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R Morilla

Publications and source records attributed to R Morilla.

61 records · Page 4Linked to original sources
PubMed1982

Chronic T-cell leukemias. II. Cytogenetic studies.

Chromosome abnormalities were documented in the PHA-stimulated lymphoid cells from 10 patients with chronic T-cell leukemias (6 T-PLL, 3 T-CLL and 1 T-LCL). One or more marker chromosomes were present in most metaphases in every case of T-PLL but they were different in each case. Structural abnormalities were also observed in T-CLL and T-LCL but less consistently. Chromosomes involved in marker formation in two or more cases were: Nos. 2, 7, 8, 9, 11 and 16. The karyotype was hypodiploid in five cases and hyperdiploid in two. Chromosomes Nos. 2 and 8 were the most frequently involved in structural and numerical abnormalities: Nos. 8 in 2 T-CLL and the 6 T-PLL and No. 2 in 1 T-CLL, 1 T-LCL and 5 T-PLL. Abnormalities of chromosome No. 2 are rare in human neoplastic disease but may be common in T-lymphoproliferative disorders. The differences between T-PLL and T-CLL reported here may have some bearing on the clinical features. T-PLL, characterised in all cases by clonal abnormalities, has an aggressive clinical course. In contrast, T-CLL with less consistent karyotypic changes has a protracted and benign clinical evolution.

Adult↗
PubMed1981

Significance of Phi bodies in acute leukaemia.

Material from 39 patients with acute leukaemia was investigated with the peroxidase cytochemical reaction using 3,3'diaminobenzidine (DAB) and other substrates in order to test their sensitivity in detecting myeloid differentiation. The proportion of positive blasts and of cases with Auer rods in acute myeloid leukaemia (AML) was significantly greater with DAB than with benzidine. In addition, Phi bodies were demonstrated in AML blasts only when DAB was used; Phi bodies were also observed in two out of seven cases of chronic granulocytic leukaemia in "myeloid" blast crisis but were not seen in any case of acute lymphoblastic leukaemia. Phi bodies were more numerous when the reaction was carried out at pH 9.7, and their number was significantly reduced in the presence of 3-amino 1,2,4-triazole. Both findings suggest that the Phi bodies derive from catalase-containing granules (microperoxisomes) and are distinct from Auer rods, which derive from peroxidase-containing (primary) granules. Like Auer rods, Phi bodies appear to be characteristics of immature myeloid cells in leukaemia but are seen with a higher frequency than Auer rods in acute myeloid leukemia.

3,3'-Diaminobenzidine↗
PubMedDate not supplied

Immunophenotype changes and loss of CD52 expression in two patients with relapsed T-cell prolymphocytic leukaemia.

T-cell prolymphocytic leukaemia (T-PLL) is an aggressive disease often resistant to conventional chemotherapy. Long lasting remissions with the monoclonal antibody CAMPATH-1H (anti-CD52) have been documented. We describe two unusual T-PLL patients treated successfully first with CAMPATH-1H in whom, at the time of relapse, the cells underwent a phenotypic switch with loss of CD52 expression. In one of them, cytogenetic analysis demonstrated the same chromosome abnormalities in the cells at diagnosis and relapse. The reasons for the immunophenotypic changes are unknown but it is likely that loss of CD52 antigen expression contributed to the resistance to CAMPATH-1H in one of the patients when re-treated.

Adult↗
PubMedDate not supplied

Definition of acute biphenotypic leukemia.

BACKGROUND AND OBJECTIVE: A minority of acute leukemias have features characteristic of both the myeloid and lymphoid lineages and for this reason are designated mixed-lineage, hybrid or biphenotypic acute leukemias (BAL). There have been difficulties in establishing whether BAL represents a distinct clinico-biological entity due to a lack of objective criteria for distinguishing BAL from acute myeloid leukemias (AML) or acute lymphoblastic leukemias (ALL) with aberrant expression of a marker from another lineage. In this work we analyze diagnostic criteria for BAL. METHODS: We describe the features of 26 patients (19 adults and 7 children) with BAL diagnosed at the Royal Marsden Hospital. BAL was defined according to a scoring system devised by our group and the European Group for the Immunological Classification of Leukemia (EGIL). This system is based on the number and degree of specificity of the markers (lymphoid and myeloid) expressed by the blasts. RESULTS: According to the FAB criteria, BAL may present as "ALL" or as one of the "AML" subtypes, often M1. It is not infrequent to identify two distinct blast populations: one of small size resembling lymphoblasts and the other larger. The most common immunophenotype is coexpression of B-lymphoid and myeloid markers and less frequently, T-lymphoid and myeloid markers. Cases with a B and T lymphoid phenotype or with trilineage differentiation are rare. BAL has a high incidence of clonal chromosomal abnormalities, the most common being the t(9;22) (q34;q11) (Ph chromosome) and structural abnormalities involving 11q23. Data are emerging that BAL has a negative prognosis in both children and adults and this may be related to the underlying chromosome abnormalities. INTERPRETATION AND CONCLUSIONS: In summary, BAL is an uncommon type of leukemia which probably arises from a multipotent progenitor cell and carries a poor prognosis. Although there are no uniform criteria about whether to treat these patients as ALL or AML, it is likely that an intensive approach with high-dose therapy followed by bone marrow transplantation will be required to eradicate the disease permanently.

Acute Disease↗