• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.545-550
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• 2005

Purpose : Newborn brain tissue has to be dissociated into a single cell suspension for flow cytometric analysis of cell death during hypoxia-ischemia. Thus the development of a method to dissociate cells from the brain tissue with least damage and maintenance of membrane and antigen integrity remains the challenge for the in vivo application of this technique. We evaluated the efficacy of mechanical or enzymatic (collagenase or tryspin) methods of brain tissue disaggregation. Methods : The extent of the damage to the plasma membrane and loss of the characteristics of the membrane induced with each dissociation method was determined by comparing the flow cytometric results labeled with both fluorescent annexin V and propidium iodide of the newborn rat pup brain tissue in the control group (n=10) and in the 48-hour after hypoxia-ischemia group (n=10). Results : In the control group, the cell percentage of damaged, apoptotic and necrotic cells of both hemispheres with the mechanical dissociation method was significantly increased compared to the trypsin or collagenase method. In the 48-hour after hypoxia-ischemia group, the cell percentage of apoptotic and necrotic cells of the right hemisphere with the collagenase method significantly increased, and live cells significantly decreased compared to the left hemisphere, control group. Although the same trend was observed, the extent of alterations made with the trypsin method was significantly less compared to the collagenase method. Conclusion : The dissociation of neonatal brain tissue for flow cytometric analysis with collagenase was most efficacious with the least cell damage and preservation of the plasma membrane characteristics.

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.16-22
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• 1995

This study was designed to investigate the antibody production to sheep red blood cells(SRBC) and proliferation of mitogen-stimulated spleen cells in Balb/c mice which received cadmium chloride. The mice were divided into three independent groups which were one control and two experimental groups by the cadmium treatment or not. No specific treatment was done for the control group. One of two experimental groups, which is called 'pre-treatment group' in this paper, was subcutaneously injected with low dose of cadmium chloride(0.5 mg/kg/day) for 5 consecutive days before the primary SRBC immunization. The other called 'non-pretreatment group' was only pretreated with normal saline. Both experimental groups were intraperitoneally injected with high dose of cadmium chloride(5 mg/kg) 8 hours before the primary immunization. Mice were intraperitoneally immunized twice with 2% SRBC suspension containing $10^8$ cells. The results obtained were as follows, 1. The PFG responses to SRBC were significantly increased in two experimental groups, cadmium pretreatment and non-pretreatment compared with that of control group(p<0.05). 2. The total antibody titers to SRBC in cadmium treated groups were similar to that of control group, but titers of IgG antibody were significantly elevated(p<0.01). 3. The proliferation response of spleen lymphocytes to various mitogens was suppressed in proportion to the concentration of cadmium and the degree of cadmium accumulation in liver was increased in the cadmium treated groups. These results suggest that cadmium chloride could affect on mouse immune response, especially its cell mediated immune response could be decreased while its humoral immune response could be increased, which may not be influenced by the administration methods or pretreatment of cadmium to mouse.

• Journal of Ginseng Research
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• v.38 no.2
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• pp.136-145
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• 2014

Background: This study aimed to develop a biocontrol system for ginseng root rot caused by Fusarium cf. incarnatum. Methods: In total, 392 bacteria isolated from ginseng roots and various soils were screened for their antifungal activity against the fungal pathogen, and a bacterial isolate (B2-5) was selected as a promising candidate for the biocontrol because of the strong antagonistic activity of the bacterial cell suspension and culture filtrate against pathogen. Results: The bacterial isolate B2-5 displayed an enhanced inhibitory activity against the pathogen mycelial growth with a temperature increase to $25^{\circ}C$, produced no pectinase (related to root rotting) an no critical rot symptoms at low [$10^6$ colony-forming units (CFU)/mL] and high ($10^8CFU/mL$) inoculum concentrations. In pot experiments, pretreatment with the bacterial isolate in the presumed optimal time for disease control reduced disease severity significantly with a higher control efficacy at an inoculum concentration of $10^6CFU/mL$ than at $10^8CFU/mL$. The establishment and colonization ability of the bacterial isolates on the ginseng rhizosphere appeared to be higher when both the bacterial isolate and the pathogen were coinoculated than when the bacterial isolate was inoculated alone, suggesting its target-oriented biocontrol activity against the pathogen. Scanning electron microscopy showed that the pathogen hyphae were twisted and shriveled by the bacterial treatment, which may be a symptom of direct damage by antifungal substances. Conclusion: All of these results suggest that the bacterial isolate has good potential as a microbial agent for the biocontrol of the ginseng root rot caused by F. cf. incarnatum.

• Journal of Food Hygiene and Safety
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• v.5 no.4
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• pp.237-242
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• 1990

This study was conducted to evaluate the usage of TBA method for the analysis of lipid peroxidation induced by streptozotocin. 5 mM streptozotocin and 1 % TBA alone showed the maximum peak at 309 nm and 358 nm respectively, although no peak was observed at 532 nm which was the wavelength to determine the absorbance for TBA method. When 5 mM streptozotocin was mixed together with 1 % TBA in vitro, new peaks at 439 nm and 532 nm had been detected, suggesting TBA did interact directly with streptozotocin forming new colored products. These results suggest that TBA method is not adequate for determination of lipid lperoxidation induced by streptozotocin.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.60-60
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• 2003

Embryonic stem (ES) cells have property of self-renewal and can differentiate into the cells of all three primary germ layers. Recently, many growth factors, alteration of culture condition and gene modifications have been used to differentiate mouse and human ES cells into specific cell types. This study was performed to evaluate the differentiation protocol for human ES cells to the endodermal lineage cells. Human ES cells (Miz-hESl ) were cultured on STO feeder layer mitotically inactivated with mitemycin C, and embryoid bodies (EBs) were formed by suspension culture. Differentiation protocol of EBs consisted of three steps: stage I, culture of EBs for 6 days with ITSFn medium; stage II, culture of stage I cells for 8 days with N2 medium ; stage III, culture of stage II cells for 22 days with N2 medium. mRNA levels of the endodermal lineage differentiation genes were analyzed by semi- quantitative RT-PCR. The Oct-4 expression, a marker of the pluripotent state, was detected in undifferentiated human ES cells but progressively decreased after EBs formation. Differentiating human ES cells expressed marker genes of endodermal differentiation and pancreatic islet cells. GATA4, a-fetoprotein, Glut-2, and Ngn3 were expressed in all stages. However, albumin and insulin were expressed in only stage III cells. The human ES cells can be differentiated into endodermal lineage cells by multiple step culture system using various supplements. We are developing the more effective protocols for guided differentiation of human ES cells.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.1
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• pp.89-94
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• 2010

Patterning bacteria and cells on substrates has potential applications in molecular biology, antimicrobial drug screening, environmental monitoring and tissue engineering. We developed a technique to deposit two-dimensional array of bacterial cells onto an agar plate by modifying commercially available thermal inkjet printers. The concentration of the bacterial solution in the cartridge was carefully determined to ensure a single cell suspension in a droplet ejected from a nozzle. We measured quantitatively the effects of the bacterial concentration and the agar concentration on patterning performance. Bacterial patterning by inkjet printer is a low-cost and versatile technique which may replace the existing sophisticated methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.237-241
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• 2006

This experiment was carried out comparison with haploid plants productivity by microspore culture among domestic cultivars of Brassica napus L. Isolated microspore from flower buds were cultured on NLN medium supplemented with 13% sucrose, $0.05mg/{\ell}$ BA and $0.5mg/{\ell}$ NAA. Genotype was important factor in haploid embryo productivity 'Tamlayuchae' showed the highest haploid embryo production frequency (176 embryos formed from 1 flower bud). But, 'Hallayuchae' and 'Youngsanyuchae' were not generated embryo even cell division. When suspension culture on NLN liquid medium at 100 rpm, embryos were developed multilobe abnormal embryo cluster. Multilobe abnormal embryos on MS medium basal solid medium were regenerated multiple shoots. Regenerated haploid plant with well developed shoots and roots on MS basal medium were successfully transferred to pots.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1622-1627
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• 2004

Nephrite has been widely used as a medicinal mineral resource to treat a numerous chronic diseases and to replenish vital essence and blood in the Korean traditional medicine. However, as of yet, there is little understanding of the pharmacological and biochemical mechanisms of its therapeutic effects as regards anti-inflammation. We therefore examined whether nephrite represses the expression of major inflammation mediators, such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), in LPS-stimulated murine macrophage cell line, RAW264.7 by using RT-PCR. The powder suspension and water extracts of nephrite significantly inhibited the mRNA expression of the mediators, despite a little toxic effects on growth of RAW 264.7 cells within the concentration range tested. These experimental results suggested that the nephrite can be utilized as a functional mineral exerting the anti-inflammation medicinal effect.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.589-600
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• 1998

This study was planned to verify the usefulness of Latin square design method in fatigue tests of cables and to see the axial fatigue behavior of wire ropes being used as hangers in suspension bridges. Three parameters : mean stress, stress range. and specimen length, were adopted for verification. The effects of these parameters are in argument except for stress range. Three classes in each parameter were used. Triple replication was performed in each cell to increase the number of replication (or degree of freedoms). The major cause of fatigue failure was fretting fatigue at trellis contact point. Three chosen parameters were proved to be significant. It was verified that the effect of stress range was in agreement with expectation, but the effect of specimen length was contrary to the expectation. It was also observed that the effect of mean stress depended upon the chosen level. Therefore Latin square design method is effective for verifying the parameters that affect fatigue behaviour under orthogonality conditions.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.608-613
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• 2010

Electricity generation of microbial fuel cells (MFC) is greatly affected by the kind of feed substrates because substrates would change microbial community of electrochemically active bacteria (EAB) able to transfer electrons to electrode. The effect of different substrates on electricity generation and microbial community of MFC was investigated. Two-chamber MFCs fed with acetate (A-MFC), butyrate (B-MFC), propionate (P-MFC), glucose (G-MFC) and a mixture (M-MFC) of the 4 substrates (acetate : butyrate : propionate : glucose = 1 : 1 : 1 : 1 as $COD_{Cr}$ base) were operated under continuous mode. The maximum power density was found from the M-MFC ($190W/m^3$) which showed the lowest internal resistance ($89{\Omega}$). The maximum power densities of the pure substrates feed MFCs were in order of A-MFC ($25W/m^3$), P-MFC ($21W/m^3$), B-MFC ($20W/m^3$) and G-MFC ($9W/m^3$). In DGGE analysis, the microbial community structure in suspension was quite different from each others depending on feed substrates, while the community structure in the biofilm was relatively similar regardless of the substrates. This result suggests that the feed substrates would affect the microbial community of suspended growth bacteria than attached growth bacteria resulting in difference of electricity generation in MFCs.