• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1984-1989
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• 2006

Deacetylated chitosan oligosaccharide (COS) had effective antiprotozoal activity against Trichomonas vaginalis (Minimal Inhibitory Concentration, MIC 0.25%), whereas 80% acetylated cas showed no antiprotozoal activity (MIC > 1 %). an the other hand, 80% acetylated cas showed growth stimulatory activity against the protozoa. When T. vaginalis was treated with 98% deacetylated COS at 0.25% concentration, the viability of the protozoa was rapidly decreased within 15 min, and the protozoa completely died within 40 min. Ultrastructural changes of trichomonads treated with COS included a loss of defined nuclear membrane and endoplasmic reticulum membranes, an increase in the number of free ribosome, vacuolation, and ultimately lysis of the cell membrane. These results indicate that deacetylated COS can be used as an antitrichomonal agent, although its lethal mechanism is not known.

• Applied Microscopy
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• v.11 no.1
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• pp.1-9
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• 1981

The study on the nerve cells in the subesophageal ganglion of 5-day-old cabbage butterfly, Pieris rapae L., was performed to observe their ultrastructures and classify them on the basis of the differences in size, shape and relative distribution of cell organelles. 1. Type I neurons: These cells are neurosecretory granules ranging 100 to 300 nm in size. 2. Type II neurons: As giant neurons averaging 25 to $30{\mu}m$ in size, such as mitochondria and Golgi apparatus. 3. Type III neurons: These spindle-shaped cells range 9 to $15{\mu}m$ in width. 4. Type IV neurons: These cells have a range of diameter from 12 to $16 {\mu}m$. The cells are abundantly observed in the subesophageal ganglion. 5. Type V neurons: These cells are very small nerve cells with 4.5 to $8.0{\mu}m$ in size and have a prominent nucleus.

• Applied Microscopy
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• v.26 no.3
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• pp.369-377
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• 1996

Ultrastructural changes of chloride cells in the gill from seawater-adapted killifish (Orizias latipes) were studied with a transmission electronmicroscope. Chloride cells contain many mitochondria and specifically developed tubular systems. Apical pits, formed by several neighboring chloride cells, were exposed to the environment. Degeneration and death of the chloride cells by apoptosis occurred more frequently than by necrosis. Apoptotic chloride cells shrank, became to apoptotic bodies, and eventually were phagocytosed and digested by the microphages around them. We conclude that apoptosis plays an important role in increased cellular turnover of chloride cells for the osmoregulation caused by changes in salinity of the environment.

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.33-40
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• 2008

Ultastructural studies of oocyte degeneration and follicle cells in female Spisula sachalinensis are described for clams collected from Jumunjin, Gangwondo, Korea. The follicle cells playan integral role in vitellogenesis and oocyte degeneration by assimilating products originating from the degenerated oocytes (thus allowed the transfer of yolk precursors needed for vitellogenesis). The functions of the follicle cells include phagocytosis and intracellular digestion of products originating from oocyte degeneration. During the period of oocyte degeneration, follicle cells of this species probably have lysosomal systems for the breakdown and reabsorption of various phagosomes(phagolysosomes) in the cytoplasm for nutrient storage; this process has been observed in other bivalves.

• Korean Journal of Veterinary Research
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• v.49 no.4
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• pp.361-363
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• 2009

Rhabdoid tumor is an aggressive neoplasm of animals and human. It is similar with rhabdomyosarcoma histopathologically. But cellular origin of this neoplasm showed no striated muscle origin by immunohistological and ultrastructural studies. Castrated male Shit-tzu dog, 6 years old, had a mass in the left gluteal region near to the tail. The mass was examined histopathologically and immunohistologically. Histopathologically, the tumor was consisted of large polygonal cell with abundant eosinophilic cytoplasm. The nuclei in some cells were marked eccentrically located. Immunohistochemically, many neoplastic cells were positive for vimentin. These findings were similar to histopathological and immunohistological features of human rhabdoid tumor and few rhabdoid tumors in animals.

• Journal of Korean Foot and Ankle Society
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• v.6 no.1
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• pp.129-133
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• 2002

Extraskeletal myxoid chondrosarcoma is an unusual soft tissue sarcoma with distinctive histologic features. It once was called chordoid sarcoma because it resembles chordoma histologically. The lesion has been shown to be of chondroblastic origin. This lesion shown to have ultrastructural and molecular features distinct from that of myxoid chondrosarcoma of bone. We report a case of extraskeletal myxoid chondrosarcoma in forefoot.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.1
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• pp.83-86
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• 2001

Myoepithelioma is histologically composed exclusively of myoepithelial cells. Myoepithelial cells are present in the major and minor salivary glands. Salivary gland neoplasms that frequently contain myoepithelial cells are the pleomorphic adenoma, adenoid-cystic carcinoma, and epithelial myoepithelial carcinoma of intercalated duct origin. Neoplasms composed exclusively of myoepithelial cells are rare. Myoepitheliomas may be composed of spindle-shaped cells, plasmacytoid(hyaline) cells, or combination of both in varying proportions. A case is reported of plasmacytoid myoepithelioma with ultrastructural confirmation, together with reviews of the English literature.

• Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.196-199
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• 2007

The spermatozoa of Leiocassis nitidus are relatively simple cells composed of a spherical head, a short midpiece, and a tail, as in most Siluriformes. The ultrastructure is characterized by the following features: Acrosome absent, as in most teleosts; around nucleus about $1.8\;{\mu}m$ long, with a deep nuclear fossa containing the proximal and distal centrioles and mitochondria. Two centrioles approximately $180^{\circ}$ from each other; 10 or more mitochondria surrounding the axoneme (with a 9+2 microtubular pattern), arranged in two layers in the postnuclear cytoplasm and separated from the axoneme by the cytoplasmic canal. Two lateral fins on the same plane as the two central microtubules; doublets 3 and 8, which are ultrastructural characteristics of the sperma tail unlike other siluroids laking the lateral fins.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.56-60
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• 1999

Sexual reproduction is an essential process in the propagation of flowering plants. Recent advances in plant cell biology and biotechnology have brought new and powerful methodologies to investigate and manipulate the reproductive processes of angiosperms including agronomically important crop plants. Successful cryopreservation of maize, rye and triticale pollen and young embryos of microspore-and zygote-origine contributes to long term preservation of important plant germ-lines in gene banks. Discovering morphogenetic characteristics of the different developmental pathways taking place in wheat and maize androgenesis in vitro helps to influence the procedure to produce genetically and phenotipically stable homozygous doubled haploid plants for breeding purposes. Detailed ultrastructural and cell-biological studies on the developmental sequences of male and female gametophyte development in wheat, experimental protocols developed to isolate and micromanipulate egg cell protoplasts, make it possible to use plant gametes and the sexual route itself to produce genetically improved organisms. Plant gametes can become useful tools for crop improvement in the near future. Recent achievements by our laboratory in this field are reviewed in the present paper

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.111-116
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• 2002

This study investigated quantitative changes in the spaces between and within myofibrils and the impact of high and low voltage electrical stimulation on muscle ultrastructure as seen in electron micrographs. In addition, the relationships of these spaces and the impact to meat tenderness were investigated. The degradation of myofibrils during aging appeared to be localized across the muscle fibre. Structural deterioration of muscle fibres was evident 1 day post-mortem, involving the weakening in the lateral integrity of the myofibrils and Z-disc regions. Meat tenderisation, as shown by objective measurements, coincided with these increases in degradation, as assessed by the sum of the gaps between and within myofibrils. The results showed that the total size of gaps between and within myofibrils can be used as an indicator of meat tenderization during aging, but that ultrastructural alteration in electrically stimulated muscle had little relationship with meat tenderness.