• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.407-415
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• 1986

This study investigated whether a correlation exists between environmental physical and biochemical factors and adherence of Candida albicans to human buccal epithelial cells by using normal and UV-irradiated strains. The results were as follows: 1. The percentage of germ tube forming activities of normal Candida albicans was 91.5% and UV-irradiated Candida albicans was 15.0%. The $LD_{50}$ of normal strains in mice were $1.0{\times}10\;cells/ml$, but could not be observed in the UV-irradiated strains even with $1.0{\times}10\;cells/ml$. It demonstrated that the virulence is decreased in the UV-irradiated strain. 2. The adherence of normal Candida albicans to human buccal epithelial cells($166{\pm}29{\sim}207{\pm}17\;cells$/100 epithelial cells) was significantly greater than UV-irradiated Candida albicans($99{\pm}21{\sim}131{\pm}25\;cells$/100 epithelial cells). 3. Candida albicans cultured at $37^{\circ}C$ adhered to buccal epithelial cells($166{\pm}16{\sim}207{\pm}17\;cells$/100 epithelial cells) in greater numbers than cultured at $25^{\circ}C$($80{\pm}15{\sim}143{\pm}22\;cells$/100 epithelial cells). 4. On comparison of the adherence of viable and nonviable(heat-killed) Candida albicans to human buccal epithelial cells, the nonviable Candida albicans demonstrated poorer adherence than viable Candida albicans. 5. Adherence in vitro of Candida albicans to human epithelial cells appeared to be effected by the pH. The adherence ability was maximum increased at pH 7.0($187{\pm}22\;cells$/100 epithelial cells) other than experimental pH. 6. The adherence was proportional to the incubation time and the Candida cell concentration in the suspension. 7. A strong correlation was shown between germ tube forming activity and increased adherence of Candida albicans to human epithelial cells, indicating that germ tube forming activity were responsible for candidal virulence.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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• pp.763-770
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• 1998

A number of substances involved in the proliferation and differentiation of the tracheobronchial epithelium have been identified. The defects in the control of the proliferation and differentiation of tracheobronchial epithelial cells appear to constitute crucial steps in the transition of normal cells to neoplastic ones. Endothelin-1 is produced by tracheal epithelial cells, and its receptors are present in tracheal epithelial cells. However, the effect of endothelin-1 on the proliferation and differentiation of tracheal epithelial cells has not been clearly elucidated. This study was undertaken to investigate these actions of endothelin-1 in primary cultured cells of rat tracheal epithelia. Endothelin-1 stimulated proliferation of tracheal epithelial cells 1.5-fold when compared with that of control cells. Endothelin-1 increased mitogen-activated protein kinase (MAPK) activity. Herbimycin A, a tyrosine kinase inhibitor, inhibited endothelin-1-induced proliferation of epithelial cells. The treatment of endothelin-1 during the primary culture of tracheal epithelial cells increased AB-PAS-stained cell population and ciliated cell population 6.5 fold and 1.5 fold, respectively, when compared with those in control cells. The responsiveness to carbachol and forskolin in the $Cl^-$ secretion was increased 1.7 and 1.9 fold, respectively, in the endothelin-treated epithelial cells. These results indicated that endothelin-1 increases proliferation via MAPK pathway and stimulates differentiation to secretory and ciliated cells in rat tracheal epithelial cells.

• Molecules and Cells
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• v.37 no.7
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• pp.562-567
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• 2014

Human Hertwig's epithelial root sheath/epithelial rests of Malassez (HERS/ERM) cells are epithelial remnants of teeth residing in the periodontium. Although the functional roles of HERS/ERM cells have yet to be elucidated, they are a unique epithelial cell population in adult teeth and are reported to have stem cell characteristics. Therefore, HERS/ERM cells might play a role as an epithelial component for the repair or regeneration of dental hard tissues; however, they are very rare population in periodontium and the primary isolation of them is considered to be difficult. To overcome these problems, we immortalized primary HERS/ERM cells isolated from human periodontium using SV40 large T antigen (SV40 LT) and performed a characterization of the immortalized cell line. Primary HERS/ERM cells could not be maintained for more than 6 passages; however, immortalized HERS/ERM cells were maintained for more than 20 passages. There were no differences in the morphological and immunophenotypic characteristics of HERS/ERM cells and immortalized HERS/ERM cells. The expression of epithelial stem cell and embryonic stem cell markers was maintained in immortalized HERS/ERM cells. Moreover, immortalized HERS/ERM cells could acquire mesenchymal phenotypes through the epithelial-mesenchymal transition via TGF-${\beta}1$. In conclusion, we established an immortalized human HERS/ERM cell line with SV40 LT and expect this cell line to contribute to the understanding of the functional roles of HERS/ERM cells and the tissue engineering of teeth.

• The Korean Journal of Zoology
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• v.32 no.2
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• pp.93-106
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• 1989

The species of the slug used in this experiment is the Korean terrestrial slug (Incilaria fruhstorferi), which is examined for the cytochemical and ultrastructural research on the mucous granule-producing cells and the epithelial cells. I. Epidermal tissue According to the part of the epidermal tissue of this slug, the epidermal tissue is divided into the mantle, the foot and the dorsal epidermis. These epidennal tissue are composed of the irregular simple columnar epithelium, which are formed into the sensory epithelial cells, the supporting epithelial cells, the mucous granule-producing cells, and the clear epithelial cells are similar to the sensory epithelial cells. Both the sensory epithelial cells and the supporting epithelial cells are observed between the mantle and the foot epidermis, but the clear epithelial cells are only seen in the dorsal epidermis. II. Mucous granule-producing cell The acid mucous granule-producing cells and the neutral mucous granule producing cells are observed between the irregular simple columnar epithelium of the mantle, the foot and the dorsal epidermis. According to the part of the epidermal tissue, the number of these mucous granule-producing epithelial cells are differently distributed between the epidermis respectively.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.691-698
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• 2008

Purpose: Periodontal pathogens can invade the host tissue. Morphologic studies have revealed bacteria within the pocket epithelium, gingival connective tissues, alveolar bone, and oral epithelium. The objective of this study was to visualize and evaluate presence of Porphyromonas gingivalis and Tannerella forsythia in crevicular epithelial cells of periodontally healthy subjects and chronic periodontitis patients. Materials and Methods: A total of 666 crevicular epithelial cells in the samples obtained from 27 chronic periodontitis patients and 9 healthy volunteers were examined. Specific probes for P. gingivalis and T. forsythia and a universal probe for detection of all eubacteria targeting 168 rRNA for fluorescence in situ hybridization was used in conjunction with confocal laser scanning microscopy. Results: 98.99% of sulcular epithelial cells from healthy volunteers and 84.40% of pocket epithelial cells from periodontitis patients were found to harbor bacteria. P. gingivalis and T. forsythia were discovered more often in crevicular epithelial cells from periodontitis patients. Conclusion: P. gingivalis and T. forsythia can invade crevicular epithelial cells and intracellular bacteria may act as a source of bacteria for persistent infection.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.44-49
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• 2003

Effects of supplementation with ruminal epithelial cells on fiber-degrading activity and cell growth of Ruminococcus albus (R. albus, strain 7) was tested using a basal substrate of rice straw and formulated concentrate. Cultures of R. albus alone and R. albus with rumen protozoa were grown at $39^{\circ}C$ for 48 h with an 8.4% crude protein (CP) substrate, 33% of the CP supplemented with either ruminal epithelial cells or defatted soybean meal. The ruminal epithelial cells had lower amounts of rumen soluble and degradable protein fractions as compared to defatted soybean meal, as determined by an enzymatic method, and the same was found with amino acid composition of protein hydrolysates. Ruminal epithelial cells were directly utilized by the R. albus, and resulted in greater growth of cell-wall free bacteria compared to defatted soybean meal. The effect of epithelial cells on bacterial growth was enhanced by the presence of rumen protozoa. In consistency with cultures of R. albus and R. albus with rumen protozoa, fermentative parameters such as dry matter degradability and total volatile fatty acid did not differ between supplementation with ruminal epithelial cells or defatted soybean meal.

• Applied Microscopy
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• v.28 no.3
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• pp.345-362
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• 1998

In order to the comparative morphological study of the non-ciliated and ciliated epithelial cells, and to elucidate the process of degeneration of non-ciliated epithelial cell of the ductus epididymidis, Korean striped field mouse, Apodemus agrarius coreae was examined with light and transmission electron microscopes. The morphological characteristics of non-ciliated epithelial cell, the cell types of the caput epididymidis (Cp), corpus epididymidis (Cr) and cauda epididymidis (Cu) were long-columnar, short-columnar and short-cuboudal, respectively. The mitochondria and rough endoplasmic reticulum tended to be broken as they immigrated from Cp to the Cu. The Golgi acted vigorously at the Cp, but the Golgi was inactive in Cr and Cu. The secretory vesicles and lysosomes were increased gradually from Cp to the Cu. The process of degeneration of the non-ciliated epithelial cells observed in the Cp, Cr and Cu epididymidis. The increase of the non-ciliated epithelial cells, and its degeneration were observed more often from Cp to the Cu. The morphological characteristics of the ciliated epithelial cells, the cell types of the Cp, Cr and Cu were long-columnar, short-columnar and short-cuboudal, respecptively like the non-ciliated epithelial cells. The stereocilia was long and slender at the Cp and Cr, while Cu was very short. The pinocytotic vesicles and absorptive vesicles were increased from the Cp to the Cu. Numerous disintergrated products was existed at the Cr including the Cp, but Cu were not observed. A significant amount of lysosomes existed at the Cp and Cr epithelial cells, but they were not observed in Cu epithelial cells.

• Development and Reproduction
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• v.13 no.4
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• pp.271-280
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• 2009

Human placenta is abundant source of adult stem cells. Especially, amniotic epithelial cells have stem cell characteristics, expressing surface markers normally present on embryonic stem cells and germ cells. However, culturing and expanding amniotic epithelial cells in vitro without feeder cells are difficult due to endogenous characteristics of epithelial cells. In the present study, amniotic epithelial cells are isolated and proliferated in several passages by applying dithiothreitol and a Rho-associated kinase inhibitor in culture media. The cultured amniotic epithelial cells showed the epithelial and stem cell characteristics. In conclusion, human placenta-derived amniotic epithelial stem cells can be a major source of stem cells for medical treatment of various diseases without any controversial issues.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.649-656
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• 2003

We have a cultured method to grow rat mammary epithelial cells (RMEC) for 1 to 14 days in 1:1 mixture of Dulbecco's Modified Eagle Medium: Nutrient and F-12 (DMEM/F-12) containing 10% fetal bovine serum (FBS), human EGF, insulin, hydrocortisone, human transferrin and $17{\beta}$-estradiol in vitro. We were able to isolate and distinguish two cell types, luminal epithelial cells and myoepithelial cells, from primary clutures of RMEC. Immunocytochemical stains were used to distingusih luminal epithelial cells and myoepithelial cells. Peanut lectin (PNA) was stained in most alveolar epithelail cells and luminal epithelial cells of rats, while Thy-1.1, a maker of potential rat mammary myoepithelial cells, was expressed in myoepithelial cells in the rat. Also, we examined the expression patterns of three types of gap junction proteins, connexin 26 ($C{\times}26$), connexins 32 ($C{\times}32$) and connexin 43 ($C{\times}43$) by immunocytochemistry and western blot analysis. In the cell types, the results show that at the early stage of culture, luminal epithelial cells were increased and these cells were surrounded by myoepithelial cells. At the late stage of culture, luminal epithelial cells were decreased, in contrast myoepithelial cells were increased. In the expression pattern of gap junction, $C{\times}26$ maintained it's expression until day 3, but afterwards gradually decreased in intensity. Expression of $C{\times}32$ remained until day 5, then decreased slightly. $C{\times}43$ gradually increased untill the middle time of culture then decreased in intensity. These results suggest that connexins may be important for the control of growth in rat mammary epithelial cell types.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.317-325
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• 1998

The primary culture of human nasal epithelial cells was performed using the inferior nasal turbinate tissues, and infected with Hantaan virus to examine the hypothesis of airborne transmission of Hantaan virus in humans. The primary culture cells were identified as epithelial cells by morphologic and immunologic analyses. The viral antigens were detected in the primary human nasal epithelial cells infected with Hantaan virus by immunofluorescence staining. The ICAM-1 induction by Hantaan virus or $IFN-{\gamma}$ was examined in the primary human nasal epithelial cells and human lung fibroblasts (WI-38). Hantaan virus induced the surface ICAM-1 in WI-38 cells in a time-dependent manner, and $IFN-{\gamma}$ induced the surface ICAM-1 in a dose-dependent manner in HNEC and WI-38 cells. These results revealed that the human nasal epithelial cells are susceptible to Hantaan viral infection supporting the hypothesis of airborne transmission of Hantaan virus in humans. The human lung fibroblasts also might have an important role in the pathogenesis of Hantaan virus through the induction of ICAM-1.