• Bulletin of the Korean Space Science Society
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• 1993.10a
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• pp.17-17
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• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.609-617
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• 1999

Background: The aims of this study were to assess the etiologies, survival and prognostic factors of patients with chronic cor pulmonale visited Pusan National University Hospital. Methods : This study included 103 patients with chronic cor pulmonale. There were 67 men and 36 women. The diagnosis of chronic cor pulmonale was primarily based on the presence of underlying lung disorder and echocardiographic finding of enlarged or hypertrophied right ventricle. Other clinical data including patients' symptoms and signs, findings of arterial blood gas analysis, hematologic and biochemical laboratory and pulmonary function test were assessed. Results: The most common underlying lung disorder was pulmonary tuberculosis(59.2%) and chronic obstructive pulmonary disease was the next(28.2%). The survival rate was 57% in one year, 45% in two years, and 34% in three years. The prognostic factors were maximal voluntary ventilation(MVV), forced vital capaoity(FVC), $FEV_1$ serum Na, vital capacity(VC), serum albumin and peak expiratory flow(PEF) in univariate analysis. And in multivariate analysis, serum albumin(p=0.0144) and VC(p=0.0078) were statistically significant. Conclusion: Pulmonary tuberculosis was the most important underlying lung disorder in chronic cor pulmonale. The survival rate was 57% in one year, 45% in two years, and 34% in three years. Serum albumin (p=0.0144) and VC(p=0.0078) were statistically significant prognostic factors.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.117-121
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• 1991

Technetium-99m-hexamethylpropyleneamine oxime $(^{99m}Tc-HM-PAO)$ is a neutral-lipophilic chelate which is used for scanning cerebral blood flow. The labeling efficiencies of $^{99m}Tc-HM-PAO$ is known to be sensitive to the amount of pertechnetate added and the quality of the pertechnetate. Because of these factors, the manufacture recommends that HM-PAO kits be reconstituted with a maximum of 30 mCi pertechnetate which was eluted <4 hr earlier from a generator which had been eluted < 24 hr previously. So we measured the labelling efficiencies and the decomposition rate constant according to the amount of pertechnetate added, the volume of pertechnette added, and generator in-growth time. We used the 3-system chromatographic methods (paper & ITLC-SG chromatography) which analyzed the labelling efficiencies of the $^{99m}Tc-HM-PAO$. There was no significant difference in labelling efficiencies between variable pertechnetate acitvities added. ($39.9{\pm}4.9\;mCi:\;87.8{\pm}5.1\;(%)$, $60.8{\pm}5.0\;mCi:\;90.7{\pm}2.2\;(%)$, $79.0{\pm}6.0\;mCi:\;86.8{\pm}3.9\;(%)$, $106.6{\pm}11.6\;mCi:\;87.7{\pm}1.2\;(%)$, p>0.05) No significant difference in labelling efficiencies were found between pertechnetate of 4ml and 5ml. (4ml : $89.1{\pm}3.2(%)$, 5ml: $87.3{\pm}4.0(%)$, p>0.05). There was no difference between 1-6 and 10-48 hr of generator in-growth time. (1-6 hr: $87.8{\pm}4.0(%)$, 10-48 hr: $89.6{\pm}1.6(%)$, p>0.05) The mean value of decomposition rate constant was $0.196{\pm}0.097\;(hr^{-1})$, and there were no difference according to the amount of pertecnetate added and the volume of pertecnetate added, ($39.9{\pm}4.9\;mCi:\;0.208{\pm}0.059\;(hr^{-1})$, $60.8{\pm}5.0\;mCi:\;0.191{\pm}0.100\;(hr^{-1})$ $79.0{\pm}6.0\;mCi:\;0.192{\pm}0.118\;(hr^{-1})$, $106.6{\pm}11.6\;mCi:\;0.212{\pm}0.030\;(hr^{-1})$, p>0.05, 4 ml: $0.200{\pm}0.074\;(hr^{-1})$, Sml: $0.193{\pm}0.115\;(hr^{-1})$, p>0.05). In the case of using the first eluate, the labelling efficiency of $^{99m}Tc-HM-PAO$ W3S 82.1%. These data suggest that there were no significant alteration in labelling efficiency of $^{99m}Tc-HM-PAO$ according to the considerable range of pertechnetate activities and volume added, and generator in-growth time. Also, it was shown that one vial of HM-PAO kit supplied the $^{99m}Tc-HM-PAO$ which was used for 3-4 patients.

• Journal of Chest Surgery
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• v.30 no.5
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• pp.471-478
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• 1997

Introduction: The use of rabbits as a cardiopulmonary bypass(CPB) animal model is extremely dif%cult mainly due to technical problems. On the other hand, deep hypothermic circulatory arrest(CA) is used to facilitate surgical repair in a variety of cardiac diseases. Although steroids are generally known to be effective in the treatment of cerebral edema, the protective effects of steroids on the brain during CA are not conclusively established. Objectives of this study are twofold: the establishment of CPB technique in rabbits and the evaluation of preventive effect of steroid on the development of brain edema during CA. Material '||'&'||' Methods: Fifteen New Zealan white rabbits(average body weight 3.5kg) were divided into three experimental groups; control CA group(n=5), CA with Trendelenberg position group(n=5), and CA with Trendelenberg position + steroid(methylprednisolone 30 mglkg) administration group(n=5). After anesthetic induction and tracheostomy, a median sternotomy was performed. An aortic cannula(3.3mm) and a venous ncannula(14 Fr) were inserted, respectively in the ascending aorta and the right atrium. The CPB circuit consisted of a roller pump and a bubble oxygenator. Priming volume of the circuit was approximately 450m1 with 120" 150ml of blood. CPB was initiated at a flow rate of 80~85ml/kg/min, Ten min after the start of CPB, CA was established with duration of 40min at $20^{\circ}C$ of rectal temperature. After CA, CPB was restarted with 20min period of rewarming. Ten min after weaning, the animal was sacrif;cod. One-to-2g portions of the following tissues were rapidly d:ssected and water contents were examined and compared among gr ups: brain, cervical spinal cord, kidney, duodenum, lung, heart, liver, spleen, pancreas. stomach. Statistical significances were analyzed by Kruskal-Wallis nonparametric test. Results: CPB with CA was successfully performed in all cases. Flow rate of 60-100 mlfkgfmin was able to be maintained throughout CPB. During CPB, no significant metabolic acidosis was detected and aortic pressure ranged between 35-55 mmHg. After weaning from CPB, all hearts resumed normal beating spontaneously. There were no statistically significant differences in the water contents of tissues including brain among the three experimental groups. Conclusion: These results indicate (1) CPB can be reliably administered in rabbits if proper technique is used, (2) the effect of steroid on the protection of brain edema related to Trendelenburg position during CA is not established within the scope of this experiment.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.119-130
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• 2004

Decrease in cardiac function after open heart surgery is due to an ischemia induced myocardial damage during surgery, and ischemic preconditioning, a condition in which the myocardial damage does not accumulate after repeated episodes of ischemia but protects itself from damage after prolonged ischemia due to myocytes tolerating the ischemia, is known to diminish myocardial damage, which also helps the recovery of myocardium after reperfusion, and decreases incidences of arrythmia. Our study is performed to display the ischemic preconditioning and show the myocardial protective effect by applying cardioplegic solution to the heart removed from rat. Material and Method: Sprague-Dawley male rats were used, They were fixed on a modified isolated working heart model after cannulation. The reperfusion process was according to non-working and working heart methods and the working method was executed for 20 minutes in which the heart rate, aortic pressure, aortic flow and coronary flow were measured and recorded. The control group is the group which the extracted heart was fixed on the isolated working heart model, recovered by reperfusion 60 minutes after infusion and preserved in the cardioplegic solution 20 minutes after the working heart perfusion and aortic cross clamp, The thesis groups were divided into group I, which ischemic hearts that were hypoxia induced were perfused by cardioplegic solution and preserved for 60 minutes; group II, the cardioplegic solution was infused 45 seconds (II-1), 1 minutes (II-2), 3 minutes (II-3), after the ischemia induction, 20 minutes after working heart perfusion and aortic cross clamp; and group III, hearts were executed on working heart perfusion for 20 minutes and aortic cross clamp was performed for 45 seconds (III-1), 1minute (III-2), 3 minutes (III-3), reperfused for 2 minutes to recover the heart, and then aortic cross clamping was repeated for reperfusion, all the groups were compared based on hemodynamic performance after reperfusion of the heart after preservation for 60 minutes. Result: The recovery time until spontaneous heart beat was longer in groups I, II-3, III-2 and III-3 to control group (p<0.01). Group III-1 (p<0.05) had better results in terms of recovery in number of heart rates compared to control group, and recovered better compared to II-1 (p<0.05). The recovery of aortic blood pressure favored group III-1 (p<0.05) and had better outcomes compared with II-1 (p<0.01). Group III-1 also showed best results in terms of cardiac output (p<0.05) and group III-2 was better compared to II-2 (p<0.05). Group I (p<0.01) and II-3 (p<0.05) showed more cardiac edema than control group. Conclusion: When the effects of other organs are dismissed, protecting the heart by infusion of cardioplegic solution after enforcing ischemia for a short period of time before the onset of abnormal heart beats for preconditioning has a better recovery effect in the cardioplegic group with preconditioning compared to the cardioplegic solution itself. we believe that further study is needed to find a more effective method of preconditioning.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.129-134
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• 2008

Purpose: We examined the roles of Ultrasonography conductors by analyzing the results of tissue biopsy of complex cystic masse under the guidance of breast US. Objects and methods: This study was performed to a group of 178 who showed breast US indicating complex cystic masses among 342 patients who were definitely diagnosed by tissue biopsies and operations in our hospital from June 30th, 2003 to June 30th, 2007. The evaluation of tissues around, calcification, the distribution state of blood flow were excluded from the analysis subjects and logic 200 made by GE corporation and gun for core biopsy(Kimal corp., K7/MBD23) were used in this study. Results: The biopsy results of 178 subjects showed FCC (fibrocystic change)(n=56 : 31.4%), Fibrosis (n=41 : 23.0%), Fibroadenoma (n=20 : 11.2%), Epithelial hyperplasia (n=17 : 9.6%), Carcinoma (n=15 : 8.4%), Fibroadipose (n=8 : 4.5%), Sclerosing adenosis (n=7 : 3.9%), Duct ectasia (n=5 : 2.8%), Papiloma (n=5 : 2.8%), and Fat necrosis (n=1 : 0.6%), Hemangioma (n=1 : 0.6%), Abscess (n=1 : 0.6%), Dystrophic calcification(n=1 : 0.6%). Conclusion: The US showed that the results of the tissue biopsy of complex cystic masses were mostly carcinoma(8.4%). Most of them were benign and only 9.6% of epithelial hyperplasia which has high progression rate into malignant tumors epidemically showed malignancy. Most of them were included in the spectrum of fibrous cystic nodule. Even though these results are confirmed, further studies are required. As a result, a nodule which is not certified by US should be right to take the tissue biopsy, but if it's difficult due to patients or another reasons, re-check tests in three months are required. And systemic ultrasonography evaluation should be well recognized to conduct more careful and specific tests.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.337-346
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• 2010

We report non-specific immune responses and disease resistance against Vibrio anguillarum, Streptococcus iniae and Edwardsiella tarda by dietary supplementation of fermented garlic powder (FGP) in olive flounder for the first time. Four isonitrogenous (45% crude protein) and isocaloric (17.1 MJ/kg) diets were formulated to have 0%, 0.5%, 1% and 2% of the FGP (G-0, G-0.5, G-1 and G-2). The experimental diets were fed to juvenile olive flounder averaging 23.4 g in triplicate groups (90 fish/group) in a flow-through system. After a five-week feeding trial, healthy fish with similar sizes from each tank were selected and injected with 1 ml of three bacteria each to evaluate disease resistance of the fish. During the 5-week feeding trial, the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, and survival of the fish were not significantly affected by the experimental diets. However, feed intake was significantly lower (P<0.05) in the fish fed the G-2 diet compared with the control group. Hemoglobin, myeloperoxidase activity, cholesterol and HDL-cholesterol were not different between the dietary groups. However, hematocrit, nitroblue tetrazolium (NBT) activity, and lysozyme activity were increased (P<0.05) with an increment of dietary FGP. Plasma triglyceride of the fish fed the G-0.5 diet was significantly lower than that of fish fed the control diet. The cumulative mortality was lower in the fish fed diets containing FGP compared with the control group in the challenge test except for the bacteria Edwardsiella tarda. The results in this study indicate that dietary supplementation of FGP can enhance the non-specific immune responses and disease resistance of olive flounder against V. anguillarum and S. iniae.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.103-117
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• 1982

In an effort to provide evidence as to the regulatory role of the central dopaminergic system on the renal function, the effects of centrally administered dopamine and its specific antagonist haloperidol were investigated. Haloperidol (HA) given intracerebroventricularly (i.c.v.) induced antidiuresis in doses of 15 and $50{\mu}g/kg$. With $15{\mu}g/kg$ sodium reabsorption in the tubules was increased, while with $50{\mu}g/kg$ free-water reabsorption was increased. However, a marked diuresis with increased sodium and potassium was observed with $150{\mu}g/kg$. Hemodynamic changes were not evident, indicating that the diuresis is of tubular origin. Dopamine (DA), on the other hand, produced antidiuresis when given i.c.v. in a dose-related fashion. With smaller doses of 5 and $15{\mu}g/kg$ the antidiuresis was related to increased reabsorption of sodium in the tubules, but higher doses of 50 and $150{\mu}g/kg$ the decreases in renal blood flow and glomerular filtration rate were evident in addition to the tubular action. After pretreatment with $150{\mu}g/kg$ HA, the effects of $15{\mu}g/kg$ DA was abolished, but the antidiuretic actions of 50 and $150{\mu}g/kg$ were not blocked, and the natriuretic diuretic action of HA was overcome and became inconspicuous. These observations indicate that the central dopaminergic system influences the renal function by producing antidiuresis, and HA elicits diuresis and natriuresis by competitively antagonizing DA specifically on the central dopaminegic receptors. The antidiuresis observed with smaller doses of HA can be best explained by the facts that there are more than two types of DA-receptors in the brain and that the presynaptic autoreceptors on the dopaminergic neurones which affect the dopamine release at the synapse are more sensitive than the postsynaptic receptors. Overall, these data provide an evidence indicating that the central dopaminergic system plays a role in the regulation of renal function in the rabbit.

• The Korean Journal of Physiology
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• v.25 no.2
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• pp.189-200
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• 1991

During the past few years it has been proposed that lithium clearance can be used as a reliable measure for the outflow of tubular fluid from the proximal tubule. This study was aimed to characterize the inflow dependent reabsorption of Na in renal tubule beyond the proximal tubule. For this purpose, lithium clearance was used as a measure for the inflow from the proximal tubule and the changes in reabsorption fraction of Na and water were determined in rabbits. Rabbits were pretreated with hypotonic saline solutions for an hour (50 mM/L NaCl, 20 ml/hr/kg). And then a hypertonic solution of 500 mM/L NaCl (20 ml/kg) was administered intraperitoneally in conjunction with a bolus of LiCl solution (2 mM/kg, i.v.) for conditioning the $C_{Li}$ and urine flow rate. To rule out the effect of $Li^+$ on tubular functions, a bolus of NaCl solution (2 mM/kg, i.v.) was administered. Fifteen, thirty, and sixty minutes after injection of hypertonic saline arterial blood and urine samples were taken. Urinary and plasma concentrations as well as urinary output of $Li^+,\;Na^+\;and\;K^+$ were measured. From these $C_{Li},\;C_{Na}$ and the reabsorption fraction of Na and water $(Fr_{Na}\;&\;FrH_2O)$ were calculated. These results were compared with those from control groups in which the same amount of isotonic saline (145 mM/L NaCl) and of 15% dextran solution were administered in the same way as that in experimental group. Followings are the results obtained. 1) The plasma concentration of $Na^+$ in rabbits injected with hypertonic saline reached the peak value after 15 min and thereafter no significant change was observed. Hematocrit values did not show any change, while urinary excretion of $Na^+$ increased markedly during the first 15 min and decreased thereafter. These results were not affected by an injection of a small amount of LiCl. 2) The clearances of $Li^+,\;Na^+\;and\;K^+$ in rabbits injected with hypertonic saline and LiCl solution decreased. 3) In spite of the variation in $C_{Li},\;Fr_{Na}$ did not show any significant change while $FrH_2O$ increased gradually. 4) $C_{Li}$ decreased also in rabbits received isotonic saline. $Fr_{Na}$ tended to be higher than that in hypertonic saline group, while $FrH_2O\;and\;Fr_{Na}$ did not associated with the decrease in $C_{Li}$. 5) $C_{Li}$ of the rabbits received dextran solution fluctuated persistently and $Fr_{Na}\;and\;FrH_2O$ did not change in along with $C_{Li}$ although $Fr_{Na}$ had a tendency to be higher than that in hypertonic saline group. 6) From the above results it was concluded that: (a) In rabbits with normal body store of $Na^+$, the $Fr_{Na}$ of renal tubule beyond proximal tubule. calculated from $C_{Li}$ as a measure of inflow from proximal tubule is constant in spite of variations in $C_{Li}$. (b) The $FrH_2O$ calculated from $C_{Li}$ is dependent largely upon ADH rather than inflow from proximal tubule. (c) When there is a decrease in plasma $Na^+$ concentration or ineffective body fluid. $Li^+$ reabsorption may occur in the thick segnent of Henle's loop and hence the determination of $Fr_{Na}$ and $FrH_2O$ will not be easy one, but $Fr_{Na}$ is constant under the same experimental conditions.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.108-118
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• 1999

Background: To evaluate the risk factor and long-term result of arterial switch operation , a retrospective study was done. Material and Method: A retrospective analysis was done to evaluate the early and long-term results on 58 patients who underwent an arterial switch operation(ASO) for transposition of the great arteries(TGA) with intact ventricular septum, between January 1988 and December 1996. Beforesurgery, 36 patients(62.1%) underwent balloon atrial septostomy, 32 patients(51.7%) received PGE1 infusion, and preparatory banding of pulmonary artery was performed on 6 patients(mean LV/RV pressure ratio 0.53$\pm$0.11). Result: The age at operation ranged from 1 to 137 days(mean 24$\pm$26 days) and the weights ranged from 1.8 to 6.8 kg (mean 3.5$\pm$0.8 kg). There were 14 early deaths(24.1%), but of the last 24 patients operated on since 1994, there were only 2 early deaths(8.3%). In the risk factor analysis, the date of operation was the only risk factor for early death(p-value < 0.01). Eight of the 14 early deaths were due to acute myocardial failure(mainly inadequate coronary blood flow). The length of follow-up ranged from 2 months to 8 years, average of 36$\pm$27 months. The follow-up included sequential noninvasive evaluations and 21 catheterizations and angiographic studies performed 5 to 32 months postoperatively with particular attention to the great vessel and coronary anastomosis, ventricular function, valvular competence, and cardiac rhythm. There were 5 late deaths(11.4%), one of thesedeaths was related to the late coronary problems, two to aspiration, one to uncontrolled chronic mediastinitis, and one to progressive aortic insufficiency and heart failure. The most frequent postoperative hemodynamic abnormality was supravalvular stenosis and the degree of pulmonary or aortic obstruction had slowly progressed in some cases, however there were no children who had to undergo a reoperation for supravalvular pulmonary or aortic stenosis. Aortic regurgitation was identified in 9 patients, which was mild in 7 and moderate in 2 and had progressed in some cases. Two patients who had an unremarkable perioperative course were identified as having coronary artery obstructions. The other late survivors were in good condition, were in sinus rhythm, and had normal LV functions. Actuarial survival rate at 8 years was 68.8%. Conclusion: We concluded that anatomic correction will be established as the optimal approach to the TGA with intact ventricular septum, though further long-term evaluations are needed.