Role of mast cells in wound healing process after glass-fiber composite implant in rats

Glass-fiber composites are frequently used in dentistry. In order to evaluate their biocompatibility we tested, in an experimental model "in vivo", their tissue response pointing our attention on presence of mast cells (MCs) and fibrotic process. Sprague Dawley rats were used for the experimental design. The fibers were introduced in a subcutaneous pocket along the middle dorsal line between the two scapulas for 7, 14 or 21 days. At the end of the treatments the skins were excised and then processed for Toluidine Blue, to determine the presence of MCs, and Picrosirius Red staining, to evaluate the presence of fibrotic tissue. Our preliminary results showed and increase of both MC number and deposition of collagen type I, which characterized the fibrotic tissue. So, subsequent aims of our study were to evaluate the role played by MCs in tissue fibrosis and to give a possible explanation regarding the mechanisms that were responsible of biological response observed, through the analyses of some proteins, such as metalloproteinase-2 (MMP-2), its inhibitor (TIMP-2) and transforming growth factor-beta (TGF-beta). Our data confirmed the involvement of TGF-beta, released by MCs, in the disruption of the equilibrium between MMP-2 and TIMP-2 that were implicated in the enhancement of fibrosis. In summary, this study demonstrate that this type of materials induced an inflammatory response at the site of implant and help to clarify what type of mechanism and which proteins are involved in this biological response. Nevertheless, more extensive investigations are in progress to better evaluate the inflammatory process.     

Microbe removal in secondary effluent by filtration

A study was carried out to assess the efficiency of filtration in reducing microbial contamination in municipal secondary effluent. After primary and secondary treatments, the wastewater underwent filtration through sand/hydroanthracite filters. A total of 20 samplings were made, each consisting of two instant samples (secondary effluent and filtered effluent). Each of the 40 samples was tested for: total and faecal coliforms,Escherichia coli, enterococci and somatic coliphages. The mean concentrations detected in the secondary effluent were in the order of 5 log for the total and faecal coliforms, 4 log for enterococci andEscherichia coli, and approx. 3 log for the coliphages. The filtration showed a higher efficacy in the reduction of feacal coliforms,Escherichia coli and in particular total coliforms. The results obtained for enterococci and coliphages were significanty lower. Filtration alone was not enough to reduce the bacterial indicators to within Italian legal limits, and showed a poor capacity to abate coliphages. However, by performing the filby-products and a consequent reduction in the chemical risk for the general population.     

Proteins and their modifications in a medieval mummy

Proteins and their modifications of the natural mummy of Cangrande della Scala (Prince of Verona, Northern Italy, 1291–1329) were studied. The nano‐LC‐Q‐TOF analysis of samples of rib bone and muscle from the mummy showed the presence of different proteins including Types I, III, IV, V, and XI collagen, hemoglobin (subunits alpha and beta), ferritin, biglycan, vitronectin, prothrombin, and osteocalcin. The structure of Type I and Type III collagen was deeply studied to evaluate the occurrence of modifications in comparison with Type I and Type III collagen coming from tissues of recently died people. This analysis showed high percentage of asparaginyl and glutaminyl deamidation, carbamylation and carboxymethylation of lysine, as well as oxidation and dioxidation of methionine. The most common reaction during the natural mummification process was oxidation—the majority of lysine and proline of collagen Type I was hydroxylated whereas methionine was oxidated (oxidated or dioxidated). To the best of our knowledge, this is the first study which reports the protein profile of a natural mummified human tissue and the first one which describes the carbamylation and carboxymethylation of lysine in mummified tissues.     

Multiscale modelling in biofluidynamics: application to reconstructive paediatric cardiac surgery

Multiscale computing is a challenging area even in biomechanics. Application of such a methodology to quantitatively compare postoperative hemodynamics in congenital heart diseases is very promising. In the treatment of hypoplastic left heart syndrome, which is a congenital heart disease where the left ventricle is missing or very small, the necessity to feed the pulmonary and systemic circulations is obtained with an interposition shunt. Two main options are available and differ from the sites of anastomoses: (i) the systemic-to-pulmonary conduit (Blalock-Taussig shunt known as the Norwood Operation (NO)) connecting the innominate artery (NO-BT) or the aorta (NO-CS) to the right pulmonary artery and (ii) the right ventricle to pulmonary artery shunt (known as Sano operation (SO)). The proposition that the SO is superior to the NO remains controversial. 3-D computer models of the NO (NO-BT and NO-CS) and SO were developed and investigated using the finite volume method. Conduits of 3, 3.5 and 4 mm were used in the NO models, whereas conduits of 4, 5 and 6 mm were used in the SO model. The hydraulic nets (lumped resistances, compliances, inertances and elastances) which represent the systemic, coronary and pulmonary circulations and the heart were identical in the two models. A multiscale approach was adopted to couple the 3-D models with the circulation net. Computer simulation results were compared with post-operative catheterization data. Results showed that (i) there is a good correlation between predicted and observed data: higher aortic diastolic pressure, decreased pulmonary arterial pressure, lower pulmonary-to-systemic flow ratio and higher coronary perfusion pressure in SO; (ii) there is a minimal regurgitant flow in the SO conduit. The close correlation between predicted and observed clinical data supports the use of mathematical modelling, with a mandatory multiscale approach, in the design and assessment of surgical procedures.     

Compositional changes in lipid microdomains of air-blood barrier plasma membranes in pulmonary interstitial edema.

We evaluated in anesthetized rabbits the compositional changes of plasmalemmal lipid microdomains from lung tissue samples after inducing pulmonary interstitial edema (0.5 ml/kg for 3 h, leading to approximately 5% increase in extravascular water). Lipid microdomains (lipid rafts and caveolae) were present in the detergent-resistant fraction (DRF) obtained after discontinuous sucrose density gradient. DRF was enriched in caveolin-1, flotillin, aquaporin-1, GM1, cholesterol, sphingomyelin, and phosphatidylserine, and their contents significantly increased in interstitial edema. The higher DRF content in caveolin, flotillin, and aquaporin-1 and of the ganglioside GM1 suggests an increase both in caveolar domains and in lipid rafts, respectively. Compositional changes could be ascribed to endothelial and epithelial cells that provide most of plasma membrane surface area in the air-blood barrier. Alterations in lipid components in the plasma membrane may reflect rearrangement of floating lipid platforms within the membrane and/or lipid translocation from intracellular stores. Lipid traffic could be stimulated by the marked increase in hydraulic interstitial pressure after initial water accumulation, from approximately -10 to 5 cmH2O, due to the low compliance of the pulmonary tissue, in particular in the basement membranes and in the interfibrillar substance. Compositional changes in lipid microdomains represent a sign of cellular activation and suggest the potential role of mechanotransduction in response to developing interstitial edema.     

The effect of season on oocyte quality and developmental competence in Italian Mediterranean buffaloes (Bubalus bubalis)

At Italian latitudes, buffalo (Bubalus bubalis) is a seasonally polyestrous species, showing an improved reproductive efficiency when daylight decreases (autumn). The aim of the present study was to evaluate the influence of the season on buffalo oocyte recovery rate, on oocyte quality, assessed on morphological basis, and developmental competence after in vitro fertilization. For this purpose, buffalo ovaries were collected from a local abattoir and the oocytes obtained by aspirating the follicles were evaluated, classified and, if considered of good quality, devolved to the different procedures of IVEP. In general, no differences were found in terms of oocyte recovery per ovary among seasons, but interestingly, the percentage of small oocytes was higher (P<0.05) during spring and summer (0.9±0.1 and 0.9±0.2) compared to autumn and winter (0.3±0.1 and 0.2±0.1). Both cleavage and embryo rate increased during the period from October to December (71.7±3.1 and 26.5±2.1, respectively) compared to the period from April to June (58.0±2.4 and 18.8±1.6, respectively), thus reflecting the in vivo reproductive behavior. Nevertheless, it is worth emphasizing that transferrable embryos were produced in vitro, even during the unfavorable season, but with decreased efficiency. In conclusion, these results suggest to avoid the oocyte collection during spring when planning OPU trials in order to save resources and improve the benefits/costs ratio.     

The use of filamentous bacteriophage fd to deliver MAGE-A10 or MAGE-A3 HLA-A2-restricted peptides and to induce strong antitumor CTL responses

Delivery of tumor-associated Ag-derived peptides in a high immunogenic form represents one of the key issues for effective peptide-based cancer vaccine development. We report herein the ability of nonpathogenic filamentous bacteriophage fd virions to deliver HLA-A2-restricted MAGE-A10(254-262)- or MAGE-A3(271-279)-derived peptides and to elicit potent specific CTL responses in vitro and in vivo. Interestingly, human anti-MAGE-A3(271-279)-specific CTLs were able to kill human MAGE-A3(+) tumor cells, even if these cells naturally express a low amount of MAGE-A3(271-279) peptide-HLA epitope surface complexes and are usually not recognized by CTLs generated by conventional stimulation procedures. MAGE-A3(271-279)-specific/CD8(+) CTL clones were isolated from in vitro cultures, and their high avidity for Ag recognition was assessed. Moreover, in vivo tumor protection assay showed that vaccination of humanized HHD (HLA-A2.1(+)/H2-D(b+)) transgenic mice with phage particles expressing MAGE-A3(271-279)-derived peptides hampered tumor growth. Overall, these data indicate that engineered filamentous bacteriophage virions increase substantially the immunogenicity of delivered tumor-associated Ag-derived peptides, thus representing a novel powerful system for the development of effective peptide-based cancer vaccines.