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Salvatore Esposito

Publications and source records attributed to Salvatore Esposito.

9 recordsLinked to original sources
PubMed2006

Ascending aorta dilatation in aortic valve disease: morphological analysis of medial changes.

We investigated whether and how the severity of medial degeneration lesions varies along the circumference of the dilated intrapericardial aorta. Two groups of aortic wall specimens, respectively harvested in the convexity and concavity of ascending aorta in 72 patients undergoing surgery for dilatation of the intrapericardial aorta associated with aortic valve disease, were separately sent for pathology, morphometry, and ultrastructural examination. Cystic medial necrosis, fibrosis, and elastic fiber fragmentation were classified into three degrees of severity; their mean degree and morphometric findings in the convexity and in the concavity specimens were compared by paired t-test. Correlation between echocardiographic degree of aortic dilatation and severity of medial degeneration was assessed separately for each of the two groups of specimens. Morphologically, medial degeneration was found in all cases; a higher mean degree was found in the convexity group (2.39 +/- 0.58 vs 1.44 +/- 0.65 in the concavity group; P < 0.001). At morphometry normal smooth muscle cells in the convexity specimens were significantly reduced (P = 0.007); the length (P = 0.012) and number (P = 0.009) of elastic fibers reduced and increased, respectively. Moreover, in the convexity specimens a significantly smaller amount of smooth muscle cells and an increase of immunohistochemical labeling of apoptosis-associated proteins in the subintimal layer of the media was noticed. Correlation between aortic ratio and medial degeneration degree was significant in the convexity group (P < 0.001), but not in the concavity group (P = 0.249). Scanning electron microscopy analysis confirmed morphological results and allowed us to better distinguish the early pathological cavities from the microvessels, which were in the outer media in normal aorta and ubiquitous in aortitis or atherosclerosis. Electron transmission microscopy analysis showed changes in the extracellular matrix and smooth muscle cells, and these changes increased from the intima to the adventitial layer of the media. In dilated intrapericardial aorta, medial degeneration changes and expression of apoptosis-associated proteins are more marked in the ascending aorta convexity, likely due to hemodynamic stress asymmetry. Ultrastructural findings allow us to distinguish the early medial changes not yet evident on light microscopy.

Aged↗
PubMed2005

c-Myc antisense oligonucleotides preserve smooth muscle differentiation and reduce negative remodelling following rat carotid arteriotomy.

OBJECTIVES: The vascular biology of restenosis is complex and not fully understood, thus explaining the lack of effective therapy for its prevention in clinical settings. The role of c-Myc in arteriotomy-induced stenosis, smooth muscle cell (SMC) differentiation and apoptosis was investigated in rat carotids applying full phosphorothioate antisense (AS) oligonucleotides (ODNs). METHODS: Carotid arteries from WKY rats were submitted to arteriotomy and to local application of ODNs through pluronic gel. Apoptosis (deoxynucleotidyl transferase-mediated dUTP nick end-labelling), SMC differentiation (SM22 immunofluorescence) and vessel morphology and morphometry (image analysis) were determined 2, 5 and 30 days after injury, respectively. RESULTS: AS ODNs induced a 60% decrease of target c-Myc mRNA 4 h after surgery in comparison to control sense (S) and scrambled ODN-treated carotids (p < 0.05). A significant 37 and 50% decrease in SM22 protein in the media of S ODN-treated and untreated carotids was detected when compared to uninjured contralateral arteries (p < 0.05). This reduction in SM22 expression was prevented in AS ODN-treated carotids. Stenosis was mainly due to adventitial constrictive remodelling. Lumen area in AS ODN-treated carotids was 35% greater than in control arteries 30 days after surgery (p < 0.05). TUNEL assay revealed increased apoptosis in AS ODN-treated carotids (p < 0.05). CONCLUSIONS: c-Myc AS ODNs reduce arteriotomy-induced negative remodelling. This is accompanied by maintained SMC differentiation and greater apoptosis. The combination of reduced c-Myc-induced proliferation and increased apoptosis may thus underlie the less severe remodelling upon treatment with c-Myc mRNA AS ODN.

Animals↗
PubMed2005

Anaplastic oligodendroglioma presenting with drop metastases in the cauda equina.

Metastatic involvement of the cerebro-spinal fluid (CSF) pathway in oligodendrogliomas is not uncommon; however, symptomatic involvement of the spinal cord is very rare: less of 10 cases have been published. To our knowledge, an intracranial oligodendroglioma presenting with symptoms of drop metastases in the cauda equina has never been reported. We report a case of 67-year-old woman who after 1 month of severe low back and legs pain developed symptoms of raised intracranial pressure. A spinal cord MRI showed multiple intradural nodular lesions at the level of the cauda equina, a MRI of the brain showed an intraventricular brain tumor. The histopathological diagnosis of both surgically treated lesions was anaplastic oligodendroglioma. The choices adopted in planning diagnostic and therapeutical procedures are discussed. The importance of the clinical and neuroradiological data in the diagnosis is stressed. Pathophysiology of the seeding of intracranial tumours via the cerebrospinal fluid is reviewed.

Cauda Equina↗
PubMed2003

Stenosis progression after surgical injury in Milan hypertensive rat carotid arteries.

BACKGROUND: Milan hypertensive rats (MHS) are characterised by an increase in renal sodium reabsorption mainly related to adducin mutations. Interest in this model relies on the genetic link between adducin polymorphisms and primary hypertension, observed also in a subset of patients. OBJECTIVES: To investigate the molecular and morphological events involved in carotid stenosis and triggered by surgery in MHS model. METHODS: Stenosis was induced through arteriotomy. At different times after injury, the expression profiles of various gene families were investigated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), while histological techniques were used to follow morphometric and morphological changes. Apoptotic nuclei were revealed by terminal deoxynucleotidyl transferase-dUTP nick end labelling (TUNEL). RESULTS: mRNAs coding for transcription factors c-jun, c-fos and c-myc were rapidly induced by injury. Analysis of apoptosis-related genes revealed a decrease of the Bcl-2/Bax ratio 4 h after vascular trauma (P<0.05), followed by a recovery of antiapoptotic factors 24 and 48 h later. ET(A) and receptor mRNAs decreased after the injury and were replaced by ET(B) and AT2 mRNAs. Both ET(A) and AT1 turned to basal level 48 h after injury. Expression profiles of chatepsins B and D were also determined. A marked neoadventitia led to maximal 60+/-9% lumen reduction (P<0.05) 30 days after surgery. Media substitution by fibrotic and granulomatous tissue was also evident. Maximal 47+/-2% apoptotic nuclei were detected 48 h after the injury (P<0.05). CONCLUSIONS: The injury applied to MHS carotids induces negative remodelling and a limited apoptotic reaction. These findings could arise from the balancing among proliferative factors, apoptosis-related molecules and relaxant anti-proliferative receptors, all stimulated by the injury.

Angiotensin I↗
PubMed2003

Aortic valve dysfunction and dilated ascending aorta. A complex and controversial association.

Several pathogenetic mechanisms account for the association of the ascending aorta dilation with aortic valve dysfunction. Functional aortic insufficiency can derive from medial degeneration of the aortic wall and annuloaortic ectasia; leaflet structural disease can determine root dilation by increasing aortic wall stress in case of both regurgitation and stenosis; aortic valve disease and aortic aneurysm can however coexist due to two different intrinsic etiologies. In the attempt to best tailor the surgical correction of such conditions to the underlying causative mechanism, several technical options have already been developed including composite or separate aortic valve and root replacement, valve-sparing operations, and aortoplasty techniques. The criteria for surgical indication cannot leave the underlying pathogenesis out of consideration as well. The newly acquired knowledge in the basic research on this topic is expected to affect the approach to the individual patient in the future.

Aorta↗
PubMed2003

Extensive retroperitoneal fibrosis with duodenal and ureteral obstruction associated with giant inflammatory aneurysm of the abdominal aorta.

We report a case of abdominal aortic aneurysm complicated by retroperitoneal fibrosis with both duodenal and bilateral ureteral obstruction. The patient underwent successful bilateral transurethral ureteral stenting, and then he was referred for surgical treatment of the aneurysm. Massive retroperitoneal fibrosis was found at surgery, and the mass was removed along with the diseased aorta, which was replaced by a bifurcated Dacron prosthesis; duodenolysis and ureterolysis were concomitantly performed. Ureteral stents were removed on the 8th postoperative day. Follow-up assessment at 1 year showed normalization of the urinary tract structure at echography and good hemodynamic performance of the vascular prosthesis at Doppler examination. To our knowledge, no other case of duodenal and bilateral ureteral stenosis secondary to massive retroperitoneal reactive fibrosis in association with abdominal aortic aneurysm has been reported.

Aged↗
PubMedDate not supplied

Scanning electron microscopy of aortic medial changes in aortic ascending dilatation.

The study of cystic cavities and collagen fibers fragmentation is useful to for a better knowledge of pathogenesis and surgical therapy of medial ascending aortic degeneration. Thus, the aim of this study was to describe by scanning electron microscopy the surfaces and shape of the cysts, measure their area, and identify microcystic spaces related to this degenerative disease. Scanning electron microscopy analysis was performed in 16 out of 36 patients who underwent surgery for ascending aorta dilatation with associated aortic valve disease. The aortic medial wall showed a cribrose appearance at low magnification (x50-100) and the intima was effuse. At high magnification (x500-2000), small cavities (clefts) lined by normal or fragmented elastic fibers and large cavities (pseudocystes) with anfractuous borders lined by fragmented elastic fibers and smooth muscle cells were observed. Furthermore, in the outer media wall microvessels lined by endothelium were also observed. These changes were lacking or less pronounced in normal aorta. SEM allows one to better identify the pathological cavities and to differentiate them from microvessels. These pathological cavities are more numerous and larger in the convexity than in the concavity of the aorta in according to our previous morphological and morphometric findings in asymmetrical aorta dilatation.

Aorta↗
PubMedDate not supplied

Morphological and ultrastructural findings of prognostic impact in craniopharyngiomas.

Craniopharyngioma is a slow-growing epithelial tumor with an unpredictable tendency to recur. To verify the reliability in predicting the clinical outcome, some morphological and immunohistochemical findings were analyzed in 37 primitive tumors and in 6 recurrences (one recurred twice). All the tumors were surgically excised and all recurrences exhibited an adamantinomatous pattern; mitotic rate was low (< 5 x 10 HPF) in both recurrent and in nonrecurrent tumors. Primary tumors showed a mean positivity of 1.7% (range 0.3-2%) to PCNA vs. 4.1% (range 0.3-8%) in recurrences. The MIB-1 Labelling Index was: 22.12% in primary tumors, 27.5% in recurrences, 31.3% in adult nonrecurrent tumors, and 4.1% in the pediatric tumor. CD34 labeling vessels/field was 9.3 in primary tumors and 9.91 in the recurrences; VEGF expression was higher in recurrences than in primary tumors (40 vs. 25%). Ultrastructural analysis showed fenestrated endothelium with hydropic changes in VEGF-positive vessels. Lack of clear correlations between morphological or immuno-staining patterns and behavior suggests that these features have no prognostic value in adult as well as in pediatric craniopharyngiomas. In this study, the only results that may be related to the aggressiveness of tumor is the major vascularization in the recurrent tumors in which the vessels show also ultrastructural changes.

Adolescent↗