438 research outputs found

    The OARSI histopathology initiative – recommendations for histological assessments of osteoarthritis in the rat

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    SummaryObjectiveDuring the development of disease-modifying osteoarthritis (OA) drugs, rat models of OA are frequently used for a first assessment of in vivo efficacy. The most efficacious compound in the rat model may then be tested in a larger animal model before entering human trials. The aim of this study was to describe a histologic scoring system for use in different models of OA in rats that allows standardization and comparison of results obtained by different investigators.MethodsThe experience of the authors with current scoring systems and the range of lesions observed in rat and human OA studies were considered in recommending this common paradigm for rat histologic scoring. Considerations were made for reproducibility and ease of use for new scorers. Additional scoring paradigms may be employed to further identify specific effects of some disease-modifying drugs.ResultsAlthough the described scoring system is more complex than the modified Mankin scores, which are recommended for some other species, the reliability study showed that it is easily understood and can be reproducibly used, even by inexperienced scorers.ConclusionsThe scoring paradigm described here has been found to be sufficiently sensitive to discriminate between treatments and to have high reproducibility. Therefore we recommend its use for evaluation of different rat OA models as well as assessment of disease-modifying effects of treatments in these models

    Cortical alpha activity predicts the confidence in an impending action

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    When we make a decision, we experience a degree of confidence that our choice may lead to a desirable outcome. Recent studies in animals have probed the subjective aspects of the choice confidence using confidence-reporting tasks. These studies showed that estimates of the choice confidence substantially modulate neural activity in multiple regions of the brain. Building on these findings, we investigated the neural representation of the confidence in a choice in humans who explicitly reported the confidence in their choice. Subjects performed a perceptual decision task in which they decided between choosing a button press or a saccade while we recorded EEG activity. Following each choice, subjects indicated whether they were sure or unsure about the choice. We found that alpha activity strongly encodes a subject's confidence level in a forthcoming button press choice. The neural effect of the subjects' confidence was independent of the reaction time and independent of the sensory input modeled as a decision variable. Furthermore, the effect is not due to a general cognitive state, such as reward expectation, because the effect was specifically observed during button press choices and not during saccade choices. The neural effect of the confidence in the ensuing button press choice was strong enough that we could predict, from independent single trial neural signals, whether a subject was going to be sure or unsure of an ensuing button press choice. In sum, alpha activity in human cortex provides a window into the commitment to make a hand movement

    Optimizing field-of-view of deep-tissue scanning microscopy

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    For centuries, the optical microscope has been a crucial instrument for new biological findings, as microscopes were the first devices allowing to observe the internal processes of the cell. Unfortunately, this observation requires the use of thin samples, as biological tissue scatters the incoming light, resulting in a blurred image. An ever increasing number of deep-tissue imaging technique have pushed the penetration depth of the optical microscope. Methods such as adaptive optics [1] allow focusing inside biological tissue by correcting for scattering introduced by the sample. However, adaptive optics methods can only correct for image distortions caused by scattering over a single small area (i.e., field-of-view) within tissue. Please click Additional Files below to see the full abstract

    Localizing ECoG electrodes on the cortical anatomy without post-implantation imaging

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    AbstractIntroductionElectrocorticographic (ECoG) grids are placed subdurally on the cortex in people undergoing cortical resection to delineate eloquent cortex. ECoG signals have high spatial and temporal resolution and thus can be valuable for neuroscientific research. The value of these data is highest when they can be related to the cortical anatomy. Existing methods that establish this relationship rely either on post-implantation imaging using computed tomography (CT), magnetic resonance imaging (MRI) or X-Rays, or on intra-operative photographs. For research purposes, it is desirable to localize ECoG electrodes on the brain anatomy even when post-operative imaging is not available or when intra-operative photographs do not readily identify anatomical landmarks.MethodsWe developed a method to co-register ECoG electrodes to the underlying cortical anatomy using only a pre-operative MRI, a clinical neuronavigation device (such as BrainLab VectorVision), and fiducial markers. To validate our technique, we compared our results to data collected from six subjects who also had post-grid implantation imaging available. We compared the electrode coordinates obtained by our fiducial-based method to those obtained using existing methods, which are based on co-registering pre- and post-grid implantation images.ResultsOur fiducial-based method agreed with the MRI–CT method to within an average of 8.24mm (mean, median=7.10mm) across 6 subjects in 3 dimensions. It showed an average discrepancy of 2.7mm when compared to the results of the intra-operative photograph method in a 2D coordinate system. As this method does not require post-operative imaging such as CTs, our technique should prove useful for research in intra-operative single-stage surgery scenarios.To demonstrate the use of our method, we applied our method during real-time mapping of eloquent cortex during a single-stage surgery. The results demonstrated that our method can be applied intra-operatively in the absence of post-operative imaging to acquire ECoG signals that can be valuable for neuroscientific investigations

    Temporal variability in trace metal solubility in a paddy soil not reflected in uptake by rice (Oryza sativa L.)

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    Alternating flooding and drainage conditions have a strong influence on redox chemistry and the solubility of trace metals in paddy soils. However, current knowledge of how the effects of water management on trace metal solubility are linked to trace metal uptake by rice plants over time is still limited. Here, a field-contaminated paddy soil was subjected to two flooding and drainage cycles in a pot experiment with two rice plant cultivars, exhibiting either high or low Cd accumulation characteristics. Flooding led to a strong vertical gradient in the redox potential (Eh). The pH and Mn, Fe, and dissolved organic carbon concentrations increased with decreasing Eh and vice versa. During flooding, trace metal solubility decreased markedly, probably due to sulfide mineral precipitation. Despite its low solubility, the Cd content in rice grains exceeded the food quality standards for both cultivars. Trace metal contents in different rice plant tissues (roots, stem, and leaves) increased at a constant rate during the first flooding and drainage cycle but decreased after reaching a maximum during the second cycle. As such, the high temporal variability in trace metal solubility was not reflected in trace metal uptake by rice plants over time. This might be due to the presence of aerobic conditions and a consequent higher trace metal solubility near the root surface, even during flooding. Trace metal solubility in the rhizosphere should be considered when linking water management to trace metal uptake by rice over time

    A randomized, placebo-controlled double-blinded comparative clinical study of five over-the-counter non-pharmacological topical analgesics for myofascial pain: single session findings

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    <p>Abstract</p> <p>Objectives</p> <p>To investigate the effects of topical agents for the treatment of Myofascial Pain Syndrome (MPS) and Myofascial Trigger Point (MTRP).</p> <p>Methods</p> <p>Subjects with an identifiable trigger point in the trapezius muscle, age 18-80 were recruited for a single-session randomized, placebo-blinded clinical study. Baseline measurements of trapezius muscle pressure pain threshold (PPT: by pressure algometer) along with right and left cervical lateral flexion (rangiometer) were obtained by a blinded examiner. An assessor blinded to the outcomes assessments applied one of 6 topical formulations which had been placed in identical plastic containers. Five of these topicals were proposed active formulations; the control group was given a non-active formulation (PLA). Five minutes after the application of the formula the outcome measures were re-tested. Data were analyzed with a 5-way ANOVA and Holms-adjusted t-tests with an alpha level of 0.05.</p> <p>Results</p> <p>120 subjects were entered into the study (63 females; ages 16-82); 20 subjects randomly allocated into each group. The pre- and post-treatment results for pressure threshold did show significant intra-group increases for the Ben-Gay Ultra Strength Muscle Pain Ointment (BG), the Professional Therapy MuscleCare Roll-on (PTMC roll-on) and Motion Medicine Cream (MM) with an increased threshold of 0.5 kg/cm<sup>2 </sup>(+/-0.15), 0.72 kg/cm<sup><b>2 </b></sup>(+/-0.17) and 0.47 Kg/cm<sup><b>2 </b></sup>(+/-0.19) respectively. With respect to the inter-group comparisons, PTMC roll-on showed significant increases in pressure threshold compared with Placebo (PLA) (p = 0.002) and Icy Hot Extra Strength Cream (IH) (p = 0.006). In addition, BG demonstrated significant increases in pressure threshold compared with PLA (p = 0.0003).</p> <p>Conclusions</p> <p>With regards to pressure threshold, PTMC roll-on, BG and MM showed significant increases in pain threshold tolerance after a short-term application on a trigger points located in the trapezius muscle. PTMC roll-on and BG were both shown to be superior vs placebo while PTMC was also shown to be superior to IH in patients with trigger points located in the trapezius muscle on a single application.</p> <p>CMCC Research Ethics Board Approval # 1012X01, 2011</p

    Raman spectroscopy for guidance of vulvar cancer surgery:A pilot study

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    For vulvar squamous cell carcinoma (VSCC), the mainstay of treatment is surgical removal with tumour-free margins. Surgeons still operate without objective tools that provide margin-status. This study assesses Raman spectroscopy potentiality for distinguishing ex-vivo VSCC from healthy tissue in 11 patients. Grid-based Raman maps were obtained from processed spectra. Water content and C-H band ratio (2,910-2,966 cm(-1) / 2810-2890 cm(-1)) were calculated per spectrum and used as linear discriminant parameters. Healthy tissue was differentiated from VSCC with 0.90 discriminative power, 0.79 sensitivity and 0.86 specificity.This is an important step towards the development of objective tools for VSCC surgical guidance

    CD47 Expression Defines Efficacy of Rituximab with CHOP in Non-Germinal Center B-cell (Non-GCB) Diffuse Large B-cell Lymphoma Patients (DLBCL), but Not in GCB DLBCL

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    Addition of rituximab (R) to "CHOP" (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy improved outcome for diffuse large B-cell lymphoma (DLBCL) patients. Approximately 40% of patients who receive R-CHOP still succumb to disease due to intrinsic resistance or relapse. A potential negative regulator of DLBCL treatment outcome is the CD47 "don't eat me" immune checkpoint. To delineate the impact of CD47, we used a clinically and molecularly well-annotated cohort of 939 DLBCL patients, comprising both germinal center B-cell (GCB) and non-GCB DLBCL subtypes, treated with either CHOP or R-CHOP. High (above median) CD47 mRNA expression correlated with a detrimental effect on overall survival (OS) when DLBCL patients received R-CHOP therapy (P = 0.001), but not CHOP therapy (P = 0.645). Accordingly, patients with low CD47 expression benefited most from the addition of rituximab to CHOP [HR, 0.32; confidence interval (CI), 0.21-0.50; P <0.001]. This negative impact of high CD47 expression on OS after R-CHOP treatment was only evident in cancers of non-GCB origin (HR, 2.09; CI, 1.26-3.47; P = 0.004) and not in the GCB subtype (HR, 1.16; CI, 0.68-1.99; P = 0.58). This differential impact of CD47 in non-GCB and GCB was confirmed in vitro, as macrophage-mediated phagocytosis stimulated by rituximab was augmented by CD47-blocking antibody only in non-GCB cell lines. Thus, high expression of CD47 mRNA limited the benefit of addition of rituximab to CHOP in non-GCB patients, and CD47-blockade only augmented rituximab-mediated phagocytosis in non-GCB cell lines. Patients with non-GCB DLBCL may benefit from CD47-targeted therapy in addition to rituximab

    Assessment and quantification of marginal lands for biomass production in Europe using soil-quality indicators

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    The cultivation of bioenergy plants in fertile, arable lands increasingly results in new land use conflicts with food production and cannot be considered as sustainable. Marginal lands have been frequently considered as potential alternatives for producing bioenergy from biomass. However, clear definitions and assessment methods for selecting marginal lands and for calculating potentials are still widely missing. The project “SEEMLA” aims at triggering the exploitation of currently underused marginal lands for biomass production for energy purposes. Study sites have been selected in different European countries: Germany, Greece, and Ukraine. The selected sites represent a wide variety of different types of marginal lands. Based on a soil assessment set given by the Muencheberg Soil Quality Rating (SQR) system potentially “marginal” sites have been investigated. The SQR system allows for clearly distinguishing between soils of higher and lower quality. Soils with SQR scores below 40 are regarded as “marginal”. They can be classified into different groups with regard to the importance of soil hazard indicators as evaluated by the SQR approach. The calculated SQR scores correlate significantly with biomass yields of bioenergy plants. Further, the SQR method was adapted for use in a GIS study on marginal-land potentials in Europe. Thus, 46&thinsp;% of the investigated European area could be classified as “marginal” with SQR scores below 40. From that area 22.6&thinsp;% can be considered as potentially suitable for producing renewable resources after eliminating protected sites or other places not suitable for any kind of land use. Taking the ecological demands of selected bioenergy plants into account it is possible to give first preliminary recommendations for regional crop cultivation. It can be concluded that Europe offers a large potential for renewable resources from marginal sites. However, the implementation into practice is often impeded by missing or varying policies and regulations. A proper implementation needs clear regulations and also incentives for farmers at the European level.</p
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