288 research outputs found

    Sprouted Innervation into Uterine Transplants Contributes to the Development of Hyperalgesia in a Rat Model of Endometriosis

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    Endometriosis is an enigmatic painful disorder whose pain symptoms remain difficult to alleviate in large part because the disorder is defined by extrauteral endometrial growths whose contribution to pain is poorly understood. A rat model (ENDO) involves autotransplanting on abdominal arteries uterine segments that grow into vascularized cysts that become innervated with sensory and sympathetic fibers. ENDO rats exhibit vaginal hyperalgesia. We used behavioral, physiological, and immunohistochemical methods to test the hypothesis that cyst innervation contributes to the development of this hyperalgesia after transplant. Rudimentary sensory and sympathetic innervation appeared in the cysts at two weeks, sprouted further and more densely into the cyst wall by four weeks, and matured by six weeks post-transplant. Sensory fibers became abnormally functionally active between two and three weeks post-transplant, remaining active thereafter. Vaginal hyperalgesia became significant between four and five weeks post-transplant, and stabilized after six to eight weeks. Removing cysts before they acquired functional innervation prevented vaginal hyperalgesia from developing, whereas sham cyst removal did not. Thus, abnormally-active innervation of ectopic growths occurs before hyperalgesia develops, supporting the hypothesis. These findings suggest that painful endometriosis can be classified as a mixed inflammatory/neuropathic pain condition, which opens new avenues for pain relief. The findings also have implications beyond endometriosis by suggesting that functionality of any transplanted tissue can be influenced by the innervation it acquires

    EP<sub>2</sub> receptor antagonism reduces peripheral and central hyperalgesia in a preclinical mouse model of endometriosis

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    Endometriosis is an incurable gynecological disorder characterized by debilitating pain and the establishment of innervated endometriosis lesions outside the uterus. In a preclinical mouse model of endometriosis we demonstrated overexpression of the PGE2-signaling pathway (including COX-2, EP2, EP4) in endometriosis lesions, dorsal root ganglia (DRG), spinal cord, thalamus and forebrain. TRPV1, a PGE2-regulated channel in nociceptive neurons was also increased in the DRG. These findings support the concept that an amplification process occurs along the pain neuroaxis in endometriosis. We then tested TRPV1, EP2, and EP4 receptor antagonists: The EP2 antagonist was the most efficient analgesic, reducing primary hyperalgesia by 80% and secondary hyperalgesia by 40%. In this study we demonstrate reversible peripheral and central hyperalgesia in mice with induced endometriosis

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

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    SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation

    Responsibility for managing musculoskeletal disorders – A cross-sectional postal survey of attitudes

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    Background: Musculoskeletal disorders are a major burden on individuals, health systems and social care systems and rehabilitation efforts in these disorders are considerable. Self-care is often considered a cost effective treatment alternative owing to limited health care resources. But what are the expectations and attitudes in this question in the general population? The purpose of this study was to describe general attitudes to responsibility for the management of musculoskeletal disorders and to explore associations between attitudes and background variables. Methods: A cross-sectional, postal questionnaire survey was carried out with a random sample of a general adult Swedish population of 1770 persons. Sixty-one percent (n = 1082) responded to the questionnaire and was included for the description of general attitudes towards responsibility for the management of musculoskeletal disorders. For the further analyses of associations to background variables 683–693 individuals could be included. Attitudes were measured by the &quot;Attitudes regarding Responsibility for Musculoskeletal disorders&quot; (ARM) instrument, where responsibility is attributed on four dimensions; to myself, as being out of my hands, to employers or to (medical) professionals. Multiple logistic regression was used to explore associations between attitudes to musculoskeletal disorders and the background variables age, sex, education, physical activity, presence of musculoskeletal disorders, sick leave and whether the person had visited a care provider. Results: A majority of participants had internal views, i.e. showed an attitude of taking personal responsibility for musculoskeletal disorders, and did not place responsibility for the management out of their own hands or to employers. However, attributing shared responsibility between self and medical professionals was also found.The main associations found between attitude towards responsibility for musculoskeletal disorders and investigated background variables were that physical inactivity (OR 2.92–9.20), musculoskeletal disorder related sick leave (OR 2.31–3.07) and no education beyond the compulsory level (OR 3.12–4.76) increased the odds of attributing responsibility externally, i.e placing responsibility on someone or something else.Conclusion: Respondents in this study mainly saw themselves as responsible for managing musculoskeletal disorders. The associated background variables refined this finding and one conclusion is that, to optimise outcome when planning the prevention, treatment and management of these disorders, people&apos;s attitudes should be taken into account

    Abnormal cortical responses to somatosensory stimulation in medication-overuse headache

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    BACKGROUND: Medication-overuse headache (MOH) is a frequent, disabling disorder. Despite a controversial pathophysiology convincing evidence attributes a pivotal role to central sensitization. Most patients with MOH initially have episodic migraine without aura (MOA) characterized interictally by an absent amplitude decrease in cortical evoked potentials to repetitive stimuli (habituation deficit), despite a normal initial amplitude (lack of sensitization). Whether central sensitization alters this electrophysiological profile is unknown. We therefore sought differences in somatosensory evoked potential (SEP) sensitization and habituation in patients with MOH and episodic MOA. METHODS: We recorded median-nerve SEPs (3 blocks of 100 sweeps) in 29 patients with MOH, 64 with MOA and 42 controls. Episodic migraineurs were studied during and between attacks. We measured N20-P25 amplitudes from 3 blocks of 100 sweeps, and assessed sensitization from block 1 amplitude, and habituation from amplitude changes between the 3 sequential blocks. RESULTS: In episodic migraineurs, interictal SEP amplitudes were normal in block 1, but thereafter failed to habituate. Ictal SEP amplitudes increased in block 1, then habituated normally. Patients with MOH had larger-amplitude block 1 SEPs than controls, and also lacked SEP habituation. SEP amplitudes were smaller in triptan overusers than in patients overusing nonsteroidal anti-inflammatory drugs (NSAIDs) or both medications combined, lowest in patients with the longest migraine history, and highest in those with the longest-lasting headache chronification. CONCLUSIONS: In patients with MOH, especially those overusing NSAIDs, the somatosensory cortex becomes increasingly sensitized. Sensory sensitization might add to the behavioral sensitization that favors compulsive drug intake, and may reflect drug-induced changes in central serotoninergic transmission

    Electric toothbrush application is a reliable and valid test for differentiating temporomandibular disorders pain patients from controls

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    <p>Abstract</p> <p>Background</p> <p>Current methods for identifying patients with pain hypersensitivity are sufficiently complex to limit their widespread application in clinical settings. We assessed the reliability and validity of a simple multi-modal vibrotactile stimulus, applied using an electric toothbrush, to evaluate its potential as a screening tool for central sensitization.</p> <p>Methods</p> <p>Fourteen female temporomandibular disorders (TMD) subjects with myofascial pain (RDC/TMD Ia or Ib) and arthralgia (RDC/TMD IIIa) were compared to 13 pain-free controls of matched age and gender. Vibrotactile stimulus was performed with an electric toothbrush, applied with 1 pound pressure for 30 seconds in four locations: over the lateral pole of the temporomandibular joint, masseter, temporalis, and mid-ventral surface of forearm. Pain intensity (0–10) was recorded following the stimulus at 0, 15, 30, and 60 seconds. Test-retest reliability was assessed with measurements from 8 participants, taken 2–12 hours apart. Case versus control differentiation involved comparison of area under the curve (AUC). A receiver operating characteristic (ROC) curve was used to determine cutoff AUC scores for maximum sensitivity and specificity for this multi-modal vibrotactile stimulus.</p> <p>Results</p> <p>Test-retest reliability resulted in an ICC of 0.87 for all 4 pooled sites. ROC-determined AUC cutoff scores resulted in a sensitivity of 57% and specificity of 92% for all 4 pooled sites.</p> <p>Conclusion</p> <p>The electric toothbrush stimulus had excellent test-retest reliability. Validity of the scores was demonstrated with modest sensitivity and good specificity for differentiating TMD pain patients from controls, which are acceptable properties for a screening test.</p

    Specific ion channels contribute to key elements of pathology during secondary degeneration following neurotrauma

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    Background: Following partial injury to the central nervous system, cells beyond the initial injury site undergo secondary degeneration, exacerbating loss of neurons, compact myelin and function. Changes in Ca 2+ flux are associated with metabolic and structural changes, but it is not yet clear how flux through specific ion channels contributes to the various pathologies. Here, partial optic nerve transection in adult female rats was used to model secondary degeneration. Treatment with combinations of three ion channel inhibitors was used as a tool to investigate which elements of oxidative and structural damage related to long term functional outcomes. The inhibitors employed were the voltage gated Ca 2+ channel inhibitor Lomerizine (Lom), the Ca 2+ permeable AMPA receptor inhibitor YM872 and the P2X 7 receptor inhibitor oxATP. Results: Following partial optic nerve transection, hyper-phosphorylation of Tau and acetylated tubulin immunoreactivity were increased, and Nogo-A immunoreactivity was decreased, indicating that axonal changes occurred acutely. All combinations of ion channel inhibitors reduced hyper-phosphorylation of Tau and increased Nogo-A immunoreactivity at day 3 after injury. However, only Lom/oxATP or all three inhibitors in combination significantly reduced acetylated tubulin immunoreactivity. Most combinations of ion channel inhibitors were effective in restoring the lengths of the paranode and the paranodal gap, indicative of the length of the node of Ranvier, following injury. However, only all three inhibitors in combination restored to normal Ankyrin G length at the node of Ranvier. Similarly, HNE immunoreactivity and loss of oligodendrocyte precursor cells were only limited by treatment with all three ion channel inhibitors in combination. Conclusions: Data indicate that inhibiting any of a range of ion channels preserves certain elements of axon and node structure and limits some oxidative damage following injury, whereas ionic flux through all three channels must be inhibited to prevent lipid peroxidation and preserve Ankyrin G distribution and OPCs

    A recent increase in global wave power as a consequence of oceanic warming

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    Wind-generated ocean waves drive important coastal processes that determine flooding and erosion. Ocean warming has been one factor affecting waves globally. Most studies have focused on studying parameters such as wave heights, but a systematic, global and long-term signal of climate change in global wave behavior remains undetermined. Here we show that the global wave power, which is the transport of the energy transferred from the wind into sea-surface motion, has increased globally (0.4% per year) and by ocean basins since 1948. We also find long-term correlations and statistical dependency with sea surface temperatures, globally and by ocean sub-basins, particularly between the tropical Atlantic temperatures and the wave power in high south latitudes, the most energetic region globally. Results indicate the upper-ocean warming, a consequence of anthropogenic global warming, is changing the global wave climate, making waves stronger. This identifies wave power as a potentially valuable climate change indicator.Funding for this project was partly provided by RISKOADAPT (BIA2017-89401-R) Spanish Ministry of Science, Innovation and Universities and the ECLISEA project part of the Horizon 2020 ERANET ERA4CS (European Research Area for Climate Services) 2016 Call

    Systems Biology by the Rules: Hybrid Intelligent Systems for Pathway Modeling and Discovery

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    Background: Expert knowledge in journal articles is an important source of data for reconstructing biological pathways and creating new hypotheses. An important need for medical research is to integrate this data with high throughput sources to build useful models that span several scales. Researchers traditionally use mental models of pathways to integrate information and development new hypotheses. Unfortunately, the amount of information is often overwhelming and these are inadequate for predicting the dynamic response of complex pathways. Hierarchical computational models that allow exploration of semi-quantitative dynamics are useful systems biology tools for theoreticians, experimentalists and clinicians and may provide a means for cross-communication. Results: A novel approach for biological pathway modeling based on hybrid intelligent systems or soft computing technologies is presented here. Intelligent hybrid systems, which refers to several related computing methods such as fuzzy logic, neural nets, genetic algorithms, and statistical analysis, has become ubiquitous in engineering applications for complex control system modeling and design. Biological pathways may be considered to be complex control systems, which medicine tries to manipulate to achieve desired results. Thus, hybrid intelligent systems may provide a useful tool for modeling biological system dynamics and computational exploration of new drug targets. A new modeling approach based on these methods is presented in the context of hedgehog regulation of the cell cycle in granule cells. Code and input files can be found at the Bionet website: www.chip.ord/~wbosl/Software/Bionet. Conclusion: This paper presents the algorithmic methods needed for modeling complicated biochemical dynamics using rule-based models to represent expert knowledge in the context of cell cycle regulation and tumor growth. A notable feature of this modeling approach is that it allows biologists to build complex models from their knowledge base without the need to translate that knowledge into mathematical form. Dynamics on several levels, from molecular pathways to tissue growth, are seamlessly integrated. A number of common network motifs are examined and used to build a model of hedgehog regulation of the cell cycle in cerebellar neurons, which is believed to play a key role in the etiology of medulloblastoma, a devastating childhood brain cancer
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