• Analytical Science and Technology
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• v.20 no.3
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• pp.237-245
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• 2007

The presence of benzene in 31 products of vitamin drinks purchased from 20 retail outlets was determined using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The sample (25 ml) was stirred at 1200 rpm for 4 min using a magnetic bar with a $100{\mu}m$ SPME fiber as an adsorbent for benzene which was then desorbed from the fiber for 1 min in the GC injector. Quantitation was achieved using the standard addition method. The limit of detection was determined as 0.56 ng/ml and over a concentration range 0-40 ng/ml the coefficient of correlation was greater than 0.999. The concentration of benzene in the drinks examined was in the range not detectable to 47.35 ng/ml. Benzene was detected in 15 of the drinks with concentration in 5 of them greater than 10 ng/ml which is the limit set for the presence of benzene in the Drinking Water Regulations. The concentrations of benzene in the 5 drinks which exceeded the limit of 10 ng/ml were 16.99, 35.14, 16.03, 47.35 and 14.28 ng/ml respectively.

• Journal of the Korean Society of Food Culture
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• v.22 no.3
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• pp.342-352
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• 2007

We investigated the intake trends of street foods for middle school, high school and colleges students through the survey study. In addition, the factors affecting the students' consumption of street foods and their perception toward hygiene status of street vendor were studied. The levels of total aerobic bacteria, coliform groups and enterobacteriaceae in Kimbab, eomuk, and eomuk-kukmul were counted using 3M petrifilms. More than ninety seven % of the respondents had experienced street foods. All the respondents ate street foods 1 to 5 times a month. Forty percent of the respondent stated that 'good taste' and 'time-saving convenience' were their reason for eating the street foods. Their favorite foods were ddokbokgi and various fried foods. All the students responded that frying oil, drinking water, and soy sauce as well as the street vendors' attire and their cooking tools in street vendor were unsanitary. Forty percent of the respondents ranked frying oil as the most unsanitary substance. Eighty percent of the respondents responded that an enforcement of hygiene should be imposed on the street foods vendor. There were significant differences (p<0.001) among the student's age in the opinion related to the reasons of eating street foods, hygiene enforcement, existence of street foods and interest of hygiene status of street foods. High correlation (p<0.05) between the frequency of street foods and snack intakes was shown, regardless of student's age. The result shows that those who eat snacks more than once a day tend to eat street foods more frequently. Aerobic plate counts in Kimbab in 5 different vendors exceeded 10$^5$/g and contamination levels of enterobacteriaceae or coliform in Kimbab exceeded more than 10$^3$/g, which did not satisfy the microbiological standards. In conclusion, although the respondents thought that the sanitation of street foods was poor, most of them want the street food vendor to be maintained with better hygiene condition. This indicated that the regulation for safe street foods should be enforced and educational information about the preparation and serving for safe street foods should be provided to street food vendor.

• Journal of Veterinary Science
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• v.24 no.4
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• pp.52.1-52.13
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• 2023

Background: Mesenchymal stem cells (MSCs) have been investigated as therapeutic agents for inflammatory bowel disease (IBD). Stimulation of MSCs with pro-inflammatory cytokines is an approach to enhance their immunomodulatory effects. However, further investigation is required to support their application in immune-mediated disorders and companion animals. Objectives: This study aimed to assess the therapeutic effect of tumor necrosis factor (TNF)-α-stimulated feline adipose tissue-derived MSCs (fAT-MSCs) in a dextran sulfate sodium (DSS)-induced colitis mouse model. Methods: Colitis mice was made by drinking water with 3% DSS and fAT-MSCs were injected intraperitoneally. Colons were collected on day 10. The severity of the disease was evaluated and compared. Raw 264.7 cells were cultured with the conditioned medium to determine the mechanism, using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: TNF-α-stimulated fAT-MSCs more improved severity of DSS-induced colitis in disease activity, colon length, histologic score, and inflammatory cytokine. In sectionized colon tissues, the group comprising TNF-α-stimulated fAT-MSCs had higher proportion of CD11b⁺CD206⁺ macrophages than in the other groups. In vitro, TNF-α-stimulation increased cyclooxygenase-2 (COX-2) expression and prostaglandin E₂ (PGE₂) secretion from fAT-MSCs. The conditioned medium from TNF-α-stimulated fAT-MSCs enhanced the expression of interleukin-10 and arginase-1 in LPS-activated Raw 264.7 cells. Conclusions: These results represent that TNF-α-stimulated fat-mscs ameliorate the inflamed colon more effectively. Furthermore, we demonstrated that the effectiveness was interlinked with the COX-2/PGE₂ pathway.

• Journal of Korean Home Economics Education Association
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• v.35 no.4
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• pp.33-45
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• 2023

The purpose of this study is to investigate the association between dietary behavior and related factors according to the generalized anxiety disorder (GAD) in adolescents. The results of analyzing demographic characteristics according to the GAD showed that gender, age, BMI, type of school, residence type, father's nationality, smoking and drinking experience, perceived health status, perception of body shape, economic status, academic achievement, physical activity, sedentary time and smartphone usage time were related to the GAD (p<0.01). The results of analyzing dietary behavior according to the GAD showed that the frequency of water intake, sweetened beverage intake, fast food intake, fruit intake and breakfast intake were related to the GAD (p<0.001). The results of analyzing depression and suicidality according to the GAD showed that depression, suicidal ideation, planning, and attempts were all related to the GAD (p<0.001). Even after adjusting for factors corresponding to demographic characteristics, it was confirmed that the level of GAD had a significant effect on depression and suicidality. This study is significant in that it provided basic data on adolescent mental health problems by analyzing dietary behavior and related factors according to the level of GAD.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.29-37
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• 2009

This study was conducted to determine the effects of dietary supplementation with chitosan feeding levels and feeding forms on the performance, proximate composition, pH, thiobarbituric acid reactive substance (TBARS), water holding capacity (WHC), shear force, meat color, and fatty acid of chicken thigh meat. Two hundred broilers (Arbor Acre Broiler, male) were randomly assigned to five groups and were fed for five weeks and slaughtered. Thigh muscle was evaluated in this experiment. The amounts of proximate composition, crude fat of control and T3 for the chitosan-treated groups were significantly higher as compared with T2 (P<0.05), but no significant effects were detected on moisture, crude protein, and crude ash. By comparison, pH was significantly increased when chitosan was included at 2% into diet or more than 1% into drinking water. TBARS was significantly lower at chitosan treated groups it was decreased with increasing chitosan level in the diets (P<0.05). Therefore, chitosan had the possibility to improve shelf life of chicken meat. Higher chitosan levels and feeding additive increased high density lipoprotein cholesterol (HDL-C) and reduced total cholesterol and low density lipoprotein cholesterol (LDL-C) (P<0.05). $L^*$ and $a^*$ of chitosan treated group was higher than the control. As the dietary chitosan levels increase, the composition of palmitic acid and oleic acid levels was increased, however, those but the rates of linoleic acid and arachidonic acid were decreased. It is concluded that dietary chitosan has a positive effect on increasing HDL-C and oleic acid and decreasing total-C, LDL-C and TBARS values. Therefore, the treatment with the most significant effects in the current study was the high level of chitosan.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.782-787
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• 2002

This study was done to investigate the effects of Korean mistletoe water extract and lectin on the apoptosis and preneoplastic lesion in chemically induced rat hepatocarcinogenesis. To attain the above objectives, weanling Sprague-Dawley male rats were fed modified AIN-76 diets containing 10% corn oil for 9 weeks. One week after feeding starts, rats were intraperitoneally injected twice with a dose of diethylnitrosamine (DEN, 50 mg/kg body weight (BW). Rats were provided with 0.05% phenobarbital (PB) in drinking water from one week after DEN treatment until the end of experiment. During the period of PB treatment, rats were injected with mistletoe extract (100 $\mu\textrm{g}$/kg BW) and lectin (10 $\mu\textrm{g}$/kg BW) twice a week. At the end of 9th week, rats were sacrificed and the formation of hepatic glutathione S-transferase placental form positive (GST-P$^{+}$) foci, apoptosis, DNA fragmentation and apoptosis related proteins were determined respectively. The formation of GST-P$^{+}$foci was significantly decreased by mistletoe extract or lectin treatment. Although there was no effect on apoptosis and DNA fragmentation in hepatic tissue by mistletoe extract or lectin treatment, caspase-9 and fas-L were increased. These results suggest that Korean mistletoe extract and lectin have a potential to inhibit hepatocarcinogenesis by increasing apoptosis.sis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.818-823
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• 2011

Recently, we showed that green tea extract (GTE) markedly lowers the intestinal absorption of $^{14}C$-benzo[a]pyrene ($^{14}C$-BaP) and enhances its secretion into the biliary route, suggesting a protective role for GTE against body burden. These findings indicate that green tea could be used as an effective dietary means against the toxicity of BaP. The present study, therefore, was designed to investigate if green tea intake could affect the tissue distribution and deposition of $^{14}C$-BaP in rats. Male Sprague-Dawley rats had free access to a nutritionally adequate AIN-93G diet and deionized water. At ~340 g of weight, the rats were injected intraperitoneally with 27.4 kBq of [4-$^{14}C$]-BaP and 5.0 mg of BaP dissolved in $300\;{\mu}L$ of olive oil and then assigned randomly to the following two groups: one group (GTE) of rats was fed the AIN-93G diet with GTE via drinking water at approx. 4.7 mg of catechins/d, whereas the other was fed the same diet but without GTE (control). At 4 wk of dietary treatment with GTE, animals were euthanized and heart, liver, brain, spleen, kidney, retroperitoneal fat, testis, and epididymal fat were collected, weighed, and analyzed for tissue $^{14}C$-BaP. Both the control and GTE groups continuously gained weight throughout the study, but there was no significant difference between the groups. No significant differences were observed in the weights of heart, liver, brain, spleen, kidney, retroperitoneal fat, testis, and epididymal fat. However, the radioactivities of $^{14}C$-BaP, expressed in dpm/g, were significantly lower in the heart, liver, brain, spleen, and epididymal fat of rats receiving GTE as compared to their respective controls. These data indicate that green tea intake markedly lowers tissue accumulation of $^{14}C$-BaP. Taken together, these findings suggest that the decreased tissue levels of BaP by GTE intake may be associated with lowered intestinal absorption of BaP and its enhanced secretion into the bile.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.639-648
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• 2010

The optimal conditions for the analysis of BPA by HPLC-MS/MS was investigated and the ultrasound degradation capacity of the BPA, with the goal to establish the proper directions for analyzing infinitesimal quantities of BPA by HPLC-MS/MS was examined. The MDL and LOQ of BPA analyzed by HPLC-MS/MS were measured 0.13 nM and 1.3 nM respectively, its sensitivity about 620 and 32 times greater than HPLC-UV (MDL: 81.1 nM, LOQ: 811 nM) and FLD (MDL: 4.6 nM, LOQ: 46 nM). In other words, the new method enables the analysis of BPA with the accuracy up to one 1,180th of the amount specified in U.S. EPA guideline for drinking water. Degradation rate of BPA by ultrasound measured over 95% under 580 kHz and 1000 kHz frequency within 30 minutes of treatment, whereas the rate showed some decrease at 28 kHz frequency. At 580 kHz of ultrasound has proven to be the most effective among others at degradation rate and $k_1$ value, so we concluded that this frequency of ultrasound creates hospitable condition for the combined process of degradation by pyrolysis and oxidization. With the addition of 0.01 mM of $CCl_4$, BPA with the initial concentration of 1 ${\mu}M$ was degraded by more than 98% within 30 minutes, the $k_1$ value measured 5 minutes and 30 minutes into the experiment both showed increases by 1.4 and 1.1 times, respectively, compared with BPA without $CCl_4$. It is also found that the main degradation mechanism of BPA by ultrasound is oxidization process by OH radical, based on the fact that the addition of 10 mM of t-BuOH decreased the rate of BPA degradation by around 60%. However, 33% of BPA degradation rate obtained with the addition of t-BuOH implies further degradation done by pyrolysis or other sorts of radical beside OH radical.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.347-364
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• 2006

This study is concerned with assessment of diethylnitrosamine (DEN 0.01 %) induced liver cell carcinogenesis by measurement of changes preceding the development of neoplasms. Therefore, it was undertaken to investigate changes of liver-specific enzyme activities in Sprague-Dawley (SD) rats by ad libitum feeding of DEN. And also. the changes of hepatic morphology in SD rats were detected by haematoxylineosin stain and immunohistochemistry (PCNA). 5- Fluorouracil (5- FU) is one of the most widely used anticancer agents for digestive cancers including hepatocellular carcinoma, and is known to affect the cell cycle and induce apoptosis of cancer cells. In the present study, SD rats were given drinking water containing 0.01% diethylnitrosamine (DEN) for 8 weeks. Minor behavioral change, brittleness of hair and decreased amount of water and diet intake were observed in rats 4 weeks after DEN administration. The body and liver weights were significantly (p < 0.05) decreased in rats 11 weeks after DEN administration. The liver weight ratio to body weight was rather stable and not significantly decreased in the all treatment groups. The liver specific enzyme activities (AST, ALT, ${\gamma}$-GTP) were significantly increased in all treatment groups compared to control group (p < 0.05). Variable size of liver tumor and hepatomegaly were observed in rats treated with DEN after 10 weeks. Numerous vacuoles were seen on the midzonal and or peripheral areas of hepatic lobules. The large and polymorphological hepatocytes with eosinophilic cytoplasm or densely basophilic mitotic nucleoli were seen. Several proliferative small round cells were seen on vacuolated and necrotic areas in peripheral hepatic lobules or portal areas. PCNA-positive cells were seen on the vacuolated portal areas and peripheral areas of hepatic lobules in the areas of small round cells. We examined functional and morphological changes of livers by 5 - FU treatments on DEN -treated rat. The DEN -treated rats compared to 5 - FU -treated rats after DEN treatment for 8 weeks. The serum total protein and triglyceride were significantly (p < 0.05) decreased, and the liver enzyme activities of AST and ALT were significantly(p < 0.05) increased. After 8 weeks, in the non-5-FU -treated group, the size of liver tumor were varied and hepatomegaly were observed, hepatocellular vacuolization, necrosis and steatosis were observed on the midzonal and peripheral areas of hepatic lobules. The large and polymorphological hepatocytes were seen, the interlobular connective tissues were proliferated. PCNA positive cells were seen in the portal areas and peripheral areas of hepatic lobules in the non-5-FU-treated group. In hepatocytes, condensation of nuclear chromatin and vacuolization were observed, shape of the nuclei were irregular, the degraded nuclei and organelles were observed. The livers of rats in the 5 - FU treatment group were seen grossly brilliant, red-brown color, and the vacuolated and degenerated regions, hyperplastic nodules were not nearly observed. In the electron microscope, the cytoplasm of the hepatocytes contained a large number of mitochondria, rough endoplasmic reticulum, developed organelles surrounding nuclei. The above findings suggest that 5 - FU will be effective as anti -liver tumor drug.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.24-25
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• 2003

Lead is ubiquitous in the human environment as a result of industrialization. China's rapid industrialization and traffic growth have increased the potential for lead emissions. Lead poisoning in children is one of the most common public health problems today, and it is entirely preventable. Children are more vulnerable to lead pollution and lead in their bodies can affect their nervous, circulatory, and digestive systems. Children are exposed to lead from different sources (such as paint, gasoline, and solder) and through different pathways (such as air, food, water, dust, and soil). Although all children are exposed to some lead from food, air, dust, and soil, some children are exposed to high dose sources of lead. Significant sources of lead for China's children include industrial emissions (often close to housing and schools), leaded gasoline, and occupational exposure that occurs when parents wear lead-contaminated clothing home from work, burning of coal for home heat and cooking, contaminated food, and some traditional medicines. To assess the blood lead level in children in China, a large-scale study was conducted in 19 cities among 9 provinces during 1997 to 2000. There were 6502 children, aged 3-5 years, were recruited in the study The result indicates that the mean blood lead level was 8.83ug/dl 3-5 year old living in city area. The mean blood lead level of boys was higher than that of girls (9.1l ug/dl vs 8.73ug/dl). Almost 30 percent childrens blood lead level exceeded 10ug/dl. The average blood lead level was higher than that of in 1985 (8.83ug/dl vs 8.lug/dl). An epidemiological study was carried on the children living around the cottage industries recycling the lead from battery. Nine hundreds fifty nine children, aged 5-12 years, living in lead polluted villages where the lead smelters located near the residential area and 207 control children live in unpolluted area were recruited in the study. The lead levels in air, soil, drinking water and crops were measured. The blood lead and ZnPP level were tested for all subjects. The results show that the local environment was polluted. The lead levels both in the air and crops were much higher than that of in control area. In the polluted area, the average blood level was 49.6ug/dl (rang 19.5-89.3ug/dl). Whereas, in the unpolluted area, the average blood level was 12.4ug/dl (rang 4.6-24.8ug/dl). This study indicates that in some countryside area, some cottage industries induce seriously lead pollution and cause children health problem. For the introducing of unleaded gasoline in some large cities, such as Beijing and Shanghai, the blood lead level showed a declined trend since 1997. By 2000, the use of leaded gasoline in motor vehicles has been prohibited in China. The most recent data available show that levels of lead in blood among children in Shanghai decreased from 8.3ug/dl in 1997 to 7.6ug/dl in 1999. The prevalence rate of children lead poisoning (blood lead >10ug/dl) was also decreased from 37.8% to 24.8%. In children living in downtown area, the blood lead level reduced dramatically. To explore the relationship between gene polymorphisms and individual susceptibility of lead poisoning, a molecular epidemiological study was conducted among children living in lead polluted environment. The result showed that the subjects with ALAD2 allele has higher ZPP level, and the subjects with VDR B allele has larger head circumference than only with b allele. In the present study, we demonstrated that ALAD genotypes modify lead effects on heme metabolism and VDR gene variants influence the skull development in highly exposed children. The polymorphism of ALAD and VDR genes might be the molecular inherited factor modifying the susceptibility of lead poisoning. Recently, Chinese government pays more attention to lead pollution and lead poisoning in children problem. The leaded gasoline was prohibited used in motor vehicles since 2000. The government has decided to have a clampdown on the high-polluted lead smelters for recycling the lead from battery in countryside. It is hopeful that the risk of lead poisoning in children will be decreased in the further