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Biomedical subjects

F Dallegri

Publications and source records attributed to F Dallegri.

At least 109 records · Page 6Linked to original sources
PubMed1981

Serum-associated inhibition of neutrophil Fc receptors in cancer patients.

Rosettes with ox erythrocytes coated with purified IgG antibody were used to detect Fc receptors on neutrophils from 60 patients with solid neoplasias and from 55 normal controls. The mean average of the rosettes in the patients was 48.10%, and that in normal controls was 79.42%, with a highly significant difference according to the Wilcoxon test [negative probability, P(w)-4.47 . 10(-5)]. The low proportion of patients' rosettes ws related to the presence of a serum factor, which also inhibited normal neutrophil rosette formation. Patient neutrophils (or normal neutrophils treated with patient sera) recovered their rosetting capacity when cultured in vitro. No correlation was found between low percentages of rosette-forming cells and the level of circulating immune complexes of the individual patients. Additional evidence also supported the finding that IC and the serum factor are probably unrelated.

Adult↗
PubMed1980

Stimulation of granulocyte adhesiveness by the chemotactic peptide N-formyl-L-methionyl-L-phenylalanine.

The in vitro effects of the peptide N-formyl-L-methionyl-L-phenylalanine on granulocytes adhesiveness and chemotaxis were investigated. N-formyl-L-methionyl-L-phenylalanine, when used at concentration chemotactically effective, increased significantly granulocyte adhesiveness. When granulocyte adhesiveness was inhibited by colchicine, the inhibition could not be reversed by subsequent treatment with N-formyl-L-methionyl-L-phenylalanine. These results suggest that microtubular system is involved in the stimulation of granulocyte adhesiveness by N-formyl-L-methionyl-L-phenylalanine.

Cell Adhesion↗
PubMed1980

Reversal by cimetidine of histamine-induced inhibition of true chemotaxis in neutrophil polymorphonuclears.

The effects of histamine and cimetidine on neutrophil locomotion were studied in vitro in experimental conditions able to dissociate random from truly directional motility. Histamine 10(-4) mol/l inhibited the true chemotactic response. Cimetidine was able to reverse the histamine-induced inhibition of true chemotaxis. Since histamine-induced inhibition of neutrophil chemotaxis may play a role in allergic patients with repeated infections, and since cimetidine has been shown to enhance cell-mediated immunity in vivo, often impaired in such cases, the use of cimetidine is suggested for the prevention of recurrences in these patients.

Chemotaxis, Leukocyte↗
PubMed1980

Neutrophil dysfunction and repeated infections: influence of levamisole and ascorbic acid.

Neutrophil function was studied in several patients with recurrent infections, mainly of the skin. Twelve patients showed impairment of neutrophil functions, either chemotaxis or bacterial killing and phagocytosis. Levamisole was given in four cases: improvement of neutrophil function and long-lasting clinical remission occurred in three of them, whilst in the fourth the drug was not tolerated. Ascorbic acid was administered to three other patients, with satisfactory improvement of neutrophil function and long-lasting clinical remission.

Adolescent↗
PubMed1980

Effects of ascorbic acid on neutrophil locomotion.

The effects of ascorbic acid on neutrophil locomotion were studied in experimental conditions able to dissociate random from truly directional motility. It was shown that the significant enhancement of chemotaxis achievable with high ascorbic acid concentrations was due to an increase of the true chemotactic response. With lower concentrations of ascorbic acid, chemotactic values were unaffected as the result of an increase in the rate of neutrophil locomotion with a concomitant inhibition of the true chemotactic response. Ascorbic acid appeared to exert its effect on the whole moving cell population.

Ascorbic Acid↗
PubMed1980

Stimulation of neutrophil locomotion by inosiplex.

Experiments were performed to investigate the in vitro effects of inosiplex on the locomotion and oxidative metabolism of human neutrophils. The drug, when used at the concentration of 500 micrograms/ml, significantly increased neutrophil random migration and chemotaxis. Enhancement of chemotaxis was due to an increased rate of locomotion as well as toan increased true chemotactic response. Inosiplex appeared to exert its effect on the whole migrating cell population. No significant effect on the oxidative metabolism of both resting and phagocytizing neutrophils was found. The results suggest that the effect of inosiplex may be related chiefly to its effect on neutrophil locomotion.

Cell Movement↗
PubMed1980

In vitro effects of synthetic chemotactic peptides on neutrophil function.

The effects of the three synthetic chemotactic N-formyl-L-methionyl peptides, namely f-met-phe, f-met-val and f-met-ala, on neutrophil chemotaxis, adhesiveness, oxidative metabolism, phagocytosis and killing were evaluated in vitro. The three peptides displayed different stimulating properties, with relative activity f-met-phe greater than f-met-val greater than f-met-alal for all functions tested. Experiments performed with chemotactically deactivated neutrophils showed that deactivation does not interfere with neutrophil functions other than chemotaxis and does not prevent further stimulation by the same chemo-attractant. The results demonstrate that the interaction of a single chemotactic agent with neutrophil membrane can trigger different cellular responses, dependent in their type and intensity on the concentrations of the chemotactic factor and on the functional state of the cell.

Cell Adhesion↗
PubMed1980

Evidence for a reversible functional state of neutrophil chemotactic deactivation.

Neutrophils pretreated with a chemotactic factor become deactivated, that is, unresponsive to a subsequent chemotactic stimulus. A decay of surface esterase activity, an increased adhesiveness, an auto-oxidative damage of the cell structures and microtubule hyperpolymerization have been previously proposed as the cause of the chemotactic deactivation. To further understand the cellular mechanisms involved in this process, we have studied the locomotory behaviour of deactivated neutrophils in an experimental system allowing differentiation among the various types of migratory cellular response to chemotactic factors. Thus, we have found that deactivated neutrophils retain a normal capacity of random locomotion, but entirely lose their true chemotactic responsiveness. Diamide, which disrupts assembled microtubules in concanavalin A-treated cells, was able to completely restore the true chemotactic response of deactivated cells. These observations suggest that neutrophil deactivation is a reversible cellular event dependent on the functional state of the microtubular system.

Cell Movement↗
PubMed1980

Prevention of neutrophil chemotactic deactivation by ascorbic acid.

The locomotion of human neutrophils deactivated by pretreatment with appropriate concentration of chemoattractant was investigated in experimental conditions capable of dissociating random from truly directional motility. It was shown that deactivated neutrophils lose true chemotactic responsiveness, being unaffected by the rate of locomotion. Ascorbic acid, when present in appropriate concentrations during the deactivation step, completely prevented the loss of true chemotactic responsiveness by cells--that is, their chemotactic deactivation.

Ascorbic Acid↗
PubMed1979

Defective neutrophil chemotaxis and bactericidal power in a child with hyperimmunoglobulinemia E.

An 11-year-old boy with a life-long history of atopic-like dermatitis and recurrent staphylococcal abscesses was found to have defective neutrophil chemotaxis, impaired-T-lymphocyte functions, hyperimmunoglobulinemia E, and delayed neutrophil bactericidal power. This latter defect has never been found in such patients. The patient's mother revealed a panhypogammaglobulinemia, while his sister and maternal grandmother who had repeated infections were immunologically normal.

Chemotaxis, Leukocyte↗
PubMed1979

In vitro function of chronic myelocytic leukemia granulocytes. Effects of irradiation and storage.

Granulocyte function was studied in 9 patients with untreated, Ph1-positive chronic myelocytic leukemia (CML). The nitroblue tetrazolium reduction by stimulated granulocytes was impaired in all patients; 4 patients also had diminished phagocytosis and 2 others defective chemotaxis. In spite of this variety of polymorphonuclear (PMN) functional impairments, there is little evidence of increased susceptibility to infections in CML patients. This suggests that CML-PMN leucocytes (PMNs) may be successfully used for transfusion into neutropenic recipients, as previously reported. To evaluate the effects of irradiation and liquid storage on CML-PMNs, 5 of our patients were subjected to leukapheresis by continuous-flow centrifugation in the Aminco Celltrifuge, and granulocyte functional capacities were also evaluated on the cell-rich plasma immediately after collection and after short-term storage at 4 degrees C with or without irradiation (1500 rads). As evaluated by in vitro studies, granulocytes maintained, even after irradiation, functional activities similar to those found immediately after collection up to 24 h of storage at 4 degrees C and presented a moderate loss of function after 48 h. Chemotaxis appeared to be the most sensitive detector for cellular damage of stored leucocytes, irradiated and non-irradiated, so that it might be used for assessment of leucocyte function before transfusion.

Adult↗
PubMed1979

Lazy leukocyte syndrome.

A-35-year-old woman with a long-lasting history of neutropenia and recurrent infections was found to have defective neutrophil chemotaxis, random motility, and in vivo migration. Although the bone marrow granulocyte reserve was normal, the patient failed to release an appropriate amount of granulocytes after injection of etiocholanolone. These features are characteristic of the so-called "Lazy leukocyte syndrome". The clinical presentation of the five cases of this syndrome so far reported and its pathophysiological aspects are discussed.

Adult↗
PubMed1979

Neutrophil functions in acne conglobata.

Chemotaxis, random migration, phagocytosis, spontaneous and stimulated NBT reduction were evaluated in neutrophils from the peripheral blood of 8 patients with acne conglobata and were found to be normal. Only 2 patients had an increased spontaneous NBT reduction, and another exhibited a defect in neutrophil adhesiveness. On this basis, intrinsic defects of the major neutrophil functions, as evaluated in vitro, can be excluded in acne conglobata.

Acne Vulgaris↗