Assessment of Developmental Toxicants using Human Embryonic Stem Cells

홍의주,정의배 한국독성학회 2013 Toxicological Research Vol.29 No.4

Embryonic stem (ES) cells have potential for use in evaluation of developmental toxicity because they are generated in large numbers and differentiate into three germ layers following formation of embryoid bodies (EBs). In earlier study, embryonic stem cell test (EST) was established for assessment of the embryotoxic potential of compounds. Using EBs indicating the onset of differentiation of mouse ES cells, many toxicologists have refined the developmental toxicity of a variety of compounds. However, due to some limitation of the EST method resulting from species-specific differences between humans and mouse, it is an incomplete approach. In this regard, we examined the effects of several developmental toxic chemicals on formation of EBs using human ES cells. Although human ES cells are fastidious in culture and differentiation, we concluded that the relevancy of our experimental method is more accurate than that of EST using mouse ES cells. These types of studies could extend our understanding of how human ES cells could be used for monitoring developmental toxicity and its relevance in relation to its differentiation progress. In addition, this concept will be used as a model system for screening for developmental toxicity of various chemicals. This article might update new information about the usage of embryonic stem cells in the context of their possible ability in the toxicological fields.

Description of Diplotriaena manipoli (Nematoda: Diplotriaenoidea) Detected in the Body Cavity of Garrulus glandarius brandtii from Republic of Korea

홍의주,류시윤,채준석,김현철,박진호,조정곤,최경성,유도현,박배근 한국임상수의학회 2019 한국임상수의학회지 Vol.36 No.3

The present study was performed to identify the nematodes recovered from the Eurasian jay, Garrulus glandarius brandtii, from Daejeon Metropolitan City, the Republic of Korea. Total five nematode worms were detected in the body cavities of two out of the twenty birds necropsied, and they were identified using morphological features, light and scanning electron microscope (SEM), and molecular (18S rRNA analysis) methods. The nematodes were all female Diplotriaena manipoli and had numerous eggs at different developmental stages in the uterus. The nematodes were long and slender measuring about 123-145 mm. The eight submedian cephalic papillae were arranged into four large, outer papillae and four small, inner-circle papillae. A pair of amphidal pores were located at the lateral portion of the mouth. The manubrium apex of trident was rounded and three branches of trident were bluntly rounded at the posterior ends. Using 18S rRNA partial sequence arrangements, DNA analysis of nematode worms was also carried out, and they were identified to be close to the Serratospiculum tendo based on a phylogenic tree analysis. To our knowledge, this is the first report on the molecular characterization and SEM study of D. manipoli.

Loss of progesterone receptor membrane component 1 decreases hepatic hepcidin levels in animal model

홍의주,Moeka Mukae,Kang Ju Jeong 충북대학교 동물의학연구소 2023 Journal of Biomedical and Translational Research Vol.24 No.4

Iron is an essential nutrient for mammalian cells. Most iron absorption occurs in the duodenal epithelial cells and is regulated by hepcidin, which is produced and secreted in the liver. High hepcidin levels can cause iron deficiency anemia due to iron absorption failure. Inside the cell, iron conjugates with a porphyrin ring and is placed with an iron coordinated to heme. One of the heme-binding proteins, known as progesterone receptor membrane component 1 (Pgrmc1), is a non-canonical progesterone receptor associated with diverse molecular gene regulation. Previous studies showed that Pgrmc1 is related to iron homeostasis via hepcidin; however, these mechanisms remain to be elucidated. In the present study, to investigate the role of Pgrmc1 in mammalian iron metabolism, we introduced Pgrmc1 knockout (KO) mice and performed molecular biological analyses using qPCR and western blotting. Pgrmc1 deficiency decreased Hamp mRNA expression and hepcidin protein levels. However, Pgrmc1 deficiency failed to decrease Hamp transcript expression and hepcidin protein levels in siPGRMC1-transfected HepG2 cells and primary Pgrmc1 KO hepatocytes, respectively. PGRMC1 knockdown cells revealed low HAMP mRNA levels upon cyclic AMP (cAMP) activation, suggesting that PGRMC1 promotes HAMP mRNA transcription via cAMP activation. It has been implicated that hepatic Pgrmc1 cannot control hepcidin directly; however, the internal environment caused by the lack of Pgrmc1 may potentially cause low hepcidin levels.

인체 Calbindin-D9k 항체 제작과 종특이적 활성

이근우, 홍의주, 이근식, Vu-Hoang Dang, 정의배 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.2

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확장된 사용자 유사도를 이용한 CF-기반 건강기능식품 추천 시스템

홍세인,정의주,김재경 한국지능정보시스템학회 2023 지능정보연구 Vol.29 No.3

With the recent rapid development of ICT(Information and Communication Technology) and the popularization of digital devices, the size of the online market continues to grow. As a result, we live in a flood of information. Thus, customers are facing information overload problems that require a lot of time and money to select products. Therefore, a personalized recommender system has become an essential methodology to address such issues. Collaborative Filtering(CF) is the most widely used recommender system. Traditional recommender systems mainly utilize quantitative data such as rating values, resulting in poor recommendation accuracy. Quantitative data cannot fully reflect the user’s preference. To solve such a problem, studies that reflect qualitative data, such as review contents, are being actively conducted these days. To quantify user review contents, text mining was used in this study. The general CF consists of the following three steps: user-item matrix generation, Top-N neighborhood group search, and Top-K recommendation list generation. In this study, we propose a recommendation algorithm that applies an extended similarity measure, which utilize quantified review contents in addition to user rating values. After calculating review similarity by applying TF-IDF, Word2Vec, and Doc2Vec techniques to review content, extended similarity is created by combining user rating similarity and quantified review contents. To verify this, we used user ratings and review data from the e-commerce site Amazon’s “Health and Personal Care”. The proposed recommendation model using extended similarity measure showed superior performance to the traditional recommendation model using only user rating value-based similarity measure. In addition, among the various text mining techniques, the similarity obtained using the TF-IDF technique showed the best performance when used in the neighbor group search and recommendation list generation step.

Urogonimus turdi (Digenea: Leucochloridiidae) from the White's Thrush, Zoothera aurea, in the Republic of Korea

김현철,홍의주,Si-Yun Ryu,Jin-Ho Park,유도현,채준석,Kyoung-Seong Choi,Cheolho Sim,박배근 대한기생충학ㆍ열대의학회 2019 The Korean Journal of Parasitology Vol.57 No.5

Avian trematodes, Urogonimus turdi (Digenea: Leucochloridiidae), were collected from the intestine of wild birds, Zoothera aurea, 2013-2017 in the Daejeon Metropolitan City, Korea. The body was ellipsoidal, attenuated and/or round ends, 1,987-2,120 long and 819-831 μm wide. The oral sucker was subterminal, rounded anteriorly, and 308-425×351-432 μm in size; the prepharynx and esophagus were almost lacking; pharynx was well-developed, 142-179×78-170 μm in size; intestine narrow, bifurcating just after pharynx, ascending to the oral sucker before looping posteriorly and terminating near the posterior end; ventral sucker larger, in almost median, 536-673×447-605 μm and approximately 1.5 times larger than oral sucker. A phylogenetic tree constructed with 18S ribosomal RNA showed inter- and intraspecific relationships. Based on these morphological and molecular findings, we report here a U. turdi from White’s thrushes in Korea.

Alaria alata (Digenea: Diplostomidae) from Korean Raccoon Dog, Nyctereutes procyonoides koreensis, in Korea

이헌우,홍의주,김현철,류시윤,박배근 대한기생충학ㆍ열대의학회 2022 The Korean Journal of Parasitology Vol.60 No.5

We report a species of diplostomid fluke recovered from 3 carcasses of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 107 diplostomid flukes were recovered from the small intestines of Korean raccoon dogs, which were obtained from the Gangwon Wildlife Medical Rescue Center. Worms fixed with 10% neutral formalin were subjected to microscopic observation and those fixed in 70% ethanol were used for molecular genomic analysis. The worm was divided into 2 separate parts, forebody and hindbody, with a total length of 3,020-4,090 (3,855) μm and a width of 1,210-1,770 (1,562) μm. The boat-shaped forebody has a pair of characteristic tentacular appendage, 2 suckers, holdfast organ, and vitelline follicles. The oval to cylindrical hindbody has reproductive organs. The ovary was round or elliptical and located in the anterior of the testes. Two large testes were slightly segmented and tandemly arranged, occupying almost half of hindbody. The short uterus contained a relatively small number of unembryonated eggs sized 130-140×85-96 μm. The partial sequence of 18S rRNA of this fluke was consistent with Alaria alata. Based on the morphological and molecular characteristics, the diplostomid flukes recovered from the small intestine of Korean raccoon dogs were identified as A. alata (Digenea: Diplostomidae).

Morphological and Molecular Characterization of Desportesius invaginatus (Nematoda: Acuariidae) from Egretta garzetta and Bubulcus ibis in Korea

이서인,홍의주,김현철,류시윤,박배근 한국임상수의학회 2021 한국임상수의학회지 Vol.38 No.2

An aquariid nematode, Desportesius invaginatus, was found in the proventriculus of an Egretta garzetta and a Bubulcus ibis from Chuncheon in the Republic of Korea. The worms were identified by light and scanning electron microscopy based on important taxonomic characteristics (body length, esophagus length, cordons, spicules, caudal alae of males, position of the vulva) and then phylogenetically analyzed using the 18S rRNA encoding gene. The nematodes were characterized by a body length of 7.0-8.0 mm in males and 10.2-13.1 mm in females, and two pairs of cordons recurrent in the anterior direction, and cordons were anastomosed by a longitudinal cuticular ridge that externally delimits a longitudinal canal. The widest cuticular plates of cordons bears over 20 posterior spines. The length of the spicules in males was also significantly different. The right spicule measured 742-821 (794) μm in length and 40-45 (42) μm in width, and the left spicule measured 493-556 (541) μm in length and 11-13 (12) μm in width. The caudal alae of males are inflated and vesicular in appearance. The vulva was situated at 56-71 (58.3) μm from the posterior extremity. Although the 18S rRNA sequences of worms were similar to the Synhimantus species, some genetic divergences were observed in comparison. In this study, the worms were recognized with genus Desportesius because genus Desportesius was considered a subgenus of Synhimantus. This is the first record of D. invaginatus in the Republic of Korea.

Morphological and molecular finding of Longicollum pagrosomi (Acanthocephala: Pomphorhynchidae) in cultured red sea bream from Korea

하나리,홍의주,류시윤,심철호,채준석,김현철,박진호,최경성,유도현,박배근 한국동물위생학회 2017 韓國家畜衛生學會誌 Vol.40 No.3

Acanthocephalan worms were harvested from the posterior intestines of the cultured marine fishes from January to July 2016 in a fish market located in Daejeon metropolitan city, Republic of Korea. Totally 450 cultured fishes (rock fish 100, olive flounder 250, red sea bream 100) were surveyed. Of the 100 red sea bream fish, 37 fishes (37%) were diagnosed as positive for Longicollum pagrosomi by light, electron microscopic and molecular examination. The number of worm was 25∼78 (mean 51±13). However, we can’t found any worm from the cultured rock fish and olive flounder. After sequencing, none of Pomphorhynchidae family are not identical based on 18S rRNA gene, and this data were identified with the first report for 18S rRNA gene sequence of L. pagrosomi. Furthermore, we confirmed that L. pagrosomi of the cultured red sea bream in Republic of Korea is very common parasite.

Morphological Characterization of Apharyngostrigea ibis Azim, 1935 (Trematoda: Diplostomoidea) from Ardea cinerea jouyi and Nycticorax nycticorax in Korea

김현철,홍의주,류시윤,최경성,유도현,조정곤,박진호,채준석,박배근 한국임상수의학회 2019 한국임상수의학회지 Vol.36 No.6

Apharyngostrigea ibis (Trematoda: Strigeidae) were obtained from the small intestine of two black-crowned night herons (Nycticorax nycticorax) and three grey herons (Ardea cinerea jouyi) between July 2006 and September 2018 in Daejeon metropolitan city and Kangwon province, Republic of Korea. The body is covered with a relatively thick cuticle, devoid of spines, and bipartite. The body measures at 2.3-3.33 × 0.86-1.20 mm, and the fore-body is ventrally concave. The oral sucker leads into a short esophagus that is devoid of a muscular pharynx. The worm was studied with a scanning electron microscope for the first time resulting in the detection of a pair of lappets located at the bilateral portion of the oral sucker. This is the first record of A. ibis in the Republic of Korea.