Toll-like receptor 2 modulates the inhibitory motor response induced by hydrogen sulphide in mouse colon

Introduction: The recognition of intestinal microbiota is in part carried out by toll-like receptors (TLR), which are responsible for initiating the innate immune response. Alterations in the intestinal microbiota and its recognition may contribute to the development of intestinal inflammatory pathologies. Otherwise, hydrogen sulphide (H2S) is an endogenous gaseous signalling molecule and it potentially plays a relevant role in the intestinal motility. In mammals, two pyridoxalphosphate-dependent enzymes are responsible for H2S synthesis: cystathionine b-synthase (CBS) and cystathionine -lyase (CSE)..

Pressure-induced metal-insulator transition in MgV_2O_4

On the basis of experimental thermoelectric power results and ab initio calculations, we propose that a metal-insulator transition takes place at high pressure (approximately 6 GPa) in MgV_2O_4.Comment: 2 pages, 3 figures, accepted in Physica B (Strongly Correlated Electron Systems '07

Toll-like receptor 9 modifies intestinal serotonergic system.

Introduction: Toll-like receptor 9 (TLR9) is expressed in intestinal epithelial cells, which recognize microbiota developing different responses 1. Several studies have shown that TLR9 seems to be involved in Inflammatory Bowel Diseases (IBD) due to an inappropriate defensive response against microorganisms 2. Moreover, intestinal serotonergic system is also altered in IBD, where extracellular serotonin (5–HT) levels are increased 3. 5-HT bioavailability is mainly regulated by the serotonin transporter (SERT), expressed in enterocytes 4. Aims & Methods: The aim of the present study was to analyse whether TLR9 activation affects SERT expression and activity, and expression of other elements from the serotonergic system (TPH1, TPH2 and 5-HT receptors). Human enterocyte-like Caco-2 cells, and ileum and colon from TLR9-/- mice and Dextran Sulphate Sodium (DSS) mouse colitis model were used as experimental models. mRNA expression was determined by RT-qPCR, and protein expression by western blot..

Toll-like receptor 9 activation affects intestinal serotonin transporter activity and expression in Caco-2 cells

Background: Toll-like Receptor 9 (TLR9) is expressed mainly in the endosomal membrane of intestinal cells and mediates intestinal host-microbiota interaction. Serotonin (5-HT) is an intestinal neuromodulator involved in the intestinal immunity and homeostasis. In addition, a high level of 5-HT has been described in intestinal inflammation. 5-HT intestinal availability is mainly regulated by the serotonin transporter (SERT) expressed in enterocytes. Aim: The interaction of TLR9 with serotoninergic system remains known. Therefore, the aim of the present study was to assess the effects of TLR9 activation on SERT activity and expression. Methods: Caco-2 cells and colon from wild type (WT) and TLR9 C57BL/10 mice were used in this study. SERT activity (5-HT uptake) in Caco-2 cells and SERT expression (RT-qPCR and western blotting) in both Caco-2 cells and colon from WT and TLR9 mice, were analyzed. TLR9 mRNA and protein levels were also measured in Caco-2 cells. Results: TLR9 activation in Caco-2 cells reduced SERT activity in a MyD88 independent-way. SERT mRNA and protein level in both cell lysate and brush border membrane, were also diminished. SERT protein expression in colon of TLR9 mice resulted augmented compared with WT mice. Interestingly, activation of TLR9 in Caco-2 cells diminished TLR9 mRNA and protein in the cell lysate; however, TLR9 protein in brush border resulted increased. Conclusions: The results of this work highlight the role of TLR9 as a mediator intestinal homeostasis and/or intestinal inflammation by regulating intestinal serotoninergic system

Study of the pressure effects in TiOCl by ab initio calculations

Electronic structure calculations on the low dimensional spin-1/2 compound TiOCl were performed at several pressures in the orthorhombic phase, finding that the structure is quasi-one-dimensional. The Ti3+ (d1) ions have one t2g orbital occupied (dyz) with a large hopping integral along the b direction of the crystal. The most important magnetic coupling is Ti-Ti along the b axis. The transition temperature (Tc) has a linear evolution with pressure, and at about 10 GPa this Tc is close to room temperature, leading to a room temperature spin-Peierls insulator-insulator transition, with an important reduction of the charge gap in agreement with the experiment. On the high-pressure monoclinic phase, TiOCl presents two possible dimerized structures, with a long or short dimerization. Long dimerized state occurs above 15 GPa, and below this pressure the short dimerized structure is the more stable phase.Comment: 3 pages, 3 embedded figures, 1 table. A. Pi\~neiro, et al.,J. Magn. Magn. Mater. (2009) (accepted

Mitochondrial DNA genetic relationships at the ancient Neolithic site of Tell Halula

The extent of racemization of aspartic acid (Asp) -expressed as D/L ratio- has been used as a marker of biomolecular degradation in ancient remains. However, Asp racemization rate is highly variable, and depends on biochemical and geochemical factors. In this paper we aim to determine to which extent the fraction analyzed and the kind of sample used may influence the D/L Asp ratios. Other factors, such as burial site and sample preservation conditions, are also considered. D/L Asp ratios were obtained in 38 ancient human samples from 30 different individuals in which Real Time PCR quantification and amplification of short mtDNA fragments had been previously achieved. Four samples were taken from bones, 16 from whole teeth and 18 from dentine. In 7 cases whole tooth and dentine fractions from the same individual were analyzed. The samples belonged to 8 archaeological sites from Pre-pottery Neolithic B (PPNB), Cardial Neolithic and Chalcolithic time periods. Results show significant differences between the D/L Asp ratios obtained in dentine and whole tooth fractions from the same tooth and individual, as well as among dentine samples from the same archaeological site and among samples of the same age from different, though nearby, archaeological sites. Ancient DNA (aDNA) could be characterized in the majority of the samples, independently from their racemization values, which suggests that other factors, apart from the sample preservation stage, are more significantly affecting the racemization rate. A generalized use of the Asp racemization ratio as a threshold value for ancient DNA preservation needs to be questioned until further methodological standardization is considered

Calculated phase diagrams, iron tolerance limits, and corrosion of Mg-Al alloys

The factors determining corrosion are reviewed in this paper, with an emphasis on iron tolerance limit and the production of high-purity castings. To understand the iron impurity tolerance limit, magnesium phase diagrams were calculated using the Pandat software package. Calculated phase diagrams can explain the iron tolerance limit and the production of high-purity castings by means of control of melt conditions; this is significant for the production of quality castings from recycled magnesium. Based on the new insight, the influence of the microstructure on corrosion of magnesium alloys is reviewed

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters