Pain
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Endometriosis (ENDO) is a painful disorder defined by extrauteral endometrial growths. It is created in rats by autotransplanting pieces of uterus (which form cysts), or, for shamENDO, fat (no cysts). ENDO induces vaginal hyperalgesia, likely via central sensitization. ⋯ We predicted that the opposing influences of estradiol on ENDO- and OVX-induced hyperalgesia would cancel each other. As predicted, OVX had no effect on ENDO-induced hyperalgesia and estradiol replacement alleviated it. These results suggest that, in intact rats, ENDO-induced vaginal hyperalgesia is exacerbated by estradiol, and that different mechanisms underlie ENDO-induced versus OVX-induced vaginal hyperalgesia.
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There are few studies on coping with fibromyalgia (FM). The aim of the present study was to assess the usefulness of a Spanish version of the Chronic Pain Coping Inventory-42 (CPCI-42) in patients with FM. A random sample (N=402) of patients with FM was obtained from the Fibromyalgia Association of Aragon, Spain. ⋯ Task persistence correlated with illness-focused strategies and negative outcomes, indicating that it should be included in the illness-focused group. However, other wellness-focused strategies, including relaxation, exercise, and coping self-statements, were correlated with each other, negatively correlated with depression, and positively correlated with quality of life. Future research directions and clinical implications are discussed.
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Metastatic bone cancer causes severe pain that is primarily treated with opioids. A model of bone cancer pain in which the progression of cancer pain and bone destruction is tightly controlled was used to evaluate the effects of sustained morphine treatment. In cancer-treated mice, morphine enhanced, rather than diminished, spontaneous, and evoked pain; these effects were dose-dependent and naloxone-sensitive. ⋯ These results indicate that sustained morphine increases pain, osteolysis, bone loss, and spontaneous fracture, as well as markers of neuronal damage in DRG cells and expression of pro-inflammatory cytokines. Morphine treatment may result in "add-on" mechanisms of pain beyond those engaged by sarcoma alone. While it is not known whether the present findings in this model of osteolytic sarcoma will generalize to other cancers or opioids, the data suggest a need for increased understanding of neurobiological consequences of prolonged opioid exposure which may allow improvements in the use of opiates in the effective management of cancer pain.
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Dysmenorrhoea patients experience intense visceral pain during menstruation. Recurrent and/or intense visceral pain can induce facilitation of somatic and visceral nociceptive processing which can lead to viscero-somatic (referred) and viscero-visceral hyperalgesia. Our aim was to study if dysmenorrhoea is associated with hypersensitivity in the referred somatic skin area or in the large bowel, i.e., viscero-visceral hyperalgesia. ⋯ There were no differences in compliance between the groups. These findings suggest that, despite the absence of overt gastro-intestinal symptoms or viscero-somatic sensitisation, dysmenorrhoea patients demonstrate intestinal hypersensitivity. This can be regarded as the result of centrally mediated viscero-visceral hyperalgesia due to recurrent intense menstrual pain.