Septation of the Intrapericardial Arterial Trunks in the Early Human Embryonic Heart / 中华医学杂志(英文版)

<p><b>Background</b>Outflow tract (OFT) septation defects are a common cause of congenital heart disease. Numerous studies have focused on the septation mechanism of the OFT, but have reported inconsistent conclusions. This study, therefore, aimed to investigate the septation of the aortic sac and the OFT in the early embryonic human heart.</p><p><b>Methods</b>Serial sections of 27 human embryonic hearts from Carnegie stage (CS) 10 to CS19 were immunohistochemically stained with antibodies against α-smooth muscle actin (α-SMA) and myosin heavy chain.</p><p><b>Results</b>At CS10-CS11, the OFT wall was an exclusively myocardial structure that was continuous with the aortic sac at the margin of the pericardial cavity. From CS13 onward, the OFT was divided into nonmyocardial and myocardial portions. The cushion formed gradually, and its distal border with the OFT myocardium was consistently maintained. The aortic sac between the fourth and sixth aortic arch arteries was degenerated. At CS16, the α-SMA-positive aortopulmonary septum formed and fused with the two OFT cushions, thus septating the nonmyocardial portion of the OFT into two arteries. At this stage, the cushions were not fused. At CS19, the bilateral cushions were fused to septate the myocardial portion of the OFT.</p><p><b>Conclusions</b>Data suggest that the OFT cushion is formed before the aortopulmonary septum is formed. Thus, the OFT cushion is not derived from the aortopulmonary septum. In addition, the nonmyocardial part of the OFT is septated into the aorta and pulmonary trunk by the aortopulmonary septum, while the main part of the cushion fuses and septates the myocardial portion of the OFT.</p>

THE EXPRESSION OF HOMOCYSTEINE INDUCED GENE IN NORMAL AND ABNORMAL HUMAN EMBRYONIC HEART / 解剖学报

Objective To study the expression of homocysteine induced gene(HCY-2) in the normal and abnormal human embryonic heart. To research the roles of HCY-2 expressing protein in the human embryonic ventricular myocardial cell development and differentiation. Methods Immunohistochemistry and the technique of picture assay were used to detect HCY-2 expression in the normal and abnormal human embryonic heart. Results HCY-2 expresses during the development of human embryonic heart and mainly in the myocardial cells.The expression increases in the congenital malformation.Conclusion HCY-2 expression protein affects the development of human embryonic heart through affecting the myocardial cells proliferation and the abnormal expression has close relation to the congenital malformation.