Effect of different cardioprotective methods on extracorporeal circulation in fetal sheep: a randomized controlled trial.

BACKGROUND: Congenital heart disease is a leading cause of death in newborns and infants. The feasibility of fetal cardiac surgery is linked to extracorporeal circulation (ECC); therefore, cardioplegic solutions need to be effective and long-lasting. METHODS: Eighteen pregnant sheep were divided into an ECC-only group, St. Thomas' Hospital cardioplegic solution (STH1) group (STH group), and HTK preservation solution (Custodiol®) group (HTK group). Markers of myocardial injury including troponin I (cTnI), troponin T (cTnT) and creatine kinase myocardial band (CKMB) were measured at specific time points (T1: pre-ECC, T2: 30 min of ECC, T3: 60 min of ECC, T4: 60 min post-ECC, T5: 120 min post-ECC). Myocardial tissue was removed from the fetal sheep at T5, and apoptosis was detected by TUNEL staining. RESULTS: Changes in the serum cTnI, cTnT and CKMB concentrations were not significantly different among the three groups before and during the ECC(T1,T2,T3). At 60 min after ECC shutdown(T4), cTnI and cTnT concentrations were significantly higher in the STH group than before the start of ECC. The concentration of cTnI was higher in the STH group than in the HTK and ECC-only groups. The concentration of cTnT was higher in the STH group than in the ECC-only group. At 120 min after ECC shutdown(T5), cTnI and cTnT concentrations were significantly higher in the ECC and HTK groups than before the start of ECC, and CKMB concentration was significantly higher in STH and HTK groups. The concentrations of cTnT, cTnI and CKMB was higher in the STH group than in the HTK and ECC-only groups. The number of TUNEL-positive cells in the HTK and STH groups was higher than in the ECC-only group. The number of TUNEL-positive cells in the STH group was higher than in the HTK group. There was no statistically significant difference among the groups in the heart rate and mean arterial pressure after ECC. CONCLUSION: The HTK preservation solution was significantly better than STH1 in reducing the release of cardiomyocyte injury markers and the number of apoptotic cells in fetal sheep ECC. Fetal sheep receiving ECC-only had an advantage in all indicators, which suggests ECC-only fetal heart surgery is feasible.

[Progress and application prospect of pig induced pluripotent stem cells].

Pig has always been the focus of establishing a big ungulate animal ES cell lines because of its convenient source, genetic similarity with humans, and their importance in animal husbandry, but little development is achieved. Induced pluripotent stem cells technology creates a new method of reprogramming somatic cells to pluripotent state. As the pig iPS cells is established and perfected, pig ES cells will be established in the coming years. The pig iPS cells will give a hint on other livestock ES cells. On the other hand, pig iPS cells can be used to improve the efficiency of transgenic cloning pigs to conduct effective breeding and conservation of breeds. It is particularly important that the pig iPS cells can provide new model for human medical research, a new donor cells for human tissue and organ engineering, and have extensive and far-reaching impact on the biomedical field. Here, we briefly review the major progress of iPS cells, and emphasize current state of pig iPS cells and its application prospect in biomedicine and animal husbandry in order to provide a useful reference for researchers working in this area.