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BJA British Journal of Anaesthesia 03/2012; 108(3):526; author reply 526-7. · 4.24 Impact Factor
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ABSTRACT: Fractionated radiotherapy allows for the safe administration of larger doses without the development of immediate or late toxicity. The influence of preoperative fractionated radiotherapy on neointima formation for expanded polytetrafluoroethylene (ePTFE) graft has not been determined.
Twenty mongrel dogs were randomly divided into radiotherapy group (a total dose of 35 Gy) or control group (no radiation). The infrarenal abdominal aorta and inferior vena cava were replaced by ePTFE grafts at 3 months after irradiation in the radiotherapy group. Grafts were explanted at 4 weeks after surgery. Histopathological techniques were undertaken to evaluate graft neointima formation. The control group was managed the same as the radiotherapy group except for not receiving irradiation.
Four grafts implanted into inferior vena cava in the irradiated group and three in the control group were found to be completely occluded. None of the grafts implanted into abdominal aorta were obstructed. In the case of the inferior vena cava graft, the thickness of the graft neointima did not differ significantly between the irradiated and control groups. However, for the abdominal aorta graft, the neointima thickness in the irradiated groups was significantly thinner than that in the control group.
Preoperative fractionated radiotherapy affects vascular healing via suppressing the development of neointima formation in the abdominal aorta graft.
European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 01/2012; 43(4):460-5. · 2.92 Impact Factor
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D Zou,
W Han,
S You,
D Ye,
L Wang,
S Wang,
J Zhao,
W Zhang, X Jiang,
X Zhang,
Y Huang
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ABSTRACT: Hypoxia-inducible factor 1α (HIF-1α) is a pivotal regulator of hypoxic and ischaemic vascular responses that drives transcriptional activation of hundreds of genes involved in vascular reactivity, angiogenesis and arteriogenesis. Previous reports based on gene knockout technology have demonstrated that HIF-1α can promote osteogenesis. However, this protein is easily degraded in a normoxic state, which makes in vitro studies of HIF-1α-induced mesenchymal stem cell (MSC) osteogenesis difficult. For better understanding of HIF-1α promoting osteogenesis, the role of HIF-1α-induced MSC osteogenesis in the normoxic state has been investigated here.
HIF-1α was made to overexpress using a lentiviral vector, and its effects on bone marrow-derived mesenchymal stem cell (BMSC) osteogenesis were investigated. Real-time quantitative and western blotting (to assess expression levels of angiogenic and osteogenic related genes regulated by Lenti-HIF-1α), alkaline phosphatase (ALP) and alizarin red-S staining analyses, were performed.
In HIF-1α gene-transfected BMSCs, expression levels of angiogenic, cartilaginous and osteogenic genes were all increased significantly compared to Lenti LacZ-transfected cells, at both mRNA and protein levels. ALP activity and alizarin red-S staining were significantly enhanced in HIF-1α transduced cells compared to control cells, on day 21.
These results indicate that Lenti-HIF-1α can induce BMSC overexpression levels of angiogenic and osteogenic genes in vitro in the normoxic state. Further study will be focused on whether HIF-1α can also improve bone repair in vivo.
Cell Proliferation 06/2011; 44(3):234-43. · 2.52 Impact Factor
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Y Zhang, X Jiang,
X Qin,
D Ye,
Z Yi,
M Liu,
O Bai,
W Liu,
X Xie,
Z Wang,
J Fang,
Y Chen
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ABSTRACT: Vascular endothelial growth factors (VEGFs) are crucial regulators of angiogenesis and vasculogenesis. The autocrine VEGF signaling is required for maintaining the homeostasis of vasculature. Dysregulation of angiogenesis is implicated in the development of many human cancers, especially in clear-cell renal cell carcinoma (ccRCC), a highly vascularized tumor. Meanwhile, antiangiogenesis has become a mainstay in the treatment of human cancers. In this study, we analyzed the functional roles of RKTG (Raf Kinase Trapping to Golgi), a negative regulator of mitogen-activated protein kinase (Raf/MEK/ERK) signaling, by sequestration of Raf kinase to the Golgi apparatus, in angiogenesis and ccRCC. Through a series of in vitro and in vivo experiments, we found that RKTG has a negative effect on cell proliferation, migration, sprouting and angiogenesis of endothelial cells. RKTG, by suppressing mitogen-activated protein kinase signaling, negatively regulates the transactivation activity of hypoxia-inducible factor 1α (HIF-1α) by inhibiting formation of HIF-1α/p300 complex and suppressing VEGF transcription, thereby reducing hypoxia-induced VEGF production. The expression level of RKTG is significantly downregulated in clinical ccRCC tumor samples, with an inverse correlation with VEGF expression level. These results highlight the functional roles of RKTG and its regulated Raf/ERK/MEK signaling cascade in angiogenesis and autocrine VEGF signaling. In addition, this study indicates that RKTG is likely implicated in the development of ccRCC through its regulation on angiogenesis.
Oncogene 09/2010; 29(39):5404-15. · 6.37 Impact Factor
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ABSTRACT: Human periodontal ligament (PDL) cells occur changes in morphology and express relative protein by stretching force. However, whether stretching force, especially excessive stretching force, induces PDL cell apoptosis is not yet clearly understood. In the present study we investigated the relationship between early apoptosis and stretching force in human PDL cells in vitro.
The human PDL cells were obtained from healthy premolars. After three to five passages, the cells were stretched by strain 1%, 10% and 20% for 30 min, 1 h, 6 h and 12 h, then early apoptosis were detected through annexin fluorescein isothiocyanate (V-FITC) binding by flow cytometry and confocal laser scanning microscopy.
The experiments indicated that human PDL apoptotic cells in the early stage increased in a time- and force-dependent manner in response to stretching strain within 6 h, and then apoptosis decreased at 12 h. Human PDL cells which stretched inclined parallel to each other and aligned their long axis perpendicular to the stretching force vector, but in the centre of the disc, cells showed minimal deformation and unidirectional alignment of PDL cells.
The overall results suggested that stretching force not only influenced morphology but also induced early apoptosis in human PDL cells.
Oral Diseases 05/2008; 14(3):270-6. · 2.49 Impact Factor
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ABSTRACT: An automatic mathematical expression (ME) understanding system is presented. This system is consisted of three procedures, i.e., pre-processing, symbol segmentation, structure analysis among symbols within the ME. In symbol segmentation procedure, a three-stage segmentation method based on dynamic programming (DP) is introduced to segment symbols in the ME image. In structure analysis procedure, a ME is decomposed into several basic expressions based on reconstructing the ME global structure. Experimental results on about 3268 ME images showed that the presented system worked well. Top-1 ME recognition accuracy reached 78.2%.
Document Analysis and Recognition, International Conference on. 2:719-723.
