Mechanisms and treatment of ischaemic stroke: insights from genetic associations

The precise pathophysiology of ischaemic stroke is unclear, and a greater understanding of the different mechanisms that underlie large-artery, cardioembolic and lacunar ischaemic stroke subtypes would enable the development of more-effective, subtype-specific therapies. Genome-wide association studies (GWASs) are identifying novel genetic variants that associate with the risk of stroke. These associations provide insight into the pathophysiological mechanisms, and present opportunities for novel therapeutic approaches. In this Review, we summarize the genetic variants that have been linked to ischaemic stroke in GWASs to date and discuss the implications of these associations for both our understanding and treatment of ischaemic stroke. The majority of genetic variants identified are associated with specific subtypes of ischaemic stroke, implying that these subtypes have distinct genetic architectures and pathophysiological mechanisms. The findings from the GWASs highlight the need to consider whether therapies should be subtype-specific. Further GWASs that include large cohorts are likely to provide further insights, and emerging technologies will complement and build on the GWAS findings

Selective cytotoxicity of green synthesized silver nanoparticles against the MCF-7 tumor cell line and their enhanced antioxidant and antimicrobial properties

Sadegh Khorrami,1 Ali Zarrabi,1 Moj Khaleghi,2 Marziyeh Danaei,3 MR Mozafari3 1Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan, Iran; 2Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran; 3Australasian Nanoscience and Nanotechnology Initiative, Monash University, Clayton, VIC, Australia Introduction: Silver nanoparticles (AgNPs) are of great interest due to their unique and controllable characteristics. Different synthesis methods have been proposed to produce these nanoparticles, which often require elevated temperatures/pressures or toxic solvents. Thus, green synthesis could be a replacement option as a simple, economically viable and environmentally friendly alternative approach for the synthesis of silver nanoparticles.Methods: Here, the potential of the walnut green husk was investigated in the production of silver nanoparticles. An aqueous solution extracted from walnut green husk was used as a reducing agent as well as a stabilizing agent. Then, the synthesized nanoparticles were characterized with respect of their anticancer, antioxidant, and antimicrobial properties. Results: Results showed that the synthesized nanoparticles possessed an average size of 31.4 nm with a Zeta potential of -33.8 mV, indicating high stability. A significant improvement in the cytotoxicity and antioxidant characteristics of the green synthesized Ag nanoparticles against a cancerous cell line was observed in comparison with the walnut green husk extract and a commercial silver nanoparticle (CSN). This could be due to a synergistic effect of the synthesized silver nanoparticles and their biological coating. AgNPs and the extract exhibited 70% and 40% cytotoxicity against MCF-7 cancerous cells, respectively, while CSN caused 56% cell death (at the concentration of 60 µg/mL). It was observed that AgNPs were much less cytotoxic when tested against a noncancerous cell line (L-929) in comparison with the control material (CSN). The free radical scavenging analysis demonstrated profound anti-oxidant activity for the synthesized nanoparticles in comparison with the extract and CSN. It was also detected that the synthesized AgNPs possess antibacterial activity against nosocomial and standard strains of both Gram-positive and Gram-negative bacteria (minimum inhibitory concentration =5–30 µg/mL). Conclusion: These findings imply that the synthesized nanoparticles using green nanotechnology could be an ideal strategy to combat cancer and infectious diseases. Keywords: green synthesis, silver nanoparticles, antimicrobial agent, antioxidant agent, anticancer agent, selective cytotoxicit

C in the presence of vitamin B-9 in food and pharmaceutical samples

Synthesis and application of NiO-multiwall carbon nanotube nanocomposite (NiO/MWCNTs) and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) in the carbon paste matrix as high sensitive sensors for voltammetric determination of vitamin C have been reported. The oxidation peak potential of vitamin C at the surface of the ([Bmim]BF4) NiO/MWCNT carbon paste electrode (NiO/MWCNTs/([Bmim]BF4/CPE) appeared at 440 mV, which was about 200 mV lower than the oxidation peak potential at the surface of the simple carbon paste electrode under a similar condition. Also, the oxidation peak current was increased for about 3.7 times at the surface of NiO/MWCNTs/([Bmim]BF4/CPE compared to carbon paste electrode. At an Optimum,condition (pH 7.0), the two peaks are separated ca. 0.44 and 0.85 V for vitamin C and vitamin B-9. This point shows that vitamin C can be determined in the presence of vitamin B-9. The linear response range and detection limit were found to be 0.1-1000 mu M and 0.06 mu M, respectively. The proposed sensor was successfully applied, for the determination of vitamin C in food and drug samples. (C) 2016 Elsevier B.V. All rights reserved