• The Plant Pathology Journal
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• v.17 no.2
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• pp.94-100
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• 2001

Roots of Chinese cabbage (Brassica campestris var. chinensis) seedlings infected with Plasmodiophora brassicae were examined by light and electron microscopy to reveal histopathological changes related to pathogenesis in the susceptible host. The pathogen colonized the cortex and partly the stele as well, invading up to the xylem. Gall tissues could be differentiated from the initially infected tissues, involving less compact organization and new vascular development. The infected cells were much hypertrophied, and contained one to several plasmodia. Except cellular hypertrophy, no pathological ultrastructural modification was noted in the infected calls. Infected cytoplasm became dense with ground cytoplasm, inconspicuous central vacuole, and increased cellular organelles such as mitochondria and dictyosomes. There were two types of nuclear states of plasmodium, uninucleate and multinucleate. Both plasmodia were structurally similar, filled with lipid droplets, bounded with envelope, and containing mitochondria, endo-plasmic reticulum, and sometimes small vacuoles. Plasmodial fragmentation, which may be regarded as a way to discharge plasmodial materials into host cytoplasm, commonly occurred, forming plasmodial fragments by outgrowth of plasmodial cytoplasm and regional compartmentalization. Plasmodial fragments were degenerated sometimes followed by forming chains of spherical vesicles especially in the uninucleate plasmodial state. These ultrastructural features indicate the biotrophic nature of the pathogen associated with its pathogenesis in the susceptible host.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.11
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• pp.1143-1149
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• 2008

In a nuclear power plant, loose part monitoring and its diagnostic technique is one of the major issues for ensuring the structural integrity of the reactor system. Typically, accelerometers are mounted on the surface of a reactor vessel to localize impact location cavsed by the impact of metallic substances on the reactor system. However, in some cases, the number of the accelerometers is not enough to estimate the impact location precisely. In such a case, one of alternative plan is to utilize another type sensors that can measure the vibration of the reactor structure even though the measuring frequency ranges are different from each others. The AE sensors installed on the reactor structure can be utilized as additional sensors for loose part monitoring. In this paper, we proposed a new method to estimate impact location by using both accelerometer signal and AE signal, simultaneously. The feasibility of the proposed method is verified by an experiment. The experimental results demonstrate that we can enhance the reliability and precision of the loose part monitoring.

• Applied Microscopy
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• v.29 no.3
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• pp.383-403
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• 1999

This study was performed to investigate the immunohistochemical and ultrastructural characterization of the choline acetyltransferase (ChAT)-immunoreactive nerve cells in the diagonal band of Broca of the rat basal forebrains, utilizing techniques of immunohistochemical and immunocytochemical microscopy. The ChAT-immunoreactivities were shown within neuronal cell bodies and processes by the light micoscope. According to cell shape and ratio of long axis vs short axis of cell body, the ChAT-immunoreaclive nerve cells in both vertical and horizontal limbs of the diagonal band of Broca were classified into 6 types. at the light microscopic level; round, oval, elongated, fusiform, triangular and polygonal types. As a result of the electron microscopic observation, the ChAT-immunoreactivated products appeared on the outer nuclear envelope, membranes of rough endoplasmic reticula (rER), free ribosomes and polysomes. Each cell type was subdivided into subtype I and II according to the several criteria such as volume of cell body, nuclear size relative to the cytoplasm, kinds and distribution of cell organelles and numbers and sorts of synapses. The subtype I of immnunoreactive nerve cells had large cell body and a small nucleus showing shallow indentations of nuclear evelope. In this subtype I with abundant cytoplasm, rER were well differentiated. Their long cisternae were parallelly ditributed and lamellated. One or two lamellar bodies and nematosomes were observed. The subtype II cell had small cell body and a large nucleus with deep indentations of nuclear envelope. In this subtype II with small cytoplasm, the rER were irregularly distributed and the lamellar body and nematosome were not found. A few axosomatic synapses in the subtype I and II were shown to be symmetric or asymmetric. The ratios of the symmetric synapse to the asymmetric one were investigated to be 1 : 2 and 1 : 4 in the subtype I and II, respectively. The axodendritic ones were almost asymmetric. But, the fusiform and triangular immunoreactive nerve cells were shown only to be subtype I. According to observations in this study, it is considered that the ultrastructural characterization in the 2 subtypes of each cell type may reflect the differences of the metabolic activities and projecting distances to the target cells.

• Applied Microscopy
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• v.41 no.3
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• pp.163-168
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• 2011

Tiger barb (Puntius tetrazona Bleeker, 1855) is a teleost belonging to Cyprinidae. The oogenesis of tiger barb was investigated by light microscope. The ovary was of white and ellipsoidal shape with the major axis 2 cm and the minor axis 1 cm. Cytoplasm of oogonia was basophilic and many nucleoli were located at inside of nuclear membrane. In early stage of primary oocyte, yolk vesicles were distributed only in the marginal area. In secondary oocyte, the egg envelope was formed and yolk vesicles was formed in the cytoplasm. The basophilic substance of cytoplasm was changed to acidic. In case of matured egg, thickness of egg envelope and size of egg were increased. The yolk vesicles were changed to yolk mass in accordance with development. Also, there is not the formation of oil droplets in cytoplasm. In conclusion, the oogenesis of tiger barb was characterized by the increase in cell size, the formation of yolk, the decrease of basophilic substance in the cytoplasm, and formation of yolk mass.

• ALGAE
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• v.29 no.2
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• pp.75-99
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• 2014

A small dinoflagellate, Ansanella granifera gen. et sp. nov., was isolated from estuarine and marine waters, and examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. In addition, the identity of the sequences (3,663-bp product) of the small subunit (SSU), internal transcribed spacer (ITS) region (ITS1, 5.8S, ITS2), and D1-D3 large subunit (LSU) rDNA were determined. This newly isolated, thin-walled dinoflagellate has a type E eyespot and a single elongated apical vesicle, and it is closely related to species belonging to the family Suessiaceae. A. granifera has 10-14 horizontal rows of amphiesmal vesicles, comparable to Biecheleria spp. and Biecheleriopsis adriatica, but greater in number than in other species of the family Suessiaceae. Unlike Biecheleria spp. and B. adriatica, A. granifera has grana-like thylakoids. Further, A. granifera lacks a nuclear fibrous connective, which is present in B. adriatica. B. adriatica and A. granifera also show a morphological difference in the shape of the margin of the cingulum. In A. granifera, the cingular margin formed a zigzag line, and in B. adriatica a straight line, especially on the dorsal side of the cell. The episome is conical with a round apex, whereas the hyposome is trapezoidal. Cells growing photosynthetically are $10.0-15.0{\mu}m$ long and $8.5-12.4{\mu}m$ wide. The cingulum is descending, the two ends displaced about its own width. Cells of A. granifera contain 5-8 peripheral chloroplasts, stalked pyrenoids, and a pusule system, but lack nuclear envelope chambers, a nuclear fibrous connective, lamellar body, rhizocysts, and a peduncle. The main accessory pigment is peridinin. The SSU, ITS regions, and D1-D3 LSU rDNA sequences differ by 1.2-7.4%, >8.8%, and >2.5%, respectively, from those of the other known genera in the order Suessiales. Moreover, the SSU rDNA sequence differed by 1-2% from that of the three most closely related species, Polarella glacialis, Pelagodinium bei, and Protodinium simplex. In addition, the ITS1-5.8S-ITS2 rDNA sequence differed by 16-19% from that of the three most closely related species, Gymnodinium corii, Pr. simplex, and Pel. bei, and the LSU rDNA sequence differed by 3-4% from that of the three most closely related species, Protodinium sp. CCMP419, B. adriatica, and Gymnodinium sp. CCMP425. A. granifera had a 51-base pair fragment in domain D2 of the large subunit of ribosomal DNA, which is absent in the genus Biecheleria. In the phylogenetic tree based on the SSU and LSU sequences, A. granifera is located in the large clade of the family Suessiaceae, but it forms an independent clade.

• Annals of Clinical Neurophysiology
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• v.6 no.2
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• pp.65-74
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• 2004

Limb-girdle muscular dystrophy (LGMD) is a heterogeneous group of inherited muscle disorders caused by the mutations of different genes encoding muscle proteins. In the past, when the molecular diagnostic techniques were not available, the subtypes of muscular dystrophies were classified by the pattern of muscle weakness and the mode of inheritance, and LGMD had been considered as a 'waste basket' of muscular dystrophy because many unrelated heterogeneous cases with 'limb-girdle' weakness were put into the category of LGMD. With the advent of molecular genetics at the end of the last century, it has been known that there are many subtypes of LGMD caused by the mutation of different genes, and now, LGMD is classified according to the results of the linkage analysis and the genes or proteins affected. Only small proportion (probably less than 10%) of LGMD is dominantly inherited, and autosomal dominant LGMD (AD-LGMD) consists of six subtypes (LGMD1A to 1F) so far. In autosomal recessive LGMD (AR-LGMD), more than 10 subtypes (LGMD2A to 2J) have been linked and most of the causative genes have been identified. Among AR-LGMDs, LGMD2A (calpain 3 deficiency), 2B (dysferlin deficiency), and sarcoglycanopathy (LGMD2C-2F) are major subtypes. The defective proteins in LGMDs are components of nuclear envelope, cytosol, sarcomere, or sarcolemma, and seem to play a different role in the pathogenesis of muscular dystrophy. It is notable that many causative genes of LGMDs are also responsible for other categories of muscular dystrophy or diseases affecting other tissue. However, by which mechanism they produce such a broad phenotypic variability is still unknown. The identification of mutation in the relevant gene is confirmative for the diagnosis, and is essential for genetic counseling and antenatal diagnosis of LGMD. Because many different genes are responsible for LGMD, differentiation of subtypes using immunohistochemistry and western blotting is the essential step toward the detection of mutation. For the effective research and medical care of the patients with muscular dystrophy in Korea, a research center with a medical facility supported by the government seems to be needed.

• BMB Reports
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• v.29 no.2
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• pp.175-179
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• 1996

Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.

• The Journal of the Korean Society for Microbiology
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• v.10 no.1
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• pp.39-58
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• 1975

These studies were carried out to detect the presence of mycotoxin producing fungi in various kind of grains and foodstuffs in Korea. The experiments were divided into three parts: bacteriologic, toxicologic and electron microscopic studies. The results were summarized as follows: 1. From the 133 various samples, 426 colonies of fungi were isolated. In 405 of 426 colonies, it was possible to identify 17 genera. Among the identified strains, the predominant genera were Penicillium, Aspergillus and Alternaria. 2. In cytotoxicity test, 20 strains showed mild to severe toxic effects in mice and 24 strains showed toxic effects on HeLa cells among the 107 strains of experiments. 3. In electron microscopic studies of liver cells from animal which had been treated with toxin like substances, the liver cells showed the cytoplasmic changes: dilatation of endoplasmic reticulum, swelling of mitochondria, disappearance of mitochondrial cristae, increased number of lipid and glycogen particles. Nucleus and nuclear envelope alterations were also noted. 4. In fine structure of HeLa cells treated with culture filtrates of mycotoxin producing fungi and experimental strains had been noted a certain specific changes induced by culture filtrates. These alterations showed the disappearance of golgi complex, endoplasmic reticulum vacuolization and mitochondrial changes. 5. As a mass screening, the cytotoxicity tests of HeLa cells and histopathologic study of mice liver cells treated with toxin-like substances, employed are feasible to detect mycotoxin producing fungi.

• Applied Microscopy
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• v.27 no.4
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• pp.461-472
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• 1997

The substantia nigra of the Mongolian gerbil was studies by tyrosine hydroxylase immunohistochemistry and immunoelectron microscopy with preembedding method. The purpose was to obtain information on the distribution and ultrastructure of the Tyrosine hydroxylase immunoreactive and dopaminergic neurons in the substantia nigra, in order to provide the necessary background for the gerbil. Large number of tyrosine hydroxylase immunoreactive neurons were located in the compact part of substantia nigra. Findings in the gerbil, compared to observations in the other species, included the presence of prominent bundles of tyrosine hydroxylase immunoreactive cytoplasmic processes passing in the dorsoventral direction from pars compacta into pars reticulata at middle and caudal levels of the substantia nigra, and the presence of a distinct tyrosine hydroxylase immunoreactive substantia nigra pars lateralis. Tyrosine hydroxylase immunoreactive neurons had well-developed cell organelles, especially rough endoplasmic reticulum, free ribosome and poly-ribosome, and showed the infoldings of the nuclear envelope. We anticipate that the present description of the cellular organization of the tyrosine hydroxylase immunoreactive dopaminergic area in the substantia nigra of gerbil will be useful for the animal experimental model of Parkinson's disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1569-1573
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• 2008

This paper describes a development of Ultrasonic NDE software to analyze steam generator of nuclear power plant. The developed software includes classical analysis method such as A, B, C and D-scan images. And it can analyze the detected internal cracks using 3D image processing method. To do such, we obtain raw data from specimens of real pipeline of power plants, and get the envelope signal using Empirical Mode Decomposition from obtained ultrasonic 1-dimensional data. The reconstructed 3D crack images offer useful information about the location, shape and size of cracks, even if there is no special 2D image analysis technique. The developed analysis software is applied to specimens containing various cracks with known dimensions. The results of application showed that the developed software provided accurate and enhanced 2D images and reconstructed 3D image of cracks.