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Psoriasis is a chronic, immune-mediated dermatologic disorder with a prevalence among children estimated at 0.1%-0.45%, and a median age of onset at approximately 7-10 years. Pediatric psoriasis is known to have negative impacts on health-related quality of life. Among the most bothersome symptoms, itch has been measured using the Itch Numeric Rating Scale (NRS). This study explored the symptom and impacts of itch with pediatric psoriasis patients and evaluated the content validity of the Itch NRS in children.
Learn More >Chronic widespread musculoskeletal pain (CWP) is a characteristic symptom of fibromyalgia, which has been shown to be associated with an altered gut microbiome. Microbiome studies to date have not examined the milder CWP phenotype specifically nor have they explored the role of raised BMI. The aim of this study was to investigate whether the microbiome is abnormal in CWP.
Learn More >As psychosocial factors have been recognised as significant predictors of the recovery trajectory from chronic back pain, the 34-item Back Pain Attitudes Questionnaire (Back-PAQ) was developed based on themes obtained from patient interviews, but previous psychometric analyses with a general population sample revealed uncertainty around the factor structure of the instrument.
Learn More >A chronic pain patient sample living in the United States who participated in a cross-sectional study to evaluate the validity and reproducibility of the Prescription Opioid Misuse and Abuse Questionnaire is characterized.
Learn More >Atopic dermatitis (AD) is a relapsing and remitting disease characterized by intense pruritus that can lead to scratching and eczematous lesions that vary in extent and severity . Over 60% of AD cases are mild, characterized by slight erythema, induration, and lichenification . Chronic pruritus, pruritus lasting more than 6 weeks, has been reported by 91% of AD patients . The pathophysiology of AD is driven by a combination of skin barrier dysfunction, neuroinflammation, and immune system dysregulation .
Learn More >Seasonal rhythms influence emotion and sociability. The brain μ-opioid receptor (MOR) system modulates a multitude of seasonally varying socioemotional functions, but its seasonal variation remains elusive with no previously reported evidence. Here, we first conducted a cross-sectional study with previously acquired human [C]carfentanil PET imaging data (132 male and 72 female healthy subjects) to test whether there was seasonal difference in MOR availability. We then investigated experimentally whether seasonal variation in daylength causally influences brain MOR availability in rats. Rats (six male and three female rats) underwent daylength cycle simulating seasonal changes; control animals (two male and one female rats) were kept under constant daylength. Animals were scanned repeatedly with [C]carfentanil PET imaging. Seasonally varying daylength had an inverted U-shaped functional relationship with brain MOR availability in humans. Brain regions sensitive to daylength spanned the socio-emotional brain circuits, where MOR availability formed a spring-like peak. In rats, MOR availabilities in the brain neocortex, thalamus and striatum peaked at intermediate daylength. Varying daylength also affected the weight gain and stress hormone. We conclude that the brain MOR availability in humans and rats shows significant seasonal variation, which is predominately associated with seasonal photoperiodic variation. Given the intimate links between MOR signaling and socioemotional behavior, these results suggest that the MOR system might underlie seasonal variation in human mood and social behavior.Seasonal rhythms influence emotion and sociability. The brain's μ-opioid receptor (MOR) system modulates numerous seasonally varying socioemotional functions, but its seasonal variation remains elusive. Here we used positron emission tomography to show that MOR levels in both human and rat brains show daylength-dependent seasonal variation. The highest MOR availability was observed at intermediate daylengths. Given the intimate links between MOR signaling and socioemotional behavior, these results suggest that the MOR system might underlie seasonal variation in human mood and social behavior.
Learn More >To characterize the distribution and severity of sensory neuropathy using a portable quantitative sensory testing (QST) device in diabetic patients (DM) hospitalized with severe COVID-19 infection.
Learn More >Of painful conditions, somatic pain of acute nociceptive origin can be effectively managed clinically, while neuropathic pain of chronic neuropathy origin is difficult to control. For molecules involved in pain sensation, substance P (SP) is algesic, exacerbating painful sensation, while its amino-terminal fragment, heptapeptide SP, confers biological activities different from its full-length parent neuropeptide precursor. We previously demonstrated SP interaction with pain processing to alleviate chronic pain. Here we evaluated SP and its C-terminal amidated analogue SPamide, together with SP and opioid agonist DAMGO. We tested mouse behaviors of both acute somatic pain in tail-flick latency assay, and neuropathic pain in sciatic nerve injury model of chronic constriction injury (CCI). DAMGO produced dose-dependent analgesia for somatic pain as expected, so did both SP and its analogue SPamide, while SP yielded the opposite effect of algesia, in a phenomenon we termed 'contrintus', meaning 'opposite from within' to denote that two peptides of the same origin (SP and its metabolic fragment SP) produced opposite effects. In CCI model, DAMGO showed a general reduction in allodynia sensitivity for both nerve-injured and normal paws, without selective effect for neuropathic pain, consistent with clinical observation that opioids are less effective for chronic neuropathic pain. On the other hand, both SP and SPamide displayed dose-dependent anti-allodynia effect that is selective for neuropathic pain. These findings suggest that SP and its analogue may be useful for developing pharmaceuticals to treat neuropathic pain.
Learn More >The mu opioid receptor-selective agonist, SR-17018, preferentially activates GTPγS binding over βarrestin2 recruitment in cellular assays, thereby demonstrating signaling bias. In mice, SR-17018 stimulates GTPγS binding in brainstem and produces antinociception with potencies similar to morphine. However, it produces much less respiratory suppression and mice do not develop antinociceptive tolerance in the hot plate assay upon repeated dosing. Herein we evaluate the effects of acute and repeated dosing of SR-17018, oxycodone and morphine in additional models of pain-related behaviors. In the mouse warm water tail immersion assay, an assessment of spinal reflex to thermal nociception, repeated administration of SR-17018 produces tolerance as does morphine and oxycodone. SR-17018 retains efficacy in a formalin-induced inflammatory pain model upon repeated dosing, while oxycodone does not. In a chemotherapeutic-induced neuropathy pain model SR-17018 is more potent and efficacious than morphine or oxycodone, moreover, this efficacy is retained upon repeated dosing of SR-17018. These findings demonstrate that, with the exception of the tail flick test, SR-17018 retains efficacy upon chronic treatment across several pain models.
Learn More >Pain is a common symptom in endodontic conditions, but differential diagnostic procedures are often needed to exclude other pain origins. General dentists and endodontists thus need to be aware of alternative painful orofacial conditions, and be able to identify them. The new International Classification of Orofacial Pain (ICOP, 2020) is the first comprehensive classification that uniquely deals with orofacial pain. The ICOP is a hierarchical classification, modelled on the International Classification of Headache Disorders (ICHD-3) and covers pain in dentoalveolar and anatomically related tissues, muscle pain, temporomandibular joint (TMJ) pain, neuropathic pain affecting cranial nerves, pain resembling primary headaches, and idiopathic pain in the orofacial region. A description of each condition is given, and structured diagnostic criteria for each condition are proposed based on research data when available. This narrative review aims to (i) give an overview and brief explanation of the ICOP system, (ii) describe and give examples of how it can be of use to general dentists and endodontists with special attention to differential diagnosis of tooth pain, and (iii) highlight how endodontic research can contribute to validation and improvement of the classification. A comparison to other classification and diagnostic systems is also included.
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