TRANSIENT ISCHEMIA-INDUCED EXPRESSION AND CHANGES OF TYROSINE KINASE A IN THE HIPPOCAMPAL DENTATE GYRUS OF THE GERBIL

HWANG, IN,LEE, HYEON,YOO, KI-YEON,KIM, DAE,KIM, JUNG,KIM, CHANG,LIM, BEONG,KANG, TAE-CHEON,BANG, KYUNG,SEONG, NAK,LEE, HAK,KIM, JONG,WON, MOO Taylor Francis 2006 International journal of neuroscience Vol.116 No.8

<P>The present study examined ischemia-related changes in tyrosine kinase A (trkA) immunoreactivity and its protein content in the dentate gyrus after 5 min of transient forebrain ischemia in gerbils. One day after ischemic insult, cresyl violet-positive polymorphic cells showed ischemic degeneration. The ischemia-induced changes in trkA immunoreactivity were found in the polymorphic layer (PL) and granule cell layer (GCL) of the dentate gyrus. In the sham-operated group, trkA immunoreactivity in the dentate gyrus was very weak. From 30 min after ischemia, trkA immunoreactivity was increased in the dentate gyrus and peaked in the dentate gyrus at 12 h after ischemia-reperfusion. Thereafter, trkA immunoreactivity was decreased time-dependently after ischemia-reperfusion. Four days after ischemic insult, trkA immunoreactivity was similar to that of the sham-operated group. In addition, it was found that ischemia-related changes in trkA protein content were similar to the immunohistochemical changes. These results suggest that the chronological changes of trkA in the dentate gyrus after transient forebrain ischemia may be associated with ischemic damage in polymorphic cells of the dentate gyrus.</P>

Clinical Experiences and Usefulness of Cervical Posterior Stabilization with Polyaxial Screw-Rod System

Hwang, In-Chang,Kang, Dong-Ho,Han, Jong-Woo,Park, In-Sung,Lee, Chul-Hee,Park, Sun-Young The Korean Neurosurgical Society 2007 Journal of Korean neurosurgical society Vol.42 No.4

Objective : The objective of this study is to investigate the safety, surgical efficacy, and advantages of a polyaxial screw-rod system for posterior occipitocervicothoracic arthrodesis. Methods : Charts and radiographs of 32 patients who underwent posterior cervical fixation between October 2004 and February 2006 were retrospectively reviewed. Posterior cervical polyaxial screw-rod fixation was applied on the cervical spine and/or upper thoracic spine. The surgical indication was fracture or dislocation in 18, C1-2 ligamentous injury with trauma in 5, atlantoaxial instability by rheumatoid arthritis (RA) or diffuse idiopathic skeletal hyperostosis (DISH) in 4, cervical spondylosis with myelopathy in 4, and spinal metastatic tumor in 1. The patients were followed up and evaluated based on their clinical status and radiographs at 1, 3, 6 months and 1 year after surgery. Results : A total of 189 screws were implanted in 32 patients. Fixation was carried out over an average of 3.3 spinal segment (range, 2 to 7). The mean follow-up interval was 20.2 months. This system allowed for screw placement in the occiput, C1 lateral mass, C2 pars, C3-7 lateral masses, as well as the lower cervical and upper thoracic pedicles. Satisfactory bony fusion and reduction were achieved and confirmed in postoperative flexion-extension lateral radiographs and computed tomography (CT) scans in all cases. Revision surgery was required in two cases due to deep wound infection. One case needed a skin graft due to necrotic change. There was one case of kyphotic change due to adjacent segmental degeneration. There were no other complications, such as cord or vertebral artery injury, cerebrospinal fluid leak, screw malposition or back-out, or implant failure, and there were no cases of postoperative radiculopathy due to foraminal stenosis. Conclusion : Posterior cervical stabilization with a polyaxial screw-rod system is a safe and reliable technique that appears to offer several advantages over existing methods. Further biomechanical testings and clinical experiences are needed in order to determine the true benefits of this procedure.

백서에서 Depulpin®과 Formocresol에 대한 치수와 치근단 조직의 반응

문형인,김선호,황윤찬,오병주,황인남,김선헌,정선와,윤창,오원만 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4

One fifth dilution of formocresol is usually for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However, the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it may also alter the pulp tissue rendering it immumologically active, and have carcinogenic potential. Recently Depulpin®(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49% paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier. But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine. Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue, in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present. it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin® group The area of necrotic tissue which had no cells and fibers , was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nucleli. A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resorption and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall. was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.

Ischemia-Related Changes in Galanin Expression in the Dentate Hilar Region after Transient Forebrain Ischemia in Gerbils

LEE, Hyeon Yong,HWANG, In Koo,KIM, Dae Ho,KIM, Jung Hwa,KIM, Chang Ho,LIM, Beong Ou,KANG, Tae-Cheon,BANG, Kyung Hwan,SEONG, Nak Sul,LEE, Hak Ju,KIM, Jong Dai,WON, Moo Ho Japanese Association for Laboratory Animal Science 2005 EXPERIMENTAL ANIMALS Vol.54 No.1

<P>Although galanin (GAL) protects hippocampal neurons from ischemic damage, no study has examined ischemia-related changes in endogenous GAL in the hippocampal dentate gyrus. We investigated the chronological changes of GAL, well-known as the potassium channel opener, expression in the dentate gyrus at various times after 5 min of transient forebrain ischemia in gerbils. A few GAL-immunoreactive (IR) neurons were found in the polymorphic layer of the sham-operated group. Three hours after ischemia-reperfusion, the pattern of GAL immunoreactivity was similar to that of the sham-operated group and the number of GAL-IR neurons and immunoreactivity were highest 12 h after ischemic insult. At this time, GAL-IR neurons in the polymorphic layer showed strong GAL immunoreactivity. Thereafter, GAL-IR neurons and immunoreactivity significantly decreased in the dentate hilar region. Four days after ischemic insult, GAL-IR neurons were not detectable. In addition, the results of a Western blot study showed a pattern of GAL expression similar to the immunohistochemical changes. GAL protein content also was highest 12 h after ischemia. In conclusion, the increased expression of endogenous GAL in the dentate gyrus after ischemia is related to response to the ischemic damage.</P>

연구논문 : 전력부문 온실가스 배출 관련 지자체의 책임성에 관한 연구

진상현 ( Sang Hyeon Jin ),황인창 ( In Chang Hwang ),한준 ( Joon Han ) 한국환경정책학회 2011 環境政策 Vol.19 No.1

The major issue of this era is how climate change can be solved. But even though most people are interested in this problem, climate change is becoming more serious. This is called the Giddens` paradox. So it is important to distinguish the emitter of greenhouse gas (GHG) and set the target of reduction. In other words, the solution of this paradox is related to responsibility of climate change. Local governments which are in charge of climate change, also know the seriousness of this problem. They try to reduce GHG emissions as well as the central governments. Nevertheless, local governments have also been in a dilemma of climate change responsibility like the central governments. In other words, there are similar issues on the details of the level of local governments : whose area is more responsible for GHG emissions, what their target of reduction is and how it can be achieved. In particular, electricity is the hottest potato in this issue among all the other energy sources. So this paper will review their responsibility for GHG emissions in electricity sector theoretically and empirically. Then, conclusions and implications of responsibility for GHG emissions will be drawn in this paper. Finally, these can be arranged in the three dimensions : the responsible agent, the scope, and the scheme for the assignment. In conclusion, cities which consume electricity must be in charge of GHG including all the indirect emissions in the way for users to take responsibility.

ACTIVE LEARNING AND OPTIMAL CLIMATE POLICY

( In Chang Hwang ),( Richard S. J. Tol ),( Marjan W. Hofkes ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2015 한국환경경제학회 학술발표논문집 Vol.2015 No.하계

This paper develops a climate-economy model with uncertainty, irreversibility and active learning. Whereas previous papers assume passive learning from one observation per period, or experiment with control variables to gain additional information, this paper considers active learning from research investment in improved observations. We restrict ourselves to improving observations of the global mean temperature. We find that the decision maker invests a significant amount of money in climate research, far more than the current level, in order to increase the rate of learning about climate change. This helps the decision maker take improved decisions. The level of uncertainty decreases more rapidly in the active learning model with research investment than in the passive learning model only with temperature observations. As a result, active learning reduces the optimal carbon tax. The greater the risk, the larger is the effect of learning. The method proposed here is applicable to any dynamic control problem where the quality of monitoring is a choice variable.

연구논문 : 사회후생함수를 중심으로 한 기후경제통합-지역평가모형 비교분석

황인창 ( In Chang Hwang ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2016 자원·환경경제연구 Vol.25 No.1

기후경제통합평가모형(Integrated assessment model of climate and the economy)은 기후변화에 관한 경제 분석과 정책제안을 위한 필수적인 도구가 되어왔다. 최근에는 기후변화에 대응하기 위한 정책적 노력들이 대부분 국가 또는 지역 수준에서 일어난다는 인식 하에 국가 또는 지역에서의 기후변화 영향과 정책수단의 효과를 평가할 수 있는 기후경제통합-지역평가모형(Regional integrated assessment model of climate and the economy)의 중요성이 더욱 커지고 있다. 이 논문에서는 국내에서 기후경제통합-지역평가모형을 개발하기 위한 첫 번째 단계로서 사회후생함수를 중심으로 기후경제통합-지역평가모형을 이론적으로 유형화했으며, RICE(Regional integrated climate-economy model) 모형을 통해 기후변화 대응전략에 따른 국가별 기후변화정책의 변화를 수치적으로 살펴보았다. 변화하는 국제 상황, 새롭게 드러나는 과학적 증거, 국내 여건 등을 모두 반영한 기후변화정책을 수립하기 위해서는 이를 분석할 수 있는 효과적인 도구를 갖추고 있어야 한다. 이 논문에서 살펴본 기후경제통합-지역평가모형은 이를 위한 유용한 도구가 될 수 있다. An integrated assessment model of climate and the economy (IAM) has been a standard tool for the economic analysis of climate change and policy recommendations. Since policy measures to address climate change take places at a national level, a regional integrated assessment model of climate and the economy (RIAM) is gaining more importance. A RIAM is a useful tool for the assessment of regional (or national) impacts of climate change. This paper investigates the main features of the currently available RIAMs. The focus is social welfare functions and the regional aspects of climate change. The comparative analysis shows that there is a huge gap between the economics of climate change and its applications to RIAMs. As an application, this paper examines the effect of social welfare functions on optimal solutions of the RICE (Regional Integrated model of Climate and the Economy) model. It is found that optimal climate policy such as carbon tax or emissions control rate is very sensitive to the assumptions on social welfare functions of RIAMs. It is better for each country to have their own RIAM as a basic tool for national climate policy-making and for international bargaining in greenhouse-gas mitigation. This is because a country`s own preferences such as efficiency, equity, and sustainable development as well as national circumstances can be reflected in RIAM. The Republic of Korea has not developed its own RIAM yet. The comparative analysis and the numerical model in this paper can be a stepping stone for the development of such a national model.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1997)

김재홍,문득곤,김정수,김용준,임동진,박상훈,김희성,이민수,송기훈,김갑형,김형석,성소영,이인섭,김석우,황지환,조창근,김경문,부태성 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.3

Background : In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. Objective & Methods : For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1997. 99 strains of N. gonorrhoeae were isolated, among which 45(45.5%) were PPNG. Conclusion : The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 45.5% in 1997.

Bacillus thuringiensis var. darmstadiensis 와 var. sotto의 내독소와 Bacillus thuringiensis var. kurstaki가 생산하는 아밀라제의 연구

이형환,김삼찬,황광현,임창로,조용칠,정인명 건국대학교 교육대학원 1991 敎育論叢 Vol.15 No.-

Endotoxin crystals produced by B.thuringiensis var. darmstadiensis cultured in modified GYS medium over 72 h were ovoidal in shape and separated using Renografin gradient centrifugation. The crystal protein bands were observed. When B.thuringiensis var sotto was grown in the modified GYS broth, it entered stationary phase at 8-9 h after inoculation. Proteinaceous crystals were banded at the position in 40% of Renografin gradient. The solubilized crystal proteins were formed by two bands, 130 Kd and 68 Kd in the SDS-PAGE. One plasmid was observed in B.thuringiensis var darmstadiensis and no plasmid in var. sotto in this study. Enzyme activity of amylase produced B.thuringiensis var kurstaki strain in the basal medium was 0.4 units per ml, and was enhanced to 0.6 units per ml in the basal medium contained soluble starch, Ca^++, Mg^++ and Mn^++ ions. Amylase production medium containing soluble starch was suitable for the amylase production and the highest activity appeared at 4-6 h after cultivation at 32℃. The amylase activity obtained by ethanol precipitation was 0.20 units per ml in 0.1 M phosphate buffer. The band of the molecular weight of 50 Kd was observed by SDS-PAGE analysis. Km value of the amylase for the soluble starch was 6.80 mg per ml.