• Journal of Life Science
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• v.28 no.5
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• pp.597-604
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• 2018

Although the core mechanisms of Attention Deficit/Hyperactivity Disorder (ADHD) are unknown, several ADHD-associated proteins have been studied. G-protein - coupled receptor kinase interacting protein-1 (GIT1) is a multifunctional adapter protein that affects neuron growth and dendrite formation. GIT1-deficient mice have shown ADHD-like behavior and also recovered through amphetamine treatment. In this study, gliotransmitters were investigated in both intracellular and extracellular space from GIT1-deficient mice. To measure the amount of gliotransmitters, primary astrocyte cultures were taken from the cerebral and cerebellar cortices of wild (WT), hetero (HE), and knock-out (KO) mice. Major gliotransmitters were analyzed using high-performance liquid chromatography. It was observed that the amount of excitatory and inhibitory gliotransmitters were dependent on genotype and showed a change in excitation/inhibition ratios. Interestingly, the major excitatory gliotransmitter, glutamate, existed at the lowest level in WT mice, but the amount of inhibitory gliotransmitters, gamma-aminobutyric acid (GABA) and glycine, varied depending on brain region. Remarkably, an increased amount of GABA was measured at the intracellular cerebrum in WT mice compared with KO mice. It was presumed that KO mice would secrete more inhibitory gliotransmitters to compensate for GIT1 depletion or else acquire a defect to reuptake-secreted GABA. This may be a possible mechanism for ADHD pathology.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.165-177
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• 1997

The purpose of this study was to perform on the biological activity of Magnolia and Zizyphi fructus extract mixtures on the wound healing of defected rat calvaria. For the determination of the mixture ratio of two extracts for oral administration, preliminary experiments were performed with the mixture combination of 2000 and $3000{\mu}g/ml$ of Magnolia extract, and also 20, 30, 200, 300, 2000 and $3000{\mu}g/ml$ of Zizyphi fructus extract, respectively and divided into 6 groups. The combination of extracts mixture were tested on the enhancing effect of cellular activity. The effect of the extracts mixture on the cellular activity was evaluated using MTT method and measured on the results with optical density by ELISA reader. The ability to tissue regeneration of the extracts mixture was performed by measuring new bone and new connective tissue regeneration on the 5mm defected rat calvaria for 1, 2 and 3 weeks after oral administration of 2 different dosages groups : 10:1(0.1g/kg) and 10:1(0.5g/kg). It was employed the same dosages of unsaponifiable fraction of Zea Mays L as positive controls. Each group of rat was sacrificed and en bloc section for histological examination. The effect on the cellular activity of each mixture ratio showed significantly higher in $2000{\mu}g/ml$ of Magnolia extract and $200{\mu}g/ml$ of Zizyphi fructus extract group to compare with other groups. These preliminary results showed that appropriate mixture ratio of two extracts was 10:1 of Magnolia and Zizyphi fructus extract. Histological examination on the activity of tissue regeneration of each group showed that 2weeks and 3weeks specimens of 0.5g/kg of 10:1 extract mixture of Magnolia and Ziziphi fructus administrated rat calvaria revealed significantly more osteoid and new bone formation of defected calvaria with unification of defected area than the specimens of any other negative and positive controls. Even though the specimen administrated the same dosages of unsaponifiable fraction of Zea Mays L, positive controls, showed the trend that they promote significantly the repair of calvarial defect, their bone reparative activities were less inductive than the same dosages of Magnolia and Ziziphi fructus extract mixture. These results implicated that the mixture of Magnolia and Zizyphi fructus extracts should be highly effective on the wound healing of bony defected site and might have potential possibilities as an useful drug to promote periodontal tissue regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.300-305
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• 2005

Purpose: For the reconstruction of maxillofacial defect created by trauma, infection, or tumor etc, the role of microvascular anastomosis or vessel graft has been increased. Many methods has been tried to increase the success rate of microvascular anastomosis. Various anticoagulants and thrombolytic agents have been used to reduce the failure rate of microvascular anastomosis and avoid re-operation. Many drugs, however, have been used in the limited cases because most of these drugs may cause complications, such as allergy, fever or systemic bleeding. This study was performed to evaluate the influence of the Argatroban on patency and thrombosis in microvascular anastomosis when it is used for local irrigation or general administration. Materials & methods: Eight mature rabbits, weighing 2kg, were used. After exposing both femoral veins, the artificial thrombotic model was made by crushing injury using a smooth needle holder, and the transverse incision were made on femoral vein. The animals were divided into 4 groups according to Argatroban administration methods; control group (n=4), topical irrigation of lumen with saline solution; experimental group 1 (n=4), topical irrigation of lumen with Argatroban saline solution; experimental group 2 (n=4), topical irrigation of lumen with heparin followed by intravenous injection of Argatroban; experimental group 3 (n=4), topical irrigation of lumen with Argatroban followed by IV of Argatroban. Microvascular anastomosis was done with 10-0 Ethilon. The patency was evaluated by empty-and-refill test 30 minutes and 3 days after microanastomosis. The thrombus formation was examined 3 days after microanastomosis by surgical microscope. The histologic findings were also examined. Results: 1. Thirty minutes after microvascular anastomosis, the patency of all experimental groups was better than that of control group, but there was no significant difference among groups. 2. Three days after microvascular anastomosis, the patency of all experimental groups was more improved than that of control group (p<0.05). There was no significant difference among experimental groups. 3. Three days after microvascular anastomosis, the amount of thrombus in all experimental groups was less than that of control group (p<0.05). There was no significant difference among experimental groups. 4. Histologically, a lot of luminal thrombus was observed around sutured area in control group. Few luminal thrombus was observed in all experimental groups. The necrotic changes were observed on the sutured vein wall in all specimens. Conclusion: These results indicate that topical irrigation and/or intravenous administration of Argatroban is effective in improving patency and preventing thrombus formation after microvascular anastomosis.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.249-264
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• 1998

The present study evaluates the effects of calcium sulfate and DFDB on alveolar bone regeneration and cementum formation and connective tissue adhesion in intrabony angulated 1 wall defects of dogs. Four millimeter-deep angulated one-wall intrabony defects were surgically created in the mesial & distal aspects of premolars and with flap operaion alone(control group), with calcium sulfate(experimental group 1), with composit graft of 50% calcium sulfate and 50% DFDB(experimental group 2), with DFDB alone(experimental group 3). Histologic analysis following 8 weeks of healing revealed the following results: 1. The lengths of connective tissue adhesion was $1.05{\pm}0.48mm$ in the control, $1.30{\pm}0.67mm$ in the test group I, $0.97{\pm}0.22mm$ in the test group II and $0.93{\pm}0.15mm$ in the test group III. There was no statistical significance between control and all experimental groups. 2. Changes in alveolar bone level was $0.97{\pm}0.27mm$ in the control group, $1.45{\pm}0.42mm$ in the test group I, $2.00{\pm}0.33mm$ in the test group II, $1.88{\pm}0.34mm$ in the test group III. There was no statistically significant difference between control and experimental group I. There was a statistically significant difference between the control and experimental group II,III.(p<0.05). There was no statistically significant difference between all experimental group. 3. Cementum formation was $1.13{\pm}0.17mm$ in the control, $1.78{\pm}0.31mm$ in the test group I, $2.17{\pm}0.38mm$ in the test group II, $2.15{\pm}0.47mm$ in the test group III with statistically significant differences between control group and all experimental group(P<0.05). There was no statistically significant differences between all experimental group. These results suggest that the use of composit graft of 50% calcium sulfate and 50% DFDB and DFDB alone in angulated 1 wall intrabony defects has little effects on connective tissue adhesion, but has significant effects on new bone and new cementum formations.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.13-21
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• 2004

Purpose: We analyzed the result of autologous bone marrow stromal cell transplantation with or without cancellous chip bone allograft for benign long bone lesions. Materials and methods: Since July 1996, eight benign bone lesions treated by curettage, cancellous chip bone allograft and bone marrow or marrow stromal cell transplantation were observed for resolution of clinical symptoms, new bone formation and consolidation. There were 6 males and 2 females. Average age was 24 (range 8 to 47) years old. Histologic diagnoses were 5 fibrous dysplasia, 2 simple bone cysts and one chondroblastoma and fibrous cortical defect each. Mean follow-up period was 16.3 (range 3 to 84) months. Results: In all four symptomatic patients, the pain was subsided in two weeks after surgery. New bone formation in the lesion was observed at 4 weeks, which incorporated into surrounding normal bone around 8 weeks. There were one pathologic fracture through the lesion at 3 weeks and one recurrence of simple bone cyst at 5 months postoperatively. Conclusion: Bone marrow or marrow stromal cell transplantation for bone defects from curettage of benign bone lesions, with or without cancellous chip bone allograft revealed rapid healing. Though it was the result of short-term follow up, it supports that bone marrow stromal cell transplantation will be very useful for the treatment of benign long bone cysts or other lesions. The complete curettage of inner cystic wall is important to prevent later recurrence, and the rigid internal fixation is also needed in selected high risk lesions of fracture.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.3
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• pp.189-199
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• 2006

Purpose of study: Partial thickness skin graft is the golden standard regimen for full-thickness skin defect caused by burn or trauma. However, in case of extensive burns of more than 50% of total body surface area, the donor site is not sufficient to cover all defects. As a second choice, allograft, xenograft and synthetic materials have been used to treat skin defect. Among them the amniotic membrane(AM) was used as a biological dressing for centuries because of its potential for wound healing. In this study, quantification of EGF in AM and effect of AM-collagen complex on full thickness skin defects was examined. Materials & Methods: The concentration of EGF in fresh, deep frozen and freeze-dried AM was evaluated by ELISA. EGF-R immunostaining was performed in freeze-dried AM. SD rats weighing 250${\sim}$300g was used for wound healing experiment. Three full thickness skin defects(28mm diameter) were made on dorsal surface of SD rat. The control group was covered by Vaselin gauze and AM-collagen complex and $Terudermis^{(R)}$. was grafted in two other defects. Healing area, Cinamon's score were evaluated before biopsy. Grafted sites were retrieved at 3 days, 1 week, 2 weeks and 4 weeks after operation. H & E and Factor VIII immunohistochemical stain was performed to evaluate the microscopic adhesion and structural integrity and microvessel formation. Results: 1. EGF concentration of fresh, deep frozen and freeze-dried AM showed similar level and EGF-R was stained in epithelial layer of freeze-dried AM. 2. At 4 weeks after grafting, the healing area of AM-collagen and Terudermis group was 99.29${\pm}$0.71% and 99.19${\pm}$0.77 of original size. However, that of control group was 24.88${\pm}$2.90. 3. The Cinamon's score of AM-Collagen and $Terudermis^{(R)}$. group at 4 weeks was 15.6${\pm}$1.26 and 14.6${\pm}$3.13 and that of control group was 3.7${\pm}$0.95. Significant difference was observed among control and experimental groups(p<0.05). 4. Histologic examination revealed that AM protected leukocyte infiltration and epithelial migration was nearly completed at 4 weeks. $Terudermis^{(R)}$. group showed mild neutrophil infiltration until 2 weeks and completion of epithelization at 4 weeks. Control group showed massive leukocyte infiltration until 4 weeks. 5. Microvessels were increased sharply at 1 week and control group at 1 and 4 week showed significant differences with $Terudermis^{(R)}$. group of same interval(p<0.05) but no differences were found with AM group(p<0.05). Conclusion: EGF and EGF-R were well preserved in freeze-dried AM. AM attached to collagen acted as excellent biologic dressing which had similar effect with $Terudermis^{(R)}$. AM showed anti-inflammatory action and healing was completed at 4 weeks after full-thickness skin defect.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.85-90
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• 1999

Purpose : The purpose of this study is to evaluate the clinical and histological results of the osteoarthritic patients who had second look arthroscopy after microfracture surgery. Materials and Methods : From Oct. 1997 to Dec. 1998, 46 patients, 48 knees were treated by microfracture technique. In the 22 patients, 24 knees, 'second-look' arthroscopies and biopsies were performed at 6 months following microfracture. Three patients were men and 19 patients were women. Average age of the patients were 58 years (range, 40-75 years). The average follow up period was 12 months(7-20 months). We analysed clinical results according to the nine-point scale. Also we observed type II collagen formation with immunohistochemical staining. Results : Clinical results were excellent in 83% and good in 17%. Among the 24 knees, more than 80% areas of chondral defect were covered with regenerated cartilage in 21 knees. Histologically, the regenerated tissue appears to be a hybrid of hyaline cartilage and fibrocartilage. Regenerated cartilage contains variable amount of type II collagen with immunohistochemical staining. Conclusion : Most of the patients had significant improvement clinically. 'Second-look' showed that the chondral defect areas were covered with newly grown grayish white tissue. Microfracture in the full thickness chondral defect provides and enriched environment for cartilaginous tissue regeneration.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.83-91
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• 2011

Purpose: Microfracture has been used as a first-line treatment to repair articular cartilage defects. In this study, a new technique using an extracelluar matrix biomembrane to cover the cartilage lesions after microfracture was evaluated in terms of cartilage repairability and clinical outcome compared with conventional microfracture technique in a prospective randomized trial. Materials and Methods: A total of 53 patients (59 cases) without osteoarthritis who had focal full thickness articular cartilage lesions were randomly assigned in two group. Seventeen patients (17 cases) underwent conventional microfracture procedure (control group) and thirty-six patients (42 cases) received microfracture and placing biomembrane cover (ArtiFilm$^{TM}$) concomitantly (experimental group). Clinical assessment was done through 6 months postoperatively using the subjective International Knee Documentation Committee IKDC questionnaire, and visual analog scale (VAS) for pain and satisfaction. Magnetic resonance imaging (MRI) was performed at 6 months after the operation in all patients. Results: In clinical outcomes, the significant difference was observed between both groups in IKDC, but not in VAS for pain and for satisfaction (final outcomes of IKDC, p=0.001; VAS for pain, p=0.074; VAS for satisfaction, p=0.194). The MRI showed good to complete defect fill (67 to 100%) in 33 patients (78.6%) of experimental group and 4 patients (23.5%) of control group, respectively. In control group, 9 of 17 patients (52.9%) showed poor defect fill (less than 33%), whereas 5 (11.9%) in experimental group (p=0.001). Assessment of peripheral integration revealed no gap formation in 35 patients (83.3%) in experimental group and 6 patients (35.3%) in control group (p=0.001). No serious complications or adverse effects related to the biomembrane were found. Conclusion: Good short-term follow-up clinical results were obtained in the group whose cartilage defects in the knee joint were covered with biomembrane after the microfracture, with the MRI findings confirming the excellent regeneration of the defective cartilage area. This suggests that the surgery to cover the defective area with biomembrane (ArtiFilm$^{TM}$) after the microfracture procedure is a safe, more effective treatment to induce cartilage regeneration.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.158-165
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• 2010

Purpose: The objective of the present study was to histologically evaluate durability and bone regeneration capacity of new synthetic membranes in comparison to clinically available collagen membrane. Material and methods: To the skulls of 12 rabbits, we created 4 bone defects of 6 mm in diameter on each of them. Each of defects were covered with at least one of 5 membranes; No membrane, Collagen ($Ossix^{TM}$), PLGA, HA-coated-PLGA and HA-PLGA/PLGA. After 4, 8, 12 weeks, we cut the skulls and dyed with H-E. And then, the histologic observation was done. Results: In current study, the control group which did not use the membrane showed bone regeneration at 12 weeks and covered the bone defect partially. New bones were formed through the underneath of endocranium, and the upper defect was filled with connective tissues and fats. Collagen membrane ($Ossix^{TM}$) showed new bones after 4 weeks, and they were formed through the membrane which maintained until 12 weeks. PLGA, HA-coated-PLGA, HA-PLGA/PLGA showed bone regeneration after 4 weeks and after 8 weeks, they mostly filled defects. At 12 weeks, we could find new bones and previous bones almost look alike and also, they united well. Membranes were unnoticeable after 4 weeks and were absorbed. Conclusion: Bone formation and maturation of PLGA, HA-coated-PLGA and HA-PLGA/PLGA were faster than the control group. They showed no difference on the application of HA and after 4 weeks, they were absorbed.