Monitoring of engraftment and progression of acute lymphoblastic leukemia in individual NOD/SCID mice

Objective. The aim of this study was to develop an animal model for human acute lymphoblastic leukemia (ALL) in which the kinetics and characteristics of leukemia can be sequentially monitored in individual mice. Materials and Methods. NOD/SCID mice were inoculated intravenously with primary ALL. Progression of leukemia was monitored throughout the development of disease by determination of absolute leukemic cell counts (LCC) in peripheral blood. Results. LCC as low as 10(4) leukemic cells/mL blood could be detected. ALL cells from 5 of 5 patients engrafted, and after identification of the first leukemic cells in peripheral blood, LCC increased exponentially. Leukemic cells showed specificity of homing to spleen and bone marrow, and LCC strongly correlated with the level of leukemic engraftment in these organs throughout disease progression, demonstrating that LCC are representative for overall leukemic burden. Cytogenetic analysis of leukemic cells recovered after six successive in vivo transfers revealed no major karyotypic changes as compared to primary cells, and selection of the dominant clones was observed. This selection process was reflected by an increase in the rate of leukemic progression as compared to the first inoculation, demonstrating the accuracy with which kinetics of leukemic progression can be studied by determination of LCC, Conclusions. This model is suitable for detailed studies of kinetics and characteristics of ALL in vivo, and it may be useful for monitoring effects of novel therapeutic regimens. (C) 2001 International Society for Experimental Hematology. Published by Elsevier Science Inc

An 11p;17p telomeric translocation in two families associated with recurrent miscarriages and Miller-Dieker syndrome

Translocations occur in a proportion of couples affected by recurrent miscarriages. We describe two such families in which the underlying cause was a cryptic subtelomeric 11p;17p translocation detected only after the birth of an affected child carrying an unbalanced form of the rearrangement. Unbalanced subtelomeric rearrangements are now recognised as a significant cause of mental impairment and we believe that these rearrangements may also be an important cause of recurrent miscarriages. In these two families the translocation is most likely to have arisen from a single ancestral event because all translocation carriers shared almost identical haplotypes around the breakpoints on both chromosomes.<br/