• 약학회지
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• 제52권1호
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• pp.33-36
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• 2008

Staphylococcus aureus KH13 and Staphylococcus aureus KH28 were resistant to chloramphenicol, ampicillin, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tobramycin, and norfloxacin. A plasmid (pKH13) and two plasmids (pKH14, pKH15) were isolated from Staphylococcus aureus KH13 and Staphylococcus aureus KH28, respectively and complete nucleotide sequences of three plasmids were determined. It was found that pKH13 and pKH15 mediated chloramphenicol resistance and pKH14 was a cryptic plasmid.

• 한국결정학회지
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• 제12권3호
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• pp.141-144
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• 2001

Na[Ga(N₃)₄]와 PPh₃의 반응으로부터 이온성 화합물 [Ph₃P(OH)]/sup +/[N₃]/sup -/ (1)이 분리되었다. 화합물1의 구조가 분광학적 방법(¹H-NMR, /sup 13/C{¹H-NMR, IR) 및 X-ray 회절법으로 규명되었다. 화합물1의 결정학 자료 : 사방정계 공간군 P2₁2₁2₁, a = 10.491(4)Å, b=11.603(5)Å, c=13.149(5)Å, Z=4, R(wR₂)=0.0547(0.0978).

• Journal of Korean Neurosurgical Society
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• 제48권1호
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• pp.14-19
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• 2010

Objective : Allelic losses or loss of heterozygosity (LOH) at many chromosomal loci have been found in the cells of meningiomas. The objective of this study was to evaluate LOH at several loci of different chromosomes (1p32, 17p13, 7q21, 7q31, and 22q13) in different grades of meningiomas. Methods : Forty surgical specimens were obtained and classified as benign, atypical, and anaplastic meningiomas. After DNA extraction, ten polymorphic microsatellite markers were used to detect LOH. Medical and surgical records, as well as pathologic findings, were reviewed retrospectively. Results : LOH at 1p32 was detected in 24%, 60%, and 60% in benign, atypical, and anaplastic meningiomas, respectively. Whereas LOH at 7q21 was found in only one atypical meningioma. LOH at 7q31 was found in one benign meningioma and one atypical meningioma. LOH at 17p13 was detected in 4%, 40%, and 80% in benign, atypical, and anaplastic meningiomas, respectively. LOH at 22q13 was seen in 48%, 60%, and 60% in benign, atypical, and anaplastic meningiomas, respectively. LOH results at 1p32 and 17p13 showed statistically significant differences between benign and non-benign meningiomas. Conclusion : LOH at 1p32 and 17p13 showed a strong correlation with tumor progression. On the other hand, LOH at 7q21 and 7q31 may not contribute to the development of the meningiomas.

• 동의생리병리학회지
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• 제18권4호
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• pp.1169-1172
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• 2004

The cytotoxic activity of 13(E)-labd-13-ene-8α, 15-diol (1) was evaluated against tumor cell lines. A comparison of IC/sub 50/ values of this compound in cancer cell lines showed that their susceptibility to this compound decreased in the following order: P388>B16{F10>MDA-MB-231>A549>KB>SNU-C4 by the MTT method. 13(E}-Labd-13-ene-8α, 15-diol (1) was the most effective growth inhibitor of P388 murine leukaemia cell lines, producing approximately 8.3㎍/mL of IC/sub 50/ in the MTT method.

• Nutrition Research and Practice
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• 제2권4호
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• pp.234-239
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• 2008

The purpose of this study was to investigate the effects of green tea ingestion on hepatocarcinogenesis before and after its initiation. Male Sprague-Dawley rats were fed an AIN76A diet with or without green tea. Initiation was induced by a single dose (200 mg/kg) of diethylnitrosamine at week 4 and 0.02% (w/w) 2-acetylaminofluorene was supplied in the diets. The control group had free access to water for 13 weeks (CTR13). Tea infusion was provided from the beginning of the experiment for 13 weeks (PRE13) or from the post-initiation stage until week 13 (POST13). Three other groups (CTR24, PRE24 and POST24) were added to examine the longer-term effects (24 weeks) with the same experimental design. The percentage area of liver sections that were positive for hepatic placental glutathione S-transferase (GST-P), which was used as a marker of preneoplastic lesions, was smaller in PRE13 ($20.2{\pm}5.0%$, $mean{\pm}SD$) and POST13 ($26.0{\pm}4.8%$) than in CTR13 ($33.2{\pm}5.8%$, p<0.05). Over the longer period, the GST-P lesions were significantly smaller for both PRE24 and POST24 ($21.6{\pm}8.5%$ and $22.2{\pm}4.0%$, respectively) than for CTR24 ($28.6{\pm}5.1%$, p<0.05), but there was no significant difference between PRE24 and POST24. The liver content of thiobarbituric acid reactive substances was significantly lower in the tea groups than in the controls (p<0.05). However, no significant differences were observed among groups of GST activity. The results show that tea consumption exhibits a stronger short-term initiation-inhibiting ability in liver carcinogenesis, but over a longer period, the preventive effects of green tea ingestion do not differ in post- and pre-initiation.

• 한국미생물·생명공학회지
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• 제33권2호
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• pp.136-141
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• 2005

고형 양식사료에 포함된 질소와 인의 미생물학적 제거 공정을 알아보기 위하여 벤치규모의 실험을 수행하였다. CK-10과 CK-13 균주가 새우양식장의 물시료로부터 분리되었다. CK-10과 CK-13의 혼합배양에서 N/P의 동시제거 실험을 실시하였다. 그 결과, $400\;{\mu}M\;NH^{+}_4$ 와 $NO^{-}_2$는 12시간 이내에 제거되었고, $NO^{-}_3$는 36시간 이내에 각각 제거되었으며, $500\;{\mu}M\;PO^{3-}_4$ 36시간 이내에 제거되었다. CK-10과 CK-13 배양을 새우양식사료에서 용출된 N와 P의 제거에 적용하였다. HPAEC-PAD 시스템을 이용하여 양식사료의 당을 분석하였으며, glucose, galactose, galatosamine, mammonse, fucose 등의 여러 가지 당이 분석되었다. 세균에 의한 질소와 인 제거를 수행하기 위하여 인공 해수에서 $0.2\%$(w/v)의 양식사료를 용출시켰으며, 72 시간동안 용출된 질소의 양은 대략 $33.3\;{\mu}M\;NH^{+}_4,\;12.9\;{\mu}M\;NO^{-}_2.\;81.5\;{\mu}M\;NO^{-}_3,\;248\;{\mu}M\;PO^{-3}_4$였다. 혼합배양은 $0.2\%$ 사료에 포함된 질소와 인을 84시간 이내에 완전히 제거하였으나, 단일배양은 주어진 배양기간동안 질소와 인을 완전제거 하지 못하였다. 이 연구에서 CK-10과 CK-13 배양은 새우양식사료에서 유래하는 질소와 인을 효과적으로 제거하는 것이 입증되었다.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2497-2502
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• 2010

Arg13 is a conserved active-site residue in all known Pi class glutathione S-transferases (GSTs) and in most Alpha class GSTs. To evaluate its contribution to substrate binding and catalysis of this residue, three mutants (R13A, R13K, and R13L) were expressed in Escherichia coli and purified by GSH affinity chromatography. The substitutions of Arg13 significantly affected GSH-conjugation activity, while scarcely affecting glutathione peroxidase or steroid isomerase activities. Mutation of Arg13 into Ala largely reduced the GSH-conjugation activity by approximately 85 - 95%, whereas substitutions by Lys and Leu barely affected activity. These results suggest that, in the GSH-conjugation activity of hGST P1-1, the contribution of Arg13 toward catalytic activity is highly dependent on substrate specificities and the size of the side chain at position 13. From the kinetic parameters, introduction of larger side chains at position 13 results in stronger affinity (Leu > Lys, Arg > Ala) towards GSH. The substitutions of Arg13 with alanine and leucine significantly affected $k_{cat}$, whereas substitution with Lys was similar to that of the wild type, indicating the significance of a positively charged residue at position 13. From the plots of log ($k_{cat}/{K_m}^{CDNB}$) against pH, the $pK_a$ values of the thiol group of GSH bound in R13A, R13K, and R13L were estimated to be 1.8, 1.4, and 1.8 pK units higher than the $pK_a$ value of the wild-type enzyme, demonstrating the contribution of the Arg13 guanidinium group to the electrostatic field in the active site. From these results, we suggest that contribution of Arg13 in substrate binding is highly dependent on the nature of the electrophilic substrates, while in the catalytic mechanism, it stabilizes the GSH thiolate through hydrogen bonding.

• The Journal of Advanced Prosthodontics
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• 제13권5호
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• pp.316-326
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• 2021

PURPOSE. Purpose of this in vitro study was to determine the accuracy of different intraoral scans versus laboratory scans of impressions and casts for the digitization of an edentulous maxilla. MATERIALS AND METHODS. A PEEK model of an edentulous maxilla, featuring four hemispheres on the alveolar ridges in region 13, 17, 23 and 27, was industrially digitized to obtain a reference dataset (REF). Intraoral scans using Cerec Primescan AC (PRI) and Cerec AC Omnicam (OMN), as well as conventional impressions (scannable polyvinyl siloxane) were carried out (n = 25). Conventional impressions (E5I) and referring plaster casts were scanned with the inEOS X5 (E5M). All datasets were exported in STL and analyzed (Geomagic Qualify). Linear and angular differences were evaluated by virtually constructed measurement points in the centers of the hemispheres (P13, P17, P23, P27) and lines between the points (P17-P13, P17-P23, P17-P27). Kolmogorov-Smirnov test and Shapiro-Wilk test were performed to test for normal distribution, Kruskal-Wallis-H test, and Mann-Whitney-U test to detect significant differences in trueness, followed by 2-sample Kolmogorov-Smirnov test to detect significant differences in precision (P < .008). RESULTS. Group PRI showed the highest trueness in linear and angular parameters (P < .001), while group E5I showed the highest precision (P < .001). CONCLUSION. Intraoral scan data obtained using Primescan showed the highest trueness while the indirect digitization of impressions showed the highest precision. To enhance the workflow, indirect digitization of the impression itself appears to be a reasonable technique, as it combines fast access to the digital workflow with the possibility of functional impression of mucosal areas.

• 한국산림과학회지
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• 제99권3호
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• pp.353-358
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• 2010

잣나무 목질부의 전질소 함량, 질소 및 탄소 동위원소비와 생장량과의 관계를 구명하고자 목편을 채취, 목질부의 질소 함량, 질소 및 탄소 동위원소비를 측정하여 목편의 연륜 폭과의 관계를 분석하였다. 목편의 연륜 폭과 ${\delta}^{13}C$ 및 전질소 함량과는 각각 p=0.003, p=0.024로 유의적 정의 상관관계가 있었고, 전질소 함량과 ${\delta}^{13}C$값과도 정의 상관관계(p=0.038)가 있어 목질부의 $^{13}C$량이 높고 또한 전질소 함량이 높을수록 잣나무 생장량도 증가하는 것으로 나타났다. 반면 목질부의 ${\delta}^{15}N$값과 C/N율이 낮을수록 연륜 폭이 증가하는 것으로 나타났다. 잣나무 가계간의 비교에서 생장이 우수한 가계일수록 그 목질부의 ${\delta}^{13}C$값이 큰 것으로 나타나 잣나무의 ${\delta}^{13}C$값이 상대적으로 높으면 생장도 우수한 것으로 추정된다. 이러한 결과로 잣나무 목질부내의 ${\delta}^{13}C$값 및 전질소 함량은 생장량과 밀접한 관계가 있는 인자로 추정된다.

• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.772-776
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• 2007

In order to study the role of residue in the active site of glutathione S-transferase (GST), Arg13 residue in human GST P1-1 was replaced with alanine, lysine and leucine by site-directed mutagenesis to obtain mutants R13A, R13K and R13L. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. Mutation of Arg13 into Ala caused a substantial reduction of the specific activity by 10-fold. Km GSH, Km DCNB and Km EPNP values of R13A were approximately 2-3 fold larger than those of the wild type. Mutation of Arg13 into Ala also significantly affected I50 values of S-methyl-GSH that compete with GSH and ethacrynic acid, an electrophilic substrate-like compound. These results appeared that the substitution of Arg13 with Ala resulted in significant structural change of the active site. Mutation of Arg13 into Leu reduced the catalytic activity by approximately 2-fold, whereas substitution by Lys scarcely affected the activity, indicating the significance of a positively charged residue at position 13. Therefore, arginine 13 participates in catalytic activity as mainly involved in the construction of the proper electrostatic field and conformation of the active site in human GST P1-1.