• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.66-74
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• 2018

Background: Tumor response to anticancer therapies can much be influenced by microenvironmental factors. In this study, we determined the effect of these microenvironmental factors on DNA methylation using A549 human lung adenocarcinoma cell line. Materials and Methods: We subjected A549 cells to various conditions mimicking tumor microenvironment including hypoxia, acidosis (sodium lactate), oxidative stress ($H_2O_2$), bystander effect (supernatant from doxorubicin (Dox)-treated or irradiated cells), and immune cell infiltration (supernatant from THP-1 or Jurkat T cells). Genomic DNA was isolated from these cells and analyzed for DNA methylation. Clonogenic cell survival, gene expression, and metabolism were analyzed in cells treated with some of these conditions. Results and Discussion: We found that DNA methylation level was significantly decreased in A549 cells treated with conditioned media from Dox-treated cells or Jurkat T cells, or sodium lactate, indicating an active transcription. To determine whether the decreased DNA methylation affects radiation sensitivity, we exposed cells to these conditions followed by 6 Gy irradiation and found that cell survival was significantly increased by sodium lactate while it was decreased by conditioned media from Dox-treated cells. We further observed that cells treated with conditioned media from Dox-treated cells exhibited significant changes in expression of genes including BAX and FAS (involved in apoptosis), NADPH dehydrogenase (mitochondria), EGFR (cellular survival) and RAD51 (DNA damage repair) while sodium lactate increased cellular metabolism rather than changing the gene expression. Conclusion: Our results suggest that various tumor microenvironmental factors can differentially influence DNA methylation and hence radiosensitivity and gene expression in A549 cancer cells.

• Journal of Korean Foot and Ankle Society
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• v.26 no.2
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• pp.88-94
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• 2022

Purpose: This study was based on the Korean Foot and Ankle Society (KFAS) member survey and aimed to report the current trends in the epidemiology, diagnosis, and management of acute Achilles tendon rupture (AATR) over the past few decades. Materials and Methods: A web-based questionnaire containing 34 questions was sent to all KFAS members in October 2021. The questions were mainly related to the clinical experience and preferred management of patients with AATR. Answers with a prevalence ≥50% of the respondents were considered a tendency. Results: Seventy-one (12.9%) of the 550 members responded to the survey. The male sex ratio in AATR was answered mean 78%, and the most common age groups were 30~40 years (n=49; 69.0%), and 40~50 years (n=37; 52.1%), in that order. The most common seasons for the occurrence of AATR were spring (37 cases; 52.1%) and autumn (27 cases; 38.0%). Also, sports-related rupture had an average occurrence of 76.2%. The most important clinical factor to determine the type of treatment was the history of previous injuries, and 75.9% of respondents started conservative treatment in the 2010s. The most preferred protocol of conservative treatment was an orthosis capable of ankle range of motion after casting (68.5%), and 53.7% 'satisfied' and 1.9% 'very satisfied' with conservative treatment. The most preferred surgical method was open repair (80.3%), and the Krackow method (60.6%), and 49.3% of treated patients responded 'satisfied' and 45.1% 'very satisfied' with this treatment. Conclusion: This study gives updated information concerning the current trend of epidemiology, diagnosis, and treatment of AATR in Korea. Both consensus and variation in the approach to AATR were identified using this survey study. This study may raise the awareness of various possible approaches toward AATR and should be used to further establish a standard protocol for the management of this injury.

• Korean Journal of Head & Neck Oncology
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• v.22 no.1
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• pp.8-14
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• 2006

Objectives: The p53 tumor suppressor gene has a key role in cellular control mechanisms involving apoptosis and DNA repair, leading to the G1 arrest following DNA damage. Its mutation is one of the most frequent alterations in human cancers. Ki-67 is identified in replicating cells of both benign and malignant lesions, so it can be the predictor of proliferative activity. The aim of this study is to evaluate the expression of p53 and Ki-67 in salivary gland tumors. Materials and Methods: Immunohistochemical analysis was used to detect expression of p53 and Ki-67 in paraffin-embedded samples from 31 benign and 27 malignant salivary gland tumors. Results were analyzed between benign and malignant tumors and compared with the clinical parameters such as stage and recurrence in malignant tumors. Results: p53 overexpression was detected in 19.6% of benign tumors and 40.7% of malignant tumors, but there was no statistical significance. p53 was significantly expressed in Warthin's tumor(45.5%) compared with pleomorphic adenoma(5.9%). Only 5.9% of pleomorphic adenoma were positive for p53, while 60% of carcinoma ex pleomorphic adenoma were positive for p53. Ki-67 was expressed in 3.2% of benign tumors and 51.9% of malignant tumors, which showed significant higher expression in malignant tumors. In malignant tumors, p53 and Ki-67 expressions bore no correlation to stage and recurrence. Conclusion: p53 overexpression is not associated with the progression of malignant tumors, and Ki-67 overexpression can be used as biologic indicator of malignant salivary gland tumors.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7303-7307
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• 2014

Objective: To explore the clinical efficacy of gemcitabine concomitant with nedaplatin and drug resistance in the treatment of non-small cell lung cancer (NSCLC) and associated molecular predicators. Materials and Methods: A total of 68 patients diagnosed with NSCLC by histology served as the study objects and were randomly divided into an observation group treated with gemcitabine concomitant with nedaplatin and a control group with cisplatin concomitant with gemcitabine, 34 cases for each group. Short-term and long-term efficacies, adverse responses as well as the expression of nucleotide excision repair cross complementing 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1) and lung resistance-related protein (LRP) in NSCLC tissues in both groups were assessed. Results: The short-term objective response rate (ORR) and disease control rate (DCR) were 35.3% (12/34) and 76.5% (26/34) in the observation group and 38.2% (13/34) and 85.3% (29/34) in the control group, respectively, the differences not being statistically significant. The time to progression (TTP) in both groups were 1~12 months, while the median TTP was 135 d and 144 d, respectively. Though the survival was slightly higher in the control group, there were no significant differences in TTP and survival time. The rates of decreased hemoglobin, vomiting and nausea as well as renal toxicity were evidently lower in the observation group, while other adverse responses demonstrated no significant difference. The positive expression rates of ERCC1, RRM1 and LRP were 47.1% (16/34), 61.8% (21/34) and 64.7% (22/34) in the observation group, respectively. Compared with negative ERCC1 expression, ORR had decreasing trend and the overall survival time (OS) decreased significantly in patients with positive ERCC1 expression, which were markedly decreased by the positive expressions of RRM1 and LRP. Conclusions: Gemcitabine concomitant with nedaplatin has significant effects in the treatment of NSCLC, with an adverse response rate obviously lower than for cisplatin concomitant with gemcitabine, suggesting that wider use in the clinic is warranted. Additionally, the positive expressions of ERCC1, RRM1 and LRP may increase patient drug resistance, so they can be applied as the chemotherapeutic predicators to guide individualized therapy of NSCLC patients.

• Korean Journal of Head & Neck Oncology
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• v.19 no.2
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• pp.164-169
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• 2003

Background and Objectives: The reconstruction is very important in Head and neck cancer surgery to repair the defect created by resection of tumors, to enable successful wound healing, to restore function and to provide acceptable cosmesis. The radial forearm free flap has been the most useful reconstructive flap because it provides a moderate amount of thin, pliable, relatively hairless skin and comparatively simple to do with minimal morbidity. The aims of this study is to estimate the outcome of the reconstruction with radial forearm free flap with the several factors in 140 head and neck cancer cases in our hospital for last 10 years. Materials and Methods: Retrospective review of the records of 140 patients underwent resection of the head and neck tumors and reconstruction with a radial forearm free flap from 1993 to 2003. The age, sex of the patients, Primary site, the complication of donor and recipient site, flap survival rate, median time to start diet, patient subjective symtoms about swallowing and articulating and the fact of revision reconstructive surgery were analyzed. Results: In primary pathologic site, 56 cases were oral cavity cancers, 44 cases, oropharyngeal cancers and 22 cases, hypopharyngeal cancers. Flap survival rate was 93.6% (13 leases). On donor site, wound dehiscence, hematoma, sensory change and infection were noted and on recipient site, most common complication were fistula and wound dehiscence. The complication rate of recipient's site was 19.1 % and donor site, 3.5%. In 118 cases (84.3%), the patients could take all kinds of food. Swallowing difficulty were noted in 22 cases 05.7%). In 5 cases, there was articulation difficulty but most of patients except patients having total laryngectomy (18 cases) couldn't have any difficulty in articulation and speaking. Conclusion: We conclude that the radial forearm free flap is the most appropriate reconstructive material for treating the defect in head and neck reconstruction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.116-129
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• 2005

Distraction osteogenesis is a new bone formation technique. There is a advantage of the environmental adaptation when distraction force is applied to the gap between osteotomy lines. But it has a disadvantage of long-term wearing of the appliance and long consolidation period. Therefore we make an effort to reduce it and repair normal function. Extracellular matrix proteins have a function to control the cellular growth, migration, shape and metabolism. In these, hyaluronic acid is a member of polysaccharide glycosaminoglycans (GAGs) and has a important function as bone formation and osteoinduction property. Purpose : In this experimental study in rabbit mandibular distraction osteogenesis, we investigated the bone enhancing property of hyaluronic acid and the expression of extracellular proteins such as osteocalcin and osteonectin. Materials and Methods : The experimental study was carried out on 24 Korean male white rabbits (both mandibular body, n=48). Distraction group was divided to distraction experimental (A, n=16) and distraction control (B, n=16) by the application of hyaluronic acid (Hyruan, LGCI, Seoul, Korea). Normal control group (C, n=16) was only osteotomized. After 5 days latency, distraction devices were activated at a rate of 1.4 mm per day (0.7 mm every 12hours) for 3.5 days. Animals were sacrificed at postoperative 3, 7, 14, and 28 days. H&E stain and immunohistochemical stain was done on decalcified section. Additionally RT-PCR analysis was done for the identification of the expression of osteocalcin and osteonectin. Results : The bone formation in distraction experimental group was much more than that in distraction and normal control group at postoperative 28 days. In immunohistochemical stain, osteocalcin was enhanced at only postoperative 14 days, but osteonectin was not different at each post-operation days. In RT-PCR analysis, osteocalcin was not different at each post-operation days, but osteonectin was strongly expressed in distraction experimental group at postoperative 7 days. The expression of osteocalcin and osteonectin was elevated during the healing period. Conclusion : We found the good bone formation ability of hyaluronic acid in distraction osteogenesis through the immunohistochemistry and RTPCR analysis to osteocalcin and osteonectin, known as a bone formation marker. The application of hyaluronic acid in distraction osteogenesis is a method to reduce the consolidation period.

• Journal of Korean society of Dental Hygiene
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• v.14 no.5
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• pp.783-788
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• 2014

Objectives : The purpose of this study was to investigate the effect of non-thermal atmospheric pressure plasma jet(NTAPPJ) on surface properties and Streptococcus mutans disinfection of denture base resin. Methods : Self-cured denture base resin (Jet denture repair resin, Lang dental Mfg, co., USA) was used to make specimen($12mm{\times}2mm$). To observe surface change before and after plasma process, surface roughness and contact angle were measured. For sterilization experiments, the surfaces of specimens were treated with nitrogen and air NTAPPJ for 1 minute after S. mutans was inoculated on the material surfaces. Results : Before plasma process, surface roughness of denture base resin was $0.21{\mu}m{\pm}0.02{\mu}m$. After air and nitrogen NTAPPJ process, surface roughness was $0.19{\mu}m{\pm}0.03{\mu}m$ and $0.18{\mu}m{\pm}0.01{\mu}m$ respectively. There was no significant difference(p>0.05). Contact angle of control group without plasma process was $83.81^{\circ}{\pm}3.14^{\circ}$, while after plasma treatment, contact angles of air NTAPPJ and nitrogen NTAPPJ groups were $63.29^{\circ}{\pm}2.27^{\circ}$ and $46.68^{\circ}{\pm}5.82^{\circ}$ respectively. The result showed a significant decrease in contact angle after plasma process(p<0.05). Compared to the control group 6020.33(CFU/mL) without plasma process, CFU decreased significantly after air NTAPPJ 90.75(CFU/mL) and nitrogen NTAPPJ 80.25(CFU/mL) treatment(p<0.05). Conclusions : It was considered that NTAPPJ can be used for denture disinfection without changing surface properties of materials.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4559-4565
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• 2013

Background: Methylenetetrahydrofolate reductase (MTHFR) is involved in DNA synthesis and repair. We here aimed to investigate two common polymorphisms, C677T and A1298C, with genotype and haplotype frequencies in colorectal cancer (CRC) cases among Jordanian. Materials and Methods: 131 CRC cases were studied for MTHFR C677T and A1298C polymorphisms, compared to 117 controls taken from the general population, employing the PCR-RFLP technique. Results: We found the frequency of the three different genotypes of MTHFR C677T among Jordanians to be CC: 61.7%, CT: 35.2%, and TT 3.1% among CRC cases and 50.9%, 38.8% and 10.3% among controls. Carriers of the TT genotype were less likely to have CRC (OR=0.25; 95%CI: 0.076-0.811; p=0.021) as compared to those with the CC genotype. Genotype analysis of MTHFR A12987C revealed AA: 38.9%, AC: 45%, and CC 16% among CRC cases and 37.4%, 50.4% and 12.2% among controls. There was no significant association between genetic polymorphism at this site and CRC. Haplotype analysis of MTHFR polymorphism at the two loci showed differential distribution of the TA haplotype (677T-1298A) between cases and controls. The TA haplotype was associated with a decreased risk for colorectal cancer (OR=0.6; 95% CI: 0.4-0.9, p=0.03). Conclusions: The genetic polymorphism of MTHFR at 677 and the TA haplotype may modulate the risk for CRC development among the Jordanian population. Our findings may reflect an importance of genes involved in folate metabolism in cancer risk.

• Korean Journal of Bronchoesophagology
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• v.8 no.1
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• pp.29-34
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• 2002

Background and Objectives : Sulfur dioxide gas is one of the major airborne Pollutants noxious to human in industrialized countries. The most vulnerable areas in the human respiratory system were the trachea and main bronchi and a gradient of decreasing damage was observed in the peripheral tracheobronchial tree. Induced functional alteration was increased mucosal permeability, and morphological changes were epithelial sloughing, intracellular edema, mitochondrial swelling, widened intercellular spaces, and ciliary cytoplamic extrusions. The laminins are a family of extracellular matrix glycoproteins localized in the basement membrane. Their primary role is cell-matrix attachment, but many additional biologic activities, including Promoting cell growth and migration, tumor growth and metastasis, wound repair, and graft survival, have been demonstrated. Materials and Methods : Histologic changes and expression of laminin in tracheal mucosa sacrificed at 1 day, 2 day, 3 day, 1 week, 2 weeks, and 3 weeks after continued SO2 exposure of 250 ppm for 30 minutes a day(to 7week) were studied in rats. In this study, mild immune reaction for laminin was noted at the apical cytoplasm of epithelial cells and basement membrane one day after a 7 week $SO_2$ exposure. The cilia and nucleoi of epithelial cells were normal and no immune reaction was noted in Goblet cells. The lamina propria of the tracheal tissue was infiltrated by monocytes and lymphocytes. Results : At 24 hours after exposure, all tracheal cells except Goblet cells revealed a mild immune reaction for laminin. No immune reactions were noted in the basement membrane. At 72 hours after exposure, mild or moderate immune reactions for laminin was seen in the tracheal cell cytoplasm. Irregular faint immune reaction for laminin was noted in the basement membrane. At 1 week after exposure, strong immune reaction for laminin was detected over all tracheal cells, and the basement membrane was seen clearly. At 2~3 weeks after exposure, strong immune reaction for laminin was seen in all tracheal epithelial cells except Goblet cells and a mild immune reaction was partly revealed in the basement membrane. Conclusion : Our study suggests that 502 produces histologic damage on the tracheal mucosa. Longer duration after exposure of $SO_2$ makes more progressive healing on the tracheal mucosa and increased immunoreactivity for laminin.

• Clinics in Shoulder and Elbow
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• v.3 no.2
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• pp.75-78
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• 2000

Purpose: The purpose of this study was to review primary traumatic anterior shoulder dislocation in the 40 years and older to determine the incidence of recurrence, rotator cuff injury and associated fractures. Materials and Methods: From May, 1991 to October, 1998, seventeen patients were available to participate in the study. The average age was 55 years(range, 40 to 75 years). Follow-up averaged 27 months(range, 12 to 48 months). There were 12 men and 5 women. 10 right and 7 left shoulders were involved. Any participant with a history of shoulder pain and limitation of motion was excluded from the study. Each shoulder was evaluated with UCLA shoulder functional assessment. Results: The overall results were excellent in 9 patients(52.9%), good in 3 patients(17 .6%), fair in 3 patients(17.6%), and poor in 2 patients(11.7%). Surgical treatment of the associated rotator cuff and greater tuberosity fracture injuries resulted in 5 patients with excellent(55.6%), 3 patients with good(33.3%) and I patient with poor(11.1 %) and Nonsurgical treatment of the associated injuries resulted in 2 patients with excellent(33.3%), 3 patients with fair(50%), 1 patient with poor(16.7%)(P=0.025). Conclusion : Our findings on small number of patients suggest that the diagnosis of a rotator cuff and other pathologies should be approached aggressively by an MRI, CT arthrogram if significant pain and weakness are still present and early surgical repair of rotator cuff and greater tuberosity can lead to restoration of shoulder function and better outcomes in selected patients.