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Biomedical subjects

D Soligo

Publications and source records attributed to D Soligo.

101 records · Page 6Linked to original sources
PubMed1979

Ultrastructural study of leukemic cell phagocytosis using the myeloperoxidase reaction.

The phagocytosis (in the absence of serum factors) of zymosan particles by peripheral leukocytes isolated from ten patients with acute leukemia (AMbL, AMoL, AMML, AUL, ALL and CML-BC) was studied at the electron microscope. An evident phagocytic activity was observed only in the cells in which cytochemical and ultrastructural features suggested that the blast elements belonged to the monocytic series. However, no phagocytosis by unclassifiable leukemic blasts was observed, even though they had some submicroscopic characteristics of the monocytic series. These findings suggest that phagocytic capacity develops during the course of cell differentiation, becoming striking only when the blast cell acquires the ultrastructural features of the pro-monocytic stage. Using the myeloperoxidase reaction, this study also demonstrates a morphological alteration in the degranulation process after the ingestion of zymosan particles in both the blasts and the mature PMN cells of leukemic patients. This defect could be related to the susceptibility to severe infections usually found in subjects with hematological malignancies.

Humans↗
PubMedDate not supplied

Scanning electron microscopy of cell surface antigens labeled with colloidal gold.

A method is described and discussed that permits the specific labeling of the surface of prefixed cells with the colloidal gold marker viewed with the scanning electron microscope. Its value depends exclusively on the use of backscattered electron imaging. Its advantages include the possibility of preserving the surface features of the labeled cells, the ease with which specificity can be established, the possibility of making total counts of the labeled surface antigenic sites, and the possibility of achieving distinct labeling for two different antigens expressed on the surface of the same cell.

Antigens, Surface↗
PubMedDate not supplied

Ultrastructural alterations of megakaryocytes in some hematologic disorders.

Bone marrow and peripheral blood samples of patients affected by hematologic disorders involving the megakaryocytic line were examined at the electron microscope. While in idiopathic thrombocytopenic purpura the megakaryocytes appeared almost normal, in primary thrombocythemia there were various ultrastructural alterations interpreted as a counterpart of ineffective thrombocytopoiesis. In one patient with blastic chronic myeloid leukemia and in another with acute megakaryoblastic leukemia, the electron microscope study was very useful in the identification of immature megakaryocytes. In fact, analysis of various ultrastructural parameters allowed some blast cells to be attributed to the megakaryocytic series. Furthermore, platelet demarcation system abnormalities and alterations of the circulating thrombocytes confirm the hypothesis that there is a block in megakaryocytic maturation.

Blood Platelets↗
PubMedDate not supplied

Clinical and laboratory findings in a new case of leukocyte adhesion deficiency.

We describe a child suffering from recurrent bacterial infections whose cells exhibited laboratory findings compatible with the leukocyte adhesion deficiency (LAD) syndrome. Surface marker analysis with monoclonal antibodies (MAbs) to the individual alpha and beta chains of LFA-1/Mac-1/p150,95 antigens revealed that the patient's neutrophils did not express the common beta chain and LFA-1/p150,95 alpha subunits, but reacted weakly with four different MAbs specific for the Mac-1 alpha chain; however, no glycoprotein was immunoprecipitated from the patient's cells using the same anti-Mac-1 alpha MAbs. Functional analysis of the patient's phagocytes revealed many of the defects in adherence-dependent functions (adherence, chemotaxis and phagocytosis) described in patients with LAD. The studies performed on the phagocytes of the patient's relatives showed normal phenotypes and function, suggesting the possibility of a non heritable form of disease in this family.

Antigens, CD↗
PubMedDate not supplied

Relevance of ultrastructural immunocytochemistry in the characterization of unclassifiable leukemias: correlation with phenotypic and genic studies.

Nine cases of acute leukemia presenting unusual phenotype were studied by light microscopy (LM) cytochemistry and transmission electron microscopy (TEM) immunocytochemistry with the immunogold staining (IGS) method; in addition, cytogenetic and molecular analyses were performed. The presence of myeloperoxidase (MPO) was studied at TEM in combination with immunophenotype to identify minor populations not characterizable at LM. Four of nine cases had no TEM/MPO reactivity, whereas the remaining five showed variable percentages of positive cells. Of the MPO negative cases, one was a megakaryoblastic leukemia with a positive platelet peroxidase (PPO) reaction, and three were lymphoid. Among the peroxidase positive cases, the percentage of MPO reactive cells was higher at TEM than at LM examination. In case 5 TEM analysis indicated that cells with some MPO reactivity at LM were non neoplastic myeloid cells. With this combined technique in cases 1 and 2 we excluded the presence of the MPO enzyme in CD15 positive lymphoid cells and, in another case, we documented the existence of CD19/MPO positive cells. The value of cytochemistry and immunology at the ultrastructural level for the characterization of blast cells and for the precise diagnosis of leukemia with "unusual" phenotype is illustrated.

Adult↗
PubMedDate not supplied

Abnormal neutrophil chemotaxis in bone marrow transplant patients correlates with impaired 31D8 monoclonal antibody binding.

BACKGROUND: 31D8 monoclonal antibody (mAb) has been shown to bind heterogeneously to human neutrophils, identifying subsets of cells which differ in their functional response to chemotactic stimuli. In this study we used 31D8 mAb to determine whether differences in neutrophil subpopulations might explain the long-lasting decreased chemotaxis observed in bone marrow transplant recipients. METHODS: Thirty patients with self-sustaining hematopoiesis 1 to 5 years bone marrow transplantation (BMT) (15 allogeneic and 15 autologous) performed for acute lymphocytic leukemia (ALL, 10 patients) or acute myelogenous leukemia in complete remission (8 patients), Hodgkin's lymphoma (2 patients), chronic myeloid leukemia (8 patients) and severe aplastic anemia (2 patients) were included in the study. Neutrophil chemotaxis was evaluated using a modified Boyden chamber assay and 31D8 binding was determined by indirect immunofluorescence and cytofluorimetric analysis. RESULTS: Neutrophil chemotaxis was significantly impaired in the BMT group with respect to controls. The chemotactic defect strikingly correlated with autologous BMT and, in particular, with ALL as the pre-existing disease. No differences between patients and controls were observed in the percentage of 31D8 bright and dull neutrophils. However, when mean fluorescence intensity (MFI) was analyzed as a relative measure of 31D8 antigen expression on the overall neutrophil population, a significant decrease was observed in neutrophils from BMT patients with respect to controls. As for chemotaxis, the impairment of 31D8 binding was more evident in autologous BMT and strikingly correlated with ALL as the pre-existing disease regardless of age, sex and time since BMT. Moreover, a significant positive correlation between impaired chemotaxis and decreased 31D8 binding was found in our patients. CONCLUSIONS: These findings suggest that the decreased neutrophil chemotaxis observed in some BMT patients may be due in part to circulating 31D8 dull neutrophils, although the causes for the decreased 31D8 binding and for the quite pronounced neutrophil defect in ALL patients remain unknown.

Adolescent↗
PubMedDate not supplied

Single-institution results of autologous bone marrow transplantation in acute myeloid leukemia.

BACKGROUND: Current results of autologous bone marrow transplantation (ABMT) suggest that this procedure may prolong disease-free survival (DFS) in patients with acute myeloid leukemia (AML). MATERIALS AND METHODS: Over the last ten years, 29 AML patients received unpurged autologous bone marrow (BM) after a conditioning regimen including Ara-C (3 g/m2/12h, days -9, -8), CTX (60 mg/kg/day, days -6, -5) and TBI (3.33 Gy/day, days -3 through -1). In 21 patients, ABMT was performed as late intensification after first CR. Eight more relapsing patients were autografted after the achievement of second CR. RESULTS: Three patients died from transplant-related complications. In the remaining patients, mean times to WBC and platelet recovery were, respectively, 23 days (range 13-55) and 55 days (range 22-790). Follow-up for censored patients ranged from 1 to 120 months. Relapse occurred in 7 patients (5 in first and 2 in second CR). Overall 5-year DFS and event-free survival (EFS) chances were, respectively, 67.3% and 60%, with no statistically significant differences between first (DFS = 67.3%, EFS = 60.3%) and second CR (DFS = 68.6%, EFS = 60%). DISCUSSION: Apart from obvious selection biases, our study suggests that outcome in first CR AML patients is improved by ABMT. Long-term DFS and EFS are clearly better than when conventional post-remission chemotherapies are used. The greater antileukemic potential of ABMT is further underlined by the results in patients autografted in second CR, when conventional chemotherapy is almost never curative.

Acute Disease↗
PubMedDate not supplied

5q- in a case of chronic myelogenous leukemia relapsed after allogeneic bone marrow transplantation.

Clonal chromosome and/or hematological abnormalities typically observed in myelodysplastic syndromes (MDS) have been described with increased frequency after autologous bone marrow transplantation (BMT) for lymphoma. We report the case of a woman with chronic myelogenous leukemia (CML) allografted with her HLA-identical sibling who, 5 years after the transplant and under immunosuppressive treatment for chronic graft host disease (GVHD), suffered a cytogenetic relapse associated with a 5q- deletion in the host metaphases. These findings suggest that myelodysplastic changes, possibly related to the chemo-radiotherapy conditioning regimen, may also present after allogeneic BMT.

Adult↗
PubMedDate not supplied

Efficacy of different prophylactic antifungal regimens in bone marrow transplantation.

BACKGROUND: Fungal infections still represent a major clinical problem in neutropenic patients; the recent availability of active imidazole derivatives, particularly fluconazole and itraconazole, has increased interest in prophylaxis. MATERIALS AND METHODS: Fifty-nine consecutive bone marrow transplant (BMT) recipients were randomized to receive either itraconazole 400 mg/day or fluconazole 300 mg/day as oral antimycotic prophylaxis during the pancytopenic phase; they were retrospectively compared with a historical control group of 30 patients who had received fluconazole 50 mg/day. Every febrile episode was treated with the same empirical antibiotic combination; amphotericin-B was added after 4-5 days in the case of persistent fever. Proven or suspected mycotic infections and the empirical use of amphotericin-B were considered as failures of prophylaxis. RESULTS: There were no differences in the number of febrile episodes in the three groups. Five patient died of bacterial sepsis: two in the fluconazole 300, two in the itraconazole and one in the fluconazole 50 group. The addition of amphotericin-B was required in 12, 16 and 11 cases, respectively, in the three groups. There were four documented fungal infections in the intraconazole and one in both fluconazole groups; three suspected fungal infections were observed in the fluconazole 300 group and two in both the itraconazole and the fluconazole 50 group. None of the differences were statistically significant. CONCLUSIONS: The present results indicate that high-dose fluconazole and itraconazole are equivalent; neither of them was superior to low-dose fluconazole, which is regarded as being devoid of prophylactic activity against systemic mycoses.

Adolescent↗
PubMedDate not supplied

Response of myelodysplastic syndrome bone marrow cells to multiple cytokine stimulation in liquid cultures: an in situ hybridization study.

BACKGROUND AND OBJECTIVE: Myelodysplastic syndrome progenitor cells can be grown and expanded in long term bone marrow liquid cultures in the presence of multiple cytokines. In this study we investigated the pattern of differentiation and response to growth factors in six cases of myelodysplastic syndrome (MDS) with well-defined cytogenetic abnormalities by means of conventional cytogenetics and fluorescence in situ hybridization (FISH). METHODS: Bone marrow cells were grown in stroma-free liquid cultures in the presence of SCF, IL-3, IL-6 and GM-CSF. RESULTS: IN three cases a CFU-GM expansion comparable to normal controls was observed, together with a decrease or increase of cells with abnormal karyotype. Two cases showed no response to growth factor stimulation, morphological signs of terminal myeloid differentiation and increase (one case) or decrease (one case) in the percentage of abnormal FISH signals along the cultures. In one additional case, while CFU-C expansion was present, clearcut leukemic transformation was observed in the culture, together with a sharp decrease in the percentage of abnormal FISH signals, indicating a leukemic transformation of MDS progenitor cells with a normal karyotype. INTERPRETATION AND CONCLUSIONS: Our data indicate that FISH analysis is generally a poor indicator of clonality in MDS; nevertheless, determining the kinetics of cytogenetically abnormal clones in liquid bone marrow cultures may provide insight as to the growth abnormalities of MDS progenitor cells and may be useful prior to in vivo growth factor administration.

Bone Marrow Cells↗