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Biomedical subjects

G Janossy

Publications and source records attributed to G Janossy.

At least 289 records · Page 16Linked to original sources
PubMed1978

Lymphoid blast crisis in chronic myeloid leukaemia and Philadelphia positive acute lymphoid leukaemia.

Membrane markers (anti-ALL and anti-Ia antisera) and an enzyme marker (terminal transferase) have been used to define an L-type or "lymphoid" type of acute transformation in chronic myeloid leukaemia and Ph1 positive acute leukaemia. Patients with L-type ("lymphoid") blasts responded to regimens including vincristine and prednisolone (VP). The markers showed better correlation with survival than did the morphology of blasts. The clinical course of patients was variable; elimination Ph1 positive clone (and hypoplasia), return to the chronic phase and relapses (including meningeal leukaemia) were observed. In contrast, patients with myeloid blasts ("M" type of blast crisis) failed to respond to vincristine and prednisolone.

Antineoplastic Agents↗
PubMed1978

Acid-phosphatase reaction in acute lymphoblastic leukaemia.

The diagnostic value of the acid-phosphatase reaction was assessed double-blind in 148 cases of acute lymphoblastic leukaemia (A.L.L.) classified by surface-membrane markers and entered into the M.R.C. U.K. A.L.L. trials. 90% of cases of T-A.L.L. showed a positive reaction in the majority of blast cells, while only 2% of common-A.L.L. and 10% of null-A.L.L. were positive. This cytochemical reaction distinguished the more aggressive form of A.L.L. any may aid the choice of therapy.

Acid Phosphatase↗
PubMed1977

Terminal deoxynucleotidyl-transferase levels and membrane phenotypes in diagnosis of acute leukaemia.

Terminal deoxynucleotidyl transferase (T.D.T.) has been measured in the cells of 112 leukaemia patients whose cells were characterised by membrane markers as well as by standard haematological and cytochemical criteria. The concentration of enzyme ranged from 0.1 to 1.4 units/10(8) cells in the bone-marrows of 20 patients with normal marrow or benign marrow hyperplasia. The enzyme level was raised in 30 of 31 patients with untreated acute lymphoblastic leukaemia (A.L.L.) whose cells reacted positively with an anti-A.L.L. serum (range 0.9-197, mean 59, units/10(8) cells) and in all 9 patients with thymic A.L.L. (Thy-A.L.L.) (range 1.5-95, mean 36, units/10(8) cells). All but 1 of 17 patients with acute myeloblastic leukaemia gave negative results (range 0-1.5, mean 0.60, units/10(8) cells), and T.D.T. was also normal in all 7 bone-marrow samples from patients with chronic granulocytic leukaemia (C.G.L.) in the chronic phase. The T.D.T. assay gave a clear distinction between 11 patients with C.G.L. in lymphoid transformation, anti-A.L.L.-serum positive (range 15-226, mean 83, units/10(8) cells), and 12 patients with C.G.L. in myeloblastic transformation, anti-A.L.L.-serum negative (range 0-1.9, mean 0.7, units/10(8) cells). Among 17 patients with otherwise unclassifiable acute leukaemia, 10 gave raised values (range 1.6-113 units/10(8) cells) and 7 gave normal values. It is concluded that the assay of T.D.T. in the peripheral blood or bone-marrow of patients with acute leukaemia is of value in differentiating lymphoid (including non-T non-B and Thy-A.L.L.) from myeloid leukaemia.

Biomarkers, Tumor↗
PubMed1977

Membrane marker analysis of 'lymphoid' and myeloid blast crisis in PH1 positive (chronic myeloid) leukemia.

The membrane phenotype of leukaemic cells was analysed during different stages of chronic myeloid leukaemia by a panel of markers. These included antisera against ALL antigen, p23,30 (Ia-like structure) and other T cell, B cell and myeloid markers 'Lymphoid' blast crisis shares the phenotype of common ALL (of non-T, non-B variety). Both leukemias react with anti-ALL serum and have pre-myeloid, pre-B lymphoid and pre-thymocyte characteristics. Their phenotype may reflect the characteristics of the pluripotential stem cell from which they derive. Nevertheless both leukaemias retain their undifferentiated characteristics and lack overt myeloid, B cell and thymocyte differentiation markers. Myeloid blast crisis and AML are negative with anti-ALL serum but some of the poorly differentiated myeloblasts react with anti-p23,30 serum (and negative for SmIg). The anti-p23,30 serum (used in a double marker assay combined with anti-immunoglobulin) detects some (4-11%) intermediate sized agranular p23,30+/SmIg-cells in peripheral blood during the chronic phase of CML as well as in normal foetal bone marrow. These could be myeloid stem cells (from which in CML the myeloid blast crisis arises). The results demonstrate that surface membrane analysis can aid exact diagnosis in different stages of CML.

Antigens, Neoplasm↗
PubMed1977

Acid esterase in human lymphoid cells and leukaemic blasts: a marker for T lymphocytes.

A non-specific acid alpha-naphthyl-acetate esterase activity was investigated in human lymphoid cell populations from tonsils, blood, thymus and in different leukaemias. Four patterns have emerged. (i) The vast majority of T lymphocytes (peripheral blood, tonsils) showed a localized, intense reaction product ("T-like"). (ii) A thymocyte subpopulation expressed faint, localized enzyme activity ("Thy-like) but the majority of thymocytes showed no esterase activity. Some cells from acute lymphoblastic leukaemias with thymocyte surface characteristics had a "Thy-like" appearance. (iii) Most B lymphocytes and cells from chronic lymphocytic leukaemias were esterase negative. No activity was seen in mitogen activated peripheral blood T and B lymphoblasts from peripheral blood and in leukaemic blasts from the common form of childhood acute "lymphoblastic" leukaemia. (iv) Myeloid cells, including peripheral blood monocytes, and blast cells from acute myeloblastic and chronic granulocytic leukaemias showed an intense, diffuse reaction product (M-like). It is concluded that the modified esterase technique is a convenient marker for small mature human T lymphocytes in tissue sections and smears. It may also be helpful in the differential diagnosis of acute lymphoblastic leukaemia with T characteristics, the common form of acute "lymphoblastic" leukaemia and acute myeloblastic leukaemia.

Diagnosis, Differential↗
PubMed1977

T-cell regulation of immunoglobulin synthesis and proliferation in pokeweed (Pa-1)-stimulated human lymphocyte cultures.

In pokeweed (Pa-1)-stimulated human lymphocyte cultures, T cells are essential for the survival, proliferation, plasma-cell development, and high-rate Ig secretion of B cells. Their effects are T-cell-specific in the sense that B-cell stimulation does not take place in the absence of T cells even when fibroblasts or monocytes are provided. The experimental system is the most effective model for activation of human B lymphocytes so far described. Plasmablast development requires approximately 7 days in culture. In T + B-cell cultures established at 1 X 10(6)/ml (1 X 10(4)/mm2) initial cell density, plasma cells can secrete, on the average, as much as 40-70 pg IgM or IgG per cell per day. When the initial T-cell density is increased well above 1.0 X 10(6)/ml, a T-cell-mediated depression of Ig synthesis becomes predominant. Thus, in the pokeweed model T-cell effects represent a balance of helper and suppressor influences. The study also shows that B cells are heterogeneous. A non-adherent IgG-committed (smIg-?) TONSIL B-cell population seems to be less susceptible to T suppressor effects than normal tonsil B cells. This subset proliferates particularly well and synthesizes large quantities of IgG in the presence of large initial proportions of T cells.

B-Lymphocytes↗
PubMed1977

ATYPICAL SURFACE MAKER CHARACTERISTICS IN A T-cell lymphoma.

A case of T-cell lymphoma with an unusual phenotype is described. The majority of malignant tumour cells did not form E-rosettes, and lacked surface immunoglobulin but reacted with an antiserum to T cells and thymocytes. Localised acid phosphatase and non-specific alpha naphthol acid esterase activities and a prominent, convoluted, nuclear pattern in some neoplastic cells also supported the T cell derivation. The results demonstrate the importance of using a panel of markers for identification of the cellular derivation of some lymphomas.

Acid Phosphatase↗
PubMed1976

Target cell in chronic myeloid leukaemia and its relationship to acute lymphoid leukaemia.

On the basis of membrane marker analysis with an antiserum made against acute lymphoblastic leukaemia and other immunological markers it is suggested that some chronic myeloid leukaemias (C.M.L.) and some acute lymphoblastic leukaemias (A.L.L.) originate in a common target cell or precursor. This is possibly a pluripotential stem cell or a closely related derivative. These leukaemic cells retain their undifferentiated membrane characteristics C.M.L. patients in blast crisis who are A.L.L.-antigen-positive and have terminal transferase enzyme activity might benefit from therapy usually given in typical Philadelphia-chromosome-negative A.L.L.

Antigens, Neoplasm↗