BACKGROUND: Differentiation of embryonic stem (ES) cells into cardiomyocytes in vitro has been studied in great detail in the world. However, much of what is currently known about cardiomyocyte differentiation from ES cells has been learned from studies on mouse in China, few studies are on human ES cells.OB JECTIVE: To investigate the differentiation effcacy of human ES cells into functional cardiomycytes with the human H14 ES cell line.DESIGN: Suspending method was used to form pseudo-embryo proper of human ES cells so as to observe ratio of pseudo-embryo proper with rhythmic contraction and expression of specific gene of myocardium in various differentiated phases.SETTING: Molecular Biology Laboratory of Stanley Ho Center for Emerging Infectious Diseases, School of Public Health, the Chinese University of Hong Kong.MATERIALS: Human ES cell line H14 was obtained from WiCell Research Institute (Wisconsin, USA) with a license agreement.METHODS: The experiments were carried out in the Molecular Biology Laboratory of Stanley Ho Center for Emerging Infectious Diseases, School of Public Health, the Chinese University of Hong Kong from August to December of 2006.The H14 ES cell colony was used to form embryoid bodies (EBs) by using suspending method. Four days later,pseudo-embryo proper was cultured in gelatin-coating 6-well culture plate (5-10 embryo proper/well) and spontaneously differentiated into moving pseudo-embryo proper. Rhythmic contraction was observed under microscope and RT-PCR was used to detect expression of special genes of myocardium.MAIN OUTCOME MEASURES: Ratio of pseudo-embryo proper with rhythmic contraction and expression of specific gene of myocardium in various differentiated phasesRESULTS: Spontaneously contracting cells appeared as cluster and were identified in approximately 2% of EBs at differentiation day 8 and increased to as many as 10% of the EBs by day 16. The beating rate of contracting cells arranged at 70-100 beats per minute. RT-PCR analyses demonstrated that cells isolated from spontaneous beating areas within the EB expressed the cardiac transcription factors GATA-4 and Nkx2.5, cardiac progenitor gene Isl-1 and cardiomyocyte marker gene α-MHC.CONCLUSION: This is the first time to report human ES cells can effectively differentiate into functional cardiomyocytes in China.

Objective:To investigate the protective effects and possible mechanisms of cortex phellodendri water extract and etha -nol extract on the myocardial injury induced by pituitrin and isoproterenol hydrochloride in rats .Methods:SD rats as the experimental animals were randomly divided into the normal control group , model group , compound Danshen tablets group , phellodendron water ex-tract group and phellodendron ethanol extract group .Pituitrin and isopropyl adrenaline hydrochloride were used to establish the myocar-dial injury model in rats.The serum CK, LDH activity, myocardial tissue SOD activity and MDA content were detected and compared . Results:Compared with those in the normal control group , the serum LDH activity , CK activity and MDA content were significantly in-creased , and the SOD activity in cardiac muscle and myocardial tissue was significantly decreased in the pituitrin -established myocardi-al injury model group (P<0.01).In the isopropyl adrenaline hydrochloride-established myocardial injury model group , the MDA con-tent in myocardial tissue was obviously increased , and the SOD activity in myocardial tissue was decreased obviously (P<0.01).The serum LDH activity, CK activity and MDA content were significantly decreased , and the SOD activity in cardiac muscle and myocardial tissue was increased significantly in all drug-taken groups when compared with those in the pituitrin-established myocardial injury model group, and the differences were statistically significant (P<0.05 or P<0.01).The MDA content in myocardial tissue was significant-ly reduced , and the SOD activity was increased significantly in all drug-taken groups when compared with those in the isopropyl adrena-line hydrochloride-established myocardial injury model group , and the differences were statistically significant (P<0.05 or P<0.01). Conclusion:Cortex phellodendri extract has certain protective effect on myocardial injury induced by pituitrin and isopropyl adrenaline hydrochloride in rats .

Objective:To investigate the kinetic metrics of 68Ga-fibroblast activation protein inhibitor (FAPI)-04 in pancreatic cancers and normal organs by using total-body PET dynamic imaging. Methods:From December 2020 to December 2021, 68Ga-FAPI-04 total-body PET/CT dynamic imaging were performed on 6 pancreatic cancer patients (3 males, 3 females, median age 55.5 years) in Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University. Images were respectively analyzed. Manual delineations of volume of interests (VOIs) on multiple normal organs and pathological lesions were performed and time-to-activity curves (TACs) were generated. A reversible two-tissue compartment model (2TCM) was fitted for each tissue TAC. Rate constants including K1, k2, k3 and k4, and the total volume of distribution ( Vt) were obtained and compared by tissue types. Wilcoxon rank sum test and Spearman correlation analysis were used for data analysis. Results:Kinetic metrics varied significantly among normal organs and pancreatic cancer lesions ( z values: 2.00-1 240.00, all P<0.05). The highest K1 among lesions was observed in primary tumor (0.30 min -1), which was observed in the spleen (1.42 min -1) among normal organs. The highest k2 among lesions was observed in peritoneal metastases (0.24 min -1), which was observed in the spleen (2.59 min -1) among normal organs. Primary tumor showed the highest k3 of 0.17 min -1 among lesions, and the pancreas had the highest k3 of 0.16 min -1 among normal organs. Primary tumor had the highest k4 of 0.03 min -1 among lesions, and the heart, lungs, parotid glands had high k4(0.06 min -1) among normal organs. Vt were higher in pathological lesions compared to normal organs, with the highest in primary tumor (13.78 ml/cm 3). There were correlations between Vt in lesions and SUV mean( rs=0.86, P<0.001) or SUV max ( rs=0.77, P<0.001). Conclusion:The rate constants including K1, k2, k3 and k4, and Vt of 68Ga-FAPI-04 vary among normal organs and lesions.