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Biomedical subjects

F Ambrogi

Publications and source records attributed to F Ambrogi.

At least 19 recordsLinked to original sources
PubMed2003

Vascular endothelial growth factor in node-positive breast cancer patients treated with adjuvant tamoxifen.

In 212 postmenopausal women with node-positive oestrogen receptor-positive (ER(LBA)) breast cancer subjected to radical surgery and adjuvant tamoxifen, the risk of 6-year relapse increased with increasing values of intratumoral vascular endothelial growth factor (VEGF) in patients whose tumours had a low/intermediate ER(LBA) content compared to patients with high-ER(LBA) tumours. These findings indicate that tumour progression, activated or sustained by high VEGF levels, may be counteracted in high-ER(LBA) cancers by tamoxifen, which in contrast fails to contrast the metastatic potential in low-ER(LBA) tumours.

Aged↗
PubMed2003

Cytokine secretion in nasal mucus of normal subjects and patients with allergic rhinitis.

Allergic rhinitis is regulated by the local production and release of several cytokines. The levels of Th2 cytokines IL-4, IL-6, IL-10 and the Th1 cytokine IFN-gamma were studied in nasal mucus from 30 subjects with allergic rhinitis and 45 non-atopic healthy controls. In this study a sampling technique for collecting nasal mucus, well tolerated by the subjects and with a minimal stimulation of the mucosa, was performed. The cytokine concentrations in nasal mucus samples were detected and quantitated by a new paramagnetic particle-based immunofluorescent assay system more sensitive than the conventional ELISA techniques. The new technique showed reliable values of the measured parameters. The nasal mucus from allergic patients contained significantly higher concentrations of IL-4 (25.5 +/- 3.6 pg/ml; P < 0.001) and IL-10 (1300 +/- 190 pg/ml; P < 0.05) compared to the nasal mucus from control subjects (15.2 +/- 2.3 and 532 +/- 28 pg/ml, respectively, for IL-4 and IL-10). No significant modification in IFN-gamma levels of allergic patients was found when compared to control group (respectively, 19.9 +/- 3.3 vs. 25.7 +/- 5.1 pg/ml; P > 0.05). Moreover, the allergic patients showed lower levels of IL-6 concentrations in the nasal mucus compared to control subjects (64.8 +/- 9.1 vs. 129.0 +/- 18.1 pg/ml; P = 0.0099). These data can be interpreted by the hypothesis that in response to environmental allergens there is a preferential Th2 polarity by activated CD4+ T cells and that the cytokines IL-6 and IL-10 have, respectively, an important anti-inflammatory and counterregulatory action in the pathogenesis of allergic rhinitis.

Adolescent↗
PubMed2001

Modulation of beta2 integrin phenotype, adhesion, chemotaxis, and oxidative burst of neutrophils by cyclosporine.

Cyclosporine (CsA) is an immunosuppressive drug widely used to prevent allograft rejection, but its action on neutrophil function is not well known. Neutrophils play an important role in tissue damage during allograft rejection; chemotactic recruitment, adhesion to endothelial cells and oxidative burst of neutrophils are early events during allograft rejection. The aim of this work was to evaluate the effect of CsA on beta2 integrins' surface expression, adhesion to human umbilical endothelial cells (HUVECs), chemotaxis and oxidative burst by neutrophils. For any neutrophil function studied, data obtained from activated neutrophils exposed to CsA were compared with those derived from untreated controls. Results show that CsA does not block neutrophil chemotaxis and does not reduce surface expression of CD11 complex and HUVECs' adhesion at all concentrations tested (15, 100 and 500 ng/mL) and at incubation times of 1, 2 and 4 h as compared to controls. On the other hand, the drug affects significantly the CD18 phenotype after two hours of treatment at the maximum concentration (500 ng/mL) (P < 0.05; ANOVA) and the oxidative burst after four hours (P < 0.01; ANOVA). This study provides evidence that in addition to the well-known CsA effects on lymphocyte functions, the drug affects some neutrophil functions with dose- and time-dependent modalities.

Antibodies, Monoclonal↗
PubMed1999

Immunological alterations in adult obsessive-compulsive disorder.

BACKGROUND: Some recent findings suggest the involvement of autoimmune mechanisms in childhood onset of obsessive-compulsive disorder (OCD), on the basis of a parallel drawn with Sydenham's chorea, a manifestation of rheumatic fever. A monoclonal antibody called D8/D17 characterizing a B-lymphocyte antigen, present in almost all patients with rheumatic fever, has been found also in children affected by OCD, Tourette syndrome, and chronic tics to a greater degree than in healthy control subjects. The few observations of disturbances of some immunologic parameters in adult OCD patients, prompted the authors to investigate and compare subsets of peripheral immunological cells for differences in adult patients with OCD and healthy control subjects. METHODS: Twenty patients suffering from OCD, with no comorbidity for other psychiatric disorders, were compared with a similar group of healthy control subjects. The immune subsets were measured by flow cytometry. RESULTS: The CD8+ lymphocytes were significantly increased and CD4+ lymphocytes significantly decreased in OCD patients, while the other cells did not differ between the two groups. No correlation was found between immunologic and clinical parameters. CONCLUSIONS: These data indicate that patients with adult OCD showed increased CD8+, i.e., suppressor T lymphocytes, and decreased CD4+, which identify helper T lymphocytes, as compared with a similar group of healthy control subjects. The findings appear peculiar to patients with OCD and are suggestive of an immunologic imbalance, which might be related to the stress deriving from the frustrating situation determined by the disorder itself.

Adolescent↗
PubMed1998

Detection of eosinophils in whole blood samples by flow cytometry.

A flow cytometric method to detect and study human eosinophils in whole blood was established. Normal subjects and patients with various types of eosinophilia (hypereosinophilic syndromes, allergic diseases, dermatitis, Hodgkin's Disease, parasitosis) were studied. Whole blood samples were treated for 10 minutes at room temperature with a commercially available reagent (FACS Lysing Solution, Becton Dickinson) which acts both as a fixative and as a lysing agent. Eosinophils were identified as a granulocytic subpopulation with higher SSC and FSC properties. This cell population was characterized by evident autofluorescence and hypodiploid DNA features after propidium iodide staining. The purity of the eosinophil population sorted after electronic gating was close to 100%. A very significant correlation between eosinophil counting by our whole blood method and other two assays, namely routine automatic counting by the H*3 Bayer System and eosinophil detection by depolarized SSC, was obtained. The phagocytic properties of eosinophils were also studied by means of a commercially available diagnostic kit, thus demonstrating that our method is also suitable for the study of those granulocytic functions which can be evaluated by flow cytometry.

Adolescent↗
PubMed1998

Anti-D treatment for chronic immune thrombocytopenic purpura: clinical and laboratory aspects.

We used low-dose anti-D immunoglobulins for home treatment of Rh+ adult patients with chronic immune thrombocytopenic purpura (ITP). After informed consent, 15 unselected outpatients (ten males and five females, aged 22 to 72), affected by chronic ITP with negative HIV test, were given intramuscular injection of 900-1500 micrograms of anti-Rh0 (D) IgG over 3 days every month for 2 or 3 consecutive months. Platelet count (mean +/- SD) significantly increased from basal value of 17,000 +/- 9,000/microL to 72,000 +/- 55,000/microL at the end of treatment. Eight patients achieved a rise in platelet count above 50,000/microL (five above 100,000/microL) and two of them maintained the increase longer than 6 months without further anti-D administration. Three patients responsive to the first cycle responded to further treatment with substantially identical results. Seven patients had no response. Four of them had not responded to previous glucocorticoid and intravenous IgG therapy. Direct antiglobulin test became strongly positive in all patients and mean serum haptoglobin decreased from a basal value of 118 +/- 59 to 61 +/- 43 mg/dL; nevertheless no clinically overt hemolysis was observed in any patient, there was no rise of serum indirect bilirubin and hemoglobin level was unchanged (mean +/- SD basal level 13.6 +/- 2.2 g/dL; after anti-D 13.9 +/- 1.2 g/dL). No hematoma developed at the injection site, and no other side effects occurred. Our results show that anti-D therapy is effective in the majority of patients well tolerated, and feasible as home treatment: thus it can be recommended as a cheap and safe alternative treatment in ITP Rh+ patients.

Adult↗
PubMed1997

Actin polymerization in neutrophils from patients affected by myelodysplastic syndromes--a flow cytometric study.

In this study F-actin polymerization in neutrophils from 21 patients affected by myelodysplastic syndromes (MDS) was evaluated by means of a flow cytometric assay. Neutrophils were stimulated with formyl-methionyl-leucyl-phenylanaline (fMLP; 10(-8) M final concentration) for 15, 30, 60 and 120 sec, and F-actin content was determined using fluorescein-isothiocyanate phallacidin as a specific probe. Eight normal subjects were studied as controls. We found that F-actin polymerization was defective in ten patients, with very impaired values after 60 and 120 sec of stimulation with fMLP. The remaining 11 patients showed a prevalent neutrophil population with normal F-actin polymerization and neutrophil sub-populations with either defective or undetectable F-actin polymerization. In the first group, patients with very poor prognosis (refractory anemia with excess blasts, refractory anemia with excess blasts in leukemic transformation, trisomy 8, multiple karyotypic abnormalities) were present, although patients with aberrations of karyotype were present in the second group. It is possible that defects in neutrophil F-actin polymerization may be responsible for neutrophil dysfunction, which has frequently been observed in MDS.

Actins↗
PubMed1997

fMLP-induced CD11b/CD18 upregulation on neutrophils from patients with non-Hodgkin's lymphomas treated with recombinant human granulocyte colony-stimulating factor.

The effects of rhG-CSF administration on fMLP-induced neutrophil CD11b and CD18 upregulation were studied in nine patients suffering from intermediate and high grade non-Hodgkin's lymphomas. Blood samples were obtained before recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration and 24 hrs after rhGSF interruption. The growth factor was administered subcutaneously for five days in a dosage of 5 microg/Kg/day. Nine normal subjects were studied as controls. Five patients showed an impaired baseline CD11b and CD18 upregulation, which was corrected by rhG-CSF therapy. Four patients showed a normal baseline CD11b and CD18 upregulation, but this function was reduced by rhG-CSF therapy. All patients showed a normal baseline fMLP-induced luminol-enhanced chemiluminiscence and significantly increased chemiluminescence values after rhG-CSF administration. We conclude that, while in some patients rhg-CSF is able to improve neutrophil CD11b and CD18 upregulation in response to chemotactic agents, in other patients a decrease of this function can occur, maybe due to a relative immaturity of the circulating neutrophils induced by rhG-CSF.

Adult↗
PubMed1996

Cell-mediated immunity in breast cancer patients.

In clinical practice, reports have been made on immunosuppression after surgical excision of primary tumor or at relapse. However, the relationship between undefined or overt metastases and the host immune system has not been sufficiently examined over a prolonged period. These aspects were investigated in 160 breast cancer patients followed up post-operatively with serial controls over a long period. One hundred and thirty-four cases (91 node negative, (N-), 43 node positive (N+)) were disease-free and 26 relapsed. In all patients, serum T cell populations, serum B lymphocytes and skin reaction of delayed hypersensitivity (SRDH) were serially determined for 39 +/- 12 months (m +/- SD). The reference values for these parameters were assessed as follows: T populations were evaluated in 24 healthy donors and SRDH in 95 healthy females. In non-relapsed patients, constant CD8+ T cell decrease and T4/T8 ratio increase were observed; the T4/T8 ratio was significantly higher (ranging from P < 0.05 - P < 0.001) than in the control group. The mean values of NK cells and B lymphocytes, the former parameter being highly significant (P < 0.001), were higher than in controls. In the 26 metastatic patients, the T4/T8 ratio from 20 months before to 30 months after the first sign of relapse decreased from 3.2 to about 1 (r = -0.256, P < 0.05) and from 30 to 92 months after relapse progressively increased to 2. Similarly, in the former subinterval a progressive decrease in the number of positive antigens and score was found (from 2.4 to 0 and from 10 to zero respectively). A significant inverse correlation between these two parameters and observation time occurred (P < 0.01 and P < 0.001 respectively). From 30 to 86 months after relapse, a progressive increase in the number of positive antigens and scores up to 2 and 12 were observed. A significant direct correlation (P < 0.05) was noted. In conclusion, these data indicate significant changes in T populations during the disease-free interval in breast cancer patients. The decrease in circulating CD8+ T cells is compatible with the hypothesis of CD8+ T cell localization at the site of the micrometastases. The increase in circulating B lymphocytes and NK cells suggests activation of aspecific humoral immunity and NK function. In addition, they show that progressive deficiency in cell-mediated immunity appears many months before and that recovery continues for a long time after overt metastatic disease.

Breast Neoplasms↗
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

Lymphocyte subsets in multiple sclerosis. A study with two-colour fluorescence analysis.

Multiple sclerosis (MS) is postulated to be an immunopathologically mediated disease. This concept is supported by the finding of abnormally distributed peripheral blood T-cell subsets and a decreased T-suppressor function. Thirty-seven MS patients have been selected according to the criteria for definite MS. Fluorescein- or phycoerythrin-conjugated monoclonal antibodies have been used to define different lymphocyte subsets: CD4+, CD5+, CD8+, CD19+, CD38+, CD45RA+, CD4+CD45RA+, CD19+CD5+, CD8+CD38+. In relapsing-remitting (RR)-MS patients a significantly decreased percentage of CD19+ cells and in progressive MS patients a significantly increased percentage of CD19+CD5+ cells have been found. During a relapse in RR-MS, a significantly decreased percentage of CD4+CD45RA+ cells and a significantly increased percentage of CD8+CD38+ cells have been observed. Moreover, in RR-MS patients a significantly increased percentage of CD38+ cells and significantly high IgM amounts have been found. The increased percentage of CD19+CD5+ and CD38+ cells (together with high IgM levels) and the reduced percentage of CD4+CD45RA+ lymphocytes could be related to an activation of both cellular and humoral immune response in acute MS.

Adolescent↗
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

Binding of GC (VDBP) to membranes of human B lymphocytes following stripping of extant protein.

The presence of Gc (vitamin D binding protein) has been consistently demonstrated on the membrane of B lymphocytes. This protein appears to be spatially associated with surface immunoglobulins. The origin of this surface protein has not yet been determined and the purpose of the present paper was to investigate if Gc may bind to human lymphocytes after immunoglobulin (Ig) capping. For this purpose the presence of Gc on B lymphocytes was examined by three different approaches. First, when cells were examined by immunofluorescence and quantified by flow cytometry, membrane Ig capping was followed by a dramatic decrease in positivity for Gc when compared to native cells. In addition, incubation of capped cells with purified Gc was followed by a significant increase in fluorescence, indicating that this protein had been able to bind again. Second, analysis of solubilized lymphocytes by Western blotting showed that native lymphocytes and capped cells incubated with purified Gc contained a large quantity of a 56kDa protein which was immunoreactive with anti Gc antibodies. This protein band was much weaker on blots from capped cells not treated with Gc. Third, radiobinding assays indicated that, following capping, cells were able to bind Gc in saturable fashion. These results suggest that membrane Gc could play a role in the entry of vitamin D metabolites into lymphocytes.

B-Lymphocytes↗
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

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↗