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Pohang, South Korea

Lee D.-H.,University of Ulsan | Lee J.-S.,Pusan National University | Yi J.-S.,Catholic University of Daejeon | Cho W.,University of Washington | And 2 more authors.
Spine Journal | Year: 2013

Background context: The proximity (<5 mm) of the plate to the adjacent disc space is known to be a critical risk factor for adjacent-level ossification development (ALOD). As plates provide many advantages including higher fusion rates and improved alignment, their use will continue. Instead, it is necessary to modify the plating techniques to minimize this complication. Purpose: To determine if our newer plating technique decreases the incidence of ALOD after anterior cervical plating. Study design: Retrospective matched cohort analysis of preoperative and postoperative radiographic data. Patient sample: One hundred patients were classified into two groups; conventional (C) and new (N) plating techniques. The control group (Group C) was matched to the study group (Group N) in a 1:1 fashion using matching criteria of age (within 5 years), gender, number of fusion levels, and comorbidities, including diabetes and tobacco use. Outcome measures: The lateral plain X-rays of cervical spine taken at postoperative 6 months and 2 years were used for analysis. Methods: In Group N, the cranial and caudal screws were started at the anterior end plate corners and angled away from the end plates so as to use the shortest possible plate and maximize the distance to the adjacent end plates. Group C was the historical control using a longer plate with more orthogonal screw angulation. On postoperative 6-week lateral films, the distances from the tip of the plate to both cranial and caudal adjacent discs (plate-to-disc distances) were measured. Based on the postoperative 2-year radiographs, the incidence of ALOD was determined, and the severity of ossification was classified on a scale ranging from Grade 0 (no ossification) to Grade 3 (complete bridging). Results: Mean plate-to-disc distances in Group N were significantly longer at both cranial and caudal adjacent levels than those in Group C (p<.001). The incidence of ALOD was significantly lower in Group N than in Group C, both at the cranial adjacent disc spaces (42% vs. 72%) and caudal adjacent disc spaces (20% vs. 42%) (p<.05). Severe ossification (Grade 2 or greater) also developed less frequently in Group N at cranial and caudal levels (6% vs. 20%, respectively; p<.05). Conclusions: The new technique of using a shorter plate with longer angulated screws resulted in significantly reduced incidence and severity of ALOD. © 2013 Elsevier Inc. All rights reserved. Source

Liu T.,University of California at Davis | Chen L.,University of California at Davis | Kim E.,Catholic University of Daejeon | Tran D.,University of California at Davis | And 3 more authors.
Life Sciences | Year: 2014

Aims Mitochondrial dysfunction is an important part of the decline in cardiac function in heart failure. We hypothesized for hypothesized that there would be specific abnormalities in mitochondrial function and proteome with the progression of ischemic heart failure (HF). Main methods We used a high left anterior descending artery (LAD) ligation in 3-4 month old male rats to generate HF. Rats were studied 9 weeks post-ligation. Key findings Electron microscopy of left ventricle samples showed mitochondrial changes including decreased size, increased number, abnormal distribution, and cristae loss. Mitochondria in ischemic HF exhibited decreased total ATP, impaired mitochondrial respiration, as well as reduced complex I activity. Analysis of LV mitochondrial proteins by mass spectrometry was performed, and 31 differentially expressed proteins (p < 0.05) of more than 500 total proteins were identified. Of these proteins, 15 were up-regulated and 16 were down-regulated in the failing heart. A set of complex I proteins was significantly decreased, consistent with the impairment of complex I activity. There were distinct changes in mitochondrial function and proteome in ischemic HF. Although there were similarities, the distinction between the reported proteomic changed with TAC pressure overload induced HF and ischemic HF in the current study suggested different pathological mechanisms. Significance Specific changes in mitochondrial protein expression, which correlate with changes in mitochondrial function, have been identified in ischemic HF for the first time. © 2014 Elsevier Inc. Source

Park S.E.,Catholic University of Korea | Lee J.-U.,Catholic University of Daejeon | Ji J.-H.,Catholic University of Korea
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2011

Both intraneural lipoma and chondroid lipoma have been reported in the previous literature as a separate disease entity on rare occasions. But intraneural chondroid lipoma has not been ever reported till now. So we present such a patient with an intraneural chondroid lipoma localized to common peroneal nerve. © 2010 Springer-Verlag. Source

Lee J.-S.,Korea Advanced Institute of Science and Technology | Choi J.,Catholic University of Daejeon | Yoo J.H.,Korea Advanced Institute of Science and Technology | Kim M.,Chungbuk National University | And 3 more authors.
Human Brain Mapping | Year: 2014

Semantic priming is affected by the degree of association and how readily a word is imagined. In the association effect, activity in the perisylvian structures including the bilateral inferior frontal gyrus, the left middle temporal gyrus, and the supramarginal gyrus was correlated. However, little is known about the brain regions related to the effect of imagery word under the preconscious condition. Forty word pairs for high (HA)-, low (LA)-, and nonassociation (NA), nonword (NW) conditions were presented. Each 40 association word pairs (HA and LA) included 20 high (HI) and 20 low (LI) imagery prime stimuli, using a visually presented lexical decision task. A trial consisted of 30 ms prime, 30 ms mask, 500 ms probe, and 2-8 s stimulus onset asynchrony. Brain activation was measured using functional magnetic resonance imaging during word discrimination. Behavioral data indicated that the shortest response time (RT) was given for HA words, followed by LA and NA, and NW showed the longest RT (P<0.01). RT was faster in HI than LI within HA, but not LA conditions (P<0.01). Functional neuroimaging showed that differential brain regions for high imagery (HI) and low imagery (LI) words within low prime-target word association were observed in the left precuneus, left posterior cingulate gyrus, and right cuneal cortex. The present findings demonstrate that the effect of the degree of imagery on semantic priming occurs during the early stage of language processing, indicating an "automatic imagery priming effect." Our paradigm may be useful to explore semantic deficit related to imagery in various psychiatric disorders. © 2014 The Authors. Source

Seo K.-S.,Chungnam National University | Park J.-H.,Chungnam National University | Heo J.-Y.,Chungnam National University | Jing K.,Chungnam National University | And 11 more authors.
Oncogene | Year: 2015

Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that has a central role in the regulation of tumour metabolism under hypoxic conditions. HIF-1α stimulates glycolytic energy production and promotes tumour growth. Sirtuins are NAD(+)-dependent protein deacetylases that regulate cellular metabolism in response to stress; however, their involvement in the hypoxic response remains unclear. In this study, it is shown that SIRT2-mediated deacetylation of HIF-1α regulates its stability in tumour cells. SIRT2 overexpression destabilized HIF-1α under hypoxic conditions, whereas HIF-1α protein levels were high in SIRT2-deficient cells. SIRT2 directly interacted with HIF-1α and deacetylated Lys709 of HIF-1α. Deacetylation of HIF-1α by SIRT2 resulted in increased binding affinity for prolyl hydroxylase 2, a key regulator of HIF-1α stability, and increased HIF-1α hydroxylation and ubiquitination. Moreover, a pharmacological agent that increased the intracellular NAD(+)/NADH ratio led to the degradation of HIF-1α by increasing SIRT2-mediated deacetylation and subsequent hydroxylation. These findings suggest that SIRT2-mediated HIF-1α deacetylation is critical for the destablization of HIF-1α and the hypoxic response of tumour cells. Source

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