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Featured researches published by Yong-Taek Lee.


Clinical Imaging | 2014

Ultrasound elastography in the early diagnosis of plantar fasciitis

So-Yeon Lee; Hee Jin Park; Hyon Joo Kwag; Hyun-Pyo Hong; Hae Won Park; Yong-Rae Lee; Kyung Jae Yoon; Yong-Taek Lee

BACKGROUND The purpose of this study was to investigate whether ultrasound (US) elastography is useful for the early diagnosis of plantar fasciitis. MATERIAL AND METHODS We retrospectively reviewed US elastography findings of 18 feet with a clinical history and physical examination highly suggestive of plantar fasciitis but with normal findings on conventional US imaging as well as 18 asymptomatic feet. RESULT Softening of the plantar fascia was significantly greater in the patient than in the control group [Reviewers 1 and 2: 89% (16/18) vs. 50% (9/18), P=.027, respectively]. CONCLUSION US elastography is useful for the early diagnosis of plantar fasciitis.


Journal of Pediatric Surgery | 2011

Risk factors for intrauterine constraint are associated with ultrasonographically detected severe fibrosis in early congenital muscular torticollis

Yong-Taek Lee; Soo Kyoung Cho; Kyungjae Yoon; Hun Kyu Shin; Eugene Kim; Yong-Bum Kim; Won-Serk Kim; Jung Mi Chun; Byung Hee Han

BACKGROUND/PURPOSE The etiology of congenital muscular torticollis (CMT) remains controversial. Ultrasonographically, severe fibrosis involving the entire sternocleidomastoid muscle (SCM; type 3 or 4) fibrosis has been associated with poor clinical outcomes and indicates a chronic state of the condition. The purpose of this study was to test whether or not type 3 or 4 fibrosis detected early after birth is associated with factors related to prolonged intrauterine constraint. METHODS Sixty-seven patients (age, <3 months) with CMT were classified into 4 different ultrasonographic types according to the severity of SCM fibrosis. The odds ratio for the relationship between probability of type 3 or 4 and factors related to intrauterine constraint were calculated by a multivariate logistic regression model. RESULTS None were classified as type 4. Twenty-three patients (34%) had a history of breech presentation, and 21 (91.3%) of them were delivered by elective cesarean section without likelihood of birth trauma. Compared with normal pregnancy, breech presentation and oligohydramnios showed a 6.7 or 7.5 times higher probability for type 3 fibrosis, respectively. CONCLUSION Risk factors for intrauterine constraint appear to be associated with ultrasonographically detected severe fibrosis involving the entire SCM muscle in early presenting CMT.


Anatomy & Cell Biology | 2010

Vitamin C acts indirectly to modulate isotype switching in mouse B cells

Ami Woo; Jin-Hee Kim; Young-Joo Jeong; Hyung Gun Maeng; Yong-Taek Lee; Jae Seung Kang; Wang Jae Lee; Young-il Hwang

Vitamin C, one of essential micronutrients, has been reported to modulate the humoral immune responses in some mammals. We investigated whether vitamin C might modulate this response in mice by directly affecting B cells. Splenic B cells were isolated and activated by CD40- and B cell receptor-ligation in vitro. The cells were cultured with a pretreatment of vitamin C from 0 to 1 mM of concentrations. Vitamin C slightly increased apoptosis of B cells dose-dependently and behaved as an antioxidant. We found that in vivo administration of vitamin C by intraperitoneal injection affected isotype switching as previously reported: the titer of antigen-specific IgG1 antibody was decreased, while that of IgG2a was unaffected. Somewhat different from those observed in vivo, in vitro exposure to vitamin C slightly decreased isotype switching to IgG1 and increased isotype switching to IgG2a. Pretreatment with vitamin C in the safe range did not affect either proliferation of cultured B cells or the expression of CD80 and CD86 in those cells. Taken together, in vivo results suggest that vitamin C acts to modulate isotype switching in the mouse. However, because of our in vitro results, we suggest that the modulation exerted by vitamin C in vivo is by indirectly affecting B cells, perhaps by directly influencing other immune cells such as dendritic cells.


Pm&r | 2009

Intra-articular Pressure Profiles of Painful Stiff Shoulders Compared With Those of Other Conditions

Sun G. Chung; Kyu Jin Lee; Hee Chan Kim; Kwan Sik Seo; Yong-Taek Lee

To test two questions raised by a previous study: whether high and steeply rising intra‐articular (IA) pressure achieved by controlled fluid infusion would be specific to the painful stiff shoulder (PSS) and whether rupture occurs immediately after the appearance of the third phase so that it could be considered as a preruptural sign.


Journal of the Neurological Sciences | 2016

Effects of anodal transcranial direct current stimulation (tDCS) on behavioral and spatial memory during the early stage of traumatic brain injury in the rats.

Kyung Jae Yoon; Yong-Taek Lee; Seoung Wan Chae; Chae Ri Park; Dae Yul Kim

Transcranial direct current stimulation (tDCS) is a noninvasive technique to modulate the neural membrane potential. Its effects in the early stage of traumatic brain injury (TBI) have rarely been investigated. This study assessed the effects of anodal tDCS on behavioral and spatial memory in a rat model of traumatic brain injury. Thirty six rats underwent lateral fluid percussion and were then randomly assigned to one of three groups: control (n=12), five-day tDCS over peri-lesional cortex at one (1W, n=12), or two (2W, n=12) weeks post-injury. The Barnes maze (BM) and Rotarod (RR) tests were evaluated in a blind manner on day 1, week 3 and week 5 post-injury. After three weeks, both the 1W and 2W groups showed significant improvements in the BM ratio (P<0.05), whereas only group 2W obtained a significant improvement in the RR ratio compared with the control group (P<0.05). However, there were no significant differences between any of the groups at five weeks after TBI. Immunohistochemistry revealed that only group 2W had a significantly higher brain-derived neurotrophic factor (BDNF) expression in the peri-lesional cortex, which was significantly correlated with the improvement of the Rotarod test at 3-week post-injury. However, BDNF expression in the ipsi-lesional hippocampus was not significantly different among the three groups. Group 1W tended to have increased choline/creatine ratios, as measured by magnetic resonance spectroscopy in the peri-lesional cortex, than the control group (P=0.051). Neither regimen aggravated the lesion volume or brain edema measured by MRI. These beneficial effects were not observed with either regimen at five weeks post-injury. In conclusions, anodal tDCS ameliorated behavioral and spatial memory function in the early phase after TBI when it is delivered two weeks post-injury. Earlier stimulation (one week post-injury) improves spatial memory only. However, the beneficial effects did not persist after cessation of the anodal stimulation.


Neuroimmunomodulation | 2012

IL-1β Induction and IL-6 Suppression Are Associated with Aggravated Neuronal Damage in a Lipopolysaccharide-Pretreated Kainic Acid-Induced Rat Pup Seizure Model

Sung-Hyun Lee; Kim Bj; Yong Bum Kim; Pil-Wook Chung; Heui-Soo Moon; Bum Chun Suh; Won Tae Yoon; Dong-Kwan Jin; Yong Shik Park; Yong-Taek Lee; Kwang-Yeol Park

Objectives: Reportedly, hippocampal neuronal degeneration by kainic acid (KA)-induced seizures in rats <14 days old was enhanced by lipopolysaccharide (LPS). This study was to test the hypothesis that cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α are associated with aggravated neuronal damage. Materials and Methods: Sixty male Sprague-Dawley, 14-day-old rats were used. Experiments were conducted in saline, LPS + saline, saline + KA and LPS + KA groups. Intraperitoneal LPS injections (0.04 mg/kg) were administered 3 h prior to KA injection (3 mg/kg). Results: The LPS + KA group showed a tendency toward shorter latency to seizure onset (p = 0.086) and significantly longer seizure duration (p < 0.05) compared with the KA group. Induction of the proconvulsant cytokine IL-1β in rat pup brains was significantly greater in the LPS + KA group compared to the KA group (38.8 ± 5.5 vs. 9.2 ± 1.0 pg/µg; p < 0.05); however, IL-6 levels were higher in the KA group than in the LPS + KA group (108.7 ± 6.8 vs. 60.9 ± 4.7 pg/µg; p < 0.05). The difference in tumor necrosis factor-α between the LPS + KA group and the KA group was insignificant (12.1 ± 0.6 vs. 10.9 ± 2.3 pg/µg; p = 0.64). Conclusions: Our results showed an increase in the proconvulsant cytokine IL-1β and a decrease in a potentially neuroprotective cytokine, IL-6, in rat pups treated with LPS + KA. These results warrant further investigation into the possible role of IL-1β induction and IL-6 suppression in LPS-promoted neuronal damage.


Cerebrovascular Diseases | 2013

Small Deep Infarction in Patients with Atrial Fibrillation: Evidence of Lacunar Pathogenesis

Yong-Shik Park; Pil-Wook Chung; Yong Bum Kim; Heui-Soo Moon; Bum-Chun Suh; Won Tae Yoon; Kyung Jae Yoon; Yong-Taek Lee; Yu Sam Won; Kwang-Yeol Park

Background: It is difficult to clarify whether small deep infarction is caused by cardioembolism or intrinsic small vessel disease in patients with atrial fibrillation (AF). The purpose of this study was to determine whether preexisting small vessel disease would differ according to the presenting infarct pattern and to determine the factors associated with acute single small deep infarction in stroke patients with AF. Methods: Between January 2008 and August 2012, 1,592 consecutive patients with acute ischemic stroke presenting within 7 days of symptom onset were entered in a prospectively maintained stroke registry. For the present study, 231 stroke patients with AF were enrolled irrespective of the stroke subtype. We divided these patients into 2 groups (lacunar infarct pattern, n = 20, vs. nonlacunar infarct pattern, n = 211) according to the acute infarct pattern on diffusion-weighted imaging. Patients with acute single small deep infarction on diffusion-weighted imaging were assigned to the lacunar infarct pattern group. We assessed the severity of preexisting small vessel disease by grading white matter lesions (WMLs) according to the Fazekas scale (periventricular WML score ranging from 0 to 3 and deep WML score ranging from 0 to 3 were added to give a total WML score ranging from 0 to 6), multilacunar state (number of chronic lacunes ≥2) and the presence of microbleeds. Demographic characteristics, vascular risk factors and neuroimaging data were compared between the two groups. Results: Patients with a lacunar infarct pattern showed more severe WMLs than those with a nonlacunar pattern [median total WML score 2.5 (range 2-4) vs. 1.0 (0-2); p < 0.001]. A multilacunar state was more prevalent in the lacunar infarct pattern group compared with the nonlacunar pattern group (65 vs. 28.9%; p = 0.001). However, the presence of microbleeds did not differ between the groups. Multiple logistic regression analyses revealed periventricular WMLs [odds ratio (OR) 4.12, 95% confidence interval (CI) 2.14-7.92], deep WMLs (OR 3.42, 95% CI 1.75-6.66) and multilacunar state (OR 7.85, 95% CI 2.45-25.6) as the predictors of a lacunar infarct pattern. Conclusions: The severity of WMLs and chronic lacunes were independent predictors of the incident infarct pattern, which suggested that acute single small deep infarction might be caused by intrinsic small vessel disease despite the presence of concomitant AF.


Journal of Organic Chemistry | 2016

Stereoselective Chirality Extension of syn,anti- and syn,syn-Oxazine and Stereochemical Analysis of Chiral 1,3-Oxazines: Stereoselective Total Syntheses of (+)-1-Deoxygalactonojirimycin and (−)-1-Deoxygulonojirimycin

Jin-Seok Kim; Yong-Taek Lee; Kun-Hee Lee; In-Soo Myeong; Jong-Cheol Kang; Changyoung Jung; Seok-Hwi Park; Won-Hun Ham

This paper describes the stereoselective total syntheses of (+)-1-deoxygalactonojirimycin and (-)-1-deoxygulonojirimycin via new chiral building blocks syn,anti,syn-oxazine 11a and syn,syn,anti-oxazine 13a. These were accomplished in four steps in 44.1 and 33.7% overall yields, respectively. These chirons were derived from the stereoselective addition of a nucleophile to the corresponding aldehydes of syn,anti-oxazine 10 and syn,syn-oxazine 12. Furthermore, this paper describes the stereochemical analysis of three types of chiral 1,3-oxazines; anti,syn-, syn,anti-, and syn,syn-oxazines using the NOESY technique.


The American Journal of Gastroenterology | 2017

Ability of High-Resolution Manometry to Determine Feeding Method and to Predict Aspiration Pneumonia in Patients With Dysphagia

Chul-Hyun Park; Yong-Taek Lee; Youbin Yi; Jung-Sang Lee; Jung Ho Park; Kyung Jae Yoon

Objectives:The introduction of high-resolution manometry (HRM) offered an improved method to objectively analyze the status of pharynx and esophagus. At present, HRM for patients with oropharyngeal dysphagia has been poorly studied. We aimed to determine feeding method and predict the development of aspiration pneumonia in patients with oropharyngeal dysphagia using HRM.Methods:We recruited 120 patients with dysphagia who underwent both HRM and videofluoroscopic swallow study. HRM was used to estimate pressure events from velopharynx (VP) to upper esophageal sphincter (UES). Feeding methods were determined to non-oral or oral feeding according to dysphagia severity. We prospectively followed patients to assess the development of aspiration pneumonia.Results:VP maximal pressure and UES relaxation duration were independently associated with non-oral feeding. Non-oral feeding was determined based on optimal cutoff value of 105.0 mm Hg for VP maximal pressure (95.0% sensitivity and 70.0% specificity) and 0.45 s for UES relaxation duration (76.3% sensitivity and 57.5% specificity), respectively. During a mean follow-up of 18.8 months, 15.8% of patients developed aspiration pneumonia. On multivariate Cox regression analysis, VP maximal pressure (P<0.01) and UES relaxation duration (P<0.05) independently predicted the development of aspiration pneumonia. Cumulative incidence of aspiration pneumonia was significantly increased in patients with readings below optimal cutoff values for VP maximal pressure (P<0.01) and UES relaxation duration (P<0.01), individually.Conclusions:We first established the optimal thresholds for HRM parameters to determine feeding method and predict the development of aspiration pneumonia in patients with oropharyngeal dysphagia.


Annals of Rehabilitation Medicine | 2016

Comparison of Diffusion Tensor Tractography and Motor Evoked Potentials for the Estimation of Clinical Status in Subacute Stroke

Kwang-Soo Chun; Yong-Taek Lee; Jong-Wan Park; Joon-Youn Lee; Chul-Hyun Park; Kyung Jae Yoon

Objective To compare diffusion tensor tractography (DTT) and motor evoked potentials (MEPs) for estimation of clinical status in patients in the subacute stage of stroke. Methods Patients with hemiplegia due to stroke who were evaluated using both DTT and MEPs between May 2012 and April 2015 were recruited. Clinical assessments investigated upper extremity motor and functional status. Motor status was evaluated using Medical Research Council grading and the Fugl-Meyer Assessment of upper limb and hand (FMA-U and FMA-H). Functional status was measured using the Modified Barthel Index (MBI). Patients were classified into subgroups according to DTT findings, MEP presence, fractional anisotropy (FA) value, FA ratio (rFA), and central motor conduction time (CMCT). Correlations of clinical assessments with DTT parameters and MEPs were estimated. Results Fifty-five patients with hemiplegia were recruited. In motor assessments (FMA-U), MEPs had the highest sensitivity and negative predictive value (NPV) as well as the second highest specificity and positive predictive value (PPV). CMCT showed the highest specificity and PPV. Regarding functional status (MBI), FA showed the highest sensitivity and NPV, whereas CMCT had the highest specificity and PPV. Correlation analysis showed that the resting motor threshold (RMT) ratio was strongly associated with motor status of the upper limb, and MEP parameters were not associated with MBI. Conclusion DTT and MEPs could be suitable complementary modalities for analyzing the motor and functional status of patients in the subacute stage of stroke. The RMT ratio was strongly correlated with motor status.

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Jin-Seok Kim

Sungkyunkwan University

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Won-Hun Ham

Sungkyunkwan University

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So-Yeon Lee

Sungkyunkwan University

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Yong Bum Kim

Sungkyunkwan University

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