PubMed Health⌕ Search

Biomedical subjects

D Soligo

Publications and source records attributed to D Soligo.

At least 91 records · Page 5Linked to original sources
PubMed1987

Simultaneous visualization of myeloperoxidase reactivity and immunogold labeling by backscattered electron imaging with the scanning electron microscope.

We describe a method to label circulating human granulocytes with an immunogold marker and then incubate them for demonstration of myeloperoxidase activity. The cells were observed in the backscattered electron imaging (BEI) mode of the scanning electron microscope. This permits simultaneous visualization of cell surface morphology, the immunological surface marker, and the cytochemical reactivity of each individual cell. Enhanced identification of the various cell types and more precise characterization of cell surface features in the different steps of leukocyte differentiation are expected to result from application of this technique.

Gold↗
PubMed1987

Immunocytochemistry of acute myeloid leukemias: an ultrastructural study by the immunogold method.

Light microscopy morphology and cytochemistry, immunology, and ultrastructural morphology, cytochemistry and immunocytochemistry studies were performed in 18 cases of acute myeloid leukemia (8 M1, 1 M2, 7 M3 and 2 M4, according to the FAB classification). The aim of the investigation was to assess the value of electron microscopy, particularly the immunogold method, in the different FAB subclasses. Transmission electron microscopy with its more recent techniques of investigation was shown to have an important role in diagnosis of early myeloid (M0-M1) and mixed (M4) cases, where it was determinant in correlating ultrastructural morphology with cytochemistry and immunology and thus identifying the different cell populations. On the contrary, in cases in which the leukemic cells showed homogeneous features, light microscopy was adequate and sufficient for correct diagnosis.

Antibodies, Monoclonal↗
PubMed1987

Immuno-scanning electron microscopy of normal and leukemic leukocytes labeled with colloidal gold.

The immunogold method, utilizing 40 nm colloidal gold particles which can be selectively visualized with the scanning electron microscope (SEM) in the backscattered electron imaging mode was used for the study of blood cells incubated with various monoclonal antibodies. Numerous anti-leukocyte monoclonal antibodies still recognize lightly glutaraldehyde prefixed antigens and can be used to identify various blood cell types and even to recognize their different maturation stages. Clearcut differences in surface morphology exist among peripheral blood normal leukocytes and even among the principal lymphocyte subclasses. Marked heterogeneity in surface morphology is, on the other hand, evident when studying precursors or leukemic cells. Immature cells show, nevertheless, relatively smooth surfaces while some distinct surface features appear on cells already committed toward a specific differentiation lineage. Hairy cells can also be precisely identified, especially when in small number in heterogeneous populations, combining their typical surface morphology with their positivity for B1 and Leu M5 monoclonal antibodies.

B-Lymphocytes↗
PubMed1987

Immunogold labeling of human leukocytes for scanning electron microscopy and light microscopy: quantitative aspects of the methodology.

When cell surface antigens are labeled with the colloidal gold marker, back-scattered electron images (BEI) reveal all the gold particles and, therefore, permit total counts. Secondary electron images (SEI) show only a small percentage of the gold particles and are inadequate for quantitative evaluation. For determination of the cellular labeling index, a time-consuming method implies the screening of 100 cells by scanning electron microscopy, at a magnification of approximately 12,000 to 15,000x, with continuous SE/BE shifts. A much more efficient method is to transfer the SEM sample or its equivalent under the light microscope and to count the total number of gold labeled cells in the epi-polarization mode. The total cell count can be evaluated under UV light, taking advantage of the autofluorescence of the glutaraldehyde fixed cells.

Antigens, Surface↗
PubMed1986

Defective granulocyte chemotaxis and natural killer activity in a patient with recurrent infections.

A 25-year-old male with a history of recurrent infections presented with fever, severe aplastic anaemia, splenomegaly and retroperitoneal node enlargement. Lympho-histiocytic granulomas were found in spleen, liver and lymph nodes. Granulocyte studies revealed normal morphology, severely impaired random migration and complete absence of directed locomotion. Whereas phagocytosis was slightly reduced, candidacidal activity and nitroblue tetrazolium reduction were normal. Basal granulocyte cyclic GMP levels were within the normal range while a 5-fold increase of cyclic AMP levels was observed. Numerous abnormalities were also found in the patient's lymphocytes: lack of delayed hypersensitivity, reduced response to mitogens, low OKT4/OKT8 ratio, absence of natural killer (NK) activity with normal number of cells recognized by NK-specific monoclonal antibodies. These observations describe a distinct clinico-pathologic entity and suggest the possibility of a common defect in granulocytes and in NK cells.

Adult↗
PubMed1986

Biphenotypic Philadelphia positive, monosomy seven acute leukaemia: ultrastructural immunocytochemical study.

A case of Ph1 positive acute leukaemia is presented in which an additional chromosome change, monosomy 7 was found. There was no clinical evidence of a pre-existing chronic myeloid leukaemia. Cytochemistry and immunology showed a predominant HLA-DR+, TdT+, cALL- phenotype, with a small percentage of HLA-DR+, Leu-Ml+ and cALL- cells. The true biphenotypic nature of this case was clearly shown by transmission electron microscopy using the immunogold method combined with myeloperoxidase (MPO). Two distinct phenotypes, lymphoid (cALL+, MPO-) and myeloid (LeuMl+, MPO+) were identified with this technique. An immuno-scanning electron microscope technique was also used to study this case, which demonstrated the presence of two different surface morphologies.

Bone Marrow↗
PubMed1985

Scanning immunoelectron microscopy of hairy cell leukemia.

Scanning electron microscopy has shown a typical cell surface morphology in hairy cell leukemia. Scanning immunoelectron microscope techniques, utilizing monoclonal antibodies and colloidal gold particles, have recently become available. Eight patients with hairy cell leukemia have been studied with a panel of monoclonal antibodies of which B1, BA1, OKM1, anti-TAC and LeuM5 were shown to be suitable for scanning immunoelectron microscopy and reactive with hairy cells. The combination of typical cell surface features with reactivity for the B1 and LeuM5 monoclonal antibodies permits accurate diagnosis of hairy cell leukemia, particularly when low percentages of hairy cells are present as in hypocellular or in interferon-treated patients.

Antibodies, Monoclonal↗
PubMed1985

Scanning electron microscope cytochemistry of blood cells.

The backscattered electron imaging (BEI) mode of scanning electron microscopy (SEM) has been applied to study various histo-cytochemical reactions in biological specimens since the early seventies. Due to numerous, recent technical improvements the BEI mode of SEM now belongs to the routine of many SEM laboratories. For cytochemistry, BEI has been mainly used to: visualize intracellular structures and organelles; recognize the different cell types in heterogeneous populations or tissues; study the correlations between enzymatic activities and cell surface features. We have evaluated the most relevant results obtained in the study of blood cells and the possible future applications of these techniques.

Blood Cells↗
PubMed1984

Scanning electron microscopy of human leukocytes.

Extensive application of scanning electron microscopy (SEM) to the study of normal as well as of pathological human leukocytes has been pursued over the last ten years. Initial efforts to recognize, under the SEM, the two main subpopulations of circulating lymphocytes have met with limited success. However, a critical evaluation of the cell preparatory methods has emerged from the initial difficulties. Highly reproducible SEM images of leukocytes can now be obtained, and their significance correlated with immunological and/or cytochemical parameters. This resulted from the development of highly specific techniques for the immuno-labeling of cell surfaces, and from the development of SEM cytochemistry in the backscattered electron imaging (BEI) mode. A basic procedure for the SEI imaging of separated peripheral blood leukocytes (PBL's) is critically presented with the hope of facilitating significant future applications of SEM in diagnostic clinical hematology.

Cell Membrane↗
PubMed1984

Spleen alterations in hairy cell leukemia: a scanning electron microscopic study.

In Hairy Cell Leukemia (HCL) peripheral blood and bone marrow cells show under the scanning electron microscope (SEM) a characteristic surface with numerous ruffles and microvilli. The spleen of a patient affected by HCL was studied by SEM after fresh sectioning and routine preparation. Cells with the typical "hairy" surface were observed infiltrating the red pulp, altering the normal reticular meshwork and causing red blood cell distortion. In the sinuses, hairy cells adhered to the endothelial cells causing sinus dilatation and destruction. Aggregates of hairy cells delimiting pooled erythrocytes were also observed and may represent the "pseudosinuses" described in previous light and transmission electron microscopic studies. These preliminary findings may explain the condition of hypersplenism which characterizes HCL. In addition, SEM is proposed as a rapid and simple method to identify HCL spleen involvement.

Bone Marrow Cells↗
PubMed1983

Scanning electron microscope cytochemistry of normal and leukaemic leukocytes.

Backscattered Electron Imaging (BEI) is a particular technique which permits to study cytochemical reactions with the Scanning Electron Microscope (SEM). The BEI data pertaining to specific enzymatic activities can be directly correlated to the surface morphology of each individual cell. Leukocytes from 5 normal individuals, 14 patients with acute nonlymphoblastic leukaemia (ANLL), 7 patients with chronic myeloid leukaemia (CML) and 3 patients with acute lymphoblastic leukaemia (ALL) were studied for myeloperoxidase activity, acid phosphatase localization, silver staining of the nuclei and phagocytosis of iron carbonyl in the BEI mode of SEM. Some normal peripheral blood leukocytes which cannot be distinguished by their surface morphology alone were satisfactorily identified with the BEI technique. Leukaemic myeloid cells can be recognized in many cases because of their positive myeloperoxidase reaction, while monocytic elements can be characterized by the presence of surface ruffles, acid phosphatase activity and active phagocytosis. The usefulness of the BEI technique in identifying different blood cell types with the SEM and its possible application to the diagnosis of certain cases of leukaemia are discussed.

Acid Phosphatase↗
PubMed1983

Cytochemical methods for the backscattered electron imaging mode of scanning electron microscopy: further applications to the study of human leukemic cells.

The Backscattered Electron Imaging (BEI) mode of Scanning Electron Microscopy (SEM) has been applied to the study of cells stained with various heavy metals in cytochemical reactions. Improvements or modifications of some of these methods and their application to the study of normal and leukemic leukocytes have been evaluated in this report. The results obtained after staining peroxidase-positive granules with osmium, copper, cobalt-nickel and gold-cobalt are compared. Granules containing non-specific esterase activity were demonstrated in the BEI mode after incubation of the cells in Hanker medium and staining with osmium. While sites of acid phosphatase activity were easily localized with a conventional lead method, alkaline phosphatase activity was demonstrated only in the phagocytic vacuoles of cells previously incubated with latex particles and subsequently stained with lead. Cell nuclei were identified in the BEI mode after silver methenamine or bismuth staining. Combining their cell surface and cytochemical characteristics a more accurate identification of the different blood cell types with the SEM becomes possible.

Acid Phosphatase↗
PubMed1982

Iron carbonyl, a tracer for phagocytosis in scanning electron microscopy.

Human peripheral blood mononuclear cells and polymorphonuclear (PMN) leukocytes, separated by Ficoll-Hypaque have been incubated with a preparation containing iron carbonyl, and studied by scanning electron microscopy (SEM) in the backscattered electron imaging (BEI) mode. Iron carbonyl particles were visible only on the cell surface when studied in the conventional secondary electron (SE) mode of the scanning electron microscope. However, ingested iron carbonyl particles were observed in high contrast when the backscattered electrons were selectively collected. The BEI mode of the scanning electron microscope appeared very useful in identifying phagocytic activity in mixed cell populations and in establishing direct correlations, at the level of each individual cell, between surface morphology and phagocytic activity.

Humans↗
PubMed1981

Ultrastructural cytochemical localizations by back-scattered electron imaging of white blood cells.

White blood cells have been studied in the back-scattered electron imaging (BEI) mode of scanning electron microscopy (SEM) with cytochemical methods for endogenous peroxidase, acid phosphatase, and a silver-staining method for nuclei. Peroxidase-positive granules were seen with good contrast and resolution in myeloid precursor cells and acid phosphatase activity was easily detected in macrophages and monoblasts. Silver staining permitted recognition of the shapes and location of the nuclei. In spite of the cytochemical procedures, cell surface structures were reasonably well-preserved in all methods, making direct correlation of BEI and secondary electron imaging (SEI) images an attractive feature in cell research with the scanning electron microscope.

Acid Phosphatase↗
PubMed1981

Backscattered electron imaging of human leukocytes.

Methods of backscattered electron imaging (BEI) have been applied to the study of normal and malignant human leukocytes. Four different elements, principally of high atomic number, have been used: iron, silver, lead and osmium. Iron, in the form of iron carbonyl, has been found to be an excellent marker for the phagocytic activity of granulocytes and monocytes. Silver staining permitted a clear observation of the shape of the nuclei and of the nucleo-cytoplasmic ratio and made the identification of polymorphonuclear cells and of certain normoblasts possible. Lead phosphate precipitates, deposited as a result of a classic acid phosphatase reaction, were detected in several cases of myelocytic and monocytic leukemias. Precipitates of osmium/diaminobenzidine complex on peroxidase-containing granules permitted the unambiguous identification of several classes of myeloid precursors. In all these techniques, the surface morphology of the cells was adequately preserved and could be correlated with the presence and/or the distribution of the various markers.

Acid Phosphatase↗