• Toxicological Research
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• 제25권4호
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• pp.189-193
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• 2009

Hypoxia inducible factor $1\alpha$ (HIF-$1\alpha$) is a potential marker of carcicnogenesis since it is overexpresssed in many human cancers such as brain, breast, and uterus, and its role has implicated in tumor cell growth and metastasis. In this study, we established a stable cell line that express green fluorescence protein (GFP)-fused hypoxia inducible factor $1\alpha$ (HIF-$1\alpha$) and evaluated the potential use of this cell line for assessment of carcinogenicity of chemical toxicants. Western blot analysis as well as fluorescence measurements showed that protein-level of GFP-HIF-$1\alpha$ was significantly enhanced in a dose-dependent manner upon treatment of hypoxia mimicking agents such as dexferrioxamine and $CoCl_2$. Well-Known tumor promoters such as mitomycin and methyl methanesulfonate. significantly induced the fluorescence intensity of GFP-HIF-$1\alpha$, whereas the known negative controls such as o-anthranilic acid and benzethonium chloride, did not. These results indicate that HIF-$1\alpha$ could be a biological parameter for detection of tumor initiators/promoters and suggest that the GFP-HIF-$1\alpha$ cell line is a useful system for screening of carcinogenic toxicants.

• Journal of Chest Surgery
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• 제41권5호
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• pp.651-654
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• 2008

외상에 의해 발생하는 쇄골하동맥의 가성동맥류는 매우 드물다. 10년전 교통사고를 당한 49세 여자환자는 외부병원에서 직장검진시 우연히 발견한 종격동 종양을 진단받고 본원에서 진단 및 치료 목적으로 개흉술을 시행 받았다. 개흉술하에 종괴의 일부분을 박리하던 중 대량 출혈 소견 보여 출혈 부위를 봉합한 후 혈관촬영을 추가로 시행하였다. 좌측 쇄골하동맥 가성동맥류 진단하에 재수술을 시행하여 동맥류를 절제하고 단단문합하였다. 환자는 술 후 특별한 문제없이 술 후 11일째 퇴원하였다.

• 대한세포병리학회지
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• 제15권2호
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• pp.81-85
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• 2004

Postmenopausal squamous atypia (PSA) is a phenomenon characterized by cellular alterations mimicking condyloma in the uterine cervix of postmenopausal women. It is not associated with human papillomavirus (HPV) infection. The aim of this study is to correlate findings with HPV infection and the cytohistologic findings of PSA. Eighty-three smears from postmenopausal women, initially interpreted as ASCUS and low-grade squamous intraepithelial lesions(LSIL), were reviewed according to the criteria of PSA. Fifty-eight cases were subsequently reclassified as PSA. Forty cases categorized as PSA were available for HPV-DNA detection by a nested polymerase chain reaction. Eight of these 40 cases(20%) showed biopsy-proven LSIL lesions. The HPV-DNA was detected in 42.5%(17/40), compared to 25%(5/20) of control cases. The HPV-DNA detection rate of biopsy-proven LSIL was 62.5%(5/8). It has been concluded that cytologic differential diagnosis of PSA from LSIL is difficult due to because of poor histologic and viral correlation.

• 대한의용생체공학회:의공학회지
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• 제29권2호
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• pp.99-106
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• 2008

To improve $B_1$ homogeneity in high field MRI, the RF power is applied to the transmit array coil elements sequentially in the time-multiplexed way. Since only a single coil element is activated in a time-multiplexing slot, the global standing wave formation in the human body is greatly suppressed. The time-multiplexing slot width is on the order of micro seconds, hence, high-order-harmonic slices can be placed far from the transmit coil and simultaneous multiple slice selection can be avoided. The $B_1$ homogeneities of a birdcage coil and an eight-channel transmit array coil have been compared through finite difference time domain simulations. The simulation results indicate that the proposed technique can reduce the peak-to-peak $B_1$ inhomogeneity down to one fourth of the transmission with a birdcage coil on the central plane of the human head model at 3 T. The mimicking experiments at 3 T, eight separate experiments with a single coil element activated and image reconstruction by combining the eight images, also show promising results. It is expected that the proposed technique has some advantages over other $B_1$ improving methods in real practice since simple RF switching circuitries are only necessary and electromagnetic coupling between the coil elements is out of concern in its realization.

• Clinics in Shoulder and Elbow
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• 제14권2호
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• pp.242-247
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• 2011

목적: 골내 침범이 동반된 비전형적인 견관절 석회화 건염 1예를 보고하고자 한다. 대상 및 방법: 만성적인 좌측 견관절 동통의 급성 악화와 운동 제한을 주소로 내원한 59세 여자 환자로 단순 방사선 상 견봉하 석회 침착과 자기 공명 영상 상 감염이나 종양과 유사하게 골 피질을 침범하고 석회 물질이 골 내부로 연장되어 있었다. 관절경하 석회 제거술과 골내 석회의 소파술, 건 결손부에 봉합 나사못을 이용한 회전근 개 봉합술을 시행하였다. 결과: 환자의 급성 견관절 통증은 술 후 즉각적인 호전을 보였고 순조로운 재활 경과와 관절 운동범위의 회복을 보였다. 술 후 5개월에 촬영한 단순 방사선 상 석회 침착의 재발은 관찰되지 않았다. 결론: 견관절 석회화 건염은 주위 골조직으로 연장된 다양한 영상 소견을 나타 낼 수 있으며, 질환을 정확히 판별함으로써 불필요한 검사나 치료를 피할 수 있을 것으로 생각된다.

• Clinical and Experimental Pediatrics
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• 제58권2호
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• pp.69-72
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• 2015

Insulinoma, which arises from insulin-producing pancreatic beta cells, is a rare tumor in children. Only 5%-10% of insulinomas are malignant and undergo metastasis. We report a case of an 11-year-old girl who experienced hypoglycemia-related seizures induced by an insulinoma; after resection of the primary tumor, she developed hepatic focal nodular hyperplasia (FNH). Laboratory test results indicated marked hypoglycemia with hyperinsulinemia. Abdominal ultrasonography (US) and computed tomography results were normal; however, magnetic resonance imaging (MRI) showed a solid mass in the pancreatic tail. Therefore, laparoscopic distal pancreatectomy was performed. Two months after the surgery, an abdominal MRI revealed multiple nodular lesions in the liver. An US-guided liver biopsy was then performed, and histological examination revealed FNH without necrosis or mitotic activity. The patient has been free of hypoglycemia for 2 years, and recent MRI studies showed a decrease in the size of FNH lesions, without any evidence of metastasis. Even though no metastatic lesions are noted on imaging, close observation and follow-up imaging studies are required in a child with insulinoma that has malignant potential on histopathologic findings.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1413-1425
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• 2018

Shiga toxins (Stxs) are the main virulence factors expressed by the pathogenic Stx-producing bacteria, namely, Shigella dysenteriae serotype 1 and certain Escherichia coli strains. These bacteria cause widespread outbreaks of bloody diarrhea (hemorrhagic colitis) that in severe cases can progress to life-threatening systemic complications, including hemolytic uremic syndrome (HUS) characterized by the acute onset of microangiopathic hemolytic anemia and kidney dysfunction. Shiga toxicosis has a distinct pathogenesis and animal models of Stx-associated HUS have allowed us to investigate this. Since these models will also be useful for developing effective countermeasures to Stx-associated HUS, it is important to have clinically relevant animal models of this disease. Multiple studies over the last few decades have shown that mice injected with purified Stxs develop some of the pathophysiological features seen in HUS patients infected with the Stx-producing bacteria. These features are also efficiently recapitulated in a non-human primate model (baboons). In addition, rats, calves, chicks, piglets, and rabbits have been used as models to study symptoms of HUS that are characteristic of each animal. These models have been very useful for testing hypotheses about how Stx induces HUS and its neurological sequelae. In this review, we describe in detail the current knowledge about the most well-studied in vivo models of Stx-induced HUS; namely, those in mice, piglets, non-human primates, and rabbits. The aim of this review is to show how each human clinical outcome-mimicking animal model can serve as an experimental tool to promote our understanding of Stx-induced pathogenesis.

• 한국산학기술학회논문지
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• 제21권5호
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• pp.103-110
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• 2020

수중 로봇의 가장 기본 성능이라 할 수 있는 동적 성능인 유영속도와 동적 효율 향상을 위해 수중생물을 모사한 로봇들이 주로 연구되고 있다. 그중에서 생체모사 소프트 로봇은 유연한 꼬리지느러미를 적용함으로써 높은 자유도를 구현할 수 있다. 다만, 유연한 구동부의 효율을 높이기 위해서는 구동 주파수에 맞추어 꼬리지느러미의 강성이 바뀌어야 한다. 따라서, 연구를 통해 새로운 형태의 가변강성 메커니즘을 구현하고, 이를 연구 과정에서 검증하였다. 본 연구에서는 실제 돌고래의 해부도에서 영감을 얻어, 가변강성 메커니즘을 적용한 돌고래 로봇을 새로이 설계하고 제작하는 과정을 기술하였다. 실제 돌고래의 척추 모양을 모사하여, 절삭과 적층형 공정으로 가변강성 구동부를 제작하였다. 로봇 돌고래를 구동하기 위한 텐던도 실제 돌고래의 텐던 위치를 고려하여 배치하였으며, 추가로 강성 변화를 위한 텐던을 설치하였다. 돌고래의 유선형 외형을 모사하여 로봇 돌고래를 제작하였고, 강성 변화에 따른 로봇 돌고래의 유영속도를 측정하였다. 동일한 구동 주파수에 꼬리지느러미 구동부의 강성을 변화시켰을 때, 로봇 돌고래의 유영속도의 차이가 약 1.24배, 추력으로는 약 1.5배 변화하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권1호
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• pp.1-8
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• 2005

Myotonic Dystrophies type 1 and 2 (DM1/2) are neuromuscular disorders which belong to a group of genetic diseases caused by unstable CTG triplet repeat (DM1) and CCTG tetranucleotide repeat (DM2) expansions. In DM1, CTG repeats are located within the 3' untranslated region of myotonin protein kinase (DMPK) gene on chromosome 19q. DM2 is caused by expansion of CCTG repeats located in the first intron of a gene coding for zinc finger factor 9 on chromosome 3q. The CTG and CCTG expansions are located in untranslated regions and are expressed as pre-mRNAs in nuclei (DM1 and DM2) and as mRNA in cytoplasm (DM1). Investigations of molecular alterations in DM1 discovered a new molecular mechanism responsible for this disease. Expansion of un-translated CUG repeats in the mutant DMPK mRNA disrupts biological functions of two CUG-binding proteins, CUGBP and MNBL. These proteins regulate translation and splicing of mRNAs coding for proteins which play a key role in skeletal muscle function. Expansion of CUG repeats alters these two stages of RNA metabolism in DM1 by titrating CUGBP1 and MNBL into mutant DMPK mRNA-protein complexes. Mouse models, in which levels of CUGBP1 and MNBL were modulated to mimic DM1, showed several symptoms of DM1 disease including muscular dystrophy, cataracts and myotonia. Mis-regulated levels of CUGBP1 in newborn mice cause a delay of muscle development mimicking muscle symptoms of congenital form of DM1 disease. Since expansion of CCTG repeats in DM2 is also located in untranslated region, it is predicted that DM2 mechanisms might be similar to those observed in DM1. However, differences in clinical phenotypes of DM1 and DM2 suggest some specific features in molecular pathways in both diseases. Recent publications suggest that number of pathways affected by RNA CUG and CCUG repeats could be larger than initially thought. Detailed studies of these pathways will help in developing therapy for patients affected with DM1 and DM2.

• 상하수도학회지
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• 제31권6호
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• pp.551-566
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• 2017

As the modern society is rapidly developing and people become affluent in materials, many new chemical compounds in different forms of products (e.g., antibiotics, pesticides, detergents, personal care products and plastic goods) are produced, used, and disposed of to the environments. Some of them are persistently having a harmful impact on the environment and mimicking endocrine properties; in general they are present in the environment at low concentrations, so they are called organic pollutants. These organic micropollutants flow to sewage treatment plants via different routes. In this study, the generation characteristics, exposure pathways, detection levels, and environmental impacts of organic micropollutants were critically reviewed. In addition, currently available risk assessment methods and management systems for the compounds were reviewed. The United States Environmental Protection Agency (US EPA), for example, has monitored organic micropollutants and set the monitoring and management of some of the compounds as a priority. To effectively manage organic micropollutants in sewer systems, therefore, we should first monitor organic micropollutants of potential concern and then make a watch list of specific substances systematically, as described in guidelines on listing water pollutants in industrial wastewater.