• Journal of Chest Surgery
• /
• v.40 no.3 s.272
• /
• pp.168-179
• /
• 2007

Background: The recent trend of an increasing number of patients with acute cardiogenic shock or chronic congestive heart failure following myocardial infarction, as well as the considerable number who can not be weaned from cardiopulmonary bypass after open heart surgery, call for immediate efforts to develop affordable ventricular assist devices that are suitable for the Korean physique. Recently, a pneumatic pulsatile ventricular assist device (VAD), named DKUH-75, has been developed by the Department of Biomedical Engineering, in collaboration with the Department of Thoracic and Cardiovascular Surgery of Dankook University College of Medicine. The feasibility of the DKUH-75 VAD was evaluated on the bases of common hemodynamic variables and echocardiographic measurements in pigs, which are subjected to an acute cardiogenic shock state following myocardial infarction, using a novel coronary artery ligation method employing the ischemic preconditioning concept. Material and Method: Acute cardiogenic shock was induced in 10 Yorkshire Landrace Duroc strain pigs by ligating the left anterior descending coronary artery via an ischemic preconditioning process. The hemodynamic variables were monitored, with epicardial echocardiographic measurements performed before and one hour after the ligation. The DKUH-75 VAD was implanted into 5 pigs one hour after the onset of the shock. The hemodynamic variables and echocardiographic measurements were taken one hour after installation of the VAD. Result: The systolic, diastolic and mean systemic arterial pressures were significantly decreased in all the experimental animals one hour after the ligation. The systolic, diastolic and mean pulmonary arterial pressures were increased (Eds note: this completely contradicts the preceding statement? However, if you mean the non-experimental animals this should be stated?). The left ventricular end diastolic pressure (LVEDP) was increased, but the cardiac index decreased, An increase in the left ventricular end systolic dimension and decreases in the fractional shortening and ejection fraction were observed all animals one hour after the coronary artery ligation. In all 5 of the VAD implanted pigs, the systolic and mean systemic arterial pressures were increased, and the pulmonary arterial pressures decreased one hour after the implantation; the LVEDP decreased, but the cardiac index was significantly increased, In the echocardiographic measurements, the left ventricular end systolic dimension decreased after the implantation of the VAD, but the fractional shortening and ejection fraction significantly increased. Conclusion: Significant improvements in the hemodynamic variables and echocardiographic measurements were observed in the 5 VAD implanted animals one hour after installation, which had been subjected to an acute cardiogenic shock state by ligation of the coronary artery, indicating that the DKUH-75 VAD could help in the recovery of the myocardial function. This suggests that the DKUH-75 VAD is feasible in the short term in relation to an acute cardiogenic shock state due to myocardial infarction.

• Journal of Chest Surgery
• /
• v.38 no.8 s.253
• /
• pp.523-528
• /
• 2005

Background: Investigation of the change of ventricular function and mitral regurgitation after surgical repair of patient with anomalous origin of left coronary artery from the pulmonary artery (ALCAPA) is key issue for the better surgical outcome. Material and Method: From April 1986 to July 2002, 12 patients presented with ALCAPA. The median age at repair was 4 months. Surgical methods included left coronary artery transfer to the aorta (10), Takeuchi procedure (1), saphenous vein free graft bypass (1). Mitral valve was repaired in 1. Result: There were 2 hospital death $(16.7\%)$. The mean follow-up period was $7.1\pm4.1$ years (range, 7 months to 13 years). Four patients required postoperative circulatory assist for $2.2\pm1.1$ days and one needed left ventricular assist device (LVAD) for 1day. Postoperative echocardiography demonstrated significant improvements in mean fractional shortening $(33.4\pm9.1\%\;vs\;17.7\pm9.6\%,\;n=10,\;p<0.05);$ left ventricular end diastolic dimension $(33.4\pm7.3\;mm\;vs\;44.8\pm7.0\;mm,\;n=10,\;p<0.05)$ and systolic dimension $(22.2\pm7.5\;mm\;vs\;33.4\pm7.9\;mm,\;n=10,\;p<0.05)$. Severities of mitral regurgitation decreased in all survivors at 1st and 4th year follow-up echocardiography. There were 2 reoperation due to residual MR and right ventricular outflow obstruction (Takeuchi case). Conclusion: Anatomic repair of anomalous left coronary artery from the pulmonary artery offered an excellent surgical results, especially in terms of the recovery of left ventricle function and mitral regurgitation. However, preoperative indications for mitral procedure is to be evaluated.

• Journal of Yeungnam Medical Science
• /
• v.11 no.1
• /
• pp.101-108
• /
• 1994

Many previously described nuclear medicine procedures to assess glomerular filtration rate have some problems because numerous blood sample is to be taken and they don't measure each separate renal function. Gates described isotopic method for the measurement of global and unilateral GFR based on the fractional renal uptake of $^{99m}Tc$-DTPA 2 to 3 minutes after its intravenous injection. We evaluated GFR using $^{99m}Tc$-DTPA in 57 people according to Gates method and compared with creatinine clearance. A good correlation was observed between creatinine clearance and GFR calculated by Gates' formula with an r value of 0.9(P<0.05). And also the relationship between parameters of $^{99m}Tc$-DTPA renal scan images and GFR was taken. They were significantly correlated with GFR calculated by Gates' formula : r value 0.66 between relative intensity of peak renal to peak aortic activity(pK/pA) and GFR, -0.42 between time between aortic and kidney peak(A-K) and GFR and -0.48 between parenchymal renal activity at 25 min compared to peak kidney activity(25K/pK) and GFR. In conclusion, the determination of GFR according to the Gates' formula shows good and reproducible of GFR with rapidity and simplicity. And the parameters from the renal scan images can use to estimate the renal function.

• Clinical and Experimental Pediatrics
• /
• v.63 no.3
• /
• pp.104-109
• /
• 2020

Background: It is challenging to diagnose asthma in preschool children. The asthma predictive index (API) has been used to predict asthma and decide whether to initiate treatment in preschool children. Purpose: This study aimed to investigate the association between questionnaire-based current asthma with API, pulmonary function, airway hyperreactivity (AHR), fractional expiratory nitric oxide (FeNO), and atopic sensitization in preschool children. Methods: We performed a population-based cross-sectional study in 916 preschool children aged 4-6 years. We defined current asthma as the presence of both physician-diagnosed asthma and at least one wheezing episode within the previous 12 months using a modified International Study of Asthma and Allergies in Childhood questionnaire. Clinical and laboratory parameters were compared between groups according to the presence of current asthma. Results: The prevalence of current asthma was 3.9% in the study population. Children with current asthma showed a higher rate of positive bronchodilator response and loose and stringent API scores than children without current asthma. The stringent API was associated with current asthma with 72.2% sensitivity and 82.0% specificity. The diagnostic accuracy of the stringent API for current asthma was 0.771. However, no intergroup differences in spirometry results, methacholine provocation test results, FeNO level, or atopic sensitization rate were observed. Conclusion: The questionnaire-based diagnosis of current asthma is associated with API, but not with spirometry, AHR, FeNO, or atopic sensitization in preschool children.

• Childhood Kidney Diseases
• /
• v.2 no.2
• /
• pp.133-137
• /
• 1998

Purpose : To investigate renal toxicity of high-dose intravenous immunoglobulin(IVIG) in children with Kawasaki disease and idiopathic thrombocytopenic purpura. Methods : 23 children with Kawasaki disease and 7 children with idiopathic thrombocytopenic purpura who were treated with high-dose IVIG(2 g/kg) were evaluated for the change of urine output, blood urea nitrogen(BUN), serum creatinine(Scr), creatinine clearance(Ccr), tubular reabsorption of phosphorus(TRP), fractional excretion of sodium(FENa), 24hour urine ${\beta}_2$-microglobulin/creatinine(${\beta}_{2}MG/cr$) ratio and urine microalbumin/creatinine(MA/cr) ratio at post-IVIG 1 and 3 day. Results : There was no significant change of urine output, BUN, Scr, Ccr, TRP, 24hour urine ${\beta}_{2}MG/cr$ and MA/cr ratio after high-dose IVIG treatment. Transient increase of FENa at post-IVIG 1 day was the only significant change. Conclusion : There was no significant renal toxicity of high-dose IVIG in children with Kawasaki disease and idiopathic thrombocytopenic purpura who had normal renal function.

• Korean Journal of Animal Reproduction
• /
• v.17 no.4
• /
• pp.339-346
• /
• 1994

An understanding of the structure and function of mammalian spermatozoa requires the iso-lation of these components. In this study, frozen-thawed bovine spermatozoa were treated by physical treatments (vortexing, 26 gauge needle, strained 26 gauge needles and freezing-thawing) or chemical treatments (trypsin, dithiothreitol, sodium dodecylsulfate and $\beta$-mercaptoethanoJ) to yield free heads and tails. The most effective treatment was repeated pumping of sperm suspension through a strained 26 gauge needle conneted to a syringe. Spermatozoa by this treatment were mainly broken at the junction of the head and the tail, resulting in 90-100% yields. Also, sperm head surface did not modify during strained 26 gauge needle treatment when either spermatozoa or sperm heads were incubated in 250${\mu}\textrm{g}$/ml of FITC-UEA 1 for 1 h at room temperature to detect the modification of sperm surface components. Other physical treatments were less efficient for the breakdown of spermatozoa. The effects of chemical treatments on bovine spermatozoa are not noticeable. Dissected sperm heads and tails should be fractional leading to nearly pure components by sucrose gradient centrifugation at 1,000 rpm for 15 min. The result suggest that the established method may be useful for the biochemical study of spermatozoal components, and the understanding of oocyte activation mechanism either by spermatozoal components during fertilization or microinjection of isolated components.

• The Journal of the Petrological Society of Korea
• /
• v.3 no.1
• /
• pp.76-93
• /
• 1994

The Precambrian Hongjesa granite is lithologically zoned from biotite granite in central part to biotite-muscovite granite towards the margin. The X_{Fe}$ (=Fe/(Fe+Mg)) value and the aluminum saturation index of biotite systematically vary as a function of mineral assemblage, and are positively related with those of bulk rock. This relationship as well as the lithological zoning are attributed to the fractional crystallization of the Hongjesa granitic magma. The trace element data corroborate that biotite-muscovite granite is more fractionated than biotite granite. The evolution of the Hongjesa granite is elucidated by using the AFM liquidus topology, where A=$Al_2O_3-CaO-Na_2O-K_2O$; F=FeO+MnO; and M=MgO. At an early magmatic stage where biotite is the only ferromagnesian mineral to crystallize, the X_{Fe}$ value and the alumina content of granitic magma continuously increase.. Muscovite subsequently crystallizes with biotite along the biotitemuscovite cotectic curve where biotite-muscovite granite forms. Local enrichments in Mn and B further crystallize garnet and tourmaline, respectively. The unique zonal pattern characterized by the occurrence of the evolved biotite-muscovite granite at the margin may be accounted for by the passive stoping during the emplacement of the Hongjesa granite. This emplacement may have occurred in continental collision environment, according to the tectonic discrimination diagram using major element chemistry.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.53-60
• /
• 2002

Motion of lung tumors from respiration has been reported in the literature to be as large as of 1-2 cm. This motion requires an additional margin between the Clinical Target Volume (CTV) and the Planning Target Volume (PTV). While such a margin is necessary, it may not be sufficient to ensure proper delivery of Intensity Modulated Radiotherapy (IMRT) to the CTV during the simultaneous movement of the DMLC. Gated treatment has been proposed to improve normal tissues sparing as well as to ensure accurate dose coverage of the tumor volume. The following questions have not been addressed in the literature: a) what is the dose error to a target volume without gated IMRT treatment\ulcorner b) what is an acceptable gating window for such treatment. In this study, we address these questions by proposing a novel technique for calculating the 3D dose error that would result if a lung IMRT plan were delivered without gating. The method is also generalized for gated treatment with an arbitrary triggering window. IMRT plans for three patients with lung tumor were studied. The treatment plans were generated with HELIOS for delivery with 6 MV on a CL2100 Varian linear accelerator with a 26 pair MLC. A CTV to PTV margin of 1 cm was used. An IMRT planning system searches for an optimized fluence map ${\Phi}$ (x,y) for each port, which is then converted into a dynamic MLC file (DMLC). The DMLC file contains information about MLC subfield shapes and the fractional Monitor Units (MUs) to be delivered for each subfield. With a lung tumor, a CTV that executes a quasi periodic motion z(t) does not receive ${\Phi}$ (x,y), but rather an Effective Incident Fluence EIF(x,y). We numerically evaluate the EIF(x,y) from a given DMLC file by a coordinate transformation to the Target's Eye View (TEV). In the TEV coordinate system, the CTV itself is stationary, and the MLC is seen to execute a motion -z(t) that is superimposed on the DMLC motion. The resulting EIF(x,y)is inputted back into the dose calculation engine to estimate the 3D dose to a moving CTV. In this study, we model respiratory motion as a sinusoidal function with an amplitude of 10 mm in the superior-inferior direction, a period of 5 seconds, and an initial phase of zero.

• Clinical and Experimental Pediatrics
• /
• v.45 no.2
• /
• pp.214-222
• /
• 2002

Purpose : The aim of this study was to evaluate myocardial injury in children treated with adriamycin by echocardiography, which is non-invasive and safe measurement for children. Methods : Left ventricular dimensions, wall stress, and contractile function were determined by echocardiographic methods in 17 patient recepients with adriamycin chemotherapy at rest(group 1) and during stress(group 2). Twenty age-matched normal subjects were established as control group. Results : End-diastolic dimension was decreased in both groups(group 1; $92{\pm}7%$ of normal, group 2; $87{\pm}8%$ of normal, P<0.05). Left ventricular end diastolic volume and wall mass were also decreased in both groups(group 1; $96{\pm}12mL/m^2$ and $145{\pm}18g/m^2$, group 2; $87{\pm}8mL/m^2$ and $137{\pm}16g/m^2$, respectively, P<0.05 and P<0.05) and group 2 showed lower values than group 1. Meridional end systolic stress(ESSm) was increased in both groups but there was no significant difference between the two groups(group 1; $52.6{\pm}6.2g/cm^2$, group 2; $63.5{\pm}8.5g/cm^2$, P<0.05, normal value $45.7{\pm}3.5g/cm^2$). The load-independent relation of rate-corrected circumferential fiber shortening velocity(Vcfc) to ESSm has a significant abnormal change in 7 out of 17(41%) in group 1 and 12 out of 17(71%) in group 2. Conclusion : The load-dependent systolic index, such as fractional shortening, may fail to show abnormality because of the compensatory changes in preload and afterload which can mask the impaired contractility. Therefore, systolic performance also should be monitored by a load-indepedent contractility index such as slope value of the end-systolic pressure-dimension relation and the position of the left ventricular stress-fiber shortening velocity after exercise.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.9
• /
• pp.1336-1343
• /
• 2005

In the present study, we screened candidates for enhancing insulin action and secretion from Cinnamomum camphora (CC) fractions, in 3T3-L1 adipocytes and Min6 cells by investigating insulin- stimulated glucose uptake and glucose-stimulated insulin secretion, respectively. CC were extracted by $70\%$ ethanol followed by XAD-4 column chromatography with serial mixture solvents of methanol and water, and the fractional extractions were utilized for determining insulin action and secretion, and $\alpha$-glucoamylase suppressing activity, A significant insulin-stimulated glucose uptake was observed in 3T3-L1 adipocytes, giving 0.5 or $5{\mu}g/mL$ of $40\%\;and\;60\%$ methanol fractions plus 0.2 nM insulin, compared to the treatment of DMSO plus 0.2 nM insulin. The treatments of $40\%\;and\;60\%$ methanol fractions plus 0.2 nM insulin reached the glucose uptake of 10 nM insulin treatment. The $40\%$ methanol fraction increased triglyceride accumulation by stimulating differentiation and triglyceride synthesis similar to pioglitazone, PPAR-$\gamma$ agonist. No inhibition of $\alpha$-glucoamylase activity of CC fractions was observed. They did not modulate the insulin secretion capacity In either low or high glucose media. These results suggest that $40\%$ methanol fraction contains a potential insulin sensitizer to have a similar function of PPAR-$\gamma$ agonist. Crude CC extract may improve glucose utilization by enhancing insulin-stimulated glucose uptake without elevating glucose stimulated insulin secretion.