期刊：
Journal of Long-Term Effects of Medical Implants,2013年23(1):67-86 ISSN：1050-6934
通讯作者：
Guidoin, R.(Robert.Guidoin@gmail.com)
作者机构：
[Lin, Jing] Key Laboratory of Textile Science and Technology of Ministry of Education and College of Textiles, Donghua University, Shanghai, China;[Guidoin, Robert] Departments of Surgery and Radiology, Laval University and Qué,bec Biomaterials Institute, Quebec, QC, Canada;Department of Surgery, University of Calgary and Calgary Health Authority, Calgary AB, Canada;Energie, Maté,riaux, Telecommunications, INRS, Varennes, QC, Canada;The Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, University of South China, Hengyang, Hunan Province, China
通讯机构：
Department of Surgery, Laval University, Ferdinand-Vandry Building, Canada
摘要：
In this study, we aimed to investigate changes to the fabric of Talent stent-grafts following implantation of aortic endografts and to determine the possible causes of fatigue and/or failure of the grafts. Six devices were explanted at reoperation (N=5) and autopsy (N=1). Selected segments were assessed nondestructively by gross observation and destructively by analyzing textile characteristics and chemical properties. All of the devices showed a 4/4 twill woven fabric of monofilament polyester. These devices, explanted at reoperation and autopsy, presented different levels of fatigue and/or failure. Numerous holes were found in the fabric of two devices. The minor damage caused by the passage of the sutures through the weave to fasten the Nitinol wires did not progress significantly over time. The sutures remained relatively intact, except for some distortions. The main failure mode was the abrasion of the yarns at the apices of adjacent Nitinol stents. In two devices, this abrasion resulted in fraying of the yarns and holes in the fabric tubes. This short series of explanted devices provides evidence of damage to polyester fabric used in aortic endografts and raises questions regarding their resistance to abrasion and the risk of endoleak associated with monofilament fabric yarn.
摘要：
Oxidized lipoprotein(a) (oxLp(a)) is a more potent marker of atherogenesis than native Lp(a). However, the molecular mechanisms of oxLp(a) activity are not clear. Reactive oxygen species (ROS) have recently been suggested as acting as intracellular second messengers. In this study, the effects of oxLp(a) on endothelial cell monolayer permeability and the role of reactive oxygen species (ROS) generation in these effects were investigated. Our results showed that oxLp(a) inhibited desmoglein-1 (DSG1) and desmocollin-2 (DSC2) expression at both mRNA and protein levels in a dose- and time-dependent manner, and increased the generation of cellular ROS. Down-regulation of DSG1 and DSC2 was strengthened by pretreatment with H2O2 and attenuated by superoxide dismutase (SOD) treatment. Furthermore, oxLp(a) increased endothelial cell monolayer permeability, and this effect was enhanced by H2O2 and blunted by SOD. Taken together, these results demonstrate that oxLp(a) increases endothelial cell monolayer permeability, which is mediated at least in part via ROS generation.
期刊：
Journal of Long-Term Effects of Medical Implants,2013年23(1):45-59 ISSN：1050-6934
通讯作者：
Guidoin, R.(robertguidoin@hotmail.com)
作者机构：
[Wang, Lu; Lin, Jing] Key Laboratory of Textile Science and Technology of Ministry of Education and College of Textiles, Donghua University, Shanghai, China;[Wei, Dangheng] The Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, University of South China, Hengyang, Hunan Province, China;[Nutley, Mark; Samis, Gregory] Department of Surgery, University of Calgary and Calgary Health Authority, Calgary, AB, Canada;[How, Thien] Department of Clinical Engineering, University of Liverpool, Liverpool, United Kingdom;[Paynter, Royston] É,nergie, Maté,riaux, Té,lé,communications, INRS, Varennes, QC, Canada
通讯机构：
Department of Surgery, Laval University, Ferdinand-Vandry Building, Canada
摘要：
The biodurability of the Nitinol wires used in stent-grafts retrieved from reoperations and autopsy was analyzed to assess the possible causes of fracture and/or corrosion of the stents. The Nitinol wires of six explanted devices presented a corrosion-free surface after in vivo service. The drawing lines in the control wires were still present, but neither burrs nor flakes were observed. Pits and crevices were rare, but some shallow ones were present. Some abrasions of the surfaces of the Nitinol wires were also observed. The chemical composition of the explanted devices showed the presence of organic contamination that covered the thick layer of titanium oxide before reaching the Nitinol itself. The durability of the Nitinol employed in the manufacture of the Talent stent-grafts was confirmed; the results of this study show the Nitinol to be resistant to corrosion. We have also concluded that the fractures of the Nitinol wires in two devices were unique adverse incidents caused by compression and bending related to the sharp angle of the Nitinol wires.
摘要：
The activation of endothelial cells by oxidized low-density lipoprotein (ox-LDL) with subsequent increases in endothelial permeability occurs in the early stage of atherosclerosis. Cathepsin L (CATL) is one of the cysteine proteases and has been implicated in advanced atherosclerotic lesions and plaque instability. This study aimed to explore the role of CATL in ox-LDL-induced early atherosclerotic events and to delineate the underlying mechanism. Results showed that ox-LDL upregulated CATL protein levels and activation in human umbilical vein endothelial cells (ECs) in a concentration-dependent manner and stimulated EC autophagy and apoptosis and increased EC monolayer permeability. Concomitantly, VE-cadherin expression was decreased. When ECs were pretreated with a CATL inhibitor, ox-LDL-induced autophagy was inhibited while apoptosis was further increased. In addition, the VE-cadherin protein level was increased, and the EC monolayer permeability was reduced. Taken together, the present study showed that the upregulated expression and activation of CATL induced by ox-LDL, increased EC autophagy and antagonized EC apoptosis, which partly neutralized the effect of increased EC monolayer permeability mediated by the downregulation of VE-cadherin. Thus, the proatherogenic effect of CATL was partly neutralized by inducing autophagy and inhibiting apoptosis in early stages of atherosclerosis.
期刊：
Journal of Long-Term Effects of Medical Implants,2013年23(4):339-357 ISSN：1050-6934
通讯作者：
Guidoin, R.(Robert.Guidoin@gmail.com)
作者机构：
[Wei, Dangheng] The Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, University of South China, Heng Yang, Hunan Province, China;[Li, Bin] Department of Vascular Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China;[Wang, Lu; Lin, Jing] Key Laboratory of Textile Science and Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, China;[Nutley, Mark; Samis, Gregory] Division of Vascular Surgery, University of Calgary, Peter Laugheed Center, Calgary, AB, Canada;[How, Thien] Department of Clinical Engineering, University of Liverpool, Liverpool, United Kingdom
通讯机构：
Departments of Surgery and Radiology, Laval University and Quebec Biomaterials Institute, Ferdinand-Vandry Building, Canada
摘要：
Using the retrieved devices from one autopsy and five reoperations, the biocompatibility of explanted Talent stent-grafts was investigated to highlight the capacity of the fabric to act as an effective scaffold to regenerate a blood conduit. The autopsy device was encapsulated both internally and externally, but the capsules did not penetrate through the fabric structure. The reoperation devices showed discrete patches of compact fibrin and irregularly scattered mural thrombi. Positive staining of α-actin, tissue plasminogen activator (tPA), urokinase (uPA), urokinase receptor (uPAR), and urokinase inhibitors (PAI 1, PAI 2, PAI 3, and protease nexin), and D-dimer was more frequently identified in the autopsy sample than in the reoperation samples. This preliminary assessment shows that the stent-graft retrieved during autopsy was better healed than those explanted at reoperation.
