A proteomic approach to investigate AuNPs effects in Balb/3T3 cells

Although gold nanoparticles (AuNPs) are currently used in several industrial products and biomedical applications, information about their biological effects is very limited. Thus, it is becoming crucial to assess their safety and adequately investigate the complexity of cell–nanoparticles interactions. In this work, the Balb/3T3 mouse fibroblast cell line was selected as an in vitro model to study the effects of AuNPs. Alteration of cellular processes and biochemical pathways caused by AuNPs exposure was investigated by analysing the differentially expressed proteome. Of interest was the difference observed in the protein pattern expression of cells exposed to AuNPs. It was found that 88 and 83 proteins were de-regulated after exposure to 5 and 15 nm AuNPs, respectively. Analysis of the proteome revealed that AuNPs triggers several pathways related to cellular growth and proliferation, cell morphology, cell cycle regulation, cellular function and maintenance, oxidative stress, and inflammatory response. Moreover, SPR analysis showed an increase of ECM proteins biosynthesis in cells exposed to AuNPs. We observed by TEM analysis that NPs are internalized and confined mainly in autophagosomes. Endoplasmic reticulum stressed and modification at mitochondrial level occurred. This study aims to improve existing knowledge necessary for a correct assessment of the balance between AuNPs potential adverse and beneficial effects and might have important implications for biomedical applications (e.g. nanomedicine).     

Nanoporous gold particles modified titanium electrode for hydrazine oxidation

A nanoporous gold particles modified titanium electrode (Au/Ti) was prepared by using a hydrothermal method. Gold nanoparticles were stably immobilized on the Ti surface from a mixture of aqueous HAuCl₄/polyethylene glycol (PEG) to form a nanoporous network texture. Electrocatalytic activity of the Au/Ti towards hydrazine oxidation in 1 M NaOH solution was assessed utilizing cyclic voltammetry (CV), linear scanning voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). At the Au/Ti electrode, hydrazine oxidation in 1 M NaOH took place at a potential of −0.55 V (vs. Ag, AgCl) which was 0.53 V less than polycrystalline Au electrode. The Au/Ti electrode also presented much larger current density of hydrazine oxidation than Au electrode. Cyclic voltammetric responses of the Au/Ti electrode showed an irreversible electro-oxidation process of hydrazine. Linear plots of the reduction peak current density from the CVs of the Au/Ti vs. hydrazine concentration provided a potential detection of low concentration hydrazine. The kinetic parameters such as the number of electrons transferred in rate-determining step and total numbers of electrons involved in the hydrazine oxidation were determined using CVs and LSVs. CVs at the Au/Ti electrode also illustrated (relatively) weak interactions of hydrazine with electrode surface at all stages of the hydrazine oxidation process. Further, EIS data showed significantly high electrocatalytic activity of the Au/Ti electrode for hydrazine oxidation in alkaline solutions.     

Usefulness of intravenous propranolol in predicting left anterior descending blood flow during anterior myocardial infarction

The effect of propranolol on precordial ST-segment elevation was studied in 24 patients with acute anterior myocardial infarction. The electrocardiographic response to the drug was correlated with the early angiographic appearance of the left anterior descending coronary artery (LAD). After a 30-minute observation period, intravenous propranolol (average dose 3.5 +/- 2.2 mg) was given a mean of 2.8 +/- 1.9 hours after the onset of persistent chest pain. Coronary angiography was performed 3.6 +/- 2.0 hours after the onset of symptoms. Patients were classified into 2 groups according to the angiographic findings. Group A consisted of 7 patients with a stenotic but patent LAD and 1 patient with excellent collateral blood flow to that area. Group B consisted of 16 patients with a completely occluded LAD and poor or absent collateral blood flow. Patients in group A showed a mean reduction in precordial ST-segment elevation of 77 +/- 18% and patients in group B showed a mean reduction of 13 +/- 14% (p less than 0.005). Left ventricular ejection fraction at discharge was 0.6 +/- 0.07 in group A and 0.37 +/- 0.08 in group B (p less than 0.001). Thus, the electrocardiographic response to intravenous propranolol given early in the course of acute anterior myocardial infarction predicts the presence of blood flow to the infarcting zone. The combination of residual blood flow and reduction of ST-segment elevation secondary to propranolol is associated with preservation of ventricular function.     

In vitro investigations on retention force behavior of conventional and modern double crown systems

ObjectiveThis study aimed to investigate the effects of long-term use on the retention force and wear behavior of double crown systems.MethodsBased on a common double crown design sixty pairs of telescopic crowns were fabricated and divided into six groups, each consisting ten samples: “Gold standard” cast gold alloy primary and secondary crown (GG) and cast non-precious alloy (NN), computer-aided design (CAD)/computer-aided manufacturing (CAM)-milled zirconia primary crown and galvanoformed secondary crown (ZG), CAD/CAM-milled non-precious alloy primary and secondary crown (CC NN), CAD/CAM-milled zirconia primary crown and non-precious alloy secondary crown (CC ZN) and CAD/CAM-milled zirconia primary crown and polyetheretherketone (PEEK) secondary crown (CC ZP). In the constant presence of artificial saliva, all samples were subjected to 10,000 joining-separation cycles at a velocity of 120 mm/min. Wear was analyzed by reflected light microscopy and confocal microscopy before and after artificial aging.ResultsRetention force losses were observed in each group after long-term use, with significant losses in the groups ZG and CC ZP (p_ZG = 0.01, p_{CC ZP} = 0.049). During artificial aging, no significant differences in pull-off force were recorded for groups GG, NN and CC ZN. Regarding wear, merely the Y-TZP primary crowns of the CC ZP group displayed no surface changes.SignificanceAll tested production methods and material combinations seem to be suitable for clinical practice. CAD/CAM technology allows similarly predictable results to be achieved as the gold standard. Confocal microscopy is recommended for surface examinations of double crowns.     

护理学基础理论课混合式“金课”的建设

目的探讨护理学基础理论课程混合式“金课”教学模式及实施效果。方法便利抽取2017级护理本科生(211名)为试验组,在护理学基础理论教学中采用混合式“金课”教学模式,依据“金课”标准从教学前期设计、创设教学情境、开展混合教学活动、课程考核评价进行教学改革,其中混合式教学包括课前自学、课堂互动和课后巩固;2016级护理本科生(238名)为对照组,进行课堂理论教学。课程结束后评价试验组学生线上学习完成情况及比较两组课程成绩、学生自主学习能力及教学满意度。结果试验组的课程平台点击率超过10万次,学生学习任务的完成率超过95%,试验组的期末考试成绩、自主学习能力总分和各维度得分、教学满意度均高于对照组(P<0.001),89.10%学生对课程教学满意。结论混合式“金课”教学在护理学基础理论教学中取得了较好成效。教师应以“金课”为标准进行课程改革,对课前、课中、课后进行全方位课程建设,打造有高阶性、创新性、挑战度的“金课”。     

Effects of Phonophoresis and Gold Nanoparticles in Experimental Model of Muscle Overuse: Role of Oxidative Stress

The aim of the study described here was to investigate the effects of pulsed ultrasound and gold nanoparticles (AuNPs) on behavioral, inflammatory and oxidative stress parameters in an experimental model of overuse. Wistar rats performed 21 d of exercise on a treadmill at different intensities and were exposed to ultrasound in the presence or absence of AuNPs. The overuse model promoted behavioral changes and increased creatine kinase, superoxide dismutase and glutathione peroxidase activity, as well as the levels of superoxide, nitrotyrosine, nitric oxide, thiobarbituric acid reactive substance, carbonyl, tumor necrosis factor α and interleukin-6. These values were significantly decreased by AuNPs and by AuNPs plus ultrasound. Catalase activity remained unchanged and the glutathione level increased significantly after exposure to AuNPs plus ultrasound. These results suggest a susceptibility to anxiety as well as elevated levels of oxidative stress. However, therapeutic interventions with AuNPs plus ultrasound reduced the production of oxidants and oxidative damage and improved the anti-oxidant defense system.     

Have traditional DMARDs had their day?

This review tries to answer the question of whether in the face of the recently introduced biologics conventional disease-modifying antirheumatic drugs (DMARDs) can still be recommended in the treatment of rheumatoid arthritis (RA). We start with an overview of the oldest conventional DMARD, injectable gold (Au), which was introduced in the treatment of RA in the 1920s. The effect of gold is directed at a number of different sites of the immune system. A significant improvement of clinical and biochemical disease activity parameters as well as an inhibition of X-ray progression has been shown in many studies. Head-to-head comparisons between gold and high-dose methotrexate (MTX) demonstrated no significant difference but some advantages for gold. Since trials comparing biologics with gold will never be performed, an indirect comparison was done by analyzing the results of trials with gold with those with biologics. Conclusions from such comparisons have to be drawn with caution especially since the methodology for performing trials has changed with time. We selected four trials with gold (two open, one placebo-controlled, and one comparison with MTX) and five trials with biologics (three placebo-controlled, one dose escalation study, and one comparison with MTX). In all these trials baseline data regarding swollen joint count (SJC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were roughly comparable and, with the exception of interleukin (IL)-1 RA, demonstrated a similar improvement of over 50% already after 6 months [with faster onset with tumor necrosis factor (TNF)-alpha blockade]. American College of Rheumatology (ACR) response data were not available for the older gold trials. European League Against Rheumatism (EULAR) response criteria could be calculated for the Au/MTX trial and were—for these compounds—only slightly inferior to the results with adalimumab. X-ray response is especially difficult to compare across studies. Although an inhibition with Au and MTX could be demonstrated, this occurred—similar to corticosteroid treatment—earlier and more pronounced with TNF-alpha blockers. We confirm the statement of Weinblatt that the most modern DMARDs do not appear to be much better than the oldest one indicating that conventional DMARDs are not outdated. Therefore, a sufficient trial of conventional DMARDs should precede the introduction of treatment with the very expensive biologics.