• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.11-17
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• 2012

The purpose of this study is to measure and evaluate radiation dose on patients in interventional radiological(IVR) procedures classified by each procedure, and aid as data for safety management. Fluroscopy time(F-time), dose area product(DAP) and number of acquired images from each kind of procedure was checked. Non-vascular procedures showed low value, and vascular procedure showed high value in all procedures except in IVC filter. F-time was longest in EVAR, which showed also the highest DAP value of all procedures. DAP-rate showed high value in TACE. By this result, we attempt to establish standard guideline of radiation dose on patients in IVR procedure.

• Imaging Science in Dentistry
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• v.38 no.1
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• pp.17-22
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• 2008

Purpose: It is important to determine the bucco-lingual inclination of implants on radiographs before the implant surgery. The purpose of this study was to compare the buccolingual inclination in alveolar bone and the tooth with dental cone beam CT and to prepare the standard for the buccolingual inclination of implant. Materials and Methods: Axial, panoramic, and buccolingually sectioned images of 80 implant cases with stent including straight marker using CB $Mercuray^{TM}$ (Hitachi, Japan) were evaluated. The comparison of the buccolingual inclination of remained alveolar bone with the tooth and the marker on butcolingually sectioned views was performed statistically. Results: The average buccolingual inclination of remained alveolar bone and tooth was $82.8{\pm}4.6^{\circ}\;and\;85.8{\pm}4.7^{\circ}$ (p<0.05, r=0.96) at the 1st molar area and $76.4{\pm}1.7^{\circ}\;and\;82.7{\pm}1.7^{\circ}$ respectively (p>0.05, r=0.12) at the 2nd premolar area in upper jaw. The average buccolingua1 inclination of remained alveolar bone and tooth was $81.3{\pm}8.3^{\circ}\;and\;87.5{\pm}6.3^{\circ}$ (p>0.05, r=0.85) at the lower 2nd premolar area and $94.3{\pm}6.6^{\circ}\;and\;93.3{\pm}7.2^{\circ}$ respectively (p>0.05, r=0.91) at the 1st molar area in lower jaw. The inclinations of markers were very different from those of remained bone at the most of areas except the upper 2nd premolar area (r=0.79). Conclusion: We recommend dental CBCT analysis for determining the buccolingual inclination of dental implant, because of significant difference, in average, between the bucco1ingual inclination of remained alveolar bone and tooth.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.363-366
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• 2003

Background: Left ventricular rupture after acute myocardial infarction is a serious complication with high mortality. Emergency operation is usually the only available treatment. A 76-year-old female with persistent chest pain and syncopal attacks was admitted. Transthoracic echocardiography showed the pericardial effusion and generalized hypokinesia of the inferolateral wall of left ventricle. Coronary angiography revealed a total occlusion of the first diagonal branch. After percutaneous transluminal coronary angioplasty with coronary stent and insertion of intraaortic balloon pump, emergency operation was performed. Under cardiopulmonary bypass and cardiac arrest with cold blood cardioplegia, coronary artery bypass graft with saphenous vein, pericardial patch covering on the rupture area with 6-0 polypropylene running sutures, and fibrin glue compression under the patch were performed. We present a case of left ventricular (free wall) rupture after acute myocardial infarction.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.7-16
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• 1998

The Scanora/sup (R)/ X-ray unit uses the principles of narrow beam radiography and spiral tomography. Starting with a panoramic overview as a scout image. multiple tomographic projections could be selected. This study evaluated the accuracy of spiral tomography in comparison to routine panoramic radiography for dental implant treatment planning. An experimental study was performed on a cadaver mandible to assess the accuracy of panoramic radiography and spiral tomography film images for measurement of metallic spheres. After radiographic images of the metallic spheres on the surgical stent were measured and corrected for a fixed magnification of radiographic images. following results were obtained. 1. In the optimal position of the mandible. the minimal horizontal and vertical distortion was evident in the panoramic radiography images. The mean horizontal and vertical magnification error in anterior sites was 5.25％ and 0.75％. respectively. The mean horizontal and vertical magnification error in posterior sites was 0.50％ and 1.50％. respectively. 2. In the displaced forward or in an eccentric position of the mandible. the magnification error of the panoramic radiography images increased significantly over the optimal position. Overall, the mean horizontal magnification error of the anterior site in the different positions changed dramatically within a range of -17.25％ to 39.00％, compared to the posterior range of -5.25％ to 8.50％. However, the mean vertical magnification error stayed with the range of 0.5％ to 3.75％ for all the mandibular positions. 3. The magnification effects in the tomographic scans were nearly identical for the anterior and posterior with a range of 2.00％ to 5.75％ in the horizontal and 4.50％ to 5.50％ in the vertical dimension, respectively. 4. A statistically significant difference between the anterior and posterior measurements was found in the horizontal measurements of the panoramic radiography images of the displaced forward and backward position of the mandible(P<0.05). Also a significant difference between the optimal panoramic and tomographic projections was found only in the vertical measurement(P<0.05).

• Imaging Science in Dentistry
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• v.41 no.3
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• pp.115-121
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• 2011

Purpose : This article is to describe a modified device for intraoral radiography which was developed to obtain reproducible radiographic images for assessment of distal osseous defects of the mandibular second molar (2 Mm) after impacted third molar (3 Mm) surgery. Materials and Methods : A commercial available alignment system for posterior region was modified by adding a reference gauge pin (millimetric) and threading a hollow acrylic cylinder at the ring of the radiographic positioner to attach the X-ray collimator. The design included customized resin acrylic stent for the occlusal surface of the 2Mm in maximum intercuspal position, individualizing the biteblock positioner. Periapical radiographs were taken before and after surgical extraction of 3 Mm, employing the radiographic technique of parallelism described by Kugelberg (1986) with this modified film holder and inserting the gauge pin on the deepest bone probing depth point. Results : This technique permitted to obtain standardized periapical radiographs with a moderate to high resolution, repeatability, and accuracy. There was no difference between the measurements on the pre- and post-operative radiographs. This technique allowed better maintenance of the same geometric position compared with conventional one. The insertion of the gauge pin provided the same reference point and localized the deepest osseous defect on the two-dimensional radiographs. Conclusion : This technique allowed better reproducibility in posterior radiographic records (distal surface of 2 Mm) and more accurate measurements of radiographic bone level by the use of a millimetric pin.

• Polymer(Korea)
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• v.33 no.6
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• pp.620-624
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• 2009

Biomedical metal implants have been used clinically for replacement, restoration, or improvement of injury bodies based on high mechanical properties, but it has some risks such as the inflammatory, late thrombosis, or restenosis due to the low biocompatibility and toxicity. In various techniques of surface treatment developed to preserve these drawbacks, this study examined the electrospray coating technology with biodegradable poly (lactic-co-glycoic acid) (PLGA) on metal surface. Based on fundamental examination of electrospraying and solution parameters, the surface morphology of coated film was closely related to the boiling point of solvent, in-flight distance, and droplet size. The thickness of polymer film was linearly proportional to the emerged volume. This result exhibits that the polymeric droplets were continuously deposited on the polymer film. Therefore, the electrospray coating technology might be applied into the fabrication of single/multi-layered polymer film in nano-/micro-thickness and the control of the topology for biomedical metal implants including stents.

• Journal of Gastric Cancer
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• v.16 no.2
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• pp.63-71
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• 2016

Pylorus-preserving gastrectomy (PPG) is a function-preserving surgery for the treatment of early gastric cancer (EGC), aiming to decrease the complication rate and improve postoperative quality of life. According to the Japanese gastric cancer treatment guidelines, PPG can be performed for cT1N0M0 gastric cancer located in the middle-third of the stomach, at least 4.0 cm away from the pylorus. Although the length of the antral cuff gradually increased, from 1.5 cm during the initial use of the procedure to 3.0 cm currently, its optimal length still remains unclear. Standard procedures for the preservation of pyloric function, infra-pyloric vessels, and hepatic branch of the vagus nerve, make PPG technically more difficult and raise concerns about incomplete lymph node dissection. The short- and long-term oncological and survival outcomes of PPG were comparable to those for distal gastrectomy, but with several advantages such as a lower incidence of dumping syndrome, bile reflux, and gallstone formation, and improved nutritional status. Gastric stasis, a typical complication of PPG, can be effectively treated by balloon dilatation and stent insertion. Robot-assisted pylorus-preserving gastrectomy is feasible for EGC in the middle-third of the stomach in terms of the short-term clinical outcome. However, any benefits over laparoscopy-assisted PPG (LAPPG) from the patient's perspective have not yet been proven. An ongoing Korean multicenter randomized controlled trial (KLASS-04), which compares LAPPG and laparoscopy-assisted distal gastrectomy for EGC in the middle-third of the stomach, may provide more clear evidence about the advantages and oncologic safety of PPG.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.349-360
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• 2018

Autophagy has been studied as a therapeutic strategy for cardiovascular diseases. However, insufficient studies have been reported concerning the influence of vascular smooth muscle cells (VSMCs) through autophagy regulation. The aim of the present study was to determine the effects of VSMCs on the regulation of autophagy under in vitro conditions similar to vascular status of the equipped micro-tubule target agent-eluting stent and increased release of platelet-derived growth factor-BB (PDGF-BB). Cell viability and proliferation were measured using MTT and cell counting assays. Immunofluorescence using an $anti-{\alpha}-tubulin$ antibody was performed to determine microtubule dynamic formation. Cell apoptosis was measured by cleavage of caspase-3 using western blot analysis, and by nuclear fragmentation using a fluorescence assay. Autophagy activity was assessed by microtubule-associated protein light chain 3-II (LC-II) using western blot analysis. Levels of intracellular reactive oxygen species (ROS) were measured using $H_2DCFDA$. The proliferation and viability of VSMCs were inhibited by microtubule regulation. Additionally, microtubule-regulated and PDGF-BB-stimulated VSMCs increased the cleavage of caspase-3 more than only the microtubule-regulated condition, similar to that of LC3-II, implying autophagy. Inhibitory autophagy of microtubule-regulated and PDGF-BB-stimulated VSMCs resulted in low viability. However, enhancement of autophagy maintained survival through the reduction of ROS. These results suggest that the apoptosis of conditioned VSMCs is decreased by the blocking generation of ROS via the promotion of autophagy, and proliferation is also inhibited. Thus, promoting autophagy as a therapeutic target for vascular restenosis and atherosclerosis may be a good strategy.

• Polymer(Korea)
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• v.35 no.3
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• pp.260-264
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• 2011

Biodegradable polymeric stents have been issued to replace the existing non-degradable metal stents due to relatively improved biocompatibility and low side effects. Fundamentally, all the stents must possess the desired mechanism strength, especially, compression or radial force to maintain the diameters of expanded vessels. Therefore, this study suggests a helical structure and focused on the relation between the lateral compression and structural factors, Unlike a cylindrical model, the radial force of the helical model is proportional to the thickness and the length to the power of one, whereas the diameter to the power of 1.6. The function obtained from these results might provide the fundamental information to design and prepare the stem for clinical applications.

• Polymer(Korea)
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• v.33 no.1
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• pp.84-90
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• 2009

Nitinol alloy (TiNi) has been widely used in vascular stents. To improve the blood compatibility of Nitinol alloy, its surface was chemically modified in this study. Nitinol was first coated with gold, then chemisorbed with L-cysteine (C/N), and followed by grafting of zwitter ionic poly(ethylene glycol) (PEG) (PEG-$N^+-SO_3{^-}$) to produce TiNi-C/N-PEG-N-S. The zwitter ionic PEG grafted on the Nitinol surface was identified by ATR-FTIR, ESCA and SEM. The hydrophilized surface was proven by the decrease of water contact angle. In addition, from the blood compatibility tests such as protein adsorption, platelet adhesion, and blood coagulation time, the surface-modified TiNi alloy exhibited a better blood compatibility as compared to the untreated Nitinol control. These results indicated a feasibility of synergistic effect of hydrophilic PEG and antithrombotic zwitter ion.