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Showing papers by "Chung-Ang University published in 1998"


Journal ArticleDOI
TL;DR: A block-overlapped histogram equalization system for enhancing contrast of image sequences and has various applications such as video door phone, security video cameras, in addition to the original target video camcorders.
Abstract: In this paper we propose a block-overlapped histogram equalization system for enhancing contrast of image sequences. The proposed system has various applications such as video door phone, security video cameras, in addition to the original target video camcorders.

430 citations


Journal ArticleDOI
TL;DR: The results show that the proposed approach gives a prediction of the worst case cache-related preemption delay that is up to 60 percent tighter than those obtained from the previous approaches.
Abstract: We propose a technique for analyzing cache-related preemption delays of tasks that cause unpredictable variation in task execution time in the context of fixed-priority preemptive scheduling. The proposed technique consists of two steps. The first step performs a per-task analysis to estimate cache-related preemption cost for each execution point in a given task. The second step computes the worst case response time of each task that includes the cache-related preemption delay using a response time equation and a linear programming technique. This step takes as its input the preemption cost information of tasks obtained in the first step. This paper also compares the proposed approach with previous approaches. The results show that the proposed approach gives a prediction of the worst case cache-related preemption delay that is up to 60 percent tighter than those obtained from the previous approaches.

264 citations


Journal ArticleDOI
TL;DR: In men with premature ejaculation clomipramine was the most useful drug in terms of efficacy and treatment with sertraline was nearly as effective and had a lower incidence of side effects.

147 citations


Journal ArticleDOI
01 May 1998-Energy
TL;DR: A combination of exergetic and economic analysis for complex energy systems is proposed in this paper, where the exergy of a material stream is decomposed into thermal, mechanical and chemical exergy flows and an entropy-production flow and a unit exergy cost is assigned to each disaggregated exergy in the streams at any state.

120 citations


Journal ArticleDOI
TL;DR: In this paper, thin-film composite reverse osmosis membranes of polyamides were prepared by interfacial polymerization and showed the typical trade-off behavior between salt rejection and water flux.
Abstract: Thin-film composite reverse osmosis membranes of polyamides were prepared by interfacial polymerization. Various benzenediamines and poly(aminostyrene) were interfacially reacted with various acyl chlorides to prepare a skin layer of composite membranes. Among the membranes prepared from the structural isomeric monomers of benzenediamines and acyl chlorides, i.e., the same chemical composition but different in the position of functional groups on the aromatic ring, the membrane with the best salt rejection was obtained when the reacting groups forming amide are located at the same position on the aromatic ring. Membranes prepared by interfacially reacting various diamines with trimesoyl chloride revealed that the salt rejection depends on the linear chain structure of polyamides and network formed by crosslinking. Membranes obtained by interfacial polymerization of poly(aminostyrene) with trimesoyl chloride showed higher water flux but lower salt rejection than those obtained by interfacial polymerization of various benzenediamines with trimesoyl chloride. Membranes obtained here showed the typical trade-off behavior between salt rejection and water flux. However, membranes prepared by interfacially reacting trimesoyl chloride with a mixture of poly(aminostyrene) and m-phenylenediamine or a mixture of poly(aminostyrene), m-phenylenediamine, and diaminobenzoic acid showed a performance advantage over usual membranes, i.e., a large positive deviation from the usual trade-off trend. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1821–1830, 1998

88 citations


Journal ArticleDOI
TL;DR: In this paper, a linear regression analysis of the linear portion of a concentration response curve reveals an IC50 of 8.5 microM with an inhibition constant of Ki = 4.7 microM in 50 mM Tris-HCl buffer.

88 citations


Journal ArticleDOI
TL;DR: A nonlinear filtered-x LMS algorithm for updating the coefficients of a nonlinear prefilter, as proposed, is shown to be viewed as an extension of the well-known filtered- x LMS algorithms.
Abstract: This article concerns the linearization of a nonlinear system by connecting a nonlinear Volterra prefilter tandemly with the nonlinear system and by adaptively adjusting the coefficients of the prefilter. "A nonlinear filtered-x LMS algorithm" for updating the coefficients of a nonlinear prefilter, as proposed, is shown to be viewed as an extension of the well-known filtered-x LMS algorithm.

78 citations


Journal ArticleDOI
TL;DR: Results indicate that PLC-delta1 is the effector for Ghalpha-mediated oxytocin receptor signalling.
Abstract: Although the oxytocin receptor modulates intracellular Ca2+ ion levels in myometrium, the identities of signal molecules have not been clearly clarified Our previous studies on oxytocin receptor signalling demonstrated that 80 kDa Ghalpha is a signal mediator [Baek, Kwon, Lee, Kim, Muralidhar and Im (1996) Biochem J 315, 739-744] To elucidate the effector in the oxytocin receptor signalling pathway, we evaluated the oxytocin-mediated activation of phospholipase C (PLC) by using solubilized membranes from human myometrium and a three-component preparation containing the oxytocin receptor-Ghalpha-PLC-delta1 complex PLC-delta1 activity in the three-component preparation, as well as PLC activity in solubilized membranes, was increased by oxytocin in the presence of Ca2+ and activated Ghalpha (GTP-bound Ghalpha) Furthermore the stimulated PLC-delta1 activity resulting from activation of Ghalpha via the oxytocin receptor was significantly attenuated by the selective oxytocin antagonist desGly-NH2d(CH2)5[Tyr(Me)2,Thr4]ornithine vasotocin or GDP Consistent with these observations, co-immunoprecipitation and co-immunoadsorption of PLC-delta1 in the three-component preparation by anti-Gh7alpha antibody resulted in the PLC-delta1 being tightly coupled to activated Ghalpha on stimulation of the oxytocin receptor These results indicate that PLC-delta1 is the effector for Ghalpha-mediated oxytocin receptor signalling

73 citations


Journal ArticleDOI
TL;DR: CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I as well as in tumor cell cytotoxicity and ex vivo antitumor activity against the human tumor xenograft models.
Abstract: We developed a novel water-soluble camptothecin analogue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respectively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for thein vivo antitumor activity against the human tumor xenograft models. CKD602 was able to induce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/ED58) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4d×4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in <5% tumor bearing mouse. This schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

69 citations


Journal ArticleDOI
TL;DR: A simultaneous out-of-focus blur estimation and restoration technique for a fully digital auto-focusing system that can make in-focused images by using only digital image processing techniques and requires neither infrared light or ultrasound nor a focusing lens assembly operated by a motor.
Abstract: We propose a simultaneous out-of-focus blur estimation and restoration technique for a fully digital auto-focusing system. The proposed auto-focusing system can make in-focused images by using only digital image processing techniques, and it requires neither infrared light or ultrasound nor a focusing lens assembly operated by a motor. As a result, it can provide savings in the volume and cost of the imaging system, which contains the proposed auto-focusing system. The proposed system first divides the input image into multiple sub-images or blocks, determines the set of blocks which contain linear edges, estimates the step response across the edge for each block in the selected set, computes the one-dimensional step response by averaging the step responses, estimates the two-dimensional point spread function (PSF) from the averaged step response, and finally provides in-focused image by an image restoration filter based on the estimated PSF. There is a limit on the amount of out-of-focus, which can be recovered by the proposed auto-focusing system. The proposed system operates under the assumption that an input image contains at least one piece-wise linear boundary between an object and the background. In spite of the above mentioned limitations, the proposed system can make an acceptable quality of focused image by using only digital signal processing.

65 citations


Journal ArticleDOI
TL;DR: In this paper, a fully digital auto-focusing system based on point spread function (PSF) estimation is proposed, where the input image is subdivided, and the step responses of edge-containing subimages are averaged.
Abstract: A fully digital auto-focusing system based on point-spread function (PSF) estimation is proposed. To increase accuracy in estimating the PSF of the defocused image, the input image is subdivided, and the step responses of edge-containing subimages are averaged. The PSF, which results from out-of-focus blur, is estimated by differentiating the averaged step response along the appropriately estimated edge direction under the assumption that an image usually contains a piece-wise linear boundary between an object and background. By using the estimated PSF, the corresponding image restoration filter is realised, based on the constrained least squares approach.

Journal ArticleDOI
TL;DR: Park et al. as mentioned in this paper examined the relationship between the locus of control and academic achievement among three samples: Korean, Korean-Chinese, and Chinese university students, and found that students with higher academic grades scored higher on internality and lower on externality.
Abstract: The authors conducted two studies to examine the relationship between attributional style, locus of control, and academic achievement. Using the scales developed by the first author (Park, 1995), the first study compared the attributional style and locus of control of honor students (those who received scholarship) with those who were on academic probation. The results indicated that compared to students on academic probation, honor students were more likely to score higher on internal locus of control and lower on external locus of control. They were more likely to attribute their success to effort and the influence of other people. For failure, the honor students were less likely to attribute their failure to a lack of ability and lack of support from significant others. The second study examined the relationship between the locus of control and academic achievement among three samples: Korean, Korean-Chinese, and Chinese university students. A 40-item locus of control questionnaire and background information section containing sex and self-reported academic grade were administered. The results showed that the Korean sample had the highest internal locus of control score and the lowest external locus of control score. The Korean-Chinese sample, in contrast, scored highest on external locus of control. These results are consistent with past research investigating the cultural influence upon the individual’s locus of control. Furthermore, as found in the first study, a significant relationship was found between locus of control and academic grade. For the Korean sample, students with higher academic grades scored higher on internality and lower on externality. For the Chinese sample, students with higher academic grades scored higher on internality. There were no significant differences for the Korean-Chinese sample. Interpretations and implications of cross-cultural and within-sample findings are discussed.

Journal ArticleDOI
TL;DR: Paraffin-embedded tissues of 42 sinonasal inverted papillomas were subjected to polymerase chain reaction using type-specific primers pairs of HPV 6, 11, 16, 18, and 33 to suggest that HPV may be involved in the pathogenesis of inverted papilomas, may cause malignant transformation of inverted Papillomas, and that there may be an apparent relationship between HPV infection and the recurrence of sinon asal inverted Papilomas.
Abstract: Paraffin-embedded tissues of 42 sinonasal inverted papillomas were subjected to polymerase chain reaction using type-specific primers pairs of HPV 6, 11, 16, 18, and 33. Two cases of HPV 11 and one of HPV 6 were amplified in 36 samples of benign inverted papilloma, and two cases of HPV 16 were amplified in five samples of inverted papilloma with co-existing squamous cell carcinoma. Inverted papillomas recurred in 1 (16%) of 6 cases exhibiting dysplasia, and in 3 (10%) of 30 cases not exhibiting dysplasia. Inverted papillomas also recurred in 2 (66%) of 3 cases positive for HPV, and in 2 (6%) of 33 cases negative for HPV. These results suggest that HPV may be involved in the pathogenesis of inverted papillomas, may cause malignant transformation of inverted papillomas, and that there may be an apparent relationship between HPV infection and the recurrence of sinonasal inverted papillomas.

Journal ArticleDOI
TL;DR: In this article, the results of a first-principles calculation of the direct band-gap pressure coefficient a{sub g} for a series of Ga and In semiconductor compounds with both the chalcopyrite and the zinc-blende structures (e.g., GaAs and InAs) were presented.
Abstract: We present the results of a first-principles calculation of the direct band-gap pressure coefficient a{sub g} for a series of Ga and In semiconductor compounds with both the chalcopyrite (e.g., CuGaSe{sub 2} and CuInSe{sub 2}) and the zinc-blende structures (e.g., GaAs and InAs). We found good agreement between the calculated and experimental pressure coefficients. We found that a{sub g} in chalcopyrites are dramatically reduced relative to zinc-blende compounds, and that the Ga{r_arrow}In substitution lowers a{sub g} in chalcopyrites more than in zinc-blende compounds. As a result, the empirical rule suggested for zinc-blende compounds, stating that for a given transition (e.g., {Gamma}{sub 15v}{r_arrow}{Gamma}{sub 1c}) a{sub g} does not depend on substitutions, has to be modified for chalcopyrites. Based on our results we question the currently accepted experimental value for CuInTe{sub 2} (2.2 meV/kbar); we calculate this value to be close to 5.9 meV/kbar. {copyright} {ital 1998} {ital The American Physical Society}

Journal ArticleDOI
TL;DR: In this article, it was shown that with increasing doping concentration, the broad-band emission centered around 530 nm gradually disappears while the sharp red-emission peaks around 620 nm exhibit a pronounced increase.


Journal ArticleDOI
TL;DR: In this article, the spontaneous gas bubble nucleation after rapid decompression in organic solution initially saturated with dissolved gas and the subsequent bubble growth to macroscopic size was studied. But the authors focused on the spontaneous growth of the bubble to the critical size.

Journal ArticleDOI
TL;DR: In this article, the diagnostic value of a 10-kDa subunit of 150-kda protein in cyst fluid (CF) of Taenia solium metacestodes was evaluated.
Abstract: The diagnostic value of a 10 kDa subunit of 150 kDa protein in cyst fluid (CF) of Taenia solium metacestodes was evaluated. Immunoblot analysis revealed that most sera from patients with neurocysticercosis recognized the 10 kDa subunit strongly (209/217 cases, 84.6%), while a few sera from individuals with other parasitic diseases including alveolar echinococcosis (AE, 2/20, 10%) and cystic echinococcosis (CE, 2/25, 8%) showed faint reactions. Sera of cases with other parasitic diseases, especially AE and CE, exhibited cross reactions against other bands in CF. Both differential immunoblot and immunoprecipitation analyses showed that the 10 kDa subunit was the most specific to cysticercosis and highly antigenic, whereas other components at 20–40, 64, 95 and 106 kDa in CF were cross-reactive. IgG subclass ELISA and immunoblot demonstrated that both IgG4 and IgG1 reactions were predominant in neurocysticercosis and recognized the 10 kDa.

Journal ArticleDOI
TL;DR: In this paper, a homologous series of polyethyleneglycol (PEG) alkylether having different numbers of methylene groups and ethylene oxide groups was used for nonionic surfactants.

Journal ArticleDOI
TL;DR: Naphthoquinone analogs as cdc25A phosphatase inactivators as potential therapeutic targets for anticancer drug were investigated.

Journal ArticleDOI
01 Dec 1998-Glia
TL;DR: The results suggest that in vivo as well as in vitro activated microglia expressed outward K+ channels and that some of the channels at least are Kv1.5.
Abstract: We examined the expression of outward rectifier K+ channels in activated microglia in vivo. For this purpose, lipopolysaccharide (LPS, 2 μg) was injected into the cortex near the hippocampal region of rat brains, and K+ channel expression was examined using antibodies against shaker-type K+ channels, Kv1.5 and Kv1.3. OX-42-positive microglia were found around the injection sites from 8 h after the LPS injection and remained there for 3 days. The OX-42-positive microglia expressed Kv1.5 immunoreactivity, and the time course of Kv1.5 expression was closely correlated with that of OX-42. In saline-injected brains, OX-42-positive cells also expressed Kv1.5 immunoreactivity even though far fewer OX-42-positive cells were found. Increase of Kv1.5 expression after LPS injection was also demonstrated by immunoblot analysis. On the other hand, Kv1.3 immunoreactivity was barely detected in OX-42-positive cells over the entire experimental period. The expression of Kv1.5 preceded that of inducible nitric oxide synthase (iNOS), which is a prominent indication of microglial activation. iNOS was not detectable until 12 h, and thereafter it was maintained for 3 days together with Kv1.5 and OX-42. These results suggest that in vivo as well as in vitro activated microglia expressed outward K+ channels and that some of the channels at least are Kv1.5. GLIA 24:408–414, 1998. © 1998 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: It is believed that this procedure could be an alternative to abdominal radical hysterectomy for selected women, especially those who have stage Ib1 cervical cancer, and acceptable in accordance with the standards of gynecologic oncology.
Abstract: Study Objective . To demonstrate the feasibility and evaluate the efficacy of laparoscopic radical hysterectomy with pelvic lymphadenectomy for early, invasive cervical cancer. Design . Prospective study (Canadian Task Force classification II-2). Setting . University-affiliated hospital. Patients Eighteen women (age range 29–70 yrs) with early, invasive cervical cancer. Intervention Laparoscopic radical hysterectomy with pelvic lymphadenectomy. Measurements and Main Results Diagnoses were squamous cell carcinoma in 15 patients and adenocarcinoma of the cervix in 3; these were graded microcarcinoma in 6 and stage lb ( Conclusion In our experience, laparoscopic radical hysterectomy with pelvic lymphadenectomy is acceptable in accordance with the standards of gynecologic oncology. Despite the longer operating time than traditional abdominal radical hysterectomy, all patients recovered as quickly as they would after laparoscopic-assisted vaginal hysterectomy. We believe that this procedure could be an alternative to abdominal radical hysterectomy for selected women, especially those who have stage lb1 cervical cancer.

Journal ArticleDOI
TL;DR: A new motion estimation algorithm which determines an initial motion vector and a search window adaptively in video codecs which code and transmit data in a block scan order is presented.
Abstract: In this paper, we present a new motion estimation algorithm which determines an initial motion vector and a search window adaptively in video codecs which code and transmit data in a block scan order. The proposed method is based on the motion information of spatio-temporal neighboring blocks. In predicting the motion, a temporal projection technique is introduced in the determination of an initial vector, and then the search window size to refine the initial vector is determined by the correlation between neighboring blocks. With a small amount of computation during motion estimation, the proposed algorithm can estimate the motion of fast moving object. Experimental results of the proposed method show significantly improved performance in image quality and the computational complexity.

Journal Article
TL;DR: In this article, the authors developed a model on relational exchanges in the context of small and medium-sized exporters and importers and examined the mediating effects of decision-making uncertainty on the relationship between relational exchange and exporting performance.
Abstract: With the internationalization of the market place, many transactions involve the transfer of goods and service across national boundaries. When marketers deal with customers in a foreign market, they encounter differences in language, consumer attitudes, law and regulations, and business practices. Developing relationships in the international market requires more time and effort because of cultural differences and the inaccessibility of ethnic or informal networks. Often an exporter's lack of cultural affinity with importing countries has been advanced as a key factor in its poor exporting record (Craig and Yetton 1994). Although the benefits of relational exchange have been discussed extensively in the marketing literature (Dwyer, Schurr, and Oh 1987; Gronroos 1995; Macneil 1980; Morgan and Hunt 1994; Sheth and Parvatiyar 1995), very little research has explored this dynamic in the relationship between exporters and importers. The overall aim of this study is to develop a model on relational exchanges in the context of small and medium-sized exporters and importers. The underlying conceptual model is shown in Figure 1. This study focuses on the relationship between Australian exporters and Korean importers. Korea was chosen because Korea is the second largest export market for Australian exporters (Craig and Yetton 1994; Jhernan 1996), Korea is one of the countries where relational exchanges are quite pervasive, and a large cultural difference exists between the two countries (Hall and Hall 1987). Making such a selection allows this study to focus on the role of cultural distance in the export-import relationship. This study developed and tested a model of antecedents and consequences of relational exchange between exporters and importers. Specifically, this study attempted to establish the role of cultural distance and transaction-specific assets (TSA) as determinants of relational exchange between exporters and importers. This study also examined the effect of relational exchange on exporting performance. Finally, the study examined the mediating effects of decision-making uncertainty on the relationship between relational exchange and exporting performance. From a managerial perspective, the results of this study are particularly important for small and medium-sized exporting firms. These firms frequently lack the resources to invest abroad and tend to rely primarily on exporting for their international engagements. Most importantly, the study will provide practical guidelines for exporters on how to develop relational exchange with their foreign importers. It will also provide insights into the inter-relationships between decision-making uncertainty and performance. This article proceeds as follows. First, we will discuss cultural distance and transaction-specific assets as antecedents to relational exchange. We then discuss performance and decision making uncertainty as consequences of relational exchange. Next, we describe an empirical test of our hypotheses in the context of the relationship between Australian exporters and Korean importers. Finally, the results of the study, an assessment of its contribution to our understanding on the exporter-importer relationships, and directions for future research are discussed. Conceptual Development Cultural Distance and Relational Exchange Foreign markets are frequently characterized by differences in language, laws and regulations, business practices, and consumer attitudes. The perceived difference between the home nation and the target country is referred to as "psychic distance" or "cultural distance" (Johanson and Valhne 1977). As cultural distance increases, investment in the foreign country is perceived by managers as less attractive (Holzmuller and Kasper 1990); joint ventures are perceived as a more acceptable mode of entry than acquisitions (Kogut and Singh 1988); and managers become increasingly willing to allow their firms to reduce their degree of control of foreign assets (Anderson and Coughlan 1987; Bello and Gilliland 1997; Erramilli and Rao 1993; Gatignon and Anderson 1988; Goodnow and Hansz 1972; Root 1983). …

Journal ArticleDOI
TL;DR: Polyoxyethylene derivatives of hydrogenated castor oil (HCO) were the most suitable emulsifiers in stabilizing emulsions containing Lipiodol as an oil phase and the length of ethylene oxide coupled to HCO rather than the hydrophilic-lipophilic balance (HLB) values was an important factor in preparing stable emulsion and in achieving sustained-release characteristics.

Journal ArticleDOI
TL;DR: In this paper, a new method for efficient and chemoselective esterification of carboxylic acids in CsF-Celite/alkyl halide/CH3CN reaction system is described.

Journal ArticleDOI
Gyu Ho Wang1
TL;DR: In this paper, the authors investigate an infinite horizon bargaining problem in which a firm and a worker bargain over two dimensions, quality and wage, and show that for all discount factors, the unique sequential equilibrium outcome is separating without delay; the firm separates the types of workers with a menu of contracts in the first period.
Abstract: We investigate an infinite horizon bargaining problem in which a firm and a worker bargain over two dimensions, quality and wage. The worker has private information about his type. Only the uninformed firm makes an offer and it can offer a menu of quality-wage contracts instead of single one. We show that for all discount factors, the unique sequential equilibrium outcome is separating without delay; the firm separates the types of worker with a menu of contracts in the first period. Our result shows that in multi-dimensional bargaining, the "Coase Conjecture" holds in the sense that the game ends in the first period. But it fails in the sense that the uninformed party can preserve the entire bargaining power.

Journal ArticleDOI
01 Aug 1998
TL;DR: In this paper, a regularized iterative image interpolation algorithm was proposed to restore high frequency details in the original high resolution image, where the regularization approach was applied to the interpolation procedure.
Abstract: This paper presents a regularized iterative image interpolation algorithm, which can restore high frequency details in the original high resolution image In order to apply the regularization approach to the interpolation procedure, we first present a two-dimensional separable image degradation model for a low resolution imaging system According to the model, we propose a regularization based spatial image sequence interpolation algorithm and apply the proposed algorithm to a spatially scalable coding

Journal ArticleDOI
TL;DR: The results strongly suggest that the cagA gene will not prove to be a useful marker to distinguish disease-specific H. pylori strains in the development of peptic ulcer diseases in Korean patients.
Abstract: Background: Helicobacter pylori strains possessing the cagA gene have been postulated to have a disease-specific relationship to peptic ulcer. The purpose of this study was to investigate the relationship between the infection with Helicobacter pylori expressing the cagA gene and the development of peptic ulcer diseases in Korean patients. Methods: Genomic DNA and bacterial mRNA in the gastric mucosa were amplified by polymerase chain reaction (PCR) and reverse transcription PCR, using synthetic oligonucleotide primers to cagA genes to compare the prevalence of cagA genes in 35 patients with non-ulcer gastritis and 99 patients with gastric or duodenal ulcer disease (53 and 46, respectively). Two different primer sets for the cagA gene were used. The first primer set amplified a 298-bp region (nucleotides 1751-2048), and the second set amplified a 349-bp region (nucleotides 1228-1249). Results: The expected 298- and 349-bp PCR amplicons were identified as follows: 1) 32 (91.4%) and 30 (85.7%) of 35 non-ulc...

Journal ArticleDOI
TL;DR: Nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.
Abstract: Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea. Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997. Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin. Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted. The resistance rate to fluoroquinolone rose to 24% in E. coli, 56% in A. baumannii and 42% in P. aeruginosa. Mean resistance rates were similar in all hospital groups: about 17% of P. aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin. In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.