• Radiation Oncology Journal
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• v.23 no.4
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• pp.211-216
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• 2005

Purpose: It has been reported that all-trans retinoic acid (ATRA) can inhibit glioma growing in vitro. However, clinical trials with ATRA alone in gliomas revealed modest results. ATRA has been shown to increase radiosensitivity in other tumor types, so combining radiation and ATRA would be one of alternatives to increase therapeutic efficacy in malignant gliomas. Thus, we intended to know the role of catalase, which is induced by ATRA, for radiosensitivity if radiation-reduced reactive oxygen species (ROS) is removed by catalase, the effect of radiation will be reduced. Materials and Methods: A rat glioma cell line (36B10) was used for this study. The change of catalase activity and radiosensitivity by ATRA, with or without 3-amino-1, 2, 4-triazole (ATZ), a chemical inhibitor of catalase were measured. Catalase activity was measured by the decomposition of $H_2O_2$ spectrophotometrically Radiosensitivity was measured with clonogenic assay. Also ROS was measured using a 2, 7-dichlorofluorescein diacetate spectrophotometrically. Results: When 36B10 cells were exposed to 10, 25 and $50{\mu}M$ of ATRA for 48 h, the expression of catalase activity were increased with increasing concentration and incubation time of ATRA. Catalase activity was decreased with increasing the concentration of AT (1, $10{\mu}M$) dose-dependently. ROS was increased with ATRA and it was augmented with the combination of ATRA and radiation. ATZ decreased ROS production and increased cell survival in combination of ATRA and radiation despite the reduction of catalase. Conclusion: The increase of ROS is one of the reasons for the increased radiosensitivity in combination with ATRA. The catalase that is induced by ATRA doesn't decrease ROS production and radiosensitivity.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.297-304
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• 1995

To evaluate the feasibility of irradiation as a control measure for metagonimiasis, the metacercariae of Metagonimus yokogcwni were irradiated with gamma ray, either after isolation from the sweetfish (Plecoglossus cltivelis) or in situ of the fish, and their survival and development in rats were observed at 7 days post-infection. The radiation dose varied from 5 to 100 Gy for the metacercaria-irradiation group and from 5 to 500 Gy for fish-irradiation group. The results showed that the worm recovery rate from the irradiation groups decreased as the radiation dose was increased. Higher doses of radiation were required for the fish-irradiation group to obtain the same results as the metacercaria-irradiation group. The LD50 of the metacercaria-irradiation group was 4.5 Gy, whereas that of the fish-irradiation group 6.2 Gy A few number of worms which survived until 7 days in rats were severely retarded especially in the growth of their reproductive organs, j.e., complete or partial failure in the development of testes and formation of uterine eggs . The present study revealed that irradiation of sweetfish by 200 Gy is effective to control infectivity as well as development of M. vokogawai metacercariae in rats.

• Food Science and Preservation
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• v.18 no.3
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• pp.374-382
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• 2011

Aflatoxin ($AFB_1$) is a potent hepatotoxic and hepatocarcinogenic mycotoxin in humans. It is also well-known to be accumulated in animal tissues via various metabolic pathways. This study was conducted to determine the effects of vitamin C on the residual $AFB_1$ in rat sera that were treated with radiation and $AFB_1$. Six week-old male Sprague-Dawley rats were randomly divided into five groups: a control group, $AFB_1$-treated group, the group treated with $AFB_1$ and vitamin C, the group treated with X-ray and AFB1, and the group treated with X-ray and $AFB_1$ with vitamin C. On the first day of the experiment, only one dose of X-rays was exposed to the entire liver at 1,500 cGy. Next, vitamin C was injected at 10 mg/kg body weight via intraperitoneal injection, followed 1 hr later by the administration of 0.4 mg/kg of $AFB_1$ via intraperitoneal injection. These treatments were then administered every three days over a period of 15 days. On the 16th day of treatments, the animals were sacrificed. The contents of $AFB_1$ in rat sera were determined via indirect competitive ELISA and HPLC method. In the quantitative analysis of $AFB_1$ in rat sera via ELISA, $5.17{\pm}0.34$ ng/mL of $AFB_1$ was detected in the $AFB_1$-treated groups, but the amount more significantly decreased to $3.23{\pm}0.76$ ng/mL in the groups treated with $AFB_1$ and vitamin C (p<0.01) than in the $AFB_1$-treated groups. The $AFB_1$ contents of the rat sera of the groups treated with X-ray and $AFB_1$ did not significantly decreased with the administration of vitamin C. The $AFB_1$ content of the rat sera that was analyzed via HPLC showed a tendency similar to that of the content that was analyzed via ELISA. With regard to these data, vitamin C was very effective in reducing $AFB_1$ residue in rat sera.

• Progress in Medical Physics
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• v.4 no.2
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• pp.69-76
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• 1993

In order to investigate radiation effects on the liver, functional changes of liver were analyzed after irradiation. Doses of 10 Gy, 15 Gy and 20 Gy were exposed partially to the liver of male rats(Sprague-Dawley) with X-ray(4MV linear accelerator) at room temperature. On 1, 2, 4 and 8 weeks after irradiation, sera of the animals were compared with those of unirradiated animal by liver function tests. Enzyme activities in sera such as alkaline phosphatase and concentrations of bilirubin in liver function tests. The content of the activities of many enzymes including alkaline phosphatase in sera were increased slightly with increasing exposure dose in all experiments and the activities of these enzymes increased markedly in 20 Gy irradiated groups. The contents of serum bilirubins including direct and indirect bilirubins increased continuously along with the time lapse after irradiation. However, in 20 Gy irradiated group, the content of serum bilirubin decreased slightly during 2 or 4 weeks after irradiation and increased markedly there after. From these above results, functional changes of the liver were induced in all irradiated groups. Damaged liver was recovered along with time collapsed after irradiation to the doses of 10 Gy and 15 Gy while no recovery was deteced within 8 weeks after irradiation to 20 Gy. These results suggest that careful attontion must be paid to liver not to be included in exposure field in radiation therapy.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.327-333
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• 1994

The purpose of this study was to investigate the irradiation effects on the palatal mucosa. For this study, Sprague-Dawley strain rats were irradiated to their head and neck region with the dose of 5Gy and l0Gy by 6MV X -radiation and sacrificed on the experimental periods after irradiation. The authors observed the histological changes of the hard and soft palatal mucosae. The results were as follows: In the light microscopic examination, hydropic change on the basal cells, increased cell size of the epithelium, and decreased epithelial cell layers were observed on the 3hours, 6hours, and 12hours groups after irradiation. But, basal cell hyperplasia, increased epithelial cell layers, and elongated rate pegs were observed on the 3days group after irradiation. After then, these changes were recovered in the mucosa of the hard palate on the 7days and 14days groups, and in the mucosa of the soft palate on the 14days and 2&lays groups after irradiation. And such changes were greater in the mucosa of the soft palate than in that of the hard palate, and more prominent in l0Gy irradiated groups than in 5Gy irradiated groups.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.39-48
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• 1989

Six to eight-month-old female albino rats were used as experimental animals. As an irradiation equipment, a Co-60 was used. The experimental animals were divided to; 6 of the control group, 12 of the 500cGy single irradiation group, 12 of the 1000cGy fractionated irradiation group, and 12 of the 1500cGy fractionated irradiation group. From the first week to the forth, 3 rats were picked from each group every week to be sacrificed and fixed with formalin. Those rats were observed by means of H-E stain after being taken radiograph and decalcified. The analysis of radiographic findings and light microscopic findings gives results as follows: 1. The delay of dental eruption rate was found in every group which underwent the irradiation experiment. Dentin niche, osteodentin, and dentin island were formed in the parts which were damaged by the irradiation. 2. The longer the observation period was, the more deposit of osteodentin and dentin island was formed. 3. In the single irradiation group, the damage effect was in proportion to the increase of radiation dose, whereas the damage was much less in the fractionated group receiving the same dose. 4. The 500cGy single irradiation group got temporary repairable damage, while the 1000cGy single irradiation group got considerable damage and showed much slower eruption rate than the 500cGy single irradiation group. The basal portion of the 1500cGy single irradiation group, whose growth was arrested, was destroyed. 5. The fractionated group were irradiated 500cGy everyweek. Repair was visible during the interval periods. The damage was accumulated as irradiation repeated, but degree of damage was lower than that of the 1000cGy and 1500cGy single irradiation group.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.411-418
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• 2004

Mercury, one of the most diffused and hazardous organ-specific environmental contaminants, exists in a wide variety of physical and chemical states. The murcury with the nature which evaporates easily can cause an acute or chronic mercury poisoning to workers at mercury-handling workplaces. Although many studies indicate that mercury induces a deleterious damage, little has been reported from the investigations of mercury effects at surrounding levels in living things. The purpose of this study was to evaluate the biological effects of mercury chloride and ionizing radiation. Prepubertal male F344 rats were administered mercury chloride in drinking water throughout the experimental period or were given wholebody irradiation with a dose of 6.5 Gy. The amount changed of body weight during the experimental period showed a 4.9% rise in the mercury-treated group and 14.4% decline in the irradiated group compared with the level of the control group. The results of hematological analysis (red blood cells, white blood cells, hemoglobin, and hematocrit) indicated the differential effects of mercury chloride and ionizing radiation. However the concentration of cortisol as assessed by radioimmunoassay increased in both of the groups. Relative expressions of mRNA related to mitochondrion-mediated apoptosis were investigated using semiquantitative reverse transcription polymerase chain reaction on gonad and urinary organs of the experimental groups. While the expression of Bcl-2 mRNA exhibited different patterns depending on the organs or the experimental groups, both of the experimental groups showed a conspicuous expressions of Bax mRNA. In conclusion, the target organ of mercury chloride seems to be a urinary organ and the pattern of damage induced by mercury chloride differs from that by ionizing radiation.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.218-222
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• 2002

Lycii Cordex Radicis extract (gigolpi) examined through SOS Chromotest showed a strong, dose-dependent antimutagenic effect on the tert-butyl hydroperoxide (t-BOOH) induced mutagenecity. Gigolpi revealed considerable superoxide anion radical scavenging activity under L-ascorbic $acid-CuSO_4$ system, but showed lower hydroxyl radical scavenging activity in photochemical test system. Hot-water gigolpi extract delayed protein oxidation, whereas lipid peroxidation of rat skin exposed to UVB radiation was inhibited. The results indicate that gigolpi possessing antioxidant activity against UVB-induced lipid peroxidation could be used as a raw ingredient for manufacturing functional cosmetics

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.791-798
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• 2005

The hepatoprotective activity of flavonol glycosides rich fraction (F-2), prepared from 70% alcohol extract of the aerial parts of V calcarata Desf., was evaluated in a rat model with a liver injury induced by daily oral administration of $CCl_4$ (100 mg/kg, b.w) for four weeks. Treatment of the animals with F-2 using a dose of (25 mg/kg, b.w) during the induction of hepatic damage by $CCl_4$ significantly reduced the indices of liver injuries. The hepatoprotective effects of F-2 significantly reduced the elevated levels of the following serum enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant activity of F-2 markedly ameliorated the antioxidant parameters including glutathione (GSH) content, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), plasma catalase (CAT) and packed erythrocytes glucose-6-phosphate dehydrogenase (G6PDH) to be comparable with normal control levels. In addition, it normalized liver malondialdehyde (MDA) levels and creatinine concentration. Chromatographic purification of F-2 resulted in the isolation of two flavonol glycosides that rarely occur in the plant kingdom, identified as quercetin-3,5-di-O-$\beta$-D-diglucoside (5) and kaempferol-3,5-di-O-$\beta$-D-diglucoside (4) in addition to the three known compounds identified as quercetin-3-O-$\alpha$-L-rhamnosyl- (${\rightarrow}6$)-$\beta$-D-glucoside [rutin, 3], quercetin-3-O-$\beta$-D-glucoside [isoquercitrin, 2] and kaempferol-3-O-$\beta$-D-glucoside [astragalin, 1]. These compounds were identified based on interpretation of their physical, chemical, and spectral data. Moreover, the spectrophotometric estimation of the flavonoids content revealed that the aerial parts of the plant contain an appreciable amount of flavonoids (0.89%) calculated as rutin. The data obtained from this study revealed that the flavonol glycosides of F-2 protect the rat liver from hepatic damage induced by $CCl_4$ through inhibition of lipid peroxidation caused by $CCl_4$ reactive free radicals.

• Imaging Science in Dentistry
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• v.30 no.3
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• pp.189-198
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• 2000

Purpose: The study was aimed to detect the induction of apoptosis, cell cycle arrest and calcified nodule formation after irradiation on primarily cultured osteoblasts. Materials and Methods: Using rat calvarial osteoblasts, the effects of irradiation on apoptosis, cell cycle arrest, and calcified nodule formation were studied. The single irradiation of 10 and 20 Gy was done with 5.38 Gy/min dose rate using the l37Cs cell irradiator at 4th and 14th day of culture. Apoptosis induction and cell cycle arrest were assayed by the flowcytometry at 1, 2, 3, and 4 days after irradiation. The formation of calcified nodules was observed by alizarin red staining at 1, 3, 10, 14 days after irradiation at 4th day of culture, and at 1, 4, 5 days after irradiation at 14th day of culture. Results: Apoptosis was not induced by 10 or 20 Gy independent of irradiation and culture period. Irradiation did not induced G1 arrest in post-irradiated ostedblasts. After irradiation at 4th-day of culture, G2 arrest was induced but it was not statistically significant after irradiation at 14th-day of culture. In the case of irradiated cells at 4th day of culture, calcified nodules were not formed and at 14th-day of culture after irradiation, calcified nodule formation did not affected. Conclusion: Taken together, these results suggest that irradiation at the dose of 10-20 Gy would not affect apoptosis induction of osteoblasts. Cell cycle and calcified nodule formation were influenced by the level of differentiation of osteblasts.