• Nuclear Engineering and Technology
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• v.5 no.2
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• pp.87-93
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• 1973

Due to the Co-60 source size, the penumbra in Co-60 teletheraphy poses a serious problem, even if the extended collimators are used, Here an empirical formula for the calculation of integral absorbed dose in the penumbra region was derived. Through a numerical calculation, the penumbra effect on integral absorbed dose was investigated. The longer the source-to-skin distance, the larger the integral absorbed dose of penumbra region, and the larger the source diameter, the larger the integral absorbed dose of penumbra region. It was also found that in some case the integral absorbed dose in penumbra region becomes several times larger than the integral absorbed dose of treatment region itself if the source-to-skin distance becomes greater. Therefore, one must consider the penumbra effect in Co-60 teletherapy.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.3
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• pp.1-13
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• 2009

Objectives : This study evaluates neuroprotective effect of Gastrodiae Rhizoma on apoptosis in the cerebral infarct. Methods : Cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) for 2 hours with intraluminal thread method in Sprague-Dawley rats. Then ethanol extract of Gastrodiae Rhizoma was administered orally for 3 days. Infarct area and volume were evaluated with TTC staining. Neuronal apoptosis was identified with TUNEL labeling. Apoptosis modulatory effect was observed with immunohistochemical Bax, Bcl-2, iNOS, and MMP-9 expressions in penumbra. Results : 1. Ethanol extract of Gastrodiae Rhizoma reduced infarct size partly and volume significantly of in the MCAO rat brain. 2. Ethanol extract of Gastrodiae Rhizoma reduced TUNEL positive cell ratio in the penumbra of MCAO rat brain significantly. 3. Ethanol extract of Gastrodiae Rhizoma suppressed Bax, iNOS and MMP-9 expression in the penumbra of MCAO rat brain significantly. 4. Ethanol extract of Gastrodiae Rhizoma did not change Bcl-2 expression in the penumbra of MCAO rat brain. But expression ratio of Bcl-2 against Bax was increased in the Gastrodiae Rhizoma group. Conclusions : These results suggest that Gastrodiae Rhizoma plays an anti-apoptotic neuroprotective effect through suppression of Bax, iNOS, and MMP-9 expressions and relative up-regulation of Bcl-2 in the ischemic brain tissue.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.596-602
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• 2006

This study evaluated neuroprotective effect of Sunghyangjungki-San (SHS) on the focal cerebral ischemia. The rats were induced infarct in cerebral cortex and caudoputamen by using temporal occlussion of the middle cerebral artery (MCAO), then water extract of SHS was treated for MCAO rats. Neuroprotective effect was evaluated by neurological score, infarct sizes and total volume, positive neurons against Bax, Caspase-3, HSP-72, and $HIF-1{\alpha}$ in infarct area with immunohistochemistry. The results obtained were as follows: Treatment of SHS improved neurological score of MCAO rats, but there was not a statistical significance. Treatment of SHS reduced significantly infarct sizes in the brain sections of MCAO rats. Treatment of SHS reduced significantly total volume of infarct of MCAO rats. Treatment of SHS reduced significantly Bax positive neurons in penumbra of cerebral cortex of MCAO rats. Treatment of SHS reduced significantly Caspase-3 positive neurons in caudoputamen and penumbra of cerebral cortex of MCAO rats. Treatment of SHS reduced significantly HSP-72 positive neurons in penumbra of cerebral cortex of MCAO rats. Treatment of SHS reduced significantly $IF-1{\alpha}$ positive neurons in penumbra of cerebral cortex of MCAO rats.

• Radiation Oncology Journal
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• v.14 no.4
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• pp.333-338
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• 1996

Purpose : To evaluate the clinical implications of scallop penumbra width that comes from multileaf collimator(MLC) effect by the daily routine patient setup error. Materials and Methods : The anales of $0^{circ},{\;}15^{circ},{\;}30^{circ},{\;}45^{circ},{\;}60^{circ},{\;}and{\;}75^{circ}$ inclined -radiation blocked fields were generated using the both conventional cerrobend block and the MLC. Film dosimetry in the phantom were performed to measure penumbral widths of differences between the dose distributions from the cerrobend block and those of respect the MLC. The patient setup error effect on scallop penumbra was simulated with respect to the table of setup error distribution. Same procedures are repeated for the cerrobend block generated field. Results : There are penumbral widths of to 3mm difference between the dose distributioins from two kinds of field shaping tools, the conventional block and the MLC with 4mm setup error model and resolution of 1cm leaf at the isocenter. Conclusion : We need not additive margin for MLC, if planning target volume is selected according to the recommendation of ICRU 50. For particular cases, we can include the target volume with less than 3mm additive margin.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.1
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• pp.13-27
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• 2009

This study aimed to validate neuroprotective effect of Chungpaesagan-tang on the early stage of cerebral ischemic damage. Cerebral ischemic damage was induced by the middle cerebral artery occlusion (MCAO) for 2 hours in the Sprague-Dawley rats. Water extract of Chungpaesagan-tang(8.7g/kg) was administered orally twice at 1 and 4 hours after the MCAO. Neurological score was tested at 3 and 24 hours after the MCAO and Chungpaesagan-tang administration. At 24 hours after the MCAO, infarct volume and edema ratio was evaluated with the TTC staining. Apoptotic cell death in cerebral cortex and caudate putamen was observed with cresyl violet staining and TUNEL labeling. Bax expression in the MCAO rat brain was stained with immunohistochemistry. Chungpaesagan-tang improved neurological and behavioral impairment of the MCAO rats and reduced infarct area, infarct volume and brain edema formation. Chungpaesagan-tang attenuated cell death percentage in cortex penumbra and reduced TUNEL positive cells in cortex penumbra and in caudate putamen of the MCAO rats. Chungpaesagan-tang reduced Bax positive neurons in caudate putamen and reduced c-Fos positive neurons in cortex penumbra of the MCAO rats. Chungpaesagan-tang intensified neuronal HSP72 expression in cortex penumbra of the MCAO rats. In results, Chunpaesagan-tang reduces infarct volume and edema formation through anti-apoptotic effect. This result suggests that Chunapaesagan-tang has an adequate neuroprotective effect on the early stage of cerebral ischemic damage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.403-409
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• 2008

In Oriental medicine daeseungki-tang is one of the prescription that is used clinically for constipation of paralytics. The objective of the study was to observe the effect of daeseungki-tang on apoptotic neuronal cell death. In the present study, middle cerebral artery occlusion(MCAO) rats were treated with daeseungi-tang for 5 days and the edema percentage of cerebral hemisphere of MCAO rats were investigated primary. Secondary, appearances of Bax, Bcl-2,-factors that is related to apoptotic neuronal cell death - and HSP72 in the brain of MCAO rats were investigated via immunohistochemistry. Daeseungki-tang significantly decreased edema percentage of the cerebral hemisphere of MCAO rats. Daeseungki-tang significantly decreased Bax positive cells, but did not change the apperances of Bcl-2 positive cells in the penumbra of the cerebral cortex and the caudoputamen of MCAO rats. Daeseungki-tang significantly decreased HSP72 positive cells in the penumbra of the cerebral cortex, but not in the caudoputamen of MCAO rats. Based on the present results, it can be suggested that treatment with daeseungki-tang may decrease edema of the cerebral hemisphere and restrain apoptotic neuronal cell death in the penumbra of the cerebral cortex.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.391-396
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• 1995

Purpose : The Conformal Radiation Therapy has bee widely used under favour of development of computer technologies. The delivery of a large number of static radiation fields are being necessary for the conformal irradiation. In this paper we investigate dosimetric characteristics on penumbra regions of a multileaf collimator(MLC), and compare to those of lead alloy block for the optimal use of the system in 3-D conformal radiotherapy. Materials and Methods : The measurement of penumbra by MLC or lead alloy block was performed with 6 or 10 MV X-rays. The film was positioned at a dmax depth and 10 cm depth, and its optical density was determined using a scanning videodensitometer. The effective penumbra, the distance from $80{\%}$ to $20{\%}$ isodose lines and $90{\%}$ to $10{\%}$ were analyzed as a function of the angle between the direction of leaf motion and the edge defined by leaves. Results : Increasing MLC angle ($0-75^{\circ}$) was observed with increasing the penumbra widths and the scalloping effect. There was no definite differences of penumbra width from $80{\%}$ to $20{\%}$ isodose lines, while being the small increase of penumbra width from $90{\%}$ to $10{\%}$ isodose line varing the depth and energy. The effective penumbra width of lead alloy block are agree resonably with those of MLC within 4.8mm. Conclusion : The comparative qualitative study of the penumbra between MLC and lead alloy block demonstrate the clinical acceptability and suitability of the multileaf collimator for 3-D conformal radiotherapy.

• Progress in Medical Physics
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• v.13 no.4
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• pp.195-201
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• 2002

Several investigators have presented the effects of external magnetic fields on the dose distributions for clinical electron and photon beams. We focus the low energy electron beam with more lateral scatter In this study we calculated the beam profiles for an clinical electron beam of 6 MeV with longitudinal magnetic fields of 0.5 T-3.0 T using a Monte Carlo code. The principle of dose enhancements in the penumbra region is to deflect the laterally scattered electrons from its initial direction by the skewness of the laterally scattered electrons along the direction of magnetic field lines due to Lorentz force under longitudinal magnetic field. To discuss the dose enhancement effect on the penumbra area from the calculated results, we introduced the simple term of penumbra reduction ratio (PRR), which is defined as the percentage difference between the penumbra with and without magnetic field at the same depth. We found that the average PRR are 33%, and 49% over the depths of 1.5 cm, 2.0 cm, and 2.4 cm for the magnetic fields of 2.0 T and 3.0 T respectively. For the case of 0.5 T and 1.0 T the effects of magnetic filed were not observed significantly. In order to obtain the dose enhancement effects by the external magnetic field, we think that its strength should be more than 2 T approximately. We expect that the PRR would be saturated to 50-60% with magnetic fields of 3 T-5 T As a result of these calculations we found that the penumbra widths can be reduced with increased magnetic fields. This Penumbra reduction is explained as a result of electron lateral spread outside the geometrical edges of the beam in a longitudinal magnetic field. This means that the electron therapy benefits from the external magnetic fields.

• The Korea Journal of Herbology
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• v.29 no.5
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• pp.23-30
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• 2014

Objectives : Dodam-tang has been reported to have a control effect against the hyperlipidemia and thrombosis. Based upon these previous reports, this study investigates the effects of Dodam-tang on the cerebral ischemic damage of the hyperlipidemic rats. Methods : Hyperlipidemia was induced by the beef tallow 30% diet for 14 days on Sprague-Dawley rats. Ischemic damage was induced by the middle cerebral artery occlusion (MCAO) for 2 hours with the intraluminal thread method. Then water extract of Dodam-tang was administered daily for 5 days. The effect of Dodam-tang was evaluated with the serum lipids, infarct volume and edema percentage, and immunohistochemical expressions of iNOS, MMP-9, and GFAP in the brain tissue. Results : The obtained results were as follows; Dodam-tang reduced significantly the infarct size in a TTC-stained 5th brain section of the hyperlipidemic MCAO rats. Dodam-tang suppressed the infarct volume of the hyperlipidemic MCAO rats, but not significant statistically. Dodam-tang suppressed the edema percentage of the hyperlipidemic MCAO rats significantly in the brain tissue. Dodam-tang suppressed significantly the iNOS expression in the cerebral penumbra and caudate putamen of the hyperlipidemic MCAO rats. Dodam-tang suppressed significantly the MMP-9 expression in the cerebral penumbra of the hyperlipidemic MCAO rats. Dodam-tang suppressed significantly the GFAP-expressed atrocytes in the cerebral penumbra of the hyperlipidemic MCAO rats. Conclusions : These results suggest that Dodam-tang suppresses the brain edema formation through the suppression of the iNOS, MMP-9 and GFAP, but the neuroprotective effect against the cerebral infarct are not distinct.

• The Journal of Korean Medicine
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• v.27 no.2 s.66
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• pp.70-85
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• 2006

Objectives; This study examined the neuroprotective effect of Hyulbuchookautang (血府逐瘀湯, HBCAT)against neural damage following focal cerebral infarction. Methods : Sprague-Dawley Rats were induced with focal cerebral infarction by temporal middle cerebral artery occlusion (MCAO). The rats were divided into 2 groups. We treated extract of HBCAT to one group after operation (sample group), and the other group wasn't treated after operation (control group). We observed neurological scores and TIC-stained infarct area, total infarct volume in brain sections and Bax-positive neurons, HSP70- positive neurons in brain regions. Results : HBCAT treatment at 3 days after MCAO reduced neurological scores induced by MCAO. HBCAT treatment at 5 days after MCAO reduced TTC-stained infarct area in brain sections induced by MCAO. HBCAT treatment at 5 days after MCAO reduced total infarct volume in brain sections induced by MCAO. HBCAT treatment after MCAO reduced Bax-positive neurons in cortex infarct core and cortex infarct penumbra and caudo-putamen of brain regions induced by MCAO. HBCAT treatment after MCAO reduced HSP70- positive neurons in cortex infarct penumbra of brain regions induced by MCAO. Conclusions : These results suggest that HBCAT has a neuroprotective effect against focal cerebral ischemia.