• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.277-285
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• 2001

Periodontal disease is characterized by inflammation and subsequent loss and/or damage to tooth-supporting tissues such as bone, cementum,and periodontal ligament. Periodontal ligament and cementum are the key tissues in the initial process of regeneration following periodontal disease. Therefore, studies on cementoblasts, which form cementum are emphasized. It is still unclear which cells cementoblast differentiate from. This study was conducted under the hypothesis that PDL fibroblast can differentiate into either cementoblast or osteoblast depending on the conditions of surrounding tissue. Clinically, with excessive traction force of orthodontic appliances or excessive occlusion hypercementosis is observed, and this has been confirmed histologically. Consequently, activation of cementoblast can be expected in rats when mechanical stimuli are given to PDL fibroblast. Therefore, the purpose of this article is to prove that PDL fibroblast differentiates into cementoblast in rats under mechanical stimuli using histologic and molecular methods. In this study, twenty rats were given hard diet. Ten of them were sacrificed after 1 week, and the others were sacrificed after two weeks. Slides were made from tooth specimen, and they were studied under the microscope. In addition, PDL fibroblast and cementum from the extracted teeth were analyzed with Northern blotting. In histologic examination, as time passed, PDL fibroblast migrated to the dentin side, differentiated into cementoblast, and formed new cementum. In Northern blotting, it was found that mRNA expression of cementoblast-specific proteins such as BSP, OC, OPN, and type I collagen were more prominent in rats sacrificed after 2 weeks of hard-diet than rats sacrificed after 1 week. From these findings we can conclude that PDL fibroblast can differentiate into cementoblast under mechanical stimuli. We think that 'Rat Models' used in this study will be beneficial to future studies regarding cementoblast.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.285-291
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• 2015

Exposure to cold sea water can be life-threatening to the drowned individual. Although appropriate life jacket can be usually be provided for the buoyance at the drowning accident, heat loss can make the drowned individual experience the hypothermia. Inflatable life jackets filled with inflatable air pocket can increase the thermal protection as well as the buoyancy force. Because it is important to know how the human body behaves unde the different life jacket, present study compares the thermal insulation capacity of solid type life jacket with that of inflatable life jacket. In order to represent the insulation capacity of life jacket, thermal resistance is estimated based on the assumption of steady-state. Also, a transient three-dimensional thermal distribution of the thigh is analyzed by using finite element method implementing the Pennes bioheat equation. The finite element model is a segmental, multi-layered representation of the body section which considers the heat conduction within tissue, bone, fat and local blood flow rate.

• Clinics in Shoulder and Elbow
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• v.10 no.2
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• pp.212-219
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• 2007

Purpose: To determine the causes of the surgical treatment results in glenoid fracture by a retrospective analysis. Materials and methods: From March 1999 to February 2004, 9 patients who underwent an open reduction due to a glenoid fracture were reviewed. The modified Ideberg classification was used. There were 1, 3, 2, 1 and 2 cases of modified Ideberg type I, II, III, V, and VI, respectively. The internal fixators were a reconstruction plate, a small plate, a one-third tubular plate, a small screw, and a cannulated screw in 6, 1, 3, 3 and 1 case, respectively. The constant score and Adam's functional assessment method were used to evaluate the postoperative shoulder function. Results: The average time for fracture union was 7 weeks. The functional assessment was excellent in 4 cases, good in 3 cases, and fair in 2 cases. There were two complications related to surgery; articular screw encroachment, and inferior glenoid bone resorption without instability. Conclusion: A glenoid fracture with glenohumeral instability or displaced that was treated by open surgery showed good clinical results. Moreover, the more comminuted fracture had a lower functional score.

• Journal of Chest Surgery
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• v.40 no.9
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• pp.617-623
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• 2007

Background: Invasive pulmonary aspergillosis, a frequent fungal infection in immunocompromised patients, is known to have a poor prognosis despite the use of antifungal therapy in leukemic patients. We studied the outcome of surgical resection of invasive pulmonary aspergillosis where bleeding tendency, localized recurrence of infection, and incidence could be reduced. Material and Method: We retrospectively reviewed 14 patients with a hematological malignancy where invasive pulmonary aspergillosis was diagnosed during the 10 years between 1998 and 2007. From the medical records, we reviewed the type and treatment of the hematological malignancy, including the diagnostic methods of invasive pulmonary aspergillosis, the preoperative hematological conditions and their management, and the surgical methods and records. We also analyzed the development of postoperative complications and patient mortality, the recurrence of postoperative invasive pulmonary aspergillosis, and if the patients had a bone marrow transplant. Result: Fourteen patients with invasive pulmonary aspergillosis and a hematological malignancy underwent a pulmonary lobectomy. One patient had a complication of bronchopleural fistula, but there were no other serious complications such as bleeding or wound infection, and none of the patients died postoperatively. Conclusion: We have shown that pulmonary lobectomy is a safe and effective therapy for invasive pulmonary aspergillosis in patients with hematological malignancies that allow further treatment of the hematological malignancy.

• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.21-29
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• 2020

This study analyzed problems of operating performance bond for public works and derived some suggestions for improvement. The Contract Law for Government Owner requires to submit performance bond which guarantees performing the construction contractor pays back compensation money when the obligation is not executed. Currently, first bid eligibility for participation is exactly required for executing company of performance bond obligation, not considering volume, technical level, and special type of remaining works. In collaboration contract, if guarantee accident occurs, it is obliged for remaining collaboration contractors to be qualified to fulfill the whole contract. This study proposes following improvement plan to solve problems of current performance bone in public works. Firstly, qualification criteria must be deregulated exceptionally for selecting proper contractor, which executing performance bond obligation, considering progress and characteristics of remaining works. Secondly, In collaboration contract, the prerequisite of remaining contractors' should be deregulated as 'implementation requirement of the remaining works'from'implementation requirement of the whole work'. Finally, defect responsibility should be included in liabilities of performance bond by specifying that owner or guarantee agency bear them.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.374-381
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• 2019

A conventional approach for the treatment of long-span edentulous areas is the use of removable dentures. However, placing implants in these areas results in superior functional outcomes by increasing the stability, support, and resistance of the prostheses and improving the masticatory efficiency. Treatment modalities utilizing implants can be further classified into either removable or fixed-type prostheses. Several factors such as the amount of alveolar bone resorption, inter-arch relationship, patient preferences, and socioeconomic status should be considered when determining the appropriate treatment approach. Monolithic zirconia has been considered a suitable material for implant-supported fixed dental prosthesis, because of the drastic improvement in its mechanical properties. It exhibits fewer incidences of fracture and chipping of the prostheses, and has greater bulk of material than metal-ceramic crowns and zirconia-veneered ceramics. Moreover, highly translucent monolithic zirconia is also available in the market, and its application is gradually increasing for anterior tooth rehabilitation. The present report describes a patient who underwent full-mouth rehabilitation with fixed dental prostheses (eight upper and three lower implant placements). All teeth, except bilateral mandibular canines and left mandibular first and second premolars, were extracted after the diagnosis of generalized chronic moderate-to-advanced periodontitis of the remaining teeth. The patient reported satisfactory esthetic and functional outcomes during the one-year follow-up visit.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.585-590
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• 2021

Wrist braces are being used for patients with wrist trauma. Recently, many studies have been conducted to manufacture custom wrist braces using 3D printing technology. Such 3D printing customized orthosis has the advantage of reflecting various factors such as reflecting different shapes for each individual and securing breathability. In this paper, the stress on the orthosis by the number and position of Velcro bands that should be considered when manufacturing a 3D printing custom wrist brace was analyzed. For customized orthosis, 3D modeling of the bone and skin regions was performed using an automatic design software (Reconeasy 3D, Seeann Solution) based on CT images. Based on the 3D skin area, a wrist orthosis design was applied to suit each treatment purpose. And, for the elasticity of the brace, a wrist brace was manufactured with an FDM-type 3D printer using TPU material. To evaluate the effectiveness according to the number and position of the Velcro band of the custom 3D printed wrist brace, the stress distribution of the brace was analyzed by the finite element method (FEM). Through the finite element analysis of the wrist orthosis performed in this study, the stress distribution of the orthosis was confirmed, and the number and position of the orthosis production and Velcro bands could be confirmed. These experimental results will help provide quality treatment to patients.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.5
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• pp.111-118
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• 2018

Nicotine of tobacco component has a controversial impact in the clinical outcome of dental implants. Although numerous nicotine effects on bone healing around implants have been presented, it is rarely reported in vitro study about normal human osteoblast(NHost) from oral and maxillofacial area at the surface of implants. The purpose of the present study was to evaluate the effect of nicotine on the proliferation and differentiation response of NHost to plasmatic and salivary levels of nicotine reported in smokers at the surface of screw-type plasma-sprayed titanium implants. NHosts were seeded on the surface of titanium implants and cultured for 21 days in ${\alpha}-MEM$ supplemented with 10% FBS, 50mg/ml ascorbic acid, 5mM ${\beta}$-glycerophosphate and 100nM dexamethasone. Seeded implants were exposed to various nicotine concentration(0.05-0.5mg/ml) from 1 to 21 days, and characterized for cell morphology, proliferation, differentiation, alkaline phosphatase(ALP) activity and ionized calcium concentration(Cai) of medium. Continuous exposure to higher nicotine concentration(above 0.3mg/ml) induced a dose- and time-dependent vacuolation of the cytoplasm, and a tendency to detach from the implant surface. 0.05mg/ml(lower nicotine concentration) did not cause significant effects in the cell proliferation and ALP activity. 0.1-0.2mg/ml caused evident dose-dependent effects in increased cell proliferation, ALP activity and earlier onset of matrix mineralization at levels up to 0.2mg/ml, while a dose-dependent inhibitory effect at 0.3-0.5mg/ml. Cai concentration of control group was decreased at 14 days. Increased Cai concentration at 0.1-0.2mg/ml, decreased Cai concentration at 0.3mg/ml and no change at 0.5mg/ml during the culture period were seen. It suggested that nicotine concentration could paly an role in modulating NHost activity as a contributing factor associated with proliferation and differentiation of NHost at the surface of implants.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.160-170
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• 2019

The lactic acid bacteria species Lactobacillus plantarum (L. plantarum) has been used extensively for vaccine delivery. Considering to the critical role of dendritic cells in stimulating host immune response, in this study, we constructed a novel CD11c-targeting L. plantarum strain with surface-displayed variable fragments of anti-CD11c, single-chain antibody (scFv-CD11c). The newly designed L. plantarum strain, named 409-aCD11c, could adhere and invade more efficiently to bone marrow-derived DCs (BMDCs) in vitro due to the specific interaction between scFv-CD11c and CD11c located on the surface of BMDCs. After incubation with BMDCs, the 409-aCD11c strain harboring a eukaryotic vector pValac-GFP could lead to more efficient expression of GFP compared with wild-type strains shown by flow cytometry analysis, indicating the enhanced translocation of pValac-GFP from L. plantarum to BMDCs. Similar results were also observed in an in vivo study, which showed that oral administration resulted in efficient expression of GFP in both Peyer's patches (PP) and mesenteric lymph nodes (MLNs) within 7 days after the last administration. In addition, the CD11c-targeting strain significantly promoted the differentiation and maturation of DCs, the differentiation of $IL-4^+$ and $IL-17A^+$ T helper (Th) cells in MLNs, as well as production of $B220^+$ $IgA^+$ B cells in the PP. In conclusion, this study developed a novel DC-targeting L. plantarum strain which could increase the ability to deliver eukaryotic expression plasmid to host cells, indicating a promising approach for vaccine study.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.17-17
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• 2023

Chrysanthemum zawadskii (C. zawadskii) is used in traditional East Asian medicine for the treatment of various diseases, including inflammatory disease. However, it has remained unclear whether extracts of C. zawadskii inhibit inflammasome activation in macrophages. The present study assessed the inhibitory effect of an ethanol extract of C. zawadskii (CZE) on the activation of the inflammasome in macrophages and the underlying mechanism. Bone marrow[-derived macrophages (BMDMs) were obtained from wild-type C57BL/6 mice. The release of IL-1β and lactate dehydrogenase in response to nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activators, such as ATP, nigericin and monosodium urate (MSU) crystals, was significantly decreased by CZE in lipopolysaccharide(LPS)-primed BMDMs. Western blotting revealed that CZE inhibited ATP-induced caspase-1 cleavage and IL-1β maturation. To investigate whether CZE inhibits the priming step of the NLRP3 inflammasome, we confirmed the role of CZE at the gene level using RT-qPCR. CZE also downregulated the gene expression of NLRP3 and pro-IL-1β as well as NF-κB activation in BMDMs in response to LPS. Apoptosis associated speck-like protein containing a caspase-recruitment domain (CARD) oligomerization and speck formation by NLRP3 inflammasome activators were suppressed by CZE. By contrast, CZE did not affect NLR family CARD domain containing protein 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome activation in response to Salmonella typhimurium and poly(dA:dT) in LPS-primed BMDMs, respectively. The results revealed that three key components of CZE, namely linarin, 3,5-dicaffeoylquinic acid and chlorogenic acid, decreased IL-1β secretion in response to ATP, nigericin and MSU. These findings suggest that CZE effectively inhibited activation of the NLRP3 inflammasome.