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Biomedical subjects

Takeyoshi Sata

Publications and source records attributed to Takeyoshi Sata.

At least 19 recordsLinked to original sources
PubMed2005

The effects of the neurosteroids: pregnenolone, progesterone and dehydroepiandrosterone on muscarinic receptor-induced responses in Xenopus oocytes expressing M1 and M3 receptors.

The neurosteroids pregnenolone, progesterone, and dehydroepiandrosterone (DHEA) occur naturally in the nervous system. They act on neural tissues, participate in neuronal signaling, and are reported to alter neuronal excitability via nongenomic mechanisms. Muscarinic receptors have important roles in neuronal functions in the brain and autonomic nervous system. In this study, we investigated the effects of pregnenolone, progesterone, and DHEA on M(1) and M(3) muscarinic receptors using the Xenopus oocyte expression system. Pregnenolone and progesterone inhibited the acetylcholine (ACh)-mediated responses of M(1) and M(3) receptors expressed in Xenopus oocytes, whereas DHEA did not. The half-maximal inhibitory concentrations (IC(50)) for pregnenolone inhibition of M(1) receptor- and M(3) receptor-mediated currents were 11.4 and 6.0 microM respectively; the IC(50) values for progesterone inhibition of M(1) receptor- and M(3) receptor-mediated currents were 2.5 and 3.0 microM respectively. The selective protein kinase C (PKC) inhibitor GF109203X had little effect on the pregnenolone or progesterone inhibition of the ACh-induced currents in Xenopus oocytes expressing M(1) or M(3) receptors. The inhibitory effects of pregnenolone and progesterone were overcome at higher concentrations of ACh. Pregnenolone and progesterone inhibited the [(3)H]quinuclidinyl benzilate (QNB) binding to M(1) and M(3) receptor expressed in Xenopus oocytes, and Scatchard plot analysis of [(3)H]QNB binding revealed that pregnenolone and progesterone altered the K(d) value and the B(max), indicating noncompetitive inhibition. In conclusion, pregnenolone and progesterone inhibited M(1) and M(3) receptor functions noncompetitively by the mechanism independent of PKC and by interfering with ACh binding to the receptors.

Acetylcholine↗
PubMed2005

Prevention of thrombosis with prostaglandin E1 in a patient with catastrophic antiphospholipid syndrome.

PURPOSE: Catastrophic antiphospholipid syndrome (CAPS) is a variant of antiphospholipid syndrome and presents with life-threatening symptoms of multiorgan failure due to thrombosis. We present a patient with CAPS secondary to an ovarian cancer. In such cases, it is believed that the thrombotic risk disappears after surgical removal of the cancer. The intraoperative management was challenging because of the risks of two opposing complications: catastrophic exacerbation of the thrombotic tendency triggered by the surgical stimulus and major bleeding due to the necessary anticoagulation. We describe the intraoperative management of hemostasis in a patient with CAPS. CLINICAL FEATURES: A 44-yr-old female patient with CAPS underwent resection of an ovarian cancer, which was suspected to be associated with her coagulation abnormality. She had both arterial and venous thromboembolism, including cerebral infarction, embolic gangrene, and pulmonary emboli. Serological examinations revealed increased anticardiolipin IgG antibody and decreased protein C activity. Before surgery, an inferior vena cava filter was placed to prevent perioperative pulmonary embolism. Prostaglandin E(1) (PGE(1); 100 ng.kg(-1).min(-1)) was given intraoperatively to suppress platelet aggregation and thrombin generation and to maintain arterial blood flow. No apparent coagulation abnormalities were observed during surgery, neither hypercoagulation nor a tendency to bleed. No additional thrombotic symptoms developed during a six-month follow-up. CONCLUSION: The use of PGE(1), an inhibitor of thrombin formation and platelet function, and placement of an inferior vena cava filter were associated with the uneventful surgical resection of an ovarian cancer in a patient with CAPS.

Adult↗
PubMed2005

Effects of fentanyl on emergence characteristics from anesthesia in adult cervical spine surgery: a comparison of fentanyl-based and sevoflurane-based anesthesia.

PURPOSE: To evaluate the effects of different anesthesia regimens on bucking, awareness, and pain during the emergence from anesthesia, which may affect neck stabilization and neurological assessment immediately after cervical spine surgery. METHODS: Patients scheduled to undergo cervical spine surgery were assigned randomly into one of three groups: maintenance of anesthesia with fentanyl and propofol TCI (group FP, n = 25); maintenance with fentanyl and supplementation with less than 1% sevoflurane (group Fs, n = 25); and maintenance solely with sevoflurane (group S, n = 25). The severity of bucking, extent of awareness during neurological examination, and perception of pain during the emergence phase were assessed using predetermined scoring scales by a nurse blinded to the method of anesthesia. RESULTS: The bucking score and pain score were significantly better in group FP and group Fs than in the group S, whereas there was no significant difference between the data of group FP and group Fs. CONCLUSION: The quality of emergence from anesthesia in patients with cervical spine surgery is improved with fentanyl-based anesthesia, but there is no difference between the use of propofol TCI and less than 1% sevoflurane as a concomitant sedative agent with fentanyl.

Adult↗
PubMed2005

N-acetyl-cysteine attenuates endotoxin-induced adhesion molecule expression in human whole blood.

Leukocyte adhesion to endothelial cells plays a pivotal role in the early stage of endotoxin shock. The attenuation of the leukocyte response to endotoxin may contribute to the prevention of further organ dysfunction. Recent evidence implies that N-acetyl-cysteine (NAC) attenuates endotoxin-induced pathophysiological changes. We investigated the effect of NAC on the expression of CD11b and CD62L in endotoxin-stimulated human whole blood. NAC (>10 mM) significantly inhibited the lipopolysaccharide (LPS)-induced upregulation of CD11b in a concentration-dependent manner. However, NAC did not affect the LPS-induced downregulation of CD62L. We also analyzed the effect of NAC on interleukin-8 (IL-8)-induced expression of CD11b in human whole blood. IL-8 (10 ng/mL) significantly upregulated the expression of CD11b, and the IL-8-induced upregulation was significantly attenuated by NAC (>10 mM) in a dose-dependent manner. We conclude that NAC attenuates the increased expression of CD11b in either LPS or IL-8-stimulated human whole blood.

Acetylcysteine↗
PubMed2005

The effects of tramadol and its metabolite on glycine, gamma-aminobutyric acidA, and N-methyl-D-aspartate receptors expressed in Xenopus oocytes.

We assessed the effects of tramadol, a centrally acting analgesic, and its major metabolite, on neurotransmitter-gated ion channels. Tramadol binds to mu-opioid receptors with low affinity and inhibits reuptake of monoamines in the central nervous system. These actions are believed to primarily contribute to its antinociceptive effects. However, little is known about other sites of tramadol's action. We tested the effects of tramadol and its M1 metabolite (0.1-100 microM) on human recombinant neurotransmitter-gated ion channels, including glycine, gamma-aminobutyric acid(A) (GABA(A)), and N-methyl-D-aspartate (NMDA) receptors, expressed in Xenopus oocytes. Tramadol and M1 metabolite did not have any effects on glycine receptors. GABA(A) receptors were significantly inhibited only at large concentrations (100 microM). NMDA receptors were inhibited in a concentration-dependent manner. Tramadol and M1 metabolite inhibited the glutamate-concentration response curve without changing the half-maximal effective concentration or the Hill coefficient, indicating a noncompetitive inhibition. This study suggests that glycine receptors do not provide the antinociceptive effect of tramadol and that the inhibition of GABA(A) receptors at large concentration might correlate with convulsions. The inhibitory effect on NMDA receptors may contribute to the antinociceptive effect of tramadol at relatively large concentrations.

Analgesics, Opioid↗
PubMed2005

The effects of the tramadol metabolite O-desmethyl tramadol on muscarinic receptor-induced responses in Xenopus oocytes expressing cloned M1 or M3 receptors.

O-desmethyl tramadol is one of the main metabolites of tramadol. It has been widely used clinically and has analgesic activity. Muscarinic receptors are involved in neuronal functions in the brain and autonomic nervous system, and much attention has been paid to these receptors as targets for analgesic drugs in the central nervous system. We have reported that tramadol inhibits the function of type-1 muscarinic (M(1)) receptors and type-3 muscarinic (M(3)) receptors, suggesting that muscarinic receptors are sites of action of tramadol. However, the effects of O-desmethyl tramadol on muscarinic receptor functions have not been studied in detail. In this study, we investigated the effects of O-desmethyl tramadol on M(1) and M(3) receptors, using the Xenopus oocyte expression system. O-desmethyl tramadol (0.1-100 microM) inhibited acetylcholine (ACh)-induced currents in oocytes expressing the M(1) receptors (half-maximal inhibitory concentration [IC(50)] = 2 +/- 0.6 microM), whereas it did not suppress ACh-induced currents in oocytes expressing the M(3) receptor. Although GF109203X, a protein kinase C inhibitor, increased the ACh-induced current, it had little effect on the inhibition of ACh-induced currents by O-desmethyl tramadol in oocytes expressing M(1) receptors. The inhibitory effect of O-desmethyl tramadol on M(1) receptor was overcome when the concentration of ACh was increased (K(D) with O-desmethyl tramadol = 0.3 microM). O-desmethyl tramadol inhibited the specific binding of [(3)H]quinuclidinyl benzilate ([(3)H]QNB) to the oocytes expressed M(1) receptors (IC(50) = 10.1 +/- 0.1 microM), whereas it did not suppress the specific binding of [(3)H]QNB to the oocytes expressed M(3) receptors. Based on these results, O-desmethyl tramadol inhibits functions of M(1) receptors but has little effect on those of M(3) receptors. This study demonstrates the molecular action of O-desmethyl tramadol on the receptors and may help to explain its neural function.

Acetylcholine↗
PubMed2005

Gargling with sodium azulene sulfonate reduces the postoperative sore throat after intubation of the trachea.

Postoperative sore throat (POST) is a complication that remains to be resolved in patients undergoing endotracheal intubation. In this study, we investigated whether preoperative gargling with sodium 1,4-dimethyl-7-isopropylazulene-3-sulfonate monohydrate (sodium azulene sulfonate, Azunol) reduces POST after endotracheal intubation. Forty patients scheduled for elective surgery under general anesthesia were randomized into Azunol and control groups. In the Azunol group, patients gargled with 4 mg Azunol diluted with 100 mL tap water (40 microg/mL). In the control group, patients gargled with 100 mL of tap water. After emergence from general anesthesia, the patients with POST were counted and POST was evaluated using a verbal analog pain scale. There were no significant differences between the two groups by age, height, body weight, gender distribution, or duration of anesthesia and surgery. In the control group, 13 patients (65%) complained of POST, which remained 24 h later in nine patients (45%). In the Azunol group, five patients (25%) also complained of POST, which completely disappeared by 24 h later. The incidence of POST and verbal analog pain scale scores in the Azunol group decreased significantly compared with the control group. We demonstrated that gargling with Azunol effectively attenuated POST with no adverse reactions.

Administration, Oral↗
PubMed2005

The effects of anesthetics and ethanol on alpha2 adrenoceptor subtypes expressed with G protein-coupled inwardly rectifying potassium channels in Xenopus oocytes.

A wide range of physiological effects are mediated by alpha2-adrenoceptors (ARs) through their association with G protein-coupled inwardly rectifying potassium (GIRK) channels. Although alpha2-ARs are divided into three subtypes (alpha2A-C), a pharmacological distinction among the subtypes is difficult to establish because of the lack of a selective agonist and antagonist; therefore, little is known about the effects of anesthetics on the alpha2-AR subtypes. We expressed each subtype together with GIRK1/GIRK2 subunits in Xenopus oocytes and observed alpha2-AR-mediated GIRK1/GIRK2 currents to test the effects of ethanol, halothane, and several IV anesthetics at clinical concentrations. UK 14,304, a selective alpha2-AR agonist, evoked GIRK1/GIRK2 currents in every subtype. None of the IV anesthetics, which included pentobarbital, propofol, ketamine, and alphaxalone, influenced UK 14,304-evoked potassium currents in any of the receptor subtypes. Ethanol enhanced the UK 14,304-evoked potassium currents, whereas halothane inhibited the currents. However, these effects were not significantly different from those on the baseline-GIRK1/GIRK2 current, suggesting that neither ethanol nor halothane acts directly on the alpha2-AR subtypes. Although none of the drugs examined had any effect on the alpha2-ARs, the physiological actions of the alpha2-ARs mediated by the GIRK1/GIRK2 channels may be affected by ethanol and halothane.

Anesthetics↗
PubMed2005

[Complications related to anesthesia method in the University of Occupational and Environmental Health Hospital].

BACKGROUND: Complications related to anesthesia remain a problem. We studied the incidence of complications during anesthesia in 2758 patients who had undergone anesthesia in the University of Occupational and Environmental Health Hospital. METHODS: We checked the anesthesia records retrospectively and analyzed the collected data for the incidence of complications during anesthesia. RESULTS: The total incidence of complications during anesthesia was 12.2%. The incidences of complication are estimated to be 13.4% in inhalation anesthesia, 11.9% in inhalation anesthesia plus epidural, spinal or conduction block, 8.9% in CSEA, zero % in epidural anesthesia and 7.5% in spinal anesthesia. CONCLUSIONS: The incidence of complications in inhalation anesthesia was almost as same as that in inhalation anesthesia plus epidural, spinal or conduction block. More study should be necessary to prevent complications related to anesthesia.

Anesthesia↗
PubMed2005

[Complications related to anesthesia in the University of Occupational and Environmental Health Hospital].

BACKGROUND: Complications related to anesthesia remain a problem. We studied the incidence of complications during anesthesia in 2688 patients who had undergone anesthesia in the University of Occupational and Environmental Health Hospital. METHODS: We checked the anesthesia records retrospectively and analyzed the collected data for the incidence of complications during anesthesia. RESULTS: The total incidence of complications during anesthesia was 8.7%:5.5% related to circulation and 1.9% to respiration. CONCLUSIONS: Complications related to anesthesia should be prevented as much as possible through anesthesiologists' efforts in protocol development and skilled assistance.

Adolescent↗
PubMed2005

[Anesthetic management of a patient in whom one-lung ventilation occurred due to an incorrectly positioned stent].

Stents are inserted for severe stenosis of the trachea owing to malignant tumors, but an incorrectly positioned stent can cause airway obstruction. Here, we report the anesthetic management of a patient undergoing removal of an incorrectly positioned stent. A 56-year-old man had a stent inserted in the trachea for stenosis caused by a tumor. One month later, he was scheduled for reinsertion of a stent for tracheal stenosis owing to growth of the tumor, but the stent was inserted in the left main bronchus interfering ventilation to the right lung. Therefore, removal of the stent under general anesthesia was scheduled. As the stent was to be removed from an incision in the cricoid, we had to maintain deep anesthesia to maintain immobility, keeping spontaneous respiration in case we could not ventilate during surgery. Since inhaled anesthetics are insufficient to maintain deep anesthesia, we anesthetized the patient with an intravenous anesthetic, sevoflurane and continuous propofol infusion. Propofol allows spontaneous respiration better than opioids. With this method we were able to anesthetize the patient maintaining spontaneous respiration and oxygenation with stable vital signs during surgery.

Anesthesia, General↗
PubMed2004

[Laryngospasm associated with anesthesia: diagnosis and management].

Securing the airway is the most important part of anesthesia safety. In clinical practice there is always the risk of encountering laryngospasm, which is defined as the occlusion of the glottis by the action of the intrinsic laryngeal muscles. Once laryngospasm occurs, it leads to acute desaturation and subsequent organ dysfunction. In spite of such a dramatic deterioration, however, there are no systematic reviews that include pathophysiology, clinical incidence, prevention and its treatment. In this paper, we have reviewed laryngospasm, according to the induction of anesthesia and emergence from it, methods for securing the airway using a tracheal tube or a laryngeal mask airway, and the timing of tracheal extubation. In addition, we have summarized a prompt diagnosis and adequate prevention and management of laryngospasm associated with anesthesia.

Anesthesia, Inhalation↗
PubMed2004

Gargling with povidone-iodine reduces the transport of bacteria during oral intubation.

PURPOSE: Nosocomial pneumonia remains a common complication in patients undergoing endotracheal intubation. This study examined the transport of bacteria into the trachea during endotracheal intubation, and evaluated the effects of gargling with povidone-iodine on bacterial contamination of the tip of the intubation tube. METHODS: In the gargling group, patients gargled with 25 mL of povidone-iodine (2.5 mg.mL(-1)). In the control group, patients gargled with 25 mL of tap water. Before tracheal intubation, microorganisms were obtained from the posterior wall of the patient's pharynx using sterile cotton swabs. After anesthesia, all patients were extubated and bacteria contaminating the tip of the tracheal tube were sampled and cultured. RESULTS: Before orotracheal intubation, all 19 patients who gargled with tap water (control group) had bacterial colonization on the posterior walls of the pharynx. This group included five patients who had methicillin-resistant staphylococcus aureus (MRSA) in their nasal cavity preoperatively and MRSA was also detected in the pharynx of four patients. Bacterial colonization was observed in all 19 patients who gargled with povidone-iodine (gargling group) and four patients carried MRSA in their nasal cavity, although no MRSA was detected in the pharynx. In the control group, all the patients had bacterial colonization at the tip of the tube after extubation. Additionally, MRSA was detected in two of the four patients. In the gargling group, povidone-iodine eradicated general bacteria and MRSA colonies in the pharynx before intubation and at the tip of the tube after extubation. CONCLUSION: Gargling with povidone-iodine before oral intubation reduces the transport of bacteria into the trachea.

Anti-Infective Agents, Local↗
PubMed2004

Anesthetic management for cardioverter-defibrillator implantation in a patient with Kearns-Sayre syndrome.

Kearns-Sayre syndrome (KSS) is a rare mitochondrial myopathy and often involves cardiac conduction abnormality and muscle weakness. We report a patient with KSS who had an implantable cardioverter-defibrillator (ICD) implanted during general anesthesia with propofol and nitrous oxide (N2O). These anesthetics did not show any effects on respiration, cardiac conduction, or neuromuscular transmission in this case. The surgery was performed successfully, and the postoperative period was uneventful. The authors recommend that propofol and N2O are suitable general anesthetics for ICD implantation in KSS patients.

Adult↗
PubMed2004

A forskolin derivative, colforsin daropate hydrochloride, inhibits the decrease in cortical renal blood flow induced by noradrenaline or angiotensin II in anesthetized rats.

A forskolin derivative, colforsin daropate hydrochloride (CDH), acts directly on adenylate cyclase to increase the intracellular cyclic adenosine monophosphate levels which produce a positive inotropic effect and a lower blood pressure. However, little is known about the effects of CDH on the renal function. We used laser Doppler flowmetry to measure the cortical renal blood flow (RBF) in male Wistar rats given a continuous intravenous infusion of CDH and evaluated the effects of CDH on the noradrenaline (NA) and angiotensin II (AngII) induced increases in blood pressure and reductions in RBF. Continuous intravenous administration of CDH at 0.25 microg/kg/min did not affect the mean arterial pressure (MAP), but increased heart rate and RBF. Continuous intravenous administration of CDH at high doses (0.5-0.75 microg/kg/min) decreased the MAP, with little effect on the RBF. The administration of exogenous NA (1.7 microg/kg) increased the MAP and decreased the RBF. However, a bolus injection of NA did not decrease the RBF during continuous intravenous administration of CDH, and CDH did not affect the NA-induced increase in MAP. The administration of exogenous AngII (100 ng/kg) increased MAP and decreased RBF and heart rate, but a bolus injection of AngII did not decrease RBF during continuous intravenous administration of CDH. These results suggest that CDH plays a protective role against the pressor effects and the decrease in RBF induced by NA or AngII.

Anesthesia↗
PubMed2004

Anesthetic management of patients with severe peripheral ischemia due to calciphylaxis.

Calciphylaxis is a small-vessel disease associated with renal failure. Here, we report the management of a 43-yr-old man with calciphylaxis who received left lower leg amputation with prostaglandin E(1) (PGE(1)) under monitoring by laser Doppler blood flowmetry in the left second and third fingers. Anesthesia was induced with midazolam, fentanyl, and vecuronium and was maintained with oxygen, nitrous oxide, and sevoflurane. The peripheral blood flow varied and decreased gradually; therefore, we added PGE(1) 20 ng. kg(-1). min(-1), which increased blood flow of the tissues. Three weeks after the operation, we again anesthetized the patient. We maintained the blood flow with PGE(1) throughout anesthesia. Monitoring by laser Doppler blood flowmetry and PGE(1) 20 ng. kg(-1). min(-1) could be useful for patients with impaired peripheral circulation, as in calciphylaxis.

Adult↗
PubMed2004

The inhibition of aortic smooth muscle cell proliferation by the intravenous anesthetic ketamine.

Smooth muscle cell (SMC) proliferation has been recognized as central to the pathology of both major forms of vascular disease, atherosclerosis and hypertension. Recently, we reported that ketamine inhibits rat mesangial cell proliferation, suggesting that ketamine inhibits cell growth. Although the IV anesthetic ketamine has been widely used clinically, the exact effects of ketamine on vascular SMC proliferation have not been studied. In this study, we investigated the effects of ketamine on vascular SMC proliferation. Ketamine inhibited [(3)H]thymidine incorporation and decreased the number of SMCs in a concentration-dependent manner (10-200 microM); neither propofol nor fentanyl inhibited [(3)H]thymidine incorporation into human aortic SMCs. The protein kinase C (PKC) inhibitor GF109203x abolished the ketamine-induced inhibition of [(3)H]thymidine incorporation into SMC, but the inhibition was not affected by either the protein kinase A inhibitor H-89 or the protein kinase G inhibitor KT5823. A histological analysis demonstrated the inhibitory effect of ketamine on the intimal thickening of the balloon-injured rat aorta. Based on these results, ketamine inhibits SMCs at clinical concentrations via the PKC pathway. Our results indicate that ketamine might prevent the proliferation of SMCs clinically.

Anesthetics, Dissociative↗