• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권2호
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• pp.115-121
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• 2022

The Yezo sika deer (Cervus nippon yesoensis) is a subspecies of sika deer originated from Hokkaido, Japan. This paper is a study on the ecological impact caused by large mammals invading the ecosystem. Two pairs of deer were donated to the Agency for Defense Development in Taean in the late 1980s, and the population expanded to over 280 in 2018. The thermal imaging camera showed that the population ranged from 8 to 53 herds, divided into approximately 10 groups. It was confirmed that some of the herds had escaped the management area and invaded the nearby natural ecosystem, causing damage to cultivated land and natural vegetation. Herds of over 50 individuals have been studied in large grassland areas near drinking water sources such as streams and ponds. In places with excessive deer concentration, 1) feeding damage to herbs, shrubs and sub-trees, 2) tree withering due to antler-rubbing, and their habit of migrating along forest edges 3) excessive soil loss on slopes, 4) destruction of herbaceous layers due to compaction, and finally 5) damage to infrastructure were also investigated. As such, it is expected that the results of this study on the ecological and economic damage of Yezo sika deer can be used to predict the impact of other exotic sika deer in South Korea with similar behavioral characteristics and to establish a management plan.

• 한국환경과학회지
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• 제32권11호
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• pp.789-800
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• 2023

A vascular flora survey was conducted in 2020 to identify flora and analyze changes in the numbers of vascular flora species over the past 10 years at Gongju-weir (GW) and Baekje-weir (BW) in the Geumgang River, Republic of Korea. A total of 241 taxa were found in GW and 279 taxa in BW, and 208 taxa (88% of total taxa) were common species. The distribution of invasive species in GW and BW were seven and eight taxa, respectively. Rare plants were not identified in any of the weirs. The Poaceae family dominated in terms of number of species, followed by Asteraceae, Legumes, Cyperaceae, and Polygonaceae. Additionally, Therophytes accounted for a high proportion of Raunkiaer life forms. The numbers of vascular plant species, total taxa, naturalized plants, and invasive species have been increasing over the last 10 years. However, long-term alterations in invasive species before and after the opening of the weirs increased much more significantly in the partially opened BW than in the fully opened GW. These results indicate that the degree of barrier opening does not affect the invasion and establishment of non-native species.

• 생명과학회지
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• 제27권1호
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• pp.78-88
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• 2017

혈관신생, 즉 새로운 혈관형성은 종양의 성장과 전이에 중요한 역할을 한다고 알려져 있으며, 암 치료에 중요한 목표물이 되고 있다. 이 연구의 목적은 황련 냉수추출물의 혈관신생 억제작용의 효과를 밝히고 항암제로서의 가능성을 평가하고자 한다. Ex vivo rat aortic ring assay 실험결과 신생혈관성장을 억제하는 결과를 확인하였고, 이것을 통해 황련 냉수추출물이 혈관신생과정의 주요한 단계와 내피세포의 증식, 이동, 침투, 혈관내피세포자극인자에 의한 반응으로 모세관 모양의 관 형성작용을 억제함을 알아내었다. 또한 황련 냉수추출물을 처리하였을 때, 세포주기가 억제되고 VEGF에 의한 반응으로 인해 G0/G1 주기에서 S 주기로 가는 과정을 예방하고, VEGF에 의해 활성화가 유도되는 MMP-2, MMP-9이 감소되었다. 따라서 이들의 결과는 황련 냉수추출물이 종양의 발달 단계 중 혈관신생을 방해하는 잠재적인 항암약물의 소재로 고려될 수 있음을 제안한다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.459-462
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• 2012

Expression of estrogen-receptor (ER), progesterone-receptor (PR) and HER-2 has recently been linked with various breast cancer subtypes identified by gene microarray. This study aimed to document breast cancer subtypes based on ER, PR and HER-2 status in Thai women, where expression of these subtypes may not be similar to those evident in Western women. During 2009 to 2010, histological findings from 324 invasive ductal carcinomas (IDC) at Siriraj Hospital were studied. Various subtypes of IDC were identified according to expression of ER, PR and HER-2: luminal-A (ER+;PR+/-;HER-2-), luminal-B (ER+;PR+/-;HER-2 +), HER-2 (ER-;PR- ;HER-2+) and basal-like (ER-;PR-;HER-2-). As well, associations of tumor size, tumor grade, nodal status, angiolymphatic invasion (ALI), multicentricity and multifocality with different breast cancer subtypes were studied. Of 324 IDCs, 143 (44.1%), 147 (45.4%), 15 (4.6%) and 12 (3.7%) were T1, T2, T3 and T4, respectively. Most tumors were grade 2 (54.9%) and had no nodal involvement (53.4%). According to ER, PR and HER-2 status, 192 (59.3%), 40 (12.3%), 43 (13.3%) and 49 (15.1%) tumors were luminal-A, luminal-B, HER-2 and basal-like subtypes. HER-2 subtype presented with large tumor (p=0.04, ANOVA). Luminal-A IDC was associated with single foci (p<0.01, ${\chi}^2$). HER-2 and basal-like subtypes were likely to have high tumor grade (p<0.01, ${\chi}^2$). In addition, HER-2 subtype had higher number of nodal involvement (p=0.048, ${\chi}^2$). In conclusion, the luminal-A subtype accounted for the majority of IDCs in Thai women. Percentages of HER-2 and basal-like IDCs were high, compared with a recent study from the USA. The HER-2 subtype was related with high nodal invasion. The findings may highlight biological differences between IDCs occurring in Asian and Western women.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1441-1446
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• 2014

Squamous cell/adenosquamous carcinoma (SC/ASC) of the gallbladder are rare tumors and there are few clinical reports in the literature. Herein we report our clinical experience with 46 patients with SC/ASC and 80 with adenocarcinoma (AC). Expression of EphB1 and Ephrin-B in each tumor was determined using immunohistochemical methods for determination of correlations with prognosis. There was no difference in EphB1 and Ephrin-B expression between SC/ASC and AC tumors (P>0.05), but greater expression in those less than 3 cm in diameter, stage I or II (TNM stage), with no lymph node metastases, with no local invasion and treated with radical resection was apparent. Expression of EphB1 (P<0.05) and Ephrin-B (P<0.01) was higher in well differentiated than in poorly differentiated AC tumors. Kaplan-Meier survival analysis indicated that degree of differentiation, tumor diameter, lymph node metastases, local invasion, surgical approach and expression rate of EphB1 and Ephrin-B were closely related to the survival of SC/ASC (P<0.05) and AC patients (P<0.01). Patients with tumors that positive expressed EphB1 and Ephrin-B, whether it is SC/ASC ($P_{SC/ASC}$ =0.000) or AC ($P_{AC}$ =0.000 or $P_{AC}$ =0.002) had longer survival than those negative expression. Cox multivariate analysis indicated a negative correlation between expression of EphB1 or Ephrin-B and overall survival. Hence, EphB1 and Ephrin-B could be regarded as independent good prognostic factorsand important biological markers for SC/ASC and AC of gallbladder.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9417-9421
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• 2014

Background: Esophageal cancer is one of the most frequently occurring malignancies and the seventh leading cause of cancer-related deaths in the world. The esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer worldwide. Materials and Methods: Our goal in this study was to detect phospholipase A2 Group IIA (PLA2G2A) and cyclooxygenase-2 (COX-2) immuno-expression in ESCC in a high-risk population in China. Results: Positive expression of PLA2G2A protein was observed in 57.2% (166/290) of the cases, while COX-2 was found in 257 of 290 samples (88.6%), both PLA2G2A and COX-2 being expressed in 153 cases (52.8%), with a significant agreement (Kappa=0.091, p=0.031).Overexpression of PLA2G2A was significantly correlated with the depth of invasion (p=0.001). Co-expression of PLA2G2A and COX-2 not only significantly correlated with the depth of invasion (p=0.004) but also with TNM stage (p=0.04). Conclusions: Our results showed that in patients with ESCC, PLA2G2A overexpression and PLA2G2A co-expression with COX-2 is significantly correlated with advanced stage. The biological role and pathophysiologic regulation of PLA2G2A and COX-2 overexpression in ESCC deserve further investigation.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3299-3304
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• 2014

Background: The aim of the present study was to analyze whether Homer1 is a potential prognostic marker for intrahepatic cholangiocarcinoma (ICC). Materials and Methods: The expression of Homer1 in ICC tissue was detected with immunohistochemistry and levels of protein in ICC and paratumor tissues were evaluated by Western blotting. Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance. Results: Homer1 expression was high in 67.4% (58/86) of ICC samples, and there was significant difference between ICC and adjacent noncancerous tissues (p<0.001); high expression was associated with poor histologic differentiation (p=0.019), TNM stage (p=0.014), lymph node metastasis (p=0.040), and lymphatic invasion (p=0.025). On Kaplan-Meier analysis, a comparison of survival curves of low versus high expressors of Homer1 revealed a highly significant difference in OS (p=0.001) and DFS (p=0.006), indicating that high expression of Homer1 was linked with a worse prognosis. Multivariate analyses showed that Homer1 expression was an independent risk factor predicting overall survival[Hazard ratio(HR), 7.52; 95% confidence interval (CI), 2.63-21.47; p=0.002] and disease-free survival (HR, 11.56; 95%CI, 5.17-25.96; p<0.001) in ICC. Conclusions: Homer1 promotes lymphatic invasion and associates with lymph node metastasis and poor prognosis of ICC. The current study shows that Homer1 may be an independent prognostic factor for ICC patients after curative resection, and it provides an important basis for screening/treating high-risk patients.

• Ecology and Resilient Infrastructure
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• 제2권4호
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• pp.274-283
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• 2015

저수지 호안은 생물 침입에 취약하다고 생각된다. 본 연구의 목적은 우리나라 저수지 호안에서 침입식물의 종조성의 현황과 외래식물상과 환경요인 사이의 관계를 파악하는 것이다. 다양한 수위 관리를 하고 있는 35 개 저수지 호안에서 외래식물 식물상과 지형, 수문, 수질 및 토양 환경 요인을 조사하였다. 조사 대상 저수지 호안에서 외래식물은 56 종이 발견되어 출현식물 총종수의 15%를 차지하였다. 이들 외래식물을 도입시기별로 분류하면 1876 - 1921 년인 개항 직후에 도입된 것이 57%로서 많았다. 또한 이들의 원산지는 아메리카와 유럽이 80% 이상으로 많았다. 특이한 분포를 나타내는 외래종은 단풍잎돼지풀 (Ambrosia trifida)이 중부 지역에, 물참새피 (Paspalum distichum)가 남부 지역에 제한적으로 분포하였다. 저수지 호안에서 외래식물 식물상에 영향을 미치는 주요한 환경 요인은 연간 수위변동폭, 중앙수위 범람빈도, 수질오염 지수, 암석노출도 및 평균 사면 경사도이었다. 결론적으로 수위 관리와 기타 인간 교란이 가해지는 저수지 호안은 외래식물의 침입에 취약하였다. 저수지 호안의 효과적인 보전을 위하여 외래식물의 초기 도입을 탐지할 수 있는 주기적 모니터링 체계가 필요할 것으로 생각된다.

• 식물분류학회지
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• 제35권4호
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• pp.273-285
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• 2005

국내에 분포하는 대표적 침입외래식물인 돼지풀과 단풍잎돼지풀이 나타내는 유전적 변이양상을 파악하기 위해 국내집단을 중심으로 돼지풀 157개체와 단풍잎돼지풀 46개체로부터 핵 rDNA의 ITS(Internal Transcribed Spacer)지역 염기서열을 분석하였다. 그 결과 돼지풀에서는 총 18개의 ITS 유형이, 단풍잎돼지풀에서는 4개의 유형이 각각 검출되었다. 돼지풀의 경우 각각의 ITS 유형간에는 1bp에서 7bp까지 차이가 나는 것으로 확인되었으며, 단풍잎돼지풀의 경우 각 유형 간에 1bp에서 2bp의 차이가 발견되었다. 돼지풀의 국내집단에서 18개에 이르는 다양한 ITS 유형이 검출되었다는 사실은 이 종이 우리나라에 여러 차례 반복해서 유입했기 때문인 것으로 풀이된다. 한편 일부 ITS 유형은 유전적 재조합에 의해 형성되었을 가능성이 있으며, 각각 한 개체에서만 발견된 12개의 소수 유형들은 점돌연변이 또는 그에 뒤이은 유전적 재조합에 의해 국내에서 독자적으로 기원했을 것으로 추정된다. 본 연구를 통해 침입과정에서 나타나는 돼지풀의 진화적 변화를 이해하는데 필요한 유용한 유전적 기초정보가 확보되었다.

• 한국수정란이식학회지
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• 제12권3호
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• pp.229-246
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• 1997

Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!