Effect of Propofol on microRNA Expression Profile in Adipocyte-Derived Adult Stem Cells / 전남의대학술지

MicroRNA (miRNA) pathways have been implicated in stem cell regulation. This study investigated the molecular effects of propofol on adipocyte stem cells (ASCs) by analyzing RNA expression arrays. Human ASCs were isolated by use of a liposuction procedure. ASCs were treated with saline, 50 microM propofol, or 100 microM propofol in culture media for 3 hours. After the isolation of total RNA, the expression of 76 miRNAs was evaluated with peptide nucleic acid-miRNA array analysis through denaturation and hybridization processes. Treatment with 50 microM propofol resulted in significant down-regulation of expression of 18 miRNAs and upregulation of expression of 25 miRNAs; 100 microM propofol resulted in significant downregulation of expression of 14 miRNAs and upregulation of expression of 29 miRNAs. The lowest expression was seen for miR-204, which was 0.07-fold with 50 microM propofol and 0.18-fold with 100 microM propofol. The highest expression was seen for miR-208b, which was 11.23-fold with 50 microM propofol and 11.20-fold with 100 microM propofol. Expression patterns of miRNAs were not significantly different between 50 microM and 100 microM propofol treatment. The results of this study suggest that propofol is involved in altering the miRNA expression level in human ASCs. Additional research is necessary to establish the functional effect of miRNA alteration by propofol.

Effect of Propofol on microRNA Expression Profile in Adipocyte-Derived Adult Stem Cells / 전남의대학술지

MicroRNA (miRNA) pathways have been implicated in stem cell regulation. This study investigated the molecular effects of propofol on adipocyte stem cells (ASCs) by analyzing RNA expression arrays. Human ASCs were isolated by use of a liposuction procedure. ASCs were treated with saline, 50 microM propofol, or 100 microM propofol in culture media for 3 hours. After the isolation of total RNA, the expression of 76 miRNAs was evaluated with peptide nucleic acid-miRNA array analysis through denaturation and hybridization processes. Treatment with 50 microM propofol resulted in significant down-regulation of expression of 18 miRNAs and upregulation of expression of 25 miRNAs; 100 microM propofol resulted in significant downregulation of expression of 14 miRNAs and upregulation of expression of 29 miRNAs. The lowest expression was seen for miR-204, which was 0.07-fold with 50 microM propofol and 0.18-fold with 100 microM propofol. The highest expression was seen for miR-208b, which was 11.23-fold with 50 microM propofol and 11.20-fold with 100 microM propofol. Expression patterns of miRNAs were not significantly different between 50 microM and 100 microM propofol treatment. The results of this study suggest that propofol is involved in altering the miRNA expression level in human ASCs. Additional research is necessary to establish the functional effect of miRNA alteration by propofol.

Correlation between HER2 Overexpression and Clinicopathological Characteristics in Gastric Cancer Patients Who Have Undergone Curative Resection

PURPOSE: At present, a human epidermal growth factor receptor 2 (HER2)-based concept of tumor biology has been established, and trastuzumab (Herceptin(R); Genentech/Roche, San Francisco, CA, USA), a monoclonal humanized antibody directed against HER2, is a pivotal agent for the management of HER2 positive (HER2+) metastatic breast cancer. It is also known that HER2 has a predictive value in gastric cancer; however, its association with the prognosis of this disease remains uncertain. The purpose of this study was to evaluate both the relationship between HER2 overexpression in the tumors of gastric cancer patients, and the prognosis of these patients who have had curative resection. MATERIALS AND METHODS: A total of 139 consecutive patients with gastric cancer who underwent surgery at the Kosin University Gospel Hospital between October 2011 and March 2012 were included in this retrospective study. All tumor samples were examined for HER2 expression by immunohistochemistry. A retrospective review of the medical records was conducted to determine the correlation between the presence of HER2 overexpression and clinicopathological factors. RESULTS: The HER2+ rate was 15.1%. HER2 overexpression was associated with histological grade (P=0.044) and Lauren classification (P=0.036). There was no significant difference in the 2-year overall survival between HER2+ and HER2- patients (P=0.396). Multivariate analysis showed that HER2 was not an independent prognostic factor. CONCLUSIONS: HER2 overexpression in tumors was associated with histological grade and Lauren classification in gastric cancer patients with curative resection. However, HER2 was not an independent prognostic factor for gastric cancer in our study.

Submucosal Tumor-like Early-stage Mucinous Gastric Carcinoma: A Case Study / 대한소화기학회지

Mucinous gastric carcinoma (MGC) is an unusual histologic subtype, and early detection of MGC is very rare. Early-stage MGC appears as an elevated lesion resembling a submucosal tumor (SMT) due to abundant mucin pools in the submucosa or mucosa. We report a rare case of SMT-like early-stage MGC. Tumor type was predicted preoperatively based on characteristic endoscopic findings, in which an SMT-like mass was observed at the gastric fundus. The tumor was covered by nearly normal mucosa, but with an opening allowing for the passage of copious mucus discharge. A total gastrectomy with Roux-en-Y esophagojejunostomy was subsequently performed. Histopathology of the tumor revealed early-stage (lamina propria) mucinous adenocarcinoma.

Four Endoscopic Predictors of Carcinoma as a Final Diagnosis after Endoscopic Resection of Forceps Biopsy-proven Gastric Adenomas

BACKGROUND/AIMS: Previous studies have reported that the frequency of re-diagnosing as carcinoma after endoscopic resection of gastric adenoma ranges between 6% and 47%. Therefore, specific endoscopic findings have been used to predict re-diagnosing as carcinoma after endoscopic resection of gastric adenoma at our center. We evaluated whether there is a use for these indicators for predicting carcinoma as a final diagnosis in forceps biopsy-proven adenomas. MATERIALS AND METHODS: We investigated 378 tissue samples from 308 patients. Classification of specimens as adenoma and carcinoma was based on postresection specimen. Endoscopic findings were reviewed for tumor location, size, gross appearance, surface nodularity, central concavity, surface color, and presence of ulcers. These variables were analyzed and compared between the adenoma group (275 cases) and the carcinoma group (103 cases), assigned based on post-resection diagnosis. RESULTS: The mean patient age was 61, and 227 of the patients were male. The mean lesion diameter was 14.9+/-8.1 mm in the adenoma group and 17.9+/-9.3 mm in the carcinoma group. A lesion size of 15 mm or greater, depressed appearance, surface nodularity, central concavity, and presence of high-grade dysplasia were all independently associated with re-diagnosing as carcinoma after endoscopic resection. CONCLUSIONS: Lesion size of 15 mm or greater, depressed-type appearance, central concavity, and nodular surface are feasible predictors of carcinoma as a final diagnosis in forceps biopsy-proven adenomas. Physicians need to recommend immediate endoscopic resection for forceps biopsy-proven adenomas with these four independent features so as not to miss the optimal window for treatment.

Four Endoscopic Predictors of Carcinoma as a Final Diagnosis after Endoscopic Resection of Forceps Biopsy-proven Gastric Adenomas

BACKGROUND/AIMS: Previous studies have reported that the frequency of re-diagnosing as carcinoma after endoscopic resection of gastric adenoma ranges between 6% and 47%. Therefore, specific endoscopic findings have been used to predict re-diagnosing as carcinoma after endoscopic resection of gastric adenoma at our center. We evaluated whether there is a use for these indicators for predicting carcinoma as a final diagnosis in forceps biopsy-proven adenomas. MATERIALS AND METHODS: We investigated 378 tissue samples from 308 patients. Classification of specimens as adenoma and carcinoma was based on postresection specimen. Endoscopic findings were reviewed for tumor location, size, gross appearance, surface nodularity, central concavity, surface color, and presence of ulcers. These variables were analyzed and compared between the adenoma group (275 cases) and the carcinoma group (103 cases), assigned based on post-resection diagnosis. RESULTS: The mean patient age was 61, and 227 of the patients were male. The mean lesion diameter was 14.9+/-8.1 mm in the adenoma group and 17.9+/-9.3 mm in the carcinoma group. A lesion size of 15 mm or greater, depressed appearance, surface nodularity, central concavity, and presence of high-grade dysplasia were all independently associated with re-diagnosing as carcinoma after endoscopic resection. CONCLUSIONS: Lesion size of 15 mm or greater, depressed-type appearance, central concavity, and nodular surface are feasible predictors of carcinoma as a final diagnosis in forceps biopsy-proven adenomas. Physicians need to recommend immediate endoscopic resection for forceps biopsy-proven adenomas with these four independent features so as not to miss the optimal window for treatment.

The TREK2 Channel Is Involved in the Proliferation of 253J Cell, a Human Bladder Carcinoma Cell

Bladder cancer is the seventh most common cancer in men that smoke, and the incidence of disease increases with age. The mechanism of occurrence has not yet been established. Potassium channels have been linked with cell proliferation. Some two-pore domain K+ channels (K2P), such as TASK3 and TREK1, have recently been shown to be overexpressed in cancer cells. Here we focused on the relationship between cell growth and the mechanosensitive K2P channel, TREK2, in the human bladder cancer cell line, 253J. We confirmed that TREK2 was expressed in bladder cancer cell lines by Western blot and quantitative real-time PCR. Using the patch-clamp technique, the mechanosensitive TREK2 channel was recorded in the presence of symmetrical 150 mM KCl solutions. In 253J cells, the TREK2 channel was activated by polyunsaturated fatty acids, intracellular acidosis at -60 mV and mechanical stretch at -40 mV or 40 mV. Furthermore, small interfering RNA (siRNA)-mediated TREK2 knockdown resulted in a slight depolarization from -19.9 mV+/-0.8 (n=116) to -8.5 mV+/-1.4 (n=74) and decreased proliferation of 253J cells, compared to negative control siRNA. 253J cells treated with TREK2 siRNA showed a significant increase in the expression of cell cycle boundary proteins p21 and p53 and also a remarkable decrease in protein expression of cyclins D1 and D3. Taken together, the TREK2 channel is present in bladder cancer cell lines and may, at least in part, contribute to cell cycle-dependent growth.

Interleukin-13 and Its Receptors in Idiopathic Interstitial Pneumonia: Clinical Implications for Lung Function

Idiopathic interstitial pneumonia (IIP) is characterized by varying degrees of interstitial fibrosis. IL-13 and IL-4 are strong inducers of tissue fibrosis, whereas IFN-gamma has antifibrotic potential. However, the roles of these substances in IIP remain unknown. IL-13, IL-4, and IFN-gamma were measured in the BAL fluid of 16 idiopathic pulmonary fibrosis (IPF) patients, 10 nonspecific interstitial pneumonia (NSIP) patients, and 8 normal controls. The expression of IL-13 and IL-13Ralpha1/alpha2 in lung tissues was analyzed using ELISA and immunohistochemistry. IL-13 levels were significantly higher in IPF patients than the others (P<0.05). IL-4 levels were higher in both IPF and NSIP patients than in normal controls (P<0.05), and IFN-gamma levels were lower in NSIP patients than in normal controls (P=0.047). IL-13 levels correlated inversely with FVC% (r=-0.47, P=0.043) and DLCO% (r=-0.58, P=0.014) in IPF and NSIP patients. IL-13 was strongly expressed in the smooth muscle, bronchial epithelium, alveolar macrophages and endothelium of IPF patients. IL-13Ralpha1, rather than IL-13Ralpha2, was strongly expressed in the smooth muscle, bronchial epithelium, and endothelium of IPF patients. IL-13 and its receptors may contribute to the pathogenesis of fibrosis in IIP and appear to be related to the severity of the disease.

Comparison of Forcep-biopsy and Cryo-biopsy by a Flexible Bronchoscopy / 결핵및호흡기질환

BACKGROUND: A forceps-biopsy is performed to acquire tissue from patients with an endobronchial carcinoma using a flexible bronchoscope. Recently, a cryo-biopsy has also been used to acquire tissue samples. Cryo-biopsy is the diagnostic application of extreme cold for the local destruction of abnormal living tissue. This technique is safe, with no radiation danger, no risk of electrical accidents, and a little risk of bleeding. This study compared a forceps-biopsy with a cryo-biopsy using a flexible bronchoscope, and examined the chemosensitivity and level of VEGF (vascular endothelial growth factor) in the specimens obtained from the cryo-biopsy. METHODS: We present a prospective study of 30 consecutive patients who underwent a forceps-biopsy between January 2007 and October 2007 with a mean age of 62.1 years and a male:female ratio of 5 : 1. A flexible bronchoscope was inserted to the area of the abnormal lesions, and a cryo-probe was then applied through the working channel of the flexible bronchoscope. A temperature of approximately -80 was delivered to the tumor site for 8 seconds. The cryo-biopsy was performed after destroying the tumor mass. RESULTS: The mean size of the tissue from the forceps-biopsy and cryo-biopsy were 2.0+/-1.2 mm and 6.0+/-3.0 mm. A chemosensitivity test was performed on 5 specimens obtained using cryo-biopsy and the level of VEGF was examined in 2 specimens obtained from a cryo-biopsy. There were no side effects in either group. CONCLUSION: Cryo-biopsy using a flexible bronchoscope is a safe and effective technique for acquiring tissue samples.

Sex-related Clinicopathologic Differences in Patients with Adenocarcinoma of the Lung / 결핵및호흡기질환

BACKGROUND: The incidence of adenocarcinoma of the lung has been increasing worldwide, and it has been generally been accepted to be relatively unrelated to smoking with a female preponderance. The aim of this study was to examine the gender-related pathological and survival differences in patients with an adenocarcinoma of the lung. MATERIAL AND METHOD: A retrospective review of the clinical information of patients diagnosed with an adenocarcinoma of the lung at Kosin Medical Center from January 1999 to September 2005 was performed. The patient's demographics (age, gender), smoking history, stage, serum tumor marker, pathology classification, EGFR mutation, K-ras mutation, treatment methods, and survival time were analyzed. RESULT: Of the 438 patients, 179 (40.9%) were female. The median age at the diagnosis was 58 years for females and 59 years for males. However, 25.8% of women and only 17.7% of men were under 50 years of age (p=0.02). The distribution of the disease stage was similar in both men and women. The bronchioloalveolar carcinoma component was diagnosed more often in women (11.2%) than in men (5.0%). The overall survival rate was higher in women than in men (p=0.01), and women had a superior therapeutic response to a combined treatment of surgery and chemotherapy. CONCLUSION: This study showed significant genders differences in terms of the smoking history, bronchioloalveolar carcinoma component, overall survival, and survival after combined treatment of surgery and chemotherapy. Therefore, gender differences should be considered when diagnosing and treating adenocarcinomas of the lung.

CT Findings of Gastrointestinal Stromal Tumor versus Lymphoma of the Small Intestine

PURPOSE: To compare CT features of gastrointestinal stromal tumors (GIST) with those of lymphomas in the small intestine. MATERIALS AND METHODS: CT findings of 11 pathologically confirmed GIST patients and 10 lymphoma patients were retrospectively reviewed. CT findings were analyzed with regard to location, size, margin, growth patterns, internal character, enhancement, invasion, vascular encasement, lymphadenopathy, intestinal obstruction and ascites. RESULTS:An extraluminal mass was present in 82% (9/11) of the GIST patients versus 30% (3/10) of the lymphoma patients. Circumferential wall thickening was observed in 80% (8/10) of the lymphoma patients (p.05). CONCLUSION: Features revealed by CT scans are highly useful in differentiating GIST from lymphoma of the small intestine. Extraluminal growth and internal necrosis or gas are more common in patients with GIST compared with lymphoma. CT features of circumferential wall thickening and associated lymphadenopathy are more common in patients with lymphoma.

Meanings of Expression of Vascular Endothelial Growth Factor in Thyroid Tumors / 대한내분비학회지

BACKGROUND: Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor(VEGF), also known as vascular permeability factor(VPF), is an angiogenic factor that plays important roles in tumor growth. Angiogenesis studies on VEGF deal with various types of malignant tumors, but little is known about the role or significance of VEGF in human thyroid neoplasms. Therefore, this study was performed to determine whether the VEGF expression in different histological types of thyroid tumors is altered and to see if there was a relationship between the expression of VEGF and either metastasis or the invasiveness of thyroid carcinomas. METHODS: Forty-two cases that underwent thyroidectomy at Kosin Medical Center, between March, 1999 and February, 2000, were included in this study. Of the 42 cases, 27 were malignant(26 papillary carcinoma, 1 Hurthle cell carcinoma) and 15 were benign lesions. The expression of VEGF was determined by immunohistochemistry using paraffin embedded thyroid tissue blocks, and was quantified as negative(absent), +(1~24%), ++(25~49%), +++(50~74%) and ++++(> or =75%), according to the extent of positive cells. RESULTS: VEGF was stained with red-brown colored granules in the cytoplasm of the thyroid tumor epithelium and was expressed in 27 of the 42 cases(+1, ++8, +++5, ++++13). Most malignant tumors(24 of 27 cases) were stained with VEGF, but only 3 of the 15 benign tumors cases were stained(P<0.001). When the VEGF expression was divided into ++ or below and +++ or above groups, the expression of VEGF was much more extensive in the malignant than benign tumors(P<0.001). Of the 27 malignant tumors cases, lymph node metastasis and/or invasion was noted in 13. VEGF expression was more extensive in malignant tumors with lymph node metastasis and/or invasion than in those without(P<0.001). CONCLUSION: In this study, the rate and extent of VEGF expression were greater in the malignant than the benign thyroid tumors, and also the extent of VEGF expression was the extent of VEGF greater in the malignant tumors with lymph node metastasis and/or invasion than those without

A Case of Synchronous Esophageal Basaloid Squamous Carcinoma and Cancer of the Base of Tongue / 대한소화기내시경학회지

Basaloid squamous cell carcinoma occurs in various organs including the upper respiratory tract, the base of the tongue, pharynx, larynx, breast, uterine cervix and anus. It is a rare tumor, but it must be distinguished from other malignancies because of its aggressive clinical behavior. Many cases present in the advanced stage at the time of diagnosis. We present here a case of esophageal basaloid squamous cancer that was diagnosed in 75-year-old male patient who had dysphagia and throat pain, and this was accompanied by squamous cell cancer of the tongue base, as was determined by laryngoscopic and esophagogastroscopic examination.

A Study on Calcium and Iron Status of Lactating Women

This study was intended to investigate the nutritional status between lactating and non- lactating women, especially calcium and iron. The subjects were 84 lactating women and 20 non-lactating women visiting a public health center and hospital in Daegu. Each subject was interviewed to collect the information on dietary intake for 2 consecutive days. Biochemical assessment of iron status and bone mineral density (BMD) measurement were conducted. Dietary intake of carbohydrate, potassium, Vit B1, B2, Vit C were significantly higher in women during lactating period (p < 0.05). However, relative intake as expressed by percentage of Korean Recommended Dietary Allowances (RDA) was not significantly different between the two groups. The dietary intake of iron and calcium were 58.8%, 60.4% of Korean RDA respectively in women during lactating period. The current food habit score of these women was significantly higher than that of non-lactating women (p < 0.05). When we compared the quality of nutritional status, the Index of nutritional quality (INQ) was significantly higher for vitamin B2, P in lactating women than in non-lactating women (p < 0.1). Mean adequacy ratio (MAR) was not significantly different between two groups. Dietary variety score (DVS) was significantly higher in women during the lactating period (p < 0.05). There was no significant difference in biomarkers (Hb, Hct, Serum ferritin, Transferrin) related to iron status between the two groups. No significant difference in bone mineral density (BMD) T-score was not observed. However, it appeared that BMD of lactating women was lower than that of non- lactating women.

Pleuropulmonary Blastoma in an Adult: Surgical Experience of One Case / 대한흉부외과학회지

Pleuropulmonary blastoma is a rare malignant neoplasm which originates from either the lungs or pleura. Pleuropulmonary blastoma usually develops in the first decade of life, mostly younger than 5 years old and shows aggressive biological behavior. Pleuropulmonary blastoma is discriminated from classic pulmonary blastoma of adulthood by its morphological features like primitive mesenchymal and sarcomatous component without carcinomatous portions. To our knowledge, report of pleuropulmonary blastoma in adulthood is very rare. Our case support the possibility that primitive neoplasm recognized as pediatric tumors can develop in adulthood. We report a case of surgical experience of pleuropulmonary blastoma which developed in 21 years old man with literature review.

Prevalence and Clinicopathologic Features of Mucinous Cystic Tumor and Intraductal Papillary Mucinous Tumor of Pancreas in Korea

BACKGROUND: Mucin producing cystic neoplasms, such as mucinous cystic tumor (MCT) and intraductal papillary mucinous tumor (IPMT) of the pancreas, are uncommon but become increasing in their incidences. The pathologic classification and biologic potential of these neoplasmsremain the subject of controversy. METHODS: The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists analyzed the clinicopathologic characteristics of 85 casesof MCT and 72 cases of IPMT and examined the expression patterns of p53, CEA and MUC1. RESULTS: IPMT was located largely in the head, and showed connection with the main pancreatic duct (MPD, 68.1%), no ovarian-like stroma (0/72), and presence of intervening intratumoralnormal or atrophic parenchyma. On the other hand, MCT was located largely in thetail (73%), and showed common ovarian-like stroma (66/80), rare connection with the MPD(7/85) and no intervening pancreatic parenchyma. CEA and p53 immunoexpressions weresignificantly increased from adenoma through borderline to carcinoma, but MUC 1 was expressedonly in the invasive carcinoma among cases of MCT and IPMT. CONCLUSIONS: The tumorlocation, ovarian-like stroma, connection with the MPD and intratumoral intervening nonneoplastictissue were helpful in the differential diagnosis between IPMT and MCT. CEA and p53expressions can be indicators of malignancy, while MUC 1 expression can indicate invasion.

Different Responses of Pulmonary Vein to High and Low Radiofrequency Energy in Canine Pulmonary Vein

BACKGROUND AND OBJECTIVES: Radiofrequency (RF) catheter ablation of the pulmonary vein (PV) can treat drug refractory focal atrial fibrillation (AF). However, high RF energy (RFE) can cause severe PV damage, and the lower limits of effective RFE in PV have not yet been elucidated. This study attempts to evaluate the changes of PV structure after various modes of RFE delivery. MATERIALS AND METHODS: Right heart and transseptal catheterization were performed in 5 anesthetized mongrel dogs. RFE was delivered at the right superior pulmonary vein (RSPV) with 50 watts and 70degreesC and at the left superior pulmonary vein (LSPV) with 20 watts and 50degreesC. After the procedures, the endocardiums of the left atrium and both superior PVs were examined. RESULTS: Total applied RFE in both PVs was 14.2+/-.2 vs. 13.5+/-.6 watts, 46.6+/-.1 vs. 64.5+/-.2degreesC (p70% luminal narrowing) developed in 4 dogs with high RFE. Mild stenosis (<50% luminal narrowing) of PV developed in 1 dog with low RFE. Histological examination of the 5 dogs revealed coagulation necrosis over the whole PV layer, including the adventitia and some portion of the myocardial sleeve, and severe hemorrhage and destruction of PVs from high energy treatment, in contrast to intimal damage and swelling of subintimal PV layers in low energy treatment. CONCLUSION: High RF current may result in severe damage of pulmonary veins and sub-structures whereas low RF current may cause suboptimal pulmonary vein damage such as intimal only damage.

Intraosseous Neurilemmoma of the Sternum: A Case Report

Intraosseous neurilemmoma is a rare benign neoplasm that accounts for less than 1% of all primary bone tumors. The most frequent site of involvement is the mandible. We report a case of intraosseous neurilemmoma of the sternum which was discovered incidentally.

Radiation Synovectomy by 166Holmium-Chitosan complex in Collagenase Induced Arthritis of the Knee in the Rabbit / 대한정형외과학회잡지

PURPOSE: To evaluate the histological changes of the synovial membrane treated by 166Ho-Chitosan complex in collagenase induced arthritis of the knee in the rabbit. MATERIAL AND METHOD: Arthritis was induced in sixteen rabbits by intra-articular injection of 1mg collagenase II and then treated by intra-articular injection of 0.4mCi 166Ho-Chitosan complex 2weeks later. The radioisotope scan was checked in each rabbit for the distribution and extra-articular leakage of the 166Ho-Chitosan complex. The synovial tissues from the femorotibial joints were evaluated for serial histological changes 2, 4, 8, 12 weeks after the 166Ho-Chitosan complex injetion. RESULTS: Two weeks after 166Ho-Chitosan complex administration, inflammatory cells such as giant cells, lymphocytes, histiocyte, and fibroblasts appeared in the subsynovial stroma. The most synovial cells were necrotized. Four weeks after 166Ho-Chitosan complex administration, the inflammatory cells were decreased and many fibroblasts appeared on the subsynovial stroma. There was neovasculization in the synovial membrane 4 weeks after administration. The fibers of collagen were noticed in the synovial membrane and subsynovial stroma at 8 weeks. There was no synoviocyte in the synovium and the thickness of fibrosis was increased at 12weeks. There were fragmentation of the nucleoli of synoviocyte and endothelial cell on the transmission electron microscope (TEM) . CONCLUSION: This study suggests that the synovial membranes treated by 166Ho-Chitosan complex in the collagenase induced arthritis of the knee in the rabbit show early radiation damage and then subsequently develop the fibrosis, and no synovial cell regeneration was observed until 12 weeks.