Pain physician
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Postherpetic neuralgia (PHN) patients suffer debilitating chronic pain, hyperalgesia, and allodynia, as well as emotional disorders such as insomnia, anxiety, and depression. The brain structure and functional basis of PHN are still not fully understood. ⋯ For PHN patients, the local brain activity abnormality was not restricted to the pain matrix. Besides regions related to pain perception, areas in charge of affective processes, emotional activity, and pain modulation also showed abnormal local brain activity in a resting state, which may suggest complicated supraspinal function and plasticity change in PHN patients. ReHo was more closely correlated with pain intensity of PHN patients than fALFF. This work indicates that besides physical and emotional pain perception, mood disorder and pain modulation could be characteristic of PHN patients. This also supports the potential use of therapeutic interventions not only restricted to pain alleviation, but that also attempt to ameliorate the cognitive and emotional comorbidities. Key words: Postherpetic neuralgia, resting-state fMRI (rs-fMRI), mood disorder, limbic system, fractional aptitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo).
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Angiogenesis is an important characteristic of cancer. Switching from the avascular phase to the vascular phase is a necessary process for tumor growth. Therefore, research in cancer treatment has focused on angiogenesis as a drug target. Despite the widespread use of opioids to treat pain in patients with cancer, little is known about the effect of these drugs on vascular endothelium and angiogenesis. ⋯ In this study, we tested the effects of 3 different opioid drugs on angiogenesis in 3 different concentrations, and we observed that morphine was a good anti-angiogenic agent, but tramadol and codeine only had anti-angiogenic effects at high doses.Key Words: Morphine, codeine, tramadol, opioid, bevacizumab, chorioallantoic membrane (CAM), angiogenesis.
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Pulsed radiofrequency (PRF) has been widely employed for ameliorating clinical neuropathic pain. How PRF alters electrophysiological transmission and modulates biomolecular functions in neural tissues has yet to be clarified. We previously demonstrated that an early application of low-voltage bipolar PRF adjacent to the dorsal root ganglion (DRG) reduced acute neuropathic pain in animals. By contrast, the present study investigated how PRF alters postsynaptic sensitization to produce early and delayed effects on neuropathic pain. ⋯ Low-voltage bipolar PRF produces LTD through selective suppression on the C-component, but not on the A-component. It also inhibits ERK activation within neurons and astrocytes in SDHs. The findings suggest that PRF alleviates long-lasting neuropathic pain by selectively and persistently modulating C-fiber-mediated spinal nociceptive hypersensitivity.Key words: Pulsed radiofrequency (PRF), dorsal root ganglion (DRG), neuropathic pain, ERK activation, evoked field potential, ATF-3, long-term depression (LTD), spinal nerve ligation (SNL).