Bone cancer induces a unique central sensitization through synaptic changes in a wide area of the spinal cord.

Background: Chronic bone cancer pain is thought to be partly due to central sensitization. Although murine models of bone cancer pain revealed significant neurochemical changes in the spinal cord, it is not known whether this produces functional alterations in spinal sensory synaptic transmission. In this study, we examined excitatory synaptic responses evoked in substantia gelatinosa (SG, lamina II) neurons in spinal cord slices of adult mice bearing bone cancer, using whole-cell voltage-clamp recording techniques.

Reduction of bone cancer pain by activation of spinal cannabinoid receptor 1 and its expression in the superficial dorsal horn of the spinal cord in a murine model of bone cancer pain.

Background: Bone cancer pain has a strong impact on the quality of life of patients, but it is difficult to treat. Therefore, development of a novel strategy for the treatment of bone cancer pain is needed for improvement of patient quality of life. This study examined whether selective spinal cannabinoid receptor 1 (CB1) activation alleviates bone cancer pain and also examined the spinal expression of CB1.

Involvement of transient receptor potential vanilloid subfamily 1 in endothelin-1-induced pain-like behavior.

Although local administration of endothelin-1 (ET-1) is known to evoke spontaneous pain, the mechanism of ET-1-induced pain has not been elucidated. We investigated the involvement of protein kinase C (PKC) and transient receptor potential vanilloid subfamily 1 (TRPV1) in ET-1-induced pain-like behavior. Intraplantar ET-1 evoked pain-like behaviors, including licking, flinching, and biting, in a dose-dependent manner in wild-type mice.

Continuous low-dose ketamine improves the analgesic effects of fentanyl patient-controlled analgesia after cervical spine surgery.

Background: The effects of fentanyl with ketamine for postoperative pain are unknown. We investigated the adjuvant effects of ketamine for fentanyl patient-controlled analgesia.

Methods: Cervical and lumbar spine surgery patients were divided into three groups: ketamine 1 mg/kg followed by 42 and 83 microg x kg(-1) x h(-1) in ketamine-1 and ketamine-2 group, respectively, and a control group.

Effects of systemic administration of lidocaine and QX-314 on hyperexcitability of spinal dorsal horn neurons after incision in the rat.

Although systemic lidocaine has been shown to suppress postoperative pain in a clinical setting, the mechanisms of action of lidocaine have not been elucidated. The present study was therefore designed to determine the relative contribution of central and peripheral sites to the action of lidocaine on incision-induced hyperexcitation of spinal dorsal horn (SDH) neurons in the rat. Receptive field (RF) areas, spontaneous activities, and responses of single wide-dynamic-range (WDR) neurons of the SDH to nonnoxious and noxious stimuli were recorded before and after longitudinal incisions of 1cm through the skin, fascia, and muscle had been made in the center of their RFs of the hindquarters.

[The optimal dose of fentanyl added to 0.2% ropivacaine for postoperative epidural analgesia after gynecological surgery].

Background: Combined administration of local anesthetics and an opioid is frequently used in order to minimize the dose of each drug and to reduce adverse effects. Although fentanyl is commonly administered with local anesthetic, side effects of fentanyl increase in a dose-dependent manner. In this study, we determined the optimal dose of epidural fentanyl after gynecological surgery.

[Coronary artery spasm during cholecystectomy with pneumoperitoneum--a case report].

A 59-year-old man without a history of ischemic heart disease underwent elective laparoscopic cholecystectomy under general anesthesia with epidural anesthesia. About 15 min after pneumoperitoneum had been achieved, the patient developed ST elevation and hypotension. Vagal stimulation resulting from stretching peritoneum, the procedure and epidural anesthesia are thought to have induced vasospasm.

[The effects of patient-controlled epidural analgesia with background infusion after abdominal surgery].

Background: Although patient-controlled epidural analgesia (PCEA) is widely known to provide good pain control after abdominal surgery, it has not been popular in Japan. We evaluated the effects of PCEA with background infusion after major abdominal surgery.

Methods: Ninety patients scheduled for abdominal surgery were randomly allocated to two groups by treatment with postoperative epidural analgesia: infuser group (n = 48); continuous infusion 5 ml.

[Comparison of zopiclone and midazolam premedication for preoperative anxiolysis].

To compare the anxiolysis property of zopiclone (ZPC) and midazolam (MDZ), 117 patients were given zopiclone 7.5 mg p.o.