Rita Spirito

A proteomic approach to differentiate histologically classified stable and unstable plaques from human carotid arteries

OBJECTIVES By using proteomics we isolated and identified proteins that were expressed/retained in stable and unstable human carotid artery atherosclerotic plaques. METHODS The criteria for plaque instability were the presence of a thin fibrous cap or fissured cap covering the foamy or necrotic core, and the presence of overt, hemorrhagic, ulcerated or thrombotic plaques. Proteins were extracted from finely minced endarterectomy specimens (19 stable and 29 unstable plaques) and separated by two-dimensional gel electrophoresis. Coomassie Blue-stained gels were analysed using PD-Quest software. RESULTS A total of 57 distinct spots corresponding to 33 different proteins were identified by matrix assisted laser desorption/ionization mass spectrometry using the NCBI database. Most of the spots were present in both types of extracts, although significantly (p<0.05) differing in abundance between them. Compared to stable plaque, unstable ones showed reduced abundance of: protective enzymes SOD3 and GST, small heat shock proteins HSP27 and HSP20, annexin A10, and Rho GDI. In unstable plaques the more abundant proteins were: ferritin light subunit, SOD 2 and fibrinogen fragment D. For fibrinogen fragment D, the increased levels in unstable versus stable plaques was confirmed by Western blot analysis. CONCLUSIONS Since many of the differentially expressed proteins are known to have a functional role in inflammation and oxidative stress, we speculate that they may be involved in events relating to plaque stability.

The anterior spinal artery: the main arterial supply of the human spinal cord--a preliminary anatomic study.

Paraplegia is the most feared complication of surgery of the thoracic aorta. Controversy continues regarding the continuity of the anterior spinal artery (ASA). We studied the arterial vascularization of human spinal cord to indagate ASA continuity and possible anatomic variations of the arteria radicularis magna (ARM). Methods. From July 1998 to January 1999, 31 spinal cords from adult cadavers of both sexes were studied (mean age 72 ± 12 years). The cause of death was well established in each case and no one had spinal, cerebral, or significant aortic disease. The abdomen, thoracic viscera, and vessels were removed after 24 to 36 hours from death; only the upper trunks of the aorta were left in situ. The anterior vertebral spinal column was exposed and the attached muscles were divided. The vertebral bodies were removed with an electrical oscillating saw. The spinal cord in situ was exposed after a longitudinal paramedian incision of the dura mater. In all cases the course of the ASA was visualized and the distribuFrom the Department of Cardiovascular Surgery, Centro Cardiologico “I Monzino” Foundation IRCCS,a and II Department of Pathology,b University of Milan, Milan, Italy. Received for publication April 6, 1999; accepted for publication Sept 20, 1999. Address for reprints: Maurizio Roberto, MD, Department of Cardiovascular Surgery, “I Monzino” Foundation IRCCS, via Parea 4, 20138 Milan, Italy. J Thorac Cardiovasc Surg 2000;119:376-9 Copyright

Quick, simple clamping technique in descending thoracic aortic aneurysm repair

BACKGROUND Although significant advances have been made in the surgical treatment of diseases affecting the descending thoracic aorta, paraplegia remains a devastating complication. We propose the quick, simple clamping technique to prevent spinal cord ischemic injury. METHODS From 1983 to 1998, 143 patients had descending thoracic aorta aneurysm repair. We divided the patients into the following three groups according to the surgical technique used: selective atriodistal bypass was used in group 1 (66 patients); simple clamping technique in group 2 (28 patients); and quick simple clamping technique in group 3 (49 patients). Mean aortic cross clamp time was 39+/-13 minutes in group 1, 37+/-11 minutes in group 2, and 17+/-6 minutes in group 3 (p<0.01 group 3 versus group 1 and group 2). RESULTS The overall incidence of paraplegia was 4.8% (7 patients), 4.5% (3 patients) in group 1, 14.3% (4 patients) in group 2, and 0 in group 3 (p<0.05 group 3 versus group 2). The overall in-hospital mortality rate was 5.5%. Multivariate logistic regression analysis showed a powerful effect of aortic cross-clamping time as risk factor for both paraplegia (p<0.008), with an odds ratio of 1.03 per minute, and in-hospital mortality (p<0.001), with an odds ratio of 2.5 per minute. The mean follow-up time was 65 months with a lower overall mortality rate in group 3 than in group 1 and group 2 (p<0.05). CONCLUSION In descending thoracic aortic aneurysm repair, spinal cord perfusion can be maintained adequately without reimplantation of segmental vessels or use of atriodistal bypass when the aortic cross-clamp time is short (<15 to 20 minutes).

Lack of Association Between Serum Immunoreactivity and Chlamydia pneumoniae Detection in the Human Aortic Wall

Background—Only a few studies have focused the attention on the relation between elevated anti–Chlamydia pneumoniae (CP) antibodies and the detection of CP in the arterial wall. The aim of our study is thus to investigate the relationship between immune response to CP and detection of CP in the aortic walls of patients with abdominal aortic aneurysm. Methods and Results—A specimen of aortic wall was obtained from 102 consecutive patients who underwent abdominal aneurysm repair. The possible presence of CP was studied by polymerase chain reaction and confirmed by nonradioactive DNA hybridization. Antibody response to CP was studied (IgG, IgA titers). We found 33 patients (32.4%) with CP DNA+. No correlation between CP DNA detection and antibody titers was found (IgG P =0.52, IgA P =0.66). High correlation between IgG and IgA titer was observed (P <0.01). Endovascular presence of CP and antibody titers was not related to the age of the patient. Conclusions—CP antibody titers are not associated with the presence of CP in the aortic wall of patients with abdominal aortic aneurysm.

Evidence for a Proinflammatory and Proteolytic Environment in Plaques From Endarterectomy Segments of Human Carotid Arteries

ObjectivesBased on previous observations on apolipoprotein(a), apo(a), in human unstable carotid plaques, we explored whether in the inflammatory environment of human atheroma, proteolytic events affect other hepatic and topically generated proteins in relation to the issue of plaque stability. Methods and ResultsForty unstable and 24 stable plaques from endarterectomy segments of affected human carotid arteries were extracted with buffered saline (PBS) and then 6 mol/L guanidine-hydrochloride (GdHCl) to identify loosely and tightly bound products, respectively. The extracts were studied before and after ultracentrifugation at d 1.21 g/mL. In the extracts, the concentrations of interleukin (IL)-6, −8, and −18 were significantly higher in the unstable plaques and correlated to those of MMP-2 and MMP-9. By Western blots, both apoB and apo(a) were highly fragmented and mostly present in the d 1.21 bottom that also contained fragments of apoE (10 and 22 kDa), decorin, biglycan, and versican. Fragmentation was higher in the unstable plaques. In baseline plasmas, concentrations of lipids, lipoproteins, and ILs did not differ between patients with unstable and stable plaques. ConclusionsIn unstable and to a lesser extent in stable plaques, there is a proinflammatory and proteolytic microenvironment with the generation of fragments with potential pathobiological significance that requires investigation.

Cardiopulmonary bypass and oxygen consumption: oxygen delivery and hemodynamics

BACKGROUND This study was undertaken to investigate the relations between whole body oxygen consumption (VO2), oxygen delivery (DO2), and hemodynamic variables during cardiopulmonary bypass. METHODS One hundred one patients were studied during cooling, hypothermia, and rewarming. Oxygen consumption, DO2, hemodynamics, and DO2crit were measured at these times. RESULTS There was a direct linear relation between DO2 and VO2 during all three times. No relation between VO2 and hemodynamics was detected during cooling; during hypothermia, an inverse linear relation with peripheral arterial resistance was found. Finally, during rewarming, there was a direct relation with pump flow rate, and an inverse relation with arterial pressure and arterial resistance. The same relations among the variables were found at delivery levels above or below DO2crit. CONCLUSIONS During cardiopulmonary bypass there is a direct linear relation between DO2 and VO2; the relations with hemodynamic variables depend on the phases of cardiopulmonary bypass. This suggests that increasing delivery levels may recruit and perfuse more vascular beds, and higher delivery levels are advisable during perfusion. During rewarming and hypothermia, lower arterial resistances are also desirable to optimize VO2.

Tissue Factor and Atherosclerosis: Not only vessel wall-derived TF, but also platelet-associated TF

In the last ten years the contribution of both vessel wall-derived tissue factor (TF) and platelets to atherosclerosis has been revisited. At the beginning of the 2000 a circulating blood-borne TF has been proposed to sustain coagulation activation and propagation on the edge of a growing thrombus. Concomitantly with the observation that platelets not only contribute to thrombus formation, but also take part to the onset of the atherosclerotic lesion, evidences have been provided that they express functionally active TF, making them able to trigger the coagulation cascade.

Determinants of Early and Late Outcome after Surgery for Type A Aortic Dissection

AbstractThe aim of this study was to identify the most important variables associated with early and late mortality in patients operated on for type A aortic dissection over a 15-year period. From January 1984 to March 1999, 110 patients underwent surgery for type A aortic dissection. The 88.1% of patients had an acute type A dissection (AD) and 11.8% had a chronic dissection (CD). Cardiac tamponade and shock occurred in 21.8% and 14.5% of the patients, respectively. The location of the primary intimal tear was in the ascending aorta in 70.9% of cases, in the arch in 17.2%, and in the descending aorta in 7.2%. Univariate and multivariate analyses were conducted to identify non-embolic variables independently correlated to in-hospital death. Kaplan-Meier and Cox regression analyses and hazard function for death risk were used to analyze factors influencing overall and surgical survival. The overall in-hospital mortality rate was 20.9% (23/110 patients), being 9% for CD and 21.6% for AD. Emergent procedures had an in-hospital mortality rate of 47.6%, whereas nonemergent operations had an in-hospital mortality rate of 13.7% (p < 0.01). Univariate analysis revealed 41 preoperative and operative variables, including age (years), age >70 years, remote myocardial infarction, cerebrovascular dysfunction, diabetes, preoperative renal failure, shock, cardiopulmonary bypass time (minutes), emergency operation, as factors associated to in-hospital death (p < 0.05). Stepwise logistic regression analysis for in-hospital death selected as independent predicting variables (p < 0.05) remote myocardial infarction [p = 0.006, odds ratio (OR) = 1.9], preoperative renal failure (p = 0.031; OR = 0.8), shock (p = 0.001; OR = 3.1), and age >70 years (p = 0.007; OR = 1.7). Follow-up ranged from 9 to 172 months (median 78 months), with Kaplan-Meier survivals for all the patients and hospital survivors of 42% and 54% at 10 years, respectively. Cox regression analysis has identified postoperative stroke [relative risk (RR) = 3.7; p = 0.012), intimal tear in the aortic arch (RR = 2.3; p = 0.036), and postoperative renal failure (RR = 4.5; p = 0.007) as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, preoperative renal dysfunction (RR = 1; p = 0.013), reoperation (RR = 1.7; p = 0.004) and intimal tear in the aortic arch (RR = 1.2; p = 0.002) emerged as risk factors. The actuarial freedom from reoperation was 85.4% at 5 years. Multiple factors still influence early and late survival after surgery for type A aortic dissection. Preoperative renal impairment both affects early and late outcome. Early postoperative course affects late outcome in hospital survivors. The presence of the intimal tear in the aortic arch has a negative impact on late survival.

Endovascular Repair of Iatrogenic Subclavian Artery Perforations Using the Hemobahn Stent-Graft

PURPOSE To report the use of a new self-expanding endograft for percutaneous treatment of iatrogenic subclavian artery perforations. CASE REPORTS The subclavian artery of 2 patients was inadvertently cannulated during percutaneous attempts to implant a permanent pacemaker in one and catheterize the subclavian vein in the other. Because both patients had serious comorbidities, endovascular repair of the subclavian perforations was performed using the Hemobahn endograft, a nitinol stent covered internally with expanded polytetrafluoroethylene. The endoprostheses were successfully deployed via an ipsilateral brachial artery access. No signs of endograft occlusion, migration, deformation, or fracture have been observed during follow-up at 12 and 10 months, respectively, in these patients. CONCLUSIONS The Hemobahn stent-graft appears well suited to repairing subclavian artery injuries. Longer follow-up will determine if the design of this endograft will resist compression in this vascular location.

Proteomic Analysis of Plasma-Purified VLDL, LDL, and HDL Fractions from Atherosclerotic Patients Undergoing Carotid Endarterectomy: Identification of Serum Amyloid A as a Potential Marker

Apolipoproteins are very heterogeneous protein family, implicated in plasma lipoprotein structural stabilization, lipid metabolism, inflammation, or immunity. Obtaining detailed information on apolipoprotein composition and structure may contribute to elucidating lipoprotein roles in atherogenesis and to developing new therapeutic strategies for the treatment of lipoprotein-associated disorders. This study aimed at developing a comprehensive method for characterizing the apolipoprotein component of plasma VLDL, LDL, and HDL fractions from patients undergoing carotid endarterectomy, by means of two-dimensional electrophoresis (2-DE) coupled with Mass Spectrometry analysis, useful for identifying potential markers of plaque presence and vulnerability. The adopted method allowed obtaining reproducible 2-DE maps of exchangeable apolipoproteins from VLDL, LDL, and HDL. Twenty-three protein isoforms were identified by peptide mass fingerprinting analysis. Differential proteomic analysis allowed for identifying increased levels of acute-phase serum amyloid A protein (AP SAA) in all lipoprotein fractions, especially in LDL from atherosclerotic patients. Results have been confirmed by western blotting analysis on each lipoprotein fraction using apo AI levels for data normalization. The higher levels of AP SAA found in patients suggest a role of LDL as AP SAA carrier into the subendothelial space of artery wall, where AP SAA accumulates and may exert noxious effects.