• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.76-78
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• 2002

Heat shock proteins (HSPs) are induced in most living cells by mild heat treatment, ethanol, heavy metal ions and hypoxia. In yeast Saccharomyces cerevisiae, mild heat pretreatment strongly induces Hsp104 and thus provide acquired thermotolerance. The ability of hsp104 deleted mutant $({\triangle}hsp104)$ to acquire tolerance to extreme temperature is severely impaired. In providing thermotolerance, two ATP binding domains are indispensible, as demonstrated in ClpA and ClpB proteases of E. coli. The mechanisms by which Hsp104 protects cells from severe heat stress are not yet completely elucidated. We have investigated regulation of mitochondrial metabolic pathways controlled by the functional Hsp104 protein using $^{13}C_NMR$ spectroscopy and observed that the turnover rate of TCA cycle was enhanced in the absence of Hsp104. Production of ROS, which are toxic to kill cells radiply via oxidative stress, was also examined by fluorescence assay. Mitochondrial dysfunction was manifested in increased ROS levels and higher sensitivity for oxidative stress in the absence of Hsp104 protein expressed. Finally, we have identified mitochondrial complex I and Ferritin as binding protein(s) of Hsp104 by yeast two hybrid experiment. Based on these observations, we suggest that Hsp104 protein functions as a protector of oxidative stress via either keeping mitochondrial integrity, direct binding to mitochonrial components or regulating metal-catalyzed redox chemistry.

• 한국컴퓨터정보학회논문지
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• 제5권4호
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• pp.82-89
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• 2000

본 논문은 실시간과 비실시간 버스트 트래픽을 가진 ATM 멀티플렉서의 셀 손실율을 분석하였다. 분석을 위하여 손실 우선순위 제어를 가진 ATM 멀티플렉서를 가정하였으며, 손실 우선순위 제어는 셀 헤더의 CLP필드를 이용하였다. 분석을 쉽게 하고 계산을 간략히 하기 위하여, ATM멀티플렉서의 다중화된 트래픽은 MMDP로 모델링하였다. ATM 멀티플렉서는 MMDP/MMDP/l/K 큐잉 모델로 시뮬레이션하였다. 분석결과, 손실우선순위 제어를 가진 ATM 멀티플렉서의 연결 수락은 낮은 우선순위를 갖는 셀손실율에 의하여 결정될 뿐만 아니라, 한계 버퍼의 크기에 의해서 결정된다는 결론을 얻었다. 따라서, ATM 멀티플렉서는 통계적 다중화 이득을 증가하기 위해서 손실 우선순위 제어를 이용하는 것이 유리함을 알 수 있었다.

• BMB Reports
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• 제38권3호
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• pp.266-274
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• 2005

High temperature requirement A (HtrA) and its homologues constitute the HtrA familiy proteins, a group of heat shock-induced serine proteases. Bacterial HtrA proteins perform crucial functions with regard to protein quality control in the periplasmic space, functioning as both molecular chaperones and proteases. In contrast to other bacterial quality control proteins, including ClpXP, ClpAP, and HslUV, HtrA proteins contain no regulatory components or ATP binding domains. Thus, they are commonly referred to as ATP-independent chaperone proteases. Whereas the function of ATP-dependent chaperone-proteases is regulated by ATP hydrolysis, HtrA exhibits a PDZ domain and a temperature-dependent switch mechanism, which effects the change in its function from molecular chaperone to protease. This mechanism is also related to substrate recognition and the fine control of its function. Structural and biochemical analyses of the three HtrA proteins, DegP, DegQ, and DegS, have provided us with clues as to the functional regulation of HtrA proteins, as well as their roles in protein quality control at atomic scales. The objective of this brief review is to discuss some of the recent studies which have been conducted regarding the structure and function of these HtrA proteins, and to compare their roles in the context of protein quality control.

• 대한구순구개열학회지
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• 제3권2호
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• pp.67-73
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• 2000

The purpose of this survey was to obtain an overall view of the status of cleft lip and palate management in Oral and Maxillofacial Surgery(OMFS) in Korea. Korea Cleft lip and Palate Association conducted mailed survey which was composed of 29 questions conceming pre-operative and post-operative management in CLP surgery and completed by 58 training hospital. Of 58 questionnaires sent, 23 were returned(response rate of 40%). Authors compared this results with those of other similar surneys, which reveal much difference between OMFS and Plastic Surgery(PS) in CLP treatment. In OMFS, many surgeons were in favor of presugical orthopaedics than lip adhesion to manage protruded premaxilla. It reflects interdisciplinary team approach between OMFS and orthodontic department reduces the need of lip adhesion through presurgical orthopaedics. Timing of palatal surgery was later than that of PS, which reflects concern for an impediment of maxillaty growth. To our knowledge, this survey may be the first on organization and management for cleft patient in OMFS in Korea.

• 대한산업공학회지
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• 제25권2호
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• pp.162-172
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• 1999

For VBR video traffic, Motion-Picture Experts Group(MPEG) coding algorithm was adopted as the standard coding algorithm by International Telecommunication Union(ITU). In this paper, we propose a traffic model of an MPEG coded video traffic in frame level and cell level, and develop an approximate model for evaluating performance of a ATM multiplexer with homogeneous MPEG video sources by considering burst-level variation of aggregated traffics. For homogeneous MPEG video traffics which are frame-synchronized, the performance of the ATM multiplexer is influenced by source correlation at the multiplexing time. When sources are highly correlated, we decompose the aggregated cell streams by the frame-type and model multiplexing process during a frame time as n*D/D/1/K queueing model and suggest an approximate method for obtaining CLP of the ATM multiplexer. In the case that sources are highly correlated, the solution has the meaning of the upper bounds of performance of the ATM multiplexer. For the verification of our model, we compare the solution of our model with simulation resets. As the number of sources increases. The CLP obtained from our model approaches to simulation results, and gives upper bounds of simulation results.

• Archives of Plastic Surgery
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• 제50권5호
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• pp.468-477
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• 2023

Background This article describes the development of the Myanmar Articulation, Resonation, Nasal Emission, and Nasal Turbulence test for children with cleft lip and palate (CLP), and evaluation of its validity and reliability. Methods It was created by three Thai researchers and a Burmese research assistant based on Burmese phonology. The content validity was evaluated by six Burmese language experts. All test items were divided into three groups: high-pressure oral consonants, low-pressure oral consonants, and nasal consonants. Results All items (58-word and 32-phrase/sentence) gave an excellent level of the expert agreement (item-level content validity indexes = 1.00). The target items were illustrated as color pictures. Each picture was clearly drawn and easy to identify. As a pilot study of face validity, all pictures were administered to 10 typical-developing children. The actual testing was assessed by 10 CLP children, and the developed test was analyzed through consultation of the Burmese teachers and interpreters from a speech camp. Testing scores for a total including three groups of target items were shown acceptable for internal consistency reliability (ranged from 0.4 to 0.88). Conclusion The constructed test is valid in terms of its content.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.346-352
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• 2010

Introduction: Heat shock protein70 (HSP70) is a highly conserved family of proteins produced after a variety of stresses. Many studies reported that the overexpression of HSP70 can improve the prognosis of the patients with sepsis through a reduction of the nitric oxide concentration. However, these results only revealed the effect of HSP70 and nitric oxide. No studies have examined the relationship between HSP70 and nitric oxide. The aim of this study was to evaluate the effect of the overexpression of HSP70 on the expression of inducible nitric oxide synthase and the nitric oxide concentration. In addition, the mechanism of the relationship of HSP70 and inducible nitric oxide synthase (iNOS) in sepsis was examined. Materials and Methods: The experiments were performed on male sprague-dawley rats. Sepsis was induced by a cecal ligation and puncture (CLP). Glutamine (GLN) or saline was administered 1 hour after the initiation of sepsis. Serum and lung tissues were acquired from the rats 12 hours or 24 hours after the initiation of sepsis. The nitric oxide concentration, the expression of HSP70 in lung, and the gene expression of iNOS in lung were analyzed. The three groups, sham operation, CLP and CLP+GLN, were compared. Results: Compared to the other groups, in CLP+GLN, GLN administered after the initiation of sepsis enhanced the expression of HSP70 in the lung at 12 hours ($47.19{\pm}10.04$ vs. $33.22{\pm}8.28$, P=0.025) and 24 hours ($47.06{\pm}10.60$ vs. $31.90{\pm}4.83$, P=0.004). In CLP+GLN, GLN attenuated the expression of iNOS messenger RNA (mRNA) in the lung at 12 hours ($5,513.73{\pm}1,051.60$ vs. $4,167.17{\pm}951.59$, P=0.025) and 24 hours ($18,740.27{\pm}8,241.20$ vs. $9,437.65{\pm}2,521.07$, P=0.016), and reduced the concentration of nitric oxide in the serum at 12 hours ($0.86{\pm}0.48$ vs. $3.82{\pm}2.53$, P=0.016) and 24 hours ($0.39{\pm}0.25$ vs. $1.85{\pm}1.70$, P=0.025). Conclusion: The overexpression of HSP70 induced by the administration of GLN in sepsis attenuates the expression of the iNOS gene but reduces the nitric oxide concentration.

• 대한치과교정학회지
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• 제31권1호
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• pp.63-69
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• 2001

구순열 및 구개열은 두개 악안면 부위에서 가장 자주 발생되는 선천성 기형으로 적절한 의료진의 확보와 의료 정책의 수립을 위해서 정착한 환자 수를 파악하는 것이 필요하다. 그러나, 기존의 국내 발생률 추정 연구는 표본선정의 문제점과 이 질환이 갖는 높은 유산율과 사산율 및 다양한 형태로 인한 분류의 어려움과 한국 내에서의 특수성 중 하나인 장애아들의 해외 입양으로 인해 정확한 환자 수의 파악이 어려웠다. 따라서, 한국인에서의 체계적인 유병률 연구가 필요하리라 사료되며, 대부분의 구순열 및 구개열 환자에서 필요한 교정 치료의 수혜 정도를 파악할 필요성이 있다고 사료된다. 이에 본 연구에서는 한국 성인 남자에서 구순열 및 구개열 환자에 대한 유병률과 이들에 대한 교정치료 수혜율을 조사하고자, 1998년도 병무청 징병 검사자 중 1979년도에 출생한 자만을 연구대상으로 하여 서울, 광주, 대구 부산의 성인 남자 218,322명에 대해 3단계 검사를 실시한 후 다음과 같은 결과를 얻었다. 1. 1979년 생 한국 성인남자에서 구순열 및 구개열 환자의 유병률은 1000명당 0.65명이었다. 2. 전후방적 심도에 따라 1000명당 각각의 유병률은 구순열이 0.26명, 구순구개열이 0.36명,구개열이 0.03명이었다. 구순열과 구순구개열은 비슷한 정도의 유병률을 보였으나, 구개열은 이에 비해 낮은 유병률을 보였다. 3. 횡적 심도에 따라 1000명당 각각의 유병률은 좌측 파열이 0.35명, 우측 파열이 0.16명, 양측 파열이 0.12명이었다. 좌측 파열은 우측 파열에 비해 매우 뚜렷하게 높은 유병률을 보였으며, 양측 파열은 편측 파열에 비해 낮게 나타났다. 4. 구순열 및 구개열 환자 중 성인남자에서의 한국 내 교정치료 수혜율은 $35\%$였으며, 구순열, 구개열, 구순구개열의 순으로 $28\%,\;29\%\;67\%$였다. 구순열이나 구개열과 같이 단독 발생된 경우보다 파열의 심도가 심한 구순구개열의 경우에서 교정치료 수혜율이 높게 나타났다.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.571-582
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• 2020

Quorum sensing (QS)-mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1,000 ㎍/ml. Sub-MIC concentrations (250 and 500 ㎍/ml) of fungal extract reduced QS-regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipids (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signaling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 ㎍/ml, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 ㎍/ml) and 4-HPA (62.5 ㎍/ml), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.229-229
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• 2002

Although hepatocellular dysfunction occurs during sepsis. the mechanism responsible for this remains unclear. Since Kupffer cells provide signals that regulate hepatic response in endotoxin and inflammation. the aim of this study was to investigate the role of Kupffer cells in the alterations in the hepatic microsomal drug metabolizing function during sepsis. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP)followed by fluid resuscitation. (omitted)