• Journal of fish pathology
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• v.19 no.2
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• pp.87-97
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• 2006

In previous study, scuticociliate P. dicentrachi was isolated from farmed flounder during the december 2004 to april 2005. Pathogenicity, mortality and infection symptom were studied using 3 cm and 5 cm groups of juvenile flounder. The ciliates were exponentially increased from bottom layer of the experimental tanks, which propagated within 2000 cells/ml (1.4 × 103 cell ㎖-1 ～ 2.5 × 103 cell ㎖-1) after 6 days of inoculation. The middle layer was maintained within 300 cells/ml. Both 3 cm and 5 cm groups were infected with ciliates, mainly 3 cm group showed high mortality during the experimental period. The death of 3 cm group was started from 5 days and showed 95.6% of mortality after 28 days of first inoculation. The control group showed 4.4% of mortality however, we could not observed any ciliates. The death of 5 cm group was started later than 3 cm group after 18 days of first inoculation. The total mortality was 71% during 28 days. No mortality and infection symptoms were observed in the control. We also studied SSU rRNA gene of ciliates which, re-isolated from infected flounder of experimental groups. When SSU rRNA in this study compared with previous data showed that the identified strain of both previous and present study was same.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.764-772
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• 2010

Staphylococcus aureus lipase is regarded as a virulence factor. The response of lipase activity to various factors can provide important insights concerning the prevention of S. aureus during meat fermentation. This study was conducted to evaluate the main effects of nutrients used in culture media, and their combined effects on the inhibition of lipase activity and cell growth of pathogenic S. aureus SK1593 isolated from fermented pork meat. A Plackett-Burman design was used to evaluate the main effects of variables, including olive oil, soybean oil, grapeseed oil, sesame oil, $CuSO_4$, $MgCl_2$, $KNO_3$, $CaCl_2$, and KCl. Significant negative effects on lipase activity were detected with soybean oil, grapeseed oil, $KNO_3$, and $CaCl_2$. Additionally, these nutrients were further selected as variables for the investigation of their combined effect on lipase activity, via response surface methodology. In order to confirm the regression model, a situation that only inhibits lipase activity was simulated. The predicted lipase activity and cell growth of the simulated situation were 14.0 U/mL and $9.6\;{\log}_{10}$ (CFU/mL), respectively, and the estimated value of those in the same medium showed 15.14 U/mL and $9.4\;{\log}_{10}$(CFU/mL) respectively. The lipase activity of the simulated medium was inhibited approximately 5-fold as compared to the basal medium, but no significant differences in cell counts were noted to exist between the basal and simulated media. These results suggest that soybean oil, grapeseed oil, $KNO_3$, and $CaCl_2$ can be used to inhibit the growth of pathogenic S. aureus during the process of meat fermentation.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.84-94
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• 1991

The purpose of this study was to evaluate the influence of high does carbon tetrachloride($CCl_4$) on the hepatotoxic effect of dimethylnitrosamine(DMN) which induces acute hemorrhagic necrosis in liver. Rats were injected intraperitoneally DMN dissolved in physiologic saline by a dose of 40mg/kg. For changes related to $CCl_4$ pretreatment, rats were injected intraperitoneally $CCl_4$ dissolved in olive oil by a dose of 0.4mg/kg, and then injected DMN. The livers were extracted from the rats 3, 6, 12, 24, 48, 72, and 120 hours after $CCl_4$ and/or DMN injection. Liver tissues were examined with light and electron microscopes. The results were summarized as follows ; Light microscopic findings : Severe centrilobular hemorrhagic necrosis developed from 12 hours after injection of DMN and continued to 120 hours. On injection of DMN after $CCl_4$ pretreatment, Massive necrosis occurred early. But active regenerative changes were produced in 24 hours. In 120 hours, the liver recovered in almost normal appearance. The degree of necrosis in pretreated group was similar to that in DMN injection only, and the time of recovery was faster in preteated group. Electron microscopic findings ; The early change was mainly disorganization of RER in DMN injection, and clumping and vesicular dilatation of ER in injection of $CCl_4$. In pretreatment group the early change was similar in appearance with $CCl_4$ group, but severer in degree. According to the results, it was revealed that acute toxic effect of DMN was recovered more rapidly in pretreatment group. Thus it was suggested that $CCl_4$ had protective effect in DMN hepatotoxicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.685-691
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• 1993

This study was designed to examine effects of the various levels of sardine and safflower oil mix on lipid contents of serveral tissues in dietary hyperlipidemic rats. Experimental oils were 16% butter(control group), 8% butter +8% olive oil(group 2) 8% butter+8% sardine oil(group 3) 8% butter+6% sardine oil+2% safflower oil(group 4), 8% butter+4% sardine oil+4% safflower oil(group 5),8% butter+2% sardine oil+6% safflower oil(group 6) and 8% butter+8% safflower oil(group 7). The diet administered to the male rats of Sprague-Dawley were fed for 4 weeks. In livers, total cholesterol and triglyceride, phospholipid concentrations were lowest in the group 5 and free cholesterol concentrations were lower in the groups 4 and 5, particularly. Total cholesterol and triglyceride concentrations in brain were significantly lower in the group 5 and phospholipids were lowest in the group 3, while free cholesterol were group 7. In testes, total cholesterol and triglyceride, phospholipid, free cholesterol concentrations were lower in the all experimental groups than the control group, but those of kidney were lower in the groups 3, 7 than in the control group. Feeding mixed oil having equal quantity of sardine oil and safflower oil were effective on the reduction of the lipid contents in the principal tissues. It might be due to the effects of appropriate ratios of P/S, 0.85 and n-6/n3-p, 2.85 in the test lipids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.543-551
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• 1993

This study was designed to observe the effects of the feeding mixed with the sardine oil containing n-3 EPA, DHA and the safflower oil in which rich n-6 linoleic acid on the improvement of the lipids and on the fatty acid matabolism of serum lipoprotein in the dietary hyperlipidemic rats. Experimental oils mixed with 16% butter(control group) and 8% butter+8% olive oil, 8% butter and various level of sardine and safflower oils were administered to the male rats of the Sprague Dawley for 4 weeks. Concentrations of total cholesterol in serum lipoproteins were highest in the LDL, followed by VLDL, HDL and chylomicron components. in the triglyceride concentrations, chylomicron were highest, and much VLDL, LDL, HDL components. There were highest in the HDL, followed by LDL, VLDL and chylomicron in phospholipid concentrations of serum lipoproteins. Concentrations of total cholesterol, triglyceride and phospholipid in serum lipoprotein were lower in the other groups than in the control groups, and particularly, lowest in the group 5(4% sardine oil+4% safflower oil). From this results, the feeding equal quantity mixed oil with n-3 PUFA rich sardine oil and n-6 PUFA rich safflower oil were effective on the improvement of the lipid composition in the serum lipoprotein. It might be due to the effects of appropriate rations of P/S, 0.85 and n-6/n-3P, 2.85 in the test lipids. In the fatty acid composition of serum lipoprotein, ratio of P/S and n-3/n-6P were influenced from the fatty acid compositions of the mixed test lipids. And EPA contents were higher in the chylomicron components.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.58-62
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• 2009

From the course of screening of useful enzyme producing microorganism from marine sedimentary layer, we isolated 2 lipase producing strains and their lipase producing activities were tested. 16S rDNA sequence analysis showed that they were Gram-positive bacteria grouped on Janibacter sp. An excellent lipase producing strain, Janibacter sp. LI-68 and J. sp. LI-80 identified by 16S rDNA analysis and biochemical methods (BIOLOG), was further studied its lipase producing characteristics. The optimum initial pH, temperature and the optimum cultral time for the enzyme production on MA medium were 8, $30{\sim}40^{\circ}C$ and 96 h, respectively.

• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.325-337
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• 2014

To assess the functional structure of prepro-melanin-concentrating hormone (pMCH), we isolated and cloned pMCH (of-pMCH) mRNA from the brain of the olive flounder, Paralichthys olivaceus, and compared its amino acid sequence with those from other animals. In addition, to examine whether activation of the brain of-pMCH gene is influenced by background color, density, and feeding, we compared pMCH mRNA activities against different background colors (bright and dark) and at different densities (100% PCA and 200% PCA). To examine whether the pMCH gene is related with malpigmentation of blind-side skin and appetite, we compared pMCH gene expression between ordinary and hypermelanic flounders, and between feeding and fasting flounders. The of-pMCH cDNA was 405 bp in the open reading frame [ORF] and encoded a protein of 135 amino acids; MCH was 51 bp in length and encoded a protein of 17 amino acids. An obvious single band of the expected size was obtained from the brain and pituitary by RT-PCR. In addition, of-pMCH gene activity was significantly higher in the bright background only at low density (< 100% PCA) making the ocular skin of fish whitening, and in ordinary fish. However, the gene activity was significantly decreased in dark background, at high density (>200% PCA), and in hypermelano fish. These results suggest that skin whitening camouflage of the flounder is induced by high MCH gene activity, and the density disturbs the function of background color in the physiological color change. Moreover, our data suggest that a low level of MCH gene activity may be related to malpigmentation of the blind-side skin. In feeding, although pMCH gene activity was significantly increased by feeding in the white background, the pMCH gene activity in the dark background was not influenced by feeding, indicating that the MCH gene activity increased by feeding can be offset by dark background color, or is unaffected by appetite. In conclusion, this study showed that MCH gene expression is related to ocular-skin whitening camouflage and blind-skin hypermelanosis, and is influenced by background color and density.

• Korean Journal of Environmental Biology
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• v.30 no.2
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• pp.136-142
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• 2012

Acute toxicity test of heavy metal (Cd, Cu, Zn) were examined using the hatching rates of fertilized eggs in the oliver flounder, Paralichthys olivaceus. Eggs were exposed to Cd, Cu, Zn (0, 10, 100, 500, 1000, 2500, 5000 ppb) and then normal hatching rates were investigated after 48 h. The normal hatching rates in the control condition (not including Cd, Cu and Zn) were greater than 80%, but suddenly decreased with increasing of heavy metal concentrations. Cd, Cu and Zn reduced the normal hatching rates in concentration-dependent way and a significant reduction occurred at concentration grater than 1000, 100, 100 ppb, respectively. The ranking of heavy metal toxicity was Zn>Cu>Cd, with $EC_{50}$ values of 584, 1015 and 1282 ppb, respectively. The no-observed-effect-concentration (NOEC) and the lowest-observed-effect-concentration (LOEC) showed each 100 and 500 ppb of normal hatching rates in exposed to Cu and Zn. The NOEC and LOEC of normal hatching rates in Cd were 500 ppb and 1000 ppb, respectively. From these results, the normal hatching rates of P. olivaceus have toxic effect at greater than the 100 ppb concentrations in Cu, Zn and the 500 ppb concentrations in Cd in natural ecosystems. These results suggest that biological assay using the normal hatching rates of P. olivaceus are very useful test method for the acute toxicity assessment of a toxic substance as heavy metal in marine ecosystems.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.93-100
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• 2020

Hybrid grouper (Epinephelus fuscoguttatus ♀×E. lanceolatus ♂) (mean weight 27.3±3.8 g, mean length 11.6±0.7 cm) were exposed to waterborne nitrite at 0, 100, 200, 400, 800, and 1600mg L^-1 for 96 hours. The hematocrit and hemoglobin values were significantly decreased by exposure to 100 mg L^-1 and 400 mg L^-1, respectively. In plasma components, no significant change was observed in magnesium. Glucose was significantly increased by 200 and 400 mg L^-1 nitrite but reduced by 800 mg L^-1. Cholesterol was significantly decreased by 400 mg L^-1 nitrite, but there was no significant change in total protein. GPT(glutamic pyruvate transaminase) was significantly increased by exposure to 200 and 400mg L^-1. ALP(Alkaline phosphatase) was significantly increased by 800 mg L^-1. The results of this study indicate that acute exposure to nitrite changes physiological parameters, such as hematological properties and plasma components.

• Toxicological Research
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• v.22 no.4
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• pp.357-364
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• 2006

This study was undertaken to develop a reliable mice model demonstrating similar immunologic phenomena as human atopic dermatitis characterized with predominance of type-2 immune response. BALB/C mice and NC/Nga mice were sensitized twice with $100{\mu}l$ of 1% 2,4-dinitrochlorobenzene (DNCB) or vehicle (acetone : olive oil=4:1 mixture) in a week and challenged twice with $100{\mu}l$ of 0.2% DNCB or the vehicle at the following week. Mice were sacrificed at 19 days following the second DNCB or vehicle challenge for NC/Nga mice and at 28 days following the second DNCB or vehicle challenge for BALB/c mice. Upregulation of plasma 1gE, a hallmark of atopic dermatitis occurrence, was evident in the plasma obtained 4 day after the second DNCB challenge from BALB/c mice (approximately 4-fold) and NC/Nga mice (approximately 6-fold) treated with DNCB in comparison with that of the vehicle treated-control mice, and remain higher $3{\sim}4$ week after the second challenge. Ratio of plasma IgG1 versus IgG2a concentration was significantly higher in the mice treated with DNCB than the control mice, which also implies the skewed type-2 reactivity in vivo. Ratio of interleukin-4 versus interferon gamma produced in the splenic T cell culture supernatants was approximately 3-fold higher in the both strains of mice treated with DNCB than their control mice, respectively. The DNCB-treated mice demonstrated atopic dermatitis-like skin legions characterized with erythma, scaling, and hemorrhage, which was not observed with the control mice. Scratching on face or dorsal area was significantly more frequent (approximately 25-fold) in the DNCB-treated mice than the control at next day of the second DNCB challenge, and scratching frequency remains higher (approximately 4-fold) in the mice treated with DNCB than the control at 14 day following the second DNCB challenge. Overall, the mice model developed through sensitization and challenge with DNCB may be useful for research on atopic dermatitis and development of treatment materials for atopic dermatitis.