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G Carulli

Publications and source records attributed to G Carulli.

At least 37 records · Page 2Linked to original sources
PubMed1996

Motility of rhG-CSF-induced neutrophils in patients undergoing chemotherapy: evidence for inhibition detected by image analysis.

The motility of circulating neutrophils from seven patients affected by intermediate and high-grade non-Hodgkin's lymphoma was investigated before and after rhG-CSF administration (5 micrograms/kg/d for 5 d subcutaneously) in the course of chemotherapy. Random motility and bacterial lipopolysaccharide-induced chemotaxis were studied by the micropore filter technique in a Boyden chamber. These functions were evaluated by a very sensitive technique, based on a computer-assisted image processing system, capable of giving several parameters about the kinetics of cell migration. Along with a significant increase in neutrophil number, a significant decrease both in random and stimulated motility was found. The kinetics of cell migration showed that the cells maintained the typical gaussian pattern of random motility. On the contrary, neutrophils were found to have lost the typical stimulated migration peak. These findings are consistent with a rhG-CSF-induced impairment of the directional movement, rather than of the ability of moving at random. These effects were found in patients who, in the same experimental conditions, had displayed an enhanced phagocytosis and phagocytosis-associated chemiluminescence along with an enhanced CD32 expression, not due to an aspecific cell manipulation. Two hypotheses may be taken into account: (i) an increased adhesiveness due to a direct or an indirect activity of the cytokine; (ii) an abnormality in the cytoskeleton maturation and/or rearrangement during the accelerated bone marrow transit of myeloid cells. These findings emphasize that rh-GCSF administration can modulate several functions which play an important role in host defence, and suggest the utility of carrying out further studies to investigate the optimum dosage both to correct neutrophil number and preserve neutrophil functional activities.

Adult↗
PubMed1996

Applications of flow cytometry in the study of human neutrophil biology and pathology.

Flow cytometry represents an interesting methodologic approach to human neutrophil biology and pathology. Several aspects of neutrophil activation can be evaluated by flow cytometry: phagocytosis, respiratory burst (superoxide anion generation, intracellular hydrogen peroxide production), intracellular pH, actin polymerization, membrane potential, aggregation, cytotoxicity, degranulation, and surface marker expression. In several instances whole blood methods have been developed and have been shown to be very specific and sensitive. Neutrophils can easily be distinguished from other circulating cells, including eosinophils, and methods for the evaluation of neutrophil phagocytosis and hydrogen peroxide production are currently used. In addition whole blood procedures for the determination of the expression of neutrophil function-associated surface antigens have been recommended in order to avoid the artifactual changes resulting from isolation methods. Purified neutrophil have to be used to study other parameters such as actin polymerization and cytotoxicity. Flow cytometry permits a multiparametric evaluation of neutrophil functions, and advances in software technology facilitate a wide variety of choices for the handling, storage, and evaluation of data. The applications of flow cytometry in human neutrophil diseases include the diagnosis of chronic granulomatous disease and leukocyte adhesion syndrome types 1 and 2, and the evaluation of granulocyte biology in several clinical conditions such as immunodeficiency conditions, recurrent infections, hematologic diseases, and noninfectious diseases caused by uncontrolled neutrophil activation.

Actins↗
PubMed1995

Luminol-enhanced, whole blood chemiluminescence of human neutrophils evaluated by means of an automated, computer-assisted, and high-sensitivity luminescence analyzer.

Luminol-enhanced whole blood chemiluminescence of human neutrophils was studied using opsonized zymosan as a stimulus. Heparinized blood (0.5 microliters) was used, and the chemiluminescence signals were recorded by a very sensitive, automated, and computer-assisted luminometer (LB 950, Berthold, Wildbad, Germany). The following parameters were provided: integral values over the total measuring time, peak values, the time to reach maximum value, and the time to reach half maximum value. Normal subjects, neutropenic patients, subjects with total or partial myeloperoxidase deficiency, patients with recurrent infections, phagocytic defects, thrombocythemic patients and those with non-Hodgkin's lymphomas undergoing therapy with recombinant human granulocyte colony-stimulating factor were studied. The integral response of chemiluminescence and the time of reach half maximal value were useful indicators of chemiluminescence defects; the assay, was able to detect chemiluminescence responses in neutropenic subjects with neutrophil levels as low as 0.6 x 10(9)/l; differences between cellular and plasma defects could be identified; the quenching effect exerted by erythrocytes was negligible.

Adolescent↗
PubMed1995

Interactions between platelets and neutrophils in essential thrombocythaemia. Effects on neutrophil chemiluminescence and superoxide anion generation.

Essential thrombocythaemia (ET) is frequently associated with neutrophil and platelet dysfunction, and with increased incidence of vascular complications (thrombosis, haemorrhage). Several interactions between platelets and neutrophils have been reported, and the reciprocal actions between these cells may have an important role both in thromboregulation and in diseases such as those caused by uncontrolled neutrophil activation. In the current paper the authors studied 15 patients affected by ET and 10 normal subjects as controls. Circulating neutrophils and platelets were purified and were recombined in constant ratios (50:1, 100:1 and 200:1) and the individual platelet to neutrophil ratio. Superoxide anion (O2-) generation and luminol-enhanced chemiluminescence (CL) were studied after neutrophil stimulation with fMLP. In normal subjects both O2- generation and CL were inhibited by autologous platelets in a dose-dependent manner. In ET patients, on the contrary, platelet-dependent inhibition of O2- generation did not occur, while a dose-dependent inhibition of CL was observed. Two groups of ET patients were found: patients with neutrophil O2- generation and CL within the normal range, and patients with significantly reduced neutrophil respiratory burst. However, no differences were found between these two groups of patients in terms of platelet effects towards fMLP-stimulated neutrophils. Therefore, platelets from ET patients were not able to exert the homeostatic control towards neutrophil O2- generation shown by platelets from normal subjects, and this phenomenon may have a role in the clinical setting. In fact, O2- has been shown to be a very strong direct platelet activator, is able to inactivate nitric oxide (which is a powerful inhibitor of platelet aggregation and adhesion to endothelium), and is directly involved in neutrophil-mediated tissue damage.

Adult↗
PubMed1995

Inhibition of neutrophil oxidative metabolism by trichinellosis patient sera. Parasite origin or host induction?

The presence of sera factors able to inhibit both neutrophil chemotaxis and phagocytosis was observed in all patients studied at two months from infection caused by Trichinella britovi and in most of them after one year. Human neutrophils with eosinophils are able to kill T. spiralis newborn larvae in an ADCC system and their major cytotoxic mechanism is oxidative metabolism products. We evaluated the effect of trichinellosis sera on neutrophil oxidative burst to determine if neutrophils are affected by circulating factors during infection. Cells were incubated with sera from trichinellosis patients. Basal or stimulated Superoxide Anion (SA) production and chemiluminescence in response to different stimulation (PMA, f-MLP, opsonized yeasts) of neutrophils incubated with trichinellosis sera were evaluated and compared with those of cells incubated with control sera. The results show that basal SA production was inhibited by 66% of sera and stimulated by 11%. On the contrary f-MLP stimulated production was significantly increased by 22% sera, and inhibited by none. Chemiluminescence in response to f-MLP or PMA was inhibited by 46 and 80% of sera, respectively. These results show that trichinellosis sera can modulate not only SA production but also other steps of the oxidative burst, irrespective of the stimulating agent, so suggesting that different neutrophil activation pathways are affected. Increased IL-2 levels observed in most of the sera did not correlate with the inhibiting capacity of sera. The hypothesis of a parasite origin of the inhibiting factors is discussed in the light of host-parasite relationship.

Animals↗
PubMed1995

Platelet-neutrophil interactions in uremic patients: effects on neutrophil superoxide anion production and chemiluminescence.

Isolated resting platelets are able to limit neutrophil activation and then can control the tissue-damaging potential of activated neutrophils. In the present study, platelet-neutrophil interactions have been evaluated in 10 uremic patients; the blood samples have been collected before the hemodialysis session. Twelve normal subjects served as controls. Platelets and neutrophils have been isolated and recombined in an autologous ex vivo system. Anion superoxide production and chemiluminescence (which is related to hypochlorous acid production) have been evaluated after stimulation with N-formyl-methionyl-leucyl-phenylalanine. Coincubation of platelets from normal subjects with autologous neutrophils led to a dose-dependent inhibition of both superoxide anion generation induced by N-formyl-methionyl-leucyl-phenylalanine and chemiluminescence. Instead, platelets from uremic patients have not affected superoxide anion production by autologous neutrophils. The chemiluminescence was reduced by coincubation with autologous platelets only at the highest platelet-neutrophil ratio (100:1). In conclusion, the modulation exerted by platelets towards neutrophil activation can be impaired in chronic uremia. Therefore, the tissue-damaging potential of circulating neutrophils, due to toxicity by superoxide anion and hypochlorous acid, may be increased.

Adult↗
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↗
PubMed1993

Vitamin D3 administration and multidrug resistance in acute nonlymphoblastic leukemia.

This article reports preliminary results from a pilot study started in 1986 on patients with acute myeloblastic leukemia treated for several months with low-dose arabinosylcytosine and 1(OH)D3. During treatment or at the time of relapse, a monoblastic component was frequently found. A high percentage of patients were P-170-positive. In 2 patients it was possible to show that blasts, previously P-170-negative, became positive after treatment. In these 2 patients, failure of clinical response to antileukemic therapy was associated with this phenotype. The addition of the revertant drug nicardipine to the previously inactive treatment induced a partial response. Thus, previously reported in vitro observations on the differentiating activity of vitamin D3 metabolites, possible induction of multidrug chemoresistance by differentiating agents and the revertant activity of the Ca++ antagonist nicardipine appear to be confirmed in vivo in the reported patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
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

The neutrophil granulocyte in chronic myeloid leukemia.

The various functional, morphological, structural and enzymatic abnormalities, which can frequently be detected in neutrophil granulocytes from chronic myeloid leukemia (CML) patients, have been reviewed. The analysis of the relevant literature has been made, taking into account the kinetic anomalies displayed by the CML myeloid cells at the various stages of maturation. A conclusion is presented which supports previously suggested hypotheses on how CML circulating neutrophils may have not reached full maturation during their stay in the bone marrow post-mitotic pool, even if they appear to be morphologically mature.

Blood Bactericidal Activity↗
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↗