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Background: Yokukansan (YKS), a traditional herbal (Kampo) medicine consisting of seven herbs, is effective in the treatment of pain disorders, such as headache, postherpetic neuralgia, fibromyalgia, and trigeminal neuralgia, and we have previously shown it to be effective against morphine analgesic tolerance in rats. It has been reported that orexin receptor antagonists prevent the development of morphine tolerance and that YKS inhibits the secretion of orexin A in the hypothalamus. This study examined whether the inhibition of the secretion of orexin A by YKS is one mechanism underlying its effect against morphine analgesic tolerance. Methods: Male Wistar rats were administered a subcutaneous injection of morphine hydrochloride (10 mg/kg/day) for 5 days. One group was preadministered YKS, starting 3 days before the morphine. The withdrawal latency following thermal stimulation was measured daily using a hot plate test. On day 5, the levels of orexin A in the plasma and the midbrain were measured, and the appearance of activated astrocytes in the midbrain was examined by immunofluorescence staining. Results: The preadministration of YKS prevented the development of morphine tolerance. The repeated administration of morphine significantly increased the plasma and midbrain levels of orexin A and the activation of astrocytes. These increases were significantly inhibited by the preadministration of YKS. Conclusion: These results suggest that the preadministration of YKS attenuated the development of antinociceptive morphine tolerance and that the inhibition of orexin A secretion may be one mechanism underlying this phenomenon. Keywords: Astrocyte, Kampo medicine, Morphine tolerance, Orexin A, Yokukansan

This study was designed to examine deviation of the bronchus by postural change from supine to lateral position during spontaneous respiration. Fifteen healthy volunteers [13 men and 2 women, mean age: 34 years (range 26-42)] participated. Chest radiograms (anterior-posterior) were acquired in the order of supine, left lateral, and right lateral position. The bilateral bronchus angles and secondary carina angles were measured in the acquired images, and the angles were compared between the supine and lateral positions to evaluate deviation of the bronchus in the lateral position. The left secondary carina angle in the supine position was 61.3° ± 4.0° and it significantly increased to 65.5° ± 6.0° in the left lateral position (P = 0.001), but no significant difference was noted in the left bronchus angle between the supine and left lateral positions (P = 0.158). The curvature of left main bronchus, which we defined more than 5° increase in secondary carina angle, was observed in a half of the male participants during left lateral position. We should be aware of these anatomical changes due to the surgical posture as a possible cause for ventilation failure during one-lung ventilation.

Electroconvulsive Therapy(以下ECT)においてプロポフォールまたはチオペンタールにて麻酔し,投与量の増減によってそれぞれを2群に分け,ECTによる痙攣時間と循環動態の変動を検討した.両薬剤ともに投与量が増すと循環動態は安定したが,投与量が少ないとチオペンタール群で変動が大きかった.プロポフォールは投与量を増すと痙攣時間が有意に短くなったが,チオペンタールは投与の増量による痙攣時間の短縮幅が小さかった.痙攣時間の観点からはプロポフォールの投与量は1.4mg・kg-1までにとどめるべきである.プロポフォールは,循環制御のため投与量をそれ以上増すと肉眼的観察をする限りECTの痙攣時間が短縮してしまう点でECTの麻酔として望ましくない.

Electroconvulsive Therapy(以下ECT)施行時の痙攣時間と循環動態の変動を,チオペンタールによる静脈麻酔群(T群)を,酸素・亜酸化窒素・セボフルラン(以下GOS)による吸入麻酔緩徐導入群(GOS群)に分け比較検討した.ECT施行による痙攣時間はT群がGOS群より長く,循環動態はT群がGOS群に比して大きく変動した.セボフルランは痙攣閾値を変化させないとされるが,ECTによる痙攣時間を短縮させた.痙攣時間が短いとECTの治療効果が減弱する可能性があり,この点でGOSはECTの麻酔として問題がある.チオペンタールはGOSに比べ循環制御の面で劣るが,血管作動薬など他の薬剤の使用により補うことができるので,ECTの治療効果からみるとGOSよりも適しているといえる.

Electroconvulsive therapy (ECT) recovers the brain function through generalized convulsion induced by electrical stimulation of the brain. While the primary targets of ECT are psychiatric disorders such as depression, schizophrenia, and schizoaffective disorder, it has been well documented that ECT has therapeutic effects on muscular rigidity of Parkinson's disease and neuroleptics-induced malignant syndrome. Recently we demonstrated that ECT reduces intractable pain and allodynia associated with deafferentation pain disorders by recovering the function of the thalamic nucleus. ECT, if applied on appropriate clinical assessments, may contribute to the therapeutics of neuropsychiatric disorders.

Characteristics of the acupuncture point in producing acupuncture analgesia (AA) were examined by the inhibition of noxious responses in the brain stem reticular formation, potentials, and neuronal activity in the dorsal periaqueductal central gray (D-PAG), and analgesia caused by low frequency stimulation of the acupuncture point. As a result, stimulation of the muscle beneath the acupuncture point was found to be effective in producing AA. AA measured by tail flick, vocalization, and writhing tests was abolished by hypophysectomy, and by antiserum of beta-endorphin administered into the 3rd ventricle. The pathway from the D-PAG to the anterior hypothalamus (AA-AH) in the AA afferent pathway from the acupuncture point to the pituitary gland was determined. The lateral hypothalamus, lateral septum, cingulate bundle, dorsal-hippocampus, and habenulo-interpeduncular tract were found, in addition to regions previously found, to belong to the AA afferent pathway. A network of divergence and convergence in their rostral and caudal relations was observed. The AA afferent pathway diverges from the D-PAG, converges to the HP, and then projects to the AA-AH.

Two acupuncture analgesia (AA) afferent pathways were identified by lesion of the lateral centromedian nucleus of thalamus(1-CM). One is, and the other is not inhibited by 1-CM during AA, 0.5 mg/kg morphine analgesia(MA) or dorsal periaqueduct central gray stimulation-produced analgesia(d-PAG-SPA). Morphine tolerance might develop in the analgesia inhibitory system.