• Title/Summary/Keyword: Biomedical technology

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Mechanical Stretch-Induced Protection against Myocardial Ischemia-Reperfusion Injury Involves AMP-Activated Protein Kinase

  • Hao, Jia;Kim, Hun-Sik;Choi, Woong;Ha, Tae-Sun;Ahn, Hee-Yul;Kim, Chan-Hyung
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.1
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    • pp.1-9
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    • 2010
  • AMP-activated protein kinase (AMPK) protects various tissues and cells from ischemic insults and is activated by many stimuli including mechanical stretch. Therefore, this study investigated if the activation of AMPK is involved in stretch-induced cardioprotection (SIC). Intraventricular balloon and aorto-caval shunt (ACS) were used to stretch rat hearts ex vivo and in vivo, respectively. Stretch preconditioning reduced myocardial infarct induced by ischemia-reperfusion (I/R) and improved post-ischemic functional recovery. Phosphorylation of AMPK and its downstream substrate, acetyl-CoA carboxylase (ACC) were increased by mechanical stretch and ACC phosphorylation was completely blocked by the AMPK inhibitor, Compound C. AMPK activator (AICAR) mimicked SIC. Gadolinium, a blocker of stretch-activated ion channels (SACs), inhibited the stretch-induced phosphorylation of AMPK and ACC, whereas diltiazem, a specific L-type calcium channel blocker, did not affect AMPK activation. Furthermore, SIC was abrogated by Compound C and gadolinium. The in vivo stretch induced by ACS increased AMPK activation and reduced myocardial infarct. These findings indicate that stretch preconditioning can induce the cardioprotection against I/R injury, and activation of AMPK plays an important role in SIC, which might be mediated by SACs.

Detection of Enterotoxins in Staphylococcus aureus Isolated from Clinical Specimens and Kimbap Using Multiplex PCR

  • Kim, Jong-Bae;Kim, Hong;Jin, Hyun-Seok;Kim, Young-Sam;Kim, Keun-Sung;Kang, Yun-Sook;Park, Jong-Seok;Lee, Dong-Ha;Woo, Gun-Jon
    • Biomedical Science Letters
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    • v.7 no.2
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    • pp.85-89
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    • 2001
  • Many Staphylococcus aureus strains produce enterotoxins causing food poisoning. Staphylococcal enterotoxins are classified by serological criteria into five major groups - subtype A to E. It is difficult, time-consuming, and expensive to detect staphylococcal enterotoxins in the clinical laboratory. In this study, we fried to detect the enterotoxin genes of Staphylococcus aureus strains isolated from clinical specimens and Kimbap - rice rolled in a sheet of laver - using multiplex PCR technique. A total of 77 strains of Staphylococcus aureus from clinical specimens and 78 strains from Kimbap were isolated. Among clinical isolates of S. aureus, 60 strains (78.0%) were identified as producing enterotoxins. A total offs strains (91.6%) in the 60 staphylococcal enterotoxin producing strains were enterotoxin subtype C. In case of kimbap: 43 (55.1%) strains were detected to produce enterotoxins and 39 (90.6%) enterotoxin producing strains were subtype A.

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The Effect of Nursing Students Satisfaction in Major and Consciousness of Biomedical Ethics on Nursing Professionalism (간호대학생의 전공만족도, 생명의료윤리인식이 간호전문직관에 미치는 영향)

  • Lee, keyoungim;Jeong, Gyeongsun
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.1
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    • pp.77-86
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    • 2020
  • Purpose : This study is a descriptive survey research that examines the effect of nursing students' satisfaction in major and consciousness of biomedical ethics on nursing professionalism. Methods : The research subjects consisted of junior and senior nursing students enrolled in four colleges located in City B, South Korea Structured questionnaires were distributed to the subject and a total of 262 copies of survey responses were analyzed. The collected data were analyzed by frequency, percentage, mean and standard deviation, t-test, and analysis of variance (ANOVA) using SPSS/WIN 22.0 program. The correlation relationship was investigated based on the Pearson correlation coefficient. Multiple regression was used to capture the effect on the nursing professionalism. Results : A positive correlation was observed between the nursing students satisfaction in major and consciousness of biomedical ethics (r=.280, p<.001), between satisfaction in major and nursing professionalism (r=.581, p<.001), and between consciousness of biomedical ethics and nursing professionalism (r=.290, p<.001). General satisfaction (β=.227, p=.001), and relationship satisfaction (β=.248, p=.000) among major satisfaction had the strongest prediction power for the nursing professionalism of nursing students, followed by right to life of fetus (β=.190, p=.000) among consciousness of biomedical ethics and motivation for admission (β=.137, p=.006). These predictors explained 36.9 % of the variable of nursing professionalism. Conclusion : Based on this study result, repeated studies are required that can confirm diverse influential factors on the nursing professionalism of nursing students. Operation of curriculums and development of programs that increase the nursing students' satisfaction in major and foster their nursing professionalism are required in the future.

Implementation of Impedance Method to Estimate Blood Flow Variation with Cuff Pressure Change (커프 압력 조절에 따른 혈류량 변화 평가를 위한 임피던스법의 구현)

  • Jeong, Do-Un;Bae, Jin-Woo;Shon, Jung-Man;Yae, Su-Yung;Choi, Byeong-Cheol;Nam, Ki-Gon;Kim, Cheol-Han;Jeon, Gye-Rok
    • Journal of Sensor Science and Technology
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    • v.13 no.6
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    • pp.462-472
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    • 2004
  • In this study, we measured the blood flow on arm by non-invasive method and implemented a system to measure variation of the blood flow by estimating bio-electrical impedance and arterial pressure according to cuff pressure. The implemented system measured impedance variation according to pressure variation applied by artificial cuff pressure on the measuring position. The system consisted of pressure measuring part and impedance measuring part using 4-electrode method. Pressure measuring part was composed of semiconductor pressure sensor and electronic circuit for signal processing of sensor output signal. In addition, impedance measuring part was composed of constant current source circuit and lock-in amplifier for detecting impedance signal. We conducted experiments of impedance measuring part using standard resistance for performance evaluation of the implemented system. In addition we experimented to estimate variation of the blood flow by measuring impedances of the experimental group. We estimated ratio of the blood flow resistance using mean arterial pressure and variation of the blood flow. As a result the ratio of the blood flow resistance and variation of blood flow were in an inverse relationship with each other and the correlation coefficient was -0.96776.

Development & Evaluation of acupuncture Point Impedance Measurement System Using 12 Channels Multi-Frequency (12채널 Multi-frequency를 이용한 경혈 임피던스 측정시스템 개발 및 평가)

  • Kim, Soo-Byeong;Lee, Jae-Woo;Lee, Seung-Wook;Lee, Na-Ra;Kim, Young-Dae;Shin, Tae-Min;Lee, Yong-Heum
    • Korean Journal of Acupuncture
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    • v.28 no.1
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    • pp.1-13
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    • 2011
  • Objectives : The object of this study is to evaluate and develop the system that reflects acupoints electrical properties by the multi-frequency using the SPAC (Single Power Alternative Current) stimulation method based on BIA (Bioelectrical impedance method). Methods : The 12 channel meridian impedance measurement system (MIMS) was designed, which sets multi-frequency with 10 steps (1~10kHz). To check acupoints electrical properties, impedance of acupoints were measured from 11 acupoints selected from the LU and ST meridians. Results : Regarding distribution of measurement values by multi-frequencies, we found the lowest response at 1kHz was in common. But frequency bands which represent the highest response at each acupoint were various. Measurement values of each acupoint by multi-frequencies were expressed similar distribution (P<0.05). Also we could check same frequency band which showed the highest response at left/right equal acupoints (P<0.05). Conclusions : Through change of acupoints electrical properties by multi-frequency stimulation, we checked oriental medical diagnostic possibilities by using this system. We would progress variable clinical trials with this system for oriental medical diagnosis.

Development of a Novel Step Detection Algorithm for Gait Evaluation of Patients with Hemiplegia Based on Trunk Accelerometer (뇌졸중으로 인한 편마비 환자의 보행평가를 위한 체중심 가속도센서 기반의 새로운 보 검출 알고리즘 개발)

  • Lee, Hyo-Ki;Hwang, Sung-Jae;Cho, Sung-Pil;Lee, Dong-Ryul;You, Sung-Hyun;Lee, Kyoung-Joung;Kim, Young-Ho;Chung, Ha-Joong
    • Journal of Biomedical Engineering Research
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    • v.30 no.3
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    • pp.213-220
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    • 2009
  • In this study, we have developed a novel step detection algorithm for gait evaluation of patients with hemiplegia based on trunk accelerometry device. For this, we have used a bandpass filter and a least square acceleration (LSA) filter which is characterized by emphasizing the peak or valley point of the acceleration signals for each 3-axis accelerometer signals. To evaluate the algorithm, the detected steps by developed algorithm and real steps by the motion analysis system were compared. As a result, we could obtain the sensitivity of 96.44%, the specificity of 99.94% and the accuracy of 99.90% for the patients' data sets and the sensitivity of 100%, the specificity of 99.93% and the accuracy of 99.93% for the normal data sets. In conclusion, the developed algorithm is useful for the step detection for patients with hemiplegia as well as normal subjects.

An Active Co-Training Algorithm for Biomedical Named-Entity Recognition

  • Munkhdalai, Tsendsuren;Li, Meijing;Yun, Unil;Namsrai, Oyun-Erdene;Ryu, Keun Ho
    • Journal of Information Processing Systems
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    • v.8 no.4
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    • pp.575-588
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    • 2012
  • Exploiting unlabeled text data with a relatively small labeled corpus has been an active and challenging research topic in text mining, due to the recent growth of the amount of biomedical literature. Biomedical named-entity recognition is an essential prerequisite task before effective text mining of biomedical literature can begin. This paper proposes an Active Co-Training (ACT) algorithm for biomedical named-entity recognition. ACT is a semi-supervised learning method in which two classifiers based on two different feature sets iteratively learn from informative examples that have been queried from the unlabeled data. We design a new classification problem to measure the informativeness of an example in unlabeled data. In this classification problem, the examples are classified based on a joint view of a feature set to be informative/non-informative to both classifiers. To form the training data for the classification problem, we adopt a query-by-committee method. Therefore, in the ACT, both classifiers are considered to be one committee, which is used on the labeled data to give the informativeness label to each example. The ACT method outperforms the traditional co-training algorithm in terms of f-measure as well as the number of training iterations performed to build a good classification model. The proposed method tends to efficiently exploit a large amount of unlabeled data by selecting a small number of examples having not only useful information but also a comprehensive pattern.

A Study of Ultrasound Rehabilitation Therapy: Physiological Effects by Change of Ultrasound Intensity (초음파 치료 시 초음파 세기 변화에 따른 생리적 효과 연구)

  • Kim, S.M.;Lee, M.P.;Choi, B.C.;Choi, S.H.;Bae, H.S.;Jung, H.S.;Park, S.Y.
    • Journal of Biomedical Engineering Research
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    • v.29 no.1
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    • pp.40-45
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    • 2008
  • Therapeutic ultrasound which is developed for rehabilitation therapy have already been used for healing joint contracture, synechia, acute and chronic inflammatory diseases. Medical devices for pain-relief and healing using therapeutic ultrasound are actively being developed. This study measured the change of PTT with the transmitted ultrasound through the human body to find out the increase of compliance of blood vessels. Measurement method of PTT in this study is employed as useful ways to acquire physiological information of patients in the clinical case in order to measure the change of mechanical characteristics of blood vessels. This study confirmed the PTT change of rehabilitation patients through the thermal effects of ultrasound by using PTT and also found that it is possible to increase PTT by adjusting the warm water and ultrasound. The increase of PTT means the decrease of the pulse wave velocity from the cardiovascular system to the peripheral arteries. The physiological effects occurred using the warm water and ultrasound.

Ginsenoside F1 Attenuates Eosinophilic Inflammation in Chronic Rhinosinusitis by Promoting NK Cell Function

  • Kim, So Jeong;Lee, Jinju;Choi, Woo Sun;Kim, Hyo Jeong;Kim, Mi-Yeon;Kim, Sun Chang;Kim, Hun Sik
    • Journal of Ginseng Research
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    • v.45 no.6
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    • pp.695-705
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    • 2021
  • Background: Ginsenosides have beneficial effects on several airway inflammatory disorders primarily through glucocorticosteroid-like anti-inflammatory activity. Among inflammatory cells, eosinophils play a major pathogenic role in conferring a risk of severe refractory diseases including chronic rhinosinusitis (CRS). However, the role of ginsenosides in reducing eosinophilic inflammation and CRS pathogenesis is unexplored. Methods: We investigated the therapeutic efficacy and underlying mechanism of ginsenoside F1 (G-F1) in comparison with those of dexamethasone, a representative glucocorticosteroid, in a murine model of CRS. The effects of G-F1 or dexamethasone on sinonasal abnormalities and infiltration of eosinophils and mast cells were evaluated by histological analyses. The changes in inflammatory cytokine levels in sinonasal tissues, macrophages, and NK cells were assessed by qPCR, ELISA, and immunohistochemistry. Results: We found that G-F1 significantly attenuated eosinophilic inflammation, mast cell infiltration, epithelial hyperplasia, and mucosal thickening in the sinonasal mucosa of CRS mice. Moreover, G-F1 reduced the expression of IL-4 and IL-13, as well as hematopoietic prostaglandin D synthase required for prostaglandin D2 production. This therapeutic efficacy was associated with increased NK cell function, without suppression of macrophage inflammatory responses. In comparison, dexamethasone potently suppressed macrophage activation. NK cell depletion nullified the therapeutic effects of G-F1, but not dexamethasone, in CRS mice, supporting a causal link between G-F1 and NK cell activity. Conclusion: Our results suggest that potentiating NK cell activity, for example with G-F1, is a promising strategy for resolving eosinophilic inflammation in CRS.

Fatty acid compositions, free radical scavenging activities, and antioxidative enzyme activities of high-preference and low-preference beef cuts of Hanwoo (Bos taurus coreanae) cows

  • Moon, Sang-Ho;Kim, Eun-Kyung;Jang, Se Young;Tang, Yujiao;Seong, Hye-Jin;Yun, Yeong Sik;Chung, Sanguk;Oh, Mirae
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.12
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    • pp.1974-1979
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    • 2018
  • Objective: This study compared fatty acid compositions and antioxidant activities of high-preference cuts (loin, tenderloin, and rib) and low-preference cuts (brisket, topside, and shank) of Hanwoo (Bos taurus coreanae) cows to obtain potentially useful information for promoting the consumption of various low-preference cuts. Methods: Individual 500 g samples of fresh beef were collected from each of the six cuts from 10 Hanwoo cows (quality grade 1) and immediately freeze-dried. The dried samples were evaluated for fatty acid composition, free radical scavenging activities (hydroxyl, alkyl, and 2, 2'-diphenyl-1-picrylhydrazyl [DPPH] radical), and antioxidative enzyme activities (glutathione peroxidase [GPx], glutathione-S-transferase [GST], and superoxide dismutase [SOD]). Results: The percentages of total polyunsaturated fatty acids were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). Hydroxyl, alkyl, and DPPH radical scavenging activities were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). In addition, the activities of antioxidant enzymes, such as GPx, GST, and SOD, were significantly higher in low-preference cuts compared with high-preference cuts (p<0.05). Conclusion: These results may influence consumers to include more low-preference cuts in their selections based on the nutritional facts, which could help to balance the beef market in South Korea.