• 생명과학회지
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• 제17권7호통권87호
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• pp.948-955
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• 2007

생체 면역반응에 중요한 역할을 하는 호중구의 세포사멸은 자연적으로 일어나거나 여러 외부자극에 의한 신호의 전달에 의해 증가하거나 지연된다. 또한 사이토카인과 같은 분화제에 의해 세포사멸이 지연되고 항원 제시 기능을 가진 수지상 세포로 분화되기도 한다. 본 연구에서는 세포사멸 억제제와 사이토카인을 이용한 시스템에서 호중구가 수지상 세포로 분화되는가를 조사하였다. Pancaspase와 serine protease의 억제제인 zVAD-fmk와 AEBSF를 처리하였을 때 호중구의 세포사멸은 현저히 감소되며 AEBSF는 caspase-3와 serine protease활성을 모두 억제하였다. 호중구의 세포사멸을 효과적으로 억제하는 AEBSF와 함께 분화제로 널리 쓰이는 CM-CSF를 같이 처리하여 3일 동안 배양하면 수지상 세포에서 높이 발현되는 CD8O, CD83 및 MHC class ll의 세포표면 마커의 발현이 증가하였다. AEBSF와 CM-CSF를 처리한 호중구를 T-세포와 함께 배양하였을 때 SEB가 존재할 경우 T-세포가 증식되었으며 SEB가 없이도 $IFN{\gamma}$는 생성되었다. 이들 결과들로 부터 serine protease 억제제인 AEBSF를 호중구에 처리하여 세포사멸을 효과적으로 억제하는 것과 수지상 세포로의 분화를 촉진하는 사이토카인인 CM-CSF의작용을 나타내게 하는 조건과는 서로 상호적으로 연관되어 작용할 수 있다는 것을 제시하고 있다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제6권3호
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• pp.364-372
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• 2000

하위범주화는 보어의 어휘 개념이 명시된 술어와 보어간 의존 관계를 정의하는 언어 정보로서 구문 및 의미 분석 등에 폭넓게 활용될 수 있는 기반 언어 자원이라는 데에 그 중요성이 있다. 본 논문에서는 표층문에서 통상 격표지로 표현되는 구문적 의존 관계뿐만 아니라, 보어가 갖는 의미역 정보가 부착되어 있으며 시소러스 개념 분류 체계와 연동 가능한 한국어 술어의 하위범주화 사전의 구축에 대해 설명하고 있다. 본 논문에서는 하위범주화 사전의 의미역 표현을 위해 총 25개의 의미역을 설정하고 있다. 이 의미역은 표층 격표지와 직접 연관되어 있기 때문에 통사적인 분석으로부터 직접 의미역 정보를 추출해서 의미 구조의 해석에 이용하는 것이 가능하다. 또한 명사 보어가 갖는 개념의 표현을 위해 상ㆍ하위어 관계를 갖는 12만 어휘 규모의 시소러스를 이용하고 있으며, 술어의 의존 관계 표현을 위해 동사, 형용사에 대해 각각 47, 17 개의 하위범주화 패턴을 이용하고 있다. 실용적 규모의 시소러스를 이용함으로써 문장에 나타난 명사의 시소러스 개념을 그대로 하위범주화 사전에 적용시켜 의미 정합 여부를 판단할 수 있는 실질적인 선택제약 체계를 구성할 수 있었고, 표층 격표지에 기초한 표준화된 술어 패턴을 이용함으로써 의미역의 결정 등에서 야기될 수 있는 비일관성을 방지하고 구축에 드는 비용을 절감할 수 있었다. 이상과 같은 방법으로 말뭉치에서 추출한 고빈도 술어 13,000 여개에 대해 하위범주화 사전을 구축하였으며, 적용 범위 평가 실험에 의하면 이 하위범주화 사전은 말뭉치에서 발견된 술어의 72.7%에 대해 하위범주화 정보를 제공할 수 있음을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.637-642
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• 2014

The pathogenesis of hepatocellular carcinoma (HCC) related to habitual betel quid (BQ) chewing is unclear. Risk of HCCis increased with adverse hepatic fibrosis. This study aimed to assess the impact of chronic viral hepatitis on adverse hepatic fibrosis in HCC related to BQ chewing. This hospital-based case-control study enrolled 200 pairs of age- and gender-matched patients with HCC and unrelated healthy controls. Serologic hepatitis B surface antigen (HBsAg), antibodies to hepatitis C virus (anti-HCV), ${\alpha}$-fetoprotein (AFP), and surrogate markers for significant hepatic fibrosis were measured. Information on substance-use habits was obtained with a questionnaire. By analysis of surrogate markers for hepatic fibrosis, the prevalence of significant hepatic fibrosis in patients chewing BQ was between 45.8% and 91.7%, whereas that for patients without BQ chewing was between 18.4% and 57.9%. The difference was significant (P <0.05 for each surrogate marker). Multivariate analysis indicated that cirrhosis with Child-Pugh C (odds ratio (OR) = 3.28; 95% confidence interval (CI), 1.29-8.37), thrombocytopenia (OR = 3.92, 95% CI, 1.77-8.68), AFP >400 mg/L (OR = 2.21, 95% CI, 1.05-4.66) and male gender (OR = 4.06, 95% CI, 1.29-12.77) were independent factors associated with habitual BQ chewing. In conclusion, adverse hepatic fibrosis and severe liver damage play important roles in the pathogenesis of BQ-related HCC, which could be aggravated by chronic hepatitis B and hepatitis C. BQ-cessation programs and prevention of chronic HBV/HCV infection are needed to prevent HCC related to BQ chewing.

• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.1-11
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• 2002

Immune responses associated with bacterial infection involve various inflammatory cells. Clinical symptoms and pathologic features are particularly influenced by the predominant cells Among inflammatory cells, T cells have the heterogenity. T cells may develop into the mature cells expressing the cell surface markers with different functions and T helper cells are categorized into Th1 and Th2 cells based on their different patterns of cytokine production. The objective of this study was to investigate the change of expression of surface markers on T cells and the Th1/Th2 immune response in pulpal inflammation associated with specific bacteria. We experimentally induced pulpal inflammation in rat incisors by drilling without coolant and innoculated with Streptococcus mutans (S.M. group), Porphyromonas endodontalis (P.E. group), or only sterile cotton (control group). After 1, 2, and 5 days, mandibular incisors were extracted and the pulp tissues were extirpated The expressions of IL-2 recepters (CD25) and ICAM-1 (CD54) on CD4+ and CD8+ cells in the pulps were determined using a flow cytometer, and the concentration of IL-2, IFN-$\gamma$ and IL-4 was measured by enzyme-linked immunosorbent assay. The results were as follows: 1 In the S.M. group, CD4+ cells were more increased at 2nd day than 1st day and in the P.E. group, CD8+ cells were more increased at 2nd day than 1st day. 2. The percentages of CD4+, CD4+25+ and CD4+54+ cells were decreased in the pulp tissues at 5th day after irritation in all groups. 3. The ratios of CD4+/CD8+, CD4+/CD4+25+ and CD4+/CD4+54+ in the pulps at 2nd day after irritation by P. endodontalis were significantly lower than the other groups. 4. The higher concentrations of IFN-$\gamma$ than IL-4 in the pulps at 2nd day after irritation by P. endodontalis showed that T helper 1 reaction were predominant in the early stage of the pulpal inflammation induced by P. endodontalis. 5. The higher concentrations of IL-4 than IFN-$\gamma$ in the pulps at 1st day and 5th day after irritation by S. mutans were measured but the differences were not significant.

• IMMUNE NETWORK
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• 제6권3호
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• pp.138-144
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• 2006

Background: There are at least two different subsets of B cells, B-1 and B-2. The characteristic features and function of B-2 cells in addition to the effect of steroids on B-2 cells are well-known. Although B-1 cells have different features and functions from B-2 cells, the effect of steroids on B-1 cells is not completely understood. Therefore, this study examined the effects of dexamethasone on peritoneal (or B-1 cells) and splenic B cells (or B-2 cells). Methods: Purified B cells were obtained from the peritoneal fluid and the spleens of mice. The isolated B cells were cultured in a medium and after adding different concentrations of dexamaethasone. The cell survival rate was measured by flow cytometry using propidium iodide. The expression level of the B cell surface marker was analyzed by flow cytometry. During the culture of these cells, immunoglobulin secreted into the culture supernatants was evaluated by an enzyme-linked immunosorbent assay. Results: The survival rate of peritoneal and splenic B cells decreased with increasing dexamethasone concentration. However, the rate of peritofieal B cell apoptosis was lower than that of splenic B cells. CDS and B7.1 expression in peritoneal B cells and CD23 and sIgM expression in splenic B cells after the dexamethasone treatment were reduced. When B cells were treated with dexamethasone, the spontaneous IgM secretion decreased with increasing dexamethasone concentration. Conclusion: Dexamethasone induces apoptosis in peritoneal and splenic B cells. However, peritoneal B cells are less sensitive to dexamethasone. The dexamethasone suppressed expression of the surface markers in peritoneal B cells is different from those in splenic B cells.

• Geosciences Journal
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• 제22권6호
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• pp.871-880
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• 2018

During and shortly after the 2017 Pohang Earthquake ($M_w$ 5.4), sand blows were observed around the epicenter for the first time since the beginning of instrumental seismic recording in South Korea. We carried out field surveys plus satellite and drone imagery analyses, resulting in observation of approximately 600 sand blows on Quaternary sediment cover in this area. Most were observed within 3 km of the epicenter, with the farthest being 15 km away. In order to investigate the ground's susceptibility to liquefaction, we conducted a trench study of a 30 m-long sand blow in a rice field 1 km from the earthquake epicenter. The physical characteristics of the liquified sediments (grain size, impermeable barriers, saturation, and low overburden pressure) closely matched the optimum ground conditions for liquefaction. Additionally, we found a series of soft sediment deformation structures (SSDSs) within the trench walls, such as load structures and water-escaped structures. The latter were vertically connected to sand blows on the surface, reflecting seismogenic liquefaction involving subsurface deformation during sand blow formation. This genetic linkage suggests that SSDS research would be useful for identifying prehistoric damage-inducing earthquakes ($M_w$ > 5.0) in South Korea because SSDSs have a lower formation threshold and higher preservational potential than geomorphic markers formed by surface ruptures. Thus, future combined studies of Quaternary surface faults and SSDSs are required to provide reliable paleoseismological information in Korea.

• Tuberculosis and Respiratory Diseases
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• 제61권1호
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• pp.41-45
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• 2006

배 경: 패혈증 환자의 예후를 예측하는 데 현재 사용되고 있는 임상적 채점 방식은 몇가지 제한점이 있다. 그래서 단백질체학(proteomics) 기법을 사용하여 표지자(proteomic biomarkers)를 찾으려 연구를 진행하였다. 방 법: 본 연구에서는 16명의 패혈증환자에게서 중환자실에 입원하자마자 혈장을 채취하였다. 패혈증의 예후를 예측할 수 있는 표지자를 찾기 위해 Surface-enhanced laser desorption/ionization time-of-flight (SELDI -TOF) mass spectrometry를 사용하였다. 결 과: 사망환자와 생존환자 사이에 통계적으로 유의한 차이가 있는 6개의 단백표지자를 발견하였고 이들은 패혈증 환자의 예후 예측과 치료계획수립에 도움이 될 것으로 생각된다. 결 론: 프로테오믹 마커는 패혈증 환자의 예후를 예측하고 치료계획을 세우는 데 있어 유용하게 이용될 가능성이 있을 것으로 사료된다.

• 생명과학회지
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• 제16권5호
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• pp.759-766
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• 2006

급성 전골수성 백혈병은 염색체 전위의 결과로 생긴 PML/RAR$({\alpha})$ 융합 단백의 과발현으로 영향을 받은 전골 수세포의 분화 정지로 발생하는 골수성 백혈병의 일종이다. 삼산화 비소는 세포고사를 유발하여 급성전골수성 백혈병의 관해를 유도한다는 것이 밝혀졌으나 이 약제에 대한 감수성이 다양하여 고형암에 적용하기에는 제한점이 있다. All-trans-retinoic acid (ATRA)에 감수성인 NB4 세포주와 내성인 UF-1 세포주 모두에 삼산화 비소가 세포고사를 유도하였다. 백혈병 세포주를 삼산화 비소로 처리하여, 세포내 GSH 농도가 낮아지고 세포고사의 감수성이 높아지는 상관관계를 찾았으며 전골수성 암세포를 수지상 세포 표면 표식자를 가진 세포로 분화시켰다. ATRA에 대한 감수성인 세포주와 내성인 세포주의 삼산화 비소에 대한 반응의 차이를 이해하고, 전골수 세포가 수지상 세포로 분화하는 과정을 규명한다면, 삼산화 비소에 의한 전골수성 백혈병의 완전관해의 기전을 밝힐 수 있고 또한 임상적용을 확대할 수 있을 것이다.

• 지구물리와물리탐사
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• 제4권3호
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• pp.80-83
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• 2001

미국 텍사스 북부 분스빌 친연가스전에서 취득한 3차원 탄성파자료로부터 4개의 탄성파 반사면과, 탄성파 event 들의 coherence를 도출하여 38개의 검층 자료와 3차원으로 통합 시각화하였다. 시간면은 반사면을 따라 시간을 취득해서 얻었으며 반사면 상에서의 속도는 탄성파 자료와 해석된 38개 검층 자료로부터 산출하였다. 38개 지점의 속도로부터 속도면을 내삽하고 속도면을 이용하여 시간면에서 깊이면으로 변환하였다. Coherence는 탄성파 자료로부터 semblence 방법을 통하여 도출하였으며 입방체로 만든 후 역시 속도면을 이용하여 깊이면으로 변환하였다. 3차원 통합시각화를 통하여 관찰할 때, coherence의 공간적 분포 양상이 잘 파악되었으며, 시간단면등 종래의 3차원 탄성파 분석법과 비교할 때 3차원 시각화 도면에서 선형의 층서적 양상이 더욱 정확함을 알 수 있었다.

• Clinical and Experimental Reproductive Medicine
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• 제29권2호
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• pp.129-138
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• 2002

Objective: This study was to compare the characteristics between parthenogenetic mES (P-mES) cells and in vitro fertilization mES cells. Materials and Methods: Mouse oocytes were recovered from superovulated 4 wks hybrid F1 (C57BL/6xCBA/N) female mice. For parthenogenetic activation, oocytes were treated with 7% ethanol for 5 min and $5{\mu}g$/ml cytochalasin-B for 4 h. For IVF, oocytes were inseminated with epididymal sperm of hybrid F1 male mice ($1{times}10^6/ml$). IVF and parthenogenetic embryos were cultured in M16 medium for 4 days. Cell number count of blastocysts in those two groups was taken by differential labelling using propidium iodide (red) and bisbenzimide (blue). To establish ES cells, b1astocysts in IVF and parthenogenetic groups were treated by immunosurgery and recovered inner cell mass (ICM) cells were cultured in LIF added ES culture medium. To identify ES cells, the surface markers alkaline phosphatase, SSEA-1, 3,4 and Oct4 staining were examined in rep1ated ICM colonies. Chromosome numbers in P-mES and mES were checked. Also, in vitro differentiation potential of P-mES and mES was examined. Results: Although the cleavage rate (${\geq}$2-cell) was not different between IVF (76.3%) and parthenogenetic group (67.0%), in vitro development rate was significantly low in parthenogenetic group (24.0%) than IVF group (68.4%) (p<0.05). Cell number count of ICM and total cell in parthenogenetic b1astocysts ($9.6{\pm}3.1,\;35.1{\pm}5.2$) were signficantly lower than those of IVF blastocysts ($19.5{\pm}4.7,\;63.2{\pm}13.0$) (p<0.05). Through the serial treatment procedure such as immunosurgery, plating of ICM and colony formation, two ICM colonies in IVF group (mES, 10.0%) and three ICM colonies (P-mES, 42.9%) in parthenogenetic group were able to culture for extended duration (25 and 20 passages, respectively). Using surface markers, alkaline phosphatase, SSEA-l and Oct4 in P-mES and mES colony were positively stained. The number of chromosome was normal in ES colony from two groups. Also, in vitro neural and cardiac cell differentiation derived from mES or P-mES cells was confirmed. Conclusion: This study suggested that P-mES cells can be successfully established and that those cell lines have similar characteristics to mES cells.