• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.346-355
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• 2014

Confocal reflection microscopy (CRM) was utilized to create 3-dimensional images of bordered pits and cell wall in the tracheid of Korean red pine (Pinus densiflora). Ultrastructures of torus, margo, and pit border were clearly observable in the CRM micrograph. Micrograph of cross-field pit revealed the connecting and supporting structure between tracheid and ray parenchyma cell. The CRM micrographs enabled to investigate detailed structures of tracheid cell wall such as S1, S2, S3 layers, transition layers between these layers, and microfibril (MF) orientation in S3 and S2 layers as well as complicated distribution of MF orientation around bordered pits. Not only concentric MF orientation of border thickening in the pit border was observed, but also changes in MF orientation from the cell wall to the border. From the experimental results, the CRM was thought to be a versatile microtechnique to investigate detailed structures of cell wall and bordered pit in the tracheid and cross-field pit between tracheid and ray parenchyma cell.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.635-645
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• 2020

Morphological and molecular characterization of clinostomid metacercariae (CMc) was performed with the specimens collected in fish from Korea and Myanmar. Total 6 batches of clinostomid specimens by the fish species and geographical localities, 5 Korean and 1 Myanmar isolates, were analyzed with morphological (light microscopy and SEM) and molecular methods (the cytochrome c oxidase 1 gene and internal transcribed spacer 1/5.8S rRNA sequence). There were some morphological variations among CMc specimens from Korea. However, some morphometrics, i.e., the size of worm body and each organ, ratio of body length to body width, and morphology of cecal lumens, were considerably different between the specimens from Korea and Myanmar. The surface ultrastructures were somewhat different between the specimens from Korea and Myanmar. The CO1 sequences of 5 Korean specimens ranging 728-736 bp showed 99.6-100% identity with Clinostomum complanatum (GenBank no. KM923964). They also showed 99.9-100% identity with C. complanatum (FJ609420) in the ITS1 sequences ranging 692-698 bp. Meanwhile, the ITS1 sequences of Myanmar specimen showed 99.9% identity with Euclinostomum heterostomum (KY312847). Five sequences from Korean specimens clustered with the C. complanatum genes, but not clustered with Myanmar specimens. Conclusively, it was confirmed that CMc from Korea were morphologically and molecularly identical with C. complanatum and those from Myanmar were E. heterostomum.

• The Korean Journal of Zoology
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• v.15 no.3
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• pp.133-147
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• 1972

Ultrastructures of spermiogeneis in other invertebrates were investigated by several workes (Anderson, et al., 1967; Bloch, et al., 1964; Christen, 1961; Gatenby, et al., 1959; Paik, et al., 1968; Silveira, 1964; Yasuzumi, 1957) but spermiogenesis of dragonfly has not been reported previously. Testes and vass deferentia of the Korean dragonfly, Crocothemis servilia, were used for electron microscopic study of spermiogenesis. Materials were prefixed for 1-2 hours at $3^{\circ}C$ in 1.25% glutaraldehyde buffered to pH 7.2 with 0.2M sodium cacodylate buffer. Fixed tissue was washed twice in 0.2M cacodylate buffer and was subsequently postfixed for 2 hours at $3^{\circ}C$ in 1% osmium tetroxide buffered to pH 7.2 with 0.4M sodium cacodylate buffer solution. Specimens were dehydrated in graded ethyl alcohol, and finally embedded in epoxy Epon resin. Thin sections prepared from all the blocks were doubly stained; first in uranyl acetate and then in lead citrate. All thin sectios were examined with a Hitachi HS-7S electron microscope. The results of this study were summarized as follows. 1. Along the condensation of chromatin in nucleus, the shpae of nucleus was changed from spherical shpae to ellipse and cone cell type. 2. During the elongation of nucleus and the migration of cytoplasm, the nucleus removed to the one side of spermatid and began to invaginate from the posterior portion of nucleus. 3. There are ring centrioles in invaginated portion and axial filaments derived from centriole extend to the tail through the tailward half of spermatid. 4. In the cross sections the axial filament consisted of a central sheath, a central fibril, and 9 peripheral doublets.

• The Korean Journal of Zoology
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• v.23 no.4
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• pp.219-228
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• 1980

The ultrastructures of the granular glands in the asiatic land salamander (Hynobius leechi) skin were observed by means of electron microsope The results were as follows; 1. The granular gland of the asiatic land salamander skin consisted of a body of gland and a duct. The body of the granular gland consisted of the glandular epithelial cells and the myoepithelial cells. The duct of the granular gland consisted of the keratinocytes. 2. The glandular epithelial cells in the asiatic land salamander skin were divided into the dark cell and the light cells in accordance with the electron density of the cytoplasm. 3. The secretory granules of the granular glands were round or oval in form and were divided into the various granules, showing the secretory granules showing weak electron density had the parts showing strong electron density near the granular membrane. 4. It is supposed that showing the different electron densities of the granules in a glandular epithelial cell is due to different mature stages and to different level of water absorption, and the chemical components of the granules showing different electron densities are identical.

• Parasites, Hosts and Diseases
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• v.34 no.3
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• pp.169-176
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• 1996

A scanning electron microscopic study was performed to observe the surface ultrastructures of the third-stage larvae of Gnathostoma hispidun. The early third-stage larvae (EL3) were collected from the viscera of Chinese loaches by the artificial digestion method . The advanced third-stage larvae (AdL3) were recovered from mice experimentally infected with EL3. Both larval worms were fixed with 2.5% glutaraldehyde, dehydrated in graded alcohol. dryad in critical point dryer, and coated with gold. The specimens were observed with a SEM (DS- l30C). On the head bulb of both larval stage, the mouth had a pair of lateral lips of equal size and of half moon shape. Each lip had a couple of labial papillae and a small amphid located between the two papillae. The hooklets on the head bulb had single-pointed tips and curved posteriorly. The cuticular spines of EL3 were larger and more densely distributed in the anterior area (about 1.8 Mm in length) and gradually decreased in size and number posteriorly. The cuticular spines in the anterior area of AdL3 were sharp-pointed and about 4.5 Mm in length, and those in the middle area were about 1.75 Mm. The velvety cuticular folds and dot-like cuticular spines were distributed in the posterior area. A cervical papilla was located between the 7th and 8th transverse striations. A dome-like body papilla was located at the posterior 1/4 of body. An ellipsoidal excretory pore was located between the 17th and 18th striations. From the above results, it is suggested that the characteristic SEM findings obtained from this study may be helpful on the species identification of larval Gncthostomn.

• Applied Microscopy
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• v.24 no.3
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• pp.23-33
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• 1994

It is well known that dichlorvos (DDVP), an organophosphate insecticide in common use, is so easily and rapidly hydrolyzed and excreted that it has usually little toxic effect on human body. In these days, however, it is widely used as an industrial and domestic insecticide and as an anthelmintic agent for animals, so that the accident of chemical poisoning occurs frequently. DDVP acts as a powerful inhibitor of carboxylic esterase, which can cause accumulation of acetylcholine at the synapses so paralysis of muscle and the transmission failure in cholinergic synapses dueing to desensitization of acetylcholin receptor may occure. Moreover accumulation of the acetylcholine brings about the elevation of the cyclic-AMP, which alters the cellular metabolisms of nucleic acid, carbohydrate, protein and lipid. Present study has undertaken to investigate the cardiotoxic effect of DDVP by electron microscopic study. A total of 30 Sprague-Dawley strain rats, weighing about 250gm were used as experimental animals. 2mg/kg/day of DDVP is intraperitonealy injected 3 times with intervals of every other day. On 1 day, 3 days, 5 days, 7 days and 14 days after drug administration, the animals were sacrified by cervical dislocation. Left ventricular cardiac muscles were resected and sliced into $1mm^3$. The specimens were embedded with Epon 812 and prepared by routine methods for electron microscopical observation. All preparations were stained with lead citrate and uranyl acetate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. In the cardiac muscle of DDVP treated rats, mitochondria with disorganized double membrane and mitochondrial crista, and vacuole formation in mitochondrial matrix were observed. But structures of mitochondria were recovered to normal in 14 days group. 2. In the cardiac muscle of DDVP treated rats, cisternae of sarcoplasmic reticulum were dilated and sacculated. But these changes were recovered to normal in 14 days group. 3. In the cardiac muscle of DDVP treated rats, glycogen particles around damaged myofibrils were decreased. But amount of glycogen particles were restored in 14 days group. 4. In the cardiac muscle of DDVP treated rats, disruption and discontinuation of myofilaments and disorganization of Z-disc were observed. But the structures of myofibrils were recovered to normal in 14 days group. It is consequently suggested that DDVP would induce the reversible degenerative changes on the ultrastructures in cardiac muscle of rat.

• Applied Microscopy
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• v.32 no.4
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• pp.411-419
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• 2002

Metallothionein (MT) is a family of ubiquitous, low molecular weight ($6,000{\sim}7,000D$), cysteine-rich ($30{\sim}35%$) inducible protein with a high affinity to metal ions and has no aromatic amino acids and histidine. Some of the known functions of MT include detoxification of heavy metals and alkylating agents and neutralization of free radicals. Also, this protein has been reported to involve in tumor pathophysiology and therapy resistance. MT expression may affect a number of cellular processes including gene expression, apoptosis, proliferation and differentiation. Many reports on the physiological and biochemical properties of MT have been published, but ultrastructural reports on the localization of MT in human gastric cancer tissues are extremely rare. The present study was undertaken to examine the ultrastructural features and the localization of MT within the gastric adenocarcinoma. Ultrastructures of gastric cancer cells were characterized by the high nuclear cytoplasmic ratio, the interdigitation between cells, the irregular nucleus containing much heterochromatin and the wide distribution of free ribosomes in the cytoplasm. Immunohistochemical reaction for MT was prominent in the gastric adenocarcinoma. And the immunogold labellings were more prominent within the nucleus than the cytoplasm. Particularly, immunogold particles were numerously seen at nulcleolus or nucleolar associated heterochromatin. These results suggest that MT expression by gastric cancer cells is associated with cell proliferative activity and is possibly synthesized in the cytoplasm, and then the protein is transported into the nucleus to participate in any transcriptional steps.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.807-815
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• 1996

The protective effect of'ischemic preconditioning'on ischemid-reperfusion injury of heart has been reported in various animal species. but without known mechAnism in detail, In An attempt to investigate the cardioprotective mechanism of ischemic preconditioning, we examined the effects of nitric oxide(UO) synthesis in preconditioned heart of rat The isolated hearts perfused by Langendorfr's method were ex- posed to 30min global ischemia followed by 30min reperfusion with oxygenated Krebs-Henseleit(K-H) sol- ution. Ischemic preconditioning was performed with three episodes of Sm n ischemia and Smin repeyfusion before the induction of prolong ischemia(30min)-reperfusion(30min). Ischemic preconditioning prevented the depression of cardiac function(left ventricular pressure .K heart rate) observed in the ischemia- reperfusion hearts and reduced the release of lactate dehydrogenase during the reperfusion period. On electromicroscopic pictures, myocardial ultrastructures wore relatively well preserved in isthemic preconditioned hearts. N6_nitro-L-arginine methyl ester(L-NAME) an inhibitor of L-arginine citric oxide pathway, was infused at a rate O.Smllmin In a dose of 10mg kg-1 before the initial ischemic preconditioning. neither the protection of cardiac function nor the reduction of LDH releAse in ischemic preconditioning hearts was altered in the presence of added L-NAME On ultrastructural finding, the preservation of morphology in ischemic preconditioning heart was not change by the pretreatment of L-UAME. The failure of the WO synthesis inhibitor to reduce t e effect of ischemic preconditioning may be related to be species specific in that NO may allot be the trigger for ischemic preconditioning in rats.

• Applied Microscopy
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• v.23 no.1
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• pp.35-55
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• 1993

cis-Dichlorodiammineplatinum (II) (cis-Platin), a metallic compound, has widely been used as an effective anticancer chemotherapeutic agent. The precise mechanism of action of this agent is still unknown, but it is postulated that cis-Platin may act on the cancer cell like bifunctional alkylating agents. Although this agent is very beneficial to the patients with cervical cancer, germinoma of testis, neuroblastoma and others, it may also damage to the normal cell so that many side effects; severe hemorrhagic enterocolitis, bone marrow depression, renal damage and liver damage will develope. This experiment has been undertaken to pursue the cytotoxic effects of the cis-Platin on the ultrastructures of the interalveolar septum in the mouse lung. A total of 55 healthy male mice of ICR strain were used as experimental animals and divided into 5 mice of normal control group and 50 mice of cis-Platin treated group. The mice of cis-Platin treated group were sacrificed by carotid exsanguination at 6, 12, 24 hours, 3 days and 7 days after intraperitoneal injection of 6.0 mg of cis-Platin ($Abiplatin^R$ Abic Co. Ltd.) per kg of mouse body weight. The specimen obtained from the lower lobe of left lung were sliced into $1mm^3$ and prefixed with 2% glutaraldehyde -2.5% paraformaldehyde solution prepared with Millonig's phosphatae buffer solution (pH 7.4) at $4^{\circ}C$ for 3-4 hours. After postfixation with 1% osmium tetroxide solution all specimens were embedded in Epon 812. Ultrathin sections about $600-800{\AA}$ in thickness were stained with uranyl acetate and lead citrate and observed with Hitachi-600 electron microscope. The results obtained were as follows: 1. Local swellings with increase of electron density and number of pinocytic vesicles in the cytoplasms of the type I pneumocyte and endothelial cell of the blood air barrier in interalveolar septum of cis-platin treated mice were observed. 2. Cisternae of rough endoplasmic reticulum were dilated and sacculated in association with detachment of membrane bound ribosomes of the type II pneumocyte in interalveolar septum of cis-Platin treated mice. 3. Swollon mitochondria with uneven electron density of their matrix were observed in the type II pneumocyte of interalveolar septum in the cis-Platin treated mice. 4. The lamellae of lammelar bodies in type II pneumocyte of interalveolar septum in cis-Platin treated mice were devoided or transformed into homogeneous electron dense material. It is consequently suggested that cis-Platin would induce the cellular edema of type I pneumocyte and endothelial cell, and degenerative changes of cytoplasmic organelles of the type II pneumocyte in the interalveolar septum of the mouse lung.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.148-152
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• 2000

To provide basic information on the integumentary system of the blenny, Pholis nebulosa, ultrastructures of epidermal and dermal layer were examined by means of the light and transmission electron microscope. The skin of the blenny consisted of epidermal and dermal layer. Epidermal layer consisted of supporting cell and unicellular gland. The supporting cells were classified into superficial cell, intermediated cell and basal cell, and the gland cells were classified into mucous secretory cell and club cell. The cytoplasm of supporting cells was divided into cortex and medullar part. In the cortex and medullar part, microfilaments and cell organelles were well developed, respectively. Superficial cell of epidermal layer was cuboidal and contained nucleus of horseshoe shape. Intermediated cell had a nucleus of irregular form and the electron density was higher than the other supporting cells, Basal cell was columnar, but nucleus was situated in the upper cytoplasm. Cell organelles of the basal cell were poor than the other supporting cells, but membrane interdigitations were well developed. The cytoplasm of mucous secretory cell had a well-developed ovoid secretory granules, which reacted to red with AB-PAS reaction. The club cell had a we31-developed round secretory granules and endoplasmic reticulum. figment cells were classified into two type. The one contained pigment granules of electron dense, and the other contained reflecting platelets. The cytoplasm of fibrocyte had n well developed rough endoplasmic reticulum.