AIM： Nitrative and oxidative DNA damage such as 8-nitroguanine and 8-oxo-7,8-dihydro-2＇-deoxyguanosine （8-oxodG） formation has been implicated in initiation and/ or promotion of inflammation-mediated carcinogenesi...AIM： Nitrative and oxidative DNA damage such as 8-nitroguanine and 8-oxo-7,8-dihydro-2＇-deoxyguanosine （8-oxodG） formation has been implicated in initiation and/ or promotion of inflammation-mediated carcinogenesis. The aim of this study is to clarify whether these DNA lesions participate in the progression of intrahepatic cholangiocarcinoma. METHODS： We investigated the relation of the formation of 8-nitroguanine and 8-oxodG and the expression of hypoxia-inducible factor-1α （HIF-1α） with tumor invasion in 37 patients with intra-hepatic cholangiocarcinoma. RESULTS： Immunohistochemical analyses revealed that 8-nitroguanine and 8-oxodG formation occurred to a much greater extent in cancerous tissues than in non-cancerous tissues. HIF-1α could be detected in cancerous tissues in all patients, suggesting low oxygen tension in the tumors. HIF-1α expression was correlated with inducible niltric oxide synthase （iNOS） expression （r = 0.369 and P = 0.025） and 8-oxodG formation （r = 0.398 and P = 0.015）. Double immunofluorescence study revealed that iNOS and HIF-1α co-localized in cancerous tissues. Notably, the formation of 8-oxodG was correlated significantly with lymphatic invasion （r = 0.386 and P = 0.018）. Moreover, 8- nitroguanine and 8-oxodG in non-cancerous tissues were associated significantly with neural invasion （P = 0.042 and P = 0.026, respectively）. These results suggest that reciprocal activation between HIF-1α and iNOS mediates persistent DNA damage, which induces tumor invasiveness via mutations, resulting in poor prognosis. CONCLUSION： The formation of 8-nitroguanine and 8-oxodG plays an important role in multiple steps of genetic changes leading to tumor progression, including invasiveness.展开更多
A 42-year-old man presented with a two-year history of progressive dysphagia and hoarseness. Esophagogram and endoscopy revealed submucosal mass effect on the upper esophagus. Computed tomography and magnetic resonanc...A 42-year-old man presented with a two-year history of progressive dysphagia and hoarseness. Esophagogram and endoscopy revealed submucosal mass effect on the upper esophagus. Computed tomography and magnetic resonance imaging revealed an elongated mass in the retrotracheal region of the lower neck with extension to the posterior mediastinum. Partial tumor resection and histopathological evaluation revealed a WHO type B2 thymoma. Adjuvant radiation and chemotherapy were subsequently administered resulting in complete tumor regression. To our knowledge, this is the first report of ectopic retrotracheal thymoma with clinical and imaging manifestations mimicking those for esophageal submucosal tumor.展开更多
ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular ...ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular carcinoma (HCC), the significance of COX-2 in progression of HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationship with VEGF level in HCC. METHODS: Fresh tumor tissues were obtained from 100 patients who underwent resection of HCC. COX-2 protein expression was examined by immunohistochemistry, and quantitatively by an enzyme immunometric assay (EIA) of tumor cytosolic COX-2 levels. Tumor cytosolic VEGF levels were measured by an ELISA. RESULTS: Immunostaining showed expression of COX-2 in tumor cells. Tumor cytosolic COX-2 levels correlated with VEGF levels (r = 0.469,P<0.001). Correlation with clinicopathological features showed significantly higher tumor cytosolic COX-2 levels in the presence of multiple tumors (P = 0.027), venous invasion (P = 0.030), microsatellite lesions (P=0.037) and advanced tumor stage (P = 0.008). Higher tumor cytosolic COX-2 levels were associated with worse patient survival. CONCLUSION: This study shows that elevated tumor COX-2 levels correlate with elevated VEGF levels and invasiveness in HCC, suggesting that COX-2 plays a significant role in the progression of HCC.展开更多
Within an agent server, the model introduces a trusted third party entity called Secure Service Station(SSS). The SSS is a non\|hardware component and is intended to prevent most attacks performed by malicious hosts, ...Within an agent server, the model introduces a trusted third party entity called Secure Service Station(SSS). The SSS is a non\|hardware component and is intended to prevent most attacks performed by malicious hosts, by providing mechanisms that ensure attack detection and provide integrity to mobile agents. This noble technique involves encapsulating partial results obtained on each intermediate host and binding these results together using a hash function, thus forming a strong bonded chain that cannot be compromised. An analytical model to explore the system performance was also developed.展开更多
基金Supported by the Khon Kaen University Research Fund in Thailand Grants-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan
文摘AIM： Nitrative and oxidative DNA damage such as 8-nitroguanine and 8-oxo-7,8-dihydro-2＇-deoxyguanosine （8-oxodG） formation has been implicated in initiation and/ or promotion of inflammation-mediated carcinogenesis. The aim of this study is to clarify whether these DNA lesions participate in the progression of intrahepatic cholangiocarcinoma. METHODS： We investigated the relation of the formation of 8-nitroguanine and 8-oxodG and the expression of hypoxia-inducible factor-1α （HIF-1α） with tumor invasion in 37 patients with intra-hepatic cholangiocarcinoma. RESULTS： Immunohistochemical analyses revealed that 8-nitroguanine and 8-oxodG formation occurred to a much greater extent in cancerous tissues than in non-cancerous tissues. HIF-1α could be detected in cancerous tissues in all patients, suggesting low oxygen tension in the tumors. HIF-1α expression was correlated with inducible niltric oxide synthase （iNOS） expression （r = 0.369 and P = 0.025） and 8-oxodG formation （r = 0.398 and P = 0.015）. Double immunofluorescence study revealed that iNOS and HIF-1α co-localized in cancerous tissues. Notably, the formation of 8-oxodG was correlated significantly with lymphatic invasion （r = 0.386 and P = 0.018）. Moreover, 8- nitroguanine and 8-oxodG in non-cancerous tissues were associated significantly with neural invasion （P = 0.042 and P = 0.026, respectively）. These results suggest that reciprocal activation between HIF-1α and iNOS mediates persistent DNA damage, which induces tumor invasiveness via mutations, resulting in poor prognosis. CONCLUSION： The formation of 8-nitroguanine and 8-oxodG plays an important role in multiple steps of genetic changes leading to tumor progression, including invasiveness.
文摘A 42-year-old man presented with a two-year history of progressive dysphagia and hoarseness. Esophagogram and endoscopy revealed submucosal mass effect on the upper esophagus. Computed tomography and magnetic resonance imaging revealed an elongated mass in the retrotracheal region of the lower neck with extension to the posterior mediastinum. Partial tumor resection and histopathological evaluation revealed a WHO type B2 thymoma. Adjuvant radiation and chemotherapy were subsequently administered resulting in complete tumor regression. To our knowledge, this is the first report of ectopic retrotracheal thymoma with clinical and imaging manifestations mimicking those for esophageal submucosal tumor.
基金Supported by the Sun C.Y. Research Foundation for Hepatobiliary and Pancreatic Surgery of the University of Hong Kong
文摘ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular carcinoma (HCC), the significance of COX-2 in progression of HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationship with VEGF level in HCC. METHODS: Fresh tumor tissues were obtained from 100 patients who underwent resection of HCC. COX-2 protein expression was examined by immunohistochemistry, and quantitatively by an enzyme immunometric assay (EIA) of tumor cytosolic COX-2 levels. Tumor cytosolic VEGF levels were measured by an ELISA. RESULTS: Immunostaining showed expression of COX-2 in tumor cells. Tumor cytosolic COX-2 levels correlated with VEGF levels (r = 0.469,P<0.001). Correlation with clinicopathological features showed significantly higher tumor cytosolic COX-2 levels in the presence of multiple tumors (P = 0.027), venous invasion (P = 0.030), microsatellite lesions (P=0.037) and advanced tumor stage (P = 0.008). Higher tumor cytosolic COX-2 levels were associated with worse patient survival. CONCLUSION: This study shows that elevated tumor COX-2 levels correlate with elevated VEGF levels and invasiveness in HCC, suggesting that COX-2 plays a significant role in the progression of HCC.
文摘Within an agent server, the model introduces a trusted third party entity called Secure Service Station(SSS). The SSS is a non\|hardware component and is intended to prevent most attacks performed by malicious hosts, by providing mechanisms that ensure attack detection and provide integrity to mobile agents. This noble technique involves encapsulating partial results obtained on each intermediate host and binding these results together using a hash function, thus forming a strong bonded chain that cannot be compromised. An analytical model to explore the system performance was also developed.
