• Journal of Oral Medicine and Pain
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• v.36 no.1
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• pp.53-63
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• 2011

Osteoarthritis (OA), the most common form of arthritis, is a result of both mechanical and biological events that destabilize the normal coupling of degradation and synthesis of articular cartilage chondrocytes and extracelluar matrix, and subchondral bone. Although it is likely that the molecular basis of pathogenesis is similar to that of other joints, additional study of the temporomandibular joint (TMJ) is required due to its unique structure and function. This study was carried out to evaluate the epidemiologic characteristics of TMJ osteoarthritis. The purpose of this study was to investigate the prevalence of TMJ OA in Patients with temporomandibular disorders (1405 men and 2922 women whose mean age was $30.2\; {\pm}\; 15.4$ and $33.1\;{\pm}\;15.2$ years, respectively) who had visited the TMJ and Orofacial Pain Clinic of Seoul National University Dental Hospital in 2007. Orthopantomograms, TMJ tomograms and transcranial radiographs were used to evaluate degenerative change of the mandibular condyle. The obtained results were as follows: 1. Degenerative change of the mandibular condyle was observed in 883 (20.4%) of 4327 subjects. The prevalence was significantly higher in women (706 patients, 24.1%) than in men (177 patients, 12.6%), and this significant difference between genders was observed in all age groups. 2. The prevalence of degenerative change of the mandibular condyle in TMD patients showed a gentle increase along with age. Such increase was statistically significant in women (P < 0.001), but not in men. 3. Sclerosis was observed the most frequently in all age groups and the mean age of the patients with osteophyte was the highest among four types of degenerative change. 4. Although men showed degenerative change in the left side more often and women showed degenerative change more frequently in both sides, the difference of distribution in sides between genders was not significant. In conclusion, the prevalence of degenerative change of the mandibular condyle in TMD patients is higher in women than in men, and increases steadily with aging, but not as dramatically as in other joints that show a steep increase in prevalence around the age of 45 years. It can be suggested that the epidemiologic characteristic of OA of the TMJ differs from those of other joints, and that a more extensive study based on the general population is necessary.

• Polymer(Korea)
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• v.32 no.2
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• pp.163-168
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• 2008

Biomedical scaffold for tissue regeneration was fabricated by one of rapid prototyping processes, bioplotting system, with a biodegradable and biocompatible poly($\varepsilon$-carprolactone)(PCL). Through dynamic mechanical test, it was observed that the PCL scaffold manufactured by the bioplotting process has the superior mechanical properties compared to the conventional scaffold fabricated by a salt-leaching process, and the plotted scaffold could be employed as a potential scaffold to regenerating hard and soft tissue. The plotted scaffold was consisted of porous structures. which were interconnected with each pore to help cells be easily adhered and proliferated in the wall of pore tunnels, and metabolic nutrients can be transported within the matrix. By using the plotting system, we could adjust the pore size, porosity, strand pitch, and, strand diameter of PCL scaffolds, which were important parameters to control mechanical properties of the scaffolds, and consequently we could determine that the mechanically controlled scaffolds could be used as a matching scaffold for any required mechanical properties of the target organ. The fabricated 3D PCL scaffold showed enough possibility as a 3D biomedical scaffold, which was cell-cultured with chondrocytes.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.149-154
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• 2007

This study was conducted to investigate the effect of ozone treatment on removal of brown color and ammonia-like odor produced from shark cartilage (SC) and to establish the optimal extraction conditions of chondroitin sulfate (CS) by NaOH and hot water. Treatment of SC with 0.3 ppm ozone water resulted in higher color $L^*$ value but lower $a^*$ and $b^*$ values compared with those of non-treated SC, without affecting its proximate compositions (moisture, protein, lipid, carbohydrate, and ash). Ozone treatment also increased the overall acceptability of SC by reducing ammonia-like odor. The optimum concentration and time for extraction of CS from SC using NaOH at $100^{\circ}C$ were 1 N and 120 min, respectively, with 10.02% of extraction yield. The total yield (10.01%) of CS obtained by 7 times repeated extraction with hot water at $100^{\circ}C$ was comparable to that of the 1 N NaOH extraction for 120 min at $100^{\circ}C$.

• Development and Reproduction
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• v.15 no.4
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• pp.281-289
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• 2011

The objective of this study was to investigate the effective cryoprotectants for the cryopreservation of porcine mesenechymal stem cells (pMSCs). In order to understand the effectiveness of various cryoprotectants on pMSCs, we studied the most commonly used cryoprotectants; dimethyl sulfoxide (DMSO), ethylene glycol (EG), DMSO and EG. pMSCs were isolated from bone marrow matrix of piglet (2 month) and characterized by alkaline phopshatase (AP) activity, colony forming, and differentiation to adipocyte. In slow cooling cryopreservation, the pMSCs were exposed to cell medium containing Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% DMSO, 1.5M EG and 5% DMSO/0.75M EG, respectively, and freezed to $-1^{\circ}C$/min from $25^{\circ}C$ up to $-80^{\circ}C$ in a cryo-container. The proportion of viable cells and the growing rates in fresh pMSCs were significantly (P<0.05) higher than those of other groups, but did not differ between the cryopreserved groups. The expression of Sox-2 and Nanog gene was increased by extending culture time in cryopreserved groups. The expression of Bax gene in cryopreserved groups was similar with fresh pMSCs. Moreover, the gene expression of adipocyte-specific marker as well as chondrogenic/osteogenic factors in cryopreserved groups was similarly to fresh pMSCs. Taken together, our results suggested that all these cryoprotectants of 10% DMSO, 1.5M EG and 5% DMSO/0.75M EG could be used for cryopreservation of the pMSCs.

• Polymer(Korea)
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• v.31 no.1
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• pp.14-19
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• 2007

Demineralized bone particle (DBP) has been used as one of the powerful inducers of bone and cartilage tissue specialization. In this study, we fabricated DBP/PLGA scaffold for tissue engineered disc regeneration. We manufactured dual-structured scaffold to compose inner cylinder and outer doughnut similar to nature disc tissue. The DBP/PLGA scaffold was characterized by porosity, wettability, and water uptake ability. We isolated and cultured nucleus pulposus (NP) and annulus fibrosus (AF) cells from rabbit intervertebral disc. We seeded NP cells into the inner core of the hybrid scaffold and AF cells into the outer portion of it. Cellular viability and proliferation were assayed by 3-(4,5-dimethylthiazole-2-yl) -2,5- diphenyltetrazolium -bromide (MTT) test. PLGA and PLGA/DBP scaffolds were implanted in subcutaneous of athymic nude mouse to observe the formation of disc-like tissue in vivo. And then we observed change of morphology and hematoxylin and eosin (H&E). Formation of disc-like tissue was better DBP/PLGA hybrid scaffold than control. Specially, we confirmed that scaffold impregnated 20 and 40% DBP affected to proliferation of disc cell and formation of disc-like tissue.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.619-624
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• 2009

Pyknodysostosis(PKND) is a rare sclerosing bone disorder that has an autosomal recessive trait, also known as Toulouse-Lautrec syndrome. Deficiency of the cathepsin enzyme K in the osteoclasts of PKND patients results in continuous endosteal bone deposits without osteoclastic resorption or remodeling. This causes a generalized increase in sclerosis and fragility of bones. Osteomyelitis in the mandible and recurrent fracture of the long bones are characteristic complicatons of PKND. The patients present typical features of PKND, such as short stature under 150 cm, open cranial suture and fontanelle, club-shaped phalanges, and underdevelopment of midface. This is a case of a 7-year-old girl with PKND, who visited our clinic with the chief complaint of anterior Open-bite and generalized crowding. The patient had been diagnosed as PKND by an orthopedist and manifested characteristic clinical and radiographic features, such as open cranial suture and fontanelle, obtuse madibular gonial angle, frontal and occipital bossing, grooved palate, club-shaped phalanges, and short stature. Orthodontic treatment was not considered because patients with PKND show abnormal bone resorption and remodeling. Instead, removal of deciduous teeth near exfoliation and TFA were performed, and periodic check-up is planned to maintain good oral hygiene.

• Polymer(Korea)
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• v.30 no.1
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• pp.14-21
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• 2006

Tissue engineering techniques require the use of a porous biodegradable/bioresorbable scaffold, which server as a three-dimensional template for initial cell attachment and subsequent tissue formation in both in vitro and in vivo. Small intestinal submucosa (SIS) has been investigated as a source of collagenous tissue with the potential to be used as biomaterials because of its inherent strength and biocompatibility. SIS-loaded poly(L-lactide-co-glicolide)(PLGA) scaffolds were prepared by solvent casting/particle leaching. Characterizations of SIS/PLGA scaffold were carried out by SEM, mercury porosimeter, and so on. Muscle-derived stem cells can be differentiated in culture into osteoblasts, chondrocytes, and even myoblasts by the controlling the culture environment. Cellular viability and proliferation were assayed by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide(MTT) test. Osteogenic differential cells were analyzed by alkaline phosphatase(ALP) activity. SIS/PLGA scaffolds were implanted into the back of athymic nude mouse to observe the effect of SIS on the osteoinduction compared with controlled PLGA scaffolds. Thin sections were cut from paraffin embedded tissues and histological sections were conducted hematoxylin and eosin (H&E), Trichrome, and von Kossa. We observed that bone formatioin of SIS/PLGA hybrid scaffold as natural/synthetic scaffold was better thean that of only PLGA scaffold. It canb be explained that SIS contains various kinds of bioactive molecules for osteoinduction.

• Journal of Chest Surgery
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• v.36 no.4
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• pp.219-228
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• 2003

Background:Liquid nitrogen freezing techniques have already met with widespread success in biology and medicine as a means of long-term storage for cells and tissues. The use of cryoprotectants such as glycerol and dimethylsulphoxide to prevent ice crystal formation, with carefully controlled rates of freezing and thawing, allows both structure and viability to be retained almost indefinitely. Cryopreservation of various tissues has various con-trolled rates of freezing. Material and Method: To find the optimal freezing curve and the chamber temperature, we approached the thermodynamic calculation of tissues in two ways. One is the direct calculation method. We should know the thermophysical characteristics of all components, latent heat of fusion, area, density and volume, etc. This kind of calculation is so sophisticated and some variables may not be determined. The other is the indirect calculation method. We performed the tissue freezing with already used freezing curve and we observed the actual freezing curve of that tissue. And we modified the freezing curve with several steps of calculation, polynomial regression analysis, time constant calculation, thermal response calculation and inverse calculation of chamber temperature. Result: We applied that freezing program on mesenchymal stem cell, chondrocyte, and osteoblast. The tissue temperature decreased according to the ideal freezing curve without temperature rising. We did not find any differences in survival. The reason is postulated to be that freezing material is too small and contains cellular components. We expect the significant difference in cellular viability if the freezing curve is applied on a large scale of tissues. Conclusion: This program would be helpful in finding the chamber temperature for the ideal freezing curie easily.

• Journal of Life Science
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• v.22 no.8
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• pp.1034-1040
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• 2012

Synovium is the soft tissue that lines the non-cartilaginous surfaces within joints. It has been reported that synovial cells are activated during the pathogenesis of rheumatoid arthritis. In this study, we quantitate and compare the cellular composition of synovia derived from individuals with non-inflammatory osteoarthritis (OA) and those with inflammatory rheumatoid arthritis (RA). Synovia from OA (n=8) and RA (n=5) patients were used for hematoxylin and eosin (H&E) staining. A light microscopic examination has shown that RA synovia were morphologically thickened and hypertrophied as compared to OA synovia. We also performed an immunohistochemistry (IHC) analysis to classify cell types in the synovia using CD68, CD90, or PGP9.5 markers. As a result, we obtained quantitative data regarding the cell populations, which are macrophages in the lining layer and FLSs in the subintimal layer of the synovium. Further Photoshop analyses of the H&E images could allow the counting of the number and layer of the cells in the synovium. The number and layers of the macrophage cells were increased in the lining layer of the RA synovia as compared to the OA synovia. FLS cells also were increased in the subintimal layer of RA synovia. Therefore, quantification of the H&E stained images via Photoshop is a possible analysis protocol for synovium study. This quantitation also supports the idea that the increases in cell number and cell activation are important processes for RA pathogenesis.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.11-12
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• 1991

편측 성대마비의 음성개선을 위하여 현재까지 알려진 치료방법은 teflon 또는 silicone 주입술, 외과적 성대 내전술, 갑상연골 성형술, 신경재식술, 등이 있으며, 근래까지는 Teflon 또는 Gelform 주입술이 제일 효과적인 방법이라 알려져 있으나, 이는 음의 높낮이 조절능력의 한계가 있고, 신경재식술의 결과 역시 만족스럽지 못한 경우가 많다. 따라서 저자는 발성기능의 생리학적인 측면에서, 보다 효과적인 음성개선의 방법을 찾기 위하여, 사람의 후두와 비교적 유사한 특성을 가진 개를 사용하여 실험을 하였다. 반회신경을 절단하여 편측 성대 마비를 유발한 뒤, 동측의 유일한 외전근인 후윤상피열근을 절제후 절단된 신경을 문합하여, 성대의 외전근 작용의 소실과, 발성시에 주로 작용하는 내전근만의 작용을 유도하여, 공동운동의 차단과, 내전운동의 향상을 기대하였다. 본 실험에 앞서, 임의적으로 신경을 자극시킬 수 있는 신경자극기와, 주위조직으로부터 신경만을 분리하여 자극할 수 있는 전극을 개발하여 사용하였으며, 또한 성대의 발성음을 임의대로 유발시킬 수 있는 생체 내 후두발성 모형(in vivo laryngeal phonation model)을 Moore(1987, 1988)등이 발표한 모형을 토대로 자체 개발하여 사용하였다. 실험은 13마리의 개를, 반회신경 절단군(3 마리), 반회신경 절단 및 후윤상피 열근 절제군(3 마리), 후윤상피열근 절제군(3 마리), 반회신경 문합 및 후윤상피 열근 절제군(4 마리)등으로 나누어 실험하였으며, 3 개월 후, 현수후두경, 후두 내시경, videolaryngoscopy, 신경자극 검사 등으로 성대의 내전운동 및 위치 변화의 관찰, 발성음의 음향분석 및 갑상피열근의 형태학적 변화를 관찰하여 다음과 같은 결과를 얻었다. 1. 반회신경 절단군과 반회 신경 절단 및 후윤상피열근 절제군은, 수술후 3 개월에 성대의 움직임이나 각도의 변화가 없었으며, 음향분석 결과 발성음이 아닌 잡음만이 포착되었다. 즉, 절단된 신경의 문합 없이 후윤상피열근 절제 만으로는 음성개선은 기대할 수 없었다. 2. 후윤상피열근 절제군에서는 수술 후 3 개월에 정상적인 성대의 내전운동이 관찰되었으며, 음향분석상 기본주파수 동요율 및 발성음의 강도는 약간의 증가를 보였다. 즉, 반회신경이 절단되지 않은 상태에서 후윤상피 열근 만을 절제하면, 발성음의 변화는 거의 없었다. 3. 반회신경을 절단후 문합하고 후윤상피열근을 절제한군 에서는 수술후 3 개월에, 성대의 정상적인 내전운동을 보였고, 음향분석상 수술직후에는 잡음만이 포착되었으나, 3 개월 후에는 잡음이 아닌 발성음을 들을 수 있었으며, 이 발성음의 기본주파수 및 강도는 수술전보다 감소되어 있었으나, 기본주파수 동요율은 증가되어 있었다. 즉 이 술식으로 인한 뚜렷한 발성음의 향상이 있었다. 이상의 결과로 미루어, 편측 신경 절단으로 인한 성대마비시, 절단된 신경을 봉합하고 성대의 유일한 외전근인 후윤상피열근을 절제하면, 공동운동의 차단과, 내향운동의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다.