Hemocompatibility of stent materials: alterations in electrical parameters of erythrocyte membranes

A Basoli1, C Cametti2, F Ginnari Satriani2, P Mariani3, P Severino31Department of Surgery, "P Stefanini," University of Rome "La Sapienza," Rome, Italy; 2Department of Physics, University of Rome "La Sapienza," Rome Italy; 3Department of Internal Medicine, University of Rome "La Sapienza," Rome, ItalyBackground: It is presently unknown if stents used in the correction of artery stenosis are fully hemocompatible or if their implantation causes alterations at the level of the plasma membrane in red blood cells.Methods: We addressed this important issue by measuring the passive electrical properties of the erythrocyte membrane before and after stent insertion by means of dielectric relaxation spectroscopy in the radiowave frequency range in a series of patients who were undergoing standard surgical treatment of arterial disease.Results: Our findings provide evidence that full hemocompatibility of stents has not yet been reached, and that there are some measurable alterations in the passive electrical behavior of the red blood cell membrane induced by the presence of the stent.Conclusion: It is possible that these changes do not have any physiological significance and simply reflect the intrinsic variability of biological samples. However, caution is urged, and the technique we describe here should be considered when investigating the hemocompatibility of a medical device at a cell membrane level.Keywords: hemocompatibility, stent, arterial disease, cell membran

Spin-coated La0.8Sr0.2Ga0.8Mg0.2O3-δ Electrolyte on Infiltrated Anodes for Direct Methane Fuel Cells

Dense micrometric La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) films were deposited by spin-coating on porous LSGM scaffolds characterized by homogeneous pore structure. Porous anodes were infiltrated with aqueous nickel and nickel/copper nitrate solutions, dried and fired at 700°C. Homogeneous metal coating with proper interconnection was observed by SEM, chemical stability was confirmed by XRD, and electrical characterization of anodic substrates was performed. Catalytic activity of different anodes was evaluated ex-situ in a quartz micro-reactor fed with CH4:CO2 mixtureat range 650 and 700°C. To investigate the redox properties of the metallic phases, the anodic substrates were subjected to redox ageing cycles and characterized by H2-TPR

Gellan hydrogel as a powerful tool in paper cleaning process: a detailed study

Hypothesis: Wet cleaning of ancient papers is one of the most critical steps during a conservation treatment. It is used to improve the optical qualities of a graphic work and remove dust and by-products resulting from cellulose degradation. Nevertheless, washing treatment usually involves a substantial impact on the original morphological structure of paper and can sometimes be dangerous for water sensitive inks and pigments. Experiments: The use of rigid hydrogel of Gellan gum as an alternative paper cleaning treatment is developed. The application of a rigid hydrogel minimizes damages caused by the use of water, and therefore is much more respectful for the original integrity of ancient paper. Findings: Gellan hydrogel has been used to clean paper samples belonging to different centuries (from XVI to XIX) and therefore, characterized by a different story in terms of degradation condition and paper composition. Several techniques, such as high-performance liquid chromatography, Fourier transform infrared spectroscopy, scanning electron microscopy and pH measurements, has been employed to assess the effectiveness and safety of the proposed cleaning method

The Gas Sensing Properties of Porphyrins-coated Laterally Grown ZnO Nanorods

AbstractPorphyrins coated ZnO is an interesting material where the exposure to light and gas may cooperate to modulate the respective sensitivities. In this work, the gas sensing properties of porphyrins functionalized laterally grown ZnO nanorods are introduced. The porphyrin layer incompletely coats the semiconductor surface in order to keep both ZnO and porphyrins in contact with analyte. It is known that UV light may prompt the chemical sensitivity of ZnO replacing the high temperature condition. Here we demonstrate that because of the photo-injection of electrons from porphyrin to the ZnO, the same impact could be acquired with visible light

A Prospective, Double-Blind, Multicenter, Randomized Trial Comparing Ertapenem 3 Vs ≥5 Days in Community-Acquired Intraabdominal Infection

Abstract: Severe secondary peritonitis is diagnosed in only 20-30% of all patients, but studies to date have persisted in using a standard fixed duration of antibiotic therapy. This prospective, double-blind, multicenter, randomized clinical study compared the clinical and bacteriological efficacy and tolerability of ertapenem (1 g/day) 3 days (group I) vs >= 5 days (group II) in 111 patients with localized peritonitis (appendicitis vs non-appendicitis) of mild to moderate severity, requiring surgical intervention. In evaluable patients, the clinical response as primary efficacy outcome were assessed at the test-of-cure 2 and 4 weeks after discontinuation of antibacterial therapy. Ninety patients were evaluable. In groups I and II, 92.9 and 89.6% of patients were cured, respectively; 95.3% in group I and 93.7% in group II showed eradication. These differences were not statistically significant. The most frequent bacteria recovered were Escherichia coli and Bacteroides fragilis. A wound infection developed in seven patients (7.7%) and an intraabdominal infection in one patient (1.1%). There was a low frequency of drug-related clinical or laboratory adverse effects in both groups. Our study demonstrated that, in patients with localized community-acquired intraabdominal infection, a 3-day course of ertapenem had the same clinical and bacteriological efficacy as a standard duration

Definitions, pathophysiology, and epidemiology of acute cholangitis and cholecystitis: Tokyo Guidelines

This article discusses the definitions, pathophysiology, and epidemiology of acute cholangitis and cholecystitis. Acute cholangitis and cholecystitis mostly originate from stones in the bile ducts and gallbladder. Acute cholecystitis also has other causes, such as ischemia; chemicals that enter biliary secretions; motility disorders associated with drugs; infections with microorganisms, protozoa, and parasites; collagen disease; and allergic reactions. Acute acalculous cholecystitis is associated with a recent operation, trauma, burns, multisystem organ failure, and parenteral nutrition. Factors associated with the onset of cholelithiasis include obesity, age, and drugs such as oral contraceptives. The reported mortality of less than 10% for acute cholecystitis gives an impression that it is not a fatal disease, except for the elderly and/or patients with acalculous disease. However, there are reports of high mortality for cholangitis, although the mortality differs greatly depending on the year of the report and the severity of the disease. Even reports published in and after the 1980s indicate high mortality, ranging from 10% to 30% in the patients, with multiorgan failure as a major cause of death. Because many of the reports on acute cholecystitis and cholangitis use different standards, comparisons are difficult. Variations in treatment and risk factors influencing the mortality rates indicate the necessity for standardized diagnostic, treatment, and severity assessment criteria

2013 WSES guidelines for management of intra-abdominal infections

Peer reviewe