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Spontaneous mutation at the adenine phosphoribosyl transferase (APRT) locus in clone 707 of the Friend cell line was examined. The frequency of cells resistant to 2,6-diaminopurine (DAP) was found to be 2.6 × 10−5 with a mutation rate of 1.81 × 10−6 cell−1 generation−1. APRT activities in 9 DAP-resistant clones were found to vary between 0 and 27% the level observed in wild-type cells. It is suggested that clone 707 cells are heterozygous or functionally hemizygous at the APRT locus. 相似文献
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H. J. McKenna 《Cancer immunology, immunotherapy : CII》1999,48(6):281-286
flt3 ligand (FL) is a growth factor that induces hematopoietic progenitor cell and dendritic cell (DC) expansion when administered
to mice. Lymphoid-related (CD8α+) and myeloid-related (CD8α−) DC are transiently expanded in multiple tissues. Treatment of tumor-bearing mice with FL results in slower tumor growth
and, in some cases, tumor rejection and the development of tumor-specific T cell immunity. The clinical use of DC as cellular
vehicles for tumor antigen presentation to generate a tumor-specific T cell response is under investigation. DC are currently
generated ex vivo, pulsed with antigen, and then infused into patients, and much effort is being directed toward optimizing
each of these steps. Administration of FL to humans induces a profound increase in circulating DC. The availability of a large
number of DC generated in vivo has important implications for tumor immunotherapy approaches.
Received: 13 May 1999 / Accepted: 14 June 1999 相似文献
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H Haines T M McKenna R M Edwards 《Comparative biochemistry and physiology. A, Comparative physiology》1987,87(3):597-601
1. Total water (TW), and extracellular water (ECW) (as sodium and chloride space) were determined in skeletal muscle and carcass of Mus musculus acclimated to long-term water shortage. 2. The presence of fat in control mice and those in early stages of acclimation resulted in an apparent increase in TW and ECW as acclimation proceeded. 3. In contrast, fluid volumes per fat-free weight were either unchanged from controls or reduced. 4. Sodium space exceeded chloride space. 5. Muscle and carcass had essentially the same pattern of fluid shifts. 6. We conclude that ECW maintenance is a preeminent component of the acclimation process in this species. 相似文献
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