Initial large-dose administration of modified St. Thomas' solution.

BACKGROUND: We introduced an initial large dose of modified St. Thomas' Hospital cardioplegic solution with the aim of providing both myocardial protection as well as a smooth intraoperative process. METHODS: In 90 cases of isolated aortic valve replacement, we used the modified technique of cardioplegia in 45 (group S) and conventional administration of glucose-insulin-potassium solution in 45 (group G). The patients were selected at random. In group S, we added 4 mEq of potassium to the original St. Thomas' Hospital solution and administered 30 mL·kg(-1) as an initial dose. The temperature was decreased to 2. RESULTS: The mean of reperfusion time after declamping in group S was significantly shorter (16.7 ± 6.4 vs. 21.5 ± 10.0 min; p = 0.007). The average of postoperative maximum creatine kinase-MB was significantly lower in group S (25.6 ± 9.5 vs. 40.6 ± 37.2 IU·L(-1); p = 0.014). On multivariate analysis, use of the modified cardioplegia and aortic crossclamp time were significantly associated with creatine kinase-MB level and reperfusion time after declamping. CONCLUSIONS: This modified technique was an acceptable option that provided a bloodless operative field and avoided multiple cardioplegic administrations.

Maintenance of cold-preserved porcine hepatocyte function with UW solution and ascorbic acid-2 glucoside.

Normal human hepatocytes are an ideal source of liver-targeted cell therapies, such as hepatocyte transplantation and bioartificial livers, but availability of human donor livers for liver cell isolation is severely limited. To effectively utilize scarce donor organs for cell therapies, it is of extreme importance to establish an efficient isolation technique and an effective cold preservation solution for transportation of isolated cells. A lateral segment of the liver was surgically resected from pigs weighing 10 kg and a four-step collagenase and dispase digestion was conducted. Isolated hepatocytes were subjected to 8-h cold storage on ice. The following preservation solutions were tested: 1) University of Wisconsin (UW) solution, 2) UW with 100 microg/ml of ascorbic acid-2 glucoside (AA2G), 3) 100% fetal bovine serum (FBS), and 4) Dulbecco's modified Eagle's medium (DMEM) supplemented with 100% FBS. The mean viability of porcine hepatocytes was 95.5 +/- 2.5% when isolated in three independent experiments. Viability, plating efficiency, membrane stability, and ammonia metabolic capacity of cold-preserved hepatocytes were significantly better maintained by the use of UW solution. When AA2G (100 microg/ml) was combined with UW solution, such parameters were further improved. It was explained by inhibition of caspase-3 activation and retention of ATP at high levels of hepatocytes preserved with UW solution containing AA2G. The present work demonstrates that a combination of UW solution with AA2G (100 microg/ml) would be a useful cold preservation means for the development of cell therapies.