Search PubMed⌕ Search

Biomedical subjects

A Villegas

Publications and source records attributed to A Villegas.

At least 73 records · Page 4Linked to original sources

Autotransplantation of peripheral blood stem cells mobilized by G-CSF in hematological malignancies: evidence for rapid and long-term sustained hematopoietic reconstitution.

We assessed the ability of granulocyte colony-stimulating factor (G-CSF) to mobilize peripheral blood stem cells (PBSC), the efficacy of PBSC infusion in the rescue of hematopoiesis after high-dose chemotherapy in 22 adult patients with hematological malignancies, and the long-term quality of engraftment. Bolus subcutaneous injections of G-CSF (12 micrograms/kg/day) were administered for 6 days. A median of three leukaphereses resulted in the collection of a median of 5.45 X 10(8) mononuclear cells/kg, 4.52 X 10(6) CD34+ cells/kg, and 3.97 X 10(4) CFU-GM/kg. G-CSF (5 micrograms/kg daily) was administered after PBSC infusion until granulocyte recovery. The median time to attain a neutrophil level > 0.5 X 10(9)/L and a platelet count > 20 X 10(9)/ L was 11 days. The median follow-up in 17 survivors was 23.8 months. These patients have maintained a complete and stable graft and some of them with neoplastic recurrence tolerated further chemotherapy. These results confirm that mobilization of PBSC by G-CSF can be performed on an outpatient setting and used in heavily pretreated patients. G-CSF mobilized PBSC transplantation provides early and complete engraftment in most patients.

Adult↗

Molecular characterization of a new family with alpha-thalassemia-1 (--MA mutation).

A Spanish family with alpha-thalassemia-1 (alpha-Thal-1), deletion (--MA), is described. In addition to the loss of 22 kb of DNA with a deletion of the alpha 1, alpha 2, psi alpha 2, and psi zeta 1 genes, a triplication of the zeta gene cluster in "cis" is produced. The structure of this triplication is formed by the psi zeta 1 gene, the interzeta region, and, possibly, the insertion of the psi alpha 2 fragment.

Adult↗

[Iron chelators].

Explore the source record for details and available documents.

Deferoxamine↗

Alpha-thalassemia-1 (--CAL mutation) in a Spanish family.

We have detected a second family (five members affected) with a large (32 kb) deletion involving the alpha 1, alpha 2, psi alpha 1, psi alpha 2, psi zeta 1, and zeta-globin genes. This mutation has been previously described in Calabria, Italy, in a child and his mother and has been named alpha-thalassemia--)AL.

Adult↗

Chromosomal disorder and neoplastic diseases in a family with inherited fragile 16. Causality or casualty?

We describe a family with an inherited fragile chromosome 16 with the concurrence of a constitutional chromosome abnormality, together with neoplastic pathology within the family. The following findings should be pointed out: in relation to the constitutional chromosome pathology, of the proband's 3 children, the eldest daughter was a carrier of the fragile 16, the same as the father, and the second child, a son, had Down syndrome (trisomy 21). Regarding the tumoral pathology of this family, one of the proband's daughters died in childhood from acute lymphoblastic leukemia, whereas the proband developed two different malignant hematologic disorders: a follicular lymphoma and an acute nonlymphocytic leukemia (M5 type). Moreover, two independent acquired chromosome disorders coexisted in the proband; each of these was related to one of the respective hematologic disorders.

Aged↗

Healing of broken human chromosomes by the addition of telomeric repeats.

We have characterized and compared a series of naturally occurring chromosomal truncations involving the terminal region of the short arm of human chromosome 16 (16p13.3). All six broken chromosomes appear to have been stabilized by the direct addition of telomeric repeats (TTAGGG)n to nontelomeric DNA. In five of the six chromosomes, sequence analysis shows that the three of four nucleotides preceding the point of telomere addition are complementary to and in phase with the putative RNA template of human telomerase. Otherwise we have found no common structural features around the breakpoint regions. These findings, together with previously reported in vitro data, suggest that chromosome-healing events in man can be mediated by telomerase and that a small region of complementarity to the RNA template of telomerase at the end of a broken chromosome may be sufficient to prime healing in vivo.

Base Sequence↗

[Acquired hemoglobin H disease associated with a myelodysplastic syndrome].

Some patients found to have clonal panmyelopathies develop an acquired defect of haemoglobin synthesis clinically similar to haemoglobin H disease. A 58 year-old male diagnosed of simple refractory anaemia developed microcytosis and hypochromia. At the same time, his myelodysplastic syndrome became a refractory anaemia with excess of blasts. 33% of the red blood cells had "golf ball" inclusions after incubation with brilliant cresyl blue. Cellulose acetate electrophoresis revealed an haemoglobin H band. The globin chain synthesis alpha/beta ratio was 0.69. The molecular analysis demonstrated the integrity of both alpha genes in each chromosome. There were no familiar antecedent of haemoglobinopathy.

Anemia, Refractory, with Excess of Blasts↗