• Journal of Trauma and Injury
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• v.35 no.1
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• pp.25-33
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• 2022

Purpose: The scoring system for traumatic liver injury (SSTLI) was developed in 2015 to predict mortality in patients with polytraumatic liver injury. This study aimed to validate the SSTLI as a prognostic factor in patients with polytrauma and liver injury through a generalized estimating equation analysis. Methods: The medical records of 521 patients with traumatic liver injury from January 2015 to December 2019 were reviewed. The primary outcome variable was in-hospital mortality. All the risk factors were analyzed using multivariate logistic regression analysis. The SSTLI has five clinical measures (age, Injury Severity Score, serum total bilirubin level, prothrombin time, and creatinine level) chosen based on their predictive power. Each measure is scored as 0-1 (age and Injury Severity Score) or 0-3 (serum total bilirubin level, prothrombin time, and creatinine level). The SSTLI score corresponds to the total points for each item (0-11 points). Results: The areas under the curve of the SSTLI to predict mortality on post-traumatic days 0, 1, 3, and 5 were 0.736, 0.783, 0.830, and 0.824, respectively. A very good to excellent positive correlation was observed between the probability of mortality and the SSTLI score (γ=0.997, P<0.001). A value of 5 points was used as the threshold to distinguish low-risk (<5) from high-risk (≥5) patients. Multivariate analysis using the generalized estimating equation in the logistic regression model indicated that the SSTLI score was an independent predictor of mortality (odds ratio, 1.027; 95% confidence interval, 1.018-1.036; P<0.001). Conclusions: The SSTLI was verified to predict mortality in patients with polytrauma and liver injury. A score of ≥5 on the SSTLI indicated a high-risk of post-traumatic mortality.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.95-95
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• 2002

Human embryonic stem (hES) cells can be induced to differentiate into tyrosine hydroxylase expressing (TH+) cells that may serve as an alternative for cell replacement therapy for Parkinson's disease (PD). To examine in vitro differentiation of hES (MB03, registered in NIH) cells into TH+ cells, hES cells were induced to differentiate according to the 4-/4+ protocol using retinoic acid (RA), ascorbic acid (AA), and/or lithium chloride (LiCl) followed by culture in N2 medium for 14 days, during which time the differentiation occurs. Immunocytochemical stainings of the cells revealed that approximately 21.1% of cells treated with RA plus AA expressed TH protein that is higher than the ratio of TH+ cells seen in any other treatment groups (RA, RA+LiCl or RA+AA+LiCl). In order to see the differentiation pattern in vivo and the ability of in vitro differentiation-induced cells in easing symptomatic motor function of PD animal model, cells (2 $\times$ 10$^{5}$ cells/2${mu}ell$) undergone 4-/4+ protocol using RA plus AA without any further treatment were transplanted into unilateral striatum of MPTP-lesioned PD animal model (C57BL/6). Following the surgery, motor behavior of the animals was examined by measuring the retention time on an accelerating rotar-rod far next 10 weeks. No significant differences in retention time of the animals were noticed until 2 weeks post-graft; however, it increased markedly at 6 weeks and 10 weeks time point after the surgery. Immunohistochemical studies confirmed that a reasonable number of TH+ cells were found at the graft site as well as other remote sites, showing the migrating nature of embryonic stem cells. These results suggest that in viかo differentiated hES cells relieve symptomatic motor behavior of PD animal model and should be considered as a promising alternative for the treatment of PD.

• Journal of Periodontal and Implant Science
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• v.54 no.2
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• pp.96-107
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• 2024

Purpose: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss^® and Bio-Oss/Collagen^®) and 2 types of synthetic hydroxyapatite (Apaceram-AX^® and Refit^®). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. Methods: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with Bio-Oss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). Results: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. Conclusions: Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.

• Molecules and Cells
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• v.27 no.2
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• pp.263-268
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• 2009

Gamma knife surgery (GKS) is used for the treatment of various human brain disorders. However, the biological effects of gamma ray irradiation on both the target area, and the surrounding tissues are not well studied. The effects of gamma ray exposure to both targeted and untargeted regions were therefore evaluated by monitoring gene expression changes in the unilateral irradiated (60 Gy) and contralateral un-irradiated striata in the rat. Striata of irradiated and control brains were dissected 16 hours post-irradiation for analysis using a whole genome 44K DNA oligo microarray approach. The results revealed 230 induced and 144 repressed genes in the irradiated striatum and 432 induced and 239 repressed genes in the unirradiated striatum. Out of these altered genes 39 of the induced and 16 of the reduced genes were common to both irradiated and un-irradiated tissue. Results of semiquantitative, confirmatory RT-PCR and western blot analyses suggested that ${\gamma}$-irradiation caused cellular damage, including oxidative stress, in the striata of both hemispheres of the brains of treated animals.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.418-434
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• 2020

Purpose: The purpose of the present study was to evaluate the effect of silica-calcium phosphate composite (SCPC) granules on bone regeneration in extraction sockets. Methods: Ten patients were selected for a split-model study. In each patient, bone healing in SCPC-grafted and control ungrafted sockets was analyzed through clinical, radiographic, histomorphometric, and immunohistochemical assessments 6 months postoperatively. Results: A radiographic assessment using cone-beam computed tomography showed minimal ridge dimension changes in SCPC-grafted sockets, with 0.39 mm and 1.79 mm decreases in height and width, respectively. Core bone biopsy samples were obtained 6 months post-extraction during implant placement and analyzed. The average percent areas occupied by mature bone, woven bone, and remnant particles in the SCPC-grafted sockets were 41.3%±12%, 20.1%±9.5%, and 5.3%±4.4%, respectively. The percent areas of mature bone and woven bone formed in the control ungrafted sockets at the same time point were 31%±14% and 24.1%±9.4%, respectively. Histochemical and immunohistochemical analyses showed dense mineralized bundles of type I collagen with high osteopontin expression intensity in the grafted sockets. The newly formed bone was well vascularized, with numerous active osteoblasts, Haversian systems, and osteocytes indicating maturation. In contrast, the new bone in the control ungrafted sockets was immature, rich in type III collagen, and had a low osteocyte density. Conclusions: The resorption of SCPC granules in 6 months was coordinated with better new bone formation than was observed in untreated sockets. SCPC is a resorbable bone graft material that enhances bone formation and maturation through its stimulatory effect on bone cell function.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.346-352
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• 2013

The study was aimed to investigate the influence of diode laser on osteoarthritis (OA) of stifle joint induced by anterior cruciate ligament transection (ACLT). Sixty 10-week-old male Sprague-Dawley rats were used in this study. Right stifle joint was operated to create ACLT or sham. There were five study groups: control, Sham, ACLT, ACLT + Laser irradiation (ACLT+L) and ACLT + meloxicam administration (ACLT+M). Low-level laser therapy (LLLT) was applied at the operated stifle joint twice a week using an 808-nm indium-gallium-arsenide (InGaAs) diode laser during 8-week experimental period. Radiographical, gross morphological and histopathological findings were examined at 2, 4 and 8 weeks post-surgery. Radiography, CBC and chemistry tests showed no significant difference between groups. ACLT+L group showed remarkable cartilage damages compared with sham group morphologically and histopathologically at 2, 4 and 8 weeks after surgery. ACLT+M group also had more cartilage damages compared with sham group. Low-level laser therapy (LLLT) showed limitation to prevent progression of OA in the rat anterior cruciate ligament transection models; on the contrary it accelerated cartilage damage. It is assumed that the aggravating results of LLLT in this study might be due to excessive unstable movement of stifle joint from the pain-relieving effect of LLLT, rather than direct damaging effect of irradiation since LLLT did not affect cell viability.

• Journal of Korean Physical Therapy Science
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• v.14 no.1_4
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• pp.11-23
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• 2007

This study was performed to evaluate the effects of low-intensity ultrasound application to the peripheral nerve injury animal model on enhancement of nerve regeneration and functional recovery. Using aseptic microsurgical techniques, the sciatic nerve of adult male Sprague-Dawley rats was crushed at the outside of right mid-thigh for 30 seconds with fine forceps. Beginning just after surgery, various continuous-wave ultrasound treatments with intensities of 0.2 W/$cm^2$, 0.5 W /$cm^2$ and 1.0 W /$cm^2$ operated at 1 MHz or sham treatment were applied to the opposite inside of the crush site for 1 minute every other day with a transducer moving speed of 2cm/sec. For evaluation of the progress of sciatic nerve regeneration, c-Fos expression in the lumbar spinal cord (L4-5) dorsal horn was investigated. c-fos expression was markedly increased at 1hour after sciatic nerve crush injury, then gradually decreased thereafter. The c-fos expressions were significantly decreased (p<0.05) in all the experimental groups in comparison with the control group until 3days post-crush, and the degrees of decrease were higher in 0.5 W/$cm^2$ and 1 W/$cm^2$ intensity ultrasound application groups. It is suggested that low-intensity ultrasound application to an animal model of sciatic crush injury may suppress pain transmission and promote nerve regeneration, and which may result in delayed progress of muscle atrophy and accelerated progress of muscle recovery and eventually may result in accelerated and improved foot function recovery.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.419-424
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• 2012

In addition to respiration, the nose performs three other major physiological functions-air-conditioning, filtering, and smelling. On the basis of our experience in experimental investigations of nasal airflows in normal and abnormal nasal cavity models, airflows in the normal model and three artificially deformed models, which simulate the results of surgical treatments (inferior turbinectomy), are investigated by PIV and CFD. The left cavities of all three models are normal, and the right cavities are modified as follows: (1) excision of the head of the inferior turbinate, (2) resection of the lower fifth of the inferior turbinate, and (3) resection of almost the entire inferior turbinate. The use of high-resolution CT data and careful surface rendering of three-dimensional computer models with the help of an ENT doctor provide more sophisticated nasal cavity models. Nasal airflows for both normal and deformed cases are also compared.

• Journal of Periodontal and Implant Science
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• v.46 no.1
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• pp.57-69
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• 2016

Purpose: The aim of this pilot study was to determine the osteoconductivity and dimensional stability of augmented sinuses using different ratios of biphasic calcium phosphate (BCP) in a rabbit sinus model. Methods: Each sinus of New Zealand white rabbits (2.5-3.5 kg) was assigned to one of two groups: BCP with a hydroxyapatite to ${\beta}$-tricalcium phosphate (HA:${\beta}$-TCP) ratio of 70:30 (group TCP30) and BCP with an HA:${\beta}$-TCP ratio of 30:70 (group TCP70). After preparing a window in the antral wall of a sinus, the Schneiderian membrane was elevated, and the applicable material was grafted. A fluorochrome calcein green was injected five days before euthanizing the animals at four months post-surgery. The specimens were analyzed histologically, histomorphometrically, and by using micro-computed tomography (micro-CT). Results: Micro-CT analysis revealed that the total augmented volume and the new bone volume did not differ significantly between the two groups whereas the resorption of materials was greater in the TCP70 group. The trabecular thickness, number, and separation also did not differ significantly between the two groups. Histomorphometrically, the areas of total augmentation, new bone, and residual material, as well as the ratio of new-bone-material contact did not differ significantly between the groups. Histologically, the residual particles were more scattered in the TCP70 group than in the TCP30 group. The fluorescence of the calcein green did not differ notably between the two groups. Conclusions: The osteoconductivity and dimensional stability of the two BCPs with different ratios tested in this study were comparable after four months of healing. Therefore, we conclude that both BCPs show promise as a bone substitute for sinus augmentation.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.294-300
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• 2010

Purpose: The template-guided implant surgery offers several advantages over the traditional approach. The purpose of this study was to evaluate the accuracy of coordinate synchronization procedure with 5-axis milling machine for surgical template fabrication by means of reverse engineering through universal CAD software. Materials and methods: The study was performed on ten edentulous models with imbedded gutta percha stoppings which were hidden under silicon gingival form. The platform for synchordination was formed on the bottom side of models and these casts were imaged in Cone beam CT. Vectors of stoppings were extracted and transferred to those of planned implant on virtual planning software. Depth of milling process was set to the level of one half of stoppings and the coordinate of the data was synchronized to the model image. Synchronization of milling coordinate was done by the conversion process for the platform for the synchordination located on the bottom of the model. The models were fixed on the synchordination plate of 5-axis milling machine and drilling was done as the planned vector and depth based on the synchronized data with twist drill of the same diameter as GP stopping. For the 3D rendering and image merging, the impression tray was set on the conbeam CT and pre- and post- CT acquiring was done with the model fixed on the impression body. The accuracy analysis was done with Solidworks (Dassault systems, Concord, USA) by measuring vector of stopping’s top and bottom centers of experimental model through merging and reverse engineering the planned and post-drilling CT image. Correlations among the parameters were tested by means of Pearson correlation coefficient and calculated with SPSS (release 14.0, SPSS Inc. Chicago, USA) ($\alpha$ = 0.05). Results: Due to the declination, GP remnant on upper half of stoppings was observed for every drilled bores. The deviation between planned image and drilled bore that was reverse engineered was 0.31 (0.15 - 0.42) mm at the entrance, 0.36 (0.24 - 0.51) mm at the apex, and angular deviation was 1.62 (0.54 - 2.27)$^{\circ}$. There was positive correlation between the deviation at the entrance and that at the apex (Pearson Correlation Coefficient = 0.904, P = .013). Conclusion: The coordinate synchronization 5-axis milling procedure has adequate accuracy for the production of the guided surgical template.