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Unexpected Increase (unexpected + increase)
Selected AbstractsStat1-mediated cytoplasmic attenuation in osteoimmunologyJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2005Hiroshi Takayanagi Abstract Signal transducer and activator of transcription 1 (Stat1) is a critical mediator of gene transcription in type I interferon (IFN-,/,) signaling that is essential for host defense against viruses. In the skeletal system, type I IFNs (IFN-,/,) also play an important physiological role in the inhibition of receptor activator of NF-,B ligand (RANKL)-induced osteoclast differentiation and bone resorption: mice deficient in IFN signaling exhibit decreased bone mass accompanied by the activation of osteoclastogenesis. On the other hand, an unexpected increase in bone mass was observed in Stat1-deficient mice, indicating that Stat1 has a hitherto unknown function in the regulation of bone formation. Indeed, Stat1 was found to have a unique, non-canonical function as a cytoplasmic attenuator of Runx2, a key transcription factor for osteoblast differentiation. Thus, the loss of Stat1 results in excessive activation of Runx2 and osteoblast differentiation, thereby tipping the balance in favor of bone formation over bone resorption. This is an interesting example in which a latent transcription factor attenuates the activity of another transcription factor in the cytoplasm, and reveals a novel regulatory mechanism of bone remodeling by immunomodulatory molecules. Here, we summarize recent advances in the study of Stat1 and IFNs in the context of osteoimmunology, including latest reports that question whether the inhibitory function of Stat1 in chondrocytes is responsible for dwarfism in achondroplasia. © 2004 Wiley-Liss, Inc. [source] Stress Development Due to Capillary Condensation in Powder Compacts: A Two-Dimensional Model StudyJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2000Stefan Lampenscherf A model experiment is presented to investigate the relationship between the humidity-dependent liquid distribution and the macroscopic stress in a partially wet powder compact. Therefore, films of monosized spherical particles were cast on silicon substrates. Using environmental SEM the geometry of the liquid necks trapped between particles was imaged as a function of relative humidity. Simultaneously the macroscopic stress in the substrate adhered particle film was measured by capacitive deflection measurement. The experimentally found humidity dependence of the liquid neck size and the macroscopic film stress are compared with model predictions. The circle,circle approximation is used to predict the size of the liquid necks between touching particles as a function of the capillary pressure. Using the modified Kelvin relation between capillary pressure and relative humidity, we consider the effect of an additional solute which may be present in the capillary liquid. The results of the stress measurement are compared with the model predictions for a film of touching particles in hexagonal symmetry. The contribution of the capillary interaction to the adhesion force between neighboring particles is calculated using the integrated Laplace equation. The resulting film stress can be approximated relating this capillary force to an effective cross section per particle. The experimentally found humidity dependence of the liquid neck size is in good agreement with the model predictions for finite solute concentration. The film stress corresponds to the model predictions only for large relative humidities and shows an unexpected increase at small values. As is shown with an atomic force microscope, the real structure of the particle,particle contact area changes during the wet/dry cycle. A solution/reprecipitation process causes surface heterogeneities and solid bridging between the particles. It is claimed that the existence of a finite contact zone between the particles gives rise to the unexpected increase of the stress at small relative humidities. [source] Effects of probiotic therapy on portal pressure in patients with cirrhosis: a pilot studyLIVER INTERNATIONAL, Issue 7 2009Puneeta Tandon Abstract Background: Recent literature has supported the role of bacterial translocation as a mediator of splanchnic vasodilatation and portal hypertension. The objective of this study was to determine whether the probiotic VSL#3 would reduce portal pressure in patients with cirrhosis. Methods: Eight patients with compensated or very early decompensated cirrhosis and hepatic venous pressure gradient (HVPG) >10 mmHg, received 2 months of VSL#3 (3600 billion bacteria daily). The HVPG, intestinal permeability, endotoxin, tumour necrosis factor (TNF)-,, interleukin (IL)-6, IL-8, renin and aldosterone were measured at baseline and study end. Results: There was no change in the HVPG or intestinal permeability from baseline to study end but there was a trend to reduction in plasma endotoxin (P=0.09), a mild but significant increase in serum TNF-, (P=0.02) and a significant reduction in plasma aldosterone (P=0.03). Conclusions: Within the limitations of small sample size, there does not appear to be a benefit of probiotic therapy for portal pressure reduction in patients with compensated or early decompensated cirrhosis. The reductions in endotoxin and aldosterone suggest possible beneficial effects of probiotics for this patient population. The clinical significance of the small but unexpected increase in TNF-, is unclear. Future studies are planned in patients with decompensated cirrhosis. [source] H4 acetylation does not replace H3 acetylation in chromatin remodelling and transcription activation of Adr1-dependent genesMOLECULAR MICROBIOLOGY, Issue 5 2006Eleonora Agricola Summary Histone acetylation regulates gene expression. Whether this is caused by a general increase in nucleosome fluidity due to charge neutralization or by a more specific code is still matter of debate. By using a set of glucose-repressed Adr1-dependent genes of Saccharomyces cerevisiae, whose transcription was previously shown to require both Gcn5 and Esa1, we asked how changes of histone acetylation patterns at the promoter nucleosomes regulate chromatin remodelling and activation. When the signal of glucose reduction reaches the cells, H4 acetylation is kept constant while an increase of H3 acetylation occurs, in an Adr1- and Gcn5-dependent manner. In cells lacking Gcn5 activity, the H3 acetylation increase does not occur and an unexpected increase of histone H4 acetylation is observed. Nevertheless, chromatin remodelling and transcription activation are impaired, suggesting that acetylation of H3 and H4 histones plays different roles. [source] Target of rapamycin in the oriental fruit fly Bactrocera dorsalis (hendel): its cloning and effect on yolk protein expressionARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2010R. Suganya Abstract Target of rapamycin (TOR), a serine/threonine protein kinase, is involved in regulating a number of growth and developmental processes of an organism, including yolk protein synthesis in insects. In this study, TOR gene was isolated, designated BdTOR (GenBank accession no. FJ167395), from the oriental fruit fly Bactrocera dorsalis (Hendel). Quantitative RT-PCR showed a higher expression of BdTOR in the pupa than in other developmental stages, as well as in ovary than in the fat body. Downregulation of BdTOR activity by rapamycin treatment and RNA interference (RNAi) in vivo resulted in a significant reduction in yolk protein transcripts in both fat body and ovary, with a substantial reduction in ovary size. However, an unexpected increase in the expression of yolk protein gene was observed in adult ovary 9 days after rapamycin treatment. Taken together, the results suggest the involvement of BdTOR in the regulation of yolk protein synthesis in B. dorsalis. © 2010 Wiley Periodicals, Inc. [source] Electronic Properties and Reactivity of Short-Chain Oligomers of 3,4-Phenylenedioxythiophene (PheDOT)CHEMISTRY - A EUROPEAN JOURNAL, Issue 11 2006Igor F. Perepichka Dr. Abstract The dimer and trimer of 3,4-phenylenedioxythiophene (PheDOT) have been synthesized. Unlike the parent systems based on 3,4-ethylenedioxythiophene (EDOT), these compounds are quite stable under atmospheric conditions. The electronic absorption spectra of di- and tri-PheDOT exhibit a well-resolved vibronic fine structure indicative of self-rigidification of the conjugated structure by noncovalent intramolecular sulfur,oxygen interactions. Comparison of UV-visible data for the PheDOT oligomers with those of the corresponding EDOT oligomers reveals a faster decrease of the HOMO,LUMO gap with chain length for the former. Cyclic voltammetric data show that whereas PheDOT oxidizes at a lower potential than EDOT, the PheDOT dimer and trimer exhibit much higher oxidation potentials than their EDOT-based analogues. A comparative analysis of the electropolymerization of the three PheDOT-based systems shows that although PheDOT is very difficult to polymerize, its dimer and trimer can be readily electropolymerized. This unexpected increase of reactivity with chain extension is discussed with the aid of theoretical calculations. [source] U.S. Monetary Policy Surprises and Currency Futures Markets: A New LookFINANCIAL REVIEW, Issue 4 2008Tao Wang G14 Abstract Intraday currency futures prices react to both surprises in the federal funds target rate (the target factor) and surprises in the anticipated future direction of Federal Reserve monetary policy (the path factor) in similar magnitude, and the reaction is short-lived. Dollar-denominated currency futures prices drop significantly in response to positive surprises (i.e., unexpected increases) in the target and path factors, but have generally little response to negative surprises. A monetary policy tightening during expansionary periods leads to an appreciation of the domestic currency, while a monetary policy loosening during recessionary periods tends to have no significant impact. [source] The influence of aggregate microenvironment on the dissolution of oxazepam in ternary surfactant interactive mixturesJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2002Peter J. Stewart ABSTRACT The purpose of this research was to test the hypothesis that the dissolution rate of oxazepam in interactive mixtures was dependent on the influence of surfactant within the microenvironment of mixed oxazepam-surfactant aggegrates produced during dissolution. The studies utilised both powder and intrinsic dissolution methodology; spectrophotometric assays were developed and validated and dissolution data were modelled using multi-exponential equations and dissolution rate constants estimated using non-linear least squares algorithms. For a series of water-soluble ternary additives to the oxazepam interactive mixture, sodium lauryl sulfate and cetrimide were shown not only to decrease aggregation through enhanced dispersion, but also to increase the dissolution rate constant. Such an increase in dissolution rate constant was observed in the intrinsic dissolution studies when surfactant concentrations exceeded the critical micelle concentration and the oxazepam solubility increased. Laser diffraction particle sizing during the dissolution process confirmed the presence of dispersed particles and aggregates and demonstrated that the presence of surfactant improved the state of dispersion. The results of studies using different rotational speeds produced unexpected increases in aggregation and decreases in dissolution rate constants at about 150 rev min,1, consistent with the transient formation of loose aggregates containing dissolved surfactant. [source] MEASURING MONETARY POLICY IN THE UK: A FACTOR-AUGMENTED VECTOR AUTOREGRESSION MODEL APPROACHTHE MANCHESTER SCHOOL, Issue 2005GIANLUCA LAGANĄ This paper investigates the determinants of UK interest rates using a factor-augmented vector autoregression model (VAR), similar to the one suggested by Bernanke, Boivin and Eliasz (Quarterly Journal of Economics, Vol. 120 (2005), No. 1, pp. 387,422). The method allows impulse response functions to be generated for all the variables in the data set and so is able to provide a more complete description of UK monetary policy than is possible using standard VARs. The results show that the addition of factors to a benchmark VAR generates a more reasonable characterization of the effects of unexpected increases in the interest rate and, in particular, gets rid of a ,price puzzle' response present in the benchmark VAR. The extra information generated by this method, however, also brings to light other identification issues, notably house price and stock market ,puzzles'. Importantly the out-of-sample prediction performance of the factor-augmented VARs is also very good and strongly superior to those of the benchmark VAR and simple autoregression models. [source] | |||||||||||||||||||