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M A Esparza-Flores

Publications and source records attributed to M A Esparza-Flores.

5 recordsLinked to original sources
PubMed2004

Increased expression of AML1-a and acquired chromosomal abnormalities in childhood acute lymphoblastic leukemia.

A semi-quantitative expression analysis of both AML1-a and AML1-total was performed by RT-PCR in 19 children with acute lymphoblastic leukemia (ALL) at diagnosis. AML1-a expression was assessed in 16 bone marrow (BM) and 13 peripheral blood (PB) samples whereas AML1-total was assessed in 17 BM and 16 PB samples. These analyses were also carried out in 15 PB samples of healthy controls. In addition, 18/19 patients were karyotyped: 11 had an unmodified constitutional karyotype (CK) and seven exhibited acquired chromosomal abnormalities (ACA). The expression of AML1-a was significantly increased in BM and PB when compared with the controls (p < 0.013 and p < 0.035, respectively). A significant increase was found in the expression of AML1-a in BM of the ACA group compared with the CK group (p < 0.0009). The expression of AML1-a in BM and PB showed a significant increase in the ACA group compared with controls (p < 0.00001 and p < 0.012, respectively); in contrast, the CK group did not differ from the controls. These observations may mean that the increase of AML1-a favours the progression of leukemia.

Adolescent↗
PubMed2003

Detection and monitoring of clonality in peripheral blood and bone marrow of patients with B-cell lymphoproliferative disorders.

Bone marrow (BM) is accepted as the tissue of choice for the detection of monoclonal populations in leukemias and lymphomas; however, obtaining BM can be painful and traumatic for the patients. Although it is possible to detect clonality in peripheral blood (PB) samples, there are no reports comparing the results observed from BM with those from PB. Lymphoblastic leukemias and lymphomas are derived from B-lymphocytes in 80% of cases. In the early stages of their maturation, the immunoglobulin heavy chain genes (IgH) undergo rearrangements among their V, D, and J segments, giving rise to the Complementarity Determining Regions (CDR). Of these, CDR3 is unique for each lymphocyte and therefore it can be used as a tumour-specific marker in these malignant disorders. Among the 104 patients from whom we obtained pre-treatment paired samples of PB and BM, 94 (90.4%) showed concordant results. Similarly, at the end of treatment, 40 of 44 patients (90.9%) showed this concordance. During treatment only 24 patients were monitored and monoclones disappeared in 12 patients; in the other half, they persisted either partial or totally. We demonstrate that the detection and monitoring of monoclonal populations in the PB, in comparison with BM, was achieved with a statistical sensitivity of 90% and specificity of 92%.

B-Lymphocytes↗
PubMed2002

Paternal isodisomy 7q secondary to monosomy 7 at recurrence in a Down syndrome child with acute myelogenous leukemia.

We report a boy with Down syndrome and leukemia who acquired uniparental isodisomy of chromosome 7q as a secondary chromosomal change during recurrence of the disease. His karyotype before therapy was 46,XY,der(1)t(1;1)(p36;q32),-7,+21c/46,idem,del(9)(p22), whereas at recurrence it was 46,XY,der(1)t(1;1)(p36;q32,-7,der(7)(qter-->p22 through pter::q10-->qter),del(9)(p22),+21c/47,XY,+21c. By using polymerase chain reaction amplification of D7S493 and D7S527 markers, we identified the loss of the maternal chromosome 7 with a consequent paternal isodisomy in the clone with dup7q. This rearrangement could be implicated in the progression of the disease by causing (1) nullisomy for a gene or genes located on 7p22-->pter, (2) functional double doses of exclusively paternal expressed genes, and (3) restoration of the effects produced by haploinsufficiency of biparental expressed genes.

Child, Preschool↗
PubMed1985

[Fanconi's anemia].

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Abnormalities, Multiple↗