Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so th...Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.展开更多
Angiotensin （Ang）-（1-7） is recognized as a new bioactive peptide in renin-angiotensin system （RAS）. Ang-（1-7） is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular di...Angiotensin （Ang）-（1-7） is recognized as a new bioactive peptide in renin-angiotensin system （RAS）. Ang-（1-7） is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular disease. Recent studies have found that Ang-（1-7） played an important role in reducing smooth muscle cell proliferation and migration, improving endothelial function and regulating lipid metabolism, leading to inhibition of atherosclerotic lesions and increase of plaque stability. Although clinical application of Ang-（1-7） is restricted due to its pharmacokinetic properties, identification of stabilized compounds, including more stable analogues and specific delivery compounds, has enabled clinical application of Ang-（1-7）. In this review, we discussed recent findings concerning the biological role of Ang-（1-7） and related mechanism during atherosclerosis development. In addition, we highlighted the perspective to develop therapeutic strategies using Ang-（1-7） to treat atherosclerosis.展开更多
We report a case of an 84-year-old male patient with primary small intestinal angiosarcoma.The patient initially presented with anemia and melena.Consecutive endoscopy revealed no signs of upper or lower active gastro...We report a case of an 84-year-old male patient with primary small intestinal angiosarcoma.The patient initially presented with anemia and melena.Consecutive endoscopy revealed no signs of upper or lower active gastrointestinal bleeding.The patient had been diagnosed 3 years previously with an aortic dilation,which was treated with a stent.Computed tomography suggested an aorto-intestinal fistula as the cause of the intestinal bleeding,leading to operative stent explantation and aortic replacement.However,an aorto-intestinal fistula was not found,and the intestinal bleeding did not arrest postoperatively.The constant need for blood transfusions made an exploratory laparotomy imperative,which showed multiple bleeding sites,predominately in the jejunal wall.A distal loop jejunostomy was conducted to contain the small intestinal bleeding and a segmental resection for histological evaluation was performed.The histological analysis revealed a lessdifferentiated tumor with characteristic CD31,cytokeratin,and vimentin expression,which led to the diagnosis of small intestinal angiosarcoma.Consequently,the infiltrated part of the jejunum was successfully resected in a subsequent operation,and adjuvant chemotherapy with paclitaxel was planned.Angiosarcoma of the small intestine is an extremely rare malignant neoplasm that presents with bleeding and high mortality.Early diagnosis and treatment are essential to improve outcome.A small intestinal angiosarcoma is a challenging diagnosis to make because of its rarity,nonspecific symptoms of altered intestinal function,nonspecific abdominal pain,severe melena,and acute abdominal signs.Therefore,a quick clinical and histological diagnosis and decisive measures including surgery and adjuvant chemotherapy should be the aim.展开更多
Objective： The aim of our study was to evaluate and sum up the experience with hepatic angiosarcoma. Methods： Retrospective study of 7 patients with hepatic angiosarcoma. Results： Symptoms and signs such as abdomin...Objective： The aim of our study was to evaluate and sum up the experience with hepatic angiosarcoma. Methods： Retrospective study of 7 patients with hepatic angiosarcoma. Results： Symptoms and signs such as abdominal pain were extremely nonspecific. The levels of the tumor markers were within the normal range. Four cases were positive for hepatitis B viruses. Among the 5 patients who received chemotherapy, improvement in survival was seen in 3 cases which also received surgery. Conclusion： Hepatic angiosarcoma is a rare and diffficult-to-diagnose malignant liver tumor. Surgery is the definitive treatment and adjuvant chemotherapy after surgery may improve survival.展开更多
The study of leaves and their architecture evolution is important for understanding the fluid dynamics of water movement in /eaves. Recent studies have shown how these systems can be involved in the performance of phy...The study of leaves and their architecture evolution is important for understanding the fluid dynamics of water movement in /eaves. Recent studies have shown how these systems can be involved in the performance of physiological aspects, which are directly connected with the density of the vascular network and stomata per unit of surface area. The vein architecture, beyond being essential for a mechanical support of the leaf, can also play a crucial role in the efficiency of the photosynthesis. The aim of the present work was to highlight the possible role of leaves vein network as cooling system. The results support the hypothesis that the vascular system of grape leaves is correlated with leaf temperature.展开更多
The rapidly increasing prevalence of diabetes mellitus worldwide is one of the most serious and challenging health problems in the 21st century. Mammalian sirtuin 1 （SIRT1） has been shown to decrease high-glucose-in...The rapidly increasing prevalence of diabetes mellitus worldwide is one of the most serious and challenging health problems in the 21st century. Mammalian sirtuin 1 （SIRT1） has been shown to decrease high-glucose-induced endothelial cell senescence in vitro and prevent hyperglycemia-induced vascular dysfunction. However, a role for SIRTI in prevention of hyperglyce- mia-induced vascular cell senescence in vivo remains unclear. We used endothelium-specific SIRT1 transgenic （SIRT1-Tg） mice and wild-type （WT） mice to construct a 40-week streptozotocin （STZ）-induced diabetic mouse model. In this mode, 42.9% of wild-type （WT） mice and 38.5% of SIRT1-Tg mice were successfully established as diabetic. Forty weeks of hyper- glycemia induced significant vascular cell senescence in aortas of mice, as indicated by upregulation of expression of senes- cence-associated markers including p53, p21 and plasminogen activator inhibitor-1 （PAI-1）. However, SIRT1-Tg diabetic mice displayed dramatically decreased expression of p53, p21 and PAI-I compared with diabetic WT mice. Moreover, man- ganese superoxide dismutase expression （MnSOD） was significantly downregulated in the aortas of diabetic WT mice, but was preserved in diabetic SIRT1-Tg mice. Furthermore, expression of the oxidative stress adaptor p66Shc was significantly de- creased in aortas of SIRT1-Tg diabetic mice compared with WT diabetic mice. Overall, these findings suggest that SIRT 1-mediated inhibition of hyperglycemia-induced vascular cell senescence is mediated at least partly through the reduction of oxidative stress.展开更多
文摘Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.
基金This work was supported by National Natural Science Foundation of China （NSFC） （No. 81400265 and No. 81270274）, and Peking University People＇s Hospital Research and Development funds （RDB2014-16）.
文摘Angiotensin （Ang）-（1-7） is recognized as a new bioactive peptide in renin-angiotensin system （RAS）. Ang-（1-7） is a counter-regulatory mediator of Ang-II which appears to be protective against cardiovascular disease. Recent studies have found that Ang-（1-7） played an important role in reducing smooth muscle cell proliferation and migration, improving endothelial function and regulating lipid metabolism, leading to inhibition of atherosclerotic lesions and increase of plaque stability. Although clinical application of Ang-（1-7） is restricted due to its pharmacokinetic properties, identification of stabilized compounds, including more stable analogues and specific delivery compounds, has enabled clinical application of Ang-（1-7）. In this review, we discussed recent findings concerning the biological role of Ang-（1-7） and related mechanism during atherosclerosis development. In addition, we highlighted the perspective to develop therapeutic strategies using Ang-（1-7） to treat atherosclerosis.
文摘We report a case of an 84-year-old male patient with primary small intestinal angiosarcoma.The patient initially presented with anemia and melena.Consecutive endoscopy revealed no signs of upper or lower active gastrointestinal bleeding.The patient had been diagnosed 3 years previously with an aortic dilation,which was treated with a stent.Computed tomography suggested an aorto-intestinal fistula as the cause of the intestinal bleeding,leading to operative stent explantation and aortic replacement.However,an aorto-intestinal fistula was not found,and the intestinal bleeding did not arrest postoperatively.The constant need for blood transfusions made an exploratory laparotomy imperative,which showed multiple bleeding sites,predominately in the jejunal wall.A distal loop jejunostomy was conducted to contain the small intestinal bleeding and a segmental resection for histological evaluation was performed.The histological analysis revealed a lessdifferentiated tumor with characteristic CD31,cytokeratin,and vimentin expression,which led to the diagnosis of small intestinal angiosarcoma.Consequently,the infiltrated part of the jejunum was successfully resected in a subsequent operation,and adjuvant chemotherapy with paclitaxel was planned.Angiosarcoma of the small intestine is an extremely rare malignant neoplasm that presents with bleeding and high mortality.Early diagnosis and treatment are essential to improve outcome.A small intestinal angiosarcoma is a challenging diagnosis to make because of its rarity,nonspecific symptoms of altered intestinal function,nonspecific abdominal pain,severe melena,and acute abdominal signs.Therefore,a quick clinical and histological diagnosis and decisive measures including surgery and adjuvant chemotherapy should be the aim.
文摘Objective： The aim of our study was to evaluate and sum up the experience with hepatic angiosarcoma. Methods： Retrospective study of 7 patients with hepatic angiosarcoma. Results： Symptoms and signs such as abdominal pain were extremely nonspecific. The levels of the tumor markers were within the normal range. Four cases were positive for hepatitis B viruses. Among the 5 patients who received chemotherapy, improvement in survival was seen in 3 cases which also received surgery. Conclusion： Hepatic angiosarcoma is a rare and diffficult-to-diagnose malignant liver tumor. Surgery is the definitive treatment and adjuvant chemotherapy after surgery may improve survival.
文摘The study of leaves and their architecture evolution is important for understanding the fluid dynamics of water movement in /eaves. Recent studies have shown how these systems can be involved in the performance of physiological aspects, which are directly connected with the density of the vascular network and stomata per unit of surface area. The vein architecture, beyond being essential for a mechanical support of the leaf, can also play a crucial role in the efficiency of the photosynthesis. The aim of the present work was to highlight the possible role of leaves vein network as cooling system. The results support the hypothesis that the vascular system of grape leaves is correlated with leaf temperature.
基金supported by the National Basic Research Program of China (Grant No. 2011CB503902)National Natural Science Foundation of China (Grant Nos. 31028005 and 31021091)
文摘The rapidly increasing prevalence of diabetes mellitus worldwide is one of the most serious and challenging health problems in the 21st century. Mammalian sirtuin 1 （SIRT1） has been shown to decrease high-glucose-induced endothelial cell senescence in vitro and prevent hyperglycemia-induced vascular dysfunction. However, a role for SIRTI in prevention of hyperglyce- mia-induced vascular cell senescence in vivo remains unclear. We used endothelium-specific SIRT1 transgenic （SIRT1-Tg） mice and wild-type （WT） mice to construct a 40-week streptozotocin （STZ）-induced diabetic mouse model. In this mode, 42.9% of wild-type （WT） mice and 38.5% of SIRT1-Tg mice were successfully established as diabetic. Forty weeks of hyper- glycemia induced significant vascular cell senescence in aortas of mice, as indicated by upregulation of expression of senes- cence-associated markers including p53, p21 and plasminogen activator inhibitor-1 （PAI-1）. However, SIRT1-Tg diabetic mice displayed dramatically decreased expression of p53, p21 and PAI-I compared with diabetic WT mice. Moreover, man- ganese superoxide dismutase expression （MnSOD） was significantly downregulated in the aortas of diabetic WT mice, but was preserved in diabetic SIRT1-Tg mice. Furthermore, expression of the oxidative stress adaptor p66Shc was significantly de- creased in aortas of SIRT1-Tg diabetic mice compared with WT diabetic mice. Overall, these findings suggest that SIRT 1-mediated inhibition of hyperglycemia-induced vascular cell senescence is mediated at least partly through the reduction of oxidative stress.
