[Design, synthesis and biological evaluation of oxadiazole derivatives as xanthine oxidase inhibitors].

Xanthine oxidase (XO) is an important target for the treatment of hyperuricemia and gout. Based on the two known non-purine xanthine oxidase inhibitors, febuxostat and topiroxostat, 14 oxadiazole derivatives have been designed and synthesized. These compounds have been evaluated against XO and five of them exhibited significant inhibitory activities at the concentrations below 10 µmol·L(-1).

Discovery of novel non-covalent inhibitors selective to the ß5-subunit of the human 20S proteasome.

A series of linear peptides (6a-6o) were designed based on the known non-covalent 20S proteasome inhibitors TMC-95A and compound 5 via a fragment-based approach. These compounds were synthesized and evaluated against the chymotrypsin-like activity of the human 20S proteasome. Three of them (6d, 6e and 6k) were potent inhibitors with IC50 values at the submicromolar level. These three compounds were selective to the ß5-subunit and showed no obvious inhibition against trypsin-like and caspase-like activities of the human 20S proteasome. Docking study of the most potent compound 6e revealed its key interactions with the ß5-subunit of the 20S proteasome. These findings have provided a new chemical template for non-covalent proteasome inhibitors, which is ready for further structural optimization to improve both potency and subunit selectivity.

[Decrease of chronic graft-versus-host disease by adding anti-human thymocyte globulin to the conditioning regimen].

OBJECTIVE: To observe the influence of adding anti-human thymocyte globulin (ATG) into conditioning regimen on graft-versus-host disease (GVHD) and life quality of the patients of allo-peripheral blood stem cell transplantation (PBSCT). METHODS: Patients were distributed into study (19 cases) and control (24 cases) groups at random. Median dose of rabbit ATG was added to the conditioning regimen based on the fludara, busufan and cyclophosphamide (FBC) in study group, and no ATG in the control group. Acute and chronic GVHD disease and Karnofsky scores were compared between two groups after allo-PBSCT. RESULTS: The patients in the study group received a mean of 6.0 (3 - 9) x 10(8)/kg mononucleated cells and 5.5 (4.5 - 7.5) x 10(6)/kg in the control group. The mean CD(34)(+) cells number was 5.5 (3.0 - 6.5) x 10(5)/kg in the study and 5.0 (3.0 - 7.0) x 10(6)/kg in the control group respectively. Eighteen patients in the study group and in the control group were successfully engrafted. The mean time of absolute neutrophil count recovered more than 500/ micro l was 13 days and 12 days respectively. Acute GVHD occurred in 6 patients of the study group, and 15 of the control group. Seven patients suffered from chronic GVHD and 14 got 90 Kanrofsky scores in a mean of 250 days follow-up in the study group, and 19 patients GVHD and 4 patients respectively in a mean of 440 days follow-up in the control group. There was a significant difference for acute and chronic GVHD and life quality between the two groups. CONCLUSIONS: Addition of anti-thymocyte globulin to the FBC conditioning regimen had no effect on stem cells engraftment but could decrease acute and chronic GVHD and improve patients life quality.

[Treatment of refractory leukemia by combined chemotherapy and halpotype lymphocytes infusion].

BACKGROUND & OBJECTIVE: The complete remission of refractory leukemia treated with conventional chemotherapy is below 50 percent. The high dose chemotherapy can cause more mortality of patients with refractory leukemia. Cytolysis of leukemia cells induced by halpotype lymphocytes was observed in vitro in our previous experiment. In order to improve the complete remission of refractory leukemia and decrease the complication of chemotherapy,the authors treated the patients with refractory leukemia by combined chemotherapy and halpotype lymphocytes infusion and to assess the therapeutic effects and the side effects of this modality. METHODS: Sixteen patients with refractory leukemia were treated by combined chemotherapy. Halpotype lymphocytes irradiated by 7.5 Gygamma radial were infused when patient's white cells count was at the lowest after the chemotherapy. A mean number of 1x10(8)/kg (range:0.8-1.2x10(8)/kg) of halpotype lymphocytes irradiated by 7.5 Gygamma radial was infused. The side effects of infusion of halpotype lymphocyte and completed remission rate were observed. RESULTS: Out of thirteen patients with refractory acute non-lymphocyte leukemia, eleven cases got complete remission and two partial remissions. Out of three patients with refractory acute lymphocyte leukemia, two got complete remission and one no reaction. The total remission rate was 81.2%. No severe side effects and no transfusion related graft versus host disease was observed. CONCLUSION: The results show that chemotherapy combined with 7.5 Gy irradiated halpotype lymphocyte infusion could improve the complete remission of refractory leukemia and decrease the complications caused by chemotherapy.

[Treatment of malignant hematologic diseases by peripheral blood stem cell transplantation combined with halotype lymphocyte infusion].

In order to observe the curative and side effects in malignant hematologic diseases treated with autologous peripheral blood stem cell transplantation (auto-PBSCT) combined with halotype lymphocyte infusion, auto-PBSCs were mobilized, harvested and stored at -196 degrees C from patients in first CR or PR with intensive chemotherapy (Ara-C 1.0 g/m(2) x 5 days or cyclophosphamide 60 mg/kg x 2 days) and G-CSF. Unpurged auto-PBSCs were infused when patients received the conditioning regimen with busulfan, total irradiation or cyclophosphamide. Halotype lymphocytes [mean 5.0 x 10(7)/kg, (4.5 - 6.5) x 10(7)/kg] irradiated with 7.5 Gy were infused to patients when WBCs were more than 1 x 10(9)/L. Hematopoietic recovery and survival of patients were observed. The results showed that in 12 cases accepted this protocol, five patients with acute non-lymphocytic leukemia got to durable remission, of which 2 had durable remission of more than 50 months. One of three patients with non-Hodgkin's lymphoma IVb reached durable remission, and two relapsed and died on 4 and 6 months after treatment, respectively. Two CML patients were also achieved durable remission. One patient with multiple myeloma relapsed on 36 months later, but he still survived disease-free with treatment of thalidomide. In a follow-up survey of 25 months, the disease-free survival was 83%. No severe side effects were observed except platelet delayed recovery after halotype lymphocyte infusion. STR-PCR analysis showed that infused donor lymphocytes disappeared in 3 recipients at 72 hours after infusion. It is concluded that auto-PBSCT combined with halotype lymphocyte infusion could decrease the relapse of malignant hematologic diseases and improve the effect of auto-PBSCT. Recovery of platelet, however, could be delayed by halotype lymphocyte infusion.

In vitro culture of human bone marrow mesenchymal stem cell clonies and induced differentiation into neuron-like cells.

OBJECTIVE: To study the long-term in vitro culture of human bone marrow mesenchymal stem cells (hMSC) and their phenotypical and functional properties. METHODS: Adherent hMSC colonies were digested by 0.25% trypsin-EDTA with a clone cycle for in vitro subculture. Flow cytometry was employed to examine the phenotypes of the cells. Their committed differentiation potential to neurons, clone-forming ability and growth curves were all investigated. RESULTS: hMSCs could be subcultured under this culture condition for 20 passages, expressing CD13, CD29 and CD59 but not CD11, CD14, CD31, CD34, CD45, CD80, CD86, CD117 and HLA-DR. The cells could be induced to differentiate into neurons when subcultured for 17 passages. CONCLUSION: hMSCs can be efficiently expanded under this culture condition, and the colony-derived hMSCs can maintain the differentiation potentials and retain their biological characteristics.