• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.362-370
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• 2019

This study was conducted to investigate effects of 12 weeks of combined exercise training with blood flow restriction (BFR) on body composition (weight, %body fat, lean body mass, body mass index (BMI)) and cardiovascular responses (brachial-ankle pulse wave velocity (ba PWV) and ankle-brachial index (ABI)) in elderly women. Participants (N = 43, Females) were randomly assigned into a combined exercise with BFR (n = 14, BFR), only combined exercise (n =14, EX) or non-exercise control group (n = 15, CON). Two-way repeated measures ANOVA with contrast testing was utilized for data analysis. Alpha was set at p < 0.05. Body composition (weight, %body fat, BMI) in BFR was significantly changed, and %body fat in EX was significantly decreased, but there was no change in the CON. In addition, the right and left ba PWV values in the BFR were significantly decreased, while only the left side ba PWV in EX was significantly decreased and there was no change in the CON. Moreover, the % change and effect size of most variables in the BFR were higher than the EX. Taken together, the results indicate that even though BFR and EX groups performed the same combined exercise training, BFR had additional stimulations of the sympathetic nerve system due to blood flow restriction. Thus, BFR training is more beneficial and has greater effects on body composition and cardiovascular responses in elderly females.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.560-569
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• 1999

Blood supply rather than nerve supply implies pulp vitality. To evaluate pulp vitality clinically, electric pulp test and thermal test which are based on sensory nerve response have been used in addition to many auxiliary data such as past dental history, visual inspection, radiographic examination, percussion, palpation and transillumination test. However, reactivity of the nerves to the stimulation is not synonymous with normalcy. Therefore measurement of pulpal blood flow using a laser Doppler flowmeter became a new trial to test the pulp vitality. The purpose of the present study was to evaluate normal pulpal blood flow level of maxillary teeth in adult to provide a guideline in determining the vitality of dental pulp. Pulpal blood flow was measured in maxillary central and lateral incisors, canines, first and second premolars and first molars of seventy nine adults of 22 - 30 years old using a laser Doppler flowmeter (PeriFlux 4001, Perimed Co., Stockholm, Sweden, 780 nm infrared laser, 1mW). For directly-made splints, silicone rubber impressions were taken directly from the mouth. For indirectly-made splints, alginate impressions were taken from the mouth and stone cast were made. After making depressions on the buccal surfaces of the cast teeth to indicate the hole positions, second impressions with vinyl polysyloxane putty were taken from the cast. Holes for the laser probes were made at the putty impressions 4mm above the gingival level. Laser probe (PF416 dental probe, 1.5mm) was inserted in the prepared hole and the splint was set in the mouth. After 10 minutes of patient relaxing, pulpal blood flow was recorded for 5 minutes on each tooth. The recorded flow was saved in the computer and calculated with a software 'Perisoft' version 5.1. Pulpal blood flow was also recorded in six teeth of five individuals with no response to electric pulp test and cold test, with periapical radiolucency, or with history of root canal treatment to compare with nonvital teeth. The difference between the mean flow values of each group of teeth were analyzed using one-way ANOVA and Duncan's Multiple Range test. The results were as follows: 1. The average pulpal blood flow values of all the tested teeth of each location were between 9 - 16 Perfusion Unit. Pulpal blood flow value was highest in maxillary lateral incisors, followed by first premolars, second premolars, canines, central incisors, and then first molars (p<0.01). 2. In six anterior teeth, indirectly-made splint group showed higher pulpal blood flow values than directly-made splint group (p<0.01). In posterior teeth, however, there was no significant flow value difference between directly-made splint group and indirectly-made splint one (p>0.05). 3. Teeth with vital pulps showed higher signal values than teeth with nonvital pulps (p<0.01), and the flow photographs showed heartbeat-synchronous fluctuations and vasomotions, while those were absent in non vital tooth.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.983-988
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• 2003

Purpose : Syncope appears to be common. However, the mechanism of syncope is not clear. Increased vagal activity and withdrawal of sympathetic stimulation cause hypotension, bradycardia and finally loss of consciousness. The purpose of this study was to evaluate changes of cerebral blood flow velocity, blood pressure, and heart rate during tilt test in children with vasovagal syncope. Methods : Sixty four children with a past history of syncope were evaluated. The stand up test was performed for 15 minutes after a rest at supine position for 10 minutes, followed by an $80^{\circ}$ tilt test lasting 45 minutes. If presyncope(lightheadedness, nausea, blurred vision, or sweating) or syncope occurred, the study was discontinued. 12-lead electrocardiography, echocardiography, and electroencephalography were performed. Transcranial Doppler study was performed at the middle cerebral artery with 2 MHz continuous Doppler probe in 10 children with positive tilt test. Systolic, diastolic, mean cerebral blood flow velocity, integral, and pulsatility index were measured with blood pressure, heart rate, and $O_2$ saturation. Results : The positive rate of tilt test was 31.3%(20/64). Systolic, diastolic, and mean cerebral blood flow velocity decreased significantly in absence of hypotension or bradycardia during presyncope. Time velocity integral of cerebral artery also decreased significantly. Conclusion : Decreased cerebral blood flow velocity can predict the presyncope manifestation. Impairment of autoregulation of cerebral blood flow might play an important role in the pathophysiology of vasovagal syncope.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.244-254
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• 2002

Purpose: This study investigated the differences between technetium-99m ethyl cysteinate dimer (Tc-99m ECD) and technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) uptake in the normal brain by means of statistical parametric mapping (SPM) analysis. Materials and Methods: We retrospectively analyzed age and sex matched 53 cases of normal brain SPECT. Thirty-two cases were obtained with Tc-99m ECD and 21 cases with Tc-99m HMPAO. There were no abnormal findings on brain MRIs. All of the SPECT images were spatially transformed to standard space, smoothed and globally normalized. The differences between the Tc-99m ECD and Tc-99m HMPAO SPECT images were statistically analyzed using statistical parametric mapping (SPM'99) software. The differences bgetween the two groups were considered significant ant a threshold of corrected P values less than 0.05. Results: SPM analysis revealed significantly different uptakes of Tc-99m ECD and Tc-99m HMPAO in the normal brains. On the Tc-99m ECD SPECT images, relatively higher uptake was observed in the frontal, parietal and occipital lobes, in the basal ganglia and thalamus, and in the superior region of the cerebellum. On the Tc-99m HMPAO SPECT images, relatively higher uptakes was observed in subcortical areas of the frontal region, temporal lobe, and posterior portion of inferior cerebellum. Conclusion: Uptake of Tc-99m ECD and Tc-99m HMPO in the normallooking brain was significantly different on SPM analysis. The selective use of Tc-99m ECD of Tc-99m HMPAO in brain SPECT imaging appears especially valuable for the interpretation of cerebral perfusion. Further investigation is necessary to determine which tracer is more accurate for diagnosing different clinical conditions.

• Journal of Biomedical Engineering Research
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• v.23 no.6
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• pp.437-449
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• 2002

Coronary arteries are subjected to very different flow conditions compared to other arteries in systemic blood circulation. We Performed a computational fluid dynamic research to investigate influence of such flow conditions in coronary arteries on development and progress of atherosclerosis in the same. The results showed big differences in the flow field of the coronary artery compared to the abdominal and femoral arteries. The coronary artery showed higher wall shear stresses due to the small vessel diameter. On the other hand, it showed only one vortex distal to the stenosis throat during a whole pulse cycle. However. several vortices were observed in the abdominal and femoral arteries in both proximal and distal sides of the stenosis throat The wall shear stresses and extent of recirculation area were increased with impedance phase angle increasing toward more negative values. Therefore, cardiac contraction and the negative impedance phase angle as large as -110。 may induce a flow field that accelerates atherosclerosis.

• Journal of Life Science
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• v.19 no.4
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• pp.508-513
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• 2009

Pine needles have long been used as a traditional health-promoting medicinal food in Korea. To investigate the effects of pine (pinus densiflora) needle extracts on blood flow and serum lipid improvement were assessed in vivo. 8 week-old Sprague Dawley strain rats were divided into four groups of seven rats each; CON, 0.5% CHOL, HOT water and Sub-supercritical group. Serum total cholesterol and triglyceride contents were lower in the CON group than the 0.5% CHOL group. Three weeks of feeding hot water and sub-supercritical extract resulted in a decrease in serum triglyceride and total cholesterol level. The level of HDL-cholesterol in the 0.5% CHOL group was significantly (p<0.05) reduced compared to the CON group, but it had a tendency to increase with pine needle extract supplementation. Blood passage time of the pine needle extracts supplemented group was higher than the 0.5% CHOL group. Microscopic observation showed that whole blood passed smoothly through the micro channels in pine needle extracts supplemented groups. The platelet aggregation ability of the groups treated with pine needle extracts was less than that of the 0.5% CHOL group. All these results suggest that pine needle extracts might improve blood homeostasis mediated via antiplatelet activities.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.367-370
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• 2014

The study was to observe hemodynamic alterations of cardiac function to design a model of canine mitral valve insufficiency (MVI) based on chordae tendinae rupture (CTR). Ten healthy beagles with normal heart function were used in this study. To measure hemodynamics, the patient monitor was equipped for invasive blood pressure and a Swan-Ganz catheter. Hemodynamic alterations were checked promptly during CTR procedures. MVI model was made by transection of the chordae tendinae with small arthroscopy hook knife through $5^{th}$ intercostal open chest. Color Doppler at the level of the mitral valve showed high-velocity regurgitant flow immediately after CTR at intraoperative echocardiography. In hemodynamic measurements, pulmonary capillary wedge pressure (PCWP) was significantly increased, while mean arterial pressure (MAP), venous pressure (VP), pulmonary arterial pressure (PAP), cardiac output (CO) and cardiac index (CI) were significantly decreased after CTR. It was known that the left atrium was overloaded by regurgitant volume from the left ventricle. In conclusion, the MVI model induced by CTR technique in this study should be used as suitable one for the effective research of canine mitral valve disease. Further study should be needed to measure the chronic alternation of mitral valve in the model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.480-489
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• 2017

Blood flow restriction(BFR) exercise is defined as low intensity and short term exercise using pneumatic pressure belts at the top of limbs, which affects the physiological functions of the body. The purpose of this study was to investigate the effects of walking exercise with BFR on inflammatory index, isokinetic muscle function, and thigh circumference in obese women. Eleven obese women(> BMI $25kg/m^2$ & > body fat 30%) wore pneumatic pressure belts on both femurs and performed walking exercise twice per day, 3 days/wk for 4 weeks (walking 2 min; resting 1 min). Data analysis was carried out using paired t-test. Body weight, BMI, and body fat significantly decreased after exercise(p<.05), and right thigh circumference significantly decreased(p<.05). The concentration of plasma IL-6 significantly increased(p<.05) after exercise. TNF-${\alpha}$ level was not statistically different but tended to slightly increase. CRP slightly decreased, although it did not reach statistical significance after exercise. Muscle strength significantly increased in the $60^{\circ}/sec$ of right/left side extension, left side flexion, and $180^{\circ}/sec$ of left side extension after training(p<.05). These results suggest that 4 weeks of blood flow restriction walking exercise has positive effects on inflammatory index and isokinetic muscle function. Therefore, we consider that blood flow restriction exercise can be used for treatment of obesity, related chronic diseases, and metabolic syndrome. Further, blood flow restriction exercise for a short time has similar effects as a high intensity resistance program.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.181-185
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• 2008

In this study, we attempted to quantify the relative importance of assumptions regarding blood rheology. Three patient-specific carotid bifurcation geometries and time-varying flow rates were obtained using magnetic resonance imaging. For each subject, CFD simulations were carried out assuming two different non-Newtonian rheology models Carreau and Ballyk models) and rescaled Newtonian viscosities based on characteristic shear rates to account for the shear-thinning property of blood. The sensitivity of WSS and oscillatory shear index (OSI) were contextualized with respect to the reproducibility of the reconstructed geometry and to assumptions regarding the inlet boundary conditions. We conclude that the assumption of Newtonian fluid is reasonable for studies aimed at quantifying the distribution of WSS-based extrema in an image-based CFD model of carotid bifurcation.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.181-185
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• 2008

In this study, we attempted to quantify the relative importance of assumptions regarding blood rheology. Three patient-specific carotid bifurcation geometries and time-varying flow rates were obtained using magnetic resonance imaging. For each subject, CFD simulations were carried out assuming two different non-Newtonian rheology models (Carreau and Ballyk models) and rescaled Newtonian viscosities based on characteristic shear rates to account for the shear-thinning property of blood. The sensitivity of WSS and oscillatory shear index (OSI) were contextualized with respect to the reproducibility of the reconstructed geometry and to assumptions regarding the inlet boundary conditions. We conclude that the assumption of Newtonian fluid is reasonable for studies aimed at quantifying the distribution of WSS-based extrema in an image-based CFD model of carotid bifurcation.