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비글개에서 l-muscone의 급성독성 및 아급성독성시험 연구
유아선,권오경,성하정,곽형일,방명주,박대규,정규혁,윤효인,조명행 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1
Single and 4 weeks oral administration of l-muscone, a major active ingredient of musk, to beagle dogs of both sexes were performed to investigate both acute and subacute toxicity. Beagle dogs(3 males and 3 females) in acute experiments were administered orally with single dosage of 2,000 ㎎/㎏ and groups of 9 male and 9 female beagle dogs in subacute experiments were given daily different dosage of l-muscone, 0.2㎎/㎏/day(low dosage group), 2 ㎎/㎏/day(middle dosage group), or 20 ㎎/㎏day(high dosage group) once a day for 4 weeks by oral route according to the Established Regulation of Korean Food and Drug Administration(1996.4.16). LD_50 value for beagle dogs was more than 2,000 ㎎/㎏ on oral route for both male and females. In animals administered with l-muscone, there were neither dead animals nor significant changes of body weights. In addition, no differences were found between control and treated groups in clinical signs, urinalysis, eye examination, hematology, serum chemistry, organ weight and other findings. No histolopathological lesions were observed in both control and treatment groups. Above data strongly suggest that l-muscone in beagle dogs is considered to be safe.
비·부비동 종양의 신생혈관 형성에서 COX-2 및 VEGF의 역할
도남용,박성용,조성일,윤혁수,박선홍,박영균,권대승,임성철 조선대학교 2003 The Medical Journal of Chosun University Vol.28 No.1
Background and Objectives : COX-2, the inducible form of cyclooxygenase(COX), is upregulated in transformed cells and in malignant cells, which have important roles in promotion of colorectal carcinogenesis, invasiveness and angiogenesis. Vascular endothelial growth factor(VEGF) may act as endothelial cell mitogen in various cancer tissues. It will increase tumor growth and angiogenesis. Aims of this study were to asses COX-2/VEGF expression and it's clinical correlation in sinonasal tumors and to investigate the effects on angiogenesis also. Materials and Method : The study samples were obtained from surgical removal of 27 cases of inverted papilloma(IPs), 5 cases of IP with malignant transformation(IP-MT), 16 cases of Squamous cell carcinoma(SCC) in sinonasal cavity COX-2 and VEGF expressions were assessed by immunohistochemical staining. Synchronism of COX-2/VEGF expression in one tumor cell was demonstrated with double immunofluorescence technique. Results : The expression rates of COX-2 were 37% in IP, 80% in IP-MT and 100% in SCC. The positive rates of VEGF were 29 6% in IP, 100% in IP-MT and SCC. COX-2 and VEGF expressions were increased as tumor progressed, and there is a positive correlation between COX-2 &EGF expressions. All clinical features which were compared are not associated with COX-2 &EGF expressions except malignant change in IP(p=0 028). Synchronism of COX-2/VEGF expressions was noted in all positive immunostaining samples. Conclusion : These findings suggest the role of COX-2 pathway could be involved in sinonasal tumor angiogenesis, which is modulated by VEGF COX-2 may act as autocrine factor in VEGF expression. There is a potential role for selective COX-2 inhibitors in the treatment of these lesions.
Membrane topology of helix 0 of the Epsin N-terminal homology domain.
Kweon, Dae-Hyuk,Shin, Yeon-Kyun,Shin, Jae Yoon,Lee, Jong-Hwa,Lee, Jung-Bok,Seo, Jin-Ho,Kim, Yong Sung Korean Society for Molecular Biology 2006 Molecules and cells Vol.21 No.3
<P>Specific interaction of the epsin N-terminal homology (ENTH) domain with the plasma membrane appears to bridge other related proteins to the specific regions of the membrane that are invaginated to form endocytic vesicles. An additional a-helix, referred to as helix 0 (H0), is formed in the presence of the soluble ligand inositol-1,4,5-trisphosphate [Ins(1,4,5)P3] at the N terminus of the ENTH domain (amino acid residues 3-15). The ENTH domain alone and full-length epsin cause tubulation of liposomes made of brain lipids. Thus, it is believed that H0 is membrane-inserted when it is coordinated with the phospholipid phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2], resulting in membrane deformation as well as recruitment of accessory factors to the membrane. However, formation of H0 in a real biological membrane has not been demonstrated. In the present study, the membrane structure of H0 was determined by measurement of electron paramagnetic resonance (EPR) nitroxide accessibility. H0 was located at the phosphate head-group region of the membrane. Moreover, EPR line-shape analysis indicated that no pre-formed H0-like structure were present on normal acidic membranes. PtdIns(4,5)P2 was necessary and sufficient for interaction of the H0 region with the membrane. H0 was stable only in the membrane. In conclusion, the H0 region of the ENTH domain has an intrinsic ability to form H0 in a PtdIns(4,5)P2-containing membrane, perhaps functioning as a sensor of membrane patches enriched with PtdIns(4,5)P2 that will initiate curvature to form endocytic vesicles.</P>
Search for a minimal machinery for Ca<sup>2+</sup>-triggered millisecond neuroexocytosis
Kweon, Dae-Hyuk,Kong, Byoungjae,Shin, Yeon-Kyun Elsevier 2019 NEUROSCIENCE Vol.420 No.-
<P><B>Abstract</B></P> <P>Neurons have the remarkable ability to release a batch of neurotransmitters into the synapse immediately after an action potential. This signature event is made possible by the simultaneous fusion of a number of synaptic vesicles to the plasma membrane upon Ca<SUP>2+</SUP> entry into the active zone. The outcomes of both cellular and <I>in vitro</I> studies suggest that soluble N-ethylmaleimide-sensitive-factor attachment protein receptors (SNAREs) and synaptotagmin 1 (Syt1) constitute the minimal fast exocytosis machinery in the neuron. Syt1 is the major Ca<SUP>2+</SUP>-sensor and orchestrates the synchronous start of individual vesicle fusion events while SNAREs are the membrane fusion machinery that dictates the kinetics of each single fusion event. The data also suggest that Ca<SUP>2+</SUP>-bound Syt1 is involved in the upstream docking step which leads to an increase in the number of fusion events or the size of the release, leaving the SNARE complex alone to carry out membrane fusion by themselves.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The single-vesicle fusion assays are promising tools to gain insights into the protein machinery for fast neuroexocytosis. </LI> <LI> Ca<SUP>2+</SUP>-bound synaptotagmin 1 may be involved in the docking step which controls the number of fusion events. </LI> <LI> SNARE complex alone may be sufficient to carry out ultrafast membrane fusion. </LI> <LI> Relationships between SNARE zippering and membrane fusion steps are yet to be determined. </LI> </UL> </P>
Hemifusion in Synaptic Vesicle Cycle
Kweon, Dae-Hyuk,Kong, Byoungjae,Shin, Yeon-Kyun Frontiers Media S.A. 2017 Frontiers in molecular neuroscience Vol.10 No.-
<P>In the neuron, early neurotransmitters are released through the fusion pore prior to the complete vesicle fusion. It has been thought that the fusion pore is a gap junction-like structure made of transmembrane domains (TMDs) of soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) proteins. However, evidence has accumulated that lipid mixing occurs prior to the neurotransmitter release through the fusion pore lined predominantly with lipids. To explain these observations, the hemifusion, a membrane structure in which two bilayers are partially merged, has emerged as a key step preceding the formation of the fusion pore. Furthermore, the hemifusion appears to be the bona fide intermediate step not only for the synaptic vesicle cycle, but for a wide range of membrane remodeling processes, such as viral membrane fusion and endocytotic membrane fission.</P>