2,320 research outputs found
Theory of photoinduced ultrafast switching to a spin-orbital ordered `hidden' phase
Photoinduced hidden phases are often observed in materials with intertwined
orders. Understanding the formation of these non-thermal phases is challenging
and requires a resolution of the cooperative interplay between different orders
on the ultrashort timescale. In this work, we demonstrate that non-equilibrium
photo-excitations can induce a state with spin-orbital orders entirely
different from the equilibrium state in the three-quarter-filled two-band
Hubbard model. We identify a general mechanism governing the transition to the
hidden state, which relies on a non-thermal partial melting of the intertwined
orders mediated by photoinduced charge excitations in the presence of strong
spin-orbital exchange interactions. Our study theoretically confirms the
crucial role played by orbital degrees of freedom in the light-induced dynamics
of strongly correlated materials and it shows that the switching to hidden
states can be controlled already on the fs timescale of the electron dynamics
Identification of prolylcarboxypeptidase as the cell matrix-associated prekallikrein activator
Investigations determined that the cell matrix-associated prekallikrein (PK) activator is prolylearboxypeptidase. PK activation on human umbilical vein endothelial cell (HUVEC) matrix is inhibited by antipain (IC50 = 50 muM) but not antifactor XIIa antibody, 3 mM benzamidine, 5 mM iodoacetic acid or iodoacetamide, or 3 mM N-ethylmaleimide. Corn trypsin inhibitor (IC50 = 100 nM) or Fmoc-aminoacylpyrrolidine-2-nitrile (IC50 = 100 muM) blocks matrix-associated PK activation. Angiotensin II (IC50 = 100 muM) or bradykinin (IC50 = 3 mM), but not angiotensin 1-7 or bradykinin 1-5, inhibits matrix-associated PK activation. ECV304 cell matrix PK activator also is blocked by 100 muM angiotensin II, 1 muM corn trypsin inhibitor, and 50 muM antipain, but not angiotensin 1-7. 1 mM angiotensin 11 or 300 muM Fmoc-aminoacylpyrrolidine-2-nitrile indirectly blocks plasminogen activation by inhibiting kallikrein formation for single chain urokinase activation. On immunoblot, prolylcarboxypeptidase antigen is associated with HUVEC matrix. These studies indicate that prolylearboxypeptidase is the matrix PK activator. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.Univ Michigan, Div Hematol & Oncol, Dept Internal Med, Ann Arbor, MI 48109 USAUniversidade Federal de São Paulo, Dept Bioquim, São Paulo, BrazilUniv Michigan, Dept Pathol, Ann Arbor, MI 48109 USAUniversidade Federal de São Paulo, Dept Bioquim, São Paulo, BrazilWeb of Scienc
Theory of photoinduced ultrafast switching to a spin-orbital ordered hidden phase
Photo-induced hidden phases are often observed in materials with intertwined orders. Understanding the formation of these non-thermal phases is challenging and requires a resolution of the cooperative interplay between different orders on the ultra-short timescale. In this work, we demonstrate that non-equilibrium photo-excitations can induce a state with spin-orbital orders entirely different from the equilibrium state in the three-quarter-filled two-band Hubbard model. We identify a general mechanism governing the transition to the hidden state, which relies on a non-thermal partial melting of the intertwined orders mediated by photoinduced charge excitations in the presence of strong spin-orbital exchange interactions. Our study theoretically confirms the crucial role played by orbital degrees of freedom in the light-induced dynamics of strongly correlated materials and it shows that the switching to hidden states can be controlled already on the fs timescale of the electron dynamics
Adenovirus 11p downregulates CD46 early in infection
AbstractAdenovirus 11 prototype (Ad11p), belonging to species B, uses CD46 as an attachment receptor. CD46, a complement regulatory molecule, is expressed on all human nucleated cells. We show here that Ad11p virions downregulate CD46 on the surface of K562 cells as early as 5min p.i. Specific binding to CD46 by the Ad11p fiber knob was required to mediate downregulation. The complement regulatory factors CD55 and CD59 were also reduced to a significant extent as a consequence of Ad11p binding to K562 cells. In contrast, binding of Ad7p did not result in downregulation of CD46 early in infection. Thus, the presumed interaction between Ad7p and CD46 did not have the same consequences as the Ad11p–CD46 interaction, the latter virus (Ad11p) being a promising gene therapy vector candidate. These findings may lead to a better understanding of the pathogenesis of species B adenovirus infections
The Huntington's disease mutation impairs Huntingtin's role in the transport of NF-κB from the synapse to the nucleus
Expansion of a polyglutamine (polyQ) tract in the Huntingtin (Htt) protein causes Huntington's disease (HD), a fatal inherited neurodegenerative disorder. Loss of the normal function of Htt is thought to be an important pathogenetic component of HD. However, the function of wild-type Htt is not well defined. Htt is thought to be a multifunctional protein that plays distinct roles in several biological processes, including synaptic transmission, intracellular transport and neuronal transcription. Here, we show with biochemical and live cell imaging studies that wild-type Htt stimulates the transport of nuclear factor κ light-chain-enhancer of activated B cells (NF-κB) out of dendritic spines (where NF-κB is activated by excitatory synaptic input) and supports a high level of active NF-κB in neuronal nuclei (where NF-κB stimulates the transcription of target genes). We show that this novel function of Htt is impaired by the polyQ expansion and thus may contribute to the etiology of HD
Host Suitability of a Gregarious Parasitoid on Beetle Hosts: Flexibility between Fitness of Adult and Offspring
Behavioral tactics play a crucial role in the evolution of species and are likely to be found in host-parasitoid interactions where host quality may differ between host developmental stages. We investigated foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi in relation to two distinct host developmental stages: larvae and pupae. Two colonies of parasitoids were reared on larvae of Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Paired-choice and non-choice experiments were used to evaluate the preference and performance of S. harmandi on larvae and pupae of the two species. Foraging decisions and offspring fitness-related consequences of S. harmandi led to the selection of the most profitable host stage for parasitoid development. Adult females from the two colonies oviposited more quickly on pupae as compared to larvae of M. alternatus. Subsequently, their offspring development time was faster and they gained higher body weight on the pupal hosts. This study demonstrates optimal foraging of intraspecific détente that can occur during host-parasitoid interactions, of which the quality of the parasitism (highest fitness benefit and profitability) is related to the host developmental stage utilized. We conclude that S. harmandi is able to perfectly discriminate among host species or stages in a manner that maximizes its offspring fitness. The results indicated that foraging potential of adults may not be driven by its maternal effects, also induced flexibly with encountering prior host quality
Toll family members bind multiple Spatzle proteins and activate antimicrobial peptide gene expression in Drosophila
The Toll signaling pathway in Drosophila melanogaster regulates several immune-related functions, including the expression of antimicrobial peptide (AMP) genes. The canonical Toll receptor (Toll-1) is activated by the cytokine Spatzle (Spz-1), but Drosophila encodes eight other Toll genes and five other Spz genes whose interactions with one another and associated functions are less well understood. Here, we conducted in vitro assays in the Drosophila S2 cell line with the Toll/interleukin-1 receptor (TIR) homology domains of each Toll family member to determine if they can activate a known target of Toll-1, the promoter of the antifungal peptide gene drosomycin. All TIR family members activated the drosomycin promoter, with Toll-1 and Toll-7 TIRs producing the highest activation. We found that the Toll-1 and Toll-7 ectodomains bind Spz-1, -2, and -5 and also vesicular stomatitis virus (VSV) virions, and that Spz-1, -2, -5, and VSV all activated the promoters of drosomycin and several other AMP genes in S2 cells expressing full-length Toll-1 or Toll-7. In vivo experiments indicated that Toll-1 and Toll-7 mutants could be systemically infected with two bacterial species (Enterococcus faecalis and Pseudomonas aeruginosa), the opportunistic fungal pathogen Candida albicans and VSV with different survival in adult females and males compared with wild-type fly survival. Our results suggest that all Toll family members can activate several AMP genes. Our results further indicate that Toll-1 and Toll-7 bind multiple Spz proteins and also VSV, but differentially affect adult survival after systemic infection, potentially because of sex-specific differences in Toll-1 and Toll-7 expression
Biologic interventions for fatigue in rheumatoid arthritis
BACKGROUND: Fatigue is a common and potentially distressing symptom for patients with rheumatoid arthritis (RA), with no accepted evidence-based management guidelines. Evidence suggests that biologic interventions improve symptoms and signs in RA as well as reducing joint damage.OBJECTIVES: To evaluate the effect of biologic interventions on fatigue in rheumatoid arthritis.SEARCH METHODS: We searched the following electronic databases up to 1 April 2014: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Current Controlled Trials Register, the National Research Register Archive, The UKCRN Portfolio Database, AMED, CINAHL, PsycINFO, Social Science Citation Index, Web of Science, and Dissertation Abstracts International. In addition, we checked the reference lists of articles identified for inclusion for additional studies and contacted key authors.SELECTION CRITERIA: We included randomised controlled trials if they evaluated a biologic intervention in people with rheumatoid arthritis and had self reported fatigue as an outcome measure.DATA COLLECTION AND ANALYSIS: Two reviewers selected relevant trials, assessed methodological quality and extracted data. Where appropriate, we pooled data in meta-analyses using a random-effects model.MAIN RESULTS: We identified 32 studies for inclusion in this current review. Twenty studies evaluated five anti-tumour necrosis factor (anti-TNF) biologic agents (adalimumab, certolizumab, etanercept, golimumab and infliximab), and 12 studies focused on five non-anti-TNF biologic agents (abatacept, canakinumab, rituximab, tocilizumab and an anti-interferon gamma monoclonal antibody). All but two of the studies were double-blind randomised placebo-controlled trials. In some trials, patients could receive concomitant disease-modifying anti-rheumatic drugs (DMARDs). These studies added either biologics or placebo to DMARDs. Investigators did not change the dose of the latter from baseline. In total, these studies included 9946 participants in the intervention groups and 4682 participants in the control groups. Overall, quality of randomised controlled trials was moderate with a low to unclear risk of bias in the reporting of the outcome of fatigue. We downgraded the quality of the studies from high to moderate because of potential reporting bias (studies included post hoc analyses favouring reporting of positive result and did not always include all randomised individuals). Some studies recruited only participants with early disease. The studies used five different instruments to assess fatigue in these studies: the Functional Assessment of Chronic Illness Therapy Fatigue Domain (FACIT-F), Short Form-36 Vitality Domain (SF-36 VT), Visual Analogue Scale (VAS) (0 to 100 or 0 to 10) and the Numerical Rating Scale (NRS). We calculated standard mean differences for pooled data in meta-analyses. Overall treatment by biologic agents led to statistically significant reduction in fatigue with a standardised mean difference of -0.43 (95% confidence interval (CI) -0.38 to -0.49). This equates to a difference of 6.45 units (95% CI 5.7 to 7.35) of FACIT-F score (range 0 to 52). Both types of biologic agents achieved a similar level of improvement: for anti-TNF agents, this stood at -0.42 (95% CI -0.35 to -0.49), equivalent to 6.3 units (95% CI 5.3 to 7.4) on the FACIT-F score; and for non-anti-TNF agents, it was -0.46 (95% CI -0.39 to -0.53), equivalent to 6.9 units (95% CI 5.85 to 7.95) on the FACIT-F score. In most studies, the double-blind period was 24 weeks or less. No study assessed long-term changes in fatigue.AUTHORS' CONCLUSIONS: Treatment with biologic interventions in patients with active RA can lead to a small to moderate improvement in fatigue. The magnitude of improvement is similar for anti-TNF and non-anti-TNF biologics. However, it is unclear whether the improvement results from a direct action of the biologics on fatigue or indirectly through reduction in inflammation, disease activity or some other mechanism
Physical function improvements and relief from fatigue and pain are associated with increased productivity at work and at home in rheumatoid arthritis patients treated with certolizumab pegol
Objectives. To evaluate the association between improvements in physical function, fatigue and pain and improvements in productivity at work and at home in patients treated with certolizumab pegol (CZP) in combination with MTX
Effect of a single dose of pregabalin on herpes zoster pain
<p>Abstract</p> <p>Background</p> <p>The effect of pregabalin on acute herpes zoster pain has not been previously evaluated.</p> <p>Methods</p> <p>In a randomized, double-blind, placebo-controlled, two-session crossover study the effect of a single oral dose of pregabalin (150 mg) on pain and allodynia was evaluated in 8 subjects with herpes zoster.</p> <p>Results</p> <p>Over 6 hours of observation, pain decreased by a mean of 33% with pregabalin and 14% with placebo (p < 0.10). Effects on allodynia and SF-MPQ were not significant.</p> <p>Conclusions</p> <p>Compared to an earlier study of gabapentin 900 mg for acute zoster pain and allodynia that followed a nearly identical protocol, pregabalin had a similar effect on pain and was well tolerated, with no difference from placebo on sleepiness. Common side effects of light-headedness, unsteady gait, and slowed thinking were almost identical to that observed in the earlier study of gabapentin. Subject recruitment proved difficult in part due to the widespread off-label use of gabapentin and pregabalin for acute zoster pain in our region of the USA.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00352651">NCT00352651</a></p
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