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Biomedical subjects

F Tumietto

Publications and source records attributed to F Tumietto.

13 recordsLinked to original sources
PubMed1999

A randomized, double-blind trial on the use of a triple combination including nevirapine, a nonnucleoside reverse transcriptase HIV inhibitor, in antiretroviral-naive patients with advanced disease.

The immunologic and virologic activity of nevirapine in combination with two nucleosides (zidovudine [ZDV] and didanosine [ddI]) was evaluated in antiretroviral-naive patients with a CD4 count <200/mm3 or clinical AIDS. In all, 68 patients were enrolled in a 48-week double-blind, placebo-controlled trial. A group of 32 patients received ZDV + ddI + nevirapine, and 36 patients received ZDV + ddI. Primary efficacy parameters were the activity on HIV-1 RNA and on peripheral blood CD4+ cells, with differences between groups analyzed by the Wilcoxon's nonparametric two-sample test. Baseline RNA was high in both treatment groups (median values, 5.8 and 5.7 log10). RNA and CD4 responses were significantly higher with the triple combination (median RNA reductions, 2.69 versus 1.05 log10 at 24 weeks and 1.97 versus 1.20 log10 at 48 weeks; median CD4 increases, 81 versus 64 cells/mm3 at 24 weeks and 101 versus 27 cells/mm3 at 48 weeks). This study demonstrates that a triple combination of ZDV + ddI + nevirapine used as first-line regimen in antiretroviral-naive patients can induce sustained virologic and immunologic response in patients with low CD4 count or a previous diagnosis of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Effects of dialysis membrane nature on intradialytic phagocytizing activity.

Blood-membrane contact in the extracorporeal circuit affects the activation of many biological systems. Among these, phagocytizing activity has been reported to be influenced by the nature of the hemodialysis membrane used, whether cellulosic or synthetic. This work reports on an ex-vivo, comparative test between cellulosics and synthetics concerning the effects of blood-membrane contact on the polymorphonucleate and monocyte phagocytizing function, both during and after the hemodialysis session. By means of flow cytometry, we evaluated the capacity for phagosoma formation and oxidative burst both in polymorphonucleates and monocytes. Ten hemodialysis patients were included in the study. Six separate dialysis procedures for each patient were considered, one per dialyzer (3 cellulosic and 3 synthetic membranes). Tests were performed at 15', 60', 210' and 4 hours after the session end. Comparative evaluation was made according to Student's t test. Polymorphonucleate phagocytosis and oxidative burst activation were globally more marked for synthetic than cellulosic membranes, tending to level out in the post-dialysis. This result could be affected by their functional exhaustion following pulmonary sequestration. Monocyte intradialytic phagocytosis and oxidative burst proved more activated by cellulosic membrane. All differences tended to vanish in the post-dialysis.

Flow Cytometry↗
PubMed1997

An erythroid and megakaryocytic common precursor cell line (B1647) expressing both c-mpl and erythropoietin receptor (Epo-R) proliferates and modifies globin chain synthesis in response to megakaryocyte growth and development factor (MGDF) but not to erythropoietin (Epo).

A human megakaryocyte cell line (B1647) has been established from bone marrow cells obtained from a patient with acute myelogenous leukaemia (FAB M2). The cells were CD34-, CD33+, HLA-DR+, CD38+, and expressed the immunophenotypic markers of the megakaryocyte lineage (CD41 and von Willebrand factor). Moreover the cells expressed the c-mpl (thrombopoietin receptor) mRNA and protein. On the other hand, the B1647 cells also possessed erythroid lineage characteristics: the vast majority of cells were glycophorin positive, and about 10% of unstimulated cells stained with an anti-globin gamma chain MoAb. In addition, S1 protection analysis demonstrated expression of beta-globin mRNA, and Epo receptor (Epo-R) protein was detected by cytofluorimetric assay. Several growth factors, when tested alone or in combination, failed to influence the B1647 cell growth. A significant increase of cell proliferation was observed only after the addition, in serum-free culture, of recombinant human megakaryocyte growth development factor (MGDF), a recombinant c-mpl ligand encompassing the receptor-binding domain and identical to thrombopoietin (TPO), at concentrations ranging from 0.01 to 1 ng/ml. Interestingly, MGDF failed to induce megakaryocytic differentiation of the B1647 cells, but significantly increased the synthesis of the globin gamma-chain. B1647 cells could be a useful model for studying the biological effect of TPO on common megakaryocyte and erythroid progenitors.

Cell Division↗
PubMed1992

Detection of circulating p24 antigen-positive CD4+ cells during HIV infection by flow cytometry.

OBJECTIVES: To determine the amount of circulating CD4+ cells positive for intracellular p24 antigen during HIV infection, and to correlate the results with clinical, virological and therapeutic parameters. METHODS: Data were obtained from 24 anti-HIV-negative subjects (controls) and 47 anti-HIV-positive patients classified according to clinical diagnosis, serum p24-antigen assay results, and antiretroviral treatment with zidovudine, using a modified flow cytometric assay for the detection of intracellular HIV p24 antigen (p24-FCA) in circulating CD4+ lymphocytes. RESULTS: The proportion of CD4+ lymphocytes positive for p24-FCA correlated well with HIV infection (1.685 +/- 1.902 versus 0.160 +/- 0.152 in controls; P < 0.001) and clinical progression [Centers for Disease Control (CDC) stage II: 1.310 +/- 1.187; CDC stage III 1.145 +/- 1.442; CDC stage IVA/C2: 2.335 +/- 2.112; CDC stage IVC1: 2.066 +/- 2.420]. The percentage of CD4+ cells positive for HIV p24-FCA was inversely correlated with an absolute peripheral blood CD4+ lymphocyte count (Spearman's rank correlation = -0.324; P < 0.05). However, there was no statistically significant difference between patients in presence (n = 27; 1.938 +/- 2.095) or absence (n = 20; 1.343 +/- 1.594) of serum p24 Ag. The variable linked most strongly to the detection of intracellular p24 in anti-HIV-positive patients was zidovudine treatment: the proportion of p24-FCA-positive CD4+ lymphocytes was significantly lower (0.825 +/- 0.910) in the treated patients (n = 25) than in the untreated patients (n = 22; 2.662 +/- 2.248; P < 0.001). CONCLUSIONS: Our results suggest that CD4+ p24 Ag-FCA is a rapid and easy test for the identification of the proportion of CD4+ lymphocytes with intracellular p24 Ag, and that it could be more appropriate than serum p24 Ag assay in evaluating disease progression and efficacy of antiretroviral treatment.

Blood Circulation↗
PubMed1992

Recombinant interleukin-2 (rIL-2) in acquired immune deficiency syndrome (AIDS): preliminary report in patients with lymphoma associated with HIV infection.

In an ongoing phase II study, 12 patients with lymphoma and HIV infection were treated with zidovudine (ZDV) and recombinant interleukin-2 (rIL-2) to evaluate if this association may produce beneficial effect on the immunologic status and the outcome of lymphoma. The protocol included daily doses of rIL-2 at 6 MIU/m2 over 5 days in c.i. per week for a total 4 courses; ZDV was associated at 600 mg/d in the period under study. An improved CD4 count, exceeding 2- to 4-fold the basal count, was obtained in patients with a basal CD4 number greater than 100/microliters accompanied by a significant increase of NK and LAK activity (p less than 0.001). From the clinical point of view the reduction of tumor manifestation was proportional to CD4 basal number; 2 patients from those with CD4 greater than 100/microliters obtained a complete remission after rIL-2 and ZVD. The p24 antigen, taken as parameter of viral replication, remained invariably negative after rIL-2 and ZDV in patients already negative and became negative in 1 patient previously positive. Our conclusion is that the association of rIL-2 and AZT is safe and useful in patients with lymphoma and HIV infection.

CD4-Positive T-Lymphocytes↗
PubMed1990

[Clinical and immunologic test of the activity of a polymicrobial vaccine in patients with chronic bronchitis during a flare-up].

The authors evaluated the effect of an orally administered polymicrobial vaccine in a group of chronic bronchitis patients in order to assess its efficacy in preventing recurrent infections and as adjuvants during minor acute episodes. Compared to the control group, vaccinated patients had 1) a reduced number of flare-ups, and these were less severe and symptoms were improved; II) lymphocyte phenotype was not altered in any of the patients but nevertheless the response to skin tests for delayed sensitivity was improved in the vaccinated patients only; III) more rapid symptomatic improvement of flare-ups. The authors stress the improvement of cell-mediated lymphocyte function as a result of vaccination, probably due to macrophage activation and with resulting improvement of the clinical course of the bronchial disorder.

Adult↗
PubMedDate not supplied

Growth hormone (GH) and the immune system: impaired phagocytic function in children with idiopathic GH deficiency is corrected by treatment with biosynthetic GH.

Thirty-seven prepubertal children evaluated for severe growth retardation were studied by assessment of total granulocyte, monocyte and lymphocyte count, lymphocyte subsets CD3+, CD3+Dr+, CD3+Dr-, CD4+, CD8+, CD8+CD57+, CD8+CD57-, CD16+, CD20+ and CD23+, serum immunoglobulin concentrations, and phagocytic activity of circulating neutrophils and monocytes (by a flow cytometric assay). Idiopathic GH deficiency was diagnosed in 21 of 37 patients; the remaining 16 healthy subjects served as controls. Fourteen patients received biosynthetic GH (rhGH), and their immune parameters were assessed at baseline and after 6 months of therapy. Phagocytic function mediated by both polymorphonuclears and monocytes was significantly impaired in GH-deficient subjects compared to controls (p < 0.003 for neutrophils, p < 0.007 for monocytes), while a significant increase of phagocytic activity was obtained during long-term rhGH replacement therapy (p < 0.02 for neutrophils, p < 0.001 for monocytes), thus suggesting that GH may affect the functional activity of circulating phagocyte cells. No significant differences were found in total granulocyte, monocyte and lymphocyte counts, T- and B-lymphocyte subsets and immunoglobulin levels, between GH-deficient patients and controls, and between values observed before and during rhGH substitution treatment.

Adolescent↗