Simple method for determining human serum 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity - possible application in clinical studies on dietary antioxidants.

BACKGROUND: 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) radical decomposition in alcohol solution is widely used, characterizing plant antioxidants that can rise in serum after fruit and vegetable intake. However, this test failed reproducible results with serum due to protein precipitation. We describe the application of serum deproteinization with acetonitrile relating to the DPPH test. METHODS: Assay sensitivity, linearity, repeatability and storage effect were determined in serum samples deproteinized with an equal volume of acetonitrile. Associations between the DPPH test and the ferric reducing ability of serum (FRAP) method, measuring total antioxidant potential, were evaluated in sera from 78 healthy non-smoking men. The effect of a single ingestion of 1 L of cloudy apple juice on the serum DPPH radical scavenging activity in healthy volunteers was also investigated. RESULTS: Assay linearity was within 5-25 microL (r=0.99, p<0.01). With 25 microL-deproteinized serum, coefficient of variation was 4.2% and detection limit was 0.5% of the initial amount of decomposed DPPH radical over 30 min incubation. There was no sera activity decrease over 14 days storage at -20 degrees C. Mean values of DPPH radical scavenging activity and FRAP obtained in human serum were 11.2+/-3.3% and 382.0+/-88.1 micromol/L, respectively. A positive significant linear correlation was observed between these two methods (r=0.42, p<0.01). Serum supplementation with 50 micromol/L of catechin, gallic acid, ascorbic acid or uric acid enhanced DPPH test results. One brisk serving of 1 L of apple juice caused a significant increment of serum DPPH radical scavenging activity (1.9+/-1.9%, p<0.01) in 12 healthy subjects 1 h after juice ingestion. CONCLUSIONS: Applicability of the DPPH test to deproteinized serum with acetonitrile revealed numerous advantages, validating its practicability, simplicity and cost effectiveness as a tool in the estimation of antioxidant status in humans.     

Triple-site biventricular pacing in patients undergoing cardiac resynchronization therapy: a feasibility study.

AIMS: To evaluate implantation safety and efficiency of triple-site (double left-single right) cardiac resynchronization therapy (CRT) and to assess the outcome of this procedure. METHODS AND RESULTS: Twenty-six patients with New York Heart Association (NYHA) class III-IV, left ventricular ejection fraction (EF) < or = 35%, and QRS > or = 120 ms underwent triple-site CRT. Procedural course and complications were analysed. NYHA class, QRS duration, echocardiographic parameters, peak oxygen consumption (VO(2)max), and 6 min walking distance (6MWD) were assessed at baseline and after 3 months. Responders were defined by survival, by no re-hospitalization for heart failure, and by >10% EF, VO(2)max, and 6MWD increase. Implantation was successful in 22 patients (84.6%). Procedure duration (199.1 min) and fluoroscopy time (38.7 min) were higher than in standard procedures. Two clinically silent coronary sinus dissections occurred intra-operatively; one phrenic nerve stimulation and one pocket infection were observed during follow-up. After 3 months of CRT, a significant reduction (P < 0.05) of NYHA class, increment of VO(2)max, 6MWD, EF, and improvement of indices of dyssynchrony were observed. Response rate in the studied group was 95.4%. CONCLUSION: Triple-site resynchronization appears to be a safe and efficient treatment method, with high response rate. Further studies are needed to evaluate the role of this pacing mode in CRT.     

Tissue factor and its inhibitor in human non-crescentic glomerulonephritis--immunostaining vs plasma and urinary levels.

BACKGROUND: Tissue factor (TF)-the most potent trigger of coagulation and emerging antiapoptotic, proliferative and angiogenic factor, along with its principal inhibitor (tissue factor pathway inhibitor, TFPI) are known to be involved in crescentic glomerulonephritis (GN). We studied the relationship between plasma and urinary levels as well as renal biopsy immunostaining of TF and TFPI antigens with reference to some clinical parameters in human chronic non-crescentic GN. METHODS: We examined plasma and urinary levels of TF and total TFPI (pre-biopsy, ELISA) and the intensity of TF, TFPI 1 and TFPI 2 staining (immunoperoxidase histochemistry) in kidney biopsy specimens from 30 chronic GN patients. RESULTS: Plasma and urinary TF (uTF) were higher in patients than in 18 healthy individuals. In normal kidneys, TF and TFPI 1/2 antigens were undetectable in glomeruli while a distinct staining of both TFPI variants was observed in tubules and interstitial microvessels. In diseased kidneys, TF was strongly expressed in glomeruli but was undetectable in tubules. In contrast, staining for TFPI 1/2 was observed in glomeruli and tubules. Neither plasma nor urinary levels of the markers correlated with the intensity of TF and TFPI 1/2 staining in biopsy specimens. uTF was significantly associated with creatinine clearance (R = 0.489, P = 0.006) and urinary TFPI (R = 0.554, P = 0.014), and tended to be lower in proliferative vs non-proliferative GN [83 (0-617) vs 281 (10-805) pg/ml; P = 0.06]. CONCLUSION: The intrarenal TF/TFPI system is profoundly disturbed in chronic GN. Plasma and urinary concentrations of TF and TFPI probably do not reflect genuine activity of the disease, likely due to a confounding effect of kidney insufficiency. uTF measurement seems to be helpful in initial identification of proliferative GN, yet further studies are required to validate its use as a marker of glomerular injury in chronic GN.     

Application of an Adsorption Process on Selected Materials,Including Waste,as a Barrier to the Pesticide Penetration into the Environment

The article presents research on using the adsorption process of aldrin (a chloro-organic pesticide that most often occurs in the environment near expired pesticide burials). The research used three sorbents: two activated carbons and compost from sewage sludge as a low-cost sorbent. Obtained adsorption isotherms belong to the L group according to the Giles classification. The test results and their analysis confirm that the IZO application facilitates the analysis of the adsorption process. The study results also confirm that compost can be a cost-effective alternative to commercial activated carbons to build barriers protecting the environment against existing leaking expired pesticide burials.     

A Novel Manufacturing Concept of LCP Fiber-Reinforced GPET-Based Sandwich Structures with an FDM 3D-Printed Core

The presented research was focused on the development of a new method of sandwich structure manufacturing involving FDM-printing (fused deposition modeling) techniques and compression molding. The presented concept allows for the preparation of thermoplastic-based composites with enhanced mechanical properties. The sample preparation process consists of 3D printing the sandwich’s core structure using the FDM method. For comparison purposes, we used two types of GPET (copolymer of polyethylene terephthalate)-based filaments, pure resin, and carbon fiber (CF)-reinforced filaments. The outer reinforcing layer “skins” of the sandwich structure were prepared from the compression molded prepregs made from the LCP (liquid-crystal polymer)-fiber fabric with the GPET-based matrix. The final product consisting of an FDM-printed core and LCP-based prepreg was prepared using the compression molding method. The prepared samples were subjected to detailed materials analyses, including thermal analyses (thermogravimetry-TGA, differencial scanning calorimetry-DSC, and dynamic thermal-mechanical analysis-DMTA) and mechanical tests (tensile, flexural, and impact). As indicated by the static test results, the modulus and strength of the prepared composites were slightly improved; however, the stiffness of the prepared materials was more related to the presence of the CF-reinforced filament than the presence of the composite prepreg. The main advantage of using the developed method is revealed during impact tests. Due to the presence of long LCP fibers, the prepared sandwich samples are characterized by very high impact resistance. The impact strength increased from 1.7 kJ/m² for pure GPET samples to 50.4 kJ/m² for sandwich composites. For GPET/CF samples, the increase is even greater. The advantages of the developed solution were illustrated during puncture tests in which none of the sandwich samples were pierced.     

The Use of Nanoscale Montmorillonite (MMT) as Reinforcement for Polylactide Acid (PLA) Prepared by Fused Deposition Modeling (FDM)—Comparative Study with Biocarbon and Talc Fillers

The subject of the presented research focuses on a comparative assessment of three types of polymer fillers used to modify highly crystalline poly(lactic acid) PLA intended for the FDM technique. The aim of the presented work was to determine the performance of the developed materials. The key aspect of the work was the use of polymer fillers of three different types. Nano-sized montmorillonite (MMT), biobased biocarbon (BC) and mineral talc. The several types of composites were prepared using extrusion technique. The maximum content for BC and talc filler was limited to 20 wt%, while for MMT it was 5 wt%. Prepared samples were subjected to detailed material analysis including mechanical tests (tensile, flexural, Charpy), thermal analysis (DSC, DMTA), HDT/Vicat tests and structure analysis. The results of the test confirmed that even relatively small amount of nano-type filler can be more efficient than micrometric particles. The used type of matrix was highly crystalline PLA, which resulted in a significant nucleation effect of the crystalline structure. However, thermomechanical tests revealed no improvement in thermal resistance. Microscopic survey confirmed that for MMT and talc filler the structure anisotropy was leading to more favorable properties, especially when compared to structures based on spherical BC particles.     

Adherence to antiplatelet treatment with P2Y12 receptor inhibitors. Is there anything we can do to improve it? A systematic review of randomized trials

Antiplatelet therapy is the cornerstone of treatment for patients with acute coronary syndromes (ACS) and/or undergoing percutaneous coronary interventions. Non-adherence to medication after ACS may lead to increased morbidity, mortality, and costs to the healthcare system due to elevated risk of stent thrombosis, myocardial infarction or death. Medication adherence is an issue of growing concern regarding the improvement of health system performance. Promoting medication adherence offers a rare opportunity to simultaneously improve health outcomes while reducing costs of treatment in patients with coronary artery disease (CAD). The aim of this systematic review was to critically discuss adherence to antiplatelet treatment with P2Y12 receptor inhibitors in CAD patients. After a systematic investigation of the literature in databases including PubMed, CENTRAL and Google Scholar, using appropriate keywords, and considering clinical randomized, prospective observational and retrospective studies, reporting on adherence to treatment with inhibitors of P2Y12 platelet receptors or educational interventions aimed to improve medication adherence in patients with CAD, seven articles were considered eligible for inclusion in this systematic review. Reported adherence to clopidogrel, despite catastrophic consequences of its premature discontinuation, is low. We identified several determinants of low adherence and early discontinuation of clopidogrel. We also present data on the usefulness, utilization and credibility of different methods of medication adherence assessment, and suggest and critically discuss available interventions aimed at improvement of adherence to clopidogrel, still showing the need for innovative approaches to achieve enhanced medication adherence and improve health outcomes after acute myocardial infarction.     

Rigid Polyurethane Foams Modified with Biochar

This paper presents results of research on the preparation of biochar-modified rigid polyurethane foams that could be successfully used as thermal insulation materials. The biochar was introduced into polyurethane systems in an amount of up to 20 wt.%. As a result, foam cells became elongated in the direction of foam growth and their cross-sectional areas decreased. The filler-containing systems exhibited a reduction in their apparent densities of up to 20% compared to the unfilled system while maintaining a thermal conductivity of 25 mW/m·K. Biochar in rigid polyurethane foams improved their dimensional and thermal stability.