• 대한기관윤리심의기구협의회지
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• 제1권1호
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• pp.5-21
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• 2019

Purpose: Institutional review board (IRB) classifies risks of clinical trials into less than minimal risk, minor increase over minimal risk, and more than minimal risk. Based on classification and evaluation for risk, IRB decides whether permitting consent exemption or asking additional protection for clinical research subject or not. The purpose of this study is to analyze how IRB members evaluate minimal risk by sending questionnaire survey with 12 predetermined scenarios. Methods: IRB members and researchers (pediatrician, gastroenterologist, neurologist, and neurosurgeon) in 11 different hospitals were asked to answer survey questions via email or online. We analyzed the differences of answers among several subgroups in each predetermined scenarios. Result: Responders were 212 personnel(110 researchers and 102 IRB members) from 11 centers. There were significant differences between IRB members and researchers in response such as blood sampling, skin prick test, one time catheterization in a girl, spinal tapping in child, non-enhance MRI in child, non-enhance MRI with chrolal hydrate in a child, spinal tapping without anesthesia in adult, bioequivalence test, gastric endoscopy, and non-enhance CT. significant differences between medical IRB members and non-medical members were also revealed in one time catheterization in a girl, spinal tapping in a child, non-enhance MRI in a child, bioequivalence test. Depending on researchers' department, they responded differently in several questionnaires as well. Conclusions: We have found that IRB members and researchers evaluate the risks differently. Researchers compared to IRB members, medical IRB members compared to non-medical members answered less than minimal risk in many cases. In assessing and evaluating the risks associated with the study, medical IRB members answered predetermined scenarios as less dangerous compared to non-medical IRB members. Difference among researchers where also revealed significantly. Researchers answered predetermined scenarios as less dangerous compare to other department researchers, especially in predetermined scenarios containing procedures they are familiar with.

• Journal of Ginseng Research
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• 제44권3호
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• pp.435-441
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• 2020

Background: As a process of aging, skeletal muscle mass and function gradually decrease. It is reported that ginsenoside Rb1 and Rb2 play a role as AMP-activated protein kinase activator, resulting in regulating glucose homeostasis, and Rb1 reduces oxidative stress in aged skeletal muscles through activating the phosphatidylinositol 3-kinase/Akt/Nrf2 pathway. We examined the effects of Rb1 and Rb2 on differentiation of the muscle stem cells and myotube formation. Methods: C2C12 myoblasts treated with Rb1 and/or Rb2 were differentiated and induced to myotube formation, followed by immunoblotting for myogenic marker proteins, such as myosin heavy chain, MyoD, and myogenin, or immunostaining for myosin heavy chain or immunoprecipitation analysis for heterodimerization of MyoD/E-proteins. Results: Rb1 and Rb2 enhanced myoblast differentiation through accelerating MyoD/E-protein heterodimerization and increased myotube hypertrophy, accompanied by activation of Akt/mammalian target of rapamycin signaling. In addition, Rb1 and Rb2 induced the MyoD-mediated transdifferentiation of the rhabdomyosarcoma cells into myoblasts. Furthermore, co-treatment with Rb1 and Rb2 had synergistically enhanced myoblast differentiation through Akt activation. Conclusion: Rb1 and Rb2 upregulate myotube growth and myogenic differentiation through activating Akt/mammalian target of rapamycin signaling and inducing myogenic conversion of fibroblasts. Thus, our first finding indicates that Rb1 and Rb2 have strong potential as a helpful remedy to prevent and treat muscle atrophy, such as age-related muscular dystrophy.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.10.1-10.8
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• 2016

Objectives Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H295R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. Methods Cortisol, aldosterone, testosterone, and $17{\beta}$-estradiol were evaluated in the H295R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/ 17/19/21) and the hydroxysteroid dehydrogenases ($3{\beta}$-HSD2 and $17{\beta}$-HSD1/4). Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. Results H295R cells exposed to EGb761 (10 and $100{\mu}g/mL$) showed a significant decrease in $17{\beta}$-estradiol and testosterone, but no change in aldosterone or cortisol. Genes (CYP19 and $17{\beta}$-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. EGb761 treatment of H295R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. The coding sequence/Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. Conclusions These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and $17{\beta}$-HSD1, and lead to a decrease in $17{\beta}$-estradiol and testosterone. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer.

• 대한방사선기술학회지:방사선기술과학
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• 제30권1호
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• pp.1-6
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• 2007

인위적으로 noise factor를 주고 그 위에 촬영을 하여 노이즈와 영상의 복합물을 만들었다. 그 후 Low Pass Filter(LPF)와 Median Filter(MF)의 두 종류의 필터를 통하여 노이즈를 제거하고 노이즈를 나타내는 지표로 Signal To Noise Ratio(SNR), Peak Signal to Noise Ratio(PSNR), Mean Square Error(MSE)를 비교하였다. 또한 Median Filter의 kernel size에 따라서도 노이즈제거효과를 평가하였다. 각각의 처리된 영상과 원 영상을 비교하여 원 영상에 가까운 영상을 찾아봄으로서 어떤 필터가 유용하며 어떤 주파수대를 제거해야 하는가를 알고자 실험하였다. Cutoff frequency가 다른 필터를 비교 했을 때 noise power 값에는 상관없이 cutoff frequency $2/3\pi{\sim}3/4\pi$까지가 원 영상에 가까우면서 SNR, PSNR이 좋다. 따라서 높은 filter 효과를 나타낸다고 할 수 있다. Median filter의 kernel size가 커짐에 따라서 SNR 값이 커지며 반대로 MSE의 값이 작아져 filter 효과는 좋아 짐을 알 수 있다. 의료 영상에 filter를 적용하는 것에 대해서 대부분의 영상들이 filter 적용 후에 왜곡된 상이 되곤 하였다. 의료 영상은 다른 영상과는 달리 공간 분해능을 유지하면서 평활화(노이즈 제거)하는 것이 중요한 문제이다. SNR 등 정량적 지표에 의한 비교와 함께 시각적 평가가 병행되어야 할 필요가 있다.

• Tuberculosis and Respiratory Diseases
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• 제75권3호
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• pp.95-103
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• 2013

Background: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. Methods: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. Results: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. Conclusion: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

• Journal of Dental Anesthesia and Pain Medicine
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• 제15권3호
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• pp.129-134
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• 2015

Background: We hypothesized that ketamine, when administered as the anesthetic induction agent, may prevent cardiovascular depression during high-dose remifentanil administration, unlike propofol. To test our hypothesis, we retrospectively compared the hemodynamic effects of ketamine, during high-dose remifentanil administration, with those of propofol. Methods: Thirty-eight patients who underwent oral surgery at the Nagasaki University Hospital between April 2014 and June 2015 were included in this study. Anesthesia was induced by the following procedure: First, high-dose remifentanil ($0.3-0.5{\mu}g/kg/min$) was administered 2-3 min before anesthesia induction;next, the anesthetic induction agent, either propofol (Group P) or ketamine (Group K), was administered. Mean arterial pressure (MAP) and the heart rate were recorded by the automated anesthesia recording system at four time points: immediately before the administration of high-dose remifentanil (T1);immediately before the administration of propofol or ketamine (T2);2.5 min (T3), and 5 min (T4) after the administration of the anesthetic induction agent. Results: In Group P, the MAP at T3 ($75.7{\pm}15.5mmHg$, P = 0.0015) and T4 ($68.3{\pm}12.5mmHg$, P < 0.001) were significantly lower than those at T1 ($94.0{\pm}12.4mmHg$). However, the MAP values in the K group were very similar (P = 0.133) at all time points. The heart rates in both Groups P (P = 0.254) and K (P = 0.859) remained unchanged over time. Conclusions: We showed that ketamine, when administered as the anesthetic induction agent during high-dose remifentanil administration, prevents cardiovascular depression.

• BMB Reports
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• 제45권9호
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• pp.509-514
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• 2012

We have found that the previously uncharacterized bone morphogenetic protein-9 (BMP9) is one of the most osteogenic factors. However, it is unclear if BMP9 cross-talks with $TGF{\beta}1$ during osteogenic differentiation. Using the recombinant BMP9 adenovirus, we find that low concentration of rh$TGF{\beta}1$ synergistically induces alkaline phosphatase activity in BMP9-transduced C3H10T1/2 cells and produces more pronounced matrix mineralization. However, higher concentrations of $TGF{\beta}1$ inhibit BMP9-induced osteogenic activity. Real-time PCR and Western blotting indicate that BMP9 in combination with low dose of $TGF{\beta}1$ potentiates the expression of later osteogenic markers osteopontin, osteocalcin and collagen type 1 (COL1a2), while higher concentrations of $TGF{\beta}1$ decrease the expression of osteopontin and osteocalcin but not COL1a2. Cell cycle analysis reveals that $TGF{\beta}1$ inhibits C3H10T1/2 proliferation in BMP9-induced osteogenesis and restricts the cells in $G_0/G_1$ phase. Our findings strongly suggest that $TGF{\beta}1$ may exert a biphasic effect on BMP9-induced osteogenic differentiation of mesenchymal stem cells.

• 한국의학물리학회지:의학물리
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• 제1권1호
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• pp.31-42
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• 1990

방사선치료에 가장 널리 사용하고 있는 Co-60 감마선과 6, 10 MV X-선등 다양한 에너지와 2 Gy 에서 10 Gy 의 조사선량 범위에 대한 정확한 선량측정은 방사선치료효과를 더욱 높힐수 있고 휴유증에 대한 선량평가에 도움을 줄 수 있다. 지금까지 방사선치료 범위에 속하는 방사선 계측은 주로 전리함을 사용하였으며 Build up cap 이나 팬텀을 이용하여 노출선량을 계측하고 계측된 값에 에너지에 따른 흡수선량 변환계수 , 측정기의 구성물질에 대한 저지능등 많은 변수를 고려해야하는 복잡성이 있으며 인체내의 선량분포측정이 어려웠다. 본실험에 사용한 Alanine 측정기는 아미노산의 일종인 유기물질로서 인체조직과 등가이고 부피가 작으므로 (0.5$\times$1cm) 조직내에 많이 삽입하여 방사선을 동시에 측정할 수 있었다. 방사선에 노출된 Alanine 은 구성분자의 일부분이 전리되어 장기간 Free radical 상태로 존재하며 마이크로파를 투과시키면 전자의 고유진동수와 일치된 전파를 흡수하는 전자스핀공명(Electron spin resonance) 이 일어나고 흡수된 전파의 강도를 측정함으로서 흡수선량을 추측할 수 있다. 방사선흡수선량 측정은 Co-60 원격치료장치의 선원에서 80cm 거리에 3개의 Alanine 측정기를 Build up holder 에 넣어 고정시키고 방사선치료 선량범위인 0.1Gy 에서 100 Gy 까지 조사하였으며 이때 ESR Spectra 의 진폭은 흡수선량에 비례하였고 선량 균일성의 표준편차는 2 Gy 에서 1% 이었으며 4 Gy 이상에서는 0.5% 이었다. 조직내 선량분포를 측정하기 위하여 인체구성과 같은 Rando phantom 내에 Alanine 측정기를 삽입하고 조사면과 에너지에 따른 방사선 흡수선량분포및 섬부율을 측정한 결과 표준 심부율과 일치하였다. 특히 Alanine 측정기는 온도 습도에 대한 변화가 적고 시간 경과에 대한 변화도 거의 없었으며 (년간 약 1% 감소 ) 에너지에 따른 변화도 없었기 때문에 치료방사선 영역의 선량 측정과 조직내 선량분포에 적당한 것으로 생각된다.

• 한국의학물리학회지:의학물리
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• 제20권4호
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• pp.225-234
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• 2009

Geant4 toolkit은 전자기적 상호작용(electromagnetic interactions)에 대한 다양한 물리적 모델을 제공한다. 이러한 물리적 모델들에 대한 검증은 신뢰성 있는 Geant4 응용을 위해서 중요한 역할을 한다. 그러므로, 본 연구의 목적은 양성자 치료 전산모사를 위해 Geant4가 제공하는 물리적 모델 중 전자기 물리 모델의 정확성을 검증하는 것이다. 검증은 물, 뼈, 지방 그리고 원자번호가 다른 물질에 대해 양성자의 CSDA 비정(continuous slowing down approximation range)과 저지능(stopping power) 데이터를 미국 국립기술표준원(National Institute of Standards and Technology, NIST)의 데이터를 각각 비교하는 방법으로 이루어졌다. 물, 뼈 그리고 지방에 대해 0.01 MeV에서 10 GeV 범위의 입사 에너지의 CSDA 비정과 저지능 전산모사 결과와 NIST값을 비교한 결과, CSDA 비정의 평균 차는 각각 1.0%, 1.4% 그리고 1.4%를 나타내었고, 저지능에 대한 평균 차는 각각 0.7%, 1.0% 그리고 1.3%를 나타내었다. 또한, 각 물질에 대한 NIST 값과의 유의성을 분석하기 위해 kolmogorov-smirnov Goodness-of-Fit 통계분석 방법을 이용한 결과, 전자기 물리 모델의 전산모사 결과 데이터와 NIST 데이터 사이의 유의성을 나타내는 p-value가 유의 수준 0.05 이상 값을 가진다는 것을 확인 하였으며, 이를 통해 Geant4 전자기 물리 모델의 정확성을 검증할 수 있었다.

• Journal of Hospice and Palliative Care
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• 제23권3호
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• pp.103-113
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• 2020

A clinical practice guideline for patients in the dying process in general wards and their families, developed through an evidence-based process, is presented herein. The purpose of this guideline is to enable a peaceful death based on an understanding of suitable management of patients' physical and mental symptoms, psychological support, appropriate decision-making, family care, and clearly-defined team roles. Although there are limits to the available evidence regarding medical issues in patients facing death, the final recommendations were determined from expert advice and feedback, considering values and preferences related to medical treatment, benefits and harms, and applicability in the real world. This guideline should be applied in a way that takes into account specific health care environments, including the resources of medical staff and differences in the available resources of each institution. This guideline can be used by all medical institutions in South Korea.