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Biomedical subjects

E Lawlor

Publications and source records attributed to E Lawlor.

At least 55 records · Page 3Linked to original sources

Isochromosome 9q in acute lymphoblastic leukemia: a new non-random finding.

The presence of an isochromosome is commonly associated with late-stage disease and has rarely been reported at diagnosis in hematological malignancies. Five patients (two males and three females aged 3, 6, 13, 13, and 35 years) with an acquired i(9q) at diagnosis of acute lymphoblastic leukemia (ALL) are presented; in one case it was the sole karyotypic change. The patients presented in November or January, two in 1983/84, three in 1987/88. The latter were three of 100 unselected ALL cases referred over a three year period for cytogenetics and successfully karyotyped. Two had a prior history of pancytopenia. Features of high risk ALL in these patients included age over 10 years (three cases), leukocyte counts greater than 200 x 10(9)/liter (two cases) and pre-B immunological phenotype (two cases). All achieved remission on standard protocols. One patient is disease free over 4.5 years from diagnosis. One relapsed at 3.5 years and is well following a bone marrow transplant in second remission. Follow-up for the remaining three patients is between 9 and 11 months. Our findings indicate that i(9q) frequently with additional chromosome change is a feature of newly diagnosed ALL.

Chromosome Aberrations↗

Visualizing gene expression in time and space in the filamentous bacterium Streptomyces coelicolor.

Streptomycetes are prokaryotic microorganisms that exhibit a complex, mycelial fungus-like cycle of morphological differentiation. Development involves at least two spatially separated types of cells: the branching hyphae of the substrate mycelium, which penetrate the stratum upon which the colony feeds, and the upwardly protruding hyphae of the aerial mycelium, which undergo metamorphosis into spores. The luciferase-encoding luxA and luxB operon of the luminescent marine bacterium Vibrio harveyi was used as a promoter probe to visualize gene expression in differentiating colonies of Streptomyces coelicolor. Promoters for developmental genes of several kinds gave distinctive temporal and spatial patterns of light emission.

DNA, Bacterial↗

Circulating cerebriform lymphoid cells (Sezary-type cells) in a B-cell malignant lymphoma.

Circulating cerebriform lymphoid cells (Sezary cells) are considered to be highly predictive of cutaneous T-cell Lymphoma (CTCL). A leukemic peripheral blood (leukocyte count 24.5 x 10(9)/l) composed predominantly of cerebriform cells was found in a 75-year-old man presenting with weight loss and generalized lymphadenopathy but without skin lesions. Cell suspensions studies and immunohistochemistry of peripheral blood revealed that the cerebriform cells were B-cells (IgM+ Kappa+, HLA DR+, Leu 1+, CALLA-, B1+, and OKT 10+). A variety of T-cell markers (other than Leu1) was negative. Computer-assisted morphometry confirmed a nuclear profile typical of CTCL (mean nuclear contour index, 7.47). A lymph node that underwent subsequent biopsy revealed a follicular malignant lymphoma of small to intermediate cells with similar morphologic and immunologic characteristics to the circulating cerebriform cells. The findings of a leukemic presentation of a cerebriform B-cell lymphoma extends the recent observation of nodal B-cell lymphomas composed of cerebriform cells and indicates that circulating cerebriform cells should not be considered to be exclusively of T-cell origin.

Aged↗

Myeloid antigen expression on common acute lymphatic leukaemia blasts after culture.

Blast cells from seven out of ten patients with common acute lymphoblastic leukaemia (cALL) developed the myeloid antigen MY7 (CD13) after culture, and one of these coexpressed the myeloid antigen MY9 (CD33). CD13 expression appeared to be independent of maturation since it could be induced more readily in cultures which did not contain the differentiation promoter 12-O-tetradecanoyl-phorbol 13 acetate (TPA). CD13 expression in culture was not seen on one null ALL, or 6 B-CLL investigated or on normal tonsillar B cells or PBMC under similar conditions. CD13 expression on cALL blasts probably represents evidence of abnormal gene expression in the leukaemic cells. However the absence of CD13 expression on the earlier B null ALL or the later B-CLL suggests we cannot exclude the possibility that CD13 expression is a feature of normal precursor B cells.

Adult↗

Relapsing large cell immunoblastic lymphoma complicating well-differentiated lymphocytic lymphoma: a report of two cases showing prolonged survival with therapy.

Two patients presented with co-existing large cell immunoblastic and well-differentiated lymphocytic lymphomas. Prolonged remissions from the large cell lymphomas were achieved following intensive combination chemotherapy but both patients suffered relapses after many years. Previous reports have grouped such patients with those developing classical Richter's syndrome implying a uniformly poor prognosis. This report suggests that this is not the case. It was not possible with immunohistochemical stains to prove or disprove that these tumours had the same stem cell origins.

Aged↗

The simultaneous presentation of peripheral T-cell lymphoma and hairy cell leukemia.

A patient who presented simultaneously with B hairy cell leukemia (HCL) and peripheral T-cell lymphoma (PTL) is described. The diagnoses of the two neoplasms were made by standard morphologic and cytochemical study and confirmed immunologically. There was no evidence of overlap in markers to suggest that they arose from a single clone of malignant cells. It is suggested that the simultaneous occurrence of the two neoplasms in the same patient reflects an underlying predisposition to the development of neoplasia in HCL.

Antibodies, Monoclonal↗

Production and characterization of a monoclonal antibody to a myeloid specific differentiation antigen.

A monoclonal antibody termed NC-1 was produced which binds to an antigen present on the human promyelocytic leukemia cell line HL-60 and peripheral blood neutrophils. The antibody bound to the majority of promyelocytes in the HL-60 culture, but not to myeloblasts. No antibody reactivity was detected to a range of other cell lines or to a limited number of normal human tissues. Peripheral blood lymphocytes, monocytes, basophils, eosinophils, erythrocytes and platelets did not react with the antibody. Bone marrow smears exhibited binding of NC-1 to myeloid cells at the promyelocyte and later stages of differentiation along the granulocyte lineage. The KG-1 myeloblastoid and U937 myelomonocytic lines could be induced to express the antigen, when exposed to neuraminidase which removes terminal sialic acid from carbohydrate residues. Similarly myeloblasts in bone marrow samples bound NC-1 when they were treated with neuraminidase. HL-60 cells induced to differentiate to granulocytes by treatment with retinoic acid continued to express the antigen. A similar result was observed when HL-60 cells were induced to differentiate to monocytes, even though blood monocytes failed to bind the antibody. These data indicate that the antibody NC-1 reacts with an antigen expressed on myeloid cells beyond the promyelocyte stage of differentiation.

Antibodies, Monoclonal↗

Variant translocation t(8;22) and abnormalities of chromosome 15(q22) and 17(q12-21) in a Burkitt's lymphoma/leukaemia with disseminated intravascular coagulation.

Severe disseminated intravascular coagulation was observed in a patient with Burkitt's lymphoma/leukaemia. Immunological studies on leukaemic blasts from relapsed bone marrow revealed a B-cell phenotype (B4+, B1+, HLA-Dr+, J5+) with membrane bound IgM lambda. Cytogenetic investigation revealed a variant Burkitt's translocation t(8;22)(q24;q11) involving the lambda light chain gene region and abnormalities of chromosomes 15 and 17 with breakpoints at q22 and q12 respectively, similar to those observed in the t(15;17) in acute promyelocytic leukaemia. Transmission electron microscopy of the leukaemic blasts showed crystalline cytoplasmic inclusions which may have had a role in precipitating the disseminated intravascular coagulation.

Adult↗

Monocytic differentiation in acute myeloid leukaemia: a cause of Fc binding of monoclonal antibodies.

Cells from 17 patients with acute myeloid leukaemia (AML) were investigated using the following IgG2a monoclonal antibodies cALL, B1 and Leu 1. Cells from six patients showed binding of cALL, five showed B1 and three showed Leu 1 positivity. Binding of the monoclonal antibodies was shown to be due to Fc binding as it was blocked by prior incubation with aggregated human IgG. Measures such as prior incubation with AB serum or incubation at 37 degrees C were insufficient to block Fc binding in all cases. Fc binding correlated with evidence of monocytic differentiation. Our findings suggest that unless Fc binding is outruled false positive results may be obtained in the investigation of lineage infidelity in AML particularly in monocytic leukaemias.

Antibodies, Monoclonal↗

Cholesterol ester storage disease in an adult presenting with sea-blue histiocytosis.

An adult patient is described with hepatomegaly and sea-blue histiocytes in the bone marrow. A diagnosis of cholesterol ester storage disease was established following enzyme and lipid analyses on liver biopsy and cultured skin fibroblasts. Acid esterase activity was deficient (approx. 5% of controls) in liver and fibroblasts using [14C]-triolein or 4-methylumbelliferyl palmitate as substrates. Cholesterol ester levels were raised about 70-fold in liver, whereas triglyceride levels were only marginally raised. Marked accumulation of cholesterol esters was also demonstrated in cultured fibroblasts. Clinically, the patient responded favourably to phenobarbitone treatment. However, this was not reflected in liver acid esterase or lipid levels.

Adult↗

Multiple neoplasms in hairy cell leukaemia.

A patient who presented simultaneously with typical hairy cell leukaemia (HCL) and multiple myeloma (MM) is described. He was treated with melphalan and irradiation and 18 months later presented with an adenocarcinoma. The occurrence of multiple neoplasms in this patient may reflect an underlying predisposition to neoplasia secondary to the immunological defects common in B cell lymphoproliferative diseases.

Adenocarcinoma↗

Acquired hypogammaglobulinemia following infectious mononucleosis.

The case of a 17-year-old male who developed hypogammaglobulinemia following infectious mononucleosis is presented. The family history revealed that a male sibling had died some years earlier with encephalitis also following infectious mononucleosis. Laboratory investigations revealed adequate numbers of T and B cells and normal proportions of helper and suppressor T lymphocytes but poor in vitro responses to mitogens and an absence of hypersensitivity to skin test antigens. Serial serological examinations for Epstein-Barr virus antibodies indicated a primary immune response to this virus in a hypogammaglobulinemic individual. The patient probably represents a case of the X-linked lymphoproliferative syndrome. The unique feature of the present case is the demonstration of Epstein-Barr virus-specific T-cell memory. The significance of this finding and the variable expression of this syndrome in two members of the same family are discussed.

Adolescent↗