ABSTRACT
Objective:To collect the imaging data and related materials of the patients with in-stent restenosis (ISR)after coronary artery stent operation with intravascular ultrasound (IVUS),and to analyze the risk factors of ISR,and to propose the reasonable intervention strategies.Methods:Fifty patients with ISR were divided into ISR ≤ 50% drug group (n = 14 )and ISR > 50% drug group (n = 36),including drug-coated balloon therapy group (n=16)and stent treatment group (n=20);IVUS virtual organization technology was used to compare the plaque area,location,tissue composition,thrombus and other factors of the patients in various groups after treatment;the data changes after 6 months of follow-up were analyzed.Results:The IVUS results showed the plaque areas and plaque loads of the ISR patients treated with intervention were significantly reduced compared with before operation (P 0.05).Conclusion:The ISR rate is higher in the patients with high degree of fiber components,plaque composition heterogeneity and distribution of diffuse tortuous and calcified lesions.ISR has no significant correlation with the plaque wall thickness and lipid content and plaque instability and necrotic tissue proportion.
ABSTRACT
BACKGROUND: Poly(ethylene glycol)-b-poly(L-lactide)-b-poly(L-glutamic acid) (PEG-PLA-PGL) tri-block copolymers have good applied foreground in constructing tissue engineering scaffold materials. Whether endothelial cells survive and grow on the materials has a direct influence on the application as a biodegradable material for the scaffold of endothelial cell vector.OBJECTIVE: To explore the cytocompatibility of PEG-PLA-PGL tri-block copolymers with human umbilical vein endothelial cells (HUVECs).DESIGN: Randomized control observation.SETTING: the Second Hospital of Jilin University.MATERIALS: The experiment was carried out in the Department of Pathobiology, School of Basic Medical Sciences, Jilin University from February to October in 2006. Human umbilical cord about 20 cm length came from one neonatal infant who was delivered normally after enough months in the Department of Gynecology and Obstetrics, the Second Hospital of Jilin University. Human umbilical cord was sampled in the informed consents of the infant's family member. The experimentation was authorized by the medical ethic committee of the hospital. PEG-PLA-PGL membranes were provided by Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. Inverted microscope and phase-contrast microscope were bought from Olympus Company (Japan).METHODS: HUVECs cultivated and grew steadily, were inoculated onto PEG-PLA-PGL membranes, serving as the experiment group. While the culture medium without PEG-PLA-PGL membranes were taken as the control group.①Cytocompatibility of PEG-PLA-PGL membranes with HUVECs was evaluated by observing cellular growth through phase-contrast microscope.②The proliferation index of cells was detected by MTT method in 1, 3, 5 and 7 days after inoculation.MAIN OUTCOME MEASURES: ①Cytocompatibility of PEG-PLA-PGL membranes with HUVECs;②The proliferation index of cells in l, 3, 5 and 7 days after inoculationRESULTS: ①Cytocompatibility of PEG-PLA-PGL membranes with HUVECs: The observation result of phase contrast microscopy showed that, endothelial cells planted on the PEG-PLA-PGL membranes began to attach and stretch after being planted 4-6 hours. Three days later, cells grew in colonies rapidly, after 5 days, colonies began to fuse and seemed like cobble-stone. The cells were shuttle or polygon in shape after passages. There were no significant differences between the experiment and control group. Cells cultured on PEG-PLA-PGL membranes for 15 days grew in inserts with membranes, but they didn't grow into patches through scanning electron microscope.②The proliferation index of cells: No significant differences of the proliferation index of cells were detected by MTT method in 1, 3, 5 and 7 days after inoculation between experiment group and control group (P＞0.05).CONCLUSION: Endothelial cells grow well in PEG-PLA-PGL membranes, and the two have good cytocompatibility.