RESUMEN
Human cryopreserved allografts of pulmonary and aortic heart valves, aortas and pulmonary trunks are used for valve replacement. However, it is unknown how the composition of these allografts relate to their mechanical properties. Our aims were to correlate the histological compositions and passive mechanical properties of aortic and pulmonary valves and to observe the microcracks of aortas and pulmonary trunks. The following parameters were quantified: ultimate stress; ultimate strain; Young's modulus of elasticity; valve cusp wall thickness; pulmonary and aortic intima-media thickness; area fraction of elastin, collagen and calcification; and length density of elastic fibres. The propagation of experimentally induced microcracks avoided elastic fibres. Ultimate strain was negatively correlated with the area fraction of calcification (r=-0.4) in aortas. Ultimate stress (r=0.27) and Young's modulus in small deformation (r=0.29) and in large deformation (r=0.32) correlated with wall thickness in valve cusps. Young's modulus (r=0.34) and ultimate strain (r=0.31) correlated with intima-media thickness. Ultimate strain correlated with the area fraction of elastin (r=-0.40) and collagen in the arteries (r=0.31). As conventional histology does not fully explain the mechanical properties of cryopreserved grafts, both morphological and biomechanical tests should be used complementarily when characterizing the ageing of the grafts.
Asunto(s)
Aorta/fisiología , Válvula Aórtica/fisiología , Arteria Pulmonar/fisiología , Válvula Pulmonar/fisiología , Aloinjertos , Aorta/anatomía & histología , Válvula Aórtica/anatomía & histología , Válvula Aórtica/trasplante , Fenómenos Biomecánicos/fisiología , Criopreservación , República Checa , Elasticidad , Humanos , Arteria Pulmonar/anatomía & histología , Válvula Pulmonar/anatomía & histología , Válvula Pulmonar/trasplante , Estrés Mecánico , Resistencia a la Tracción , Bancos de TejidosRESUMEN
Congenital stenosis of airways is a rare and possibly life-threatening congenital defect with difficult treatment and uncertain prognosis. In our report, we describe a rare case of a 1-month-old newborn with concomitant stenosis of trachea and main bronchus and its successful treatment using slide plasty.
Asunto(s)
Bronquios/anomalías , Bronquios/cirugía , Estenosis Traqueal/congénito , Estenosis Traqueal/cirugía , Constricción Patológica , Humanos , Recién Nacido , Masculino , Procedimientos Quirúrgicos Torácicos/métodos , Estenosis Traqueal/complicacionesRESUMEN
Inhibitors of apoptosis, including bcl-2 and survivin (a novel gene encoding a unique apoptosis inhibitor), regulate cell proliferation by promoting cell survival. Although survivin has been detected in several human cancers, its prognostic significance and relationship to bcl-2 are not well characterized in lung cancer. Tissue sections from 102 non-small cell lung carcinomas (NSCLC) were immunostained using antibodies against survivin and bcl-2. Staining results were correlated with prognostic variables. Immunoreactivity for survivin and bcl-2 was observed in 53% and 21% of NSCLCs, respectively. Fifty-two percent of the 50 squamous cell carcinomas and 54% of the 52 adenocarcinomas expressed survivin. Survivin positivity correlated with tumor stage in squamous cell carcinoma. On univariate analysis, survivin expression correlated with decreased patient survival in NSCLC and in the subset of squamous cell carcinomas, but not in adenocarcinomas. On multivariate analysis, survivin was an independent predictor, along with distant metastasis and large tumor size. Eighteen percent of squamous cell carcinomas and 24% of adenocarcinomas expressed bcl-2. On univariate analysis, bcl-2 expression correlated with increased patient survival in NSCLC and in the subset of squamous cell carcinomas. An inverse correlation between the expression of survivin and bcl-2 was noted. Survivin immunoreactivity is an independent predictor of shortened survival in NSCLC, while bcl-2 protein expression correlated with prolonged patient survival. These findings indicate an inverse relationship between survivin and bcl-2 expression and suggest that these two inhibitors of apoptosis function through different pathways in the regulation of tumorigenesis in NSCLC.