Nanocomposites based on the graphene family for food packaging: historical perspective,preparation methods,and properties

Nanotechnology experienced a great technological advance after the discovery of the graphene family (graphene – Gr, graphene oxide – GO, and reduced graphene oxide-rGO). Based on the excellent properties of these materials, it is possible to develop novel polymeric nanocomposites for several applications in our daily routine. One of the most prominent applications is for food packaging, offering nanocomposites with improved thermal, mechanical, anti-microbial, and barrier properties against gas and water vapor. This paper reviewed food packaging from its inception to the present day, with the development of more resistant and intelligent packaging. Herein, the most common combinations of polymeric matrices (derived from non-renewable and renewable sources) with Gr, GO, and rGO and their typical preparation methods are presented. Besides, the interactions present in these nanocomposites will be discussed in detail, and their final properties will be thoroughly analyzed as a function of the preparation technique and graphene family-matrix combinations.

Food packaging based on nanotechnology of polymeric nanocomposites of graphene and graphene oxide results in packaging with better thermal, mechanical, antimicrobial, electrical packaging, moisture barrier and gas properties.     

Actualización en fascitis necrotizante

Necrotizing fasciitis is defined as a rapidly progressive infection of the skin and soft tissue that usually involves severe systemic toxicity. The incidence of this infection has increased in the last few decades and is estimated to affect one out of every 100,000 inhabitants in western European countries. This disease is the most serious form of skin and soft tissue infection, due to rapid destruction and necrosis of the fascia and subcutaneous fat, and the development of shock and multiorgan failure in about one third of patients.Although there are several predisposing factors for the development of the disease, especially for type I, or polymicrobial, necrotizing fasciitis, many patients are young and have no underlying chronic diseases, as is the case for type II, or streptococcal, necrotizing fasciitis. The diagnosis is mainly clinical, and urgent surgical consultation is required as soon as possible once suspicion is high, as the main determinant of mortality is the delay in surgical treatment. Overall mortality remains high, affecting more than 25% of patients. Surgical debridement is the mainstay of treatment, along with hemodynamic support and broad-spectrum antibiotics.     

Oblique radiographs compared favorably with computed tomography images in assessing cervical foraminal area

Oblique radiographs are often ordered to evaluate the patency of cervical intervertebral foramina. Previous studies have shown that computed tomography (CT) provides accurate measurements of foraminal dimensions. Up until now, no study has directly compared the diagnostic utility of oblique radiographs and CT. We conducted a study to quantify the correlation between cervical foramina dimensions measured on oblique radiographs and on CT scans. Heights, widths, and cross-sectional areas were evaluated at every level from C2-C3 through C7-T1 using both oblique radiographs and oblique CT reconstructions. Both measurements were performed at a 50% oblique angle. Interreliability and intrareliability statistics for radiographs and CT were 0.91 and 0.99 for height, 0.90 and 0.97 for width, and 0.84 and 0.92 for area. Pearson correlation coefficients for height, width, and area were 0.439, 0.871, and 0.899, respectively. Oblique radiographs of the cervical spine provide accurate estimates of intervertebral foraminal dimensions--estimates similar to those generated from CT reconstructions. Thus, these radiographs may serve as an acceptable first-line imaging study for initial assessment of patients suspected of having nerve root compression that precludes the higher cost and radiation exposure associated with CT scans.     

Defective differentiation of regulatory FoxP3+ T cells by small-intestinal dendritic cells in patients with type 1 diabetes

OBJECTIVE

The gut environment modulates the pathogenesis of type 1 diabetes (T1D), but how it affects autoimmunity toward pancreatic β-cells, a self-tissue located outside the intestine, is still unclear. In the small intestine, lamina propria dendritic cells (LPDCs) induce peripheral differentiation of FoxP3⁺ regulatory T (Treg) cells. We tested the hypothesis that the intestinal milieu impinges on human T1D by affecting differentiation of FoxP3⁺ Treg cells.

RESEARCH DESIGN AND METHODS

We collected duodenal biopsies of 10 T1D patients, 16 healthy subjects, and 20 celiac individuals and performed a fluorescent-activated cell sorter analysis to measure percentages of various immune cell subsets, including CD4⁺ and CD8⁺ T cells, NK cells, γδ T cells, CD103⁺CD11c⁺ LPDCs, and CD4⁺CD25⁺FoxP3⁺CD127⁻ Treg cells. In parallel, we assessed the tolerogenic function (i.e., capacity to induce differentiation of FoxP3⁺ Treg cells) by LPDCs of T1D patients and control subjects.

RESULTS

Our analysis revealed a significant reduction in the percentage of intestinal CD4⁺CD25⁺FoxP3⁺CD127⁻ Treg cells in T1D patients compared with healthy subjects (P = 0.03) and celiac individuals (P = 0.003). In addition, we found that LPDCs from T1D patients completely lacked their tolerogenic function; they were unable to convert CD4⁺CD25⁻ T cells into CD4⁺CD25⁺FoxP3⁺CD127⁻ Treg cells.

CONCLUSIONS

Our data indicate that T1D patients have a reduced number of intestinal FoxP3⁺ Treg cells as a result of their defective differentiation in the gut. These findings suggest that intestinal immune regulation is not only calibrated to tolerate commensal bacteria and food components but also is instrumental in maintaining immune tolerance toward pancreatic β-cells and preventing T1D.Type 1 diabetes (T1D) is a destructive islet β-cell specific autoimmune disease resulting from a yet undefined interaction between genetic and environmental factors (1). A dramatic increase in T1D incidence was recorded in most developed countries in the past 40 years (e.g., a threefold increase in Western countries) (2,3). The steady and rapid increase in T1D incidence cannot be ascribed to genetic variations and, thus, it must be related to environmental changes. Environmental agents such as viral infections (i.e., enteroviruses and rotaviruses) (4,5), reactions to dietary antigens (i.e., cow’s milk and gluten) (6–8), and microbiota alterations (9) that act at the intestinal level have been observed in association with, or as risk factors for, the development of T1D. The observation that development of clinical diabetes in patients is preceded by intestinal alterations such as increased permeability, immune activation, and ultrastructural abnormalities of the epithelium (10–16) provides additional evidence on the crucial role of the gut environment in human T1D. Although existing evidence is suggestive of a causative link between the gut milieu and the pathogenesis of T1D, it is still unclear whether and by which mechanism(s) a dysfunction in the intestine promotes autoimmunity elsewhere (i.e., in the pancreatic β-cells) and if it does, how this process occurs.Important immune regulatory mechanisms reside in the intestinal mucosa. FoxP3⁺ regulatory T (Treg) cells, a Treg cell subset that is instrumental to controlling T1D (17), arise centrally in the thymus and peripherally in the gut (18). Specifically, lamina propria CD103⁺CD11c⁺ dendritic cells (LPDCs) are responsible for extrathymic FoxP3⁺ Treg cell development and expansion (18,19). Considering the key immune regulatory role of FoxP3⁺ Treg cells, it is clear that their defective peripheral differentiation in the gut could lead to failure of self-tolerance and autoimmune disease, particularly in tissues such as pancreatic islets and lymph nodes that are directly connected to the intestinal mucosa and gut-associated lymphoid tissue (20).Here we demonstrate that the extrathymic differentiation of FoxP3⁺ Treg cells by gut-resident CD103⁺CD11c⁺ dendritic cells (DCs) is selectively impaired in humans affected by T1D. Our findings indicate that organ-specific autoimmune diseases such as T1D could be initiated and possibly maintained by virtue of changes in peripheral FoxP3⁺ Treg cell differentiation and/or expansion in the gut.     

Efficacy and safety profile of a novel technique,ThuLEP (Thulium laser enucleation of the prostate) for the treatment of benign prostate hypertrophy. Our experience on 148 patients

Background

Over the past years laser technology has played a predominant role in prostate surgery, for the treatment of benign prostate hypertrophy (BPH). Various laser devices have been introduced in clinical practice, showing good results in terms of complications and urodynamic outcomes efficacy compared with TURP and Open Prostatectomy.

In this study we describe the efficacy and the safety profile of a novel laser technique, ThuLEP (Thulium Laser Enucleation of Prostate) that permits a complete anatomical endoscopic enucleation of prostatic adenoma independently to prostate size.

Methods

148 patients with a mean age of 68.2 years were enrolled between September 2009 and March 2012 (36 months), and treated for BPH with ThuLEP. Every patient was evaluated at base line according to: Digital Rectal Examination (DRE), prostate volume, Post-Voided volume (PVR), International Prostate Symptoms Score (I-PSS), International Index of Erectile Function-5 (IIEF-5), Quality of Life (QoL), PSA values, urine analysis and urine culture, uroflowmetry. The same evaluation was conducted after a 12 month follow-up. ThuLEP was performed by 2 expert surgeons.

Results

Our data showed a better post-operative outcome in terms of catheter removal, blood loss, TURP syndrome, clot retention and residual tissue compared to large series of TURP and OP. Only 1.3% of patients had bladder wall injury during morcellation. I-PSS, Qmax, Prostate Volume, QoL and PVR showed a highly significant improvement at 12 month follow-up in comparison to preoperative assessment.

Conclusion

ThuLEP represent an innovative option in patients with BPH. It is a size independent surgical endoscopic technique and it can be considered the real alternative, at this time, to TURP and even more to Open Prostatectomy for large prostate, with a complete removal of adenoma and with a low complication rate.

     

Aortic valve replacement in severe aortic stenosis with left ventricular dysfunction: determinants of cardiac mortality and ventricular function recovery

Objective: The influence of left ventricular (LV) dysfunction on survival of patients with severe aortic stenosis is poorly characterized. Few data are available about preoperative predictors of cardiac mortality and LV function recovery after aortic valve replacement of such patients. The aim of our study was to examine the outcome and the preoperative predictors of postoperative cardiac death and of LV function recovery in these patients. Methods: We evaluated 85 consecutive patients with severe aortic stenosis (aortic valve area <1 cm²) and severe depression of LV ejection fraction (EF) <35% at cardiac catheterization. Among them, 52 underwent aortic valve replacement and they were compared to patients who were not operated on. All patients had a mean clinical follow-up of 53 months and 94% of them had a mean echocardiographic follow-up of 14 months after aortic valve replacement. Results: The mean baseline characteristics included: LVEF 28±6%, peak-to-peak transvalvular gradient 51±29 mmHg, aortic valve area 0.63±0.25 cm². Thirty-three patients did not undergo aortic valve replacement: 32 of them died within 3 years. Fifty-two patients underwent aortic valve replacement and 16 had a concomitant coronary bypass surgery. In-hospital mortality was 8%. Postoperative NYHA functional class changed from 2.84±0.67 to 1.43±0.44 (P<0.001) and LVEF from 29±6% to 43±10% (P<0.001). At follow-up 10 patients died of heart disease. By multivariate analysis, preoperative LV end-systolic volume index (ESVI) was the only covariate of cardiac death (LVESVI/10 ml/m², OR 1.3, CI 1.1–1.8, P<0.028). By using a receiver operating characteristic curve, LVESVI≤90 ml/m² was the best cut-off value (sensitivity and specificity 78%) to fit with a better survival (93% vs. 63%, P<0.01) and with LVEF recovery after aortic valve replacement (EF improved by 15±10% vs. 8±5%, P<0.001). Conclusions: Despite LV dysfunction, aortic valve replacement appears to change drastically the natural history of severe aortic stenosis. Preoperative LV levels predict different postoperative survival rate and LVEF recovery.     

Long-term reendothelialization of excimer laser-assisted nonocclusive anastomoses compared with conventionally sutured anastomoses in pigs

OBJECT: In contrast to conventional anastomosis methods, the excimer laser-assisted nonocclusive anastomosis (ELANA) technique involves a platinum ring and intima-adventitia apposition with a rim of medial and adventitial layers exposed to the bloodstream. The authors assessed the reendothelialization of porcine carotid arteries through ELANA compared with conventional anastomosis by using scanning electron microscopy. METHODS: In 28 pigs a bypass with one ELANA and one conventional anastomosis was made on the left common carotid artery. All patent anastomoses were evaluated intraoperatively with the aid of an ultrasonographic flowmeter and postoperatively by using scanning electron microscopy at 2 weeks, 2 months, 3 months, and 6 months thereafter. Twenty-four of 28 bypasses (48 of 56 end-to-side anastomoses) were fully patent at the time of evaluation. On scanning electron microscopic evaluation of the bypasses, all 48 patent anastomoses showed complete reendothelialization, including all 24 ELANAs in which the endothelium covered the rim and the laser-ablated edge completely. No endothelial difference was observed between conventional anastomoses and ELANAs, aside from the obvious anatomical differences like the platinum ring, which had been completely covered with endothelium. At 6 months postsurgery, remodeling of the ELANA was observed, leaving the ring covered with a layer of endothelium as the most narrow part of the anastomosis. CONCLUSIONS: In long-term experiments, ELANA allows reendothelialization comparable to that achieved with conventional anastomosis. Considering its nonocclusive and high-flow characteristics, the ELANA technique is preferable in cerebral revascularization procedures.     

New perspectives for anticoagulation in non-rheumatic atrial fibrillation: oral antithrombins]

Non-rheumatic atrial fibrillation (NRAF) is one among the major public health problems, because it is associated with a high incidence of stroke or systemic thromboembolism. Warfarin significantly reduces cerebral/systemic events mainly in high-risk patients; unfortunately such drug is often as well under-used in eligible patients as under-dosed in treated patients. Traditional therapy with oral anticoagulants has several disadvatages: narrow therapeutic window, and often unpredictable dose-response so that frequent monitoring of the INR is required. It is therefore crucial that patients preferences and education be integrated into the decision-making process. Physicians often underprescribe oral anticoagulants since they perceive the risk of major bleeding as unacceptable because of some well known risk factors (e.g. previous bleedings, severe hypertension), and of qualms about drug interactions or alleged poor compliance. Therefore, the development of easy-to-use antithrombotic agents is still a challenge. New agents such as oral direct thrombin inhibitors are going to hold the promise for the next future. Ximelagatran is an orally active small molecule; being the first new oral anticoagulant used in large clinical trials. This molecule has many advantages in comparison to warfarin, such as the rapid onset/offset of action, the fixed oral dose, the no need of dose adjustment or of anticoagulation monitoring, as well the lack of food/alcohol intake interference as of drug interactions. The SPORTIF III and V trials have shown that ximelagatran is not inferior to warfarin in the prevention of strokes in patients with NRAF (both persistent and paroxysmal), but a side effect--consisting in the significant elevation of liver enzymes (> 3 times the upper limit of normal) in 6% of patients--was found. Further randomized trials are clearly needed, while current data suggest that ximelagatran will be able to represent a future viable therapeutic option for prevention of thromboembolism in patients with NRAF, offering huge advantages with respect to classic oral anticoagulants.