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F Ambrogi

Publications and source records attributed to F Ambrogi.

At least 37 records · Page 2Linked to original sources
PubMed1995

An image processing procedure for the assessment of normality curves of motility of human granulocytes in micropore filters.

With the conventional methods used in current practice, the results of human granulocyte motility assays are expressed by a numerical value that defines the leading front of cells into micropore filters. The authors have developed a fast procedure which allows the complete curve of polymorphonuclear leukocyte (PMN) migration to be obtained, from the initial plane of a filter to the maximum propagation depth. In this way, more information is given than that expressed by a single parameter. The paper describes the procedure used to determine the normality curves both for random and stimulated migration, according to a simple model which defines the PMN propagation in micropore filters. A normality band that defines variations due to the stochastic process is also reported.

Cell Movement↗
PubMed1995

Effects of lysine-arginine association on immune functions in patients with recurrent infections.

Combined L-lysine-L-arginine therapy is capable of inducting recovery in age-related decline of thymic activity in mice and in elderly humans. The clinical usefulness of the association has also been shown in children with recurrent respiratory infections, while an increase in the number of CD3+ lymphocytes has been shown in patients with chronic lymphatic leukaemia. Recently, in vitro effects of the association on neutrophil function have been reported. In particular, the association was able to increase random migration, chemotaxis, phagocytosis-associated- and f-MLP-induced chemiluminescence. In this paper the authors evaluate the effects of L-lysine-L-arginine combination (lisargin) on several humoral and cell-mediated immunologic parameters in patients with recurrent infection. An increase of neutrophil random migration and chemotaxis (evaluated by a new technique, based on a computer assisted image processing system) was found. Furthermore an increase in the absolute number of lymphocytes involved in cytotoxic activity and IgG levels was observed.

Adult↗
PubMed1995

[The role of flow cytometry in the study of physiopathology of neutrophilic granulocytes].

Flow cytometry represents an interesting methodological approach to human neutrophil function assessment and to the study of neutrophil biology. Several aspects of neutrophil activation can be evaluated by means of such technology: phagocytosis, respiratory burst, surface markers, modifications in intracellular pH, actin polymerization, membrane potential, aggregation. Neutrophil flow cytometric evaluation is suitable for whole blood evaluation and has been shown to be very specific and sensitive. In particular, whole blood methods have been developed in order to investigate phagocytosis, hydrogen peroxide production, and surface markers expression (integrins, receptors for the Fc fragment of IgG, selectins, etc.). Other aspects of neutrophil activation have to be investigated by using purified neutrophils.

Flow Cytometry↗
PubMed1995

Neutrophil functions in essential thrombocythemia.

Chronic myeloproliferative diseases, such as chronic myeloid leukemia and polycythemia vera, are associated with neutrophil dysfunction. Very little data is available on essential thrombocythemia (ET). In the current study we evaluated 21 patients with ET. All patients were studied at least 16 weeks after any cytostatic therapy and 10 days after any other therapy. Neutrophil functions were investigated as follows: flow cytometric evaluation of whole blood phagocytosis of opsonized FITC-conjugated E. coli; whole blood chemiluminescence after stimulation with opsonized zymosan and evaluation by an automated, computer-assisted luminometer (LB 950, Berthold); and chemiluminescence and superoxide anion generation by purified neutrophils after f-MLP and PMA stimulation. Chemiluminescence and superoxide anion generation after f-MLP stimulation were found to be significantly lower than in normal subjects, whereas values within the normal ranges were registered after PMA stimulation. Phagocytosis-associated chemiluminescence was found to be impaired both by using zymosan opsonized with autologous plasma and zymosan opsonized with normal plasma, despite a normal phagocytic activity. These data show the presence in ET of a complex neutrophil dysfunction that may be related to an impaired signal transduction during both the phagocytic process and f-MLP stimulation.

Adult↗
PubMed1994

3H-NECA binding to polymorphonuclear membrane: effect of sera from patients with Hodgkin's disease.

Several studies have shown that sera from patients with Hodgkin's disease contain factors capable of inhibiting polymorphonuclear functions, among them chemotaxis. In the present study, we investigated whether these sera, which were able to inhibit PMN chemotaxis in the agarose test, were also able to affect the 3H-NECA binding to PMN membrane obtained from healthy donors. Control experiments were carried out using PMN incubated with a pool of sera from healthy volunteers. No significant difference was found in the maximum number of binding sites; on the contrary, the equilibrium dissociation constant was significantly increased in the membrane preparation of PMN incubated with pathological serum.

Adenosine↗
PubMed1993

Is binding of vitamin D binding protein related to cell differentiation?

Vitamin D binding protein (Gc) is present on the surface of several blood cells and may interfere with the activity of 1,25(OH)2D3. It has previously been reported that Gc may bind to the U-937 line which is known to differentiate upon exposition to 1,25(OH)2D3. In the present paper, we evaluate the expression of Gc on the surface of U-937 and HL-60 lines. Both cell lines did not express Gc on their surface but U-937 cells were able to bind human purified Gc added to the medium whereas HL-60 were not. After culturing with 1,25(OH)2D3, HL-60 became able to bind Gc. This property seems to be related to the monocytic differentiation induced by 1,25(OH)2D3. Conversely, when present together, 1,25(OH)2D3 reduces binding on U-937.

Calcitriol↗
PubMed1993

Lysine-arginine association and human neutrophil function: enhancement of functions related to microbicidal activity.

The effects of L-lysine, L-arginine, and lysine-arginine association on human neutrophil function were studied. The combination of the two agents, used at pharmacological concentrations, was able to increase both the phagocytosis-associated and the f-MLP-induced chemiluminescence, in the presence of luminol as amplifier agent. Neither superoxide anion production nor phytohaemagglutinin-induced aggregation were affected by the lysine-arginine association. The two amino-acids did not show any effect when used as single agents. L-canavanine (competitive inhibitor of nitric oxide synthesis starting from L-arginine) did not reduce chemiluminescence. These results show that the association lysine-arginine may increase the microbicidal potential of human neutrophils, probably by increasing the production of hypochlorous acid. In addition, a role for nitric oxide in these effects can be excluded.

Arginine↗
PubMed1993

Mycobacterial infection in HIV+ patients detected with a new immunological method (TB test).

Antibody response to antigen A60 (a mycobacterial antigen) was evaluated in ELISA in 18 HIV+ subjects with clinical and cultural evidences of mycobacterial infections, in 10 HIV+ subjects without Mycobacterial infections and in 22 healthy donors. We found higher levels of specific IgG in the HIV+ patients with Mycobacterial infections (mean 179.2 +/- 83 U) compared to the values of the donors (mean 92.5 +/- 35.5 U: p < 0.01). This test may be useful in the diagnosis of tuberculosis, but it needs clinical validation.

AIDS-Related Opportunistic Infections↗
PubMed1993

In vitro effects of an immunoglobulin preparation for intravenous use (IVIG) on T-cells activation.

The "in vitro" effect of different concentrations of polyclonal human immunoglobulins for intravenous use (IVIG) on cultured T-lymphocyte response to phytohemagglutinin (PHA) was evaluated. Four dilutions of IVIG corresponding with the "in vitro" doses currently employed in therapy have been tested by the effect on PHA stimulated cultures. The dilution of IVIG corresponding with a low therapeutical dose gives a higher statistically significant stimulating effect. The results obtained in our work agree with previous studies performed on activated B-cells. We can suppose the immunoglobulins may control the T-lymphocyte activation either by a direct link with a specific Fc-receptor expressed on the surface of activated T-cell or by affecting the cytokines release from monocyte cells.

Cells, Cultured↗
PubMed1992

CD5+ B lymphocytes and T-cell subsets in a case of juvenile rheumatoid arthritis.

Recent research has demonstrated that CD5+ B lymphocytes have an important role in autoimmune and rheumatic diseases. In a case of juvenile rheumatoid arthritis (JRA), we observed the behavior of these cells and other subpopulations of T lymphocytes of peripheral blood before and after therapy with thymopentin (TP5). All the lymphocyte subpopulations returned to normal range, except the CD5+ B cells, where the percentage remained abnormally high (60%). These data suggest that CD5+ B cells can be a useful monitoring index and confirm their important role in the pathogenesis of juvenile rheumatoid arthritis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

An image processing workstation for automatic evaluation of human granulocyte motility.

Polymorphonuclear (PMN) motility is currently determined by a method using chemotactic chambers with micropore filters. PMN locomotive capacity is measured by evaluating the maximum distance travelled by the cells, or by counting the number of cells which have moved through the filter. Although in recent years some attempts to improve the analysis of chemotaxis data by computer-assisted systems have been made no technique has been shown capable of both measurement and correlation of these parameters in real time. In the present paper we describe an automated technique, based on a workstation capable of exploring microporous filters employed in chemotactic chambers and of measuring PMN motility in a reliable, reproducible, rapid manner, independent of the subjectivity of the operator. The measurement is carried out by custom software capable of undertaking computerized image analysis of microscopic fields acquired by a TV camera and of driving the motorized microscopic table. Depth of migration, cell distribution at each plane, correlation index of the random behaviour with the model described by a gaussian distribution and data about the patient or assay under study, are computed, displayed, stored in a data base and printed in real time.

Algorithms↗
PubMed1992

FcRIII (CD16) expression on neutrophils from chronic myeloid leukemia. A flow cytometric study.

FcRIII (CD16) expression on neutrophils from 17 patients with chronic myeloid leukemia (CML) was studied by flow cytometry using monoclonal antibodies. A variable proportion of CD16-negative neutrophils were found both in CML patients in chronic phase (3 out of 8 patients) and in CML patients in hematological remission (3 out of 9 patients). Neutrophils with reduced FcRIII expression showed more defective chemiluminescence and phagocytosis than neutrophils with normal FcRIII expression. Circulating myeloid cells from three patients in chronic phase, showing a normal percentage of CD16-positive neutrophils, were isolated and fractionated by discontinuous Percoll gradients. This study showed that CD16 appears at the stage of metamyelocyte, that band cells and segmented neutrophils display an identical pattern of membrane FcRIII, and that the fluorescence intensity shown by metamyelocytes is different from that displayed by more mature cells. The association between low FcRIII expression and function abnormality could be suggestive of a defect in CML neutrophil maturation.

Female↗
PubMed1992

Immune cell imbalance in major depressive and panic disorders.

We investigated subsets of peripheral immunologic cells in 12 drug-free patients affected by major depression according to DSM-III-R criteria, and who had recent evidence of somatic diseases. They were compared with 10 drug-free depressives, with 10 patients with panic disorder, and with 12 healthy volunteers, all without somatic disease. The immune subsets were measured by flow cytometry. The results showed that both groups of depressives had the same abnormalities in immune cells compared with the healthy volunteers or the panic disorder patients; in particular they presented a lower number of CD3+, CD8+ and HLA-DR+. The patients with panic attacks did not differ from healthy controls, except for CD4+ cells which were significantly lowered, even in comparison with the depressive groups. These data, although preliminary and in a small sample, suggest that some immune parameters may be influenced by the presence of a major psychiatric disorder.

Adolescent↗
PubMed1992

IgE modification of the specific antidermatophagoides during the first year of specific immunotherapy (SIT).

Six subjects (4 female, 2 male), aged from 16 to 25 years, presented with allergic rhinitis to Dermatophagoides mites and received SIT by the sub-cutaneous route with delayed-release alpha fraction Bayropharm at the standard doses. Diagnosis was based on clinical history, skin tests and measurement of specific IgE at 0, 3, 9, and 12 months, by the fluoro-enzymatic technique (FAST). For comparison, in a reference group (n = 20) the IgE varied between 0.32 and 0.11 IU/ml for D1 and 0.31 to 0.09 IU/ml for D2. The eight patients had specific IgE titres of D1 = 0.96, D2 = 0.99. For these authors, the FAST technique used for the measurement of specific IgE, although less sensitive than the RIA technique of RAST, gives a good evaluation of SIT.

Adolescent↗
PubMed1991

In vivo effectiveness of lithium on impaired neutrophil chemotaxis in Shwachman-Diamond syndrome.

The effect of lithium treatment on the impaired neutrophil chemotactic function of a patient affected by Shwachman-Diamond syndrome is reported. We found that (1) a cytoskeletal cellular defect seems to be involved in the impairment of neutrophil function (and perhaps of cellular secretion and chondrocyte function) in the syndrome; (2) intermittent neutropenia is always present in the syndrome, and (3) lithium seems capable, in addition to its capacity of inducing leukocytosis, of modulating leukocyte functions by modulating the microtubular system. The drug, at usual therapeutic dosage, was able to normalize neutrophil functions without side effects. As no therapy is available in this syndrome to date, our data suggest the therapeutic use of lithium in order to improve these cytoskeleton-mediated functions and the degree of neutropenia.

Chemotaxis, Leukocyte↗
PubMed1991

Analgesia by nefopam: does it act through serotonin?

In an attempt to clarify the possible mode of action of nefopam, a new analgesic compound, the authors tested its effects on imipramine (IMI) binding to platelet membranes. The results showed that nefopam exerted a concentration-dependent inhibition of IMI binding, with a potency comparable to that of tricyclic antidepressants. This finding suggests a possible intervention of serotonergic mechanisms in nefopam-related analgesia.

Analgesia↗