• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.231-239
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• 1999

In oral and maxillofacial surgery, there are many cases requiring the graft of epidermal tissues such as maxillectomy, and vestibuloplasty. There have been so many challenges for the culture of the epidermal tissue. Observing the ultrastructure of the cultured human oral kertinocytes, we could compare this findings with that of in vivo ones. With that, we could find the differencies and similarities between cultured cells and in vivo ones, and evaluate the clinical applications of cultured tissue. Human gingiva was obtained and the specimen was explanted on 24-well plate. Two types of culture media were used in this culture system. One was for the growth of the keratinocytes (Media I), and the other was for the stratification (Media II). Media I had special ingredients for the epidermal growth. Those were 0.5% dimethyl sulfoxide (DMSO), 30ng/ml of epidermal growth factor (EGF), 30ng/ml of cholera toxin, and $5{\mu}g/ml$ of transferrin. We cultured the oral keratinocytes for 3 weeks, and at that time the cultured keratinocytes were processed to prepare the specimen for the TEM study. The results were as follows.; 1. In the phase contrast micrograph, epidermal outgrowth firstly appeared on the 3rd day after explantation, and the growing keratinocytes were activley mitotic, and had polygonal shape and increased N/C ratio. 2. In the phase contrast micrograph, the outer most cells exhibited areas where broad cytoplasmic processes extended out onto the culture subtratum(fan-like appaearance). 3. In the TEM micrographs, the cultured keratinocytes showed stratification. The cells were in elongated form, and there were no morphologic differencies among the layers usually found in the in vivo gingiva. 4. Most of cellular organelles underwent lysis, and keratohyaline granules were seen. Tonofibrils were dispersed in the cytoplasm. 5. The cells were interconnected by desmosomes, and their frequency of distribution was considered to be lower than that of in vivo keratinocytes. 6. We could conclude the cultured oral keratinocytes exhibited signs of terminal differentiation.

• Molecules and Cells
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• v.23 no.1
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• pp.49-56
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• 2007

One of the goals of stem cell technology is to control the differentiation of human embryonic stem cells (hESCs), thereby generating large numbers of specific cell types for many applications including cell replacement therapy. Although individual hESC lines resemble each other in expressing pluripotency markers and telomerase activity, it is not clear whether they are equivalent in their developmental potential in vitro. We compared the developmental competence of three hESC lines (HSF6, Miz-hES4, and Miz-hES6). All three generated the three embryonic germ layers, extraembryonic tissues, and primordial germ cells during embryoid body (EB) formation. However, HSF6 and Miz-hES6 readily formed neuroectoderm, whereas Miz-hES4 differentiated preferentially into mesoderm and endoderm. Upon terminal differentiation, HSF6 and Miz-hES6 produced mainly neuronal cells whereas Miz-hES4 mainly formed mesendodermal derivatives, including endothelial cells, leukocyte progenitors, hepatocytes, and pancreatic cells. Our observations suggest that independently-derived hESCs may differ in their developmental potential.

• Molecules and Cells
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• v.25 no.1
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• pp.78-85
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• 2008

In a search for new molecular pathways associated with asthma, we performed an mRNA differential display analysis using total RNA extracted from the tracheal tissues of ovalbumin (OVA)-challenged mice and sham controls. cDNAs corresponding to mRNAs for which expression levels were altered by OVA-challenge were isolate and sequenced. Twenty-eight genes differentially expressed in sham and OVA challenged mice were identified. A GenBank BLAST homology search revealed that they were related to cytoskeleton remodeling, transcription, protein synthesis and modification, energy production, and cell growth and differentiation. Two were selected for further characterization. Up-regulation of both the perinatal skeletal myosin heavy chain (skMHC) and fast skeletal muscle myosin light chain (skMLC) genes was confirmed by RT-PCR of trachea tissue from OVA challenged mice. Overexpression of skMLC protein was observed in the smooth muscle layers of OVA-challenged mice by immunohistochemistry, and the surface areas stained with skMLC antibody increased in the OVA-challenged mice. The overexpression of skMLC in murine asthma may be associated with the changes of bronchial smooth muscle.

• Development and Reproduction
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• v.15 no.3
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• pp.205-213
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• 2011

Ethanol treatment during the brain growth spurt period has been known to induce the death of Purkinje cells. The underlying molecular mechanisms and the role of reactive oxygen species (ROS) in triggering ethanol-induced Purkinje cell death are, however, largely unresolved. We undertook TUNEL staining, western blotting assay and immunohistochemistry for the cleaved forms of caspase-3 and -9, with calbindin D28K double immunostaining to identify apoptotic Purkinje cells. The possibility of ROS-induced Purkinje cell death was immunohistochemically determined by using anti-8-hydroxy-2'deoxyguanosine (8-OHdG), a specific cellular marker for oxidative damage. The results show that Purkinje cell death of PD 5 rat cerebellum following ethanol administration is mediated by the activation of caspase-3 and -9. However, unexpectedly, TUNEL staining did not reveal any positive Purkinje cells while there were some TUNEL-positive cells in the internal and external granular layer. 8-OHdG was detected in the Purkinje cell layers at 8 h, peaked at 12-24 h, but not at 30 h post-ethanol treatment. No 8-0HdG immunoreactive cells were detected in the internal and external granular layer. The lobule specific 8-OHdG staining patterns following ethanol exposure are consistent with that of ethanol-induced Purkinje cell loss. Thus, we suggest that ethanol-induced Purkinje cell death may not occur by the classical apoptotic pathway and oxidative damage is involved in ethanol-induced Purkinje cell death in the developing cerebellum.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.150-155
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• 1997

Modelling and Simulation of the activation process for the myocardium is meaningful to understand special excitation conduction system in the heart and to study cardiac functions. In this paper, we propose two dimensional cellular automata model for the activation process of the myocardium and simulated by means of discrete time and discrete event algorithm. In the model, cells are classified into anatomically similar characteristic parts of heart; SA node, internodal tracks, AV node, His bundle, bundle branch and four layers of the ventricular muscle, each of which has a set of cells with preassigned properties, that is, activation time, refractory duration and conduction time between neighbor cell. Each cell in this model has state variables to represent the state of the cell and has some simple state transition rules to change values of state variables executed by state transition function. Simulation results are as follows. First, simulation of the normal and abnormal activation process for the myocardium has been done with discrete time and discrete event formalism. Next, we show that the simulation results of discrete time and discrete event cell space model is the same. Finally, we compare the simulation time of discrete event myocardium model with discrete time myocardium models and show that the discrete event myocardium model spends much less simulation time than discrete time myocardium model and conclude the discrete event simulation method Is excellent in the simulation time aspect if the interval deviation of event time is large.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1177-1182
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• 2004

The effect of poly[2-methacryloyloxyethyl phosphorylcholine] (pMPC) on the skin permeation property was investigated by performing in vitro skin permeation study of a model drug, nicotinic acid (NA). Effect of pMPC polymer in donor solution on skin permeation rates was evaluated using side-by-side diffusion cells. Also, the structural alterations in the stratum corneum (SC), inter-lamellar bilayer (ILB) and dermis layers in pMPC-treated and -untreated skin sections were investigated with transmission electron microscopy (TEM). The permeation profile of NA without pMPC in donor solution showed biphasic mode: initial $1^{st} phase and 2^{nd}$ hydration phase. The sudden, more than 10-fold increase in flux from the initial steady state (43.5 $\mu g/cm^2$/hr) to the $2^{nd}$ hydration phase (457.3 $\mu g/cm^2$/hr) suggests the disruption of skin barrier function due to extensive hydration. The permeation profile of NA with 3% pMPC in the donor solution showed monophasic pattern: the steady state flux (10.9 $\mu g/cm^2$/hr) without abrupt increase of the flux. The degree of NA permeation rate decreased in a concentration-dependent manner of pMPC. TEM of skin equilibrated with water or 2% pMPC for 12 h showed that corneocytes are still cohesive and epidermis is tightly bound to dermis in 2% pMPC-treated skin, while wider separation between corneocytes and focal dilations in inter-cellular spaces were observed in water-treated skin. This result suggests that pMPC could protect the barrier property of the stratum corneum by preventing the disruption of ILB structure caused by extensive skin hydration during skin permeation study.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.305-310
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• 2008

A 10-year-old female Yorkshire terrier with the clinical signs of nasal swelling, epistaxis and nasal discharge was presented to the Veterinary Teaching Hospital in the Cheju National University. Abnormal nasal mass was detected in physical examination and radiographic findings. After surgical excision, the sample of nasal mass was referred to Pathology Department of Veterinary Medicine. Grossly, the mass was soft, friable, and $2.5{\times}4cm$ cm in size. Histopathologically, the mass was composed of mediumsized non-keratinizing columnar to polyhedral cells arranged in anastomosing ribbon and large nest. It has complex in-folding of thick epithelial layers separated by fibrovascular septa. Tumor cells showed characteristic palisading arrangement of columnar cells, and perpendicularly distributed to the basement membrane. The cells had pale basophilic cytoplasm, oval nucleus and one or more nucleoli, and indistinct cellular border. Many tumor cell emboli were presented in lymphatics. Immunohistochemistry revealed that tumor cells were cytokeratin (CK) 19 and CK clone MNF116 positive and but CK7 and CK high molecular weight negative. Based on the gross, histopathologic, and immunohistochemical findings, the mass was diagnosed as transitional carcinoma in nasal cavity. In our best knowledge, this is the first report of transitional carcinoma originated from transitional zone of canine nasal cavity in Korea.

• Journal of Plant Biology
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• v.35 no.2
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• pp.143-153
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• 1992

Nectar secretion from extrafloral nectary cells of Prunus yedoensis was examined by light and electron microscopy. Nectaries were composed of two or three layers of secretory cells and one layer of subsectretory cells. Vascular bundles in the petioles were connected to those of the subsectretory cell layer. Secretory cells had a number of mitochondria with poorly developed cristae. Plastids had little thylakoids and small vesicles, about 0.2 to 0.3 mm in diameter; however, no plastids had starch grains. Calcium oxalate crystals and plasmodesmata were frequently observed in the subsectretory and secretory cells, respectively. And nectar substances were observed in phloem of petiole, subsectretory, and secretory cells of the secretory gland. These results suggested that the nectar moved by symplastic transport through the plasmodesmata. On the other hand, the nectar droplets were observed in the secretory cell walls. in the cuticular layer just beyond of the former, and on the outer surface of the cuticular layer: such observations indicated that a apoplastic movement was involved in the final step of the nectar secretion. Cellular components related to the nectar transport, such as plasma membrane, cell wall and cuticle were not destroyed but intact: it was interpreted as a eccrine secretion.retion.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.399-402
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• 2013

An 8-year-old, female, mixed Thoroughbred horse was presented for the evaluation of the left upper eyelid mass with ocular discharge during 4 months. After unilateral surgery, excised eyelid mass and left eye were submitted for diagnosis. Grossly, the removed mass was $6{\times}7{\times}2$ cm in size and dome shape with rough irregular surface. On the cut surface, mass was firm and yellowish white in color. Histopathologically, severely proliferated stratified squamous epithelia were heavily invaginated into dermis, and then formed rete ridge or numerous squamous islands. These neoplastic islands were composed of multiple layers of prickle cells with intercellular bridge and central laminated keratin pearls or necrotic cellular debris. Based on the above results, this case was diagnosed as squamous cell carcinoma in upper eyelid of horse.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.1-16
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• 1991

In order to see the possible effect of the functional load-bearing after osseointegration of the titanium root form implant in dog a histologic study was conducted. One side of lower jaw was surgically prepared edentulousness and titanium implants were inserted. Some implants were functionally loaded through fixed detachable prosthesis and some are isolated and unloaded. The dog was sacrificed four months later and bone sections with implants were processed for histologic evaluation and the results were as follows ; (1) The bone to implant interface after four months of load bearing presented no mobility and no marginal bone loss radiographically and histologically. (2) The interface zone between compact bone and implant revealed a direct bone to implant contact and in some areas marrow tissue contacts were examined at the light microscopic level. (3) At the ultrastructural level the interface of surrounding compact bone matrix and implant, three types of superficial layers were found ; one with moderate electron dense amorphous granular substance layer, other with high electron dense fine granular substance layer, and another type of amorphous granular substance covered with high electron dense line of minute granules. (4) The osteoblasts in the marrow tissue neighboring implants and osteocytes in compact bone showed typical normal characteristics and in the marrow tissues some of lymphocytes and mast cells were observed. (5) The abscence of abnormal tissue reactions at a cellular level indicates a high degree of biocompatibility for the experimental titanium implant and basically no difference was found between functionally loaded and unloaded implants.