Integrin and chemokine receptor gene expression in implant-adherent cells during early osseointegration

The mechanisms of early cellular recruitment and interaction to titanium implants are not well understood. The aim of this study was to investigate the expression of pro-inflammatory cytokines, chemokines and adhesion markers during the first 24 h of implantation. Anodically oxidized and machined titanium implants were inserted in rat tibia. After 3, 12, and 24 h the implants were unscrewed and analyzed with quantitative polymerase chain reaction. Immunohistochemistry and scanning electron microscopy revealed different cell types, morphology and adhesion at the two implant surfaces. A greater amount of cells, as indicated by higher expression of small subunit ribosomal RNA (18S), was detected on the oxidized surface. Higher expression of CXC chemokine receptor-4 (at 12 h) and integrins, αv (at 12 h), β1 (at 24 h) and β2 (at 12 and 24 h) was detected at the oxidized surfaces. Significantly higher tumor necrosis factor-α (at 3 h) and interleukin-1β (at 24 h) expression was demonstrated for the machined surface. It is concluded that material surface properties rapidly modulate the expression of receptors important for the recruitment and adhesion of cells which are crucial for the inflammatory and regenerative processes at implant surfaces in vivo.     

Comparative microscopic and spectroscopic analysis of temperature-dependent growth of WO3 and W0.95Ti0.05O3 thin films

We present a comparative microscopic and spectroscopic study of the morphology and composition of WO₃ and W_0.95Ti_0.05O₃ thin films, grown by radio-frequency magnetron reactive sputtering at substrate temperatures varied from room temperature to 500 °C, using atomic force microscopy (AFM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). With increasing growth temperature, the AFM results show increase in the average crystallite size and in the surface roughness for both undoped and doped samples. The AFM data, along with the Raman results, clearly indicate that for the given set of experimental conditions, higher growth temperatures are required to obtain crystalline Ti-doped WO₃ films than for WO₃ films. Also, the Raman results suggest a potential phase transformation from a monoclinic WO₃ structure to an orthorhombic, but more probably a tetragonal, configuration in the W_0.95Ti_0.05O₃ thin films. This remark is based on the observed shifting, with Ti doping, to lower frequencies of the Raman peaks corresponding to W–O–W stretching modes of WO₃ at 806 and 711 cm⁻¹ to 793 and 690 cm⁻¹, respectively. XPS data indicate that the doped material has a reduced WO_3−x stoichiometry at the surface, with the presence of W⁶⁺ and W⁵⁺ oxidation states; this observation could also be related to the existence of a different structural phase of this material, corroborating with the Raman measurements.     

Differential impedance spectroscopy for monitoring protein immobilization and antibody-antigen reactions

This work describes the theoretical and experimental approaches for monitoring the interfacial biomolecular reaction between immobilized antibody and the antigen binding partner using novel differential impedance spectroscopy. The prerequisite of any biosensor is the immobilization of macromolecules onto the surface of a transducer. It is clear that the function of most macromolecules changes from what is observed in solution once immobilization has occurred. In the worst case, molecules entirely lose their binding activity almost immediately after immobilization. Certain conditions (e.g., denaturation, interfacial effects based on ionic strength, surface charge, dielectric constants, etc.) at interfaces are responsible for alterations of binding activity; it is not clear whether a combination of such processes is understood. However, these processes in combination must be reliably modeled in order to predict the outcome for most macromolecules. This work presents the theoretical and practical means for elucidating the surface reactivity of biomolecular reagents using ion displacement model with antibody-antigen (Ab-Ag) reaction as the test case. The Ab-Ag reaction was directly monitored using a dual-channeled, impedance analyzer capable of 1 measurement/s using covalent immobilization chemistry and polymer-modified electrodes in the absence of a redox probe. The evidence of Ab-Ag binding was revealed through the evolution of differential admittance. The surface loading obtained using the covalent immobilization chemistry was 9.0 x 10(16)/cm2, whereas with polymer-modified electrodes, the surface loading was 9.0 x 10(15)/cm2, representing a 10 times increase in surface reactivity. The proposed approach may be applicable to monitoring other surface interfacial reactions such as DNA-DNA interactions, DNA-protein interactions, and DNA-small molecule interactions.     

High Performance Ni Based Catalyst for Toluene Hydrocracking

The one step hydrocracking of toluene to n-paraffins was successfully carried out using a Ni-based bifunctional catalyst supported on H-ZSM-5 zeolite. Two methods of catalyst preparation were compared and a quantifiable difference in selectivity was identified depending on the preparation method. Additionally, a high C₂₊ n-alkane selectivity of ~75% was obtained with both catalysts, which is comparable to previous work using Pd. Both catalysts generated a toluene conversion of 100%.     

Galvanostatic desorption of hydrogen from Pd layers—III. The anodic volmer reaction

The anodic Volmer reaction on equilibrated α-(PdH) electrodes has been studied using the galvanostatic technique within the anodic current range of 0.1–20 mA. The influence of the concentration of electrolyte solution (H₂SO₄ and Na₂SO₄ solutions), surface structure and temperature on the anodic transfer coefficient, α and the formal rate constant, βk⁰_a have been reported. Generally α-values diminish, while βk⁰_a-values increase with the anodic current density. This effect is stronger in so far as the electrode surface is more activated by electrodeposition of Pd-black. The apparent activation energy of the overall oxidation reaction depends on the surface structure: it is high on an unactivated surface (～ 11 kcal/g-atom H), and practically negligible on an activated surface. This is interpreted on the basis of complex structure of surface region on a (PdH) electrode.     

Intergroup consensus/disagreement in support of group-based hierarchy: An examination of socio-structural and psycho-cultural factors.

A meta-analysis examined the extent to which socio-structural and psycho-cultural characteristics of societies correspond with how much gender and ethnic/racial groups differ on their support of group-based hierarchy. Robustly, women opposed group-based hierarchy more than men did, and members of lower power ethnic/racial groups opposed group-based hierarchy more than members of higher power ethnic/racial groups did. As predicted by social dominance theory, gender differences were larger, more stable, and less variable from sample to sample than differences between ethnic/racial groups. Subordinate gender and ethnic/racial group members disagreed more with dominants in their views of group-based hierarchy in societies that can be considered more liberal and modern (e.g., emphasizing individualism and change from traditions), as well as in societies that enjoyed greater gender equality. The relations between gender and ethnic/racial groups are discussed, and implications are developed for social dominance theory, social role theory, biosocial theory, social identity theory, system justification theory, realistic group conflict theory, and relative deprivation theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Dietary Oil Type and Late Feed Restriction Elicit Synergistic Effects on Growth,Caeca Bacteria,Carcass, Fat Accretion,and Muscle Lipids in Female Broilers

The influence of dietary oil type (OT) and late feed restriction (FR) on growth, caeca bacteria count, carcass, separable fat depots, serum and muscle lipids, and meat quality in broilers is examined. In total, 224, 21-day-old female Arbor acres broilers are randomly allotted to either PN, Unrestricted+50 g kg⁻¹ palm oil (PO); PR, 25%-FR+PO; SN, Unrestricted+50 g kg⁻¹ soybean oil (SO); or SR, 25%-FR+SO for 21 d. The SN and PR birds have the heaviest and lightest body weight gain (BWG), respectively. Feed conversion ratio (FCR) is poorer in the PN birds. Feed-restricted birds have more caeca Lactobacillus and lower Salmonella, serum cholesterol, and triglycerides. Carcass yield is higher in SR birds and lower in PN birds. The FR-OT interaction is significant for muscle lipids and weight of fat depots. The PN birds deposit more abdominal, intramuscular, sartorial, mesentery and neck fats, muscle saturated fatty acids, and C18:1n-9 and lower C18:3n-3 and C20:5n-3 than other birds. Neither OT nor FR affects the pH, color, water holding capacity, and oxidative stability of breast meat. The changes elicited by 25%-FR on BWG, FCR, carcass yield, depot fats, and muscle lipids in female broilers are dependent on dietary OT. Practical Application: Fast growth rate and unrestricted access to feed can predispose broiler chickens to excessive fat accretion, which is counterproductive. Producing high-quality carcasses that meet consumers’ expectation is crucial for sustainable and efficient broiler production. The possible interaction between dietary OT and late quantitative FR in mitigating excessive fat accretion and altering production indices in female broilers is explored. Late quantitative FR reduces BWG, FCR, serum lipids, caeca pH and Salmonella spp. and fat accretion in fat depots, and enhances carcass yield and caeca Lactobacillus spp. However, the impacts are more pronounced in the PO birds than the SO birds. Late FR improves the C18:3n-3 and C18:2n-6 contents in PO meat while reducing the C14:0 and C16:0 contents in SO meat. These findings explicate that dietary OT and late quantitative FR can be synergistically used to mitigate excessive fat accretion and alter growth, caeca microflora, and muscle lipids in broilers.     

Diversity of stress tolerance in Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus paraplantarum: A multivariate screening study

Sixty-three strains of the taxonomically related species Lactobacillus plantarum subsp. plantarum, L. plantarum subsp. argentoratensis, L. paraplantarum and L. pentosus isolated from sourdoughs and other food and non-food sources and 14 strains of other members of the genus Lactobacillus were screened for their tolerance of acid, alkaline, heat, oxidative, osmotic, detergent and starvation stresses in order to evaluate the diversity of stress response. Most strains of the L. plantarum group were highly tolerant of acid, alkaline and osmotic stress and highly sensitive to detergent stress, while a larger diversity was found for other stress. Multivariate analysis allowed grouping the strains in clusters with similar response patterns. Stress response patterns in the L. plantarum group were similar to those of species of the L. casei/L. paracasei group but clearly different from those of other mesophilic Lactobacillus. No relationship was found between grouping obtained on the basis of stress response patterns and by genotypic fingerprinting (rep-PCR), nor with the taxonomic position or isolation source of the strains. Further experiments with selected strains showed that exponential phase cells were generally but not always more sensitive than stationary phase cells. The ability to grow under stressful conditions showed a slightly better correlation with the ecological conditions prevailing in the isolation niches of the strains.This study will be the basis for further investigations to identify and exploit the basis of diversity in the stress response of lactic acid bacteria.     

Antifungal Activity of the Frog Skin Peptide Temporin G and Its Effect on Candida albicans Virulence Factors

The increasing resistance to conventional antifungal drugs is a widespread concern, and a search for new compounds, active against different species of fungi, is demanded. Antimicrobial peptides (AMPs) hold promises in this context. Here we investigated the activity of the frog skin AMP Temporin G (TG) against a panel of fungal strains, by following the Clinical and Laboratory Standards Institute protocols. TG resulted to be active against (i) Candida species and Cryptococcus neoformans, with MIC₅₀ between 4 µM and 64 µM after 24 h of incubation; (ii) dermatophytes with MIC₈₀ ranging from 4 to 32 µM, and (iii) Aspergillus strains with MIC₈₀ of 128 µM. In addition, our tests revealed that TG reduced the metabolic activity of Candida albicans cells, with moderate membrane perturbation, as proven by XTT and Sytox Green assays, respectively. Furthermore, TG was found to be effective against some C. albicans virulence factors; indeed, at 64 µM it was able to inhibit ~90% of yeast–mycelial switching, strongly prevented biofilm formation, and led to a 50% reduction of metabolic activity in mature biofilm cells, and ~30–35% eradication of mature biofilm biomass. Even though further studies are needed to deepen our knowledge of the mechanisms of TG antifungal activity, our results suggest this AMP as an attractive lead compound for treatment of fungal diseases.