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N Maggiano

Publications and source records attributed to N Maggiano.

113 records · Page 7Linked to original sources
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Xenotransplantation rejection is antibody-mediated in both sensitized and nonsensitized recipients.

This study analyzes the mechanisms involved in xenotransplantation rejection between closely related species. Hamster hearts were transplanted heterotopically into both normal rats and rats previously sensitized by the transfusion of donor blood. Sequential ultrastructural and immunohistochemical analyses were performed on the grafts, spleens, and sera. The data obtained support the view that induced antibodies directed against the xenograft endothelium play a very important role in producing graft damage. Moreover, the demonstration of antibodies against myocyte determinants suggests that it is possible, in this particular model, that the antiendothelial antibodies are not the only ones involved in the injury process.

Animals↗
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Ampullary carcinoma: prognostic significance of ploidy, cell-cycle analysis and proliferating cell nuclear antigen (PCNA).

BACKGROUND/AIMS: The aim of the present study is to assess the nuclear DNA ploidy patterns, the fraction of cells in the various phases of the cell cycle as determined by flow cytometry and to evaluate Proliferative cell-nuclear antigen (PCNA) expression in order to examine the relationships between phase-two molecular factors, clinicopathological aspects and outcome of patients with cancers of the ampulla of Vater. METHODOLOGY: Paraffin-embedded specimens from 18 cases of cancers of ampulla of Vater radically resected between 1985 and 1995 were analyzed by flow-cytometry and immunohistochemical staining with monoclonal antibody to the PCNA. The relationships between cell-proliferation kinetics, PCNA-positive cancer cells, clinicopathological findings and the clinical course were evaluated. RESULTS: Pathologist reports documented 17 papillary adenocarcinomas and one case of mucinous carcinoma. According to the TNM classification, 4 patients were in stage I, 7 in stage II and 7 in stage III. Locally advanced ampullary tumors (T3-T4) had a significantly worse prognosis (p = 0.01); survival at 3 and 5 years for stage I-II patients (11 cases) was 90% and 79% as compared to 42% and 42% for patients with stage III (8 cases), respectively (p = n.s.). Thirteen cancers (72%) were diploid and 5 (28%) aneuploid. Patients with aneuploid tumors were younger (mean age: 59 years) than patients with diploid tumors (mean age: 66 years; p = 0.04). No significant correlation was found between size of the tumor (T), lymphnodal status (N), grading (G) or aneuploidy. Difference in terms of survival between aneuploid and diploid patients was relevant (16 vs. 121 months) but, due to the small number of cases, was not statistically significant (p = n.s). The mean value of S-phase fraction (SPF) was 14.8%. PCNA positive rate significantly correlates with size of the tumor (T1-T2 vs. T3-T4; p = 0.03). Actuarial overall survival resulted in 70%, 63% and 31% at 1, 5 and 10 years, respectively. The high rate of diploidy (72%) supports the relative benign behavior of ampullary cancers. CONCLUSIONS: PCNA positive rate significantly correlates with size of the disease. Aneuploidy, although without significant prognostic value, correlates well with survival. Because of the wide range of all variables, more data are needed to establish the relationships between pathological factors, DNA ploidy and PCNA rate and their significance as molecular predictors of prognosis in ampulla of Vater cancers.

Adult↗
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[Recent advances concerning etiopathogenesis of nasal polyposis].

The way nasal polyps arise and why they tend to recur is still unknown. Quite frequently they are found in association with asthma, rhinitis and ASA-intolerance, thus suggesting a multifactorial etiopathogenesis. The incidence of atopy in patients affected with nasal polyposis is quite low (16.8%). Recent studies stress the involvement of mast cell mediators due to various degranulating stimuli other than those mediated by IgE. The finding of the interleukin-2 receptor (IL2-R) on murine mast cells and on human peripheral blood basophils, together with the possibility of inducing basophil degranulation through IL2 stimulation, have led the authors to seek IL2R on human nasal polyp mast cells and to study subpopulations of nasal polyp lymphoid infiltrates. Nasal polyps obtained from 4 patients, admitted to the E.N.T. Department of the Catholic University of Rome in 1988, were snap frozen soon after their surgical removal through transmaxillary ethmoidectomy. In this study the following monoclonal antibodies (MoAb) were used: Leu-2a (CD8), Leu-3a/3b (CD4), Leu-4 (CD3), anti-HLA-DR and anti-IL2-R (CD25), OKM1 (CD11), OKB2 (CD24) and 1HT4-4H3 (CD 25). In no patient was there evidence of atopy, asthma or ASA-intolerance. Several mast cells (MC) were observed, chiefly in the connective axis and perivascular areas. These cells were characterized by a large number of cytoplasmatic monomorphic granules. The MC displayed the IL2-R and they were very often close to T-lymphocytes. T-cell subpopulations were predominantly composed of CD4-positive cells (about 75% of all lymphocytes) often associated in clusters and located both in the submucosa and in the connective axis. CD8-positive cells (10-15% of the lymphoid cells) were located most often just under the epithelium. They were hardly ever scattered within the CD4-positive cell clusters. Almost all T cells were activated, above all those surrounding the MC. These results would appear to suggest the presence of a cell-mediated immune response in nasal polyp pathogenesis where MC degranulation, determined by activated T-cell cytokines, plays an important role.

Adult↗