• Title/Summary/Keyword: Critical materials

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Frameless Fractionated Stereotactic Radiaton Therapy in Recurrent Head & Neck Cancers (국소재발된 두경부종양의 무고정틀 정위적 분할방사선치료)

  • Kim In-Ah;Choi Ihl-Bhong;Jang Ji-Young;Kang Ki-Mun;Jho Seung-Ho;Kim Hyung-Tae;Lee Kyung-Jin;Choi Chang-Rak
    • Korean Journal of Head & Neck Oncology
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    • v.14 no.2
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    • pp.156-163
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    • 1998
  • Background & Objectives: Frameless fractionated stereotactic radiotherapy(FFSRT) is a modification of stereotactic radiosurgery(SRS) with radiobiologic advantage of fractionation without losing mechanical accuracy of SRS. Local recurrence of head and neck cancer at or near skull base benefit from reirradiation. Main barrier to successful palliation is dose limitation secondary to normal tissue tolerance. We try to evaluate the efficacy and safety of FFSRT as a new modality of reirradaton in these challenging patients. Materials & Methods: Seven patients with recurrent head & neck cancer involving at or near skull base received FFSRT from September 1995 to November 1997. Six patients with nasopharyngeal cancer had received induction chemotherapy and curative radiation therapy. One patient with maxillary sinus cancer had received total maxillectomy and postoperative radiation therapy as a initial treatment. Follow-up ranged from 11 to 32 months with median of 24 months. Three of 7 patients received hyperfractionated radiation therapy(1.1-1.2Gy/fraction, bid, total 19.8-24Gy) just before FFSRT. All patients received FFSRT(3-5Gy/fraction, total 15-30Gy/5-10fractions). Chemotherapy(cis-platin $100mg/m^2$) were given concurrently with FFSRT in four patients. Second course of FFSRT were given in 4 patients with progression or recurrence after initial FFSRT. Because IF(irregularity factor; ratio of surface area of target to the surface area of sphere with same volume as a target) is too big to use conventional stereotactic RT using multiple arc method for protection of radiation damage to critical normal tissue, all patients received FFSRT with conformal method using irregular static ports. Results: Five of 7 patients showed complete remission in follow-up CT &/or MRI. Three of these five patients who developed marginal, in-field, and out-field recurrences, respectively. Another one of complete responders has been dead of G-I bleeding without evidence of local recurrence. One partial responder who showed progressive disease 15 months after initial FFSRT has received additional FFSRT, and then he is well-being with symptomatic improvement. One minmal responder who showed progression of locoregional disease 9 months after $1^{st}$ FFSRT has received 2nd FFSRT, and then he is alive with stable disease. Five of 7 case had showed direct invasion to skull base and had complaint headache and various symptoms of cranial nerve involvement. Four of these five case showed improvement of neurologic symptoms after FFSRT. No significant neurologic complicaltion related to FFSRT was observed during follow-up periods. Tumor volumes were ranged from 3.9 to 50.7 cc and surface area ranged from 16.1 to $114.9cm^2$. IF ranged from 1.21 to 1.74. The average ratio of volume of prescription isodose shell to target volume was 1.02 that indicated the improvement of target coverage and dose distribution with FFSRT with conformal method compared to target coverage with FFSRT with multiple arc method. Conclusion: Our initial experience suggests that FFSRT with conformal method was relatively effective and safe modality in the treatment of recurrent head and neck cancer involving at or near skull base. Treatment benefit included good palliation of symptoms and reasonable radiographic response. However, more experience and additional follow-up are needed to better assess its ultimate role in treating these challenging patients.

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Microbiological Hazard Analysis and Verification of Critical Control Point (CCP) in a Fresh-Cut Produce Processing Plant -Case Study of a Fresh-Cut Leaf Processing Plant- (신선편이 농산물 가공업체의 미생물학적 위해 요소 분석 및 중점 관리 지점(CCP)의 검증 -신선편이 엽채류 가공업체를 대상으로-)

  • Kim, Su-Jin;Sun, Shih-Hui;Min, Kyung-Jin;Yoon, Ki-Sun
    • Journal of the East Asian Society of Dietary Life
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    • v.21 no.3
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    • pp.392-400
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    • 2011
  • The objectives of this study were to analyze environmental microbial contamination levels by sampling the surfaces of processing lines and equipment and to verify CCPs of the HACCP plan in a fresh-cut produce processing plant The level of airborne microorganisms in the processing plant was $10^1$ log CFU/plate/15min. Total plate counts and coliform groups of the processing facilities were 1~2 log CFU/100 $cm^2$. No E. coli or S. aureus were detected in the processing plant. However, total plate counts on the cutting board for raw materials and on the spin-dryer were $4.20{\pm}2.12$ log CFU/$cm^2$ and $4.57{\pm}0.92$ log CFU/$cm^2$, respectively. These levels were higher than the safe microbial level, and therefore, the chance of cross-contamination during processing was increased. According to the results of microbiological analyses, total aerobic bacteria and coliform groups of the samples were increased after the second washing and spin-drying steps, due to cross-contamination from the spin-dryer. Thus, an effective method that can be used for microbial control during the washing and drying steps is needed for microbial control in fresh-cut produce processing plants. The results of a verification study also suggest that modification of the HACCP plan is needed along with additional CPs, which were identified as a second washing, spin drying, and the cold storage of final products.

Crystal Structure and Mossbauer Studies of 57Fe Doped TiO2 (57Fe가 치환된 TiO2의 결정학적 및 뫼스바우어 분광학적 연구)

  • Lee, Hi-Min;Shim, In-Bo;Kim, Chul-Sung
    • Journal of the Korean Magnetics Society
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    • v.13 no.6
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    • pp.237-242
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    • 2003
  • $Ti_{1-x}$$^{57}$ F $e_{x}$ $O_2$(0.0$\leq$x$\leq$0.07) compounds were fabricated using the sol-gel method, and the crystal structure and magnetic properties were investigated as a function of doped $^{57}$ Fe concentration. X-ray diffraction patterns showed a pure anatase single phase, without any segregation of Fe into particulate. With varying $^{57}$ Fe concentration, we could observe unusual magnetic phenomena in these materials. Doping $^{57}$ Fe into the Ti $O_2$ nonmagnetic semiconductor formed magnetic properties, but the gradual increase of $^{57}$ Fe concentration decreased rapidly the ferromagnetic properties rather than enhanced the ferromagnetic properties. Obvious ferromagnetic behavior was shown for the samples with x$\leq$0.01, while paramagnetic behavior was shown for the sample with x$\geq$0.03. These phenomena could be verified using Mossbauer measurement. Separation of the ferromagnetic phase (sextet) and the paramagnetic phase (doublet) of the samples with different $^{57}$ Fe concentration was characterized. Samples with x$\leq$0.01 have sextet and doublet simultaneously, but samples with x$\geq$0.03 have only doublet at room temperature. This indicates that the sample x$\leq$0.01 have the ferromagnetic phase at room temperature. This result corresponded with the M-H loops referenced above and reveals an interesting feature that there is a critical limit of $^{57}$ Fe concentration (0.01$\leq$0.01 samples was fundamentally attributable to the paramagnetic phase as well as the ferromagnetic phase.e.

Kinetics Study for Wet Air Oxidation of Sewage Sludge (하수슬러지의 습식산화반응에 대한 동력학적 연구)

  • Ahn, Jae-Hwan
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.7
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    • pp.746-752
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    • 2005
  • In this study, the effect of reaction parameters including reaction temperature, time, and pressure on sludge degradation and conversion to intermediates such as organic acids were investigated at low critical wet air oxidation(LC-WAO) conditions. Degradation pathways and a modified kinetic model in LC-WAO were proposed and the kinetics model predictions were compared with experimental data under various conditions. Results in the batch experiments showed that reaction temperature directly affected the thermal hydrolysis reaction rather than oxidation reaction. The efficiencies of sludge degradation and organic acid formation increased with the increase of the reaction temperature and time. The removal of SS at $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 10 min of reaction time were 52.6%, 68.3%, 72.6%, and 74.4%, respectively, indicating that most organic suspended solids were liquified at early stage of reaction. At $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 40 min of reaction time, the amounts of organic acids formed from 1 g of sludge were 93.5 mg/g SS, 116.4 mg/g SS, 113.6 mg/g SS, and 123.8 mg/g SS, respectively, and the amounts of acetic acid from 1 g of sludge were 24.5 mg/g SS, 65.5 mg/g SS, 88.1 mg/g SS, and 121.5 mg/g SS, respectively. This suggested that the formation of sludge to organic acids as well as the conversion of organic acids to acetic acid increased with reaction temperature. Based on the experimental results, a modified kinetic model was suggested for the liquefaction reaction of sludge and the formation of organic acids. The kinetic model predicted an increase in kinetic parameters $k_1$ (liquefaction of organic compounds), $k_2$ (formation of organic acids to intermediate), $k_3$ (final degradation of intermediate), and $k_4$ (final degradation of organic acids) with reaction temperature. This indicated that the liquefaction of organic solid materials and the formation of organic acids increase according to reaction temperature. The calculated activation energy for reaction kinetic constants were 20.7 kJ/mol, 12.3 kJ/mol, 28.4 kJ/mol, and 54.4 kJ/mol, respectively, leading to a conclusion that not thermal hydrolysis but oxidation reaction is the rate-limiting step.

Expression Pattern of KLF4 in Korean Gastric Cancers (한국인 위암에서 KLF4 단백 발현 양상)

  • Song, Jae-Hwi;Cho, Yong-Gu;Kim, Chang-Jae;Park, Cho-Hyun;Kim, Su-Young;Nam, Suk-Woo;Lee, Sug-Hyung;Yoo, Nam-Jin;Lee, Jung-Young;Park, Won-Sang
    • Journal of Gastric Cancer
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    • v.5 no.3 s.19
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    • pp.200-205
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    • 2005
  • Purpose: KLF4, a member of the KLF family, is a zinc finger tumor suppressor protein that is critical for gastric epithelial homeostasis. Our aim was to determine whether the altered expression of KLF4 might be associated with gastric cancer development and, if so, to determine to which pathologic parameter it is linked. Materials and Methods: For the construction of the gastric cancer tissue microarray, 84 paraffin-embedded tissues containing gastric cancer areas were cored 3 times and transferred to the recipient master block. The expression pattern of KLF4 was examined on tissue microarray slides by using immunohistochemistry and was compared with pathologic parameters, including histologic type, depth of invasion, lymph node metastasis, and peritoneal dissemination. Results: The KLF4 protein was expressed in cytoplasm and nucleus of superficial and foveolar epithelial cells in the normal gastric mucosa. We found markedly reduced or loss of KLF4 expression in 43 (51.2%) of the 84 gastric cancer tissues. There was no significant correlation between KLF4 expression and pathologic parameters, including histologic type, depth of invasion, lymph node metastasis and peritoneal dissemination. Conclusion: Our findings suggest that altered expression of KLF4 may contribute to abnormal regulation of gastrointestinal epithelial cell growth and differentiation and to the development of Korean gastric cancer, as an early event.

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EFFECT OF NERVE GROWTH FACTOR GENE INJECTION ON THE NERVE REGENERATION IN RAT LINGUAL NERVE CRUSH-INJURY MODEL (백서 설신경 압박손상모델에서 신경성장인자 유전자 주입이 신경재생에 미치는 영향)

  • Gao, En-Feng;Chung, Hun-Jong;Ahn, Kang-Min;Kim, Soung-Min;Kim, Yun-Hee;Jahng, Jeong-Won;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.5
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    • pp.375-395
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    • 2006
  • Purpose: Lingual nerve (LN) damage may be caused by either tumor resection or injury such as wisdom tooth extraction, Although autologous nerve graft is sometimes used to repair the damaged nerve, it has the disadvantage of necessity of another operation for nerve harvesting. Moreover, the results of nerve grafting is not satisfactory. The nerve growth factor (NGF) is well-known to play a critical role in peripheral nerve regeneration and its local delivery to the injured nerve has been continuously tried to enhance nerve regeneration. However, its application has limitations like repeated administration due to short half life of 30 minutes and an in vivo delivery model must allow for direct and local delivery. The aim of this study was to construct a well-functioning $rhNGF-{\beta}$ adenovirus for the ultimate development of improved method to promote peripheral nerve regeneration with enhanced and extended secretion of hNGF from the injured nerve by injecting $rhNGF-{\beta}$ gene directly into crush-injured LN in rat model. Materials and Methods: $hNGF-{\beta}$ gene was prepared from fetal brain cDNA library and cloned into E1/E3 deleted adenoviral vector which contains green fluorescence protein (GFP) gene as a reporter. After large scale production and purification of $rhNGF-{\beta}$ adenovirus, transfection efficiency and its expression at various cells (primary cultured Schwann cells, HEK293 cells, Schwann cell lines, NIH3T3 and CRH cells) were evaluated by fluorescent microscopy, RT-PCR, ELISA, immunocytochemistry. Furthermore, the function of rhNGF-beta, which was secreted from various cells infected with $rhNGF-{\beta}$ adenovirus, was evaluated using neuritogenesis of PC-12 cells. For in vivo evaluation of efficacy of $rhNGF-{\beta}$ adenovirus, the LNs of 8-week old rats were exposed and crush-injured with a small hemostat for 10 seconds. After the injury, $rhNGF-{\beta}$ adenovirus($2{\mu}l,\;1.5{\times}10^{11}pfu$) or saline was administered into the crushed site in the experimental (n=24) and the control group (n=24), respectively. Sham operation of another group of rats (n=9) was performed without administration of either saline or adenovirus. The taste recovery and the change of fungiform papilla were studied at 1, 2, 3 and 4 weeks. Each of the 6 animals was tested with different solutions (0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) by two-bottle test paradigm and the number of papilla was counted using SEM picture of tongue dorsum. LN was explored at the same interval as taste study and evaluated electro-physiologically (peak voltage and nerve conduction velocity) and histomorphometrically (axon count, myelin thickness). Results: The recombinant adenovirus vector carrying $rhNGF-{\beta}$ was constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. GFP expression was observed in 90% of $rhNGF-{\beta}$ adenovirus infected cells compared with uninfected cells. Total mRNA isolated from $rhNGF-{\beta}$ adenovirus infected cells showed strong RT-PCR band, however uninfected or LacZ recombinant adenovirus infected cells did not. NGF quantification by ELISA showed a maximal release of $18865.4{\pm}310.9pg/ml$ NGF at the 4th day and stably continued till 14 days by $rhNGF-{\beta}$ adenovirus infected Schwann cells. PC-12 cells exposed to media with $rhNGF-{\beta}$ adenovirus infected Schwann cell revealed at the same level of neurite-extension as the commercial NGF did. $rhNGF-{\beta}$ adenovirus injected experimental groups in comparison to the control group exhibited different taste preference ratio. Salty, sweet and sour taste preference ratio were significantly different after 2 weeks from the beginning of the experiment, which were similar to the sham group, but not to the control group.

THE EFFECT OF RESORBABLE MEMBRANE ON BONE REGENERATION IN CALVARIAL DEFECTS OF RATS (백서의 두개골 결손부에서 탈단백우골 이식 시 흡수성악의 효과)

  • Park, Young-Jun;Choi, Guen-Ho;Jang, Jung-Rok;Jung, Seung-Gon;Kim, Young-Joon;Yu, Min-Gi;Kook, Min-Suk;Oh, Hee-Kyun;Ryu, Sun-Youl;Park, Hong-Ju
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.5
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    • pp.365-374
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    • 2009
  • Purpose : This research evaluates the effect of the use of absorbable membrane barrier with deproteinized bovine bone (Bio-$Oss^{(R)}$, Switzerland) on bone healing in surgically created critical-sized defects in rat calvaria. Materials and Methods : Two standardized transosseous circular calvarial defects (5 mm in diameter) are made in each calvarium of 30 rats. These rats are divided into negative control group(n=15), positive control group(n=15) and two experimental groups(n=15). In the negative control group, defects are only filled with blood clots. In the positive control group, defects are filled with autogenous bone obtained from calvarium; in the experimental group 1, defects are filled with deproteinized bovine bone; and in the experimental group 2, defects are filled with deproteinized bovine bone with absorbable membrane. At the postoperative 1 week, 3 weeks. and 6 weeks, clinical. histologic and histomorphometric evaluations of the defects are performed. Results : 1. The grafted bone without membrane in the calvarial bone defect was scattered but, the grafted bone with membrane was stable. 2. $BioMesh^{(R)}$ membrane was absorbed beginning at 3 weeks, and was absorbed considerably at 6 weeks while maintaining the structural form of the membrane. 3. The use of membrane blocked soft tissue invasion. 4. In histomorphometric analysis. it showed the greatest amount of new bone formation in the positive control group. The amount of new bone formation was greater in the experimental group 2 than experimental group 1. At 6 weeks. the amount of new bone formation was greater in the positive control group than experimental group l(p<0.005). Conclusion : These results suggest that membrane increase the stability of grafted bone and protects from soft tissue invasion, and the use of the membrane may promote new bone formation in deproteinized bovine bone graft area.

Structural equation modeling for association between patient satisfaction and quality of life after implant surgery (임플란트 만족도와 삶의 질 간의 관련성에 대한 구조방정식모델 분석)

  • Chung, Sun-Young;Cho, Jin-Hyun;Lee, Kyu-Bok;Choi, Youn-Hee;Song, Keun-Bae
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.4
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    • pp.291-299
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    • 2011
  • Purpose: This study was designed to measure patient satisfaction and oral health-related quality of life and to assess an association between patients' satisfaction and oral health-related quality of life after implant surgery by using structural equation modeling. Materials and methods: A total of 257 participants who visited 6 dental clinics located in Daegu city for the purpose of implant treatment participated in this study. Six months after completion of implant surgery, the patients' satisfaction and oral health-related quality of life were surveyed. The effect of factors associated with patients' satisfaction such as functions and aesthetics, maintenance and cost on oral health-related quality of life after implant surgery was analyzed using AMOS 4.0. Results: Oral health-related quality of life was improved in all dimensions of OHIP-14 after implant surgery. Functions and aesthetics as well as maintenance had a significant effect on oral health-related quality of life (P<.05), while cost was not a critical factor influencing oral health-related quality of life. Conclusion: High satisfaction with functional aspects and maintenance aspects significantly affected good quality of life. The result of this study supported the fact that education and management for patients after implant therapy were positively related to good quality of life based on a theoretical model.

Trial for Drug Susceptibility Testing of Mycobacterium tuberculosis with Live and Dead Cell Differentiation (세포 염색 방법을 이용한 결핵균 감수성 검사법)

  • Ryu, Sung-Weon;Kim, Hyun-Ho;Bang, Mun-Nam;Park, Young-Kil;Park, Sue-Nie;Shim, Young-Soo;Kang, Seongman;Bai, Gill-Han
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.3
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    • pp.261-268
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    • 2004
  • Background : The resurgence of tuberculosis and outbreaks of multidrug resistant (MDR) tuberculosis have increased the emphasis for the development of new susceptibility testing of the Mycobacterium tuberculosis for the effective treatment and control of the disease. Conventional drug susceptibility testings, such as those using egg-based or agar-based media have some limits, such as the time required and difficulties in determining critical inhibitory concentrations, but these are still being used in many diagnostic laboratories because of no better lternatives, considering cost and accuracy. To overcome these limits, a rapid and simple method for new susceptibility testing, using live and dead assays, was applied for a bacterial cell viability assay to distinguish dead from live bacterial cells based on two-color fluorescence. Materials and Methods Strains : Forty strains were used in this study, 20 susceptible to all antituberculosis drugs and the other 20 resistant to the four first line antituberculosis drugs isoniazid, rifampicin, streptomycin and ethambutol. Antibiotics : The four antibiotics were dissolved in 7H9 broth to make the following solutions: $0.1{\mu}g\;isoniazid(INH)/m{\ell}$, $0.4{\mu}g\;rifampicin(RMP)/m{\ell}$, $4.0{\mu}g\;streptomycin(SM)/m{\ell}$ and $4.0{\mu}g\;ethambutol(EMB)/m{\ell}$. Results : Live and dead Mycobacterium tuberculosis cells fluoresced green and red with the acridin (Syto 9) and propidium treatments, respectively. These results are very well accorded with conventional drug susceptibility testing by proportional method on Lowensen-Jensen media (L-J) containing 4 drugs (INH, RMP, EMB and SM), showing a 93.7 % accordance rate in susceptible strains and 95% in resistant strains. Conclusion : The results of the drug susceptibility testing using the live and dead bacterial cell assay showed high accordance rates compared with the conventional proportion method on L-J. This finding suggests that the live and dead bacterial cell assay can be used as an alternative to conventional drug susceptibility testing for M. tuberculosis strains.

Glomus Tumor in Soft Tissue (연부 조직에 발생한 사구종)

  • Kim, Do-Yeon;Lee, Soo-Hyun;Kim, Min-Ju;Shin, Kyoo-Ho
    • The Journal of the Korean bone and joint tumor society
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    • v.15 no.1
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    • pp.34-43
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    • 2009
  • Purpose: Glomus tumors are rare benign vascular tumors, usually located in the skin or soft tissue of extremities. Approximately 30-50% of glomus tumors occur in subungal area, but glomus tumors have been described in every location even where glomus bodies are not or rarely present. The purpose of this study was to identify clinical, histologic and MRI characteristics of soft tissue glomus tumor. Materials and Methods: Between 1993 and 2008, eight patients underwent surgery of soft tissue Glomus tumor at our institution. Exclusion criteria were patients with Glomus tumors in digits, stomach, trachea and glomus tympanicum. We analyzed medical records, interviews, physical examinations, MR findings and histolocial types retrospectively. Results: There were four men and four women. The mean age was fourty-seven years. The mean prevalence time was eight-point-nine years. In the classic triad of symptoms, all eight patients had pain and tenderness. Two patients complained of cold sensitivity. Two showed skin color changes. After surgery, two showed symptom improvement (VAS $9^{\circ}{\rightarrow}8$, $8^{\circ}{\rightarrow}5$) and?six showed complete disappearance of symptoms. Slightly symptom improvemented (VAS $9^{\circ}{\rightarrow}8$) one had additional surgery two times after first surgery due to relapse/remaining Glomus tumor. The mean size was 13.9 mm. In histology, six were 'solid glomus tumor', one was a mixture of 'solid glomus tumor' and 'lomangioma' and one was 'malignant glomus tumor'. MR findings showed isointense signal on T1 image, high signal on T2 image and strong enhancement on the Gadolinium enhanced image. Conclusion: Glomus tumor has low recurrence rate and malignant change, rapid diagnosis and surgical excision is critical in treatment to prevent unnecessary pain of patient.

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