61 research outputs found

    Pharmacodynamic effect of gabapentin on central nervous system in patients with chronic low back pain: a [99mTc]Tc-ECD SPECT study

    Get PDF
    Background: Gabapentin is an effective therapeutic alternative for chronic low back pain, indicated in several guidelines for treating neuropathic pain as first-line medication. This study aimed to describe the pharmacodynamics of gabapentin in the central nervous system of patients with chronic low back pain (CLBP) by using single-photon emission CT (SPECT) with [99mTc]Tc-ECD. Methods: We selected 13 patients with CLBP due to lumbar disc herniation. They underwent SPECT before and after using gabapentin, compared with a SPECT database of healthy volunteers. A second analysis compared regional cerebral blood flow (rCBF) changes between responders and non-responders to gabapentin and the healthy controls. Results: The mean age of patients was 41 years, and the mean pain intensity was 5.92 points, measured by the Numeric Rating Scale. After using gabapentin, SPECT showed an increase of rCBF in the bilateral anterior cingulate gyrus and a decrease of rCBF in periaqueductal gray matter. Non-responder patients with gabapentin showed a post-treatment decrease of rCBF in the paracentral lobule of the brain. Conclusions: A lack of improvement in some patients with gabapentin may be associated with an activated affective circuit of pain, evidenced by the increase of rCBF of the anterior cingulate cortex. A maladaptive brain state in chronic pain can explain the decrease of rCBF in the default mode network structures. Gabapentin acts directly or indirectly on neurons of periaqueductal gray substance by increasing the pain threshold and decreasing the rCBF of this structure

    Neurobiological substrates of chronic low back pain (CLBP): a brain [âčâčᔐTc]Tc-ECD SPECT study

    Get PDF
    Background: Recent neuroimaging studies have demonstrated pathological mechanisms related to cerebral neuroplasticity in chronic low back pain (CLBP). Few studies have compared cerebral changes between patients with and without pain in the absence of an experimentally induced stimulus. We investigated the neurobiological substrates associated with chronic low back pain using [99mTc]Tc-ECD brain SPECT and correlated rCBF findings with the numeric rating scale (NRS) of pain and douleur neuropathique en 4 questions (DN4). Ten healthy control volunteers and fourteen patients with neuropathic CLBP due to lumbar disc herniation underwent cerebral SPECT scans. A quantitative comparison of rCBF findings between patients and controls was made using the Statistical Parametric Mapping (SPM), revealing clusters of voxels with a significant increase or decrease in rCBF. The intensity of CLBP was assessed by NRS and by DN4. / RESULTS: The results demonstrated an rCBF increase in clusters A (occipital and posterior cingulate cortex) and B (right frontal) and a decrease in cluster C (superior parietal lobe and middle cingulate cortex). NRS scores were inversely and moderately correlated with the intensity of rCBF increase in cluster B, but not to rCBF changes in clusters A and C. DN4 scores did not correlate with rCBF changes in all three clusters. / CONCLUSIONS: This study will be important for future therapeutic studies that aim to validate the association of rCBF findings with the pharmacokinetic and pharmacodynamic profiles of therapeutic challenges in pain

    Selection of suitable aquaponics system for empurau (Tor tambroides) fries nursery in polyculture method

    Get PDF
    Long-term use of the recirculated water for fish and crop production in the aquaponics system that is the major concern in sustainable aquaculture for reduction of the water quality led to explore the alternative way of short-time use of recirculated water in the aquaponics system that can be in nursery management. Three individual aquaponics (nutrient film “NFT,” deep water “DWC,” media bed “MBD”) along with a new combined aquaponics system (CAS) were used to explore the most suitable aquaponics system for empurau fries nursery. It was done by determining the comparison of growth performance and survivability of fish fries and plants along with the cost–benefit analysis among 4 aquaponics systems. The study was conducted in two phases. Phase 1 comprised of determining the effectiveness test of filters in newly designed CAS and the selection of suitable plant for the second phase. The suitability test for the selection of an aquaponics system for empurau fries nursery was done in the second phase. The polyculture method was adopted in both phases. The newly designed CAS with filter and the leafy vegetables (Apium graveolens var. secalinum) were selected from the first phase for further study in phase 2. The suitability results in the second phase exhibited that the NFT aquaponics system was significantly (P DWC ≄ CAS > MDB. Therefore, the study suggests using the NFT aquaponics system for empurau (Tor tambroides) fries’ nursery in short term

    The GAA triplet-repeat is unstable in the context of the human FXN locus and displays age-dependent expansions in cerebellum and DRG in a transgenic mouse model

    Get PDF
    Friedreich ataxia (FRDA) is caused by homozygosity for FXN alleles containing an expanded GAA triplet-repeat (GAA-TR) sequence. This expanded GAA-TR sequence is unstable in somatic cells of FRDA patients, showing age-dependent expansions in dorsal root ganglia (DRG), the tissue where pathology occurs earliest and is most significant. This is thought to be the basis for the progressive, tissue-specific pathology seen in FRDA, but the mechanism(s) for this somatic instability is unknown. We show that transgenic mice containing the expanded GAA-TR sequence (190 or 82 triplets) in the context of the human FXN locus show tissue-specific and age-dependent somatic instability that mimics the human condition. Small pool PCR analysis, which allows quantitative analysis of instability by assaying individual transgenes in vivo, showed age-dependent expansions specifically in the cerebellum and DRG. The (GAA)190 allele showed some instability by 2 months, progressed at about 0.3 – 0.4 triplets/week, resulting in a significant number of expansions by 12 months. Repeat length determined the age of onset of somatic instability, and the rate and magnitude of expansion. Whereas the GAA-TR was unstable in the context of the human FXN locus, pure GAATR sequences at other genetic loci in the human and murine genomes showed no instability. These data indicate that somatic instability of the GAA-TR sequence in the human FXN gene is determined by a combination of unique cis and trans-acting factors. This mouse model will serve as a useful tool to delineate the mechanism(s) of diseasespecific somatic instability in FRDA

    A search for pair-produced resonances in four-jet final states at root s=13 TeV with the ATLAS detector

    Get PDF
    A search for massive coloured resonances which are pair-produced and decay into two jets is presented. The analysis uses 36.7 fb−1 − 1 of √ s = 13 TeV pp collision data recorded by the ATLAS experiment at the LHC in 2015 and 2016. No significant deviation from the background prediction is observed. Results are interpreted in a SUSY simplified model where the lightest supersymmetric particle is the top squark, ̃ t ~ , which decays promptly into two quarks through R-parity-violating couplings. Top squarks with masses in the range 100 GeV<̃<410 100 GeV < m t ~ < 410 GeV GeV are excluded at 95% confidence level. If the decay is into a b-quark and a light quark, a dedicated selection requiring two b-tags is used to exclude masses in the ranges 100 GeV<̃<470 100 GeV < m t ~ < 470 GeV GeV and 480 GeV<̃<610 480 GeV < m t ~ < 610 GeV GeV . Additional limits are set on the pair-production of massive colour-octet resonances

    Measurements of electroweak Wjj production and constraints on anomalous gauge couplings with the ATLAS detector

    Get PDF
    Measurements of the electroweak production of a W boson in association with two jets at high dijet invariant mass are performed using root s = 7 and 8 TeV proton-proton collision data produced by the Large Hadron Collider, corresponding respectively to 4.7 and 20.2 fb(-1) of integrated luminosity collected by the ATLAS detector. The measurements are sensitive to the production of a W boson via a triple-gauge-boson vertex and include both the fiducial and differential cross sections of the electroweak process

    Feedback revisited: Adding perspectives based on positive psychology implications for theory and classroom practice

    No full text
    Teacher feedback has mainly been described from the point of view of cognitive psychology. We aim to add to the body of knowledge on teacher feedback by considering the perspective of positive psychology. We describe possible consequences of two concerns of positive psychology: (1) the importance of (positive) emotions and (2) character strengths. We argue that emotions are an important issue in the discussion about feedback and challenge the over-simplification of feedback about the self. As a way of stimulating positive emotions and character strengths, we propose to focus on progress feedback as a complement to gap feedback. (C) 2014 Elsevier Ltd. All rights reserved

    IL-21 is pivotal in determining age-dependent effectiveness of immune responses in a mouse model of human hepatitis B

    No full text
    HBV is a noncytopathic hepadnavirus and major human pathogen that causes immune-mediated acute and chronic hepatitis. The immune response to HBV antigens is age dependent: viral clearance occurs in most adults, while neonates and children usually develop chronic infection and liver disease. Here, we characterize an animal model for HBV infection that recapitulates the key differences in viral clearance between early life and adulthood and find that IL-21 may be part of an effective primary hepatic immune response to HBV. In our model, adult mice showed higher HBV-dependent IL-21 production in liver, compared with that of young mice. Conversely, absence of the IL-21 receptor in adult mice resulted in antigen persistence akin to that of young mice. In humans, levels of IL-21 transcripts were greatly increased in blood samples from acutely infected adults who clear the virus. These observations suggest a different model for the dichotomous, age-dependent outcome of HBV infection in humans, in which decreased IL-21 production in younger patients may hinder generation of crucial CD8+ T and B cell responses. These findings carry implications for therapeutic augmentation of immune responses to HBV and potentially other persistent liver viruses
    • 

    corecore