Eiichiro Umeda

National Defense Medical College, Tokorozawa, Saitama, Japan

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Publications (6)5.77 Total impact

  • Pediatric Anesthesia 08/2009; 19(7):714-5. · 2.44 Impact Factor
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    ABSTRACT: Spinal muscarinic receptors are involved in the mediation of antinociceptive effects. The modulation of noradrenaline (NA) release on muscarinic receptor subtypes in the rat spinal cord was investigated in in vitro perfusion experiments. After rat spinal cord slices were preincubated in [3H]NA, the slices were perfused with a superfusion apparatus. The slices were field stimulated during the 4th (S1) and 11th (S2) superfusion collection periods. Perfusion of drugs was initiated at the 8th collection period and was maintained until the 14th collection period. Fractional release was calculated as the percentage of the radioactivity present in the slices at the beginning of the stimulation period. Drugs were administered between S1 and S2. The following drugs were used: [3H]NA, neostigmine, pirenzepine (M1 antagonist), AFDX116 (M2 antagonist), atropine. Neostigmine significantly increased the release of [3H]NA in a concentration-dependent manner. Pirenzepine (1 microM) and atropine (0.3 microM) significantly reduced the release of [3H]NA, but AFDX116 (1 microM) did not significantly reduce release in the presence of neostigmine (1 microM). The results of this study indicate that neostigmine can enhance noradrenergic neurotransmission, and that acetylcholine can stimulate spinal cord NA release via M1 muscarinic receptor subtypes.
    Brain Research Bulletin 07/2006; 70(1):99-102. · 2.94 Impact Factor
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    ABSTRACT: We studied the changes in the bispectral index (BIS) of 22 patients during electroconvulsive therapy (ECT) under propofol and succinylcholine anesthesia. BIS values (mean+/-SD) were 94+/-4 before anesthesia, 51+/-15 before ECT, 49+/-20 after ECT, and 60+/-17 at complete re-awakening. The BIS values at re-awakening were significantly different from those before anesthesia (P<0.05). In conclusion, our study suggests that the BIS values following ECT might not reliably correlate with the patients' clinical level of consciousness.
    Masui. The Japanese journal of anesthesiology 08/2004; 53(7):810-2.
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    ABSTRACT: Endogenous opioids and catecholamines are involved in autonomic activity. Nitroglycerin provocation tilt is a useful modality for evaluating neurally mediated syncope. Endogenous opioids and epinephrine might play an important role in nitroglycerin provocation tilt. To investigate whether or not opioids and catecholamines are involved in the pathogenesis of nitroglycerin provocation tilt, we measured the temporal changes of the plasma levels of beta endorphin, norepinephrine, and epinephrine in 64 patients with syncope of unknown etiology, and compared the findings with those of 16 patients who underwent isoproterenol provocation tilt (1-3 microg/min) test with a positive response. We performed a 20 minute control tilt (80 degrees) followed by a nitroglycerin provocation tilt of 20 minutes with the intravenous infusion of nitroglycerin. Nitroglycerin infusion was started at 250 microg/h, and was increased by 250 microg/h every 3 minutes up to 1500 microg/h during the tilt test. Beta-endorphin, norepinephrine, and epinephrine were measured in peripheral venous blood in the supine position 2, 10, and 20 minutes after the start of the tilt test, and also at the onset of syncope. Twenty-six patients had a positive response to the control tilt (group 1), and 22 patients had a positive response to nitroglycerin provocation tilt (group 2). The remaining 16 patients had a negative response to both control tilt and nitroglycerin provocation tilt (group 3), compared with isoproterenol provocation tilt patients (group 4). Beta-endorphin and epinephrine only significantly increased in groups 1 and 2 (beta-endorphin; from 7.3 +/- 3.3 pg/mL to 19.9 +/- 17.7 pg/mL, in group 1, P < 0.05; from 7.3 +/- 2.9 to 16.5 +/- 10.7 pg/mL, in group 2, P < 0.05; epinephrine; from 42 +/- 58 pg/mL to 157 +/- 161 pg/mL, in group 1, P < 0.05: from 33 +/- 25 to 202 +/- 252 pg/mL, in group 2, P < 0.05), but not in groups 3 and 4. Beta-endorphin and epinephrine might participate in the pathophysiology in conventional tilt-induced as well as nitroglycerin provocation tilt-induced syncope in patients with neurally mediated syncope.
    Japanese Heart Journal 07/2003; 44(4):493-503. · 0.40 Impact Factor
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    ABSTRACT: To evaluate the effect of perioperative intravenous administration of flurbiprofen, a nonsteroidal anti-inflammatory drug, on the postoperative pain after minor ear, neck and nose surgery, eighty patients were randomly allocated into three groups. Control group of 40 patients, received a placebo. The second group (n = 20) received 1 mg.kg-1 flurbiprofen i.v. at the end of surgery, and the third group (n = 20) received the same dose of flurbiprofen before the start of surgery. The ratio of the patients and the time for requirement of analgesics after the operation and the serum concentration of flurbiprofen were assessed. The ratio of the patients who required analgesics was higher in control group (0.45, 0.35 and 0.10 in each group). The time without analgesics was longer in pre-treatment group. The serum concentration of flurbiprofen decreased in pre-treatment group at the end of surgery, but the effectiveness of flurbiprofen on postoperative pain might be more apparent in pre-treatment group. Administration of flurbiprofen before the start of surgery is more effective for peri-operative analgesia in minor ear, neck and nose surgery.
    Masui. The Japanese journal of anesthesiology 09/2002; 51(8):857-61.
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    ABSTRACT: The effect of the additional administration of midazolam or flumazenil on bispectral index (BIS) during propofol anesthesia was investigated in 22 scheduled surgical patients. Midazolam 10 or 30 micrograms.kg-1, or flumazenil 6 or 12 micrograms.kg-1 was injected to the patients to evaluate their effect on BIS after achieving steady state of hypnosis more than 1 hr of propofol anesthesia with 5 mg.kg-1.hr-1. The only midazolam 30 micrograms.kg-1 significantly reduced BIS value from 47.8 +/- 8.6 to 36.8 +/- 6.5. The synergistic interaction between midazolam and propofol assessed by BIS might be less clear than that assessed by hypnotic dose of propofol using psychopharmacological investigation.
    Masui. The Japanese journal of anesthesiology 08/2002; 51(7):733-6.