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Lee S, Chu YS, Yoo SK, Choi S, Choe SJ, Koh SB, Chung KY, Xing L, Oh B, Yang S. Augmented decision-making for acral lentiginous melanoma detection using deep convolutional neural networks. J Eur Acad Dermatol Venereol 2020; 34:1842-1850. [PMID: 31919901 DOI: 10.1111/jdv.16185] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/13/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Several studies have achieved high-level performance of melanoma detection using convolutional neural networks (CNNs). However, few have described the extent to which the implementation of CNNs improves the diagnostic performance of the physicians. OBJECTIVE This study is aimed at developing a CNN for detecting acral lentiginous melanoma (ALM) and investigating whether its implementation can improve the initial decision for ALM detection made by the physicians. METHODS A CNN was trained using 1072 dermoscopic images of acral benign nevi, ALM and intermediate tumours. To investigate whether the implementation of CNN can improve the initial decision for ALM detection, 60 physicians completed a three-stage survey. In Stage I, they were asked for their decisions solely on the basis of dermoscopic images provided to them. In Stage II, they were also provided with clinical information. In Stage III, they were provided with the additional diagnosis and probability predicted by the CNN. RESULTS The accuracy of ALM detection in the participants was 74.7% (95% confidence interval [CI], 72.6-76.8%) in Stage I and 79.0% (95% CI, 76.7-81.2%) in Stage II. In Stage III, it was 86.9% (95% CI, 85.3-88.4%), which exceeds the accuracy delivered in Stage I by 12.2%p (95% CI, 10.1-14.3%p) and Stage II by 7.9%p (95% CI, 6.0-9.9%p). Moreover, the concordance between the participants considerably increased (Fleiss-κ of 0.436 [95% CI, 0.437-0.573] in Stage I, 0.506 [95% CI, 0.621-0.749] in Stage II and 0.684 [95% CI, 0.621-0.749] in Stage III). CONCLUSIONS Augmented decision-making improved the performance of and concordance between the clinical decisions of a diverse group of experts. This study demonstrates the potential use of CNNs as an adjoining, decision-supporting system for physicians' decisions.
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Affiliation(s)
- S Lee
- Department of Dermatology, Yonsei University Wonju College of Medicine, Wonju, Korea.,Department of Preventive Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Y S Chu
- Department of Biomedical Engineering, Yonsei University, Wonju, Korea
| | - S K Yoo
- Department of Biomedical Engineering, Yonsei University, Wonju, Korea
| | - S Choi
- Department of Dermatology and Cutaneous Biology Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - S J Choe
- Department of Dermatology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - S B Koh
- Department of Preventive Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - K Y Chung
- Department of Dermatology and Cutaneous Biology Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - L Xing
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
| | - B Oh
- Department of Dermatology and Cutaneous Biology Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - S Yang
- Department of Biomedical Engineering, Yonsei University, Wonju, Korea
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Shin KY, Lee TB, Jin SO, Choi SH, Yoo SK, Huh Y, Kim JU, Kim JY. Characteristics of the pulse wave in patients with chronic gastritis and the healthy in Korean medicine. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2012:992-5. [PMID: 23366061 DOI: 10.1109/embc.2012.6346100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chronic gastritis is a disease that occurs in one in every 10 persons in Korea. Endoscopic examination is needed to diagnose chronic gastritis in western medicine, but it causes patients pain, long period of examinations and financial burden. In KM (Korean Medicine), on the other hand, it can be known whether stomach is abnormal or not through a pulse diagnosis. The 'Guan' position of the right wrist is related to a stomach in KM. Thus, the pulse wave of the right-hand "Guan" of patients with chronic gastritis and the healthy were measured. Then, the diagnostic parameter and features to distinguish between the patients with chronic gastritis and the healthy were discovered. Through P-H curve, consequently, it can be concluded that the pulse waves of patients with chronic gastritis appear as a floating pulse, whereas the pulse waves of the healthy appear as a normal pulse.
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Affiliation(s)
- K Y Shin
- Korea Electrotechnology Research Institute, Ansan, Korea.
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Lee C, Yoo SK, Park Y, Kim N, Jeong K, Lee B. Using neural network to recognize human emotions from heart rate variability and skin resistance. Conf Proc IEEE Eng Med Biol Soc 2012; 2005:5523-5. [PMID: 17281504 DOI: 10.1109/iembs.2005.1615734] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this paper is to estimate emotions using Neural network and the changes in activities of autonomic nervous system(ANS). Since ANS cannot be controlled artificially, we presumed that the changes in emotions would be reflected to the changes in ANS. In order to observe those changes, we provided the subjects with some video clips which can induce a variety of emotions and measured the changes in ANS, especially in Heart Rate Variability(HRV) and in Galvanic Skin Response(GSR). With those analyzed results from the experiments, we established an algorithm based on Neural network, finally we could reach the estimating rate of 80.2%
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Affiliation(s)
- Chung Lee
- Yonsei University, Seoul, Korea (phone: 822-222-81922; fax: 822-361-9923; e-mail: )
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Kim JC, Kim DY, Jung SM, Lee MH, Kim KS, Lee CK, Nah JY, Lee SH, Kim JH, Choi WJ, Yoo SK. Implementation and performance evaluation of mobile ad hoc network for Emergency Telemedicine System in disaster areas. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2009:1663-6. [PMID: 19964544 DOI: 10.1109/iembs.2009.5333889] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
So far we have developed Emergency Telemedicine System (ETS) which is a robust system using heterogeneous networks. In disaster areas, however, ETS cannot be used if the primary network channel is disabled due to damages on the network infrastructures. Thus we designed network management software for disaster communication network by combination of Mobile Ad hoc Network (MANET) and Wireless LAN (WLAN). This software maintains routes to a Backbone Gateway Node in dynamic network topologies. In this paper, we introduce the proposed disaster communication network with management software, and evaluate its performance using ETS between Medical Center and simulated disaster areas. We also present the results of network performance analysis which identifies the possibility of actual Telemedicine Service in disaster areas via MANET and mobile network (e.g. HSDPA, WiBro).
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Affiliation(s)
- J C Kim
- Graduate Programs of Biomedical Engineering, Univ. of Yonsei. Seoul. Korea.
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Han MR, Kwon MC, Lee HY, Kim JC, Kim JD, Yoo SK, Sin IS, Kim SM. pH-dependent release property of alginate beads containing calcium carbonate particles. J Microencapsul 2008; 24:787-96. [DOI: 10.1080/02652040701657820] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Yun HY, Yoo SK, Kim DK, Rim Kim S. Performance Evaluation of Telemedicine System based on multicasting over Heterogeneous Network. Conf Proc IEEE Eng Med Biol Soc 2007; 2005:2175-7. [PMID: 17282662 DOI: 10.1109/iembs.2005.1616893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
For appropriate diagnosis, medical image such as high quality image of patient's affected part and vital signal, patient information, and teleconferencing data for communication between specialists will be transmitted. After connecting patient and specialist the center, sender acquires patient data and transmits to the center through TCP/IP protocol. Data that is transmitted to center is retransmitted to each specialist side that accomplish connection after being copied according to listener's number from transmission buffer. At transmission of medical information data in network, transmission delay and loss occur by the change of buffer size, packet size, number of user and kind of networks. As there lies the biggest delay possibility in ADSL, buffer Size should be established by 1Mbytes first to minimize transmission regionalism and each packet's size must be set accordingly to MTU Size in order to improve network efficiency by maximum. Also, listener's number should be limited by less than 6 people. Data transmission consisted smoothly all in experiment result in common use network- ADSL, VDSL, WLAN, LAN-. But, possibility of delay appeared most greatly in ADSL that has the most confined bandwidth. To minimize the possibility of delay, some adjustment is needed such as buffer size, number of receiver, packet size.
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Affiliation(s)
- H Y Yun
- Yonsei University, Seoul, Korea (phone: 822-222-81922; fax: 822-361-9923; e-mail: )
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Lee J, Lee KJ, Yoo SK. Development of a new signal processing algorithm based on independent component analysis for single channel ECG data. Conf Proc IEEE Eng Med Biol Soc 2007; 2006:224-6. [PMID: 17271650 DOI: 10.1109/iembs.2004.1403132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In this paper, we proposed a new signal processing algorithm based on independent component analysis (ICA) for single channel ECG data. For the application ICA to single channel data, mixed (multi-channel) signals are constructed by adding some delay to original data. By ICA, signal enhancement is acquired. For validation of usefulness of this signal, QRS complex detection was accompanied. In QRS detection process, Hilbert transform and wavelet transform were used and good QRS detection efficacy was obtained. Furthermore, a signal, which could not be filtered properly using existing algorithm, also had better signal enhancement. In future, we need to study on the algorithm optimization and simplification.
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Affiliation(s)
- J Lee
- Dept. of Biomedical Eng., College of Health Science, Yonsei Univ., South Korea
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Chae HJ, Choi KH, Chae SW, Kim HM, Shin TK, Lee GY, Jeong GS, Park HR, Choi HI, Kim SB, Yoo SK, Kim HR. Placenta hominis protects osteoporosis in ovariectomized rats. Immunopharmacol Immunotoxicol 2006; 28:165-73. [PMID: 16684675 DOI: 10.1080/08923970600626197] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In China, Japan, and Korea, placenta hominis extracts (PHEs) are used clinically for the treatment of osteoporosis. The anti-osteoporotic effect of PHEs was studied. The trabecular bone area and thickness in OVX rats decreased by 50% from those in sham-operated rats; these decreases were completely inhibited by administration of PHEs for 7 weeks. Osteoclast numbers and the osteoblast surface were enhanced in OVX rats, but PHEs had no effect on these phenomena. Serum phosphorus and alkaline phosphatase in OVX rats increased compared to those in sham-operated rats, but the increases were not affected by the administration of PHEs. Thyroxine (T4) level was stimulated in OVX rats. The extracts inhibited the T4 level in the OVX rats. These results strongly suggest that PHEs be effective in preventing the development of bone loss induced by OVX in rats.
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Affiliation(s)
- H J Chae
- Department of Dental Pharmacology and Wonkwang Biomaterial Implant Research Institute, School of Dentistry, Iksan, Chonbuk, South Korea
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Chae HJ, Park JM, Lee GY, Park HR, Chae SW, Jeong GS, Kim HM, Kim SB, Yoo SK, Kim HR. Yuk-Hap-Tang induces apoptosis by intervening mn-SOD in human cervical carcinoma HeLa cells. Am J Chin Med 2005; 32:883-95. [PMID: 15673194 DOI: 10.1142/s0192415x04002491] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Yuk-Hap-Tang (YHT) induces cell death in human cervical carcinoma HeLa cells. Caspase-3, -6 and -9 were markedly activated in HeLa cells treated with YHT. The preferred substrate for caspase-3 cysteine protease, PARP, was cleaved to its 85-kDa cleavage product. YHT increased the amount of the anti-apoptotic protein, Bcl-2, and the pro-apoptotic protein, Bax. Although p53 has been reported to accumulate in cancer cells in response to anticancer agents, the p53 expression level was not changed in HeLa cells treated with YHT. Manganese (Mn)-TBAP, a mitochondria-specific SOD mimetic agent and NAC/GSH (N-acetyl cysteine/ reduced glutathione) reduced the YHT-induced cytotoxicity and decreased the number of the YHT-induced apoptotic cells. Furthermore, YHT reduced the expression of Mn-SOD protein and its activity in HeLa cells. The data demonstrate that YHT induces the apoptosis of human cervical carcinoma HeLa cells by intervening Mn-SOD.
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Affiliation(s)
- H J Chae
- Department of Pharmacology and the Institute of Cardiovascular Research, School of Medicine, Chonbuk National University, Jeonju, Chonbuk 565-701, South Korea
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Chae HJ, Chae SW, Yun DH, Keum KS, Yoo SK, Kim HR. Prevention of Bone Loss in Ovariectomized Rats: The Effect ofSalvia miltiorrhizaExtracts. Immunopharmacol Immunotoxicol 2004; 26:135-44. [PMID: 15106738 DOI: 10.1081/iph-120029951] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The preventive effect of Salvia miltiorrhiza extracts (SMEs) on the progress of bone loss induced by ovariectomy (OVX) was studied in rats. We measured body weight and bone histomorphometry in sham, OVX or SMEs-administered OVX rats. From light microscopic analyses, a porous or erosive appearances were observed on the surface of trabecular bone of tibia in OVX rats, whereas those of the same bone in sham rats and in SMEs-administered rats were composed of fine particles. The trabecular bone area and trabecular thickness in OVX rats decreased by 50% from those in sham rats, these decreases were completely inhibited by administration of SMEs for 7 weeks. In this study, the mechanical strength in femur neck was significantly enhanced by the treatment of SMEs for 7 weeks. In OVX rats, free T3 was normal in all cases, whereas free T4 was significantly increased. Although there was no difference between OVX and SMEs-administered rats in T3 level, we have found significant difference between them in T4 level. These results strongly suggest that SMEs are effective in preventing the development of bone loss induced by OVX in rats.
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Affiliation(s)
- H J Chae
- Department of Pharmacology, Institute of Cardiovascular Research, School of Medicine, Chonbuk National University, South Korea
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Chae HJ, Chae SW, An NH, Kim JH, Kim CW, Yoo SK, Kim HH, Lee ZH, Kim HR. Cyclic-AMP inhibits nitric oxide-induced apoptosis in human osteoblast: the regulation of caspase-3, -6, -9 and the release of cytochrome c in nitric oxide-induced apoptosis by cAMP. Biol Pharm Bull 2001; 24:453-60. [PMID: 11379759 DOI: 10.1248/bpb.24.453] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) induces apoptotic cell death and cAMP has a significantly protective effect on NO-induced cytotoxicity in human osteoblasts, MG-63 cells. Treatment with S-nitroso-N-acetylpenicillamine (SNAP) (0.6 mM) resulted in genomic DNA fragmentation, characteristic of apoptosis. However, concomitant incubation of the cells with either DBcAMP or forskolin markedly inhibited SNAP-induced apoptosis in a dose-dependent manner. Furthermore, pretreatment of MG-63 cells with H-89 or KT5720, which is known to inhibit cAMP-dependent protein kinase (PKA), abolished the protective effect of DBcAMP and forskolin on SNAP-induced apoptosis. In this study, we explored the involvement of caspases in the regulatory mechanism of SNAP-induced apoptosis by cAMP. Our data show that DBcAMP or forskolin blocked SNAP-induced caspase-3-like cysteine protease activation and that H-89, a PKA inhibitor, reversed the cAMP-induced regulatory effect of caspase-3 like protease. Consistent with the results, cAMP inhibited the proteolytic cleavage of caspase-3, -6, -9 and cytochrome c release to cytoplasm. The inhibition of caspase-3 activation did not block SNAP-induced cytochrome c release to cytoplasm, suggesting that caspase-3 activation may occur downstream of cytochrome c release. In summary, these findings show that the exposure of MG-63 cells to cAMP analogs renders them more resistant to NO-induced damage and suggests the presence of regulatory mechanisms of the cell death pathway by cAMP in which caspase-3, -6, and -9 and cytochrome c release serves to mediate NO-induced apoptosis.
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Affiliation(s)
- H J Chae
- Department of Dental Pharmacology and Wonkwang Dental Research Institute, School of Dentistry, Chonbuk, South Korea
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Yoo SK, Kim SH, Kim NH, Kang YT, Kim KM, Bae SH, Vannier MW. Design of a PC-based multimedia telemedicine system for brain function teleconsultation. Int J Med Inform 2001; 61:217-27. [PMID: 11311675 DOI: 10.1016/s1386-5056(01)00143-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
During time-critical brain surgery, the detection of developing cerebral ischemia is particularly important because early therapeutic intervention may reduce the mortality of the patient. The purpose of this system is to provide an efficient means of remote teleconsultation for the early detection of ischemia, particularly when subspecialists are unavailable. The hardware and software design architecture for the multimedia brain function teleconsultation system including the dedicated brain function monitoring system is described. In order to comprehensively support remote teleconsultation, multi-media resources needed for ischemia interpretation were included: EEG signals, CSA, CD-CSA, radiological images, surgical microscope video images and video conferencing. PC-based system integration with standard interfaces and the operability over the Ethernet meet the cost-effectiveness while the modular software was customized with a diverse range of data manipulations and control functions necessary for shared workspace and standard interfaces.
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Affiliation(s)
- S K Yoo
- Department of Medical Engineering, Yonsei University College of Medicine, 120-140 Sudaemoon-Gu, Shinchon-Dong 134, Seoul, South Korea.
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Kim SY, Sohn JH, Kang HA, Yoo SK, Pyun YR, Choi ES. Cloning and characterization of the Hansenula polymorpha homologue of the Saccharomyces cerevisiae MNN9 gene. Yeast 2001; 18:455-61. [PMID: 11255253 DOI: 10.1002/yea.699] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A gene homologous to Saccharomyces cerevisiae MNN9 has been cloned and characterized in the methylotrophic yeast Hansenula polymorpha. This gene was cloned from a H. polymorpha genomic DNA library using the S. cerevisiae MNN9 gene as a probe. The H. polymorpha MNN9 homologue (HpMNN9) contained a 1062 bp open reading frame encoding a predicted protein of 354 amino acids. The deduced amino acid sequence showed 58% and 51% identity, respectively, with the S. cerevisiae and Candida albicans Mnn9 proteins. Disruption of HpMNN9 leads to phenotypic effects suggestive of cell wall defects, including detergent sensitivity and hygromycin B sensitivity. The hygromycin B sensitivity of S. cerevisiae mnn9 null mutant was complemented in the presence of the HpMNN9 gene. The DNA sequence of the H. polymorpha homologue has been submitted to GenBank with the Accession No. AF264786.
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Affiliation(s)
- S Y Kim
- Division of Life Sciences, Korea Research Institute of Bioscience and Biotechnology, Taejon 305-333, Korea
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Abstract
The preventive effect of the herbal formulation, "Dae-Bo-Won-Chun" (DBWC), on the progress of bone loss induced by ovariectomy (OVX) was studied in rats. From light microscope analyses, porous or erosive appearances were observed on the surface of trabecular bone of tibia in ovariectomized rats, whereas those of the same bone in sham-operated rats were composed of fine particles. The trabecular bone area and trabecular thickness in ovariectomized rats decreased by 50% from those in sham-operated rats, these decreases were completely inhibited by administration of DBWC at a concentration of 10 mg/kg per day for 7 weeks. The mechanical strength of the neck of the femur was decreased by ovariectomy, and this was significantly suppressed by the administration of DBWC. Serum phosphorus, alkaline phosphatase and thyroxine levels in ovariectomized rats increased compared with those in sham-operated rats, and increases were completely inhibited by the administration of DBWC. These results strongly suggest that DBWC is effective in preventing the development of bone loss induced by ovariectomy in rats.
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Affiliation(s)
- H J Chae
- Department of Dental Pharmacology and Wonkwang Dental Research Institute, School of Dentistry, Iksan, Chonbuk 570-749, 570-749, South Korea
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Abstract
Lipids are important entomopathogenic nematode nutritional components because they are energy reserves and serve as indicators of nematode quality. The composition and concentration of the media lipid component determine bacterial and nematode yields. Heterorhabditis bacteriophora and its symbiont, Photorhabdus luminescens, were cultured in media containing various lipid sources. As lipid concentration increased from 2.5% to 8.0% (w/v), the final yield and productivity [calculated from the number of infective juveniles (IJ)] increased significantly from 2.1 x 10(5) IJ ml(-1) to 2.8 x 10(5) IJ ml(-1) (P < 0.05) and from 8.9 x 10(5) IJ l(-1) day(-1) to 11.8 x 10(5) IJ l(-1) day(-1) (P < 0.05), respectively. The nematode yield coefficient (IJ per gram of media), however, decreased from 2.8 x 10(6) to 2.2 x 10(6) (P < 0.05), while recovery increased from 45.3% to 58.0% (P < 0.05). Bacterial cell mass remained constant at 4.6 mg ml(-1) with changing lipid content (P > 0.05). The largest nematode yield (2.8 x 10(5) IJ ml(-1)) was achieved within 8 days, using a medium containing an 8% (w/v) olive and canola oil (50:50 w/v) combination. Moreover, developmental synchrony was achieved in this medium with 96% infective juveniles. In short, lipid sources rich in mono-unsaturated fatty acids and poor in saturated fatty acids produced optimal nematode growth.
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Affiliation(s)
- S K Yoo
- Department of Entomology, Rutgers University, New Brunswick, NJ 08901, USA
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Abstract
In this paper, the three-dimensional geometry of the human cochlea is modeled by the helico-spiral seashell model. The 3-D helico-spiral model, the generalized representation of the Archimedian spiral model, provides a framework for measuring cochlear features based on consistent estimation of model parameters. Nonlinear least square minimization based algorithms are developed for the identification of rotation, center and intrinsic parameters of the helico-spiral representation. Two algorithms are designed for the rotation axis aligned to the modiolar axis: one is more susceptible in the presence of noise, while the other allows applicability to two-dimensional data sets. The estimated center and intrinsic parameters allow the calculation of length, height and angular positions needed for frequency mapping of multichannel cochlear implant electrodes. Model performance is evaluated with numerically synthesized curves with different levels of added random noise, histologic data and real human cochlear spiral computed tomography data.
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Affiliation(s)
- S K Yoo
- Department of Radiology, University of Iowa School of Medicine, Iowa City 52242, USA. sun-yoo@.uiowa.edu
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Lee Y, Yoo SK, Lee JS, Kwon YM. Genomic structure of ornithine carbamoyltransferase gene from Canavalia lineata. Mol Cells 2000; 10:480-5. [PMID: 10987149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The nucleotide sequences of the complete ornithine carbamoyltransferase (OCT) gene containing 3,964 bp 3' region and 1,701 bp promoter region were determined from Canavalia lineata leaves. The exons range in size from 131 bp to 390 bp, while the introns range in size from 102 bp to the relatively large size of 1,465 bp; all the splicing junctions followed the conserved GT/AG rule. The transcription initiation site is located 12 bp upstream of the ATG translation initiation site and 69 bp downstream of TATA-box. The regulatory elements located in the 1,701 bp 5' upstream region are GT-1, GATA motif, I-box, SBF-1, Nit2 etc. The structure of the OCT gene from C. lineata was compared with Arabidopsis thaliana, in which two genes consist of 5 exons and 4 introns. The nucleotide sequence of exons and deduced amino acid sequence exhibits 70% and 69% homology, respectively. The deduced amino acid sequences show identical conserved "HPXQ" box, carbamoyl phosphate and ornithine binding sites. The introns of C. lineata OCT gene are larger than those of A. thaliana, except for intron 3. Genomic DNA blot analysis showed that a single ornithine-dependent OCT gene exists in the C. lineata genome.
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Affiliation(s)
- Y Lee
- School of Biological Sciences, Seoul National University, Korea
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Abstract
The glk gene from Corynebacterium glutamicum was isolated by complementation using Escherichia coli ZSC113 (ptsG ptsM glk). We sequenced a total of 3072 bp containing the 969-bp open reading frame encoding glucose kinase (Glk). The glk gene has a deduced molecular mass of 34.2 kDa and contains a typical ATP binding site. Comparison with protein sequences revealed homologies to Glk from Streptomyces coelicolor (43%) and Bacillus megaterium (35%). The glk gene in C. glutamicum was inactivated on the chromosome via single crossover homologous recombination and the resulting glk mutant was characterized. Interestingly, the C. glutamicum glk mutant showed poor growth on rich medium such as LB medium or brain heart infusion medium in the presence or absence of glucose, fructose, maltose or sucrose as the sole carbon source. Growth yield was reduced significantly when maltose was used as the sole carbon source using minimal medium. The growth defect of glk mutant on rich medium was complemented by a plasmid-encoded glk gene. A chromosomal glk-lacZ fusion was constructed and used to monitor glk expression, and it was found that glk was expressed constitutively under all tested conditions with different carbon sources.
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Affiliation(s)
- S Y Park
- Environmental Bioresources Laboratory, Korea Research Institute of Bioscience and Biotechnology, College of Engineering, Yonsei University, Seoul, Korea
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Yoo SK, Wang G, Rubinstein JT, Skinner MW, Vannier MW. Three-dimensional modeling and visualization of the cochlea on the Internet. IEEE Trans Inf Technol Biomed 2000; 4:144-51. [PMID: 10866413 DOI: 10.1109/4233.845207] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Three-dimensional (3-D) modeling and visualization of the cochlea using the World Wide Web (WWW) is an effective way of sharing anatomic information for cochlear implantation over the Internet, particularly for morphometry-based research and resident training in otolaryngology and neuroradiology. In this paper, 3-D modeling, visualization, and animation techniques are integrated in an interactive and platform-independent manner and implemented over the WWW. Cohen's template shape with mean cross-sectional areas of the human cochlea is extended into a 3-D geometrical model. Also, spiral computer tomography data of a patient's cochlea is digitally segmented and geometrically represented. The cochlear electrode array is synthesized according to its specification. Then, cochlear implantation is animated with both idealized and real cochlear models. Insertion length, angular position, and characteristic frequency of individual electrodes are estimated online during the virtual insertion. The optimization of the processing parameters is done to demonstrate the feasibility of this technology for clinical applications.
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Affiliation(s)
- S K Yoo
- Department of Radiology, University of Iowa School of Medicine, Iowa City 52242, USA
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21
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Abstract
A thermophilic lipase of Bacillus thermoleovorans ID-1 was cloned and sequenced. The lipase gene codes 416 amino acid residues and contains the conserved pentapeptide Ala-X-Ser-X-Gly as other Bacillus lipase genes. The optimum temperature of the lipase is 75 degrees C, which is higher than other known Bacillus lipases. For expression in Escherichia coli, the lipase gene was subcloned in pET-22b(+) vector with a strong T7 promoter. Lipase activity was approximately 1.4-fold greater than under the native promoter.
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Affiliation(s)
- A R Cho
- Department of Biotechnology, College of Engineering and Bioproducts Research Center, Yonsei University, 134 Shinchon-Dong, Sudaemun-Ku, Seoul, South Korea
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22
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Abstract
A new system designed for cell surface display of recombinant proteins on Escherichia coli was evaluated for expression of eukaryotic viral antigens. The major surface antigen of hepatitis B virus (HBsAg) was fused to the ice nucleation protein (INP), an outer membrane protein of Pseudomonas syringae. Western blotting, immunofluorescence microscopy, whole-cell ELISA, and ice nucleation activity assay confirmed expression of recombinant proteins on the surface of Escherichia coli. This study indicated that INP-based cell surface display can be used for epitope mapping and recombinant bacteria expressing hepatitis viral antigens may be used for developing live vaccines.
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Affiliation(s)
- E J Kim
- Department of Biotechnology, College of Engineering and Bioproducts Research Center, Yonsei University, Seoul, Korea
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23
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Yoo SK, Yoon M, Park UJ, Han HS, Kim JH, Hwang HJ. A radioimmunoassay method for detection of DNA based on chemical immobilization of anti-DNA antibody. Exp Mol Med 1999; 31:122-5. [PMID: 10551259 DOI: 10.1038/emm.1999.20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
High selectivity provided by biomolecules such as antibodies and enzymes has been exploited during the last two decades for development of biosensors. Of particular importance are efficient immobilization methods for biomolecules in order to preserve their biological activities. In this study, we have evaluated immobilization strategies for an anti-DNA antibody on a self-assembled monolayer of omega-functionalized thiols. The antibody was immobilized via peptide bond formation between the primary amines in the antibody and the carboxyl groups on the self-assembled monolayer. The peptide bond coupling was achieved by activating COOH groups on the surface through N-Hydroxysuccimide (NHS)-ester formation, followed by acylation of NH2 group in the antibody. DNA binding activity of the immobilized antibody was examined by counting beta emission from 35S-labeled DNA.
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Affiliation(s)
- S K Yoo
- Department of Chemistry, Kyung Hee University, Seoul, Korea
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24
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Kwak YD, Yoo SK, Kim EJ. Cell surface display of human immunodeficiency virus type 1 gp120 on Escherichia coli by using ice nucleation protein. Clin Diagn Lab Immunol 1999; 6:499-503. [PMID: 10391850 PMCID: PMC95715 DOI: 10.1128/cdli.6.4.499-503.1999] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A new system designed for cell surface display of recombinant proteins on Escherichia coli has been evaluated for expression of eukaryotic viral proteins. Human immunodeficiency virus type 1 (HIV-1) gp120 was fused to the C terminus of ice nucleation protein (INP), an outer membrane protein of Pseudomonas syringae. Western blotting, immunofluorescence microscopy, fluorescence-activated cell-sorting analysis, whole-cell enzyme-linked immunosorbent assay, and ice nucleation activity assay confirmed the successful expression of HIV-1 gp120 on the surface of Escherichia coli. This study shows that the INP system can be used for the expression of eukaryotic viral proteins. There is also a possibility that the INP system can be used as an AIDS diagnostic system, an oral vaccine delivery system, and an expression system for various heterologous higher-molecular-weight proteins.
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Affiliation(s)
- Y D Kwak
- Department of Biotechnology, College of Engineering and Bioproduct Research Center, Yonsei University, 134 Shinchon-Dong, Sudaemun-Ku, Seoul 120-749, Korea
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25
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Abstract
Thiopental intravenous injections before temporary clipping and mild hypothermia have protective effects in the setting of cerebral ischemia, and are used clinically in some centers. However, it is not known whether mild hypothermia affects thiopental-induced electroencephalogram (EEG) burst suppression. In this study, the authors compared the onset and duration of EEG suppression by thiopental in normothermic (n=10) and mildly hypothermic (n=10) patients undergoing cerebral aneurysm surgery. Spectral analysis was used to compare the prethiopentonal continuous EEG patterns in normothermic and mild hypothermic patients. The patients' body temperatures were controlled by a circulating water mattress and intravenous fluids (normothermia = 36.4+/-0.1 degrees C, mild hypothermia = 33.3+/-0.1 degrees C). Immediately before temporary clipping, thiopental sodium (5 mg/kg) was administered intravenously. Onset time (the amount of time from thiopental injection to the first complete EEG suppression), duration of suppression (the amount of time from the first complete EEG suppression to recovery on continuous EEG from burst suppression), and maximum duration of isoelectric EEG (the longest time interval between two bursts during burst suppression) were measured. Onset time was shortened (25.8+/-1.4 versus 43.5+/-5.6 seconds), and duration of suppression (531.0+/-56.6 versus 165.0+/-16.9 seconds) and the maximum duration of isoelectric EEG (47.7+/-5.8 versus 22.8+/-2.0 seconds) were prolonged in the patients with mild hypothermia. In two normothermic patients, the standard dose of thiopental did not produce burst suppression, but only a mild decrease in spectral edge frequency. The authors concluded that the effects of mild hypothermia on thiopental-induced EEG suppression are not simply additive, but synergistic.
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Affiliation(s)
- J H Kim
- Department of Anesthesiology, Yonsei University, College of Medicine, Seoul, Korea
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26
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Huh JM, Yoo SK, Kim NH, Chang BC, Lee DY, Cho BK, Bae SH, Kim KM, Kim EJ, Kim GD. Implementation of a low-cost PACS/CR for clinical use in Yonsei Cardiovascular Center. Stud Health Technol Inform 1998; 52 Pt 2:1091-4. [PMID: 10384629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
The PACS/CR for clinical use in Yonsei Cardiovascular Center has been designed and implemented. Our system is open architecture to comply with emerging standards such as DICOM. database SQL, TCP/IP and to reduce operational and maintenance costs, PC-based low cost workstations running Microsoft Windows, database as Microsoft SQL based on Client/Server, Long-term storage using CD-ROM Jukebox are developed. Also, auto routing and image pre-fetching are implemented.
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Affiliation(s)
- J M Huh
- Cardiovascular Research Institute, Yonsei University College of Medicine, Seoul, Korea
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27
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Kim NH, Yoo SK, Kim KM, Kang YT, Bae SH, Kim SR. Development of a medical record and radiographic image transmission system using a high-speed communication network. Stud Health Technol Inform 1998; 52 Pt 1:282-5. [PMID: 10384462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
A medical record and radiographic image transmission system has been developed using a high-speed communication network. The databases are designed to store and transmit the data acquired from the scanner. To maximally utilize the communication bandwidth, the medical records and radiographic images are compressed using the G3 facsimile and JPEG coding standard method, respectively. TCP/IP, OOP and Windows-based system software enable a modular design, future expandability, open system interconnectivity, and diverse image manipulation functions.
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Affiliation(s)
- N H Kim
- Dept. of Medical Eng., College of Medicine, Yonsei University, Seoul, Korea
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28
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Lee KH, Kwak BY, Kim JH, Yoo SK, Yum SK, Jeong HS. Genetic polymorphism of cytochrome P-4502E1 and mitochondrial aldehyde dehydrogenase in a Korean population. Alcohol Clin Exp Res 1997; 21:953-6. [PMID: 9309300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mitochondrial aldehyde dehydrogenase (ALDH2) is mainly responsible for the oxidation of acetaldehyde generated during alcohol oxidation in vivo. Cytochrome P-4502E1 (CYP2E1), a liver microsomal enzyme, also metabolizes acetaldehyde and ethanol. Genetic polymorphism of ALDH2 and CYP2E1 was investigated among 481 Korean adults. A new restriction fragment-length polymorphism method was developed to determine the genotype of the ALDH2 alleles. This method proved to be simpler and faster than the hybridization method using allele-specific oligonucleotide probes and polymerase chain reaction-directed mutagenesis. The allele frequencies of ALDH2(1) and ALDH2(2) were 0.840 and 0.160, respectively. This allele frequency of ALDH2(2) is less than in Japanese people. Genetic polymorphism of CYP2E1 was investigated using polymerase chain reaction and restriction fragment-length polymorphism. The estimated allele frequencies for c1 and c2 were 0.808 and 0.192.
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Affiliation(s)
- K H Lee
- Biotechnology Laboratory of Jinro Central Research Institute, Kyungki-Do, Korea
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29
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Yoo SK, Kim KM, Kim NH, Huh JM, Chang BC, Cho BK. Design of a medical image processing software for clinical-PACS. Yonsei Med J 1997; 38:193-201. [PMID: 9339126 DOI: 10.3349/ymj.1997.38.4.193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Software modules for interactive display, manipulation and retrieval of medical images have been designed for a Picture Archiving and Communications System (PACS). The target of these modules is not for a high-end diagnostic workstation for radiologists, but for a PC-based low cost clinical workstation for a referring physician. This software is constructed based on a concept of an object-oriented language which is designed to be modular and expandable. It consists of several functional modules: (a) a communication module for image retrieval, (b) a standard module for the interpretation of the DICOM images, (c) a user interface module for the non-computer oriented clinicians and (d) a tool module for viewing and manipulating images as well as editing the annotation.
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Affiliation(s)
- S K Yoo
- Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea
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30
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Affiliation(s)
- S K Yoo
- Department of Medical Engineering, College of Medicine, Yonsei University, Sudaemoon-ku, Seoul, Korea
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31
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Abstract
In clinical surgery, there are frequent needs for communication between the house staff and the attending physician in an emergency situation. To overcome the limitation of voice communication through the telephone line, we have designed an 'emergency teleradiology system' which can be used for emergency surgical and medical decision making. This system can transmit the high quality images of CT, MRI, and other X-ray data using a PC attached to a modem through the conventional telephone line. It is based on the progressive transmission system which enables the successive update of a received image. The iterative residual coding/decoding algorithm efficiently compresses the image to maximally utilize the low bandwidth PSTN channels. This system also satisfies design requirements such as low-cost, ease of operation, fast transmission, and interactive image communication including voice. Test results using several CT, MR, and X-ray images evaluate the compression performance, image quality, transmission time and computational time of the coding and decoding processes, thus demonstrate the usefulness of this system in an emergency situation.
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Affiliation(s)
- S K Yoo
- Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea
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32
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Abstract
In vitro studies have demonstrated that single-stranded DNA molecules containing the 3' terminal nucleotides of the PRD1 DNA replication origin can support initiation by a protein-primed mechanism. We have determined the minimal requirements for priming by analyzing the template activity of various deletion derivatives. Our results showed that the 3'-terminal 15 nucleotides of the replication origin are sufficient for priming. The finding that the requirements for recognition of replication origin are different from those for priming suggests that there are two distinct steps during initiation of PRD1 DNA replication: first, recognition of the replication origin on double-stranded DNA and second, the priming event on single-stranded DNA. In addition our results showed that additional bases at the 3' end of templates did not affect priming activity, suggesting that the priming site is searched for from inside the template.
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Affiliation(s)
- S K Yoo
- Department of Microbiology and Immunology, College of Medicine, University of Arizona Tucson 85724
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33
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Abstract
In vitro studies have demonstrated that linear duplex, protein-free DNA molecules containing an inverted terminal repeat (ITR) sequence of the PRD1 genome at one end can undergo replication by a protein-primed mechanism. No DNA replication was observed when the ITR sequence was deleted or was not exposed at the terminus of the template DNA. We have determined the minimal origin of replication by analyzing the template activity of various deletion derivatives. Our results showed that the terminal 20 base-pairs of ITR are required for efficient in vitro DNA replication. We have found that, within the minimal replication origin region, there are complementary sequences. A site-specific mutagenesis analysis showed that most of the point mutations in the complementary sequences markedly reduced the template activity. The analyses of the results obtained with synthetic oligonucleotides have revealed that the specificity of the replication origin is strand specific and even on a single-stranded template a particular DNA sequence including a 3'-terminal C residue is required for the initiation of PRD1 DNA replication in vitro.
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Affiliation(s)
- S K Yoo
- Department of Microbiology and Immunology, College of Medicine, University of Arizona, Tucson 85724
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34
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Abstract
A group of proteins that act as primers for initiation of linear DNA replication are called DNA-terminal proteins (terminal proteins). We have found a short stretch of conserved amino acid sequence among the terminal proteins from six different sources. The location of this sequence motif is also similar among the different terminal-proteins. To determine the functional role of this terminal-protein domain in DNA replication, we have studied the bacteriophage PRD1 system. The PRD1 terminal protein and DNA polymerase genes were cloned into expression vectors, and the recombinant plasmids were used for constructing PRD1 terminal protein mutants. Site-directed mutagenesis and functional analysis showed that one of the two arginines (Arg-174) in the conserved sequence is critical for the initiation complex-forming activity of the PRD1 terminal protein. Replacement of Arg-174 by noncharged amino acids resulted in nonfunctional terminal protein. Phenylglyoxal, an alpha-dicarbonyl compound that reacts with the guanidino group of arginine, inhibits initiation complex formation between PRD1 terminal protein and dGMP. On the basis of these results, we propose that Arg-174 represents, at least in part, the binding site for phosphate groups of dGTP.
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Affiliation(s)
- J C Hsieh
- Department of Microbiology and Immunology, College of Medicine, University of Arizona, Tucson 85724
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35
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Abstract
Software which can be used to simulate stereotactic surgery on a personal computer was developed. Using the modified Todd-Wells frame coordinates, it can reconstruct a three-dimensional image of the brain structure and simulate the target trajectories before the operation. Also, it can calculate the volume of the target region and the distance between the target and certain points in arbitrary trajectory angles. Its optional mode can be used for simulation of conventional brain surgery for previewing deep-seated brain lesions in the operating position.
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Affiliation(s)
- S H Kim
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, South Korea
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36
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Abstract
A cell-free system has been developed from cells of an Escherichia coli strain, carrying cloned genes 1 and 8 of bacteriophage PRD1, that catalyzes protein-primed DNA synthesis. DNA synthesis in vitro is entirely dependent upon the addition of PRD1 DNA-protein complex as template, Mg2+, and four deoxyribonucleoside triphosphates. No in vitro DNA synthesis was observed when deproteinized PRD1 DNA was used as template. The origin and direction of PRD1 DNA replication in vitro was determined by restriction enzyme analysis of 32P-labeled PRD1 DNA synthesized in this system. Replication starts at both ends of the linear PRD1 DNA template. Alkaline sucrose gradient centrifugation and agarose gel electrophoresis showed that full-length PRD1 DNA is synthesized in vitro. DNA synthesis in this system is inhibited by the drug aphidicolin. We also observed that dimethyl sulfoxide (DMSO) stimulates in vitro DNA synthesis, although it inhibits bacterial DNA polymerase.
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Affiliation(s)
- S K Yoo
- Department of Microbiology and Immunology, University of Arizona Health Sciences Center, Tucson 85724
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37
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Lee SH, Ko HW, Yoo SK, Kim WK, Lee HS, Lee HY. Development of a computerized EEG imaging system with a personal computer. Yonsei Med J 1989; 30:45-53. [PMID: 2662633 DOI: 10.3349/ymj.1989.30.1.45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The authors developed a computerized electroencephalography imaging system with an IBM PC AT. The EEG signals amplified with a 16 channel EEG machine were digitized at 51.2 Hz (512 samples per epoch). The shifted DC potential and 60Hz artificats were removed by a high pass filter and 60Hz notch filter. A window function consisting of a 10% cosine taper was obtained by weighting the points at either end of the epoch by a cosine bell. A fast Fourier transform was applied to every epoch and the power spectrum estimates were computed in 0.39 Hz steps. The activity estimates for the delta, theta, alpha and beta bands were computed by summimg adjacent values. The outline of the top-down maps was formed from a series of sagittal cuts, then 32 electrodes were placed on the map. A file was created which contained a table of weighting parameters for calculating the interpolated values for every point within the outline. Each weight was in inverse linear proportion to the distance of the pixel to the nearest four electrodes. The map was finally generated with computation of the spectral EEG in each pixel according to the weighting parameter. The functioning of this system was tested with a functional generator and a human subject.
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38
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Abstract
A spontaneous deletion mutant of bacteriophage phi 29 (phi 29 delta 1) has been characterized. This mutant has a 1112-bp deletion, which covers almost the entire sequence of genes 14 and 15, including an early promoter (B2). While lysis is very delayed, the phage DNA synthesis and internal phage development appear to be normal in the cells infected with this deletion mutant. These results indicate that the early functions are intact in phi 29 delta 1. Our results also suggest that genes 14 and 15 are dispensable for bacteriophage phi 29 growth and that the B2 promoter may also be dispensable for early functions in phi 29.
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