• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.177-186
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• 1989

Observations were made on the differences in cell-mediated immune responses in the mice infected with strongly pathogenic Naegleria fewleyi ITMAP 359, weakly pathogenic Naegzeria jadini 0400, or non.pathogenic Naegleria gruberi EGB, respectively. Variations in cell-mediated responses and changes in antibody titers according to the duration after infection wore noted. Infections were done by dropping $5{\;}{\mu}l$ saline suspension containing $10{\times}10^4$ trophozoites cultured Bxenically in the CGVS medium into the right nasal cavity of ICR mice aging about 6~7 weeks, under the anesthesia by intraperitoneal injection of'secobarbital. Following infection, delayed type hypersensitivity(DTH) iesponses in the footpad and blastogenic responses of the mouse spleen cells using [$^3H$]-thymidine were observed on the day 1, 4, 7, 10 and 14 after infection. For the preparation of amoeba Iysates, each of cultured trophosoites were homogenized with an ultrasonicator, and centrifugated at 20,000 g. The supernatants of amoeba Iysates were used as the mitogen'and antigen for ELISA. Confanavalin A(Con. A) and lipopolysaccharide(LPS) were also used as mitogens in the blastogenic response. 1. The mice infected with N, fowleri showed the mortality rate of 75.7%. The rate was 6.2% for the N. jadini infected group, while no dead mouse was observed for N. gruberi infections. 2. In regard to DTH responses in the H. fewleri infected mice, the level increased in com- parison to the control group but declined after 7 days. An increase was also noted for the JV. jadini group after 1 day, but gradual decreases were observed through the infection period. In addition, no difference was noted between the N. gruberi infected and control groups. 3. Concerning the blastogenic response of the splenocytes, it increased after 10 days in the experimental group of N, fcwleri infection, but the differences ware not statistically significant compared with control group. It was evident that N. jadini group was not different from control group either, while there was a tendency of decrease in SV. gruberi infected group. In regard to the blastogenic response of the splenocytes by LPS, it was found that the N. fowlgri, N. jadini and N. gruberi infected groups had no differences from the control group. 4. The serum antibody titer of N. fcwleri and N. jadini infected mice increased from the day 7 and 14 after infection respectively, while the N. gruberi infected mice showed no increase. In summary of the results, it was observed that there were differences in the cell-mediated immune responses and serum antibody titers in the mice infected with strongly pathogenic JV. fowleri, weakly pathogenic N. jadini, or non.pathogenic N. gruberi, respectively.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.163-169
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• 2001

OSBA(oocytes-sperm binding assay) is a tool developed for rapid test of optimal condition of IVF medium and protein source by binding ability of mouse sperm and egg. Mouse oocyte-cumulus complexes were prepared by removing of the cumulus cells with 0.1% hyaluronidase. 10$\pm$2 oocytes per 30 ${mu}ell$ medium drop were inseminated with 3 ${mu}ell$ sperm suspension and were cultured f3r 3 hours and 24 hours, respectively. And the oocytes were recovered gently and the No. of sperm bound on oocytes were counted. In the Exp. 1, the ratio of oocytes bound with one sperm at least were 60.2%(50/83), 2%(2/77) and 100%(79/79) in the medium with no protein, FBS(15%, v/v) and BSA(0.4%. w/v), respectively, Fetal bovine serum(FBS) seriously inhibited sperm binding on oocyte, although bovine serum albumin(BSA) promoted the binding ability. The inhibiting effect of FBS was dependent on the concentration of FBS. The sperm binding ability according to oocyte maturity was tested in the Exp. 2. There was no significant difference between Met. II (mature) and Met. I (intermediate mature) oocytes in the number of oocytes bound with sperm and the number of sperm bound on oocytes. Finally, in Exp. 3, two batches of Ham's F10 medium with good and poor quality by OSBA were tested (The ratios of embryos developed from PN 1-cell stage to hatched blastocyst; 25% vs. 70%). In the medium with good quality, sperm binding ability was significantly increased (P ＜ 0.05). The ratio of oocytes bound with one sperm at least was 66% and 90% in the medium with poor and good quality, respectively. Conclusively, It was possible to test IVF medium condition rapidly and easily by OSBA.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.325-329
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• 2018

This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at $30^{\circ}C$, $37^{\circ}C$, and $42^{\circ}C$ to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at $42^{\circ}C$ than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.

• Korean Journal of Medicinal Crop Science
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• v.2 no.1
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• pp.60-66
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• 1994

This study was conducted to determine the optimum conditions of inducing callus, proliferating callus, forming somatic embryos, and regenerating plantlets via somatic embryogenesis, for the purpose of producing artificial seeds and substantially developing plant factory technologies that can be employed to all seasons production of Bupleurum plants. Callus was efficiently induced from leaf tissues at three leaf stage in the MS medium supplemented with 2, 4-D 2mg /1 and thidiazuron(TDZ) 0.lmg /1. Callus induction from leaf tissues at maturity was mostly effective in the mixture of 2,4- D 2mg /1 and TDZ 1.0mg /1 while that from flower bud tissues was fairly good in the MS medium containing 2,4-D 1 or 2mg /1.Callus was formed in 15 to 20 days after culture initiation in the MS media supplemented with 2, 4- D 1-2mg /1 and TDZ 0.l-1.0mg /1. Such hormones as kinetin 3mg /1, GA 1mg /1, and the mixture of GA 1mg /1 and TDZ 1mg /1 effected markedly to proliferate the callus cells.The optimum temperature and light intensity for callus culture were found to be $25^{\circ}C$ and 3000 Lux, respectively. Direct plant regeneration from cultured callus was fairly made on hormone-free MS or half-strength MS medium. Somatic embryogenesis was most frequently observed in hormone-free media:60 somatic embryos per 20ml in MS medium and 28 somatic embryos per 20ml in half -strength MS medium. There were three stages-globular, heart, and torpedo-in development of somatic embryos, among which globular stage was more frequently observed in MS medium rather than in half-strength MS medium. Somatic embryos induced from suspension culture fairly differentiated a number of shoots and roots on hormone-free and half-strength MS solid medium.