Transthyretin의 Glutathione 자동산화 촉진작용

박종근,정신,김재휴,김수한,강삼석,이제혁,안봉환 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.8

When reduced glutathione(GSH) was incubated at neutral pH and at 37°, its concentration decreased slowly with formation of oxidized glutathione(GSSG). Autooxidation of GSH was accelerated by Cu^(2+) and Hg^(2+), but not by other common mono-, di-, and tri-valent cations. Transthyretin was found to stimulate autooxidation of GSH in the presence or absence of Cu^(2+) and Hg^(2+). EDTA inhibited perfectly the autooxidation of GSH regardless of the presence of transthyretin. The stimulating activity of transthyretin was maximal at pH 7.0, declining progressively with increase or decrease of pH from 7.0. Sulfhydryl-blocking agents such as p-hydroxymercuribenzoic acid and Nethylmaleimide markedly inhibited the stimulating activity of transthyretin. Transthyretin stimulated autooxidation of other sulfhydryl compounds such as clithiothreitol and cysteine. However, it did not show a significant effect on autooxidation of sulfhydryl group of egg albumin and eye lens proteins. And transthyretin did not cause any oxidative change to thyroxine(T₄), 3, 5, 3Ltri iodo thyronine(T₃) and 3, 3: 5~triiodothpnine(rT₃) bound to it in the presence of GSH and Cu^(2+). The above results suggest that transthyretin may play a role in regulation of oxidized status of sulfhydryl groups in blood plasma and cerebrospinal fluid

직접 황 회수공정에서 Ce_(1-x)Zr_(x)O₂촉매를 이용한 반응특성 연구 : H₂O 와 석탄가스의 영향 Effect of H₂O and Coal Gas

김봉석,이종대,전진혁,박노국,류시옥,이태진,김재창 한국화학공학회 2004 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.42 No.2

본 연구는 직접 황 회수공정에서 H_(2)O와 석탄가스의 영향에 대해서 조사하였다. Ce_(0.8)Zr_(0.2)O_(2)촉매를 이용하여 H_(2)O가 반응에 미치는 영향을 조사한 결과, 산화제인 H_(2)O의 첨가에 의해 반응가스의 환원력이 저하됨을 알 수 있었다. CO/H_(2)O-TRP 실험을 통해서는 반응온도 영역에서 water gas shift 반응이 일어나는 것을 확인 할 수 있었고, H_(2)O의 재산화 실험으로부터 환원된 촉매가 H_(2)O에 의해 재산화 됨을 알 수 있었다. Ce_(0.8)Zr_(0.2)O_(2) 촉매하에서 석탄가스를 환원제로 사용하여 반응온도 (500℃), 공간속도(30,000 ㎖/g-catㆍh), [CO+H_(2)]/[SO_(2)] 몰비(2.5)의 반응조건에서 실험한 결과 최대 75.8%의 원소 황 수율을 얻을 수 있었다. 이는 환원제로 석탄가스를 이용함으로써 H_(2)O에 의한 부반응을 억제할 수 있었으며 경제적인 측면에서 유리하므로 공정기술의 실증화 가능성을 향상시킬 수 있음을 확인할 수 있었다. The effect of H₂O and coal gas on a direct sulfur recovery process using Ce_(1-x)Zr_(x)O₂ catalysts was investigated in this study. As the reducing power of reactants was lowered in the present of H₂O, the activity of catalysts decreased. Temperature programmed reduction experiments showed that a water gas shift reaction took place in the temperature range of this study and that the reduced catalyst was re-oxidized by H₂O. DSRP was carried out on Ce_(1-x)Zr_(x)O₂ catalysts using a coal gas as a reductant. Maximum 76.8% yield of elemental sulfur was obtained at 500℃ with a space velocity of 30,000㎖/g-cat·h and [CO+H₂]/[SO₂] ratio of 2.5. The side reaction by H₂O could be inhibited using a coal gas.

유전자 재조합 사람 IFN-beta인 제네베타와 베네세린의 생물학적 활성의 비교

하종천,이협준,박봉환,김진숙,유대근,남상윤 전주대학교 자연과학종합연구소 2003 전주대학교 자연과학연구소 학술논문집 Vol.15 No.1

Background: Recombinant IFN-beta products have been approved for the treatment of several diseases. Recently, Inbionet, Co. has successfully developed rhIFN-beta product, Genebeta. This study was performed in a purpose of confirming the biological activity of Genebeta by comparison with another recombinant IFN-beta, Beneserin which was already approved. Methods: In vitro antiporliferative activity, regulation of MHC class I expression, antiviral activity, regulation of natural killer cell cytotoxicity were studied for functional comparison of these two rhIFN-beta products. Results: Proliferation assay data showed that two recombinant IFN-beta inhibited T cell and Daudi cell proliferation to a similar extent. When antiviral activity was compared, there was no significant difference between them. The treatment of these two rhIFN-beta also resulted in a similar level of upregulation of class I expression on the surface of A549 cells. Cytotoxicity experiment against tumor cells revealed that both of rhIFN-beta could enhance NK cell cytotoxicity to comparable level. Conclusion: All comparison data indicated that rhIFN-beta products, Genebeta and Beneserin have comparable potentials as a biological response modifier.

저열팽창성 Fe-29Ni-17Co 코바 합금의 고온균열 발생과 고온연성에 미치는 S 및 Mn의 영향

이기안,박종혁,조봉현,남궁정,김문철 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.12

The effect of S & Mn on the hot ductility of Fe-29Ni-17Co Kovar alloy and the mechanism of high temperature cracking occurrence were investigated. It has been found that the brittle intergranular fracture at high temperature cracking is closely associated with the sulfide along grain boundary. Experimental results showed, especially when the S content was high and the Mn content was free, that small cavities could be nucleated easily on FeS particles along grain boundary and propagated fast at high temperature. The hot ductility of Kovar alloy was drastically increased with the addition of Mn and it was also increased with decreasing S content. SEM and FE-SEM analyses showed that the Mn addition in this alloy could cause ductile intergranular fracture appearance below 1150℃ by the precipitation of MnS. It was proposed from the results that the addition of Mn and optimum S content (below 30 ppm) in Kovar alloy was necessary in order to reduce the hot cracking susceptibility.

Fe-Ni-Co 저열팽창성 합금의 고온 변형 특성 및 열간가공에 따른 열팽창 거동 연구

이기안,박종혁,조봉현,남궁정,김문철 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.9

The high temperature deformation behavior and the effect of hot compression on the thermal expansion behavior of Fe-29Ni-17Co low thermal expansion Kovar alloy were investigated in the compressive temperature range of 900~1300℃ at the strain rate range of 25~0.01 sec.^(-1). The temperature (T) and strain rate (ε˙) dependence of the flow stress (σ_(0.7)) could be well described by hyperbolic sine law as ε˙= A [sinh(0.0084 σ)^(5.2018)] exp(-330.41/RT). Surface hot cracking and significant voids around grain boundary could be found at low temperature below 1000℃ and low strain rate (0.01 sec.^(-1)). Thermal expansion coefficient α_(30~400) generally increased with increasing compressive temperature. Moreover, α_(30~400) remarkably increased as strain rate decreased at high temperature above 1100℃. However the thermal expansion coefficient α_(30~400) of low compressive temperatures (900℃ and 1000℃) anomalously increased especially at high strain rates. Experimental results indicated that not only α phase appearance but also grain size had definite influence on the thermal expansion behavior with hot deformation. The correlation between microstructure and thermal expansion behavior of Kovar alloy were also discussed.

담즙정체성 간염의 임상적 양상

최선택,은종렬,임상우,김봉준,이헌주,구미진,최준혁 영남대학교 기초/임상의학연구소 2001 Yeungnam University Journal of Medicine Vol.18 No.1

Background: Cholestatic hepatitis is failure of bile to reach the duodenum with hepatocellular damage and no demonstrable obstruction of the major bile ducts. The prognosis is usually good with recovery in less than 4 weeks after withdrawal of the offending drug. However, a prolonged course lasting over 3 months is possible and, in rare cases, progression to ductopenia with development of a vanishing bile duct syndrome occurs. A differential diagnosis with other causes of Chronic liver disease is needed. Materials and Methods: From January 1991 through Jaunary 2000, 14 patients diagnosed as cholestatic hepatitis by liver biopsy were inclouded. The possible causative drug, clinical features, laboatory findings, and progression of cholestatic hepatitis were evaluated. The semiquantitative study of liver lesions was performed by two independent observers. Results: Causes of cholestatic hepatitis are 5 cases of oriental medicine, 3 cases of anti-tuberculosis medication, 1 case of ticlopidine and antibiotics and 4 cases of unknown causes. The clinical features of cholestatic hepatitis were jaundice, itching, urine color change, and general weakness. During 6 to 30 months, LFT of 5 patients showed prolonged elevation. Elevated total cholesterol ≥250 mg/dL in 6 patients, pheripheral blood eosinophilia in 5 patients, auto-antibody positive in 6 patients were observed respectively. The biopsies showed intralobular bilirubinostasis with a mixed portal inflammatory infiltration. Conclusion: In cholestatic hepatitis. durations of abnormal LFT are variable regardless of causative drugs. If cholestatic hepatitis progresses toward chronic course, viral hepatitis, primary biliary cirrhosis, and autoimmune hepatitis should be differentially diagnosed and sequential liver biopsies are needed.

사람 뇌척수액중 Transthyretin의 항산화작용

양성렬,최기오,박종근,류문희,홍석노,김수한,안봉환,이제혁,이민화 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.4

Protective effects of human cerebrospinal fluid antioxidants against enzyme inactivation caused by metal-catalyzed oxidation systems were investigated. When purified glutamine synthetase(GS) was incubated with human cerebrospinal fluid(CSF), the enzyme was progressively inactivated. Catalase and EDTA could inhibit the enzyme inactivation by 50-80%. Small-molecular(Mr< -10,000) fraction of CSF inactivated the exogenous GS, but large-molecular(Mr> -10,000) fraction did not. The GS inactivation by the small-molecular fraction was also markedly inhibited by catalase and EDTA. These results suggested that metal-catalyzed oxidation is involved in the GS inactivation by the small-molecular fraction of CSF. Dithiothreitol(DTT) was shown to inhibit almost completely the oxidative inactivation of GS by CSF. However, DTT inhibited only partially the oxidative inactivation of GS caused by small-molecular fraction of CSF. When large-molecular fraction of CSF was separated by anion-exchange HPLC chromatogrpahy, there was a peak of antioxidant activity inhibiting the small-molecular fraction-induced GS inactivation in the presence of DTT. The antioxidant activity was neutralized by monoclonal antibodies to transthyretin. Purified transthyretin was found to efficiently inhibit ascorbate/Cu^(2+)-induced GS inactivation in the presence of DTT. Uric acid and glucose did not show any protective effect on the GS inactivation in the same condition. The above results suggest that metal-catalyzed oxidation occurs normally in human CSF, and that transthyretin may play an important role as a CSF antioxidant in protecting proteins from metal-catalyzed oxidation.

운동형태의 차이가 Alloxan유발 당뇨쥐의 혈당 및 인슐린 농도에 미치는 영향

윤진환,정일규,김종오,이희혁,지용석,오봉석,채정룡 대한스포츠의학회 2003 대한스포츠의학회지 Vol.21 No.1

The Purpose of this study was to investigate the effect of exercise intensity on blood glucose and insulin levels in diabetic rats with alloxan. Twenty sprague-dawley male rats were assigned to power training groups(n=10) and endurance training groups(n=10). Diabetes was induced by single injection of alloxan(50 mg/kg B.W) Blood glucose and insulin were determined every week for 4-weeks. The conclusion of this study follows as below: 1) There was significantly different on blood glucose levels in two groups. 2) There was significantly different on insulin levels in two groups These results suggest that proper exercise intensity in diabetic rats can significantly decrease blood glucose and insulin level and make good glycemic control. In conclusion, it has been found that regular prolonged endurance training with diabetic rats, improves insulin and blood glucose.

Supine Bicycle Ergometer 운동이 뇌파와 기분상태에 미치는 영향

윤진환,정일규,김영표,김종오,이희혁,오봉석,김창주 대한스포츠의학회 2003 대한스포츠의학회지 Vol.21 No.1

In this study we investigated the effects of supine ergometer exercise on physiological and psychological relaxation. Seven healthy young men(aged 24.4±2.00years) volunteered for the experiment. The experiment consisted of the following three successive segments" A pre-exercise period of 10 min, during which the subjects rested in a supine posture with their eyes closed for the final 5 min; an supine ergometer exercise period of approximately 10 min, during which the subjects performed intensity of 50%HRmax exercises; A post-exercise recovery of 5 min, and a recovery of 10 min, which was similar to the pre-exercise rest period. The electroencephalo-graphic(EEG) activity of the central cortex of the brain were measured pre-exercise, post-exercise 5 min, and recovery phase 10min. Fast Fourier Transformation of the EEG was used to obtain power spectrum areas in the delta(0.5~4 Hz), theta(4~8 Hz), alpha(8~13 Hz) and beta(13~30 Hz) frequencies. We compared the relative power values(power %) of the electroencephalogram alpha bands(8~13 Hz) and korean edition of the profile of mood states(K-POMS) before and after the supine ergometer exercise. We also estimated the percentage of maximal heart rate(%HRmax) throughout the experiment to ascertain the intensity of the supine bicycle ergometer exercise. The results of %HRmax indicated that the intensity of supine exercises practised in the experiments ranged from low to moderate. The power % of EEG alpha bands had increased significantly after the supine ergometer exercise compared with the pre-exercise rest(p<0.05). From the POMS results, we observed that positive mood(vigour) increased and negative mood(tension, depression, and total mood)decreased significantly after the supine ergometer exercise(p<0.05). This study found that the subjects showed increased physiological and psychological indices of relaxation after supine bicycle ergometer exercise.

중증 재생불량성 빈혈 환자에서 신우신염에 대한 광범위항생제치료 중에 속발한 Saccharomyces cerevisiae 진균감염 1예

김철희,이정호,이정찬,강정현,곽상혁,배광봉,김현수,김종숙,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

Most patients with aplastic anemia who do not respond to immunosuppressive treatment or are not candidates for bone marrow transplantation die of infection or bleeding. The neutropenia in acute leukemia, aplastic anemia, or occurring subsequently to chemotherapy and bone marrow transplantation increases susceptibility to infection. In general, the number of infectious episodes correlate with the degree and duration of neutropenia. Global immunosuppression produced by conditioning for bone marrow transplantation or graft-versus-host disease, is associated with unusual bacterial and fungal pathogens, or serious viral and protozoan infections. In addition, repeated treatment with broad-spectrum antibiotics is associated with the emergence of resistant organisms and fungal diseases because of the altered microbial microenvironment of the host. The incidence of invasive fungal infection caused by Saccharomycetes eerevisiae in immunosuppressed patients is very rare, compared with that of infection by candida or aspcrgillus species. Cases of Saccharomycetes cerevisiae fungemia occurring in the course of treatment with broad-spectrum antibiotics are reported in patients with extensive burn or with prosthetic valve endocarditis. We experienced a case of urinary tract infection by Saccharomycetes cerevisiae in a 27-year old female patient with severe aplastic anemia. We report the case with a review of relevant literatures.