• Korean Journal of Clinical Laboratory Science
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• v.56 no.1
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• pp.1-9
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• 2024

Exosomes are nano-sized membrane-bound extracellular vesicles containing various biological molecules, such as nucleic acids, proteins, and lipids, which can be used to modulate physiological processes. The exosomal molecules secreted by cells can be extensively used as tools for diagnosis and therapy. Exosomes carry specific molecules released by the cells they originate from, which can be transferred to surrounding cells or tissues by the exosome. For these reasons, exosomes can be exploited as biomarkers for diagnosis, carriers for drug delivery, as well as therapeutics. In stem cell technology, exosomes have been an attractive option because they can be used as safer therapeutic agents for stem cell-based cell-free therapy. Recently, studies have demonstrated the safety and efficacy of mesenchymal stem cell-derived exosomes in alleviating symptoms associated with coronavirus disease 2019 as they have anti-inflammatory and immunomodulatory potential. Performing multiple studies on exosomes would provide innovative next-generation options for clinical diagnostics and therapy. This review summarizes the use of exosomes focusing on their diverse roles. In addition, the potential of exosomes is illustrated with a focus on how exosomes can be exploited as powerful tools in the days to come.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.77-90
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• 1990

There have been conflicting reports concerning the effect of Panax ginseng on the contractility of vascular smooth muscle, i.e., Panax ginseng extract has been reported to cause relaxation, contraction or to have no effect on the tension of vascular smooth muscle. A further investigation of $Ca^{++}$ stores which supply $Ca^{++}$ for contraction of vascular smooth muscle is needed to understand the underlying mechanisms of this conflicting effect of ginseng alcohol extract (GAE). The present study was intended to examine the sources of calcium mobilized for contraction of vascular smooth muscle by GAE. Aortic ring preparations were made from the rabbit thoracic aorta and endothelial cells were removed from the ring. The contractility of the aortic ring was measured under various experimental conditions and $Ca^{++}$ flux across the membrane of aortic ring and the sarcoplasmic reticulum and mitochondria were measured with a calcium selective electrode. The result were summarized as follows; 1) At low concentration of extracellular $Ca^{++}$, GAE increased the contractility of vascular smooth muscle in dose-dependent fashion except high concentration $Ca^{++}$ (1 mM). 2) In the presence of ryanodine, GAE still increased contractility of vascular smooth muscle as much as control group, but in the presence of caffeine, GAE increased it significantly. i.e. Their effects seemed to be additive. 3) In the presence of verapamil+lanthanum, and verapamil+lanthanum+ryanodine, the contractility of the vascular smooth muscle was decreased, but a dose dependent increase in vascular tension was still demonstrated by GAE although total tension was low. 4) GAE increased $Ca^{++}$ efflux from vascular smooth muscle cells, but have no effect on $Ca^{++}$ influx. 5) GAE increased $Ca^{++}$ efflux from sarcoplasmic reticulum and mitochondria vesicles. From the above results, it may be concluded that GAE increased the release of $Ca^{++}$ from sarcoplasmic reticulum, mitochondria or other intracellular $Ca^{++}$ stores of vascular smooth muscle, but it does not increase $Ca^{++}$ influx across the plasma membrane.

• Archives of Pharmacal Research
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• v.20 no.1
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• pp.1-6
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• 1997

We determined the microviscosity of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex and liposomes of total lipids (SPMTL) and phospholipids (SPMPL) extracted from SPMV. Changes in the microviscosity induced by the range and rate of lateral diffusion were measured by the intramolecular excimerization of 1, 3-di(1-pyrenyl)propane (Py-3-Py). The microviscosity values of the direct probe environment in SPMV, SPMTL and SPMPL were 38.17, 31.11 and 27.64 cP, respectively, at$37^{\circ}C$and the activation energies $(E_a)$ of the excimer formation of Py-3-Py in SPMV, SPMTL and SPMPL were 8.236, 7.448 amd 7.025 kcal/mol, respectively. Probe location was measured by polarity and polarizability parameters of the probe Py-3-Py and probe analogues, pyrene, 1-pyrenenonanol and 1-pyrenemethyl-3${\beta}$-hydroxy-22, 23-bisnor-5-cholenate (PMC), incorporated into membranes or solubilized in reference solvents. There existed a good linear relationship between the first absorption peak of the $^1_a$ band and the polarizability parameter $(n^{2}-1)/(2n^{2}+1)$.The calculated refractive index values for SPMV, SPMTL and SPMPL were close to 1.50, which is higher than that of liquid paraffin (n=l.475). The probe location was also determined by using a polarity parameter $(f-1/2f^{I})$. Here f=$({\varepsilon}-1)/(2{\varepsilon}+1)$ is the dielectric constant function and $f^I=(n^2-1)/(2n^2+1)$ is the refractive index function. A correlation existed between the monomer fluorescence intensity ratio and the solvent polarity parameter. The probes incorporated in SPMV, SPMTL, and SPMPL report a polarity value close to that of 1-hexanol $({\varepsilon}=13.29)$. In conclusion, Py-3-Py is located completely inside the membrane, not in the very hydrophobic core, but displaced toward the polar head groups of phospholipid molecules, e.g., central methylene region of aliphatic chains of phospholipid molecules.

• Applied Microscopy
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• v.29 no.4
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• pp.459-470
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• 1999

To investigate the changes during the differentiation of the cerebral neurons of the embryogenic day (ED) 9 and 10, investigated the ultrastructural changes in the cerebral neurons by Electromicroscope, also cerebral protein, the activity of dehydronases (LDH, MDH and SDH) and changes of adenosine triphosphate concentration were analyzed, the result obtained are as follows. In the ultrastructural changes in the cerebral neurons, chromatin in 9 day-old chick embryos are comparatively distributed to even in neucleoplasm and could investigate very prominently that nuclear membrane is double-layer. Esperially, Rough endoplasmic reticulum (RER) and Golgi complex are developed well, also polysome is investigated and synaptic vesicles were scattered. In 10 day-old chick embryos, chromatin evenly spread and nuclear membrane could be differentiated prominently. Rough endoplasmic reticulum (RER) contain cytoplasm, mitochondria and Golgi complex are comparatively developed well. In 9 day-old cultural group of chick embryo cerebrum were separated 37 polypeptide bands and In 10 day-old cultural group of chick embryo cerebrum were separated 38 poly -peptide bands. The more culture time increase, the more the activity of dehydronases (LDH, MDH and SDH) increase. LDH activity was 11.07 (9th day) and 12.12 (10th day), MDH activity was 11.89 (9th day) and 13.44 (10th day) and SDH activity was 8.45 (9th day) and 10.52 (10th day) respectively. The ATP concentration degreesed 10 day-old cultural group than 9 day-old cultural group.

• International Journal of Oral Biology
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• v.42 no.4
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• pp.175-181
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• 2017

The aim of this study was to provide a basis for the molecular mechanism underlying the pharmacological action of ethanol. We studied the effects of 1-propanol on the location of n-(9-anthroyloxy)palmitic acid or stearic acid (n-AS) within the phospholipids of synaptosomal plasma membrane vesicles (SPMV). The SPMV were isolated from the bovine cerebral cortex and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL). 1-Propanol increased the rotational mobility of inner hydrocarbons, while decreasing the mobility of membrane interface, in native and model membranes. The degree of rotational mobility varied with the number of carbon atoms at positions 16, 12, 9, 6 and 2 in the aliphatic chain of phospholipids in the neuronal and model membranes. The sensitivity of increasing or decreasing rotational mobility of hydrocarbon interior or surface by 1-propanol varied with the neuronal and model membranes in the following order: SPMV, SPMVPL and SPMVTL.

• The Korean Journal of Zoology
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• v.32 no.1
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• pp.55-73
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• 1989

The effect of tryptophan or serotonin on the early stage of chick brain development has been morphologically investigated using an electron microscope. The electron micrographs of neural plate cells of 1-day chick embryo treated with tryptophan or serotonin showed irregularity, evagination and disruption of nuclear membrane and nuclear chromatin condenstation, nucleolar margination and segregation. Hypertrophy of stalks, vesicles and vaculoes were seen and dilated and disrupted rough endoplasmic reticulum and underdeveloped neurotubules were also observed. In mesenchyme cells of tryptophan or serotonin administered 18 hr embryo, irregular nuclear membrane, swollen mitochondria, dilated rough endoplasmic reticulum and very large yolk granules were observed. Furthermore, DNA, RNA and protein contents of the embryos treated with typtophan or serotonin were considerably lower than those of control group. The amount of tubulin of the experimental groups was also greatly lower than that of control, suggesting that the impairment of microtubule formation occurred. Tryptophan or serotonin administration might depress the biosynthesis, of nucleic acid and protein including some enzymes tested. It seems that the serotonin formed from exogeneous tryptophan might inhibit the degradation of yolk granule by feedback regulation mechanism so as to impair microtububle and microvilli formation followed by a malformation of chick embryos.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.137-150
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• 1985

The dorsal skin of Rana temporaria dybowskii Guenther was examined under electron microscope. The results of the fine structures in the xanthophores, iridophores and melanophores were as follows: Xanthophores: Xanthophores were filled with pterinosomes and carotenoid vesicles. Type I pterinosomes had a clear limiting membrane. Type II pterinosomes had the inner fibrous structures. Tyep III pterinosomes were characterized by a few superficial lamellae and type IV pterinosomes by multiple concentric lamellae. Especially typical type II and type III pterinosomes were evenly distributed in the cytoplasm. Iridophores: Iridophores were situated between a xanthophore and a melanophore in the outer part of the dermis just below the basement membrane. Iridophores were filled with reflective platelets, each of which is rectangular and convex lens-like in shape. These platelets were closely contiguous and leave no interspace between them. Endoplasmic reticulum and a few mitochondria were observed in the supranuclear cytoplasm. Melanophores: Dermal melanophores contained numerous melanosomes. The dendritic precesses of the melanophore containing the melanin granules extented up the lateral sides of the iridophore. Epidermal melanophores were filled with melanin granules which appered as the same electron density. A few melanin granules were observed in a cornified surface cell.

• Applied Microscopy
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• v.39 no.4
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• pp.333-340
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• 2009

In the present study, ultrastructural features of the mesophyll tissue have been investigated in Crassulacean acid metabolism (CAM)-performing succulent Orostachys. A large central vacuole and numerous small vacuoles in the peripheral cytoplasm were characterized at the subcellular level in both developing and mature mesophyll cells. The most notable feature was the invagination of vacuolar membranes into the secondary vacuoles or multivesicular bodies. In many cases, tens of single, membrane-bound secondary vacuoles of various sizes were found to be formed within the central vacuole. multivesicular bodies containing numerous small vesicles were also distributed in the cytoplasm but were better developed within the central vacuole. Occasionally, electron-dense prevacuolar compartments, directly attached to structures appearing to be small vacuoles, were also detected in the cytoplasm. One or more huge central vacuoles were frequently observed in cells undergoing differentiation and maturation. Consistent with the known occurrence of morphologically distinct vacuoles within different tissues, two types of vacuoles, one representing lytic vacuoles and the other, most likely protein storage vacuoles, were noted frequently within Orostachys mesophyll. The two types coexisted in mature vegetative cells but did not merge during the study. Nevertheless, the coexistence of two distinct vacuole types in maturing cells implies the presence of more than one mechanism for vacuolar solute sorting in these species. The vacuolar membrane is known to be unique among the intracellular compartments for having different channels and/or pumps to maintain its function. In CAM plants, the vacuole is a very important organelle that regulates malic acid diurnal fluctuation to a large extent. The membrane invagination seen in Orostachys mesophyll likely plays a significant role in survival under the physiological drought conditions in which these Orostachys occur; by increasing to such a large vacuolar volume, the mesophyll cells are able to retain enormous amounts of acid when needed. Furthermore, the mesophyll cells are able to attain their large sizes with less energy expenditure in order to regulate the large degree of diurnal fluctuation of organic acid that occurs within the vacuoles of Orostachys.

• Applied Microscopy
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• v.30 no.2
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• pp.153-163
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• 2000

This study aims to demonstrate the effect of squalene (SQ), one of the natural chelator, on the ultrastructural changes in the mouse liver caused by $HgCl_2$. A total of 40 healthy ICR that weighted 30 gm $({\pm}2gm)$ was used for experiment. The experimental group was divided into two groups; group A and B. The group A administrated $HgCl_2$ (4.0mg/kg) to the intraperitoneal. The group B administrated $HgCl_2$ (4.0 mg/kg) to the intraperitoneal treated with SQ (180 mg/kg, 2 times/day). Each group was observed at 24, 48, 72, 96 hours after injected $HgCl_2$. The results were as follows: 1. Group A Nucleus showed condensation of nuclear membrane at the 24 hours. At the 48 hours, observed distinct condensation. But nuclear membrane be seen relative rounded-shape at the 96 hours. At overall the time, inner cavity of mitochondria swollen and development of cristae weakened. Also electron density of matrix was a little low. At the 72 hours, destruction of the inner and outer membrane of mitochondria observed occasionally. Swelling of inner cavity of rER and destruction of lamellae be found from 24 hours to 72 hours, but at the 96 hours, only some swelling 2. Group B Nuclear membrnae and chromatin be seen normal shape at overall the time. Mitochondria showed destruction of the inner membrane until the 48 hours, but mostly normal shapes. Electron density showed high on the all groups. RER be found swelling of inner cavity at the 24 and 48 hours, but found typical lamellae and observed a number of transfer vesicles around rER at the 72 and 96 hours. These results suggest that squalene attenuates the toxic effect of the $HgCl_2$ in the mouse liver.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.213-219
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• 2007

It has been well established that aluminum (Al) inhibits root tip growth rapidly in acid soil. We report the correlation between Al induced growth inhibition and impaired $H^+-flux$ in mung bean (Vigna radiate L. cv. Kumsung). The root growth inhibition was dependent on Al concentration (0, 10, 25, 50, $100{\mu}M$) and exposure time (12 and 24 h). Using Hematoxylin staining, it was observed that the root damage was occurred preferentially in regions with high Al accumulation. Using the pH indicator, it was shown that the surface pH of root tip was strongly alkalized in the control whereas changed only slightly in the $50{\mu}M$ Al-treated root. The $H^+-ATPase$ activity of plasma membrane vesicles was inhibited by 56% in the Al-treated roots compared to control root. Decrease in the amount of the plasma membrane $H^+-ATPase$ (100 kDa) translation in the plant roots under Al stress was demonstrated by Western blot analysis. These results indicate that the dynamics of $H^+-flux$ across the root tip play an important role in root growth under Al stress.