• Parasites, Hosts and Diseases
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• v.41 no.3
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• pp.147-154
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• 2003

Toxoplasma gondii tachyzoites were isolated from the blood of an ocular patient, and have been successfully passaged in the laboratory, for over a year, by peritoneal inoculation in mice. The isolated parasite was designated the Korean Isolate-1 (KI-1) and its characteristics were compared with those of the RH strain, a well-known virulent strain originating from a child who suffered from encephalitis. The morphology, pathogenicity, infectivity and cell culture characteristics of the KI-1 were similar to those of the RH strain. Both RH and KI-1 antigens were detected by an anti-T gondii monoclonal antibody (mAb), Tg563, against the major surface protein SAG1 (30 kDa), whereas no reaction was observed against an anti-Neospora caninum mAb, 12B4. The KI-1 was confirmed as an isolate of T. gondii. A long-term laboratory maintenance and characterization of a local T gondii isolate is reported for the first time in the Republic of Korea.

• Korean Journal of Veterinary Research
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• v.26 no.2
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• pp.283-292
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• 1986

Isolation and identification of Mycoplasma were performed to clarify Mycoplasma infection of mice fed by conventional feeding at two ($K_1$, $K_2$) institutes in Korea. The twenty mice to be tested were randomly sampled from each of 10 breeding colonies in respective institute. Identification of the Mycoplasma strains isolated from the nasal cavity, lung and synovia of mice was made according to the morphology of colonies, biological and biochemical properties with special reference to M. pulmonis, M. arthrotodis and M. neurolyticum. In addition, growth inhibition test was performed using hyperimmune rabbit antisera to the strain PG-22 of M. pulmonis, the strain PG-6 of M, arthritidis and the strain PG-28 of M. neurolyticum and also differentiation of isolates from L-form bacteria was dont by Dieses staining and culture method with passage of the isolates on liquid media eliminated antibacterial drug. On the other hand, a total of 13 strains out of the 44 isolated M. pulmonis from mice was investigated for their susceptibility against 16 antibiotics in vitro. The antibiotic sensitivity test was made using $3{\times}10^4$ organisms/0.3ml on each plate(90mm diameter) with antibiotic mono-or tri-disk. The results obtained are summarized as follows: 1. Out of 20 mice from 10 breeding colonies in Kl institute, mycoplasma-like strains from the nasal cavity of 16 mice(80%) and from the lung of 8 mice(40%) were isolated, while out of 20 mice in K2 institute, M-like strains were isolated from the nasal cavity of 14 mice(70%) and from the lung of 6 mice(30%). However, no mycoplasma-like organisms were isolated from the synovia of the 40 mice examined. All the 44 strains isolated were identified as the organisms of M. pulmonis. 2. Out of the 16 antibiotics tested, penicillin, oleandomycin and bacitracin showed no activity against all the 13 M. pulmonis strains. On the contrary, lincomycin, clindamycin, chloramphenicol, tetracycline, minocycline, kanamycin, gentamycin and tobramycin showed high activity with three different antibiotic concentration of tridisk, but amikasin and spiramycin showed intermediate activity. Other antibiotics such as polymyxin B and colistin showed low activity, while erythromycin showed lower activity than others.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1102-1107
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• 2003

The ES cell can provide a useful system for studying differentiation and development in vitro and a powerful tool for producing transgenic animalds. To investigate the culture condition of chicken embryonic stem (CES) cells which can retain their multipotentiality or totipotency, three kinds of feeder layer cells, SNL cells, primary mice embryonic fibroblasts (PMEF) cells and primary chicken embryonic fibroblasts (PCEF) cells, were used as the feeder cells in media of DMEM supplemented with leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF) and stem cell factor (SCF) for co-culture with blastoderm cells from stage X embryos of chicken. The alkaline phosphatase (AKP) test, differentiation experiment in vitro and chimeric chicken production were carried out. The results showed that culture on feeder layer of PMEF yielded high quality CES cell colonies. The typical CES cells clone shape revealed as follows: nested aggregation (clone) with clear edge and round surface as well as close arrangement within the clone. Strong alkaline phosphatase (AKP) reactive cells were observed in the fourth passage cells. On the other hand, the fourth passage CES cells could differentiate into various cells in the absence of feeder layer cells and LIF in vitro. The third and fourth passage cells were injected into the subgerminal cavity of recipient embryos at stage X. Of 269 Hailan embryos injected with CES cells of Shouguang Chickens, 8.2% (22/269) survived to hatching, 5 feather chimeras had been produced. This suggests that an effective culture system established in this study can promote the growth of CES cells and maintain them in the state of undifferentiated and development, which lays a solid foundation for the application of CES cells and may provide an alternative tool for genetic modification of chickens.

• Korean Journal of Veterinary Research
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• v.53 no.1
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• pp.29-35
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• 2013

To develop a live vaccine candidate using an attenuated strain of Salmonella Typhimurium (ST), biochemical properties, plasmid profile, PFGE patterns and pathogenic analysis of the ST isolate were carried out after sequential passage of the ST isolate in porcine neutrophils. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. Also, changes including deletion of the gene fragments were observed in PFGE analysis of the neutrophil-adapted isolates. Two plasmids, 105kb and 50kb, were cured in the strain passaged over 15 times in porcine neutrophils. The 50% of lethal dose ($LD_{50}$) of the parent strain was changed from $1{\times}10^5\;LD_{50}$ to $6{\times}10^6\;LD_{50}$ by the passage in intraperitoneal injection of the strains into mice. These results suggested that bacterial genotypic and phenotypic responses might be globally altered depending on the inside environment of neutrophils.

• BMB Reports
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• v.44 no.8
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• pp.512-516
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• 2011

Establishment of immortalized human dermal papilla cells (DPCs) retaining the characteristics of DPCs would be a great help for hair researchers. We recently established a simian virus 40T (SV40T)-transformed human DP cell line (SV40TDPC). However, the cell line senesced around passage 25 and ceased proliferation. In this study, we introduced the human telomerase reverse transcriptase (hTERT) gene into SV40T-DPC and established an immortalized human DP cell line. The cell line, SV40T-hTERT-DPC, did not induce tumors when inoculated into nude mice. SV40T-hTERT-DPC maintained morphology of early passage DPCs, expressed markers of DPCs, and retained responses to Wnt/${\beta}$-catenin and bone morphogenic protein (BMP) signaling pathways known to be required for hair-inducing activity of DPCs. The data strongly suggest that SV40T-hTERT-DPC retains many characteristics of human DPCs in vivo without malignant transformation.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.1
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• pp.86-93
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• 2020

The establishment of porcine embryonic stem cells (ESCs) from porcine somatic cell nuclear transfer (SCNT) blastocysts is influenced by in vitro culture day of porcine reconstructed embryo and feeder cell type. Therefore, the objective of the present study was to determine the optimal in vitro culture period for reconstructed porcine SCNT embryos and mouse embryonic fibroblast (MEF) feeder cell type for enhancing colony formation efficiency from the inner cell mass (ICM) of porcine SCNT blastocysts and their outgrowth. As the results, porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days showed significantly increased efficiency in the formation of colonies, compared to those for 7 days. Moreover, MEF feeder cells derived from outbred ICR mice showed numerically the highest efficiency of colony formation in blastocysts produced through in vitro culture of porcine SCNT embryos for 8 days and porcine ESCs with typical ESC morphology were maintained more successfully over Passage 2 on outbred ICR mice-derived MEF feeder cells than on MEF feeder cells derived from inbred C57BL/6 and hybrid B6CBAF1 mice. Overall, the harmonization of porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days and MEF feeder cells derived from outbred ICR mice will greatly contribute to the successful establishment of ESCs derived from porcine SCNT blastocysts.

• Biomedical Science Letters
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• v.27 no.2
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• pp.99-104
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• 2021

Treatment techniques that affect homeostasis by non-invasive regulation in peripheral organs will advance disease research. Here, we demonstrate a non-invasive method of conditioning within an organ using a low-frequency stimulator superposition of alternating microcurrent wave in stages. It is first applied to the inflammatory response in H3N2-infected sinusitis mice. To check the progress of the treatment, mice were sacrificed every week for 3 weeks, nasal tissue was removed, and the inflammatory response was investigated through H & E staining. The low-frequency stimulation treatment group was found to alleviate the proliferation of epithelial cells and invasion of inflammatory cells compared to the control group as the passage of treatment time. The reduction of inflammatory cytokines in the nasal lavage fluid was observed in H3N2-infected sinusitis mice treated with of low-frequency stimulation using superposition of alternating microcurrent wave compared to H3N2-infected sinusitis mice after 3 weeks. These data demonstrate that low-frequency stimulation device in the form of using alternating current wave superposition on within organs provides a new method to regulate specific physiological functions. Therefore, it is necessary to prove the inhibitory effect of low-frequency stimulation using alternating current wave superposition on inflammatory diseases by various methods through further studies and clinical studies.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.289-295
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• 1998

Used gasoline engine oils(UGEO) are carcinogenic in long term studies and capable of increasing the number of carcinogen-DNA adducts in short term studies when dermally applied to mice. The carcinogenic risk of UGEO has been attributed to the concentration of polycyclic aromatic hydrocarbons(PAH) which accumulate in the lubricating system during the combustion of gasoline. When dermally exposed to UGEO, the use of hand cleanser was commonly recommended for removing it. But generally workers who dermally exposed oils, use kerosene as cleaner which make skin trouble. During this study, female mice aged 4-6 weeks were utilized to evaluate the efficiency of kerosene, as solvent-based cleanser, following dermal exposure to UGEO. DNA adduct were detected at skin and lung tissues by using the $^{32}P$-postlabeling method. Washing with cleansers were done at two different interval times following dermal application of UGEO. The total DNA adducts in skin and lung tissues were statistically significantly increased in positive control groups, and of which the total adduct level in skin tissues was statistically significant higher than those in lung tissues(p=0.005). When washing kerosene, the DNA adduct level in skin tissues was statistically significantly decreased(p=0.0001). But DNA adducts in lung tissue was statistically increased(p=0.0039), and that washed at 8hr post exposure was more severly increase(p<0.05). The slope of regression between DNA adducts of lung between skin tissues was 1.0802. In conclusion, skin cleaning with kerosene facilitates passage of carcinogens to the lungs of animals dermally treated with used gasoline engine oils(UGEO).

• Parasites, Hosts and Diseases
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• v.37 no.2
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• pp.85-92
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• 1999

To determine the pathogenicity of Acanthamoeba spp. isolated in Korea and to develop a isoenzymatic maker, the mortality rate of infected mice, in vitro cytotoxicity against target cells and isoenzyme band pattern were observed. Five isolates of Acanthamoeba spp. (YM-2, YM-3, YM-4, YM-5 and YM-7) were used in this study as well as three reference Acanthamoeba spp. (A. culbertsoni, A. hatchetti, and A. royreba). According to the mortality rate of infected mice, Korean isolated could be categorized into three groups: high virulent (YM-4), low virulent (YM-2, YM-5, YM-7) and the nonpathogenic group (YM-4), In addition, the virulence of Acanthamoeba spp. was enhanced by brain passage in mice. In the cytotoxicity assay against chinese hamster ovary cells, especially, the cytotoxicity of brain-passaged amoebae was relatively higher than the long-term cultivated ones. The zymodeme patterns of glucose-6-phosphate dehydrogenase (G6PD), malate dehydrogenase (MDH), hexokinase (HK), glutamate oxaloacetate transaminase (GOT) and malic enzyme (ME)of Acanthamoeba spp. were different among each isolate, and also between long-term cultrued amoebae and brain passaged ones. In spites of the polymorphic zymodemes, a slow band of G6PD and K, and an intermediate band of MDH were only observed in pathogenic Acanthamoeba spp., which should be used as isoenzymatic makers.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.48-50
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• 2002

Cartilage defects are common and painful conditions that affect people of all ages. Although many techniques have developed, none of the current available treatment options is satisfactory. Recent advances in biology and materials science have pushed tissue engineering to the forefront of new cartilage repair techniques. The purpose of this study is to determine effective regeneration method for tissue-engineered cartilage. A serum free medium was developed for cartilage tissue engineering. Chondrocyte passage number was found to influence greatly on cartilage tissue formation in vivo. Injectable, biodegradable polymer matrix was developed for chondrocyte transplantation through injection. Transplantation of chondrocytes mixed with the injectable matrices resulted in the cartilage formation in nude mice's subcutaneous sites and rabbit knees. This study may lead to the development of tissue-engineered cartilage appropriate for clinical applications.