Comparison of central venous oxygen saturation and mixed venous oxygen saturation during liver transplantation.

Central venous catheterisation is commonly performed during major surgery and intensive care, and it would be useful if central venous oxygen saturation could function as a surrogate for mixed venous oxygen saturation. We studied 50 patients undergoing living related liver transplantation. Blood samples were taken simultaneously from central venous and pulmonary artery catheters at nine time points during the pre-anhepatic, anhepatic, and postanhepatic phases. Four hundred and fifty sets of measurement were obtained. There was a good correlation between central venous oxygen saturation and mixed venous oxygen saturation. The mean (SD) difference (95% limit of agreement) was lowest at the first time point (1.06 (0.65)%, -1.94% to 2.7%) and then increased throughout the study but remained acceptable. The change in mixed venous oxygen and central venous oxygen saturations occurred mostly in parallel and as a result changes in mixed venous oxygen saturation were reflected adequately in the change in central venous oxygen saturation. The correlation between mixed venous oxygen saturation and cardiac output was poor.

Optimization of cultural conditions for thermostable beta-1,3-1,4-glucanase production by Bacillus subtilis ZJF-1A5.

The optimization of cultural conditions for Beta-glucanase production by Bacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on Beta-glucanase production which maximized at optimal temperature of 37 degrees C and decreased significantly when temperature was over 37 degrees C. Charge quantity affected Beta-glucanase production significantly. Adding oxygen vector N-dodecane or acetic ether benefited Beta-glucanase production, but it depended on the concentration and charge quantity. The results of fractional factorial design showed that age and size of inoculum and shaking speed were the key factors affecting Beta-glucanase production and the cultivation time span to reach the highest Beta-glucanase activity. The optimal cultural conditions for Beta-glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82%(v/v)), shaking speed 210 r/min, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37 degrees C for 50 h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of Beta-glucanase, Alpha-amylase and neutral protease produced by B subtilis ZJF-1A5 was associated partially with cell growth. Those three enzymes' activities increased following the cell growth and increased significantly when cells entered the stationary phase.