• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.37-44
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• 1987

As a series of systematic classification for Korean common liver fluke, Fasciola sp., karyotype was investigated by means of the modified air-drying technique and of the regular Giemsa staining. Also, C-staining method was applied for detailed karyological analysis from the germ cells of the fluke. The following is a brief summary of the leading facts gained through the experiment. 1. Korean Pasciola sp. was classified into three types based on their chromosomal complements; individuals with 20 or 30 chromosomes and with a 20/30 mosaic constitution. Worms having 30 chromosomes represent a triploid form with 3 sets of 10 basic chromosomes, while those with 20 chromosomes were diploid and mosaic individuals were 2n/3n mixoploid. 2. The frequency of the individual type calculated is as follows; 67.45% of 212 flukes examined was of diploid, 10.85%, triploid, and the rest, 21.7%, mixoploid, respectively. In many cases, two or three types were found in the peculiar bovine host while single type inhabitant was about 20% out of 52 cases. 3. The twenty chromosomes consisted of 1 pair of large metacentrics, 4 pairs of medium-sized subtelocentrics, and 5 pairs of small submetacentrics, while constitution of the thirty chromosomes was nearly interpreted as a triploid form with 3 sets of 10 basic chromosomes. The high centromeric indexes of both types are the first Pairs among all the examined, and 37.93% was of diploid and 47.93%, triploid, respectively. 4. In mixoploid individuals, constitution of the chromosomes of diploid or triploid cells was the same as that of diploid or triploid individuals. 5. All the chromosomes of the germ cells in both types showed C-band around the centromeric region and especially the chromosomes no's 3,7, and 8 showed a remarkable C-band distinguished from other chromosomes. 6. The variance for the sizes of the worms and the eggs were not parallel with three different genotypes in Korean common liver fluke.

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.131-135
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• 1995

This study was performed to develop immnoassay method of detecting the residual tylosin and to investigate the residues using HPLC(high performance liquid chromatography) in animal products. Obtained results are the followings: 1. To develop immunoassay method, the conjugation of activated tylosin tartarate ester derivatives and BSA (bovine serum albumin) was certified at the 290nm of maximal absorbance which tylosin tartrate have. 2. The titration of anti-serum produced from rabbit immunized with the conjugator as an immunogen was too low to analyze the tylosin. 3. The residual tylosin can be detected by 0.2 ppm using HPLC. 4. Recovery of tylosin from spiked pork samples measured using HPLC was $87.4{\pm}4.0%$. 5. When the levels of tylosin residues in swine liver and kindney were measured on HPLC. The level was over the maximum tolerance level in one out of ten samples of each organ.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.116-121
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• 2010

Long-chain polyunsaturated fatty acids (LC-PUFA) promote the development of brain and vision of the fetus, relieve inflammation, inhibit oral dysplasia of rumor cell, decrease the incidence of cardiovascular disease and regulate arrhythmia. ${\Delta}-6$ desaturase is the rate-limited enzyme in the desaturation process. This study reports the cloning, characterization and tissue expression of a ${\Delta}-6$ desaturase gene in the chicken. PCR primers were designed based on the predicted sequence of chicken ${\Delta}-6$ desaturase (accession number: XM421053) and used to isolate a cDNA fragment of 1,323 bp from chicken liver. Based on the 1,323 bp fragment an EST (BI390105) was obtained by BLAST. The EST and 5'nd of the 1,323 bp fragment were partially overlapped. Gene specific primers derived from the EST were used for amplification of the 5'nd. Another gene-specific primer derived from the 1,323 bp fragment was used for amplification of the 3'nd by 3'ACE. Then the three overlapping cDNA sequences obtained were assembled with DNAMAN software and a full-length ${\Delta}-6$ desaturase of 2,153 bp was obtained. The full-length cDNA contained an ORF of 1,335 bp with a 5'ntranslated region of 147 nucleotides followed by an ATG initiation codon. Stop codon TGA was at position 1,481-1,483 bp. The deduced amino acids shared an homology above 77% with bovine, mice, orangutan, rat and human. The protein sequence had three histidine-rich regions HDFGH (HisI region), HFQHH (HisII region) and HH (HisIII region), a cytochrome $b_{5}$-like domain containing a heme-binding motif and two transmembrane domains. Sequence analysis of the chicken genomic DNA revealed that the coding sequence of chicken ${\Delta}-6$ desaturase included 12 exons and 11 introns. Semi-quantitative RT-PCR showed that the ${\Delta}-6$ desaturase expression levels were in turn liver, spleen, pancreas, lung, breast muscle, heart, and abdominal fat. The expression of ${\Delta}-6$ desaturase in liver was significantly higher than that in breast muscle (p<0.01). The expression of ${\Delta}-6$ desaturase in lung was significantly higher than that in abdominal fat (p<0.01). This is the first clone of chicken ${\Delta}-6$ desaturase.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.49-57
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• 2000

This study was conducted to investigate the developmental potential of cloned embryos derived from bovine fetal fibroblast cells, and the effect of quiescent treatment, passage number and origin of donor cells on in vitro development of cloned embryos. Fetal skin and liver-derived fibroblast cells were transferred to enucleated oocytes after serum starvation or nontreatment (cycling). After electrofusion. reconstituted embryos were activated with $Ca^{＋＋}$-ionophore and cycloheximide, and cocultured for 7~9 days with BRL cells. Some blastocysts were transferred to recipient cows 7~8 days post estrus. The development rate to the blastocyst stage of serum starved cell-derived embryos was higher (25.3%) than that of actively dividing cells-derived embryos (15.9%), The rates of blastocyst formation were 23.1~25.0% after transfer of cell passaged 4 to 6 times, and 23.8 and 25.2% after transfer of fetal skin and liver cells, respectively. After embryo transfer, 34.4% and 15.6% of recipient cows were pregnant on Day 60 and 120, respectively, and one male calf was produced from skin-derived vitrified blastocyst. The result of this study showed that the development of cloned embryos. was enhanced by quiescent treatment, but did not different among the cells passaged 4 to 6 times, and between skin and liver cells. This result also confirms that offspring can be obtained from the vitrified clone embryo derived from fetal skin cell.

• Korean Journal of Environmental Agriculture
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• v.10 no.2
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• pp.167-177
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• 1991

O-ethyl S-methyl ethylphosphonothioate [$LD_{50}$ (rat, oral) 4.6mg/kg ; $K_i$(bovine erythrocyte acetylcholinesterase) 303 $M^{-1\;min-1}$] was selected as a model compound to study the mode of action of O, S-dialkyl alkylphosphonothioates which have been hypothesized to be toxic via a bioactivation process. Two chemical oxidants, meta-chloroperoxybenzoic acid and monoperoxyphthalic acid, and rat liver microsomal oxidases were used to mimic the action of mixed function oxidases on the model compound. The formation of S-oxide, a very unstable active intermediate, was proposed based on the identification of metabolic products.Furthermore, a trapping experiment with ethanol showed that the unstable intermediate S-oxide had the ability to phosphorylate acetylcholinesterase which is an important enzyme in nerve systems. The S-oxide intermediates are presumed to be responsible for the toxicity of O,S-dialkyl alkylphosphonothioates.

• Food Science of Animal Resources
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• v.23 no.2
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• pp.137-144
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• 2003

This study was carried out to investigate safety evaluation of IGEs separated and refined from bovine milk and commercial recombinant human IGFs. In order to evaluate toxicity of these samples, acute toxicity test and short term toxicity test were investigated with IGF-I separated and refined from colostrum and commercial recombinant human IGF-I from R&D systems company. for acute toxicity test, we selected recombinant human IGF-I from R&D systems company and establish one control group and three dose-level groups(0, 10, 20 and 50 $\mu\textrm{g}$ per rat). We have intravenously injected tail of rats with selected sample once. After 20 days, pathological cellular tissue analyses were investigated with liver, kidney and spleen of 12 rats in all test groups. However, Morbid tissue and abnormal statistical results were not discovered in all cellular tissues. For short term toxicity test, we selected IGF-I separated and refined from colostrum and establish one control group and three dose-level groups(0, 5, 10 and 15 $\mu\textrm{g}$/day per rat). Rats were orally injected with selected sample once a day during two weeks. After short term toxicity test period, Pathological cellular tissue analyses were investigate with liver, kidney and spleen of 12 rats in all test groups. However, Morbid tissue and abnormal statistical results were not discovered in all cellular tissues. These results suggest that IGF-I treated groups show no significant toxicological findings with changes of body weight, food consumption, water consumption, and pathological findings compared with control groups.

• The Journal of the Acoustical Society of Korea
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• v.31 no.3
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• pp.151-160
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• 2012

In medical ultrasound imaging, elasticity imaging helps to diagnose tumors such as cancer. This paper is concerned with the application of acoustic radiation force to soft tissue of interest to implement elasticity imaging. In order to reduce the data acquisition time, instead of relying on transmit focusing, a plane wave of burst type is transmitted to apply the acoustic radiation force simultaneously to an entire imaging region to be observed. A homogeneous phantom experiment confirms that increasing the transmit excitation duration instead of employing transmit focusing generates a high enough acoustic radiation force to obtain elasticity images. It is found, however, that a different displacement versus time characteristic is observed unlike the case of using a conventional focused acoustic radiation force. Experimental results obtained through the use of an ultrasound phantom and a bovine liver show that lesions can be correctly differentiated.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.262-270
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• 1994

The established methods in the residue analysis of endosulfan require an extensive sample clean-up prior to quantification by relatively complex equipment. A radioimmunoassay(RIA) provides a simple procedure with theoretically higher sensitivity and specificity necessitating only a minimum of sample clean-up. Endosulfan-specific antibodies were developed in rabbits by using a bovine serum albumin(BSA) conjugate wherein the alcohol form of endosulfan was multiply bound to the protein via succinylation. Produced antibodies showed the high titers to endosulfan-BSA(1 : 32,000). An RIA method was developed in water and carp by using $^{14}C-labeled$ endosulfan as a tracer. The lowest detection amount of endosulfan was 1 ng in the liver, kidneys, gut and water samples, and 3 ng in the whole body sample of carp without any clean-up, corresponding to 0.1 ppb of endosulfan.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.960-967
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• 2007

The co-immobilization of Aspergillus niger glucose oxidase (GOD) with bovine liver catalase (CAT) onto florisil (magnesium silicate-based porous carrier) was investigated to improve the catalytic efficiency of GOD against $H_2O2$ inactivation. The effect of the amount of bound CAT on the GOD activity was also studied for 12 different initial combinations of GOD and CAT, using simultaneous and sequential coupling. The sequentially co-immobilized GOD-CAT showed a higher efficiency than the simultaneously co-immobilized GOD-CAT in terms of the GOD activity and economic costs. The highest activity was shown by the sequentially co-immobilized GOD-CAT when the initial amounts of GOD and CAT were 10 mg and 5 mg per gram of carrier. The optimum pH, buffer concentration, and temperature for GOD activity for the same co-immobilized GOD-CAT sample were then determined as pH 6.5, 50 mM, and $30^{\circ}C$, respectively. When compared with the individually immobilized GOD, the catalytic activity of the co-immobilized GOD-CAT was 70% higher, plus the reusability was more than two-fold. The storage stability of the co-immobilized GOD-CAT was also found to be higher than that of the free form at both $5^{\circ}C\;and\;25^{\circ}C$. The increased GOD activity and reusability resulting from the co-immobilization process may have been due to CAT protecting GOD from inactivation by $H_2O2$ and supplying additional $O_2$ to the reaction system.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.194-199
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• 2002

Many oxidative metabolites of tetrahydrocannabinols (THCs), active components of marijuana, were pharmacologically active, and 11-hydroxy-THCs, 11-oxo-${\Delta}^8$-THC, 7-oxo-${\Delta}^8$-THC, 8$\beta$, 9$\beta$-epoxyhexahydrocannabinol (EHHC), 9$\alpha$, l0$\alpha$-EHHC and 3'-hydroxy-${\Delta}^9$-THC were more active than THC in pharmacological effects such as catalepsy, hypothermia and barbiturate synergism in mice. Cannabidiol (CBD), another major component, was biotransfomred to two novel metabolites, 6-hydroxymethyl-${\Delta}^9$-THC and 3-pentyl-6, 7, 7a, 8, 9, lla-hexahydro-I, 7-dihydroxy-7, 1O-dimethyldibenzo[b, d]oxepin (PHDO) through 8R, 9-epoxy-CBD and 85, 9-epoxy-CBD, respectively. Both metabolites exhibited some pharmacological effects comparable to d9 - THe. Cannabinol (CBN), the other major component, was mainly metabolized to ll-hydroxy-CBN by hepatic microsomes of animals including humans. The pharmacological effects of the metabolite were higher than those of CBN demonstrating that II-hydroxylation of CBN is metabolic activation pathway of the cannabinoid as is the case in THCs. Tolerance and reciprocal cross-tolerance developed to pharmacological effects d8 - THC and ll-hydroxy-d8-THC , and the magnitude of tolerance development produced by the metabolite was significantly higher than that by d8-THC. The results indicate that ll-hydroxy-d8-THC has an important role not only in the pharmacological effects but also its tolerance development of d8 - THe. THCs and their metabolites competed to the specific binding of CP-55, 940, an agonist of cannabinoid receptor, to synaptic membrane from bovine cerebral cortex. The Ki value of THCs and their metabolites were closely paralleled to their pharmacological effects in mice. A novel cytochrome P450 (cyp2c29) was purified and identified as a major enzyme responsible for the metabolic activation of d8-THC at the II-position in the mouse liver. cDNA of CYP2C29 was cloned from a mouse cDNA library and its sequence was determined. The oxidation mechanism of THC by cyp2c29 was proposed.