The Von Willebrand Factor Antigen Plasma Concentration: a Monitoring Marker in the Treatment of Aortic and Mitral Valve Diseases.

Von Willebrand disease is a commonly inherited bleeding disorder caused by defects of von Willebrand factor (vWF). In the most common valve diseases, aortic valve stenosis (AVS) and mitral valve regurgitation (MVR), a bleeding tendency has been described in a number of patients. This has been associated to a high turbulence of blood flow through the compromised valve, promoting degradation of vWF with loss of high-molecular-weight multimers of vWF (HMWM), leading to an acquired von Willebrand syndrome (AvWS). We analysed three groups of patients, one affected by AVS, treated with transcatheter aortic valve implantation (TAVI), the second group of patients affected by MVR, treated with Mitraclip® mitral valve repair. The third group was represented by patients also affected by AVS, but not eligible for TAVI and treated with standard surgery. A fourth group of patients that underwent percutaneous coronary intervention (PCI) with stenting was used as a control. Our results demonstrated that the level of vWF measured as antigen concentration (vWF:Ag) increases in all cohorts of patients after treatment, while in control PCI patients, no modification of vWF:Ag has been registered. Western blot analysis showed only a quantitative loss of vWF in the pre-treatment time, but without significant HMWM modification. The monitoring of the vWF:Ag concentration, but not the quality of HMWM, can indicate the status of blood flow in the treated patients, thus introducing the possibility of using the vWF antigen detection in monitoring the status of replaced or repaired valves.

Role of the TAp63 Isoform in Recurrent Nasal Polyps.

The pathogenic molecular mechanisms underlying the insurgence of nasal polyps has not been completely defined. In some patients, these lesions can have a recurrence after surgery removal, and the difference between recurrent and not recurrent patients is still unclear. To molecularly characterize and distinguish between these two classes, a cohort of patients affected by nasal polyposis was analysed. In all patients we analysed the p63 isoform expression using fresh tissues taken after surgery. Moreover, confocal immunofluorescence analysis of fixed sections was performed. The results show high ΔNp63 expression in samples from the nasal polyps of patients compared to the normal epithelia. Analysis of the expression level of the TAp63 isoform shows differential expression between the patients with recurrence compared to those not recurring. The data, considered as the ΔN/TAp63 ratio, really discriminate the two groups. In fact, even though ΔNp63 is expressed in non-recurrent patients, the resulting ratio ΔN/TAp63 is significantly lower in these patients. This clearly indicates that the status of TAp63 expression, represented by the ΔN/TAp63 ratio, could be considered a prognostic marker of low recurrence probability. In these samples we also investigated the expression of OTX2 transcription factor, known to be a selective activator of TAp63, detecting a significant correlation. Database analysis of HNSCC patients showed increased survival for the patients presenting OTX2 amplification and/or overexpression. These results, together with the fact that TAp63 can be selectively upregulated by HDAC inhibitors, open the possibility to consider local treatment of recurrent nasal polyps with these molecules.

Interfacing Sca-1(pos) mesenchymal stem cells with biocompatible scaffolds with different chemical composition and geometry.

An immortalized murine mesenchymal stem cell line (mTERT-MSC) enriched for Lin(neg)/Sca-1(pos) fraction has been obtained through the transfection of MSC with murine TERT and single-cell isolation. Such cell line maintained the typical MSC self-renewal capacity and continuously expressed MSC phenotype. Moreover, mTERT-MSC retained the functional features of freshly isolated MSC in culture without evidence of senescence or spontaneous differentiation events. Thus, mTERT-MSC have been cultured onto PLA films, 30 and 100 microm PLA microbeads, and onto unpressed and pressed HYAFF-11 scaffolds. While the cells adhered preserving their morphology on PLA films, clusters of mTERT-MSC were detected on PLA beads and unpressed fibrous scaffolds. Finally, mTERT-MSC were not able to colonize the inner layers of pressed HYAFF-11. Nevertheless, such cell line displayed the ability to preserve Sca-1 expression and to retain multilineage potential when appropriately stimulated on all the scaffolds tested.

Embryonic gene expression in nonoverloaded ventricles of hereditary hypertrophic cardiomyopathic hamsters.

Current information regarding the molecular and biochemical mechanisms of myocardial hypertrophy, as obtained from isolated cardiomyocytes and/or healthy animals with aortic banding, does not permit dissection of the hierarchical relationship among different steps and triggers of the pathogenic process in vivo. The aim of the present study was to depict the temporal relationship among myocardial structural and functional characteristics, the embryonic gene program, and transforming growth factor (TGF) beta 1 expression in euthyroid hereditary hypertrophic cardiomyopathic hamsters (CMPH). This investigation was performed using Western and Northern blot and in situ hybridization techniques. The results show that in CMPH, the severity of the hemodynamic overload is not related to any modification in structural myocardial characteristics (cardiac mass, cardiomyocyte dimensions, total RNA, and protein content), whereas an early activation of the embryonic gene program occurs in not yet overloaded 90-day-old CMPH (left ventricular end diastolic pressure < 15 mm Hg). In these animals, a 30% to 90% decrease in the alpha myosin heavy chain (alpha MHC) relative content was found in ventricles, whereas beta MHC increased 5-fold. In addition, the alpha skeletal actin expression was enhanced 2-fold versus age-matched controls. No modifications were observed in myosin function evaluated by in vitro motility assay, whereas the administration of L-thyroxine (100 micrograms/kg intraperitoneally daily) to CMPH was able to reinduce the ventricular expression of the alpha MHC isoform (5-fold increase). Conversely, no changes were found in alpha cardiac actin and myosin light chain 2 (MLC2) expression. A close temporal relationship occurred in CMPH ventricles between the re-expression of the embryonic gene program and a 3-fold enhancement of the expression of TGF beta 1. These results indicate that the CMPH provides a useful model for investigating the expression of embryonic genes in hypertrophic ventricles in the absence of mechanical and hormonal stimuli, and that TGF beta 1 is involved in regulating in vivo the "embryonic step" of myocardial hypertrophy. Furthermore, the study offers new insights into the pathophysiologic mechanisms leading to heart failure.

The influence of severe bulb deformity on duodenal ulcer relapse.

In order to evaluate the prognostic role of duodenal bulb deformation in the recurrence of peptic ulcer, duodenal bulb morphology and the complete healing of duodenal ulcer were endoscopically evaluated in sixty patients, who were subsequently allocated at random to either maintenance therapy with ranitidine or no treatment. Endoscopic checkups were done at regular intervals, up to the first ulcer recurrence. As expected, long-term ranitidine treatment significantly reduced the relapse rate (12 month cumulative relapse rate was 32% versus 86% in the untreated). A set of prognostic factors which might interfere with this result (sex, age, alcohol consumption, history of ulcerous relatives, duration of the disease, previous H2-blocking treatment, previous complications, smoking and morphology of the duodenal bulb) were evaluated by multivariate analysis using the Cox regression model. Only duodenal bulb morphology appeared to have any independent prognostic value. In the untreated group ulcer recurrence seemed to occur earlier (median relapse time = 2 months) in the patients with severe non-stenosing bulb deformity, and later in those with normal or mildly deformed bulb (median relapse time = 8 months); ranitidine treatment delayed relapse in deformed bulb patients (median relapse time = 14 months) and almost eliminated it in those with normal duodenal bulb morphology. No association was found between the presence of duodenal bulb deformity and the above-mentioned covariates. Our study confirms the primary importance of anti-H2 treatment and suggests that anatomical characteristics of the duodenal bulb also influence the occurrence of ulcer relapse.