• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1010-1017
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• 2007

Two alternative pathways for methionine biosynthesis are known in Corynebacterium glutamicum: one involving transsulfuration (mediated by metB and metC) and the other involving direct sulfhydrylation (mediated by metY). In this study, MetB (cystathionine ${\gamma}-synthase$) and MetY (O-acetylhomoserine sulfhydrylase) from C. glutamicum were purified to homogeneity and the biochemical parameters were compared to assess the functional and evolutionary importance of each pathway. The molecular masses of the native MetB and MetY proteins were measured to be approximately 170 and 280 kDa, respectively, showing that MetB was a homotetramer of 40-kDa subunits and MetY was a homohexamer of 45-kDa subunits. The $K_m$ values for the O-acetylhomoserine catalysis effected by MetB and MetY were 3.9 and 6.4 mM, and the maximum catalysis rates were $7.4\;(k_{cat}=21\;S^{-1})\;and\;6.0\;(k_{cat}=28\;S^{-1})\;{\mu}mol\;mg^{-1}\;min^{-1}$, respectively. This suggests that both MetB and MetY can be comparably active in vivo. Nevertheless, the $K_m$ value for sulfide ions by MetY was 8.6mM, which was too high, considering the physiological condition. Moreover, MetB was active at a broad range of temperatures $(30\;and\;65^{\circ}C)$ and pH (6.5 and 10.0), as compared with MetY, which was active in a range from 30 to $45^{\circ}C$ and at pH values from 7.0 to 8.5. In addition, MetY was inhibited by methionine, but MetB was not. These biochemical data may provide insight on the role of the parallel pathways of methionine biosynthesis in C. glutamicum with regard to cell physiology and evolution.

• Journal of Chest Surgery
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• 제50권3호
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• pp.153-162
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• 2017

Background: The mesenchymal-epithelial transition factor (MET) receptor can be overexpressed in solid tumors, including small cell lung cancer (SCLC). However, the molecular mechanism regulating MET stability and turnover in SCLC remains undefined. One potential mechanism of MET regulation involves the C-terminus of Hsp70-interacting protein (CHIP), which targets heat shock protein 90-interacting proteins for ubiquitination and proteasomal degradation. In the present study, we investigated the functional effects of CHIP expression on MET regulation and the control of SCLC cell apoptosis and invasion. Methods: To evaluate the expression of CHIP and c-Met, which is a protein that in humans is encoded by the MET gene (the MET proto-oncogene), we examined the expression pattern of c-Met and CHIP in SCLC cell lines by western blotting. To investigate whether CHIP overexpression reduced cell proliferation and invasive activity in SCLC cell lines, we transfected cells with CHIP and performed a cell viability assay and cellular apoptosis assays. Results: We found an inverse relationship between the expression of CHIP and MET in SCLC cell lines (n=5). CHIP destabilized the endogenous MET receptor in SCLC cell lines, indicating an essential role for CHIP in the regulation of MET degradation. In addition, CHIP inhibited MET-dependent pathways, and invasion, cell growth, and apoptosis were reduced by CHIP overexpression in SCLC cell lines. Conclusion: C HIP is capable of regulating SCLC cell apoptosis and invasion by inhibiting MET-mediated cytoskeletal and cell survival pathways in NCI-H69 cells. CHIP suppresses MET-dependent signaling, and regulates MET-mediated SCLC motility.

• Journal of Nutrition and Health
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• 제47권3호
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• pp.176-185
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• 2014

본 연구는 PCOS 환자를 대상으로 MetS 여부에 따른 플라보노이드 섭취량의 차이를 분석하고 MetS과 플라보노이드 섭취와의 관련성을 알아보기 위해 수행되었다. 이 연구를 통해 관찰된 결과는 다음과 같다. 첫째, MetS이 없는 군에 비해 MetS이 있는 군은 총 6종의 플라보노이드군 중 플라보놀 (flavonols)을 유의적으로 적게 섭취하는 것으로 나타났다. 둘째, 간이식생활진단 (MDA)을 통한 식습관을 조사한 결과, '과일이나 과일주스를 매일 먹는다'라는 질문에 대해 '아닌 편이다'라고 응답한 비율이 MetS이 없는 군에 비해 MetS이 있는 군이 높았다. 셋째, 플라보놀 (flavonols)의 섭취량과 MetS의 교차비 (OR)를 분석한 결과, 모든 혼란변수를 보정한 후, 최하위 섭취군 대비 최상위 섭취군에서 MetS에 대한 교차비가 유의적으로 낮았다. 이상 PCOS 환자를 대상으로 MetS과 플라보노이드 섭취와의 관련성을 조사한 결과, MetS이 있는 군이 MetS이 없는 군에 비해 플라보놀 (flavonols)의 섭취량이 유의적으로 낮았고 플라보놀 (flavonols)의 섭취량은 MetS의 위험도와 역의 관계를 나타냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1804-1808
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• 2003

A layer experiment was conducted to determine the effects of supplementary methionine chelates (Cu, Zn and Mn), individual or in combination, on laying performance, eggshell quality, gizzard erosion, and IgG level of serum for 8 weeks. Five hundred 96-wk-old force molted ISA Brown layers were assigned to five dietary treatments. Basal diet was formulated to meet or exceed the nutrients requirements listed in NRC (1994). Five experimental diets were control, Zn-methionine chelate (Zn-Met) supplemented, Cumethionine chelate (Cu-Met) supplemented, Zn-Mn-methionine chelate (Zn-Mn-Met) supplemented and Zn-Mn-Cu-Met supplemented diet. Each treated diet was supplemented with respective mineral(s) at the level of 100 ppm in the form of methionine chelate. Egg production was increased by Cu-Met supplementation but decreased by Zn-Met supplementation. Egg weight was significantly (p<0.05) lower in Cu-Met treatment than those of the control and Zn-Met treatment. Specific gravity of eggs and eggshell strength were highest and soft egg production was lowest in Cu-Met treatment. Gizzard erosion index was significantly increased by supplementation of Cu-Met, Zn-Mn-Met or Zn-Mn-Cu-Met. Zinc content in liver significantly increased by Zn-Met, but not by Zn-Mn-Cu-Met treatment. In conclusion, 100 ppm Cu in Cu-Met chelate improved laying performance and eggshell quality but also increased gizzard erosion index. Supplementation of Zn-Met or its combination with other mineral chelates had no beneficial effects on laying performance and eggshell quality.

• 대한두경부종양학회지
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• 제21권1호
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• pp.15-20
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• 2005

Objectives: The hepatocyte growth factor(HGF)/c-Met pathway may play various roles in the carcinogenesis of various organs. Although HGF/c-Met signalling pathway has been shown to demonstrate various cellular responses including mitogenic, proliferative, morphogenic and angiogenic activities, the study on their expression related to clinicopathological parameters in thyroid tumor is relatively rare. So we want to find out the clinical significance of the c-Met in thyroid tumor. Materials and Methods: We assess the mRNA and protein expression of the c-Met genes by means of RT-PCR method and the immunohistochemical stain in 100 cases of thyroid tumors(50 papillary carcinomas, 10 follicular carcinomas, 20 follicular adenomas, 20 nodular hyperplasia). Results: By RT-PCR, c-Met mRNA was detected in 43(86%) in papillary carcinoma, 4(40%) in follicular carcinoma, 4(20%) in follicular adenoma and 2(10%) in nodular hyperplasia cases. By immunohistochemistry, c-Met protein expression was detected in 44(88%), 2(20%), 3(15%) and 1(5%). Expression of the c-Met mRNA and protein expression was significantly highly recognized in papillary carcinoma. The c-Met protein overexpression was significantly correlated with the grade of the differentiation. Conclusion: These results suggest that c-Met expression may be associated with thyroid papillary cancer progression. The differential expression of c-Met protein and mRNA suggests that these molecules may be a reliable diagnostic marker in thyroid papillary cancer.

• Journal of Gastric Cancer
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• 제16권3호
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• pp.141-151
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• 2016

Purpose: The aim of the present study was to elucidate the clinicopathological significance and diagnostic accuracy of immunohistochemistry (IHC) for determining the mesenchymal epidermal transition (c-MET) expression in patients with gastric cancer (GC). Materials and Methods: The present meta-analysis investigated the correlation between c-MET expression as determined by IHC and the clinicopathological parameters in 8,395 GC patients from 37 studies that satisfied the eligibility criteria. In addition, a concordance analysis was performed between c-MET expression as determined by IHC and c-MET amplification, and the diagnostic test accuracy was reviewed. Results: The estimated rate of c-MET overexpression was 0.403 (95% confidence interval [CI], 0.327~0.484) and it was significantly correlated with male patients, poor differentiation, lymph node metastasis, higher TNM stage, and human epidermal growth factor receptor 2 (HER2) positivity in IHC analysis. There was a significant correlation between c-MET expression and worse overall survival rate (hazard ratio, 1.588; 95% CI, 1.266~1.992). The concordance rates between c-MET expression and c-MET amplification were 0.967 (95% CI, 0.916~0.987) and 0.270 (95% CI, 0.173~0.395) for cases with non-overexpressed and overexpressed c-MET, respectively. In the diagnostic test accuracy review, the pooled sensitivity and specificity were 0.56 (95% CI, 0.50~0.63) and 0.79 (95% CI, 0.77~0.81), respectively. Conclusions: The c-MET overexpression as determined by IHC was significantly correlated with aggressive tumor behavior and positive IHC status for HER2 in patients with GC. In addition, the c-MET expression status could be useful in the screening of c-MET amplification in patients with GC.

• 한방재활의학과학회지
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• 제24권1호
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• pp.93-100
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• 2014

Objectives To evaluate the clinical utility of MET performed on sternocleidomastoid muscle of acute nuchal pain patients, we measured a change of meridian electromyography. Methods We compared electrical activity before and after MET performed on sternocleidomastoid muscle of acute nuchal pain patients in same group (n=20) in isometric exercise state during five seconds. We analyzed amplitudes and areas of electrical activity and asymmetry index (AI). Results 1. After MET performed on sternocleidomastoid muscle of acute nuchal pain patients, maximum voluntary isomeric contraction (MVIC) was significantly increased more than before MET performed (p<0.005). 2. Comparing with before MET performed on sternocleidomastoid muscle of acute nuchal pain patients, muscle fatigue after MET performed on sternocleidomastoid muscle of acute nuchal pain patients decreased but there was no significant difference. 3. Comparing with before MET performed on sternocleidomastoid muscle of acute nuchal pain patients, asymmetry index (AI) after MET performed on sternocleidomastoid muscle of acute nuchal pain patients decreased but there was no significant difference. Conclusions According to above results, after performing MET on sternocleidomastoid muscle of acute nuchal pain patients, maximum voluntary isomeric contraction (MVIC) increased significantly, so it is certain that performing MET on sternocleidomastoid muscle has a clinical effect.

• 한방재활의학과학회지
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• 제23권1호
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• pp.15-23
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• 2013

Objectives : To evaluate the clinical utility of MET in elector spinae muscle on low back pain patients. Methods : We compared electrical activity between a before MET and a after MET in elector spinae muscle on low back pain patients in same group(n=30) in dynamic flexion-reextension state during five seconds. We analyzed amplitudes and areas of electrical activity and asymmetry index(AI). Results : 1. After MET in elector spinae muscle on low back pain patients were significantly decreased in Visual Analogue Scale(VAS) than before MET in elector spinae muscle on low back pain patients(p<0.05). 2. After MET in elector spinae muscle on low back pain patients were lower electrical activity than before MET in elector spinae muscle on low back pain patients but it is not a pointless observation(p<0.05). 3. AI of the after MET in elector spinae muscle on low back pain patients significantly decreased compared with before MET in elector spinae muscle on low back pain patients(p<0.05). Conclusions : According to above results, there is clinical effect MET on low back pain patients.

• 한국식품영양과학회지
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• 제26권2호
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• pp.319-326
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• 1997

Met과 Se의 공급수준이 흰쥐의 알코올대사 효소계에 미치는 영향을 관찰하고자, Sprague-Dawley종의 웅성 흰쥐에게 Se 무첨가 및 정상공급식이 (0, 0.45mg/kg diet)에 Met(0, 3, 9g/kg diet)을 투여한 후 5주와 10주간 사육하여 간조직중의 알코올 대사효소와 항산화 방어 효소계 활성도를 관찰하였다. 알코올은 aldehyde dehydrogenase와 microsomal ethanol oxidizing system 활성도를 유의적으로 증가시켰으며, Met과 Se의 동시 결핍시 현저하게 감소하였고 Met과 Se의 동시 공급군의 경우 알코올 투여기간이 길수록 그 활성이 유의적으로 증가하였다. Aldehyde dehydrogenase 활성도는 알코올 투여로 감소하였으며 Met과 Se 동시 결핍군에서는 현저한 감소를 나타내었고, 사육기간이 길수록 그 활성이 유의적으로 감소되었다. Cytochrome P-450과 xanthine oxidase 활성도는 알코올 투여 시 유의적으로 증가되었는데 Se 결핍시 Met 결핍군과 과량공급군에서 그 증가가 현저하였으며, 5주 실험군에 비해 10주 실험군에서 유의적인 증가를 나타내었다. Superoxide dismutase, catalase 및 glutathione S-transferase 활성도는 알코올 투여시 증가되었으며, superoxide dismutase와 catalase 활성도는 알코올 투여기간이 길수록 유의적인 증가를 나타내었다. 알코올 투여시 glutathione peroxidas 활성도는 감소되었으며, Met 수준이 높을수록 증가하는 경향이었고, Met과 Se 동시 결핍시 현저하게 감소하였다. 이상의 결과에서 식이성 Met과 Se은 동물의 성장 및 정상적 대사유지에 필수적인 영양소로서 알코올 투여 시 Met과 Se 첨가에 따라 알코올대사 효소활성도와 항산화 방어효소 활성도의 변화를 유도할 수 있었다. 또한 식이 kg당 3g의 Met과 0.45mg의 Se 동시 공급시 원활한 알코올대사를 유도하여 알코올성 간손상을 가장 효율적으로 경감시킬 수 있는 것으로 나타났다.

• 한국작물학회지
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• 제29권1호
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• pp.55-61
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• 1984

1981년부터 최 등이 재래종 옥수수의 수집종 가운데서 병발한 한계통(MET)을 분얼이 많이되고 또한 개체당 이삭(수)수도 많아서 사료용 옥수수의 육종재료로 가치가 있다고 생각되었으나 이 옥수수에 대한 유전적 분석이 확실히 되어 있지를 않았다. 따라서 본연구에서는 MET와 비분얼성이며 이삭도 하나 밖에 달리지 않는 수원 19호 (Mo17$\times$B68) 교잡종을 이용하여 F$_1$, F$_2$, BC$_1$, 세대를 양성하고 Mather의 세대평균분석법에 의하여 분석한 결과 MET 계통의 다수.다얼성은 염색체상의 유전인자에 의한 다기 보다 세포질적 유전인자에 의한다는 것을 확인하였다. 이같은 결론은 MET계통을 모계로 하여 교잡한 려잡종 세대에서 확실히 얻을 수가 있었다. 즉 MET 계통을 모계로 이용했을 때의 평균분얼과 이삭수는 MET를 부계로 이용했을 때의 분얼수와 이삭수 보다 많았는데 이는 이같은 특성들이 모계유전을 하기 때문이다. 그러나 이같은 특성들이 F$_1$이나 F$_2$에서 나타나지 않은 것은 F$_1$에서 특히 보여주는 잡종강세현상 때문에 옥수수의 정부우세성이 매우커서 상반적으로 분얼이나 이삭의 발달이 억제되었기 때문이라고 생각된다. 그리고 분얼이나 이삭의 절대수가 모계로 이용했던 MET에서 보다 잡종세대가 진전될수록 적어지는 것은 잡종강세외에도 MET계통의 세포질약 내지 유전인자적 축적량(Dose)이 적어지기 때문이라고 생각되어진다. 이같은 MET계통의 특성은 려교잡에 의한 MET계통의 세포질을 유지하거나 축적하므로써 사료용 옥수수의 육종에 이용될 수 있을 것으로 보여졌다.