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Biomedical subjects

B Leszko

Publications and source records attributed to B Leszko.

At least 19 recordsLinked to original sources
PubMed1995

Activity of platelet alpha-6-fucosyltransferase is inversely related to blood platelet concentration.

The activity of serum alpha-6-fucosyltransferase, a platelet derived enzyme, determined in sera of 22 normal individuals and 86 patients with various disorders was positively correlated with platelet counts. When the enzyme activity in 1 microliters serum was calculated per 1000 of platelets in blood (coefficient F/P) an inverse correlation became evident in that F/P was proportionally the higher the lower was platelet count in blood. The F/P values were in a good agreement with the results of direct assays of enzyme activities in isolated platelets. Neither granulocytes, lymphocytes nor red cells significantly contributed to serum enzyme activity though granulocytes enhanced the thrombin-induced enzyme release from platelets. In platelets separated by centrifugation in density gradients the enzyme was shown to be present in platelets of intermediate and high density but missing from the light ones. It is suggested that alpha-6-fucosyltransferase of platelets may be a marker of the ploidy level of megakaryocytes.

Blood Platelets↗
PubMed1991

[Pseudothrombocytopenia].

Pseudothrombocytopenia in four patients has been described. It was due to platelet "++EDTA-dependent" antibodies. The number of platelets was described only in EDTA blood while the number was normal when platelet were evaluated in citrate blood. The importance of distinguishing pseudothrombocytopenia from thrombocytopenia is discussed, especially in view of unnecessary treatment, delayed operation etc.

Adult↗
PubMed1989

ALG/ATG treatment--a useful alternative for BMT in selected aplastic anaemia patients.

8 patients with severe and 4 with non-severe aplastic anaemia, aged 7 to 46 years, whose suppressor lymphocyte activity was in most cases elevated and who had no histocompatible sibling donor, underwent 1-2 courses of ALG/ATG treatment. 6 patients got CR and 1 PR and during 1-4 years they live with sustaining haemopoiesis, independent of blood transfusion (except one in PR). Among these seven responders increased suppressor lymphocyte activity normalized in 6. The adverse effects of the treatment were granulocyto- and thrombocytopenia, subfebrile states, hepatotoxicity, serum sickness and skin allergy. Five patients died because of early or late complications of the treatment or it's failure. Our results, similar to other authors', are like after BMT and supports the immunological mechanism of A.A. Immunosuppressive treatment with ALG/ATG has many advantages: no need to have identical bone marrow donor, no GVHD, possibility of treatment of patients over 30, even pretreated with blood transfusions, and finally much lower costs and efforts.

Adolescent↗
PubMed1983

Immunoregulatory factors controlling terminal differentiation of malignant B-lymphocytes.

B-lymphocytes of patients with chronic lymphocytic leukemia differentiate in vitro towards plasma cells upon activation with Pokeweed mitogen (PWM) and Cowan. The level of response is much lower than that of normal cells and so is the helper T-cell function. However, concanavalin A-activated suppressor T-cell function of Ig synthesis is normal. Malignant B-cells have a normal capacity to stimulate Ig synthesis in the mixed lymphocyte cultures, but they respond poorly to an allogeneic stimulus. Thymosin (TFX) causes a marked enhancement of PWM-driven differentiation of malignant B-cells.

B-Lymphocytes↗
PubMed1983

The dynamics of morphological and cytoenzymatic changes in peripheral blood lymphocyte lysosomes in patients with chronic lymphocytic leukemia during treatment.

Changes in the number of lysosomes were studied by method of Blum and the activity of acid phosphatase was determined by the method of Barka and Anderson in the peripheral blood lymphocytes of patients with chronic lymphocytic leukemia in relation to the phase of the disease (according to Rai) and the method of treatment. Treatment with powerful cytostatic agents (cyclophosphamide with vinblastine) significantly changed the fluorescent and cytochemical findings, with a different pattern of changes in cases treated with success (remission) and in cases with unsuccessful treatment (death). The morphological evaluation of lysosomes in the lymphocytes can be used as a simple criterion of success in the treatment, and prognosis in this disease.

Acid Phosphatase↗
PubMed1983

Nucleoli in peripheral blood lymphocytes of patients with chronic lymphocytic leukemia treated with cytostatic drugs.

Quantitative and morphological changes of the nucleoli in the lymphocytes were studied in patients with chronic lymphocytic leukemia treated with cyclophosphamide and vinblastine, and were compared with the lymphocytes of patients treated with leukeran and healthy subjects. The nucleolar index was 1.20 in the lymphocytes of patients with chronic lymphocytic leukemia in stages II, III and IV of the disease, according to Rai's classification, and it showed no significant correlation with the mode and effect of treatment. The index was significantly higher than in the lymphocytes of healthy subjects (p less than 0.05). The activity of nucleoli in the lymphocytes of the patients treated with cyclophosphamide with vinblastine was significantly higher than in the leukeran-treated patients and healthy subjects, and it increased with progression of the disease and with successive passage from stage II to III and IV. In the patients in whom clinical improvement was achieved and the treatment with cytostatics was withdrawn, the proportion of active nucleoli in the lymphocytes was decreased.

Cell Nucleolus↗
PubMed1980

Nucleoli of peripheral blood lymphocytes in patients with chronic lymphocytic leukemia.

Morphological and cytochemical changes of the nuclei were investigated by the method of Smetana in peripheral blood lymphocytes of patients with chronic lymphocytic leukemia nontreated and treated with Leukeran. The material was divided into groups according to Rai. In the lymphocytes of the patients with nucleolar coefficient and the proportion of dense nucleoli and micronucleoli were increased, while at the same time, the proportion of ring-shaped nucleoli, the main form of nucleoli in the lymphocytes of healthy subjects, was decreased. The changes in the values of different nucleolar parameters indicated the successive stages of the diseases and served as an auxiliary distinctive feature of leukemic lymphocytes.

Adult↗
PubMed1980

Morphological and cytochemical changes of peripheral blood lymphocyte lysosomes in chronic lymphocytic leukemia.

Morphological changes of lysosomes (according to Blum) and the activity of acid phosphatase (by the method of Barka and Andersen) were investigated in peripheral blood lymphocytes in patients with chronic lymphocytic leukemia non-treated or treated with Leukeran. The division into groups was carried out according to Rai. Pathological lymphocytes in relation to lymphocytes of healthy subjects showed a decreased number of lysosomes and an increased number of cells with diffuse type of reaction to acid phosphatase. A relation was found between the intensity of morphological changes of lysosomes in pathological lymphocytes and the clinical state of the patients. Morphological evaluation of lysosomes in lymphocytes is a good diagnostic criterion of treatment effectiveness providing prognostic cues.

Acid Phosphatase↗
PubMed1976

[Surface immunoglobulins of lymphocytes in chronic lymphocytic leukemia].

Using the fluorescence technique the presence of various immunoglobulin classes (IgG, IgA, IgM) was determined on the surface of peripheral blood lymphocytes obtained from healthy subjects (10 cases) and from patients with chronic lymphatic leukaemia (65 cases). In the investigations the effect of treatment and clinical course on the values of these parameters was taken into consideration. Nearly in all cases of this leukaemia the percent of lymphocytes binding immunoglobulins on their surface was raised in comparison with the lymphocytes of healthy subjects. Presence of one or more classes of immunoglobulins was demonstrated on the surface of leukaemic lymphocytes.

Adult↗
PubMed1975

Renal function in polycythaemia.

In 23 patients with polycythaemia vera and symptomatic erythrocytosis, glomerular filtration rate and urine concentration ability see article were determined under conditions of antidiuresis. The restriction of fluid intake caused a significant reduction of GFR and modified the osmotic function of the kidneys. The results were similar in both types of polycythaemia.

Adult↗