Recombinant allergens

A great variety of recombinant plant, mite, mold, mammal, and insect allergens have been expressed in heterologous hosts (e.g., Escherichia coli), their cDNA being used as a template. The number of biologically active recombinant allergens available for experimental, diagnostic, and therapeutic purposes is increasing tremendously. Recombinant allergens have proven to be valuable tools to investigate T-cell and B-cell recognition of allergens as well as to study mechanisms of specific IgE regulation. The immunologic equivalence of many relevant recombinant allergens with their natural counterparts has been demonstrated, and the three-dimensional structures of several recombinant allergens have been described recently. As a result of extensive cross-reactivities among the relevant allergens, it appears that the number of epitopes needed for diagnosis and specific immunotherapy is less diverse than originally anticipated and might be soon covered by recombinant molecules. Recombinant allergens have been used for successful in vitro, as well as in vivo, allergy diagnosis, and work is in progress to produce recombinant allergen derivatives with reduced anaphylactic potential to improve current forms of immunotherapy.     

"Approach and avoidance coping responses among older problem and nonproblem drinkers": Clarification.

Reports a clarification in the article by R. H. Moos et al (Psychology and Aging, 1990[Mar], Vol 5[1], 31–40). The authors wish to note that research reported in the article by P. L. Brennan and R. H. Moos (see record 1991-10154-001) was based on the sample used in the research reported by Moos et al and that this information was inadvertently deleted in the Brennan and Moos article. (The following abstract of the article by Moos et al originally appeared in PA, Vol 77:14961.) The Coping Responses Inventory (CRI) was used to study coping among older problem and nonproblem drinkers. The CRI organizes coping efforts according to their focus (approach or avoidance) and method (cognitive or behavioral). Compared with nonproblem drinkers, older problem drinkers were more likely to use cognitive and behavioral avoidance responses to manage life stressors. Problem drinkers who experienced more negative life events and more severe stressors used both more approach and more avoidance coping. Those who had more financial and social resources relied more on approach and less on avoidance coping. Problem drinkers who relied more on avoidance coping tended to have more drinking problems and to report more depression and physical symptoms and less self-confidence. Positive reappraisal was associated with less depression and more self-confidence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Acute Antiallodynic Effect of Tolperisone in Rat Neuropathic Pain and Evaluation of Its Mechanism of Action

Current treatment approaches to manage neuropathic pain have a slow onset and their use is largely hampered by side-effects, thus there is a significant need for finding new medications. Tolperisone, a centrally acting muscle relaxant with a favorable side effect profile, has been reported to affect ion channels, which are targets for current first-line medications in neuropathic pain. Our aim was to explore its antinociceptive potency in rats developing neuropathic pain evoked by partial sciatic nerve ligation and the mechanisms involved. Acute oral tolperisone restores both the decreased paw pressure threshold and the elevated glutamate level in cerebrospinal fluid in neuropathic rats. These effects were comparable to those of pregabalin, a first-line medication in neuropathy. Tolperisone also inhibits release of glutamate from rat brain synaptosomes primarily by blockade of voltage-dependent sodium channels, although inhibition of calcium channels may also be involved at higher concentrations. However, pregabalin fails to affect glutamate release under our present conditions, indicating a different mechanism of action. These results lay the foundation of the avenue for repurposing tolperisone as an analgesic drug to relieve neuropathic pain.     

Isobutylene polymerization in the presence of t-BuCl/SnCl4

Summary The effect of tert-butyl chloride in the polymerizations of isobutylene carried out in the presence of SnCl₄ in dichloromethane at temperatures-20°C and-78°C was investigated. Synthesized polyisobutylene samples showed a bimodal molecular weight distribution (MWD) and it was found that the weight content of the lowermolecular weight (LMW) fraction increased with increasing t-BuCl concentration in the polymerization mixture. The effect of ageing of the initiation mixture t-BuCl/SnCl₄ in CH₂Cl₂ prepared in advance on MWD of the PIB samples was also studied. Ageing of the initiation system supports the formation of the LMW fraction and this oily PIB is the only product of the polymerization at-20°C, .     

Preparation of aqueous polyaniline dispersions by micellar‐aided polymerization

Polyaniline (PAn) dispersed in water was prepared with sodium dodecylsulfonate (SDS) as a surfactant with varying concentrations of aniline and HCl and molar ratios of SDS/aniline. The PAn dispersion was homogeneous and stable, and its pH value could be adjusted. The conductivity of PAn powder, precipitated from this dispersion, was as high as 20 S/cm. The transmission electron microscopy morphology of PAn assembled in the dispersion was particle‐like, fiber‐like, or coil‐like, depending on the initial concentration of SDS and aniline. The polymerization of aniline was accelerated by SDS, which was confirmed by open‐circuit potential measurement during the polymerization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1550–1555, 2003     

Thermal and mechanical properties of polyisobutylene‐based thermoplastic polyurethanes

We investigated thermal and mechanical properties of thermoplastic polyurethanes (TPUs) with the soft segment comprising of both polyisobutylene (PIB) and poly(tetramethylene)oxide (PTMO) diols. Thermal analysis reveals that the hard segment in all the TPUs investigated is completely amorphous. Significant mixing between the hard and soft segments was also observed. By adjusting the ratio between the hard and soft segments, the mechanical properties of these TPUs were tuned over a wide range, which are comparable to conventional polyether‐based TPUs. Constant stress creep and cyclic stress hysteresis analysis suggested a strong dependence of permanent deformation on hard segment content. The melt viscosity correlation with shear rate and shear stress follows a typical non‐Newtonian behavior, showing decrease in shear viscosity with increase in shear rate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 891‐897, 2013     

Visualizing biochemical activities in living cells through chemistry

The development of molecular probes to visualize cellular processes is an important challenge in chemical biology. One possibility to create such cellular indicators is based on the selective labeling of proteins with synthetic probes in living cells. Over the last years, our laboratory has developed different labeling approaches for monitoring protein activity and for localizing synthetic probes inside living cells. In this article, we review two of these labeling approaches, the SNAP-tag and CLIP-tag technologies, and their use for studying cellular processes.     

Binary [Cu2O/MWCNT] and ternary [Cu2O/ZnO/MWCNT] nanocomposites: formation, characterization and catalytic performance in partial ethanol oxidation

Cuprous oxide agglomerates composed of 4-10 nm Cu2O nanoparticles were deposited on multiwalled carbon nanotubes (MWCNTs) and on ZnO/MWCNTs to give binary [Cu2O/MWCNT] and ternary [Cu2O/ZnO/MWCNT] composites. Di-aqua-bis[2-(methoxyimino)propanoato]copper Cu[O2CCCH3NOMe](2)·2H2O 1 in DMF was used as single source precursor for the deposition of nanoscaled Cu2O. The precursor decomposes either in air or under argon to yield CuO2 by in situ redox reaction. Thermogravimetric coupled mass spectroscopic analysis (TG-MS) of 1 revealed that methanol formed during the decomposition of 1 acts as a potential in situ reducing agent. Scanning electron microscopy (SEM) of the binary [Cu2O/MWCNT] nano-composite shows an increase of cuprous oxide loading depending on the precursor amount, along the periphery of the MWCNTs as well as formation of larger particle agglomerates. Transmission electron microscopy (TEM) of the sample shows crystalline domains of size 4-10 nm surrounded by an amorphous region within the larger particles. SEM and TEM of ternary [Cu2O/ZnO/MWCNT] clearly reveal that Cu2O nanoparticles are primarily deposited on ZnO rather than on MWCNTs. The catalytic activities of the [Cu2O/MWCNT] and [Cu2O/ZnO/MWCNT] binary and ternary composites were studied for the selective partial oxidation of ethanol to acetaldehyde with molecular oxygen. While using binary [Cu2O/MWCNT] (13.8 wt% Cu) as catalyst, acetaldehyde was obtained with a yield of 87% at 355 °C (selectivity 96% and conversion 91%). When nanoscale ZnO is present, the resulting [Cu2O/ZnO/MWCNT] composite shows preferential hydrogen and CO2 formation due to the fact that the dehydrogenation and total oxidation pathway is more favoured compared to the binary composite. Significant morphological changes of the catalyst during the catalytic process were observed.     

Micro RNA-124a Regulates Lipolysis via Adipose Triglyceride Lipase and Comparative Gene Identification 58

Lipolysis is the biochemical pathway responsible for the catabolism of cellular triacylglycerol (TG). Lipolytic TG breakdown is a central metabolic process leading to the generation of free fatty acids (FA) and glycerol, thereby regulating lipid, as well as energy homeostasis. The precise tuning of lipolysis is imperative to prevent lipotoxicity, obesity, diabetes and other related metabolic disorders. Here, we present our finding that miR-124a attenuates RNA and protein expression of the major TG hydrolase, adipose triglyceride lipase (ATGL/PNPLA2) and its co-activator comparative gene identification 58 (CGI-58/ABHD5). Ectopic expression of miR-124a in adipocytes leads to reduced lipolysis and increased cellular TG accumulation. This phenotype, however, can be rescued by overexpression of truncated Atgl lacking its 3''UTR, which harbors the identified miR-124a target site. In addition, we observe a strong negative correlation between miR-124a and Atgl expression in various murine tissues. Moreover, miR-124a regulates the expression of Atgl and Cgi-58 in murine white adipose tissue during fasting as well as the expression of Atgl in murine liver, during fasting and re-feeding. Together, these results point to an instrumental role of miR-124a in the regulation of TG catabolism. Therefore, we suggest that miR-124a may be involved in the regulation of several cellular and organismal metabolic parameters, including lipid storage and plasma FA concentration.