. It is suggested that 3 cellulolytic variants induced by gamma-ray in this experiment could play a useful role to reuse cellulosic bioresources.

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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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    • v.10 no.4
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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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    • v.15 no.6
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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.

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

  • Huh, Seung-Jae
    • Radiation Oncology Journal
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    • v.27 no.1
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    • pp.1-9
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    • 2009
  • There has been recent interest in radiation-induced bone injury in clinical conditions, especially for pelvic insufficiency fracture (PIF). A PIF is caused by the effect of normal or physiological stress on bone with demineralization and decreased elastic resistance. Pelvic radiotherapy (RT) can also contribute to the development of a PIF. A PIF has been regarded as a rare complication with the use of megavoltage equipment. However, recent studies have reported the incidence of PIFs as $8.2{\sim}20%$ after pelvic RT in gynecological patients, an incidence that was higher than previously believed. The importance of understanding a PIF lies in the potential for misdiagnosis as a bony metastasis. If patients complain of pelvic pain after whole-pelvis radiation therapy, the presence of a PIF must be considered in the differential diagnosis. The use of multibeam arrangements and conformal RT to reduce the volume and dose of irradiated pelvic bone can be helpful to minimize the risk of fracture. In addition to a PIF, osteonecrosis and avascular necrosis of the femoral head can develop after radiation therapy. Osteoradionecrosis of the pelvic bone is a clinical diagnostic challenge that must be differentiated from an osseous metastasis. A post-radiation bone sarcoma can result as a long-term sequela of pelvic irradiation for uterine cervical cancer.

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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    • v.16 no.7
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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.

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

  • Choi, Wook-Hee;Ann, Hyoung-Soo;Ahn, Ryoung-Me
    • Journal of Environmental Health Sciences
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    • v.31 no.1
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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.

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

  • Shin, Hae Seung;Kim, Jae Hyoun
    • Journal of Environmental Health Sciences
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    • v.40 no.2
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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.

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

  • Yin, Xing Fu;Jeon, Young Eun;Kim, Tae-Keun;Shim, Jae-Hoon;Kang, Il-Jun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.11
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    • pp.1534-1539
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    • 2012
  • This study was conducted to evaluate the possible subacute toxicity of gamma-irradiated Tarakjuk. Tarakjuk was irradiated at a dose of 30 kGy at room temperature. For the animal study, AIN-93G as a control diet and 30 kGy irradiated and non-irradiated Tarakjuk diets were administered to male and female ICR mice (10 mice per group) for 3 months. During the experimental period, the group fed 30 kGy irradiated Tarakjuk did not show any changes in appearance, behavior, mortality, body weight, organ weight, or food consumption compared to control. Further, all biochemical parameters were in normal ranges. In the histopathological examination of liver and kidney tissues of ICR mice, there were no significant differences between the control and 30 kGy irradiated Tarakjuk groups. These results indicate that Tarakjuk irradiated at 30 kGy did not cause any toxic effects under these experimental conditions.