• Journal of Magnetics
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• 제16권3호
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• pp.253-258
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• 2011

The purpose of this study was to identify the effect of pulsed electromagnetic fields on the expression of neurotrophic factors after spinal cord injury. Sprague-Dawley male rats were given a spinal cord hemisection and randomly divided into 2 groups, the control and experimental groups. The experimental group was administered a fifteen minutes session of pulsed electromagnetic field once a day, five days a week. In order to observe the effect of these pulsed electromagnetic fields, this study observed the BDNF expression in the rat's lumbar spinal cord and the H&E staining in the gastrocnemius at 3, 7, 14, 21 days group after spinal cord hemisection. The results of this showed that the immunoreactivity of the BDNF in the rat's spinal cord gradually increased in each group. At 21 days, there is a significant difference between the control and experimental groups. The morphological shape of the gastrocnemius was gradually changed from 3days to 21days, and the gastrocnemius at 21 days was significantly degraded. However, the experimental group showed a slightly more organized gastrocnemius than the control group at 21days. The Results of this study suggest that pulsed electromagnetic field application decreases the degeneration of a rat's gastrocnemius morphology, and increases the immunoreactivity of the BDNF in the rat's spinal cord after spinal cord hemisection.

• 대한치과교정학회지
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• 제19권3호
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• pp.15-33
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• 1989

The purpose of this study was to investigate changes of the mandible of a growing rat when they are subjected to a retractive force and those after removal of the retractive force. The experimental animals were Sprague-Dawley male rats of four weeks of age. A mandible was retracted with 50 grams of force on each side in the posterior and superior direction for 8 hours per day. The animals were sacrificed after 1 week, 2-week and 4-week force application, and after 4-week force application-4-week force removal period. The changes of rat mandibular growth following retractive force on the growing rat mandible were observed histologically and biometrically. The findings were as follows ; 1. Histologically, the thickness of the condylar cartilage was slightly reduced in the anterosuperior region with the retractive force. However, in the group of 4-week force application-4-week force removal, there was no significant difference in the thickness of the condylar cartilage. 2. There were no significant histological changes in the articular disk and glenoid fossa through the experimental period. 3. The length and anterior height of the mandible subjected to the retractive force were significantly smaller and greater than those of the control group. 4. There were no significant differences in the mandibular length between 4-week force application - 4-week force removal and the control group. 5. It was concluded that a mandibular retractive force produced inhibitory effects in the growth of the mandible, but that these effects were not sustained during mandibular growth in this experimental model.

• 한국한의학연구원논문집
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• 제16권1호
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• pp.141-147
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• 2010

Objectives : The aim of present study is to examine the effect of methanolic extract from the root of Bupleurum falcatum L. (BF) on acute cocaine-induced c-Fos expression in the rat caudate putamen (CPu), a major dopaminergic terminal. Methods : Male Sprague-Dawley rats were subjected to an intraperitoneal injection with either cocaine hydrochloride (20 mg/kg) or saline 30 min after an administration of either extract of BF (100 mg/kg, i.p.) or vehicle. Animals were sacrificed 2 hr after treatment with cocaine or saline for immunohistochemistry. Quantification of brain slices was examined for c-Fos positive nuclei using light microscopy. Results : Pretreatment with BF significantly attenuated cocaine-induced c-Fos expression in the rat CPu. Conclusions : This finding suggests that BF has the inhibitory effect on cocaine-induced c-Fos expression in the rat CPu via possibly modulating the activities of central dopaminergic systems.

• Mass Spectrometry Letters
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• 제4권3호
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• pp.55-58
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• 2013

Dioscin is a biologically active steroidal saponin with anticancer and hepatoprotective effects. A rapid, selective, and sensitive liquid chromatographic method with electrospray ionization tandem mass spectrometry was developed for the quantification of dioscin in rat plasma. Dioscin was extracted from rat plasma using ethyl acetate at acidic pH. The analytes were separated on a Halo C18 column using gradient elution of acetonitrile and 0.1% formic acid and detected by tandem mass spectrometry in selected reaction monitoring mode. The standard curve was linear ($r^2$ = 0.998) over the concentration range of 1-100 ng/mL. The lower limit of quantification was 1.0 ng/mL using 50 ${\mu}L$ of plasma sample. The coefficient of variation and relative error for intra- and inter-assay at four QC levels were 1.3 to 8.0% and -5.4 to 10.0%, respectively. This method was applied successfully to the pharmacokinetic study of dioscin after oral administration of dioscin at a dose of 29.2 mg/kg in male Sprague-Dawley rats.

• 한방안이비인후피부과학회지
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• 제28권3호
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• pp.76-87
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• 2015

Objectives : Allergic rhinitis is highly increased in these days. We aimed to investigate therapeutic effect ofShinchulsanby observing changes in blood cells and the protein expression level of IL-4 in spleen of Sprague-Dawley(SD) rats with allergic rhinitis.Methods : Fifteen SD rats were divided into three groups: normal, control, and sample group. Allergic rhinitis was induced in the control and sample group by intraperitional and intranasal sensitization with 0.1% and 0.4% Ovalbumin solution. ThenShinchulsanwas orally administered only to the sample group for 28 days, while the rats in the control group was given normal saline.Results : 1.Shinchulsanshowed significantly decreased eosinophil level on the serum of the rat model.2.Shinchulsanshowed significantly decreased IgE level on the serum of the rat model.3.Shinchulsanshowed significantly decreased the protein expression levels of IL-4 in spleen of the rat model.4.Shinchulsanhad no hepatoxicity, according to AST and ALT on the serum.Conclusion : According to the above results, it is considered thatShinchulsanis helpful in treatment of allergic rhinitis.

• 동의생리병리학회지
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• 제24권3호
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• pp.426-429
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• 2010

This study was conducted to investigate the acute toxicity and safety of Pyungwi-san (Pingwei-san) in Sprague-Dawley rat though the current regulatory guideline. The preliminary study showed that the single oral administration of Pyungwi-san (Pingwei-san) did not induce any toxic effect at a dose level of 2000 mg/kg. Based on the results, 2000 mg/kg was selected as the limited dose. In this study, 10 rats of each sex were randomly assigned to two groups of 5 rats each and were administrated singly by gavage at dose levels of 0 and 2000 mg/kg. After single administration, Mortalities, clinical signs, body weight changes, gross findings were observed for the 15-day period. Throughout the study period, no treatment-related deaths were observed. There were no adverse effects on clinical signs, body weight, and gross findings at all treatment groups. These results showed that the single oral adminstration of Pyungwi-san (Pingwei-san) did not cause any toxic effect at the dose levels of 2000 mg/kg in rats. In conclusion, the $LD_{50}$ of Pyungwi-san (Pingwei-san) was considered to be over 2000 mg/kg body for both sexes.

• 한방안이비인후피부과학회지
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• 제23권1호
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• pp.111-117
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• 2010

Objectives : This study was conducted to evaluate the acute toxicity and safety of Bangpungtongsung-san (Fangfengtongsheng-san) in Sprague-Dawley rat though the current regulatory guideline. Methods : The preliminary study showed that the single oral administration of Bangpungtongsung-san (Fangfengtongsheng-san) did not induce any toxic effect at a dose level of 2000 mg/kg. Based on the results, 2000 mg/kg was selected as the limited dose. In this study, 10 rats of each sex were randomly assigned to two groups of 5 rats each and were administrated singly by gavage at dose levels of 0 and 2000 mg/kg. Mortalities, clinical signs, and body weight changes were monitored for the 15-day period following administration. At the end of observation period, all animals were sacrificed and complete gross postmortem examinations were performed. Results : Throughout the study period, no treatment-related deaths were observed. There were no adverse effects on clinical signs, body weight, and gross findings at all treatment groups. Conclusions : These results showed that the single oral adminstration of Bangpungtongsung-san (Fangfengtongsheng-san) did not cause any toxic effect at the dose levels of 2000 mg/kg in rats. In conclusion, the $LD_{50}$ of Bangpungtongsung-san (Fangfengtongsheng-san) was considered to be over 2000 mg/kg body for both sexes.

• 한국정밀공학회지
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• 제24권1호
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• pp.110-117
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• 2007

This study investigated changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the ovariectomised (OVX) rat. In previous researches, there were many studies for morphology of osteoporotic bones based on Micro-Computed Tomography (Micro-CT). However, there were few studies for detecting and tracking changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the OVX rat. For this study, the 4th lumbar of the OVX rat (female Sprague-Dawley) was utilized as a specimen. An OVX rat was scanned at week 0 (just before surgery), at week 4, and week 8 after surgery. Micro-finite element (${\mu}-FE$) analysis was used to investigate mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae for an OVX rat. When the OVX rat (at week 8) was compared with the OVX rat (at week 0), the structural modulus of cortical and trabecualr bone was decreased by 52% and 99%, respectively. This study showed the change of mechanical characteristics of cortical bone as well as trabecular bone of an OVX rat. Detecting and tracking changes of mechanical characteristics could greatly contribute to an experiment test for the trabecular and cortical bone in the lumbar vertebrae of an OVX rat by using In-vivo Micro-CT.

• Journal of electromagnetic engineering and science
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• 제6권1호
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• pp.47-52
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• 2006

The objective of this study is to evaluate the effects of size and permittivity on the specific absorption rate(SAR) values of rat brains during microwave exposure at mobile phone frequency bands. A finite difference time domain (FDTD) technique with perfect matching layer(PML) absorbing boundaries is used for this evaluation process. A color coded digital image of the Sprague Dawley(SD) rat based on magnetic resonance imaging(MRI) is used in FDTD calculation with appropriate permittivity values corresponding to different tissues for 3, 4, 7, and 10 week old rats. This study is comprised of three major parts. First, the rat model structure is scaled uniformly, i.e., the rat size is increased without change in permittivity. The simulated SAR values are compared with other experimental and numerical results. Second, the effect of permittivity on SAR values is examined by simulating the microwave exposure on rat brains with various permittivity values for a fixed rat size. Finally, the SAR distributions in depth, and the brain-averaged SAR and brain 1 voxel peak SAR values are computed during the microwave exposure on a rat model structure when both size and permittivity have varied corresponding to different ages ranging from 3 to 10 weeks. At 900 MHz, the simulation results show that the brain-averaged SAR values decreased by about 54 % for size variation from the 3 week to the 10 week-old rat model, while the SAR values decreased only by about 16 % for permittivity variation. It is found that the brain averaged SAR values decreased by about 63 % when the variations in size and permittivity are taken together. At 1,800 MHz, the brain-averaged SAR value is decreased by 200 % for size variation, 9.7 % for permittivity variation, and 207 % for both size and permittivity variations.

• 동의생리병리학회지
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• 제16권4호
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• pp.674-679
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• 2002

The toxicity and bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) continues to be a focus of research in human and various species. The main human exposure is via the dietary route. This study was carried out to investigate the protective effect of Cornu Cervi Parvum extract on clinical parameters and hepatotoxicity in Sprague-Dawley rat (SD rat) accutely exposured to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Male SD rats received single intraperitoneal (ip) injection of TCDD (40 ㎍/kg), and administered 10 or 20 mg/kg/day of the ethanol extract oral injection for 4 weeks from 1 week before TCDD treatment. The gain in body weight was less in group treated with TCDD than in CON group, while that of C/H+ TCDD group (Cornu Cervi Parvum extract 20 mg/kg/day) increased. The decrease in spleen and testis weight caused by TCDD was prevented by Cornu Cervi Parvum extract 20 mg/kg/day. The fluctuation in BUN content, WBC and platelet count by TCDD intoxication were significantly attenuated by the ethanol extract treatment (20 mg/kg/day for 4 weeks). Treatments of rats with the extract (10 or 20 mg/kg/day) were significantly reduced AST and ALT levels compared with TCDD-treated group. Moderate swelling of hepatocytes, hyperchromatism, acidophilic cytoplasm and cytoplasmic vacuolation were observed in TCDD-treated animals (TCDD group). The administration of EtOH extract 10 or 20 mg/kg along with TCDD significantly alleviated the liver histopathological alteration induced by TCDD. These results suggest that Cornu Cervi Parvum extract can be useful as a protective agent against TCDD, an endocrine disruptor.