• 공업화학
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• 제34권6호
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• pp.660-664
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• 2023

In this study, a new system to determine the concentration of cholesterol using a color change was developed. The system comprised diacetylene vesicles and cholesterol oxidase (ChOx). 10,12-Pentacosadiynoic acid (PCDA) was used as the diacetylene compound, and PCDA vesicles were formed using sonication. The H₂O₂ produced during the reaction between cholesterol and ChOx was used to initiate the polymerization of the PCDA in the vesicles. During polymerization, the vesicles changed from colorless to blue. Therefore, the cholesterol concentration was proportional to the intensity of the blue color. The absorption at 665 nm indicated that the blue color was directly proportional to the cholesterol concentration. This indicates that the system can be used for cholesterol detection. The minimum cholesterol concentration detected using this system was 1.0 mM.

• International Journal of Stem Cells
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• 제16권3호
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• pp.260-268
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• 2023

Intrauterine adhesion (IUA) can occur after trauma to the basal layer of the endometrium, contributing to severe complications in females, such as infertility and amenorrhea. To date, the proposed therapeutic strategies are targeted to relieve IUA, such as hysteroscopic adhesiolysis, Foley catheter balloon, and hyaluronic acid injection have been applied in the clinic. However, these approaches showed limited effects in alleviating endometrial fibrosis and thin endometrium. Mesenchymal stem cells (MSCs) can offer the potential for endometrium regeneration owing to reduce inflammation and release growth factors. On this basis, MSCs have been proposed as promising methods to treat intrauterine adhesion. However, due to the drawbacks of cell therapy, the possible therapeutic use of extracellular vesicles released by stem cells is raising increasing interest. The paracrine effect, mediated by MSCs derived extracellular vehicles (MSC-EVs), has recently been suggested as a mechanism for their therapeutic properties. Here, we summarizes the main pathological mechanisms involved in intrauterine adhesion, the biogenesis and characteristics of extracellular vesicles, explaining how these vesicles could provide new opportunities for MSCs.

• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1616-1622
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• 2002

If the surfaces of vesicles are chemically modified so that they can be dispersed in organic solvents, the application of vesicular colloids may be expanded. A polymerizable surfactant (BDAC) and nonpolymerizable bipolar surfactant (BPAS) were synthesized in multi-steps. Large vesicles composed of BDAC and BPAS with embedded a cross-linking agent (divinylbenzene) underwent a radical polymerization. BPAS was extracted out using methanol (skeletonization). The headgroup of BDAC was cleaved off via hydrolysis in an acidic condition to yield vesicles where surfaces were covered with -COOH groups. There was no significant change in the overall shape. The skeletonized vesicles appear to have many holes with diameters up to about 25 nm. The holes retained even after hydrolysis. The hydrolyzed vesicles were not dispersed in water and most organic solvents such as tetrahydrofuran and chloroform, but dispersed in methanol.

• KSBB Journal
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• 제32권2호
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• pp.103-107
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• 2017

The effect of the trehalose incorporation on the biological membranes was investigated with respect to the phase of the membranes using the fluorescence intensity change. Spherical phospholipid bilayers, vesicles, were prepared only with the variation in the phase of each layer via a double emulsion technique. In the aqueous inside of the vesicles, 8-Aminonaphthalene-1,3,6-trisulfonic acid disodium salt(ANTS) was encapsulated. As a quencher, p-Xylene-bis(N-pyridinium bromide)(DPX) was included in the buffer where the vesicles were dispersed. The fluorescence scale was calibrated with the fluorescence of ANTS vesicles in p-Xylene-bis(N-pyridinium bromide)(DPX)-included-buffer taken as 100% fluorescence and the mixture of ANTS and DPX in the buffer as 0% fluorescence. Trehalose injection into the vesicle solution led the distortion of the membrane. It was found that the distortion was related to the phase of each layer the vesicle up on the ratio of trehalose to lipid. In the identical measurements at glucose, the behavior of the distortion was completely different from that of trehalose. These results seem to depend on the stability of the vesicles, due to the osmotic and volumetric effects on the headgroup packing disruption.

• BMB Reports
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• 제29권1호
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• pp.22-26
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• 1996

Agents that activate or inhibit the $Ca^{2+}$ release channel in cardiac sarcoplasmic reticulum (SR) were tested for their abilities to affect the activity of the SR $Ca^{2+}$-ATPase. Vesicles of junctional SR (heavy SR, HSR) from terminal cisternae were prepared from porcine cardiac muscle by density gradient centrifugation. The steady-state activity of $Ca^{2+}$-ATPases in intact HSR vesicles was/$347{\pm}5\;nmol/min{\cdot}mg$ protein (${\pm}$ SD). When the HSR vesicles were made leaky, the activity was increased to $415{\pm}5\;nmol/min{\cdot}mg$ protein. This increase is probably due to the uncoupling of HSR vesicles. Caffeine (10 mM), an agonist of the SR $Ca^{2+}$ release channel, increased $Ca^{2+}$-ATPase activity in the intact HSR vesicle preparation to $394{\pm}30\;nmol/min{\cdot}mg$ protein. However, caffeine had no significant effect in the leaky vesicle preparation and in the purified $Ca^{2+}$-ATPase preparation. The effect of caffeine on SR $Ca^{2+}$-ATPase was investigated at various concentrations of $Ca^{2+}$. Caffeine increased the pump activity over the whole range of $Ca^{2+}$ concentrations, from $1\;{\mu}M$ to $250\;{\mu}M$, in the intact HSR vesicles. When the SR $Ca^{2+}$-ATPase was inhibited by thapsigargin, no caffeine effect was observed. These results imply that the caffeine effect requires the intact vesicles and that the increase in $Ca^{2+}$-ATPase activity is not due to a direct interaction of caffeine with the enzyme. We propose that the activity of SR $Ca^{2+}$-ATPase is linked indirectly to the activity of the $Ca^{2+}$ release channel (ryanodine receptor) and may depend upon the amount of $Ca^{2+}$ released by the channels.

• Molecules and Cells
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• 제40권9호
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• pp.643-654
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• 2017

Autophagy is a degradation pathway in eukaryotic cells in which aging proteins and organelles are sequestered into double-membrane vesicles, termed autophagosomes, which fuse with vacuoles to hydrolyze cargo. The key step in autophagy is the formation of autophagosomes, which requires different kinds of vesicles, including COPII vesicles and Atg9-containing vesicles, to transport lipid double-membranes to the phagophore assembly site (PAS). In yeast, the cis-Golgi localized t-SNARE protein Sed5 plays a role in endoplasmic reticulum (ER)-Golgi and intra-Golgi vesicular transport. We report that during autophagy, sed5-1 mutant cells could not properly transport Atg8 to the PAS, resulting in multiple Atg8 dots being dispersed into the cytoplasm. Some dots were trapped in the Golgi apparatus. Sed5 regulates the anterograde trafficking of Atg9-containing vesicles to the PAS by participating in the localization of Atg23 and Atg27 to the Golgi apparatus. Furthermore, we found that overexpression of SFT1 or SFT2 (suppressor of sed5 ts) rescued the autophagy defects in sed5-1 mutant cells. Our data suggest that Sed5 plays a novel role in autophagy, by regulating the formation of Atg9-containing vesicles in the Golgi apparatus, and the genetic interaction between Sft1/2 and Sed5 is essential for autophagy.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3509-3513
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• 2014

Phospholipase D (PLD) catalyzed the generation of phosphatidic acid (PA) from phosphatidylcholine (PC) at the outer layer of the vesicles prepared through layer by layer via a double emulsion technique. The generation induced a curvature change in the vesicles, which eventually led them to fuse each other. The ratio of two-fatty-acid-tail ethanolamine (PE) to one-fatty-acid-tail ethanolamine (PE) was found to acquire the condition where the mixed-phospholipid vesicles were stable identically with pure two-fatty-acid-tail PC. The effect of the outer-layer mixture on the PLD-induced vesicle fusion was investigated using the fluorescence intensity change. 8-Aminonaph-thalene-1,3,6-trisulfonic acid disodium salt (ANTS) and p-Xylene-bis(N-pyridinium bromide) (DPX) were encapsulated in the vesicles, respectively, for the quantification of the fusion. The fluorescence scale was calibrated with the fluorescence of a 1/1 mixture of ANTS and DPX vesicles in NaCl buffer taken as 100% fluorescence (0% fusion) and the vesicles containing both ANTS and DPX as 0% fluorescence (100% fusion), considering the leakage into the medium studied directly in a separate experiment using vesicles containing both ANTS and DPX. The fusion data for each composition were acquired with the subtraction of the leakage from the quenching. From the monitoring, the vesicle fusion caused by the PLD reaction seems dominantly to occur rather than the vesicle lysis, because the composition effect on the fusion was observed identically with that on the change in the vesicle structure. Furthermore, the diameter measurements also support the fusion dominancy.

• Applied Microscopy
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• 제28권2호
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• pp.171-180
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• 1998

본 연구에서는 dehydrocholic acid를 투여한 흰쥐 간세포의 vacuolar apparatus를 세포화학적으로 관찰하고자 하였다. 박절편에서 Golgi 장치의 형성면 수조는 소낭상으로 팽대된 부분이 열지어 있었으며 어떤것은 돌출되어 있었다. 이러한 소낭 모양의 돌출부는 용해소체 표면에서도 관찰되었다. 소포들은 Golgi 장치의 형성면 수조와 용해소채 및 담세관 주위에서 볼 수 있었으며 소포가 담세관에 융합되어 있는 것도 관찰되었다. 이러한 소견들은 dehydrocholic acid 투여 후 20분이 경과된 흰쥐에서 현저하였다. 정상군이나 실험군에서 거의 모든 Golgi 장치의 형성면은 담세관을 향하고 있었다. 박절편에서 Golgi 장치의 형성면 수조와 소낭 모양의 돌출부 및 소포는 가시물질을 거의 함유하고 있지 않았다. Osmium은 이들구조에서 심하게 침착되어 있었다. 용해소체와 그 주위에 있는 소포에서는 acid phosphatase 활성이 나타났다. 그러나 담세관 주위에 있는 소포에서는 osmium의 침착이나 acid phosphatase 활성이 경하게 나타나거나 관찰되지 않았다. 이러한 증거들로 미루어 소포는 Golgi 장치의 형성면과 용해소체에서 유래되며 이들소포가 담세관에 융합됨으로서 담즙산이 분비될 것으로 생각된다. 그러나 소포가 담세관에 접근해 감에 따라 소포의 효소활성은 저하되는 것 같이 보인다.

• Applied Microscopy
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• 제8권1호
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• pp.53-66
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• 1978

An attempt has been made to discriminate the synapses in the striatum consisting caudate nucleus, putamen and fundus striati of the cat with emphasis on the characteristic structures of axon terminals and postsynaptic profiles. The differentiation is based on the size and shape of vesicle in the bouton terminal, and the symmetrical or asymmetrical thickening the pre- and postsynaptic membrane. Four types of synapses could be differentiated: Type I: the bontons with asymmetrical,synaptic thickenings contain round 45 nm diameter vesicles and contact cell soma, dendritic shafts and dendritic spines (74%). Type II : the boutons contain round 45nm diameter vesicles and are associated with symmetrical membrane thickenings. These synapses are formed on the soma and dendritic shafts (6%). Type III: the boutons with symmetrical membrane thickenings contain 50-60 nm diameter pleomorphic vesicles, and contact soma and dendritic shafts (18%). Type IV: the terminals contain flattened vesicles ($25{\times}45 nm$) and are associated with symmetrical membrane thickenings. These synapses are found in contact with soma and dendritic shafts. Additionally, the bouton en passant, which is expanded from myelinated or unmyelinated axons containing round vesicles (45nm diameter) contacts the dendritic shaft or dendritic spine with asymmetrical membrane thickenings. Two unusual types of synapses, axo-axonic and dendro-dendritic, are found occasionally.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.107-114
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• 2005

Molecular aggregates of surfactant molecules consisting of one or more bilayers arranged in a hollow, closed, usually spherical geometry are termed “esicles”or “iposomes” In recent years it has been found that in certain systems the vesicular structure forms spontaneously and is long lived, and it has been suggested that these structures may in fact constitute the equilibrium state in these cases (as is true of micelles) This paper deals with the mixed CMC, vesicles, phase behavior, phase transition, geometrical structure, their formation and characterization in the aqueous solutions of mixed cationic/anionic surfactants systems. TEM micrographs revealed that the vesicles were of spherical shape and that their size was of around 180 nm. The zeta potentials are positive at CGS1-rich regions and negative at SLES-rich regions. In the region where SLES/CGS1 (6/4), the zeta potentials are very small, implying that the vesicles at this surfactant ratio may be less stable. At other surfactant ratios, the vesicles are thought to be stable, supported by large absolute values of zeta potentials and little change in UV absorbance for several months.