RESUMO
Follicular lymphoma (FL) is a common form of non-Hodgkin lymphoma with an ability to transform into a more aggressive disease, albeit infrequently to B-lymphoblastic leukemia/lymphoma. While t(14;18)(q32;q21) has been associated with approximately 90% cases of FL, that alteration alone is insufficient to cause FL and associated mutations are still being elucidated. The transformation of FL to B-lymphoblastic leukemia generally includes the dysregulation of MYC gene expression, typically through IGH rearrangement. Such cases of "double-hit" leukemia/lymphoma with both BCL2 and MYC translocations warrant further study as they are often not identified early, are associated with a poor prognosis, and are incompletely understood in molecular terms. Here we describe a patient with a diagnosis of FL that transformed to B-lymphoblastic leukemia. Detailed cytogenetic characterization of the transformed specimen using karyotype, fluorescence in situ hybridization, microarray and gene rearrangement analyses revealed a complex karyotype comprised principally of whole chromosome or whole arm copy number gains or losses. Smaller, single-gene copy number alterations identified by microarray were limited in number, but included amplification of a truncated EP300 gene and alterations in NEIL1 and GPHN. Analyses defined the presence of an IGH/BCL2 fusion due to a translocation as well as a MYC/IGH fusion due to an insertion, with both rearrangements involving the same IGH allele. The data illustrate the value in characterizing double-hit lymphoma cases with both traditional and novel technologies in the detailed cytogenetic workup.
RESUMO
The difficulties of monitoring allelochemical concentrations in soil and their dynamics over time have been a major barrier to testing hypotheses of allelopathic effects. Here, we evaluate three diffusive sampling strategies that employ polydimethylsiloxane (PDMS) sorbents to map the spatial distribution and temporal dynamics of root-exuded thiophenes from the African marigold, Tagetes erecta. Solid phase root zone extraction (SPRE) probes constructed by inserting stainless steel wire into PDMS tubing were used to monitor thiophene concentrations at various depths beneath marigolds growing in PVC pipes. PDMS sheets were used to map the distribution of thiophenes beneath marigolds grown in thin glass boxes. Concentrations of the two major marigold thiophenes measured by these two methods were extremely variable in both space and time. Dissection and analysis of roots indicated that distribution of thiophenes in marigold roots also was quite variable. A third approach used 1 m lengths of PDMS microtubing placed in marigold soil for repeated sampling of soil without disturbance of the roots. The two ends of the tubing remained out of the soil so that solvent could be washed through the tubing to collect samples for HPLC analysis. Unlike the other two methods, initial experiments with this approach show more uniformity of response, and suggest that soil concentrations of marigold thiophenes are affected greatly even by minimal disturbance of the soil. Silicone tube microextraction gave a linear response for alpha-terthienyl when maintained in soils spiked with 0-10 ppm of this thiophene. This method, which is experimentally simple and uses inexpensive materials, should be broadly applicable to the measurement of non-polar root exudates, and thus provides a means to test hypotheses about the role of root exudates in plant-plant and other interactions.
