Changes in circadian rhythm for mRNA expression of melatonin 1A and 1B receptors in the hypothalamus under a neuropathic pain-like state.

Several clinical reports on neuropathic pain of various etiologies have shown that it significantly interferes with sleep. Inadequate sleep due to neuropathic pain may contribute to the stressful negative consequences of living with pain. It is generally recognized that melatonin (MT) system in the hypothalmus is crusial for circadian rhythm and sleep-wake transition. However, little, if any, is known about whether neuropathic pain could affect the MT system associated with sleep disturbance. In this study, we investigated the possible changes in circadian rhythm for the expression of MT receptors, especially MT1A and MT1B receptors, in the hypothalamus of mice with sciatic nerve ligation. The samples for real-time RT-PCR assay were prepared at 8:00, 14:00, 20:00, and 2:00 on day 7 after sciatic nerve ligation or sham operation. The mRNA expression of MT1A and MT1B receptors at 2:00 in sciatic nerve-ligated mice, which exhibited thermal hyperalgesia along with an increase in wakefulness and a decrease in nonrapid eye movement sleep, was significantly greater than those in sham-operated mice, whereas the levels of both MT1A and MT1B receptors at 8:00 in sciatic nerve-ligated mice were significantly lower than those in sham-operated mice. These findings suggest that neuropathic pain-like stimuli lead to sleep disturbance in parallel with changes in circadian rhythm for mRNA expression of MT 1A and 1B receptors in the hypothalamus of mice.

Changes in the circadian rhythm of mRNA expression for µ-opioid receptors in the periaqueductal gray under a neuropathic pain-like state.

Variation in the production of opioid receptors over a 24-h period is considered to contribute to circadian alterations in neuropathic pain. In this study, we investigated the possible changes in the circadian rhythm of mRNA expression for µ-opioid receptor (MOR), κ-opioid receptor (KOR), and adrenaline α2a receptor (α2a) in the periaqueductal gray, frontal cortex, thalamus, and spinal cord following sciatic nerve ligation in mice. In sham-operated mice, the latencies of hind paw-withdrawal in response to thermal stimuli at 14:00 and 20:00 were significantly greater than that at 8:00 and the latency at 2:00 was significantly less than those at 14:00 and 20:00, indicating a "rest" period-dominant circadian rhythm for thermal pain-thresholds. In sciatic nerve-ligated mice, the latencies of hind paw-withdrawal in response to thermal stimuli at 14:00 and 20:00 were significantly less than that at 8:00, and the latency at 2:00 was significantly greater than those at 14:00 and 20:00. A correlative tendency between the time-variation of pain latency and the time-variation of MOR mRNA expression was observed in the periaqueductal gray of sham-operated and sciatic nerve-ligated mice. In contrast, neither mouse showed a strong circadian rhythm for the expressions of KOR and α2a mRNAs in any region. The present data suggest that changes in MOR mRNA expression in the periaqueductal gray may be synchronized with the circadian rhythm for the pain threshold for noxious thermal stimuli. In contrast, neuropathic pain in mice exhibited a negative circadian pattern for the expression of MOR, KOR, and α2a receptors in the frontal cortex, thalamus, and spinal cord.

[A case of intraoperative cardiac arrest in a patient with mitochondrial encephalomyopathy undergoing lung resection].

We report a case of intraoperative cardiac arrest in a patient with mitochodorial encephalomyopathy undergoing pulmonary wedge resection. The patient is a 50-year-old female who had been diagnosed as progressive external ophthalmoplegia at the age of 44 and underwent resection of mediastinal tumor 11 months before without major events. The patient was found to have lung cancer in the left lung and scheduled for wedge resection. Induction and maintenance of anesthesia using remifentanil and propofol infusion with rocuronium were uneventful until traction and resection of the left bronci when profound hypotension with systolic arterial pressure of 20 mmHg and sinus bradycardia occurred. The rhythm deteriorated to ventricular fibrillation which was refractory to pharmacological therapy including adrenaline (a total dose of 5 mg), lidocaine and nifekalant, and DC shock. The patient was finally stabilized after intraaortic balloon pumping and percutaneous cardiopulmonary support. Although the diagnosis of Takotsubo myopathy was made by echocardiography after surgery, the cause of cardiac arrest was not known.

[Anesthesia induction for patients with cervical spinal disease].

BACKGROUND: In the cases in which the flexibility of the patient's neck is limited, it is often difficult to achieve intubation. Fiberoptic intubation has been chosen for patients with arthroses. However, as it requires techniques, it has been difficult for inexperienced anesthesiologists. METHODS: Awake induction using AirWay Scope was performed for 8 patients with cervical spinal diseases. Midazolam, propofol or dexmedetomidine is selected as a sedative drug. RESULTS: Intubation was performed easily and safely without any complications in all cases. No patients had memories of intubation. CONCLUSIONS: Awake intubation using AirWay Scope for patients with cervical spinal diseases is a safe and useful anesthesia method. As dexmedetomidine causes no respiratory depression and can expect cooperation from patients, it may give safe and efficient sedation in awake intubation cases.

Anesthesia for patients with PTRF mutations: a case report.

BACKGROUND: Polymeraze I and transcript release factor (PTRF) mutations are a newly recognized disease, which cause congenital generalized lipodystrophy associated with myopathy. CASE PRESENTATION: A 29-year-old man (height 126 cm; weight 22 kg) with a PTRF mutation was scheduled for mandibular dentigerous cystectomy. His primary symptoms were lipodystrophy, myopathy, long QT syndrome, refractory nephrosis, and abnormal lipid metabolism. Defibrillator pads were applied soon after the patient entered the operating room. Anesthesia was induced using continuous administration of dexmedetomidine (4 µg/kg/h) for 15 min; midazolam (7 mg) was added while monitoring the bispectral index and his vital signs. Remifentanil and rocuronium were administered before endotracheal intubation. The surgeon used local anesthesia, and dexmedetomidine and remifentanil were titrated throughout the surgery. The surgery was performed uneventfully, and the patient was extubated following the administration of sugammadex and flumazenil. CONCLUSION: Patients with PTRF mutations require careful anesthetic planning. We planned to administer lipid-free, non-inhalational agents for the induction and maintenance of anesthesia. The anesthetic method used for this minor surgery was safe and effective.