Roberto Scorza

Matrix Metalloproteinase-1 and Matrix Metalloproteinase-3 Gene Promoter Polymorphisms Are Associated With Carotid Artery Stenosis

Background and Purpose— The matrix metalloproteinases (MMPs) are a family of enzymes that are important in the resorption of extracellular matrix and are involved in atherogenesis. Recently, 2 common polymorphisms on MMP-1 (1G/2G) and MMP-3 (5A/6A) gene promoters have been described. The aim of this study was to investigate a possible association between MMP polymorphisms and increased risk of internal carotid artery (ICA) stenosis. Methods— We studied 91 patients consecutively recruited for ICA stenosis who had undergone carotid endarterectomy and 133 subjects without ICA stenosis (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. Results— The frequency of the 6A allele was significantly different between cases and controls: 0.62 and 0.50, respectively (odds ratio [OR], 1.58; 95% CI, 1.08 to 2.33;P =0.017). The frequency of 6A/6A genotype was significantly higher in cases with involvement of both carotids (OR, 3.13; 95% CI, 1.14 to 8.5;P =0.026) and in patients with stenosis >70% (OR, 2.55; 95% CI, 1.07 to 6.07;P =0.033). No significant differences were observed in MMP-1 distribution. Patients who were homozygous for both the 6A and 2G alleles had an elevated relative risk of ICA stenosis (OR, 2.66; 95% CI, 1.23 to 5.72;P =0.016). Multiple logistic regression analysis using the common risk factors and the 6A and 2G allele variants revealed that the 6A allele was an independent risk factor for ICA stenosis (P =0.049). When 6A/6A and 2G/2G were combined, the risk factor for ICA stenosis was 3-fold higher (OR, 3.31; 95% CI, 1.48 to 7.42;P =0.004). Conclusions— Homozygosity for the 6A allele of the MMP-3 promoter is associated with carotid stenosis and, in association with MMP-1 2G homozygosity, predicts an increased risk of ICA stenosis. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid-related stroke.

Internal carotid artery occlusive disease and polymorphisms of fractalkine receptor CX3CR1: A genetic risk factor

Background and Purpose— Fractalkine (FKN), a chemokine expressed by inflamed endothelium, induces leukocyte adhesion and migration via the receptor CX3CR1. The polymorphisms V249I and T280M affect receptor expression and function. The role of FKN in atherosclerosis has been recently demonstrated. The aim of this study was to investigate a possible association between CX3CR1 polymorphisms and increased risk of internal carotid artery (ICA) occlusive disease. Methods— We studied 108 patients consecutively recruited for ICA occlusive disease, 84 of whom underwent operation for carotid endarterectomy, and 204 subjects without ICA occlusive disease (controls). Polymorphic genotypes were determined by polymerase chain reaction and sequencing analysis. Results— The adjusted odds ratio (OR) associated with the presence of the M280 (TM+MM versus TT genotype) was 0.55 (95% CI: 0.29 to 0.99; P = 0.037). Therefore, this allele is associated with a reduced risk of ICA occlusive disease. No significant differences were observed in I249 distribution. The frequency of I249 allele was significantly higher in cases of hard plaques, which are considered more stable than soft ones (OR: 0.38; 95% CI: 0.13 to 1.05; P = 0.037). Multiple logistic regression analysis using the common risk factors and the I249 and M280 allele variants revealed that the M280 allele was an independent risk factor for ICA stenosis (P = 0.047). Conclusion— The results show that the CX3CR1 M280 is an independent genetic risk factor for ICA occlusive disease and that I249 is involved in the stability of carotid plaques. Even if obtained from a relatively limited patient series, these results might have relevant implications for treatment of ICA stenosis and possibly prevention of carotid related stroke. Further prospective cross-sectional studies are needed to confirm these results.

Loss of heterozygosity of the NOS3 dinucleotide repeat marker in atherosclerotic plaques of human carotid arteries

We have investigated 28 atherosclerotic plaques of human carotid arteries with a panel of 39 microsatellite markers for the presence of LOH. The objective of this research was to verify if LOH, described in association with tumorigenic process, could be involved also in benign fibroproliferative disease. Seventy percent of samples demonstrated allelic imbalance: 50% of cases showed LOH at a minimum of one locus, 3.5% at a minimum of two loci and 14.3% at three or more loci. The percentages of LOH ranged between 3.8 and 14.3% and the highest involved polymorphic marker is the NOS3 internal dinucleotide repeat. Our results indicate that, like tumorigenesis, the atherogenic process could also involve LOH mechanism. Furthermore, the finding regarding the NOS3 internal polymorphism suggests a possible role of the gene as cofactor in formation of the atheromas.

Xanthine Oxido-reductase Activity in Ischemic Human and Rat Intestine

We measured time course and extent of xanthine dehydrogenase (XD) to xanthine oxidase (XO) conversion in ischemic human and rat intestine. To model normothermic no-flow ischemia, we incubated fresh biopsies for 0, 2, 4, 8 and 16 h. At [Formula: See Text] XO was less in humans than in rats [Formula: See Text] while XD was essentially the same [Formula: See Text] After 16 h incubation at 37°C, there was no appreciable XD-to-XO conversion and no change in neither XO nor XD activity in human intestine. In contrast, the rat intestine had [Formula: See Text] ratio doubled in the first 2 h and then maintained that value until [Formula: See Text] In conclusion, no XO-to-XD conversion was appreciable after 16 h no-flow normothermic ischemia in human intestine; in contrast, XO activity in rats increased sharply after the onset of ischemia. An immunohistochemical labelling study shows that, whereas [Formula: See Text] expression in liver tissue is localised in both hepatocytes and endothelial cells, in the intestine that expression is mostly localised in epithelial cells. We conclude that XO may be considered as a major source of reactive oxygen species in rats but not in humans.

Hirnbeteiligung bei extrakraniellen Aneurysmata der A. carotis interna

Background: No prospective study of extracranial internal carotid artery aneurysms (EICAA) has been reported to date. The aim of this study was to evaluate central nervous system complications associated with surgical intervention for EICAA. Patients and methods: A total of seven patients, representing all cases observed at our institution from December 1997 to December 1998, were entered in this prospective study. Three patients had bilateral involvement. The aneurysms were both atherosclerotic and dysplastic. All patients were males, with mean age of 70 years (range 65 to 74). Internal or common carotid artery to EICAAs diameter ratios were calculated on the angiograms. The transverse diameter as well as the craniocaudal extension of the lesions were accurately measured intraoperatively. Follow-up evaluations were performed at three, six and twelve months postoperatively, and consisted of a clinical evaluation by both a neurologist and a vascular surgeon who were not part of the primary surgical team. R...BACKGROUND No prospective study of extracranial internal carotid artery aneurysms (EICAA) has been reported to date. The aim of this study was to evaluate central nervous system complications associated with surgical intervention for EICAA. PATIENTS AND METHODS A total of seven patients, representing all cases observed at our institution from December 1997 to December 1998, were entered in this prospective study. Three patients had bilateral involvement. The aneurysms were both atherosclerotic and dysplastic. All patients were males, with mean age of 70 years (range 65 to 74). Internal or common carotid artery to EICAAs diameter ratios were calculated on the angiograms. The transverse diameter as well as the craniocaudal extension of the lesions were accurately measured intraoperatively. Follow-up evaluations were performed at three, six and twelve months postoperatively, and consisted of a clinical evaluation by both a neurologist and a vascular surgeon who were not part of the primary surgical team. RESULTS Six patients presented with neurological symptoms ranging from non-hemispheric TIAs to hemispheric stroke. One patient was asymptomatic. The severity of symptoms was correlated with the size of the aneurysm. Preoperative symptoms were more severe in EICAAs of > or = 3 cm in transverse diameter. One case had a postoperative stroke, no perioperative deaths occurred. All the internal carotid arteries operated on were patent during follow-up evaluations. No new neurologic event was observed during follow-up. CONCLUSIONS The severity of central neurologic symptoms seems to depend on the size of the aneurysmatic lesion. Prompt surgical management of small EICAAs may reduce the occurrence of severe CNS complications, both preoperatively and postoperatively, due to the lower risk of embolization associated with small aneurysms compared to larger lesions.

Brain involvement in extracranial internal carotid artery aneurysms

Background: No prospective study of extracranial internal carotid artery aneurysms (EICAA) has been reported to date. The aim of this study was to evaluate central nervous system complications associated with surgical intervention for EICAA. Patients and methods: A total of seven patients, representing all cases observed at our institution from December 1997 to December 1998, were entered in this prospective study. Three patients had bilateral involvement. The aneurysms were both atherosclerotic and dysplastic. All patients were males, with mean age of 70 years (range 65 to 74). Internal or common carotid artery to EICAAs diameter ratios were calculated on the angiograms. The transverse diameter as well as the craniocaudal extension of the lesions were accurately measured intraoperatively. Follow-up evaluations were performed at three, six and twelve months postoperatively, and consisted of a clinical evaluation by both a neurologist and a vascular surgeon who were not part of the primary surgical team. R...BACKGROUND No prospective study of extracranial internal carotid artery aneurysms (EICAA) has been reported to date. The aim of this study was to evaluate central nervous system complications associated with surgical intervention for EICAA. PATIENTS AND METHODS A total of seven patients, representing all cases observed at our institution from December 1997 to December 1998, were entered in this prospective study. Three patients had bilateral involvement. The aneurysms were both atherosclerotic and dysplastic. All patients were males, with mean age of 70 years (range 65 to 74). Internal or common carotid artery to EICAAs diameter ratios were calculated on the angiograms. The transverse diameter as well as the craniocaudal extension of the lesions were accurately measured intraoperatively. Follow-up evaluations were performed at three, six and twelve months postoperatively, and consisted of a clinical evaluation by both a neurologist and a vascular surgeon who were not part of the primary surgical team. RESULTS Six patients presented with neurological symptoms ranging from non-hemispheric TIAs to hemispheric stroke. One patient was asymptomatic. The severity of symptoms was correlated with the size of the aneurysm. Preoperative symptoms were more severe in EICAAs of > or = 3 cm in transverse diameter. One case had a postoperative stroke, no perioperative deaths occurred. All the internal carotid arteries operated on were patent during follow-up evaluations. No new neurologic event was observed during follow-up. CONCLUSIONS The severity of central neurologic symptoms seems to depend on the size of the aneurysmatic lesion. Prompt surgical management of small EICAAs may reduce the occurrence of severe CNS complications, both preoperatively and postoperatively, due to the lower risk of embolization associated with small aneurysms compared to larger lesions.