Current Opinion in LAIV: A Matter of Parent Virus Choice

Influenza is still a frequent seasonal infection of the upper respiratory tract, which may have deadly consequences, especially for the elderly. This is in spite of the availability of vaccines suggested for persons above 65 years of age. Two types of conventional influenza vaccines are currently licensed for use—live attenuated and inactivated vaccines. Depending on local regulatory requirements, live attenuated vaccines are produced by the reverse genetics technique or by classical reassortment in embryonated chicken eggs. Sometimes, the efficiency of classical reassortment is complicated by certain properties of the wild-type parent virus. Cases of low efficacy of vaccines have been noted, which, among other reasons, may be associated with suboptimal properties of the wild-type parent virus that are not considered when recommendations for influenza vaccine composition are made. Unfortunately, knowledge surrounding the roles of properties of the circulating influenza virus and its impact on the efficacy of the reassortment process, vaccination efficiency, the infectivity of the vaccine candidates, etc., is now scattered in different publications. This review summarizes the main features of the influenza virus that may dramatically affect different aspects of the preparation of egg-derived live attenuated vaccine candidates and their effectiveness. The author expresses her personal view, which may not coincide with the opinion of other experts in the field of influenza vaccines.     

Sperm of Fruit Fly Drosophila melanogaster under Space Flight

Studies of reproductive function under long-term space flight conditions are of interest in planning the exploration of deep space. Motility, including the use of various inhibitors, cellular respiration, and the content of cytoskeletal proteins were studied, assessing the level of expression of the corresponding genes in spermatozoa of Drosophila melanogaster, which were in space flight conditions for 12 days. The experiment was carried out twice on board the Russian Segment of the International Space Station. Sperm motility speed after space flight, and subsequently 16 h after landing, is reduced relative to the control by 20% (p < 0.05). In comparison with the simulation experiment, we showed that this occurs as a result of the action of overloads and readaptation to the Earth’s gravity. At the same time, cellular respiration, the content of proteins of the respiratory chain, and the expression of their genes do not change. We used kinase inhibitor 6-(dimethylamino)purine (6-DMAP) and phosphatase inhibitors; 6-DMAP restored the reduced the speed of spermatozoa in the flight group to that of the control. These results can be useful in developing a strategy for protecting reproductive health during the development of other bodies in the solar system.     

The Functional Characterization of GCaMP3.0 Variants Specifically Targeted to Subcellular Domains

Calcium (Ca²⁺) ions play a pivotal role in physiology and cellular signaling. The intracellular Ca²⁺ concentration ([Ca²⁺]_i) is about three orders of magnitude lower than the extracellular concentration, resulting in a steep transmembrane concentration gradient. Thus, the spatial and the temporal dynamics of [Ca²⁺]_i are ideally suited to modulate Ca²⁺-mediated cellular responses to external signals. A variety of highly sophisticated methods have been developed to gain insight into cellular Ca²⁺ dynamics. In addition to electrophysiological measurements and the application of synthetic dyes that change their fluorescent properties upon interaction with Ca²⁺, the introduction and the ongoing development of genetically encoded Ca²⁺ indicators (GECI) opened a new era to study Ca²⁺-driven processes in living cells and organisms. Here, we have focused on one well-established GECI, i.e., GCaMP3.0. We have systematically modified the protein with sequence motifs, allowing localization of the sensor in the nucleus, in the mitochondrial matrix, at the mitochondrial outer membrane, and at the plasma membrane. The individual variants and a cytosolic version of GCaMP3.0 were overexpressed and purified from E. coli cells to study their biophysical properties in solution. All versions were examined to monitor Ca²⁺ signaling in stably transfected cell lines and in primary cortical neurons transduced with recombinant Adeno-associated viruses (rAAV). In this comparative study, we provide evidence for a robust approach to reliably trace Ca²⁺ signals at the (sub)-cellular level with pronounced temporal resolution.     

Network level bridges maintenance planning using Multi-Attribute Utility Theory

Bridge infrastructure managers are facing multiple challenges to improve the availability and serviceability of ageing infrastructure, while the maintenance planning is constrained by budget restrictions. Many research efforts are ongoing, for the last few decades, ranging from development of bridge management system, decision support tools, optimisation models, life cycle cost analysis, etc. Since transport infrastructures are deeply embedded in society, they are not only subject to technical requirements, but are required to meet the requirements of societal and economic developments. Therefore, bridge maintenance planning should accommodate multiple performance goals which need to be quantified by various performance indicators. In this paper, an application of Multi-Attribute Utility Theory (MAUT) for bridge maintenance planning is illustrated with a case study of bridges from the Netherlands road network. MAUT seeks to optimise multiple objectives by suggesting a trade-off among them and finally assigns a ranking to the considered bridges. Moreover, utility functions of MAUT appropriately account for the involved uncertainty and risk attitude of infrastructure managers. The main contribution of this study is in presenting a proof-of-concept on how MAUT provides a systematic approach to improve the decision-making of maintenance planning by making use of available data, accommodating multiple performance goals, their uncertainty, and preferences of infrastructure managers.     

Cermets surface transformation under erosive and abrasive wear

The subsurface developed in ceramic-metal composites WC-Co, TiC-NiMo and Cr₃C₂-Ni during tribological testing (abrasion, sliding, erosion) under different conditions (impact angle, velocity, pressure, temperature) is the primary concern of the study. Mechanisms responsible for mechanically mixed layer (MML) development and wear resistance of materials are discussed in details. Instrumented indentation combined with consecutive polishing-testing procedure was used for mechanical characterisation. Microstructural features of the worn surface and subsurface region were studied with the help of optical microscope and scanning electron microscope equipped with energy dispersive spectroscopy analyser to evaluate difference between properties of the bulk and modified subsurface layers of materials.Formation of subsurface layer is found to be an essential feature of materials response to applied loading. Modified layer consists of highly deformed binder metal; cracked and decohesed large grains of carbides; embedded and/or fused debris of erosive/abrasive particles; and products of oxidation.     

Phase behavior of gelatin in the presence of pectin in water-acid medium

Summary Phase separation of alkaline gelatin in water-acid solutions in the presence of low etherified pectin (ED 38%) were investigated. The effects of the pectin weight fraction in pectin/gelatin mixture (q_o) as well as two conditions of complex formation, namely, mixing of the binary biopolymer-solvent systems at pH 3.5 (‘mixing conditions’), or preparation of the ternary gelatin-pectin-water systems at pH 7.5 and their subsequent acidification up to pH 3.5 (‘titration conditions’), on phase equilibrium and macrostructure of the concentrated complex phase were established using phase analysis, and optical microscopy. At q_o<0.5 the aggregative phase separation was observed in both conditions of complex formation leading to the almost complete concentration of both biopolymers in the bottom phase at q_o=0.3 (‘mixing conditions’) and at q_o=0.5 (‘titration conditions’). At q_o>0.5 unusual three phase separation took place in the ‘mixing conditions’, leading to formation of supernatant (phase 1), complex coacervate (phase 2) and concentrated pectin solution (phase 3). Possible mechanism of such phenomenon was discussed in term of segregative and aggregative phase separations.     

Highly potent and specific GSK-3beta inhibitors that block tau phosphorylation and decrease alpha-synuclein protein expression in a cellular model of Parkinson's disease

Research by Klein and co-workers suggests that the inhibition of GSK-3beta by small molecules may offer an important strategy in the treatment of a number of central nervous system (CNS) disorders including Alzheimer's disease, Parkinson's disease, and bipolar disorders. Based on results from kinase-screening assays that identified a staurosporine analogue as a modest inhibitor of GSK-3beta, a series of 3-indolyl-4-indazolylmaleimides was prepared for study in both enzymatic and cell-based assays. Most strikingly, whereas we identified ligands having poor to high potency for GSK-3beta inhibition, only ligands with a Ki value of less than 8 nM, namely maleimides 18 and 22, were found to inhibit Tau phosphorylation at a GSK-3beta-specific site (Ser 396/404). Accordingly, maleimides 18 and 22 may protect neuronal cells against cell death by decreasing the level of alpha-Syn protein expression. We conclude that the GSK-3beta inhibitors described herein offer promise in defending cells against MPP+-induced neurotoxicity and that such compounds will be valuable to explore in animal models of Parkinson's disease as well as in other Tau-related neurodegenerative disease states.     

The genesis of polyaniline nanotubes

Aniline has been oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. Protons are produced in the course of oxidation and the pH decreases as the reaction proceeds. The oxidation had two subsequent phases: (1) the oxidation of the neutral aniline molecules and the initially produced low-molecular weight aniline oligomers at low acidity, followed by (2) the oxidation of the anilinium cation after the acidity became higher. The two phases of oxidation gave different products, aniline oligomers with mixed ortho- and para-coupling of aniline molecules, and polyaniline nanotubes, respectively.The aniline oligomers are produced at first at low acidity, pH > 4, some of them as rod-like crystals. The molecular weight of the oligomers has been assessed by gel-permeation chromatography to be of several thousands. The 2-3 wt.% content of sulfur in deprotonated samples suggests that the oxidation products are partly sulfonated. The oxidation of ortho-coupled anilines combined with intramolecular cyclization produces phenazine units or their blocks, as indicated by FTIR spectra. A high-molecular weight polyaniline is produced at pH < 2. The protonation of the intermediate pernigraniline form of polyaniline is a prerequisite for the polymerization.The nano-sized oligomer crystallites serve as starting templates for the nucleation of PANI nanotubes. Further growth of nanotubes proceeds by the self-organization of the phenazine units or their blocks located at the ends of the PANI chains. Polyaniline nanotubes have a typical outer diameter of 100-200 nm, with a wall thickness of 50-100 nm, an inner diameter of 0-100 nm, and a length extending to several micrometres.