ABSTRACT
Objective To study the relationships between differences in tumorigenicity and immu-nogenetic backgrounds of nude mice. Methods According to the Chinese Pharmacopoeia, positive and neg-ative groups were set up in both Laboratory A and B with ten nude mice in each group. Organ tissues were collected for clinicopathological analysis. Blood samples were collected and detected using flow cytometry. DNA was extracted and analyzed with 23 STR markers. Results The positive group of Laboratory B was in-valid (7/10 tumor formation). The two laboratories showed no significant difference in the results of patho-logical analysis, but had significant differences in CD25, CD8, CD4, Th1 and Th2. There were 13 and 18 polymorphic sites respectively found in nude mice of Laboratory A and B. Further analysis of the non-tumor-bearing nude mice in Laboratory B positive group revealed that CD25, Th2, D3Mit29 and D5Mit48 were the specific indexes. Conclusion Differences in tumorigenicity might be related to the diversity of immunoge-netic backgrounds of nude mice.
ABSTRACT
Objective To accumulate operating experience and background data for housing mice in individually ventilated cages (IVC).Methods 5 weeks old Balb /c male mice(n =80) were allocated to 8 groups(n =10), which then housed in 5 or 10 per cage in 3 IVC systems(30,50 and 70 air changes /h, respectively) and one open-top cages (OTC) shelf for 8 weeks.Body weight was assessed at the initial date and every week .By the end of the experiment, necropsy was done and organs were separated and weighed .Excelland SPSS software statistics was made to draw the growth curve, and comparative analysis of body weight and organ coefficients was performed between the groups .Results 1.The growth curves of 5-mice per cage were better than that of 10-mice per cage.2.In the IVC groups, the curves trend and fluency of 50 air changes /h were more similar to that of 5-mice housed OTC group.3.The previously mentioned differences were statistically not significant (P >0.05).4.In the liver coefficients, there was a statistically significant difference between the 10-mice housed OTC group and 5-mice housed IVC group with 30 air changes /h(P 0.05).Conclusions Based on the results of this study, the air change frequency on 50 times per hour and keeping 5 Balb/c mice per cage is recommended as the best condition for mouse housing in IVC .