The silver doped poly ( L-lysine ) modified glassy carbon electrode was fabricated by cyclic voltammetry, the surface of the electrode was characterized by scanning electron microscopy and electrochemical impedance spectroscopy. The electrochemical behaviors and the simultaneous detection of xanthine and uric acid were studied by cyclic voltammetry and differential pulse voltammetry. The results indicated that this modified electrode exhibited excellent electrocatalytic activity towards the oxidation of xanthine and uric acid. The stable oxidation peaks of xanthine and uric acid appeared with the peak potential of 0. 980V and 0. 600V respectively at the modified electrode in pH 3. 0 phosphate buffer solution. The oxidation peaks of xanthine and uric acid were separated at 380 mV. Under the optimum conditions, the linear ranges for the determination of xanthine and uric acid were 1 . 00 × 10-6-2 . 50 × 10-4 mol/L respectively by differential pulse voltammetry. The detection limits were 5. 0×10-7mol/L. The method has been applied to the simultaneous detection of xanthine and uric acid in healthy human urine with satisfactory results.

The silver doped poly(L-aspartic acid) modified electrode was prepared by cyclic voltammetric method. The voltammetric behavior of dopamine and cyclic voltammetric method for the determination of dopamine were studied on the silver doped poly(L-aspartic acid) modified electrode. In pH 7.0 phosphate buffer solution, the peak potential was 0.191 V of Epa and 0.161 V of Epc(vs.Ag/AgCl) at the scan rate of 50 mV/s. The linear ranges for the determination of dopamine were 3.0×10-7-1.0×10-5 mol/L and 1.0×10-5-5.0×10-4 mol/L. The detection limit was 5.0×10-8 mol/L. The method was applied to the determination of dopamine in drug and urine with satisfactory results.

Objective To evaluate the efficacy and feasibility of Flu/ivBu/Tl" conditioning regimen for the treatment of refractory or relapsed acute non-lymphocytic leukemia in patients receiving allogeneic hematopoietie stem cell transplantation. Methods Seven patients with refractory or relapsed acute non-lymphocytic leukemia received HLA identical peripheral blood hematopoietie stem cell transplantation (PBSCT) following Flu/ivBu/TY conditioning regimen, which consisted of fludarbine, busulfex and thiotepa. All patients received cyclos-porin A (CsA) and mycophenolet mofetil (MMF) for prophylaxis of graft - versus - host disease (GVHD). Results The Flu/IVBu/TT regimen was tolerated very well, without severe regimen related toxicity. In the 31-month median follow-up duration, 5 of 7 patients were a-live in disease-free situation. Conclusion The Flu/ivBu/TT conditioning regimen reduced transplantation-related toxicities and offered high long-term disease-free survival, and was tolerated very well. Allogeneie hematopoietie stem cell transplantation using Flu/ivBu/TT condition-ing regimen is a safe and effective option for the patients with refractory/relapsed acute non-lymphocytic leukemia.

Objective To evaluate the efficacy of Flu/CTX conditioning regimen for the treatment of severe aplastic anemia in pa- tients receiving allogeneic hematopoietic stem cell transplantation. Methods Nine patients with severe aplastic anemia received HLA identi- cal peripheral blood hematopoietic stem cell transplantation (PBSCT) using Flu/CTX conditioning regimen, which consisted of fludarbine [30 mg/(m2 d) for5 days (-7 to -3) ], CTX [50mg/(kg d) for4 days(-5 to-2)]. All patients received cyclosporin A (CsA) and mycophenolet mofetil (MMF) for prophylaxis of graft-versus-host disease(GVHD). Results The Fiu/CTX regimen was very well toler- ated, with no severe regimen related toxicity. In all patients, the median days of neutrephil exceeding 0. 5×109/L and platelet exceeding 20 ×109/L were 12 days (range 10-16 days) and 16 days (range 14-19 days), respectively. Complete chimerism was achieved in all pa- tients at one month after PBSCT. Two patients had acute GVHD and one had chronic GVHD. In the 39-month median follow-up duration, all patients were alive in disease-free situation. Conclusion The Flu/CTX conditioning regimen may reduce transplantation-related toxicities and can achieve full chimerism and high long-term disease-free survival. Allogeneic hematopoietic stem cell transplantation using intravenous Fiu/CTX conditioning regimen is a safe and effective treatment method for the patients with severe aplastic anemia.

BACKGROUND: Magnetic field can affect the growth and division of cancer cells both in vivo and in vitro, however, the effects on apoptosis of human liver cancer cells induced by magnetic field is still unclear.OBJECTIVE: To explore the inducing effect of extremely low fre quency (ELF) magnetic field on apoptosis of human liver cancer cell SK-HEP- 1.JESIGN: An open experiment with cells as the observational subjects.SETTING: Institute of Biotechnology, Shanghai Jiaotong University.MATERIALS: The experiment was carried out at the Institute of Biotechnology, Shanghai Jiaotong University from September 2004 to January 2005. The subject was human liver cancer cell line SK-HEP-1, purchased from cell bank of Chinese Academy of Science, Shanghai.METHODS: SK-HEP-1 cells were inoculated to T-flasks at the density of 2.0×107 cells L-1, and cultivated in the DMEM containing 0.1 volume fraction of heat-inactivated fetal bovine serum and 2 mmol/L L-glutamine. Exposure groups were exposed to 50 Hz, 20 mT magnetic field and the control groups were run concurrently under the same conditions with the exposed cultures but in a separate incubator which was free of magnetic field during 8-day culture process. The apoptosis of SK-HEP-1 cells were defined by DNA ladder assay, Hoechst 33258 staining and AO/EB staining respectively on day 8.MAIN OUTCOME MEASURES: ① DNA fragmentation pattern formation. ② The abnormal nucleus formation. ③ The percentage of apoptotic cells.RESULTS: ① Detection of internucleosomal DNA fragmentation by DNA ladder assay: After 8-day ELF magnetic field exposure, DNA fragmentation pattern was detected by DNA ladder assay, which was not observed in control groups (free of exposure). ② Fluorescence microscopy analysis of apoptosis by Hoechst 33258 staining: Hoechst 33258 staining was used to investigate the changes in the nucleus of cells, and many apoptotic bodies containing nuclear fragments were found in ELF magnetic field exposed cells, but just about none in untreated cells. At the same time, cytoplasmic shrinkage was observed in cells cultured under the exposure. And in some cells, even the cell membrane was unable to keep intact. ③ Fluorescence microscopy analysis of cell apoptosis by acridine orange/ethidium bromide (AO/EB) double staining: After ELF magnetic field exposure, the percentage of viable cells in exposure groups (9.2%) was rather low compared with the control groups (91.8%), and was accompanied with a high apoptotic rate (72.3%), while only 4.2% in control group. A large number of apoptotic cells were at the early stage of apoptosis. The rate of apoptotic cells (18.5%)after treated by magnetic field was higher than that of control group (4%). With the AO/EB double staining, control cells appeared to be round,intact and bright green while some of the exposed cells exhibited irregular cell morphology and condensed nucleus.CONCLUSION: Apoptosis of human liver cancer cell SK-HEP-1 could be induced by 50 Hz, 20 mT magnetic field in vitro.