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K Lucas

Publications and source records attributed to K Lucas.

57 records · Page 4Linked to original sources

A linkage between dendritic cell and T-cell development in the mouse thymus: the capacity of sequential T-cell precursors to form dendritic cells in culture.

The earliest T precursor population in the adult mouse thymus (CD4lo8-3-44+25-c-kit+) was previously shown to be lymphoid-restricted (T, B, NK) but to have a capacity to form dendritic cells (DC). This led to the concept of a lineage of lymphoid-derived DC. DC could be generated with high efficiency in culture from this low CD4 precursor, using a complex mix of cytokines, a mix that notably did not include GM-CSF, the cytokine normally used for development in culture of myeloid-derived DC. Using this new culture system we now show that the capacity to form DC extends to the pro-T precursor population (CD4-8-3-44+25+c-kit+) but is lost by the pre-T precursor stage (CD4-8-3-44-25+c-kit+), the point of T-cell antigen-receptor beta-gene rearrangement. The DC generated in the cultures resemble mature thymic DC by most markers, but differ in their lack of expression of BP-1 and CD8 alpha.

Animals↗

Relapse in acute lymphoblastic leukemia as a function of white blood cell and absolute neutrophil counts during maintenance chemotherapy.

Several reports document an inverse correlation between bioavailability of maintenance chemotherapeutic agents and the likelihood of relapse in childhood. White blood cell counts (WBC) and absolute neutrophil counts (ANC) are easily ascertainable parameters which might be expected to reflect plasma levels of chemotherapy. To determine whether WBC and ANC predict outcome of children with acute lymphoblastic leukemia (ALL), we did a multivariate analysis of means of these values during maintenance therapy in patients with ALL treated on a single protocol. Of the 52 patients, 15 (29%) relapsed. For those still disease-free, minimum time of follow-up is 7-8/12 years. During the first year of maintenance therapy, mean WBC (x 10(3)/mm3) in the relapsed and nonrelapsed groups were 4.5 +/- 0.9 and 3.9 +/- 0.7, respectively (p = 0.03); mean ANC (x 10(3)/mm3) were 3.0 +/- 0.9 and 2.5 +/- 0.6 (p = 0.05). However, the range of values was large with considerable overlap between the two groups. There was no obvious difference in distribution of values when confounding prognostic features were adjusted for in the analysis. No significant differences were seen between WBC or ANC during the second year of therapy. Larger numbers of patients will be needed to ascertain whether specific guidelines for dosage modifications can be made on the basis of serial WBC. Future pharmacokinetic studies should look at possible correlations with mean WBC and ANC.

Antineoplastic Combined Chemotherapy Protocols↗