• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1059-1064
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• 2014

Staphylococcus aureus is a major human pathogen, implicated in both community and hospital acquired infections. The therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections is becoming more difficult because of multidrug resistance and strong biofilm-forming properties. Schiff bases have attracted attention as promising antibacterial agents. In this study, we investigated the in vitro activity of taurine-5-bromosalicylaldehyde Schiff base (TBSSB) against MRSA. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) were determined using a microtiter broth dilution method. TBSSB effectively inhibited planktonic MRSA, with an MIC of $32{\mu}g/ml$. The time-kill curve confirmed that TBSSB exhibited bactericidal activity against MRSA. TBSSB was also found to significantly inhibit MRSA biofilm formation at 24 h, especially at $1{\times}MIC$ and sub-MIC levels. Furthermore, scanning electron microscopy and transmission electron microscopy showed remarkable morphological and ultrastructural changes on the MRSA cell surface, due to exposure to TBSSB. This study indicated that TBSSB may be an effective bactericidal agent against MRSA.

• 한국콘텐츠학회논문지
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• 제10권6호
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• pp.360-363
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• 2010

본 연구는 방사선치료 시 환자 체위고정과 정확한 부위를 표시하기 위해 사용되는 Themo-plastic, Vac-lock, Cotton, Plaster의 보조기구가 전자선 에너지의 변화에 따라 환자의 피부선량이 얼마나 달라지는지 알아보고자 한다. 실험방법으로는 선형가속기를 이용하여 전자선 6Mev, 9Mev, 12Mev, 15Mev의 에너지로 평행 평판형 전리함을 설치하고 선원에서 표면까지의 거리는 100cm, 조사야의 크기 $10cm{\times}10cm$, 입사각도 $0^{\circ}$로 위치시킨 상태에서 보조기구 종류에 따른 표면선량을 측정하였다. 매회 선량은 100MU를 조사하였고 측정값은 오차를 줄이기 위하여 3회 반복 측정하였다. 결과로서는 Vac-lock이 표면선량이 가장 높게 나타났으며, 그 다음 순으로 Themo-plastic, Plaster, Cotton으로 나타났다.

• Clinical and Experimental Reproductive Medicine
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• 제18권2호
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• pp.189-196
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• 1991

Long-term administration of luteinizing hormone-releasing hormone(LHRH) agonists, through a process of pituitary desensitization and down-regulation of receptors, inhibits the secretion of gonadotropin and sex-steroids and induces a reversible suppression of gonadal activity. This approach can be used as an effective endocrine therapy for some hormone-dependent tumors. We have used D-Trp6-LHRH, a long acting LHRH agonist, for the treatment of eleven patients with uterine leiomyomas, thereafter myomectomy was performed in seven cases and observed the ultrastructural changes of leiomyoma with an electron microscope. The use of LHRH agonist may be effective in reducing the size of a myoma considerably by primarily inducing medical hypophysectomy and would allow easier surgical removal. Electron microscopic findings of myoma cells after the use of LHRH agonist included the following: loss of cristae and swelling nuclear chromatin, perinuclear vacuolation in cytoplasm. Bone mineral density was slightly decreased, however, the difference was not statistically significant.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.94-96
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• 2002

In order to achieve the radiotherapy more precisely using highly energetic heavy charged particles, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. We can directly obtain the 2-D distribution of the electron density in a sample from a heavy ion CT image. For this purpose, we have developed a heavy ion CT system using a broad beam. The performance, especially the position resolution, of this system is estimated in this work. All experiments were carried out using the heavy ion beam from the HIMAC. We have obtained the projection data of polyethylene samples with various sizes using He 150 MeV/u, C 290 MeV/u and Ne 400 MeV/u beams. The used targets are the cylinders of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. The dependence of the spatial resolution on the target size and the kinds of beams will be discussed.

• 대한방사선치료학회지
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• 제18권2호
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• pp.105-112
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• 2006

목 적: 전자선 조사야 내에서 조직결손이 큰 경우 일어나는 선량의 불균일도를 물 볼루스를 사용하여 감소시키고자 하였으며 이 때 물을 쉽게 제어할 수 있는 방법을 강구하였다. 대상 및 방법: 조직결손이 심하여 일반적인 볼루스를 사용할 수 없는 환자에 대하여 치료계획 장치(Pinnacle, Philips, USA)의 결손조직 보상 기능을 사용하여 이를 보상하는 치료계획을 수립하였다. 결손 된 조직 부분에 해당하는 조직 보상체는 물을 사용하기로 하였고, Mev-green을 환자 몸 위에서 만들어 물을 보다 쉽게 제어할 수 있는 증기를 제작하였다. 제작된 장치는 환자 개개인의의 체표 모양에 맞게 제작하였다. 물을 채운 비닐을 Mev-green 안쪽에 넣어 물이 결손 된 조직을 보상해주는 역할을 하도록 하였다. 자체 제작한 물 볼루스의 효과를 평가하기 위해 CT스캔을 시행한 후 결손조직 보상 기능을 이용하여물 볼루스 사용전후의 치료계획을 수립하여 그 결과를 비교하였다. 결 과: 흉벽 조직결손으로 인해 생긴 선량의 불균일도는 자체 제작한 물 볼루스 사용 시 감소하였고, 또한 폐와 간의 정상조직의 선량 역시 감소하였다. 볼루스를 사용하지 않은 경우 최대 표적선량이 132%였으나 물 볼루스 사용 시는 최대 표적선량이 110.4%로 21.6%가 감소하였다. 그리고 우측 폐에 들어가는 선량이 볼루스를 사용하지 않은 경우 19.49%에서 물 볼루스를 사용한 경우 1.02%로 줄었고 간에서는 볼루스를 사용하지 않은 경우 17.1%에서 물 볼루스 사용으로 인해 6.8%로 감소하여 정상조직을 보호할 수 있었다. 결 론: 자체 제작한 물 볼루스 장치를 사용한 결과 PTV내에서 선량의 균일도가 향상됨을 확인할 수 있었고, 인접장기 선량의 현저한 감소로 정상조직을 더 많이 보호할 수 있었다. 이 방법은 불균등한 체표에서의 전자선 치료 시 발생할 수 있는 정상조직의 부작용을 줄일 수 있을 것으로 예상된다.

• 대한방사선치료학회지
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• 제5권1호
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• pp.115-119
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• 1992

The beam characteristics and dosimetric measurements of the 6MV X-ray and 6MeV electron beam from a ML-6M linear accelerator are examined. The Percent Depth Dose(PDD) table and the tissue Maximum Ratio(TMR) table are taken from measurement as a function of the field size and the depth. The calculated TMR table from PDD table is compared with those from measurement. Other beam characteristics such as output factor, beam profile(including flatness, symmetry and penumbra), wedge, and the variation of Dmax are presented. All of these dosimetric measurements sufficiently characterized the beam to permit safe clinical use.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1992년도 춘계학술대회
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• pp.148-151
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• 1992

There is a definite requirement to continuously monitor the operating characteristics of radiation therapy machines. It is advisable to monitor the symmetry, flatness, and energy stability of x-ray beams. The semiconductor system was developed using commercially available rectifier diode for th assessment of quality assurance In radiation therapy, which is capable of the above measurements. The beam characteristics of 6MV, 10MV and 21MV photon of Microtron electron accelerator were measured using seven-diodes as detectors and the results were compared with that of using a film results dosimetry with a X-Y plotter. The seven-diode detetor is versatile enough to be used for checking beam profile, flatness, symmetry and energy.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.135-138
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• 2012

Objective: To investigate whether apoptin is a apoptosis-inducing protein with a potential for bladder cancer therapy. Methods: We constructed a PCDNA3/Apoptin eukaryotic expression vector, and transfected this vector into bladder cancer cell lines BIU-87 and EJ, then observed the results by RT-PCR, transmission electron microscopy, MTT assay and the flow cytometry (TUNEL method). Results: PCDNA3/Apoptin successfully induced a high level apoptosis in both bladder cancer cell lines, compared with the controls (p<0.05). Conclusions: Apoptin can induce high level apoptosis in human bladder cancer EJ and BIU-87 cells, which suggests a potential for human bladder cancer therapy.

• IEIE Transactions on Smart Processing and Computing
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• 제4권5호
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• pp.297-304
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• 2015

A multilayer gaseous detector has been developed for fast dose-verification measurements of raster-scan-mode therapeutic beams in particle therapy. The detector, which was constructed with eight thin parallel-plate ionization chambers (PPICs) and polymethyl methacrylate (PMMA) absorber plates, is closely tissue-equivalent in a beam's eye view. The gas-electron signals, collected on the strips and pad arrays of each PPIC, were amplified and processed with a continuous charge.integration mode. The detector was tested with 190-MeV raster-scan-mode beams that were provided by the Proton Therapy Facility at Samsung Medical Center, Seoul, South Korea. The detector responses of the PPICs for a 190-MeV raster-scan-mode proton beam agreed well with the dose data, measured using a 2D ionization chamber array (Octavius model, PTW). Furthermore, in this study it was confirmed that the detector simultaneously tracked the doses induced at the PPICs by the fast-oscillating beam, with a scanning speed of 2 m s-1. Thus, it is anticipated that the present detector, composed of thin PPICs and operating in charge.integration mode, will allow medical scientists to perform reliable fast dose-verification measurements for typical dynamic mode therapeutic beams.

• Parasites, Hosts and Diseases
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• 제56권2호
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• pp.105-112
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• 2018

Blastocystis is an enteric Straminopile in tropical, subtropical and developing countries. Metronidazole has been a chemotheraputic for blastocystosis. Failures in its regimens were reported and necessitate new studies searching for alternative therapeutic agents. Aim of current study is to investigate potential effects of Atorvastatin (AVA) compared to the conventional chemotherapeutic MTZ in experimentally Blastocystis-infected mice. Anti-Blastocystis efficacy of AVA was evaluated parasitologically, histopathologically and by transmission electron microscopy using MTZ (10 mg/kg) as a control. Therapeutic efficacy of AVA were apparently dose-dependent. Regimens of AVA (20 and 40 mg/kg) proved effective against Blastocystis infections with highreduction in Blastocystis shedding (93.4-97.9%) compared to MTZ (79.3%). The highest reductions (98.1% and 99.4%)were recorded in groups of combination treatments AVA 20-40 mg/kg and MTZ 10 mg/kg. Blastocystis was nearly eradicated by the 20th day post infection. Genotype analysis revealed that genotype I was most susceptible, genotype III was less. Histopathologic and ultrastructural studies revealed apoptotic changes in Blastocystis and significant improvement of intestinal histopathological changes more remarkable in combinational therapy groups. Thus, the present study offers AVA as a potential candidate for Blastocystis therapy combined with MTZ.