• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.4
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• pp.441-451
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• 2019

When a store is launched, the umbilical plug should be separated from the launcher without any physical interference and fragments. In order to satisfy these conditions, an umbilical plug and an umbilical separating device were designed. The plug is separated from the receptacle of the store while moving along inclined planes by the store thrust and the spring force connected from the launcher to the plug. As a result of the prototype test, the hanger on the store collided with the plug. Several tests were conducted after some actions were taken to prevent the collision. However, not only the same phenomenon was repeated, but also fragmentation occurred. In this study, the non-colliding conditions were analyzed through rigid and flexible multi-body dynamics analysis.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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• pp.335-340
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• 2015

Here, we investigated the role of zerumbone, a natural cyclic sesquiterpene of Zingiber zerumbet Smith, on angiogenesis using human umbilical vein endothelial cells (HUVECs). Zerumbone inhibited HUVECs proliferation, migration and tubule formation, as well as angiogenic activity by rat aorta explants. In particular, zerumbone inhibited phosphorylation of vascular endothelial growth factor receptor-2 and fibroblast growth factor receptor-1, which are key regulators of endothelial cell function and angiogenesis. In vivo matrigel plug assay in mice demonstrated significant decrease in vascularization and hemoglobin content in the plugs from zerumbone-treated mice, compared with control mice. Overall, these results suggest that zerumbone inhibits various attributes of angiogenesis, which might contribute to its reported antitumor effects.

• Advances in pediatric surgery
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• v.3 no.2
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• pp.168-171
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• 1997

Appendiceal perforation is uncommon in the neonate. Diess reported the first case in 1908. Approximately 111 additional cases have been reported since that time. However, with exclusion of neonatal appendicitis associated with inguinal or umbilical hernias, necrotizing enterocolitis, meconium plug, and Hirschsprung's disease, there are only 36 cases of primary neonatal appendicitis. We treated a 12 days old boy with perforation of the appendix. The infant was 3000 g at birth and had a normal spontaneous vaginal delivary at 35 weeks of gestation. The mother was 31-year-old and had premature rupture of membrane. After normal feeding for the first 5 days of life, the infant had emesis of undigested milk, decreased activity and jaundice. The baby was admitted to the Pediatrics. Progressive abdominal distension, fever, decreased activity, and vomitting developed over the next six days. Erect abdominal radiography showed pneumoperitoneum. At exploratory laparotomy, a $0.8{\times}0.6$ cm sized perforation was noted at antime-senteric border of midportion of the appendix. Trasmural inflammation and the presence of ganglion cells were noticed on histology.

• Journal of Acupuncture Research
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• v.24 no.5
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• pp.23-32
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• 2007

Objectives : Angiogenesis consists of the proliferation, migration, and differentiation of endothelial cells, and angiogenic factors and matrix protein interactions modulate this process. The aim of this study was to determine whether herbs medicine(KHBJs) could induce angiogenic activity in human umbilical vein endothelial cells(HUVECs). Methods : The angiogenic activity of KHBJs were evaluated by proliferation using BrdU assay, chemotactic migration assay, tube formation assay, and measurement of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor(VEGF) in HUVECs. Also, In order to identify enhance angiogenic activity by activity guided fractionation, the angiogenic activity of fractions of KHBJs such as KHBJB or KHBJR were evaluated in vitro and in vivo Matrigel plug angiogenesis asaay. Results : About 9 KHBJs significantly increased HUVECs proliferation in a dose-dependent manner. In addition, 9 herbs medicine(KHBJs) increased migration and tube-like formation in HUVECs. Interestingly the expression of bFGF and VEGF, an angiogenesis-inducing growth factor, were dose-dependently increased by KHBJs. However, angiogenic activity of fractionated KHBJs(KHBJB or KHBJR) not enhanced more than KHBJs in HUVECs and Matrigel plug in vivo angiogenesis assay. Conclusions : 9 KHBJs significantly induces angiogenesis in in vitro and in vivo. These results suggest that 9 KHBJs potent angiogenic agents and promising drug for the induction of neovascularization.

• Journal of Acupuncture Research
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• v.22 no.2
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• pp.171-180
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• 2005

Background & Objective : Angiogenesis consists of the proliferation, migration, and differentiation of endothelial cells, and angiogenic factors and matrix protein interactions modulate this process. The aim of this study was to determine whether Puerariae radix could induce angiogenic activity in human umbilical vein endothelial cells (HUVECs). Methods: The angiogenic activity of Puerariae radix were evaluated by using BrdU assay, chemotactic migration assay, tube formation assay, measurement of bFGF in HUVECs, and Matrigel plug assay in mice. Results : Puerariae radix significantly increased HUVECs proliferation in a dose-dependent manner. In addition, Puerariae radix increased migration and tube-like formation in HUVECs. Interestingly,the expression of basic fibroblast growth factor (bFGF), an angiogenesis-stimulating growth factor, was dose-dependently increased by Puerariae radix. The angiogenic activity of Puerariae radix was confirmed using an in vivo Matrigel angiogenesis model, showing promotion of blood vessel formation. Conclusion : Puerariae radix significantly induces angiogenesis in vitro and in vivo. These results suggest that Puerariae radix is a potent angiogenic agent, and a promising drug, for the induction of neovascularization.

• Molecules and Cells
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• v.39 no.11
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• pp.790-796
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• 2016

Dental pulp is a highly vascularized tissue requiring adequate blood supply for successful regeneration. In this study, we investigated the functional role of stem cells from human exfoliated deciduous teeth (SHEDs) as a perivascular source for in vivo formation of vessel-like structures. Primarily isolated SHEDs showed mesenchymal stem cell (MSC)-like characteristics including the expression of surface antigens and in vitro osteogenic and adipogenic differentiation potentials. Moreover, SHEDs were positive for NG2, ${\alpha}$-smooth muscle actin (SMA), platelet-derived growth factor receptor beta ($PDGFR{\beta}$), and CD146 as pericyte markers. To prove feasibility of SHEDs as perivascular source, SHEDs were transplanted into immunodeficient mouse using Matrigel with or without human umbilical vein endothelial cells (HUVECs). Transplantation of SHEDs alone or HUVECs alone resulted in no formation of vessel-like structures with enough red blood cells. However, when SHEDs and HUVECs were transplanted together, extensive vessel-like structures were formed. The presence of murine erythrocytes within lumens suggested the formation of anastomoses between newly formed vessel-like structures in Matrigel plug and the host circulatory system. To understand underlying mechanisms of in vivo angiogenesis, the expression of angiogenic cytokine and chemokine, their receptors, and MMPs was compared between SHEDs and HUVECs. SHEDs showed higher expression of1VEGF, SDF-$1{\alpha}$, and $PDGFR{\beta}$ than HUVECs. On the contrary, HUVECs showed higher expression of VEGF receptors, CXCR4, and PDGF-BB than SHEDs. This differential expression pattern suggested reciprocal interactions between SHEDs and HUVECs and their involvement during in vivo angiogenesis. In conclusion, SHEDs could be a feasible source of perivascular cells for in vivo angiogenesis.

• Molecules and Cells
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• v.40 no.6
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• pp.386-392
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• 2017

Periodontal ligament stem cells (PDLSCs) are multipotent stem cells derived from periodontium and have mesenchymal stem cell (MSC)-like characteristics. Recently, the perivascular region was recognized as the developmental origin of MSCs, which suggests the in vivo angiogenic potential of PDLSCs. In this study, we investigated whether PDLSCs could be a potential source of perivascular cells, which could contribute to in vivo angiogenesis. PDLSCs exhibited typical MSC-like characteristics such as the expression pattern of surface markers (CD29, CD44, CD73, and CD105) and differentiation potentials (osteogenic and adipogenic differentiation). Moreover, PDLSCs expressed perivascular cell markers such as NG2, ${\alpha}-smooth$ muscle actin, platelet-derived growth factor receptor ${\beta}$, and CD146. We conducted an in vivo Matrigel plug assay to confirm the in vivo angiogenic potential of PDLSCs. We could not observe significant vessel-like structures with PDLSCs alone or human umbilical vein endothelial cells (HUVECs) alone at day 7 after injection. However, when PDLSCs and HUVECs were co-injected, there were vessel-like structures containing red blood cells in the lumens, which suggested that anastomosis occurred between newly formed vessels and host circulatory system. To block the $SDF-1{\alpha}$ and CXCR4 axis between PDLSCs and HUVECs, AMD3100, a CXCR4 antagonist, was added into the Matrigel plug. After day 3 and day 7 after injection, there were no significant vessel-like structures. In conclusion, we demonstrated the perivascular characteristics of PDLSCs and their contribution to in vivo angiogenesis, which might imply potential application of PDLSCs into the neovascularization of tissue engineering and vascular diseases.

• Animal Bioscience
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• v.36 no.1
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• pp.43-52
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• 2023

Objective: This study aimed to examine the influence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on pregnancy in cytokeratin-18 (K18)-hACE2 transgenic mice. Methods: To determine the expression of hACE2 mRNA in the female reproductive tract of K18-hACE2 mice, real-time polymerase chain reaction (RT-PCR) was performed using the ovary, oviduct, uterus, umbilical cord, and placenta. SARS-CoV-2 was inoculated intranasally (30 μL/mouse, 1×10⁴ TCID₅₀/mL) to plug-checked K18-hACE2 homozygous female mice at the pre-and post-implantation stages at 2.5 days post-coitum (dpc) and 15.5 dpc, respectively. The number of implantation sites was checked at 7.5 dpc, and the number of normally born pups was investigated at 20.5 dpc. Pregnancy outcomes, including implantation and childbirth, were confirmed by comparison with the non-infected group. Tissues of infected mice were collected at 7.5 dpc and 19.5 dpc to confirm the SARS-CoV-2 infection. The infection was identified by performing RT-PCR on the infected tissues and comparing them to the non-infected tissues. Results: hACE2 mRNA expression was confirmed in the female reproductive tract of the K18-hACE2 mice. Compared to the non-infected group, no significant difference in the number of implantation sites or normally born pups was found in the infected group. SARS-CoV-2 infection was detected in the lungs but not in the female reproductive system of infected K18-hACE2 mice. Conclusion: In K18-hACE2 mice, intranasal infection with SARS-CoV-2 did not induce implantation failure, preterm labor, or miscarriage. Although the viral infection was not detected in the uterus, placenta, or fetus, the infection of the lungs could induce problems in the reproductive system. However, lung infections were not related to pregnancy outcomes.

• Journal of Life Science
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• v.33 no.9
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• pp.703-712
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• 2023

Angiogenesis, the formation of blood vessels from pre-existing vessels, is a multistep process regulated by modulators of angiogenesis. It is essential for various physiological processes, such as embryonic development, chronic inflammation, and wound repair. Dysregulation of angiogenesis causes many diseases, such as cancer, autoimmune diseases, rheumatoid arthritis, cardiovascular disease, and delayed wound healing. However, the number of effective anti-angiogenic drugs is limited. Recent research has focused on identifying potential drug candidates from natural sources. For example, marine natural products have been shown to have anti-cancer, anti-oxidant, anti-inflammatory, antiviral, and wound-healing effects. Thus, this study aimed to describe the angiogenesis inhibitory effect of Hizikia fusiforms (brown algae) extract. The hexane extract of H. fusiformis has shown inhibitory effects on in vitro angiogenesis assays, such as cell migration, invasion, and tube formation in human umbilical vein endothelial cells (HUVECs). The hexane extract of H. fusiformis (HFH) inhibited in vivo angiogenesis in a mouse Matrigel gel plug assay. In addition, the protein expression of vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK)/extracellular signal kinase, and AKT serine/threonine kinase 1 decreased following treatment with H. fusiformis extracts. Our results demonstrated that the hexane extract of H. fusiformis (HFH) inhibits angiogenesis in vitro and in vivo.