Late recurrent high degree atrioventricular block after percutaneous closure of a perimembranous ventricular septal defect / 中华医学杂志(英文版)

High degree atrioventricular block (HDAVB) is a serious complication of transcatheter closure of a perimembranous ventricular septal defect (PMVSD). We report one patient who developed transient HDAVB seven days after transcathter closure of PMVSD and had recurrent HDAVB 42 months after the procedure.

Generation of a P19-alphaMHC-EGFP reporter line and cardiomyocyte differentiation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To generate a P19-alphaMHC-EGFP reporter line and induce cardiomyocyte differentiation of this reporter line.</p><p><b>METHODS</b>The P19 cells were transfected with palphaMHC-EGFP, a P19-alphaMHC-EGFP reporter line was obtained after G418 selection and limited dilution of recombinant clones. The reporter line was induced to differentiate into cardiomyocytes which would beat and express green fluorescent protein. A comparison of cardiomyocyte differentiation rate and cTnI expression amount between the reporter line and the untransfected P19 cells was also performed. The ultrastructure was observed under transmission electron microscope.</p><p><b>RESULTS</b>The ultrastructure characteristics indicated cardiomyocytes-like changes on induction day 10. The beating cardiomyocytes which express GFP appear in the seventh induction day. The cardiomyocyte differentiation rate and cTnI expression amount of P19-alphaMHC-EGFP reporter line were similar as those in untransfected P19 cells (P > 0.05).</p><p><b>CONCLUSION</b>The P19-alphaMHC-EGFP reporter line is of great benefit for identifying and purifying cardiomyocytes from undifferentiated P19 cells without influencing the differentiation of P19 cells. This feature makes P19-alphaMHC-EGFP reporter line a promising cell source for clinical cardiomyocyte replacement therapy.</p>

Expression of HCK Gene in Cardiomyocyte Differentiation of Mouse Embryonic Stem Cells / 实用儿科临床杂志

Objective To explore the expression of HCK gene during the cardiomyocyte differentiation of mouse embryonic stem cells and analyze the role of HCK gene in maintenance of pluripotency of embryonic stem cells.Methods Mouse embryonic stem cells were cultured,then induced to differentiate into cardiomyocytes.Total RNAs were isolated from mouse embryonic stem cells in the differentiation days:0 day(D0),the second day(D2),the fourth day(D4),the sixth day(D6),the eighth day(D8),respectively.The levels of HCK mRNAs were assessed by the method of semi-quantitive reverse transcriptase-polymerase chain reaction(RT-PCR).In the meanwhile,Total proteins were also isolated from mouse embryonic stem cells in the differentiation D0,D2,D4,D6,D8,and the levels of HCK proteins were evaluated by Western-blot.Results HCK mRNAs could be detected in the mouse embryonic stem cells in D0 and D2,however,they were undetectable from D4 to D8.The expression of HCK mRNAs was rapidly down-regulated during cardiomyocyte differentiation of mouse embryonic stem cells.Expression of HCK proteins,which coincided with HCK mRNAs,down-regulated during differentiation and couldn't be detected in D4.Conclusions With the cardiomyocyte differentiation of mouse embryonic stem cells,the expression of HCK in the levels of mRNA and proteins are sharply down-regulated;HCK may play an important role in maintaining the pluripotency of embryonic stem cell.