The results obtained suggest the presence in plaques of a serum-like GGT protein, indicating that a direct contribution of serum GGT to enzyme activity found within atherosclerotic lesions is possible. Data also indicate the occurrence of GGT-mediated redox reactions within plaque environment, which might influence plaque progression.

Background and Purpose-Percutaneous transluminal angioplasty with stent (CAS) is an alternative method to endarterectomy in the revascularization of carotid artery stenosis. Protected CAS is currently used to prevent distal embolization. Diffusion-weighted MRI (DWI) is the most sensitive tool to evaluate silent cerebral ischemia. The purpose of this research was to assess the incidence of cerebral embolic lesions during CAS and to evaluate whether cerebral protection devices can reduce the number of silent cerebral ischemia with respect to unprotected CAS. Methods-Fifty-two patients with high-grade internal stenosis underwent CAS; 30 patients (group a) were treated with a cerebral protection device, and 22 (group b) were treated without it. All of the patients were evaluated preoperatively and postoperatively with fluid-attenuated inversion recovery and DWI sequences to depict the number of new embolic silent cerebral lesions. Results-Embolic

Much of the morbidity of intracranial meningiomas is related to the degree of tumour vascularity and the extent of peritumoural vasogenic oedema. Several studies have shown that vascular endothelial growth factor (VEGF) is up-regulated in meningiomas, although its relationship with tumour vasculature is still unclear. In order to better understand the angiogenic assessment of intracranial meningiomas, we analysed its vascular pattern, both as number and as morphologic configuration of microvessels. Moreover, we investigated the mRNA-VEGF expression, relating this expression to vascular pattern. A total of 40 intracranial meningiomas, classified as benign (31 cases), atypical (7 cases), and anaplastic (2 cases) were analysed. RT-PCR analyses of mRNA-VEGF and competitive-PCR were performed. VEGF expression and microvessel density (MVD) were also immunohistochemically investigated. Grade II-III meningiomas showed numerous small microvessels (mean: 34), while the majority of Grade I showed few larger vessels (mean: 13.09) (P = 0.000003). A microvessel pattern overlapping into atypical subtype was found in eignt of the 31 (25.8%) Grade I meningiomas. A significant association was found between grading and vascular pattern (P = 0.0002), as well as between the MVD and the immunohistochemical expression of VEGF (P = 0.0005). The expression of mRNA agreed with the immunohistochemical expression of the protein (P < 0.0001). A total of 39 cases expressed the 121 VEGF isoform and, among these, 28 cases also expressed the 165 isoform. Only 9 cases expressed both isoforms 165 and 189. Grade II and III meningiomas showed a preponderant expression of soluble isoforms (121 and 165). These results prompt us to speculate that the microvessel pattern could underlie a higher metabolic demand, probably due to a rapid growth with a consequent worse clinical behaviour of the tumour. In this sense, the vascular pattern may be used as a prognostic factor, in order to mostly focus attention on those Grade I meningiomas which have a higher likelihood of either recurrence or development of perilesional oedema. The pattern of vasculature itself seems to be dependent on the types of VEGF isoforms: the Grade II-III meningiomas (that presented numerous microvessels) expressed the soluble isoforms 121 and 165, while the isoform 189 was more frequently detected in Grade I meningiomas.

Microvessel density (MVD) represents a measure of angiogenesis and may be used as an indicator of neoplastic aggressiveness. Vascular endothelial growth factor (VEGF) plays a pivotal role as angiogenic promoter by stimulating endothelial cell proliferation and migration and enhancing vascular permeability. The aim of this study was to investigate MVD and VEGF expression in human pituitary adenomas and normal pituitary gland tissues by immunohistochemistry, and to correlate data with clinical characteristics. Fragments from 46 pituitary adenomas (18 non-functioning, 12 ACTH-secreting, 12 GH-secreting, 4 PRL-secreting) and 19 specimens of normal anterior pituitary gland obtained at surgery were evaluated. MVD in normal anterior pituitary was significantly higher than in tumors (69.2 +/- 28.5 vs 29.3 +/- 19.7; p < 0.0001). Within adenomas, no difference was found in MVD when different histotype, size, sex, age, rate of recurrence or medical pre-surgical treatment were considered. The degree of vascularity was somewhat related only to clinical invasiveness, as evaluated by pre-surgical MRI grading (grade 0 p < 0.05 vs grade 1 and vs grade 2). No statistically significant difference in VEGF expression was found between normal tissue and adenomas and among tumors of different histotype (p = 0.3978). Size, sex, age, rate of recurrence and medical pre-surgical treatment did not influence VEGF expression. No correlation was found between MVD and VEGF expression. In conclusion, MVD was reduced in pituitary adenomas with respect to normal gland. VEGF expression is however well preserved in adenomas and this might contribute to adequate tumoral vascular supply with complex mechanisms other than endothelial cells proliferation.

Background and Purpose-In patients with severe internal carotid artery stenoses, thromboendarterectomy significantly reduces both ischemic stroke and the risk of more ischemic attacks. Digital subtraction angiography (DSA) is the accepted preoperative test to determine whether a high-grade stenosis is present and requires surgical therapy. However, DSA has a procedural risk of stroke between 0.7% and 1%. An accurate, noninvasive imaging protocol with no risk of severe complications would significantly increase the benefit of surgical treatment. The aims of the study were (1) to evaluate the diagnostic accuracy of contrast-enhanced magnetic resonance angiography (CEMRA) in detecting and grading internal carotid artery stenoses and (2) to assess the misclassification rate of vessels suitable for revascularization by CEMRA. Methods-Ninety-two patients with sonographic evidence of neck vessel stenosis were enrolled in the study. All patients were submitted to CEMRA and DSA. CEMRA images were evaluated for the presence of mild, moderate, or severe stenosis and occlusion. Results-Sensitivity, specificity, and diagnostic accuracy were 97%, 82%, and 92.5%, respectively. Agreement with DSA was optimal at ϭ0.87. The misclassification rate of CEMRA was 3.1% because of its tendency to overestimate the stenosis. Conclusions-The high diagnostic accuracy and limited misclassification rate suggest that CEMRA can be considered a powerful tool for the preoperative, noninvasive evaluation of atherosclerotic pathology of carotid arteries.