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Search Results: 1 - 10 of 3969 matches for " Toshiyasu Suzuki "
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Effects of Continuous Intravenous Infusion of Dexmedetomidine on the Duration of Spinal Anesthesia: A Prospective, Double-Blind, Randomized, Controlled Trial  [PDF]
Mariko Watanabe, Masahiro Kanazawa, Toshiyasu Suzuki
Open Journal of Anesthesiology (OJAnes) , 2018, DOI: 10.4236/ojanes.2018.83006
Abstract: Background: Spinal anesthesia with sedation is a common anesthetic technique in infraumbilical surgeries. Dexmedetomidine has been widely used as a sedative during spinal anesthesia, and is recognized as an adjuvant that prolongs the duration of spinal anesthesia. We compared the effects of a continuous intravenous infusion of dexmedetomidine to provide intraoperative sedation on the duration of sensory and motor blockade induced by spinal anesthesia, with those of midazolam. Methods: A double-blind randomized controlled trial was performed on 40 patients, aged between 20 and 75 years, who requested intraoperative sedation, and were classified as American Society of Anesthesiologists (ASA) physical status I-II, and underwent elective surgeries under spinal anesthesia. After spinal anesthesia with 13 mg (2.6 ml) of 0.5% hyperbaric bupivacaine, patients were randomized to receive intravenous dexmedetomidine 3 μg/kg/h for 10 mins followed by an infusion of 0.5 μg/kg/h (Group D), or intravenous midazolam 0.15 mg/kg/h for 10 mins followed by an infusion of 0.025 mg/kg/h (Group M). Sedation was titrated to Observer’s Assessment of Alertness/Sedation (OAA/S) score of 3. Sensory and motor blockade was evaluated using the pinprick test and modified Bromage scale, respectively. Results: The time taken to achieve OAA/S score 3 was similar in the two groups. The maximal level of sensory blockade was 5.3 ± 1.3 min in group D and 4.1 ± 1.5 in group M (P = 0.03). No significant differences were observed in the time taken to achieve the maximal level or the two-segment regression time of sensory blockade between the two groups. The time to sensory regression to the L2 level was significantly longer in group D than in group M (234.6 ± 78.1 mins versus 172.4 ± 41.5 mins, respectively, P = 0.008). The time to motor regression to modified Bromage score 1 was significantly longer in group D than in group M (232.2 ± 79.3 versus 176.5 ± 48.8, respectively, P = 0.02). Conclusion: Continuous intravenous dexmedetomidine to provide sedation during spinal anesthesia significantly prolongs the duration of sensory and motor blockade induced by spinal anesthesia over that with midazolam.
Simplified Intraoperative Goal-Directed Therapy Using the FloTrac/Vigileo System: An Analysis of Its Usefulness and Safety  [PDF]
Kenji Ito, Miho Ito, Aki Ando, Yuki Sakuma, Toshiyasu Suzuki
Open Journal of Anesthesiology (OJAnes) , 2017, DOI: 10.4236/ojanes.2017.71001
Abstract: Purpose: We investigated whether the simplified intraoperative Goal-Directed Therapy (GDT) could improve the factors affecting medical costs, and contribute in standardizing intraoperative fluid management. Methods: The enrolled patients underwent esophagectomy, pancreatoduodenectomy, or aortic stent grafting in 2012, and between March 2013 and October 2014. We conducted a comparison study on the effects of GDT, between the before-GDT historical control group (n = 100) and GDT group (n = 100). The hemodynamic indices used for control group patients were conventional: Blood pressure, heart rate, and urine output. For GDT group, additionally, we used stroke volume variation (SVV) and stroke volume index (SVI). The primary outcomes were the length of intensive care unit (ICU) stay and hospital stay (LOS). Regression analysis was used to identify factors affecting LOS. The secondary outcomes were the albumin use, the fluid amount administered, and the variation in the fluid administration rate. Results: The control and GDT groups comprised 96 and 99 patients, respectively. The patient characteristics were similar. The length of ICU stay was significantly shorter (2.1 ± 2.1 days vs. 2.8 ± 1.9 days, P = 0.0009) and LOS was shorter but without statistical significance (24.5 ± 17.7 days vs. 27.7 ± 20.1 days, P = 0.21) in the GDT group than in the control group. The fluid amount administered and the presence/ absence of albumin use were factors affecting LOS. The variation of the fluid administration rate was significantly lower in the GDT group.
High Preoperative Anxiety Level and the Risk of Intraoperative Hypothermia  [PDF]
Noriyoshi Tanaka, Yuko Ohno, Megumi Hori, Mai Utada, Kenji Ito, Toshiyasu Suzuki
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.36085
Abstract: Aim: The relationship between preoperative anxiety level and intraoperative hypothermia (<36℃) was investigated. Background: Core temperature often decreases during surgery, with an initial rapid decrease followed by a slower decrease for about 2 hours. Preoperative anxiety may influence perioperative physiological responses. The relationship between preoperative anxiety level and perioperative decrease in core temperature has not been studied closely. Design: A prospective observational study. Methods: This study enrolled 120 adult patients who underwent elective major abdominal surgery under combined epidural and general anesthesia. Tympanic membrane temperature was used to measure core temperature preoperatively and during the operation. The relationship between anxiety level according to the State-Trait Anxiety Inventory (STAI) and core temperature was examined using descriptive and multivariate risk analysis. Results: High anxiety level was found in 61 patients (51%), of which 26 (43%) developed hypothermia during the first hour and 40 (66%) developed hypothermia during the first 2 hours of anesthesia. After adjustment for covariates, patients with a high anxiety level were found to have a 2.17-fold higher risk of hypothermia during the first hour and a 1.77-fold higher risk of hypothermia during the first 2 hours than patients with a low/moderate anxiety level. Conclusions: The risk of hypothermia in the early phase of general anesthesia can be predicted by measurement of the preoperative anxiety level using the STAI. Relevance to Clinical Practice: Patients with a high anxiety level had a significantly higher risk of intraoperative hypothermia. Preoperative preventive nursing care programs should include anxiety management and thermal care.
Safety of Landiolol Infusion in Patients Undergoing Lung Resection  [PDF]
Kenji Ito, Masahisa Nozaki, Reinii Sakamoto, Toshiyasu Suzuki, Ryota Masuda, Masayuki Iwazaki
Open Journal of Anesthesiology (OJAnes) , 2014, DOI: 10.4236/ojanes.2014.48026
Abstract:

The efficacy of landiolol hydrochloride, an ultrashort-acting b-blocker with high b1 selectivity, has been confirmed in patients undergoing cardiac surgery in Japan, but there have been few reports about its use for patients having lung resection. We investigated the safety of continuous infusion of landiolol in patients undergoing lung resection. Between May 2008 and May 2011, 200 patients scheduled for lung resection were enrolled. Patients who underwent surgery before the introduction of landiolol in February 2010 were studied retrospectively (Group C) and were compared with those who received landiolol along with surgery (Group L). During the 48-hour study period, the incidence of arrhythmias, changes in heart rate and blood pressure, and occurrence of adverse reactions were examined. The white blood cell count and C-reactive protein level were measured before and after surgery to assess the anti-inflammatory effect. The heart rate was significantly lower in Group L throughout the study period. No patient in Group L developed hypotension requiring discontinuation of landiolol therapy, and no respiratory symptoms (including asthma or hypoxemia) were observed. White blood cell and C-reactive protein were significantly increased after surgery in both groups, and there were no between-group differences. Arrhythmic events occurred in 1.1% (1/99) and 9.2% (7/76) of Group L and Group C, respectively. One patient in Group C developed ventricular tachycardia. Landiolol can be administered safely during the perioperative period in patients undergoing lung resection.

Difficult Intubation in a Patient with Dysphagia after Posterior Occipitocervical Fusion: A Case Report  [PDF]
Junichi Nishiyama, Aki Ando, Tomohiko Murata, Mariko Watanabe, Hajime Yamazaki, Satoru Saito, Toshiyasu Suzuki
Open Journal of Anesthesiology (OJAnes) , 2017, DOI: 10.4236/ojanes.2017.75012
Abstract: The authors encountered a case involving difficult intubation during anesthesia for revision of cervical fixation angle in a 62-year-old woman, with a history of chronic rheumatoid arthritis, who experienced dysphagia after initial posterior occipitocervical fusion to correct atlantoaxial subluxation. Two days after initial surgery, she developed trismus with neck flexion and dysphagia, and underwent revision surgery. General anesthesia was planned; however, tracheal intubation using the McGrath laryngoscope and bronchofiberscope was difficult, which prolonged anesthesia induction. Narrowing of the oral and pharyngeal cavities associated with overcorrection of the cervical spine was believed to be the reason for difficulty in manipulating the tracheal intubation devices. In posterior occipitocervical fusion, intraoperative evaluation of the occipito-second cervical vertebra (O-C2) angle is reported to be useful in preventing postoperative dyspnea and/or dysphagia, and avoids the need for revision of fixation angle. However, when revision surgery is needed, selection of airway management methods and tracheal intubation devices are important considerations because patients are likely to have restricted mobility in the cervical spine and narrowing of the oral and pharyngeal cavities.
Influence of Epidural Needle Treatment at the Heel of the Bevel on Catheter Breakage  [PDF]
Genya Urimoto, Kenji Ito, Keiichiro Saito, Suhei Tetsu, Kai Yamazaki, Toshiyasu Suzuki
Open Journal of Anesthesiology (OJAnes) , 2019, DOI: 10.4236/ojanes.2019.91001
Abstract: Background: Epidural anesthesia continues to play a central role in postoperative analgesia. Epidural catheter breakage and fragment retention in the body is a complication related to epidural anesthesia. To reduce the risk of epidural catheter damage by epidural needles, needles with special changes to the heel of the bevel are commercially available. The present study aimed to assess the effectiveness of blasting and drilling treatments at the heel of the epidural needle bevel to determine which treatment is more appropriate. Methods: The epidural needles with blasting, drilling, or no treatment to the heel of the bevel were prepared. The catheter was pulled out from the tip of the epidural needle, folded back 180？, and then pulled up at a speed of 400 mm/min until it was fractured. The force needed to break the catheter (FB) was measured. Subsequently, low-density polyethylene (0.05 mm) was vertically penetrated with the needles at a speed of 200 mm/min, and the maximum force at penetration (FP) was measured. Results: The FB values for the blasted, drilled, and control needles were 21.3, 12.23, and 6.27 N, respectively (p < 0.01). The FP values for the blasted, drilled, and control needles were 0.82, 0.69, and 0.73 N, respectively. Conclusion: Blasting treatment is the most effective approach for the prevention of catheter rupture; however, it can increase the puncture force.
Effect of Peptidase Inhibitors on Dynorphin A (1-17) or (1-13)-Induced Antinociception and Toxicity at Spinal Level  [PDF]
Mitsumasa Matsuda, Masanobu Yoshikawa, Takugi Kan, Mariko Watanabe, Junko Ajimi, Shigeru Takahashi, Masaaki Miura, Kenji Ito, Hiroyuki Kobayashi, Toshiyasu Suzuki
Pharmacology & Pharmacy (PP) , 2017, DOI: 10.4236/pp.2017.82003
Abstract: Our group has earlier demonstrated that three enzymes sensitive to peptidase inhibitors (PIs), amastatin (A)-, captopril (C)-, and phosphoramidon (P), played an important role in inactivation of enkephalins at the spinal level. Dynorphin-converting enzyme (DCE) hydrolyzes dynorphin (Dyn) A (1-17) or Dyn A (1-13) mainly at the Arg6-Arg7 bond. Dynorphin A and its derived peptides interact with opioid and glutamate receptors at their N- and C-terminals, respectively. The purpose of the present study was to evaluate the antinociceptive potency and toxicity of intrathecal administered Dyn A (1-17), Dyn A (1-13), or Dyn A (1-6) under pretreatment with ACP and/or the DCE inhibitor p-hydroxymercuribenzoate (PHMB). The effect of these PIs on Dyn A (1-17)-induced inhibition of electrically-evoked contractions in mouse vas deferens was also investigated. The inhibitory potency of Dyn A (1-17) on electrically-evoked contractions in mouse vas deferens under pretreatment with ACP was higher than that with AC, AP, or CP. Pretreatment with ACP augmented Dyn A (1-17) or (1-13)-induced antinociception by approximately 50- or 30-fold with no sign of allodynia when administered intrathecally at low doses. Pretreatment with ACP and PHMB induced neuropathy. These findings showed that intrathecal administration of low-dose Dyn A (1-17) or DynA (1-13) increased antinociception under pretreatment with ACP, but without signs of allodynia in rat.
In-Situ Corrosion Monitoring of Scratched Epoxy Coated Carbon Steel in Saturated Ca(OH)2 with or without 3% NaCl by Scanning Electrochemical Microscopy and Electrochemical Impedance Spectroscopy  [PDF]
Thangaraj Balusamy, Toshiyasu Nishimura
American Journal of Analytical Chemistry (AJAC) , 2016, DOI: 10.4236/ajac.2016.77049
Abstract: The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)2 with and without 3% NaCl using SECM and correlated with EIS. The results obtained from EIS analysis showed that the corrosion resistance of scratched epoxy coated carbon steel decreases in Cl- containing solution as the increase in wet/ dry corrosion cycles. This was indicated by decrease in film resistance (Rf) and charge transfer resistance (Rct), while the coated steel maintain the resistance values in saturated Ca(OH)2, most of which recovered after drying. The corrosion process was monitored using SECM by setting the tip potential at -0.70 V vs Ag/AgCl, where the consumption of dissolved oxygen occurred at the surface of test sample. The consumption of dissolved oxygen current (I’oxy-c) values was increased during the immersion in a solution with 3% NaCl. However, in wet/dry corrosion cycles, I’oxy-c was decreased due to the coverage of hydroxides/oxides at scratch area which suppressed the consumption of dissolved O2. It was found that the continuous decrease in corrosion was mainly attributed to continuous formation of corrosion products at anodic spots.
Optical Properties of Pentacene and Perfluoropentacene Thin Films
Alexander Hinderhofer,Ute Heinemeyer,Alexander Gerlach,Stefan Kowarik,Robert M. J. Jacobs,Youichi Sakamoto,Toshiyasu Suzuki,Frank Schreiber
Physics , 2007, DOI: 10.1063/1.2786992
Abstract: The optical properties of pentacene (PEN) and perfluoropentacene(PFP) thin films on various SiO2 substrates were studied using variable angle spectroscopic ellipsometry. Structural characterization was performed using X-ray reflectivity and atomic force microscopy. A uniaxial model with the optic axis normal to the sample surface was used to analyze the ellipsometry data. A Strong optical anisotropy was observed and enabled the direction of the transition dipole of the absorption bands to be determined. Furthermore, comparison of the optical constants of PEN and PFP thin films with the absorption spectra of the monomers in solution shows significant changes due to the crystalline environment. Relative to the monomer spectrum the HOMO-LUMO transition observed in PEN (PFP) thin film is reduced by 210 meV (280 meV). Surprisingly, a second absorption band in the PFP thin film shows a slight blueshift (40 meV) compared to the spectrum of the monomer with its transition dipole perpendicular to that of the first absorption band.
TOPICAL REVIEW: Corrosion resistance of Si–Al-bearing ultrafine-grained weathering steel
Toshiyasu Nishimura
Science and Technology of Advanced Materials , 2008,
Abstract: In the Ultra-steel project at the National Institute for Materials Science (NIMS), which run from 1996 to 2005, high-Si–Al-content ultrafine-grained (UFG) weathering steel was developed by grain refinement and weathering guidance. It was found that this steel has excellent strength, toughness and corrosion resistance. Samples were prepared by multi pass warm rolling at temperatures between 773 and 873 K. The grain size of steel rolled at 873 K was about 1 μ m, and the tensile strength (TS) and elongation (EL) had excellent values of 800 MPa and 20%, respectively. In general, steels with high Si and Al contents exhibit inferior toughness to carbon steel (SM); however, the toughness of the developed sample was markedly improved by grain refinement. Cyclic corrosion tests in the presence of chloride ions confirmed that the developed steel exhibited excellent corrosion resistance, superior to that of SM. Electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) analyses showed that Si and Al mainly exist in the inner rust layer. Si and Al were identified as existing in the Si2 + and Al3 + states in the nanoscale complex oxides constituting the inner rust layer. Electrochemical impedance spectroscopy(EIS) measurement showed that the corrosion reaction resistance (Rt) of the developed steel was much greater than that of SM. In the developed steel, the nanoscale complex oxides were formed in the inner rust layer, which increased Rt, and resulted in the excellent corrosion resistance.
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