Objective To construct the plasmid pSilencer4.1/HtrA1 and stably transfect human trophoblastic cell line HPT-8.Methods We detected the expression of HtrA1 in cell line HPT-8 with immunohistochemical SABC,constructed the plasmid pSilencer4.1/HtrA1,transfected human trophoblastic cell line HPT-8 with plasmid pSilencer4.1/HtrA1 and negative plasmid pSilencer4.1, and observed the cell expression after transfection. Results About 90% of cellular cytoplasm of HPT-8 was dyed brown while the nucleus was negatively stained. Selective concentration of G418 was 200 μg/mL for HPT-8 to be transfected pSilencer4.1/HtrA1.With RT-PCR and Western blot methods,the expression of HPT-8 transfected plasmid Psilence4.1/HtrA1 was significantly downregulated compared with that of cells with negative plasmid and normal cells (P < 0.05 ).There was no significant difference in absorbance value between blank plasmid group and HPT-8 group (P >0.05).Conclusion We successfully constructed stable trophoblastic cell line HPT-8/ pSilencer4.1-HtrA1 with silenced expression of HtrA1,which lays foundation for further research.

Objective:To investigate the best neutralization ratio of protamine and heparin during off-pump coronary artery bypass grafting(OPCABG) by analyzing the advantages and disadvantages of heparin residue after OPCABG.Methods:From July 2018 to January 2019, 112 patients undergoing elective OPCABG were included in this study. The patients’ whole blood was drawn at 2 time points, including before entering operating room and entering intensive care unit, to receive thrombelastography(TEG) and heparinase-modified thromboelastography(hmTEG) . Conventional coagulation indexes such as activated coagulation time(ACT) were also detected. All the patients were divided into 3 groups, the non-heparin residue group(30 cases), heparin residue group 1(42 cases) and heparin residue group 2(40 cases) according to the laboratory results of TEG, hmTEG and ACT. We observed the dosage of each group of protamine and heparin, as well as the ratio of heparin and protamine. The changes of R time in TEG and ACT between 3 groups were analyzed and compared. Postoperative chest tube drainage at postoperative 12 h and 48 h, cTnI peak value, incidence of perioperative myocardial infarction(MI), incidence of reoperation and poor wound healing, amount of blood loss and transfusion, and acute renal injury were compared between the 3 groups.Results:No significant trio-group differences existed in basic clinical characteristics(all P>0.05). Postoperative R(CKH)time was similar in the 3 groups( P>0.05). Comparing with heparin residue group 1 and heparin residue group 2, the ACT after protamine neutralizing heparin and postoperative R time were decreased, the dosage of protamine, ratio of heparin and protamine, cTnI peak value were increased in the non-heparin residue group( P<0.05). Comparing with heparin residue group 2, the dosage of heparin, postoperative chest tube drainage at postoperative 12h and 48h, amount of blood transfusion and transfusion probability were significantly decreased in non-heparin residue group( P<0.05), but compared with group 1 of heparin residue, there was no significant difference in the above indexes( P>0.05). The perioperative myocardial infarction, incidence of reoperation and poor wound healing, postoperative acute renal injury and time of in ICU stay showed no significant differences between the 3 groups( P>0.05). Conclusion:Moderate heparin residue after OPCAB suggests that it has myocardial protective effect, and does not significantly increase the risk of bleeding. A large number of heparin residues can affect the coagulation function and lead to bleeding tendency, increase the amount of blood loss and transfusion. It is reasonable to make ACT after protamine neutralize heparin higher than the level of ACT before operation, and not higher than 20% of the level before operation.