Influence of the heat treatment on the particles size and on the crystalline phase of TiO2 synthesized by the sol-gel method

Titanium biomaterials' response has been recognized to be affected by particles size, crystal structure, and surface properties. Chemical and structural properties of these nanoparticle materials are important, but their size is the key aspect. The aim of this study is the synthesis of TiO2 nanoparticles by the sol-gel method, which is an ideal technique to prepare nanomaterials at low temperature. The heat treatment can affect the structure of the final product and consequently its biological properties. For this reason, the chemical structure of the TiO2 nanoparticles synthesized was investigated after each heat treatment, in order to evaluate the presence of different phases formed among the nanoparticles. FTIR spectroscopy and XRD have been used to evaluate the different structures. The results of these analyses suggest that an increase of the calcination temperature induces the formation of mixed-crystalline-phases with different content of anatase and rutile phases. The results obtained by SEM measurements suggest that an increase in the particles size accompanied by a noticeable aggregation of TiO2 nanoparticles is due to high temperatures achieved during the thermal treatments and confirmed the presence of different content of the two crystalline phases of titanium dioxide

Laparoscopic paraesophageal hernia repair with absorbable mesh: a systematic review

Background: Laparoscopic repair is the standard of care for patients with paraesophageal hernia (PEH). Different prosthetic materials have been proposed to bolster the hiatus thus theoretically minimizing the probability for hernia recurrence. The use of non-absorbable mesh has been reported however, their safety profile has been questioned because the noteworthy mesh-related complication rate. Opposite, absorbable mesh (synthetic and biologic) seems associated with mitigated mesh-related complications and comparable hernia recurrence in the short- and medium-term. Methods: PubMed, MEDLINE, EMBASE, Scopus, Google Scholar, and ClinicalTrials.gov were executed according to the PRISMA statement until May 2022. Primary endpoints were technical details and surgical outcomes of adult patients (>= 18 years old) that underwent laparoscopic PEH repair and crural reinforcement with absorbable mesh. The ROBINS-I tool was used to assess the methodological quality of included studies. Results: Thirty-nine studies (3,103 patients) were included. The age of the patient population ranged from 18 to 93 years old and 62.8% were females. Posterior cruroplasty was performed in all patients. U-shape (83.7%), circumferential (8.1%), keyhole (5.4%) and starburst (2.8%) mesh configuration were described. Different methods for mesh fixation (sutures vs. fibrin glue vs. absorbable tacks) were adopted while Nissen (75.1%) and Toupet (21.1%) fundoplication were mainly fashioned. The overall postoperative complication rate was 2.5%. Pulmonary and cardiac complication rates were 1.8% and 0.9%, respectively while in-hospital mortality was 0.2%. Postoperative follow-up ranged from 12 to 166 months. Mesh-related complication rate was 0.06% (esophageal stricture related to fibrosis). Hernia recurrence rate was 12.7% while re-do surgery was required in 1.9% of patients. Postoperative dysphagia rate was 5.1%. Discussion: Consensus concerning the optimal mesh material for crural buttressing is lacking. Given the potential for tissue ingrowth rather than encapsulation and reduced degree of perivisceral inflammation, absorbable meshes are mostly preferred over non-absorbable meshes. The use of absorbable mesh seems safe and effective with low overall and mesh-related complications, acceptable recurrence rate and low need for re-do surgery in the short/medium-term. Because heterogeneity related to different hernia characteristics, intraoperative technical variations (i.e., method for mesh fixation, etc.), definition of hernia recurrence and diverse follow-up, a conclusive evidence is still to be defined

Schwann cell hamartoma: case report

<p>Abstract</p> <p>Background</p> <p>Colorectal polyps of mesenchymal origin represent a small percentage of gastrointestinal (GI) lesions. Nevertheless, they are encountered with increasing frequency since the widespread adoption of colonoscopy screening.</p> <p>Case presentation</p> <p>We report a case of a small colonic polyp that presented as intramucosal diffuse spindle cell proliferation with a benign cytological appearance, strong and diffuse immunoreactivity for S-100 protein, and pure Schwann cell phenotype. Careful morphological, immunohistochemical and clinical evaluation emphasize the differences from other stromal colonic lesions and distinguish it from schwannoma, a circumscribed benign nerve sheath tumor that rarely arises in the GI tract.</p> <p>Conclusion</p> <p>As recently proposed, this lesion was finally described as mucosal Schwann cell hamartoma.</p

A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease