-
[show abstract]
[hide abstract]
ABSTRACT: Adenosine, which pre-junctionally modulates neuromuscular transmission, and adenosine uptake inhibitors, which increase extracellular adenosine, have been used clinically. We investigated the effects of adenosine, dipyridamole and midazolam on the neuromuscular blocking action of rocuronium.
Isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect (phrenic nerve) supra-maximal stimulation at 0.1 Hz were evaluated (n=6 in all data).
Pre-treatments with adenosine (0.1 and 1 microM) and CCPA (1 microM, adenosine A(1) receptor agonist), but not that with CGS21680 (0.5 microM, A(2) receptor agonist), shifted the rocuronium concentration-twitch tension curves to the left and decreased the rocuronium concentration for 50% twitch depression (IC(50)) compared with the control (P<0.01). The leftward shift induced by 1 microM adenosine was inhibited by pre-treatments with theophylline (50 microM, non-selective adenosine receptor antagonist) and DPCPX (0.2 microM, A(1) receptor antagonist) but not by that with DPMA (5 microM, A(2) receptor antagonist). Pre-treatments with dipyridamole and midazolam, adenosine uptake inhibitors, shifted the curve to the left and decreased IC(50) at supra-therapeutic concentrations (10 and 2.5 microM, respectively) but not at clinical concentrations (2 and 0.5 microM, respectively), and the leftward shifts were inhibited by pre-treatment with DPCPX (0.2 microM).
The results indicate that adenosine potentiates the neuromuscular blocking action of rocuronium mediated by adenosine A(1) receptors and that supra-therapeutic concentrations of dipyridamole and midazolam also potentiate the action of rocuronium by increasing endogenous adenosine concentration.
Acta Anaesthesiologica Scandinavica 12/2008; 52(10):1415-22. · 2.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Both paradoxical intracranial embolism, an intracranial arterial embolism caused by venous embolic material that has passed through a right-to-left shunt, and pulmonary arterial embolism are life-threatening complications of joint arthroplasty. We report a case of severe paradoxical intracranial embolism and pulmonary embolism that occurred during hip hemiarthroplasty.
BJA British Journal of Anaesthesia 01/2004; 91(6):911-3. · 4.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The use of covered stents in an infected field is controversial. It is generally recommended that infected aneurysms be treated using autografts or allografts. We report a case of infected brachial pseudoaneurysms that developed after medical debridement of a methicillin-resistant Staphylococcus aureus (MRSA)-infected wound of the right arm and emergency brachial artery bypass-grafting using the saphenous vein, which was successfully treated by endovascular stent-grafting followed by antibiotic administration. The present case suggests that endovascular stent-grafting prevents rupture and occlusion of infected aneurysms and enables the continued administration of antibiotics.
Infection 07/2003; 31(3):186-8. · 2.66 Impact Factor
-
American Journal of Emergency Medicine 08/2001; 19(4):326-7. · 1.98 Impact Factor
-
American Journal of Emergency Medicine 04/2001; 19(2):169-71. · 1.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated the contribution of adenosine neuromodulation to mechanisms of pentobarbital-induced depression of excitatory synaptic transmission in vitro. Transverse hippocampal slices were prepared from brains removed from isoflurane-anesthetized male Wistar rats. Field excitatory postsynaptic potentials (fEPSPs), elicited by orthodromic electrical stimulation of Schaffer collateral at 0.05 Hz, were recorded from the CA1 region in oxygenated artificial cerebrospinal fluid. Amplitude of fEPSP was analyzed for assessing drug effects. Pentobarbital (100 microM) transiently depressed fEPSPs (P<0.01); i.e., fEPSP was initially depressed to approximately 60% of control and then recovered to approximately 80% of control. The fEPSP depression was partially suppressed by pretreatment with 50 microM aminophylline, a nonselective adenosine receptor antagonist, and 0.2 microM 3, 7-Dimethyl-1-propagylxanthine, an adenosine A(1) receptor antagonist (P<0.01 each). However, the fEPSP depression was not affected by pretreatment with 10 microM 8-cyclopentyl-1, 3-dipropylxanthine, an A(2) receptor antagonist, or 10 microM bicuculline, a gamma-aminobutyric acid (GABA) A receptor antagonist. The results indicate that adenosine neuromodulation through A(1) receptors and other undefined mechanisms, which are independent from GABAergic mechanisms, are involved in pentobarbital-induced depression of excitatory synaptic transmission.
Anesthesia & Analgesia 01/2001; 91(6):1537-41. · 3.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated the effects of polyethylene glycol-adsorbed superoxide dismutase (PEG-SOD), polyethylene glycol-adsorbed catalase (PEG-CAT), and DMSO on diaphragmatic contractility and malondialdehyde (MDA) concentrations in septic peritonitis in vitro. One hundred eighty-six rats were divided into two groups. One group (CLP group) was treated with cecal ligation and perforation (CLP), and the other (sham group) was treated with laparotomy. PEG-SOD, PEG-CAT, and DMSO were administered intraperitoneally 30 min before and 12 h after CLP. The left hemidiaphragm was removed at 10 h or 16 h after the operation. We assessed the diaphragmatic contractility by twitch characteristics and force-frequency curves in vitro. We measured MDA concentrations, as an index of oxygen-derived free radical-mediated lipid peroxidation, and the activities of two main antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GPx), as an index of antioxidant defenses, after CLP. Diaphragmatic force generation capacity was significantly reduced after CLP. Diaphragmatic MDA levels were significantly elevated after CLP. PEG-SOD, PEG-CAT, and DMSO significantly improved diaphragmatic contractility and prevented the elevation in diaphragmatic MDA concentrations after CLP. Diaphragmatic SOD activities were significantly increased after CLP. These results suggest that several types of oxygen-derived free radicals play a role in the reduction in diaphragmatic contractility after CLP.
American Journal of Respiratory and Critical Care Medicine 01/2001; 162(6):2159-65. · 11.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To assess the alterations in diaphragmatic contractility measured in vitro during experimental septic peritonitis and to evaluate the effect of polyethylene glycol-absorbed superoxide dismutase (PEG-SOD) on the alterations in contractility.
Prospective, randomized, controlled animal trial.
Research laboratory.
A total of 321 male Wistar rats, weighing 250-300 g.
Rats were treated with cecal ligation and puncture (CLP). In the first experiment, diaphragmatic contractility was measured at 4, 10, 12, and 16 hrs after CLP. In the second experiment, PEG-SOD (4,000 units/kg) was administered intraperitoneally, and then diaphragmatic contractility was measured at 10 and 16 hrs after CLP. Levels of lipid peroxides and antioxidant enzymes in the diaphragm tissue were measured at 10 and 16 hrs after CLP.
In experiment 1, diaphragmatic twitch characteristics and force-frequency relationships were determined at 4, 10, 12, and 16 hrs after CLP. In experiment 2, the effects of administration of PEG-SOD on twitch characteristics and force-frequency relationships were determined at 10 and 16 hrs after CLP. The levels of diaphragmatic thiobarbituric acid reactive substances and superoxide dismutase (SOD) and glutathione peroxidase activities were measured at 10 and 16 hrs after CLP. Twitch tension and force-frequency curves were significantly lower in the CLP groups than in the sham-operated group. Administration of PEG-SOD attenuated the reduction in twitch tension and the downward shift of force-frequency curves after CLP. Diaphragmatic levels of thiobarbituric acid reactive substances increased after CLP. However, the administration of PEG-SOD prevented increases in levels of diaphragmatic thiobarbituric acid reactive substances after CLP. Diaphragmatic SOD activity, but not glutathione peroxidase activity, was increased after CLP.
Intra-abdominal sepsis (CLP) induced a marked reduction in diaphragmatic contractility, but PEG-SOD attenuated this reduction. Therefore, we conclude that oxygen-derived free radicals play an important role in the alterations in diaphragmatic contractility during intra-abdominal sepsis.
Critical Care Medicine 08/2000; 28(7):2406-14. · 6.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The transient property of the dipyridamole-induced depression of excitatory synaptic transmission was analyzed using field EPSPs (fEPSPs) recorded from the CA1 region in rat hippocampal slices. The fEPSPs were depressed by 1 microM dipyridamole and then gradually recovered to the control level. The depression was antagonized by aminophylline or DPCPX, although it was not significantly affected by DMPX. The results suggest that the fEPSP depression is induced by a mechanism through the A(1) receptor.
Brain Research 05/2000; 862(1-2):284-7. · 2.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated the effects, and the mechanism of the effects, of isoproterenol on diaphragmatic contractility and fatigue in septic peritonitis in vitro. Ninety-six rats were divided into two groups of 48. One group (CLP group) was treated with cecal ligation and perforation (CLP) and the other (sham group) was treated with laparotomy. The left hemidiaphragm was removed at 16 h after the operation. We assessed the diaphragmatic contractility by twitch characteristics and force-frequency curves in vitro. Diaphragm fatigue was induced by rhythmically stimulating strips to contract at 60/ min (20 Hz, 0.33-s trains, 1 train/s) over a 4-min period. Force-frequency curves were determined before and after fatigue. Isoproterenol (10(-9), 10(-8), and 10(-7) M), a beta-adrenoceptor agonist, was cumulatively administered to the organ bath. Isoproterenol significantly increased diaphragmatic contractility. There were no significant changes in diaphragmatic contractility in the sham group. Isoproterenol (10(-7) M) significantly accelerated diaphragmatic recovery of fatigue and increased cAMP levels both in the sham group and the CLP group. Propranolol (10(-7) M), a general beta-adrenoceptor blocker, completely abolished the positive inotropic effect of isoproterenol (10(-7) M) and increased cAMP levels in the CLP group. Dibutyryl cAMP (10(-3) M), a derivative of cyclic AMP, mimicked the effects of isoproterenol in the CLP group. These results suggest that isoproterenol increases diaphragmatic contractility and accelerates diaphragmatic recovery of fatigue in septic peritonitis by activating the adenylate cyclase system.
American Journal of Respiratory and Critical Care Medicine 03/2000; 161(2 Pt 1):440-6. · 11.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We estimated the effect of d-tubocurarine (dTc) on neuromuscular transmission and the action of propofol on dTc-induced twitch depression by using sham control and septic rat nerve-hemidiaphragm preparations in vitro. Isometric twitch tension elicited by indirect (phrenic nerve) or direct (muscle) stimulation at 0.1 Hz was evaluated. Sepsis induced by panperitonitis attenuated the twitch tension elicited by indirect and direct stimulation (P < 0.01 in each group) in the absence of significant morphological inflammatory damage to the diaphragm. dTc (1 microM) decreased the twitch tension elicited by indirect stimulation (P < 0.01) less intensely in the septic group than in the sham group (P < 0.01). Propofol accentuated dTc-induced depressed twitch more intensely in the septic group (P < 0.01 or 0.05). These results demonstrate that sepsis attenuates both muscle contractile force and the effect of a neuromuscular blocker and that propofol more intensely enhances dTc-induced twitch depression during sepsis. IMPLICATIONS: Propofol and nondepolarizing muscle relaxants are widely used for various clinical cases, including sepsis. Interactions between nondepolarizing muscle relaxants and propofol during sepsis are interesting from a clinical point of view. We demonstrated that propofol significantly enhances d-tubocurarine-induced twitch depression in vitro in the septic rat model compared with that in the nonseptic rat model.
Anesthesia & Analgesia 01/2000; 90(1):80-4. · 3.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Prolonged effects of non-depolarizing muscle relaxants in septic patients have been reported, although the influence of sepsis on neuromuscular transmission has not yet been clarified satisfactorily. These studies were intended to elucidate the influence of sepsis on neuromuscular transmission and on the action of drugs being utilized for regulation of muscle tone (a neuromuscular blocker and anti-cholinesterase (anti-ChE) drugs).
The effect of d-tubocurarine (dTc) on neuromuscular transmission and the antagonistic action of anti-ChE drugs (neostigmine and edrophonium) on dTc-induced twitch depression were estimated using sham control and septic rat nerve-hemidiaphragm preparations in vitro. Isometric twitch tension elicited by indirect (phrenic nerve) or direct (muscle) stimulation at 0.1 Hz was evaluated.
Sepsis induced by panperitonitis attenuated the twitch tension elicited by indirect or direct stimulation (P < 0.01) without obvious morphological inflammatory damage to the diaphragm. dTc dose-dependently decreased twitch tension elicited by indirect stimulation (P < 0.01) less intensely in the septic group than in the sham group (P < 0.01). The antagonistic actions of the anti-ChE drugs on dTc (1 microM)-induced twitch depression were less intense in the septic group (P < 0.01 or 0.05).
These results demonstrate that sepsis in the acute phase attenuates the effects of a neuromuscular blocker and anti-ChE drugs and depresses muscle contractility simultaneously.
Acta Anaesthesiologica Scandinavica 03/1999; 43(2):196-201. · 2.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Phosphodiesterase (PDE) inhibitors are occasionally used in patients receiving non-depolarizing muscle relaxants during anesthesia and intensive care. However, little is known about the influence of PDE III inhibitors on the effects of non-depolarizing muscle relaxants. The aim of this study was to elucidate the effects of milrinone, a PDE III inhibitor, on d-tubocurarine (dTc)-induced muscle relaxation in vitro and then to compare its effects with those of other activators of the adenylate cyclase (AC) system (aminophylline, a non-selective PDE inhibitor; forskolin, a direct AC activator; and isoproterenol, a beta-adrenoceptor agonist). Isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect or direct stimulation (0.1 Hz) were measured. Indirectly elicited twitch tension partially depressed by dTc (1 microM) was antagonized by milrinone, aminophylline, and forskolin but was attenuated by isoproterenol. Directly elicited twitch tension was increased by aminophylline, forskolin, and isoproterenol but was not altered by milrinone. The results indicate that milrinone antagonizes dTc-induced muscle relaxation by recovering the neuromuscular transmission. It is noteworthy that PDE inhibitors and a beta-adrenergic agonist affect non-depolarizing muscle relaxation in opposite direction.
Research communications in molecular pathology and pharmacology 02/1999; 104(2):219-28.
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated whether adenosine neuromodulation is involved in a benzodiazepine (midazolam)-induced depression of excitatory synaptic transmissions in the CA1 and dentate gyrus (DG) regions in rat hippocampal slices. Field excitatory postsynaptic potentials (fEPSPs), evoked by electrical stimulation of the CA1-Schaffer collateral or the DG-perforant path, were recorded with extracellular microelectrodes from CA1-stratum radiatum or DG-stratum moleculare in oxygenated ACSF. The initial slope of the fEPSPs was analyzed for assessing the drug effects. Midazolam (1 microM) transiently depressed CA1- and DG-fEPSPs. The fEPSPs were depressed to approximately 75% of the control values, and then gradually recovered. The depression was not affected by bicuculline, a GABAA receptor antagonist, although it was completely antagonized by aminophylline, an adenosine receptor antagonist. Dipyridamole (5 microM), an adenosine uptake inhibitor, depressed the fEPSPs in a similar manner to midazolam. An adenosine deaminase inhibitor, EHNA, also transiently depressed the fEPSPs, but in a different manner. Exogenous adenosine persistently depressed the fEPSPs. The effects of the drugs were not significantly different in the CA1 and DG regions. The results suggest that midazolam (1 microM) depresses excitatory synaptic transmissions through the adenosine neuromodulatory system by inhibiting adenosine uptake in the CA1 and DG regions of the hippocampus.
Neuroscience Research 02/1999; 33(1):57-64. · 2.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the effects of intraarterial infusion chemotherapy (IAIC) for advanced breast cancer, we examined the grade of histological responses of preoperative IAIC on tumors at the time of operation and estimated the patients' prognoses for 19 years. IAIC was done preoperatively using timely epochal anticancer drugs on 105 patients with locally advanced (Stage IIIa, IIIb) and metastatic (Stage IV) breast cancer. The survival rate of the Stage IIIb patients who showed a good histological response (Grade IIb< or =) to IAIC was 68.1% for 5 years, and 62.4% for 10 years, respectively. This was in contrast to that of the patients classified as Stage IIIb who showed a poor histological response (Grade IIa> or =) to IAIC. On the other hand, there was no significant difference in the survival rates between the Stage IIIa and IV patients with good and poor histological responses to IAIC. However, the findings showed that a good histological response to IAIC reflected a prolonged survival while the Stage IIIb and IV patients acquired a "down clinical staging" by IAIC. These results strongly suggest that IAIC thus appears to be a useful modality in the multidisciplinary treatment of advanced breast cancer, especially for Stage IIIb patients.
Surgery Today 02/1998; 28(5):509-16. · 1.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the onset of vecuronium neuromuscular blockade in the hand with an arterio-venous shunt for haemodialysis.
In 15 adult patients receiving haemodialysis for renal failure the onset of vecuronium-induced neuromuscular blockade after 0.08 mg-kg-1 vecuronium i.v. was measured. Using train-of-four mechanomyographic monitoring, the force of contraction of the adductor pollicis of both hands with and without arterio-venous shunt was measured simultaneously.
The times from the injection to the first depression of twitch response (latent onset) and 95% twitch depression (onset) in the hand with and without arterio-venous shunt were 114.7 +/- 33.4 and 218.7 +/- 59.9 and 117.3 +/- 34.3 and 208.7 +/- 60.9 sec respectively. No difference in the onset of vecuronium neuromuscular blockade in the hand an arterio-venous shunt was demonstrated.
The presence of an arteriovenous fistula does not modify the onset on neuromuscular blockade. Either arm can be used to monitor onset of neuromuscular blockade in chronic renal failure patients with an arterio-venous shunt in the hand for haemodialysis.
Canadian Journal of Anaesthesia 12/1997; 44(11):1208-10. · 2.35 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A 13-day-old infant with multiple teratisms of the oral cavity was scheduled for resection of the epignathus. Her oral cavity was occupied by large epignathus, submandibular tumor, congenital bifid tongue and cleft palate, but she had no other congenital abnormalities. We anticipated that an endotracheal intubation would be difficult because of the large size of the tumor in relation to the oral cavity. Initially, awake intubation using a standard laryngoscope was attempted. Although a large elastic epignathus did not interrupt the insertion of the curved laryngoscope blade, the hard submandibular tumors protruded from the submaxillary ramport interfered with mid-line management of the laryngoscope. After several attempts of intubation, a better exposure was obtained and she was successfully intubated using a stylet under deep sedation. We recognized that a careful observation of anatomical abnormalities in the oral cavity is important to keep airway in an infant with multiple abnormalities of the oral cavity.
Masui. The Japanese journal of anesthesiology 09/1997; 46(8):1114-7.
-
[show abstract]
[hide abstract]
ABSTRACT: Ideally, in preoperative intra-arterial infusion chemotherapy (regarding advanced breast cancer) is to obtain the most significant effects concerning histological features. Intra-arterial infusion chemotherapy using epirubicin (EPI), used in conjunction with daily doses of 1,200 mg medroxyprogesterone acetate (MPA), have recently been performed. This procedure has shown remarkable histological effects in the metastatic lymph nodes as well as in the primary lesions. These results were especially remarkable in the patients who were administered MPA (daily) two weeks prior to EPI infusion. These patients showed a complete disappearance of tumor cells. The results were interesting in view of the mechanism of action. Intra-arterial infusion chemotherapy combined with MPA may also be valuable in treating metastatic liver tumors and recurrent lesions in the regional lymph nodes such as supraclavicular tumors. A high response rate was obtained in the chemo-endocrine therapy when combined with MPA as a pretreatment. Thus, MPA may be expected to be available as a systemic therapy, too. In the future, a new development in the field of intra-arterial infusion chemotherapy may be achieved by utilizing a combination of angiogenesis inhibitors and peripheral blood stem cell transplantation.
Gan to kagaku ryoho. Cancer & chemotherapy 05/1995; 22 Suppl 1:94-101.
-
[show abstract]
[hide abstract]
ABSTRACT: The classical view of the neuromuscular transmission is that non-depolarizing muscle relaxants (MRs) enhance run-down of the endplate potentials (epps) by blocking pre-junctional nicotinic acetylcholine (ACh) receptors. Several recent investigations, when extended to pharmacology, have provided evidence to suggest the existence of other types of enhancement of run-down of epps by MRs; the enhancement of epps occurs without reduction of ACh release in the presence of MRs. It has been generally accepted that the enhancement of run-down of epps causes the tetanic fade of tension response. However, recent evidence indicates that run-down of epps does not always cause this wane in tension. The electrophysiological mechanism of run-down of epps at the neuromuscular junction and the relationship between that phenomenon and the extent of reduction of tension response are described based on a review of literature and our current investigations.
Masui. The Japanese journal of anesthesiology 11/1994; 43(10):1446-53.
-
[show abstract]
[hide abstract]
ABSTRACT: Arterial infusion therapy with anticancer drugs is now attracting attention as a valuable modality for locally advanced breast cancer. Since 1977, we have used this therapy in 122 patients with primary breast cancer. The present report mainly discusses the clinical and histological response as well as the prognosis. The anticancer drugs were mainly given by two routes, infusion into the internal mammary artery and the subclavian artery. Continuous infusion of 5-FU and intermittent injections of MMC, ADR, 4'-epi-ADR and THP-ADR were jointly or individually made in each artery. Clinical response, defined as CR + PR, was noted in 48.4% of 5-FU group and 72.7% of ADR-MMC group. Histological response according to Shimosato Criteria, defined as grade IIb or better, appeared in 45.2% of main tumors and 25.4% of metastatic lymph nodes in the 5-FU group, and 70.9% main tumors and 46.3% of metastatic lymph nodes in the ADR-MMC group. The non-infusion group contained 27.7% of stage IIIb, against 72.2% in the infusion group. The 5-year overall survival rates were non-infusion group 62%, 5-FU group 34.1% and ADR-MMC group 66.2%. A significant difference was seen between the 5-FU infusion group and the ADR-MMC group (p = 0.03). Administration of high dose medroxy progesterone acetate for two weeks and 4'-epi-ADR infusion chemotherapy resulted in an excellent histological response. This combination therapy is a promising neoadjuvant chemo-endocrine therapy for advanced breast cancer.
Gan to kagaku ryoho. Cancer & chemotherapy 07/1994; 21 Suppl 2:264-71.
