Clinical analysis of post pancreatoduodenectomy hemorrhage / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the factors of post pancreatoduodenectomy hemorrhage.</p><p><b>METHODS</b>The clinical data of 263 cases between January 1998 and April 2008 underwent pancreatoduodenectomy were analyzed prospectively.</p><p><b>RESULTS</b>The overall mortality rate was 4.94% (13/263). Postoperative bleeding occurred in 23 patients (8.75%), with 8 episodes ending fatally (34.8%). The tumor size, Child classification, caput total resection and pancreatic leakage were identified as significant risk factors for post pancreatoduodenectomy hemorrhage by means of univariate analysis. The multivariate Logistic regression analysis revealed that all of the five factors turned out to be the independent risk factors.</p><p><b>CONCLUSIONS</b>The prevention of these bleeding complications depends in the first place on meticulous hemostatic technique. The pancreatic leakage is also one of the most important factors due to postoperative bleeding. The prophylactic use of somatostatin is not necessary.</p>

Study on production of acrylamide by microbial method (I)--Culture of bacterium cells and expression of high activity of nitrile hydratase / 生物工程学报

The cultural conditions for the growth of Norcardia cell were studied in this paper. Controlling pH value, adding nutrient and optimizing the quantity of inducer during cultivation, the activity of nitrile hydratase reached 6567 u/mL (culture medium), which was the highest value appeared in native journals. In the farther hydratase experiments, no by-product, crylic acid, was detected. It showed that the activity of amidase was not promoted obviously while the activity of nitrile hydratase was increased greatly. The results set a strong foundation for the industrial application and the research on new technology.

Study on production of acrylamide by microbial method (II)--enzyme catalytic kinetics and de-active dynamics of nitrile hydratase / 生物工程学报

The hydration reaction by microbial method is the crisis of the procedure of acrylamide production from acrylonitrile. This research studied the enzyme catalytic kinetics and de-active kinetics of nitrile hydratase in the type of free cell. Firstly, the effects of the concentration of cells, the temperature, pH value, the concentration of acrylonitrile and the concentration of acrylamide on the activity of nitrile hydratase was investigated. The result is that the temperature and the concentration of acrylamide are the most important among these factors. The activity of the nitrile hydratase was 5659 u/mL (broth) at 28 degrees C; the counterpart was only 663 u/mL (broth) at 5 degrees C. And the activity of NHase in solution of 45% acrylamide was just about half of that in solution of 5% acrylamide. After study on the relation of temperature and the reaction speed, It was found that the activation energy of the hydration of NHase was 65.57 kJ.mol-1. This paper studied the effects of concentration of cells, temperature, pH value, concentrations of acrylonitrile and acrylamide on the deactivation of Nhase, as well as the related enzyme de-active kinetics. The result also showed that the temperature and the concentration of acrylamide are the most important among these factors. In solution of 35% acrylamide, the residual activity was about 0% of the original value after 55 h; but in solution of 10% acrylamide, after the same period of time, the residual activity was 50% of the original one. It was also found that the concentration of acrylonitrile had little effect on the stability of NHase. The coefficient of deactivation at 28 degrees C was 21.77 times of the one at 5 degrees C. Correlating the temperature and the coefficient of deactivation, the activation energy of the de-active reaction was found to be 92.28 kJ.mol-1.