• Title/Summary/Keyword: Event Studies

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The Influence of Obstructive Sleep Apnea on Systemic Blood Pressure, Cardiac Rhythm and the Changes of Urinary (폐쇄성 수면 무호흡이 전신성 혈압, 심조율 및 요 Catecholamines 농도 변화에 미치는 영향)

  • Lo, Dae-Keun;Choi, Young-Mee;Song, Jeong-Sup;Park, Sung-Hak;Moon, Hwa-Sik
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.153-168
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    • 1998
  • Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

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The Audience Behavior-based Emotion Prediction Model for Personalized Service (고객 맞춤형 서비스를 위한 관객 행동 기반 감정예측모형)

  • Ryoo, Eun Chung;Ahn, Hyunchul;Kim, Jae Kyeong
    • Journal of Intelligence and Information Systems
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    • v.19 no.2
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    • pp.73-85
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    • 2013
  • Nowadays, in today's information society, the importance of the knowledge service using the information to creative value is getting higher day by day. In addition, depending on the development of IT technology, it is ease to collect and use information. Also, many companies actively use customer information to marketing in a variety of industries. Into the 21st century, companies have been actively using the culture arts to manage corporate image and marketing closely linked to their commercial interests. But, it is difficult that companies attract or maintain consumer's interest through their technology. For that reason, it is trend to perform cultural activities for tool of differentiation over many firms. Many firms used the customer's experience to new marketing strategy in order to effectively respond to competitive market. Accordingly, it is emerging rapidly that the necessity of personalized service to provide a new experience for people based on the personal profile information that contains the characteristics of the individual. Like this, personalized service using customer's individual profile information such as language, symbols, behavior, and emotions is very important today. Through this, we will be able to judge interaction between people and content and to maximize customer's experience and satisfaction. There are various relative works provide customer-centered service. Specially, emotion recognition research is emerging recently. Existing researches experienced emotion recognition using mostly bio-signal. Most of researches are voice and face studies that have great emotional changes. However, there are several difficulties to predict people's emotion caused by limitation of equipment and service environments. So, in this paper, we develop emotion prediction model based on vision-based interface to overcome existing limitations. Emotion recognition research based on people's gesture and posture has been processed by several researchers. This paper developed a model that recognizes people's emotional states through body gesture and posture using difference image method. And we found optimization validation model for four kinds of emotions' prediction. A proposed model purposed to automatically determine and predict 4 human emotions (Sadness, Surprise, Joy, and Disgust). To build up the model, event booth was installed in the KOCCA's lobby and we provided some proper stimulative movie to collect their body gesture and posture as the change of emotions. And then, we extracted body movements using difference image method. And we revised people data to build proposed model through neural network. The proposed model for emotion prediction used 3 type time-frame sets (20 frames, 30 frames, and 40 frames). And then, we adopted the model which has best performance compared with other models.' Before build three kinds of models, the entire 97 data set were divided into three data sets of learning, test, and validation set. The proposed model for emotion prediction was constructed using artificial neural network. In this paper, we used the back-propagation algorithm as a learning method, and set learning rate to 10%, momentum rate to 10%. The sigmoid function was used as the transform function. And we designed a three-layer perceptron neural network with one hidden layer and four output nodes. Based on the test data set, the learning for this research model was stopped when it reaches 50000 after reaching the minimum error in order to explore the point of learning. We finally processed each model's accuracy and found best model to predict each emotions. The result showed prediction accuracy 100% from sadness, and 96% from joy prediction in 20 frames set model. And 88% from surprise, and 98% from disgust in 30 frames set model. The findings of our research are expected to be useful to provide effective algorithm for personalized service in various industries such as advertisement, exhibition, performance, etc.

Effects of Customers' Relationship Networks on Organizational Performance: Focusing on Facebook Fan Page (고객 간 관계 네트워크가 조직성과에 미치는 영향: 페이스북 기업 팬페이지를 중심으로)

  • Jeon, Su-Hyeon;Kwahk, Kee-Young
    • Journal of Intelligence and Information Systems
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    • v.22 no.2
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    • pp.57-79
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    • 2016
  • It is a rising trend that the number of users using one of the social media channels, the Social Network Service, so called the SNS, is getting increased. As per to this social trend, more companies have interest in this networking platform and start to invest their funds in it. It has received much attention as a tool spreading and expanding the message that a company wants to deliver to its customers and has been recognized as an important channel in terms of the relationship marketing with them. The environment of media that is radically changing these days makes possible for companies to approach their customers in various ways. Particularly, the social network service, which has been developed rapidly, provides the environment that customers can freely talk about products. For companies, it also works as a channel that gives customized information to customers. To succeed in the online environment, companies need to not only build the relationship between companies and customers but focus on the relationship between customers as well. In response to the online environment with the continuous development of technology, companies have tirelessly made the novel marketing strategy. Especially, as the one-to-one marketing to customers become available, it is more important for companies to maintain the relationship marketing with their customers. Among many SNS, Facebook, which many companies use as a communication channel, provides a fan page service for each company that supports its business. Facebook fan page is the platform that the event, information and announcement can be shared with customers using texts, videos, and pictures. Companies open their own fan pages in order to inform their companies and businesses. Such page functions as the websites of companies and has a characteristic of their brand communities such as blogs as well. As Facebook has become the major communication medium with customers, companies recognize its importance as the effective marketing channel, but they still need to investigate their business performances by using Facebook. Although there are infinite potentials in Facebook fan page that even has a function as a community between users, which other platforms do not, it is incomplete to regard companies' Facebook fan pages as communities and analyze them. In this study, it explores the relationship among customers through the network of the Facebook fan page users. The previous studies on a company's Facebook fan page were focused on finding out the effective operational direction by analyzing the use state of the company. However, in this study, it draws out the structural variable of the network, which customer committment can be measured by applying the social network analysis methodology and investigates the influence of the structural characteristics of network on the business performance of companies in an empirical way. Through each company's Facebook fan page, the network of users who engaged in the communication with each company is exploited and it is the one-mode undirected binary network that respectively regards users and the relationship of them in terms of their marketing activities as the node and link. In this network, it draws out the structural variable of network that can explain the customer commitment, who pressed "like," made comments and shared the Facebook marketing message, of each company by calculating density, global clustering coefficient, mean geodesic distance, diameter. By exploiting companies' historical performance such as net income and Tobin's Q indicator as the result variables, this study investigates influence on companies' business performances. For this purpose, it collects the network data on the subjects of 54 companies among KOSPI-listed companies, which have posted more than 100 articles on their Facebook fan pages during the data collection period. Then it draws out the network indicator of each company. The indicator related to companies' performances is calculated, based on the posted value on DART website of the Financial Supervisory Service. From the academic perspective, this study suggests a new approach through the social network analysis methodology to researchers who attempt to study the business-purpose utilization of the social media channel. From the practical perspective, this study proposes the more substantive marketing performance measurements to companies performing marketing activities through the social media and it is expected that it will bring a foundation of establishing smart business strategies by using the network indicators.

An Examination into the Illegal Trade of Cultural Properties (문화재(文化財)의 국제적 불법 거래(不法 去來)에 관한 고찰)

  • Cho, Boo-Keun
    • Korean Journal of Heritage: History & Science
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    • v.37
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    • pp.371-405
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    • 2004
  • International circulation of cultural assets involves numerous countries thereby making an approach based on international law essential to resolving this problem. Since the end of the $2^{nd}$ World War, as the value of cultural assets evolved from material value to moral and ethical values, with emphasis on establishing national identities, newly independent nations and former colonial states took issue with ownership of cultural assets which led to the need for international cooperation and statutory provisions for the return of cultural assets. UNESCO's 1954 "Convention for the Protection of Cultural Property in the Event of Armed Conflict" as preparatory measures for the protection of cultural assets, the 1970 "Convention on the Means of Prohibiting and Preventing the Illicit Import and Transfer of Ownership of Cultural Property" to regulate transfer of cultural assets, and the 1995 "Unidroit Convention on Stolen or Illegally Exported Cultural Objects" which required the return of illegally acquired cultural property are examples of international agreements established on illegal transfers of cultural assets. In addition, the UN agency UNESCO established the Division of Cultural Heritage to oversee cultural assets related matters, and the UN since its 1973 resolution 3187, has continued to demonstrate interest in protection of cultural assets. The resolution 3187 affirms the return of cultural assets to the country of origin, advises on preventing illegal transfers of works of art and cultural assets, advises cataloguing cultural assets within the respective countries and, conclusively, recommends becoming a member of UNESCO, composing a forum for international cooperation. Differences in defining cultural assets pose a limitation on international agreements. While the 1954 Convention states that cultural assets are not limited to movable property and includes immovable property, the 1970 Convention's objective of 'Prohibiting and preventing the illicit import, export and transfer of ownership of cultural property' effectively limits the subject to tangible movable cultural property. The 1995 Convention also has tangible movable cultural property as its subject. On this point, the two conventions demonstrate distinction from the 1954 Convention and the 1972 Convention that focuses on immovable cultural property and natural property. The disparity in defining cultural property is due to the object and purpose of the convention and does not reflect an inherent divergence. In the case of Korea, beginning with the 1866 French invasion, 36 years of Japanese colonial rule, military rule and period of economic development caused outflow of numerous cultural assets to foreign countries. Of course, it is neither possible nor necessary to have all of these cultural properties returned, but among those that have significant value in establishing cultural and historical identity or those that have been taken symbolically as a demonstration of occupational rule can cause issues in their return. In these cases, the 1954 Convention and the ratification of the first legislation must be actively considered. In the return of cultural property, if the illicit acquisition is the core issue, it is a simple matter of following the international accords, while if it rises to the level of diplomatic discussions, it will become a political issue. In that case, the country requesting the return must convince the counterpart country. Realizing a response to the earnest need for preventing illicit trading of cultural assets will require extensive national and civic societal efforts in the East Asian area to overcome its current deficiencies. The most effective way to prevent illicit trading of cultural property is rapid circulation of information between Interpol member countries, which will require development of an internet based communication system as well as more effective deployment of legislation to prevent trading of illicitly acquired cultural property, subscription to international conventions and cataloguing collections.

Edge to Edge Model and Delay Performance Evaluation for Autonomous Driving (자율 주행을 위한 Edge to Edge 모델 및 지연 성능 평가)

  • Cho, Moon Ki;Bae, Kyoung Yul
    • Journal of Intelligence and Information Systems
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    • v.27 no.1
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    • pp.191-207
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    • 2021
  • Up to this day, mobile communications have evolved rapidly over the decades, mainly focusing on speed-up to meet the growing data demands of 2G to 5G. And with the start of the 5G era, efforts are being made to provide such various services to customers, as IoT, V2X, robots, artificial intelligence, augmented virtual reality, and smart cities, which are expected to change the environment of our lives and industries as a whole. In a bid to provide those services, on top of high speed data, reduced latency and reliability are critical for real-time services. Thus, 5G has paved the way for service delivery through maximum speed of 20Gbps, a delay of 1ms, and a connecting device of 106/㎢ In particular, in intelligent traffic control systems and services using various vehicle-based Vehicle to X (V2X), such as traffic control, in addition to high-speed data speed, reduction of delay and reliability for real-time services are very important. 5G communication uses high frequencies of 3.5Ghz and 28Ghz. These high-frequency waves can go with high-speed thanks to their straightness while their short wavelength and small diffraction angle limit their reach to distance and prevent them from penetrating walls, causing restrictions on their use indoors. Therefore, under existing networks it's difficult to overcome these constraints. The underlying centralized SDN also has a limited capability in offering delay-sensitive services because communication with many nodes creates overload in its processing. Basically, SDN, which means a structure that separates signals from the control plane from packets in the data plane, requires control of the delay-related tree structure available in the event of an emergency during autonomous driving. In these scenarios, the network architecture that handles in-vehicle information is a major variable of delay. Since SDNs in general centralized structures are difficult to meet the desired delay level, studies on the optimal size of SDNs for information processing should be conducted. Thus, SDNs need to be separated on a certain scale and construct a new type of network, which can efficiently respond to dynamically changing traffic and provide high-quality, flexible services. Moreover, the structure of these networks is closely related to ultra-low latency, high confidence, and hyper-connectivity and should be based on a new form of split SDN rather than an existing centralized SDN structure, even in the case of the worst condition. And in these SDN structural networks, where automobiles pass through small 5G cells very quickly, the information change cycle, round trip delay (RTD), and the data processing time of SDN are highly correlated with the delay. Of these, RDT is not a significant factor because it has sufficient speed and less than 1 ms of delay, but the information change cycle and data processing time of SDN are factors that greatly affect the delay. Especially, in an emergency of self-driving environment linked to an ITS(Intelligent Traffic System) that requires low latency and high reliability, information should be transmitted and processed very quickly. That is a case in point where delay plays a very sensitive role. In this paper, we study the SDN architecture in emergencies during autonomous driving and conduct analysis through simulation of the correlation with the cell layer in which the vehicle should request relevant information according to the information flow. For simulation: As the Data Rate of 5G is high enough, we can assume the information for neighbor vehicle support to the car without errors. Furthermore, we assumed 5G small cells within 50 ~ 250 m in cell radius, and the maximum speed of the vehicle was considered as a 30km ~ 200 km/hour in order to examine the network architecture to minimize the delay.

Correlates of Subjective Well-being in Korean Culture (한국문화에서 주관안녕에 영향을 미치는 사회심리 요인들)

  • Hahn, Doug-Woong
    • Korean Journal of Culture and Social Issue
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    • v.12 no.5_spc
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    • pp.45-79
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    • 2006
  • The purpose of this paper was to review the results of the subjective well-being(swb) studies performed by Hahn and coworkers in Korean culture. As the correlates of swb, we dealt with demographic/individual difference variables, intrapersonal variables, interpersonal process variables, and Korean cultural variables. We proposed that the components of swb were consisted of quality of life(cognitive swb) and overall happy feelings about one's own life(emotional swb). It was also assumed that a measure of total swb could be calculated by summated mean of cognitive swb and emotional swb measures. The data of the swb studies were analyzed and interpreted according to the above three measures of swb. The results of a nationwide survey(Hahn, 2004) from age of 19 to 75 years ald(n=2,230) showed significant simple correlation coefficients between the following demographic/individual difference variables and swb: Gender difference in swb was found(total swb r=.08, p<.001; life satisfaction r=.10, p<.001; overall emotional swb r=.05, p<.05). Men were happier than women in terms of all three measures of swb. It was also found that women appeared to experience greater positive and negative emotions. Correlation between age and emotional swb(r=.09, p<.001) was significant, but life satisfaction was not significant(r=.04, n.s). Correlations between economic status and swb were also significant(total swb r =.23, p<.001; life satisfaction r=.15 p<.001; overall emotional swb r=.15, p<.001l). Although existence of father was negatively related to emotional swb(r=-.05, p<.05), the existence of mother was not related to any of swb measures. Similarly existence of brothers was related positively to overall emotional swb, but existence of sisters was not. Though existence of son was not related to swb, daughter contributed negatively to swb(total swb -.12, p<.01; life satisfaction -.09, p<.05; emotional swb r=-.12, p<.01). We assumed that family member-in-Iaw also contributed to swb because the extended dose social networks were important in Korean culture. The results showed that the following family member-in-law variables were related to swb: Parents-in-law(total swb r=.11, p<.01; life satisfaction r=.10, p<.01; emotional swb r=.10, p<.01), father-in-law(total swb r=.11, p<.01; life satisfaction r=.11, p<.01; emotional swb r=.06, n.s). The result suggested that especially father-in-law contributed to swb through financial and social support. Correlations between emotional experiences in everyday life and swb were also presented. The range of correlation coefficients between the positive emotion measures and swb were r=.30~.48(p<.001) when the above two measures obtained at same time. But the range decreased to r=.19~32(p<.001) when the swb measure was obtained 9 month later longitudinally. Intercorrelations between positive emotional experience; and life satisfaction were r=.37~58(p<.001) when two measures were obtained at same time. We also examined the effects of the intrapersonal cognitive responses to the most stressful life event upon swb. The results of nationwide survey(n=1,021) showed that self-disclosure(total swb r=.09, p<.010; life satisfaction r=.10, p<.01; emotional swb r=.07, p<.01), rumination(total swb r=-.17, p<.001), thought avoidance(total swb r=.12, p<.001; life satisfaction r=-.08; emotional swb r=-.12, p<.001) and suppression(total swb r=-.13, p<.001; life satisfaction r=-.08, p<.05: emotional swb r=-.13, p<.001) contributed to swb. It was also suggested that mismatch between self-guide and regulatory focus contributed negatively to emotional swb. It was also found that social comparison motives and fulfillment of the motives contributed to swb. The results of a survey research(n=363 college students) revealed that the higher the general social comparison motive, the lower the swb(total swb r=-.15, P<.01: life satisfaction r=-.17. p<.01; emotional swb r=-.10, p<.05). It was also found that satisfaction level of self-evalution motive contributed positively to swb(total swb r=-.14. p<.01: life satisfaction r=-.12, p<.05; emotional swb r=.15, p<.001). Both of self-improvement motive(r=.13, p<.05) and satisfaction level of self-improvement motive(r=.12, p<.05) contributed positively to emotional swb, respectively. The above results suggested that swb was depended upon the interaction effect of social comparison motive; and level of fulfillment of the motives. We also reported the significant multiple predictors of swb in a sample of age from 60years to 89years olds. The results of multiple regression analysis showed that the significant multiple predictors of swb were past illness(β=.174, p<.001), economic status(β=.418, p<.001), marital satisfaction(β=.0841, p<.001), satisfaction of offsprins(β=.065, p<.01), expectation level of social support from offsprings(β=-.049, p<.001), and negative emotions(β=-.454. p<.001) among 16 social psychological factors. It was also found that swb was an important multiple predictors of physical health. This finding was replicated in a longitudinal study. Both of positive and negative emotional experiences were significant multiple predictors of physical health one year later. The results of the discriminant analysis showed both of total swb and positive emotional experiences contributed to discriminate the happy and healthy olds from unhappy and unhealthy olds. We paper also examined the effects of the nonnative social behaviors upon swb in Korean culture. The main hypotheses of the study(Hahn, 2006, in press) was that the important nonnative behaviors would influence on swb through both of the mediation processes of adjustment to social relationships and psychological stress. The survey data were collected from 2,129 adults age of 19 to 75, from 7 regional areas in Korea. The results of the study revealed that almost all of correlation coefficients between 15 normative social behaviors and the above three criteria w-ere significant. The fitness test results of the covariance structural equation model showed that all of the fitness indices were satisfactory (GFI=.974, AGFI=.909, NNFI=.922, NFI=.973, CFI=.974. RMR=.049, RMSEA=.073). The results of the analysis revealed that the following five path coeffi6ents from behaviors to social adjustment were significant; behavior tor family and family members(t=5.87, p<.001), courteous behavior(t=4.39, p<.001), faithful behavior (t=2.15. p<.05). collectivistic behavior(t=8.31, p<.001). Seven path coefficients from the normative behaviors to psychological stress were significant; behavior for family and family members (t=-4.63, p<.001), faithful behavior(t=-3.86, p<.001). suppression of emotional expression(t=3.99, p<.001), trustworthy and dependable behavior(t=-2.21, p<.05), collectivistic behavior(t=3.72, p<.001), effortful and diligent behavior(t=2.94, p<.001), husbandry and saving behavior(t=3.40, p<.001). The above results suggested that four normative behaviors among seven behaviors contributed negatively to psychological stress in current Korean society. The results abo confirmed the hypothesized paths from social adjustment (t=10.40, p<.001) to swb and from psychological stress(t=-19.74, p<.001) to swb. The important results of the study were discussed in terms of the Confucian traditions and recent social changes in Korean culture. Finally limitations of this review paper were discussed and the suggestions for the future study were also proposed.

A Randomized, Double-Blind Study to Assess the Efficacy and Safety of Oral LB20304 (Gemifloxacin) at Doses of 160mg or 320mg (Equivalent to 200mg or 400mg of the Mesylate Salt) Once Daily for 7 Days for the Treatment of Acute Exacerbations of Chronic Bronchitis (AECB) in Korean Adult Population (한국인에서 만성기관지염의 급성악화를 치료하기 위한 LB20304(Gemifloxacin) 160mg 또는 320mg 1일 1회 7일간 투여의 유효성과 안전성에 대한 연구)

  • Kim, Young Whan;Shim, Young-Soo;Kim, Won Dong;Shim, Tae Sun;Kang, Hong Mo;Choi, ByoungWhui;Kim, Jae-Yeol;Kwon, O Jung;Kim, Hojoong;Kim, Ju Ock;Jung, Ki-Suck;Hyeon, In Gyou;Mo, Eun Kyung;Lee, Seung-Joon;Nam, Gui Hyun;Lee, Kye Young;Park, Jae Seuk
    • Tuberculosis and Respiratory Diseases
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    • v.55 no.1
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    • pp.69-87
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    • 2003
  • Background : LB20304(gemifloxacin) is a new fluoroquinolone antibacterial agent with excellent activity against both Gram-negative and Gram-positive organisms. In vitro studies using clinical isolates have shown gemifloxacin to be highly active against penicillin-resistant strains of S. pneumoniae and in contrast to other reference quinolones, gemifloxacin retained good activity against clinical isolates of S. pneumoniae that were resistant to other members of the quinolone class. Therefore, gemifloxacin is thought to be effective in treating acute bacterial exacerbation of chronic bronchitis(AECB). The objective of this study was to evaluate the efficacy and safety of oral gemifloxacin at doses of 160mg or 320mg once daily for 7 days for the treatment of AECB in Korean adult population. Methods : This was a randomized, multicenter, double-blind, parallel group Phase II study to assess the clinical and antibacterial efficacy and safety of oral gemifloxacin for the treatment of AECB. Treatment Group A (67 patients) took oral gemifloxacin 160mg once daily for seven days and treatment Group B (70 patients) took oral gemifloxacin 320mg once daily for seven days. Results : The demographic profiles of the two treatment groups were similar. The clinical response at follow-up was 84.2% in the gemifloxacin 160-mg group, and 88.7% in the gemifloxacin-320 mg group, showing no statistically significant difference between two treatment groups(p=0.49). The clinical response at the end of therapy was 96.5% in the 160-mg group, and 96.4% in the 320-mg group. The bacteriological response at the end of therapy and follow-up were 81.8% and 78.9%, respectively, in the 160-mg group, and 86.4% and 84.2%, respectively, in the 320-mg group, showing no statistically significant difference between two treatment groups(p=0.68 and 0.68, respectively). S. pneumoniae(12 isolates) and H. influenzae(10 isolates) were the most prevalent pathogens. The MICs were lower for gemifloxacin than other quinolones against these key pathogens, and for S. pneumoniae, the MICs for gemifloxacin were considerably lower(${\leq}0.03$ ug/mL) than those for other quinolones, beta-lactams and macrolides. In the period on-therapy plus 30 days post-therapy, a total of 18 patients(26.9%) in the gemifloxacin 160mg group and 22 patients(31.4%) in the 320mg group reported at least one adverse event(AE). The most frequently reported AE was abdominal pain(3/67 patients, 4.5%) in the gemifloxacin 160mg group and increased level of hepatic enzyme(5/70 patients, 7.1%) in the 320mg group. The overall AE profiles for the two treatment groups were similar. Two out of 67 patients(3.0%) in the gemifloxacin 160mg group and 1/70 patients(1.4%) in the 320mg group reported at least one serious AE, however, none of which was considered by the investigator to be of suspected or probable relationship to study medication. Conclusion : The results of this study showed that gemifloxacin at doses of 160mg or 320mg once daily for 7 days in the treatment of acute exacerbations of chronic bronchitis(AECB) in adult Koreans was a very effective and safe treatment both clinically and bacteriologically.