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Sabina Pistolesi

Publications and source records attributed to Sabina Pistolesi.

6 recordsLinked to original sources
PubMed2006

Expression of endothelin 1 and its angiogenic role in meningiomas.

Meningiomas are one of the most frequent central nervous system tumours. Although slow-growing at times, they continue to be a cause of morbidity and mortality. The endothelin (ET) family consists of three isoforms: ET-1 is the most abundant one. ET-1 may be involved in meningioma tumourigenesis in concert with other growth factors, in particular with angiogenic agents. We analysed ET-1 expression by immunohistochemistry and its activating system by reverse-transcription-polymerase chain reaction in 56 cases of meningioma. We found an association between high-grade meningiomas and high ET-1 expression levels (p=0.002). Moreover, we evaluated the potential angiogenic role of ET-1, finding an elevated microvessel count in tumours with high ET expression levels (p=0.004). ET-1 may contribute to meningioma growth by inducing formation of new blood vessels. The finding that ET-1 expression positively correlates with vascular endothelial growth factor (VEGF) expression in meningiomas (p=0.03) also supports the hypothesized modulating effect of ET-1 on angiogenesis. Thus, the influence of the ET system on the progression of meningiomas may occur through stimulation of VEGF. The association of ET-1 and meningioma represents a potential area for therapeutic intervention with selective ET inhibitors. Additional clinical studies will be needed before inhibitors can be incorporated in clinical practice.

Adult↗
PubMed2005

Distal embolization during primary angioplasty: histopathologic features and predictability.

BACKGROUND: Distal embolization during primary percutaneous coronary interventions (PCIs) may affect myocardial reperfusion. We evaluated the prevalence and features of embolization during primary PCI and its relationship with clinical and angiographic variables. METHODS: Forty-six consecutive patients with acute myocardial infarction underwent primary PCI with a filter-based distal protection device. Histopathologic analysis was performed on retrieved embolic fragments, assessing the presence and relative amount of fibrin, necrosis, lipid droplets, collagen, mucopolysaccharides, and leukocytes, as well as the total debris volume. Such variables were related to baseline clinical and angiographic variables. RESULTS: Embolic material was recovered in 41 (89%) of 46 cases, with a mean total debris volume of 1.2 +/- 2.2 mm3. Prevalent histopathologic patterns were organized thrombus (47%), fresh thrombus (29%), and plaque fragments (24%). At multivariate analysis, none of the baseline clinical variables considered significantly predicted the total debris volume. Among angiographic variables, angiographic signs of high thrombus burden (cut-off coronary occlusion pattern or large intracoronary minus image) independently predicted the total debris volume at multivariate analysis (odds ratio 15.8, P < .005). Compared with its nonuse, abciximab did not affect the total number and the mean total volume of embolized material (15 +/- 16 vs 10 +/- 8 fragments, 1.5 +/- 2.5 vs 1.0 +/- 1.9 mm3, respectively, for both P > .20), or its qualitative composition. CONCLUSIONS: Distal embolization occurs in most patients during primary PCI and mainly consists of plaque fragments and partially organized thrombi, which are likely to be scarcely responsive to antiplatelet drugs. Baseline angiographic signs of a high thrombus burden are the only significant predictors of the extent of distal embolization.

Angioplasty↗
PubMedDate not supplied

The role of somatostatin in vasogenic meningioma associated brain edema.

Many tumors, including meningiomas, express somatostatin receptors, suggesting the application of somatostatin analogues for therapy and diagnosis. Sixty percent of meningiomas are associated with perilesional edema, whose development seems to be related to the vascular endothelial growth factor, although it requires an efficient pial blood supply. However, in several neoplastic models, other mediators seem to cooperate with vascular endothelial growth factor in regulating angiogenesis. We evaluated somatostatin receptors (sst2) in relation to the possibility that somatostatin analogues may influence vascular endothelial growth factor production with reduction of edema. Of 35 studied meningiomas, 21 presented peritumoural edema. Vascular endothelial growth factor, microvascular density and pial blood supply were significantly related to the edema (P = 0.0001, P = 0.0001, P = 0.0005). Similarly, a relation was found between sst2 and microvascular density (r = 0.58, P < 0.001) and between sst2 and vascular endothelial growth factor expression (P = 0.03). This suggests that somatostatin analogues may be relevant for the treatment of meningiomas.

Adult↗
PubMedDate not supplied

Immunohistochemical and molecular study of radiation-induced multiple meningiomas with pleural and pulmonary metastasis.

In the present study, the telomerase activity and the putative alterations of genes involved in cell-cycle control (p53, Fas and pRb) were investigated in a radiation-induced meningioma with multiple recurrences and pleural-pulmonary metastases (the patient, a 34-year-old male, had a history of carcinoma of the tongue of testicular lymphocytic lymphoma). Expression of VEGF and vasculature pattern were also studied. Expression of VEGF, pRb and p53 were evaluated by immunohistochemistry on formalin-fixed, paraffin-embedded samples of the tumor. VEGFmRNA was determined by competitive PCR. Fas, FasL and hTERT were evaluated by RT-PCR. Telomerase activity was examined by the TRAP assay. An intense vascularization was observed, supported by high expression of VEGFmRNA (isoforms 121 and 165). pRb and p53 were overexpressed. Fas was undetectable with PCR, whereas FasL was positive. Furthermore, the lesion showed an elevated telomerase activity (TPG, 22), according to the high expression of hTERT. These findings emphasized that even among generally benign neoplasms, such as meningiomas, some highly malignant tumors may develop, as in our case, in which several mechanisms were activated in the cancer progression to guarantee the immortalization of cellular clones (angiogenic phenomenon, activation of telomerase and of anti-apoptotic mechanisms) and the blood spread. Thus, the data illustrate the importance of searching for genetic aberrations (which are a hallmark of malignancy) in meningiomas, as predictive and reliable factors of the possibility to recur and to metastasize.

Adult↗