BACKGROUND:There are many studies concerning rat bone marrow mesenchymal stem cells for immune tolerance following transplantation and tissue repair.However,there are no reports on umbilical cord mesenchymal stem cells(UCMSCs).OBJECTIVE:To establish a method of separating mesenchymal stem cells(MSCs)from rat umbilical cord,and to study its biological characteristics.METHODS:MSCs were separated from rat umbilical cord with enzyme method and tissue mass method,and then incubated in DMEM-LG medium.Cell morphology was observed under an inverted microscope.Growth curves of cells were drawn using cell counting.Cell cycle and surface antigen were detected with flow cytometry.Adipogenic differentiation and osteogenic differentiation were tested by immunohistochemistry.RESULTS AND CONCLUSION:Both of the two methods could obtain plenty of MSCs from rat umbilical cord.Primary culture showed that the efficiency of enzyme method was higher than tissue mass method.Passage time of the former was about 10 days and the latter was 14 days.The passage time of latter except primary culture was the same.Immunophenotype analysis showed that MSCs from rat umbilical cord expressed adhesion molecule and stromal cell markers,CD90 and CD106,but did not express hematopoietic cell markers,CD34 and CD45.In vitro induction test verified that rat UCMSCs have the potentials of adipogenic and osteogenic differentiation.

Objective To study the therapeutic effects of Bizhi pills in mycobacterium tuberculosis infection.Methods KunMing mice were infected by intratail-vein injection with mycobacterium tuberculosis H37Rv, then treated with saline(A)or Rifampin(B) or Bizhi pills(C).The lungs,hvers and spleens were taken to observe their pathological changes,weighted and performed mycobacterial culture after 4 months of treatment.Results After 4 months of treatment, indexes of the lung in group C were markedly lower than that in group A (P＜0.05),but higher than that in group B,although the differences were not significant.The lesion of lung in group C were similar as that in group B,and were lessen than that in group A.No obvious lesion of lung was observed in 8 mice of group B and C,but the differences were not significant.Swell of spleen was observed in 9 mice in group A,2 mice in group B and5 mice in group C,the differences were significant(P＜0.01).The numbers of bacteria in the lung and spleen of the female mice of C group were remarkably less than that in group A, and decreased 4 times and 10 times respectively compared with group A(P＜0.01),the numbers of bacteria in the lung and spleen of the male mice of C group were less than that in group A, and decreased 3 times and 2 times respectively.However,the numbers of bacteria in the lung and spleen of the male mice of B group was decreased 14 times and 7 times respectively(P＜0.01).Conclusions The therapeutic efficacy of Bizhi pills in mice with mycobacterium tuberculosis infection is significant, but it is not as good as Rifampin.The therapeutic efficacy of Bizhi pills in female mice of mycobacterium tuberculosis infection is better than that in male mice.

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) can prolong the survival time of mice and baboons' alloskin graft and degrade acute and chronic graft-versus-host disease (GVHD) incidence after hematopoietic stem cell transplantation. But, at present there is no report that rat umbilical cord mesenchymal stem cells (UC-MSCs) reduced rejection response following heart transplantation. OBJECTIVE: To study the immunomodulatory effects of rat UC-MSCs on a model of allogeneic heart transplantation. METHODS: A total of 20 DA rats served as donors, and 20 Lewis rats as recipients. They were equally and randomly assigned to 2 groups: drug intervention and control groups (n=10). Using double cannulation, the left pulmonary artery and innominate artery of rat donors and external jugular vein and common carotid artery of rat recipients received end-to-end anastomosis under a microscope to establish heterotopic cardiac transplantation. One Wistar pregnant rat was selected to harvest UC-MSCs by collagenase digestion method. Following model establishment, rats in the cell transplantation group received UC-MSCs via caudal vein. Rats in the control group received sodium chloride. Survival time of the transplanted heart was determined. The transplanted heart received histopathology score using the acute rejection diagnosis criteria. Lymphocyte infiltration of transplanted heart was observed using hematoxylin-eosin staining. RESULTS AND CONCLUSION: Compared with the control group, the survival time of the transplanted heart was significantly longer in the cell transplantation group (P = 0.001), and the pathological score of acute rejection was significantly reduced (P = 0.000 4). There were lots of lymphocyte and monocyte infiltration in the myocardium in the control group. Little lymphocyte infiltration was detected in the myocardium in the cell transplantation group, with the presence of mild edema of myocardial interstitial substance. Results verified that rat UC-MSCs can induce immune tolerance of heart transplantation, soften immunological rejection and prolong xenograft survival.

OBJECTIVE:To observe the activity of Pyrazinamide gel against Mycob ac terium tuberculosis in vitro and its security in bronchial interventional therap y METHODS:The MIC and MBC of Pyrazinamide and Pyrazinamide gel were measured b y handwork method and instrument method and secuity of Pyrazinamide gel was asse ssed by bronchial interventional therapy in rabbits RESULTS:The MICs of pyrazi namide gel to M tuberculosis H37 RV,M bovis and M phlei were 1mg/L,1mg/L,1 0mg/L,the MBCs of Pyrazinamide gel to M tuberculosis H37RV,M bovis and M ph lei were 10mg/L,10mg/L,40mg/L respectively;the MIC and MBC of Pyrazinamide gel and those of Pyrazinamide had no significant differences;the animal security ex periment was negative CONCLUSION:These results suggest that Pyrazinamide gel a nd Pyrazinamide have the same efficacy against M tuberculosis,because carbomer dose not affect the activity of Pyrazinamide against M tuberculosis;Pyrazinami de gel which contains carbomer is safe in bronchial interventional therapy

Objective To study the therapeutic effects of Ag85A plasmid DNA vaccines in a mouse model of multi-drug resistant-(MDR-) Mycobacterium tuberculosis infection. Methods BALB/c mice were infected with Mycobacterium tuberculosis clinical strain HB361 with isoniazid and rifampin resist-ance by intratail-vein injection and were subsequently divided into 6 groups. At the third day after infection, the mice were treated with saline (group A), vector pVAX1 (greup B), rifampin (group C), vaccae (group D), Ag85A plasmid DNA vaccines (group E),rifampin and Ag85A plasmid DNA vaccines (group F) for 60 d. The lungs and spleens from the mice were taken and their pathological changes, weight and number of myeobacterial colony were examined at the third week after the end of treatment. Results At third week af-ter the end of treatment, the gross pathological observation and histopathological examination in lung showed that the lung lesions were limited, the profile of the alveoli was relatively clear, and normal structure could be seen in 2/3 areas of the lung sections in group D, E and F. The extent of lung lesion was 50% in group D,20% in group E and F. The pathological changes in group A, B, and C were more severer than those in group D, E and F. Compared with group A, the colony-forming units (CFU) in the lungs from mice in group D,E and F decreased 52%, 68%, 78%, respectively. The CFU in the spleens from mice in group D,E and F decreased 48%, 65%, 79%, respectively. Conclusion Ag85A plasmid DNA vaccines alone or Ag85A plasmid DNA vaccines along with chemotherapy have significant therapeutic effects on the mouse model of MDR-Mycobacterium tuberculosis infection.