Oxidative toxicity in diabetes and Alzheimer’s disease: mechanisms behind ROS/ RNS generation

Reactive oxidative species (ROS) toxicity remains an undisputed cause and link between Alzheimer’s disease (AD) and Type-2 Diabetes Mellitus (T2DM). Patients with both AD and T2DM have damaged, oxidized DNA, RNA, protein and lipid products that can be used as possible disease progression markers. Although the oxidative stress has been anticipated as a main cause in promoting both AD and T2DM, multiple pathways could be involved in ROS production. The focus of this review is to summarize the mechanisms involved in ROS production and their possible association with AD and T2DM pathogenesis and progression. We have also highlighted the role of current treatments that can be linked with reduced oxidative stress and damage in AD and T2DM.     

The non-equivalence of binding sites of coenzyme quinone and rotenone in mitochondrial NADH-CoQ reductase

The fluorescent probe erythrosine 5′-iodoacetamide (ER) binds to mitochondrial NADH-CoQ reductase (Complex-I) accompanied by an enhancement of the fluorescence intensity. The binding of the CoQ analogue, 2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone (DB), decreased the fluorescence intensity of the ER:Complex-I system. The ‘site 1’ inhibitor rotenone did not decrease the fluorescence intensity showing the non-identical nature of the binding sites of DB and rotenone. Also, the reduced form of DB did not decrease the fluorescence intensity. The decrease of the fluorescence intensity by DB was shown to be due to the removal of bound ER by DB. The rapid kinetics of ER binding was studied by temperature-jump relaxation. While DB caused complete elimination of the relaxation process in the ER:Complex-I system, rotenone caused only a decrease in the relaxation rate, suggesting conformational change. The relaxation rate showed a pH dependence with a maximum around pH 7.5.     

Two different protein kinase activities phosphorylate Ras2 protein in Saccharomyces cerevisiae

In this report, we show that Ras2 protein in the yeast Saccharomyces cerevisiae is phosphorylated in vivo by protein kinase(s) and the phosphorylation is stable. Ras2 protein is phosphorylated by cAMP dependent protein kinase and by an additional protein kinase activity which is independent of cAMP levels.     

Antimicrobial and antioxidant properties of novel synthesized nanocomposites based on polystyrene packaging material waste

This work aims at preparation and characterization of novel synthesized nanocomposites based on polystyrene (Psty) packaging material waste. Moreover, the antimicrobial and antioxidant properties were examined and evaluated. The Psty was grafted with two different monomers such as acrylic and maleic acids (AAc and MAc, respectively) in presence of montmorillonite (MMT) using potassium persulfate as initiator under nitrogen atmosphere. The prepared nanocomposites were characterized using Fourier transform infrared spectroscopy (FT-IR), transmission (TEM) and scanning electron microscopes (SEM). Moreover, the antimicrobial activity was evaluated using agar disc diffusion method against gram negative bacteria such as: Klebsiella pneumonia, and Escherichia coli and gram positive bacterium (Sarcina lutea); in addition to the yeast fungus (Candida albicans). Furthermore, the radical scavenging ability of the prepared nanocomposites has been examined using the DPPH assay.     

Outline of the arcuate nucleus in the human medulla oblongata.

The outline of the arcuate nucleus in the human medulla oblongata was studied in a series of serial sections of brain stems of newborn and young children. The nucleus lies on the ventral aspect of the pyramid. At higher levels the nucleus lies on the ventral and medial aspect of the pyramid. In the upper regions of the medulla the two nuclei fuse together, giving rise to a median dorsal extension, which in the uppermost part of the medulla extends to the floor of the fourth ventricle. The nucleus sends numerous branches to the corticospinal portion of the pyramidal tract, while the dorsal extension of the arcuate nucleus sends numerous transverse rays on either side which consist of nerve fibres and cells. These rays extend in the areas of the medulla occupied by the medial lemniscus, tectospinal portion, and medial longitudinal bundle. The significance of the findings is discussed.