• Title, Summary, Keyword: NOS

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Synthetic Regulatory Elements of the Nopaline Synthase Promoter in Higher Plants (고등 식물에서 Nopaline Synthase Promoter의 합성 조절 요소)

  • Kim, Young-Hee
    • Korean Journal of Plant Tissue Culture
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    • v.22 no.4
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    • pp.201-205
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    • 1995
  • The synthetic oligomers called nos right palindrome (RP) element and left palindrome (LP) element were inserted into nos.minimal promoter nos 5'-101 deletion mutant The activity of nos promoter was measured by studying the expression pattern of gene fusion between nos promoter and reporter genes such as chloramphenicol acetyltransferase and $\beta$-glucuconidase. Analysis of transgenic tobacco plane carrying transgene showed that the activity of nos minimal promoter activity was recovered by insertion of synthetic nos RP element. Nos RP element insertion of nos minimal promoter was induced by auxin, dithiothreitol, salicylic acid and methyl jasmonate.

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Endotoxin-induced renal tolerance against ischemia and reperfusion injury is removed by iNOS, but not eNOS, gene-deletion

  • Kim, Jee-In;Jang, Hee-Seong;Park, Kwon-Moo
    • BMB Reports
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    • v.43 no.9
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    • pp.629-634
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    • 2010
  • Endotoxin including lipopolysaccharide (LPS) confers organ tolerance against subsequent challenge by ischemia and reperfusion (I/R) insult. The mechanisms underlying this powerful adaptive defense remain to be defined. Therefore, in this study we attempted to determine whether nitric oxide (NO) and its associated enzymes, inducible NOS (iNOS) and endothelial NOS (eNOS, a constitutive NOS), are associated with LPS-induced renal tolerance against I/R injury, using iNOS (iNOS knock-out) or eNOS (eNOS knock-out) gene-deleted mice. A systemic low dose of LPS pretreatment protected kidney against I/R injury. LPS treatment increased the activity and expression of iNOS, but not eNOS, in kidney tissue. LPS pretreatment in iNOS, but not eNOS, knock-out mice did not protect kidney against I/R injury. In conclusion, the kidney tolerance to I/R injury conferred by pretreatment with LPS is mediated by increased expression and activation of iNOS.

Altered Vascular Expression of Nitric Oxide Synthase Isozymes in Hypertension (고혈압에서 혈관 산화질소 합성 동위 효소 발현 변화)

  • 김인광;강대길;이종은;오봉석
    • The Korean Journal of Thoracic and Cardiovascular Surgery
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    • v.32 no.2
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    • pp.138-143
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    • 1999
  • Background: The endothelium-dependent vasorelaxation has been largely accounted for by the release of nitric oxide (NO). Three distinct isoforms of NO synthases (NOS) have been characterized, i.e., brain(bNOS), inducible (iNOS), and endothelial constitutive (ecNOS). Although hypertension hasbeen associated with a vascular endothelial dysfunction, changes in the vascular expression of NOS isoforms have not been established. The present study was aimed at exploring the vascular expression of NOS isozymes in hypertension. Material and Method: Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were induced in rats. The expression of different NOS isozymes in the thoracic aorta was determined by Western blot analysis. The vascular tissue contents of nitrites were measured by colorimetric assay. Result: Arterial blood pressure was significantly higher in experimental groups of 2K1C and DOCA-salt rats compared with their corresponding control rats. The vascular expression of bNOS as well as that of ecNOS was decreased in both models of hypertension. iNOS was not changed in DOCA-salt hypertension, but was also decreased in 2K1C hypertension. The vascular contents of nitrites were significantly decreased in DOCA-salt as well as in 2K1C hypertension. Conclusion: These results suggest that 2K1C and DOCA-salt hypertension are associated with decreases in the vascular expression of NOS isozymes and nitrite contents.

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Teaching Models for Scientific Inquiry Activity through the Nature of Science (NOS)

  • Park, Jong-Won
    • Journal of The Korean Association For Science Education
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    • v.28 no.7
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    • pp.759-767
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    • 2008
  • This article arose from the previous studies, which suggested a synthetic list for the nature of science (NOS), discussed the relationship between the NOS and scientific inquiry and the development of the NOS in the context of scientific inquiry. In this article, for teaching scientific inquiry through the NOS, I proposed three teaching models - reflection, interaction, and the direct model -. Within these teaching models, understanding the NOS is viewed as a prerequisite condition for the improved performance of scientific inquiry. In the reflection model, the NOS is embedded and reflected in scientific inquiry without explicit introduction or direct explanation of the NOS. In the interaction model, concrete interaction between scientific inquiry and the NOS is encouraged during the process of scientific inquiry. In the direct model, subsequent to directly comprehending the NOS at the first stage of activity, students conduct scientific inquiry based on their understanding of the NOS. The intention of this present article is to facilitate the use of these models to develop teaching materials for more authentic scientific inquiry.

A Study of New Models for Scientific Inquiry Activity through Understanding the Nature of Science (NOS): - A Proposal for a Synthetic View of the NOS -

  • Park, Jong-Won
    • Journal of The Korean Association For Science Education
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    • v.27 no.2
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    • pp.153-167
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    • 2007
  • In this study, it is assumed that understanding the nature of science (NOS) would enhance students' performance of scientific inquiry in more authentic ways. The ultimate goal of this study is to suggest new models for developing scientific inquiry activities through understanding the NOS by linking the NOS with scientific inquiry. First, the various definitions and statements of the NOS are summarized, then the features of the developmental nature of scientific knowledge and the nature of scientific thinking based on the philosophy of science are reviewed, and finally a synthetic list of the elements of the NOS is proposed, consisting of three categories: the nature of scientific knowledge, the nature of scientific inquiry, and the nature of scientific thinking. This suggested synthetic list of the NOS is used to suggest a model of scientific inquiry through the understanding of the NOS. This list was designed to provide basic standards regarding the NOS as well as practical guidance for designing activities to improve students' understanding of the NOS.

THE EXPRESSION OF NITRIC OXIDE SYNTHETASE IN THE EXPERIMENTAL TOOTH MOVEMENT IN RATS (백서의 실험적 치아이동시 Nitric Oxide Synthetase의 발현 양상)

  • Park, Dong-Kwon;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.31 no.1
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    • pp.107-120
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    • 2001
  • Nitric oxide(NO) has been reported to be one of the mediators relating to bone remodelling. Nitric oxide is synthesized from L-arguinine by nitric oxide synthetase(NOS), which is largely divided Into two groups. One group which is composed of $NOS_1\;and\;NOS_3$, is dependent of calcium or calmodulin. The other consisted of $NOS_2$, which is independent of calcium or calmodulin. NOS is thought to be a possible intermediate affecting in the course of tooth movement. This study was designed to evaluate the expression of nitrous oxide synthetase(NOS) in periodontal tissue during the experimental movement of rat incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for $NOS_2\;and\;NOS_3$. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental groups(24 rats), to which 75g of force was applied, with helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. After that, the tissues of the control group and experimental groups were studied immunohistochemically. The results were as follows: 1. In control group, the expression of $NOS_3$ was rare in gingiva, dentin, periodontal ligament and alveolar bone, and was mild in the capillaries of pulp and intermaxillary suture. And the expression of $NOS_2$ showed similar pattern to that of $NOS_3$. 2. There were no differences in the expression of $NOS_2\;or\;NOS_3$ in dentin, gingiva, cementum, cementoblast and odontoblast, between control and experimental groups, regardless of the duration of the force application. 3. The expression of $NOS_3$ began to increase at 4 days and showed to the highest degree at 7 days after force application, in the apical region of pressure side of periodontal ligament in experimental groups. 4. The expression of $NOS_3$ in alveolar bone was rare until 7 days, after which it increased to mild degree at 14 days through 28 days in experimental group. But there was no difference between pressure and tension side of periodontal ligament. 5. The expression of $NOS_2$ in periodontal ligament was mild from 7 days after force application, regardless of the side of periodontium, which was generally more evident than that of $NOS_3$. 6. The expression of $NOS_2$ in alveolar bone increased to mild degree at 14 days after force application, and it was evident in osteoblasts, osteoclasts and osteocytes. And the expression of $NOS_2$ was little more stronger in the tension side than that of pressure side of alveolar bone.

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Expression and localization of endothelial and inducible nitric oxide synthase in bovine uterus (소 자궁에서 endothelial nitric oxide synthase(NOS) 및 inducible NOS의 발현)

  • Lee, Yongduk;Kim, Seungjoon;Moon, Changjong;Shin, Taekyun
    • Korean Journal of Veterinary Research
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    • v.43 no.4
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    • pp.551-554
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    • 2003
  • Nitric oxide synthase (NOS) has been reported in uterus. We examined the expression of the NOS isoforms, constitutive endothelial (eNOS) and inducible NOS (iNOS), in bovine uterus by immunohistochemistry. eNOS immunoreactivity was localized predominantly to the endothelial cells that line uterine microvessels and to endometrial glandular epithelial cells, but was barely detectable in endometrial stromal cells. iNOS immunostaining was detected in glandular epithelial and stromal cells in the endometrium and in the endothelial cells of myometrial blood vessels. These findings suggest that both eNOS and iNOS may play important roles in the physiology of the uterus, possibly by generating NO.

An Exploration of Science Teachers' NOS-PCK: Focus on Science Inquiry Experiment (과학교사의 과학의 본성 수업에 대한 교과교육학 지식(NOS-PCK) 탐색 -과학탐구실험을 중심으로-)

  • Kim, Minhwan;Shin, Haemin;Noh, Taehee
    • Journal of The Korean Association For Science Education
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    • v.40 no.4
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    • pp.399-413
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    • 2020
  • In this study, we analyzed science teachers' NOS-PCK in Science Inquiry Experiment lessons. Four science teachers in charge of Science Inquiry Experiment in high schools located in the Seoul metropolitan area participated in the study. NOS Lessons were observed, all of the teaching-learning materials were collected, and semi-structured interviews were conducted. All the collected data were analyzed according to five factors of NOS-PCK. As a result of the study, their understanding and consideration of the curriculum related to NOS were insufficient in some cases. They thought that given inquiry activities or textbook composition was not effective for NOS teaching so that they actively reconstructed the curriculum. In terms of teaching strategies, their lessons were close to explicit approaches. However reflective approaches were generally lacking. They were neglected in evaluating NOS for reasons that views of NOS are individually subjective or that NOS is not an area of cognitive learning. They guessed the state of students by relying on their own experiences rather than based on evaluation results. They recognized a specific aspect of values of NOS learning. And intention to teach NOS played an important role throughout their classes. Based on the above results, we discuss some ways to improve the professionalism of science teachers for NOS teaching.

Nitric Oxide Synthase Expressions in ADR-induced Cardiomyopathy in Rats

  • Liu, Baogang;Li, Hongli;Qu, Hongyan;Sun, Baogui
    • BMB Reports
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    • v.39 no.6
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    • pp.759-765
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    • 2006
  • In this study, we investigate Nitric oxide synthase (NOS) expressions in adriamycin (ADR)-induced cadiomyopathy in rats. Sixty male Wistar rats were randomly divided into two main groups: control and ADR groups. Myocardial histopathological observation was performed; Expressions of 3 isoforms of NOS genes were examined by RT-PCR analysis; Expressions of 3 isoforms of NOS protein was assessed by Western blot analysis. Myocardium exhibited intensive morphological changes after 8 weeks of ADR treatment. The expression levels of inducible NOS (iNOS) gene and protein were significantly increased in ADR-treated rats after 8 weeks of treatment and then slightly increased at weeks 9 and 10. No significantly difference of neuronal NOS (nNOS) or endothelial NOS (eNOS) gene and protein were observed in the myocardium obtained from the control rats and ADR-injected rats at any time point. iNOS gene expression is selectively induced by ADR in heart. The upregulation of iNOS gene and protein may be somehow correlated with morphological changes seen in heart of rat treated with ADR.

Pretreatment of Macrophages with Paclitaxel Inhibits iNOS Expression

  • Li Mei-Hong;Kang Jong-Soon;Kim Hwan-Mook;Jeon Young-Jin
    • Toxicological Research
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    • v.22 no.2
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    • pp.103-107
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    • 2006
  • We demonstrate that paclitaxel, an antitumor agent derived from yew tree, inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Previously, paclitaxel has been known to induce iNOS gene expression in macrophages. However, in this report we described that the pre-treatment of macrophages with paclitaxel ($0.1{\mu}M$) for 8 h inhibited LPS-induced iNOS gene expression. Pretreatment of RAW 264.7 cells with paclitaxel significantly inhibited LPS-stimulated nitric oxide (NO) production. Western immunoblot of iNOS and RT-PCR analysis showed that the decrease of NO was due to the inhibition of iNOS gene expression in RAW 264.7 cells. Immunocytochemical staining of iNOS further confirmed that pretreatment of macrophages with paclitaxel inhibited macrophage activation. Electrophoretic mobility shift assay showed that paclitaxel inhibited $NF-_{\kappa}/Rel$ DNA binding. Collectively, these series of experiments indicate that paclitaxel inhibits iNOS gene expression by blocking $NF-_{\kappa}B/Rel$ activation.