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Biomedical subjects

Do Youn Park

Publications and source records attributed to Do Youn Park.

15 recordsLinked to original sources
PubMed2006

Gene expression in mixed type liposarcoma.

AIMS: Mixed type liposarcomas are rare. Here, we analysed the characteristics of an unusual case of mixed type liposarcoma, which consisted of a well-differentiated liposarcoma (WDL) and a pleomorphic liposarcoma (PL), with a special emphasis on molecular alterations. METHODS: Microscopic and immunohistochemical approaches were used to investigate this case of mixed type liposarcoma, and to identify molecular alterations in this tumour, gene expression was examined in PL, WDL, and normal adipose tissue (NA) samples using a 17,000 cDNA microarray. RESULTS: The tumour mass, 9 x 5 x 5 cm, was located in the left upper arm of a 76-year-old man. Grossly, the proximal portion of the tumour was composed of a yellowish fatty lesion, whereas the distal portion of the tumour was whitish and necrotic in nature. Histologically, the tumour was composed of two distinct components. The proximal component of the tumour was a WDL and the distal component was a PL. Immunohistochemically, S100 protein immunoreactivity highlighted lipoblasts in both tumour portions. The Ki-67 proliferation index was <1% in the WDL and 20% in the PL. MDM2 was positive in the WDL, but negative in the PL. p53 was negative in both areas. Numerous differentially expressed genes were found, which included genes coding for signal transduction, transcription, cell cycle, enzyme, structural protein, immune system and others. CONCLUSIONS: Our data demonstrate that multiple genes are differentially expressed in mixed type liposarcoma and suggest that these genes are associated with the differences in the morphological characteristics and pathogenesis of mixed type liposarcoma.

Adipose Tissue↗
PubMed2006

CDX2 expression is increased in gastric cancers with less invasiveness and intestinal mucin phenotype.

OBJECTIVE: CDX2 is an intestinal transcription factor that might be involved in the regulation of proliferation and differentiation of intestinal epithelial cells. It is well known that both gastric and intestinal phenotypic cell markers are expressed in gastric cancers. The aims of this study were to analyze the CDX2 expression and its relationship with the patients' clinicopathological characteristics and the mucin phenotypes by performing immunohistochemistry. MATERIAL AND METHODS: A total of 259 gastric cancer cases (122 early and 137 advanced cancers) were evaluated histologically and phenotypically. CDX2 expression was assessed by immunohistochemistry. RESULTS: Increased CDX2 expression correlated with a higher proportion of intestinal-type cancers of Lauren and early gastric cancers (p<0.001 and p<0.001, respectively) and a lower proportion of perineural invasion and lymph node metastasis (p<0.001 and p=0.003, respectively). Increased expressions of intestinal mucin (MUC-2, CD10) and decreased gastric mucin (MUC5AC) were associated with an increased CDX2 expression (p<0.001, p=0.045 and p=0.004, respectively). MUC6 expression was not associated with CDX2 expression. There was a significantly increased CDX2 expression in the intestinal phenotype compared with the other phenotypes (p<0.001). CONCLUSIONS: These results suggest that CDX2 might be a useful marker in predicting the clinical outcome for patients with gastric cancers.

Biomarkers, Tumor↗
PubMed2006

Analysis of endoscopic electronic image of intramucosal gastric carcinoma using a software program for calculating hemoglobin index.

Hemoglobin is the predominent pigment in the gastrointestinal mucosa, and the development of electronic endoscopy has made it possible to quantitatively measure the mucosal hemoglobin volume, by using a hemoglobin index (IHb). The aims of this study were to make a software program to calculate the IHb and then to investigate whether the mucosal IHb determined from the electronic endoscopic data is a useful marker for evaluating the color of intramucosal gastric carcinoma with regard to its value for discriminating between the histologic types. We made a software program for calculating the IHb in the endoscopic images. By using this program, the mean values of the IHb for the carcinoma (IHb-C) and those of the IHb for the surrounding non-cancerous mucosa (IHb-N) were calculated in 75 intestinal-type and 34 diffuse-type intramucosal gastric carcinomas. We then analyzed the ratio of the IHb-C to the IHb-N (C/N ratio). The C/N ratio in the intestinal-type carcinoma group was higher than that in the diffuse-type carcinoma group (p<0.001). In the diffuse-type carcinoma group, the C/N ratio in the body was lower than that in the antrum (p=0.022). The accuracy rate, sensitivity, specificity, and the positive and negative predictive values for the differential diagnosis of the diffuse-type carcinoma from the intestinal-type carcinoma were 94.5%, 94.1%, 94.7%, 88.9% and 97.3%, respectively. IHb is useful for making quantitative measurement of the endoscopic color in the intramucosal gastric carcinoma, and the C/N ratio by using the IHb would be helpful for distinguishing the diffuse-type carcinoma from the intestinal-type carcinoma.

Biomarkers, Tumor↗
PubMed2005

Recommendations for the management of cystic thyroid nodules.

BACKGROUND: The management of cystic thyroid nodules has not been standardized with respect to an initial fine-needle aspiration cytology (FNAC) cystic change result, which is defined as fluid aspiration and a smear with numerous macrophages but scant or no follicular cells. In the present study the physical characteristics of cystic thyroid nodules predictive of the pathology were investigated, and recommendations made on their management. METHODS: The aspiration results of 1436 thyroid nodules managed between 1998 and 2000 were investigated. A total of 157 patients who had a subsequent operation or follow-up data with reaspiration were the subjects of the present study. Age, sex, nodule characteristics and others were examined as possible predictors of cancer risk. RESULTS: The malignancy rate was 8.9%. Ten cases (71%) of malignancy were not cytologically diagnosed. Male sex and a nodule size of > or = 4 cm were found to be statistically significant predictors of malignancy. The malignancy rate was highest (100%) when a cystic lesion had malignant cytology on reaspiration and local invasion on radiology. CONCLUSIONS: When a cystic change is observed by initial FNAC of thyroid nodules, nodules of > or = 4 cm must be reaspirated and a firm cytologic diagnosis made to rule out malignancy. Nodules should be considered for surgery having taken into account other characteristics, in particular male sex and radiologic findings of local invasion.

Adult↗
PubMed2005

Clinicopathologic significance of gastric and intestinal phenotypic marker expression in gastric carcinomas.

BACKGROUND: It is well known that both gastric and intestinal phenotypic cell markers are expressed in gastric cancers. This study was aimed at investigating the correlation between gastric and intestinal phenotypic marker expression patterns of tumors and the clinicopathologic characteristics of gastric carcinomas. METHODS: We evaluated phenotypic marker expression by immunohistochemical staining with monoclonal antibodies. All tumors were classified as gastric (G), gastric and intestinal mixed (GI), intestinal (I), or null (N) phenotype. RESULTS: The tumors were phenotypically divided into G-phenotype tumors (33.2%), GI-phenotype tumors (25.7%), I-phenotype tumors (26.8%), and N-phenotype tumors (14.3%). N-phenotype tumors were associated with more corporeal location than GI- and I-phenotype tumors (o=0.009 and p=0.007, respectively), a larger size than I-phenotype tumors (0=0.007), a higher proportion of advanced gastric cancers than G-, GI-, and I-phenotype tumors (0=0.003, p<0.001, and p<0.001, respectively), more perineural invasion than G-, GI-, and I-phenotype tumors (p=0.076, p=0.003, and p=0.003, respectively), and more lymph node metastasis than GI-phenotype tumors (p=0.017). I-phenotype tumors were associated with a higher proportion of intestinal-type tumors than G-, GI-, and N-phenotype tumors (p<0.001, p=0.011, and p<0.001, respectively). CONCLUSION: Our results indicate that the gastric and intestinal phenotypic marker expression pattern of tumors is prognostically useful for patients with gastric carcinoma.

Antibodies, Monoclonal↗
PubMed2005

Relationships between the expressions of CDX1 and CDX2 mRNA and clinicopathologic features in colorectal cancers.

BACKGROUND: CDX1 and CDX2 are members of the caudal-type homeobox gene family and control the proliferation and differentiation of intestinal mucosal cells. Their expressions are commonly reduced in colorectal cancer, but reports about the relationships between their expressions and clinicopathologic features are rare. The aim of this study was to examine the expressions of CDX1 and CDX2 mRNAs in colorectal cancers and to assess the relationships between their expressions and clinicopathologic features. METHODS: CDX1 and CDX2 mRNA expressions were analyzed by real-time polymerase chain reaction in 48 colorectal cancers and in adjacent non-tumorous normal mucosal tissue. RESULTS: CDX1 and CDX2 mRNA expressions were significantly reduced in colorectal cancer tissues versus normal mucosal tissues (p=0.001, p=0.042, respectively). As compared with paired normal mucosal tissues, colorectal tissues showed reduced CDX1 mRNA expression in 64.6% (31/48) and reduced CDX2 mRNA expression in 66.7% (32/48) of cases. A statistically significant positive correlation was found between the expressions of CDX1 mRNA and CDX2 mRNA in colorectal cancer (r=0.543, p<0.001). However, the expressions of CDX1 and CDX2 mRNAs were not related to age, sex, cancer location, differentiation, lymphatic or vascular invasion, lymph node metastasis, stage or serum carcinoembryonic antigen level. CONCLUSIONS: CDX1 and CDX2 mRNA expressions were found to be significantly reduced in colorectal cancers but these expressional changes were not found to be related to clinicopathologic features.

CDX2 Transcription Factor↗
PubMed2005

[A case of primary angiosarcoma of small intestine presenting as recurrent gastrointestinal bleeding].

Angiosarcoma is a rare malignant tumor which occurs frequently in the skin and soft subcutis. Moreover, primary gastrointestinal angiosarcomas are very rare. This tumor manifests as non-specific symptoms such as gastrointestinal bleeding, abdominal pain and nausea. The diagnosis is often made at an advanced stage. Surgery, chemotherapy and radiotherapy are the mainstay of treatment. However, the prognosis is very poor. We report a case of primary angiosarcoma of the small intestine presenting as recurrent gastrointestinal bleeding. A 54-year-old man was admitted with recurrent gastrointestinal bleeding. An abdominal CT scan revealed an ileo-ileal intussusception. Segmental resection was performed with ileo-ileal anastomosis. The ileal mass was diagnosed as angiosarcoma on immunohistochemical stain. He received 3 cycles of chemotherapy, but died 5 months after the diagnosis.

Gastrointestinal Hemorrhage↗
PubMed2005

[A case of gastric metastasis of breast carcinoma resembling early gastric cancer].

Many patients suffering from breast carcinoma have metastases at initial diagnosis. The common metastatic sites are skeleton, liver and lung. Metastases to stomach are rare and only three cases have been reported in Korea. The endoscopic features of gastric metastases from breast carcinoma can be divided into three main categories: diffuse infiltration, external compression, and localized tumor deposition with ulceration or with a polypoid mass. However, metastatic gastric lesions which resemble early gastric carcinoma are rare. Typically, gastric metastases are confined to submucosa and muscularis, so that mucosal biopsy specimens might be false-negative. We report a case of gastric metastasis from infiltrative lobular carcinoma of the breast in a 66-year-old woman who had undergone left mastectomy with postoperative radiotherapy 17 years earlier. Initial diagnosis was early gastric carcinoma, signet ring cell type on gastric biopsy findings. However, definitive diagnosis of metastatic breast cancer was confirmed after endoscopic mucosal resection of a presumed primary early gastric carcinoma.

Aged↗
PubMed2003

Expressions of transforming growth factor (TGF)-beta1 and TGF-beta type II receptor and their relationship with apoptosis during chemical hepatocarcinogenesis in rats.

The expression of transforming growth factor (TGF)-beta1, which regulates cell proliferation, is tightly associated with that of TGF-beta type II receptor (TGR2), and has been regarded as an important change during hepatocarcinogenesis. Our aim in this study was to investigate the expression and localization of TGF-beta1 and TGR2 and to determine their relationships with apoptosis in chemical hepatocarcinogenesis of the rat produced by Solt and Farber's method. Northern blot analysis showed that a slight increase of TGF-beta1 transcripts and a decrease of TGR2 transcripts during hepatocarcinogenesis. Immunohistochemistry revealed that TGF-beta1-positive preneoplastic hepatocytes increased with time, and that this correlated with a reduction TGR2 expressing preneoplastic lesions. Hepatocellular carcinoma (HCC) tissues showed higher levels of TGF-beta1 transcripts and protein and lower levels of TGR2 transcripts and protein compared to the paired adjacent liver parenchyme. TUNEL revealed that apoptotic cells increased with time and were more numerous in the adjacent liver parenchyme than in preneoplastic lesions and HCC tissues. Our data suggest that the down regulation of TGR2 in preneoplastic lesions and HCC tissues might contribute to resistance to the growth inhibitory effects of TGF-beta1, and to the roles of TGF-beta1 in the development and progression of preneoplastic lesions and HCC in a chemically induced rat hepatocarcinogensis model.

Journal Article↗
PubMed2003

Differential expression of hypoxia inducible factor-1 alpha and tumor cell proliferation between squamous cell carcinomas and adenocarcinomas among operable non-small cell lung carcinomas.

This study aimed to evaluate whether the elevated level of hypoxia-inducible factor-1alpha (HIF-1alpha) correlated with histologic types, angiogenesis, tumor cell proliferation, and clinical parameters in common non-small cell lung carcinomas (NSCLCs). We performed immunohistochemical stains using paraffin-embedded tissue blocks from 84 cases of operable NSCLC [No. of squamous cell carcinoma (SCC), 45; No. of adenocarcinoma (AC), 39]. HIF-1alpha expression was related with histologic types (66.7% in SCCs vs 20.5% in ACs, p<0.001), but not with lymph node status, tumor stage, vascular endothelial growth factor expression, microvessel density (MVD), and proliferating cell nuclear antigen (PCNA) index (p>0.05, respectively). As for the histologic types, MVD and PCNA index were significantly higher in SCCs than in ACs (p=0.009 and p=0.016, respectively). Among HIF-1alpha positive carcinomas, MVD was significantly higher in HIF-1alpha positive SCCs than in HIF-1alpha positive ACs (p=0.023). The overall survival curves were not associated with HIF-1alpha expression or any other histologic parameters (p>0.05). These findings suggest that HIF-1alpha expression in NSCLCs may play a differential role according to histologic types, but its prognostic significance is indeterminate.

Adenocarcinoma↗
PubMed2003

Expression and localization of the transforming growth factor-beta type I receptor and Smads in preneoplastic lesions during chemical hepatocarcinogenesis in rats.

Little is known about the involvement of Smad-related molecules in the regulation of the Transforming Growth Factor (TGF)-beta signaling pathway during hepatocarcinogenesis, particularly with respect to preneoplastic lesions of a rat liver. The aims of this study were to investigate the localizations and temporal expressions of TGF-beta Receptor Type 1 (TGR1) and Smads during the promotion stage of chemical hepatocarcinogenesis in rats. We investigated expressions and localizations of TGR1, Smad2, Smad4, and Smad7 by using semi-quantitative RT-PCR and immunohistochemistry in preneoplastic lesions during rat chemical hepatocarcinogenesis induced by Solt and Farber's method. The down-regulation of TGR1, Smad2, and Smad4 was evident during the later steps of the promotion stage of chemical hepatocarcinogenesis. In contrast with other Smads, increased Smad7 expression was evident during the later steps of the promotion stage. Also immunohistochemistry revealed that the main site of TGR1, Smad2, Smad4, and Smad7 expression was mainly in hepatocytes of the preneoplastic lesions of a rat liver. Dysregulation of the downstream effectors of TGF-beta such as TGR1, Smad2, Smad4 and, Smad7 might contribute to the progression of preneoplastic lesions during chemical hepatocarcinogenesis in a rat.

Activin Receptors, Type I↗
PubMed2003

Pleuropulmonary blastoma in a young adult presenting as a ruptured cystic teratoma in radiology.

Pleuropulmonary blastoma (PPB) is a rare malignant dysontogenetic neoplasm primarily affecting children and is characterized histologically by a variably mixed blastematous and sarcomatous patterns. We herein report a very exceptional adult case of PPB. A 21-yr-old male patient presented with a left chest pain of two weeks' duration. A computed tomography scan revealed a large, multicystic tumor occupying the left lower hemithorax, leading to the impression of a ruptured mediastinal cystic teratoma. A thoracotomy for resection of the tumor was performed. On histologic examination, the tumor consisted of cystic walls and associated solid lesions which showed undifferentiated blastemal tissues with focal fibrosarcomatous and rhabdoid features. Immunohistochemically the tumor cells only showed diffuse strong positivity for vimentin. The histologic findings corresponded to a type II PPB. The authors suggest that PPB, especially of type I or II, should be included in the radiologic differential diagnosis of mediastinal cystic neoplasms in a young adult.

Adult↗
PubMed2003

Comparison of polymerase chain reaction with histopathologic features for diagnosis of tuberculosis in formalin-fixed, paraffin-embedded histologic specimens.

Objective.-To investigate the relationship between various histopathologic features and the results of the tuberculosis (TB)-polymerase chain reaction (PCR) method in routinely submitted histologic specimens for the histopathologic diagnosis of TB. Design.-We used 95 formalin-fixed, paraffin-embedded tissue blocks from 81 patients who were clinically suspected of having TB. We assessed the presence of histopathologic features including well-formed granuloma, poorly formed granuloma, caseous necrosis, and Langhans-type giant cells. We performed nested PCR for IS6110 and Ziehl-Neelsen staining for acid-fast bacilli (AFB). Results.-Of the 81 patients studied, 53 patients had chronic granulomatous inflammation, whereas 28 patients had only chronic inflammation without definite granulomatous inflammation. Of the 53 cases with chronic granulomatous inflammation, 17 (32%) were AFB positive and 36 (68%) were TB-PCR positive. Among cases with chronic granulomatous inflammation, the percentage that were positive and negative by TB-PCR differed significantly with the presence of various histopathologic features. All of the 13 cases with well-formed granuloma, caseous necrosis, and Langhans-type giant cells were TB-PCR positive; however, 10 (36%) of the 28 cases with chronic inflammation without granulomatous lesions were also TB-PCR positive. Conclusions.-TB-PCR is a rapid, sensitive method for the diagnosis of TB in routinely processed formalin-fixed, paraffin-embedded histologic specimens and is readily available in histopathology laboratories. We recommend use of TB-PCR when TB is suspected clinically, especially in cases of chronic inflammation without definite evidence of granulomatous inflammation.

Chronic Disease↗
PubMedDate not supplied

Magnetic resonance imaging assessment of fibrovascular ingrowth into porous polyethylene orbital implants.

BACKGROUND: To evaluate fibrovascular ingrowth into porous polyethylene orbital implants, using serial gadolinium (Gd)-enhanced magnetic resonance imaging (MRI). METHODS: 40 rabbits were divided into two groups, according to the surgical techniques used. Group 1 underwent enucleation of one eye and Medpor implantation, group 2 underwent evisceration and Medpor implantation. All subjects from each group were examined via MRI, and the implants were assessed histologically on the first, second, fourth and eighth postoperative weeks. The degree to which fibrovascular ingrowth occurred was then assessed by measuring the Gd-enhanced portion via MRI, as well as by histologic examination. RESULTS: There was a significant correlation between the enhanced area on MRI and the fibrovascularized area observed upon histological examination in the two study groups (group 1: r = 0.850 P < 0.001, group 2: r = 0.788, P < 0.001). The area enhanced on MRI was 2.70% smaller in mean value than the fibrovascularized area observed upon histological examination. There was no differences in fibrovascular ingrowth between group 1 and 2. It was also found that there was no differences between the two groups with regard to the enhanced areas on MRI. CONCLUSION: Gd-enhanced MRI study proved to be an excellent method for the assessment of fibrovascular ingrowth into the Medpor orbital implants, after both enucleation and evisceration.

Animals↗