• Journal of Chest Surgery
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• v.29 no.10
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• pp.1076-1080
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• 1996

The results about the myocardial protection of recta of the nitric oxide precursor L-arginine upon reperrusion injury after ischemia are diverse. These diversities may be model dependent. Experiments were designed and performed to investigate myocardial protection effects according to the concentration of L-arginine. The Isolated rat hearts were subjected in a 30 minutes oi normothermic ischemia and reperfused for 30 minutes with reperfusate containing 0, 1, 2, 3, 4 moil L-arginine. After 30 minutes of reperfusion, group with 1 and 2 mM/L L-arginine showed a trend of better recovery in left ventricular systolic function(left ventricular developed pressure, positive maximum dpfdt), diastolic function(negative maximum dpfdt) and coronary flow compared to control group(reperfusate no L-arginine). Recovery was impaired with a higher concentration, and at 4 moil L-arginine r covery was worse than control(p (0, 05). These results suggest that optimal concentration of L-arginine Is Important or the recovery of myocardial and endothelial function after ischemia and reperfusion.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.3
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• pp.136-141
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• 2012

The hearts of highly trained athletes show morphologic and electrocardiographic (ECG) changes that suggest the presence of cardiovascular disease, including sinus bradycardia, a striking increase in precordial R-wave or S-wave voltages, ST segment depression, and T-wave inversions. Despite a number of previous observational surveys, the determinants of abnormal ECG patterns in trained athletes remain largely unresolved. In this study, we compared the electrocardiographic characteristics of athletes to determine any sensitive indicators. Comparison between ECG patterns and cardiac physiology was performed in 21 junior athletes and 25 untrained subjects with no signs of cardiac disease. Sinus bradycardia was detected in a subset of athletes but not statistically significant between the athletes ($69.9{\pm}11.1bpm$) and the control ($72.7{\pm}9.9bpm$) group. The mean values of the PR and QTc intervals in the athletes' group were $149.2{\pm}15.4ms$ and $402.3{\pm}28.8ms$, respectively. Also, there were no significantly differences between control group and the athletes' group. In addition, the athletes demonstrated a spectrum of alterations in the 12-lead ECG pattern, including marked increase in precordial R-wave or S-wave voltages ($$SV_1+RV_5{\geq_-}35mm$$, 23.8%), QRS duration ($${\geq_-}90ms$$, 90.5%), suggestive of left ventricular hypertrophy. However, left axis deviation, ST segment depression, and T-wave changes in V5, V6 were not observed in either the athletes or control group. Our findings suggest that sinus bradycardia, precordial R-wave or S-wave voltages, and QRS duration seem to be more sensitively detected in athletes than in control group. Further researches on the electrocardiographic patterns of athletes should be carried out to improve the sensitivity and specificity of diagnostic criteria.

• Journal of the Korean Home Economics Association
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• v.37 no.2
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• pp.127-144
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• 1999

The purposes of this study were to identify the housing maintenance cost, imputed rent fee and total housing cost of households living in rental house, to analyze the factors related to their housing maintenance cost, imputed rent fee and total housing cost and to investigate the factors contributing to total housing cost to total household income ratio. The data used for these purposes, was 97 KHPS of Daewoo Economic Research Institute. Sample size of households living in rental house, was 663. Statistics performed for the analysis were frequencies, percentiles, t-test, Lorenz cutie and Gini coefficient, Tobit analysis, OLS and Logistic analysis. The results of this study were as fellows: First, monthly cost of monthly rent & maintenance and repairs of households living in rental house with a deposit was lower than rental house, while the imputed rent fee of households living rental house with a deposit was higher than monthly rent households'And, total housing cost of households living in rental house with a deposit was higher than monthly rent households'. Second, Gini coefficient of the housing maintenance cost was 0.440, Gini coefficient of imputed rent fee was 0.362, and Gini coefficient of total housing cost was 0.291. Third, the variables related to their housing maintenance cost were family type, total household expenditure of socio-demographic characteristics and residence, type of rent, housing type of housing environmental factor. Also, the variables contributing to imputed rent fee were job type and educational attainment of household hearts, the number of family members, total household expenditure, residence, type of rent, housing type and tole number of rooms. In addition, the variables associated with total housing cost were job type and educational attainment of household head, total household income and residence, type of rent, housing type and the number of room. Finally, age, job type, educational attainment of household head, wife's employment status, the number of family members, family type, total household expenditure, residence, rent type of rent, housing type, the size of living space, and the number of room were significant variables contributing to total household cost to total household income ratio.

• Journal of the Korean Geographical Society
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• v.40 no.6 s.111
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• pp.595-612
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• 2005

This paper is to inquire into nature of the educated's geography from 1905 to 1910 by researching relevant geographical resources in HAKBO published by the Academic Society. At that time, the Patriotic Enlightenment Movement was active, and the Academic Society attempted to enlighten people, to enrich the country, and to restore the sovereign right. The educated tried to understand the reality in view of social Darwinism and make their country the winner as well as the fit in the struggle for existence by this movement. Their effort can be seen in HAKBO and geography in it. The contents of geography in HAKBO was related to world-wide geographical information and intended to instil patriotism into the hearts of people. As their research methods, they adopted systematic geographical method by comparing between region and region, or studying relationships of the nature and human, and Hettner's regional geographical method which describes human after the nature. Hence, it is proved that the educated's geography in HAKBO introduced modem geography in western society for Patriotic Enlightenment and it used its geographical methods.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.175-182
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• 1999

In the present study, the underlying mechanisms for diabetic functional derangement and insulin effect on diabetic cardiomyopathy were investigated with respect to sarcoplasmic reticulum (SR) $Ca^{2+}-ATPase$ and phospholamban at the transcriptional and translational levels. The maximal $Ca^{2+}$ uptake and the affinity of $Ca^{2+}-ATPase$ for $Ca^{2+}$ were decreased in streptozotocin-induced diabetic rat cardiac SR, however, even minimal amount of insulin could reverse both parameters. Levels of both mRNA and protein of phospholamban were significantly increased in diabetic rat hearts, whereas the mRNA and protein levels of SR $Ca^{2+}-ATPase$ were significantly decreased. In case of phospholamban, insulin treatment reverses these parameters to normal levels. Minimal amount of insulin could reverse the protein levels; however, it could not reverse the mRNA level of SR $Ca^{2+}-ATPase$ at all. Thus, the decreased SR $Ca^{2+}$ uptake appear to be largely attributed to the decreased SR $Ca^{2+}-ATPase$ level, which is further impaired due to the inhibition by the increased level of phospholamban. These results indicate that insulin is involved in the control of intracellular $Ca^{2+}$ in the cardiomyocyte through multiple target proteins via multiple mechanisms for the decrease in the mRNA for both SR $Ca^{2+}-ATPase$ and phospholamban which are unknown and needs further study.

• Korean Journal of Veterinary Research
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• v.56 no.2
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• pp.129-131
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• 2016

Five eastern great egrets with a history of ataxia, wry neck, and wet feathers were submitted to the Veterinary Diagnostic Center for pathologic examination. Slightly enlarged livers with diffuse white-grayish nodules were observed. Microscopically, the hepatic and lung parenchyma contained granulomatous lesions consisting of central necrosis. Some hearts showed myofiber necrosis with infiltration of histiocytes and heterophils. Partial 16SrRNA and gyrB gene sequences of all isolates showed high similarities (99-100%) to those of Salmonella (S.) enterica subsp. enterica. Based on pathological and molecular biological results, S. enterica subsp. enterica systemic infections were diagnosed in eastern great egrets of Korea.

• The Korean Journal of Physiology
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• v.22 no.1
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• pp.1-12
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• 1988

The changes in membrane potential and intracellular $Ca^{2+}$ activities along with adenosine triphosphate (ATP) and creatine phosphate (CP) contents of guinea pig hearts were studied during the cardioplegia and recovery phase. The results obtained were summarized as follows: 1) A low concentration of $Ca^{2+}$ in the cardioplegic solution caused significant changes in membrane potential during the cardioplegia and action potential configurations of the first beat after cardioplegia. 2) Intracellular $Ca^{2+}$ activities were decreased significantly during cardioplegia and increased when the cardiac tissue was reperfused with the normal Tyrode solution. The magnitude of increase in intracellular $Ca^{2+}$ activities was larger in the 0.1 mM $Ca^{2+}-cardioplegic$ solution than the 1.8 mM $Ca^{2+}-solution$. 3) ATP and CP contents of cardiac ventricular tissue were decreased during the cardioplegia, regardless of $Ca^{2+}$ concentration in the cardioplegic solutions, and CP contents were recovered with the reperfusion of normal Tyrode solution faster than those of ATP. And, there were no significant differences in the recovery of CP contents with different concentrations of $Ca^{2+}$ in the cardioplegic solutions tested, while the recovery of ATP contents was faster with $15mM\;K^{+},\;0.1mM\;Ca^{2+}$ cardioplegic solution. These results suggest that the $Ca^{2+}$ concentration in the cardioplegic solution is one of major factors influencing the recovery of cardiac tissue from the cardioplegia.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.114-119
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• 1994

[$^3$H]Ouabain binding parameters ( $K_{D}$ and $B_{max}$) to control rat ventricular strips and Langendorff preparations which were not previously exposed to ouabain were compared with those to both preparations that had been first exposed to a complete ouabain dose range of dose-response curve (10$^{-8}$ to 10$^{4}$M). In rat ventricular strips and Langendorff perfused heart preparations, cumulative dose-response curves of ouabain revealed biphasic positive inotropic effects, a "low-dose" effect and a "high-dose" effect with E $d_{50}$ values of 0.5 $\mu$M and 35 $\mu$M ouabain, respectively. The "low-dose" effect in ventricular strip disappeared or was diminished significantly when the ouabain dose-response curve was repeated after the washout of the effects of the first dose-response curve, whereas there were no significant differences in the maximal "high-dose"effect in both exposures to oubain. However, both of the control and ouabain-preexposed Langendorff perfused hearts revealed the same low-dose effects. The $K_{D}$ value for [$^3$H] ouabain binding and the ouabain binding site concentration ( $B_{max}$) estimated by [$^3$H]ouabain displacement assay in control preparations were 230 nM and 2 pmol/mg protein, respectively. [$^3$H]Ouabain binding parameters were not changed by repeated exposure to high concentrations of ouabain. These results suggest that digitalis receptor desensitization in the rat ventricular strip may due to the change of post-receptor events induced by ouabain binding to a high affinity site ($\alpha$$_2$isoform).).).).).

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.161-167
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• 2009

The purpose of this study was to investigate whether two different exercises, acute exhaustive exercise and long-term endurance exercise training could affect to the expression of Mn-SOD, HSP70, and PPAR-γ protein in myocardium. The Wistar-Kyoto rats(n=24, 4 weeks) were used and randomly divided into 3 groups; endurance exercise training group (EET, n=8), acute exhaustive exercise group (AEE, n=8) or control group (CON, n=8). EET performed treadmill exercise for 12 weeks (5 days/week, 30~60 min/day). AEE exercised treadmill running (speed increased gradually to 14-26 m/min, 60 min ±10min) until exhausted when EET finished the program. Then, all the rats were sacrificed 48 hours rest at least after the last session of their own exercise program. Hearts were isolated and then the expression of Mn-SOD, HSP70, and PPAR-γ were analyzed by western blotting. One-way repeated ANOVA was used and p value under 0.05 was considered as statistical significance. The results were followed as; the expression of Mn-SOD of AEE was decreased compared with CON. However, the expression of Mn-SOD of EET was increased compared with CON. There was significant difference between AEE and EET in the expression of Mn-SOD. The expressions of HSP70 and PPAR-γ in the both AEE and EET were significantly increased compared with CON. In conclusion, acute exhaustive exercise might induce oxidative stress wheres endurance exercise training could ameliorate the oxidative conditions by increase of Mn-SOD, HSP70, and PPAR-γ. Therefore, we suggested that endurance exercise training could enhance the complementary antioxidant system and improve to prevent apoptosis. Further, a long-term moderat aerobic exercise program might play a important role in mitochondrial biogenesis in the heart.

• International Journal of Stem Cells
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• v.16 no.2
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• pp.145-155
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• 2023

Background and Objectives: Embryologically, mesodermal development is closely related to the development of various organs such as muscles, blood vessels, and hearts, which are the main organs that make up the body. However, treatment for mesoderm developmental disorders caused by congenital or acquired factors has so far relied on surgery and drug treatment for symptom relief, and more fundamentally, treatment for mesoderm developmental disorders is needed. Methods and Results: In our study, microRNA (miRNA), which plays an important role in the mesoderm development process, was identified and the developmental function was evaluated. miRNAs consist of small nucleotides, which act as transcription factors that bind to the 3' untranslated region and suppressed target gene expression. We constructed the human embryonic stem cell (hESC) knockout cell line and analyzed the function and characteristics of miR-5739, which plays an important role in mesoderm lineage. miR-5739 acts as a transcription factor targeting SMA, Brachyury T, Hand1, which controls muscle proliferation and differentiation, and KDR gene, which regulates vessel formation in vitro. In vivo results suggest a role in regulating muscle proliferation and differentiation. Gene ontology analysis confirmed that the miR-5739 is closely related to genes that regulate muscle and vessel proliferation and differentiation. Importantly, abnormal expression of miR-5739 was detected in somatic cells derived from patients with congenital muscle disease. Conclusions: Our study demonstrate that miR-5739 gene function significantly affects transcriptional circuits that regulate muscle and vascular differentiation during embryonic development.