• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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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.

• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.82-89
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• 2000

This study analyzes the cell loss probability of an ATM multiplexer with real time and non-real time bursty traffics. It is assumed that an ATM multiplexer with loss priority control for the analysis. The loss priority control uses the CLP Reld of cell header. For easy analysis and less computation. the multiplexed traffic of the ATM multiplexer was modeled by the MMDP. The ATM multiplexer is simulated by the MMDP/MMDP/l/K queueing system. From the above results, The connection admission of an ATM multiplexer with loss priority control is determined by the cell loss probability with low priority as well as the size of threshold buffer. Therefore, to increase the statistical multiplexing gain it will be good to utilize the loss priority control in order.

• BMB Reports
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• v.38 no.3
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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.

• Korean Journal of Cleft Lip And Palate
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• v.3 no.2
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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.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.2
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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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• v.50 no.5
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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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• v.36 no.5
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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.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.63-69
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• 2001

Cleft lip and/or palate(CLP) is the most common congenital deformity in the craniofacial region. For a practical public health system for these patients it is necessary to have an understanding on the prevalence of CLP. However, it was difficult to estimate the exact number of CLP patients due to problems in sample selection, higher miscarriage and still birth rate, difficulty in classification, and adoptions to foreign countries. Therefore this study was to estimate the prevalence of CLP and the rate of orthodontic treatment, which is usually necessary in cleft lip and/or palate patients. The samples consisted of 218,322 Korean male adults from Seoul, Kwangju, Taegu and Pusan, all born in 1979. The screening method for recognizing the CLP patients was proceeded in steps and the results are as follows. 1. The prevalence of cleft lip and/or palate in Korean male adults born in 1979 was 0.65 out of the 1000 samples. 2. In the anteroposterior aspect of the 1000 samples, the prevalence of cleft lip, cleft lip and palate, and cleft palate was 0.26, 0.36 and 0.03 respectively. 3. In the transverse aspect of the 1000 samples, the prevalence of left, right and bilateral cleft was 0.35, 0.16, 0.12 respectively. The cleft in the left showed a much higher prevalence than in the rirht, while bilateral cleft showed a lower prevalence than unilateral cleft. 4. The orthodontic treatment rate of Korean male adults among cleft lip and/or palate Patients was $35\%$, and it was in the order of cleft lip and Palate, cleft lip, and cleft Palate, being $67\%,\;29\%\;and\;29\%$ respectively. The orthodontic treatment rate in patients with the more severe cleft lip and palate was higher than in patients solely having cleft lip or cleft palate.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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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.

• Proceedings of the PSK Conference
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• 2002.10a
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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)