• Journal of fish pathology
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• v.16 no.3
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• pp.153-159
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• 2003

The high mortality of cultured juvenile turbot, Scophthalmus maximus occurred in Gochang on June, 2003. The diseased fish was lethargic with reduced feed intake. Grossly, these fish showed pale body, abdominal extension and exophthalmia. The dominant internal gross features of diseased fish were severely enlarged spleen, pale gills and/ or liver. Diseased fish histologically showed basophilic enlarged cells in the kidney, spleen, gill, heart, stomach, intestine, liver, pancreas and adipose tissue. Transmission electron microscopy (TEM) reveled hexagonal virions in the cytoplasm of necrotic cells. The viral particles lead a central electron-dense core and an electron translucent zone, and were 136-159 nm in diameter. These results suggest that the virus belonging to the iridoviridae was responsible for the mortality of cultured juvenile turbot.

• Journal of fish pathology
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• v.9 no.1
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• pp.33-40
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• 1996

A filamentous form of mollicute-like bacterium was detected during a routine health survey of wild adult kuruma shrimp Penaeus japonicus. The kuruma shrimp were native to Japan and were imported to Korea. The histology showed no pathological changes. Transmission electron microscopy revealed extensive infections of hepatopancreatic epithelial cell by a pleomorphic, filamentous intracellular bacterium. The filamentous bacterium was of about 60 nm in diameter and 300 nm to more than $1{\mu}m$ in length. Teh morphology of bacteria were filamentous and branched with terminal blebs, or knobs, on the branches. They lacked the cell wall, and were bounded by the plasma membrane. They contained typical prokaryotic ribosomes and fibrillar DNA-like strands. No additional internal structure has been observed. They are considered to be mollicutes, based upon the morphological appearance and upon the cellular location.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.135-143
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• 2014

Exopeptidase active fractions from the hepatopancreas of the Argentina shortfin squid Illex argentinus, were obtained with acetone (AC 30-40%), ammonium sulfate (AS 60-70% saturation), anion exchange chromatography (AE-II, 0.2 M NaCl) and gel filtration chromatography (GF-I, 30-50 kDa) fractionation methods. A bitter peptide solution that has a bitterness equivalent to that of 2% glycylphenylalanine and prepared by tryptic hydrolysis of milk casein, was treated with the exopeptidase active fractions. The GF-I fraction was the best based on aminopeptidase activity (35.3 U/mg), percentage of recovery (30.7%) and a sensory evaluation (1.7). The amount of released amino acids increased as incubation time increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides as revealed by the reverse-phase high performance liguid chromatography profile, with three peaks (3, 5 and 6) decreasing in area (%) and three peaks (1, 2 and 4) increasing in area (%). Therefore, the GF-I fraction appeared to be ideally suited to reduce bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.112-122
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• 2020

This study investigated some enzymatic properties and bitterness improvement of an aminopeptidase retentate fraction (ARF) from common squid Todarodes pacificus hepatopancreas extract (HPE), obtained by ultrafiltration with a 10 kDa molecular weight cut off membrane. Endoprotease and aminopeptidase (AP) activity, and the purity of the ARF (>10 kDa) increased by 6.69-18.11 U/mg and 1.5-2.6 fold, respectively, compared to HPE (2.63-9.37 U/mg). The AP activity toward LeuPNA was stable at 20-55℃ and pH 5-9, but decreased slightly with increasing concentration of NaCl in the reaction mixture. The ARF was the most active MetPNA and preferentially hydrolyzed Glu, Leu and AlaPNA. The bitterness tryptic casein hydrolysates (BTCHs) were treated with ARF, and the bitterness of ARF-BTCHs significantly decreased with increasing amounts of released amino acids Ala, Val, Met, Ile and Leu, which show strong correlations with bitterness. Therefore, the ARF of T. pacificus HPE obtained by ultrafiltration may have a considerable potential for application in protein hydrolysis and appears to be ideally suited to the purpose of lowing bitterness in protein hydrolysates.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.77-86
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• 2011

The unwanted artificial oil-spill has severely contaminated the coastal environment in the world. Level of contamination has so far been monitered by various indicator species including mussel, oysters, flounder, and cockle. In this study, we decided to use the oyster as a model organism to observe the morphological changes being exposed to the artificial oil-spill in the coastal areas in Taean, Korea. The oysters were collected from four local sites (Sindu-ri, Uiwang-ri, Jonghyeon-dong, Ansan and Uihang-ri) exposed to various levels of pollution after an oil spill in Taean. Microscopic analysis of the hepatopancreatic microstructure in the digestive gland from the collected oysters show that the swelling, whorl, and destruction phenomenon of the nuclear membrane, a well-known microstructure induced by heavy metal exposure, was observed. Nuclear body (Nb), another typical characteristic of contamination or infection were also observed in some samples. Necrosis was observed in tissue samples collected from the area with a high degree of oil pollution. In addition, parasite-like particles (virus, perkinsus) were observed in most samples. Taken together, these results suggest that oil contamination in the oyster habitats influences the cytopathological changes in Crassostrea gigas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.724-732
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• 2021

This study used response surface methodology to investigate the optimal conditions to reduce the bitterness of alcalase-treated anchovy hydrolysate (AAH) by the aminopeptidase active fraction (AAF) derived from the common squid Todarodes pacificus hepatopancreas. The central composite design selected AAF/AAH ratio (X₁, %) and hydrolysis time (X₂, h) as independent variables, and the degree of hydrolysis (Y₁) and bitterness (Y₂) as dependent variables. The uncoded values of the multiple response optimization for independent variables were 3.4% for the AAF/AAH ratio and 9.2 h for the hydrolysis time. The predicted values of the yield and bitterness score of alcalase-AAF continuously treated anchovy hydrolysate (AAAH) under the optimized conditions were 68.9% and 4.6 points, respectively. Their measured values of 69.5% for yield and 4.6±0.5 points for bitterness were similar to the predicted values. The food components of AAAH were 91.4% (moisture), 7.5% (protein), 0.1% (lipid) and 0.6% (ash). The findings indicate the potential value for use as an anchovy seasoning base. The results also confirm that the bitterness of AAH was remarkably improved by AAF and implicates AAF derived from squid hepatopancreas as a good enzyme to catalyze reduced bitterness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.21-26
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• 2005

Although the sesame lignans, sesamol, have been shown to possess antioxidative activity, less is known about the metabolism and antioxidative properties of sesamol, a major constituent of sesame oil. To determine the ability of sesamol to act as an antioxidant in vivo, we fed rats a diet containing 0.5% sesamol for 3 wk and studied its metabolism and its effects on oxidative stress. Body weight gain and weight of liver, kidneys were significantly higher in the rats fed sesamol than in rats fed the control diets. GST and GST-Px activities in rat liver microsomes were higher in rats fed sesamol and CAT activities were found to be significantly increased in rats fed sesamol. The formation of TBARS was decreased in the liver of rat fed the 0.5% sesamol diet than in controls. We detected sesamol metabolites in liver and kidneys of rats fed sesamol and its metabolites were present as conjugated glucuronides and sulfates. In contrast, not detected sesamol peak in other organs such as colon, small intestine and pancreas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.684-691
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• 2001

This study was designed to investigate the effects of Coriandrum sativum L. on lipid metabolism in nondiaetic and stretozotocin-induced diabetic.Thirty two mael Sprague-Dawley rats weighting 108$\pm$13 g were divided into four groups as follow: control (C), leaf(L), seed (S) and root (R) groups. For four weeks of experimental periods, the C group were fed basal diet and the L, S and R groups were fed Coriandru sativum L. diets containing 5% dried leaf, seed and root of Coriandrum sativum L, respectively. diet intakes, weight gain and food efficiency were not significantly different among the four groups. The liver and heart weights of L, s and R groups were significantly different amount the control group. The levels of plasma insulin was significantly increased but the plasma glucose levels was not decreased in all Coriandrum group. The levels of plasma lipids was not significantly different among the four groups. the levels of plasma total cholesterol was significantly decreased in R groups. The levels of plasma and liver TBARS values were significantly decreased in R groups. The levels of plasma vitamin E were tendency to decrease in all coriandum groups. These results indicate feeding diet with coriander did not show the hypolipidemic effect but show the antioxidative effect.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.201-207
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• 2019

Temperature is one of the most important criteria considered in species preference for aquaculture. Acute drop in temperature during winter is a cause of disease and mass mortality in farmed fish. This study was carried out the low water temperature tolerance, oxygen consumption, hematologic and histological responses to use as basic data for the management of fish farming which frequently cause death due to winter water temperature drop. Low-lethal water temperature for 4 days of file fish Thamnaconus modestus (4day-LT₅₀) was 6.97℃ (6.69~7.27℃). Oxygen consumption rate decreased with decreasing water temperature, showing a significant difference between water temperatures. SOD activity increased significantly at 6℃ experimental group than control group (10℃) (p<0.05), but CAT did not show any significant difference between experimental temperatures (p>0.05). Cortisol increased with decreasing experimental water temperature compared to control group. Histological changes in the liver include decreased blood vessels in the blood vessels, proliferation of acid cells, condensation of the nucleus, atrophy of pancreatic exocrine gland cells, and enzyme source granules.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.149-159
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• 2008

The purposes of this study are to analyze abnormal dilatation of the extrahepatic bile ducts by using transabdominal ultrasound, to confirm the existence of bile ducts diseases and their interrelationship, and for it to give a new theoretical basis for the technical access to extrahepatic bile ducts, upon which to analyze the ripple effects of the scan training. After teaching technical access process based on the new theory about extrahepatic bile duct to the thirty students who are studying ultrasonography, we allocated three hours per one student (30 mins ${\times}$ 6 times) to focus on the training of scanning skill. Training has been performed by one-to-one method. For evaluation, all the students have to perform the scans on (1) confluence of the right and left hepatic ducts (extrahepatic bile ducts and cystic duct), (2) the suprapancreatic bile duct, (3) the intrapancreatic bile duct, (4) intrapapilla Duct, based on the clearly divided concept. The existing training and methods have had low confidency about transabdominal ultrasonography of the extrahepatic bile duct and had limitation with which they could image only the suprapancreatic bile duct. The evaluation after finishing the train based on the new theory, however, all the students (30students) can access to (1) confluence of the right and left hepatic ducts(extrahepatic bile ducts and cystic duct), (2) the suprapancreatic bile duct objectively. 24 students can access to (3) the intrapancreatic bile duct and only one student can even make an image for (4) the intrapapilla Duct Though the evaluation on extrahepatic bile duct has to be performed with multi-sided method considering intrahepatic cause, bile duct cause and pathophysiological cause, only if we can image the extrahepatic bile duct to ampular of Vater objectively and confidently, we can greatly reduce invasive procedure such as ERCP, which is for the purpose of simple differential diagnosis and painful to the patients. Therefore if we concentrate on the scanning train based on the new theory to raise the confidency about ultrasonography, the effect will be doubled.