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Biomedical subjects

Gaetano Thiene

Publications and source records attributed to Gaetano Thiene.

At least 73 records · Page 4Linked to original sources
PubMed2004

Overexpression of tumor necrosis factor (TNF)alpha and TNFalpha receptor I in human viral myocarditis: clinicopathologic correlations.

Proinflammatory cytokines, including tumor necrosis factor (TNF)alpha, have been recognized as important physiopathogenetic factors in the initiation and continuation of inflammatory cardiomyopathies. Experimental and preliminary human studies have demonstrated that TNFalpha plays a crucial role in enteroviral-induced myocarditis. In this study, we investigated the expression of TNFalpha and both its receptors (TNFRI and TNFRII) in both viral and nonviral myocarditis. Myocardial expression of TNFalpha was then correlated with different clinical and pathologic findings. TNFalpha expression was investigated in endomyocardial biopsies obtained from 38 patients with myocarditis and from eight control subjects by using reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemistry. Viral etiology was diagnosed by PCR in 20 cases: enterovirus in seven, Epstein-Barr virus in four, hepatitis C virus in three, adenovirus in two, influenza virus in two, cytomegalovirus in one, and double infection adenovirus and enterovirus in one. Immunohistochemistry was also used to analyze both TNFalpha receptors (RI and RII). A semiquantitative analysis was employed (score 0-3) for necrosis, inflammation, fibrosis and immunohistochemical findings. TNFalpha mRNA and TNFalpha protein were significantly more present in viral myocarditis than in nonviral myocarditis (16/20 vs 3/18, P=0.001). Remarkable immunostaining was observed for both receptors, particularly TNFRI. Histological analysis revealed that myocardial necrosis (mean score 1.89 vs 1.15, P=0.01) and cellular infiltration (mean score 2.26 vs 1.78, P=0.05) were more prominent in TNFalpha-positive cases. Among TNFalpha-positive cases, the greater TNFalpha mRNAs, the more impaired was cardiac function. Our findings suggest that the expression of TNFalpha may play an important role in the pathogenesis of viral myocarditis of any etiology and may influence the severity of cardiac dysfunction. Cytokine effects are more strictly linked to overexpression of TNFRI.

Adolescent↗
PubMed2004

Alterations in the coagulation profile in renal pig-to-monkey xenotransplantation.

Five monkey recipients of a porcine renal xenograft were studied to determine the relationship between fibrin formation in acute humoral xenograft rejection (AHXR) and procoagulant and anticoagulant factor levels to establish whether changes in coagulation parameters could be used to predict AHXR and determine whether AHXR is associated with overt disseminated intravascular coagulopathy (DIC) in this model. Variable degrees of compensated consumptive coagulopathy were observed in each primate. Elevated thrombin-antithrombin (TAT), F1+2 and D-dimer levels consistent with thrombin generation and fibrin formation were recorded. There was no consumption of the main clotting inhibitors (including antithrombin) or a progressive, severe drop in fibrinogen levels and platelet counts, although grafts were left in situ. After transplantation, D-dimer levels remained persistently high, so they were of limited value in defining this coagulopathy. At post mortem, no cases of multiorgan involvement typical of overt DIC were observed. The lack of a rapid postoperative recovery of clotting inhibitor levels after transplantation was invariably associated with early poor outcome. This study shows that AHXR is associated with various degrees of compensated consumptive coagulopathy in our pig-to-primate model. No clear relationship was found between coagulation parameter levels and graft outcome.

Animals↗
PubMed2004

Ureteral stenosis in HDAF pig-to-primate renal xenotransplantation: a phenomenon related to immunological events?

The aim of this study was to analyze the incidence of ureteral stenosis in a life-supporting human decay-accelerating factor (hDAF) transgenic pig-to-cynomolgus monkey kidney transplantation model and determine the role of possible immunological events in its pathogenesis. Thirty consecutive bi-nephrectomized cynomolgus monkeys received a kidney from hDAF transgenic pigs with or without a ureteral stent. Four monkeys were euthanized prematurely after transplantation. In the remaining 26 cases, the mean survival was 24 +/- 19 days. Except in one case, there was a close relationship between ureter and kidney in terms of type and severity of rejection. There were six ureteral stenoses; five were repaired by stent positioning and resurgery extended survival for an additional 16 +/- 10 days. The stenotic ureters showed diffuse acute humoral xenograft rejection (AHXR), while all cases with no or only focal signs of ureteral rejection never revealed ureteral obstruction. Use of a ureteral stent extends the survival of a xenografted primate, thereby helping to clarify the immunological events surrounding the onset of AHXR in kidneys in long-term xenograft recipients.

Animals↗
PubMed2004

Immune and nonimmune predictors of cardiac allograft vasculopathy onset and severity: multivariate risk factor analysis and role of immunosuppression.

We studied 361 patients, to evaluate risk factors for cardiac allograft vasculopathy (CAV) onset and severity/diffusion in heart transplantation (HT). Rejection scores (RS) on endomyocardial biopsy were calculated (first year and whole follow-up). CAV onset was defined as any lesion seen at yearly angiography. A CAV severity/diffusion index was calculated for each patient summing up the scores of all lesions. Cox multivariate analysis included: donor age, sex, and weight; recipient sex, age, pre-HT diagnosis, hypertension, diabetes and hyperlipidemia post-HT; number of treated rejections and RS; and immunosuppressive dosage at 3, 6, and 12 months. CAV frequency was 2% at 1 year, 22% at 5 and 39% at 10 years. Risk factors for CAV onset were older donor age [p < 0.0001, relative risk (RR) = 9.9], male donor (p < 0.001, RR = 3.2), high RS for severe (> or = 3A) grades (p < 0.02, RR = 2.01), high cyclosporine at 3 months (p < 0.02, RR = 1.9). Risk factors for CAV severity/diffusion were higher donor weight (p < 0.01, RR = 7.5), high prednisone dosage at 1 year (p < 0.0001, RR = 21.1), and coronary disease pre-HT (p < 0.002, RR = 9.7). High RS was an independent predictor for CAV onset, not severity/diffusion. This suggests an immune basis for CAV onset and nonimmune modulation for progression. High RS for severe grades may provide a predictor for patients at risk.

Adult↗
PubMed2003

Does sports activity enhance the risk of sudden death in adolescents and young adults?

OBJECTIVES: We sought to assess the risk of sudden death (SD) in both male and female athletes age 12 to 35 years. BACKGROUND: Little is known about the risk of SD in adolescents and young adults engaged in sports. METHODS: We did a 21-year prospective cohort study of all young people of the Veneto Region of Italy. From 1979 to 1999, the total population of adolescents and young adults averaged 1,386,600 (692,100 males and 694,500 females), of which 112,790 (90,690 males and 22,100 females) were competitive athletes. An analysis by gender of risk of SD and underlying pathologic substrates was performed in the athletic and non-athletic populations. RESULTS: There were 300 cases of SD, producing an overall cohort incidence rate of 1 in 100,000 persons per year. Fifty-five SDs occurred among athletes (2.3 in 100,000 per year) and 245 among non-athletes (0.9 in 100,000 per year), with an estimated relative risk (RR) of 2.5 (95% confidence interval [CI] 1.8 to 3.4; p < 0.0001). The RR of SD among athletes versus non-athletes was 1.95 (CI 1.3 to 2.6; p = 0.0001) for males and 2.00 (CI 0.6 to 4.9; p = 0.15) for females. The higher risk of SD in athletes was strongly related to underlying cardiovascular diseases such as congenital coronary artery anomaly (RR 79, CI 10 to 3,564; p < 0.0001), arrhythmogenic right ventricular cardiomyopathy (RR 5.4, CI 2.5 to 11.2; p < 0.0001), and premature coronary artery disease (RR 2.6, CI 1.2 to 5.1; p = 0.008). CONCLUSIONS: Sports activity in adolescents and young adults was associated with an increased risk of SD, both in males and females. Sports, per se, was not a cause of the enhanced mortality, but it triggered SD in those athletes who were affected by cardiovascular conditions predisposing to life-threatening ventricular arrhythmias during physical exercise.

Adolescent↗
PubMed2003

Implantable cardioverter-defibrillator therapy for prevention of sudden death in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a condition associated with the risk of sudden death (SD). METHODS AND RESULTS: We conducted a multicenter study of the impact of the implantable cardioverter-defibrillator (ICD) for prevention of SD in 132 patients (93 males and 39 females, age 40+/-15 years) with ARVC/D. Implant indications were a history of cardiac arrest in 13 patients (10%), sustained ventricular tachycardia in 82 (62%), syncope in 21 (16%), and other in 16 (12%). During a mean follow-up of 39+/-25 months, 64 patients (48%) had appropriate ICD interventions, 21 (16%) had inappropriate interventions, and 19 (14%) had ICD-related complications. Fifty-three (83%) of the 64 patients with appropriate interventions received antiarrhythmic drug therapy at the time of first ICD discharge. Programmed ventricular stimulation was of limited value in identifying patients at risk of tachyarrhythmias during the follow-up (positive predictive value 49%, negative predictive value 54%). Four patients (3%) died, and 32 (24%) experienced ventricular fibrillation/flutter that in all likelihood would have been fatal in the absence of the device. At 36 months, the actual patient survival rate was 96% compared with the ventricular fibrillation/flutter-free survival rate of 72% (P<0.001). Patients who received implants because of ventricular tachycardia without hemodynamic compromise had a significantly lower incidence of ventricular fibrillation/flutter (log rank=0.01). History of cardiac arrest or ventricular tachycardia with hemodynamic compromise, younger age, and left ventricular involvement were independent predictors of ventricular fibrillation/flutter. CONCLUSIONS: In patients with ARVC/D, ICD therapy provided life-saving protection by effectively terminating life-threatening ventricular arrhythmias. Patients who were prone to ventricular fibrillation/flutter could be identified on the basis of clinical presentation, irrespective of programmed ventricular stimulation outcome.

Adolescent↗
PubMed2003

Myocarditis and inflammatory cardiomyopathy: microbiological and molecular biological aspects.

Myocarditis is an inflammatory disease of the myocardium associated with cardiac dysfunction. The natural history of myocarditis is frequently characterised by the evolution in dilated cardiomyopathy. Due to its variable clinical manifestation from latent to very severe clinical forms, such as acute congestive heart failure and sudden death, its prevalence is still unknown and probably underestimated. In spite of the development of various diagnostic modalities, early and definite diagnosis of myocarditis still depends on the detection of inflammatory infiltrates in endomyocardial biopsy specimens according to the Dallas criteria. Routine application of immunohistochemistry, used for identification and characterisation of inflammatory cell populations, has now significantly increased the sensistivity of the diagnosis of inflammatory cardiomyopathy. Various molecular techniques, such as PCR, gene sequencing and real-time PCR, often applied on the same endomyocardial specimen, have become an essential part of the diagnostic armamentarium for rapid, specific and sensitive identification of infective agents. The correct application of molecular techniques will allow increasingly more information to be obtained: new epidemiology, new patient risk stratification and overall more appropriate medical treatment.

Adolescent↗
PubMed2003

Leaflet escape in a new bileaflet mechanical valve: TRI technologies.

BACKGROUND: Leaflet escape is a mode of structural valve failure for mechanical prostheses. This complication previously has been reported for both monoleaflet and bileaflet valve models. We report 2 leaflet escape occurrences observed in 2 patients who underwent valve replacement with a TRI Technologies valve prosthesis. METHODS AND RESULTS: At the University of Padua, between November 2000 and February 2002, 36 TRI Technologies valve prostheses (26 aortic and 10 mitral) were implanted in 34 patients (12 women and 22 men) with a mean age of 59.9+/-10.3 years (range, 30 to 75 years). There were 5 deaths: 3 in hospital, 1 early after discharge, and 1 late. Two patients experienced a catastrophic prosthetic leaflet escape; the first patient was a 52-year-old man who died 10 days after aortic valve and ascending aorta replacement, and the second was a 58-year-old man who underwent a successful emergency reoperation 20 months after mitral valve replacement. Examination of the explanted prostheses showed in both cases a leaflet escape caused by a leaflet's pivoting system fracture. Prophylactic replacement was then successfully accomplished so far in 12 patients, without evidence of structural valve failure in any of them. Among other significant postoperative complications, we observed 3 major thromboembolisms, 1 hemorrhage, and 1 paravalvular leak. CONCLUSIONS: These catastrophes prompted us to interrupt the implantation program, and they cast a shadow on the durability of the TRI Technologies valve prosthesis because of its high risk of structural failure.

Adult↗
PubMed2003

Immunosuppressive therapy for active lymphocytic myocarditis: virological and immunologic profile of responders versus nonresponders.

BACKGROUND: The beneficial effect of immunosuppressive treatment on myocarditis is still controversial, possibly because the immunologic and virological profile of potential candidates is largely unknown. METHODS AND RESULTS: Out of 652 biopsied patients, 112 had a histological diagnosis of active lymphocytic myocarditis; 41 of these 112 patients were characterized by progressive heart failure despite conventional therapy and were treated with prednisone and azathioprine for 6 months. All were resubmitted to cardiac catheterization, angiography, and endomyocardial biopsy at 1 and 6 months and followed-up for 1 year. A total of 21 patients responded with prompt improvement in left ventricular ejection fraction from 25.7+/-4.1% to 47.1+/-4.4% and showed evidence of healed myocarditis at control biopsy. Conversely, 20 patients failed to respond and showed a histological evolution toward dilated cardiomyopathy: 12 remained stationary, 3 underwent cardiac transplantation, and 5 died. We retrospectively performed a polymerase chain reaction on frozen endomyocardial tissue for the most common cardiotropic viruses and assessed circulating serum cardiac autoantibodies. Viral genomes were present in biopsy specimens of 17 nonresponders (85%), including enterovirus (n=5), Epstein-Barr virus (n=5) adenovirus (n=4), both adenovirus and enterovirus (n=1), influenza A virus (n=1), parvovirus-B19 (n=1), and in 3 responders, who were all positive for hepatitis C virus. Cardiac autoantibodies were present in 19 responders (90%) and in none of the nonresponders. CONCLUSIONS: In patients with active lymphocytic myocarditis, those with circulating cardiac autoantibodies and no viral genome in the myocardium are the most likely to benefit from immunosuppression. The beneficial effect of immunosuppression in hepatitis C virus myocarditis suggests a relevant immunomediated component of damage.

Adolescent↗