Arginine catabolism metabolites and atrial fibrillation or heart failure risk: 2 case-control studies within the Prevención con Dieta Mediterránea (PREDIMED) trial

Background Arginine-derived metabolites are involved in oxidative and inflammatory processes related to endothelial functions and cardiovascular risks. Objectives We prospectively examined the associations of arginine catabolism metabolites with the risks of atrial fibrillation (AF) or heart failure (HF), and evaluated the potential modifications of these associations through Mediterranean diet (MedDiet) interventions in a large, primary-prevention trial. Methods Two nested, matched, case-control studies were designed within the Prevención con Dieta Mediterránea (PREDIMED) trial. We selected 509 incident cases and 547 matched controls for the AF case-control study and 326 cases and 402 matched controls for the HF case-control study using incidence density sampling. Fasting blood samples were collected at baseline and arginine catabolism metabolites were measured using LC-tandem MS. Multivariable conditional logistic regression models were applied to test the associations between the metabolites and incident AF or HF. Interactions between metabolites and intervention groups (MedDiet groups compared with control group) were analyzed with the likelihood ratio test. Results Inverse association with incident AF was observed for arginine (OR per 1 SD, 0.83; 95% CI: 0.73–0.94), whereas a positive association was found for N1-acetylspermidine (OR for Q4 compared with Q1 1.58; 95% CI: 1.13–2.25). For HF, inverse associations were found for arginine (OR per 1 SD, 0.82; 95% CI: 0.69–0.97) and homoarginine (OR per 1 SD, 0.81; 95% CI: 0.68–0.96), and positive associations were found for the asymmetric dimethylarginine (ADMA) and symmetric dimethlyarginine (SDMA) ratio (OR per 1 SD, 1.19; 95% CI: 1.02–1.41), N1-acetylspermidine (OR per 1 SD, 1.34; 95% CI: 1.12–1.60), and diacetylspermine (OR per 1 SD, 1.20; 95% CI: 1.02–1.41). In the stratified analysis according to the dietary intervention, the lower HF risk associated with arginine was restricted to participants in the MedDiet groups (P-interaction = 0.044). Conclusions Our results suggest that arginine catabolism metabolites could be involved in AF and HF. Interventions with the MedDiet may contribute to strengthen the inverse association between arginine and the risk of HF. This trial was registered at controlled-trials.com as ISRCTN35739639

Perforated peptic ulcer (PPU) treatment: an Italian nationwide propensity score-matched cohort study investigating laparoscopic vs open approach

BackgroundPerforated peptic ulcer (PPU) remain a surgical emergency accounting for 37% of all peptic ulcer-related deaths. Surgery remains the standard of care. The benefits of laparoscopic approach have been well-established even in the elderly. However, because of inconsistent results with specific regard to some technical aspects of such technique surgeons questioned the adoption of laparoscopic approach. This leads to choose the type of approach based on personal experience. The aim of our study was to critically appraise the use of the laparoscopic approach in PPU treatment comparing it with open procedure.MethodsA retrospective study with propensity score matching analysis of patients underwent surgical procedure for PPU was performed. Patients undergoing PPU repair were divided into: Laparoscopic approach (LapA) and Open approach (OpenA) groups and clinical-pathological features of patients in the both groups were compared.ResultsA total of 453 patients underwent PPU simple repair. Among these, a LapA was adopted in 49% (222/453 patients). After propensity score matching, 172 patients were included in each group (the LapA and the OpenA). Analysis demonstrated increased operative times in the OpenA [OpenA: 96.4 +/- 37.2 vs LapA 88.47 +/- 33 min, p = 0.035], with shorter overall length of stay in the LapA group [OpenA 13 +/- 12 vs LapA 10.3 +/- 11.4 days p = 0.038]. There was no statistically significant difference in mortality [OpenA 26 (15.1%) vs LapA 18 (10.5%), p = 0.258]. Focusing on morbidity, the overall rate of 30-day postoperative morbidity was significantly lower in the LapA group [OpenA 67 patients (39.0%) vs LapA 37 patients (21.5%) p = 0.002]. When stratified using the Clavien-Dindo classification, the severity of postoperative complications was statistically different only for C-D 1-2.ConclusionsBased on the present study, we can support that laparoscopic suturing of perforated peptic ulcers, apart from being a safe technique, could provide significant advantages in terms of postoperative complications and hospital stay

High Differentiation among Eight Villages in a Secluded Area of Sardinia Revealed by Genome-Wide High Density SNPs Analysis

To better design association studies for complex traits in isolated populations it's important to understand how history and isolation moulded the genetic features of different communities. Population isolates should not “a priori” be considered homogeneous, even if the communities are not distant and part of a small region. We studied a particular area of Sardinia called Ogliastra, characterized by the presence of several distinct villages that display different history, immigration events and population size. Cultural and geographic isolation characterized the history of these communities. We determined LD parameters in 8 villages and defined population structure through high density SNPs (about 360 K) on 360 unrelated people (45 selected samples from each village). These isolates showed differences in LD values and LD map length. Five of these villages show high LD values probably due to their reduced population size and extreme isolation. High genetic differentiation among villages was detected. Moreover population structure analysis revealed a high correlation between genetic and geographic distances. Our study indicates that history, geography and biodemography have influenced the genetic features of Ogliastra communities producing differences in LD and population structure. All these data demonstrate that we can consider each village an isolate with specific characteristics. We suggest that, in order to optimize the study design of complex traits, a thorough characterization of genetic features is useful to identify the presence of sub-populations and stratification within genetic isolates

Artificial teeth manufacturing: inspection of mould and teeth by contactless scanning systems

The recent development of non-contact digitizing systems dedicated to dental applications has introduced innovative procedures, based on Reverse Engineering techniques, for the production of artificial teeth. Starting from the reconstructed 3D model of each tooth, first the mould CAD model is created and then the milling path is computed for machining. At the moment there is no indication of the quality of such innovative procedure, so it is investigated in this study by evaluating the deviation introduced by each manufacturing step. A machined mould for the production of acrylic molars and premolars is inspected by means of a contactless scanner and some teeth are selected as manufactured samples. Scan data of such samples allow to evaluate the deviations introduced by each operation. A comparison of two optical digitizers is based on the results of this study and economic considerations related to costs and times are also include

A benchmark for accuracy evaluation of dental crowns up-to-date manufacturing

In recent years, digitizing and automation have gained an important role in manufacturing of dental devices. Instead of the traditional plaster model procedure, scanning techniques may be used for the geometry acquisition. Point clouds are processed and converted into standard CAD models, from which metal tooth cap can be fabricated by milling, integrating CAM tool, or by rapid manufacturing (RM) techniques. Good quality control is critical to ensure the crown fit: an improper fit could cause crown falling off. So far there is no standard procedure for evaluating quality of both 3D digitization and milling/RM cap making processes. Thus, a specific benchmark is designed to represent critical features of a stone replica, like a dental arch with studs resembling teeth prepared for crowns installation. The benchmark is then produced and measured by means of a coordinate measuring machin

Evaluation of innovative techniques for dental crowns manufacturing

A structured procedure for evaluating the accuracy at each step of the crown restoration manufacturing sequence is proposed. This procedure includes the definition of an innovative benchmark and it is applied to evaluate the accuracy of both digitization and cap production phases. Three different up-to-date manufacturing processes are analyse

Surface and sub surface evaluation in coated-wire electrical discharge machining (WEDM) of INCONEL® alloy 718

Wire Electncal Discharge Machining (WEDM) is one of the most versatile and useflil technological processes for cuttmg complex shapes made of conductive matenals such as those typical of aerospace applications. With the aim to optimize process parameters, this paper studies the surface and subsurface modifications of INCONEL® alloy 718 (UNS N077 18) machined by WEDM using a Zinc coated brass wire. Machining was perfomwd under roughing and finishing conditions by setting different values of discharge energy and wire feed rate. Surface roughness of the cut surfaces was measured as well as the micro-hardness profile on polished sections. WED-machined surfaces and their cross sections were also observed by Scannmg Electron Microscope (SEM) and analyzed by Energy Dispersive X-ray Spectroscopy (EDS) to evaluate possible vanations of the surface chemical composition. In this investigation, results are discussed as a ifinction of the feed rate and of the smgle pulse discharge energy, which is determined by duration, peak current and discharge voltage of the discharge pulse. The research demonstrates that the required surface roughness can be achieved by properly settmg the feed rate and the smgle pulse discharge energy on the WEDM machme. Expenmental results also show that under the re-melted layer thickness no significant white layer formation or thermal modification occur, indicatmg that the chosen set of operatmg parameters minimizes secondary and unwanted chemical reactions

Tolerance analysis for cast vs machined dental implants

The paper addresses the dimensional tolerance and assembly accuracy of prosthetic components obtained by different manufacturing processes. The success of single tooth implant replacements hangs on the stability of the hexagonal connection, but no standard control procedures are available for its evaluation. The research aims at proposing a new protocol for the dimensional assessment of implant-abutment connections, based on non-contact measurement and statistical data processing. The procedure is applied to machined- and cast-on abutments, as well of the matching implants. Samples are measured using an optical measuring microscope and data are processed to obtain the international tolerance (IT) grade. The rotational misfit is then calculated using the apothems of the external and the internal hexagon. As to the results, all the components are classified between IT8 and IT9 and the maximum rotational misfit is around 4° for all the assemblies, inferior to the critical limits for the screw joint stability. An objective dimensional characterization of prosthetic components and assemblies is reported, which is the basis for their reliability in clinical applications. From a wider perspective, an original measuring protocol is proposed, independent of parts assembly and based on international tolerances

Thermoplastic Resin Transfer Moulding in a rapid manufactured mould

Resin Transfer Moulding (RTM) is a low-cost process for the production of composite parts with thermosetting resins. However, the economic convenience is lost in the case of large components, such as aeronautical panels, because of the high tooling cost. Step milling of a resin master for the electro-deposition of a nickel shell is proposed in this study as a valid alternative for the fabrication of a resin transfer mould. This solution allows overcoming the limitations regarding part size and cutting down tooling costs, but the expected dimensional accuracy needs to be assessed. On the field of materials, innovative thermoplastic resins are now available that can be used in the formof lowviscosity oligomers for optimal mould filling and fibre impregnation. Subsequent in situ polymerization provides high toughness composites. Cyclic Butylen Terephtalate (CBT), which polymerizes into PBT (Poly-Butylen Terephtalate), is studied in this work. The research focuses on two objectives: quantifying the dimensional accuracy of the technological chain and setting up the process of in situ polymerizatio