Search PubMed⌕ Search

Biomedical subjects

B Dreyfus

Publications and source records attributed to B Dreyfus.

At least 109 records · Page 6Linked to original sources
PubMed1976

The cellular distribution of erythrocyte and normoblast A1 and A antigens in normal and preleukemic states. An immunoelectron microscopy study.

A1 and A alloantigens were visualized on human erythrocytes and normoblasts by immunoelectron microscopy using peroxidase-coupled antibodies. Specimens were obtained from patients with preleukemia and associated antigen weakening, and from individuals with normal antigen values. Cells were fixed by glutaraldehyde and subsequently reacted with antibodies.

ABO Blood-Group System↗
PubMed1976

Surface features of cells in human lymphoproliferative disorders. An immunoelectron microscopy study.

Peroxidase conjugated antibodies were applied to cell suspensions in order to detect surface associated immunoglobulins. Cell suspensions were fixed prior to incubation with reagents, a procedure avoiding membrane alterations induced by antibodies to surface component. By immunoelectron microscopy an identification of B lymphocytes could be made with simultaneous observation of their surface architecture. Basic findings were that normal circulating human B lymphocytes had a villous surface. This relationship was not confirmed however by examinating samples from various B and T cell proliferations establishing that surface morphology is not sufficient to categorize cells in disease. Specimens from hairy cell leukemia were also examined. Despite salient surface characteristics as revealed by the present method, the categorization of cells remains unclear.

B-Lymphocytes↗
PubMed1976

[Heterogeneity of the cellular distribution of erythrocytic A antigens. Ultramicroscopic study].

A and A1 antigens have been detected on cells of the human erythrocyte series by immunoelectron microscopy. These antigens have been revealed by an indirect method involving various anti-A and anti-A1 antibodies (allo, auto, hetero-antibodies) and peroxidase-conjugated anti-immunoglobulin antibodies. Immunologic labelling has been carried out with erythrocyte or bone marrow cell suspensions which were fixed prior to incubation with reagents. Cells from various A phenotypes were examined. A and A1 antigens were visualized on maturing normoblasts, at every developmental stage. In addition cell to cell variations of the surface labelling of erythrocytes was found in normal phenotypes, suggesting the existence of several populations of cells according to antigenic load.

ABO Blood-Group System↗
PubMed1976

The heterogeneity of erythrocyte antigen distribution in human normal phenotypes: an immunoelectron microscopy study.

A and A1 antigen were detected on human blood erythrocytes by immunoelectron microscopy using peroxidase-conjugated antibodies. Cells were obtained from various normal A subgroups, including rare weak A phenotypes and infant (cord blood) samples. Erythrocytes were fixed prior to incubation with specific reagents. The detection of surface antigens was carried out by an indirect method involving anti-A and anti-A1 antibodies and conjugated anti-immunoglobulin antibodies. The surface labelling was seen as a diffuse dense layer. Haemperoxidase-like activity resulted in a faint background which did not interfere at the level of ultrathin sections, with surface staining due to exogeneous peroxidase. The most significant finding was the existence, in a given sample, of several populations of cells as revealed by their antibody-binding capacity. The distribution of the various populations varied from one sample to another according to its subgroup. The progressive weakening of phenotype expression which characterizes the various subgroups from A1 to A weak was paralleled by a decreasing number of "antigen rich" cells, which were still detectable in weak phenotypes as a minor population. This study confirms that a given normal phenotype in fact represents a mixture of antigenically different populations of erythrocytes.

ABO Blood-Group System↗
PubMed1976

A new case of monoclonal IgA kappa cold agglutinin with anti-Pr1d specificity in a patient with persistent HB antigen cirrhosis.

A new case of cold agglutinin disease in a patient who had a long lasting Raynaud's phenomenon without hemolysis and a persistent HB antigen cirrhosis, is reported. The cold agglutinin is a monoclonal IgA kappa antibody which reacts at 4degreesC to a titer of 256. As the three other cases described in the literature, it demonstrates Pr1 specificity. The eluate from human cells reacts with rat and dog cells whose receptor is destroyed by both papain and neuraminidase, thus eliciting the characteristic Pr1d specificity.

Aged↗
PubMed1976

Preleukemic states. I. Definition and classification. II. Refractory anemia with an excess of myeloblasts in the bone marrow (smoldering acute leukemia).

Approaches to the diagnosis and classification of preleukemic states involving chronic cytopenias are presented and discussed. Diagnosis of these states is facilitated by the identification of anomalies in all the myeloid cell lines (i.e., those derived from the bone marrow). These cellular anomalies may be morphologic, biochemical, or functional in nature or may affect the quantity of cell in each line in the bone marrow and the peripheral blood. Such anomalies may occur alone or may be associated. A tentative classifiction is proposed which is based on one or several of these anomalies. Among the quantitative criteria of classification is a moderate and static excess of myeloblasts and promyelocytes in the bone marrow. Refractory anemia with an excess of myeloblasts (RAEM) in the most frequent of these states. Its main clinical and hematologic features are described. The disease course is quite typical, the mean survival being 20 months; some patients survive for more than 30 months. Acute myeloid leukemia (AML) was the cause of death in less than 28% of cases. Infection in the absence of severe neutropenia was frequent. The relationship between RAEM and AML is disc,ssed, and the individual characteristics of RAEM are emphasized.

Aged↗
PubMed1976

[Acute monoblastic leukemia. Clinical and therapeutic aspects in 20 cases].

Twenty cases of acute monoblastic leukemia are studied according to definite criterias: cytology, cytochemical staining, lysozyme production. The study points out the tumoral characters: hematodermy, gingivitis, central nervous system leukemia and the lack of important bone marrow incompetence. 47 per cent of complete remissions are obtained with daunorubicin, aracytin combination therapy. Other useful chemical agents, and prospects for maintenance therapy are discussed.

Adolescent↗
PubMed1976

[Morphologic criteria of surface studies by electron microscopy and classification of lymphoproliferative syndromes. Critical study].

Surface associated immunoglobulins (s.Ig) have been detected on human lymphocytes, in normal individuals and in disease, by an immunoelectron microscopic method using peroxidase-labeled antibodies. Experiments have been carried out on fixed cell suspensions, in order to avoid membrane alterations induced by anti-immunoglobulin antibodies. Normal human blood B lymphocytes have a villous surface. However this relationship between microvilli and detectable s.Ig, as found in the normal state, is not confirmed by examinating various T and B cell proliferative states. Thus surface morphology alone is not sufficient for classifying cells in disease. The precise nature of mononuclear cells from hairy cell leukemia remains nuclear.

B-Lymphocytes↗
PubMed1975

[Post-hepatitic aplasia treated by grafts of allogenic bone marrow. Remission for more than 2 years. Persistance of a total hematopoietic chimera. Graft versus host reaction].

A successfull bone marrow transplant was achieved in a case of post hepatitic aplastic anemia after cyclophosphamide immunosuppression. Caryotype analysis, erythrocytic phenotype and IgG Gm allotype demonstrated evidence of complete chimerism. Anti-thymocyte serum undoubtly was able to suppress a life threatening episode of graft versus host reaction. Severe long lasting skin lesions are now persisting 2 years after the graft.

Adolescent↗
PubMed1975

The surface morphology of human B lymphocytes as revealed by immunoelectron microscopy.

Surface immunoglobulins (sIg) were detected on human lymphocytes by immunoelectron microscopy with peroxidase-conjugated antibodies. Blood, marrow, and thymus cells from normal individuals and patients with lymphoproliferative disorders were examined. Samples were fixed before exposure to specific reagents. Normal lymphocyts with detectable sIg, i.e. B lymphocytes, were characterized by a villous surface; nonlabeled blood lymphocytes and thymocytes were smooth cells. Intermediate cells were also found which in sections appeared moderately villous and labeled, thus identified as B lymphocytes. Further evidence for a relationship between villous surface and sIg was given by the finding of a few lymphocytes with polar concentration of labeled microvilli. In chronic lymphocytic leukemia patients, most cells exhibited a villous surface with parallel variations of the number of microvilli and of anti-immunoglobulin-binding capacity. However, some labeled smooth blastic cells were also observed. On the other hand, abnormal lymphocytes from Sézary's syndrome which could exhibit segments of villous membrane had no detectable sIg. This study confirms that in most cases human B lymphocytes have a characteristic surface appearance and that the detection of sIg in normal lymphocytes correlates with the presence of microvilli.

B-Lymphocytes↗
PubMed1975

Partial myeloperoxidase deficiency in a case of preleukaemia. I. Studies of fine structure and peroxidase synthesis of promyelocytes.

The ultrastructural localization of peroxidase activity has been studied in the circulating neutrophils and in a neutrophilic series of bone marrow cells from a patient with preleukaemia. Light microscopic examination showed 36% of the polymorphonuclear leucocytes to be totally devoid of myeloperoxidase, while 50% were normally stained and 14% were slightly positive for this enzyme. Electron microscopic studies revealed considerable heterogeneity in the promyelocyte population, since the number of peroxidase-deficient azurophil granules was seen to vary from 0 to 100% in these cells. Thus, several types of promyelocytes were identified. One cell type, which resembled that seen in normal subjects, contained myeloperoxidase within its azurophil granules and also within the cisternae of the rough endoplasmic reticulum and Golgi complex. A second type of promyelocyte, which was at an early stage of development, lacked myeloperoxidase in its secretory apparatus. These cells contained two species of azurophil granules, the first of which was devoid of peroxidase activity whereas the other reacted positively. These observations suggest that the premature arrest of myeloperoxidase synthesis in the promyelocytes from a preleukaemic patient may give rise to several populations of circulating neutrophils which can exhibit varying contents of myeloperoxidase.

Adult↗
PubMed1975

Partial myeloperoxidase deficiency in a case of preleukaemia. II. Defects of degranulation and abnormal bactericidal activity of blood neutrophils.

A patient with a refractory anaemia preceding acute myeloblastic leukaemia had an increased susceptibility to infection due to Staphylococcus aureus. 36% of neutrophils lacked myeloperoxidase (MPO) activity and, in vitro, these polymorphonuclear neutrophils (PMN) had a defect of bactericidal activity against Staphylococcus aureus. Cytochemical studies of phagocytosis with the electron miscroscope have shown that the degranulation of primary granules (MPO+ or MPO-) was normal after phagocytosis of Escherichia coli which were normally lysed. A defective destruction of Staphylococcus aureus and Candida albicans was observed in some PMN with or without MPO activity, suggesting that MPO deficiency itself was not the only cause of this defect. In PMN which appeared normal, most MPO(+) granules were unable to fuse with the phagocytic vacuole containing intact germs even after 90 min of contact. There was, therefore, in addition to a partial MPO deficiency, a defect in cellular degranulation. This defect, the mechanism of which is unknown, may be in part responsible for the defective bacterial degradation.

Blood Bactericidal Activity↗