GAP-43 mRNA detection by in situ hybridization, direct and indirect in situ RT-PCR in hippocampal and cerebellar tissue sections of adult rat brain

The growth-associated protein GAP-43 is a presynaptic membrane phosphoprotein that is expressed at high levels during development and axonal growth. To evaluate the cellular distribution of GAP-43 mRNA in the hippocampus and cerebellum of adult rats we applied in situ hybridization (ISH) as well as direct and indirect in situ RT-PCR using biotin as a reporter molecule. ISH resulted in a positive signal in most cerebellar granular cells and in 30% of hippocampal CA3 neurons. Direct in situ RT-PCR yielded cells with strong signals in every region investigated, with elevated background levels most likely related to incorporation of labeled nucleotides into non-specific amplicons through internal priming and DNA repair activity. Indirect in situ RT-PCR turned out to be the best approach for detecting GAP-43 mRNA positive cells. Cerebellar cells exhibiting a positive signal for GAP-43 mRNA were of the granular cell type (98%). Hippocampal neurons with a positive reaction for GAP-43 mRNA included all the neuron groups analyzed, namely CA1 (99%) and CA3 pyramidal cells (94%) and dentate gyrus granule cells (92%). Dentate gyrus granule cells have not tested positive for GAP-43 mRNA detection by molecular morphology analysis. These data show that in normal rats GAP-43 mRNA is present in different cell populations of hippocampal formation, supporting the role of this protein in the ongoing processes of synaptic plasticity.     

Syndiotactic polystyrene films with a cocrystalline phase including carvacrol guest molecules

A monoclinic δ‐clathrate form of syndiotactic polystyrene (s‐PS) with carvacrol (a relevant natural phenolic antimicrobial) has been prepared and characterized by X‐ray diffraction. Very informative are Fourier transform infrared spectra, in particular their OH stretching region that shows a narrow peak and a broad band, corresponding to carvacrol molecules being isolated guest of the co‐crystalline phase or dissolved in the amorphous phase, respectively. Analogous spectral features allow discriminating, for many different s‐PS guests, between molecules being in crystalline or in amorphous phases. s‐PS co‐crystalline films with carvacrol molecules being prevailingly (more than 90%) guest of the co‐crystalline phase have been prepared, even for high carvacrol content (up to 10–11 wt %). The location of most antimicrobial molecules in the crystalline phase assures a decrease of desorption diffusivity of two to three orders and hence long‐term antimicrobial release. © 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 657–665     

New Cyclodextrin‐Bearing 8‐Hydroxyquinoline Ligands as Multifunctional Molecules

Recent investigations have rekindled interest in 8‐hydroxyquinolines as therapeutic agents for cancer, Alzheimer’s disease, and other neurodegenerative disorders. Three new β‐cyclodextrin conjugates of 8‐hydroxyquinolines and their copper(II) and zinc(II) complexes have been synthesized and characterized spectroscopically. In addition to improving aqueous solubility, due to the presence of the cyclodextrin moiety, the hybrid systems have interesting characteristics including antioxidant activity, and their copper(II) complexes are efficient superoxide dismutase (SOD) mimics. The ligands and their copper(II) complexes show low cytotoxicity, attributed to the presence of the cyclodextrin moiety. These compounds have potential as therapeutic agents in diseases related both to metal dyshomeostasis and oxidative stress.     

An investigation on the role of 3-hydroxykynurenine in pigment formation by matrix-assisted laser desorption/ionization mass spectrometry

In order to investigate the role of tryptophan and its metabolites in biogenesis of melanins, a study on the enzymatic reaction of 3-hydroxykynurenine with tyrosinase and peroxidase was performed. The reaction at different pH values was monitored by sampling at different times, with ultrafiltration used before analysis by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The data obtained in this way showed that oligomerization processes take place with both enzymes, but with different behaviour, also depending on pH. 3-Hydroxykynurenine in the presence of tyrosinase at pH 6.0 leads to formation of xanthommatin, and at pH 8.0 hydroxanthommatin is formed in the first step of the reaction followed by formation of black-brown pigments. In contrast, the formation of oligomerization products by peroxidase action is observed in high yields under both acidic and basic conditions; however, at pH 6.0, a more extensive oligomerization process is observed. Thus peroxidase is able to activate oligomerization analogous to that observed in the case of tyrosinase without depending on the variation of pH. Due to the early formation of decarboxylated hydroxykynurenine, hydroxanthommatin and decarboxylated hydroxanthommatin, the enzymatic reaction leads to mixed oligomers, which can be considered as precursors of new pathways in pigment production.     

Ligand exchange chiral separations by cyclodextrin derivatives in capillary electrophoresis

A beta-cyclodextrin substituted by an imidazole-bound histamine (CDmh) was successfully used to separate underivatised tryptophan racemate in capillary electrophoresis in the presence of copper(II) ion by the ligand exchange mechanism. To the best of our knowledge, this is the first example of a cyclodextrin derivative behaving as the first coordination sphere ligand in the complex added to the background electrolyte (BGE).     

Luminescent 1,10-Phenanthroline β-Diketonate Europium Complexes with Large Second-Order Nonlinear Optical Properties

Substitution of the diglyme ligand of [Eu(hfa)₃(diglyme)] (where hfa is hexafluoroacetylacetonate) with a simple 1,10-phenanthroline leads to a six-fold increase of the product μβ_EFISH, as measured by the Electric-Field-Induced Second Harmonic generation (EFISH) technique. Similarly, [Eu(tta)₃(1,10-phenanthroline)] (where Htta is 2-thenoyltrifluoroacetone) is characterized by a large second-order NLO response. Both 1,10-phenanthroline europium complexes have great potential as multifunctional materials for photonics.     

Short Synthesis of Cytotoxic 4‐Arylcoumarins

A short synthesis of cytotoxic 4‐arylcoumarins via condensation of phenols with cinnamic acids in the presence of CF₃COOH, followed by dehydrogenation with DDQ, is described.     

Ordered Mesoporous Silica Incorporating Platinum Nanoparticles as Electrode Material for Paracetamol Detection

High ordered mesoporous materials (SBA-15) modified with Al and/or B and Pt nanoparticles (Pt NPs) were used for preparing modified graphite paste electrodes (Pt/M−SBA-15-GPE, where M=Al−, B− or Al−B−) and applied for paracetamol (PA) detection. The electrodes were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Square wave voltammetry (SWV) technique was used to obtain the analytical parameters for PA detection. The acquired values of electrochemical and analytical parameters recommend the mesoporous compound containing Pt NPs to be used as composite electrode material for PA detection in real samples.     

A novel diamine adduct of zinc bis(2-thenoyl-trifluoroacetonate) as a promising precursor for MOCVD of zinc oxide films

A novel diamine (N,N,N',N'-tetramethyletilendiamine) adduct of zinc bis(2-thenoyl-trifluoroacetonate) has been synthesized in a single-step reaction. Single-crystal X-ray diffraction studies of Zn(tta)(2).tmeda provide evidence of a mononuclear structure with a six-coordinated zinc ion. The thermal behavior of this adduct points to mass-transport properties suitable for its application to MOCVD processes. This novel compound has been successfully applied as a precursor for the deposition of ZnO films on (100) Si and quartz substrates. The good quality of the deposited films indicates that the adduct is a very attractive precursor for MOCVD applications.     

Synthesis of New Carnosine Derivatives of β‐Cyclodextrin and Their Hydroxyl Radical Scavenger Ability

Several in vitro and in vivo studies have suggested that carnosine can act as a scavenger of reactive oxygen species and intracellular proton buffer. On the other hand, carnosinase is a specific peptidase able to destroy the biological active dipeptide. To overcome this constraint, β‐cyclodextrin (β‐CD) was functionalized with carnosine to give the following new compounds: 6^A‐[(3‐{[(1S)‐1‐carboxy‐2‐(1H‐imidazol‐4‐yl)ethyl]amino}‐3‐oxopropyl)amino]‐6^A‐deoxy‐β‐cyclodextrin ( 1 ), 6^A‐[(β‐alanyl‐L ‐histidyl)amino]‐β‐cyclodextrin ( 2 ), and (2^AS,3^AR)‐3^A‐[(3‐{[(1S)‐1‐carboxy‐2‐(1H‐imidazol‐4‐yl)ethyl]amino}‐3‐oxopropyl)amino]‐3^A‐deoxy‐β‐cyclodextrin ( 3 ). Pulse‐radiolysis investigation showed that the β‐CD derivatives 1 – 3 are excellent scavengers of OH^. radicals. Their activity is not only due to the formation of the stable imidazole‐centered radical, but also to the scavenger ability of the glucose moieties of the macrocycle (Scheme). This effect is independent of the disposition of the imidazole ring. In fact, the quenching constant values are similar for the three compounds.