• Journal of Life Science
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• v.26 no.2
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• pp.190-197
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• 2016

Aflatoxin M₁ can be produced in cow’s milk when cows eat contaminated produce. Milk is a major source of food for infants and for children who have a weak level of immunity, and the detection of Aflatoxin M₁ for risk assessment is necessary in order to reduce the amount of it in milk. In this study, the Aflatoxin M₁ level was monitored for one year in raw milk samples obtained from Chungnam Province, Korea. The milk samples were divided into three categories: 1. milk samples from a standard general farm, 2. milk samples from a HACCP controlled farm, and 3. milk samples from the supply of Aflatoxin M₁ reduced fodder. The average concentrations of Aflatoxin M₁ in milk were 0.023±0.005 ug/l for the standard general farm, 0.017±0.004 ug/l for the HACCP controlled farm, and 0.013±0.003 ug/l for the supply of Aflatoxin M₁ reduction fodder. Milk collected from the supply of Aflatoxin M₁ reduction fodder had the lowest level of Aflatoxin M₁. However, when efficiency and economic aspects are considered the most effective way of reducting Aflatoxin M₁, could be taking milk from the HACCP controlled farm and implementing good feed management. Institutional support from the government, careful management of dairy farming, and a strict farm sanitation program are required in order to lower the level of Aflatoxin M₁ in milk.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.368-374
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• 2007

The purpose of this study was to investigate the effects of different type of triglycerides (MCT & LCT) on weight, survival time, energy substrate (FFA, TG, pyruvate, lactate), insulin and lipase in the trained rats. Fifty-four Sprague-Dawley rats were divided into 3 groups: control group (CG, n=18), MCT supplement group (MG, n=18), and LCT supplement group (LG, n=18). They also were divided into 3 periods: trained resting (R, n=6) and trained & exercise load (E, n=6), and survival time test was performed to know the supplemented effects. Body weight of all animals was checked every week, MCT group and LCT group received supplementary MCT and LCT orally and preliminary swimming training for 6 days before the start of main experiment. All animals received 15-minute swimming training 5 times during first week of experiment, and swimming training time was increased 15 minutes every week until it reached 90 minutes at last 9th week. After last swimming training, animals were fasted for 12 hours and blood samples were taken from abdominal aorta in the Department of Animal Medicine at the D university Animal Center. Among the CGE, MGE, and LGE groups, the MGE had the greatest increase in physical performance time. In the FFA levels, there was significant differences(p<.05) in CG, MG and LG groups, and also there was major difference of FFA levels in the MG and LG. In the lipase levels, there was signifi.ant differences (p<.05) in CG, MG and LG groups. MG was the greatest than the other groups. In the insulin hormone levels, there was the great differences (p<.05) in LG compare to CG groups, whereas there was no significant difference in the CG and MG. In conclusion, these results suggest that regular prolonged physical training with MCT supplementation, improves exercise performance time through the increase of energy substrate utilization, lipase activity and FFA levels, irrespective of insulin hormone responses.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.435-443
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• 2007

Antimicrobial susceptibility test of the 116 strains of Mycoplasma pneumoniae isolates were performed by a broth micro-dilution method against to moxifloxacin, levofloxacin, sparfloxacin, ofloxacin, ciprofloxacin, clarithromycin minocycline, erythromycin, josamycin, and tetracycline. The initial-minimum inhibitory concentration (I-MIC) was evaluated as the lowest concentration of antimicrobial agents that prevented a color change in the medium at that time when the drug-free growth control, about 7 days after incubation, and the final-minimum inhibitory concentration (F-MIC) was defined a color change about 14 days after incubation. The evaluation to the drug-resistant M. pneumoniae isolates were determined the $MIC{\pm}1.0$ ${\mu}g/ml$ of each antimicrobial agent. According to the I-MIC, single drug-resistant M. pneumoniae strains to ciprofloxacin, ofloxacin, clarithromycin and erythromycin were 79.3, 53.5, 10.3, and 7.8%, respectively. Two kinds of drug-resistant M. pneumoniae strains to ofloxacin and ciprofloxacin, or ciprofloxacin and clarithromycin were 42.2 and 9.5%. Three kinds of drug-resistant M. pneumoniae strains to erythromycin, ofloxacin, and ciprofloxacin, or ofloxacin, ciprofloxacin and clarithromycin were 6.9 and 6.0% . According to the F-MIC, single drug-resistant M. pneumoniae strains to tetracycline, ciprofloxacin, ofloxacin, minocycline,erythromycin, josamycin, clarithromycin and sparfloxacin were 91.4, 91.4, 91.4, 89.7, 68.1, 52.6, 28.5, and 11.2%, respectively. The incidence of two kinds of drug-resistant M. pneumoniae strains were from 20.7% to 91.4%, three kinds of drug-resistant M. pneumoniae strains were from 28.5% to 89.7%, four kinds of drug-resistant M. pneumoniae strains were 2.6%, five kinds of drug-resistant M. pneumoniae were from 2.6% to 21.6%, six kinds of drug-resistant M. pneumoniae strains were from 0.9% to 24.1%, seven kinds of drug-resistant M. pneumoniae strains were from 0.9% to 2.6%, and eight kinds of drug-resistant M. pneumoniae strains were 1.7%. These results suggest that sparfloxacin, moxifloxacin and levofloxacin might be promising antimicrobial agents for the treatment of M. pneumoniae infection in Korea. However, most strains of M. pneumoniae isolates were single or multi-resistance pattern to the other tested antimicrobial agents. Therefore, tetracycline, minocycline, erythromycin, clarithromycin, and second-generation quinolones are more carefully used to patients with M. pneumoniae infection in Korea.

• Journal of Life Science
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• v.17 no.12
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• pp.1660-1668
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• 2007

The non-ionic surfactant (NIS) Tween 80 was evaluated for its ability to influence invitro cumulative gas production, dry matter digestibility, cellulolytic enzyme activities, anaerobic microbial growth rates, and adhesion to substrates by mixed rumen microorganisms on rice straw, alfalfa hay, cellulose filter paper and tall fescue hay. The addition of NIS Tween 80 at a level of 0.05% increased significantly (P<0.05) in vitro DM digestibility, cumulative gas production, microbial growth rate and cellulolytic enzyme activity from all of substrates used in this study. In vitro cumulative gas production from the NIS-treated substrates; rice straw, alfalfa hay, filter paper and tall fescue hay was significantly (P<0.05) improved by 274.8, 235.2, 231.1 and 719.5% compared with the control, when substrates were incubated for 48 hr in vitro. The addition of 0.05% NIS Tween 80 to cultures growing on alfalfa hay resulted in a significant increase in CMCase (38.1%), xylanase (121.4%), Avicelase (not changed) and amylase (38.2%) activities after 36 h incubation. These results indicated that the addition of 0.05% Tween 80 could greatly stimulate the release of some kinds of cellulolytic enzymes without decreasing cell growth rate in contrast to trends reported with aerobic microorganism. Our SEM observation showed that NIS Tween. 80 did not influence the microbial adhesion to substrates used in the study. Present data clearly show that improved gas production, DM digestibility and cellulolytic enzyme activity by Tween 80 is not due to increased bacterial adhesion on the substrates.

• Journal of Life Science
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• v.17 no.12
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• pp.1641-1648
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• 2007

Yippee-like proteins, which have been identified as the homolog of Drosophila yippee protein containing a zinc-finger domain, are known to be highly conserved among eukaryotes. However, their functional roles are still poorly understood. Recently we initiated ordered differential display (ODD)-polymerase chain reaction (PCR) to isolate genes of which expressions are altered following activation of human T cells. On the ODD-PCR image, one PCR-product detected in unstimulated T cells was not detectable at the time when the activated T cells traversed near $G_1/S$ boundary following activation by immobilized anti-CD3. Cloning and nucleotide sequence analysis revealed that the PCR-product was yippee-like 5 (YPEL5) gene, which was known as a human homolog of the Drosophila yippee gene. Northern blot analysis confirmed the amount of ${\sim}2.2$ kb YPEL5 mRNA expression detectable in unstimulated T cells was sustained until 1.5 hr after activation and then rapidly declined to undetectable level by 5 hr. Ectopic expression of YPEL5 gene in human cervix epitheloid carcinoma HeLa cells caused a significant reduction in cell proliferation to the level of 47% of the control. Expression of GFP-YPEL5 fusion protein in HeLa cells showed its nuclear localization. These results demonstrated that the expression level of human YPEL5 mRNA was negatively regulated in the early stage of T cell activation, and suggested that YPEL5 might exert an inhibitory effect on the cell proliferation as a nuclear protein.

• Journal of Life Science
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• v.22 no.3
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• pp.407-416
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• 2012

In this study, we purified the extracts from the seeds and the roots of various plant species, including Q. acutissima, C. lanceolata, P. mirifica, P. bambusoides, and S. repens, and then investigated the effects of these extracts on cell growth and fat accumulation in adipocytes. We found that the extracts purified from Q. acutissima, C. lanceolata, P. mirifica, P. bambusoides, and S. repens more effectively increased the cell growth, as well as promoting the fat accumulation in adipocytes to a greater extent, than other extracts in vitro. Therefore, we made breast packs containing these effective extracts, and then investigated whether they were effective in enhancing the elasticity and volume of women's breasts. The measurements of breast elasticity and size revealed that the breast packs efficiently increased the elasticity and size of women's breasts. Furthermore, evaluation of the questionnaires related to usage of the breast packs indicated great satisfaction in terms of the lift, firmness, and elasticity of breasts. In conclusion, extracts purified from Q. acutissima, C. lanceolata, P. mirifica, P. bambusoides, and S. repens leading to cell growth and fat accumulation in adipocytes can effectively contribute to improving the elasticity and size of women's breasts.

• Journal of Life Science
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• v.23 no.2
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• pp.282-289
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• 2013

This study was conducted to investigate the effect of Makgeolli and Makgeolli precipitate on hepatotoxity and the serum lipid content in rats. First, we investigated the effect of Makgeolli and ethanol on the progress of alcoholic fatty liver. The effect of Makgeolli precipitate on carbon tetrachloride ($CCl_4$)-induced hepatotoxicity in the rats was then studied. Indicators of the health status of the experimental period, the body weight gain in ethanol-treated group tended to be lower than those in the control and the Makgeolli-treated groups. The weight of the liver tissue decreased significantly following the administration of ethanol. However, this was not seen following the administration of Makgeolli. The activities of serum aspartate transaminase (AST) and alanine transaminase (ALT) were decreased in the Makgeolli group compared to the ethanol group. Serum cholesterol concentrations increased in the ethanol group, but decreased in the Makgeolli-treated group to an equal volume of the ethanol-treated group. The serum HDL-cholesterol content was significantly higher in the Makgeolli group than in the ethanol group. Analysis of the impact of the Makgeolli precipitate on toxicity induced by $CCl_4$ in the liver showed that the $CCl_4$ treatment significantly increased the activities of serum ALT and AST. However, the levels of cholesterol and triglyceride in serum were decreased. The $CCl_4$ treatment increased the activities of AST and ALT. However, the raw Makgeolli precipitate decreased their activities. Moreover, raw Makgeolli precipitate significantly reduced the $CCl_4$-induced elevation of serum lipids more than heated Makgeolli precipitate. These results suggest that raw Makgeolli precipitate may exert a protective effect against $CCl_4$-induced liver injury by preventing lipid peroxidation.

• Journal of Life Science
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• v.23 no.2
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• pp.197-206
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• 2013

The present study investigated whether leukemia-maintaining cells reside in a differentiation-resistant fraction using a megakaryocytic differentiation model of K562 cells. Treatment with phorbol-12-myristate-13-acetate (PMA) significantly inhibited the colony-forming efficiency of the K562 cells. At a PMA concentration of 1 nM or higher, colony was not formed, but approximately 40% of K562 cells still survived in soft agar. Approximately 70% of colony-forming cells that were isolated following the removal of PMA after exposure to the agent were differentiated after treatment with 10 nM PMA for 3 days. The differentiation rate of the colony-forming cells was gradually increased and reached about 90% 6 weeks after colony isolation, which was comparable to the level of a PMA-treated K562 control. Meanwhile, imatinib-resistant variants from the K562 cells, including K562/R1, K562/R2, and K562/R3 cells, did not show any colony-forming activity, and most imatinib-resistant variants were CD44 positive. After 4 months of culture in drug-free medium, the surface level of CD44 was decreased in comparison with primary imatinib-resistant variants, and a few colonies were formed from K562/R3 cells. In these cells, Bcr-Abl, which was lost in the imatinib-resistant variants, was re-expressed, and the original phenotypes of the K562 cells were partially recovered. These results suggest that leukemia-maintaining cells might reside in a differentiation-resistant population. Differentiation therapy to eliminate leukemia-maintaining cells could be a successful treatment for leukemia if the leukemia-maintaining cells were exposed to a differentiation inducer for a long time and at a high dose.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.26-33
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• 2005

Purpose: The purpose of this study is to evaluate migration of technetium-99m hexamethylpropylene amine oxime ($^{99m}Tc$-HMPAO) labeled immature and mature dendritic cells (DC) in the mouse. Methods: DC were collected from bone marrow (BM) of tibiae and femurs of mice. Immature and mature DC from BM cells were radiolabeled with $^{99m}Tc$-HMPAO. To evaluate the functional and phenotypic changes of DC from radiolabeling, the allogeneic mixed lymphocyte reaction (MLR) and fluorescence-activated cell sorting (FACS) analysis were performed before and after labeling with $^{99m}Tc$-HMPAO. Migration of intravenously injected DC (iv-DC) was assessed by serial gamma camera images of mice with or without subcutaneous tumor. Percent injected dose per gram (%ID/g) was calculated in lungs, liver, spleen, kidneys, and tumor through dissection of each mice after 24 hours of injection. Results: Labeling efficiency of immature and mature DC were $60.4{\pm}5.4%\;and\;61.8{\pm}6.7%$, respectively. Iv-DC initially appeared in the lungs, then redistributed mainly to liver and spleen. Migration of mature DC to spleen was significantly higher than that of immature DC ($38.3{\pm}4.0%\;vs.\;32.2{\pm}4.1%$ in control group, $40.4{\pm}4.1%\;vs.\;35.9{\pm}3.8%$ in tumor group; p<0.05). Migration to tumor was also significantly higher in mature DC than in immature DC ($2.4{\pm}0.3%\;vs\;1.7{\pm}0.2%$; p=0.034). Conclusion: Assessment of migration pattern of DC in mice was possible using $^{99m}Tc$-HMPAO labeled immature and mature DC. Migration of mature DC to spleen and tumor was higher than that of immature DC when they were i.v. injected.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.388-397
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• 1999

Purpose: Propranolol is known to decrease portal pressure by reducing blood flow of portal vein. Perrectal portal scintigraphy with Tc-99m pertechnetate has been introduced to evaluate the portal circulation and early diagnosis of liver cirrhosis. We evaluated the effects of propranolol on portal circulation by using per-rectal portal scintigraphy. Materials and Methods: We analyzed the portal hemodynamics by per-rectal portal scintigraphy in 51 patients with liver cirrhosis, 10 chronic hepatitis and 10 normal subjects. 38 patients with cirrhosis underwent per-rectal portal scintigraphy before and after propranolol medication. Perrectal portal scintigraphy was performed after per-rectal administration of 370 MBq of Tc-99m pertechnetate. The shunt index was calculated as the ratio, expressed as a percentage of heart radioactivity to the sum of heart and liver radioactivity during the first 30 seconds. Results: The shunt index in 40 patients with cirrhosis ($59.8{\pm}27.2%$) was significantly higher than that of normal control ($5.0{\pm}1.2%$. p<0.01) and chronic hepatitis ($11.4{\pm}3.5%$, p<0.01). Shunt index was significantly different according to Child's classification and the degree of esophageal varix (p<0.01). After propranolol medication, shunt index was significantly decreased from $59.9{\pm}27.3%$ to $51.3{\pm}15.3%$ (p<0.01) in 38 patients with liver cirrhosis. There was no significant difference of the amount of shunt index reduction after propranolol according to Childs' classification and the degree of esophgageal varix. Conclusion : The effect of propranolol on portal circulation was demonstrated as decreasing shunt index on per-rectal portal scintigraphy in patients with liver cirrhosis. Per-rectal portal scintigraphy may be useful to evaluate the portal circulation and to predict the effect of propranolol in patients with liver cirrhosis.