1,721,000 research outputs found
Definizione della nicchia staminale nella colecisti normale e patologica. Isolamento, caratterizzazione,differenziazione, dimostrazione dell’abilità delle cellule staminali isolate di rigenerare il tessuto epatico in modelli sperimentali di danno epatico ed efficace criopreservazione.
Full text linkAll'interno delle ghiandole peribiliari dell’albero biliare umano adulto sono state evidenziate cellule staminali che esprimono marcatori di endoderma primitivo. Le stesse cellule hanno dimostrato di possedere la capacità di differenziarsi in vitro e in vivo in epatociti e colangiociti maturi e insule pancreatiche funzionanti. Nulla è finora conosciuto sull’esistenza di cellule staminali/progenitrici nella colecisti umana. Gli obiettivi dello studio sono stati la caratterizzazione della nicchia staminale della colecisti umana, la possibilità di isolare cellule staminali di origine endodermica dalla colecisti umana normale o patologica e la definizione delle condizioni ideali per la loro criopreservazione. N° 19 colecisti sono state ottenute da donatori cadavere adulti esenti da patologie epato-bilio-pancreatiche attraverso il Consorzio Regionale Trapianti d’Organo del Lazio (Italia). N°14 colecisti patologiche sono state prelevate da pazienti affetti da litiasi sintomatica o da pazienti affetti da litiasi asintomatica sottoposti ad exeresi chirurgica in corso di chirurgia bariatrica. Il tessuto colecistico è stato digerito con collagenasi e DNAsi e la sospensione cellulare è stata sottoposta ad immunoselezione per un marcatore di cellule staminali di origine endodermica (EpCAM-Epithelial Cell Adhesion Molecule). Le colture cellulari ottenute sono state mantenute in coltura in Kubota’s Medium (KM), un mezzo di coltura privo di fattori di crescita sviluppato per l’espansione di cellule staminali epatiche in vitro. La valutazione della multi potenzialità è stata effettuata in vitro utilizzando mezzi di coltura a base di KM arricchiti con fattori di crescita e di induzione specifici per i diversi destini maturi di derivazione endodermica (epatociti, colangiociti, isole pancreatiche). Risultati: La colecisti non contiene ghiandole peribiliari, tuttavia, all’interno delle cripte della mucosa colecisti umana sono state individuate popolazione cellulari che esprimono marcatori di cellule progenitrici bilio-pancreatiche (SOX17, PDX1, EpCAM) e di cellule di endoderma primitivo (CXCR4). I risultati dell’analisi morfologica e fenotipica della colecisti patologica sono paragonabili a quelli ottenuti nelle colecisti normali. Cellule immunoselezionate per EpCAM dalla colecisti umana si espandono clonogenicamente su plastica e in un mezzo privo di siero adattato per progenitori endodermici (KM). Cellule isolate dalle colonie, dopo un mese di coltura in KM, sono state trasferite in tre distinti medium bidimensionali ed hanno dato origine a colonie cellulari con caratteristiche epatocitarie, colangiocitarie e di insule pancreatiche funzionanti. Abbiamo condotto studi pre-clinici in modelli sperimentali di epatopatie (topi immunodeficenti SCID) trattati per 7 settimane con trettracloruro di carbonio (CCL4) attraverso l’utilizzo di cellule staminali/progenitrici della colecisti umana (human gallbladder stem/progenitor cells, hGSCs). Al termine gli animali sono stati sacrificati e dopo aver valutato l’attecchimento, la proliferazione, la differenziazione in vivo, abbiamo dimostrato, analizzando i test funzionali sul siero dei topi sacrificati, che solo i topi trattati con le hGSCs mostrano un miglioramento degli indici sierologici di funzionalità epatica. Al fine di individuare la migliore strategia per la criopreservazione delle hGSCs, è stato condotto uno studio in cui sono state analizzate soluzioni criopreservanti con diversa composizione. E’ stata identificata una metodica efficace per il congelamento di cellule staminali/progenitrici, comprese le hGSCs. Le hGSCs sono facilmente isolabili da tessuti umani di donatori di ogni età ed immediatamente utilizzabili per la creazione di banche di cellule staminali/progenitrici che possono essere conservate e utilizzate in pazienti con grave e letale compromissione della funzione del fegato, i quali spesso non sopravvivono all’attesa del trapianto di fegato
Echocardiographic diagnosis of posterior ventricular septal defect: preliminary observations
No full textEchocardiographic evaluation of left ventricular outflow tract obstruction in complete transposition of the great arteries
Full text linkSubpulmonic stenosis in complete d-transposition of the great arteries (d-TGA) is a frequently associated malformation, the precise diagnosis of which is essential for optimal medical and surgical treatment. Sixteen patients with d-TGA and subpulmonic stenosis have been studied by M-mode and two-dimensional (2DE) echocardiography and cardiac catheterization. Dynamic obstruction was found in six patients and fixed stenosis in 10. Systolic anterior motion of the mitral valve without fixed obstruction of the left ventricular outflow tract (LVOT) was present in patients with dynamic stenosis. Measurements of left ventricular end-diastolic posterior wall thickness to minor semiaxis ratio correlated well (p < 0.001) with the pressure gradient across the LVOT. Various types of anatomic fixed obstruction are described. M-mode echocardiography provides assessment of dynamic obstruction but does not allow quantitative evaluation of the length of the narrowed segment. The latter can be achieved by 2DE, which offers improved definition of different anatomic types
[Acute viral myocarditis: new aspects of an old disease]
No full textThe causes of acute myocarditis include infections (viral, bacterial, protozoal), toxins, drugs, hypersensitivity, chemical and physical agents. One of the most interesting and not completely understood of these conditions is the viral myocarditis. This diagnosis is often invoked to explain non-specific chest pain in the absence of coronary artery disease, spontaneous onset of arhythmias associated or not to congestive heart failure of unidentified origin. In most instances, there is little evidence that myocarditis is the underlying pathology. The challenge for physicians is not only to recognize and treat myocarditis, but also to identify which patient might be at risk for progression to dilated cardiomyopathy. Although in most cases myocarditis is limited and does not progress to chronic left ventricular dysfunction, nevertheless a casual relationship exists between viral myocarditis and dilated cardiomyopathy. This association was initially supported by observation during epidemics of Coxsackie B infection since as many as 12% of infected patients manifested clinical sign of cardiac involvement and few of these developed subsequently a dilated cardiomyopathy. Experimentally, in animals affected by acute viral myocarditis, the T lymphocytes appear to mediate continued myocyte necrosis in the apparent absence of virus. In addition, cellular infiltration and myocardial necrosis are minimal in the athymic mouse where T lymphocytes are depleted: thus T lymphocytes may play some role in the subsequent development of chronic congestive cardiomyopathy. However, until the application of endomyocardial biopsy, arguments for and against this relationship were based primary on circumstantial evidence from clinical, serologic, epidemiologic findings. recent studies using endomyocardial biopsy have demonstrated that myocarditis is associated to dilated cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS
Insorgenza della sindrome X in età geriatrica The onset of syndrome x in old age
No full textsindrome x nell'anzianoSummary: There is evidence that angina-like chest pain associated with normal coronary angiograohy (syndrome X) may appear in adult patients. We have reviewed the clinical documentation of all the patient 65 or moreadmitted to our hospital because of recent onset typical or atypical angina, who underwent an exercise tollerance test and coronary angiography. Exclusion criteria were ischaemic or valvular heart disease and significant arterial hypertension
[Development of echocardiographic diagnosis of congenital cardiopathies: from M-mode to color Doppler].
No full textEchocardiographic features of truncal abnormalities- Special emphasis to the evaluation of pulmonary arteries
No full text9 patients with persistent truncus arteriosus, 11 patients with pseudotruncus and 2 patients with hemitruncus, ranging in age from 6 months to 29 years, have been studied by M-mode and two-dimensional echocardiography (2-D echo). In all patients the diagnosis was confirmed by cardiac catheterization and angiocardiography; in 10 of them surgical or autopsy documentation was available. Peripheral contrast echocardiography was performed in 13 patients. A variable degree of truncal or aortic override was observed in 7 of 9 patients with truncus arteriosus and in all patients with pseudotruncus by M-mode or two-dimensional echocardiography. By 2-D echo the truncal origin of the right and left pulmonary arteries was visualized in 7 of 9 of the patients with truncus arteriosus. Visualization of one aberrant pulmonary artery from the aortic wall was assessed retrospectively in 2 patients with hemitruncus. A pulmonary atretic valve region was recorded in 10 of 11 of the patients with pseudotruncus. Peripheral contrast echocardiography enabled to distinguish patients with complete obstruction to pulmonary flow from patients with unobstructed right ventricular outflow tract. By showing no direct connection between the pulmonary arteries and the ascending aorta or direct continuity between one or both pulmonary arteries and truncal or aortic root, differentiation of pseudotruncus arteriosus from truncus or hemitruncus may be achieved by 2-D echo
Echocardiographic assessment of congenital mitral stenosis.
Full text linkTo assess the severity and precise anatomy of congenital mitral stenosis (MS), 17 patients with congenital left ventricular inflow obstruction were studied by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. In six patients MS was an isolated lesion and in 11 it was combined with other cardiovascular malformations. The diagnosis was confirmed at operation or autopsy in 15 patients. Twenty normal subjects of the same age and sex were selected as controls. M-mode amplitude and speed of diastolic closure (E-F slope) of the anterior mitral valve leaflet were determined in all patients. Mitral valve areas were traced after careful short-axis 2DE scans in 15 patients. Supravalvar, valvar, or subvalvar obstruction was evaluated in patients with surgical or autopsy documentation. Analysis of M-mode echocardiograms showed a reduction of E-F slope in all patients compared to normal control subjects but a poor correlation between E-F slope and hemodynamic data (mitral valve areas or pressure gradients). Diastolic fluttering of either or both mitral valve leaflets was found in 12 patients. It is concluded that M-mode echocardiography may be useful for qualitative assessment of congenital MS, even in the presence of associated heart defects, but less useful in evaluating its severity. Analysis of 2DE revealed good correlation between mitral valve areas as calculated with 2DE and with the Gorlin formula at cardiac catheterization, despite the complexity of the congenital mitral lesion. Anatomic varieties of congenital left ventricular inflow obstruction, such as stenosing supravalvar mitral ring or parachute deformity of the mitral valve, were recognized at 2DE.(ABSTRACT TRUNCATED AT 250 WORDS
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