Objective:To observe serum cystatin C (Cys C)level in patients before and after off-pump coronary ar-tery bypass grafting (OPCABG),and explore its relationship with coronary artery lesion.Methods:A total of 321 patients,who received OPCABG in department of heart surgery of our hospital from Aug 2013 to Nov 2013,were selected.According to number of diseased coronary vessels,they were divided into single-vessel group (n= 11), double-vessel group (n=33)and multi-vessel group (n=277).Double antibody enzyme linked immunosorbent assay (ELISA)was used to measure serum Cys C level in all groups.Results:The Cys C levels in single-vessel group, double-vessel group,multi-vessel group before OPCABG were (0.732 ± 0.286)mg/L, (0.807 ± 0.265)mg/L, (0.911±0.273)mg/L respectively,there were significant difference (F=3.942,P =0.038);and after OPCABG were (0.616±0.198)mg/L,(0.607±0.201)mg/L, (0.646±0.166)mg/L respectively ,there were no signifi-cant difference (F=0.493,P =0.617),namely there was no significant relationship between coronary artery disease extent and Cys C level after OPCABG,P >0.05. Conclusion:There is no significant relationship between original coronary artery disease extent and serum cystatin C level after off-pump coronary artery bypass grafting,namely off-pump coronary artery bypass grafting is an effective therapeutic measure for patients with coronary heart disease.

Objective To construct a model of small caliber vascular endothelial growth factor(VEGF) in tissue engineering,to investigate the performance of the sustained-release microspheres and vascular stent,and to provide materials and theoretical basis for animal experiment.Methods The sheep carotid arteries were treated with a cellular reagents,the cellular conditions and the stent properties were observed.Preparation of sustained release microspheres containing VEGF,particle size,encapsulation efficiency,drug loading and release curve were measured.The effective combination of the slow release microsphere and the vascular stent was used in the freeze drying technology.The rat vascular endothelial cells grown in tissue engineered blood vessel model release lumen,observe the growth of endothelial cells.Results After the treatment,the original performance of the vascular stent can be maintained.The average particle size of the microspheres was (9.8 ± 6.0) μm,which could be released slowly in 20 days,and the release rate was 70％.Microspheres can effectively with the tissue.engineering blood vessel tight binding.Rat vascular endothelial cells can grow in the vascular stent surface.Conclusion Using Triton X-100,DNA/RNA ribozyme for acellular reagent,stent performance is good.PLGA microspheres have good sustained release performance,and constructing appropriate tissue engineered small caliber vascular release model by using freeze drying technology can make the stent compact structure.

Objective:To conduct a systematic study of the immunologic response of rats to transplanted glutaraldehyde ( GA)-treated porcine blood vessels in vivo.Methods: The experiment was divided into two groups:fresh group and glutaraldehyde-treated group.Twenty cases of fresh and glutaraldehyde-treated porcine pulmonary arteries were subcutaneously embedded in rats.We compared the changes using HE staining and immunohistochemistry.Results:HE staining showed that there were stronger expression on day 12 and day 30 in the fresh group than that in the glutaraldehyde group.There were similar results in morphology in CD68,C3,IgG.The results of integral optical density ( IOD) in immunohistochemistry showed that IOD started rising from day 4 and got the peak on day 12 or day 30 and or fell on day 60.Conclusion: Innate immunity played an important role in the research on xenogenic immunological rejection mechanism.The immunogenicity of glutaraldehyde-treated xenogenic blood vessels is lower than that in fresh blood vessels.However there is still immunogenicity in glutaraldehyde-treated xenogenic blood vessels.We will explore better ways to obviously weaken the rejection.

In February 2023, the National Health Commission, together with the Ministry of Science and Technology, the Ministry of Education, and the State Administration of Traditional Chinese Medicine issued the Ethical Review Measures for Life Science and Medical Research Involving Humans, which emphasizes that research participants involving vulnerable groups such as children, intellectual disabilities, and mental disabilities should be given special protection. This paper expounded the current situation of protecting vulnerable groups from six aspects: inadequate protection of vulnerable groups by relevant laws and regulations, unclear definition of vulnerable groups, insufficient supervision by relevant departments, insufficient review ability of ethics committee to satisfy the protection of vulnerable groups, difficulty in fair inclusion of vulnerable groups, and the need to improve the ethical awareness of researchers and vulnerable groups. This paper also analyzed the new requirements for the protection of vulnerable groups in the Ethical Review Measures for Life Science and Medical Research Involving Humans from the following three aspects: expanding attention to potentially vulnerable research participants, paying more attention to the consent of research participants without or with limited capacity for civil conduct, and re-informed consent after the improvement of civil capacity level. Finally, suggestions on strengthening the protection of vulnerable groups were put forward from six aspects: improving the relevant legal system, clarifying the category of vulnerable groups, strengthening the implementation by regulatory departments, establishing a research participant protection system by research institutions, improving the ethical review capacity of ethics committees, formulating review guidelines by industry associations, and strengthening the education and training of all parties, so as to minimize the risk of vulnerable groups participating in clinical research and boost the quality and speed of clinical research in China.

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.