• 한양메디칼리뷰
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• 제33권1호
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• pp.10-16
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• 2013

Follicular helper T cells (Tfh) play a significant role in providing T cell help to B cells during the germinal center reaction, where somatic hypermutation, affinity maturation, isotype class switching, and the differentiation of memory B cells and long-lived plasma cells occur. Antigen-specific T cells with IL-6 and IL-21 upregulate CXCR5, which is required for the migration of T cells into B cell follicles, where these T cells mature into Tfh. The surface markers including PD-1, ICOS, and CD40L play a significant role in providing T cell help to B cells. The upregulation of transcription factor Bcl-6 induces the expression of CXCR5, which is an important factor for Tfh differentiation, by inhibiting the expression of other lineage-specific transcription factors such as T-bet, GATA3, and RORγt. Surprisingly, recent evidence suggests that CD4 T cells already committed to Th1, Th2, and Th17 cells obtain flexibility in their differentiation programs by downregulating T-bet, GATA3, and RORγt, upregulating Bcl-6 and thus convert into Tfh. Limiting the numbers of Tfh within germinal centers is important in the regulation of the autoantibody production that is central to autoimmune diseases. Recently, it was revealed that the germinal center reaction and the size of the Tfh population are also regulated by thymus-derived follicular regulatory T cells (Tfr) expressing CXCR5 and Foxp3. Dysregulation of Tfh appears to be a pathogenic cause of autoimmune disease suggesting that tight regulation of Tfh and germinal center reaction by Tfr is essential for maintaining immune tolerance. Therefore, the balance between Tfh and Tfr appears to be a critical peripheral tolerance mechanism that can inhibit autoimmune disorders.

• 한국지리정보학회지
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• 제23권2호
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• pp.83-94
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• 2020

연구대상지인 부산광역시는 1995년 본격적인 지방 자치 제도의 시행과 함께 광역시로 승격하게 됨에 따라 인구와 공간 부족 문제를 해결하고자 주변지역을 흡수하면서 전체적인 변화를 맞이하였다. 현재는 광역도시로 개편된 지 25년이 지난 시점으로 공간구조차원에서 도시전체의 균형 있는 발전이 이루어지고 있는지 진단해볼 필요가 있다. 이에 본 연구에서는 미래 공간상호작용을 위한 잠재력의 의미인 인구잠재력을 시공간적으로 적용함으로써 공간구조 변화와 권역별 특징을 분석하였다. 분석 결과, 도시기본계획에서 도심 및 부도심으로 설정된 지역을 중심으로 발전은 이루어지고 있었으나, 광역도시 개편에 의해 편입된 강서구와 기장군은 정체된 것으로 나타났다. 따라서 도시전체의 균형발전을 위하여 상대적으로 낙후된 지역에 대한 지역혁신성장 방안이 마련되어야 할 것이다. 추가적으로 도시외곽에 존재하는 개발제한구역에 의해 공간의 발전축이 억제되는 것으로 나타났지만, 연구대상지 내에 개발제한구역이 존재하는 다른 권역은 편입된 지역과 다르게 성장하는 패턴이 나타났다. 따라서 편입지역의 정체 원인을 토지이용규제에 국한할 것이 아니라 지역 특성을 고려한 지속적인 성장 관리방안 수립을 통하여 계획해야 할 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4215-4218
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• 2015

Gastric cancer (GC) is one of the most common malignancies in the world. It is the first cause of cancer deaths in both sexes In Iranian population. Circulating insulin-like growth factor-one (IGF-1) levels have been associated for gastric cancer. IGF-1 protein has central roles involved in the regulation of epithelial cell growth, proliferation, transformation, apoptosis and metastasis. Single nucleotide polymorphism in IGF-1 regulatory elements may lead to alter in IGF-1expression level and GC susceptibility. The aim of this study was to investigate the influence of IGF-1 gene polymorphism (rs5742612) on risk of GC and clinicopathological features for the first time in Iranian population. In total, 241 subjects including 100 patients with GC and 141 healthy controls were recruited in our study. Genotypes were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay with DNA from peripheral blood. The polymorphism was statistically analyzed to investigate the relationship with the risk of GC and clinicopathological properties. Logistic regression analysis revealed that there was no significant association between rs5742612 and the risk of GC. In addition, no significant association between genotypes and clinicopathological features was observed (p value>0.05). The frequencies of the CC, CT, and TT genotypes were 97%, 3%, and 0%, respectively, among the cases, and 97.9%, 2.1%, and 0%, respectively, among the controls. CC genotype was more frequent in cases and controls. The frequencies of C and T alleles were 98.9% and 1.1% in controls and 98.5% and 1.5% in patient respectively. Our results provide the first evidence that this variant is rare in Iranian population and it may not be a powerful genetic predisposing biomarker for prediction GC clinicopathological features in an Iranian population.

• Journal of Plant Biotechnology
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• 제43권1호
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• pp.12-20
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• 2016

DNA 염기서열 분석기술의 진보는 많은 근본적인 생명현상을 이해하는데 기여해왔다. 유례없는 저비용에 염기서열을 대량으로 분석을 할 수 있게 되어 단일 규모의 실험실에서도 관심이 있는 종의 신규유전체를 해독할 수 있다. 게다가 유전집단의 전체 염기서열을 편향되지 않은 채 분석하여 무수한 분자마커를 발굴할 수 있게 됨에 따라 집단유전학 연구도 두드러지게 가속화되어 왔다. 그러나 식물의 유전체가 이형접합성, 반복염기서열, 배수성과 같은 복잡한 특성이 있다는 것을 고려해 볼 때 기술이 매우 빠르게 진화함에 따라 적절한 개체 혹은 집단을 확보하는 것이 식물 연구에서 주요한 문제가 되었다. 이러한 난제는 오래되었지만 매우 효율적인 기술인 반수체 육성을 통하여 극복될 수 있을 것이다. 정상적인 개체가 갖는 염색체의 절반을 보유하는 반수체 식물은 주로 자방이나 화분과 같은 배우체 세포를 배양함으로써 빠르게 구축될 수 있다. 뒤이은 반수체 식물의 염색체 배수화는 완벽한 동형접합성을 보이는 안정된 배가반수체를 만든다. 본 논문에서는 반수체 식물을 육성하고 판별하기 위한 고전적인 방법론을 요약할 것이다. 게다가 동원체의 히스톤을 후성적으로 조절함으로써 반수체를 유도하는 방법을 설명할 것이다. 마지막으로, 유전체 시대에 반수체 식물의 활용 방안을 유전체 해독과 집단 유전학의 측면에서 논의할 것이다.

• The Korean Journal of Ecology
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• 제28권2호
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• pp.99-103
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• 2005

중간습원 무제치 습원의 현존식생도와 오리나무 개체군의 공간적 분포양식을 규명하였으며, 그 보존을 위한 생태학적 정보를 발굴하였다. 자늪과 웅늪의 1:100 실측지형도 상에서 총3,036개의 격자(5m $\times$ 5m)를 이용하여 1996년 상세 현장조사가 이루어졌다. 현존식생도는 쇠털골형, 진퍼리새형, 오리나무형, 억새형, 삼림형 그리고 개방나지 등의 6 가지 식생범례로 제작되었으며, 습원 고유의 진퍼리새형과 비고유의 억새형이 가장 넓은 면적을 차지하고 있었다. 오리나무 1,491개체에 대한 매목조사와 티센망도(thiessen polygons) 분석으로부터 오리나무 개체군의 발달은 습원의 훼손(토사 및 산화 등)으로부터 매우 급속히 진행되고 있는 것으로 나타났다. 웅늪은 자늪에 비하여 보다 온전한 구조로 유지되고 있는 중간습원으로 평가되었으나, 자늪과 웅늪 모두 다년생 목본 식물종에 의한 산지 참나무림과 오리나무 우점의 산지 습생림의 발달에 의한 진퍼리새군강으로 대표되는 중간습원의 입지환경 변화와 그 소멸이 급격히 진행되고 있었다. 결국 진퍼리새군강의 중간습원 보존은 임도와 산불에 따른 토양의 부영양화에 대한 응급조치가 필요함이 지적되었다.

• 한국어병학회지
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• 제33권1호
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• pp.23-34
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• 2020

In recent years, global warming is causing dramatic environmental changes and deterioration, such as hypoxia, leading to reduced survival rate and growth performance of farmed aquatic animals. Hence, understanding systemic immuno-physiological changes in fish under environmental stress might be important to maximize aquaculture production. In this study, we investigated physiological changes in rainbow trout exposed to hypoxic stress by monitoring changes in blood chemistry, leukocyte population, and expression levels of related cytokine genes. Hematological and serological factors were evaluated in blood obtained from rainbow trout sampled at a dissolved level of 4.6 mg O₂ L^-1 and 2.1 mg O₂ L^-1. Blood and head kidney tissue obtained at each sampling time point were used to determine erythrocyte size, leukocyte population, and cytokine gene expression. The level of LDH and GPT in fish under progressive hypoxia were significantly increased in plasma. Likewise, the (Granulocyte + Macrophage)/lymphocyte ratio (%) of fish exposed to hypoxia was significantly lower than that in fish in the control group. Such changes might be due to the rapid movement of lymphocytes in fish exposed to acute hypoxia. In this study, significant up-regulation in expression levels of IL-1β and IL-6 gene appeared to be involved in the redistribution of leukocytes in rainbow trout. This is the first study to demonstrate the involvement of cytokines in leukocyte trafficking in fish exposed to hypoxia. It will help us understand systemic physiological changes and mechanisms involved in teleost under hypoxic stress.

• Ocean and Polar Research
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• 제26권4호
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• pp.551-557
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• 2004

Polymorphism of the lipoprotein lipase (LPL) gene which plays an important role in regulation of lipid deposition was analysed in two red seabream (pagrus major) populations (KF4, cultured KORDI line, n=100 : JPN, imported from Japan, n=100). We amplified a DNA fragment (1,091 bp) including the exon 2 region of the LPL gene, and conducted PCR-RFLP analysis using MspI and AluI. The PCR products were also sequenced. Two alleles (A and B) were found in MspI digestion and Sve alleles (A, B, C, D and E) in AluI digestion. The sequenced data revealed four nucleotide substitutions including one transversion at the MspI recognition site (nt 2,235, $C{\rightarrow}10$) and three transitions at the AluI recognition sites (nt 1,721, $A{\rightarrow}G;$ nt 2,319, $C{\rightarrow}T;$ nt 2,319, $T{\rightarrow}C$). Among them, substitutions at the nt 2,235 and 2,319 sites which are located in the exon 2 were proved to be silent point mutations. MspI polymorphism resulted in 3 genotypes, and the allele frequency was significantly different between the two fish populations, KF4 and JPN. In the case of AluI polymorphism, the 5 alleles (A, B, C, D, E) comprised 12 genotypes of the 5 alleles. KF4 population, alleles D and I were specific to the LPL gene Polymorphisms would be useful DNA markers for red seabream population.

• Journal of Periodontal and Implant Science
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• 제31권1호
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• pp.135-148
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• 2001

Gingival fibroblasts are major cellular component of gingiva. However, the molecular mechanisms of senescence of human gingival fibroblasts are unknown. Human fibroblasts undergo replicative senescence in vitro after a limited number of population doublings. A reduced rate of proliferation is a prominent phenomenon observed in senescent fibroblasts. This phenomenon is controled by cell cycle regulatory proteins. The purpose of present study was to investigate the effect of replicative senescence on cell cycle progression and to find out its molecular mechanisms in human gingival fibroblasts. Replicative senescence of gingival fibroblasts were induced by subsequent cultures that were repeated up to 18 passage. In the present study, I examined change of cell proliferation, cell activity, cell viability and cell cycle progression during the replicative process. Also, I examined expression of cell cycle regulatory proteins which was estimated by western blot analysis. Cell proliferation, cell activity and cell viability of gingival fibroblasts were notably decreased with increase of population doubling level(PDL). S phase was decreased and G1 phase was increased with increase of PDL. Western blot analysis showed that levels of P16, p21 and p53 of senescent gingival fibroblasts(PDL41, PDL58) were higher than young fibroblasts(PDL27) and cdk4 were lower than young fibroblasts(PDL27). In conclusion, these results suggest that proliferative function of human gingival fibroblasts may be decreased by replicative senescence and its molecular mechanisms may be activatied with p16, p21, p53 and pRB, and repressed wtih cdk4.

• 한국조사연구학회지:조사연구
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• 제7권1호
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• pp.109-129
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• 2006

그동안 인구주택총조사의 조사결과에 대한 연구와 정보는 많았으나 총조사를 어떻게 준비하는지에 대한 조사방법 관련 논의가 없었다. 이 글은 이러한 논의를 활성화하기 위해 2005년 인구주택총조사를 준비하는 2년여 과정에서 거처를 파악하고 조사구를 설정하는 방법을 소개하였다. 특히 1999년 읍 면 동의 통계기능축소를 보완하기 위해 개발된 여러 방법들을 기술하였다. 주요한 방법으로는 과거 인구주택총조사 DB, 행정자료, 수치지도의 활용 등이 있다. 이들은 대체로 IT 기술을 기반으로 개발된 조사방법들이다. 한편, 취약한 지방자치단체의 행정자료관리체계는 IT 기술 활용의 제약이었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2035-2038
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• 2014

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is an important protein involved in the regulation of the immune system. The +49 G/A polymorphism is the only genetic variation in the CTLA-4 gene that causes an amino acid change in the resulting protein. It is therefore the most extensively studied polymorphism among all CTLA-4 genetic variants and contributions to increasing the likelihood of developing cancer are well known in various populations, especially Asians. However, there have hiterto been no data with respect to the effect of this polymorphism on breast cancer susceptibility in our North Indian population. We therefore assayed genomic DNA of 250 breast cancer subjects and an equal number of age-, sex- and ethnicity-matched healthy controls for the CTLA-4 +49 G/A polymorphism but no significant differences in either the gene or allele frequency were found. Thus the CTLA-4 +49 G/A polymorphism may be associated with breast cancer in other Asians, but it appears to have no such effect in North Indians. The study also highlights the importance of conducting genetic association studies in different ethnic populations.