• The Korean Journal of Physiology and Pharmacology
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• v.20 no.6
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• pp.657-667
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• 2016

Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at $10^6$ or $10^5$ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.

• The Korean Journal of Physiology
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• v.9 no.1
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• pp.69-76
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• 1975

Cardiac performances were analyzed in intact turtle heart(Amyda japonica), perfusing with turtle Ringer-Locke's solution containing various hydrogen ion concentration, at several levels of arterial and venous pressure. 1. Ventricular work increased when venous pressure, or venous filling pressure increased, and also increased when arterial pressure increased. 2. The higher the arterial pressure, the lower the cardiac to output, for arterial pressure is the resistance to the ventricular blood flow. On the other hand, in specific arterial pressure, cardiac output was proportional to the venous filling pressure. 3. Heart rates did not change significantly during the perfusion with Ringel· solution of various pH. 4. In the heart Perfused with Ringer solution of various pH, ventricular work was the highest at PH 7.6 (at 6 $cmH_2O$ arterial pressure and 8 $cmH_2O$ venous pressure, the ventricular work was 63.09m$\cdot$cm). However, within the range of pH $7.1{\sim}7.6$, there were no significant changes in cardiac output and ventricular work. Below the level of pH 7.0, ventricular work decreased to less than 56% of maximium value (at $6cmH_2O$ arterial pressure and $8cmH_2O$ venous Pressure, ventricular work was 36.0$gm{\cdot}$ at pH 7.0). At pH 7.7 ventricular work decreased to less than 48% of maximum value (ventricular work: 30.0 $gm{\cdot}$). The nature of the cardiac performance at the various arterial and venous pressures was similar to that of normal heart. 5. Turtle heart seemed to be relatively insensitive to acid-base disturbances. The mechanism of negative inotropic effect of hydrogen ion was discussed.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.249-250
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• 1998

In this study, we modeled moving-actuator type Total Artificial Heart (TAH) with cardiovascular system as a form of electric circuit. The bronchial circulation, important for the imbalance between the left cardiac output and the right one, was considered and added to the model. In the model, the relations of hemodynamic variables, just as blood pressures, volumes, or flow rates of each part of body, can be expressed as simultaneous first order ordinary differential equations. To solve the equations by the numerical analysis, Runge-Kutta forth order approximation method was adopted. The simulation software (SimTAH), implemented in C++ as a window-based application program, was developed to display the hemodynamic variables and to receive control inputs from users. SimTAH was evaluated by comparison of the simulation results with the results of mock-circulation tests, in vitro.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.399-405
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• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $316.7{\pm}6.18g$) was determined under the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.4%, 0.6%, and 0.8% of body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $21-24^{\circ}C$ for 3 weeks. Weight gain (WG) and specific growth rate (SGR) were significantly higher in fish fed to satiation (1.0% BW/day) than in those in other treatments. These parameters were negative and significantly lower in the starved fish than in fish fed the experimental diet at all feeding rates. There were no significant differences in WG and SGR among fish fed at 0.4%, 0.6%, and 0.8% BW/day. Hematocrit and hemoglobin in fish fed to satiation were significantly lower than those in other treatments. Histological changes of fish fed at 0.6% BW/day indicated that this group was in the best condition; differences were not found in tissues of fish fed at 0%, 0.6% and 1.0% BW/day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 317 g was 0.99% BW per day at the optimum water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.234-240
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• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. We determined the optimum feeding rate (initial fish mean weight of $240{\pm}10.9$ g) at the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.5%, 0.75%, and 1.0% body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $19-21^{\circ}C$ for three weeks. Weight gain (WG) for fish fed to satiation was significantly higher than that of unfed fish and fish fed at 0.5% and 0.75% BW per day. The WG of fish fed at 1.0% BW per day was significantly higher than that of unfed fish and of fish fed at 0.5% BW per day. However, there were no significant differences in WG between fish fed at 0.5% BW per day and those fed at 0.75% BW per day, between fish fed at 0.75% BW per day and those fed at 1.0% BW per day, and between fish fed at 1.0% BW per day and those fed to satiation. The specific growth rates of fish fed at 1.0% BW per day and those fed to satiation were significantly higher than those of unfed fish and of fish fed at 0.5% BW per day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 240 g was 1.09% BW per day at the optimum water temperature.

• Journal of Chest Surgery
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• v.28 no.6
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• pp.571-578
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• 1995

Rastelli operation in which right ventricle[RV and pulmonary artery[PA is connected with an artificial graft is effective in increasing the pulmonary blood flow in certain types of congenital heart disease but, in many, it requires a reoperation because of the relative stenosis of graft that develops as the patients become old. The purpose of this study is to evaluate the various factors which many influence the long term outcome of such patients following a Rastelli operation. A total of 47 patients underwent a Rastelli operation during a 15 year period between November, 1978 and October 1993. The mean follow-up period is 76.1 51.3 months.1 Among the 47 patients, a valved conduit was used in 30[63.8% , and non-valved conduit in 17[36.2% patients. In the 8 patients[17.0% who died postoperatively, a valved conduit was used in 5 [16.6% and a non-valved conduit in 3[17.6% . There was no statistical difference in mortality between the 2 groups. There was a good linear correlation between the body surface area[X and the conduit size[Y [Y=3.86X + 14.6, R=0.55, P=0.01 .2 Ten patients underwent replacement of the conduit during the follow-up period. The type of conduit used and the frequency of subsequent replacement were as follows: Ionescu-Shiley, valved-33.3%, Carpentier-Edwards, valved-30.8%, Hancock, valved-80% and non-valved conduit-9.1%. The median period free of reoperation was 110 months for the valved and 79 months for the non-valved group, there being no statistical difference between the 2 groups. 3 The patients who did not require reoperation are all doing well [New York Heart Association Functional Classification: Class I . Pressure gradient between the RV and the PA was 20 mmHg in 10 randomly selected patients who did not require reoperation and 92 9 mmHg in 10 patients who did require reoperation.4 In the 10 patients who underwent a conduit replacement procedure.5 Among patients undergoing reoperation, 2 died from endocarditis.The remaining 8 patients are doing well without limitation in physical activity at a mean follow-up period of 32.7 33.9 months [range 2 to 89 months . 6 At 5, 7, and 10 years, the reoperation-free rates among all patients were 96%, 91% and 29% and the survival rates were 82%, 82% and 71%. In conclusion, Rastelli operation is an effective procedure in ameliorating symptoms in a select group of patients with congenital heart disease. Because of the inherent nature of relative graft stenosis and degeneration, a long-term follow-up is required under the proper selection of the graft material.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.1063-1068
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• 2014

We investigated the effects of feeding rate on the growth performance and blood components of sub-adult olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $370{\pm}5.72g$) was determined under the low water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.3%, 0.4%, 0.5%, and 0.6% body weight (BW) per day, and to satiation (0.75%). Feeding trial was conducted under a flow-through system with 12 1.2-metric ton aquaria receiving filtered seawater at $12-14^{\circ}C$ for 4 weeks. Weight gain (WG) and specific growth rate (SGR) for fish fed at 0.6% BW per day was significantly higher than that of unfed fish (0%) and fish fed at 0.3% and 0.4% BW per day. There were no significant differences in WG and SGR among fish fed at 0.5%, 0.6%, and 0.75%. These parameters were negative and significantly lower in the starved fish than in fish fed the experimental diet at all feeding rates. Survival for unfed fish (0%) was significantly lower than that of fish fed at 0.4%, 0.5%, and 0.6%. Hematocrit and hemoglobin content of fish fed at 0% and 0.75% (satiation) were significantly lower than that of fish fed at 0.4% BW per day. Total protein content in unfed fish was significantly lower than those in other treatments. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 370 g was 0.51% BW per day at the low water temperature.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1205-1211
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• 2011

In this paper, we developed a pacemaker that can increase the efficacy of a left ventricular assist device (LVAD) and increase the survival rate for patients suffering end-stage heart failure. Because LVAD patients can experience arrhythmia, the pacemaker incorporated into the LVAD has the important role of sustaining sufficient blood circulation during arrhythmia. The electrode of the pacemaker is located at the apex of the left ventricle, where the VAD's inlet cannula is connected. This is efficient placement, in that the electrode can transmit electrical stimulation directly to the Purkinje fibers of the myocardium. The pacemaker can change the stimulation rate from 0 bpm to 191.4 bpm when a button is pressed on the external control module, and the pacemaker normally stimulates the heart at 60 bpm with 0.25 J of energy. We performed animal experiments to evaluate the performance and reliability of the combination of the LVAD and pacemaker. At pacemaker stimulation rates of 86.4 bpm, 100.2 bpm, 126.6 bpm, we recorded the ECGs, aortic pressures, and flow rates to analyze the heart loads.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.243-251
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• 2005

Objective: Low-dose aspirin have been proposed to improving endometrial receptivity and pregnancy rate in COH-IVF by increasing endometrial perfusion. However, the effect of low-dose aspirin in COH-IVF could be negligible because there have been large quantity of other important factors responsible for changing endometrial perfusion accompanied by COH procedure. In contrast, in frozen-thawed embryo transfer cycles which were not accompanied by COH procedure, the effects of low-dose aspirin in endometrial blood flow seems to be more certain than in COH-IVF cycles. In this study, we analyzed the effect of low-dose aspirin treatment on implantation and pregnancy rates in patients undergoing frozen-thawed embryo transfer Methods: From January 2003 to December 2003, total 264 cycles from 264 patients who attended infertility clinic at Samsung Cheil Hospital were enrolled in this study. All cases included in this study, embryos were frozen and thawed at the pronuclear stage and three days after incubation, at least 2 or more good quality embryos were transferred into uterus. In study group, low dose aspirin (100 mg/day) was administrated from the first or second date of menstrual day to 9 days after embryo transfer. On the other hand, control group did not take any medicine except estradiol valerate for endometrial priming. Several variables including implantation and pregnancy rates were compared in both groups. After then, each groups were stratified by endometrial thickness checked at embryo transfer (ET) day such as (28 mm versus <8 mm) and same variables above described were compared between study and control groups. Results: The mean age, infertility duration, endometrial thickness at embryo transfer day and mean number of transferred embryo were not significantly different in both groups. Also, implantation rates (study group: 15.8%, control group: 20.5%) and pregnancy rate (study group: 45.1%, control group: 43.5%) were not significantly different between two groups. (p>0.05) After we analyzed same variables stratified by endometrial thickness checked at embryo transfer day, we could not found any significant difference between study and control groups. Conclusions: Low-dose aspirin treatment seems to have no advantage of improving implantation and pregnancy rates in patients undergoing frozen-thawed embryo transfer.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1738-1746
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• 2002

Research was carried out to ascertain whether or not the volume of saliva flowing into the rumen regulates dry forage intake in ruminants. Goats with a parotid fistula were fed roughly crushed alfalfa hay cubes, concentrated beef cattle feed and $NaHCO_3$ wice daily (10:00-12:00, 16:00-18:00). Except for the days on which experiments were conducted, the animals were free access to drinking water. The animals were intraruminally infused every day prior to the morning feeding period with parotid saliva collected from the parotid fistula over a 24 h period. The present experiment consisted of three treatments, non-infusion (NI), intraruminal infusion of parotid saliva (RSI), and intraruminal infusion of warm water (RWI). In the RSI treatment, approximately 4-5 kg of parotid saliva (280-290 mOsm/l) collected over a 24 h period was intraruminally infused 1 h prior to the commencement of morning feeding. In the RWI treatment, parotid saliva was substituted for warm water ($36^{\circ}C$). After infusions, the animals were fed on roughly crushed alfalfa hay cubes for 2 h. During feeding, eating and saliva secretion rates were measured. Blood samples were also periodically collected from the jugular vein. After 2 h feeding, water intake was measured for 30 min. These measurements were used to define thirst levels. On the day of the experiment, the animals were not access to drinking water during the morning feeding. It is thought that rumen fill in RSI and RWI treatments was higher than the NI treatment. In comparison with the NI treatment however, cumulative feed intake increased by 39.3% with RSI treatment and by 45.9% with RWI treatment after completion of the 2 h feeding period. After 2 h feeding, thirst level in the RSI treatment showed only a 10% decrease compared to the NI treatment, but thirst level in the RWI treatment decreased 49.8%. Despite the significant differences in thirst levels between RSI and RWI treatments, the cumulative feed intake in both treatments was similar. When comparing accumulated saliva secretion volumes 2 h after feeding, volumes in the RSI treatment were significantly 35.9% lower than the NI treatment while volumes in the RWI treatment were unchanged. However, the volumes of saliva and fluid flowing into the rumen were greater in both RSI and RWI treatments when compared to the NI treatment. The results indicate that the amount of saliva flowing into the rumen is a factor regulating feed intake in ruminants fed on dry forage.