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Covalently anchored Ni(II)–C-protected amino acid ( l -histidine, l -cysteine, and l -cystine) complexes inspired by the active site of the Ni-superoxide dismutase enzyme were synthesised using chloropropylated silica gel as support. The structural features of the surface complexes were studied by the Kjeldahl method and ICP-MS, mid/far IR, UV–vis diffuse reflectance, and X-ray absorption spectroscopies. The enzyme-like activities of the materials were determined in a biochemical test reaction. Covalent grafting and building the complex onto the surface of the support were successful in all cases. It was found that in many instances the structures obtained and the coordinating groups substantially varied upon changing the conditions of the syntheses. All the covalently immobilised Ni(II)-complexes displayed enzyme-like activity. They also were active in the liquid-phase oxidation of cyclohexene, providing the epoxide with high selectivity. [ABSTRACT FROM AUTHOR]

• Cu(Cit) complexes had the highest affinity to the protamine-coated HNT. • Charge neutralization by complex adsorption led to particle aggregation. • The presence of nanotubular supports improved the SOD-like function of Cu(Cit). Nanocomposites of antioxidant activity were developed by immobilization of a superoxide dismutase (SOD) mimicking metal complex on three types of nanotubular systems. First, bare halloysite nanotubes (h-HNT) and then, protamine sulfate (PSP) functionalized h-HNT (h-HNT-PSP) and finally polyimidazolium-based polymer (IP-2) coated h-HNT (h-HNT-IP-2) were used as carriers of copper(II)-citrate (Cu(Cit)) complexes in aqueous dispersions. Stable colloids were obtained at low Cu(Cit) concentrations in all systems, while particle aggregation occurred for h-HNT-PSP and h-HNT-IP-2 at elevated complex doses due to adsorption of Cu(Cit) and decrease in the magnitude of surface charges. Enzymatic assays showed that Cu(Cit) possesses significant SOD-like function in homogeneous solution. Upon immobilization on h-HNT-PSP and h-HNT-IP-2, higher superoxide radical anion scavenging activities were obtained than for the non-immobilized Cu(Cit) complex due to structural changes and to the possible interaction between the radicals and the oppositely charged carriers. The developed nanotubular systems are promising candidates as antioxidant agents in various processes, where natural or immobilized enzymes are not adequate choices giving rise to their high sensitivity to the environmental conditions and to the subsequent loss of enzymatic activity. [Display omitted] [ABSTRACT FROM AUTHOR]

Wedge structures and involutions suggest that Late Pleistocene frozen ground, either permafrost or deep seasonal frost, extended at least as far south as latitude 47° N in central Europe (the Pannonian Basin). Optically stimulated luminescence dating of the sand infill from a number of wedges indicates that emplacement of the sand infill occurred during the Late Pleistocene (22.2-15.7 ka). This suggests that during this time the mean annual air temperature was depressed by at least ∼15° C relative to the present. Either continuous or discontinuous permafrost was probably present in the north and NW of the Pannonian Basin. The subsequent thaw of frozen ground is indicated by the widespread occurrence of deformed sediments. The presence of soil (ground) wedges suggests conditions of deep seasonal frost probably existed during the period when climate ameliorated following the Last Permafrost Maximum ( LPM). [ABSTRACT FROM AUTHOR]

Objectives. The role was studied of multiple single nucleotide polymorphisms in tooth agenesis in the Hungarian population using a complex approach. Methods. Eight SNPs, PAX9 -912 C/T, PAX9 -1031 A/G, MSX1 3755 A/G, FGFR1 T/C rs881301, IRF6 T/C rs764093, AXIN2-8150 A/G, AXIN2-8434 A/G and AXIN2-30224 C/T, were studied in 192 hypodontia and 17 oligodontia cases and in 260 healthy volunteers. Case-control analysis was performed to test both allelic and genotypic associations as well as associations at the level of haplotypes. Multivariate exploratory Bayesian network-based multi-level analysis of relevance (BN-BMLA) as well as logistic regression analysis were performed. Results. Conventional statistics showed that PAX9 SNP -912 C/T and the MSX1 SNP changed the incidence of hypodontia, although after Bonferroni correction for multiple hypothesis testing, the effects were only borderline tendencies. Using a statistical analysis better suited for handling multiple hypotheses, the BN-BMLA, PAX9 SNPs clearly showed a synergistic effect. This was confirmed by other multivariate analyses and it remained significant after corrections for multiple hypothesis testing ( p < 0.0025). The PAX9-1031-A- PAX9-912-T haplotype was the most relevant combination causing hypodontia. Interaction was weaker between PAX9 and MSX1, while other SNPs had no joint effect on hypodontia. Conclusion. This complex analysis shows the important role of PAX9 and MSX1 SNPs and of their interactions in tooth agenesis, while IRF6, FGFR1 and AXIN2 SNPs had no detectable role in the Hungarian population. These results also reveal that risk factors in hypodontia need to be identified in various populations, since there is considerable variability among them. [ABSTRACT FROM AUTHOR]

Abstract: Three β-cyclodextrin-based chiral stationary phases were developed applying novel bonding chemistry. The separation performances of β-cyclodextrin, (R,S)-2-hydroxypropyl-β-cyclodextrin, and permethyl-β-cyclodextrin-based CSPs were compared in the resolution of structurally divergent analytes, such as coumarins, dansyl amino acids, and propionic acid derivatives. Separations were carried out in reversed phase mode applying 0.1% triethylammonium phosphate (pH 3.5)/MeOH mobile phase systems in different compositions. Of the three novel CSPs the permethyl-β-cyclodextrin bonded phase proved to be the most effective one for the enantioseparation of investigated analytes. [Copyright &y& Elsevier]

Abstract: Salivary gland products are essential for oral health. Saliva is produced by three pairs of major salivary glands, the parotid, the submandibular and sublingual glands and by numerous minor salivary glands scattered around the oral cavity. Salivary water and electrolyte secretion is an energy consuming active two-stage process. First the acini secrete isotonic primary saliva into the luminal terminal end pieces of the gland parenchyma. This saliva is then modified by electrolyte reabsorption to form a hypotonic secretion in the ductal systems. Salivary proteins are continuously synthesized, and stored in secretory granules within the cell. Both electrolyte and protein secretion are highly regulated processes. Electrolyte secretion is primarily stimulated by parasympathetic stimulation while protein secretion is preferentially activated by sympathetic stimulation, but there is a considerable cross-talk and synergism between the two regulatory pathways. Approximately 1.0–1.5 litres of saliva is secreted by healthy persons each day, consisting of water, electrolytes, lubricants, antimicrobial compounds, enzymes and growth factors. These components of saliva facilitate speech, mastication and swallowing, and initiate food digestion. In addition, it protects the oral mucosa and the teeth. Thus, saliva secreted into the oral cavity is essential to maintain physiological conditions in the mouth. [Copyright &y& Elsevier]

Direct liquid chromatographic methods were developed to investigate the enantioseparation of 19 β-lactams on three cyclodextrin-bonded chiral stationary phases: permethyl-β-cyclodextrin, β-cyclodextrin and R,S-hydroxypropyl-β-cyclodextrin, prepared by a novel synthetic route. 17 of the 19 β-lactam stereoisomers were partially or baseline-separated on at least one of the tested chiral stationary phases. The influence of the structures of the β-lactams (the positions and types of the substituents, the size of the attached rings) on the enantiomer separation is discussed. The permethylated β-cyclodextrin selector proved to be the most effective one for the tested analytes. [ABSTRACT FROM AUTHOR]

Abstract: Preparation of (6-monoureido-6-monodeoxy) permethylated β-cyclodextrin bonded chiral stationary phase from permethylated 6-monoamino-6-monodeoxy-β-cyclodextrin is described. The optimized chiral stationary phase was evaluated by using HPLC separation of racemates of coumarin derivatives. Column characterization was performed by solid-state 13C, 15N, 29Si NMR using cross-polarization at the magic angle spinning. The development process was supported by CE experiments where the complex formation between cyclodextrins and warfarin was investigated. The results demonstrate good enantio-discrimination for coumarin derivatives. [Copyright &y& Elsevier]

Ectomesenchymal stem cells derived from the dental pulp are of neural crest origin, and as such are promising sources for cell therapy and tissue engineering. For safe upscaling of these cells, microcarrier-based culturing under dynamic conditions is a promising technology. We tested the suitability of two microcarriers, non-porous Cytodex 1 and porous Cytopore 2, for culturing well characterized dental pulp stem cells (DPSCs) using a shake flask system. Human DPSCs were cultured on these microcarriers in 96-well plates, and further expanded in shake flasks for upscaling experiments. Cell viability was measured using the alamarBlue assay, while cell morphology was observed by conventional and two-photon microscopies. Glucose consumption of cells was detected by the glucose oxidase/Clark-electrode method. DPSCs adhered to and grew well on both microcarrier surfaces and were also found in the pores of the Cytopore 2. Cells grown in tissue culture plates (static, non-shaking conditions) yielded 7 × 105 cells/well. In shake flasks, static preincubation promoted cell adhesion to the microcarriers. Under dynamic culture conditions (shaking) 3 × 107 cells were obtained in shake flasks. The DPSCs exhausted their glucose supply from the medium by day seven even with partial batch-feeding. In conclusion, both non-porous and porous microcarriers are suitable for upscaling ectomesenchymal DPSCs under dynamic culture conditions. [ABSTRACT FROM AUTHOR]

Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria–zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed. Due to the developed strategy, exclusively diketone-selective, recyclable, versatile heterogeneous catalytic transformation of aldehydes can be realized under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Cystic fibrosis (CF) is a fatal inherited disease caused by the absence or dysfunction of the CF transmembrane conductance regulator (CFTR) Cl- channel. About 70% of CF patients are exocrine pancreatic insufficient due to failure of the pancreatic ducts to secrete a HCO3--rich fluid. Our aim in this study was to investigate the potential of a recombinant Sendai virus (SeV) vector to introduce normal CFTR into human CF pancreatic duct (CFPAC-1) cells, and to assess the effect of CFTR gene transfer on the key transporters involved in HCO3- transport. Using polarized cultures of homozygous F508del CFPAC-1 cells as a model for the human CF pancreatic ductal epithelium we showed that SeV was an efficient gene transfer agent when applied to the apical membrane. The presence of functional CFTR was confirmed using iodide efflux assay. CFTR expression had no effect on cell growth, monolayer integrity, and mRNA levels for key transporters in the duct cell (pNBC, AE2, NHE2, NHE3, DRA, and PAT-1), but did upregulate the activity of apical Cl-/HCO3- and Na+/H+ exchangers (NHEs). In CFTR-corrected cells, apical Cl-/HCO3- exchange activity was further enhanced by cAMP, a key feature exhibited by normal pancreatic duct cells. The cAMP stimulated Cl-/HCO3- exchange was inhibited by dihydro-4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (H2-DIDS), but not by a specific CFTR inhibitor, CFTRinh-172. Our data show that SeV vector is a potential CFTR gene transfer agent for human pancreatic duct cells and that expression of CFTR in CF cells is associated with a restoration of Cl- and HCO3- transport at the apical membrane. J. Cell. Physiol. 214: 442–455, 2008. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]