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Biomedical subjects

B Brando

Publications and source records attributed to B Brando.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Polymorphonuclear cell phagocytosis and surface receptor modulation after extracorporeal circulation.

Polymorphonuclear cells (PMN) from patients treated with hemodialysis (HD) or plasma exchange (PE) were analyzed by flow cytometry to determine modulation in phagocytic capacity and Fc-gamma and C3bi receptor expression following extracorporeal circulation (EC). Fluorescent microbeads (phi 2.02 m) were used in the evaluation of phagocytosis, and phycoerythrin conjugated Leu11c and Leu15 monoclonals identified Fc-gamma and C3bi receptors respectively. The percentage of positive cells and mean receptor density on PMN surfaces were calculated for each antibody before and after the procedures. Fc-gamma receptor expression was reduced overall in HD and PE cases, but unaffected after EC even with specific paraprotein removal. C3bi receptor was normally expressed on PMNs before and after EC, but receptor density on the cell surface increased, and phagocytosis was qualitatively and quantitatively depressed after EC. The resulting effect of EC on PMNs was therefore a temporary increase in C3bi receptor density after the procedure, which was independent of HD or PE technique, of the primary disease, and of the quality of the PE reinfusion solutions, suggesting a procedure-related effect, and a down-regulation of PMN phagocytic activity. Both effects may be related to membrane biocompatibility.

Antigens, Differentiation↗
PubMedDate not supplied

CD90.

Explore the source record for details and available documents.

Amino Acid Sequence↗
PubMedDate not supplied

Diagnostic and prognostic value of flow cytometric immunophenotyping in malignant hematological diseases.

Flow cytometry is a diagnostic cell analysis technique with ever increasing applications in modern hematological practice. To date immunophenotyping of clonal hematological diseases represents one of the primary clinical applications of flow cytometry. Immunophenotyping of abnormal cells is now considered a fundamental tool to establish the cell lineage assignment and to obtain a more precise identification of the various cell subtypes. A number of observations have emerged showing strong association between specific immunophenotypes and genetic recurrent abnormalities underlying the malignant transformation, with prognostic value.

Biomarkers↗
PubMedDate not supplied

Panleucogating as an accurate and affordable flow cytometric protocol to analyse lymphocyte subsets among HIV-positive patients on HAART treatment in Mozambique.

In Africa tens of millions of people are HIV+. Prevention alone is not effective, and needs to be coupled with anti-retroviral treatment (HAART). Laboratory tests as CD4+ T cell count are fundamental tools in HIV disease monitoring, but they require costly equipment, reagents and specialised manpower. The goal of this study was to minimise and optimise the reagents needed for a reliable routine CD4+ cell count in a resource-poor setting (Mozambique). Panleucogating protocol (PLG), requires two antibodies only, CD45 and CD4, or three if CD8 is requested for special clinical reasons. PLG was compared with the current protocol used in two Mozambique hospitals, based on FSC/SSC gating and CD3/CD4/CD8 staining. 189 samples from HIV+ patients, included in the Community of Sant'Egidio's DREAM program and on HAART were processed with both protocols. The overall correlation of the lymphocyte subsets measurements was satisfactory, with r2 always >0.96. The Bland-Altman analysis of CD4+ cell count showed a negative bias when CD4+ cells were <15%, due to the imprecise FSC/SSC gating used previously. When CD4+ cells were >15% the negative bias tended to zero, further confirming the better quality of the PLG gating strategy. Two- or three color PLG protocol, in double platform, currently seems the most accurate and affordable method to monitor CD4+ lymphocytes and CD4/CD8 ratio by flow cytometry in resource-poor medical settings.

Antiretroviral Therapy, Highly Active↗
PubMedDate not supplied

Flow cytometry to estimate circulating hematopoietic progenitors for autologous transplantation: comparative analysis of different CD34 monoclonal antibodies.

We report that the 2 fluorescein (FITC) conjugated CD34 monoclonal antibodies available to date, namely FITC-8G12 and FITC-QBEND10, exhibit different capabilities of detecting circulating hematopoietic progenitors (CHP) as cells expressing the CD34 antigen (CD34+) by direct immunofluorescence flow cytometry. Mean fluorescence intensity conferred by FITC-QBEND10 to CD34+ CHP is 2.8-4.3 times lower than that conferred by FITC-8G12. By indirect immunofluorescence, native unconjugated QBEND10 and 8G12 antibodies detect CD34+ CHP in a comparable manner, thus indicating that the decrease in QBEND10 affinity is due to FITC-conjugation. Utilization of FITC-QBEND10 instead of FICT-8G12 to estimate infrequent (usually less than or equal to 5%) CD34+ CHP for clinical decision-making in autologous transplantation of CHP exposes clinicians to the risk of either overestimating (false positive) or underestimating (false negative) these cells in peripheral blood. Recently published guidelines for large-scale collection of CHP for autologous transplantation in cancer patients were based on data obtained with FITC-8G12. The same guidelines cannot be considered valid if FITC-QBEND10 is employed. We recommend FITC-8G12 as the optimal reagent to date for standardizing results of autologous CHP transplantation in cancer therapy.

Antibodies, Monoclonal↗
PubMedDate not supplied

Heterogeneity of circulating hematopoietic progenitors in cancer patients treated with high-dose cyclophosphamide and recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF).

Antigen CD34+ cells represent 1-4% of adult bone marrow cells comprising virtually all hematopoietic colony-forming progenitors in-vitro and probably also stem cells capable of restoring hematopoiesis of lethally irradiated hosts. We report that sizable numbers of CD34+ cells transiently circulate in the peripheral blood (PB) of patients treated with high-dose (7 g/sqm) cyclophosphamide (HD-CTX) with or without recombinant human glycosylated granulocyte macrophage colony stimulating factor (rhGM-CSF). Evidence is presented demonstrating that CD34+ cells from PB possess qualitatively normal hematopoietic colony growth and high cloning efficiency similarly to marrow CD34+ cells. In addition, CD34+ cells from PB are shown to display heterogeneous flow cytometry characteristics and differentiation antigens analogous to those from bone marrow, i.e., CD34+/CD33-, CD34+/CD13-, CD34+/CD38-, CD34+/CD11b, CD34+/DRlow+ cells have light scatter properties of small lymphocytes while CD34+/CD33+, CD34+/CD13+, CD34+/CD38+, CD34+/CD11b+, CD34+/DRhigh+ cells have light scatter properties of blast-like cells. In HD-CTX treated patients, CD34+ cell circulation is 5-fold enhanced by rhGM-CSF 5.5 micrograms/kg/day by continuous iv infusion for 14 days. During the second-third week after HD-CTX, large-scale collection of PB leukocytes by 3-4 continuous-flow leukaphereses allows the yield of 2.19-2.73 x 10(9) or 0.45-0.56 x 10(9) CD34+ cells, depending on whether or not patients receive rhGM-CSF. The number of CD34+ cells retrieved from PB by leukaphereses exceeds the number that can be harvested by multiple bone marrow aspirations under general anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Immunotoxin mediated killing of clonable T-lymphocytes infiltrating an irreversibly rejected human renal allograft.

We isolated and treated in vitro with a novel CD5-specific saporin immunotoxin, referred to as OKT1-SAP, the cells infiltrating an irreversibly rejected renal allograft from a patient who rejected while on cyclosporine plus steroids and then failed to respond to multiple courses of high-dose steroids, intravenous OKT3 antibody, and local irradiation to the graft. We report here that under experimental conditions achievable in vivo the immunotoxin OKT1-SAP was capable of eliminating in vitro more than 95% of clonable T-lymphocytes infiltrating the rejected allograft of this patient despite their resistance to previous aggressive immunosuppression. To our knowledge, this is the first report of an immunotoxin-mediated suppression of the clonogenic growth of rejected renal allograft infiltrating T-lymphocytes.

Adult↗
PubMedDate not supplied

Flow cytometric study of immunocompetent cell phenotypes and phagocytosis in CAPD effluent.

The immunocompetent cells from peritoneal effluent in 22 stable CAPD patients were studied for surface phenotype distribution and for phagocytic properties by flow cytometry. The following monoclonal antibody couples were employed with direct dual color immunofluorescence: HLA-DR/CD 4, CD 8/CD 11c, Leu 7/CD 16, CD 14/CD 13, and Anti-Leucocyte/CD33. The phagocytic properties of peritoneal macrophages and polymorphs (PMN) were evaluated by the ingestion of 2.02 microns O fluoresceinated microspheres. The same analyses were also performed in peripheral blood. A FACStar laser-operated flow cytometer was employed. A remarkable heterogeneity of CAPD fluid cells was demonstrated, even in the absence of any obvious infection, suggesting the possible occurrence of aborted inflammatory processes. Activated T helper cells, T suppressors (CD8+/CD11+) and Fc gamma+ cells prevailed among lymphocytes, whereas variable amounts of monocytes and PMNs were present. The phagocytic activity of CAPD fluid phagocytes ranged from very depressed to normal values, whereas it was only moderately reduced in blood, suggesting local blocking phenomena, possibly due to interfering metabolites. Flow cytometry is the method of choice for a rapid and accurate analysis of phenotypic and functional properties of cells recovered from various body fluids. This study may be helpful in evaluating local immune response mechanisms in CAPD patients.

Adult↗