• Title/Summary/Keyword: TMT

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Inducible nitric oxide synthase is involved in neuronal death induced by trimethyltin in the rat hippocampus (Trimethyltin에 의한 랫드 해마의 신경세포 사멸과 iNOS의 연관성)

  • Jang, Sukwon;Choi, Sungyoung;Park, Changnam;Ahn, Meejung;Shin, Taekyun;Kim, Seungjoon
    • Korean Journal of Veterinary Research
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    • v.51 no.3
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    • pp.185-191
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    • 2011
  • Trimethyltin chloride (TMT) has been used as a neurotoxin for inducing brain dysfunction and neuronal death. Neuronal death in the hippocampus by TMT may generate excessive nitric oxide, but there are few studies about nitric oxide synthase enzyme involved in the synthesis of nitric oxide. The purpose of present study is to analyze the TMT toxicity in each region of rat hippocampus. To evaluate the involvement of nitric oxide, we analyzed the effects of aminoguanidine known as a selective inhibitor for inducible nitric oxide synthase on behavioral changes and the hippocampus of rat by TMT toxicity. 6-week-old male Sprague-Dawley rats were administered with a single dose of TMT (8 mg/kg b.w., i.p.) and the control group was similarly administered with distilled water. TMT + aminoguanidine-treated groups were administered with aminoguanidine (10 mg/kg or 100 mg/kg b.w., i.p.) for 3 days prior to TMT injection. The rats were sacrificed 2 days after TMT administration. In the TMT-treated group, a number of cell losses were seen in CA1, CA3 and the dentate gyrus. In the TMT + aminoguanidine-treated group, neuronal death was seen in CA1 and CA3, but reduced in the dentate gyrus compared to the TMT-treated group. Western blot analysis showed that cleaved caspase-3 expression was increased in the TMT-treated group compared to the control group. However, the expression significantly declined in the TMT + aminoguanidine-treated group. The present findings suggest that inducible nitric oxide synthase is involved in neuronal death induced by TMT.

Experimental Study on the Crop Cultivation Using Dredged Soil (준설토를 이용한 작물재배 시험연구)

  • 손재권;최진규;구자웅
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.2
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    • pp.159-170
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    • 1998
  • This study was initiated to investigate the applicability of the dredged soil from agricultural reservoirs on the crop cultivation. Four reservoirs were selected for this experiment, and properties of the dredged soils were analyzed physically and chemically. Soil textures were sandy loam(SL), silty loam(SiL), gravelly loam(GL), graveHy silty loam(GSiL), respectively. General chemical components, organic matter contents, main cations, heavy metals, etc. showed no adverse effects on crop growth. Tomato, cucumber, radish, Chinese cabbage were cultivated during 8 months period, in the soil treated with fertilizer and compost(Tmt.1), fertilizer(Tmt.2), compost(Tmt.3) and none (Tmt.4). Data for plant height, root zone depth and crop yield were collected and analyzed, and the yield for most crops showed increase as Tmt.1 >Tmt.2>Tmt.3>Tmt.4 by fertilizing methods, and as GL>GSiL>SL>SiL by soil textures. From the results, the crop cultivation using dredged soil was considered to be effective, due to its soil texture, organic matter content and fertilization.

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Cognitive Function in Non-Insulin Dependent Diabetic Patients (인슐린 비의존성 당뇨병 환자의 인지기능)

  • Jung, Mi-Ha;So, Hee-Young
    • The Korean Journal of Rehabilitation Nursing
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    • v.8 no.1
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    • pp.38-49
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    • 2005
  • Purpose: The purpose of this study was to examine the cognitive function in NIDDM patients. Method: The data were collected at MI OPD in C University hospital. with Digit Span Forward & Backward, Trail Making Test-A, Trail Making Test-B, and MMSE. Result: There were significant differences in DF, DB, TMT-A, and TMT-B according to gender, and in TMT-A according to living with spouse and comorbidity. There were significant differences in DF, DB, TMT-A, TMT-B, and MMSE according to monthly income, and in DF, TMT-A, and TMT-B according to hypertensive state. But, there was no difference in cognitive function score according to diabetes-related complication and diabetes treatment modality. There was a significant positive correlation between duration of NIDDM and TMT-A(r=.215, p=.025). The global cognition score was explained 42.1% of varient by age, duration of education, monthly income, and hypertensive state. Conclusion: As above results showed, among age, duration of education, monthly income, and hypertensive state, prevented and managed hypertensive state which is modifiable factor may reduce or delay cognitive function impairment in NIDDM patients. And DF & DB, TMT-A & B could be more utilized as useful cognitive function measurements because those tests reflected cognitive function in NIDDM patients better than MMSE.

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Thiol Methyltransferase Activity in Cholestatic Rat Liver Induced by Commom Bile Duct Ligation

  • Joo, Il;Kwak, Chun-Sik;Yoon, Chong-Guk
    • Biomedical Science Letters
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    • v.10 no.1
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    • pp.43-48
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    • 2004
  • Changes of thiol methyltransferase (TMT) activity in cholestatic rat liver were studied. Hepatic subcellular and serum TMT activities were determined in cholestatic rat induced by common bile duct (CBD) ligation over a period 28 days. The mitochondrial and microsomal TMT activities in cholestatic rat liver were found to be significantly increased between the 1st and the 28th day after CBD ligation. The TMT activity in serum was significantly increased throughout the experiments. The Vmax values of the above hepatic TMT in cholestatic rat were significantly increased at the 7th day after CBD ligation. However, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results indicate that the biosynthesis of TMT was increased in cholestatic rat liver. The elevated serum TMT activity is most likely caused by increased hepatocytes membrane permeability due to cholestasis mediated liver cell necrosis.

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New Perspective of Radical Innovation based on Upper Echelon Theory

  • Park, Junghyun;Chung, Doohee;Shin, Jiseon
    • Proceedings of the Korea Technology Innovation Society Conference
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    • 2017.05a
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    • pp.651-685
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    • 2017
  • This study examines how experience diversity of chief technology officer (CTO) drives radical innovation of the firm, and the moderation effect of group attributes of top management team. Using data of 148 firms in U.S. manufacturing industries, this study finds that a CTO's diverse functional experience increases a firm radicalness, and diverse industrial experience also increases the radicalness. This study also examined the moderating effect of top management team (TMT) characteristics such as TMT size, TMT tenure, and gender composition in TMT. The positive relationship of CTO knowledge diversity and firm radicalness is weakened as TMT size or TMT tenure increased while the relationship is strengthened as gender diversity in TMT increased. These results of the analysis of firm-level radicalness provide implications for both academics and practitioners.

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Top Management Team Heterogeneity, Interaction and Organizational Performance in Korean Hospitals (최고경영자 팀이 의료기관의 성과에 미치는 영향)

  • Jung, Moung-Suk;Lee, Se-Hoon;Kim, Kwang-Jum
    • Health Policy and Management
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    • v.20 no.1
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    • pp.137-154
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    • 2010
  • This study empirically analyzed the effects of the Top Management Team (TMT) on organizational performance. We verified whether the age heterogeneity, job heterogeneity (core career, core function and major), and process (communication and integration) of the TMT affect organizational performance (management performance and healthcare service quality evaluation level). We collected data about 473 members of the 2006 TMT in 81 medical institutions. We also utilized statistics of organizational performance from the Ministry for Health, Welfare and Family Affairs and the Korean Institute of Hospital Management. Results of the study showed that the age heterogeneity of TMT exerted a negative effect on the healthcare service quality evaluation level, while the process exerted a positive effect. However, the age heterogeneity, job heterogeneity, and process had no influence on management performance. We discussed the implications of such outcome of the investigation in comparison with the former studies on TMT and organizational performance, and presented its restrictions and future plans.

Corporate Social Responsibility and Firm Performance: the Moderating Role of Top Management Team Characteristics and Heterogeneity

  • Meng, La-Mei;Byun, Hae-Young
    • Asia-Pacific Journal of Business
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    • v.12 no.2
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    • pp.39-60
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    • 2021
  • Purpose - The purpose of this paper is exploring whether the characteristics and heterogeneity of the TMT play a moderating role in CSR and corporate value or not. Design/methodology/approach - The literature research method includes collecting, organizing, and analyzing the literature on the characteristics and heterogeneity of the TMT, the effect of corporate social responsibility (CSR), and corporate value. We analyze the contributions and limitations in existing research, grasp the current research status, and develop the research content of this article. The empirical analysis method is based on the data of Chinese A-share listed companies from 2001 to 2017. This allows us to study the moderating effect of the characteristics and heterogeneity of the TMT on CSR and corporate value. Findings - The TMT age, education degree, overseas background, and compensation have a positive moderating effect on CSR and corporate market value. The comprehensive heterogeneity of the TMT also has a positive effect on CSR and financial performance. Research implications or Originality - The research on the relationship between CSR and corporate value is still inconclusive. Some results have found a positive relationship, while others show a negative relationship. Studies exist that report mixed findings as well. This study has attempted to clarify this problem by adding potentially missing variables related on the TMT characteristics and heterogeneity, investigating causality effects.

Molecular Cloning and Characterization of ${\gamma}-tocopherol$ Methyltransferase cDNA from Perilla frutescens (들깨 ${\gamma}-tocopherol$ methyltransferase cDNA 유전자의 분리 및 특성)

  • Hwang, Seon-Kap;Kim, Dong-Hern;Lee, Jai-Youl;Kim, Young-Hwan;Hwang, Young-Soo;Kim, Kyung-Hwan
    • Applied Biological Chemistry
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    • v.45 no.4
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    • pp.203-206
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    • 2002
  • ${\gamma}-Tocopherol$ methyltransferase (TMT) is an enzyme catalyzing ${\gamma}-tocopherol$ into ${\alpha}-tocopherol$ at the final step of ${\alpha}-tocopherol$ synthesis pathway. Putative TMT cDNA clone specific to Perilla frutescens immature seeds was isolated from cDNA library. The cDNA clone consisted of 1369 bp open reading frame encoding 369 amino acids with a relative Mw of 42 kDa. Results revealed the CDNA has 60% homology to Arabidopsis thaliana TMT, and possesses methyltransferase and S-adenosyl methionine-binding domains, suggesting that cDNA encodes a ${\gamma}-tocopherol$ methyltransferase To characterize the properties of the TMT gene, the cDNA sequences coding for mature TMT were expressed in E. coli and assayed to determine the enzyme activity in vitro.

The Compensation Gap between Top Management Team(TMT) and Employee, and Firm Performance : Moderating Role of Promotion Probability and Opportunity, and Satisfaction with TMT (경영진과 종업원 간 보상격차가 기업성과에 미치는 영향 : 승진가능성 및 기회, 경영진에 대한 만족도의 조절효과)

  • Choi, Suk Bong
    • Journal of Korean Society for Quality Management
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    • v.49 no.3
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    • pp.313-326
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    • 2021
  • Purpose: Prior studies have sought to find antecedent to improve firm performance. However, research on compensation systems and employees' psychological mechanisms have been relatively limited. In this sense, this study has investigated the impact of compensation gap between TMT and employees on firm performance, and explored the factors that affect the above relationship. Specifically, this study analyzed the direct impact of compensation gap on firm performance. In addition, the process of compensation gap to firm performance is assumed to be significantly influenced by employees' recognized promotion system and satisfaction with TMT. Therefore, we examined moderating effects of both promotion probability and opportunity, and satisfaction with TMT on the relationship between compensation gap and firm performance. Methods: For empirical test, financial variables were collected from TS-2000 database, and moderating variables were collected form Job Planet for listed firms in Korea. We conducted hierarchical regression analysis to test hypotheses. Results: The findings of empirical analysis are as follows. First, compensation gap between TMT and employees had a positive effect on firm performance. Second, when promotion probability and opportunity was high, the effect of compensation gap on firm performance was strengthened. Third, when satisfaction with TMT was high, the positive effect of compensation gap on firm performance was also strengthened. Conclusion: Our findings have expanded prior research on human resource management and labor relation by identifying the positive role of compensation gap between TMT and employees on firm outcome. Moreover, our results also indicated that promotion probability and opportunity, and satisfaction with TMT, which has not been addressed well in previous studies, were important conditions enhancing the positive relationship between compensation gap and firm performance. Finally, this study suggest several theoretical and managerial implication with future research direction.

Effect of the Electroacupuncture at ST36 in TMT-induced Memory Deficit Rats

  • Shim, Hyun-Soo;Park, Hyun-Jung;Lee, Hye-Jung;Shim, In-Sop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.4
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    • pp.691-696
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    • 2011
  • In order to the neuroprotective effect of electroacupuncture (EA), the present study examined the effects of electroacupuncture inacupoint ST36 (Stomach 36) on trimethyltin chloride (TMT)-induced cognitive impairments rat using the Morris water maze (MWM) task and immunohistochemistry staining. The rats were randomly divided into the following groups: naive rat (Normal), TMT injection rat (Control), TMT injection + EA treated rat inacupoint ST36 (ST36) and TMT injection + EA treated rat in non-acupoint, base of tail (Non-AC). Electroacupuncture (2Hz, 2mA, and 10 minutes)was applied either to the acupuncture point ST36 or the nonacupuncture point in the tail for the last 14 days. In the water maze test, the animals were trained to find a platform in a fixed position during 4d and then received 60s probe trial on the $5^{th}$ day following removal of platform from the pool. Rats with TMT injection showed impaired learning and memory of the tasks and treatment with EA in acupoint ST36 (P<0.05) produced a significant improvement in escape latency to find the platform after $2^{nd}$ day and retention trial in the Morris water maze. Consistent with behavioral data, treatment with EA in acupoint ST36 also significantly increased expression of Choline acetyltransferase (ChAT) and Acetylcholinesterase (AChE) immunoreactive neurons in the hippocampus compared to the Control group. These results demonstrated that EA in acupoint ST36 has a protective effect against TMT-induced neuronal and cognitive impairments. The present study suggests that EA in acupoint ST36 might be useful in the treatment of TMT-induced learning and memory deficit.