• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.638-643
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• 1999

In this study we prepared 5 types of nutritional beverage base samples containing various ratios of soy protein isolate (SPI) and sodium caseinate as protein source. The rheological properties of each sample were measured and the results were as followes; Samples changed their rheological properties with the ratio of SPI. Samples represented newtonian property with low ratio of SPI, pseudoplastic property with the increment of SPI, and bingham pseudoplastic property with higher increment of SPI (80% as protein source). In this result we conjectured that the more was the SPI, the more was the formation of progel during heat treatment, which could be the reason of the rheological changes. In the test of the relationship between temperature and apparent viscosity, apparent viscosity of samples decreased along with the increment of temperature. In observing the relationship between time and apparent viscosity, we found sample, containing high ratio of SPI (80%), represented thixotropic property clearly with the hysteresis loop.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.203-209
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• 2005

Real time-polymerase chain reaction (RT-PCR) is currently considered as the most sensitive method to detect low abundant DNAs in samples. Compared to conventional PCR, real-time PCR has a high reliability because of excluding false-positive results and can allow a simultaneous faster detection and quantification of target DNAs. This study was carried out to identify the Hanwoo (Korean native cattle) beef by genotyping after DNA extraction of commercial beef in 41 restaurants. Since Hanwoo, Holstein and imported cattle meat have different patterns in the MC1R gene associated with the coat colors of cattles (C-type, C/T-type or T-type), we could identify the genotype using real-time PCR The result of real-time PCR assay for beef samples in 41 restaurants which are asserted to sell Hanwoo beef only, showed that 29 of 41 samples were Hanwoo beef gene type (T-type) and 12 of 41 samples were Holstein or imported cattle gene type (C-type or C/T-type). Therefore, the proportion of Han-woo beef was $70.7\%$ and the proportion of Holstein or imported cattle meat was $29.3\%(C/T-type; 12.2\%,\;C-type; 17.1\%)$.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.65-72
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• 1970

Two peptides (Im pr-M, Im ch-M) derived from Im ${\lambda}-type$ of Bence Jones Protein and one peptide (Ikch-M) from Ik were separated and purified using the Dowex $50{\times}2$ column $(1{\times}20\;cm)$ and Dowex $1{\times}2(0.9{\times}50\;cm)$. The buffer solution was composed of 1% pyridine and IM formic acid in Dowex $1{\times}2$ column. The blocked N-terminal was examined with ninhydrin reaction before and after alkaline hydrolysis, which was fractionated by Dowex $1{\times}2$ column. Pyrro-glutamic acid in N-terminal residue was identified by comparing with the authentic pyrro-glutamic acid through a high voltage electrophoresis (pH 3.5, 3000 V.) after the peptide Im pr-M (PCA. Ser) was cleavaged at the position of serine with cone. (12 N) HCl and the pyrro-glutamic acid was converted to glutamic acid by treating it with N-NaOH for 116 hours at $27^{\circ}C$. The substractive method was applied to find out the sequence of peptides and carboxypeptidase A was employed to release C-terminal residue from the peptide. In present study PCA. Ser in Im Pr-M was isolated from the pronase digested ${\lambda}$-type Bence Jones protein. The yield of the Im Pr-M was 79.6 percent of its theoretical value, based on the molecular weight of Bence Jones Protein. Im ch-M (PCA. Ser Val. Leu) was isolated from the chymotrypsin digested ${\lambda}$-type Bence Jones Protein. The yield of the Im ch-M was 72.2 percent. based on the molecular weight of Bence Jones Protein. Ik ch-M (PCA. Ser. Ala. Leu) was isolated from the chymotrypsin digested ${\lambda}$-type Bence Jones Protein and its yield was 42% based on the molecular weight of Bence Jones Protein.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.279-285
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• 1993

Alterations of the p53 gene arc among the most frequent genetic changes in human cancer and often result in increased levels of p53 protein within the malignant cells. Detection of accumulated p53 protein can be a useful prognostic tool in human cancer. In order to make polyclonal antibodies for immunohistochemical screening. human p53 gene was expressed in E. coli in the form of GST (glutathione S-transfi.:rase) fusion proteins. Two p53 gene fragments. which were N('()I small fragment encoding amino acid residues of 1-151-: and Ncol large fragment of 159-393. were subeloned into the unique BamHI site present within the pGEX-2T vector using BamHI linker and recombinant plasmids pGTNS and pGTNL were constructed. respectively. The p53 cDNA fragment (from pC53-$SN_3$,) encoding amino acid 38-145 (proline at residue 72) was amplified by polymerase chain reaction(PCR). The amplified DNA was digested with BamHI and Prull and inserted into the BamHI-Smal sites of pG EX-2T and recombinant plasmid pGTBP was constructed. After IPTG induction of these plasmids for 4 hours. fusion proteins were purified from E. coli extracts with glutathione Sepharose beads. The bound proteins were resolved by 10% SDS-polyacrylamide gel electrophoresis and the molecular weights were 54 kDa. 53 kDa and 40 kDa. respectively. Approximately one milligram of fusion proteins were purified from 1 -liter cultures.

• Korean Journal of Animal Reproduction
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• v.17 no.4
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• pp.339-346
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• 1994

An understanding of the structure and function of mammalian spermatozoa requires the iso-lation of these components. In this study, frozen-thawed bovine spermatozoa were treated by physical treatments (vortexing, 26 gauge needle, strained 26 gauge needles and freezing-thawing) or chemical treatments (trypsin, dithiothreitol, sodium dodecylsulfate and $\beta$-mercaptoethanoJ) to yield free heads and tails. The most effective treatment was repeated pumping of sperm suspension through a strained 26 gauge needle conneted to a syringe. Spermatozoa by this treatment were mainly broken at the junction of the head and the tail, resulting in 90-100% yields. Also, sperm head surface did not modify during strained 26 gauge needle treatment when either spermatozoa or sperm heads were incubated in 250${\mu}\textrm{g}$/ml of FITC-UEA 1 for 1 h at room temperature to detect the modification of sperm surface components. Other physical treatments were less efficient for the breakdown of spermatozoa. The effects of chemical treatments on bovine spermatozoa are not noticeable. Dissected sperm heads and tails should be fractional leading to nearly pure components by sucrose gradient centrifugation at 1,000 rpm for 15 min. The result suggest that the established method may be useful for the biochemical study of spermatozoal components, and the understanding of oocyte activation mechanism either by spermatozoal components during fertilization or microinjection of isolated components.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.272-278
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• 2007

Proteases are enzymes that break peptide bonds between amino acids of other proteins and occupy a crucial position with respect to their applications in both physiological and commercial fields. In order to screen new source of protease, bacteria producing extracellular proteases at low temperature were isolated from deep sea water of East Sea, Korea. A bacterium showing the best growth rate and production of an extracellular protease at low temperature was designated HJ 47. The DNA sequence analysis of the 16S rRNA gene, phenotypic tests and morphology led to the placement of this organism in the genus Pseudoalteromonas. Although maximal growth was observed at $37^{\circ}C$, enzyme production per culture time was maximum at $20^{\circ}C$. At this temperature, extracellluar protease production was detected from the end of the exponential phage to stationary phase, and maximal at 15 hours after initial production. The optimum temperature and pH of the protease were found to be $35^{\circ}C$ and 8.

• Journal of Life Science
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• v.24 no.1
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• pp.1-7
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• 2014

Eukaryotic gene expression is an important process, which is initiated by several transcription factors and RNA polymerases that occupy the promoter region of genomic DNA. Although there are many experiments to identify the promoter region in a gene, it is time and labor consuming to finalize it. In this study, we utilized bioinformatic programs, including Ensembl, NCBI, and CpG plots, to identify the cloning promoter region in SETDB1 genomic DNA. We performed PCR amplification to obtain the SETDB1 promoter on an approximately 2 kb region upstream from the TSS named SETDB1-P1. The PCR product was ligated with TA cloning vectors, and we confirmed the insert size using restriction enzyme digestion. Sequentially, the insert was subcloned into a pGL3-luc vector to produce pGL3-SETDB1- P1-luc and then confirmed by DNA sequencing. We also obtained a fragmented PCR product called P2 and P3 and performed a luciferase assay using pGL3-SETDB1-P1-luc transfection. We found that several anticancer drugs, including taxol, 4-FU, and doxorubicin, decreased the promoter activity of SETDB1. We obtained consistent data on the regulation of SETDB1 gene expression after anticancer drug treatment using Western blot analysis and RT-PCR. Our results suggest that promoter cloning of the human SETDB1 gene utilizing bioinformatics is a very useful and timesaving approach to study gene expression.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.99-105
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• 2007

In clinical practice, air bubbles trapped in the pit and fissure may increase early loss of sealing materials for fracture, wear and microleakage. The purpose of this investigation was to examine the bubble behavior of pit and fissure sealant. The 140 replicas made of epoxy resin were used to this experiment. Following conditioning, light-polymerized sealants were applied and then exposed to the light source. After stereoscopic examination of standarized specimen by grinding, bubble behavior was analysed. The results obtained were as follows; 1. Ultraseal $XT^{(R)}$ plus grops irrespective of using time were higher than groups of $Helioseal^{(R)}$ with clinpro tip and metal tip in the frequency of bubble(p<0.05), 2. Ultraseal $XT^{(R)}$ plus old group was more than $Clinpro^{(R)}$, Teethmate $F-l^{(R)}$ and $Helioseal^{(R)}$ with brush tip in the number of bubble under 200 magnified cross section(p<0.05). 3. The widest mean area of bubble was shown in the Teethmate $F-1^{(R)}$. 4. No statistically significant difference of the frequency and the site of bubble between $Clinpro^{(R)}$ and $Helioseal^{(R)}$ groups(p>0.05).

• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.232-238
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• 2002

연구목적 : Cytokine은 유해 미생물에 대한 숙주의 방어기전으로서의 염증반응에서 숙주세포 상호간의 작용을 매개해 주는 역할을 하며, 인간의 치수조직에서도 그 존재가 확인된 바 있다. Interleukin-6와 Interleukin-10은 염증의 초기에 작용하는 cytokine으로 알려져 있으나, 치수 및 치근단 질환에서의 역할과 상호작용에 대해서는 잘 알려져 있지 않다. 본 연구에서는 치수염의 원인균으로 알려진 Prevotella nigrescens를 이용하여 백서의 치수염을 유도한 후 시간의 변화에 따른 Interleukin-6, Interleukin-10의 농도의 변화를 측정하여 이들의 치수염에서의 작용을 알아보는 것을 목적으로 한다. 방법 : 실험적으로 치수의 염증반응을 일으키기 위하여 치수염의 원인균으로 알려진 Prevotella nigrescens를 이용하였다. 실험동물의 하악절치의 incisal tip부분을 절단한 후(n=120), 치수강을 개방시켰다. 실험군에서는 Prevotella nigrescens를 멸균된 면구에 묻혀서 개방된 치수강 내에 접종하였으며, 대조군에서는 균을 접종하지 않고 멸균된 면구만을 개방된 치수강 내에 위치시켰다. 그 후 1, 2, 5일이 경과되었을 때 실험에 사용된 치아를 발치하여, 치수조직을 적출하였다. Amersham사의 ELISA kit를 사용하여 적출된 치수조직내의 Interleukin-6와 Interleukin-10의 양을 측정하였으며 그 결과를 Mann-Whitney rank sum test를 사용하여 통계학적 유의성을 검증하였다. 조직학적 검사를 위해서는 발치된 치아를 nitric acid를 사용하여 탈회시킨 후 헤마톡실린-에오신 염색을 시행한 후 관찰하였다. 결과 : 1) Interleukin-6의 농도는 균접종 후 1일, 2일, 5일 모두에서 실험군에서 대조군보다 높게 나타났으며, 균접종 1일째의 결과는 통계적 유의성이 있었다(P<0.05). 2) Interleukin-10의 농도는 균접종 후 1일, 2일, 5일 모두에서 실험군에서 대조군보다 높게 나타났으며, 균접종 1일째의 결과는 통계적 유의성이 있었다(P<0.05). 3) Interleukin-10/1nterleukin-6 ratio는 실험군과 대조군 모두에서 1일보다 2일째의 결과에서 더 높은 값을 보였으며 대조군에서는 통계적 유의성을 보였다(P<0.05). 4)조직학적 관찰결과 균접종 후 2일째의 조직표본에서는 림프구의 침윤과 부분적인 조직의 괴사 등 염증반응의 양상을 관찰할 수 있었으며, 균접종 5일째의 조직표본에서는 염증의 정도가 감소되는 양상을 확인할 수 있었다.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.244-252
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• 2006

The aims of this study were to determine if flowable composites can be used as pit and fissure sealants without bonding agents. Three flowable composites(Filtek Flow, Tetric Flow, Charmfil Flow) and a filled sealant (Ultraseal XT plus) were used. The pattern of resin tag formation in the four sealant materials were compared using SEM. For the microleakage assessment, 54 extracted human premolar teeth were randomly divided into 3 groups containing 18 premolars each. In each group, a conventional filled sealant and one of the three flowable composites were applied to occlusal fissures. The teeth were thermocycled(1200 cycles between $5^{\circ}{\pm}2^{\circ}C\;and\;55^{\circ}{\pm}2^{\circ}C$ with a dwell time of 30 seconds) and immersed in a 1% methylene blue solution for 48 hours. Each tooth was sectioned and examined to determine the extent of dye penetration. Three flowable composites and a filed sealant showed a similar resin tag formation pattern. The three flowable composites showed significantly more microleakage in each group than the filled sealant. The level of microleakage was similar in the three flowable composites. Flowable composites are not recommended as pit and fissure sealants because more microleakage can occur even when occlural fissures are mechanically widened.