Objective To explore the relevant factors of hypotension in the patients applied hemodialysis.Methods 45 patients who had intradialytic hypotension in our dialysis room were selected for the analysis.Results The patients with diabetic nephropathy,the elderly,high temperature,hyponatremia,higher ultrafiltration volume,stepwise ultrafihration and the constant ultrafihration showed higher incidence of hypotension during hemodialysis(x2 =9.87,81.22,171.02,130.12,all P ＜0.01).Conclusion The primary disease,age of the patient,uhrafiltration volume,temperature,sodium concentration and the ultrafiltration are all the relevant factors for intradialytic hypotension

BACKGROUND: Axial-flow blood pump is a main pump for ventricle assistance. Previous researches demonstrate that poor hemocompatibility of blood pump is an important factor for hemolysis and thrombus.OBJ ECTTVE: To design an axial-flow blood pump based on previous kinds of blood pumps through changing whole appearance and impeller shape of the pump by using Computer-Aided Design CAD) and Computational Fluid Dynamics (CFD), and manufacture it successfully.DESIGN: Rationality of theoretical design was verified by practical tests.SETTTNG: Beijing Anzhen Hospital of Capital University of Medical Sciences Department of Biomedical Engineering,Beijing Institute of Heart, lung and Blood Vessel Diseases; the Faurteenth Institute of China-Aerospace Science and Industry Corporation.MATERIALS: Body of blood pump and impeller were titanium alligation, and shaft bearing was ceramic. Test in vitro was accorded to artificial ventricular assist device which was provided by Department of Biomedical Engineering, Beijing Anzhen Hospital of Capital University of Medical Sciences. Experimental goats were provided by Experimental Animal Center, Beijing Anzhen Hospital of Capital University of Medical Sciences.METHODS: Since the beginning of 2005, a model of axial flow blood pump was designed in the 14th Institute of China-Aerospace Science and Industry Corporation base on decreasing shearing force and circulating dead bands. In the process, CAD and CFD were used to generate the geometrical data document of pump's structure, which included the figures of pump's body, shape and number of impeller's vanes, the structure and position of the guide vanes, and the size of impeller's screw-pitch. And then, NC machine tool was used for shaping. Finally, axial-flow blood pump was fixed on artificial ventricular assist device which was provided by Department of Biomedical Engineering, Beijing Anzhen Hospital of Capital University of Medical Sciences. The pump's hemodynamic output was 5 L/min and the average pressure was 13.3 kPa under the mixture of glycerin and water and fresh anticoagulation goat blood. The samples were collected at every one half hour during pumps being pumping for 4 hours. According to testing pressure output of blood pump, normalized index of hemolysis (NIH) was used to reflect content of free hemoglobin in plasma, observe thrombogenesis in pump and verify pump's hemodynamic output and vascular damaging degree.RESULTS: Shaped axial-flow blood pump included body, impeller, guide vanes, ceramic shaft bearing, export and import. The volume was 63 mL. Experimental results in vitro indicated that when the rotation speed of blood pump was 10 000 r/min, its pressure and flow output were 21.01 kPa and 6.0 L/min. The hemodynamic output might satisfy for left ventricular assistance. Surface temperature did not change obviously during successive rotation. The calculation indicated that most parts in blood pump showed a streaming flow. The mean NIH was (0.047±0.017) g/100 L, which was less than that of previous pumps; while, thrombogenesis was not observed in blood pump.CONCLUSTON: Axial-flow blood pump designed by using CAD and CFD can not only satisfy for the hemodynamics of a left ventricular assistant devices, but also the blood damage is milder than previous pumps. Therefore, axial-flow blood pump improves blood compatibility.

Objective To analyse the relationship between catechol-O-methyltransferase (COMT) activity and affective disorders, and explore the biological mechanism of the etiology of affective disorders.Methods The activities of erythrocytes COMT from 112 affective disorders and 120 normal control were measured with high performance liquid chromatography, all examined data were tested by SPSS 11.0v.Results COMT activity frequency distribution of patients group and control group are at the range of 2～23nmol/ml RBC/hr and 7～28nmol/ml RBC/hr respectively. The average activity of COMT in patients group and control group were (11.0±3.8) nmol/ml RBC/hr and (16.1±4.3) nmol/ml RBC/hr representatively. COMT activity in male and female patient were (11.2±3.7) nmol/ml RBC/hr and (10.6± 4.0) nmol/ml RBC/hr., male and female in control group were (16.5 ±4.6) nmol/ml RBC/hr and (15.4±3.9) nmol/ml RBC/hr, there were significant difference between patients group and control group and also between male and female (P <0.001).conclusion The activity of erythrocytes COMT in affective disorders is lower than normal population and suggested that the lower COMT activity of erythrocytes is associated with affective disorders.