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Biomedical subjects

G Presani

Publications and source records attributed to G Presani.

33 records · Page 2Linked to original sources
PubMed1989

Flow cytometric detection of anti-gliadin antibodies.

A very sensitive solid-phase fluorescent immunoassay to detect anti-alpha-gliadin IgA class antibodies is described. The solid phase consisted of polystyrene carboxylated microspheres, of 5 microns diameter, coated with alpha-gliadin. Serum-specific antibodies bound to the alpha-gliadin were measured by flow cytometry using fluorescein-conjugated anti-human IgA. 41 samples were tested and the results compared with those obtained by a standard method: an enzyme-linked immunosorbent assay (ELISA). A good correlation was found between the two techniques (r = 0.96). The sera of untreated coeliac children showed significantly higher antibody values than the sera of children on a gluten-free diet or healthy control groups. The flow cytometric method was more sensitive when the Kolgomorov/Smirnov test was used to analyse the histograms. This method provides an alternative screening test for coeliac disease and may also be used to confirm borderline results obtained in the ELISA test.

Celiac Disease↗
PubMed1989

Flow cytometric analysis of DNA content in cervical lesions.

Flow cytometry is used to screen gynaecologic specimens for Cervical Intraepithelial Neoplasia (CIN) and its precancerous lesions, possibly associated with human papilloma virus (HPV), in order to investigate the role of aneuploidy as a biological marker in HPV and CIN lesions. A total of 299 cervical samples was collected by scraping and the cellular DNA content was measured using the propidium iodide staining procedure. Two groups of patients were studied; a group of 142 negative controls for cytology and groups of patients assigned to mild, moderate or severe dysplasia, carcinoma in situ diagnosed by histologic classification according to the Papanicolaou staining technique. Pathological samples showing an alteration of the DNA index or perturbation of the cellular phase S compartment ranged from 6.4% to 41.9%. Our results confirm those obtained by other authors and suggest the hypothesis that aneuploidy is present with permanence of viral DNA in early stages of carcinogenesis, which can be used as a marker in the transition from benign to malignant cells. This work is of potential interest for the possible follow-up of patients having condyloma and could aid the early diagnosis of cervical carcinoma.

Aneuploidy↗
PubMed1989

Rapid flow cytometric studies of Borrelia burgdorferi phagocytosis by human polymorphonuclear leukocytes.

The interactions between a strain of Borrelia burgdorferi and human polymorphonuclear leukocytes were studied by flow cytometry in the presence of specific or non-specific opsonizing factors. The capacity of the borrelias to stimulate leukocyte metabolism was also investigated. The results indicated that a low phagocytosis by isolated purified polymorphonuclear leukocytes did occur in the presence or absence of specific antibodies. Within whole blood the percentages of phagocytosting leukocytes increased in the presence of non-specific opsonizing factors. No stimulation of the oxidative metabolism stimulated by Borrelia was observed and PMA or zymosan stimulation of leukocytes was inhibited by the spirochaetes.

Borrelia↗
PubMed1989

Evaluation of the serum T cell population variations induced by PUVA therapy.

In the present study we evaluated the effects of UVA irradiation on the serum T cell subpopulations (CD3, CD4, CD8, CD4/CD8, NK, T lymphocytes/mm3) by means of a Fluorescence Activate Cell Sorter (F.A.C.S. 420, Becton Dikinson). Twenty-eight psoriatic patients, never previously treated with PUVA, received UVA radiations (cabin Waldman 8001 K). Blood samples were taken before therapy and after 60 J/cm2 and 120 J/cm2 irradiations. Results were compared with those of our healthy control group of volunteers. A decrease of CD4 positive cells was observed in the psoriatic group before therapy. PUVA did not induce any statistically significant modification of the populations studied, except for a progressively increasing trend of CD4 positive cells. These data seem to stress that a medium-term PUVA therapy does not significantly modify the serum level of the T cell populations.

Adult↗
PubMed1986

Functional C8 associated with human platelets.

Haemolytic assay for C8 revealed its association in functionally active form with washed human platelets. Platelet-bound C8 haemolytic activity was inhibited by F(ab')2 anti-C8 and was undetectable in the platelet suspension obtained from three C8 deficient patients. Incubation of platelets from C8 deficient individuals in normal plasma did not restore C8 haemolytic activity, indicating that platelets do not absorb C8 from plasma in vitro during platelet preparation. Thrombin, a mediator of the platelet release reaction, did not induce the release of C8 from normal platelets. Conversely, lysis of EAC1-7.9 by platelet bound C8 was not accompanied by release of beta-thromboglobulin or serotonin from the platelets. C8 was detected in a homogenate prepared from platelets as well as in the supernatant collected after high speed centrifugation of the homogenate. The association of C8 with platelets as an individual component rather than as part of the C5b-9 membrane-attack complex was supported by the following evidence: platelet bound C8 eluted from a Sephacryl S-200 column at the same volume as C8 from normal human serum; F(ab')2 anti-C8, but not F(ab')2 anti-C5, inhibited platelet C8 activity; the platelet homogenate, which lysed EAC1-7.9, had no effect on EAC43 which are susceptible to the lytic activity of the C5b-9 complex.

Blood Platelets↗
PubMed1983

An analysis of T-lymphocyte subpopulations in psoriasis using monoclonal antibodies.

We evaluated subpopulations of T-lymphocytes by using the monoclonal antibodies OKT3, OKT4 and OKT8 in two groups of psoriatic patients, with active and stable psoriasis respectively. Whereas data from the patients with stable psoriasis were similar to those obtained from the control group, the patients in an acute flare condition revealed a relative decrease in lymphocytes reactive with OKT8, and a slight increase in the proportion of lymphocytes reactive with OKT4. The results of this study are analysed.

Acute Disease↗
PubMedDate not supplied

Serum IgA and IgG antibodies to alpha-gliadin: comparison between two ELISA methods.

We have developed two ELISA methods, i.e., enzyme immunoassay (EIA) and fluorescence immunoassay (FIA), for the semiquantitative detection of specific IgA and IgG antibodies directed against alpha-gliadin. The tests differ only for the enzyme substrate and, when optimized, could be used in large routine screening of celiac disease. Several serum samples from patients with celiac disease and gastrointestinal disorders as well as from control subjects were tested. Both methods gave good correlation with clinical data, were easily performed and had some specificity features, while FIA proved to be more sensitive.

Adolescent↗
PubMedDate not supplied

Treatment of juvenile idiopathic arthritis with intra-articular triamcinolone hexacetonide: evaluation of clinical effectiveness correlated with circulating ANA and T gamma/delta + and B CD5+ lymphocyte populations of synovial fluid.

OBJECTIVE: The aims of the study were to assess the effect of intra-articular treatment with triamcinolone hexacetonide (TH) in juvenile idiopathic arthritis (JIA) and to investigate whether treatment response correlates with the presence of antinuclear antibodies (ANA) in the serum and/or B CD5+ and T gamma/delta + lymphocytes in the synovial fluid. METHODS: A total of 37 patients (81% females, 56% ANA+) with oligoarticular JIA involving knees were treated with intra-articular injections of TH after failing to respond to NSAIDs for two months. Eighteen patients were treated within 6 months of onset, 19 were treated more than 6 months after onset. RESULT: Mean duration of remission was 13.9 months. Twelve patients (7 ANA+) had stable remission after a single injection; 13 patients (3 ANA+) experienced more than 6 months' remission but subsequently had a relapse; 12 patients (11 ANA+) had a relapse within six months of injection. Of 20 patients treated within 6 months of onset, 17 had stable remission whereas only 8 out of 17 who were treated during relapse attained stable remission (p = 0.03). The mean percentage of T gamma/delta + and of B CD5+ lymphocytes in synovial fluid was the same as in peripheral blood of normal subjects. CONCLUSION: Our data indicate that local treatment with slow-release steroids is very effective in oligoarticular JIA. Prolonged remission was less likely in the presence of ANA positivity, probably because the disease is immunologically more active. Finally, our data suggest that the earlier the treatment, the easier it is to obtain a protracted, and possibly permanent, response.

Anti-Inflammatory Agents↗
PubMedDate not supplied

[Effects of interferon on immunoglobulin production in normal subjects and in patients with selective IgA deficiency. An "in vitro" study].

The ability of Interferon (IFN) alpha, beta and gamma to induce IgA production from IgA deficient patients lymphocytes was tested "in vitro". In affected patients IgG and IgM production was similar to the normal cases but no effect on IgA production was observed. In normal cases variable concentration of alpha- beta- and gamma-IFN resulted in different immunoglobulin production. In IgA selective deficiency a low number of SmIgA bearing cells and defective transformation in IgA-plasma cells was noted as possible primary defect.

Adolescent↗
PubMedDate not supplied

Study of IL-2, IL-6, TNF alpha, IFN gamma and beta in the serum and synovial fluid of patients with juvenile chronic arthritis.

In the last few years the important role played by various cytokines in the pathogenesis of chronic inflammatory diseases has emerged. In the present study, serum and synovial fluid levels of IL-2, IL-6, TNF alpha, IFN beta and IFN gamma were evaluated in a group of 66 patients with juvenile chronic arthritis (JCA). At the same time the ESR, CRP, hemoglobin, immunoglobulins, platelet count and Ritchie index were measured. In the serum of pauciarticular patients, IL-6 and TNF alpha levels were only slightly elevated compared with controls, but there was no correlation between these cytokines and clinical and other laboratory parameters. Serum IL-2 and IFN gamma were undetectable. In contrast, in the synovial fluid IL-6 levels were very high in all of the patients examined and there was a significant correlation between synovial fluid IL-6 levels and Ritchie's articular index. TNF alpha tended to be elevated but to a lesser extent, while synovial fluid IL-2 and IFN gamma were undetectable or very low, as in the serum. In polyarticular and systemic patients, on the other hand, serum IL-6 was elevated and statistically correlated with the majority of the laboratory parameters and with the Ritchie articular index. TNF alpha levels were only slightly elevated; on the other hand, IL-2 and IFN gamma were undetectable. There was an inverse correlation between IFN beta levels and the Ritchie articular index and a significant correlation with hemoglobin levels. In conclusion, our study demonstrates that not only IL-1 (as shown in other studies), but also IL-6 and to a lesser extent TNF alpha play a central role in the pathogenesis of JCA. IFN beta on the other hand, would seem to play an anti-inflammatory role.

Adolescent↗
PubMedDate not supplied

Flow cytometric assay for the evaluation of phagocytosis and oxidative burst of polymorphonuclear leukocytes and monocytes in myelodysplastic disorders.

BACKGROUND: Myelodysplastic syndromes are clonal diseases characterized by pancytopenia of variable degree. Neutropenia is common and several morphologic and functional abnormalities of polymorphonuclear neutrophilic granulocytes (PMNs) and/or monocytes have been described. On the basis of these observations, the phagocytic and oxygen intermediates production of PMNs and monocytes was determined in a group of forty-seven patients affected by myelodysplastic syndromes of varying severity. METHODS: A rapid, simple and reliable flow cytometric method was developed to evaluate, in a one-step procedure, the phagocytosis rate and the oxidative burst in PMNs and monocytes using a small amount of whole blood. RESULTS: Phagocytosis of PMNs and monocytes was not significantly reduced in refractory anemia (RA), while in refractory anemia with excess of blasts (RAEB) and in chronic myelomonocytic leukemia (CMML) a clear decrease (p < 0.05) of this function was found in both PMNs and monocytes. The production of oxygen intermediates by PMNs and monocytes was significantly (p < 0.01) reduced in RA as well as in RAEB and in CMML. CONCLUSIONS: This study indicates the presence in myelodysplastic syndromes of a severe reduction in phagocytosis and oxygen intermediates production (two crucial functions to protect the host against pyogenic agents) in both PMNs and monocytes. This observation could explain the severe morbidity and mortality from infections in patients affected by these hematological malignancies.

Adult↗