• Applied Microscopy
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• v.21 no.2
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• pp.117-125
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• 1991

This study has been carried out to investigate the development of dictyosome, and roles of dictyosome about the formation of spherosome in the endosperm cell during seed formation of Panax ginseng with electron microscope. The result is as follows; In the endosperm cells of early stage during seed formation of Panax ginseng, plastid, mitochondria, endoplasmic reticulum, dictyosome and ribosomes are evenly distributed in cytoplasm. Electron lucent vesicles derived from dictyosome are observed in endosperm cells. Vesicles that contain low electron density are derived from forming face of dictyosome and releases into the cytosol. This vesicles formed multi vesicular body or fused with the plasma membrane. The spherical spherosomes are formed from dictyosome containing the lipid materials of even electron density and are gradually increased in size and number. Dictyosome is located in between vacuole and spherosome and it's cisternae form a semicircle and a circle. Some membrane of the protein body that accumulate the storage protein are originate from the spherical vacuole which interfused between vesicles and vacuoles derived from dictyosome.

• Journal of Biomedical Engineering Research
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• v.45 no.1
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• pp.20-25
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• 2024

Extracellular vesicles (EVs) are nano-sized lipid bilayer vesicles released by cells. EVs act as messengers for cell-to-cell communication. Inside, it contains various substances that show biological activity, such as proteins, lipids, nucleic acids, and metabolites. The study of EVs extracted from terrestrial organisms and stem cells on inflammatory environments and tissue regeneration have been actively conducted. However, marine organisms-derived EVs are limited. Therefore, we have extracted EVs from sea urchins belonging to the Echinoderm group with their excellent regenerative ability. First, we extracted extracellular matrix (ECM) from sea urchin gonads treated with hypotonic buffer, followed by collagenase treatment, and filtration to collect ECM-bounded EVs. The size of sea urchin gonad-derived EVs (UGEVs) is about 20-100 nm and has a round shape. The protein content was higher after EVs burst than before, which is evidence that proteins are contained inside. In addition, proteins of various sizes are distributed inside. PKH-26 was combined with UGEVs, which means that UGEVs have a lipid membrane. PHK-26-labeled UGEVs were successfully uptaken by cells. UGEVs can be confirmed to have the same characteristics as traditional EVs. Finally, it was confirmed that Schwann cells were not toxic by increasing proliferation after treatment.

• Applied Microscopy
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• v.12 no.1
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• pp.49-56
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• 1982

A case of systemic cryptococcosis developed in 4 year old boy was described and illustrated by light and electron microscope. Light microscopically, the upper dermis of the skin showed chronic nonspecific inflammation with numerous spherical spores surrounded by a clear halo created by the wide gelatinous capsule. Ultrastructurally, the C. neoformans showed the wide capsule containing microfibrils that appeared to radiate from the cell wall and to coil and interwine in various directions. The cell was uninucleate with a single nucleolus. Along the inner nuclear envelope, numerous small vesicles were present. In addition, C. neoformans presented membranous organelles derived from the plasma membrane and comparable to bacterial mesosomes.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.56-63
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• 2007

Insulin stimulates the fusion of intracellular vesicles containing glucose transporter 4 (GLUT4) with plasma membrane in adipocytes and muscle cells. Here we show that adipocyte differentiation results in enhanced insulin sensitivity of glucose uptake. On the other hand, glucose uptake in response to platelet-derived growth factor (PDGF) stimulation was markedly reduced by adipocyte differentiation. Expression level of insulin receptor and caveolin-1 was dramatically increased during adipocyte differentiation. Adipocyte differentiation caused :ilightly enhanced activation of acutely transforming retrovirus AKT8 in rodent T cell lymphoma (Akt) by insulin stimulation. However, activation of Akt by PDGF stimulation was largely reduced. Activation of ERK was not detected in both fibroblasts and adipocytes after stimulation with insulin. PDGF-dependent activation of ERK was reduced by adipocyte differentiation. Insulin-dependent glucose uptake was abrogated by LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, in both fibroblasts and adipocytes. Also disassembly of caveolae structure by $methyl-\beta-cyclodextrin$ caused impairment of Akt activation and glucose uptake. Finally, insulin receptor, Akt, SH2-domain-containing inositol 5-phosphatase 2 (SHIP2), and regulatory subunit of PI3K are localized at lipid raft domain and the translocation was facilitated upon insulin stimulation. Given these results, we suggest that lipid raft provide proper site for insulin action for glucose uptake.