• Title/Summary/Keyword: Wave Control

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Evaluation of cardiac function by tissue Doppler imaging in children with cancer (Tissue Doppler imaging을 이용한 소아 종양 환자에서의 심기능 평가)

  • Kim, Yeo Hyang
    • Clinical and Experimental Pediatrics
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    • v.49 no.4
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    • pp.417-423
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    • 2006
  • Purpose : The objectives of this study were to assess ventricular function by tissue Doppler imaging in children who were receiving chemotherapy or who had received chemotherapy, and to apply repeated tissue Doppler imaging to make an early assessment in cardiac toxicity studies. Methods : This study was conducted on 23 oncology patients on-treatment or off-treatment from April 2005 to July 2005 at Dongsan Medical Center, Keimyung University. All patients(group 1) were divided into two groups, fractional shortening(FS) over 29 percent(group 2) and FS under 28 percent (group 3) in the first category. These same patients were also divided into the following groups : group treated with anthracyclin(group 4) and group treated without anthracyclin(group 5). Deceleration time(DT), isovolumic relaxation time(IVRT), FS, peak early diastolic(E), and peak late diastolic (A) velocity of transmitral flow were measured by M-mode and pulsed wave Doppler. Systolic(Sm), peak early diastolic(Em), and peak late diastolic(Am) velocity in apical 4-chamber and 2-chamber views were measured by tissue Doppler imaging. The author calculated a modified Tei index, E/A, E/Em ratio by using measured values. Results : Twenty three patients were enrolled : 12 boys and 11 girls. The average age of patients was 8 years and 4 months. Thirteen out of 23 patients were in the group treated with anthracyclin (group 4) and 6 had FS under 28 percent(group 3). E/Em ratio showed a significant difference between group 1 and control group($6.46{\pm}1.85$ vs $7.06{\pm}1.64$, P<0.05). Other parameters had no difference statistically. Conclusion : This study showed that the change of cardiac function developed earlier in diastolic function than in systolic function, as E/Em ratio reflecting the mean LV diastolic pressure showed a significant difference between the control group and chemotherapy groups. Echocardiography using tissue Doppler imaging is a non-invasive, comfortable and reliable method for post-chemotherapy follow up.

Development and Reliability of Intraoral Appliance for Diagnosis and Control of Bruxism (이갈이 진단 및 조절용 구내장치의 개발과 신뢰도 조사)

  • Kim, Seung-Won;Kim, Mee-Eun;Kim, Ki-Suk
    • Journal of Oral Medicine and Pain
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    • v.30 no.1
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    • pp.69-77
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    • 2005
  • The purposes of this study were to develop and introduce a novel intraoral appliance for bruxism composed of power switch and biofeedback device and further to examine inter- and intra-reliability of the appliance prior to clinical tests. The newly-developed appliance consisted of detection sensors, a central processing unit (CPU), a reactor and a storage unit and a displayer. Compact-sized, waterproof switches were selected as bruxism detection sensor and any sensor activation by clenching or grinding event was processed at the CPU and transmitted, by radio wave, to the reactor and storage unit and triggered auditory or vibratory signal, subsequently producing biofeedback to the patient with bruxism. The data on bruxing event in the storage unit can be displayed on the computer, making it possible analyzing frequency, duration and nature of bruxism. Cast models were obtained from ten volunteers with normal occlusion to evaluate reliability of the appliances. For inter-operator reliability on the intraoral appliances, each operator of the two fabricated the appliance for the same subject and compared the minimal contact forces provoking auditory biofeedback reaction in vertical, lateral and central directions. Intra-operator reliability was also investigated on the appliances made by a single operator at two separate times with an interval of two days. Conclusively, the newly-developed appliance is compact and safe to use in oral circumstance and easy to make. Furthermore, it had to be proven reliability excellent enough to apply in clinical settings. Thus, it is assumed that this appliance with the processor and the storage of data and auditory or vibratory biofeedback function is available and useful to analyze and control bruxism.

Identification of LED Lights for the Attraction of Bemisia Tabaci and Effect of Host Plant in the Initial Periods (담배가루이 유인용 LED 선발과 기주식물이 초기 유인력에 미치는 영향)

  • Kwon, D.H.;Kwon, M.J.;Yang, D.Y.;Ahn, Y.K.;Hong, K.H.;Park, M.R.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.22 no.2
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    • pp.123-133
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    • 2020
  • Four LEDs (blue, green, red, and white light) were tested to identify the most attractive wave length to utilize as the forecasting tools for the B. tabaci in glass houses. Attractiveness was evaluated by the total number of the B. tabaci attached to a yellow sticky trap. In the condition of no host plant supplement, the attraction efficacy was ordered from high to low as blue light (107.3±2.5), white light (83.0±12.1), red light (58±21.8), and green light (39.7±8.1). In the supplement of the host plant, the attraction was observed in the order of blue light (52±17.4), red light (38.7±5.8), green light (12.7±1.5), and white light (11.7±5.0). In both experimental conditions, blue light showed the highest attraction. In terms of the host plant effect to LED attraction, it varied following as white light (85.9%), green light (68.1%), blue light (51.6%), and red light (33.3%). This result suggests that red light is the least affected by the host plant. In the evaluation of the relative control efficacy, it was determined following as red light (66.7%), blue light (48.5%), green light (31.9%) and white light (14.1%) (F3,8 = 14.7, P = 0.001). Taken together, blue light had a very high initial attraction, and red light was revealed low attraction effect by the supplement of the host plant. In field demonstration experiments, a high attractive efficacy was not observed due to low-temperature conditions, but similar higher attractive efficacy was observed in blue and red lights compared to the control. The commercialization of LEDs using red and blue in the future is expected to provide important information regarding B. tabaci population density forecast in glass house.

System Development for Measuring Group Engagement in the Art Center (공연장에서 다중 몰입도 측정을 위한 시스템 개발)

  • Ryu, Joon Mo;Choi, Il Young;Choi, Lee Kwon;Kim, Jae Kyeong
    • Journal of Intelligence and Information Systems
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    • v.20 no.3
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    • pp.45-58
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    • 2014
  • The Korean Culture Contents spread out to Worldwide, because the Korean wave is sweeping in the world. The contents stand in the middle of the Korean wave that we are used it. Each country is ongoing to keep their Culture industry improve the national brand and High added value. Performing contents is important factor of arousal in the enterprise industry. To improve high arousal confidence of product and positive attitude by populace is one of important factor by advertiser. Culture contents is the same situation. If culture contents have trusted by everyone, they will give information their around to spread word-of-mouth. So, many researcher study to measure for person's arousal analysis by statistical survey, physiological response, body movement and facial expression. First, Statistical survey has a problem that it is not possible to measure each person's arousal real time and we cannot get good survey result after they watched contents. Second, physiological response should be checked with surround because experimenter sets sensors up their chair or space by each of them. Additionally it is difficult to handle provided amount of information with real time from their sensor. Third, body movement is easy to get their movement from camera but it difficult to set up experimental condition, to measure their body language and to get the meaning. Lastly, many researcher study facial expression. They measures facial expression, eye tracking and face posed. Most of previous studies about arousal and interest are mostly limited to reaction of just one person and they have problems with application multi audiences. They have a particular method, for example they need room light surround, but set limits only one person and special environment condition in the laboratory. Also, we need to measure arousal in the contents, but is difficult to define also it is not easy to collect reaction by audiences immediately. Many audience in the theater watch performance. We suggest the system to measure multi-audience's reaction with real-time during performance. We use difference image analysis method for multi-audience but it weaks a dark field. To overcome dark environment during recoding IR camera can get the photo from dark area. In addition we present Multi-Audience Engagement Index (MAEI) to calculate algorithm which sources from sound, audience' movement and eye tracking value. Algorithm calculates audience arousal from the mobile survey, sound value, audience' reaction and audience eye's tracking. It improves accuracy of Multi-Audience Engagement Index, we compare Multi-Audience Engagement Index with mobile survey. And then it send the result to reporting system and proposal an interested persons. Mobile surveys are easy, fast, and visitors' discomfort can be minimized. Also additional information can be provided mobile advantage. Mobile application to communicate with the database, real-time information on visitors' attitudes focused on the content stored. Database can provide different survey every time based on provided information. The example shown in the survey are as follows: Impressive scene, Satisfied, Touched, Interested, Didn't pay attention and so on. The suggested system is combine as 3 parts. The system consist of three parts, External Device, Server and Internal Device. External Device can record multi-Audience in the dark field with IR camera and sound signal. Also we use survey with mobile application and send the data to ERD Server DB. The Server part's contain contents' data, such as each scene's weights value, group audience weights index, camera control program, algorithm and calculate Multi-Audience Engagement Index. Internal Device presents Multi-Audience Engagement Index with Web UI, print and display field monitor. Our system is test-operated by the Mogencelab in the DMC display exhibition hall which is located in the Sangam Dong, Mapo Gu, Seoul. We have still gotten from visitor daily. If we find this system audience arousal factor with this will be very useful to create contents.

The Factors Affecting on the Franchisor's Performance and Its Intention of Recontracting with Franchisees : Focused on the Chinese Franchise Market (프랜차이즈 본부의 성과 및 재계약의도에 영향을 미치는 요인들에 관한 연구 : 중국프랜차이즈 시장을 중심으로)

  • Shuai, Su;Seo, Sang-Yun;Lee, Hoon-Yong
    • Journal of Distribution Research
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    • v.17 no.3
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    • pp.1-24
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    • 2012
  • Franchises have recently emerged as the most rapidly expanding industry positioned to create a large impact in the domestic economic. The Chinese franchise industry developed rapidly in the period prior and subsequent to WTO accession with more than 50% of new franchises brands emerging since 2000. M&A transactions in the Chinese franchise industry have progressed actively. In the period from 2005-2007, due to the wholesale and retail market opening in accordance with the guidelines laid forth within the MOU by the WTO the Chinese franchise market is now the largest market in the world all despite a short history of only 20 years. The amount of franchise market research on China is disproportional to its current size and development potential. Beginning in the 1990s, market research conducted by the International Franchise Association focused on emerging markets in Eastern Europe and China. While the research dealt with the Chinese investment environment, it insufficiently explained the market region and cultural environment. The purpose of this research is (i) to investigate the determinants of the performance of franchise systems in China and (ii) new contract renewals based on performance factors. This study will complement existing research in terms of the franchisee perspective. This study may also prove of the benefit to the franchise companies entering the Chinese franchise market enabling them to develop an effective strategy. This study shows that support, incentives, and system standardization by franchisor yielded a positive effect on management performance. This is consistent with previous studies by Shin (2000) and Kim (2008) targeting Korean franchises. Therefore, in the Chinese market, the franchisor must focus on support, incentives, and system standardization rather than concentrate only on the recruitment of franchisees in order to improve revenue. Hypotheses regarding franchisor control have been dismissed in existing research, in the opinion of this study, due to their complexity and inability to control the merchant as a one-kind-assessment-standard. Our findings show that the franchisees' financial condition, management ability and entrepreneurial spirit, among franchisee's characteristics, have a positive effect on franchisor's business performance and satisfaction for the franchisee. This is consistent with previous studies on headquarters' management performance of Lussier (1996), Heo and Jang (2008), and franchisees' financial condition, management ability and entrepreneurial spirit effect on franchisor's satisfaction of Weaven and Franzer (2007), Kim (2009), Han (2009), and Yoon etc. (2008). Therefore, when permitting a franchisee, financial condition, management ability, entrepreneurship of the franchisee should be carefully considered. Among relational factors between franchisor and franchisee, trust has the positive influence on the management performance of the franchisor while conflict has a negative effect. However, trust, commitment and conflict factors have been shown not to have any impact on the satisfaction of the franchise headquarters. This result is consistent with the previous studies of Pavlou and Ba (2000), Morrison (1999), Weaven and Frazer (2007), Kim and Park (1994), Sohn (2007) which show that trust between franchisor and the franchisees have a positive effect and that conflict has a negative impact on franchisor's management performance. Other factors causing a negative effective on the franchisor's management performance are a rapid environmental changes and uncertainty in the business. This is consistent with Campbell et al (2007), Kim and Kim (2009), Han and Baek (2008). Finally, the high management performance and satisfaction of the franchise headquarters has a positive effect on the intention of franchise renewal. In the case of large markets such as China, the franchisor's strategy and the role is very important. In this study, we also investigated the characteristics of franchisor and franchisee, relationship, and environmental uncertainty affecting on the management performance and satisfaction of franchisor. Recently, Korean franchises are attempting to enter foreign markets through the rise in popularity of Korean culture and entertainment commonly referred to as the Korean wave. This study provides recommendations for Korean franchises intending on entering the Chinese market. First, in order to achieve stable profits, the franchise corporation needs to support the operation of the individual franchisee through incentives and standardization of services. Second, because trust between the franchisor and franchisee has a positive effect on management performance, on-going discussion and cooperation is necessary to reduce the level of conflict.

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A Microcomputer-Based Data Acquisition System (Microcomputer를 이용(利用)한 Data Acquisition System에 관(關)한 연구(硏究))

  • Kim, Ki Dae;Kim, Soung Rai
    • Journal of Biosystems Engineering
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    • v.7 no.2
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    • pp.18-29
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    • 1983
  • A low cost and versatile data acquisition system for the field and laboratory use was developed by using a single board microcomputer. Data acquisition system based on a Z80 microprocessor was built, tested and modified to obtain the present functional system. The microcomputer developed consists of 6 kB ROM, 5 kB RAM, 6-seven segment LED display, 16-Hex. key and 8 command key board. And it interfaces with an 8 channel, 12 bits A/D converter, a microprinter, EPROM programmer for 2716, and RS232C interface to transfer data between the system and HP3000 mini-computer manufactured by Hewlett Packard Co., A software package was also developed, tested, and modified for the system. This package included drivers for the AID converter, LED display, key board, microprinter, EPROM programmer, and RS232c interface. All of these programs were written in 280 assembler language and converted to machine codes using a cross assembler by HP3000 computer to the system during modifying stage by data transferring unit of this system, then the machine language wrote to the EPROM by this EPROM programmer. The results are summarized as follows: 1. Measuring program developed was able to control the measuring intervals, No. of channels used, and No. of data, where the maximum measuring speed was 58.8 microsec. 2. Calibration of the system was performed with triangle wave generated by a function generator. The results of calibration agreed well to the test results. 3. The measured data was able to be written into EPROM, then the EPROM data was compared with original data. It took only 75 sec. for the developed program to write the data of 2 kB the EPROM. 4. For the slow speed measurements, microprinter instead of EPROM programmer proved to be useful. It took about 15 min. for microprinter to write the data of 2 kB. 5. Modified data transferring unit was very effective in communicating between the system and HP3000 computer. The required time for data transferring was only 1~2 min. 6. By using DC/DC converting devices such as 78-series, 79-series. and TL497 IC, this system was modified to convert the only one input power sources to the various powers. The available power sources of the system was DC 7~25 V and 1.8 A.

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THE CURRENT STATUS OF BIOMEDICAL ENGINEERING IN THE USA

  • Webster, John G.
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.27-47
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    • 1992
  • Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

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Assessment of Right Ventricular Function in Patients with Chronic Obstructive Pulmonary Disease Using Echocardiographic Tei Index (만성 폐쇄성 폐질환 환자에서 Tei 지수를 이용한 우심실기능 평가)

  • Oh, Yoon-Jung;Shin, Joon-Han;Kim, Deog-Ki;Choi, Young-Hwa;Park, Kwang-Joo;Hwang, Sung-Chul;Lee, Yi-Hyeong
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.3
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    • pp.343-352
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    • 2001
  • Background : Advanced chronic obstructive pulmonary disease is characterized by progressive pulmonary hypertension leading to right heart dysfunction, which plays a Important role in clinical evaluation but remains difficult and challenging to quantify. The noninvasive doppler echocardiographic value referred to as the Tei index has been suggested as a simple, reproducible and reliable parameter of the right ventricular function. The purpose of this was to assess the right ventricular function in patients with chronic obstructive pulmonary disease using the Tei index and to evaluate its relationship with the pulmonary functional status. Methods : The study population comprised of 26 patients with chronic obstructive pulmonary disease and 10 normal control subjects. The Tei index was obtained by dividing the sum of the isovolumetric contraction and the relaxation times by the ejection time using a pulsed-wave doppler. It was compared with the other available Doppler echocardiographic parameters of systolic or diastolic function and with the pulmonary function of the patients. Results : The Tei indices of the patients with COPD were significantly higher than those of normal subjects($0.45{\pm}0.17$ vs. $0.27{\pm}0.03$, p<0.01). The isovolumetric contraction time/ejection time($0.32{\pm}0.08$ vs. $0.25{\pm}0.05$, p<0.05), the isovolumetric relaxation time/ejection time($0.29{\pm}0.16$ vs. $0.15{\pm}0.08$, p<0.05)and the preejection period/ejection time ($0.46{\pm}0.10$ vs. $0.38{\pm}0.06$, p<0.05) were prolonged and the ejection time ($255.2{\pm}32.6$ vs. $314.2{\pm}16.5$ msec, p<0.05) was significantly shortened in patients with COPD compared to normal subjects. The tei indices were inversely correlated with the $FEV_1$ (r=-0.46, p<0.05) and were prolonged significantly in patients with a severe obstructive ventilatory dysfunction(less than 35% of predicted $FEV_1$) compared to those with a mild and moderate ventilatory dysfunction. The tei indices showed an inverse correlation to with the ejection time (r=-0.469), the isovolumetric contraction time/ejection time(r=0.453), the isovolumetric relaxation time/ejection time(r=0.896) and the preejection period/ejection time(r=0.480). Conclusion : The tei index appeared to be a useful noninvasive means of evaluating the right ventricular function. It revealed a significant correlation with the pulmonary function in patients with COPD.

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Clinical Features of Isolated Noncompaction of the Ventricular Myocardium (심근의 단독 비경화증(Isolated Noncompaction of Ventricular Myocardium)의 임상 양상)

  • Moon, Eun-Kyoung;Lee, Hoon-Young;Chang, Mea-Young;Kil, Hong-Ryang;Chung, Yong-Hun
    • Clinical and Experimental Pediatrics
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    • v.45 no.12
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    • pp.1528-1533
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    • 2002
  • Purpose : Isolated noncompaction of the ventricular myocardium(INVM) is one of the unclassified cardiomyopathies that is characterized by numerous, excessively prominent trabeculations, and deep intertrabecular recesses. We performed this study to evaluate the clinical features of INVM in children. Methods : The medical records of 10 patients with INVM were reviewed. We analyzed the clinical manifestations, hemodynamics, pattern of inheritance, and long-term prognosis of INVM in children. Results : Age at diagnosis was $45{\pm}53months$(1 day-14 years) with follow-up lasting as long as 78 months. Most INVM was asymptomatic on diagnosis. Associated cardiac anomalies were noted in six patients(ventricualr or atrial septal defect, patent ductus arteriosus with mitral valve prolapse, or mitral valve cleft). Depressed or flat changes of T wave in lead II, III and aVF were observed on electrocardiography. Various arrhythmia including WPW syndrome with paroxysmal supraventricular tachycardia, third-degree atrioventricular block, and familial sick sinus node dysfuction were observed. The degree of trabeculation in INVM was significantly prominent from level of mitral valve to apex compared to age-matched control. Familial recurrences were noted in two patients. The systolic function of the left ventricle was decreased in 20% of patients during the follow-up period, but systemic embolism or ventricular tachycardia was not observed. Conclusion : INVM is not a rare disorder. The cardiac function may be deteriorated in children as well as adults during long-term follow up. Thus early diagnosis and long-term follow-up must be done. So, the nation-wide multicenter clinical study would be mandatory to evaluate the incidence, long-term prognosis, and establishment of objective diagnostic criteria of INVM.

Influence of Phenobarbital on the Circadian Rhythm of Opiate Receptor in Rat Brain (백서의 뇌내 Opiate 수용체의 일중 변동에 미치는 Phenobarbital의 영향)

  • Park, Yeoung-Gul;Kim, Kee-Won;Cho, Kyu-Park
    • The Korean Journal of Pharmacology
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    • v.21 no.2
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    • pp.128-141
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    • 1985
  • To investigate the influence of phenobarbital sodium on the action of morphine and on the diurnal rhythms of both opiate receptor binding and ${\beta}-endorphin$ contents, the amount of specifically bound $(^3H)$-morphine and immunoreactive ${\beta}-endorphin$ were measured in the midbrain of phenobarbital-treated rats at 4h intervals in a day. Rats were housed and adapted to a controlled cycle of either 12 h light-12 h dark or 24 h constant dark. After 3 weeks of adaptation, 0.5 ml of physiological saline or phenobarbital sodium (20mg/kg/day, i.p.) were administered twice a day for 2 weeks. Highly significant diurnal rhythms of opiate receptor binding and ${\beta}-endorphin$ were present in rat midbrain. In control group, the peak of maximum $(^3H)$-morphine binding was observed at 22:00 h, whereas the peak of ${\beta}-endorphin$ content was found at 06:00 h. Even in the absence of time cues these diurnal rhythms persisted, but they were highly modified with respect to the wave form as well as differences in the timing of peak and nadir. In the phenobarbital-treated group, these diurnal rhythms were also modified in shape, phase and amplitude, as well as in timing of peak and nadir. In this group, 24 h mean of opiate receptor binding was significantly decreased, while the 24 h mean level of ${\beta}-endorphin$ content was highly increased. However, Kd values in all experimental groups did not change. This indicates that differences in binding were not due to changes in the affinity, but in the number of binding sites. Statistical analysis of regression line indicates that changes of receptor binding were closely correlated with the changes of ${\beta}-endorphin$ content. These results suggest that phenobarbital may influence the action of morphine by changing the number of opiate receptors and that the modification of diurnal rhythm of opiate receptor by the agent is possibly due to changes of ${\beta}-endorphin$ content.

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