RESUMO
BACKGROUND: The TEL-AML1 fusion in precursor-B ALL is generated by a cryptic 12;21 translocation that is detectable by fluorescence in situ hybridization (FISH). It is generally considered a favorable prognostic indicator. Some TEL-AML1+ ALL patients present at diagnosis with extra copies of the fusion, enumerated by FISH. The aim of the study was to determine whether additional copies of TEL-AML1 have clinical significance. PROCEDURE: Charts of all TEL-AML1+ ALL patients at the UM and Children's Hospitals and Clinics of Minnesota between 1996 and 2004 were reviewed. RESULTS: Eight patients (7 males/1 female, mean age 46 months) with two or more TEL-AML1 fusion signals and 24 with single TEL-AML1 fusion signals (18 males/6 females, mean age 52 months) were identified. There was no statistically significant difference in age or gender between the two groups. Patients with double TEL-AML1+ had a higher frequency of myeloid markers CD13 (P = 0.04) or CD33 (P = 0.003) than single TEL-AML1+ patients. Single TEL-AML1+ patients had higher WBC (P = 0.04) than double TEL-AML1+ patients. A trend toward slower therapy response was seen in double TEL-AML1+ patients versus single, (1 of 7 [14%] <5% marrow blasts on Day 7 vs. 13 of 23 [56%], P = 0.09). Double TEL-AML1+ patients had a higher relapse rate (P = 0.09) than single TEL-AML1+ patients. CONCLUSIONS: Utilizing FISH to distinguish subgroups of TEL-AML1 fusion patients may have important prognostic implications. The presence of an extra fusion may portend poorer prognosis. A larger and longer-term follow-up study will be required to verify the possible clinical significance of the presence of multiple TEL-AML1 fusions.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Repressoras/genética , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Antígenos CD13/análise , Criança , Pré-Escolar , Cromossomos Humanos 21-22 e Y , Cromossomos Humanos 6-12 e X , Feminino , Humanos , Hibridização in Situ Fluorescente , Lactente , Contagem de Leucócitos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Prognóstico , Estudos Retrospectivos , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico , Translocação Genética , Variante 6 da Proteína do Fator de Translocação ETSRESUMO
Energy metabolism of brown lemmings in summer pelage was measured over long periods at several air temperatures, with and without a real nest or artificial nest material. Resting metabolism of lemmings at T a=-16°C was 43% higher than that of lemmings in nests. As T a increased, the difference between resting metabolism of animals with and without nests decreased and was similar at T a=20°C. The energy saved at rest is equivalent to a reduction of approximately 40% in the thermal conductance. Independent estimates of energy savings due to nest insulation by analysis of cooling curves of a lemming model with and without a nest suggest a 46% reduction in thermal conductance due to the nest. At T a=0°C, baby lemmings huddled in a nest had equilibrium temperature excesses (T b-T a) four to five times higher than isolated nestlings outside the nest. These data indicate that there is a substantial energy savings at ecologically relevant air temperatures, and that energy savings increase as T a decreases. If the insulative value of the nest is similar whether the animal is in summer or winter pelage, these data suggest that heat production of a resting lemming would be 0.88 W (about 1.6 times BMR), while in nests at subnivean air temperatures typical of Barrow, Alaska, during the winter.