Epistasis between ADIPOQ rs1501299 and PON1 rs662 polymorphisms is potentially associated with the development of knee osteoarthritis

Molecular Biology Reports - Overweight produces oxidative stress (OS) on the articular cartilage, with the subsequent risk of developing knee osteoarthritis (OA). Associations between genetic...     

IC-tagged proteins are able to interact with each other and perform complex reactions when integrated into muNS-derived inclusions

We have recently developed a versatile tagging system (IC-tagging) that causes relocation of the tagged proteins to ARV muNS-derived intracellular globular inclusions. In the present study we demonstrate (i) that the IC-tag can be successfully fused either to the amino or carboxyl terminus of the protein to be tagged and (ii) that IC-tagged proteins are able to interact between them and perform complex reactions that require such interactions while integrated into muNS inclusions, increasing the versatility of the IC-tagging system. Also, our studies with the DsRed protein add some light on the structure/function relationship of the evolution of DsRed chromophore.     

Ratiometric Imaging of Extracellular pH in Bacterial Biofilms with C-SNARF-4

pH in the extracellular matrix of bacterial biofilms is of central importance for microbial metabolism. Biofilms possess a complex three-dimensional architecture characterized by chemically different microenvironments in close proximity. For decades, pH measurements in biofilms have been limited to monitoring bulk pH with electrodes. Although pH microelectrodes with a better spatial resolution have been developed, they do not permit the monitoring of horizontal pH gradients in biofilms in real time. Quantitative fluorescence microscopy can overcome these problems, but none of the hitherto employed methods differentiated accurately between extracellular and intracellular microbial pH and visualized extracellular pH in all areas of the biofilms. Here, we developed a method to reliably monitor extracellular biofilm pH microscopically with the ratiometric pH-sensitive dye C-SNARF-4, choosing dental biofilms as an example. Fluorescent emissions of C-SNARF-4 can be used to calculate extracellular pH irrespective of the dye concentration. We showed that at pH values of <6, C-SNARF-4 stained 15 bacterial species frequently isolated from dental biofilm and visualized the entire bacterial biomass in in vivo-grown dental biofilms with unknown species composition. We then employed digital image analysis to remove the bacterial biomass from the microscopic images and adequately calculate extracellular pH values. As a proof of concept, we monitored the extracellular pH drop in in vivo-grown dental biofilms fermenting glucose. The combination of pH ratiometry with C-SNARF-4 and digital image analysis allows the accurate monitoring of extracellular pH in bacterial biofilms in three dimensions in real time and represents a significant improvement to previously employed methods of biofilm pH measurement.     

Gene expression changes in spleens of the wildlife reservoir species, Eurasian wild boar （Sus scrofa）, naturally infected with Brucella suis biovar 2

Brucella suis is responsible for swine brucellosis worldwide.Of the five different 8.suis biovars (bv.), bv.2 appears restricted to Europe where it is frequently isolated from wild boar and hares, can infect pigs and can cause human brucellosis.In this study, the differ-ential gene expression profile was characterized in spleens of Eurasian wild boar naturally infected with B.suis by.2.Of the 20,201 genes analyzed in the microarray, 633 and 1,373 were significantly (fold change＞1.8; P＜0.01) upregulated and downregulated, respectively,in infected wild boar.The analysis was focused on genes that were over represented after conditional test for biological process gene on-tology.Upregulated genes suggested that B.suis bv.2 infection induced cell maturation, migration and/or proliferation in infected animals.The genes downregulated in infected wild boar impaired the activity of several important cellular metabolic pathways such as metabolism,cytoskeleton organization and biogenesis, immune response and lysosomal function and vesicle-mediated transport.In addition, the re-sponse to stress, sperm fertility, muscle development and apoptosis seemed to be also impaired in infected animals.These results sug-gested that B.suis by.2 may use strategies similar to other smooth brucellae to facilitate intraeellular multiplication and the developmentof chronic infections.To our knowledge, this is the first report of the analysis of gene expression profile in hosts infected with B.suis by.2, which is important to understand the molecular mechanisms at the host-pathogen interface in the main reservoir species with possible implications in the zoonotic cycle of the pathogen.     

Autonomic Adaption to Clinical Simulation in Psychology Students: Teaching Applications

Simulation is used to facilitate new learning in a variety of situations. One application of simulation could be to help therapists gain therapeutic skills prior to seeing clients. This particular study was interested in measuring changes in stress response by looking at subjective and objective measures of distress (as measured by SUDS, HR, and HRV) over three sessions of simulated therapy. 16 second year psychology students participated in three sessions, and had their HR and HRV measured by Polar watches. Over the three sessions, there was a decrease in perceived distress, as measured by SUDS ratings. During and between sessions, there was inconclusive change in physiological parameters.     

Impact of single-site axonal GABAergic synaptic events on cerebellar interneuron activity

Axonal ionotropic receptors are present in a variety of neuronal types, and their function has largely been associated with the modulation of axonal activity and synaptic release. It is usually assumed that activation of axonal GABA_ARs comes from spillover, but in cerebellar molecular layer interneurons (MLIs) the GABA source is different: in these cells, GABA release activates presynaptic GABA_A autoreceptors (autoRs) together with postsynaptic targets, producing an autoR-mediated synaptic event. The frequency of presynaptic, autoR-mediated miniature currents is twice that of their somatodendritic counterparts, suggesting that autoR-mediated responses have an important effect on interneuron activity. Here, we used local Ca²⁺ photolysis in MLI axons of juvenile rats to evoke GABA release from individual varicosities to study the activation of axonal autoRs in single release sites. Our data show that single-site autoR conductances are similar to postsynaptic dendritic conductances. In conditions of high [Cl⁻]_i, autoR-mediated conductances range from 1 to 5 nS; this corresponds to ∼30–150 GABA_A channels per presynaptic varicosity, a value close to the number of channels in postsynaptic densities. Voltage responses produced by the activation of autoRs in single varicosities are amplified by a Na_v-dependent mechanism and propagate along the axon with a length constant of 91 µm. Immunolabeling determination of synapse location shows that on average, one third of the synapses produce autoR-mediated signals that are large enough to reach the axon initial segment. Finally, we show that single-site activation of presynaptic GABA_A autoRs leads to an increase in MLI excitability and thus conveys a strong feedback signal that contributes to spiking activity.     

Effect of P144? (Anti-TGF-β) in an “In Vivo” Human Hypertrophic Scar Model in Nude Mice

Background

Hypertrophic scars are one of the most important complications in surgery due to their cosmetic and functional impairments. Previous studies in tissue fibrotic disorders have shown promising results by inhibiting the biological activity effect of Transforming Growth Factor-beta 1 (TGF-β1). The aim of the current study was to determine the clinical effect of the inhibition of TGF-β1 signaling in human hypertrophic scars implanted in nude mice by topical application of an inhibitor of TGF-β1 (P144®).

Material and Methods

A total of 30 human hypertrophic scars were implanted in 60 nude mice. The animals were divided in two groups, group A (placebo) and group B (treatment). Group C (basal) was considered as the preimplanted scar samples and they were not implanted in the nude mice. After the shedding period, topical application of a lipogel containing placebo (group A) or P144 (group B) was daily administered during two weeks. The animals were sacrificed upon completion of the study. Total area, thickness and collagen fibers area were measure and compared across all groups. Immunohistochemistry was also performed in order to quantify collagen type I and type III and elastic fiber expressions present in the dermis.

Results

Successful shedding was achieved in 83,3% of the xenografts. The mean time for shedding was 35±5.4 days. Statistically significant differences were found in the total area, collagen fibers area and thickness between the groups. Increased elastic fibers and decreased collagen I were found in the P144-treated group compared to the basal group.

Conclusion

Topical application of an inhibitor of TGF-β1 may promote scar maturation and clinical improvement of hypertrophic scar morphology features in an “in vivo” model in nude mice after two weeks of treatment.     

3D Stationary electric current density in a spherical tumor treated with low direct current: an analytical solution

Electrotherapy with direct current delivered through implanted electrodes is used for local control of solid tumors in both preclinical and clinical studies. The aim of this research is to develop a solution method for obtaining a three-dimensional analytical expression for potential and electric current density as functions of direct electric current intensity, differences in conductivities between the tumor and the surrounding healthy tissue, and length, number and polarity of electrodes. The influence of these parameters on electric current density in both media is analyzed. The results show that the electric current density in the tumor is higher than that in the surrounding healthy tissue for any value of these parameters. The conclusion is that the solution method presented in this study is of practical interest because it provides, in a few minutes, a convenient way to visualize in 3D the electric current densities generated by a radial electrode array by means of the adequate selection of direct current intensity, length, number, and polarity of electrodes, and the difference in conductivity between the solid tumor and its surrounding healthy tissue.     

Cytoprotective properties of alpha-tocopherol are related to gene regulation in cultured D-galactosamine-treated human hepatocytes

Vitamin E (alpha-tocopherol) has demonstrated antioxidant activity and gene-regulatory properties. d-Galactosamine (D-GalN)-induced cell death is mediated by nitric oxide in hepatocytes, and it is associated with hepatic steatosis. The beneficial properties of alpha-tocopherol and their relation to oxidative stress and gene regulation were assessed in D-GalN-induced cell death. Hepatocytes were isolated from human liver resections by a collagenase perfusion technique. alpha-Tocopherol (50 microM) was administered at the advanced stages (10 h) of D-GalN-induced cell death in cultured hepatocytes. Cell death, oxidative stress, alpha-tocopherol metabolism, and NF-kappaB-, pregnane X receptor (PXR)-, and peroxisome proliferator-activated receptor (PPAR-alpha)-associated gene regulation were estimated in the hepatocytes. D-GalN increased cell death and alpha-tocopherol metabolism. alpha-Tocopherol exerted a moderate beneficial effect against apoptosis and necrosis induced by D-GalN. Induction (rifampicin) or inhibition (ketoconazole) of alpha-tocopherol metabolism and overexpression of PXR showed that the increase in PXR-related CYP3A4 expression caused by alpha-tocopherol enhanced cell death in hepatocytes. Nevertheless, the reduction in NF-kappaB activation and inducible nitric oxide synthase expression and the enhancement of PPAR-alpha and carnitine palmitoyl transferase gene expression by alpha-tocopherol may be relevant for cell survival. In conclusion, the cytoprotective properties of alpha-tocopherol are mostly related to gene regulation rather than to antioxidant activity in toxin-induced cell death in hepatocytes.     

Productivity: key factor affecting grazing exclusion effects on vegetation and soil

In this study, we inquire into the effects of short-term goat grazing abandonment on plant species and functional composition, bare ground and net primary productivity (NPP) in two traditionally grazed pastures located in the Canarian Network of Natural Protected Areas and the Natura 2000 Network. In addition, we analyse soil chemical properties, biomass tannin content and energetic value to find out how grazing abandonment affects soil fertility and forage quality of these agroecosystems. Grazing exclusion effects on plant species and functional composition, as well as on soil fertility depended on the productivity of the studied pasture. Erect forbs and shrubs (endemic to Macaronesian region and native) were favoured by grazing removal in the most productive pasture, while soil fertility decreased in the driest and least productive site. An increase in NPP after exclusion was consistent among study sites. Although we consider goat grazing as necessary for maintaining traditional agroecosystems, we also suggest controlling it over time, allowing some periods of rest to give endemic shrub species time to recover from near propagule sources.