1,598 research outputs found
Regulation of peripheral inflammation by spinal p38 MAP kinase in rats.
BackgroundSomatic afferent input to the spinal cord from a peripheral inflammatory site can modulate the peripheral response. However, the intracellular signaling mechanisms in the spinal cord that regulate this linkage have not been defined. Previous studies suggest spinal cord p38 mitogen-activated protein (MAP) kinase and cytokines participate in nociceptive behavior. We therefore determined whether these pathways also regulate peripheral inflammation in rat adjuvant arthritis, which is a model of rheumatoid arthritis.Methods and findingsSelective blockade of spinal cord p38 MAP kinase by administering the p38 inhibitor SB203580 via intrathecal (IT) catheters in rats with adjuvant arthritis markedly suppressed paw swelling, inhibited synovial inflammation, and decreased radiographic evidence of joint destruction. The same dose of SB203580 delivered systemically had no effect, indicating that the effect was mediated by local concentrations in the neural compartment. Evaluation of articular gene expression by quantitative real-time PCR showed that spinal p38 inhibition markedly decreased synovial interleukin-1 and -6 and matrix metalloproteinase (MMP3) gene expression. Activation of p38 required tumor necrosis factor alpha (TNFalpha) in the nervous system because IT etanercept (a TNF inhibitor) given during adjuvant arthritis blocked spinal p38 phosphorylation and reduced clinical signs of adjuvant arthritis.ConclusionsThese data suggest that peripheral inflammation is sensed by the central nervous system (CNS), which subsequently activates stress-induced kinases in the spinal cord via a TNFalpha-dependent mechanism. Intracellular p38 MAP kinase signaling processes this information and profoundly modulates somatic inflammatory responses. Characterization of this mechanism could have clinical and basic research implications by supporting development of new treatments for arthritis and clarifying how the CNS regulates peripheral immune responses
Familial adenomatosis polyposis–related desmoid tumours treated with low-dose chemotherapy: results from an international, multi-institutional, retrospective analysis
[Introduction] Desmoid tumour (DT) is a locally aggressive fibroblastic proliferative disease representing the most common extraintestinal manifestation of familial adenomatosis polyposis (FAP). As data on the activity of chemotherapy in these patients are limited, we examined the outcomes of patients treated with low-dose methotrexate (MTX)+vinca alkaloids (vinorelbine or vinblastine).[Patients and methods] We retrospectively reviewed clinical and outcome data from all patients with confirmed FAP-associated DTs treated with weekly MTX+vinca alkaloids in seven European sarcoma reference centres between January 2000 and December 2018. Radiological responses were assessed using RECIST V.1.0 and V.1.1. The Kaplan-Meier method associated to the log-rank test was used to estimate and compare survival curves.[Results] We identified 37 patients (median age 29 years, range 7–44). According to RECIST, 20/37 (54.1%) patients achieved partial response (PR), 15/37 (40.5%) patients had stable disease and 2/37 (5.4%) had progressive disease as best response. Overall, the median progression-free survival (PFS) was 6.5 years (range, 0.3–12.1 years). In the subset of patients achieving PR as best response, the median PFS was not reached. In a subset of 11 patients with progressive disease offered MTX+vinca alkaloids rechallenge (after chemotherapy withdrawal following prolonged disease control), the disease control rate was 100%, resulting in a median PFS after rechallenge of 5.8 years.[Conclusions] This is the largest series on the activity of low-dose chemotherapy in patients with FAP-related DT. In this population, MTX+vinca alkaloids is an active combination, as already reported in patients with sporadic DT
Attractor dynamics approach to joint transportation by autonomous robots: theory, implementation and validation on the factory floor
This paper shows how non-linear attractor dynamics can be used to control teams of two autonomous mobile robots that coordinate their motion in order to transport large payloads in unknown environments, which might change over time and may include narrow passages, corners and sharp U-turns. Each robot generates its collision-free motion online as the sensed information changes. The control architecture for each robot is formalized as a non-linear dynamical system, where by design attractor states, i.e. asymptotically stable states, dominate and evolve over time. Implementation details are provided, and it is further shown that odometry or calibration errors are of no significance. Results demonstrate flexible and stable behavior in different circumstances: when the payload is of different sizes; when the layout of the environment changes from one run to another; when the environment is dynamice.g. following moving targets and avoiding moving obstacles; and when abrupt disturbances challenge team behavior during the execution of the joint transportation task.- This work was supported by FCT-Fundacao para a Ciencia e Tecnologia within the scope of the Project PEst-UID/CEC/00319/2013 and by the Ph.D. Grants SFRH/BD/38885/2007 and SFRH/BPD/71874/2010, as well as funding from FP6-IST2 EU-IP Project JAST (Proj. Nr. 003747). We would like to thank the anonymous reviewers, whose comments have contributed to improve the paper
Robust Reproducible Resting State Networks in the Awake Rodent Brain
Resting state networks (RSNs) have been studied extensively with functional MRI in humans in health and disease to reflect brain function in the un-stimulated state as well as reveal how the brain is altered with disease. Rodent models of disease have been used comprehensively to understand the biology of the disease as well as in the development of new therapies. RSN reported studies in rodents, however, are few, and most studies are performed with anesthetized rodents that might alter networks and differ from their non-anesthetized state. Acquiring RSN data in the awake rodent avoids the issues of anesthesia effects on brain function. Using high field fMRI we determined RSNs in awake rats using an independent component analysis (ICA) approach, however, ICA analysis can produce a large number of components, some with biological relevance (networks). We further have applied a novel method to determine networks that are robust and reproducible among all the components found with ICA. This analysis indicates that 7 networks are robust and reproducible in the rat and their putative role is discussed
Why Firms Relocate Their Production Overseas? The Answer Lies Inside: Corporate, Logistic and Technological Determinants
Ice-Age Climate Adaptations Trap the Alpine Marmot in a State of Low Genetic Diversity.
Some species responded successfully to prehistoric changes in climate [1, 2], while others failed to adapt and became extinct [3]. The factors that determine successful climate adaptation remain poorly understood. We constructed a reference genome and studied physiological adaptations in the Alpine marmot (Marmota marmota), a large ground-dwelling squirrel exquisitely adapted to the "ice-age" climate of the Pleistocene steppe [4, 5]. Since the disappearance of this habitat, the rodent persists in large numbers in the high-altitude Alpine meadow [6, 7]. Genome and metabolome showed evidence of adaptation consistent with cold climate, affecting white adipose tissue. Conversely, however, we found that the Alpine marmot has levels of genetic variation that are among the lowest for mammals, such that deleterious mutations are less effectively purged. Our data rule out typical explanations for low diversity, such as high levels of consanguineous mating, or a very recent bottleneck. Instead, ancient demographic reconstruction revealed that genetic diversity was lost during the climate shifts of the Pleistocene and has not recovered, despite the current high population size. We attribute this slow recovery to the marmot's adaptive life history. The case of the Alpine marmot reveals a complicated relationship between climatic changes, genetic diversity, and conservation status. It shows that species of extremely low genetic diversity can be very successful and persist over thousands of years, but also that climate-adapted life history can trap a species in a persistent state of low genetic diversity.This work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001134), the UK Medical Research Council (FC001134), and the Wellcome Trust (FC001134). CB and AC are supported by the Agence Nationale de la Recherche (project ANR-13-JSV7-0005) and the Centre National de la Recherche Scientifique (CNRS), CB is supported by the Rhône-Alpes region (Grant 15.005146.01). LD is supported by Agence Nationale de la Recherche (project ANR-12-ADAP-0009). TIG is supported by a Leverhulme Early Career Fellowship (Grant ECF-2015-453) and a NERC grant (NE/N013832/1). JMG is supported by a Hertha Finberg Fellowship (FWF T703). LDR is supported by the Diabetes UK RD Lawrence Fellowship (16/0005382)
The human phylome
The human phylome, which includes evolutionary relationships of all human proteins and their homologs among thirty-nine fully sequenced eukaryotes, is reconstructed
From Plants to Birds: Higher Avian Predation Rates in Trees Responding to Insect Herbivory
BACKGROUND: An understanding of the evolution of potential signals from plants to the predators of their herbivores may provide exciting examples of co-evolution among multiple trophic levels. Understanding the mechanism behind the attraction of predators to plants is crucial to conclusions about co-evolution. For example, insectivorous birds are attracted to herbivore-damaged trees without seeing the herbivores or the defoliated parts, but it is not known whether birds use cues from herbivore-damaged plants with a specific adaptation of plants for this purpose. METHODOLOGY: We examined whether signals from damaged trees attract avian predators in the wild and whether birds could use volatile organic compound (VOC) emissions or net photosynthesis of leaves as cues to detect herbivore-rich trees. We conducted a field experiment with mountain birches (Betula pubescens ssp. czerepanovii), their main herbivore (Epirrita autumnata) and insectivorous birds. Half of the trees had herbivore larvae defoliating trees hidden inside branch bags and half had empty bags as controls. We measured predation rate of birds towards artificial larvae on tree branches, and VOC emissions and net photosynthesis of leaves. PRINCIPAL FINDINGS AND SIGNIFICANCE: The predation rate was higher in the herbivore trees than in the control trees. This confirms that birds use cues from trees to locate insect-rich trees in the wild. The herbivore trees had decreased photosynthesis and elevated emissions of many VOCs, which suggests that birds could use either one, or both, as cues. There was, however, large variation in how the VOC emission correlated with predation rate. Emissions of (E)-DMNT [(E)-4,8-dimethyl-1,3,7-nonatriene], beta-ocimene and linalool were positively correlated with predation rate, while those of highly inducible green leaf volatiles were not. These three VOCs are also involved in the attraction of insect parasitoids and predatory mites to herbivore-damaged plants, which suggests that plants may not have specific adaptations to signal only to birds
Three-dimensional reconstruction of synapses and dendritic spines in the rat and ground squirrel hippocampus: New structural-functional paradigms for synaptic function
Published data are reviewed along with our own data on synaptic plasticity and rearrangements of synaptic organelles in the central nervous system. Contemporary laser scanning and confocal microscopy techniques are discussed, along with the use of serial ultrathin sections for in vivo and in vitro studies of dendritic spines, including those addressing relationships between morphological changes and the efficiency of synaptic transmission, especially in conditions of the long-term potentiation model. Different categories of dendritic spines and postsynaptic densities are analyzed, as are the roles of filopodia in originating spines. The role of serial ultrathin sections for unbiased quantitative stereological analysis and three-dimensional reconstruction is assessed. The authors data on the formation of more than two synapses on single mushroom spines on neurons in hippocampal field CA1 are discussed. Analysis of these data provides evidence for new paradigms in both the organization and functioning of synapses
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