Biomedical subjects

Jang-Ho Bae

Publications and source records attributed to Jang-Ho Bae.

14 recordsLinked to original sources

PubMed2006

Association of angiotensin-converting enzyme inhibitors and serum lipids with plaque regression in cardiac allograft vasculopathy.

We assessed clinical predictors of the process of cardiac allograft vasculopathy (CAV) in 39 consecutive patients (mean 49 years old) using three-dimensional intravascular ultrasound (3-D IVUS) examination of the left anterior descending coronary artery at 36 +/- 38 months and 47 +/- 40 months after cardiac allotransplantation (TX). Compared with 17 patients with plaque progression, 22 patients with plaque regression were more likely to be male (P < .01), to have a higher use of angiotensin-converting enzyme inhibitors (ACEI, P < .05), and to have a lower volumetric remodeling index (P < .001). The changes in plaque volume correlated with the changes in total cholesterol (P < .005) and low-density lipoprotein cholesterol (P < .02). Plaque progression of CAV was independently associated with time after TX, hypertension, nonuse of ACEI, donor age, and changes in total cholesterol and triglycerides. In conclusion, plaque progression is associated with positive vascular remodeling and plaque regression is associated with lower serum lipids and ACEI in patients after TX.

Adult↗

PubMed2006

Individual measurement and significance of carotid intima, media, and intima-media thickness by B-mode ultrasonographic image processing.

OBJECTIVE: We assessed the clinical significance of intima (IT), media (MT), and intima-media (IMT) thickness of the common carotid artery using B-mode ultrasonographic image processing. METHODS AND RESULTS: One hundred seventy consecutive patients underwent common carotid artery scanning using high-resolution ultrasonography. A total of 150 patients could be analyzed off-line using ultrasonographic image processing, devised for individual measurement of IT, MT, and IMT. By univariate analysis, IT (range, 0.27 to 0.41 mm) was associated with age, whereas MT (range, 0.27 to 0.74 mm) and IMT (range, 0.49 to 1.12 mm) were associated with age, fibrinogen, and creatinine. Among atherosclerosis risk factors, hypertension was associated with thickness of all 3 layers, whereas smoking was associated with IT only. By multivariate analysis, IT was associated with age, hypertension, and smoking, whereas MT and IMT were associated with age, hypertension, and blood urea nitrogen level. CONCLUSIONS: Carotid IT is associated with smoking, whereas age and hypertension are associated with thickness of all 3 arterial layers. Our results suggest a differential response of the vasculature to systemic risk factors.

Aged↗

PubMed2006

Independent component analysis for synthetic aperture magnetometry in magnetocardiography.

We propose independent component analysis (ICA) as a pre-process for synthetic aperture magnetometry (SAM) in magnetocardiogram. SAM is a very useful method for source current imaging. However, SAM cannot separate one source from the others when there are time-correlated multi-sources, especially for successively active sources. The proposed method compensates the intrinsic drawback of SAM with ICA, which is feasible for 3-D imaging of the myocardial current distribution of specific temporal features. By using our method, we successfully localized an accessory pathway of a patient suffering from the WPW syndrome.

Adult↗

PubMed2006

Feasibility of a pressure wire and single arterial puncture for assessing aortic valve area in patients with aortic stenosis.

BACKGROUND: Determination of a transvalvular pressure gradient for measurement of aortic valve area (AVA) by hemodynamic cardiac catheterization usually requires 2 catheters and 2 arterial access sites. We assessed the feasibility of using a single arterial puncture and a 0.014 inch pressure wire for evaluation of aortic stenosis. METHODS: Eighteen patients (mean age, 76 years; 10 men) underwent hemodynamic catheterization for assessment of AVA. Cardiac output was determined by thermodilution (using a pulmonary artery catheter), and the transvalvular pressure gradient was obtained from simultaneous pressure recordings (using a pressure wire to measure left ventricular pressure and a 5 Fr catheter to measure ascending aortic pressure). RESULTS: This novel technique was technically feasible in all patients. Calibration of the pressure wire with the pressure of the fluid-filled catheter was possible and accurate in the left ventricle and aorta. The method required 36.4 +/- 9.6 minutes from injection of a local anesthetic to completion of AVA measurement; 53.3 +/- 18.6 minutes were required to finish all catheterization procedures, including coronary angiography. Measurements of AVA (mean, 1.01 +/- 0.43 cm2) and pressure gradients (mean, 27.5 +/- 10.5 mmHg) taken by a pressure wire were similar to measurements taken by Doppler echocardiography (1.07 +/- 0.58 cm2 and 32.9 +/- 12.1 mmHg, respectively); the correlation was significant (r = 0.856; p < 0.001, and r = 0.741; p < 0.001, respectively). CONCLUSIONS: Our findings suggest that a single arterial approach using a pressure wire is feasible, safe, accurate and rapid for the invasive assessment of aortic stenosis.

Aged↗

PubMed2005

Effects of lacidipine on vascular responses in patients with coronary artery disease.

BACKGROUND: To evaluate the effects of the calcium channel blocker lacidipine on vascular responses, such as endothelial function and carotid intima-media thickness (IMT), and on levels of high-sensitivity C-reactive protein (hs-CRP) in patients with coronary artery disease (CAD). METHODS: Endothelial function was assessed by measuring the flow-mediated vasodilation (FMD) of the brachial artery and IMT was measured in the common, bifurcating, and in the internal carotid artery by using high-resolution ultrasound. The study population consisted of 96 consecutive patients [mean age 60 years, male (n) = 70] who showed at least one coronary artery narrowed by more than 50% (coronary angiography). These patients were randomly assigned to lacidipine treatment (4 mg/day, n = 48) or to a placebo (n = 48). We measured FMD, IMT, and hs-CRP prior to and after 6 months of treatment and following coronary angiography in all patients. RESULTS: Clinical and medical history revealed no significant differences between the groups. IMT of the common carotid artery was significantly diminished from 0.92 +/- 0.15 to 0.87 +/- 0.15 mm 6 months after treatment with lacidipine (p < 0.005). However, IMT of any region in the carotid artery did not show any significant changes in the placebo group. Endothelial function and hs-CRP levels were slightly improved (insignificant) in the lacidipine group. In the placebo group, there were no significant changes. CONCLUSION: Lacidipine leads to a significant reduction of the common carotid artery IMT as well as to a decrease in markers of inflammation in patients with CAD during a relatively short period (6 months).

Blood Flow Velocity↗

PubMed2005

Nonlinear characteristics of heart rate time series: influence of three recumbent positions in patients with mild or severe coronary artery disease.

The aim of this study was to investigate the nonlinear characteristics of heart rate variability (HRV) for three recumbent positions: the supine, left lateral and right lateral decubitus positions. Recently, using a linear analyses method (for time and frequency domains), the effect of the right lateral decubitus position on vagal modulation has been found to increase parasympathetic activity and decrease sympathetic modulation. Little is known about the nonlinear dynamics of HRV for the three recumbent positions. Therefore, we studied the correlation dimension (CD), the largest Lyapunov exponent (LLE), the sample entropy (SampEn), the approximate entropy (ApEn) and the exponent alpha of the 1/falpha power spectrum as nonlinear characteristics of HRV. In response to the right lateral decubitus position, the CD, LLE, SampEn and ApEn increased significantly in both coronary artery disease (CAD) and control groups. In the linear analyses, the normalized high-frequency power (nHF) increased in the right lateral decubitus position. The CD, LLE, ApEn and SampEn correlated positively to the nHF. The alpha exponent did not correlate to either linear measure or CD, but correlated negatively to LLE, ApEn and SampEn. Among the three recumbent positions, it was found that the right lateral decubitus position can increase the complexity of the human physiological system and the vagal modulation of the cardiac autonomic nervous system the most.

Algorithms↗

PubMed2005

Impact of sirolimus-eluting stent on the outcome of patients with chronic total occlusions.

Several randomized trials have demonstrated that stent implantation after successful recanalization of long-term total occlusions decreases restenosis and reocclusion rates. The sirolimus-eluting stent (SES) has recently proved its efficacy to decrease restenosis in selected patients. However, the efficacy of SES implantation in patients who have chronic total occlusions is currently unknown. Therefore, we investigated procedural and 6- and 12-month angiographic outcomes (analyzed by quantitative coronary angiography) and left ventricular function in 60 patients who received SESs and 120 patients who received bare metal stents (BMSs). Minimum luminal diameter did not differ immediately after recanalization (SES group 3.04 +/- 0.50 mm vs BMS group 3.12 +/- 0.48 mm). After 6 months, the SES group still had significantly larger luminal diameters (3.04 +/- 0.44 mm vs 1.94 +/- 0.98 mm) and significantly lower restenosis and reocclusion rates (2% and 0%, respectively) than did the BMS group (32% and 6%, respectively). Late loss was significantly smaller in the SES group than in the BMS group. At follow-up, the SES group had fewer cardiac events, including target lesion revascularization (p <0.001), than did the BMS group. In conclusion, SES implantation after recanalization of chronic total occlusion provides a better clinical outcome with less restenosis and target lesion revascularization after 6 months than does BMSs.

Aged↗

PubMed2004

Impact of left ventricular ejection fraction on endothelial function in patients with coronary artery disease.

BACKGROUND: Endothelial dysfunction is present in patients with coronary artery disease (CAD) or with congestive heart failure. HYPOTHESIS: This study was performed to evaluate the impact of systolic heart function on endothelial function in patients with CAD. METHODS: The study population consisted of 283 consecutive patients (mean age 59 years, 176 men) undergoing coronary angiography. Endothelial function was assessed by measuring flow-mediated vasodilation (FMD) of the brachial artery. RESULTS: Patients (n = 236) with an ejection fraction (EF) > or = 55% on routine echocardiogram were younger (mean age 58 vs. 62 years), showed a lower prevalence of diabetes (15 vs. 38%) and myocardial infarction (13 vs. 66%), and showed a higher FMD (4.8 +/- 2.4 vs. 4.0 +/- 2.0%, p < 0.05) than patients (n = 47) with an EF < 55%. The correlation coefficient between FMD/endothelial function and EF/systolic heart function was 0.149 (p < 0.02) in the overall study population. Multivariate analysis showed that of age, gender, frequency of diabetes mellitus, myocardial infarction, and CAD extent, EF was the only significant independent parameter correlating with FMD in patients with CAD. CONCLUSIONS: Compared with the other tested risk factors, EF surprisingly was the only significant independent parameter correlating with endothelial function in patients with CAD. Our results support the view that endothelial function is an independent prognostic factor in patients with CAD.

Brachial Artery↗

PubMed2004

Effects of low-dose atorvastatin on vascular responses in patients undergoing percutaneous coronary intervention with stenting.

BACKGROUND: The primary endpoint of this study was to evaluate the effects of low-dose atorvastatin on carotid intima-media thickness (IMT) and endothelial function, and the secondary endpoint comprised restenosis and target lesion revascularization (TLR) in patients undergoing percutaneous coronary intervention (PCI) with stenting for the treatment of coronary artery disease. METHODS: Two hundred five consecutive patients (mean age, 60 years) undergoing PCI were prospectively randomized to usual therapy (control group, n = 100) or to 10 mg of atorvastatin daily plus usual therapy (statin group, n = 105). Carotid IMT, endothelial function (flow-mediated dilatation [FMD] of the brachial artery), and coronary angiograms were taken before the study and 6 months after randomization. The 6-month follow-up measurements of the above factors were obtained in 83 patients (83%) of the control group and in 97 patients (92%) of the statin group. RESULTS: No significant differences were noted in the baseline clinical and angiographic findings in either group. FMD was significantly improved during the 6 months in the statin group (4.38% +/- 1.7% vs 4.85% +/- 1.6%, P = .003), but did not change in the control group. Carotid IMT did not show any significant changes at 6 months in either group. There was a trend in favor of statin in terms of restenosis rate (26.8% vs 36.1%, P = .177) and TLR rate (18.6% vs 25.3%, P = .274). The changes of FMD were significantly correlated with the changes of total cholesterol and the changes of low-density lipoprotein, respectively (r = -0.336, P = .009, and r = -0.310, P = .046). CONCLUSION: Low-dose atorvastatin reduces endothelial dysfunction as measured by FMD, which coincides with the beneficial effects on lipid profiles, and can decrease restenosis and TLR rate in patients undergoing PCI with stenting.

Aged↗

PubMed2003

Gabapentin effect on neuropathic pain compared among patients with spinal cord injury and different durations of symptoms.

STUDY DESIGN: This study evaluated the effect of gabapentin on neuropathic pain in patients with spinal cord injury. OBJECTIVE: To compare the effect of gabapentin on neuropathic pain refractory to conventional analgesics in patients with spinal cord injury and different durations of symptoms. SUMMARY OF BACKGROUND DATA: Neuropathic pain in patients with spinal cord injury severely compromises their quality of life. Gabapentin is a new antiepileptic drug that may additionally have a role in the treatment of neuropathic pain. So far, there has been little prospective research investigating the effect of gabapentin on neuropathic pain in patients after spinal cord injury or comparing gabapentin-treated patients with varying durations of symptoms after spinal cord injury. METHODS: The study included 31 patients who had experienced neuropathic pain associated with spinal cord injury or cauda equina syndrome. These subjects were divided into two groups. Group 1 (n = 13) was composed of patients whose duration of pain was less than 6 months, and Group 2 (n = 18) comprised patients whose symptoms of neuropathic pain had lasted more than 6 months. Although these patients had been treated with conventional analgesics such as antidepressants, anticonvulsants, membrane stabilizer, and neuroleptics, they reported that their condition did not improve after a medication trial of at least 2 weeks duration. In this study, conventional analgesics were continued at a therapeutic level, and gabapentin was administrated for an 18-day titration period followed by a 5-week maintenance period at a dosage of 1800 mg/day or the maximum tolerable dosage. The efficacy of gabapentin administration was gauged by a pain score and a sleep interference score using a 100-mm visual analogue scale (VAS) every 2 weeks. The scores of the two groups were compared every 2 weeks over the course of the 8-week study. RESULTS: The mean pain score and the mean sleep interference score for Group 1 decreased more than that of Group 2 during the interval between 2 to 8 weeks (P < 0.05). The mean pain score for Group 1 decreased from 7.3 +/- 0.5 initially to 3 +/- 0.6 after 8 weeks of treatment, whereas the corresponding score for Group 2 decreased from 7.6 +/- 0.4 to 5.1 +/- 0.6 ( < 0.05). The mean sleep interference score for Group 1 decreased from 5.7 +/- 0.9 initially to 1.8 +/- 0.8 after 8 weeks of treatment, whereas the corresponding score for Group 2 decreased from 5.9 +/- 0.8 to 4.2 +/- 0.7 (P < 0.05). As compared with the onset of this study, a decrease in pain score of 2 or more was reported at the completion of this study for 11 patients (100%) in Group 1 and 10 (71%) of 14 patients in Group 2. A decrease of 2 or more in sleep interference scores was reported for 8 (89%) of 9 patients with sleep interference in Group 1 and for 8 (62%) of 13 patients with sleep interference in Group 2. Some adverse effects such as somnolence were noted, but they were mild or moderate in intensity. CONCLUSIONS: Gabapentin may be effective in decreasing neuropathic pain refractory to conventional analgesics in some patients with spinal cord injury whose duration of symptoms is less than 6 months, although those with duration of symptoms longer than 6 months showed a significant decrease as well. The drug is unlikely to cause serious adverse effects that limit its use in patients with spinal cord injury.

Acetates↗

PubMed2003

Significance of the intima-media thickness of the thoracic aorta in patients with coronary atherosclerosis.

BACKGROUND: The prevalence and clinical significance of atherosclerotic aortic disease have now been documented in a variety of patient populations by use of transesophageal echocardiography (TEE). There are many reports that atherosclerotic aortic plaques detected by TEE are a marker for coronary artery disease (CAD). HYPOTHESIS: The study was undertaken to evaluate the significance of the intima-media thickness (IMT) and formation of atherosclerotic plaques of the thoracic aorta (TA) in patients with CAD, especially in terms of a correlation between the IMT of the TA and the extent of coronary atherosclerosis. METHODS: The IMT of the TA was measured using TEE. The study population comprised 100 patients (68 men, mean age 59 years). The extent of coronary atherosclerosis was divided into four groups (0, 1, 2, 3) according to the number of coronary arteries narrowed > or = 50%. RESULTS: There was no significant difference in the IMT of the ascending TA according to the presence of significant (> 50% narrowed) coronary stenosis, but there was a significant difference in the IMT of the descending TA (1.39 vs. 1.88 mm, p = 0.005). There was a significant correlation between the extent of coronary atherosclerosis and the IMT of the ascending and descending TA (r = 0.24, p < 0.05; r = 0.352, p < 0.001, respectively). The plaques in the TA were seen in 7, 41, 52, and 65% of patients in Groups 0, 1, 2, and 3, respectively. Among atherosclerosis risk factors, hyperlipidemia was the only factor analyzed that affected the IMT of the descending TA (2.11 vs. 1.78 mm, p < 0.05). CONCLUSION: The IMT of the TA correlates significantly with coronary atherosclerosis, and correlation of the descending TA IMT with coronary atherosclerosis is better than that of ascending TA IMT. Age is associated with coronary atherosclerosis, and TA IMT and hyperlipidemia are associated with descending TA IMT. Therefore, although TEE is not recommended for measuring TA IMT or for evaluating aortic plaques in patients with CAD, measurement of TA IMT as well as carotid artery IMT is very helpful for understanding the extent of coronary atherosclerosis.

Adult↗

PubMed2003

Postprandial hypertriglyceridemia-induced endothelial dysfunction in healthy subjects is independent of lipid oxidation.

BACKGROUND: To analyze the effects of postprandial hypertriglyceridemia with or without antioxidant supplementation-on endothelial function as related to lipid oxidation in healthy young subjects. METHODS AND RESULTS: Ten healthy male subjects (mean age: 26 years) were examined three times in fasting state (10 hours) following a high-fat meal, a low-fat meal, or a high-fat meal with additional antioxidant vitamin E (800 IU), respectively. Serum triglycerides significantly increased 2 and 4 hours after eating the high-fat meal with or without additional vitamin E. Endothelium-dependent, flow-mediated brachial artery vasodilations (FMD; percentage change in diameter) changed from 13.3+/-1.1% to 6.6+/-1.1% (p<0.05), 7.1+/-0.6% (p<0.05), or 13.2+/-0.8% at 2, 4, or 6 hours after eating a high-fat meal. However, there were no changes of FMD observed following either a low-fat meal or a high-fat meal with additional vitamin E. The flow-dependent vasodilation inversely correlated to postprandial hypertriglyceridemia (r=-0.54, p<0.05). Serum malondialdehydes (MDA; lipid oxidation products) did not significantly change following ingestion of any of the 3 types of meal. CONCLUSIONS: This study suggests that postprandial hypertriglyceridemia-induced endothelial dysfunction is not associated with lipid oxidation and that the protective effects of vitamin E on endothelial function may be due to some alternative, as of yet unknown, mechanism.

Adult↗

PubMed2002

Comparison of clinical outcomes and natural morphologic changes between sequestered and large central extruded disc herniations.

A prospective and longitudinal investigation concerning clinical outcomes and morphologic changes of large lumbar disc herniations by MR imaging. To compare the clinical outcomes and the natural morphologic changes of between sequestered and large central extruded disc herniations. The spontaneous disappearance or diminution of large herniated lumbar discs in the spinal canal is known. Poor clinical outcome and small changes of herniated discs have been shown for large central extruded disc herniations with conservative treatment. The study population consisted of 22 patients with sequestration and a large central as extrusion established by an MR imaging study. Seventeen (11 patients with sequestration, and 6 patients with a large central extrusion) patients underwent a follow-up MR imaging study. The size of the herniated disc was measured on serial MR imaging studies, and the changes in size were classified into four categories. Clinical evaluations were also performed using a visual analogue scale (VAS), the Oswestry low back pain disability questionnaire, the straight leg raising test (SLRT) and so forth. Both the sequestered and large central extruded disc herniations showed a successful clinical outcome after conservative treatment in 17 of 22 patients (77%) in total: 11 of 13 patients (85%) with sequestered disc herniations, and 6 of 9 patients (67%) with large central extruded disc herniations. VAS and Oswestry disability scoring showed a greater change in the group with sequestration than in the group with large central extrusions. In the group with sequestration, seven patients reported the disappearance of herniated disc materials, and four patients showed a marked decrease in the size of their herniated discs in follow-up MR images. However, in the group with large central extrusions, only two patients showed a decrease in the size of their herniated discs. Large central extruded disc herniations can be treated successfully by conservative treatment. Outcomes seemed to be as good as or slightly inferior to those of sequestered disc herniations. However, a greater morphologic decrease in the herniated discs occurred more frequently for sequestered disc herniations than for large central extruded disc herniations.

Adult↗

PubMed2002

Endothelial dysfunction: its relationship with acute hyperglycaemia and hyperlipidemia.

Endothelial dysfunction has been proposed as an early manifestation of atherosclerosis. The risk for atherosclerosis is increased in patients with diabetes mellitus, but the mechanism of the increased risk in these patients remains to be elucidated. Emerging evidence suggests that postprandial hyperglycaemia and hyperlipidemia are important risk factors in the development of atherosclerosis in patients with diabetes. Using a high-resolution ultrasound technique, we evaluated the acute effects of oral glucose loading on endothelium-dependent flow-mediated dilation (EFMD) and endothelium-independent flow-mediated dilation (EIFMD) of the brachial artery in 11 men (mean age: 59 +/- 5 years) with type 2 diabetes without chronic complications of diabetes. During these examinations, changes in the level of superoxide anion formation in the neutrophils were also measured. In addition, to investigate the relationship between acute hypertriglyceridemia and EFMD, we assessed the effects of high- and low-fat meals on EFMD of the brachial artery in 12 healthy volunteers. EFMD was diminished after glucose loading (13.2% +/- 6.4%, 7.3% +/- 3.3%*, 12.8% +/- 5.6%, in fasting and at 1 and 2 hours, respectively; *P<0.001 vs fasting). Superoxide anion formation by neutrophils (expressed as 10(-7) nmol/10(6) cells/30 min) was increased after glucose loading (4.7 +/- 2.8 and 6.2 +/- 2.2, in fasting and at one hour, respectively; P<0.05). EIFMD and triglyceride concentrations were not significantly affected by glucose loading. EFMD was also decreased by high-fat feeding (13.1% +/- 4.3%, 7.7% +/- 3.7%*, 7.3% +/- 2.2%*, basal, 2 hours, and 4 hours, respectively; *P<0.01 vs basal). These decreases were reversed by vitamin E treatment. These results show that acute hyperglycaemia induced by 75 gm oral glucose intake and acute hypertriglyceridemia induced by high-fat feeding are implicated in endothelial dysfunction. In addition, these results suggest that chronic and repeated hyperglycaemia and hypertriglyceridemia may play important roles in the development and progression of vascular complications in diabetes, probably through increased oxidative stress.

Adult↗