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Cell-substratum interactions play a peculiar role in cell proliferation, differentiation and migration. They are regulated by various glycoproteins, among which fibronectin, and by receptors connecting cells to the extracellular matrix, i.e. integrins. Therefore, the aim of this study was to correlate the proliferation rates of the human fibroblast line WI-38 cultured in presence of titanium dental implants to cell adhesion capability to substrata. WI-38 fibroblasts were cultured in presence of four dental implants in titanium (one hydroxyapatite coated) for 48, 72 and 96 hours. Cell proliferation was evaluated by detecting 5-bromodeoxyuridine incorporation. Fibronectin organization and alpha5beta1 integrin expression were evidenced by indirect immunofluorescence. A correlation between fibronectin organization and cell proliferation rates was demonstrated: cultures showing fibronectin mainly organized in fibrils presented the highest cell proliferation degrees. After 96 hours, the observed decrease of the number of proliferating cells corresponded to a different fibronectin organization. In presence of the hydroxyapatite coated implant, colocalization of fibronectin and alpha5beta1 integrin was represented in focal contacts in cultures exhibiting the highest proliferation rate, while cells with the lowest proliferation one expressed alpha5beta1 integrin in point contacts. Evidences obtained in this work showed that both the organization of fibronectin and the expression of alpha5beta1 integrin are strictly correlated to cell proliferation rates. Therefore, these parameters could be useful for evaluating the biocompatibility of dental materials in vitro.

Purpose: The aim of this study was to investigate whether an electrical device for dental adhesive application (ElectroBond) influences bonding of two-step etch-and-rinse adhesives. Materials and Methods: Human teeth were selected and cut perpendicularly to their long axis to expose middle/deep dentin. Specimens were then longitudinally sectioned into halves (experimental and control halves) to create two similar bonding substrates. Experimental halves were bonded using an ElectroBond-assisted application, while control halves were bonded with disposable sponges. The adhesives tested were Adper Scotchbond 1XT and XP-BOND. Bonded specimens were submitted to the microtensile bond strength test. Additional adhesive interfaces were prepared and processed for nanoleakage investigation involving TEM examination. Results: The microtensile bond test revealed higher values (p < 0.05) for both adhesives if ElectroBond was used during layering (55.5 +/- 7.9 IVIPa for Adper Scotchbond 1XT and 54.7 +/- 7.1 IVIPa for XP-BOND) compared to the conventional mechanical adhesive application technique (41.1 +/- 6.1 MPa for Adper Scotchbond 1XT and 38.0 +/- 7.8 MPa for XP-BOND). No difference between the two adhesives was found under the same application conditions. With electricity-assisted application, TEM micrographs revealed a significant decrease in nanoleakage expression compared to the controls. Conclusion: The use of an electric current produced by ElectroBond during the application of two-step etch-and-rinse adhesives may enhance resin impregnation, thus improving dentin hybridization. Further studies should be done to confirm that this device can similarly improve adhesive application in vivo.

The nature of the bone-implant interface has been much focused in investigating dental implant materials, whereas the relationship between implant and fibroblasts has received much less attention. To evaluate the biocompatibility degree of an implant material, both cell adhesion and cell growth must be tested in the presence of the implant. Four dental implant (A,B,C,D) made in titanium alloy and one of them (C) hydroxyapatite (HA)-coated in fibroblast cultures (48 and 72 h) were tested, by performing immunocytochemical techniques and then by observing fibronectin (FN) arrangement for cell adhesion and counting 5-bromodeoxyuridine (5-BrdU) to evaluate cell proliferation. Different FN arrangements were observed-i.e. organized in fibrils, or in focal adhesion plaques, as well as dispersed in the intercellular space-which varied for the different implants employed at the various culture stages. Equally, the per cent ratio of 5-BrdU positive cells was different, with a more significant increase (p0.001) between 48 and 72 h for implant C and the controls. It was observed that the higher percentages of 5-BrdU positive cells were in cultures where FN was organized mainly in focal adhesions, as well as 5-BrdU positive cells increased after 72 h in cultures, which after 48 h presented much FN dispersed in the intercellular space. It may be assumed that a correlation exists between FN arrangement and the percentage of 5-BrdU positive cells and that these two parameters vary in the presence of the different implants. Moreover, the HA-coated implant seems to be the most biocompatible in fibroblast cultures.

Compomers are defined as polyacid-modified resin composites. They are supposed to combine the advantages of traditional glass-ionomer cements with resin composites. This study clinically evaluated a compomer in cervical cavities. Sixty cervical cavities in premolars and molars (24 with cervical caries and 36 with abrasions) randomly divided into two groups of 30 teeth (Group 1 and Group 2) were restored with Dyract (DeTrey-Dentsply, York, PA 17405-0872). The cavities of Group 2 were etched for 30 seconds with orthophosphoric acid before compomer application, while the Group 1 cavities received no treatment. All the restorations were evaluated every six months, up to 48 months: characteristics assessed according to USPHS-modified standards were retention, secondary caries, post-operative sensitivity, marginal adaptation and discoloration, color and wear. The Kaplan-Meier's survival analysis was performed. In both groups, retention was high without any statistically significant difference. No difference was found between the two groups for caries, post-operative sensitivity and wear--that all had a low incidence. Color was not perfectly matched, however, there was no statistically significant difference between the two groups. Marginal discoloration and marginal adaptation loss were significantly higher in non-etched group (p < 0.05). Clinically relevant failure required 17.2% of restorations in the non-etched group and 10% in the etched group to be replaced: this difference was not statistically significant. Dyract has an acceptable clinical behavior when used in cervical cavities. Its marginal adaptation is enhanced by etching.

The aim of the study was to evaluate the reaction exothermia of 2 relining resins for temporary crowns. The resins used were Duralay, a methacrylate-based resin, and Protemp II, a bisacrylic resin. METHODS: The coronal parts of an adult molar and of an impacted one were used. Abutments were obtained from the crowns, while the radicular part was sectioned in order to insert a thermocouple into the pulpal chamber. During the experiment the tooth with the polymerising resin was put into an oral cavity simulator to keep a constant temperature. The thermal increase during polymerisation of the 2 resins was recorded for 6 minutes at 5 seconds intervals and with 1 and 2.5 mm dentin thickness (n = 10). Data were statistically analysed by variance analysis with Scheffe test. RESULTS: The intrapulpal thermal increase was significantly higher in relation to the type of resin (Duralay p < 0.0001), thickness (1 mm p < 0.0001) and type of dentin (young dentin p < 00001). CONCLUSIONS: In order to protect the pulp, during the direct relining of a temporary crown, it is recommendable to choose the best combination among resin, type of dentin and its residual thickness, besides adequate cooling techniques.

Objective: To assess the results of tricuspid annuloplasty performed with the Edwards MC3 remodeling ring. Methods: From 2005 to 2007, 140 patients with tricuspid regurgitation (TR) secondary to left-sided valve disease (mean age 63.8 +/- 11.6, permanent pacemaker in 7.8%, LVEF 56.4 +/- 10.1%, LVEDD 54.1 +/- 8 mm, SPAP 52.5 +/- 14.4 mmHg) underwent tricuspid annuloplasty using the MC3 ring. Dilatation of the tricuspid annulus was present in all patients. Other concomitant mechanisms of TR (moderate leaflet prolapse, pacemaker wires, leaflets' retraction) were documented in 21 cases (15%). All patients underwent concomitant left-sided valve surgery. Ring size was between 28 and 32 in 84.3% of patients. Results: Hospital mortality was 3.5% and actuarial survival at 3 years 94.8 +/- 2.1%. Mean follow-up of the 135 hospital survivors was 22 +/- 9.5 months (median 23 months). Echocardiography at hospital discharge documented no or mild TR in 119 patients (87%), moderate TR (2+/4+) in 15 (11%) and moderate-to-severe (3+/4+) in 1 patient (0.7%). At echocardiographic follow-up moderate TR was present in 14 patients (10.3%) and moderate-to-severe TR in 2 (1.4%). At 3 years freedom from TR >= 2+ was 88.1 +/- 2.78% and freedom from TR >= 3+ was 94.3 +/- 4.89. Predictors of TR >= 2+ at hospital discharge and at follow-up were preoperative LVEF (OR:0.8; p = 0.001 at discharge; HR:0.9; p = 0.003 at follow-up) and the presence of other mechanisms of TR besides annular dilatation (OR:10.8; p = 0.007 at discharge; HR:6.1; p = 0.003 at follow-up). Conclusion: Tricuspid annuloplasty with the MC3 ring provides satisfactory early results which remain stable at mid-term follow-up. The presence of other mechanisms besides annular dilatation leads to residual valve insufficiency after ring annuloplasty alone. doi: 10.1111/j.1540-8191.2012.01443.x (J Card Surg 2012;27:288-294)

Objectives: To describe results from a novel percutaneous technique designed to minimize the risk of hemorrhage in the event of a major complication during transcatheter aortic valve implantation. Background: Vascular access management is a major challenge in transfemoral TAVI due to the large introducer sheathes required. Methods: Fifty-two pts underwent TAVI between November 2007 and March 2009. Of these, 37 received an Edwards-Sapien Valve (23 mm valve: 17/37; 26 mm valve: 20/37) whilst 15 patients received a CoreValve (26 mm valve: 6/15; 29 mm valve: 9/15). Using a crossover technique, the opposing femoral artery was cannulated with a 7Fr long sheath. This allowed contralateral passage of a balloon and inflation in the proximal iliac. The sheath was then removed and Prostar sutures tied in a dry field. Balloon optimization of the puncture site was performed as required. Results: In three subjects, elective surgical repair was undertaken due to excessive femoral arterial calcification. In the remaining 49, the crossover technique was employed and closed with two Prostar devices (Edwards-Sapien) or one (CoreValve). There were serious “on-table” complications in seven patients, six due to the large introducer sheathes used in the TAVI procedure—iliac avulsion, two iliac dissections, iliac perforation, common femoral perforation and scrotal hematoma. All were repaired safely by combined surgical and endovascular techniques, using the crossover technique to ensure patient stability. All made a good recovery and were independently ambulant at discharge. Conclusion: Using crossover balloon inflation as an adjunct to Prostar closure may be helpful for managing TAVI vascular access sites. © 2009 Wiley-Liss, Inc.

Objective: Despite its efficacy and swiftness, bipolar radiofrequency is generally not used on the left isthmus for concern of injuring a coronary branch. Incomplete lesion sets or use of an additional unipolar device are often considered. We report a technique to perform a full left lesion set involving the mitral line using a standard bipolar radiofrequency device. Methods: An innovative complete left atrial lesion set was performed using only bipolar radiofrequency in 70 consecutive patients (study group). In 67/70 patients (96%) mitral valve disease was the main indication to surgery. Atrial fibrillation was permanent in 42 patients (60%), persistent in 25 (36%) and paroxysmal in three patients (4%). After beating-heart pulmonary vein isolation on-pump, the coronary-free area of the AV groove was marked epicardially by sticking a needle into the left atrial wall, behind the coronary sinus. The projection of the needle marker on the mitral annulus was then identified through the atriotomy and an endo-epicardial ablation was performed with the bipolar device involving the atrial wall, the coronary sinus, up to the annulus. The lesion set was then completed by connecting the encirclings and the left appendage, which was then sutured. Follow-up was 100% complete. Results were compared with those of a control group of 33 patients receiving bipolar radiofrequency left atrial ablations and a mitral connecting line with a second unipolar device. Results: All patients survived. No major complication occurred. Haematoma of the AV groove was observed during retrograde cardioplegia in one case. No myocardial ischaemia or re-exploration for bleeding (median 325 cc, interquartile range 250-442) occurred. Two out of 70 patients required a permanent pacemaker for AV block. Freedom from atrial fibrillation was 84% (95% CI: 75%, 93%) at 6 months and 81% (95% CI: 70%, 93%) at 1 year. One patient had left flutter. Comparison with the control group did not show any difference in clinical outcomes, but revealed bipolar ablation to the mitral annulus to abate the per patient cost of the ablation devices (1245 ± 50 ∈ vs 2403 ± 17 ∈; p < 0.0001). Conclusions: Performing the mitral line with bipolar radiofrequency is safe and cost-effective. A complete left atrial ablation with a single bipolar radiofrequency device yields excellent clinical mid-term results.

Objective. Most of current dental adhesive systems show favorable immediate results in terms of retention and sealing of bonded interface, thereby counteracting polymerization shrinkage that affects resin-based restorative materials. Despite immediate efficacy, there are major concerns when dentin bonded interfaces are tested after aging even for short time period, i.e. 6 months. Methods. This study critically discusses the latest peer-reviewed reports related to formation, aging and stability of resin bonding, focusing on the micro and nano-phenomena related to adhesive interface degradation. Results- Most simplified one-step adhesives were shown to be the least durable, while three-step etch-and-rinse and two-step self-etch adhesives continue to show the highest performances, as reported in the overwhelming majority of studies. In other words, a simplification of clinical application procedures is done to the detriment of bonding efficacy. Among the different aging phenomena occurring at the dentin bonded interfaces, some are considered pivotal in degrading the hybrid layer, particularly if simplified adhesives are used. insufficient resin impregnation of dentin, high permeability of the bonded interface, sub-optimal polymerization, phase separation and activation of endogenous collagenolytic enzymes are some of the recently reported factors that reduce the longevity of the bonded interface. Significance. In order to overcome these problems, recent studies indicated that (1) resin impregnation techniques should be improved, particularly for two-step etch-and-rinse adhesives; (2) the use of conventional multi-step adhesives is recommended, since they involve the use of a hydrophobic coating of nonsolvated resin; (3) extended curing time should be considered to reduce permeability and allow a better polymerization of the adhesive film; (4) proteases inhibitors as additional primer should be used to increase the stability of the collagens fibrils within the hybrid layer inhibiting the intrinsic collagenolytic activity of human dentin.

Aim of this study was to investigate the distribution of versican proteoglycan within the human dentine organic matrix by means of a correlative immunohistochemical analysis with field emission in-lens scanning electron microscope (FEI-SEM), transmission electron microscope (TEM), fluorescence microscope (FM) and biochemical assay. Specimens containing dentine and predentine were obtained from non carious human teeth and divided in three groups: 1) FEI-SEM group: sections were exposed to a pre-embedding immunohistochemical procedure; 2) TEM group: specimens were fixed, demineralised, embedded and submitted to a post-embedding immunohistochemical procedure; 3) FM group: sections mineralised and submitted to a pre-embedding immunohistochemical procedure with fluorescence labelling. Specimens were exposed to two different antibodies to assay distribution of versican fragments and whole versican molecule. Western Blotting analysis of dentine and pulp extracts was also performed. The correlative FEI-SEM,TEM and FM analysis revealed positive immunoreaction for versican fragments both in predentine and dentine, while few gold particles identifying the whole versican molecule were found in predentine only under TEM. No labelling of versican whole molecule was detected by FEI-SEM and FM analysis. The immunoblotting analysis confirmed the morphological findings. This study suggests that in fully developed human teeth versican fragments are significant constituents of the human dentine and predentine organic matrix, while versican whole molecule can be visualised in scarce amount within predentine only. The role of versican fragments within human dentine organic matrix should be further elucidated.

Atrial fibrillation becomes a self-perpetuating arrhythmia as a consequence of electrophysiologic and structural remodeling involving the atrium. Oxidative stress may be a link between this rhythm disturbance and electrophysiologic remodeling. The aim of this study was to evaluate whether the heme oxygenase-1 (HO-1) marker of oxidative stress was more expressed in left atrial sites with stronger structural remodeling in patients affected by chronic atrial fibrillation (CAF) and mitral valve disease (MD). Myocardial samples were taken from the left atrial posterior wall (LAPW) and left atrial appendage (LAA) of 24 patients with CAF-MD in addition to 10 autopsy controls. The levels of HO-1 messenger RNA (mRNA) and HO-1 protein in each pathologic LAPW and LAA were quantified using reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Furthermore, light microscopy was used to morphometrically evaluate the differential myocyte and interstitial changes in the same CAF-MD LAPW and LAA samples. In controls, HO-1 protein was quantified using enzyme-linked immunosorbent assay. Unlike controls, patients with CAF-MD had higher levels of HO-1 mRNA and its protein product, expressed as LAPW/LAA ratios, in the LAPW (2.18 +/- 1.18, P.0001, and 1.55 +/- 0.67, P.005), and their LAPW also showed greater histologic changes in myocytolytic myocytes (15.1% +/- 3.1% versus 6.9% +/- 3.3%, P.0001), interstitial fibrosis (8.2% +/- 2.2% versus 2.8% +/- 1.2%, P.0001), and capillary density (816 +/- 120 number/mm(2) versus 1114 +/- 188 number/mm(2); P.05). In addition, markers of oxidative stress were immunohistochemically studied with antinitrotyrosine and anti-iNOS antibodies. In patients with CAF-MD, the inducible enzyme HO-1 is more expressed in the left atrial areas that show greater structural remodeling. This finding strongly suggests a pathogenetic relationship between oxidative stress and the degree of histologic change.

All patients undergoing heart surgery experience a certain amount of nonspecific myocardial injury documented by the release of cardiac biomarkers and associated with poor outcome. We investigated the role of unipolar radiofrequency ablation of atrial fibrillation on the release of cardiac biomarkers in 71 patients undergoing mitral valve surgery and concomitant left atrial ablation case-matched with 71 patients undergoing isolated mitral surgery. The study was powered to detect a 3 ng/mL difference. There was no difference between the 2 groups in terms of cardiac troponin 1 (10 +/- 5.3 versus 12 + 10.4 ng/mL; P = 0.7) or creatine kinase-MB (50 +/- 21.8 versus 57 +/- 62.0 ng/mL; P = 0.5) release. Postoperative peak cardiac troponin I levels had univariate associations with the duration of cardiopulmonary bypass (P = 0.002) and aortic cross-clamping (P = 0.001) and with the surgical technique (15 +/- 12 ng/mL for mitral valve replacement versus 9 +/- 14.8 for mitral valve repair; P = 0.0007) at univariate analysis. Mitral valve replacement was the only independent predictor of postoperative peak release of cardiac troponin I identified with multivariate analysis (P = 0.005). Radicifrequency ablation of atrial fibrillation does not significantly increase cardiac biomarker release compared with isolated mitral surgery; mitral valve repair is associated with less release of cardiac biomarkers compared with mitral valve replacement.

It has been found that the pulmonary veins and adjacent left atrial posterior wall (LAPW) are deeply involved in both the initiation and maintenance of atrial fibrillation (AF), and the identification of these high-risk sites has aroused great interest in investigating their histopathologic substrate. We used light and conventional electron microscopy to evaluate the differential myocyte and interstitial changes in LAPW and left atrial appendage (LAA) samples from 28 patients with chronic AF undergoing mitral valve surgery and from 12 autoptic controls. There were always more myocytes with loss of sarcomeres in the LAPW than in the LAA (19.9% +/- 7.7% versus 8.2% +/- 5.0%; P < .0001), and the LAPW showed more marked immunohistochemical evidence of dedifferentiation, characterized by the reexpression of smooth muscle actin. In pathological left atria, myocyte diameter in the LAPW and LAA was comparable (19.0 +/- 1.5 versus 18.5 +/- 2.0 microm; not significant) but larger than in the controls (11.9 +/- 0.8 and 12.1 +/- 1.3 microm, respectively; P < .0001). A terminal deoxynucleotidyltransferase assay did not reveal any myocyte apoptosis. The LAPW also showed more interstitial fibrosis than the LAA (7.49% +/- 3.34% versus 2.80% +/- 1.35%; P < .0001). Ultrastructural examination confirmed the presence of myocyte myocytolysis in the perinuclear area and showed changes in mitochondrial shape. In conclusion, the LAPW in patients with chronic AF related to mitral valve disease seems to be a particular anatomical site in which major myocyte and interstitial changes are concentrated, whereas the LAA is more protected. This remodeling may increase the heterogeneity of LAPW electrical conduction, thus confirming this location as an elective target for the ablation treatment of AF.

The biocompatibility of six single-phase dental metal alloys was studied by determining cell proliferation rates correlated to the arrangement of fibronectin (FN) in fibroblast cultures. Immunocytochemical methods were used to detect cell proliferation by 5-bromodeoxyuridine (BrdU) incorporation, and FN organization [i.e. diffuse in the extracellular matrix and organized in fibrils or in focal adhesions (FA)] in human fibroblast cultures. Cell proliferation rates were related to FN arrangement and in particular a higher percentage of cells in the S-phase was related to a predominance of FA. The greatest difference in behaviour compared to that of the controls was detected after 120 and 168 hr: at these times, as well as at previous ones, the alloy with the highest Au content seemed the most biocompatible among those tested, as it behaved in a very similar way to the controls. In contrast, fibroblasts exposed to the other five alloys showed different behaviours from the controls. It is assumed that a correlation exists between FN organization and the percentage of BrdU-positive cells, and that these features vary in the presence of different alloys. The observation of FN arrangement together with cell proliferation rates could be another useful tool in determining the biocompatibility of dental metal alloys.

The degeneration of a previously surgically implanted aortic bioprosthesis is an increasing etiology of aortic stenosis in the elderly, but reoperative surgery may present prohibitive risks. The feasibility of transcatheter aortic valve implantation into a conventional bioprosthesis (valve-in-valve concept) has been evaluated to decrease the reoperative risk for patients with a failed bioprosthesis. There have been several reports of valve-in-valve procedures using the self-expandable prosthesis CoreValve (Medtronic Inc.), whereas the feasibility of this procedure with the Sapien balloon expandable valve (Edwards Lifesciences Inc.) is still not well established. Here we report the case of a patient submitted to balloon-expandable aortic valve-in-valve implantation in an emergency setting to treat a severe aortic stenosis due to the premature failure of a surgical bioprosthesis.

A short-term (72-96 hours) biocompatibility evaluation in vitro of four single phase dental metal alloys was conducted by determining cell proliferation rates correlated to the organization of the extracellular matrix protein fibronectin in human fibroblast cultures. Immunocytochemical methods were performed to detect both cell proliferation rates by 5-bromodeoxyuridine (BrdU) incorporation, and fibronectin arrangement, i.e., diffuse in the extracellular matrix, organized in fibrils or in focal adhesions. We showed that cell proliferation rates were related to fibronectin expression. In particular, a higher percentage of cells in the S-phase were related to a predominance of fibronectin organized both in fibrils and in focal adhesions. The alloy with the highest Au content seemed the most biocompatible among those tested, since it behaved in a very similar manner to the controls. On the contrary, fibroblasts exposed to the alloy with the highest percentage of Ag had the most different behavior as compared to the controls. We can assume that a correlation exists between fibronectin organization and the percentage of BrdU-positive cells and that these parameters are varying with the different metal composition of the alloys. The observation of fibronectin arrangement together with cell proliferation rates could be considered a useful tool to determine the biocompatibility of these biomaterials. (J. Oral Sci. 42, 1-7, 2000)