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Objective To prepare biofilm scaffolds by using mesenteric acellular matrix, so as to investigate their physicochemical and biological characteristics. Methods The mesenteric tissues were subjected to trypsin digestion, and the mesenteric cells were removed after repeated freezing and thawing of mesenteric tissue. Mesenteries were divided into mesenteric matrix group (Group A) and acellular mesenteric matrix group (Group B). The physical and chemical properties of mesenteric matrix in two groups were tested by HE staining, electron microscopy, DNA detection, cytotoxicity test and tensile mechanics test. The blood flow of the vessels was detected by ultrasonography at 1st week, 1st month and 2nd month, and the vessels were observed by pathological examination. Results HE staining and electron microscopy showed that the mesentery of Group B was loose in acellular mesentery matrix, and the arrangement of fibers was neat, with no cells remaining. Compared with Group A, the expression level of DNA in Group B was lower, with more completely decellularized cells. CCK-8 cytotoxicity test showed that there was no cytotoxicity in Group A and Group B. FDA-PI fluorescence staining showed no cytotoxicity of cells in both groups. Cells in Croup A and Group B survived well, and no dead cells were found. Tensile mechanics test showed that there were no significant differences in maximum tensile force, maximum elongation, yield strength, yield point elongation between Group A and Group B. The early patency of acellular mesenteric stent implantation was good, and endothelial hyperplasia was obvious at 2nd month after stent implantation. Conclusion sMesenteric cells were removed by freeze-thaw and enzymatic digestion. Mesenteric stroma was completely removed without cytotoxicity, which showed good mechanical characteristics. Mesenteric stent implantation had good early patency and endothelial proliferation after 2 months.
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Objective To investigate the effect of hydromorphone postconditioning on ischemiareperfusion (I/R) injury in isolated rat hearts and the role of mitochondial permeability transition pore (mPTP).Methods Male Sprague-Dawley rats, aged 2-3 months, weighing 250-320 g, were used in the study.The rats were heparinized and anesthetized with intraperitoneal 10％ chloral hydrate 350 mg/kg.The hearts were excised, and perfused in a Langendorff apparatus with K-H solution saturated with 95％ O2-5％ CO2 at 36.5-37.5 ℃.Forty isolated rat hearts were randomly divided into 4 groups (n=10 each)using a random number table: control group (group C), group I/R, hydromorphone postconditioning group (group H), and hydromorphone postconditioning + mPTP opener lonidamine group (group HL).Group C was continuously perfused with K-H solution for 120 min.Group I/R was perfused with K-H solution for 30 min, the perfusion was then suspended for 30 min, and group I/R was perfused with K-H solution for another 30 min.Group H was perfused with K-H solution for 30 min, the perfusion was then suspended for 30 min, and group H was perfused with K-H solution containing 0.3 μmol/L hydromorphone for 10 min, and then with K-H solution for 50 min.Group HL was perfused with K-H solution for 30 min, the perfusion was then suspended for 30 min, and group HL was perfused with K-H solution containing 0.3 μmol/L hydromorphone and 30 μmol/L lonidamine for 10 min, and then with K-H solution for 50 min.At 30 min of equilibration (T0), and 30 and 60 min of reperfusion (T2,3), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP) , ±dp/dtmax, heart rate (HR), and coronary flow (CF) were measured.The concentrations of lactic dehydrogenase (LDH), creatine kinase-MB (CK-MB) , and troponin-T (Tn-T) in the coronary effluent were determined at T0 and T3.The coronary effluent was collected at T0 and 15 min of reperfusion (T1),nicotinamide-adenine dinucleotide (NAD+) concentrations were measured using enzyme-linked immunosorbent assay to reflect the degree of mPTP opening.The myocardial infarct size was determined at T3 by TTC staining.Results Compared with group C, LVDP, HR, ±dp/dtmax and CF were significantly decreased, and LVEDP was increased at T2,3, and the concentrations of LDH, CK-MB and Tn-T in the coronary effluent, myocardial infarct size at T3, and NAD+ concentrations in the coronary effluent at T1 were increased in group I/R (P＜0.05).Compared with I/R and HL groups, LVDP, ±dp/dt CF and HR were significantly increased, and LVEDP was decreased at T2,3, and the concentrations of LDH, CK-MB and Tn-T in the coronary effluent, myocardial infarct size at T3, and NAD+ concentrations in the coronary effluent at T1 were decreased in group H (P＜0.05).Conclusion Hydromorphone postconditioning can reduce myocardial I/R injury in isolated rat hearts, and the mechanism is related to inhibition of mPTP opening.
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Objective In this study ,to explore the relationship between the renal blood flow PI ,and the AKI was caused by CPB .Methods 14 cases with heart disease were accepted .The renal aorta and renal segmental artery PI of all cases were monitored by the CDFI at the preoperative and postoperative 1 h ,2 h ,4 h ,8 h ,16 h ,24 h .The renal blood urea nitrogen (Urea) ,uric acid (UA) ,creatinine (Crea) ,were detected at the same time .All datas for statistical analysis .Results The renal aorta PI was higher at the postoperative 1 h ,2 h ,4 h ,8 h ,16 h than that at the preoperative .The renal segmental artery PI was higher at the postoperative 1 h ,2 h ,4 h ,16 h than that at the preoperative .The renal blood flow PI was positively correlated with Urea ,UA and Crea .Conclu-sion The renal aorta ,renal segmental artery PI was positively correlated with Urea ,UA and Crea after CPB .The PI may be seen as an evaluation index to assess AKI after CPB .
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Objective To investigate feasibility and validity of endovascular aortic repair (EVAR) of traumatic thoracic aortic injuries (TTAI).Methods A retrospective analysis was conducted on data of 13 patients with TTAI.Pathological changes were evaluated by spinal CT angiography (CTA) preoperatively and re-evaluated by digital subtraction angiography (DSA) in EVAR.CTA was performed again to confirm therapeutic effects at postoperative 3,6,12 months and annually thereafter.Results All patients had successful EVAR.Complete or partial cover of left subclavian artery was observed in four patients.Endoleak in angiography shortly after stent delivery was noticed in three patients.However,endoleak disappeared in one patient after short stent placement for twice; endoleak was evidently decreased in one patient after balloon dilation.Follow-up was performed for another patient with slight endoleak.A total of 12 patients were followed up,which showed no complications,such as endoleak,ischemia of left upper extremity,paralysis or stent-graft migration.Conclusion EVR is safe and effective in treatment of TTAI.
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The present paper is to research the expression level of the mRNA of scavenger receptor class B type 1-receptor of high-density lipoprotein in endothelial cells after being treated by different shear stress. The second to fourth generations of the cultured human umbilical vein endothelial cells (HUVECs) were used in the experiment. The cells were divided into two groups. The first group was the control group which was not dealt with shear stress; the second group was the experimental group which concluded low shear stress group (4.2 dyne/cm2), moderate shear stress group (8.4 dyne/cm2) and high shear stress group (15 dyne/cm2). The load time was 1h, 2h, 4h and 8h, respectively. Harvesting the cells and extracting total RNA after being treated by different shear stresses, the expression level of the SR-B1 mRNA was detected by semi-quantitative RT-PCR technic. It was found that the expression of SR-B1 mRNA became weaker and weaker compared to the control group when it was stimulated continuously by the low shear stress, the lowest expression of SR-B1 mRNA appeared at 8h. In the moderate shear stress group, the expression of SR-B1 mRNA increased obviously. Compared to the control group, there was significant difference after being treated with 2h. In the high shear stress group, the expression of SR-B1 mRNA increased immediately when it was stimulated by the shear stress. And the expression of SR-B1 mRNA arrived peak value at 4h. Compared to the control group, there was significant difference after being treated for 1h. It was concluded that the harmful mechanism of the low shear stress is that it can increase the incidence of the atherosclerosis by reducing the reverse cholesterol transport and endothelial protection through decreasing the expression of the SR-B1. Otherwise, the high shear stress prevent the genesis of atherosclerosis by the contrary mechanism.
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Humans , Atherosclerosis , Cells, Cultured , Human Umbilical Vein Endothelial Cells , Cell Biology , Metabolism , RNA, Messenger , Genetics , Metabolism , Scavenger Receptors, Class B , Genetics , Metabolism , Stress, MechanicalABSTRACT
To understand the local hemodynamics of modified TF-AHCB carotid bifurcation model, using particle image velocimetry technique to measure the instantaneous velocity distribution of the model attatched to a circuit. The velocity was controlled by regulating the height of the reservoir. The working fluid consists of glycerine and water mixture with viscosity of 3.75 mPa.s similar to human blood. Instantaneous velocity fields were obtained by PIV and the shear stresses were calculated according to the velocity. The results showed that inside the model, there were a large flow separation and an anticlockwise rotating vortex on the lateral wall of ICA, The location and distance of the vortex changed with the flow velocity. The higher the flow velocity, the smaller the vortex distance, and the farther the location. The shear stresses on the lateral wall were significantly lower in all work condition. And there a low shear stress kernel when the velocity was lower than 0.839 m/s. The location of the low shear stress was just the position of atherosclerosis. The flow pattern inside the model consists of large flow separation and vortex zones. And there are low shear stress zones at the lateral wall of ICA, Where are thought to be associated with the genesis of atherosclerosis.