Details of a Researcher - YAMAKAGE Michiaki

Misc - YAMAKAGE Michiaki

Division display 221 - 240 of about 297 ／ All the affair displays >>

Carbon dioxide absorbents containing potassium hydroxide produce much larger concentrations of compound A from sevoflurane in clinical practice

M Yamakage, S Yamada, XD Chen, S Iwasaki, N Tsujiguchi, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 91 ( 1 ) 220 - 224 2000.07

We investigated the concentrations of degraded sevoflurane Compound A during low-flow anesthesia with four carbon dioxide (CO2) absorbents. The concentrations of Compound A, obtained from the inspiratory limb of the circle system, were measured by using a gas chromatograph. In the groups administered 2 L/min fresh gas flow with 1% sevoflurane, when the conventional CO2 absorbents, Wakolime(TM) (Wako, Tokyo, Japan) and Dragersorb(TM) (Drager, Lubeck, Germany), were used, the concentrations of Compound A increased steadily from a baseline to 14.3 ppm (mean) and 13.2 ppm, respectively, at 2 h after exposure to sevoflurane. In contrast, when the other novel types of absorbents containing decreased or no potassium hydroxide/sodium hydroxide, Medisorb(TM) (Datex-Ohmeda, Louisville, CO) and Amsorb(TM) (Armstrong, Coleraine, Northern Ireland), were used, Compound A remained at baseline (<2 ppm) throughout the study. In the groups administered 1 L/min fresh gas now with 2% sevoflurane, Wakolime(TM) and Dragersorb(TM) produced much larger concentrations of Compound A (35.4 ppm and 34.2 ppm, respectively) at 2 h after exposure to sevoflurane. Medisorb(TM) showed measurable concentrations of Compound A (8.6 ppm at 2 h), but they were significantly smaller than those produced by the two conventional absorbents. In contrast, when Amsorb(TM) was used, Compound A concentrations remained at baseline throughout the study period.

Low-temperature modification of the inhibitory effects of volatile anesthetics on airway smooth muscle contraction in dogs

N Yamakage, N Tsujiguchi, J Hattori, Y Kamada, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 93 ( 1 ) 179 - 188 2000.07

Background: Because exposure to low temperature can modify the effect of volatile anesthetics on airway smooth muscle contraction, this study was conducted to investigate low-temperature modifications of the inhibitory effects of isoflurane and sevoflurane on canine tracheal smooth muscle tone by simultaneously measuring the muscle tension and intracellular concentration of Ca2+ ([Ca2+](i)) and by measuring voltage-dependent Ca2+ channel activity. Methods: [Ca2+](i) was monitored by the 500-nm light emission ratio of preloaded fura-2, a Ca2+ indicator. Isometric tension was measured simultaneously. Whole cell patch clamp recording techniques were used to observe voltage-dependent Ca2+ channel activity in dispersed muscle cells. Isoflurane (0-3.0%) or sevoflurane (0-3%) was introduced to a bath solution at various temperatures (37, 34, or 31 degrees C). Results: Low temperature (34 or 31 degrees C) reduced high-K+-induced (72.7 mM) muscle contraction and increased [Ca2+](i), but it enhanced carbachol-induced (1 mu M) muscle contraction with a decrease in [Ca2+](i). The volatile anesthetics tested showed significant inhibition of both high-K+-induced and carbachol-induced airway smooth muscle contraction, with a concomitant decrease in [Ca2+](i). The inhibition of the carbachol-induced muscle contraction by volatile anesthetics was abolished partially by exposure to low temperature. Volatile anesthetics and low-temperature exposure significantly inhibited voltage-dependent Ca2+ channel activity of the smooth muscle. Conclusions: Exposure of airway smooth muscle to low temperature leads to an increase in agonist-induced muscle contractility, with a decrease in [Ca2+](i). The inhibition of voltage-dependent Ca2+ channel activity by exposure to low temperature and by volatile anesthetics cam be attributed, at least in part, to the decrease in [Ca2+](i).

The usefulness of celite-activated thromboelastography (sonoclot (TM)) in cardiac surgery for evaluating fibrinolyctic status

M Yamakage, Y Kamada, T Niiya, S Kohro, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 90 ( 2 ) U76 - U76 2000.02

Research paper, summary (international conference)

Modified simple technique of anesthetic induction in adults by administering sevoflurane via the face mask

M Yamakage, J Hattori, Y Kamada, N Tsujiguchi, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 90 ( 2 ) 2000.02

Research paper, summary (international conference)

Predictive variables of hypothermia in the early phase of general anesthesia

M Yamakage, Y Kamada, Y Honma, N Tsujiguchi, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 90 ( 2 ) 456 - 459 2000.02

Core temperature decreases precipitously for 1 h and then decreases slowly for 2-3 h after the induction of general anesthesia. WE investigated the predictive variables of hypothermia by measuring peripheral skin temperature and total body fat (TBF). We studied 60 adult patients who required general anesthesia with isoflurane. The following variables were measured preoperatively: right palmar skin temperature by using an infrared thermometer and skin thickness at arm and scapula by using a standard caliper. TBF was calculated by using the regression equation of Durnin and Womersley. Rectal temperature, taken to represent core temperature, was measured during the operation. The gradient of hypothermia induced by general anesthesia was divided into two parts: 1) a precipitous decrease for the first hour and 2) a slow decrease for the following 2-3 h. Preoperative palmar skin temperature had a significant linear relationship with the precipitous decrease in temperature over the first hour (r = 0.69, P < 0.0001), and TBF had a significant linear relationship with the subsequent slow decrease in temperature (r = 0.63, P < 0.0001). By simple measurements, we can predict the extent of hypothermia in the early phase of general anesthesia and prevent its onset by using body-warming techniques. Implications: After the induction of general anesthesia, palmar skin temperature had a Linear relationship with the precipitous decrease in rectal temperature over the first hour, and total body fat had a linear relationship with the subsequent decrease in temperature. Thus, by simple measurements, we can predict the extent of hypothermia in the early phase of general anesthesia.

Preoperative evaluation

Expert Nursing for Management of Anesthesia in Operating Rooms 2000

Anesthetic management of a patient with Freeman-Sheldon syndrome

M. Namiki, T. Kawamata, M. Yamakage, A. Matsuno, A. Namiki

Japanese Journal of Anesthesiology 49 ( 8 ) 901 - 902 2000

We describe a case of Freeman-Sheldon syndrome that presented some problems for anesthetic management. A 2-yr-old girl required orthopedic surgery for the bilateral lower extremities. Anesthesia was induced via a mask with oxygen (2l · min-1), nitrous oxide (4l · min-1) and sevoflurane (-5%). Tracheal intubation by direct laryngoscopy was successfully achieved. Combined caudal epidural block was, however, avoided because spina bifida occulta was suspected. Spina bifida occulta was revealed postoperatively by X-ray. For anesthetic management of a patient with Freeman-Sheldon syndrome, the spine should be evaluated preoperatively when performing epidural/spinal anesthesia.

PubMed

Meaning of Statistics

Basic Statistics and How to Make Figures and Slides 2000

General anesthesia with epidural block and control of body temperature

J Clin Anesth (Jpn) 24 1416 - 1424 2000

麻酔の申し込み，麻酔前診察

手術室における麻酔・全身管理エキスパートナーシング 2000

統計学の意味

図解−やさしい統計学と図表・スライドの作り方 2000

硬膜外麻酔併用全身麻酔と体温調節

臨床麻酔 24 1416 - 1424 2000

Direct inhibitory effect of intravenous anesthetics on the myometrium of pregnant rats

N Tsujiguchi, M Yamakage, Y Kamada, J Hattori, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 91 ( 3A ) U442 - U442 1999.09

Research paper, summary (international conference)

Volatile anesthetics inhibit voltage-dependent Ca2+channels in the myometrium from pregnant rats

M Yamakage, M Watanabe, J Hattori, Y Kamada, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 91 ( 3A ) U443 - U443 1999.09

Research paper, summary (international conference)

Direct effects of adrenergic stimulus on the CA2+and K+ channel activities of dorsal root ganglion neurons in a rat neuropathic pain model

Y Honma, M Yamakage, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 91 ( 3A ) U381 - U381 1999.09

Research paper, summary (international conference)

The predictive parameters of hypothermia in the early phase of general anesthesia

M Yamakage, Y Kamada, Y Honma, N Tsujiguchi, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 91 ( 3A ) U265 - U265 1999.09

Research paper, summary (international conference)

Changes in respiratory pattern and arterial blood gases during sedation with propofol or midazolam in spinal anesthesia

M Yamakage, Y Kamada, M Toriyabe, Y Honma, A Namiki

JOURNAL OF CLINICAL ANESTHESIA ( ELSEVIER SCIENCE INC ) 11 ( 5 ) 375 - 379 1999.08

Study Objectives: To investigate changes in respiratory pattern and arterial blood gases during sedation with, propofol or midazolam in spinal anesthesia. Design: Randomized, placebo-controlled study. Setting: Operating room of a university-affiliated hospital. Patients: 40 ASA physical status I and II patients who required spinal anesthesia. Interventions: Spinal anesthesia with tetracaine and subsequent sedation with propofol (n = 15), midazolam (n = 15), or placebo (n = 10) was performed. Measurements: Respiratory pattern [rib cage contribution to the tidal volume (%RC) and phase shift between rib cage and abdominal movements (PSrc-ab)] with a respiratory inductive plethysmograph (Respigraph(TM)) and arterial blood gas analysis (pH, pO(2), and pCO(2)) Were recorded. Main Results: Spinal anesthesia per se increased %RC by 35% without changing PSrc-ab values (1.00). Sedation with propofol and midazolam decreased %RC by 60% and by 40%, respectively. PSrc-ab increased in both groups following sedation, and the increase in this parameter was higher in the propofol group (1.12) than in the midazolam group (1.04). In the placebo group, %RC decreased by 20% without ang change in PSrc-ab. The decrease in pO(2) was more significant in the propofol group (65.1 mmHg) than in the midazolam (74.2 mmHg) and placebo (83.1 mmHg) groups. Conclusion: Significant decreases in %RC and pO(2) during propofol sedation seem to depend on paradoxical respiration due, in part, to upper airway obstruction; therefore, attention should be directed to the respiratory pattern during sedation, especially with propofol. (C) 1999 by Elsevier Science Inc.

DOI

健常者ならびに全身麻酔症例での安全で効果的な電気敷布の設定方法

川端ルミ, 伊東琴絵, 平野裕子, 堀内千尋, 山内正憲, 山蔭道明, 並木昭義

臨床体温 ( 「臨床体温」編集委員会 ) 17 ( 1 ) 49 - 53 1999.08

意識のある健常者ならびに全身麻酔症例で,電気敷布の温度設定の違いが体温変化に与える影響を検討した.健常者では体の下に敷いた電気敷布(電子制御敷毛布CS-262C,東京芝浦電気)の温度設定の違いにより,最も低い温度設定で使用した「L群」,最も高い温度設定で使用した「H群」,その中間で使用した「M群」の3群に健常者を分けた.全身麻酔症例(A群)は耳鼻科手術を受ける症例を対象とした.60分間の電気敷布の使用後の温度はL群35.5℃,M群38.0℃,H群41.9℃であった.健常者は3群とも核心温に変化はなかった.H群では電気敷布が43℃以上となると発汗を生じる者がいた.反対にL群では寒さを訴える者がいた.A群はM群と同じ温度設定で電気敷布を使用したところ,核心温,末梢温共に良好に保たれた.健常者,全身麻酔症例共に長時間の使用に安全で効果的な電気敷布の温度設定は37℃前後であることが明らかとなった

Effects of adrenergic stimulus on the activities of Ca2+ and K+ channels of dorsal root ganglion neurons in a neuropathic pain model

Y Honma, M Yamakage, T Ninomiya

BRAIN RESEARCH ( ELSEVIER SCIENCE BV ) 832 ( 1-2 ) 195 - 206 1999.06

We hypothesized that abnormal activity and adrenergic sensitivity in injured dorsal root ganglion (DRG) neurons are due to an intrinsic alteration of the cell body membrane. We investigated the effects of adrenergic stimulus on the activities of Ca2+ and K+ channels of DRG neurons in a rat chronic constriction injury (CCI) model. At first, we demonstrated thermal hyperalgesia and sprouting sympathetic nerve fibers in the ipsilateral L4-L5 DRGs. Using whole-cell patch clamp techniques, we found that alpha(2)-adrenergic stimulus by 10 mu M norepinephrine (NE) inhibited inward currents (I-Ba, Ba2+ as a charge carrier) through voltage-dependent Ca2+ channels (VDCCs) of DRGs in the CCI model by 42%, whereas it enhanced the I-Ba by 18% in control animals. The inhibitory effect of NE disappeared by pretreatment with the N-type VDCC antagonist omega-conotoxin GVIA (1 mu M). NE shifted the inactivation curve to a more negative potential, showing that it has inhibitory effects on I-Ba both in activated and in inactivated states. alpha(2)-Adrenergic stimulus also inhibited outward K+ currents by 24% in the CCI model, while it had no effect on the currents in control animals. The inhibitory effect of NE was blocked by pretreatment with the Ca2+-activated K+ (K-Ca) channel antagonist charybdotoxin (40 nM). The NE-induced inhibitory effects both on N-type VDCC and on K-Ca channels in injured DRG neurons of the CCI model could lead to cell membrane depolarization, resulting in a spontaneous discharge of action potential and an increase in sensitivity to adrenergic stimulus. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI PubMed CiNii

The direct effects of heparin and protamine on canine tracheal smooth muscle tone

M Yamakage, T Matsuzaki, N Tsujiguchi, T Mori, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 88 ( 6 ) 1232 - 1238 1999.06

Heparin and protamine are used for cardiopulmonary bypass in cardiac surgery; however, the direct effects and mechanisms of these drugs on airway smooth muscle tone are still not fully known. We investigated the in vitro effects of these drugs on canine tracheal smooth muscle by measuring the muscle tension and intracellular Ca2+ con centration ([Ca2+](i)) and by measuring inward Ca2+ currents (I-Ca) through voltage-dependent Ca2+ channels. [Ca2+](i) was monitored by the 500-nm light emission ratio of preloaded Ca2+ indicator fura-2. Isometric tension was measured simultaneously. Whole-cell patch clamp recording techniques were used to investigate the effects of the drugs on I-Ca in freshly dispersed smooth muscle cells. Heparin (0.12-120 U/mL), protamine (0.15-150 U/mL), or heparin-protamine complex (4:5 U/U) was introduced into a bath solution. Protamine and heparin-protamine complex dose-dependently inhibited both carbachol-induced contraction of the muscle and increase in [Ca2+](i). These drugs also decreased the I-Ca of the muscle cells and shifted the inactivation curve to a more negative potential. Heparin itself had a slight enhancing effect on carbachol-induced muscle contraction without changing [Ca2+](i). Protamine and heparin-protamine complex can decrease the agonist-induced increase in [Ca2+](i), by the inhibition of voltage-dependent Ca2+ channels both in the activated and inactivated states. Implications: Protamine and heparin-protamine complex inhibited carbachol-induced canine tracheal smooth muscle con traction by inhibiting the increase in int acellular concentration of free Ca. These drugs can decrease the agonist-induced increase in intracellular Ca2+ by the inhibition of voltage-dependent Ca2+ channels in both the activated and inactivated states.

DOI

　 PREV - NEXT 　

<YAMAKAGE Michiaki>

Misc - YAMAKAGE Michiaki