OBJECTIVE:To establish a method for the determination of the content and molar ratio of Ornithine aspartate for in-jection. METHODS:HPLC was performed on the column of Thermo HYPERSIL Aps-2 amino column with mobile phase of aceto-nitrile-0.05mol/L Potassium dihydrogen phosphate solution,the flow rate was 0.9 ml/min,the column temperature was 30℃,the de-tection wavelength was 200 nm,and the injection volume of 20 μl. The results determined by HPLC and potentiometric titration were compared. RESULTS:The linear range of ornithine aspartate was 0.02-10.01 mg/ml(r=0.999 9);RSDs of precision,stabili-ty and reproducibility tests were lower than 2%;recovery was 99.15%-100.15%(RSD=0.35%,n=9). The content of 3 batches of Ornithine aspartate for injection was 100.04%-100.64% and molar ratio was 0.982-0.989. The content is similar to the results de-termined by potentiometric titration with national standards. CONCLUSIONS:The method is simple,accurate,specific and sensi-tive,and suitable for the determination of the content and molar ratio of Ornithine aspartate for injection.

BACKGROUND: Cellulose is natural material, which has good chemical stability and biocompatibility. The modified material from cellulose has new properties besides its inherent properties.OBJECTIVE: Based on cytocompatibility evaluation tests, this study is designed to evaluate the cytocompatibiUty of materials synthesized from cellulose to make sure its reliability.DESIGN: Contrast study.SETTING: Department of High Polymer, Material Science and Engineering College, Beijing University of Technology.MATERIALS: This study was performed in the Material Science and Engineering College, Beijing University of Technology between March 2003 and June 2004. The material from cellulose prepared by Beijing University of Technology was white, granules, no taste, and no volatilization (density: 1.2 g/cm3, pH: 6-7). L-929 vigorous cells were provided by Chinese Military Academy of Medical Science. Ten male New Zealand rabbits were provided by Animal Center of Chinese Military Academy of Medical Science.METHODS: Based on GB/T16175-1996 standard, cytotoxicity of the materials from cellulose on L-929 cells was evaluated by growth suppression technique (MTr chromatometry). In addition, based on GB-T14233.2-1993 standard, hemolysis in vitro was evaluated through measuring erythrocyte lysis and ferrohemoglobin freeing degree with indirect contact method.MAIN OUTCOME MEASURES: Cytotoxicity test and hemolysis test.RESULTS: Cytotoxicity test showed that the materials from cellulose did not have obvious toxicity on L-929 cells, and the cytotoxicity graduation of the materials from cellulose was 1 or 0. Hemolysis test suggested that the materials from cellulose did not have obvious hemolysis reaction, and the hemolysis rate in vitro was 1.5 %, which was less than the national standard (5%).CONCLUSION: The materials from cellulose do not have obvious cytotoxicity but have great cytocompatibility.

Objective To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio (RVv/LVv) measured by chest CT with pulmonary arterial pressure estimated by echocardiography before lung transplantation.Methods We reviewed 104 cases of lung transplant.According to the mean pulmonary arterial pressure (mPAP) exceeding 25 mmHg by right heart catheterization,hypertensive group (n =74) and normotensive group (n =30) were set up.Risk factors were assessed individually and adjusted for confounding by a multivariable logistic regression analysis.The area under the curve (AUC) for predicting pulmonary hypertension on chest CT and echocardiography was calculated.Results RVv/LVv and echocardiography-derived ptlmonary arterial systolic pressure (PASP) were significantly different between the two groups (P ＜ 0.05).In the hypertensive group,there was strong correlation between the RVv/LVv and PASP from catheterization (R =0.82,P＜0.001),also between the P ASP from echocardiography and catheterization (R =0.60,P＜ 0.001).The ROC curve displayed that with 0.85 as the cutoff for RVv/LVv,the sensmitivity,specificity and accuracy rate for predicting mPAP over 25 mmHg were 87.5％,91.8％ and 90.9％,respectively.The ROC curve also displayed that based upon an echocardiography-derived PASP of 35 mmHg as the cutoff point,the sensitivity,specificity and accuracy rate for predicting mPAP over 25 mmHg were 91.2％,90.8％ and 88.4％,respectively.Conclusion RV/LV volume ratios on chest CT and echocardiographic evaluation correlate well with PASP assessed by right heart catheterization and can be used to predict pulmonary hypertension with high sensitivity and specificity.