Pain
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Functional magnetic resonance imaging (fMRI) is a technique that uses blood oxygen-level-dependent (BOLD) signals to elucidate discrete areas of neuronal activity. Despite the significant number of fMRI human brain studies, few researchers have applied fMRI technology to investigating neuronal activity within the human spinal cord. Our study goals were to demonstrate that fMRI could reveal the following: (i) appropriate somatotopic activations in response to noxious stimuli in the deep and superficial dorsal horn of the human cervical spinal cord, and (ii) lateralization of fMRI activations in response to noxious stimulation in the right and left upper extremity. ⋯ During nociceptive stimulation of all 4 sites (left deltoid, right deltoid, left thenar eminence and right thenar eminence), we found ipsilateral dorsal horn activation. Stimulation of the deltoid activated C5, whereas stimulation of the thenar eminence activated C6. Our study contributes to creating an objective analysis of pain transmission; other investigators can use these results to further study central nervous system changes that occur in patients with acute and chronic pain.
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Musculoskeletal disorders constitute major public health problems. Few studies have, however, examined risk of disability pension among persons sickness absent due to musculoskeletal diagnoses. Thus, we constructed a prospective nationwide population-based cohort study based on Swedish registers, consisting of all 4,687,756 individuals living in Sweden December 31, 2004/2005, aged 20-64 years, who were not on disability or old-age pension. ⋯ Similar associations were observed among both women and men sickness absent due to all 3 musculoskeletal diagnostic categories. Moreover, increased risks of disability pension because of cancer, mental, circulatory and musculoskeletal diagnoses were observed among individuals sickness absent because of any musculoskeletal diagnostic category (disability pension due to musculoskeletal diagnoses, adjusted model, category 2 diagnoses, IRR = 50.66, 95% CI = 49.06-52.32). In conclusion, this nationwide cohort study reveals strongly increased risks of all-cause and diagnosis-specific disability pension among those sickness absent due to musculoskeletal diagnoses.
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Cannabinoid CB(2) receptor activation by selective agonists has been shown to produce analgesic effects in preclinical models of inflammatory, neuropathic, and bone cancer pain. In this study the effect of a novel CB(2)agonist (MT178) was evaluated in different animal models of pain. First of all, in vitro competition binding experiments performed on rat, mouse, or human CB receptors revealed a high affinity, selectivity, and potency of MT178. ⋯ CB(2) receptor mechanism of action was investigated in dorsal root ganglia where MT178 mediated a reduction of [(3)H]-d-aspartate release. MT178 was also able to inhibit capsaicin-induced substance P release and NF-κB activation. These results demonstrate that systemic administration of MT178 produced a robust analgesia in different pain models via CB(2) receptors, providing an interesting approach to analgesic therapy in inflammatory and chronic pain without CB(1)-mediated central side effects.