• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1545-1556
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• 2020

Recently, the International Commission on Radiological Protection (ICRP) has developed the Mesh-type Reference Computational Phantoms (MRCPs) for adult male and female to overcome the limitations of the current Voxel-type Reference Computational Phantoms (VRCPs) described in ICRP Publication 110 due to the limited voxel resolutions and the nature of voxel geometry. In our previous study, the MRCPs were used to calculate the dose coefficients (DCs) for idealized external exposures of photons and electrons. The present study is an extension of the previous study to include three additional particles (i.e., neutrons, protons, and helium ions) into the DC library by conducting Monte Carlo radiation transport simulations with the Geant4 code. The calculated MRCP DCs were compared with the reference DCs of ICRP Publication 116 which are based on the VRCPs, to appreciate the impact of the new reference phantoms on the DC values. We found that the MRCP DCs of organ/tissue doses and effective doses were generally similar to the ICRP-116 DCs for neutrons, whereas there were significant DC differences up to several orders of magnitude for protons and helium ions due mainly to the improved representation of the detailed anatomical structures in the MRCPs over the VRCPs.

• 대한의용생체공학회:의공학회지
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• 제34권2호
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• pp.55-62
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• 2013

Wrist joints consist of irregularly shaped carpal bones and other complicated structures. Thus, evaluating the motion of a wrist joint is a challenging task. In this study, we used an infrared camera to perform a kinematic analysis of a dart-throwing motion. We measured the difference between the movement of a normal wrist and constrained wrist (wrist with a wrist glove) in the dart-throwing motion with thirty six healthy participants. We measured the ulna flexion - radial extension motion using the attached passive marker and analyzed it using Polygon software and SPSS. The pitch and yaw motions with a glove was bigger than the ones without a glove by 20 and 15 degrees, respectively. On the other hand, the roll motion without a glove was bigger than the one with a glove by 7 degree. Wilcoxon signed rank test (p<0.05) confirmed that there are significant differences between the motion with and without a glove. It was found that the magnitude of the pitch and yaw motion with a constrained wrist joint toward radial extension in dart-throwing motion is smaller than the one with a normal wrist joint. However, a normal wrist joint showed a bigger movement in the roll direction.

• 전기학회논문지
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• 제63권12호
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• pp.1671-1674
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• 2014

This paper presents a frequency-dependent cell impedance analysis chip for use in cancer and normal cell discrimination. The previous cell impedance analysis chips for flowing cells cannot allow enough time for cell-to-electrode contact to monitor frequency-dependent impedance response. Another type of the previous cell impedance analysis chips for the cells clamped by membranes need complex sample control for making stable cell-to-electrode contact. We present a new impedance analysis chip using the microchamber array, on which a PDMS cover is placed to make stable cell-to-electrode contact for the individual cell trapped in each microchamber; thus achieving frequency-dependent single-cell impedance analysis without complex sample control. Compared to the normal cells, the magnitude of NHBE cells is $60.07{\sim}97.41k{\Omega}$ higher than A549 cells in the frequency range of 95.6 kHz~2MHz and the phase of NHBE is $3.96^{\circ}{\sim}20.8^{\circ}$ higher than A549 cells in the frequency range of 4.37 kHz~2MHz, respectively. It is demonstrated experimentally that the impedance analysis chip performs frequency-dependent cell impedance analysis by making stable cell-to-electrode contact with simple sample control; thereby applicable to the normal cell and cancer cell discrimination.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1373-1377
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• 2016

Background: We vigorously reviewed patients' operation record who had adhesion of the Denonvilliers' fascia and found out most of these patients had prostatic bleeding after prostatic gland biopsies. We examined the magnitude of prostatic bleeding and frequency after biopsies and the relationship with oncological outcomes. Materials and Methods: A total of 285 patients were selected for the final analyses. Inclusion criteria were as follows: receiving MRI three weeks after biopsiesand laparoscopic radical prostatectomy within 300 days after biopsy. We divided the patients into two groups with (group A) or without (group B) prostatic bleeding. We examined the magnitude of prostatic bleeding after biopsies and the relationship with operation time (OT), positive surgical margin (PSM), biochemical recurrence (BCR) and other factors. Furthermore, we created a logistic-regression model to derive a propensity score for prostatic bleeding after biopsies, which included all patient and hospital characteristics as well as selected interaction terms, and we examined the relationship with PSM and BCR. Results: In all patients, the OT in the group B was shorter than the group A (p < 0.001). Prostatic bleeding was associated with PSM (p=0.000) and BCR (p=0.036). In this propensity-matched cohort, 11 of 116 patients in the group B had PSM as compared with 36 of 116 patients from group A (match-adjusted odds ratio, 4.30; 95%CI confidence interval, 2.06 to 8.96; P=0.000). In addition, eight of 116 patients in group B encountered BCR, as compared with 18 of 116 patients in group A (match-adjusted odds ratio, 2.48; 95%CI, 1.03 to 5.96; P=0.042). Kaplan-Meier analysis in the propensity matching cohort showed a significant biochemical recurrence-free survival advantage for being free of prostate bleeding after biopsies. Conclusions: Our findings in the present cohort should help equip surgeons to pay attention to careful excision especially for those who experienced deferred prostatic bleeding.

• BMB Reports
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• 제44권4호
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• pp.217-231
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• 2011

T cell exhaustion develops under conditions of antigen-persistence caused by infection with various chronic pathogens, such as human immunodeficiency virus (HIV) and myco-bacterium tuberculosis (TB), or by the development of cancer. T cell exhaustion is characterized by stepwise and progressive loss of T cell function, which is probably the main reason for the failed immunological control of chronic pathogens and cancers. Recent observations have detailed some of the intrinsic and extrinsic factors that influence the severity of T cell exhaustion. Duration and magnitude of antigenic activation of T cells might be associated with up-regulation of inhibitory receptors, which is a major intrinsic factor of T cell exhaustion. Extrinsic factors might include the production of suppressive cytokines, T cell priming by either non-professional antigenpresenting cells (APCs) or tolerogenic dendritic cells (DCs), and alteration of regulatory T (Treg) cells. Further investigation of the cellular and molecular processes behind the development of T cell exhaustion can reveal therapeutic targets and strategies for the treatment of chronic infections and cancers. Here, we report the properties and the mechanisms of T cell exhaustion in a chronic environment.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5599-5605
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• 2015

In oncology various imaging modalities play a crucial role in diagnosis, staging, restaging, treatment monitoring and follow up of various cancers. Stand-alone morphological imaging like computerized tomography (CT) and magnetic resonance imaging (MRI) provide a high magnitude of anatomical details about the tumor but are relatively dumb about tumor physiology. Stand-alone functional imaging like positron emission tomography (PET) and single photon emission tomography (SPECT) are rich in functional information but provide little insight into tumor morphology. Introduction of first hybrid modality PET/CT is the one of the most successful stories of current century which has revolutionized patient care in oncology due to its high diagnostic accuracy. Spurred on by this success, more hybrid imaging modalities like SPECT/CT and PET/MR were introduced. It is the time to explore the potential applications of the existing hybrid modalities, developing and implementing standardized imaging protocols and train users in nuclear medicine and radiology. In this review we discuss three existing hybrid modalities with emphasis on their technical aspects and clinical applications in oncology.

• Journal of Preventive Medicine and Public Health
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• 제38권3호
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• pp.267-275
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• 2005

Evidence on the relation of socioeconomic position (SEP) with health and illness is mounting in South Korea. Several unlinked studies and individually linked studies (longitudinal study) showed a graded inverse relationship between SEP and mortality among South Korean males and females. Based on the mortality relative ratios by occupational class reported in the published papers of South Korea and western countries, the magnitude of the socioeconomic inequality in mortality in South Korea seems to be similar to or even greater than that in western industrialized countries. A potential contribution of health related selection, health behaviors and psychosocial factors to explain this socioeconomic inequality in mortality was discussed. It was suggested that early life exposure measures would demonstrate a greater ability to explain socioeconomic inequalities in all-cause mortality than the above pathway variables in South Korea. This is based on the cause-specific structure of mortality among the South Korean population who have a relatively greater proportion of stomach cancer, hemorrhagic stroke, liver cancer and liver disease, and tuberculosis, which share early life exposures as important elements of their etiology, than western countries. However, the relative contribution of early and later life socioeconomic conditions in producing socioeconomic inequality in health may differ according to the outcome, thus remains to be investigated.

• 한국대기환경학회지
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• 제8권2호
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• pp.100-104
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• 1992

본 연구는 비교 위험도 평가 기법을 사용하여, 도시 고형 폐기물의 소각에 따른 대기 오염 중 발암성 금속이 호흡기를 통해 소각로 주변 주민에게 미치는 암 위험도를 다옥신과 비교해 평가하였다. 어떤 물질이 인체에 암을 유발할 가능성이 있는 경우, 이 발암성은 물질의 화학적 형태 및 피폭경로에 관련될 지도 모른다. 물질의 발암성에 대한 이러한 사실이 조사되었고 위험도 정량화에 고려되었다. 본 연구 결과, 도시 고형 폐기물의 소각시 방출되는 발암성 금속으로 인한 위험도는 디옥신으로 인한 위험도의 약 5배 정도로 평가되었고, 위험도의 측면에서 가장 중요한 금속은 6가 크롬과 카드뮴인 것으로 판명되었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권2호
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• pp.124-136
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• 2001

Heat shock protein (HSP) expression is unregulated in tumor cells and, HSP expression is likely marker of the malignant potential of oral epithelial lesion. Furthermore, the 70kDa HSP is implicated in the degree of tumor differentiation, the rate of tumor proliferation and the magnitude of the anti-tumor Immune response. Accordingly, the distribution and intensity of HSP70 and HSP47 expression was assessed in the DMBA induced oral carcinogenesis in hamster. Golden Syrian hamsters which were 3 months-age and $90{\sim}120g$ were collected. 9,10-dimethyl -1,2-benzanthracene (DMBA) in a 0.5% solution in mineral oil was painted on the buccal pouch mucosa 3 times per week in the study group. In each control and experimental groups of 6, 8, 10, 12, 14, 16, 18, 20 weeks, specimen were sectioned for immunohistochemical study with anti-HSP47 and anti-HSP70 antibody. The following results were obtained. 1. HSP47 positive cells were race or negative of normal oral mucosa, increased mildly in basal and suprabasal basal layer, and spinous cell layer after experimental 6 weeks (dysplastic or CIS stage). In CIS stage, HSP47 expression is prominent in dysplastic free or normal adjacent epithelium. 2. HSP47 positive cells in connective tissue were mainly inflammatory cells, which is gradually increased from control to precancerous and cancer stage. But HSP47 positive cells after 14 weeks were decreased, especially normal and cancer adjacent epithelium. 3. The positive staining cells of HSP70 in control, dysplastic, and CIS stage were not seen. But they were mild findings in basal layer and moderate findings in spinous layer after experimental 14 weeks (cancer stage). 4. HSP70 positive cells were increased in precancerous and cancer stage than control group in connective tissue. After experimental 16 weeks, we could not find the HSP expression in cancer cells according to cancer differentiation or cancer stage. It is concluded that HSP70 or HSP47 expression is not a definitive marker of oral malignancy or malignant potential. However, with further development, HSP immunoreactivity may be valuable as an adjunct to conventional histology for assessing the malignant potential of oral mucosal lesions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권4호
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• pp.362-372
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• 1998

Heat shock protein (HSP) expression is unregulated in tumor cells and, HSP expression is likely marker of the malignant potential of oral epithelial lesion. Furthermore, the 70kDa HSP is implicated in the degree of tumor differentiation, the rate of tumor proliferation and the magnitude of the anti-tumor immune response. Accordingly, the distribution and intensity of HSP 70 and HSP 47 expression was assessed in the DMBA induced oral carcinogenesis in hamster. Golden Syrian hamsters which were 3 months-age and 90-120g were collected. 9,10-dimethyl-1,2-benzanthracene (DMBA) in a 0.5% solution in mineral oil was painted on the buccal pouch mucosa 3 times per week in the study group. In each control and experimental groups of 6, 8, 10, 12, 14, 16, 18, 20 weeks, specimen were sectioned for immunohistochemical study with anti-HSP47 and anti-HSP70 antibody. The following results were obtained. 1. HSP47 positive cells were rare or negative of normal oral mucosa, increased mildly in basal and suprabasal basal layer, and spinous cell layer after experimental 6 weeks (dysplastic or CIS stage). In CIS stage, HSP47 expression is prominent in dysplastic free or normal adjacent epithelium. 2. HSP 47 positive cells in connective tissue were mainly inflammatory cells, which is gradually increased from control to precancerous and cancer stage. But HSP47 positive cells after 14 weeks were decreased, especially normal and cancer adjacent epithelium. 3. The positive staining cells of HSP70 in control, dysplastic, and CIS stage were not seen. But they were mild findings in basal layer and moderate findings in spinous layer after experimental 14 weeks (cancer stage). 4. HSP70 positive cells were increased in precancerous and cancer stage than control group in connective tissue. After experimental 16 weeks, we could not find the HSP expression in cancer cells according to cancer differentiation or cancer stage. It is concluded that HSP70 or HSP47 expression is not a definitive marker of oral malignancy or malignant potential. However, with further development, HSP immunoreactivity may be valuable as an adjunct to conventional histology for assessing the malignant potential of oral mucosal lesions.