• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.4
• /
• pp.477-483
• /
• 2018

Transcranial doppler is a non-invasive method that measures the blood flow velocity and the direction of cerebral blood vessels through the doppler principle. The pulsatility index is an index for measuring the transcranial doppler that reflects the distal vascular resistance and is used as an index for the presence and diffusion of cerebral small vessel diseases. The purpose of this study was to evaluate the risk factors affecting the basilar artery pulsatility index in ischemic stroke patients. From January 2014 to May 2015, 422 patients were selected by measuring the transcranial doppler pulsatility index, considering their basilar artery pulsatility index. Univariate analysis was performed using the basilar artery pulsatility index as a dependent variable. Multiple regression analysis was performed considering the factors affecting the pulsatility index as variables. Univariate analysis revealed age, presence of hypertension, presence of diabetes mellitus, presence of hyperlipidemia, and hematocrit (P<0.1) as factors. Multiple regression analysis showed statistically significant results with age (P<0.001), presence of diabetes (P=0.004), and presence of hyperlipidemia (P=0.041). The risk factors affecting the basilar artery pulsatility index of transcranial doppler were age, diabetes, and hyperlipidemia. Further research will be needed to increase the cerebral pulsatility index as a surrogate marker of the elderly, diabetes, and hyperlipidemia.

• Journal of computational fluids engineering
• /
• v.9 no.4
• /
• pp.34-40
• /
• 2004

It is known that the non-planar model of bypass is more profitable to suppress the development of intimal hyperplasia that tends to occur preferentially in regions of low time averaged shear stress and rapid temporal changes in wall shear stress. In this study it was numerically simulated the blood flow in an coronary artery grafted by artificial bypass to determine the flow characteristic variations due to the anastomosis angle changing. 5 different non-planar anastomosis angle models such as 45°, 60°, 90°, 120° and 135° were considered. When the anastomosis angle is higher, the backward flow region is spatially extended near the downstream region of the anastomosis because of the development of horseshoes vortex. For the case of the nan-planar 45° and 60° of anastomosis, the area of low-OSI zone was decreased by 26% and 13% respectively and the time averaged wall shear stress was increased by more than 55% as compared with 45° of planar model. However, both of the area of the low-OSI zone and the time averaged wall shear stress of 90°, 120° model were significantly increased.

• Journal of Korean Neurosurgical Society
• /
• v.67 no.2
• /
• pp.158-165
• /
• 2024

Objective : Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is conducted for flow augmentation. In this study, we measured the STA cut flow of a Korean population and evaluated the relationship between STA cut flow and long-term patency of the bypass. Methods : A retrospective study was conducted. Intraoperative measurement of STA flow was conducted using a microvascular flow meter on patients who underwent STA-MCA. After cutting the distal end, the STA flow rate was measured with no resistance and recorded. After finishing anastomosis, STA flow was measured and recorded. The cut flow index was calculated by dividing post anastomosis flow by cut flow in intracranial atherosclerotic stenosis patients. Results : The median STA cut flow was 35.0 mL/min and the post anastomosis flow was 24.0 mL/min. The cut flow of STA decreased with aging (p=0.027) and increased with diameter (p=0.004). The cut flow showed no correlation with history of hypertension or diabetes mellitus (p=0.713 and p=0.786), but did correlate a positively with history of hyperlipidemia (p=0.004). There were no statistical differences in cut flow, STA diameter, and post anastomosis flow between the frontal and parietal branches (p=0.081, p=0.853, and p=0.990, respectively). Conclusion : The median STA cut flow of a Korean population was 35 mL/min. Upon reviewing previous articles, it appears that there are differences in the STA cut flow between Western and Asian patients.

• Clinical and Experimental Reproductive Medicine
• /
• v.13 no.2
• /
• pp.181-185
• /
• 1986

To estimate the penile blood flow changes during artificial with erection intracorporeal papaverine injection, we injected 99 m Technitium-Human Serum Albumin via antecubital vein simultaneously and calculate the radioisotope activity of the penis using computerized Gamma Camera. We classified the results into 3 groups according to the transit time, erection persistent time and venous index in 67 impotence patients. We defined the arteriogenic impotence with the delayed transit time (more than 600 seconds) in 13 patients and venogenic with the shortened erection persistant time (less than 200 seconds) and decreased venous index (less than 0.8) in 11 patients. The rest of them (43 patients) were regarded as equivocal impotence, probably nonvasculogenic or psychogenic.

• Journal of Cardiovascular Imaging
• /
• v.31 no.3
• /
• pp.145-149
• /
• 2023

BACKGROUND: ¹⁸F-sodium fluoride positron emission tomography/computed tomography (¹⁸F-NaF PET/CT) has been proven to be useful in identification of microcalcifications, which are stimulated by inflammation. Blood speckle imaging (BSI) is a new imaging technology used for tracking the flow of blood cells using transesophageal echocardiography (TEE). We evaluated the relationship between turbulent flow identified by BSI and inflammatory activity of the aortic valve (AV) as indicated by the ¹⁸F-NaF uptake index in moderate aortic stenosis (AS) patients. METHODS: This study enrolled 18 moderate AS patients diagnosed within the past 6 months. BSI within the aortic root was acquired using long-axis view TEE. The duration of laminar flow and the turbulent flow area ratio were calculated by BSI to demonstrate the degree of turbulence. The maximum and mean standardized uptake values (SUVmax, SUVmean) and the total microcalcification burden (TMB) as measured by ¹⁸F-NaF PET/CT were used to demonstrate the degree of inflammatory activity in the AV region. RESULTS: The mean SUVmean, SUVmax, and TMB were 1.90 ± 0.79, 2.60 ± 0.98, and 4.20 ± 2.18 mL, respectively. The mean laminar flow period and the turbulent area ratio were 116.1 ± 61.5 msec and 0.48 ± 0.32. The correlation between SUVmax and turbulent flow area ratio showed the most positive and statistically significant correlation, with a Pearson's correlation coefficient (R²) of 0.658 and a p-value of 0.014. CONCLUSIONS: The high degree of trans-aortic turbulence measured by BSI was correlated with severe AV inflammation.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.10
• /
• pp.893-899
• /
• 2010

A previous study showed that hemodynamics is correlated with stenosis in the coronary artery. The flow characteristics and the distributions of the hemodynamic wall parameters in the coronary artery are investigated under physiological flow condition. The present study also aims to establish the mechanism of the generation of atherosclerosis by analyzing the hemodynamic variables in the coronary artery where atherosclerosis frequently occurs. The stenosis phenomena due to atherosclerosis are related to not only the biochemical reaction between blood and blood vessels but also the hemodynamic factors sush as flow separation and oscillatory wall shear stress. As the bifurcated angle increases, the size of the recirculation area that appears in the cross section increases and disturbed flow is observed in this area. We speculate that this area is the starting point of atherosclerosis in the coronary artery.

• Clinical and Experimental Reproductive Medicine
• /
• v.42 no.4
• /
• pp.163-168
• /
• 2015

Objective: To investigate the impact of fibroids on the blood flow of the uterine and subendometrial arteries and in vitro fertilization (IVF) outcomes. Methods: In this study, we analyzed 86 IVF/intracytoplasmic sperm injection (ICSI) cycles in which a gonadotropin-releasing hormone antagonist protocol was used for controlled ovarian stimulation between January 2008 and March 2009. The subjects comprised 86 infertile women with (fibroid group, n=43) or without (control group, n=43) uterine fibroids. Results: Patient characteristics were similar between the fibroid and control groups. The IVF/ICSI outcomes in patients with fibroids were similar to those of patients in the control group. The resistance index (RI) and pulsatile index (PI) of the uterine and subendometrial arteries on the day of embryo transfer were also comparable between the two groups. IVF outcomes and uterine hemodynamics in patients with multiple (${\geq}2$) fibroids were similar to those of patients with a single fibroid. However, clinical pregnancy and implantation rates were significantly lower in patients with fibroids who experienced uterine cavity distortion than in patients with fibroids who had a normal uterine cavity (both p<0.05). The RI and PI of the subendometrial artery were significantly higher on the day of embryo transfer in patients with fibroids who experienced uterine cavity distortion than in patients with fibroids who had a normal uterine cavity (both p<0.05). Conclusion: Fibroids which distorting the uterine cavity might impair the subendometrial artery blood flow clinical pregnancy rate and embryo implantation rate in infertile patients undergoing IVF. Otherwise, IVF outcomes were not influenced by the presence of uterine fibroids.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.363-371
• /
• 2021

The goal of this study was to investigate the influence of exercise training with or without blood flow restriction (BFR) on physical performance and balance in elderly females. Participants (N = 43) were randomly divided into combined exercise with BFR group (n = 14, EX-BFR), only combine exercise group (n =14, EX) or a non-exercise control group (n = 15, CON). Both EX-BFR and EX groups had completed exercise training for 12 weeks. During the training period, the CON group maintained their normal lives. After baseline tests, two-way repeated measures ANOVA with contrast testing was conducted using SPSS 22.0. Study results found that physical performance and balance in both EX-BFR and EX groups were significantly improved, and fall index in both EX-BFR and EX groups were significantly decreased. There were no changes in the CON group. In addition, the % change and effect size of all variables in the EX-BFR group were larger than the EX group. So, the results showed that the EX-BFR group had performed more intense exercise caused by restricted blood flow during the training period compared to the EX group. Thus, exercise with BFR training may additionally influence physical performance and balance in elderly females.

• Journal of Ginseng Research
• /
• v.43 no.4
• /
• pp.618-624
• /
• 2019

Background: Ginsenoside Re (Re) is one of the major components of Panax ginseng Meyer. Ginsenoside $Rk_3$ ($Rk_3$) is a secondary metabolite of Re. The aim of this study was to investigate and compare the effects and underlying mechanisms of Re and $Rk_3$ on cyclophosphamide-induced myelosuppression. Methods: The mice myelosuppression model was established by intraperitoneal (i.p.) injection of cyclophosphamide. Peripheral blood cells, bone marrow nucleated cells, and colony yield of hematopoietic progenitor cells in vitro were counted. The levels of erythropoietin, thrombopoietin, and granulocyte macrophage colony-stimulating factor in plasma were measured by enzyme-linked immunosorbent assay. Bone marrow cell cycle was performed by flow cytometry. The expression of apoptotic protein bcl-2, bax, and caspase-3 was detected by Western blotting. Results: Both Re and $Rk_3$ could improve peripheral blood cells, bone marrow nucleated cell counts, thymus index, and spleen index. Furthermore, they could enhance the yield of colonies cultured in vitro and make the levels of granulocyte macrophage colony-stimulating factor, erythropoietin, and thrombopoietin normal, reduce the ratio of $G_0/G_1$ phase cells, and increase the proliferation index. Finally, Re and $Rk_3$ could upregulate the expression of bcl-2, whereas they could downregulate the expression of bax and caspase-3. Conclusion: Re and $Rk_3$ could improve the hematopoietic function of myelosuppressed mice. The effect of $Rk_3$ was superior to that of Re at any dose. Regulating the levels of cytokines, promoting cells enter the normal cell cycle, regulating the balance of bcl-2/bax, and inhibiting the expression of caspase-3 may be the effects of Re and $Rk_3$ on myelosuppression.

• Journal of Biomedical Engineering Research
• /
• v.17 no.3
• /
• pp.337-346
• /
• 1996

The patency of small size vascular grafts is poor, and the blood flow characteristics in the artery graft anastomosis are suspected as one of the important factors influencing intimal hyperplasia. Disturbed flow patterns caused by sixte and compliance mismatch generate unfavorable flow environment which promotes intimal thickening. Tapered vascular yuts are suggested in order to reduce sudden expansion near the anastomosis. The photochromic flow visualization method is used to measure the flout fields in the end-to-end anastomosis model under the carotid and femoral artery flow wave form. The results show that flow disturbance near the anastomosis is diminished in the tapered grafts comparing to the tubular graft. As the divergent ang1e decreases, we can reduce the low and oscillatory wall shear stress zone which is prone to intimal hyperplasia. The flow wave form effects the wall shear rate dis- tribution significantly. The steep deceleration and back flow in the femoral flow wAve form cause low mean wall shear rate and high oscillatory shear index.