Details of a Researcher - YAMAKAGE Michiaki

Misc - YAMAKAGE Michiaki

Division display 241 - 260 of about 297 ／ All the affair displays >>

In vitro effects of propofol on blood coagulability and fibrinolysis by the use of thromboelastograph technique

S Kohro, M Yamakage, T Omote, A Namiki

ACTA ANAESTHESIOLOGICA SCANDINAVICA ( MUNKSGAARD INT PUBL LTD ) 43 ( 2 ) 217 - 219 1999.02

Background: To investigate the in vitro effects of propofol on blood coagulability and fibrinolysis by the use of thromboelastograph (TEG) technique. Methods: The blood samples, obtained from 14 healthy volunteers, were divided into two groups: propofol (n=7) and intralipid (n=7), and 360 mu l volumes of whole blood were incubated with 2 mu l of 1% propofol and with its solvent intralipid, respectively. The incubated sample was then used for TEG measurements. Results: The maximum amplitude (MA), which reflects coagulability, in the intralipid group significantly increased by about 7% and 16% compared to the control and propofol groups, respectively (P<0.05), whereas the MA in the propofol group did not change. The fibrinolytic rate (FR) in the propofol group significantly increased by about 170% and 210% compared to the control and intralipid groups, respectively (P<0.05), whereas the FR in the intralipid group did not change. Conclusions: Propofol, per se, has at the concentration of 55.6 mu g . ml(-1) an in vitro accelerative effect on blood fibrinolysis detected by TEG.

DOI

Circulatory response to endotracheal intubation after propofol induction - Comparative study of fentanyl with nitrous oxide sevoflurane anesthesia

H Tsuchida, A Matsuno, H Iwasaki, M Yamakage, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 88 ( 2 ) U78 - U78 1999.02

Research paper, summary (international conference)

Does sevoflurane anesthesia shorten vecuronium muscle relaxation during induction?

H Tsuchida, M Yamakage, H Iwasaki, A Matsuno, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 88 ( 2 ) U45 - U45 1999.02

Research paper, summary (international conference)

Inhibitory effects of diazepam and midazolam on Ca2+ and K+ channels in canine tracheal smooth muscle cells

M Yamakage, T Matsuzaki, N Tsujiguchi, Y Honma, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 90 ( 1 ) 197 - 207 1999.01

Background: Benzodiazepines have a direct bronchodilator action in airway smooth muscle, but the mechanisms by which these agents produce muscle relaxation are not fully understood, The current study was performed to identify the effects of the benzodiazepines diazepam and midazolam on Ca2+ and K+ channels in canine tracheal smooth muscle cells. Methods: Whole-cell patch-clamp recording techniques were used to evaluate the effects of the benzodiazepines diazepam (10(-8) to 10(-3) M) and midazolam (10(-8) to 10(-3) M) on inward Ca2+ and outward K+ channel currents in dispersed canine tracheal smooth muscle cells. The effects of the antagonists flumazenil (10(-5) M) and PK11195 (10(-5) M) on these channels were also studied. Results: Each benzodiazepine tested significantly inhibited Ca2+ currents in a dose-dependent manner, with 10(-6) nr diazepam and 10(-5) ar midazolam each causing approximately 50% depression of peak voltage-dependent Ca2+ currents. Both benzodiazepines promoted the Inactivated state of the channel at more-negative potentials. The Ca2+-activated and voltage-dependent K+ currents were inhibited by diazepam and midazolam (> 10(-5) M and > 10(-4) M, respectively). Flumazenil and PK11195 had no effect on these channel currents or on the inhibitory effects of the benzodiazepines. Conclusions: Diazepam and midazolam had inhibitory effects on voltage-dependent Ca2+ channels, which lead to muscle relaxation. However, high concentrations of these agents were necessary to inhibit the K+ channels. The lack of antagonized effects of their antagonists is related to the non-gamma-aminobutyric acid-mediated electrophysiologic effects of benzodiazepines on airway smooth muscle contractility.

Mechanisms of contraction and relaxation of airway smooth muscle

Anesthesiologists and Basic Research - Muscle contraction/relaxation and anesthetics 1999

MAC

Volatile Anesthetic Sevofrane 1999

術中体温管理のポイント

オペナーシング 14 33 - 37 1999

Points of intraoperative management of body temperature

Ope Nursing 14 33 - 37 1999

気道平滑筋の収縮・弛緩機構

麻酔科医と基礎研究「筋の収縮・弛緩と麻酔薬」 1999

The usefulness of celite-activated thromboelastography for evaluation of fibrinolysis

M Yamakage, N Tsujiguchi, S Kohro, H Tsuchida, A Namiki

CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE ( CANADIAN ANAESTHETISTS SOC INC ) 45 ( 10 ) 993 - 996 1998.10

Purpose: Although thromboelastography is useful for measuring both coagulability and fibrinolysis, it takes about two hours to measure all parameters including fibrinolytic rate. The present study aimed to investigate the usefulness of celite-activated thromboelastography (TEGc) to evaluate fibrinolytic status in non-cardiac surgery. Methods: Whole blood samples were obtained from 30 patients for non-cardiac surgery, and used for measurements of both native TEG (TEGn) and TEGc. The final concentration of I % (w/v) celite was used for TEGc. Results: Time for measurement of the fibrinolytic rate (FR) of TEGc in patients (56.7 +/- 4.0 min) was less than half that of FR of TEGn (123.3 +/- 15.6 min) (P < 0.05), suggesting a more rapid assessment of fibrinolytic status. A linear relationship was observed between FR values of TEGc and those of TEGn (r = 0.93, P < 0.0001), suggesting the usefulness of the fibrinolytic parameter of TEGc. Conclusion: TEGc is a useful technique for a more rapid assessment fibrinolytic status.

Inhibitory effect of noradrenalin on voltage-dependent Ca2+ channels of rat sensory neurons in neuropathic pain model

Y Honma, M Yamakage, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 89 ( 3A ) U934 - U934 1998.09

Research paper, summary (international conference)

Inhibitory effects of halothane, isoflurane, and sevoflurane on contractility and intracellular Ca2+ concentration of pregnant myometrium in rats

M Yamakage, T Mori, N Tsujiguchi, S Kawana, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 89 ( 3A ) U881 - U881 1998.09

Research paper, summary (international conference)

Low-temperature modification of the inhibitory effect of halothane on airway smooth muscle contraction in dogs

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

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 89 ( 3A ) U1054 - U1054 1998.09

Research paper, summary (international conference)

Formalin-induced releases of glutamate and nitric oxide, and their relationship in the skin of the rat hindpaw

K Omote, T Kawamata, M Kawamata, M Yamakage, E Narimatsu, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 89 ( 3A ) U723 - U723 1998.09

Research paper, summary (international conference)

小児前投薬のアトロピンとミダゾラムが体温に与える影響

土田亜矢, 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 ) 16 ( 1 ) 45 - 49 1998.08

小児の小手術において前投薬に用いるアトロピンによる体温上昇の程度,及び術前の鎮静状態と体温の関係について検討した.前投薬としてのアトロピン投与により手術室入室時に37.0℃以上となる症例数は多かったが,ミダゾラム投与による鎮静はアトロピンの体温上昇作用を抑制できなかった.麻酔前投薬としてのアトロピン投与は麻酔導入時の口腔内分泌物を減少させるが,手術室入室時の体温上昇は避けがたい

Role of intracellular Ca2+ stores in the inhibitory effect of halothane on airway smooth muscle contraction

M Yamakage, S Kohro, T Matsuzaki, H Tsuchida, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS ) 89 ( 1 ) 165 - 173 1998.07

Background Halothane directly inhibits contraction of airway smooth muscle, mainly by decreasing the intracellular concentration of free Ca2+ ([Ca2+](i)). The role of intracellular Ca2+ stores, sarcoplasmic reticulum, is still unclear. We investigated the role of sarcoplasmic reticulum in the inhibitory effect of halothane on contraction of airway smooth muscle by measuring [Ca2+](i) and intracellular concentration of inositol 1,4,5-triphosphate ([IP3](i)), a second messenger for release of Ca2+ from sarcoplasmic reticulum, Methods: [Ca2+](i) was monitored by measuring the 500-nm light emission ratio (F-340/F-380) of a Ca2+ indicator fura-2 with isometric tension of canine tracheal smooth muscle strip. During Ca2+-free conditions, carbachol (10(-5) M) was introduced with pretreatment of halothane (0-3%). During Ca2+-free conditions, 20 nM caffeine, a Ca2+-induced Ca2+ release channel opener, was introduced with or without halothane, We measured [IP3](i) during exposure to carbachol and halothane by radioimmunoassay technique. Results Pretreatment with halothane significantly diminished carbachol-induced increases in [Ca2+](i) by 77% and muscle tension by 83% in a dose-dependent manner. Simultaneous administration of halothane significantly enhanced caffeine-induced transient increases in [Ca2+](i) and muscle tension in a dose-dependent manner, by 97% and 69%, respectively. Pretreatment with halothane abolished these responses. Rapid increase in [IP3](i) produced by carbachol was significantly inhibited by 32% by halothane in a dose-dependent manner. Conclusions: Halothane, during Ca2+-free conditions, inhibits transient contraction of airway smooth muscle induced by muscarinic receptor stimulation, mainly by attenuating the increase in [Ca2+](i). Depletion of Ca2+ from sarcoplasmic reticulum via Ca2+-induced Ca2+ release channels also may contribute to the attenuation of the increase in [Ca2+](i) by halothane.

DOI

急速輸液の中枢温の及ぼす影響と輸液加温装置の有用性

山内正憲, 中山禎人, 山蔭道明

麻酔 ( 克誠堂出版(株) ) 47 ( 5 ) 606 - 610 1998.05

心臓血管外科手術を受ける成人35名を対象に,30分間に投与する乳酸リンゲル液の温度(室温又は38℃),輸液量(1,000又は250ml)及び投与経路(前腕末梢静脈又は鎖骨下静脈)の違いが,中枢温(肺動脈温)の変化に及ぼす影響について検討した.室温(約19℃)で,かつ投与量が多い場合(1,000ml),中枢温は有意に低下した(0.8〜1.0℃).輸液温を38℃と一定に保つ加温装置HOT LINEを用いて輸液を投与すると,輸液経路に依存せずにこの体温低下を50〜80%予防できた

Surgical/tourniquet pain accelerates blood coagulability but not fibrinolysis

S Kohro, M Yamakage, J Arakawa, M Kotaki, T Omote, A Namiki

BRITISH JOURNAL OF ANAESTHESIA ( PROF SCI PUBL ) 80 ( 4 ) 460 - 463 1998.04

Tissue damage during surgery induces coagulation factors and activates platelets. Surgical pain may provoke release of catecholamines, leading to hypercoagulability. We have investigated the effect of surgical pain on blood coagulability and fibrinolysis in orthopaedic operations using tourniquets in 22 patients undergoing total knee replacement. Patients were allocated to one of two groups to receive extradural anaesthesia (EA; n=11) or general anaesthesia (GA; n=11). The EA group received lumbar extradural block with lidocaine. The GA group received only general anaesthesis, maintained with 1.5-2.5% sevoflurane and 66% nitrous oxide in oxygen. Using a thrombelastogram technique, blood coagulability and fibrinolysis were measured. Mean maximum amplitude (MA), which reflects coagulability, increased after tourniquet inflation (11%) in group GA whereas MA in group EA did not change. After tourniquet deflation, MA values in both GA and EA groups increased significantly (10% and 20%, respectively) (P<0.05), and there was also a significant difference in MA between groups (P<0.05). The fibrinolytic rate did not change in either group during tourniquet inflation, but increased significantly (160%) after tourniquet deflation. There was no significant difference in fibrinolytic rate between the groups. We conclude that the hypercoagulability seen in group GA could have been caused by surgical or tourniquet pain, or both, and that extradural anaesthesia is a useful technique to prevent hypercoagulability.

Triggering delay time and work of breathing in three paediatric patient-triggered ventilators

Y Nakae, M Yamakage, M Aimono, K Tamiya, A Namiki

CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE ( CANADIAN ANAESTHETISTS SOC INC ) 45 ( 3 ) 261 - 265 1998.03

Purpose: To compare the effectiveness of three patient-triggered ventilators by evaluating triggering delay time and pressure-volume loops during initiation of inspiration. Methods: In a two-part study, a model lung was used in part I and 20 children, after tracheal intubation, in part 2. Triggering delay time and work of breathing (WOB) during pressure support ventilation using three patient-triggered ventilators: Servo Ventilator 300(TM), VIP Bird(TM), and SLE 2000 Neonatal Ventilator(TM), Triggering delay time was from the beginning of negative deflection in the oesophageal pressure trace, to re onset of inspiration. The WOE was estimated directly by measuring the oesophageal pressure-volume loop, Results: The Servo demonstrated superior triggering delay time and reduced WOE in the model study The VIP Bird demonstrated shorter triggering delay and reduced WOE in the clinical component of the study in the model lung, triggering delay time in the Servo 300 [62 +/- 6 msec (mean +/- SD)] was shorter than that in the VIP Bird (76 +/- 7 msec) (P < 0.05), and WOE with the SLE 2000 (202 +/- 37 g.cm) was greater than with other ventilators, (Servo 300, 112 +/- 32 gem and VIP Bird 72 +/- 41 g.cm) (P < 0.05), in the clinical study, triggering delay time in the VIP Bird (52 +/- 19 msec) was shorter than in the other ventilators, Servo 300 (66 +/- 14 msec), SLE 2000 (68 +/- 65 msec) (P < 0.05). The Servo 300 (56 +/- 34 g.cm) required higher WOE than the other ventilators: VIP Bird (22 +/- 12 g.cm), SLE 2000 (14 +/- 3 g.cm) (P < 0.05, Conclusion: Comparative model lung performance of these ventilators does not correspond with their clinical performance, In our clinical evaluation, the VIP Bird ventilator demonstrated superior performance with shorter triggering delay time, low WOB needed to initiate inspiration, and little air leak.

Effect of recycled autologous blood transfusion on in vitro blood coagulability and fibrinolysis

T Takeda, S Kohro, M Yamakage, N Tsujiguchi, H Tsuchida, A Namiki

ANESTHESIA AND ANALGESIA ( LIPPINCOTT WILLIAMS & WILKINS ) 86 ( 2S ) U79 - U79 1998.02

Research paper, summary (international conference)

　 PREV - NEXT 　

<YAMAKAGE Michiaki>

Misc - YAMAKAGE Michiaki