Sleep stage and obstructive apneaic epoch classification using single-lead ECG

Background  

Polysomnography (PSG) is used to define physiological sleep and different physiological sleep stages, to assess sleep quality and diagnose many types of sleep disorders such as obstructive sleep apnea. However, PSG requires not only the connection of various sensors and electrodes to the subject but also spending the night in a bed that is different from the subject's own bed. This study is designed to investigate the feasibility of automatic classification of sleep stages and obstructive apneaic epochs using only the features derived from a single-lead electrocardiography (ECG) signal.     

Thermodynamic and structural analysis of interactions between peptide ligands and SEB

Staphylococcal enterotoxin B (SEB) is an exotoxin produced by Staphylococcus aureus and commonly associated with food poisoning. In this study, SEB‐binding peptides were identified by screening a phage displayed peptide library. The binding of peptides to SEB was tested with isothermal titration calorimetry (ITC) and of the five selected peptides, three showed affinity to SEB, with one measured to have the highest affinity constant (10⁵ M^?1). ITC revealed that the interaction of peptide ligands with SEB was driven entropically and the binding was dominated by hydrophobic interactions. Circular dichroism (CD) measurements and molecular dynamics (MD) simulations, together, give a structural insight into the interaction of peptides with SEB. While SEB binding peptides showed random coil structure before binding, after complex formation they had more ordered structures. The peptide with highest affinity to SEB showed stable conformation during MD simulation. Taken together, our approach about thermodynamic and structural characterization of peptide ligands can be used to develop aptamers, with high affinity and selectivity, for biosensor applications. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of Selenium Supplementation on Antioxidant Defense and Glucose Homeostasis in Experimental Diabetes Mellitus

The objective of this study was to investigate the effects of different forms of Se supplementation on the antioxidant defense and glucose homeostasis in experimental diabetes. Sodium selenate (SS) or selenomethionine (SM) were administered (2 μmol Se kg⁻¹ day⁻¹) via orogastric route to streptozotocine (STZ)-induced diabetic rats in addition to basal diet for 12 weeks. Glucose levels in whole blood, glutathione peroxidase (GSH-Px) activity in erythrocytes, Se and fructosamine levels in plasma were evaluated monthly. Plasma Se levels increased significantly in all diabetic groups compared to basal measurements, being more prominent in SM group [p(SM₃/SM₀) = 0.018]. The increase in GSH-Px activities was significant at the end of the second month in SS [p(SS₂/SS₀) = 0.028], whereas at the end of the third month in SM the value was lower [p(SM₃/SM₀) = 0.018] and the unsupplemented diabetic control (DC) groups, p(DC₃/DC₀) = 0.012. Glucose increased significantly only in DC group. Fructosamine increased gradually in all diabetic groups, being significant in DC and SS groups. At the end of the third month, highest fructosamine levels were observed in SS group, which were significantly higher than the SM group [p(SM/SS) = 0.010]. In conclusion, Se augmented the antioxidant defense by increasing GSH-Px activity and this effect was more prominent when Se was supplemented as SM, which exerted positive effects also on glucose homeostasis.     

Screening of antimicrobial,antioxidant, antidiabetic activities,anatomical and morphological properties of Colchicum speciosum Steven (Colchicaceae)

Protoplasma - Colchicum speciosum Steven species is a perennial stemless plant. C. speciosum is a flowering herb native to mountainous regions of northern Turkey, the Caucasus, and northern Iran....     

Citric acid production by a novel autochthonous Candida zeylanoides isolate: optimization of process parameters

Biotechnology Letters - In this study, citric acid (CA) production by autochthonous Candida zeylanoides 7.12 was investigated and optimized. Response surface methodology (RSM) was used for...     

3-Pyridinylboronic Acid Ameliorates Rotenone-Induced Oxidative Stress Through Nrf2 Target Genes in Zebrafish Embryos

Neurochemical Research - Parkinson’s disease (PD) is one of the most common forms of neurodegenerative diseases and research on potential therapeutic agents for PD continues. Rotenone is a...