[Effect of sphingosine-1-phosphate on chemotherapy-induced ovarian damage and on the efficacy of chemotherapy in mice bearing S180 tumor].

OBJECTIVE: To investigate the effects of sphingosine-1-phosphate (S1P) on cyclophosphamid (CTX) and cisplatin (DDP)-induced ovarian damage and on the efficacy of chemotherapy in mice bearing S180 murine sarcoma. METHODS: Fifty-two female C57BL/6 mice were randomized into normal control group (n=10), tumor-bearing model group (n=14), CTX+DDP group (n=14), and S1P+CTX+DDP group (n=14). Before medication and on day 11 of medication during diestrus stage, the mice were sacrificed to measure the ovarian weight, numbers of primordial follicles and growing follicles, tumor weight, and serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol ( E2). RESULTS: At day 11 of medication, the levels of serum FSH and E2, but not LH, showed significant differences in CTX+DDP group from those in the other groups (P<0.01). FSH, E2, and LH levels were comparable between S1P+CTX+DDP group and the control group (P>0.05). The number of primodial follicles and weight of ovaries in CTX+DDP group decreased significantly compared to those in the other groups (P<0.01). The number of growing follicles in CTX+DDP group was significantly lower than that in the control and model groups(P<0.01), but similar to that in S1P group (P>0.05). The number of primodial follicles and growing follicles and ovarian weight in S1P+CTX+DDP group were close to those in the control and model groups (P>0.05). In CTX+DDP and S1P+CTX+DDP groups, the tumor weight were significantly lower than that in the other two groups (P<0.01), and the tumor inhibition rates were both higher than 60%. CONCLUSION: S1P can ameliorate chemotherapy-induced ovarian damage in mice without affecting the efficacy of chemotherapy.

[Removal of pentachlorophenol catalyzed by immobilized horseradish peroxidase].

The removal of PCP using HRP immobilized by Fe3O4 sorption-gelatin embedding-cross linkage method as catalyzer was studied. Reaction conditions including the reacting time, different buffer systems and pH value, PCP initial concentration, HRP dosage were discussed in detail compared with free HRP. The results indicate that the equilibrium time of PCP removal reaction catalyzed by immobilized HRP is about 30 min, which is as fast as free HRP. The optimal pH for PCP removal by immobilized HRP is between 4-6, the proper pH should be more extensive than using free HRP. The highest catalyzing removal percent is 41% at pH 5. Low concentration of immobilized HRP can remove PCP effectively. PCP removal quantity increases but the removal percent decreases with the increase of initial concentration of PCP. The catalyzing removal percent goes down from 39.68% to 24.4%. Immobilized HRP can remove PCP repetitively. The catalyzing removal percent is still above 39% at 0.05 U/mL dosage of HRP when using 7 times repeatedly.