• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.728-733
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• 2007

Presence and distribution of bacteria and fungi in inner compartment of PCs(Personal Computers) were investigated. Samples for the analysis were collected from inside of PCs which had been used in various facilities including public computer facilities, laboratories and computer training rooms of a university. Total number of PC examined in this study was 51 each. When the total CFU(colony forming unit) of the inner compartment of the PCs was measured, the bacterial count was found to be dependent on the operation time(total running time) of PCs. When the distribution of bacteria in the inner compartment of PCs was estimated, CPU(Central Processing Unit) cooling fan area showed the highest bacterial concentration(average 605 $CFU/cm^2$). In the case of the fungi, various opportunistic pathogens including Aspergillus sp. and Penicillium sp. were isolated and identified in the inner compartment of PCs. And the average of bacterial number in the dust collected from the PCs was 212 CFU/mg. These results indicated that handling of PC might have a risk of infection by the microorganism.

• Mycobiology
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• v.33 no.3
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• pp.158-162
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• 2005

The immunomodulatory effect of aqueous extract of Inonotus obliquus, called as Chaga, was tested on bone marrow cells from chemically immunosuppressed mice. The Chaga water extract was daily administered for 24 days to mice that had been treated with cyclophosphamide (400 mg/kg body weight), immunosuppressive alkylating agent. The number of colony-forming unit (CFU)-granulocytes/macrophages (GM) and erythroid burst-forming unit (BFU-E), increased almost to the levels seen in non-treated control as early as 8 days after treatment. Oral administration of the extract highly increased serum levels of IL-6. Also, the level of $TNF-{\alpha}$ was elevated by the chemical treatment in control mice, whereas was maintained at the background level in the extract-treated mice, indicating that the extract might effectively suppress $TNF-{\alpha}$ related pathologic conditions. These results strongly suggest the great potential of the aqueous extract from Inonotus obliquus as immune enhancer during chemotherapy.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.6-15
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• 2004

This study was performed to evaluate the hemopoietic effects of 6 species of deer antlers from origins and parts in vitro. CD34 positive cells were isolated and confirmed the its population by FACS analysis. In a week liquid culture, there was any statistical significance between extracts of three parts of six species of deer antlers in the experiments as colony forming assay, proliferation assay, differentiation assay and observation of morphology. However, after 2 weeks- culture with extracts of three parts of six species of deer antlers, colonies were counted. six species of deer antlers, such as middle part of Korean nippon deer, upper part of Chinese nippon deer, upper part of Newzealand horse deer, middle part of Korea horse deer and middle part of Newzealand red deer, significantly increased the CFU-GM (colony forming unit garnulocyte-macrophage) of CD34 positive cells re1atεd to production of leucocytes such as eosinophil, basophil and neutrophil, while only middle part of Korea horse deer significantly increased the BFU-E (burst forming unit-erythroid) at 1 mg/ml seggesting progenting red blood cells (RBC). In the molecular study with CD34+ cells pretreated with cyclophosphamide, antagonist of hemopoietic activity, upper Part of Korean nippon deer and upper part of Chinese nippon deer effectively increased TPO involved in a late pathway of hematopoiesis just like in ELISA assay of IL-3, TPO and GM-CSF. Taken together, these results indicate exσacts of deer antler had some hemopoietic activity still proposing more clinical study and more basic mechanism research.

• Biomaterials Research
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• v.22 no.4
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• pp.271-278
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• 2018

Background: The chondrogenic differentiation of mesenchymal stem cells (MSCs) is regulated by many factors, including oxygen tensions, growth factors, and cytokines. Evidences have suggested that low oxygen tension seems to be an important regulatory factor in the proliferation and chondrogenic differentiation in various MSCs. Recent studies report that synovium-derived mesenchymal stem cells (SDSCs) are a potential source of stem cells for the repair of articular cartilage defects. But, the effect of low oxygen tension on the proliferation and chondrogenic differentiation in SDSCs has not characterized. In this study, we investigated the effects of hypoxia on proliferation and chondrogenesis in SDSCs. Method: SDSCs were isolated from patients with osteoarthritis at total knee replacement. To determine the effect of oxygen tension on proliferation and colony-forming characteristics of SDSCs, A colony-forming unit (CFU) assay and cell counting-based proliferation assay were performed under normoxic (21% oxygen) or hypoxic (5% oxygen). For in vitro chondrogenic differentiation, SDSCs were concentrated to form pellets and subjected to conditions appropriate for chondrogenic differentiation under normoxia and hypoxia, followed by the analysis for the expression of genes and proteins of chondrogenesis. qRT-PCR, histological assay, and glycosoaminoglycan assays were determined to assess chondrogenesis. Results: Low oxygen condition significantly increased proliferation and colony-forming characteristics of SDSCs compared to that of SDSCs under normoxic culture. Similar pellet size and weight were found for chondrogensis period under hypoxia and normoxia condition. The mRNA expression of types II collagen, aggrecan, and the transcription factor SOX9 was increased under hypoxia condition. Histological sections stained with Safranin-O demonstrated that hypoxic conditions had increased proteoglycan synthesis. Immunohistochemistry for types II collagen demonstrated that hypoxic culture of SDSCs increased type II collagen expression. In addition, GAG deposition was significantly higher in hypoxia compared with normoxia at 21 days of differentiation. Conclusion: These findings show that hypoxia condition has an important role in regulating the synthesis ECM matrix by SDSCs as they undergo chondrogenesis. This has important implications for cartilage tissue engineering applications of SDSCs.

• Journal of Radiation Protection and Research
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• v.33 no.3
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• pp.99-104
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• 2008

According to the increase in the use of radiotherapy to cancer patients, many approaches have been tried to develop new agents for the protection of surrounding normal tissues. However, it is still few applied in the clinic as a radioprotector. We aim to find a representative parameter for radioprotection to easily predict the activity of in vivo experiment from the results of in vitro screening. The polysaccharide extracted from Panax ginseng was used in this study because the immunostimulator has been regarded as one of the radioprotective agent category and was already reported having a promising radioprotective activity through the increase of hematopoietic cells and the production of several cytokines. Mitogenic activity, AK cells activity and nitric oxide production were monitored for the in vitro immunological assay, and endogenous colony-forming unit (e-CFU) was measured as in vivo radioprotective parameter. The immunological activity was increased by the galactose contents of ginseng polysaccharide dependently. The result of this study suggests that mitogenic activity of splenocytes demonstrated a good correlation with in vivo radioprotective effect, and may be used as a representative parameter to screen the candidates for radioprotector.

• The Journal of the Korean dental association
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• v.58 no.1
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• pp.19-26
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• 2019

Purpose: The purpose of this study is to compare the adhesion of Candida albicans according to build angle in 3D printing denture base resin. Methods: The 3D printing was performed by setting the build angle of the disk type specimen designed by CAD program at 0 degree, 30 degrees, 60 degrees, and 90 degrees. Surface roughness was measured using a non-contact 3D microsurface profiler. The specimens were incubated in Candida albicans suspension for 24 hours. The attached Candida albicans were detached by cell scraper. The suspension of detached C. albicans was serially diluted and plated on Trypticase soy broth. After 48 hours of incubation, total colony forming unit was counted. Results: There was no significant difference in surface roughness(Sa) between the test groups, but the interlayer boundary was observed. There was no statistically significant difference in total colony forming units of Candida albicans between the test groups. Conclusion: There was no difference in the average surface roughness and adhesion of Candida albicans between the specimens. It is considered that the setting of the build angle should be set considering the accuracy or strength rather than the roughness of the surface.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.209-214
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• 2008

VBNC (Viable but nonculturable) state is an adaptive response of cells in adverse environments, which lead cell not grow on routine nutrient agar. In this study, we induced VBNC in Escherichia coli using copper and verify the characterization of it. After treatment of copper, we didn't detect any cells via plate cultivation, namely, colony forming unit (CFU) was zero. However, we identified the existence of VBNC by staining live cells with Live/Dead BacLight bacterial viability kit and counting them through flow cytometry. Then we isolated genomic DNA and RNA from VBNC-induced cells and analyzed the stability of them. Degradation of RNA is more severe than that of DNA and RNA is degraded as specific fragments. In addition, we showed the morphology of VBNC cell by Bio-Transmission Electron Microscope (Bio-TEM). VBNC cell showed impaired periplasmic space and inner and outer membrane were separated and the amount of cytosol were significantly decreased.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.120-127
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• 2020

The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) using plaque disclosing agent, 10 - 20 mM erythrosine, as a photosensitizer. Multispecies cariogenic biofilms containing Streptococcus mutans, Lactobacillus casei and Candida albicans were formed on hydroxyapatite disc. 20 μM, 10 mM and 20 mM erythrosine were applied as a photosensitizer for 3 minutes, and then light-emitting diode (LED) irradiated for 24 seconds. Colony-forming unit (CFU) were measured and biofilms were observed using confocal laser scanning microscopy (CLSM). CFU were significantly decreased in the PDT groups using 10 - 20 mM erythrosine (10 mM, 20mM) and the results were also confirmed by CLSM. This study confirms the high antimicrobial effect of photodynamic therapy using plaque disclosing agent as a photosensitizer.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.279-284
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• 2002

Flacherie symptom was found in the fifth instar larvae of silkworm, Bombyx mori. The bacterial pathogen was isolated from the hemolymph of the infected silkworm and identified. The isolated bacteria caused a significant flacherie pathogenicity to the fifth instar larvae of B. mori when $5{\times}10^{6}$ cfu (colony-forming unit) of the bacteria was injected into each larva. The infected larvae began to die at 6 days after injection and resulted in complete mortality at 10 days. The bacterium was identified as Staphylococcus gallinarum based on the morphological and physiological characteristics described in Bergey's manual. This identification was further supported by the characters of carbohydrate utility analyzed from a bacterial identification system ($MicroLog^{\circledR}$) and also by the molecular structure of 165-23S rDNA internal transcribed spaces. As an insecticidal action, S. gallinarum caused hemolymph septicemia by its cytotoxic effect on the hemocytes of B. mori.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5773-5778
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• 2011

Results regarding the anti-oxidative, anti-allergic, anti-bacterial and anti-cancer effects of lotus leaf and dandelion have been reported through active research on the medical effects of medicine prepared from crude drugs. This paper aimed to examine the anti-bacterial effect of lotus leaf and dandelion extracts on S. mutans by evaluating the colony forming unit and growth curve. In accordance with the growth inhibition rate of S. mutans according to the addition of lotus leaf and dandelion extracts, the higher the extract concentration was, the higher the growth inhibition rate of S. mutans was. This paper therefore verifies that lotus leaf and dandelion extracts have an effect in inhibiting the growth of S. mutans.