• Journal of Periodontal and Implant Science
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• v.41 no.6
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• pp.293-301
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• 2011

Purpose: We have previously reported that tetra-cell adhesion molecule (T-CAM) markedly enhanced the differentiation of osteoblast-like cells grown on anorganic bone mineral (ABM). T-CAM comprises recombinant peptides containing the Arg- Gly-Asp (RGD) sequence in the tenth type III domain, Pro-His-Ser-Arg-Asn (PHSRN) sequence in the ninth type III domain of fibronectin (FN), and the Glu-Pro-Asp-Ilu-Met (EPDIM) and Tyr-His (YH) sequence in the fourth fas-1 domain of ${\beta}$ig-h3. Therefore, the purpose of this study was to evaluate the cellular activity of osteoblast-like cells and the new bone formation on ABM coated with T-CAM, while comparing the results with those of synthetic cell binding peptide (PepGen P-15). Methods: To analyze the cell viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed, andto analyze gene expression, northernblot was performed. Mineral nodule formations were evaluated using alizarin red stain. The new bone formations of each group were evaluated using histologic observation and histomorphometrc analysis. Results: Expression of alkaline phosphatase mRNA was similar in all groups on days 10 and 20. The highest expression of osteopontin mRNA was observed in the group cultured with ABM/P-15, followed by those with ABM/T-CAM and ABM on days 20 and 30. Little difference was seen in the level of expression of collagen type I mRNA on the ABM, ABM/T-CAM, and ABM/P-15 cultured on day 20. There were similar growth and proliferation patterns for the ABM/T-CAM and ABM/P-15. The halo of red stain consistent with $Ca^{2+}$ deposition was wider and denser around ABM/T-CAM and ABM/P-15 particles than around the ABM particles. The ABM/T-CAM group seemed to have bone forming bioactivity similar to that of ABM/P-15. A complete bony bridge was seen in two thirds of the defects in the ABM/T-CAM and ABM/P-15 groups. Conclusions: ABM/T-CAM, which seemed to have bone forming bioactivity similar to ABM/P-15, was considered to serve as effective tissue-engineered bone graft material.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.97-106
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• 2010

Aim of the study: An alternative source of adult stem cells that could be obtained in large quantities, under local anesthesia, with minimal discomfort would be advantageous. Adipose tissue could be processed to obtain a fibroblast-like population of cells or adipose tissue-derived stromal cells (ATSCs). This study was performed to confirm the availability of ATSCs in bone tissue engineering. Materials amp; Methods: In this study, adipose tissue-derived mesenchymal stem cell was extracted from the liposuctioned abdominal fat of 24-old human and cultivated, and the stem cell surface markers of CD 105 and SCF-R were confirmed by immunofluorescent staining. The proliferation of bone marrow mesenchymal stem cell and ATSCs were compared, and evaluated the osteogenic differentiation of ATSCs in a specific osteogenic induction medium. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific BMP-2, ALP, Cbfa-1, Osteopontin and osteocalcin were confirmed by RT-PCR. With differentiation of ATSCs, calcium concentration was assayed, and osteocalcin was evaluated by ELISA (Enzyme-linked immunosorbant assay). The bone formation by 5-week implantation of HA/TCP block loaded with bone marrow mesenchymal stem cells and ATSCs in the subcutaneous pocket of nude mouse was evaluated by histologic analysis. Results: ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. ATSCs could be easily identified through fluorescence microscopy, and bone formation in vivo was confirmed by using ATSC-loaded HA/TCP scaffold. Conclusions: The present results show that ATSCs have an ability to differentiate into osteoblasts and formed bone in vitro and in vivo. So ATSCs may be an ideal source for further experiments on stem cell biology and bone tissue engineering.

• Radiation Oncology Journal
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• v.3 no.2
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• pp.113-121
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• 1985

This is a retrospective analysis of 54 patients with stage I or II Non-Hodgkin's lymphoma involving the head and neck region treated with curative radiotherapy in the Department of Therapeutic Radiology, Seoul National University Hospital during the period of February 1979 through September 1982. The minimum follow-up period was 24 months. The review of histologic slides was available in 36 cases. Waldeyer's ring was the most common extranodal sites $(40\%)$. $41\%$ of patients were in the stage 1 and $59\%$ in the stage II by Ann Arbor classification. Of the 44 patients who responded after radiotherapy, 24 patients$(54.4\%)$subsequently relapsed. Regional recurrence rate was $29\%$, distant metastasis was $54\%$ and simultaneous regional recurrence and distant metastasis was $17\%$. The survival rate and disease free survival at 2 years were $57\%\;and\;45\%$ respectively. Those patients with a large primary lesion (over 6cm in diameter), multiple conglomerated, extranodal site and diffuse ceil type, experienced a high rate of distant metastasis. Therefore it seems desirable to study the use of adjuvant chemotherapy in those patients with a high probability of distant metastasis.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.19-26
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• 1995

Purpose : Surgery is the treatment of choice for resectable non-small cell lung cancer. For patients who are medically unable to tolerate a surgical resection or who refuse surgery, radiation therapy is an acceptable alternative. A retrospective analysis of Patients with stage I non-samll cell lung cancer treated with curative radiation therapy was performed to determine the results of curative radiation therapy and patterns of failure, and to identify factors that may influence survival. Materials and Methods : From 1986 through 1993, 39 Patients with T2N0M0 non-small cell lung cancer were treated with curative radiation therapy at department of radiation oncology, Kyungpook national university hospital. All Patients were not candidates for surgical resection because of either Patient refusal (16 patients), poor pulmonary function (12 patients), old age (7 patients), Poor Performance (2 patients) or coexisting medical disease (2 patients). Median age of patients was 67 years. Histologic cell type was squamous cell carcinoma in 36, adenocarcinoma in 1, large cell carcinoma in 1 and mucoepidermoid carcinoma in 1. All patients were treated with megavoltage irradiation and radiation dose ranged from 5000cgy to 6150cGy with a median dose of 6000cGy. The median follow-up was 17 months with a range of 4 to 82 months, Survival was measured from the date therapy initiated. Results : The overall survival rate for entire Patients was $40.6\%$ at 2 years and $27.7\%$ at 3 years, with a median survival time of 21 months. The disease-free survival at 2 and 3 years was $51.7\%$ and $25.8\%$, respectively. Of evaluable 20 patients with complete response, 15 patients were considered to have failed. Of these, 13 patients showed local failure and 2 patients failed distantly. Response to treatment (p=0.0001), tumor size (p=0.0019) and age (p=0.0247) were favorably associated with overall survival. Only age was predictive for disease-free survival (p = 0.0452). Conclusion : Radiation therapy is an effective treatment for small (less than 3cm) tumors, and should be offered as an alternative to surgery in elderly or infirm patients. Since local failure is the prominent Patterns of relapse, potential methods to improve local control with radiation therapy are discussed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.2
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• pp.139-147
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• 1998

This study has been performed to evaluate the relationship between the remained mineral components in a decalcified bone matrix and an ectopic bone formation efficiency. The freezed rat diaphyseal cortical bones measuring 0.5cm in length were demineralized in heated 0.6N HCl at $60^{\circ}C$ for 5, 10, 15, 20, 25, 30, 35, 40 minutes, respectively, using a controlled heat ultrasonic cleaner. Each 1cc of decalcifying solution taken during decalcification procedure was used to calculate calcium content using calcium dignostics kit under 600nm of spectrophotomer. After decalcification, each specimen was also weighed. Then each prepared specimen was implanted into the dorsal pouch of 24 Sprague-Dawley rats divided into 8 groups by time course. The implants were harvested at 1, 2, and 3 weeks and prepared for routine H-E stain specimens to evaluate osteogenic activity. The results are as follows: 1. There was statistical significant difference in change of calcium concentration up to demineralization of 30 minutes and each allogenic bones decalcifed up to 20 minutes revealed 99.65% of decalcification in average. 2. There was statistical significant difference in change of weight in demineralized allogenic bone up to 20 minutes treatment but, no significant change was noted after that time. 3. The histologic analysis revealed active ectopic bone formation in the implanted allografts demineralized for 20, 25, 30 minutes, respectively. However, the other groups of allografts showed relatively poor osteoinductive activity. These findings suggest that complete decalcification with a minimized degeneration of collagen matrix is necessary to induce maximal osteogenesis by decalcified bone allograft.

• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.132-138
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• 2010

Purpose: The purpose of this study was to compare the bone regeneration effects of cortical, cancellous, and cortico-cancellous human bone substitutes on calvarial defects of rabbits. Methods: Four 8-mm diameter calvarial defects were created in each of nine New Zealand white rabbits. Freeze-dried cortical bone, freeze-dried cortico-cancellous bone, and demineralized bone matrix with freeze-dried cancellous bone were inserted into the defects, while the non-grafted defect was regarded as the control. After 4, 8, and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. Micro-computed tomography (micro-CT) was performed to calculate the percent bone volume. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation. Results: In micro-CT evaluation, freeze-dried cortico-cancellous human bone showed the highest percent bone volume value among the experimental groups at week 4. At week 8 and week 12, freeze-dried cortical human bone showed the highest percent bone volume value among the experimental groups. In histologic evaluation, at week 4, freeze-dried cortico-cancellous human bone showed more prominent osteoid tissue than any other group. New bone formation was increased in all of the experimental groups at week 8 and 12. Histomorphometric data showed that freeze-dried cortico-cancellous human bone showed a significantly higher new bone formation percentile value than any other experimental group at week 4. At week 8, freeze-dried cortical human bone showed the highest value, of which a significant difference existed between freeze-dried cortical human bone and demineralized bone matrix with freeze-dried cancellous human bone. At week 12, there were no significant differences among the experimental groups. Conclusions: Freeze-dried cortico-cancellous human bone showed swift new bone formation at the 4-week healing phase, whereas there was less difference in new bone formation among the experimental groups in the following healing phases.

• Journal of Periodontal and Implant Science
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• v.44 no.4
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• pp.178-183
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• 2014

Purpose: The aim of this study was to assess the possible paracrine effect of bone morphogeneticprotein-2 (BMP-2) at the experimental site on the adjacent control site for validating a rabbit calvarial defect model as a means of verifying the effect of BMP-2. Methods: Sixteen rabbits were divided into two groups (n=8 in each) according to whether or not BMP-2 would be used. Two circular defects (8 mm in diameter) were created side by side, 2 mm apart, in the calvarium of all of the rabbits. In each animal, one of the defects was grafted with either BMP-2-loaded carrier or carrier material alone. The control defects adjacent to these grafted defects, designated CB (the nongrafted defect adjacent BMP-2-loaded carrier-grafted defect) and CC (the nongrafted defect adjacent to carrier only-grafted defect), respectively, were the focus of this study, and were filled only with a blood clot in all of the animals. Histologic observation and histomorphometric analysis were performed at 2 and 8 weeks (n=4 animals per point in time) after surgery. Results: There was no noteworthy difference in the healing pattern, and no statistically significant differences in histomorphometric parameters such as the defect closure, new bone area, or total augmented area between the CC and CB groups. Conclusions: The results of this study suggest that rabbit calvarial defects separated by a distance of 2 mm are suitable for evaluating the effects of BMP-2 and the control defect can be regarded not to be affected by BMP-2 applied defect.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.519-525
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• 2010

Purpose: Of various effects of relaxin, we assumed that anti-fibrotic effects, neovascularization effects and vasodilatation effects of relaxin might enhance the survival rate of skin flap. In the current study, we used adenovirus expressing relaxin genes to examine whether these genes could enhance the survival rate of a skin flap. Methods: A total of 30 Sprangue-Dawley rats were divided into three groups: RLX group (10; relaxin virus injected group), CTR group (10; no gene coded virus injection group), and PBS group (10; PBS injected group). Each group was intradermally injected with the virus ($10^7$ PFU) and PBS 48 hours before and immediately before the flap elevation. A distally based flap $3{\times}9\;cm$ in size was elevated on the dorsal aspect of each rat. Following this, a flap was placed in the original location and then sutured using a #4-0 Nylon. A surviving area of the flap was measured and then compared on postoperative days 3, 7 and 10. Using a laser Doppler, the amount of blood flow was measured. On postoperative day 10, tissues were harvested for histologic examination and the number of blood vessels was counted. Results: There was a significant increase in the area of the flap survival in the RLX group on postoperative days 3 and 7. The Doppler measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. The number of blood vessels was significantly greater in the RLX group in the tissue harvested on postoperative day 10. The VEGF concentration was significantly higher in the RLX group than others in the tissues harvested on postoperative day 10. Conclusion: Following an analysis of the effects of relaxin-secreting adenovirus on the survival of a flap, the surviving area of the flap and the blood flow also increased. A histopathology also showed an increase in the number of blood vessels and the concentration of VEGF.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.112-119
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• 2011

Purpose: Collagen membranes are used extensively as bioabsorbable barriers in guided bone regeneration. However, collagen has different effects on tissue restoration depending on the type, structure, degree of cross-linking and chemical treatment. The purpose of this study was to evaluate the inflammatory reaction, bone formation, and degradation of dehydrothermal treated porcine type I atelocollagen (CollaGuide$^{(R)}$) compared to of the non-crosslinked porcine type I, III collagen (BioGide$^{(R)}$) and the glutaldehyde cross-linked bovine type I collagen (BioMend$^{(R)}$) in surgically created bone defects in rat mandible. Methods: Bone defect model was based upon 3 mm sized full-thickness transcortical bone defects in the mandibular ramus of Sprague-Dawley rats. The defects were covered bucolingually with CollaGuide$^{(R)}$, BioMend$^{(R)}$, or BioGide$^{(R)}$ (n=12). For control, the defects were not covered by any membrane. Lymphocyte, multinucleated giant cell infiltration, bone formation over the defect area and membrane absorption were evaluated at 4 weeks postimplantation. For comparison of the membrane effect over the bone augmentation, rats received a bone graft plus different covering of membrane. A $3{\times}4$ mm sized block graft was harvested from the mandibular angle and was laid and stabilized with a microscrew on the naturally existing curvature of mandibular inferior border. After 10 weeks postimplantation, same histologic analysis were done. Results: In the defect model at 4 weeks post-implantation, the amount of new bone formed in defects was similar for all types of membrane. Bio-Gide$^{(R)}$ membranes induced significantly greater inflammatory response and membrane resorption than other two membranes; characterized by lymphocytes and multinucleated giant cells. At 10 weeks postoperatively, all membranes were completely resorbed. Conclusion: Dehydrotheramal treated cross-linked collagen was safe and effective in guiding bone regeneration in alveolar ridge defects and bone augmentation in rats, similar to BioGide$^{(R)}$ and BioMend$^{(R)}$, thus, could be clinically useful.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.312-320
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• 1992

Radiotherapeutically, nasopharyngeal cancer is an important disease in korea. Because of its blind anatomic location, early detection is relatively uncommon. Clinically, most of cases are locally advanced and nodal involvement are common. Recently better understanding of nature of the disease and improvement of radio-therapy technique permit better treatment results, including locoregional control and survival rate, and minimal normal tissue damages comparing with previously published data. We analyzed 31 patients of pathologically proven and previously untreated naso-pharyngeal carcinoma with different treatment techniques, retrospectively. Minimal and maximal follow up period of the survuor is 6 months and 68 months, respectively. Thirteen patients with squamous cell carcinoma are included in this analysis. The median age is 49 years(range from 20 to 64 years). Twenty two patients are stage III. Eleven patients are treated with radiotherapy alone and 20 are treated with comblined modalities treatment. The degree of responses after radiotherapy are categorized by 3-classes, i.e. complete response, partial response. In spite of simioarities of complete response rate and 1-year survival rate between two different treatment techniques, those patients with undifferentiated carcinoma appear to benefit from the adjuvant chemotherapy. In addition, systemic failure is more prominant in radiotherapy alone group than in combined modalities treatment group. These results suggest that adjuvant therapy in the radiotherapeutic management of nasopharyngeal cancers needs additional research according to histologic types and future extensive clinical trials.