• Biomedical Science Letters
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• v.27 no.4
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• pp.329-333
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• 2021

We previously identified that tumor cells genetically modified with a 4-1BBL co-stimulatory molecule had anticancer effects in a CT26 mouse colorectal tumor model. To identify the distinction between immune cells in a mouse tumor model treated with tumor cells genetically modified with 4-1BBL or β-gal, we examined the immune cells in CT26-WT, CT26-βgal, and CT26-4-1BBL tumor bearing mice 21 days after tumor cell administration. The CD8+ T cells population in mice treated with tumor cells genetically modified with 4-1BBL was significantly increased on day 21 compared to that of tumor cells genetically modified with β-gal in the spleen and tumor tissue. The CD4+ T cell population was not different between the two mice groups. The Foxp3+CD25^high CD4 T cell population decreased on day 21 in tumor tissues, but the decrease was not significant. We also found that CD8 T cells had pivotal roles in inhibiting tumor growth by treating mice with ant-CD4 and CD8 antibodies. These results suggest that tumor cells genetically modified with 4-1BBL could inhibit tumor growth by affecting on CD8 T lymphocytes.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.664-671
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• 2006

Modeling the growth kinetics of lactic acid bacteria (LAB), one of the most valuable microbial groups in the food industry, has been actively pursued in order to understand, control, and optimize the relevant fermentation processes. Most modeling approaches have focused on the development of single population models. Primary single population models provide fundamental kinetic information on the proliferation of a primary LAB species, the effects of biological factors on cell inhibition, and the metabolic reactions associated with cell growth. Secondary single population models can evaluate the dependence of primary model parameters, such as the maximum specific growth rate of LAB, on the initial external environmental conditions. This review elucidates some of the most important single population models that are conveniently applicable to the LAB fermentation analyses. Also, a well-defined mixed population model is presented as a valuable tool for assessing potential microbial interactions during fermentation with multiple LAB species.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.112-120
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• 2008

A series of experiments were conducted to establish a marine ecotoxicological standard method using marine primary producers, Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, Tetraselmis suecica as candidate test species. Marine diatom, S. costatum was selected as standard test species in terms of the ecological roles and international uses as test species. Test methods and test acceptability criteria are as follows; $72{\sim}96$ hr population growth inhibition $EC_{50}$ as endpoint. Static non-renewal method, and population growth rates over 0.04/hr in control as test acceptability criterium. S. costatum is widely distributed in the world ocean and used for standard species of marine toxicity test method by ISO (International Standardization Organization). Possible salinity ranges for this test method are $20{\sim}35\;psu$, and reproducibility and interlaboratory test results were consistent through the calibration tests. Sensitivity of the test method was comparable or better than other toxicity tests such as rotifer neonate mortality, bioluminescent bacterial inhibition, seaweed sporulation and sea urchin fertilization tests.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.19-26
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• 2010

Batch experiments were conducted to investigate growth and nutrient removal performance of microalgae Chlorella vulgaris by using piggery wastewater in different concentration of pollutants and the common growth models (logistic, Gompertz and Richards) were applied to compare microalgal growth parameters. Removal of nitrogen (N) and phosphorus (P) by Chlorella vulgaris showed correlation with biomass increase, implying nutrient uptake coupled with microalgae growth. The higher the levels of suspended solids (SS), COD and ammonia nitrogen were in the wastewater, the worse growth of Chlorella vulgaris was observed, showing the occurrence of growth inhibition in higher concentration of those pollutants. The growth parameters were estimated by non-linear regression of three growth curves for comparative analyses. Determination of growth parameters were more accurate with population as a variable than the logarithm of population in terms of R square. Richards model represented better fit comparing with logistic and Gompertz model. However, Richards model showed some complexity and sensitivity in calculation. In the cases tested, both logistic and Gompertz equation were proper to describe the growth of microalgae on piggery wastewater as well as easy to application.

• Ocean Science Journal
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• v.40 no.2
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• pp.91-100
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• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• Journal of Nutrition and Health
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• v.27 no.7
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• pp.717-728
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• 1994

This study was aimed to screen edible herbs which control the composition of intestinal microflora. With in vitro experiments, we screened the water or ethanol extracts of about 60 edible herbs and wild plants in terms of the inhibition activity on the growth of the harmful Clostridium perfringens and growth promoting activity for the beneficial Bifidobacteria. The water extracts of mugwort and small water dropwort inhibited the growth of Cl.perfringens both in agar diffusion method and broth culture. On the other hand, the water extracts of petasites, mugwort, yellow day-lily and bitter cress have shown the promotion effect on the growth of Bifidobacterium longum. In the culture test using human feces as starter, the extracts of the above selected herbs increased the population of Bifidobacteria and Lactobacillus while they reduced the numbers of Cl.perfringens and E.coli.

• Journal of Food Hygiene and Safety
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• v.10 no.1
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• pp.7-12
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• 1995

The inhibitory effects of vegetables, collected from Jinju district, on the growth of Listeria monocytogenes were investigated. Among 12 vegerables, garlic, leek, onion and cabbage were remarkably effective to inhibit the growth of the strain. Especially with the addition of extract equivalent 0.25g of raw garlic per ml broth, the population of the strain was decreased wignificantly, and completely inhibited with the addition of 0.625g or more. During the incubation with the addition of extract equivalent 0.25g of raw garlic per ml broth, the degree of inhibition was gradually increased with the lapse of time, and completely inhibited the growth of the strain after 48 hrs. While the pH value of treated broth remained unchanged almost, those of control were slightly reduced.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.973-981
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• 2007

In the present study, we investigated the antiproliferative activity of the water extract of Samgibopae-tang (SGBPT) in NCI-H460 and A549 non-small-cell lung cancer cell lines. We found that exposure of A549 cells to SGBPT resulted in the growth inhibition in a dose-dependent manner as measured by MTT assay, however SGBPT did not affect the growth of NCI-H460 cells. The antiproliferative effect by SGBPT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. SGBPT treatment did not induce the cell cycle arrest in both cell lines, however the frequency of sub-G1 population was concentration-dependently increased by SGBPT treatment in A549 cells. SGBPT treatment partially induced the expression of tumor suppressor p53 in A549 cells and the expression of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) was markedly increased in both transcriptional and translational levels in A549 cells. The up-regulation of p21 by SGBPT occurred in a similar a concentration dependent manner to that observed with the inhibition of cell viability and induction of sub-G1 population of the cell cycle. However SGBPT treatment did not affect other growth regulation-related genes such as early growth response-1 (Egr-1), nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1), inducible nitric oxide synthease (iNOS), cyclooxygenases (COXs), telomere-regulatory factors in A549 as well as NCI-H460 cells. Taken together, these findings suggested that SGBPT-induced inhibition of human lung carcinoma A549 cell growth was aoosciated with the induction of p21 and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of SGBPT.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.1
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• pp.12-23
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• 1992

This experiment was conducted to determine the optimum dosage of gamma rays for inducing artificial mutation of several mutant characters in the flue-cured tobacco. 1) In Hicks and BY 104, the gammarays irradiation has no significantly different effect on seed germination from the control. However, the average dosage for 50% growth inhibition was 25-30kr for all the varieties tested, which inhibition 46-52% and 43-57% of the seedling growths for Hicks and BY 104, respectively. 2) A mutant line 83H-5 was selected from Hicks by irradiation gamma ray at the level of 30kr. It has white flower, more resistance to bacterial wilt, Pssudomonas solanacearum, lower plant and stalk height, narrower leaf width, larger leaf shape index(lento width) and later days to flower when compared with the original variety Hicks. 3) White flower was recessive to pink flower in F, and Br (F1 X Hicks) progenies. F2 population of the cross gave segregation ratio of 3 pink flower:1 white flower, and B, (F1 X 83H-5) Population gave 1:1 ratio. Results showed that the white flower character is governed by a single recessive gene.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.744-746
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• 1998

Control effect of acidified nutrient solution on bacterial wilt of tomato plants was tested by examining the degree of bacterial growth inhibition and plant damage due to the acidity. Ralstonia solanacearum, the causal bacterium of bacterial wilt of tomato plants, showed 105 times population reduction when the bacterium was cultured in the acidified nutrient solution (pH 3.5∼4.0). However, fruit yields were decreased only fifteen to twenty percents. These results suggest that control of the bacterial wilt of tomato plants may be possible with supplying acidified nutrient solution.