• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.561-578
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• 1999

The goal of periodontal therapy is the periodontal regeneration by the removal of microorganisms and their toxic products from the periodontally diseased root surface. To achieve periodontal regeneration, root conditioning as an adjunct to root planing has been done. There are low pH etchants such as citric acid, tetracycline-HCl, and EDTA solution which is a neutral chelating agent. The purpose of present study was to examine the effect of root conditioning by citric acid, tetracycline HCl, and EDTA. Total 35 root specimens(6${\times}$3${\times}$2mm) were prepared from the periodontally diseased teeth, scaled and root planed. The specimens were treated with normal saline for 1 minute, saturated citric acid(pH 1) for 3 minutes, 50mg/ml tetracycline-HCl(pH 2) for 5 minutes, 15% EDTA(pH 7) for 5 minutes using rubbing technique. The specimens were examined under scanning electron microscopy at 1000, and 3000 magnification. On the microphotographs taken at 1000 magnification, the numbers of opened and patent dentinal tubules per unit area(10,640${\mu}m^2$) were counted. And the diameters of opened dentinal tubules per unit are (10,640${\mu}m^2$) were measured. The differences of number and diameter among all groups were statistically analyzed by Kruskal Wallis Test. The results were as follows; 1. In the specimens applied with normal saline(control group), the root surface was finely cracked, and was covered by irregular smear layer. Neither exposed dentinal tubules nor any patent dentinal tubules could be seen. 2. In the specimens applied with saturated citric acid(experimental 1 group), the globular collagen fibers were exposed around the peritubular space, and many dentinal tubules were revealed. 3. In the specimens applied with tetracycline-HCl(experimental 2 group), the process-like collagen fibers were exposed around the peritubular space, and some dentinal tubules were revealed. 4. In the specimens applied with 15% EDTA(experimental 3 group), the root surface was covered by the collagenous fibrillar network, and many dentinal tubules were revealed. 5. The numbers of opened and patent dentinal tubules were significantly more in exp. 1 group and exp. 3 group than in exp. 2 group(P<0.05). But there was no significant difference between exp. 1 group and exp. 3 group. In control group, the number of opened and patent dentinal tubules could not be counted because any dentinal tubules couldn't be seen. 6 . The diameter of opened dentinal tubules was significantly smaller in exp. 1 group and exp. 3 group than in exp. 2 group(P<0.05). But there was no significant difference between exp. 1 group and exp. 3 group. In control group, the diameter of opened dentinal tubules could not be measured because any dentinal tubules couldn't be seen. The results demonstrate that root conditioning with citric acid, tetracycline- HCl, and EDTA is more effective in periodontal healing than only root planing, and 15% EDTA solution can replace low pH etching agents such as citric acid, tetracycline-HCl for root conditioning.

• Journal of Chest Surgery
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• v.30 no.10
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• pp.949-960
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• 1997

Background. Limited ischemic tolerance of the lung has remained one of the factors that limits the expansion of pulmonary transplantation as a treatment for end-stage pulmonary disease. Numerous studies on safe long term preservation for lung transplantation has been performed for the purpose of developing ideal preservation solution with extracellular type or intracellular type solutions. In this. study, we examined the efficacy of L DG solution in lung preservation longer than 20 hours by comparison with modified Euro-Collins solution. Iwethods. Thirty-(our adult mongrel dogs were divided into two groups. Donor lungs were flushed with LPDG solution(n=9) or modified Euro-Collins(MEC) solution(n=8) and stored for 24 hours at 1$0^{\circ}C$. All donor lungs were perfused through the pulmonary arteries with solutions containing prostaglandin El and verapamil. Left canine lung allotransplantations wereperformed. Assessment(hemodynamic indices and arterial blood gas analysis) of left implanted lung was made by occluding the right pulmonary artery for ten minutes using pulmonary artery Cuff. Assessment was repeated at the interval of 30 minutes, one hour, and two hours later after reperfusion and then chest X-ray, computed tomogram and lung perfusion scan were obtained. In survival dogs follow-up studies were done with assessment with chest X-ray, computed tomogram of the chest and lung perfusion scan on 7th day postoperatively. After preservation above 20 hours, pathological examinations for ultrastructural findings on right lung were performed in each group. Results. With respect to arterial oxygen tension, LPDG group was superior to MEC but there was no statistical significance for 2 hours after reperfusion. Mean pulmonary artery pressure was less increased(p < 0.05) and cardiac output higher(p <0.05) than MEC group until 2 hours after reperfusion. After 2 hours of reperfusion, both groups showed transplanted lung function deteriorated gradually. Perfusion scan of the transplanted lung in LPDG group showed better perfusion rate in immediate post-reperfusion, 3 days and 7 days later respectively but there was no statistical significance and corelation with PaO2 and computed tomoRravhic views. In scanning electron microscopy of pulmonary artery after preservation, LPDG group relatively shows less irregular protrusion of the inner surface of endothelial cell of poulmonary artery than MEC group. Conclusions, e concluded that LPDG solution can offer safe lung preservation above 20 hours with adequate immunosuppressive therapy and prevention of the infection.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.213-219
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• 2009

Purpose:Iron is a critical nutritional element that is essential for a variety of important biological processes, including cell growth and differentiation, electron transfer reactions, and oxygen transport, activation, and detoxification. Iron is also required for neoplastic cell growth due to its catalytic effects on the formation of hydroxyl radicals, suppression of host defense cell activities, and promotion of cancer cell multiplication. Chronic transfusion-dependent patients receiving chemotherapy may have iron overload, which requires iron-chelating therapy. We performed this study to demonstrate whether the iron chelating agent deferoxamine induces apoptosis in Saos-2 osteosarcoma cells, and to investigate the underlying apoptotic mechanism. Methods:To analyze the apoptotic effects of an iron chelator, cultured Saos-2 cells were treated with deferoxamine. We analyzed cell survival by trypan blue and crystal violet analysis, apoptosis by nuclear condensation, DNA fragmentation, and cell cycle analysis, and the expression of apoptotic related proteins by Western immunoblot analysis. Results:Deferoxamine inhibited the growth of Saos-2 cell in a time- and dose-dependent manner. The major mechanism for growth inhibition with the deferoxamine treatment was by the induction of apoptosis, which was supported by nuclear staining, DNA fragmentation analysis, and flow cytometric analysis. Furthermore, bcl-2 expression decreased, while bax, caspase-3, caspase-9, and PARP expression increased in Saos-2 cells treated with deferoxamine. Conclusion:These results demonstrated that the iron chelating agent deferoxamine induced growth inhibition and mitochondrial-dependent apoptosis in osteosarcoma Saos-2 cells, suggesting that iron chelating agents used in controlling neoplastic cell fate can be potentially developed as an adjuvant agent enhancing the anti-tumor effect for the treatment of osteosarcoma.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.337-347
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• 1994

Breast conserving surgery and irradiation is now accepted as preferable treatment method for the patients with stage I and II breast cancer. Our institution activated team approach for breast conservation in 1991 and treated one hundred and fourty patients during the next three years. Purpose : To present our early experience with eligibility criteria, treatment techniques, and the morbidities of primary radiotherapy. Materials and Methods: Sixty four patients with early stage breast cancer who received breast conserving treatment between January 1991 and December 1992 were evaluated. All patients received partial mastectomy(wide excision to quadrantectomy) and axillary node dissection followed by radiotherapy. Total dose of 4500-5040 cGy in 5-5 1/2 weeks was given to entire involved breast and boost dose of 1000-2000 cGy in 1-2 weeks was given to the primary tumor site. Linac 4 MV X-ray was used for breast irradiation and electron beam was used for boost. Thirty five Patients received chemotherapy before or after radiotherapy. Patients characteristics, treatment techniques, and treatment related morbidities were analyzed. Results : Age distribution was ranged from 23 to 59 year old with median age of 40. Twenty-seven patients had T1 lesions and 34 patients had T2 lesions. In three patients, pathologic diagnosis was ductal carcinoma in situ. Thirty-seven Patients were N0 and 27 patients were Nl. There were three recurrences, one in the breast and two distant metastases during follow-up period(6-30 months, median 14 months). Only one breast recurrence occured at undetected separate lesion with microcalcifications on initial mammogram. There was no serious side reaction which interrupted treatment courses or severe late complication. Only one symptomatic radiation pneumonitis and one asymptomatic radiation pneumonitis were noted. Conclusions: Conservative surgery and primary radiotherapy for early breast cancer is Proven to be safe and comfortable treatment method without any major complication. Long-term follow up is needed to evaluate our treatment results in terms of loco-regional control rate, survival rate, and cosmetic effect.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.79-84
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• 2010

Purpose: We retrospectively analyzed the long-term results of radical surgery and intraoperative radiation therapy (IORT) in patients with stomach cancer. Materials and Methods: From 1988 to 1994, 51 patients were treated with curative surgery and IORT. Postoperative external beam radiotherapy (EBRT) was administered to 30 patients, while adjuvant chemotherapy was administered to 35 patients. A dose of 15 Gy was irradiated with a 9 MeV electron beam as the IORT and a median dose of EBRT was 43.2 Gy (range, 7.2 to 45 Gy). The follow-up period ranged from 1~254 months, with a median follow-up period of 64 months. Results: The median age of all the patients was 58 years (range, 30 to 71 years). The distribution of pathologic stage (American Joint Committee on Cancer [AJCC] 2002 tumor-note-metastasis [TNM]) was as follows: 13 stage I (25.5%), 10 stage II (19.6%), 25 stage III (49.0%), and 3 stage IV (5.9%). Distant metastases occurred in 11 patients (10 in the peritoneum and 1 in bone), including one patient with concurrent local recurrence (anastomosis site). The 5-year locoregional control, disease free survival and overall survival rates were 94.7%, 66.5%, and 51.7%, respectively. For the multivariate analysis, age, TNM stage, and EBRT were significant prognostic factors for overall survival, and only TNM stage for disease free survival. Conclusion: We could have achieved a high loco-regional control rate in patients with locally advanced stomach cancer by adding IORT to radical surgery. However, the benefit of IORT on survival remains to be elucidated.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.160-169
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• 2019

Purpose: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. Materials and Methods: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. Results: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. Conclusion: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.