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Sample records for binding volatile anesthetics

  1. Titration calorimetry of anesthetic-protein interaction: negative enthalpy of binding and anesthetic potency.

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    Ueda, I; Yamanaka, M

    1997-04-01

    Anesthetic potency increases at lower temperatures. In contrast, the transfer enthalpy of volatile anesthetics from water to macromolecules is usually positive. The transfer decreases at lower temperature. It was proposed that a few selective proteins bind volatile anesthetics with negative delta H, and these proteins are involved in signal transduction. There has been no report on direct estimation of binding delta H of anesthetics to proteins. This study used isothermal titration calorimetry to analyze chloroform binding to bovine serum albumin. The calorimetrically measured delta H cal was -10.37 kJ.mol-1. Thus the negative delta H of anesthetic binding is not limited to signal transduction proteins. The binding was saturable following Fermi-Dirac statistics and is characterized by the Langmuir adsorption isotherms, which is interfacial. The high-affinity association constant, K, was 2150 +/- 132 M-1 (KD = 0.47 mM) with the maximum binding number, Bmax = 3.7 +/- 0.2. The low-affinity K was 189 +/- 3.8 M-1 (KD = 5.29 mM), with a Bmax of 13.2 +/- 0.3. Anesthetic potency is a function of the activity of anesthetic molecules, not the concentration. Because the sign of delta H determines the temperature dependence of distribution of anesthetic molecules, it is irrelevant to the temperature dependence of anesthetic potency.

  2. Anesthetic action of volatile anesthetics by using Paramecium as a model.

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    Zhou, Miaomiao; Xia, Huimin; Xu, Younian; Xin, Naixing; Liu, Jiao; Zhang, Shihai

    2012-06-01

    Although empirically well understood in their clinical administration, volatile anesthetics are not yet well comprehended in their mechanism studies. A major conundrum emerging from these studies is that there is no validated model to assess the presumed candidate sites of the anesthetics. We undertook this study to test the hypothesis that the single-celled Paramecium could be anesthetized and served as a model organism in the study of anesthetics. We assessed the motion of Paramecium cells with Expert Vision system and the chemoresponse of Paramecium cells with T-maze assays in the presence of four different volatile anesthetics, including isoflurane, sevoflurane, enflurane and ether. Each of those volatiles was dissolved in buffers to give drug concentrations equal to 0.8, 1.0, and 1.2 EC50, respectively, in clinical practice. We could see that after application of volatile anesthetics, the swimming of the Paramecium cells was accelerated and then suppressed, or even stopped eventually, and the index of the chemoresponse of the Paramecium cells (denoted as I ( che )) was decreased. All of the above impacts were found in a concentration-dependent fashion. The biphasic effects of the clinical concentrations of volatile anesthetics on Paramecium simulated the situation of high species in anesthesia, and the inhibition of the chemoresponse also indicated anesthetized. In conclusion, the findings in our studies suggested that the single-celled Paramecium could be anesthetized with clinical concentrations of volatile anesthetics and therefore be utilized as a model organism to study the mechanisms of volatile anesthetics.

  3. Drug interactions: volatile anesthetics and opioids.

    Science.gov (United States)

    Glass, P S; Gan, T J; Howell, S; Ginsberg, B

    1997-09-01

    Multiple drugs are used to provide anesthesia. Volatile anesthetics are commonly combined with opioids. Several studies have demonstrated that small doses of opioid (i.e., within the analgesic range) result in a marked reduction in minimum alveolar concentration (MAC) of the volatile anesthetic that will prevent purposeful movement in 50% of patients at skin incision). Further increases in opioid dose provide only a further small reduction in MAC. Thus, a ceiling effect of the opioid is observed at a MAC value of the volatile anesthetic equal to its MAC awake. Recovery from anesthesia when an opioid is combined with a volatile anesthetic is dependent on the rate of decrease of both drugs to their respective concentrations that are associated with adequate spontaneous ventilation and awakening. Through an understanding of the pharmacodynamic interaction of volatile anesthetics with opioids and the pharmacokinetic processes responsible for the recovery from drug effect, optimal dosing schemes can thus be developed. A review of these pharmacodynamic and pharmacokinetic principles that will allow clinicians to administer drugs to provide a more optimal anesthetic is provided.

  4. Sodium channels as targets for volatile anesthetics

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    Karl F. Herold

    2012-03-01

    Full Text Available The molecular mechanisms of modern inhaled anesthetics although widely used in clinical settings are still poorly understood. Considerable evidence supports effects on membrane proteins such as ligand- and voltage-gated ion channels of excitable cells. Na+ channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetics. Inhibition of presynaptic Na+ channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic effects: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na+ currents by volatile anesthetics. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na+ channel isoforms implicated inhibition of presynaptic Na+ channels in anesthetic actions. Volatile anesthetics reduce peak Na+ current and shift the voltage of half-maximal steady-state inactivation towards more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed together with an enhanced use-dependent block during pulse train protocols. These effects can reduce neurotransmitter release by depressing presynaptic excitability, depolarization and Ca entry, and ultimately transmitter release. This reduction in transmitter release is more portent for glutamatergic vs. GABAergic terminals. Involvement of Na+ channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na+ channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na+ channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na+ channels by volatile anesthetics is involved in mediating some of

  5. An innovative technique to improve safety of volatile anesthetics suction from the cardiopulmonary bypass circuit

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    Francesco De Simone

    2017-01-01

    Full Text Available Context: Myocardial injury during cardiac surgery on cardiopulmonary bypass (CPB is a major determinant of morbidity and mortality. Preclinical and clinical evidence of dose- and time-related cardioprotective effects of volatile anesthetic drugs exist and their use during the whole surgery duration could improve perioperative cardiac protection. Even if administering volatile agents during CPB are relatively easy, technical problems, such as waste gas scavenging, may prevent safe and manageable administration of halogenated vapors during CPB. Aims: The aim of this study is to improve the safe administration of volatile anesthesia during CPB. Settings and Design: Tertiary teaching hospital. Subjects and Methods: We describe an original device that collects and disposes of any volatile anesthetic vapors present in the exit stream of the oxygenator, hence preventing its dispersal into the operating theatre environment and adaptively regulates pressure of oxygenator chamber in the CPB circuit. Results: We have so far applied a prototype of this device in more than 1300 adult cardiac surgery patients who received volatile anesthetics during the CPB phase. Conclusions: Widespread implementation of scavenging system like the one we designed may facilitate the perfusionist and the anesthesiologist in delivering these cardioprotective drugs with beneficial impact on patients' outcome without compromising on safety.

  6. Does chronic occupational exposure to volatile anesthetic agents influence the rate of neutrophil apoptosis?

    LENUS (Irish Health Repository)

    Goto, Y

    2012-02-03

    PURPOSE: The purpose of this preliminary investigation was to determine whether the rate of neutrophil apoptosis in health care workers is influenced by exposure to volatile anesthetic agents. METHODS: Percentage neutrophil apoptosis (Annexin-V FITC assay) was measured in health care workers (n = 20) and unexposed volunteers (n = 10). For the health care workers, time weighted personal exposure monitoring to N2O, sevoflurane and isoflurane was carried out. RESULTS: The sevoflurane and isoflurane concentrations to which health care workers were exposed were less than recommended levels in all 20 cases. Percent apoptosis was less at 24 (but not at one and 12) hr culture in health care workers [50.5 (9.7)%; P = 0.008] than in unexposed volunteers [57.3 (5.1)%]. CONCLUSION: Inhibition of neutrophil apoptosis at 24 hr culture was demonstrated in health care workers chronically exposed to volatile anesthetic agents. Exposure was well below recommended levels in the both scavenged and unscavenged work areas in which the study was carried out. Further study is required to assess the effect of greater degrees of chronic exposure to volatile anesthetic agents on neutrophil apoptosis.

  7. Volatile anesthetics influence blood-brain barrier integrity by modulation of tight junction protein expression in traumatic brain injury.

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    Serge C Thal

    Full Text Available Disruption of the blood-brain barrier (BBB results in cerebral edema formation, which is a major cause for high mortality after traumatic brain injury (TBI. As anesthetic care is mandatory in patients suffering from severe TBI it may be important to elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ such as zonula occludens-1 (ZO-1 and claudin-5 (cl5 play a central role for BBB stability. First, the influence of the volatile anesthetics sevoflurane and isoflurane on in-vitro BBB integrity was investigated by quantification of the electrical resistance (TEER in murine brain endothelial monolayers and neurovascular co-cultures of the BBB. Secondly brain edema and TJ expression of ZO-1 and cl5 were measured in-vivo after exposure towards volatile anesthetics in native mice and after controlled cortical impact (CCI. In in-vitro endothelial monocultures, both anesthetics significantly reduced TEER within 24 hours after exposure. In BBB co-cultures mimicking the neurovascular unit (NVU volatile anesthetics had no impact on TEER. In healthy mice, anesthesia did not influence brain water content and TJ expression, while 24 hours after CCI brain water content increased significantly stronger with isoflurane compared to sevoflurane. In line with the brain edema data, ZO-1 expression was significantly higher in sevoflurane compared to isoflurane exposed CCI animals. Immunohistochemical analyses revealed disruption of ZO-1 at the cerebrovascular level, while cl5 was less affected in the pericontusional area. The study demonstrates that anesthetics influence brain edema formation after experimental TBI. This effect may be attributed to modulation of BBB permeability by differential TJ protein expression. Therefore, selection of anesthetics may influence the barrier function and introduce a strong bias in experimental research on pathophysiology of BBB dysfunction. Future research is required to investigate

  8. Recognition of anesthetic barbiturates by a protein binding site: a high resolution structural analysis.

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    Simon Oakley

    Full Text Available Barbiturates potentiate GABA actions at the GABA(A receptor and act as central nervous system depressants that can induce effects ranging from sedation to general anesthesia. No structural information has been available about how barbiturates are recognized by their protein targets. For this reason, we tested whether these drugs were able to bind specifically to horse spleen apoferritin, a model protein that has previously been shown to bind many anesthetic agents with affinities that are closely correlated with anesthetic potency. Thiopental, pentobarbital, and phenobarbital were all found to bind to apoferritin with affinities ranging from 10-500 µM, approximately matching the concentrations required to produce anesthetic and GABAergic responses. X-ray crystal structures were determined for the complexes of apoferritin with thiopental and pentobarbital at resolutions of 1.9 and 2.0 Å, respectively. These structures reveal that the barbiturates bind to a cavity in the apoferritin shell that also binds haloalkanes, halogenated ethers, and propofol. Unlike these other general anesthetics, however, which rely entirely upon van der Waals interactions and the hydrophobic effect for recognition, the barbiturates are recognized in the apoferritin site using a mixture of both polar and nonpolar interactions. These results suggest that any protein binding site that is able to recognize and respond to the chemically and structurally diverse set of compounds used as general anesthetics is likely to include a versatile mixture of both polar and hydrophobic elements.

  9. Blood flow and tissue oxygen pressures of liver and pancreas in rats: effects of volatile anesthetics and of hemorrhage.

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    Vollmar, B; Conzen, P F; Kerner, T; Habazettl, H; Vierl, M; Waldner, H; Peter, K

    1992-09-01

    The object of this investigation was to compare the effects of volatile anesthetics and of hemorrhage at comparable arterial blood pressures on splanchnic blood flow (radioactive microspheres) and tissue oxygenation of the liver and pancreas (surface PO2 [PSO2] electrodes). In contrast to earlier studies, we did not use identical minimum alveolar anesthetic concentration multiples as a reference to compare volatile anesthetics; rather, we used the splanchnic perfusion pressure. Under general anesthesia (intravenous chloralose) and controlled ventilation, 12 Sprague-Dawley rats underwent laparotomy to allow access to abdominal organs. Mean arterial pressure was decreased from 84 +/- 3 mm Hg (mean +/- SEM) at control to 50 mm Hg by 1.0 +/- 0.1 vol% halothane, 2.2 +/- 0.2 vol% enflurane, and 2.3 +/- 0.1 vol% isoflurane in a randomized sequence. For hemorrhagic hypotension, blood was withdrawn gradually until a mean arterial pressure of 50 mm Hg was attained. Volatile anesthetics and hemorrhage reduced cardiac output, and hepatic arterial, portal venous, and total hepatic blood flows by comparable degrees. Mean hepatic PSO2 decreased significantly from 30.7 +/- 2.6 mm Hg at control to 17.4 +/- 2 and 17.5 +/- 2 mm Hg during enflurane and isoflurane (each P less than 0.05) anesthesia, respectively. The decrease to 11.5 +/- 2.5 mm Hg was more pronounced during halothane anesthesia. Hemorrhagic hypotension was associated with the lowest hepatic PSO2 (3.4 +/- 1.3 mm Hg) and the highest number of hypoxic (0-5 mm Hg 86%) and anoxic PSO2 values (0 mm Hg 46%). Pancreatic blood flow and oxygenation remained unchanged from control during halothane and enflurane administration, whereas isoflurane increased both variables. Hemorrhagic hypotension slightly reduced pancreatic flow (-8%) but significantly decreased PSO2 from 58 +/- 5 mm Hg at control to 36 +/- 3 mm Hg, with 7% of all measured values in the hypoxic range. Thus, volatile anesthetics preserved pancreatic but not hepatic

  10. Volatile anesthetics for status asthmaticus in pediatric patients: a comprehensive review and case series.

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    Carrié, Sabrina; Anderson, Thomas Anthony

    2015-05-01

    Status asthmaticus is an acute, intractable asthma attack refractory to standard interventions that can lead to progressive respiratory failure. Successful management requires a fundamental understanding of the disease process, its clinical presentation, and proper evaluation. Treatment must be instituted early and is aimed at reversing the airway inflammation, bronchoconstriction, and hyper-reactivity that often lead to lower airway obstruction, impaired ventilation, and oxygenation. Most patients are effectively treated with standard therapy including beta2-adrenergic agonists and corticosteroids. Others necessitate adjunctive therapies and escalation to noninvasive ventilation or intubation. We will review the pathophysiology, evaluation, and treatment options for pediatric patients presenting with status asthmaticus with a particular focus on refractory status asthmaticus treated with volatile anesthetics. In addition, we include a proven approach to the management of these patients in the critical care setting, which requires close coordination between critical care and anesthesia providers. We present a case series of three patients, two of which have the longest reported cases of continuous isoflurane use in status asthmaticus. This series was obtained from a retrospective chart review and highlights the efficacy of the volatile anesthetic, isoflurane, in three pediatric patients with refractory life-threatening status asthmaticus. © 2015 John Wiley & Sons Ltd.

  11. Day-surgery patients anesthetized with propofol have less postoperative pain than those anesthetized with sevoflurane.

    LENUS (Irish Health Repository)

    Tan, Terry

    2012-02-01

    BACKGROUND: There have been recent studies suggesting that patients anesthetized with propofol have less postoperative pain compared with patients anesthetized with volatile anesthetics. METHODS: In this randomized, double-blind study, 80 patients undergoing day-case diagnostic laparoscopic gynecological surgery were either anesthetized with IV propofol or sevoflurane. The primary outcome measured was pain on a visual analog scale. RESULTS: Patients anesthetized with propofol had less pain compared with patients anesthetized with sevoflurane (P = 0.01). There was no difference in any of the other measured clinical outcomes. CONCLUSIONS: The patients anesthetized with propofol appeared to have less pain than patients anesthetized with sevoflurane.

  12. The influence of volatile anesthetics on alveolar epithelial permeability measured by noninvasive radionuclide lung scan

    International Nuclear Information System (INIS)

    Hung, Chih-Jen; Wu, Rick Sai-Chuen; Lin, Cheng-Chieh; Kao, Albert; Tsai, Jeffrey J.P.

    2003-01-01

    Many volatile anesthetics have long been thought to affect pulmonary functions including lung ventilation (LV) and alveolar epithelial permeability (AEP). The purpose of this study is to examine the influence of volatile anesthetics on LV and AEP by noninvasive radionuclide lung imaging of technetium-99m labeled diethylene triamine pentaacetic acid radioaerosol inhalation lung scan (DTPA lung scan). Twenty patients undergoing surgery and receiving volatile anesthesia with 1% halothane were enrolled as the study group 1. The other 20 patients undergoing surgery and receiving volatile anesthesia with 1.5% isoflurane were enrolled as the study group 2. At the same time, 20 patients undergoing surgery with intravenous anesthesia drugs were included as a control group. Before surgery, 1 hour after surgery, and 1 week after surgery, we investigated the 3 groups of patients with DTPA lung scan to evaluate LV and AEP by 99m Tc DTPA clearance halftime (T1/2). No significant change or abnormality of LV before surgery, 1 hour after surgery, or 1 week after surgery was found among the 3 groups of patients. In the control group, the 99m Tc DTPA clearance T1/2 was 63.5±16.4, 63.1±18.4, and 62.8±17.0 minutes, before surgery, 1 hour after surgery, and 1 week after surgery, respectively. In group 1, it was 65.9±9.3, 62.5±9.1, and 65.8±10.3 minutes, respectively. No significant change in AEP before surgery, 1 hour after surgery, or 1 week after surgery was found. However, in group 2, the 99m Tc DTPA clearance T1/2 was 65.5±13.2, 44.9±10.5, and 66.1±14.0 minutes, respectively. A significant transient change in AEP was found 1 hour after surgery, but it recovered 1 week after surgery. We conclude that volatile anesthesia is safe for LV and AEP, and only isoflurane can induce transient change of AEP. (author)

  13. The Volatile Anesthetic Isoflurane Increases Endothelial Adenosine Generation via Microparticle Ecto-5′-Nucleotidase (CD73) Release

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    Kim, Mihwa; Ham, Ahrom; Kim, Katelyn Yu-Mi; Brown, Kevin M.; Lee, H. Thomas

    2014-01-01

    Endothelial dysfunction is common in acute and chronic organ injury. Isoflurane is a widely used halogenated volatile anesthetic during the perioperative period and protects against endothelial cell death and inflammation. In this study, we tested whether isoflurane induces endothelial ecto-5′-nucleotidase (CD73) and cytoprotective adenosine generation to protect against endothelial cell injury. Clinically relevant concentrations of isoflurane induced CD73 activity and increased adenosine generation in cultured human umbilical vein or mouse glomerular endothelial cells. Surprisingly, isoflurane-mediated induction of endothelial CD73 activity occurred within 1 hr and without synthesizing new CD73. We determined that isoflurane rapidly increased CD73 containing endothelial microparticles into the cell culture media. Indeed, microparticles isolated from isoflurane-treated endothelial cells had significantly higher CD73 activity as well as increased CD73 protein. In vivo, plasma from mice anesthetized with isoflurane had significantly higher endothelial cell-derived CD144+ CD73+ microparticles and had increased microparticle CD73 activity compared to plasma from pentobarbital-anesthetized mice. Supporting a critical role of CD73 in isoflurane-mediated endothelial protection, a selective CD73 inhibitor (APCP) prevented isoflurane-induced protection against human endothelial cell inflammation and apoptosis. In addition, isoflurane activated endothelial cells Rho kinase evidenced by myosin phosphatase target subunit-1 and myosin light chain phosphorylation. Furthermore, isoflurane-induced release of CD73 containing microparticles was significantly attenuated by a selective Rho kinase inhibitor (Y27632). Taken together, we conclude that the volatile anesthetic isoflurane causes Rho kinase-mediated release of endothelial microparticles containing preformed CD73 and increase adenosine generation to protect against endothelial apoptosis and inflammation. PMID:24945528

  14. The scavenging of volatile anesthetic agents in the cardiovascular intensive care unit environment: a technical report.

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    Pickworth, Thomas; Jerath, Angela; DeVine, Rita; Kherani, Nazmin; Wąsowicz, Marcin

    2013-01-01

    The use of volatile-based sedation within critical care environments has been limited by difficulties of drug administration and safety concerns over environment pollution and staff exposure in an intensive care unit (ICU) with no scavenging. The aim of this study was to develop a simple scavenging system to be used with the Anesthesia Conserving Device (AnaConDa(®)) and to determine whether or not ambient concentrations of residual anesthetic are within current acceptable limits. The scavenging system consists of two Deltasorb(®) canisters attached to the ICU ventilator in series. AnaConDa is a miniature vaporizer designed to provide volatile-based sedation within an ICU. The first ten patients recruited into a larger randomized trial assessing outcomes after elective coronary graft bypass surgery were sedated within the cardiac ICU using either isoflurane or sevoflurane. Sedation was guided by the Sedation Agitation Scale, resulting in an end-tidal minimum anesthetic concentration of volatile agent ranging from 0.1-0.3. At one hour post ICU admission, infrared photometric analysis was used to assess environmental contamination at four points along the ventilator circuit and scavenging system and around the patient's head. All measurements taken within the patient's room were below 1 part per million, which satisfies criteria for occupational exposure. This study shows that volatile agents can be administered safely within critical care settings using a simple scavenging system. Our scavenging system used in conjunction with the AnaConDa device reduced the concentration of environmental contamination to a level that is acceptable to Canadian standards and standards in most Western countries and thus conforms to international safety standards. The related clinical trial was registered at www.clinicaltrials.gov (NCT01151254).

  15. Binding of long-lasting local anesthetics to lipid emulsions.

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    Mazoit, Jean-Xavier; Le Guen, Régine; Beloeil, Hélène; Benhamou, Dan

    2009-02-01

    Rapid infusion of lipid emulsion has been proposed to treat local anesthetic toxicity. The authors wanted to test the buffering properties of two commercially available emulsions made of long- and of long- and medium-chain triglycerides. Using the shake-flask method, the authors measured the solubility and binding of racemic bupivacaine, levobupivacaine, and ropivacaine to diluted Intralipid (Fresenius Kabi, Paris, France) and Medialipide (B-Braun, Boulogne, France). The apparent distribution coefficient expressed as the ratio of mole fraction was 823 +/- 198 and 320 +/- 65 for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively, at 500 mg in the Medialipide/buffer emulsion; and 1,870 +/- 92 and 1,240 +/- 14 for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively, in the Intralipid/buffer emulsion. Decreasing the pH from 7.40 to 7.00 of the Medialipide/buffer emulsion led to a decrease in ratio of molar concentration from 121 +/- 3.8 to 46 +/- 2.8 for bupivacaine, and to a lesser extent from 51 +/- 4.0 to 31 +/- 1.6 for ropivacaine. The capacity of the 1% emulsions was 871 and 2,200 microM for the 1% Medialipide and Intralipid emulsions, respectively. The dissociation constant was 818 and 2,120 microM for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively. Increasing the temperature from 20 to 37 degrees C led to a greater increase in affinity for ropivacaine (55%) than for bupivacaine (27%). When the pH of the buffer was decreased from 7.40 to 7.00, the affinity was decreased by a factor of 1.68, similar for both anesthetics. The solubility of long-acting local anesthetics in lipid emulsions and the high capacity of binding of these emulsions most probably explain their clinical efficacy in case of toxicity. The long-chain triglyceride emulsion Intralipid appears to be about 2.5 times more efficacious than the 50/50 medium-chain/long-chain Medialipide emulsion. Also, because of their higher hydrophobicity

  16. Paired assessment of volatile anesthetic concentrations with synaptic actions recorded in vitro.

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    Stuart J McDougall

    Full Text Available The volatile anesthetic isoflurane poses a number of experimental challenges in the laboratory. Due to its rapid evaporation, the open conditions of most in vitro electrophysiological recording systems make the determination of actual isoflurane concentrations a challenge. Since the absolute anesthetic concentration in solution is directly related to efficacy, concentration measurements are important to allow comparisons between laboratory and clinical studies. In this study we quantify the sources of isoflurane loss during experimentation and describe a method for the measurement of isoflurane concentrations using gas chromatography and mass spectrometry simultaneous to in vitro electrophysiological measurements. Serial samples of perfused bath solution allowed correlation of isoflurane concentrations with ongoing biological effects. Saturated physiological solutions contained 13.4 +/- 0.2 mM isoflurane and were diluted to desired "nominal" concentrations for experiments. The perfusion system established stable isoflurane concentrations within the bath by 2 minutes. However, bath isoflurane concentrations varied substantially and unpredictably between experiments. The magnitudes of such discrepancies in isoflurane concentrations spanned clinically important levels. Our studies suggest that, despite countermeasures, solution handling significantly impacted the isoflurane content in the tissue bath. The magnitude of these discrepancies appears to necessitate systematic direct measurement of bath isoflurane concentrations during most in vitro conditions.

  17. Effects of anesthetics on vesicular monoamine transporter type 2 binding to 18F-FP-(+)-DTBZ: a biodistribution study in rat brain

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    Chen, Zhengping; Tang, Jie; Liu, Chunyi; Li, Xiaomin; Huang, Hongbo; Xu, Xijie; Yu, Huixin

    2016-01-01

    Objectives: The in vivo binding analysis of vesicular monoamine transporter type 2 (VMAT2) to radioligand has provided a means of investigating related disorders. Anesthesia is often inevitable when the investigations are performed in animals. In the present study, we tested effects of four commonly-used anesthetics: isoflurane, pentobarbital, chloral hydrate and ketamine, on in vivo VMAT2 binding to 18 F-FP-(+)-DTBZ, a specific VMAT2 radioligand, in rat brain. Methods: The transient equilibrium time window for in vivo binding of 18 F-FP-(+)-DTBZ after a bolus injection was firstly determined. The brain biodistribution studies under anesthetized and awake rats were then performed at the equilibrium time. Standard uptake values (SUVs) of the interest brain regions: the striatum (ST), hippocampus (HP), cortex (CX) and cerebellum (CB) were obtained; and ratios of tissue to cerebellum were calculated. Results: Isoflurane and pentobarbital did not alter distribution of 18 F-FP-(+)-DTBZ in the brain relative to the awake group; neither SUVs nor ratios of ST/CB and HP/CB were altered significantly. Chloral hydrate significantly increased SUVs of all the brain regions, but did not significantly alter ratios of ST/CB and HP/CB. Ketamine significantly increased SUVs of the striatum, hippocampus and cortex, and insignificantly increased the SUV of the cerebellum; consequently, ketamine significantly increased ratios of ST/CB and HP/CB. Conclusions: It is concluded that in vivo VMAT2 binding to 18 F-FP-(+)-DTBZ are not altered by isoflurane and pentobarbital, but altered by chloral hydrate and ketamine. Isoflurane and pentobarbital may be promising anesthetic compounds for investigating in vivo VMAT2 binding. Further studies are warranted to investigate the interactions of anesthetics with VMAT2 binding potential with in vivo PET studies.

  18. Effects of common anesthetic agents on [(18)F]flumazenil binding to the GABAA receptor

    DEFF Research Database (Denmark)

    Palner, Mikael; Beinat, Corinne; Banister, Sam

    2016-01-01

    in preclinical imaging studies and clinical imaging studies involving patient populations that do not tolerate relatively longer scan times. The objective of this study was to examine the effects of anesthesia on the binding of [(18)F]flumazenil to GABAA receptors in mice. METHODS: Brain and whole blood...... mice. CONCLUSIONS: Anesthesia has pronounced effects on the binding and blood-brain distribution of [(18)F]flumazenil. Consequently, considerable caution must be exercised in the interpretation of preclinical and clinical PET studies of GABAA receptors involving the use of anesthesia.......BACKGROUND: The availability of GABAA receptor binding sites in the brain can be assessed by positron emission tomography (PET) using the radioligand, [(18)F]flumazenil. However, the brain uptake and binding of this PET radioligand are influenced by anesthetic drugs, which are typically needed...

  19. $1.8 Million and counting: how volatile agent education has decreased our spending $1000 per day.

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    Miller, Scott A; Aschenbrenner, Carol A; Traunero, Justin R; Bauman, Loren A; Lobell, Samuel S; Kelly, Jeffrey S; Reynolds, John E

    2016-12-01

    Volatile anesthetic agents comprise a substantial portion of every hospital's pharmacy budget. Challenged with an initiative to lower anesthetic drug expenditures, we developed an education-based intervention focused on reducing volatile anesthetic costs while preserving access to all available volatile anesthetics. When postintervention evaluation demonstrated a dramatic year-over-year reduction in volatile agent acquisition costs, we undertook a retrospective analysis of volatile anesthetic purchasing data using time series analysis to determine the impact of our educational initiative. We obtained detailed volatile anesthetic purchasing data from the Central Supply of Wake Forest Baptist Health from 2007 to 2014 and integrated these data with the time course of our educational intervention. Aggregate volatile anesthetic purchasing data were analyzed for 7 consecutive fiscal years. The educational initiative emphasized tissue partition coefficients of volatile anesthetics in adipose tissue and muscle and their impact on case management. We used an interrupted time series analysis of monthly cost per unit data using autoregressive integrated moving average modeling, with the monthly cost per unit being the amount spent per bottle of anesthetic agent per month. The cost per unit decreased significantly after the intervention (t=-6.73, Pper unit decreased $48 after the intervention, with 95% confidence interval of $34 to $62. As evident from the data, the purchasing of desflurane and sevoflurane decreased, whereas that of isoflurane increased. An educational initiative focused solely on the selection of volatile anesthetic agent per case significantly reduced volatile anesthetic expense at a tertiary medical center. This approach appears promising for application in other hospitals in the rapidly evolving, value-added health care environment. We were able to accomplish this with instruction on tissue partition coefficients and each agent's individual cost per MAC

  20. Discriminative stimulus effects of inhaled 1,1,1-trichloroethane in mice: comparison to other hydrocarbon vapors and volatile anesthetics.

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    Shelton, Keith L

    2009-04-01

    Because the toxicity of many inhalants precludes evaluation in humans, drug discrimination, an animal model of subjective effects, can be used to gain insights on their poorly understood abuse-related effects. The purpose of the present study was to train a prototypic inhalant that has known abuse liability, 1,1,1-trichloroethane (TCE), as a discriminative stimulus in mice, and compare it to other classes of inhalants. Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 12,000 ppm inhaled TCE vapor from air and seven mice were trained to discriminate 4,000 ppm TCE from air. Tests were then conducted to characterize the discriminative stimulus of TCE and to compare it to representative aromatic and chlorinated hydrocarbon vapors, volatile halogenated anesthetics as well as an odorant compound. Only the 12,000 ppm TCE versus the air discrimination group exhibited sufficient discrimination accuracy for substitution testing. TCE vapor concentration- and exposure time-dependently substituted for the 12,000 ppm TCE vapor training stimulus. Full substitution was produced by trichloroethylene, toluene, enflurane, and sevoflurane. Varying degrees of partial substitution were produced by the other volatile test compounds. The odorant, 2-butanol, did not produce any substitution for TCE. The discriminative stimulus effects of TCE are shared fully or partially by chlorinated and aromatic hydrocarbons as well as by halogenated volatile anesthetics. However, these compounds can be differentiated from TCE both quantitatively and qualitatively. It appears that the degree of similarity is not solely a function of chemical classification but may also be dependent upon the neurochemical effects of the individual compounds.

  1. The location and nature of general anesthetic binding sites on the active conformation of firefly luciferase; a time resolved photolabeling study.

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    Sivananthaperumal Shanmugasundararaj

    Full Text Available Firefly luciferase is one of the few soluble proteins that is acted upon by a wide variety of general anesthetics and alcohols; they inhibit the ATP-driven production of light. We have used time-resolved photolabeling to locate the binding sites of alcohols during the initial light output, some 200 ms after adding ATP. The photolabel 3-azioctanol inhibited the initial light output with an IC50 of 200 µM, close to its general anesthetic potency. Photoincorporation of [(3H]3-azioctanol into luciferase was saturable but weak. It was enhanced 200 ms after adding ATP but was negligible minutes later. Sequencing of tryptic digests by HPLC-MSMS revealed a similar conformation-dependence for photoincorporation of 3-azioctanol into Glu-313, a residue that lines the bottom of a deep cleft (vestibule whose outer end binds luciferin. An aromatic diazirine analog of benzyl alcohol with broader side chain reactivity reported two sites. First, it photolabeled two residues in the vestibule, Ser-286 and Ile-288, both of which are implicated with Glu-313 in the conformation change accompanying activation. Second, it photolabeled two residues that contact luciferin, Ser-316 and Ser-349. Thus, time resolved photolabeling supports two mechanisms of action. First, an allosteric one, in which anesthetics bind in the vestibule displacing water molecules that are thought to be involved in light output. Second, a competitive one, in which anesthetics bind isosterically with luciferin. This work provides structural evidence that supports the competitive and allosteric actions previously characterized by kinetic studies.

  2. Anesthesia and Duchenne or Becker muscular dystrophy: review of 117 anesthetic exposures.

    Science.gov (United States)

    Segura, Leal G; Lorenz, Jessica D; Weingarten, Toby N; Scavonetto, Federica; Bojanić, Katarina; Selcen, Duygu; Sprung, Juraj

    2013-09-01

    Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are associated with life-threatening perioperative complications, including rhabdomyolysis, hyperkalemia, and hyperthermia. Current recommendations contraindicate use of succinylcholine and volatile anesthetics; however, the latter recommendation remains controversial. To review the perioperative outcomes of patients with DMD and BMD. We reviewed records of patients with DMD or BMD who underwent anesthetic management at our institution from January 1990 through December 2011. We identified 47 patients (DMD, 37; BMD, 10) who underwent 117 anesthetic exposures (DMD, 101; BMD, 16). Volatile anesthetic agents were used 66 times (DMD, 59; BMD, 7). One patient with undiagnosed BMD received succinylcholine and developed acute rhabdomyolysis and hyperkalemic cardiac arrest. All other major complications were attributed to the procedure (i.e., large bleeding), to preexisting comorbidities (i.e., respiratory failure, cardiac disease), or to both. Use of succinylcholine in children with dystrophinopathy is contraindicated. These patients have significant comorbidities and are frequently undergoing extensive operations; complications related to these factors can develop, as evidenced by our series. These complications may occur with use of volatile and nonvolatile anesthetics. However, because most of our patients were older than 8 years at the time of surgery, our observation cannot be generalized to younger dystrophin-deficient children. © 2013 John Wiley & Sons Ltd.

  3. Choice of primary anesthetic regimen can influence intensive care unit length of stay after coronary surgery with cardiopulmonary bypass

    NARCIS (Netherlands)

    de Hert, Stefan G.; van der Linden, Philippe J.; Cromheecke, Stefanie; Meeus, Roel; ten Broecke, Pieter W.; de Blier, Ivo G.; Stockman, Bernard A.; Rodrigus, Inez E.

    2004-01-01

    BACKGROUND: Volatile anesthetics protect the myocardium during coronary surgery. This study hypothesized that the use of a volatile agent in the anesthetic regimen would be associated with a shorter intensive care unit (ICU) and hospital length of stay (LOS), compared with a total intravenous

  4. Relationship between potency and boiling point of general anesthetics: a thermodynamic consideration.

    Science.gov (United States)

    Dastmalchi, S; Barzegar-Jalali, M

    2000-07-20

    The most important group of nonspecific drugs is that of the general anesthetics. These nonspecific compounds vary greatly in structure, from noble gases such as Ar or Xe to complex steroids. Since the development of clinical anesthesia over a century ago, there has been a vast amount of research and speculation concerning the mechanism of action of general anesthetics. Despite these efforts, the exact mechanism remains unknown. Many theories of narcosis do not explain how unconsciousness is produced at a molecular level, but instead relate some physicochemical property of anesthetic agents to their anesthetic potencies. In this paper, we address some of those physicochemical properties, with more emphasis on correlating the anesthetic potency of volatile anesthetics to their boiling points based on thermodynamic principles.

  5. Sedation with volatile anesthetics in cardiothoracic intensive care unit patients

    OpenAIRE

    Hellström, Jan

    2014-01-01

    Volatile anaesthetics have been reported to provide protection against myocardial ischemia and reperfusion injury. This effect has been demonstrated in experimental studies when the volatile anaesthetics were provided either before (preconditioning) or after the ischemic period (postconditioning). Clinical trials of volatile anaesthetics versus intravenous anaesthesia for coronary artery bypass grafting (CABG) have reported reduced postoperative release of troponin, a biomarker...

  6. Local anesthetics disrupt energetic coupling between the voltage-sensing segments of a sodium channel.

    Science.gov (United States)

    Muroi, Yukiko; Chanda, Baron

    2009-01-01

    Local anesthetics block sodium channels in a state-dependent fashion, binding with higher affinity to open and/or inactivated states. Gating current measurements show that local anesthetics immobilize a fraction of the gating charge, suggesting that the movement of voltage sensors is modified when a local anesthetic binds to the pore of the sodium channel. Here, using voltage clamp fluorescence measurements, we provide a quantitative description of the effect of local anesthetics on the steady-state behavior of the voltage-sensing segments of a sodium channel. Lidocaine and QX-314 shifted the midpoints of the fluorescence-voltage (F-V) curves of S4 domain III in the hyperpolarizing direction by 57 and 65 mV, respectively. A single mutation in the S6 of domain IV (F1579A), a site critical for local anesthetic block, abolished the effect of QX-314 on the voltage sensor of domain III. Both local anesthetics modestly shifted the F-V relationships of S4 domain IV toward hyperpolarized potentials. In contrast, the F-V curve of the S4 domain I was shifted by 11 mV in the depolarizing direction upon QX-314 binding. These antagonistic effects of the local anesthetic indicate that the drug modifies the coupling between the voltage-sensing domains of the sodium channel. Our findings suggest a novel role of local anesthetics in modulating the gating apparatus of the sodium channel.

  7. The use of a volatile anesthetic regimen protects against acute normovolemic hemodilution induced myocardial depression in patients with coronary artery disease

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    Lorsomradee Sratwadee

    2009-01-01

    Full Text Available Background: Previous studies indicated that acute normovolemic hemodilution (ANH was associated with a depression of myocardial function in coronary surgery patients with baseline heart rate faster than 90 bpm. It was suggested that this phenomenon could be explained by the occurrence of myocardial ischemia. In the present study, we hypothesized that the cardioprotective properties of a volatile anesthetic regimen might protect against the ANH related myocardial functional impairment. Materials and Methods: Forty elective coronary surgery patients with baseline heart rate faster than 90 bpm were randomly allocated to receive different anesthetic regimens. Group A (n = 20 received midazolam-based anesthesia. Group B (n = 20 received a sevoflurane-based anesthesia. Five-lead electrocardiogram, pulse oximetry, capnography, radial arterial pressure, and Swan Ganz continuous thermodilution cardiac output via right internal jugular vein were monitored. Measurements were obtained before and after ANH. Data were compared using paired t test. All data were expressed as mean ± SD. Data were considered significant if P < 0.05. Results: After ANH, systemic vascular resistance was slightly decreased in group A while there was a significant decrease in group B. In group A, cardiac output was slightly decreased from 5.07±1.17 l/min to 5.02±1.28 l/min after ANH, whereas in group B, cardiac output was significantly increased from 4.84±1.21 l/min to 6.02±1.28 l/min after ANH. Conclusion: In coronary surgery patients, with baseline heart rate faster than 90 bpm, anesthesia with sevoflurane during ANH was associated with an improvement in myocardial function after ANH, which was not present in patients anesthetized with midazolam.

  8. Changes in Alpha Frequency and Power of the Electroencephalogram during Volatile-Based General Anesthesia

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    Darren Hight

    2017-05-01

    Full Text Available Oscillations in the electroencephalogram (EEG at the alpha frequency (8–12 Hz are thought to be ubiquitous during surgical anesthesia, but the details of how this oscillation responds to ongoing changes in volatile anesthetic concentration have not been well characterized. It is not known how often alpha oscillations are absent in the clinical context, how sensitively alpha frequency and power respond to changes in anesthetic concentration, and what effect increased age has on alpha frequency. Bipolar EEG was recorded frontally from 305 patients undergoing surgery with sevoflurane or desflurane providing general anesthesia. A new method of detecting the presence of alpha oscillations based on the stability of the rate of change of the peak frequency in the alpha range was developed. Linear concentration-response curves were fitted to assess the sensitivity of alpha power and frequency measures to changing levels of anesthesia. Alpha oscillations were seen to be inexplicably absent in around 4% of patients. Maximal alpha power increased with increasing volatile anesthetic concentrations in half of the patients, and decreased in the remaining patients. Alpha frequency decreased with increasing anesthetic concentrations in near to 90% of patients. Increasing age was associated with decreased sensitivity to volatile anesthesia concentrations, and with decreased alpha frequency, which sometimes transitioned into the theta range (5–7 Hz. While peak alpha frequency shows a consistent slowing to increasing volatile concentrations, the peak power of the oscillation does not, suggesting that frequency might be more informative of depth of anesthesia than traditional power based measures during volatile-based anesthesia. The alpha oscillation becomes slower with increasing age, even when the decreased anesthetic needs of older patients were taken into account.

  9. The Molecular Mechanisms of Anesthetic Action: Updates and Cutting Edge Developments from the Field of Molecular Modeling

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    Edward J. Bertaccini

    2010-07-01

    Full Text Available For over 160 years, general anesthetics have been given for the relief of pain and suffering. While many theories of anesthetic action have been purported, it has become increasingly apparent that a significant molecular focus of anesthetic action lies within the family of ligand-gated ion channels (LGIC’s. These protein channels have a transmembrane region that is composed of a pentamer of four helix bundles, symmetrically arranged around a central pore for ion passage. While initial and some current models suggest a possible cavity for binding within this four helix bundle, newer calculations postulate that the actual cavity for anesthetic binding may exist between four helix bundles. In either scenario, these cavities have a transmembrane mode of access and may be partially bordered by lipid moieties. Their physicochemical nature is amphiphilic. Anesthetic binding may alter the overall motion of a ligand-gated ion channel by a “foot-in-door” motif, resulting in the higher likelihood of and greater time spent in a specific channel state. The overall gating motion of these channels is consistent with that shown in normal mode analyses carried out both in vacuo as well as in explicitly hydrated lipid bilayer models. Molecular docking and large scale molecular dynamics calculations may now begin to show a more exact mode by which anesthetic molecules actually localize themselves and bind to specific protein sites within LGIC’s, making the design of future improvements to anesthetic ligands a more realizable possibility.

  10. Carbon monoxide production from five volatile anesthetics in dry sodalime in a patient model: halothane and sevoflurane do produce carbon monoxide; temperature is a poor predictor of carbon monoxide production

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    Perez Roberto SGM

    2005-06-01

    Full Text Available Abstract Background Desflurane and enflurane have been reported to produce substantial amounts of carbon monoxide (CO in desiccated sodalime. Isoflurane is said to produce less CO and sevoflurane and halothane should produce no CO at all. The purpose of this study is to measure the maximum amounts of CO production for all modern volatile anesthetics, with completely dry sodalime. We also tried to establish a relationship between CO production and temperature increase inside the sodalime. Methods A patient model was simulated using a circle anesthesia system connected to an artificial lung. Completely desiccated sodalime (950 grams was used in this system. A low flow anesthesia (500 ml/min was maintained using nitrous oxide with desflurane, enflurane, isoflurane, halothane or sevoflurane. For immediate quantification of CO production a portable gas chromatograph was used. Temperature was measured within the sodalime container. Results Peak concentrations of CO were very high with desflurane and enflurane (14262 and 10654 ppm respectively. It was lower with isoflurane (2512 ppm. We also measured small concentrations of CO for sevoflurane and halothane. No significant temperature increases were detected with high CO productions. Conclusion All modern volatile anesthetics produce CO in desiccated sodalime. Sodalime temperature increase is a poor predictor of CO production.

  11. Dexmedetomidine as the primary anesthetic agent during cardiac surgery in an infant with a family history of malignant hyperthermia

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    Aymen Naguib

    2011-01-01

    Full Text Available Malignant hyperthermia (MH is an acute hypermetabolic crisis triggered in susceptible patients by the administration of succinylcholine or a volatile anesthetic agent. When providing anesthetic care for MH-susceptible agents, a total intravenous anesthetic (TIVA technique is frequently chosen. When choosing the components for TIVA, several options exist including the combination of propofol or dexmedetomidine with an opioid. We present our experience with the use of dexmedetomidine as a key component of the anesthetic regimen in a 5-month-old infant with a family history of MH. Previous reports of the use of dexmedetomidine in MH-susceptible patients are reviewed and its benefits in such patients discussed.

  12. Anesthetic gases and global warming: Potentials, prevention and future of anesthesia.

    Science.gov (United States)

    Gadani, Hina; Vyas, Arun

    2011-01-01

    Global warming refers to an average increase in the earth's temperature, which in turn causes changes in climate. A warmer earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. Greenhouse gases make the earth warmer by trapping energy inside the atmosphere. Greenhouse gases are any gas that absorbs infrared radiation in the atmosphere and include: water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halogenated fluorocarbons (HCFCs), ozone (O3), perfluorinated carbons (PFCs), and hydrofluorocarbons (HFCs). Hazardous chemicals enter the air we breathe as a result of dozens of activities carried out during a typical day at a healthcare facility like processing lab samples, burning fossil fuels etc. We sometimes forget that anesthetic agents are also greenhouse gases (GHGs). Anesthetic agents used today are volatile halogenated ethers and the common carrier gas nitrous oxide known to be aggressive GHGs. With less than 5% of the total delivered halogenated anesthetic being metabolized by the patient, the vast majority of the anesthetic is routinely vented to the atmosphere through the operating room scavenging system. The global warming potential (GWP) of a halogenated anesthetic is up to 2,000 times greater than CO2. Global warming potentials are used to compare the strength of different GHGs to trap heat in the atmosphere relative to that of CO2. Here we discuss about the GWP of anesthetic gases, preventive measures to decrease the global warming effects of anesthetic gases and Xenon, a newer anesthetic gas for the future of anesthesia.

  13. Early exposure to volatile anesthetics impairs long-term associative learning and recognition memory.

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    Bradley H Lee

    Full Text Available Anesthetic exposure early in life affects neural development and long-term cognitive function, but our understanding of the types of memory that are altered is incomplete. Specific cognitive tests in rodents that isolate different memory processes provide a useful approach for gaining insight into this issue.Postnatal day 7 (P7 rats were exposed to either desflurane or isoflurane at 1 Minimum Alveolar Concentration for 4 h. Acute neuronal death was assessed 12 h later in the thalamus, CA1-3 regions of hippocampus, and dentate gyrus. In separate behavioral experiments, beginning at P48, subjects were evaluated in a series of object recognition tests relying on associative learning, as well as social recognition.Exposure to either anesthetic led to a significant increase in neuroapoptosis in each brain region. The extent of neuronal death did not differ between groups. Subjects were unaffected in simple tasks of novel object and object-location recognition. However, anesthetized animals from both groups were impaired in allocentric object-location memory and a more complex task requiring subjects to associate an object with its location and contextual setting. Isoflurane exposure led to additional impairment in object-context association and social memory.Isoflurane and desflurane exposure during development result in deficits in tasks relying on associative learning and recognition memory. Isoflurane may potentially cause worse impairment than desflurane.

  14. Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

    Science.gov (United States)

    Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

    2017-02-01

    General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

  15. Local anesthetics: New insights into risks and benefits

    NARCIS (Netherlands)

    Lirk, P.

    2014-01-01

    Conventional local anesthetics in contemporary use block the voltage-gated sodium channel by binding to a specific site on the inner facet of the channel pore. Only little fractions of local anaesthetic are thought to participate in nerve blockade, the rest is absorbed into surrounding tissues or

  16. Nitrous Oxide and Nitrous Oxide-Free Low-Flow Anesthesia Using Bispectral Index Monitoring: Effects on Hemodynamics, Recovery Times, Volatile Anesthetic Consumption and Costs

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    Bengü Gülhan Köksal

    2010-12-01

    Full Text Available Aim: In this study, we aimed to compare the effects of desfluraneN2O and desflurane-fentanyl combinations on hemodynamics, recovery times, volatile anesthetic consumption and costs in low-flow desflurane anesthesia by bispectral index (BIS monitoring of depth of anesthesia. Methods: After approval of ethics committee and obtaining patient consents, 60 patients were divided into two equal groups randomly. Non-invasive blood pressure measurement, ECG, SpO2 and BIS were monitored. All patients received 10 L .min-1 100% oxygen with mask for 5 minute before intubation. 2 mg.kg-1 propofol, 2 μg.kg-1 fentanyl and 0.6 mg.kg-1 rocuronium bromide were administered at induction in both groups. Desfluran 6% was chosen for anesthesia maintenance. Group 1 received 50% O2-N2O mixture in 6 L.min-1 and Group 2 received 50% O2-air mixture in 6 L.min-1 as carrier gas. Low-flow anesthesia (1 L.min-1 was started after a 10-min period of initial high flow (6 L.min-1. In Group 2, infusion of fentanyl was begun in 1 μg.kg.hour-1 rate. Desflurane level was adjusted at a main BIS value of 40-60. Blood pressure, heart rate, FiO2, etO2, FiN22, EtN2O, FiCO2, EtCO2, Fidesfluran and Etdesflurane were recorded. Results: There were no significant differences between the two groups in terms of heart rate, arterial blood pressure, settings of desfluran and recovery time. BIS values (p<0.001 and anesthetic agent costs (p<0.001 were higher in Group 2. Conclusion: Using fentanyl infusion instead of nitrous oxide in low flow-anesthesia with desflurane did not alter the hemodynamic parameters. Fentanyl infusion with medical air-oxygen as carrier gas is an alternative technique, but increases BIS values and anesthetic agent costs. (The Medical Bulletin of Haseki 2010; 48: 132-8

  17. Antenna-predominant and male-biased CSP19 of Sesamia inferens is able to bind the female sex pheromones and host plant volatiles.

    Science.gov (United States)

    Zhang, Ya-Nan; Ye, Zhan-Feng; Yang, Ke; Dong, Shuang-Lin

    2014-02-25

    Insect chemosensory proteins (CSPs) are proposed to capture and transport hydrophobic chemicals across the sensillum lymph to olfactory receptors (ORs), but this has not been clarified in moths. In this study, we built on our previously reported segment sequence work and cloned the full length CSP19 gene (SinfCSP19) from the antennae of Sesamia inferens by using rapid amplification of cDNA ends. Quantitative real time-PCR (qPCR) assays indicated that the gene was expressed in a unique profile, i.e. predominant in antennae and significantly higher in male than in female. To explore the function, recombinant SinfCSP19 was expressed in Escherichia coli cells and purified by Ni-ion affinity chromatography. Binding affinities of the recombinant SinfCSP19 with 39 plant volatiles, 3 sex pheromone components and 10 pheromone analogs were measured using fluorescent competitive binding assays. The results showed that 6 plant volatiles displayed high binding affinities to SinfCSP19 (Ki = 2.12-8.75 μM), and more interesting, the 3 sex pheromone components and analogs showed even higher binding to SinfCSP19 (Ki = 0.49-1.78 μM). Those results suggest that SinfCSP19 plays a role in reception of female sex pheromones of S. inferens and host plant volatiles. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Three odorant binding proteins may regulate the behavioural response of Chrysopa pallens to plant volatiles and the aphid alarm pheromone (E)-β-farnesene.

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    Li, Z-Q; Zhang, S; Cai, X-M; Luo, J-Y; Dong, S-L; Cui, J-J; Chen, Z-M

    2017-06-01

    Artificial Chrysopa pallens release is a well-known method for suppressing aphids, but it is difficult to establish lacewing populations in the field. Understanding the functions of C. pallens odorant-binding proteins (CpalOBPs) and behavioural responses of C. pallens to plant volatiles and aphid alarm pheromone (E)-ß-farnesene has important implications for population establishment after lacewing release. Based on our previous study, five antennae-enriched CpalOBPs were selected. Sequence alignment and phylogenetic analysis revealed that these five CpalOBPs were Classic OBPs and separated into different clades. Of them, CpalOBP10 clustered in the same clade with aphid OBP7, which mediates the perception of green leaf volatiles and (E)-ß-farnesene. Ligand-binding assays showed 31 compounds, including plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene, had high binding affinities for at least one of these five CpalOBPs. Of the 31 compounds, the pest-induced volatiles (Z)-3-hexenyl hexanoate and 2-hexyl-1-decanol, used in host location by the black bean aphid, elicited significant attractive behavioural responses from C. pallens. Conversely, (E)-ß-farnesene elicited strongly repellent behavioural responses. It is conceivable that C. pallens utilizes plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene as foraging cues. Our studies provide new insights into the interrelationships amongst C. pallens, its prey and the host plants. Compounds that elicited significant behavioural responses from C. pallens were also identified. © 2017 The Royal Entomological Society.

  19. Effects of nitrous oxide on the rat heart in vivo: another inhalational anesthetic that preconditions the heart?

    NARCIS (Netherlands)

    Weber, Nina C.; Toma, Octavian; Awan, Saqib; Frässdorf, Jan; Preckel, Benedikt; Schlack, Wolfgang

    2005-01-01

    BACKGROUND: For nitrous oxide, a preconditioning effect on the heart has yet not been investigated. This is important because nitrous oxide is commonly used in combination with volatile anesthetics, which are known to precondition the heart. The authors aimed to clarify (1) whether nitrous oxide

  20. Anesthetic agents in patients with very long-chain acyl-coenzyme A dehydrogenase deficiency: a literature review.

    Science.gov (United States)

    Redshaw, Charlotte; Stewart, Catherine

    2014-11-01

    Very long-chain acyl-coenzyme A dehydrongenase deficiency (VLCADD) is a rare disorder of fatty acid metabolism that renders sufferers susceptible to hypoglycemia, liver failure, cardiomyopathy, and rhabdomyolysis. The literature about the management of these patients is hugely conflicting, suggesting that both propofol and volatile anesthesia should be avoided. We have reviewed the literature and have concluded that the source papers do not support the statements that volatile anesthetic agents are unsafe. The reports on rhabdomyolysis secondary to anesthesia appear to be due to inadequate supply of carbohydrate not volatile agents. Catabolism must be avoided with minimal fasting, glucose infusions based on age and weight, and attenuation of emotional and physical stress. General anesthesia appears to be protective of stress-induced catabolism and may offer benefits in children and anxious patients over regional anesthesia. Propofol has not been demonstrated to be harmful in VLCADD but is presented in an emulsion containing very long-chain fatty acids which can cause organ lipidosis and itself can inhibit mitochondrial fatty acid metabolism. It is therefore not recommended. Suxamethonium-induced myalgia may mimic symptoms of rhabdomyolysis and cause raised CK therefore should be avoided. Opioids, NSAIDS, regional anesthesia, and local anesthetic techniques have all been used without complication. © 2014 John Wiley & Sons Ltd.

  1. Effects of local anesthetics on cholinergic agonist binding affinity of central nervous system. cap alpha. -bungarotoxin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Lukas, R.L.; Bennett, E.L.

    1979-12-01

    In general, pharmacological effects of local anesthetics may be attributed to their ability to reversibly block the propagation of nerve and muscle action potentials. At physiologically potent concentrations, local anesthetics (LA) also act as noncompetitive antagonists of the physiological response of post-synaptic nicotinic acetylcholine receptors (nAChR) to cholinergic agonists, and increase agonist binding affinities of nAChR from electric organ. It is postulated that the primary site of LA action on nAChR function is at the receptor-coupled ionophore. Furthermore, LA-nAChR ionophore interactions are thought to accelerate physiological desensitization of nAChR, manifest biochemically as increased affinity of nAChR for agonist. Specific receptors for ..cap alpha..-bungarotoxin (..cap alpha..-Bgt), a potent competitive antagonist at nAChR sites in the periphery, have been detected in rat central nervous system membrane preparations. The affinity of these central ..cap alpha..-Bgt receptors (..cap alpha..-BgtR) for cholinergic agonists is found to increase on exposure to agonist. Nevertheless, on the basis of inconsistent pharmacological and physiological results, uncertainty remains regarding the relationship between ..cap alpha..-BgtR and authentic nAChR in the CNS, despite a wide body of biochemical and histological evidence consistent with their identity. Reasoning that if CNS ..cap alpha..-BgtR are true in nAChR, coupled to functional ion channels, LA might be expected to cause biochemically measurable increases in ..cap alpha..-BgtR affinity for cholinergic agonists, we have undertaken a study of the effects of LA on the ability of acetylcholine (ACh) to inhibit interaction of ..cap alpha..-BgtR with /sup 3/H-labeled ..cap alpha..-Bgt.

  2. Identification of Host-Plant Volatiles and Characterization of Two Novel General Odorant-Binding Proteins from the Legume Pod Borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae.

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    Jing Zhou

    Full Text Available Chemoreception is a key feature in selection of host plant by phytophagous insects, and odorant-binding proteins (OBPs are involved in chemical communication of both insects and vertebrates. The legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae is one of the key pest species of cowpea and widely distributed throughout tropical and subtropical regions, causing up to 80% of yield loss. In this study, we investigated the electrophysiological responses of female M. vitrata to floral volatiles from V. unguiculata. Seventeen electroantennogram-active compounds were identified from floral volatiles of V. unguiculata by coupled gas chromatography-electroantennography (GC-EAD and gas chromatography-mass spectrometry (GC-MS. Then, we cloned two novel full-length GOBP genes (MvitGOBP1 and MvitGOBP2 from the antennae of M. vitrata using reverse transcription PCR. Protein sequence analysis indicated that they shared high sequence similarity with other Pyralididae insect GOBPs and had the typical six-cysteine signature. Real-time PCR analysis indicated that MvitGOBP1-2 mRNA was highly expressed in the antennae of female adult with several thousands-fold difference compare to other tissue. Next, the recombinant MvitGOBP1-2 was expressed in Escherichia coli and purified using Ni ion affinity chromatography. Fluorescence binding assays demonstrated that MvitGOBP1-2 had different binding affinities with 17 volatile odorant molecules including butanoic acid butyl ester, limonene, 4-ethylpropiophenone, 1H-indol-4-ol, butanoic acid octyl ester and 2-methyl-3-phenylpropanal. In the field trapping experiment, these six floral volatiles could effectively attract female moths and showed significant difference compared with the blank lure. These results suggested that MvitGOBPs and the seventeen floral volatiles are likely to function in the olfactory behavior response of female moths, which may have played crucial roles in the selection of oviposition

  3. Participation of the GABAergic system in the anesthetic effect of Lippia alba (Mill.) N.E. Brown essential oil

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    Heldwein, C.G.; Silva, L.L. [Departamento de Farmácia Industrial, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Reckziegel, P. [Departamento de Fisiologia e Farmacologia, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Barros, F.M.C. [Departamento de Farmácia Industrial, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Bürger, M.E.; Baldisserotto, B. [Departamento de Fisiologia e Farmacologia, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Mallmann, C.A. [Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Schmidt, D.; Caron, B.O. [Departamento de Ciências Agronômicas e Ambientais, Universidade Federal de Santa Maria, Campus de Frederico Westphalen, Frederico Westphalen, RS (Brazil); Heinzmann, B.M. [Departamento de Farmácia Industrial, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2012-04-05

    The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA{sub A} receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA{sub A} receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.

  4. Participation of the GABAergic system in the anesthetic effect of Lippia alba (Mill.) N.E. Brown essential oil

    International Nuclear Information System (INIS)

    Heldwein, C.G.; Silva, L.L.; Reckziegel, P.; Barros, F.M.C.; Bürger, M.E.; Baldisserotto, B.; Mallmann, C.A.; Schmidt, D.; Caron, B.O.; Heinzmann, B.M.

    2012-01-01

    The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABA A receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABA A receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish

  5. Allyl m-Trifluoromethyldiazirine Mephobarbital: An Unusually Potent Enantioselective and Photoreactive Barbiturate General Anesthetic

    Energy Technology Data Exchange (ETDEWEB)

    Savechenkov, Pavel Y.; Zhang, Xi; Chiara, David C.; Stewart, Deirdre S.; Ge, Rile; Zhou, Xiaojuan; Raines, Douglas E.; Cohen, Jonathan B.; Forman, Stuart A.; Miller, Keith W.; Bruzik, Karol S. (Harvard-Med); (Mass. Gen. Hosp.); (UIC)

    2012-12-10

    We synthesized 5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid (14), a trifluoromethyldiazirine-containing derivative of general anesthetic mephobarbital, separated the racemic mixture into enantiomers by chiral chromatography, and determined the configuration of the (+)-enantiomer as S by X-ray crystallography. Additionally, we obtained the {sup 3}H-labeled ligand with high specific radioactivity. R-(-)-14 is an order of magnitude more potent than the most potent clinically used barbiturate, thiopental, and its general anesthetic EC{sub 50} approaches those for propofol and etomidate, whereas S-(+)-14 is 10-fold less potent. Furthermore, at concentrations close to its anesthetic potency, R-(-)-14 both potentiated GABA-induced currents and increased the affinity for the agonist muscimol in human {alpha}1{beta}2/3{gamma}2L GABA{sub A} receptors. Finally, R-(-)-14 was found to be an exceptionally efficient photolabeling reagent, incorporating into both {alpha}1 and {beta}3 subunits of human {alpha}1{beta}3 GABAA receptors. These results indicate R-(-)-14 is a functional general anesthetic that is well-suited for identifying barbiturate binding sites on Cys-loop receptors.

  6. Direct Pore Binding as a Mechanism for Isoflurane Inhibition of the Pentameric Ligand-gated Ion Channel ELIC.

    Science.gov (United States)

    Chen, Qiang; Kinde, Monica N; Arjunan, Palaniappa; Wells, Marta M; Cohen, Aina E; Xu, Yan; Tang, Pei

    2015-09-08

    Pentameric ligand-gated ion channels (pLGICs) are targets of general anesthetics, but molecular mechanisms underlying anesthetic action remain debatable. We found that ELIC, a pLGIC from Erwinia chrysanthemi, can be functionally inhibited by isoflurane and other anesthetics. Structures of ELIC co-crystallized with isoflurane in the absence or presence of an agonist revealed double isoflurane occupancies inside the pore near T237(6') and A244(13'). A pore-radius contraction near the extracellular entrance was observed upon isoflurane binding. Electrophysiology measurements with a single-point mutation at position 6' or 13' support the notion that binding at these sites renders isoflurane inhibition. Molecular dynamics simulations suggested that isoflurane binding was more stable in the resting than in a desensitized pore conformation. This study presents compelling evidence for a direct pore-binding mechanism of isoflurane inhibition, which has a general implication for inhibitory action of general anesthetics on pLGICs.

  7. Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

    International Nuclear Information System (INIS)

    Souza, Kátina M.; Braz, Leandro G.; Nogueira, Flávia R.; Souza, Marajane B.; Bincoleto, Lahis F.; Aun, Aline G.; Corrente, José E.; Carvalho, Lídia R.; Braz, José Reinaldo C.; Braz, Mariana G.

    2016-01-01

    Highlights: • Anesthesiologists exposed to the most commonly used anesthetic gases were evaluated. • No alterations were detected for lymphocyte DNA damage detected by the comet assay. • Decreased frequencies of basal cells were detected in exfoliated buccal cells (BMCyt). • Increased frequencies of micronucleus and cytotoxicity were observed in BMCyt assay. • Anesthesiologists have genomic instability due to occupational exposure. - Abstract: Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N 2 O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N 2 O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170 ppm for N 2 O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and pyknosis, and

  8. Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Kátina M.; Braz, Leandro G.; Nogueira, Flávia R.; Souza, Marajane B.; Bincoleto, Lahis F.; Aun, Aline G. [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil); Corrente, José E.; Carvalho, Lídia R. [Instituto de Biociências de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Bioestatística, Botucatu (Brazil); Braz, José Reinaldo C. [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil); Braz, Mariana G., E-mail: mgbraz@hotmail.com [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil)

    2016-09-15

    Highlights: • Anesthesiologists exposed to the most commonly used anesthetic gases were evaluated. • No alterations were detected for lymphocyte DNA damage detected by the comet assay. • Decreased frequencies of basal cells were detected in exfoliated buccal cells (BMCyt). • Increased frequencies of micronucleus and cytotoxicity were observed in BMCyt assay. • Anesthesiologists have genomic instability due to occupational exposure. - Abstract: Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N{sub 2}O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N{sub 2}O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170 ppm for N{sub 2}O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and

  9. Availability of anesthetic effect monitoring: utilization, intraoperative management and time to extubation in liver transplantation.

    Science.gov (United States)

    Schumann, R; Hudcova, J; Bonney, I; Cepeda, M S

    2010-12-01

    Titration of volatile anesthetics to anesthetic effect monitoring using the bispectral index (BIS) has been shown to decrease anesthetic requirements and facilitate recovery from anesthesia unrelated to liver transplantation (OLT). To determine whether availability of such monitoring influences its utilization pattern and affect anesthetic care and outcomes in OLT, we conducted a retrospective analysis in recipients with and without such monitoring. We evaluated annual BIS utilization over a period of 7 years, and compared 41 BIS-monitored patients to 42 controls. All received an isoflurane/air/oxygen and opioid-based anesthetic with planned postoperative ventilation. Data collection included age, body mass index (BMI), gender, Model for End-stage Liver Disease (MELD) score, and time to extubation (TtE). Mean preanhepatic, anhepatic, and postanhepatic end-tidal isoflurane concentrations were compared, as well as BIS values for each phase of OLT using the Kruskal-Wallis and Wilcoxon signed-rank tests, respectively. The use of anesthetic effect monitoring when available increased steadily from 15% of cases in the first year to almost 93% by year 7. There was no significant difference in age, gender, BMI, MELD, or TtE between groups. The BIS group received less inhalational anesthetic during each phase of OLT compared to the control group. However, this difference was statistically significant only during the anhepatic phase (P = .026), and was clinically not impressive. Within the BIS group, the mean BIS value was 38.74 ± 5.25 (mean ± standard deviation), and there was no difference for the BIS value between different transplant phases. Availability of anesthetic effect monitoring as an optional monitoring tool during OLT results in its increasing utilization by anesthesia care teams over time. However, unless integrated into an intraoperative algorithm and an early extubation protocol for fast tracking of OLT recipients, this utilization does not appear to provide

  10. Detection of volatile and soluble general anesthetics using a fluorescence-based fiber optic sensor: recent progress in chemical sensitivity and noise sources

    Science.gov (United States)

    Yager, Paul; Abrams, Susan B.

    1992-04-01

    A fiber optic sensor for general anesthetics based on the phase transition of immobilized phospholipid vesicles is under development. Current work centers on evaluating the sensor response to different anesthetics and instrumentation design. The fluorescence of laurdan- doped liposomes is found to respond linearly to the infusible anesthetics thiopental sodium and Propofol. Preliminary experiments have been performed to determine sources of noise in the optical and electronic components of the sensor as it is now configured. One potential noise source is the liposome sample at the fiber tip; photobleaching and thermal fluctuations due to heating by the illuminating 360 nm radiation can affect measurement of the anesthetic level. Heating of the sample is a factor at high illumination levels, but photobleaching, which reduces the signal intensity, does not alter the intensity ratio upon which the anesthetic concentration measurement is based. Optical microscopy of fiber tips embedded in liposomes allows direct observation of the light intensity near the tip of the fiber despite the extreme turbidity of the suspension. Light intensity drops to less than 10% of its maximum intensity at the fiber tip within 300 micrometers . Further use of this technique should allow monitoring the effects of photobleaching on the spatial distribution of the liposomes responsible for the measured optical signal.

  11. Local Anesthetic-Induced Neurotoxicity

    NARCIS (Netherlands)

    Verlinde, Mark; Hollmann, Markus W.; Stevens, Markus F.; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

    2016-01-01

    This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk

  12. Anesthetic management of comprehensive dental restoration in a child with glutaric aciduria type 1 using volatile sevoflurane

    Directory of Open Access Journals (Sweden)

    Wei-Nung Teng

    2014-10-01

    Full Text Available Glutaric aciduria type 1 (GA1 is a rare, inherited mitochondrial disorder that results from deficiency of mitochondrial glutaryl-CoA dehydrogenase. Most patients develop neurological dysfunction early in life, which leads to severe disabilities. We present a 37-month-old girl with GA1 manifested as macrocephaly and hypotonia who received comprehensive dental restoration surgery under general anesthesia with sevoflurane. She was placed on specialized fluid management during a preoperative fasting period and anesthesia was administered without complications. All the physiological parameters, including glucose and lactate blood levels and arterial blood gas were carefully monitored and maintained within normal range perioperatively. Strategies for anesthetic management should include prevention of pulmonary aspiration, dehydration, hyperthermia and catabolic state, adequate analgesia to minimize surgical stress, and avoidance of prolonged neuromuscular blockade. We administered general anesthesia with sevoflurane uneventfully, which was well tolerated by our patient with GA1. Additionally, communication with a pediatric geneticist and surgeons should be undertaken to formulate a comprehensive anesthetic strategy in these patients.

  13. Characterization of a high affinity cocaine binding site in rat brain

    International Nuclear Information System (INIS)

    Calligaro, D.; Eldefrawi, M.

    1986-01-01

    Binding of [ 3 H]cocaine to synaptic membranes from whole rat brain was reversible and saturable. Nonlinear regression analysis of binding isotherms indicated two binding affinities: one with k/sub d/ = 16 nM, B/sub max/ = 0.65 pmoles/mg protein and the other with K/sub d/ = 660 nM, B/sub max/ = 5.1 pmoles/mg protein. The high-affinity binding of [ 3 H]cocaine was sensitive to the actions of trypsin and chymotrypsin but not carboxypeptidase, and was eliminated by exposure of the membranes to 95 0 C for 5 min. Specific binding at 2 nM was higher at pH 8.8 than at pH 7.0. Binding of [ 3 H]cocaine (15 nM) was inhibited by increasing concentrations of Na + ions. Several cocaine analogues, neurotransmitter uptake inhibitors and local anesthetics displaced specific [ 3 H]cocaine binding at 2 nM with various potencies. The cocaine analogue (-)-norcocaine was the most potent (IC 50 = 10 nM), while the local anesthetic tetracaine was the least potent in inhibiting [ 3 H]cocaine binding. Several biogenic amine uptake inhibitors, including tricyclic antidepressants and phencyclidine, had IC 50 values below μM concentrations

  14. Adhesion of volatile propofol to breathing circuit tubing.

    Science.gov (United States)

    Lorenz, Dominik; Maurer, Felix; Trautner, Katharina; Fink, Tobias; Hüppe, Tobias; Sessler, Daniel I; Baumbach, Jörg Ingo; Volk, Thomas; Kreuer, Sascha

    2017-08-21

    Propofol in exhaled breath can be measured and may provide a real-time estimate of plasma concentration. However, propofol is absorbed in plastic tubing, thus estimates may fail to reflect lung/blood concentration if expired gas is not extracted directly from the endotracheal tube. We evaluated exhaled propofol in five ventilated ICU patients who were sedated with propofol. Exhaled propofol was measured once per minute using ion mobility spectrometry. Exhaled air was sampled directly from the endotracheal tube and at the ventilator end of the expiratory side of the anesthetic circuit. The circuit was disconnected from the patient and propofol was washed out with a separate clean ventilator. Propofol molecules, which discharged from the expiratory portion of the breathing circuit, were measured for up to 60 h. We also determined whether propofol passes through the plastic of breathing circuits. A total of 984 data pairs (presented as median values, with 95% confidence interval), consisting of both concentrations were collected. The concentration of propofol sampled near the patient was always substantially higher, at 10.4 [10.25-10.55] versus 5.73 [5.66-5.88] ppb (p tubing was 4.58 [4.48-4.68] ppb, 3.46 [3.21-3.73] in the first hour, 4.05 [3.77-4.34] in the second hour, and 4.01 [3.36-4.40] in the third hour. Out-gassing propofol from the breathing circuit remained at 2.8 ppb after 60 h of washing out. Diffusion through the plastic was not observed. Volatile propofol binds or adsorbs to the plastic of a breathing circuit with saturation kinetics. The bond is reversible so propofol can be washed out from the plastic. Our data confirm earlier findings that accurate measurements of volatile propofol require exhaled air to be sampled as close as possible to the patient.

  15. Seeking Structural Specificity: Direct Modulation of Pentameric Ligand-Gated Ion Channels by Alcohols and General Anesthetics

    Science.gov (United States)

    Trudell, James R.; Harris, R. Adron

    2014-01-01

    Alcohols and other anesthetic agents dramatically alter neurologic function in a wide range of organisms, yet their molecular sites of action remain poorly characterized. Pentameric ligand-gated ion channels, long implicated in important direct effects of alcohol and anesthetic binding, have recently been illuminated in renewed detail thanks to the determination of atomic-resolution structures of several family members from lower organisms. These structures provide valuable models for understanding and developing anesthetic agents and for allosteric modulation in general. This review surveys progress in this field from function to structure and back again, outlining early evidence for relevant modulation of pentameric ligand-gated ion channels and the development of early structural models for ion channel function and modulation. We highlight insights and challenges provided by recent crystal structures and resulting simulations, as well as opportunities for translation of these newly detailed models back to behavior and therapy. PMID:24515646

  16. Adherence of volatile propofol to various types of plastic tubing.

    Science.gov (United States)

    Maurer, F; Lorenz, D J; Pielsticker, G; Volk, T; Sessler, D I; Baumbach, J I; Kreuer, S

    2017-01-23

    Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration. Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N 2 to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFA or PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol, with PTFE as an alternative.

  17. Postoperative environmental anesthetic vapour concentrations following removal of the airway device in the operating room versus the postanesthesia care unit.

    Science.gov (United States)

    Cheung, Sara K; Özelsel, Timur; Rashiq, Saifee; Tsui, Ban C

    2016-09-01

    This study was designed to compare waste anesthetic gas (WAG) concentrations within patients' breathing zones after removal of the patient's airway device in the postanesthesia care unit (PACU) vs in the operating room (OR). Following Research Ethics Board approval and patient consent, we recruited patients undergoing surgery who received volatile anesthesia via an endotracheal tube or supraglottic airway. Patients had their airway device removed in the OR or in the PACU depending on the attending anesthesiologist's preference. Upon the patient's arrival in the PACU, concentrations of exhaled sevoflurane and desflurane were measured at their breathing zone (i.e., 15 cm from the patient's mouth and nose) using a single-beam infrared spectrophotometer. Seventy patients were recruited during the five-month study period. The median [interquartile range] WAG levels in the patients' breathing zones were higher when their airway devices were removed in the PACU vs in the OR. The WAG levels for sevoflurane were 0.7 [0.4-1.1] parts per million (ppm) vs 0.5 [0.4-0.7] ppm, respectively; median difference, 0.3; 95% confidence interval (CI), 0.1 to 0.6; P = 0.04. The WAG levels for desflurane were 2.4 [1.2-3.4] ppm vs 4.1 [2.5-5.2] ppm, respectively; median difference, 1.5; 95% CI, 0.3 to 2.7; P = 0.04. After a volatile-based anesthetic, our results suggest that removal of the airway device in the PACU vs in the OR increases the amount of waste anesthetic gas in a patient's breathing zone and thus potentially in the PACU nurse's working zone.

  18. MAC-sparing effect of nitrous oxide in sevoflurane anesthetized sheep and its reversal with systemic atipamezole administration

    Science.gov (United States)

    Scanu, Antonio; Melosu, Valentino; Careddu, Giovanni Mario; Sotgiu, Giovanni

    2018-01-01

    Introduction Nitrous oxide (N2O) is an anesthetic gas with antinociceptive properties and reduces the minimum alveolar concentration (MAC) for volatile anesthetic agents, potentially through mechanisms involving central alpha2-adrenoceptors. We hypothesized that 70% N2O in the inspired gas will significantly reduce the MAC of sevoflurane (MACSEVO) in sheep, and that this effect can be reversed by systemic atipamezole. Materials and methods Animals were initially anesthetized with SEVO in oxygen (O2) and exposed to an electrical current as supramaximal noxious stimulus in order to determine MACSEVO (in duplicates). Thereafter, 70% N2O was added to the inspired gas and the MAC re-determined in the presence of N2O (MACSN). A subgroup of sheep were anesthetized a second time with SEVO/N2O for re-determination of MACSN, after which atipamezole (0.2 mg kg-1, IV) was administered for MACSNA determinations. Sheep were anesthetized a third time, initially with only SEVO/O2 to re-determine MACSEVO, after which atipamezole (0.2 mg kg-1, IV) was administered for determination of MACSA. Results MACSEVO was 2.7 (0.3)% [mean (standard deviation)]. Addition of N2O resulted in a 37% reduction of MACSEVO to MACSN of 1.7 (0.2)% (p <0.0001). Atipamezole reversed this effect, producing a MACSNA of 3.1 (0.7)%, which did not differ from MACSEVO (p = 0.12). MACSEVO did not differ from MACSA (p = 0.69). Cardiorespiratory variables were not different among experimental groups except a lower ETCO2 in animals exposed to SEVO/N2O. Conclusions N2O produces significant MACSEVO-reduction in sheep; this effect is completely reversed by IV atipamezole confirming the involvement of alpha2-adrenoreceptors in the MAC-sparing action of N2O. PMID:29315308

  19. 21 CFR 868.5550 - Anesthetic gas mask.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

  20. General anesthetics in children: neurotoxic or neuroprotective?

    Directory of Open Access Journals (Sweden)

    Jéssica Farias Rebouças

    2017-02-01

    Full Text Available Introduction: general anesthetics are involved in neuroprotection in adults after ischemic events and cognitive impairment, thus, they also may be associated with learning disorders in children exposed to them before three years of age. Objective: Describe about the neurotoxic effects of general anesthetics in experimental animals and children. Method: This is a systematic review, performed from search in databases and on PubMed using the keywords "neurotoxicity" and "general anesthetics," and "general anesthetics," "neurotoxicity", "children", "young child "and" pediatric ". Results: The search resulted in 185 articles. Out of these, 78 met our inclusion criteria. We found that there was a significant evidence of neurotoxicity induced by general anesthetics in experimental animals that were just born, resulting in late and permanent cognitive deficits. This effect was associated with multiple exposures, exposure length of time and combination of drugs. However, some studies found cognitive impairment after a single exposure to anesthetic. Conclusion: There is insufficient evidence to state that general anesthetics are neurotoxic and have the potential to trigger learning and behavior disabilities in children. However, we suggest caution in indicating surgery in children under three years old, analyzing risk-benefit and inserting the family in the decision process.   Keywords: Neurotoxicity; Neuroprotection; Cognitive Impairment; Children; General Anesthesics

  1. Methods to produce calibration mixtures for anesthetic gas monitors and how to perform volumetric calculations on anesthetic gases.

    Science.gov (United States)

    Christensen, P L; Nielsen, J; Kann, T

    1992-10-01

    A simple procedure for making calibration mixtures of oxygen and the anesthetic gases isoflurane, enflurane, and halothane is described. One to ten grams of the anesthetic substance is evaporated in a closed, 11,361-cc glass bottle filled with oxygen gas at atmospheric pressure. The carefully mixed gas is used to calibrate anesthetic gas monitors. By comparison of calculated and measured volumetric results it is shown that at atmospheric conditions the volumetric behavior of anesthetic gas mixtures can be described with reasonable accuracy using the ideal gas law. A procedure is described for calculating the deviation from ideal gas behavior in cases in which this is needed.

  2. Interaction of Local Anesthetics with Biomembranes Consisting of Phospholipids and Cholesterol: Mechanistic and Clinical Implications for Anesthetic and Cardiotoxic Effects

    Directory of Open Access Journals (Sweden)

    Hironori Tsuchiya

    2013-01-01

    Full Text Available Despite a long history in medical and dental application, the molecular mechanism and precise site of action are still arguable for local anesthetics. Their effects are considered to be induced by acting on functional proteins, on membrane lipids, or on both. Local anesthetics primarily interact with sodium channels embedded in cell membranes to reduce the excitability of nerve cells and cardiomyocytes or produce a malfunction of the cardiovascular system. However, the membrane protein-interacting theory cannot explain all of the pharmacological and toxicological features of local anesthetics. The administered drug molecules must diffuse through the lipid barriers of nerve sheaths and penetrate into or across the lipid bilayers of cell membranes to reach the acting site on transmembrane proteins. Amphiphilic local anesthetics interact hydrophobically and electrostatically with lipid bilayers and modify their physicochemical property, with the direct inhibition of membrane functions, and with the resultant alteration of the membrane lipid environments surrounding transmembrane proteins and the subsequent protein conformational change, leading to the inhibition of channel functions. We review recent studies on the interaction of local anesthetics with biomembranes consisting of phospholipids and cholesterol. Understanding the membrane interactivity of local anesthetics would provide novel insights into their anesthetic and cardiotoxic effects.

  3. Anesthetic equipment, facilities and services available for pediatric ...

    African Journals Online (AJOL)

    2011-04-09

    Apr 9, 2011 ... standards and increased use of disposable anesthetic equipment. An audit of equipment and facilities for anesthetic care in pediatric patients is important and should be carried out periodically to appraise the situation for upgrading of essential anesthetic facilities and equipment. Appendix A. 18th March, ...

  4. A Novel Anti-Pollution Filter for Volatile Agents During Cardiopulmonary Bypass: Preliminary Tests.

    Science.gov (United States)

    Nigro Neto, Caetano; Landoni, Giovanni; Tardelli, Maria Angela

    2017-08-01

    Concerns regarding pollution of the operating room by volatile anesthetics and effects on atmospheric ozone depletion exist. Volatile agents commonly are used during cardiopulmonary bypass to provide anesthesia independent of any supposed myocardial protective effects. The authors' aim was to create and to assess the performance of a prototype filter for volatile agents to be connected to the cardiopulmonary bypass circuit to avoid the emission of volatile agents to the operating room, and also to the environment without causing damage to the membrane oxygenator. Observational trial. University hospital. Prototype filter for volatile agents. The prototype filter was tested in a single ex vivo experiment. The main data measured during the test were pressure drop to detect interference with the performance of the oxygenator, back pressure to detect overpressure to the outlet gas jacket of the oxygenator, analysis of exhaled sevoflurane after the membrane oxygenator, and after the filter to detect any presence of sevoflurane. The prototype filter adsorbed the sevoflurane eliminated through the outlet portion of the oxygenator. During the entire test, the back pressure remained constant (4 mmHg) and pressure drop varied from 243 mmHg to 247 mmHg. The prototype filter was considered suitable to absorb the sevoflurane, and it did not cause an overpressure to the membrane oxygenator during the test. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Pharmacokinetics of inhaled anesthetics in green iguanas (Iguana iguana).

    Science.gov (United States)

    Brosnan, Robert J; Pypendop, Bruno H; Barter, Linda S; Hawkins, Michelle G

    2006-10-01

    To test the hypothesis that differences in anesthetic uptake and elimination in iguanas would counter the pharmacokinetic effects of blood:gas solubility and thus serve to minimize kinetic differences among inhaled agents. 6 green iguanas (Iguana iguana). Iguanas were anesthetized with isoflurane, sevoflurane, or desflurane in a Latin-square design. Intervals from initial administration of an anesthetic agent to specific induction events and from cessation of administration of an anesthetic agent to specific recovery events were recorded. End-expired gas concentrations were measured during anesthetic washout. Significant differences were not detected for any induction or recovery events for any inhalation agent in iguanas. Washout curves best fit a 2-compartment model, but slopes for both compartments did not differ significantly among the 3 anesthetics. Differences in blood:gas solubility for isoflurane, sevoflurane, and desflurane did not significantly influence differences in pharmacokinetics for the inhalation agents in iguanas.

  6. Local anesthetics: interaction with human erythrocyte membranes as studied by 1H and 31P nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Fraceto, Leonardo Fernandes; Paula, Eneida de

    2004-01-01

    The literature carries many theories about the mechanism of action of local anesthetics (LA). We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been studied by 1 H and 31 P nuclear magnetic resonance spectroscopy. It was found that lidocaine (LDC) and benzocaine (BZC) bind to the membranes, increase the mobility of the protons of the phospholipids acyl chains, and decrease the mobility and/or change the structure of the polar head groups. The results indicate that lidocaine molecules are inserted across the polar and liquid interface of the membrane, establishing both electrostatic (charged form) and hydrophobic (neutral form) interactions. Benzocaine locates itself a little deeper in the bilayer, between the interfacial glycerol region and the hydrophobic core. These changes in mobility or conformation of membrane lipids could affect the Na + -channel protein insertion in the bilayer, stabilizing it in the inactivated state, thus causing anesthesia. (author)

  7. Pharmacoeconomics of inhaled anesthetic agents: considerations for the pharmacist.

    Science.gov (United States)

    Chernin, Eric L

    2004-10-15

    Types of economic analyses used for inhaled anesthetic agents, factors to consider in calculating the cost of inhaled anesthetics, limitations of pharmacoeconomic studies of these agents, and strategies for controlling inhaled anesthetic costs are discussed. Inhaled anesthetic agents comprise a substantial component of drug budgets. Calculation of the cost of administering an inhaled anesthetic should take into consideration the cost per mL, potency, waste, concentration and duration of gas delivery, fresh gas flow rate, molecular weight, and density. The use of newer inhaled anesthetic agents with low solubility in blood and tissue provides a more rapid recovery from anesthesia than older, more soluble agents, and also provides the same level of control of depth of anesthesia at a lower fresh gas flow rate and possibly a lower cost than older agents at a higher fresh gas flow rate. A more rapid recovery may facilitate fast-track recovery and yield cost savings if it allows the completion of additional surgical cases or allows a reduction in personnel overtime expenses. Interpretation of pharmacoeconomic studies of inhaled anesthetics requires an appreciation of the limitations in methodology and ability to extrapolate results from one setting to another. Pharmacists' efforts to reduce anesthetic waste and collaborate with anesthesiologists to improve the use of these agents can help contain costs, but improving scheduling and efficiency in the operating room has a greater potential to reduce operating room costs. Much can be done to control costs of anesthetic agents without compromising availability of these agents and patient care.

  8. LOCAL ANESTHETICS IN PATIENTS WITH CARDIOVASCULAR DISEASES.

    Directory of Open Access Journals (Sweden)

    risto Daskalov

    2015-03-01

    Full Text Available A significant problem in the dental medicine is pain alleviation. Many studies in the dental anesthesiology result in the production of new agents for locoregional anesthesia. Objective: This article aim to present the results of the last studies on the effect of the local anesthetics used in the oral surgery on patients with cardiovascular diseases. Material: A general review of the existing literature on the effect of the adrenaline, included as vasoconstrictor in the local anesthetics, used in patients with cardiovascular diseases is made. The benefits of vasoconstrictors for the quality of the anesthetic effect are proven. Conclusion: A small amount of adrenaline in the anesthetic solution does not result in complications development in patients with controlled cardiovascular diseases. Articaine is recommended agent of first choice for local anesthesia in the oral surgery.

  9. Can anesthetic treatment worsen outcome in status epilepticus?

    Science.gov (United States)

    Sutter, Raoul; Kaplan, Peter W

    2015-08-01

    Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Identification of Glossina morsitans morsitans odorant binding ...

    African Journals Online (AJOL)

    Tsetse flies are vectors of trypanosome parasites, causative agents of Trypanosomiasis in humans and animals. Odorant Binding Proteins (OBPs) are critical in insect olfaction as they bind volatile odours from the environment and transport them to receptors within olfactory receptor neurons for processing providing critical ...

  11. The use of compound topical anesthetics: a review.

    Science.gov (United States)

    Kravitz, Neal D

    2007-10-01

    The author reviewed the history of, federal regulations regarding, risks of and adverse drug reactions of five compound topical anesthetics: tetracaine, adrenaline/epinephrine and cocaine (TAC); lidocaine, adrenaline/epinephrine and tetracaine (LET); lidocaine, tetracaine and phenylephrine (TAC 20 percent Alternate); lidocaine, prilocaine and tetracaine (Profound); and lidocaine, prilocaine, tetracaine and phenylephrine with thickeners (Profound PET). The author reviewed clinical trials, case reports, descriptive articles, and U.S. Food and Drug Administration (FDA) regulations and recent public advisory warnings regarding the federal approval of and risks associated with the use of compound topical anesthetics. Compound topical anesthetics are neither FDA-regulated nor -unregulated. Some compounding pharmacies bypass the new FDA drug approval process, which is based on reliable scientific data and ensures that a marketed drug is safe, effective, properly manufactured and accurately labeled. Two deaths have been attributed to the lay use of compound topical anesthetics. In response, the FDA has announced the strengthening of its efforts against unapproved drug products. Compound topical anesthetics may be an effective alternative to local infiltration for some minimally invasive dental procedures; however, legitimate concerns exist in regard to their safety. Until they become federally regulated, compound topical anesthetics remain unapproved drug products whose benefits may not outweigh their risks for dental patients.

  12. Vasoconstriction Potency Induced by Aminoamide Local Anesthetics Correlates with Lipid Solubility

    Directory of Open Access Journals (Sweden)

    Hui-Jin Sung

    2012-01-01

    Full Text Available Aminoamide local anesthetics induce vasoconstriction in vivo and in vitro. The goals of this in vitro study were to investigate the potency of local anesthetic-induced vasoconstriction and to identify the physicochemical property (octanol/buffer partition coefficient, pKa, molecular weight, or potency of local anesthetics that determines their potency in inducing isolated rat aortic ring contraction. Cumulative concentration-response curves to local anesthetics (levobupivacaine, ropivacaine, lidocaine, and mepivacaine were obtained from isolated rat aorta. Regression analyses were performed to determine the relationship between the reported physicochemical properties of local anesthetics and the local anesthetic concentration that produced 50% (ED50 of the local anesthetic-induced maximum vasoconstriction. We determined the order of potency (ED50 of vasoconstriction among local anesthetics to be levobupivacaine > ropivacaine > lidocaine > mepivacaine. The relative importance of the independent variables that affect the vasoconstriction potency is octanol/buffer partition coefficient > potency > pKa > molecular weight. The ED50 in endothelium-denuded aorta negatively correlated with the octanol/buffer partition coefficient of local anesthetics (r2=0.9563; P<0.001. The potency of the vasoconstriction in the endothelium-denuded aorta induced by local anesthetics is determined primarily by lipid solubility and, in part, by other physicochemical properties including potency and pKa.

  13. Implications of Climate Volatility for Agricultural Commodity Markets in the Presence of Biofuel Mandates

    Science.gov (United States)

    Verma, M.; Diffenbaugh, N. S.; Hertel, T. W.; Beckman, J.

    2011-12-01

    In presence of bio-fuels, link between energy and agricultural commodity markets has become more complex. An increase in ethanol production to minimum 15bn gallons a year - Renewable Fuel Standard (RFS) and current technically permissible maximum 10% blending limit - Blend Wall (BW); make the link even stronger. If oil prices in future do not rise significantly from their current levels, this minimum production requirement would likely be binding. In such a scenario any fluctuation in crop production will have to be absorbed by the non-ethanol usage of the crop and would translate into crop prices adjusting to clear the markets and therefore the commodity prices will be more volatile. At high oil prices it is possible that the BW may become binding, severing the link between oil prices and commodity prices as well, potentially leading to higher price volatility. Hertel and Beckman (2010) find that, with both RFS and BW simultaneously binding, corn price volatility due to supply side shocks (which could arise from extreme climate events) could be more than 50% as large as in the absence of bio-fuel policies. So energy markets are important determinants of agricultural commodity price volatility. This proposal intends to introduce the increased supply side volatility on account of climate change and volatility, in the framework. Global warming on account of increased GHG concentrations is expected to increase the intensity and frequency of hot extremes in US (Diffenbaugh et al. 2008) and therefore affect corn yields. With supply shocks expected to increase, binding RFS and BW will exacerbate the volatility, while if they are non-binding then the price changes could be cushioned. We propose to model the impacts of climate changes and volatility on commodity prices by linking three main components - a. Projections for change in temperature and precipitation using climate model b. A statistical model to predict impacts of change in climate variable on corn yields in US

  14. Management of exposure to waste anesthetic gases.

    Science.gov (United States)

    Smith, Francis Duval

    2010-04-01

    Anesthetic agents were developed in the 1700s, and nitrous oxide was first used in 1884. Research on the effects of waste anesthetic gas exposure started appearing in the literature in 1967. Short-term exposure causes lethargy and fatigue, and long-term exposure may be linked to spontaneous abortion, congenital abnormalities, infertility, premature births, cancer, and renal and hepatic disease. Today, perioperative staff members are exposed to trace amounts of waste anesthetic gas, and although this exposure cannot be eliminated, it can be controlled. Health care facilities are required to develop, implement, measure, and control practices to reduce anesthetic gas exposure to the lowest practical level. Exposure levels must be measured every six months and maintained at less than 25 parts per million for nitrous oxide and 2 parts per million for halogenated agents to be compliant with Occupational Safety and Health Administration standards. Copyright 2010 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  15. Nocebo-induced hyperalgesia during local anesthetic injection.

    Science.gov (United States)

    Varelmann, Dirk; Pancaro, Carlo; Cappiello, Eric C; Camann, William R

    2010-03-01

    Common practice during local anesthetic injection is to warn the patient using words such as: "You will feel a big bee sting; this is the worst part." Our hypothesis was that using gentler words for administration of the local anesthetic improves pain perception and patient comfort. One hundred forty healthy women at term gestation requesting neuraxial analgesia were randomized to either a "placebo" ("We are going to give you a local anesthetic that will numb the area and you will be comfortable during the procedure") or "nocebo" ("You are going to feel a big bee sting; this is the worst part of the procedure") group. Pain was assessed immediately after the local anesthetic skin injection using verbal analog scale scores of 0 to 10. Median verbal analog scale pain scores were lower when reassuring words were used compared with the harsher nocebo words (3 [2-4] vs 5 [3-6]; P words improves the subjective experience during invasive procedures.

  16. Anesthetic salts used in dentistry: a literature review

    Directory of Open Access Journals (Sweden)

    Guilherme Klein Parise

    2017-08-01

    Full Text Available Local anesthetics allow a better and suitable control of pain in patients that submit to dental treatments. The pharmacology of local anesthetics is too complex, therefore it is important to know how to select the correct drug to each procedure to be accomplished. Thus, it is concluded that the production of a literary review material is of great relevance in order to gather current and important information about the local anesthetics most used in dentistry.

  17. Comparison of anesthetic agents in the sea otter

    Energy Technology Data Exchange (ETDEWEB)

    Williams, T.D.; Kocher, F.H.

    1978-01-01

    Five anesthetic agents (CI744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

  18. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  19. Challenges Encountered Using Ophthalmic Anesthetics in Space Medicine

    Science.gov (United States)

    Bayuse, T.; Law, J.; Alexander, D.; Moynihan, S.; LeBlanc, C.; Langford, K.; Magalhaes, L.

    2015-01-01

    On orbit, ophthalmic anesthetics are used for tonometry and off-nominal corneal examinations. Proparacaine has been flown traditionally. However, the manufacturers recently changed its storage requirements from room temperature storage to refrigerated storage to preserve stability and prolong the shelf-life. Since refrigeration on orbit is not readily available and there were stability concerns about flying proparacaine unrefrigerated, tetracaine was selected as an alternative ophthalmic anesthetic in 2013. We will discuss the challenges encountered flying and using these anesthetics on the International Space Station.

  20. Local Anesthetics: Review of Pharmacological Considerations

    Science.gov (United States)

    Becker, Daniel E; Reed, Kenneth L

    2012-01-01

    Local anesthetics have an impressive history of efficacy and safety in medical and dental practice. Their use is so routine, and adverse effects are so infrequent, that providers may understandably overlook many of their pharmacotherapeutic principles. The purpose of this continuing education article is to provide a review and update of essential pharmacology for the various local anesthetic formulations in current use. Technical considerations will be addressed in a subsequent article. PMID:22822998

  1. Addition of lacal anesthetics to contrast media. Pt. 2

    International Nuclear Information System (INIS)

    Nilsson, P.; Almen, T.; Golman, K.; Jonsson, K.; Nyman, U.; Malmoe Allmaenna Sjukhus

    1988-01-01

    The acute intravenous toxicity (i.v. LD 50 ) of solutions of the ratio 1.5 contrast media metrizoate or diatrizoate and the ratio 3.0 contrast medium metrizamide was determined in mice with and without the addition of local anesthetics to the solutions. The two local anesthetics mepivacaine or lidocaine were added to final concentrations up to 2.0 mg/ml of the contrast medium solutions. This corresponds to clinically used concentrations. All additions of local anesthetics to the solutions increased the mortalities caused by the contrast medium solutions. Addition of local anesthetics to a final concentration of 2 mg/ml approximately doubled the acute intravenous toxicity of the contrast media. The ratio 3 contrast media produce less hypertonic solutions than the ratio 1.5 contrast media and should be preferred for angiography because they cause less pain and do not require the addition of local anesthetics which increase the acute toxicity of the solutions. (orig.)

  2. Life cycle greenhouse gas emissions of anesthetic drugs.

    Science.gov (United States)

    Sherman, Jodi; Le, Cathy; Lamers, Vanessa; Eckelman, Matthew

    2012-05-01

    Anesthesiologists must consider the entire life cycle of drugs in order to include environmental impacts into clinical decisions. In the present study we used life cycle assessment to examine the climate change impacts of 5 anesthetic drugs: sevoflurane, desflurane, isoflurane, nitrous oxide, and propofol. A full cradle-to-grave approach was used, encompassing resource extraction, drug manufacturing, transport to health care facilities, drug delivery to the patient, and disposal or emission to the environment. At each stage of the life cycle, energy, material inputs, and emissions were considered, as well as use-specific impacts of each drug. The 4 inhalation anesthetics are greenhouse gases (GHGs), and so life cycle GHG emissions include waste anesthetic gases vented to the atmosphere and emissions (largely carbon dioxide) that arise from other life cycle stages. Desflurane accounts for the largest life cycle GHG impact among the anesthetic drugs considered here: 15 times that of isoflurane and 20 times that of sevoflurane on a per MAC-hour basis when administered in an O(2)/air admixture. GHG emissions increase significantly for all drugs when administered in an N(2)O/O(2) admixture. For all of the inhalation anesthetics, GHG impacts are dominated by uncontrolled emissions of waste anesthetic gases. GHG impacts of propofol are comparatively quite small, nearly 4 orders of magnitude lower than those of desflurane or nitrous oxide. Unlike the inhaled drugs, the GHG impacts of propofol primarily stem from the electricity required for the syringe pump and not from drug production or direct release to the environment. Our results reiterate previous published data on the GHG effects of these inhaled drugs, while providing a life cycle context. There are several practical environmental impact mitigation strategies. Desflurane and nitrous oxide should be restricted to cases where they may reduce morbidity and mortality over alternative drugs. Clinicians should avoid

  3. Stochastic volatility of volatility in continuous time

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Veraart, Almut

    This paper introduces the concept of stochastic volatility of volatility in continuous time and, hence, extends standard stochastic volatility (SV) models to allow for an additional source of randomness associated with greater variability in the data. We discuss how stochastic volatility...... of volatility can be defined both non-parametrically, where we link it to the quadratic variation of the stochastic variance process, and parametrically, where we propose two new SV models which allow for stochastic volatility of volatility. In addition, we show that volatility of volatility can be estimated...

  4. Detomidine reduces isoflurane anesthetic requirement (MAC) in horses.

    Science.gov (United States)

    Steffey, Eugene P; Pascoe, Peter J

    2002-10-01

    To quantitate the dose- and time-related magnitude of the anesthetic sparing effect of, and selected physiological responses to detomidine during isoflurane anesthesia in horses. Randomized cross-over study. Three, healthy, young adult horses weighing 485 ± 14 kg. Horses were anesthetized on two occasions to determine the minimum alveolar concentration (MAC) of isoflurane in O 2 and then to measure the anesthetic sparing effect (time-related MAC reduction) following IV detomidine (0.03 and 0.06 mg kg -1 ). Selected common measures of cardiopulmonary function, blood glucose and urinary output were also recorded. Isoflurane MAC was 1.44 ± 0.07% (mean ± SEM). This was reduced by 42.8 ± 5.4% and 44.8 ± 3.0% at 83 ± 23 and 125 ± 36 minutes, respectively, following 0.03 and 0.06 mg kg -1 , detomidine. The MAC reduction was detomidine dose- and time-dependent. There was a tendency for mild cardiovascular and respiratory depression, especially following the higher detomidine dose. Detomidine increased both blood glucose and urine flow; the magnitude of these changes was time- and dose-dependent CONCLUSIONS: Detomidine reduces anesthetic requirement for isoflurane and increases blood glucose concentration and urine flow in horses. These changes were dose- and time-related. The results imply potent anesthetic sparing actions by detomidine. The detomidine-related increased urine flow should be considered in designing anesthetic protocols for individual horses. Copyright © 2002 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

  5. Validation of the bispectral index as an indicator of anesthetic depth in Thoroughbred horses anesthetized with sevoflurane.

    Science.gov (United States)

    Tokushige, Hirotaka; Kakizaki, Masashi; Ode, Hirotaka; Okano, Atsushi; Okada, Jun; Kuroda, Taisuke; Wakuno, Ai; Ohta, Minoru

    2016-01-01

    To evaluate the bispectral index (BIS) as an indicator of anesthetic depth in Thoroughbred horses, BIS values were measured at multiple stages of sevoflurane anesthesia in five horses anesthetized with guaifenesin and thiopental following premedication with xylazine. There was no significant difference between the BIS values recorded at end-tidal sevoflurane concentrations of 2.8% (median 60 ranging from 47 to 68) and 3.5% (median 71 ranging from 49 to 82) in anesthetized horses. These BIS values during anesthesia were significantly lower (Phorses (median 98 ranging from 98 to 98) or sedated horses (median 92 ranging from 80 to 93). During the recovery phase, the BIS values gradually increased over time but did not significantly increase until the horses showed movement. In conclusion, the BIS value could be useful as an indicator of awakening during the recovery period in horses, as previous reported.

  6. Intravenous sub-anesthetic ketamine for perioperative analgesia

    Directory of Open Access Journals (Sweden)

    Andrew W Gorlin

    2016-01-01

    Full Text Available Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine′s metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain.

  7. The cholinergic ligand binding material of axonal membranes

    International Nuclear Information System (INIS)

    Mautner, H.G.; Coronado, R.; Jumblatt, J.E.

    1986-01-01

    Choline acetyltransferase and acetylcholinesterase, the enzymes responsible for the synthesis and hydrolysis of ACh, are present in nerve fibers. In crustacean peripheral nerves, release of ACh from cut nerve fibers has been demonstrated. Previously closed membrane vesicles have been prepared from lobster walking leg nerve plasma membrane and saturable binding of cholinergic agonsist and antagonists to such membranes have been demonstrated. This paper studies this axonal cholinergic binding material, and elucidates its functions. The binding of tritium-nicotine to lobster nerve plasma membranes was antagonized by a series of cholinergic ligands as well as by a series of local anesthetics. This preparation was capable of binding I 125-alpha-bungarotoxin, a ligand widely believed to be a specific label for nicotinic ACh receptor. The labelling of 50 K petide band with tritium-MBTA following disulfide reduction is illustrated

  8. Anesthetic equipment, facilities and services available for pediatric ...

    African Journals Online (AJOL)

    Background: Facilities and equipment are known to contribute to improved patient care and outcome. Hospitals for sub‑specialized pediatric anesthetic service are routinely available worldwide. In Nigeria, such hospitals now exist. It is therefore relevant to study the facilities and equipment available for pediatric anesthetic ...

  9. [Anesthetic management of four patients with Fournier syndrome].

    Science.gov (United States)

    Sato, Rui; Tomioka, Toshiya; Orii, Ryo; Yamada, Yoshitsugu

    2008-03-01

    We experienced anesthetic managements of four patients with Fournier syndrome. In the anesthetic management of the patients with Fournier syndrome the following three points should be kept in mind; (a) the necessity of careful preoperative examination, (b) the better anesthesia, and (c) the careful postoperative care.

  10. THE EFFECT OF LOCAL ANESTHETICS ON TEAR PRODUCTION

    African Journals Online (AJOL)

    that local anesthetics measure only basic secretion thus reducing normal tear production/secretion, which is both reflex and basic. This could be attributed to the fact that local anesthetics have an adrenergic potentiating effects and because lacrimal fluid receive a preganglionic parasympathetic supply from lacrimal muscles ...

  11. Blood profiles in unanesthetized and anesthetized guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Williams, Wendy R; Johnston, Matthew S; Higgins, Sarah; Izzo, Angelo A; Kendall, Lon V

    2016-01-01

    The guinea pig is a common animal model that is used in biomedical research to study a variety of systems, including hormonal and immunological responses, pulmonary physiology, corticosteroid response and others. However, because guinea pigs are evolutionarily a prey species, they do not readily show behavioral signs of disease, which can make it difficult to detect illness in a laboratory setting. Minimally invasive blood tests, such as complete blood counts and plasma biochemistry assays, are useful in both human and veterinary medicine as an initial diagnostic technique to rule in or rule out systemic illness. In guinea pigs, phlebotomy for such tests often requires that the animals be anesthetized first. The authors evaluated hematological and plasma biochemical effects of two anesthetic agents that are commonly used with guinea pigs in a research setting: isoflurane and a combination of ketamine and xylazine. Hematological and plasma biochemical parameters were significantly different when guinea pigs were under either anesthetic, compared to when they were unanesthetized. Plasma proteins, liver enzymes, white blood cells and red blood cells appeared to be significantly altered by both anesthetics, and hematological and plasma biochemical differences were greater when guinea pigs were anesthetized with the combination of ketamine and xylazine than when they were anesthetized with isoflurane. Overall these results indicate that both anesthetics can significantly influence hematological and plasma biochemical parameters in guinea pigs.

  12. Dose-Dependent Protective Effect of Inhalational Anesthetics Against Postoperative Respiratory Complications

    DEFF Research Database (Denmark)

    Grabitz, Stephanie D; Farhan, Hassan N; Ruscic, Katarina J

    2017-01-01

    OBJECTIVES: Inhalational anesthetics are bronchodilators with immunomodulatory effects. We sought to determine the effect of inhalational anesthetic dose on risk of severe postoperative respiratory complications. DESIGN: Prospective analysis of data on file in surgical cases between January 2007...... with endotracheal intubation. INTERVENTIONS: Median effective dose equivalent of inhalational anesthetics during surgery (derived from mean end-tidal inhalational anesthetic concentrations). MEASUREMENTS AND MAIN RESULTS: Postoperative respiratory complications occurred in 6,979 of 124,497 cases (5.61%). High...... inhalational anesthetic dose of 1.20 (1.13-1.30) (median [interquartile range])-fold median effective dose equivalent versus 0.57 (0.45-0.64)-fold median effective dose equivalent was associated with lower odds of postoperative respiratory complications (odds ratio, 0.59; 95% CI, 0.53-0.65; p

  13. Anesthetic neuroprotection: antecedents and an appraisal of preclinical and clinical data quality.

    Science.gov (United States)

    Ishida, Kazuyoshi; Berger, Miles; Nadler, Jacob; Warner, David S

    2014-01-01

    Anesthetics have been studied for nearly fifty years as potential neuroprotective compounds in both perioperative and resuscitation medicine. Although anesthetics present pharmacologic properties consistent with preservation of brain viability in the context of an ischemic insult, no anesthetic has been proven efficacious for neuroprotection in humans. After such effort, it could be concluded that anesthetics are simply not neuroprotective in humans. Moreover, pharmacologic neuroprotection with non-anesthetic drugs has also repeatedly failed to be demonstrated in human acute brain injury. Recent focus has been on rectification of promising preclinical neuroprotection data and subsequent failed clinical trials. This has led to consensus guidelines for the process of transferring purported therapeutics from bench to bedside. In this review we first examined the history of anesthetic neuroprotection research. Then, a systematic review was performed to identify major clinical trials of anesthetic neuroprotection. Both the preclinical neuroprotection portfolio cited to justify a clinical trial and the design and conduct of that clinical trial were evaluated using modern standards that include the Stroke Therapy Academic Industry Roundtable (STAIR) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. In publications intended to define anesthetic neuroprotection, we found overall poor quality of both preclinical efficacy analysis portfolios and clinical trial designs and conduct. Hence, using current translational research standards, it was not possible to conclude from existing data whether anesthetics ameliorate perioperative ischemic brain injury. Incorporation of advances in translational neuroprotection research conduct may provide a basis for more definitive and potentially successful clinical trials of anesthetics as neuroprotectants.

  14. Cell shape changes induced by cationic anesthetics

    Science.gov (United States)

    1976-01-01

    The effects of local anesthetics on cultivated macrophages were studied in living preparations and recorded in still pictures and time-lapse cine-micrographs. Exposure to 12mM lidocaine or 1.5 mM tetracaine resulted in rounding in 10-15 min. Rounding was characterized by cell contraction, marked increase in retraction fibrils, withdrawal of cell processes, and, in late stages, pulsation-like activity and zeiosis. Cells showed appreciable membrane activity as they rounded. Respreading was complete within 15 min of perfusion in drug-free medium and entailed a marked increase in surface motility over control periods. As many as eight successive cycles of rounding and spreading were obtained with lidocaine without evidence of cell damage. The effects of anesthetics were similar to those observed with EDTA, but ethylene- glycol-bis(beta-aminoethylether)-N, N'-tetraacetic acid-Mg was ineffective. Rounding was also induced by benzocaine, an anesthetic nearly uncharged at pH 7.0. Quaternary (nondischargeable) compounds were of low activity, presumably because they are slow permeants. Lidocaine induced rounding at 10 degrees C and above but was less effective at 5 degrees C and ineffective at 0 degrees C. Rounding by the anesthetic was also obtained in media depleted or Na or enriched with 10 mM Ca or Mg. The latter finding, together with the failure of tetrodotoxin to induce rounding, suggests that the anesthetic effect is unrelated to inhibition of sodium conductance. It is possible that the drugs influence divalent ion fluxes or some component of the contractile cells' machinery, but a metabolic target of action cannot yet be excluded. PMID:814194

  15. ANESTHETIC MANAGEMENT FOR A PATIENT WITH ACUTE INTERMITTENT PORPHYRIA

    Directory of Open Access Journals (Sweden)

    Nenad Savić

    2010-09-01

    Full Text Available Acute intermittent porphyria is a rare metabolic disorder resulting from a partial deficiency of porphobilinogen deaminase, enzyme in the heme biosynthetic pathway. Its inheritance is autosomal dominant. A deficiency of porphobilinogen deaminase is not sufficient by its self to produce acute intermittent porphyria, and other activating factors must also be present. These include some drugs, hormones, infection, injury and alcohol. Besides others, anesthetics have been implicated in the triggering of a number of severe porphyric reactions. Although there is no clinical evidence, the fear of hypothesized porphyrinogenicity of repetitive anesthetics exposures still remains. Despite these doubts, we report here the case of uneventful repeated exposure to anesthetics in a patient suffering from acute intermittent porphyria, within a fifteen- month period. On both occasions, the patient was safely exposed to certain anesthetics included: propofol, sevoflurane, rocuronium, midazolam and fentanyl.

  16. Gas-liquid partitioning of halogenated volatile organic compounds in aqueous cyclodextrin solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ondo, Daniel; Barankova, Eva [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dohnal, Vladimir, E-mail: dohnalv@vscht.cz [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2011-08-15

    Highlights: > Binding of halogenated VOCs with cyclodextrins examined through g-l partitioning. > Complex stabilities reflect host-guest size matching and hydrophobic interaction. > Presence of halogens in the guest molecule stabilizes the binding. > Thermodynamic origin of the binding varies greatly among the systems studied. > Results obey the guest-CD global enthalpy-entropy compensation relationship. - Abstract: Gas-liquid partitioning coefficients (K{sub GL}) were measured for halogenated volatile organic compounds (VOCs), namely 1-chlorobutane, methoxyflurane, pentafluoropropan-1-ol, heptafluorobutan-1-ol, {alpha},{alpha},{alpha}-trifluorotoluene, and toluene in aqueous solutions of natural {alpha}-, {beta}-, and {gamma}-cyclodextrins (CDs) at temperatures from (273.35 to 326.35) K employing the techniques of headspace gas chromatography and inert gas stripping. The binding constants of the 1:1 inclusion complex formation between the VOCs and CDs were evaluated from the depression of the VOCs volatility as a function of CD concentration. The host-guest size matching and the hydrophobic interaction concept were used to rationalize the observed widely different affinity of the VOC-CD pairs to form the inclusion complex. The enthalpic and entropic component of the standard Gibbs free energy of complex formation as derived from the temperature dependence of the binding constant indicate the thermodynamic origin of the binding to vary greatly among the systems studied, but follow the global enthalpy-entropy compensation relationships reported previously in the literature.

  17. Tolerance to acute isovolemic hemodilution. Effect of anesthetic depth

    NARCIS (Netherlands)

    van der Linden, Philippe; de Hert, Stefan; Mathieu, Nathalie; Degroote, Françoise; Schmartz, Denis; Zhang, Haibo; Vincent, Jean-Louis

    2003-01-01

    BACKGROUND: Acceptance of a lower transfusion trigger in the perioperative period requires study of the effects of anesthetic depth on the tolerance to acute isovolemic anemia. Anesthetic agents with negative effects on the cardiovascular system may exert proportionately greater depressant effects

  18. Toxic keratopathy due to abuse of topical anesthetic drugs.

    Science.gov (United States)

    Yeniad, Baris; Canturk, Serife; Esin Ozdemir, Fatma; Alparslan, Nilufer; Akarcay, Koray

    2010-06-01

    To describe 8 cases of toxic keratopathy due to abuse of topical anesthetic drugs. Clinical findings from patients with toxic keratopathy were investigated retrospectively. Two patients had toxic keratopathy bilaterally. Five of 8 patients had an ocular history of a corneal foreign body, 1 had basal membrane dystrophy, 1 had ultraviolet radiation, and 1 had chemical burn. All patients had undergone psychiatric consultation. Four patients had anxiety disorder and 1 had bipolar disease. Clinical signs were improved in all patients with discontinuation of topical anesthetic drug use along with adjunctive psychiatric treatment. Penetrating keratoplasty was performed in 2 patients. Toxic keratopathy due to topical anesthetic abuse is a curable disease. Early diagnosis and prevention of topical anesthetic drug use are the most important steps in the treatment of this condition. As these patients commonly exhibit psychiatric disorders, adjunctive psychiatric treatment may help to break the chemical addiction.

  19. Probing the molecular forces involved in binding of selected volatile flavour compounds to salt-extracted pea proteins.

    Science.gov (United States)

    Wang, Kun; Arntfield, Susan D

    2016-11-15

    Molecular interactions between heterologous classes of flavour compounds with salt-extracted pea protein isolates (PPIs) were determined using various bond disrupting agents followed by GC/MS analysis. Flavour bound by proteins decreased in the order: dibutyl disulfide>octanal>hexyl acetate>2-octanone=benzaldehyde. Benzaldehyde, 2-octanone and hexyl acetate interacted non-covalently with PPIs, whereas octanal bound PPIs via covalent and non-covalent forces. Dibutyl disulfide reacted with PPIs covalently, as its retention was not diminished by urea and guanidine hydrochloride. Using propylene glycol, H-bonding and ionic interactions were implicated for hexyl acetate, benzaldehyde, and 2-octanone. A protein-destabilising salt (Cl3CCOONa) reduced bindings for 2-octanone, hexyl acetate, and benzaldehyde; however, retention for octanal and dibutyl disulfide increased. Conversely, a protein-stabilising salt (Na2SO4) enhanced retention for benzaldehyde, 2-octanone, hexyl acetate and octanal. Formation of a volatile flavour by-product, 1-butanethiol, from dibutyl disulfide when PPIs were treated with dithiothreitol indicated occurrence of sulfhydryl-disulfide interchange reactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Comparison of use of an infrared anesthetic gas monitor and refractometry for measurement of anesthetic agent concentrations.

    Science.gov (United States)

    Ambrisko, Tamas D; Klide, Alan M

    2011-10-01

    To assess agreement between anesthetic agent concentrations measured by use of an infrared anesthetic gas monitor (IAGM) and refractometry. SAMPLE-4 IAGMs of the same type and 1 refractometer. Mixtures of oxygen and isoflurane, sevoflurane, desflurane, or N(2)O were used. Agent volume percent was measured simultaneously with 4 IAGMs and a refractometer at the common gas outlet. Measurements obtained with each of the 4 IAGMs were compared with the corresponding refractometer measurements via the Bland-Altman method. Similarly, Bland-Altman plots were also created with either IAGM or refractometer measurements and desflurane vaporizer dial settings. Bias ± 2 SD for comparisons of IAGM and refractometer measurements was as follows: isoflurane, -0.03 ± 0.18 volume percent; sevoflurane, -0.19 ± 0.23 volume percent; desflurane, 0.43 ± 1.22 volume percent; and N(2)O, -0.21 ± 1.88 volume percent. Bland-Altman plots comparing IAGM and refractometer measurements revealed nonlinear relationships for sevoflurane, desflurane, and N(2)O. Desflurane measurements were notably affected; bias ± limits of agreement (2 SD) were small (0.1 ± 0.22 volume percent) at < 12 volume percent, but both bias and limits of agreement increased at higher concentrations. Because IAGM measurements did not but refractometer measurements did agree with the desflurane vaporizer dial settings, infrared measurement technology was a suspected cause of the nonlinear relationships. Given that the assumption of linearity is a cornerstone of anesthetic monitor calibration, this assumption should be confirmed before anesthetic monitors are used in experiments.

  1. Scientometrics of anesthetic drugs and their techniques of administration, 1984–2013

    Directory of Open Access Journals (Sweden)

    Vlassakov KV

    2014-12-01

    Full Text Available Kamen V Vlassakov, Igor Kissin Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Abstract: The aim of this study was to assess progress in the field of anesthetic drugs over the past 30 years using scientometric indices: popularity indices (general and specific, representing the proportion of articles on a drug relative to all articles in the field of anesthetics (general index or the subfield of a specific class of anesthetics (specific index; index of change, representing the degree of growth in publications on a topic from one period to the next; index of expectations, representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000 biomedical journals covered by PubMed; and index of ultimate success, representing a publication outcome when a new drug takes the place of a common drug previously used for the same purpose. Publications on 58 topics were assessed during six 5-year periods from 1984 to 2013. Our analysis showed that during 2009–2013, out of seven anesthetics with a high general popularity index (≥2.0, only two were introduced after 1980, ie, the inhaled anesthetic sevoflurane and the local anesthetic ropivacaine; however, only sevoflurane had a high index of expectations (12.1. Among anesthetic adjuncts, in 2009–2013, only one agent, sugammadex, had both an extremely high index of change (>100 and a high index of expectations (25.0, reflecting the novelty of its mechanism of action. The index of ultimate success was positive with three anesthetics, ie, lidocaine, isoflurane, and propofol, all of which were introduced much longer than 30 years ago. For the past 30 years, there were no new anesthetics that have produced changes in scientometric indices indicating real progress. Keywords: anesthetics, anesthetic adjuvants, mortality, safety margins, therapeutic indices

  2. Evaluation of local anesthetic and antipyretic activities of Cinchona ...

    African Journals Online (AJOL)

    Purpose: To evaluate the local anesthetic and antipyretic activities of an aqueous extract of Cinchona officinalis (C. officinalis) in experimental animal models. Methods: Various doses of the aqueous extract was tested for its local anesthetic activity in guinea pigs and frogs using intracutaneous and plexus anesthesia, ...

  3. Mechanism of sodium channel block by local anesthetics, antiarrhythmics, and anticonvulsants.

    Science.gov (United States)

    Tikhonov, Denis B; Zhorov, Boris S

    2017-04-03

    Local anesthetics, antiarrhythmics, and anticonvulsants include both charged and electroneutral compounds that block voltage-gated sodium channels. Prior studies have revealed a common drug-binding region within the pore, but details about the binding sites and mechanism of block remain unclear. Here, we use the x-ray structure of a prokaryotic sodium channel, NavMs, to model a eukaryotic channel and dock representative ligands. These include lidocaine, QX-314, cocaine, quinidine, lamotrigine, carbamazepine (CMZ), phenytoin, lacosamide, sipatrigine, and bisphenol A. Preliminary calculations demonstrated that a sodium ion near the selectivity filter attracts electroneutral CMZ but repels cationic lidocaine. Therefore, we further docked electroneutral and cationic drugs with and without a sodium ion, respectively. In our models, all the drugs interact with a phenylalanine in helix IVS6. Electroneutral drugs trap a sodium ion in the proximity of the selectivity filter, and this same site attracts the charged group of cationic ligands. At this position, even small drugs can block the permeation pathway by an electrostatic or steric mechanism. Our study proposes a common pharmacophore for these diverse drugs. It includes a cationic moiety and an aromatic moiety, which are usually linked by four bonds. © 2017 Tikhonov and Zhorov.

  4. Emission of volatile organic compounds from petunia flowers is facilitated by an ABC transporter.

    Science.gov (United States)

    Adebesin, Funmilayo; Widhalm, Joshua R; Boachon, Benoît; Lefèvre, François; Pierman, Baptiste; Lynch, Joseph H; Alam, Iftekhar; Junqueira, Bruna; Benke, Ryan; Ray, Shaunak; Porter, Justin A; Yanagisawa, Makoto; Wetzstein, Hazel Y; Morgan, John A; Boutry, Marc; Schuurink, Robert C; Dudareva, Natalia

    2017-06-30

    Plants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of a Petunia hybrida adenosine triphosphate-binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport. PhABCG1 down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  5. Effects of the Trilemma Policies on Inflation, Growth and Volatility in Bulgaria

    Directory of Open Access Journals (Sweden)

    Yu HSING

    2012-04-01

    Full Text Available This paper finds evidence of the trilemma for Bulgaria, suggesting that exchange rate stability, monetary independence and free capital mobility are binding and constrained. The policy combination of exchange rate stability and monetary independence has been prevalent. More exchange rate stability increases the growth rate of real GDP whereas more monetary independence or free capital mobility reduces the growth rate. The inflation rate, inflation volatility and output volatility are not affected by either one of the three trilemma policies.

  6. Effects of mixed volatile fatty acid sodium salt on insulin-like growth ...

    African Journals Online (AJOL)

    Effects of mixed volatile fatty acid sodium salt on insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) in plasma and rumen tissue, and rumen epithelium development in lambs.

  7. Local anesthetic interaction with human ether-a-go-go-related gene (HERG) channels: role of aromatic amino acids Y652 and F656

    DEFF Research Database (Denmark)

    Siebrands, Cornelia C; Schmitt, Nicole; Friederich, Patrick

    2005-01-01

    was to determine the effect of the mutations Y652A and F656A in the putative drug binding region of HERG on the inhibition by bupivacaine, ropivacaine, and mepivacaine. METHODS: The authors examined the inhibition of wild-type and mutant HERG channels, transiently expressed in Chinese hamster ovary cells...... by bupivacaine, ropivacaine, and mepivacaine. Whole cell patch clamp recordings were performed at room temperature. RESULTS: Inhibition of HERG wild-type and mutant channels by the different local anesthetics was concentration dependent, stereoselective, and reversible. The sensitivity decreased in the order...... bupivacaine > ropivacaine > mepivacaine for wild-type and mutant channels. The mutant channels were approximately 4-30 times less sensitive to the inhibitory action of the different local anesthetics than the wild-type channel. The concentration-response data were described by Hill functions (bupivacaine...

  8. Topical anesthetic versus lidocaine infiltration in arteriovenous fistula cannulation

    Directory of Open Access Journals (Sweden)

    Anisha George

    2014-01-01

    Full Text Available Background: End stage renal disease (ESRD patients on maintenance hemodialysis undergo arterio-venous fistula (AVF cannulation prior to each hemodialysis session for blood access. Prior to cannulation lidocaine infiltration is done, which is often perceived as painful. Eutectic mixture of local anesthetic (EMLA has been found to significantly reduce pain associated with radial artery cannulation compared with lidocaine infiltration. Aims: To evaluate the efficacy of EMLA compared to infiltration of lidocaine in hemodialysis patients for AVF cannulation. Materials and Methods: A single-centre, crossover study of patients with an AVF on regular maintenance hemodialysis was performed in the dialysis unit of a tertiary care teaching hospital. The site of AVF, number of attempts for AVF cannulation and cannula insertion time were recorded. The patients were asked about the acceptability of application of the anesthetic, delay between anesthetic and cannulation and to score the pain on cannulation. Results: Fifty patients were included in the study. With the visual analog scale, pain score on infiltration was 4.8. Pain score on cannulation after topical application was 2.9 and after infiltration, 2.0. The number of attempts for cannulation and the cannula insertion time were similar. Anesthesia was more stressful in the injectable group rather than the topical group (P < 0.001. Delay between anesthetic and cannulation was unacceptable in the topical group (P < 0.001. Patient compliance was better during infiltration compared to topical (P < 0.005. Mean pain score during infiltration of anesthetic was significantly higher than cannulation pain after either anesthetic, although pain on cannulation was higher in the topical group (P < 0.001. Conclusions: EMLA offers a suitable alternative to lidocaine infiltration for patients using AVF for blood access.

  9. Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke.

    Science.gov (United States)

    Wang, Hailian; Li, Peiying; Xu, Na; Zhu, Ling; Cai, Mengfei; Yu, Weifeng; Gao, Yanqin

    2016-01-01

    Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

  10. Multivariable analysis of anesthetic factors associated with time to extubation in dogs.

    Science.gov (United States)

    Kleine, Stephanie; Hofmeister, Erik; Egan, Katrina

    2014-12-01

    The purpose of this study was to identify factors that prolong the time to extubation in dogs. Anesthetic records of 900 dogs at a university teaching hospital were searched. Multiple linear regression was used to compare independent predictors (patient demographics, anesthetic and intraoperative variables) with the dependent variable (time to extubation). Induction with propofol (P temperature (P = 0.0000), and by 0.096 minutes for every 1 minute increase in anesthetic duration (P = 0.000). Anesthetic variables, which can be manipulated by the anesthetist, include choice of premedication and induction drugs, hypothermia, and duration of anesthesia. Published by Elsevier Ltd.

  11. Anesthetic Approach to a Child with Noonan's Syndrome

    Directory of Open Access Journals (Sweden)

    Zehra Hatipoglu

    2015-03-01

    Full Text Available Noonan syndrome is characterized by fascial and physical features along with congenital heart disease. In these patients, fascial features include short webbed neck, micrognathia, limited mouth opening and high arched palate. Pulmonary stenosis and hypertrophic obstructive cardiomyopathy are highly prevalent in Noonan's syndrome. The anesthetic management is important because of difficult airway and severe cardiac abnormalities. We reported that anesthetic management of a child with Noonan's syndrome. [Cukurova Med J 2015; 40(Suppl 1: 47-50

  12. Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke

    Directory of Open Access Journals (Sweden)

    Hailian Wang

    2016-01-01

    Full Text Available Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

  13. Economic considerations in the use of inhaled anesthetic agents.

    Science.gov (United States)

    Golembiewski, Julie

    2010-04-15

    To describe the components of and factors contributing to the costs of inhaled anesthesia, basis for quantifying and comparing these costs, and practical strategies for performing pharmacoeconomic analyses and reducing the costs of inhaled anesthetic agents. Inhaled anesthesia can be costly, and some of the variable costs, including fresh gas flow rates and vaporizer settings, are potential targets for cost savings. The use of a low fresh gas flow rate maximizes rebreathing of exhaled anesthetic gas and is less costly than a high flow rate, but it provides less control of the level of anesthesia. The minimum alveolar concentration (MAC) hour is a measure that can be used to compare the cost of inhaled anesthetic agents at various fresh gas flow rates. Anesthesia records provide a sense of patterns of inhaled anesthetic agent use, but the amount of detail can be limited. Cost savings have resulted from efforts to reduce the direct costs of inhaled anesthetic agents, but reductions in indirect costs through shortened times to patient recovery and discharge following the judicious use of these agents are more difficult to demonstrate. The patient case mix, fresh gas flow rates typically used during inhaled anesthesia, availability and location of vaporizers, and anesthesia care provider preferences and practices should be taken into consideration in pharmacoeconomic evaluations and recommendations for controlling the costs of inhaled anesthesia. Understanding factors that contribute to the costs of inhaled anesthesia and considering those factors in pharmacoeconomic analyses and recommendations for use of these agents can result in cost savings.

  14. Response of corn markets to climate volatility under alternative energy futures.

    Science.gov (United States)

    Diffenbaugh, Noah S; Hertel, Thomas W; Scherer, Martin; Verma, Monika

    2012-07-01

    Recent price spikes(1,2) have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades(3,4). However, commodity price volatility is also influenced by other factors(5,6), which may either exacerbate or buffer the effects of climate change. Here we show that US corn price volatility exhibits higher sensitivity to near-term climate change than to energy policy influences or agriculture-energy market integration, and that the presence of a biofuels mandate enhances the sensitivity to climate change by more than 50%. The climate change impact is driven primarily by intensification of severe hot conditions in the primary corn-growing region of the US, which causes US corn price volatility to increase sharply in response to global warming projected over the next three decades. Closer integration of agriculture and energy markets moderates the effects of climate change, unless the biofuels mandate becomes binding, in which case corn price volatility is instead exacerbated. However, in spite of the substantial impact on US corn price volatility, we find relatively small impact on food prices. Our findings highlight the critical importance of interactions between energy policies, energy-agriculture linkages, and climate change.

  15. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  16. Anesthetizing the obese child

    DEFF Research Database (Denmark)

    Mortensen, Anette; Lenz, Katja; Abildstrøm, Hanne

    2011-01-01

    drugs. This has important implications on how to estimate the optimal drug dose. This article offers a review of the literature on definition, prevalence and the pathophysiology of childhood obesity and provides suggestions on preanesthetic evaluation, airway management and dosage of the anesthetic...... drugs in these patients. The authors highlight the need of supplemental studies on various areas of the subject....

  17. A novel approach to scavenging anesthetic gases in rodent surgery.

    Science.gov (United States)

    Nesbitt, Jeffrey C; Krageschmidt, Dale A; Blanco, Michael C

    2013-01-01

    Laboratory animal procedures using gas anesthetics may amass elevated waste gas concentrations in operating rooms if controls are not implemented for capturing and removing the vapors. Area sampling using an infrared analyzer indicated isoflurane concentrations likely to exceed occupational exposure guidelines. Our study showed environmental concentrations of oxygen as high as 40% and isoflurane concentrations >100 ppm when no controls or merely passive controls were utilized. These extraneous isoflurane emissions were determined to be originating from the pre-procedural induction process as well as the gas delivery nose cone. A novel waste gas collection cylinder was designed to enclose the gas delivery nose cone and animal head during the administration of anesthetic gases. The vented cylinder utilized a house vacuum to remove the waste anesthetic gases from the surgical field. A commercially available induction chamber designed to be actively and externally exhausted was used to lower concentrations during the induction process. With implementation of local exhaust ventilation controls, waste anesthetic gas concentrations decreased to below recommended occupational exposure levels. In vitro (sham) testing compared favorably to in vivo measurements validating the reduction capability of active ventilation during rodent anesthetic administration. In vivo isoflurane reductions for the induction chamber emissions, the operating room, and the surgeon's breathing zone were 95%, 60%, and 53%, respectively. The same measurements for an in vitro procedure were 98%, 84%, and 87%, respectively.

  18. Anesthetic activity of Brazilian native plants in silver catfish (Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    Lenise de Lima Silva

    Full Text Available There is an increasing demand for inexpensive and safe anesthetics that can reduce fish stress caused by some procedures such as capture and handling. In this context, the present study evaluated the potential of essential oils (EO of three Brazilian native plants (Hesperozygis ringens, Lippia sidoides and Ocotea acutifolia as anesthetics for the silver catfish - Rhamdia quelen. Moreover, an analysis was made of the chemical composition of these oils and their influence on stress parameter. EO of H. ringens and O. acutifolia were effective as anesthetics, without behavioral side effects. EO of O. acutifolia (150 µL L-1 promoted an increase in blood glucose level. Regarding to the composition, pulegone accounts for 96.63% of the EO of H. ringens, and caryophyllene oxide amounts to 56.90% of the EO of O. acutifolia. Two chemotypes, thymol and carvacrol (68.40% and 67.89%, respectively were verified for EO of L. sidoides. Both samples of EO of L. sidoides showed anesthetic activity in silver catfish, but exposure also caused loss of mucus and mortality. Thus, only the EO of H. ringens and O. acutifolia are advised for anesthetic use

  19. Cardiovascular responses to microinjections of GABA or anesthetics into the rostral ventrolateral medulla of conscious and anesthetized rats

    Directory of Open Access Journals (Sweden)

    Lacerda J.E.C.

    2003-01-01

    Full Text Available The rostral ventrolateral medulla (RVLM contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv anesthetized Wistar rats (300-350 g. In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7. A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl. However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7 or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6 was significantly increased after urethane anesthesia. In contrast, there was no difference between conscious (from 117 ± 4.1 to 92 ± 5.9 mmHg, N = 7 and anesthetized rats (from 123 ± 6.9 to 87 ± 8.7 mmHg, N = 7 when lidocaine (34 nmol/200 nl was microinjected into the RVLM. The heart rate variations were not consistent and only eventually reached significance in conscious or anesthetized rats. The right position of pipettes was confirmed by histology and glutamate microinjection into the RVLM. These findings suggest that in conscious animals the RVLM, in association with the other sympathetic premotor neurons, is responsible for the maintenance of sympathetic vasomotor tone during bilateral RVLM inhibition. Activity of one or more of these premotor neurons outside the RVLM can compensate for the effects of RVLM inhibition. In addition, the effects of lidocaine suggest that fibers passing through the RVLM are involved in the maintenance of blood pressure in conscious animals during RVLM inhibition.

  20. Occurrence of paresthesia after dental local anesthetic administration in the United States.

    Science.gov (United States)

    Garisto, Gabriella A; Gaffen, Andrew S; Lawrence, Herenia P; Tenenbaum, Howard C; Haas, Daniel A

    2010-07-01

    Several studies have suggested that the likelihood of paresthesia may depend on the local anesthetic used. The purpose of this study was to determine if the type of local anesthetic administered had any effect on reports of paresthesia in dentistry in the United States. The authors obtained reports of paresthesia involving dental local anesthetics during the period from November 1997 through August 2008 from the U.S. Food and Drug Administration Adverse Event Reporting System. They used chi(2) analysis to compare expected frequencies, on the basis of U.S. local anesthetic sales data, with observed reports of oral paresthesia. During the study period, 248 cases of paresthesia occurring after dental procedures were reported. Most cases (94.5 percent) involved mandibular nerve block. The lingual nerve was affected in 89.0 percent of cases. Reports involving 4 percent prilocaine and 4 percent articaine were 7.3 and 3.6 times, respectively, greater than expected (chi(2), P paresthesia occurs more commonly after use of 4 percent local anesthetic formulations. These findings are consistent with those reported in a number of studies from other countries. Until further research indicates otherwise, dentists should consider these results when assessing the risks and benefits of using 4 percent local anesthetics for mandibular block anesthesia.

  1. Influence of Ventilation Strategies and Anesthetic Techniques on Regional Cerebral Oximetry in the Beach Chair Position: A Prospective Interventional Study with a Randomized Comparison of Two Anesthetics.

    Science.gov (United States)

    Picton, Paul; Dering, Andrew; Alexander, Amir; Neff, Mary; Miller, Bruce S; Shanks, Amy; Housey, Michelle; Mashour, George A

    2015-10-01

    Beach chair positioning during general anesthesia is associated with cerebral oxygen desaturation. Changes in cerebral oxygenation resulting from the interaction of inspired oxygen fraction (FIO2), end-tidal carbon dioxide (PETCO2), and anesthetic choice have not been fully evaluated in anesthetized patients in the beach chair position. This is a prospective interventional within-group study of patients undergoing shoulder surgery in the beach chair position that incorporated a randomized comparison between two anesthetics. Fifty-six patients were randomized to receive desflurane or total intravenous anesthesia with propofol. Following induction of anesthesia and positioning, FIO2 and minute ventilation were sequentially adjusted for all patients. Regional cerebral oxygenation (rSO2) was the primary outcome and was recorded at each of five set points. While maintaining FIO2 at 0.3 and PETCO2 at 30 mmHg, there was a decrease in rSO2 from 68% (SD, 12) to 61% (SD, 12) (P positioning. The combined interventions of increasing FIO2 to 1.0 and increasing PETCO2 to 45 mmHg resulted in a 14% point improvement in rSO2 to 75% (SD, 12) (P position. There was no significant interaction effect of the anesthetic at the study intervention points. Increasing FIO2 and PETCO2 resulted in a significant increase in rSO2 that overcomes desaturation in patients anesthetized in the beach chair position and that appears independent of anesthetic choice.

  2. Dual effect of local anesthetics on the function of excitable rod outer segment disk membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mashimo, T.; Abe, K.; Yoshiya, I.

    1986-04-01

    The effects of local anesthetics and a divalent cation, Ca2+, on the function of rhodopsin were estimated from the measurements of light-induced proton uptake. The light-induced proton uptake by rhodopsin in the rod outer segment disk membrane was enhanced at lower pH (4) but depressed at higher pHs (6 to 8) by the tertiary amine local anesthetics lidocaine, bupivacaine, tetracaine, and dibucaine. The order of local anesthetic-induced depression of the proton uptake followed that of their clinical anesthetic potencies. The depression of the proton uptake versus the concentration of the uncharged form of local anesthetic nearly describes the same curve for small and large dose of added anesthetic. Furthermore, a neutral local anesthetic, benzocaine, depressed the proton uptake at all pHs between 4 and 7. These results indicate that the depression of the proton uptake is due to the effect of only the uncharged form. It is hypothesized that the uncharged form of local anesthetics interacts hydrophobically with the rhodopsin in the disk membrane. The dual effect of local anesthetics on the proton uptake, on the other hand, suggests that the activation of the function of rhodopsin may be caused by the charged form. There was no significant change in the light-induced proton uptake by rhodopsin when 1 mM of Ca2+ was introduced into the disk membrane at varying pHs in the absence or presence of local anesthetics. This fact indicates that Ca2+ ion does not influence the diprotonating process of metarhodopsin; neither does it interfere with the local anesthetic-induced changes in the rhodopsin molecule.

  3. Anesthetic keratopathy presenting as bilateral Mooren-like ulcers

    Directory of Open Access Journals (Sweden)

    Khakshoor H

    2012-10-01

    Full Text Available Hamid Khakshoor,1 Majid Moshirfar,2 Rachel G Simpson,3 Hamid Gharaee,1 Amir H Vejdani,1 Steven M Christiansen,2 Jason N Edmonds,2 Nicholas L Behunin21Mashhad University of Medical Sciences, Department of Ophthalmology, Mashad, Iran; 2John A Moran Eye Center, University of Utah, Salt Lake City, UT, 3The University of Arizona College of Medicine, Phoenix, AZ, USAAbstract: This observational case report describes the development of bilateral Mooren-like ulcers in a patient with anesthetic keratopathy. A 42-year-old man with a recent history of minor eye trauma and pain self-treated with tetracaine eye drops presented with complaints of acutely worsening vision and severe pain bilaterally. His visual acuity at presentation was limited to hand motion. Slit-lamp examination revealed bilateral epithelial defects at the center of the cornea, and an area of stromal infiltration and thinning with an undermining leading edge resembling a Mooren's ulcer in both eyes. Corneal haze and hypopyon were visible. Anesthetic use was halted immediately and the patient was started on prednisolone and mycophenolate mofetil (Cellcept®, after which visual acuity gradually improved and pain decreased. Despite improvement of symptoms, residual epithelial defects remained, and the patient was ultimately treated with keratoplasty for recovery of vision. We suggest that anesthetic keratopathy should be included in the differential diagnosis for any patient presenting with ring-shaped stromal infiltrates or nonhealing epithelial defects.Keywords: anesthetic abuse, corneal damage, corneal ulceration

  4. Monitoring Anesthetic Depth Modification, Evaluation and Application of the Correlation Dimension

    NARCIS (Netherlands)

    Broek, P.L.C. van den

    2003-01-01

    Anesthesia is administered to patients to facilitate surgical and diagnostic procedures. The anesthesiologist generally determines the amount of anesthetics needed on the basis of body weight. However, the inter-individual variation in sensitivity to anesthetics is wide and the needed level of

  5. Radiographic assessment of laryngeal reflexes in ketamine-anesthetized cats

    International Nuclear Information System (INIS)

    Robinson, E.P.; Johnston, G.R.

    1986-01-01

    The competence of the laryngeal closure reflexes of cats anesthetized with ketamine was assessed. Radiographic evaluations of the respiratory and digestive tracts were made after colloidal barium suspension was instilled into the pharynges of conscious and ketamine-anesthetized cats. There was a significant ketamine dose-related response of spread of contrast medium into the supraglottic laryngeal area and into the stomach 2 minutes after contrast medium was instilled into the pharynx (P less than 0.05). Cats did not aspirate contrast medium into the lower respiratory tract. Three ketamine-anesthetized cats aspirated contrast medium into the subglottic area of the larynx, and 2 of these cats also aspirated the material into the cranial part of the trachea. This material was coughed up and swallowed within 5 minutes. Transit time of contrast medium into the stomach seemed to be increased in 11 of the 15 cats given the larger dosages of ketamine (24, 36, 48 mg/kg of body weight), compared with that in conscious cats and those given ketamine at 12 mg/kg. Competent laryngeal protective reflexes in cats can be maintained with ketamine anesthesia. Contrast radiography could be used as a diagnostic aid in ketamine-anesthetized cats suspected of laryngeal reflex abnormalities

  6. Synthesis and receptor binding studies of (+/-)1-iodo-MK-801

    International Nuclear Information System (INIS)

    Yang, D.J.; Ciliax, B.J.; Van Dort, M.E.; Gildersleeve, D.; Pirat, J.L.; Young, A.B.; Wieland, D.M.

    1989-01-01

    The glutamate analogue N-methyl-D-aspartate (NMDA) binds to a subset of glutamate receptors that are coupled to a voltage-sensitive cation channel. This NMDA-linked channel is the likely binding locus of the potent anticonvulsant MK-801. To develop single-photon emission computed tomography (SPECT) probes of this brain channel, we synthesized (+/)1-iodo-MK-801 and (+/-)1-[ 125 I]iodo-MK-801. The effect of (+/-)1-iodo-MK-801 on ligand binding to the NMDA-linked glutamate receptor site was assessed using a rat brain homogenate assay. (+/-)1-Iodo-MK-801 displaced the dissociative anesthetic ligand [ 3 H]N-[1-(2-thienyl)cyclohexyl]piperidine ([ 3 H]TCP) binding with an IC50 of 1 microM, which is a 10-fold lower binding affinity than that of (+/-)MK-801. In in vivo autoradiographic studies, (+/-)MK-801 failed to block selective uptake of (+/-)1-iodo-MK-801 in rat brain. These results suggest that (+/-)1-iodo-MK-801 may not be a suitable ligand for mapping NMDA-linked glutamate receptor channels

  7. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock m......, a positive or risk-premium effect exists between return and the volatile component, yet the persistent component is not significantly priced for return dynamic process....... markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets...

  8. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    OpenAIRE

    Chen, Jinghui; Kobayashi, Masahito; McAleer, Michael

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The proposed test is a stochastic volatility version of the co-movement test proposed by Engle and Susmel (1993), who investigated whether international equity markets have volatility co-movement using t...

  9. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Boyce, J. W.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Magna, T.; Ni, P.; Tartese, R.; hide

    2017-01-01

    The chapter will begin with an introduction that defines magmatic volatiles (e.g., H, F, Cl, S) versus geochemical volatiles (e.g., K, Rb, Zn). We will discuss our approach of understanding both types of volatiles in lunar samples and lay the ground work for how we will determine the overall volatile budget of the Moon. We will then discuss the importance of endogenous volatiles in shaping the "Newer Views of the Moon", specifically how endogenous volatiles feed forward into processes such as the origin of the Moon, magmatic differentiation, volcanism, and secondary processes during surface and crustal interactions. After the introduction, we will include a re-view/synthesis on the current state of 1) apatite compositions (volatile abundances and isotopic compositions); 2) nominally anhydrous mineral phases (moderately to highly volatile); 3) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar pyroclastic glass beads; 4) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar basalts; 5) volatile (moderately to highly volatile) abundances in and isotopic compositions of melt inclusions; and finally 6) experimental constraints on mineral-melt partitioning of moderately to highly volatile elements under lunar conditions. We anticipate that each section will summarize results since 2007 and focus on new results published since the 2015 Am Min review paper on lunar volatiles [9]. The next section will discuss how to use sample abundances of volatiles to understand the source region and potential caveats in estimating source abundances of volatiles. The following section will include our best estimates of volatile abundances and isotopic compositions (where permitted by available data) for each volatile element of interest in a number of important lunar reservoirs, including the crust, mantle, KREEP, and bulk Moon. The final section of the chapter will focus upon future work, outstanding questions

  10. Oil and stock market volatility: A multivariate stochastic volatility perspective

    International Nuclear Information System (INIS)

    Vo, Minh

    2011-01-01

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: → This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. → The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. → The volatility in each market is very persistent. → Innovations that hit either market can affect the volatility in the other market. → The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  11. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock ma...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....... markets. Their in-mean effects on returns are tested. The empirical results show that the persistent component is much more important for the volatility dynamic process than is the volatile component. However, the volatile component is found to be a significant pricing factor of asset returns for most...

  12. Anesthetic activity of plant essential oils on Cyprinus carpio (koi carp).

    Science.gov (United States)

    Khumpirapang, Nattakanwadee; Pikulkaew, Surachai; Anuchapreeda, Songyot; Okonogi, Siriporn

    2018-03-19

    The aims of this study were to investigate the anesthetic and cytotoxic effects of essential oils (EOs) of Ocimum basilicum (OBO), O. canum (OCO), and O. sanctum (OSO) on Cyprinus carpio (koi carp). For anesthetic effect, induction time to surgical anesthesia and recovery time were determined. For cytotoxicity effect, viability of fish peripheral blood nuclear cells (PBMCs) was investigated. Results indicated that increasing oil concentration caused significant (p OSO at 100, 200, and 300 mg/L gave the induction time of 169.5 ± 10.2, 62.8 ± 2.3, 45.3 ± 2.2 sec, respectively, significantly shorter than OCO, and OBO. The recovery time of anesthetized fish was dose dependent (p OSO and OBO, respectively. Within 10 min contact time of the EOs and fish PBMCs, the fish PBMC viability was higher than 80%. Increase contact time and EO concentration caused an increase in cytotoxicity to fish PBMC. OBO showed less toxic than OSO and OCO. Based on the desired induction and recovery times for anesthetizing koi carp, OBO, OCO, and OSO at 300, 200, and 100 mg/L, respectively were suggested to be the most suitable. It was concluded that OBO, OCO, and OSO can be used as natural anesthetics for fish.

  13. Ring Keratitis Associated With Topical Abuse of a Dilute Anesthetic After Refractive Surgery

    Directory of Open Access Journals (Sweden)

    Yu-Chih Hou

    2009-12-01

    Full Text Available Anesthetic toxic keratitis is rare and presents as a ring keratitis, which is often misdiagnosed as Acanthamoeba keratitis. Here, we report an unusual case of toxic keratitis caused by topical abuse of a dilute anesthetic. A 26-year-old woman presented with bilateral corneal edema, ring infiltrates, pigmented keratic precipitate, Descemet's membrane folding, and strong anterior chamber reactions 2 weeks after laser subepithelial keratomileusis surgery. Tracing back her medical history, topical dilute 0.1% proparacaine was prescribed and frequently used for 1 month. Toxic keratitis was suspected. After discontinuation of the topical anesthetic and initiation of treatment with topical 20% autologous serum, complete corneal epithelialization was achieved within 1 week. Corneal infiltrates and anterior chamber reaction gradually subsided. Vision improved from finger counting to 20/20 in the right eye and 20/25 in the left eye, but confocal microscopy showed decreased corneal endothelial cells. Topical abuse of a dilute topical anesthetic can cause severe toxic keratitis and endothelial cell loss. The physician must be aware of the signs of topical anesthetic abuse and should not prescribe even a dilute anesthetic for long-term use. Autologous serum can help in the recovery of toxic keratitis.

  14. Increased inspiratory pressure for reduction of atelectasis in children anesthetized for CT scan

    International Nuclear Information System (INIS)

    Sargent, Michael A.; Jamieson, Douglas H.; McEachern, Anita M.; Blackstock, Derek

    2002-01-01

    Background: Atelectasis is more frequent and more severe in children anesthetized for CT scan than it is in children sedated for CT scan.Objective: To determine the effect of increased inspiratory pressure on atelectasis during chest CT in anesthetized children. Materials and methods: Atelectasis on chest CT was assessed by two observers in three groups of patients. Group A comprised 13 children (26 lungs) anesthetized at inspiratory pressures up to and including 25 cm H 2 O. Group B included 11 children anesthetized at inspiratory pressures ≥30 cm H 2 O. Group C included 8 children under deep sedation. Results: Atelectasis was significantly more severe in group A than in groups B and C. There was no significant difference between groups B and C. Conclusion: An inspiratory pressure of 30 cm H 2 O is recommended for children anesthetized for CT scan of the chest. (orig.)

  15. Volatility in energy prices

    International Nuclear Information System (INIS)

    Duffie, D.

    1999-01-01

    This chapter with 58 references reviews the modelling and empirical behaviour of volatility in energy prices. Constant volatility and stochastic volatility are discussed. Markovian models of stochastic volatility are described and the different classes of Markovian stochastic volatility model are examined including auto-regressive volatility, option implied and forecasted volatility, Garch volatility, Egarch volatility, multivariate Garch volatility, and stochastic volatility and dynamic hedging policies. Other volatility models and option hedging are considered. The performance of several stochastic volatility models as applied to heating oil, light oil, natural gas, electricity and light crude oil are compared

  16. Cardiac evaluation of anesthetized Grevy's zebras (Equus grevyi).

    Science.gov (United States)

    Adin, Darcy B; Maisenbacher, Herbert W; Ojeda, Nyurka; Fiorello, Christine V; Estrada, Amara H; Prosek, Robert; Citino, Scott B

    2007-02-01

    To determine ECG and echocardiographic measurements in healthy anesthetized Grevy's zebras (Equus grevyi). 20 healthy zebras. Auscultation, base-apex ECG, and echocardiography were performed on anesthetized zebras. Low-grade systolic murmurs were detected in the left basilar region in 4 of 20 zebras. Evaluation of ECGs from 19 zebras revealed sinus rhythm with a predominantly negative QRS complex and a mean +/- SD heart rate of 67 +/- 10 beats/min. Echocardiograms of sufficient image quality were obtained for 16 zebras. Interventricular septal thickness in diastole, left ventricular chamber in diastole and systole, left atrial diameter, and left ventricular mass were significantly and moderately correlated with estimated body weight (r values ranged from 0.650 to 0.884). Detectable swirling of blood in the right and sometimes the left ventricles was detected in 9 of 16 zebras, whereas physiologic regurgitation of blood was detected for the aortic valve in 3 zebras, pulmonary valve in 2 zebras, mitral valve in 2 zebras, and tricuspid valve in 1 zebra. Results of this study provide reference information for use in the cardiac evaluation of anesthetized Grevy's zebras.

  17. Anesthetic success of 1.8ml lidocaine 2% for mandibular tooth extraction. A pilot study

    Directory of Open Access Journals (Sweden)

    Pedro Aravena

    2013-04-01

    Full Text Available Aim: To determine the anesthetic effect of a 1.8ml cartridge of anesthetic lidocaine 2% with epinephrine 1:100,000 in inferior alveolar nerve block (NAI for the extraction in mandibular teeth. Material and methods: A pilot study with analitic design. Participating patients of Dental Emergency Service volunteers from Valdivia-Chile for mandibular teeth extractions attending between May and July of 2010. The anesthetic technique was performed by a dentist using only one cartridge of anesthetic to the NAI. After 15 minutes, the effect was considered effective when anesthetic not require reinforcement with additional anesthesia during extraction of teeth. We analyzed the relationship between success anesthetic effect with sex, age, diagnosis of tooth and type and level of pain observed (chi-square and logistic regression, p<0.05. Results: 62 patients were selected, of which only 47(75.8% was achieved anesthetic success. There was no statistical association with sex, age, type or dental diagnosis and perceived pain. Conclusion: Using a 1.8ml cartridge of anesthesia was effective in three of four patients treated by extraction of mandibular teeth. It suggests further research in relation to the clinical effectiveness of other anesthetics with the same dose in NAI.

  18. Anesthetic-Induced Oxidative Stress and Potential Protection

    Directory of Open Access Journals (Sweden)

    Cheng Wang

    2010-01-01

    Full Text Available Prolonged exposure of developing mammals to general anesthetics affects the N-methyl-D-aspartate (NMDA–type glutamate or γ-aminobutyric acid (GABA receptor systems and enhances neuronal toxicity. Stimulation of immature neurons by NMDA antagonists or GABA agonists is thought to increase overall nervous system excitability and may contribute to abnormal neuronal cell death during development. Although the precise mechanisms by which NMDA antagonists or GABA agonists cause neuronal cell death are still not completely understood, up-regulation of the NMDA receptor subunit NR1 may be an initiative factor in neuronal cell death. It is increasingly apparent that mitochondria lie at the center of the cell death regulation process. Evidence for the role of oxidative stress in anesthetic-induced neurotoxicity has been generated in studies that apply oxidative stress blockers. Prevention of neuronal death by catalase and superoxide dismutase in vitro, or by M40403 (superoxide dismutase mimetic in vivo, supports the contention that the involvement of reactive oxygen species (ROS and the nature of neuronal cell death in rodents is mainly apoptotic. However, more evidence is necessary to in order verify the role of the NMDA receptor subunit NR1 and ROS in anesthetic-induced neurodegeneration.

  19. Increasing topical anesthetic efficacy with microneedle application.

    Science.gov (United States)

    Buhsem, Ömer; Aksoy, Alper; Kececi, Yavuz; Sir, Emin; Güngör, Melike

    2016-10-01

    Since topical anesthetics alone seldom provide adequate analgesia for laser resurfacing procedures, injectable forms of anesthesia are often required. However, their application is uncomfortable for the patient. In this study, it is investigated whether microneedle application would enhance the efficacy of topical anesthetics. Forty-seven patients participated in the study. Topical anesthetic agent EMLA was applied to the whole face of the patients. Microneedle treatment was applied to one side of the face with a roller-type device. Whole-face carbon dioxide laser resurfacing therapy was carried out then. The pain that patients experienced was assessed by using visual analog scale (VAS) method. VAS scores of two sides of the face were compared by using Wilcoxon signed-rank test. The mean of VAS score of the microneedle treated side was 2.1 ± 1.1 while that of the untreated side was 5.9 ± 0.9 and this difference was statistically significant (Wilcoxon signed-rank test, the Z-value is - 5.9683 and the p-value is < 0.001). This study revealed that microneedle application, with a roller-type device, is a safe and easy procedure in providing sufficient anesthesia for facial laser resurfacing without the need for supplementary nerve blocks or injections.

  20. From micro- to nanostructured implantable device for local anesthetic delivery

    Science.gov (United States)

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

  1. Hydrogen-1 NMR relaxation time studies in membrane: anesthetic systems

    International Nuclear Information System (INIS)

    Pinto, L.M.A.; Fraceto, L.; Paula, E. de; Franzoni, L.; Spisni, A.

    1997-01-01

    The study of local anesthetics'(LA) interaction with model phospholipid membranes is justified by the direct correlation between anesthetic's hydrophobicity and its potency/toxicity. By the same reason, uncharged LA species seems to play a crucial role in anesthesia. Most clinically used LA are small amphiphilics with a protonated amine group (pKa around 8). Although both charged (protonated) and uncharged forms can coexist at physiological pH, it has been shown (Lee, Biochim. Biophys. Acta 514:95, 1978; Screier et al. Biochim. Biophys. Acta 769:231, 1984) that the real anesthetic pka can be down-shifted, due to differential partition into membranes, increasing the ratio of uncharged species at pH 7.4. We have measured 1 H-NMR longitudinal relaxation times (T 1 ) for phospholipid and three local anesthetics (tetracaine, lidocaine, benzocaine), in sonicated vesicles at a 3:1 molar ratio. All the LA protons have shown smaller T 1 in this system than in isotropic phases, reflecting LA immobilization caused by insertion in the membrane. T 1 values for the lipid protons in the presence of LA were analyzed, in an attempt to identify specific LA:lipid contact regions. (author)

  2. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity......). Finally, we compute volatility discovery for 30 actively traded stocks in the U.S. and report that Nyse and Arca dominate Nasdaq....

  3. Level Shifts in Volatility and the Implied-Realized Volatility Relation

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; de Magistris, Paolo Santucci

    We propose a simple model in which realized stock market return volatility and implied volatility backed out of option prices are subject to common level shifts corresponding to movements between bull and bear markets. The model is estimated using the Kalman filter in a generalization to the mult......We propose a simple model in which realized stock market return volatility and implied volatility backed out of option prices are subject to common level shifts corresponding to movements between bull and bear markets. The model is estimated using the Kalman filter in a generalization...... to the multivariate case of the univariate level shift technique by Lu and Perron (2008). An application to the S&P500 index and a simulation experiment show that the recently documented empirical properties of strong persistence in volatility and forecastability of future realized volatility from current implied...... volatility, which have been interpreted as long memory (or fractional integration) in volatility and fractional cointegration between implied and realized volatility, are accounted for by occasional common level shifts....

  4. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    NARCIS (Netherlands)

    J. Chen (Jinghui); M. Kobayashi (Masahito); M.J. McAleer (Michael)

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The

  5. Exploring microsolvation of the anesthetic propofol

    NARCIS (Netherlands)

    Leon, I.; Cocinero, E. J.; Millan, J.; Jaeqx, S.; Rijs, A. M.; Lesarri, A.; Castano, F.; Fernandez, J. A.

    2012-01-01

    Propofol (2,6-diisopropylphenol) is a broadly used general anesthetic. By combining spectroscopic techniques such as 1- and 2-color REMPI, UV/UV hole burning, infrared ion-dip spectroscopy (IRIDS) obtained under cooled and isolated conditions with high-level ab initio calculations, detailed

  6. Administration and monitoring of intravenous anesthetics

    NARCIS (Netherlands)

    Sahinovic, Marko M.; Absalom, Anthony R.; Struys, Michel M. R. F.

    2010-01-01

    Purpose of review The importance of accuracy in controlling the dose-response relation for intravenous anesthetics is directly related to the importance of optimizing the efficacy and quality of anesthesia while minimizing adverse drug effects. Therefore, it is important to measure and control all

  7. Methylparaben concentration in commercial Brazilian local anesthetics solutions

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Rodriguez da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo. Separation was performed using high performance liquid chromatography (HPLC with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v, pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v to 0.16% (m/v. One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

  8. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Directory of Open Access Journals (Sweden)

    Armstead Valerie

    2006-11-01

    Full Text Available Abstract Candida albicans is a dimorphic fungus that can grow in yeast morphology or hyphal form depending on the surrounding environment. This ubiquitous fungus is present in skin and mucus membranes as a potential pathogen that under opportunistic conditions causes a series of systemic and superficial infections known as candidiasis, moniliasis or simply candidiasis. There has been a steady increase in the prevalence of candidiasis that is expressed in more virulent forms of infection. Although candidiasis is commonly manifested as mucocutaneous disease, life-threatening systemic invasion by this fungus can occur in every part of the body. The severity of candidal infections is associated with its morphological shift such that the hyphal morphology of the fungus is most invasive. Of importance, aberrant multiplication of Candida yeast is also associated with the pathogenesis of certain mucosal diseases. In this study, we assessed the anti-candidal activity of the volatile anesthetic isoflurane in liquid form in comparison with the anti-fungal agent amphotericin B in an in vitro culture system. Exposure of C. albicans to isoflurane (0.3% volume/volume and above inhibited multiplication of yeast as well as formation of hyphae. These data suggest development of potential topical application of isoflurane for controlling a series of cutaneous and genital infections associated with this fungus. Elucidiation of the mechanism by which isoflurane effects fungal growth could offer therapeutic potential for certain systemic fungal infections.

  9. In vivo binding, pharmacokinetics and metabolism of the selective M2 muscarinic antagonists [3H]AF-DX 116 and [3H]AF-DX 384 in the anesthetized rat

    International Nuclear Information System (INIS)

    Mickala, Patrick; Boutin, Herve; Bellanger, Cecile; Chevalier, Cyril; MacKenzie, Eric T.; Dauphin, Francois

    1996-01-01

    The pharmacokinetics, in vivo binding and metabolism of two M 2 muscarinic receptor antagonists, [ 3 H]AF-DX 116 and [ 3 H]AF-DX 384, were studied in anesthetized rats, which received either the tracer alone or following a saturating injection of atropine. Both radioligands were cleared from the circulation with distribution half-lives of 17 and 14 sec and elimination half-lives of 17 and 40 min for [ 3 H]AF-DX 116 and [ 3 H]AF-DX 384, respectively. A radioactive distribution, predominant in peripheral organs when compared to brain, was found at each time studied after tracer injection. Atropine-displaceable tracer uptake was evidenced at 20-40 min in brain (31%), submandibular glands (26%), spleen (37%) and notably heart (55%) for [ 3 H]AF-DX 116 but only in heart (50%) for [ 3 H]AF-DX 384 at 10-20 min. Regional brain sampling revealed a relatively uniform distribution of [ 3 H]AF-DX 384 and a -45% atropine saturation effect (i.e., specific binding) in the thalamus 20 min after injection. Sequential thin-layer chromatographic studies performed on tissue extracts demonstrated the rapid appearance of labeled metabolites of both radiotracers in brain (but less so in liver) and especially in cardiac tissues, where almost 70% of total radioactivity still corresponded to authentic tracer 40 min after injection. Thus, based on their low blood-brain barrier permeability and the high presence of labeled metabolites in the central nervous system, AF-DX 116 and AF-DX 384 might be more helpful in the study of M 2 muscarinic receptors present in heart rather than brain. Labeled with positron emittors, these M 2 antagonists might be applicable to the pathophysiological study of disease states, such as cardiomyopathies

  10. Range-based volatility, expected stock returns, and the low volatility anomaly

    Science.gov (United States)

    2017-01-01

    One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics. PMID:29190652

  11. Range-based volatility, expected stock returns, and the low volatility anomaly.

    Science.gov (United States)

    Blau, Benjamin M; Whitby, Ryan J

    2017-01-01

    One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

  12. Range-based volatility, expected stock returns, and the low volatility anomaly.

    Directory of Open Access Journals (Sweden)

    Benjamin M Blau

    Full Text Available One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility, which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

  13. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  14. New procedure to synthesize silver nanoparticles and their interaction with local anesthetics

    Directory of Open Access Journals (Sweden)

    Mocanu A

    2013-10-01

    Full Text Available Aurora Mocanu,1 Roxana Diana Pasca,1 Gheorghe Tomoaia,2 Corina Garbo,1 Petre T Frangopol,1 Ossi Horovitz,1 Maria Tomoaia-Cotisel11Chemical Engineering Department, Babes-Bolyai University, 2Orthopedic Department, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, RomaniaAbstract: Silver nanoparticles (AgNPs were prepared in aqueous colloid dispersions by the reduction of Ag+ with glucose in alkaline medium. Tetraethyl orthosilicate and l-asparagine were added as stabilizers of NPs. The AgNPs were characterized, and their interaction with three local anesthetics (procaine, dibucaine, or tetracaine was investigated. Optical spectra show the characteristic absorption band of AgNPs, due to surface plasmon resonance. Modifications in the position and shape of this band reflect the self-assembly of metal NPs mediated by anesthetic molecules and the progress in time of the aggregation process. Zeta-potential measuring was applied in order to characterize the electrostatic stability of the NPs. The size and shape of the AgNPs, as well as the features of the assemblies formed by their association in the presence of anesthetics, were evidenced by transmission electron microscopy images. Atomic force microscopy images showed the characteristics of the films of AgNPs deposited on glass support. The effect of the anesthetics could be described in terms of electrostatic forces between the negatively charged AgNPs and the anesthetic molecules, existing also in their cationic form at the working pH. But also hydrophobic and hydrogen bonding interactions between the coated nanoparticles and anesthetics molecular species should be considered.Keywords: self-assembled nanostructures, UV-vis spectra, TEM, AFM, zeta potential

  15. The anesthetics influence (ethilic-eter and urethane) on renal radiopharmaceuticals

    International Nuclear Information System (INIS)

    Muramoto, E.; Achando, S.S.; Araujo, E.B. de; Hamada, H.S.; Silva Valente Goncalves, R. da; Pereira, N.P.S. de; Silva, C.P.G. da.

    1990-01-01

    A comparative study was done using anesthetics like ether ethilic and urethane, in rats (Wistar). A significative variation was observed in the results obtained when renal radiopharmaceuticals were investigated. Using urethane, the renal uptake increase progressivelly due to the inhibition of the renal filtration and it starts to recuperate when the anesthetic effect was eliminated. Using ether ethilic the radiopharmaceuticals are quickly eliminated from the kidneys (tubular or glomerular filtration), showing that the renal function was protected. (author) [pt

  16. Combined use of intravenous anesthetics and hypothermia in treating refractory status epilepticus

    Directory of Open Access Journals (Sweden)

    Guo-ping REN

    2015-11-01

    Full Text Available The primary choice of treating refractory status epilepticus (RSE is intravenous anesthetics, but the seizures of some patients can not get a good control. Thus, other therapies must be combined. Hypothermia not only can terminate seizures, but also play a part in brain protection. Though combined use of intravenous anesthetics and hypothermia is not a regular clinical scheme, the favorable effect has been proved by a lot of clinical research. This paper mainly focuses on the dose of intravenous anesthetics, the time, temperature and procedure of hypothermia, the indications and contraindications of combined therapy, and so on. DOI: 10.3969/j.issn.1672-6731.2015.11.006

  17. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. An improved method for lifting and transporting anesthetized pigs within an animal facility

    DEFF Research Database (Denmark)

    Schumacher-Petersen, Camilla; Hammelev, Karsten Pharao; Flescher, Jens Erik

    2014-01-01

    Transporting anesthetized pigs in a laboratory setting often requires strenuous manual lifting, posing a hazard to the safety of animal care personnel and to the welfare of the pigs. The authors developed an improved approach to lifting and transporting anesthetized pigs weighing up to 350 kg using...... mechanical lifts. Different equipment was used to accommodate pigs of different sizes as well as the building designs of three animal facilities. Using the lifts, anesthetized pigs are carried on sheets to maintain their comfort while being transported. The approach refines previous methods for handling...

  19. Binding kinetics of 11C-N-methyl piperidyl benzilate (11C-NMPB) in a rhesus monkey brain using the cerebellum as a reference region

    International Nuclear Information System (INIS)

    Itoh, Takashi; Tanaka, Masayasu; Suzuki, Kasutoshi; Kobayashi, Kaoru; Inoue, Osamu

    2005-01-01

    The binding kinetics of' 11 C-N-methyl piperidyl benzilate ( 11 C-NMPB) in rhesus monkey brain were studied using animal positron emission tomography (PET) (SHR2000). This study is intended to assess the validity of the method using the cerebellum as a reference region, and to evaluate the effects of anesthesia on 11 C -NMPB binding. Two monkeys, anesthetized with ketamine, received intravenous 11 C-NMPB alone (370-760 MBq, 11 C-NMPB accumulated densely in the striatum and cerebral cortex with time. In contrast, the tracer accumulation significantly decreased with increased doses of nonradioactive NMPB. In the cerebellum, on the other hand, the accumulation of 11 C-NMPB remained low and the tracer was slowly eliminated from the brain following the injection. 11 C-NMPB binding in the cerebellum was barely affected by the increased dose of nonradioactive NMPB. We thus concluded that the specific 11 C-NMPB binding was negligible in the cerebellum, and performed simplified evaluation of 11 C-NMPB binding in each brain region by a graphical method using the cerebellum as a reference region. PET was conducted 26 times, in total both in ketamine-anesthetized and awake monkeys (n=3 each). Measurements of 11 C-NMPB binding showed good run-to-run reproducibility within individual animals. When 11 C-NMPB binding was compared between ketamine-treated and awake animals, a significant increase in 11 C-NMPB binding was observed in the striatum but not in other brain regions of ketamine-treated animals. (author)

  20. Anesthetic management for Cesarean delivery in parturients with a diagnosis of dwarfism.

    Science.gov (United States)

    Lange, Elizabeth M S; Toledo, Paloma; Stariha, Jillian; Nixon, Heather C

    2016-08-01

    The literature on the anesthetic management of parturients with dwarfism is sparse and limited to isolated case reports. Pregnancy complications associated with dwarfism include an increased risk of respiratory compromise, an increased risk of Cesarean delivery, and an unpredictable degree of anesthesia with neuraxial techniques. Therefore, we conducted this retrospective review to evaluate the anesthetic management of parturients with a diagnosis of dwarfism. We used a query of billing data to identify short statured women who underwent a Cesarean delivery during May 1, 2008 to May 1, 2013. We then hand searched the electronic medical record for qualifying patients with heights diagnosis of dwarfism. The extracted data included patient demographics and obstetric and anesthetic information. We identified 13 women with dwarfism who had 15 Cesarean deliveries in total. Twelve of the women had disproportionate dwarfism, and ten of the 15 Cesarean deliveries were due to cephalopelvic disproportion. Neuraxial anesthesia was attempted in 93% of deliveries. The dose chosen for initiation of neuraxial anesthesia was lower than the typical doses used in parturients of normal stature. Neuraxial anesthetic complications included difficult neuraxial placement (64%), high spinal (7%), inadequate surgical level (13%), and unrecognized intrathecal catheter (7%). The data collected suggest that females with a diagnosis of dwarfism may have difficult neuraxial placement and potentially require lower dosages of local anesthetic for both spinal and epidural anesthesia to achieve adequate surgical blockade.

  1. Anesthetic management of a child with autistic spectrum disorder and homocysteinemia

    Directory of Open Access Journals (Sweden)

    Deepak Choudhary

    2016-01-01

    Full Text Available Autistic spectrum disorder (ASD is a developmental disability of the central nervous system with rapid worsening. A subset of patients also has mitochondrial dysfunction leading to increased sensitivity to various anesthetic agents. Rarely, gene mutation in these patients results in homocysteinemia which causes higher incidences of thromboembolism, hypoglycemia, and seizures. Anesthetic management of ASD with homocysteinemia and refractory seizures has not been previously reported.

  2. Iodine volatility

    International Nuclear Information System (INIS)

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

  3. Evolution of camel CYP2E1 and its associated power of binding toxic industrial chemicals and drugs.

    Science.gov (United States)

    Kandeel, Mahmoud; Altaher, Abdullah; Kitade, Yukio; Abdelaziz, Magdi; Alnazawi, Mohamed; Elshazli, Kamal

    2016-10-01

    Camels are raised in harsh desert environment for hundreds of years ago. By modernization of live and the growing industrial revolution in camels rearing areas, camels are exposed to considerable amount of chemicals, industrial waste, environmental pollutions and drugs. Furthermore, camels have unique gene evolution of some genes to withstand living in harsh environments. In this work, the camel cytochrome P450 2E1 (CYP2E1) is compromised to detect its evolution rate and its power to bind with various chemicals, protoxins, procarcinogens, industrial toxins and drugs. In comparison with human CYP2E1, camel CYP2E1 more efficiently binds to small toxins as aniline, benzene, catechol, amides, butadiene, toluene and acrylamide. Larger compounds were more preferentially bound to the human CYP2E1 in comparison with camel CYP2E1. The binding of inhalant anesthetics was almost similar in both camel and human CYP2E1 coinciding with similar anesthetic effect as well as toxicity profiles. Furthermore, evolutionary analysis indicated the high evolution rate of camel CYP2E1 in comparison with human, farm and companion animals. The evolution rate of camel CYP2E1 was among the highest evolution rate in a subset of 57 different organisms. These results indicate rapid evolution and potent toxin binding power of camel CYP2E1. Copyright © 2016. Published by Elsevier Ltd.

  4. Asymmetric Realized Volatility Risk

    Directory of Open Access Journals (Sweden)

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  5. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    The persistent nature of equity volatility is investigated by means of a multi-factor stochastic volatility model with time varying parameters. The parameters are estimated by means of a sequential matching procedure which adopts as auxiliary model a time-varying generalization of the HAR model f...

  6. Advanced Pre-clinical Research Approaches and Models to Studying Pediatric Anesthetic Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Cheng eWang

    2012-10-01

    Full Text Available Advances in pediatric and obstetric surgery have resulted in an increase in the duration and complexity of anesthetic procedures. A great deal of concern has recently arisen regarding the safety of anesthesia in infants and children. Because of obvious limitations, it is not possible to thoroughly explore the effects of anesthetic agents on neurons in vivo in human infants or children. However, the availability of some advanced pre-clinical research approaches and models, such as imaging technology both in vitro and in vivo, stem cell and nonhuman primate experimental models, have provided potentially invaluable tools for examining the developmental effects of anesthetic agents. This review discusses the potential application of some sophisticaled research approaches, e.g., calcium imaging, in stem cell-derived in vitro models, especially human embryonic neural stem cells, along with their capacity for proliferation and their potential for differentiation, to dissect relevant mechanisms underlying the etiology of the neurotoxicity associated with developmental exposures to anesthetic agents. Also, this review attempts to discuss several advantages for using the developing rhesus monkey models (in vivo, when combined with dynamic molecular imaging approaches, in addressing critical issues related to the topic of pediatric sedation/anesthesia. These include the relationships between anesthetic-induced neurotoxicity, dose response, time-course and developmental stage at time of exposure (in vivo studies, serving to provide the most expeditious platform toward decreasing the uncertainty in extrapolating pre-clinical data to the human condition.

  7. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  8. Evaluating the binding efficiency of pheromone binding protein with its natural ligand using molecular docking and fluorescence analysis

    Science.gov (United States)

    Ilayaraja, Renganathan; Rajkumar, Ramalingam; Rajesh, Durairaj; Muralidharan, Arumugam Ramachandran; Padmanabhan, Parasuraman; Archunan, Govindaraju

    2014-06-01

    Chemosignals play a crucial role in social and sexual communication among inter- and intra-species. Chemical cues are bound with protein that is present in the pheromones irrespective of sex are commonly called as pheromone binding protein (PBP). In rats, the pheromone compounds are bound with low molecular lipocalin protein α2u-globulin (α2u). We reported farnesol is a natural endogenous ligand (compound) present in rat preputial gland as a bound volatile compound. In the present study, an attempt has been made through computational method to evaluating the binding efficiency of α2u with the natural ligand (farnesol) and standard fluorescent molecule (2-naphthol). The docking analysis revealed that the binding energy of farnesol and 2-naphthol was almost equal and likely to share some binding pocket of protein. Further, to extrapolate the results generated through computational approach, the α2u protein was purified and subjected to fluorescence titration and binding assay. The results showed that the farnesol is replaced by 2-naphthol with high hydrophobicity of TYR120 in binding sites of α2u providing an acceptable dissociation constant indicating the binding efficiency of α2u. The obtained results are in corroboration with the data made through computational approach.

  9. Oral Topical Doxepin Rinse: Anesthetic Effect in Normal Subjects

    Directory of Open Access Journals (Sweden)

    Joel B Epstein

    2003-01-01

    Full Text Available Oral doxepin rinse has been reported to provide pain relief in patients with oral mucosal lesions due to cancer or cancer therapy. The purpose of this study was to assess the anesthetic effect of doxepin oral rinse in normal subjects to identify the duration of effect and to contrast the anesthetic effect with reported pain relief in patients with oral mucosal lesions. Normal volunteers were provided a solution of doxepin (5 mg/mL for oral rinsing. Oral numbness and adverse effects were recorded for a period of 4 h after rinsing. Doxepin rinse resulted in mucosal anesthesia in all subjects. Sedation/fatigue was reported in four of seven subjects. There were no taste complaints and no nausea reported. The limited duration of numbness/anesthesia in normal subjects compared with prior studies showing pain relief for more than 3 h in patients with mucosal lesions, suggests that the extended duration of pain relief in patients was due to analgesic effects rather than anesthetic effects. The majority of normal subjects reported sedation after use, but this was less common in patients with mucosal lesions.

  10. Development of lidocaine gels for enhanced local anesthetic action.

    Science.gov (United States)

    Shin, Sang-Chul; Cho, Cheong-Weon; Yang, Kyu-Ho

    2004-12-09

    In relieving local pains, lidocaine, one of ester type local anesthetics, has been used. To develop the lidocaine gels of enhanced local anesthetic effects, hydroxypropyl methylcellulose (HPMC) based bioadhesive polymer gel containing an enhancer was formulated. As the drug concentration in the gels increased up to 3%, the permeation rate of drug linearly increased, thereafter reaching a plateau. As the temperature of surrounding solutions increased, the permeation of drug increased. The activation energy of drug permeation was 3.29 kcal/mol for lidocaine. The permeation rate of drug through skin was studied using various enhancers, such as glycols, non-ionic surfactants, and bile salts. Among the enhancers studied, diethylene glycol showed the greatest enhancing effects on drug permeation through skin. The analgesic activity was examined using a tail-flick analgesimeter. In the area under the efficacy curve (AUEC) of the rat-tail flick tests, lidocaine gel containing diethylene glycol showed about 3.89-fold increase in analgesic activity compared with the control. The addition of vasoconstrictor in the gels prolonged the analgesic effects. The result of this study supports that the bioadhesive gel with efficient anesthetic effect could be developed using HPMC with combination of enhancer and vasoconstrictor.

  11. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  12. Impact of hyaluronidase on anesthetic distribution in retrobulbar region following sub-Tenon anesthesia

    Directory of Open Access Journals (Sweden)

    Šurbatović Maja

    2008-01-01

    Full Text Available Background/Aim. Sub-Tenon's block is nowadays commonly used in ophthalmic surgery because of its safety and efficacy. The aim of this study was to investigate the distribution of the anesthetic solution with different amounts of hyaluronidase in the retrobulbar space, following an injection into the Sub-Tenon's space. Methods. In this experimental study, 40 pig cadaver heads were used (80 eyeballs. The material was divided into four groups (of 20 eyeballs each. Each group was administered 4.5 ml of a mixture of 2% lignocaine, 0.5% bupivacaine, and 0.5 ml of Indian ink, with different amounts of hyaluronidase - 15 IU/ml, 75 IU/ml, 150 IU/ml, except the control one. Samples of retrobulbar tissue were analyzed using the standard histopathological procedure. After that, they were also analyzed using the Adobe Photoshop program® (Windows, USA. The retrobulbar space was divided into eight zones by four perpendicular lines, which crossed in the centre of the optic nerve. The presence of ink in fat and muscle tissues and in the sheath of the optic nerve was observed. Results. The presence of the local anesthetic solution was significantly higher in inferonasal and superonasal quadrants of the fat and muscle tissues (p < 0.01. The distribution in optic nerve sheath is similar in each quadrant. Distribution of local anesthetic in each zone of the muscle tissue (I-VIII was strongly influenced by the amount of hyaluronidase added. In the fat tissue, the distribution of local anesthetic under the influence of hyaluronidase was significantly higher (p < 0.05 in the areas which were distant from the place of injection (I-IV. The distribution in the optic nerve sheath is significantly higher (p < 0.01 in the group with 150 IU/ml of hyaluronidase. Conclusions. Following a sub-Tenon block local anesthetic was present in the retrobulbar space in a high percentage of the cases. The presence of local anesthetic solution in retrobulbar space depends on the amount of

  13. Assessment of the densities of local anesthetics and their combination with adjuvants: an experimental study.

    Science.gov (United States)

    Imbelloni, Luiz Eduardo; Moreira, Adriano Dias; Gaspar, Flávia Cunha; Gouveia, Marildo A; Cordeiro, José Antônio

    2009-01-01

    The relative density of a local anesthetic in relation to that of the cerebrospinal fluid (CSF) at 37 degrees C is one of the most important physical properties that affect the level of analgesia obtained after the subarachnoid administration of the drug. The objective of this study was to determine the density of local anesthetic solutions, with and without glucose, and the combination of the local anesthetic with adjuvants at 20 degrees C, 25 degrees C, and 37 degrees C. The density (g.mL(-1)) was determined by using a DMA 450 densimeter with a sensitivity of +/- 0.00001 g.mL(-1). The densities, and variations, according to the temperature were obtained for all local anesthetics and their combination with opioids at 20 degrees C, 25 degrees C, and 37 degrees C. The solution is hyperbaric if its density exceeds 1.00099, hypobaric when its density is lower than 1.00019, and isobaric when its density is greater than 1.00019 and lower than 1.00099. The densities of both local anesthetics and adjuvants decrease with the increase in temperature. At 37 degrees C, all glucose-containing solutions are hyperbaric. In the absence of glucose, all solutions are hypobaric. At 37 degrees C, morphine, fentanyl, sufentanil, and clonidine are hypobaric. The densities of local anesthetics and adjuvants decrease with the increase in temperature and increase when glucose is added. The knowledge of the relative density helps select the most adequate local anesthetic to be administered in the subarachnoid space.

  14. Effects of anesthesia and species on the uptake or binding of radioligands in vivo in the Göttingen minipig

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Landau, Anne M.; Holden, James E.

    2013-01-01

    Progress in neuroscience research often involves animals, as no adequate alternatives exist to animal models of living systems. However, both the physiological characteristics of the species used and the effects of anesthesia raise questions of common concern. Here, we demonstrate the confounding...... influences of these effects on tracer binding in positron emission tomography (PET). We determined the effects of two routinely used anesthetics (isoflurane and propofol) on the binding of two tracers of monoamine function, [ C 11 ]SCH23390, a tracer of the dopamine D1 and D5 receptors, and the alpha2...

  15. Anesthetic management of a parturient with Guillain-Barre syndrome posted for emergency caesarian section

    Directory of Open Access Journals (Sweden)

    Abhijit Paul

    2012-01-01

    Full Text Available We report the anesthetic management of a case of Guillain-Barre syndrome in the 34 th week of gestation coming for an emergency Cesarean section. The perioperative anesthetic challenges have been discussed with emphasis on the medical and anesthetic management which includes the use of plasma-pheresis, intravenous gamma-globulin, and the safety of preservative free 0.75% isobaric ropivacaine, which was administered intrathecally in this difficult medical condition with excellent hemodynamic, maternal, and fetal outcome. The sensory and motor blocks achieved were well suited to the clinical risks and conditions.

  16. Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2013-01-01

    textabstractIn this paper we document that realized variation measures constructed from highfrequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive.

  17. Anesthetic drugs accelerate the progression of postoperative metastases of mouse tumors.

    OpenAIRE

    Shapiro, J; Jersky, J; Katzav, S; Feldman, M; Segal, S

    1981-01-01

    Experiments were made to investigate the effect of four anesthetic drugs that are commonly used in surgical practice on the postoperative growth of mouse tumors in syngeneic recipients. These experiments revealed that some of the anesthetics when applied for surgical excision of the local tumor, strongly accelerated postoperative progression of spontaneous lung metastases produced by the 3LL Lewis lung carcinoma and by the B16 melanoma. Some of the drugs caused the appearance of metastases in...

  18. Assessment of patient satisfaction with the preoperative anesthetic evaluation

    Directory of Open Access Journals (Sweden)

    Gebremedhn EG

    2014-09-01

    Full Text Available Endale Gebreegziabher Gebremedhn, Vidhya Nagaratnam Department of Anesthesia, School of Medicine, Gondar College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia Background: The evaluation of patient satisfaction is a core aspect of the continuous quality improvement in anesthesia service that can be affected by the preoperative anesthetist visit. This visit enables the anesthetist to know about the patient's general health status and the nature of surgery, to choose the type of anesthesia, and to discuss perioperative complications and their management with the patient. Patients have sometimes complained about the information given during the preoperative anesthetic evaluation in the University of Gondar teaching and referral hospital. The aim of this study was to determine the level of patient satisfaction with the preoperative anesthetist visit. Methods: A cross-sectional study was conducted from February 15 to April 15, 2013. All consecutive elective patients who were operated upon under anesthesia during the study period were interviewed 24 hours after operation. A pretested questionnaire and checklists, which were developed based on the hospital's anesthetic evaluation sheet, were used for data collection. Results: A total of 116 elective patients were operated upon under anesthesia during the study period. Of these, 102 patients were included in our study, with a response rate of 87.9%. Anesthetists introduced themselves to ~24% patients; provided information about anesthesia to ~32%, postoperative complications to ~21%, postoperative analgesia to ~18, and postoperative nausea and vomiting to ~21%; and spent adequate time with ~74%. Patients' questions were answered by the anesthetist in ~65% of cases, and ~65% of patients had reduced anxiety after the anesthetist visit. The patients' overall satisfaction with the preoperative anesthetist visit was ~65%. Conclusion and recommendation: Patient satisfaction with the

  19. Effects of saw palmetto extract on micturition reflex of rats and its autonomic receptor binding activity.

    Science.gov (United States)

    Oki, Tomomi; Suzuki, Mayumi; Nishioka, Yasuhiko; Yasuda, Akio; Umegaki, Keizo; Yamada, Shizuo

    2005-04-01

    We examined the effects of saw palmetto extract (SPE) on the rat micturition reflex and on autonomic receptors in the lower urinary tract. The effect of SPE was examined on cystometrograms of anesthetized rats induced by intravesical infusion of saline or 0.1% acetic acid. SHR/NDmc-cp (cp/cp) rats received repeat oral administration of SPE and nighttime urodynamic function was determined. The autonomic receptor binding activity of SPE in the rat bladder and prostate was examined by radioligand binding assay. Intraduodenal administration of SPE (60 mg/kg) in anesthetized rat cystometry caused a significant increase in the micturition interval, micturition volume and bladder capacity during intravesical saline infusion. Also, similar administration of SPE at doses of 12 and 20 mg/kg significantly reversed the shortened micturition interval as well as the decreased micturition volume and bladder capacity due to 0.1% acetic acid infusion in a dose dependent manner. In conscious SHR/NDmc-cp (cp/cp) rats repeat oral administration of SPE (6 mg/kg daily) constantly increased the micturition interval and concomitantly decreased voiding frequency. SPE inhibited specific binding of [H]NMS ([N-methyl-H]scopolamine methyl chloride) (bladder) and [H]prazosin (prostate) with IC50 values of 46.1 and 183 microg/ml, respectively. SPE significantly alleviates urodynamic symptoms in hyperactive rat bladders by increasing bladder capacity and subsequently prolonging the micturition interval. Our data may support the clinical efficacy of SPE for the treatment of lower urinary tract symptoms.

  20. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  1. A novel local anesthetic system: transcriptional transactivator peptide-decorated nanocarriers for skin delivery of ropivacaine

    Directory of Open Access Journals (Sweden)

    Chen CY

    2017-06-01

    Full Text Available Chuanyu Chen, Peijun You Department of Anesthesiology, Shandong Jining No 1 People’s Hospital, Jining, Shandong, People’s Republic of China Purpose: Barrier properties of the skin and physicochemical properties of drugs are the main factors for the delivery of local anesthetic molecules. The present work evaluates the anesthetic efficacy of drug-loaded nanocarrier (NC systems for the delivery of local anesthetic drug, ropivacaine (RVC. Methods: In this study, transcriptional transactivator peptide (TAT-decorated RVC-loaded NCs (TAT-RVC/NCs were successfully fabricated. Physicochemical properties of NCs were determined in terms of particle size, zeta potential, drug encapsulation efficiency, drug-loading capacity, stability, and in vitro drug release. The skin permeation of NCs was examined using a Franz diffusion cell mounted with depilated mouse skin in vitro, and in vivo anesthetic effect was evaluated in mice. Results: The results showed that TAT-RVC/NCs have a mean diameter of 133.2 nm and high drug-loading capacity of 81.7%. From the in vitro skin permeation results, it was observed that transdermal flux of TAT-RVC/NCs was higher than that of RVC-loaded NCs (RVC/NCs and RVC injection. The evaluation of in vivo anesthetic effect illustrated that TAT-RVC/NCs can enhance the transdermal delivery of RVC by reducing the pain threshold in mice. Conclusion: These results indicate that TAT-decorated NCs systems are useful for overcoming the barrier function of the skin, decreasing the dosage of RVC and enhancing the anesthetic effect. Therefore, TAT-decorated NCs can be used as an effective transdermal delivery system for local anesthesia. Keywords: local anesthetic system, ropivacaine, transcriptional transactivator peptide, nanocarriers, skin delivery

  2. Anesthetic exposure and health of dental personnel, 1 June 1978-30 November 1980

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, E.N.

    1980-01-01

    An epidemiologic survey was conducted to determine possible health hazards in the dental profession, with particular attention being given to the results of exposure to anesthetic gases. The survey contacted 30,650 dentists and 30,547 chairside assistants who were subsequently grouped according to exposure to inhalation anesthetics in the dental operatory during the course of their employment experience. An increase in liver disease 1.7 above that expected was noted in male dentists heavily exposed to anesthetics, combined with a 1.2 fold increase for kidney disease and 1.9-fold increase for neurological disease. The spontaneous abortion rate in wives of male dentists was 1.5-fold higher than expected. Occupational exposure to anesthetics, either direct or indirect, was associated with significant increases in spontaneous abortion over control levels during the first and second trimester of pregnancy. Women who smoked during pregnancy showed increased risk of spontaneous abortion, with a 27% increase occurring in dental assistants and a 21% increase in wives of dentists. A 34% increased risk of babies having congenital abnormalities was noted among smoking dental assistants.

  3. Anesthetic Management and Complications of Percutaneous Aortic Valve Implantation

    Directory of Open Access Journals (Sweden)

    Tailur Alberto Grando

    2013-05-01

    Full Text Available Background and objective: Aortic stenosis is a highly prevalent and life-threatening disease. In elderly patients with comorbidities, percutaneous valve implantation is an option. The aim of the study was to describe the anesthetic management and complications of general anesthesia Method: Case series with 30-day and 24-month follow-ups after implantation of the CoreValve device performed at the Institute of Cardiology/University Foundation of Cardiology between December 2008 and January 2012. The patients underwent general anesthesia monitored with mean arterial pressure (PAM, electrocardiogram (ECG, pulse oximetry, capnography, transesophageal echocardiography, thermometry, and transvenous pacemaker. Results: Twenty-eight patients, mean age 82.46 years, 20.98% mean EuroSCORE, functional class III/IV, successfully underwent valve implantation. Nine patients required permanent pacemaker implantation. During follow-up, two patients died: one during surgery due to LV perforation and the other on the third day of unknown causes. At 24 months, one patient diagnosed with multiple myeloma died. This anesthetic technique proved to be safe. Conclusion: The initial experience with percutaneous aortic valve implantation under general anesthesia has proven to be safe and effective, with no significant anesthetic complications during this procedure. Keywords: Aesthesia, General, Cardiac Surgical Procedures, Aortic Valve Stenosis, Aged.

  4. Realized volatility and absolute return volatility: a comparison indicating market risk.

    Science.gov (United States)

    Zheng, Zeyu; Qiao, Zhi; Takaishi, Tetsuya; Stanley, H Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods.

  5. Realized volatility and absolute return volatility: a comparison indicating market risk.

    Directory of Open Access Journals (Sweden)

    Zeyu Zheng

    Full Text Available Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods.

  6. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common...... in Finance. Nonparametric estimators are well suited for these events due to the flexibility of their functional form and their good asymptotic properties. However, the local polynomial kernel estimators are not consistent at points where the volatility function has a break. The estimator presented...

  7. Molecular recognition of floral volatile with two olfactory related proteins in the Eastern honeybee (Apis cerana).

    Science.gov (United States)

    Li, Hongliang; Zhang, Linya; Ni, Cuixia; Shang, Hanwu; Zhuang, Shulin; Li, Jianke

    2013-05-01

    The honeybee relies on its sensitive olfaction to perform the foraging activities in the field. In the antennal chemoreception system of honeybee, odorant-binding proteins (OBPs) and chemosensory protein (CSPs) are major two protein families capable of binding with some plant volatiles and chemical ligands. However, the chemical binding interaction of plant odors with OBPs and CSPs in the honeybee olfactory system is still not clear yet. Hence, complex fluorescent spectra, ultraviolet absorption spectra, circular dichroism spectra and molecular docking were used to investigate the binding property of AcerASP2 (an OBP of Apis cerana) and AcerASP3 (a CSP of Apis cerana) with β-ionone, one of ordinary floral volatiles in botanical flower. As a result, β-ionone had a strong capability to quench the fluorescence that the two proteins produced, and their interaction was a dynamic process that was mainly driven by a hydrophobic force. AcerASP2 had a larger hydrophobic cavity than that of AcerASP3 and the conformation of AcerASP2 was changed less than AcerASP3 when binding with β-ionone. Our data suggests that OBPs like AcerASP2 might make a large contribution toward assisting the honeybee in sensing and foraging flowers, and A. cerana has evolved a good circadian rhythm to perceive a flower's odor following the fluctuation of temperature in the olfactory system. This significantly extends our knowledge on how to strengthen the honeybees' pollination service via manipulation of target proteins in the olfactory system. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Aplastic anemia during pregnancy: a review of obstetric and anesthetic considerations

    Science.gov (United States)

    Riveros-Perez, Efrain; Hermesch, Amy C; Barbour, Linda A; Hawkins, Joy L

    2018-01-01

    Aplastic anemia is a hematologic condition occasionally presenting during pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management is challenging, and treatment requires a coordinated effort by an interdisciplinary team, in order to provide safe care to these patients. In this review, we describe the current state of the literature as it applies to the complexity of aplastic anemia in pregnancy, focusing on pathophysiologic aspects of the disease in pregnancy, as well as relevant obstetric and anesthetic considerations necessary to treat this challenging problem. A multidisciplinary-team approach to the management of aplastic anemia in pregnancy is necessary to coordinate prenatal care, optimize maternofetal outcomes, and plan peripartum interventions. Conservative transfusion management is critical to prevent alloimmunization. Although a safe threshold-platelet count for neuraxial anesthesia has not been established, selection of anesthetic technique must be evaluated on a case-to-case basis. PMID:29535558

  9. Uses and Doses of Local Anesthetics in Fish, Amphibians, and Reptiles.

    Science.gov (United States)

    Chatigny, Frederic; Kamunde, Collins; Creighton, Catherine M; Stevens, E Don

    2017-05-01

    Local anesthetics are an integral part of routine pain management in mammals, yet their use is relatively limited in fish, amphibians and reptiles. These animals frequently undergo potentially painful surgical procedures and therefore could possibly benefit from those drugs. Some recommendations are currently available in the literature concerning analgesic use in these animals. However the pharmacological properties, safety and often efficacy of local anesthetic drugs have not been investigated yet in fish, amphibians, or reptiles. This review compiled current information concerning the use of those agents in fish, reptiles and amphibians to help clinicians make an informed decision as to which dose and drug to use. The resulting literature search showed that the literature concerning use of local analgesics in fish and amphibians is very limited while the literature for reptiles is more extensive. We found few experimental studies evaluating the efficacy of local anesthetics. Further studies would provide additional information for developing guidelines to improve the welfare of fish, amphibians and reptiles.

  10. Role of Network Science in the Study of Anesthetic State Transitions.

    Science.gov (United States)

    Lee, UnCheol; Mashour, George A

    2018-04-23

    The heterogeneity of molecular mechanisms, target neural circuits, and neurophysiologic effects of general anesthetics makes it difficult to develop a reliable and drug-invariant index of general anesthesia. No single brain region or mechanism has been identified as the neural correlate of consciousness, suggesting that consciousness might emerge through complex interactions of spatially and temporally distributed brain functions. The goal of this review article is to introduce the basic concepts of networks and explain why the application of network science to general anesthesia could be a pathway to discover a fundamental mechanism of anesthetic-induced unconsciousness. This article reviews data suggesting that reduced network efficiency, constrained network repertoires, and changes in cortical dynamics create inhospitable conditions for information processing and transfer, which lead to unconsciousness. This review proposes that network science is not just a useful tool but a necessary theoretical framework and method to uncover common principles of anesthetic-induced unconsciousness.

  11. Hypnosis control based on the minimum concentration of anesthetic drug for maintaining appropriate hypnosis.

    Science.gov (United States)

    Furutani, Eiko; Nishigaki, Yuki; Kanda, Chiaki; Takeda, Toshihiro; Shirakami, Gotaro

    2013-01-01

    This paper proposes a novel hypnosis control method using Auditory Evoked Potential Index (aepEX) as a hypnosis index. In order to avoid side effects of an anesthetic drug, it is desirable to reduce the amount of an anesthetic drug during surgery. For this purpose many studies of hypnosis control systems have been done. Most of them use Bispectral Index (BIS), another hypnosis index, but it has problems of dependence on anesthetic drugs and nonsmooth change near some particular values. On the other hand, aepEX has an ability of clear distinction between patient consciousness and unconsciousness and independence of anesthetic drugs. The control method proposed in this paper consists of two elements: estimating the minimum effect-site concentration for maintaining appropriate hypnosis and adjusting infusion rate of an anesthetic drug, propofol, using model predictive control. The minimum effect-site concentration is estimated utilizing the property of aepEX pharmacodynamics. The infusion rate of propofol is adjusted so that effect-site concentration of propofol may be kept near and always above the minimum effect-site concentration. Simulation results of hypnosis control using the proposed method show that the minimum concentration can be estimated appropriately and that the proposed control method can maintain hypnosis adequately and reduce the total infusion amount of propofol.

  12. ACCURACY OF NONINVASIVE ANESTHETIC MONITORING IN THE ANESTHETIZED GIRAFFE (GIRAFFA CAMELOPARDALIS)

    DEFF Research Database (Denmark)

    Bertelsen, Mads F; Grøndahl, Carsten; Stegmann, George F

    2017-01-01

    This study evaluated the accuracy of pulse oximetry, capnography, and oscillometric blood pressure during general anesthesia in giraffes (Giraffa camelopardalis). Thirty-two giraffes anesthetized for physiologic experiments were instrumented with a pulse oximeter transmittance probe positioned...... on the tongue and a capnograph sampling line placed at the oral end of the endotracheal tube. A human size 10 blood pressure cuff was placed around the base of the tail, and an indwelling arterial catheter in the auricular artery continuously measured blood pressure. Giraffes were intermittently ventilated...... using a Hudson demand valve throughout the procedures. Arterial blood for blood gas analysis was collected at multiple time points. Relationships between oxygen saturation as determined by pulse oximetry and arterial oxygen saturation, between arterial carbon dioxide partial pressure and end...

  13. Pluto's Volatile Transport

    Science.gov (United States)

    Young, Leslie

    2012-10-01

    Pluto's varying subsolar latitude and heliocentric distance leads to large variations in the surface volatile distribution and surface pressure. I present results of new volatile transport models (Young 2012a, b). The models include insolation, thermal emission, subsurface conduction, heating of a volatile slab, internal heat flux, latent heat of sublimation, and strict global mass balance. Numeric advances include initial conditions that allow for rapid convergence, efficient computation with matrix arithmetic, and stable Crank-Nicholson timesteps for both bare and volatile-covered areas. Runs of the model show six distinct seasons on Pluto. (1) As Pluto approaches perihelion, the volatiles on the old winter pole (the Rotational North Pole, RNP) becomes more directly illuminated , and the pressure and albedo rise rapidly. (2) When a new ice cap forms on the Rotational South Pole, RSP, volatiles are exchanged between poles. The pressure and albedo change more slowly. (3) When all volatiles have sublimed from the RNP, the albedo and pressure drop rapidly. (4-6) A similar pattern is repeated near aphelion with a reversal of the roles and the poles. I will compare results with earlier Pluto models of Hansen and Paige (1996), show the dependence on parameters such as substrate inertia, and make predictions for the New Horizons flyby of Pluto in 2015. This work was supported, in part, by funding from NASA Planetary Atmospheres Grant NNG06GF32G and the Spitzer project (JPL research support Agreement 1368573). Hansen, C. J. and D. A. Paige 1996. Seasonal Nitrogen Cycles on Pluto. Icarus 120, 247-265. Young, L. A. 2012a. Volatile transport on inhomogeneous surfaces: I - Analytic expressions, with application to Pluto’s day. Icarus, in press Young, L. A. 2012b. Volatile transport on inhomogeneous surfaces: II. Numerical calculations, with application to Pluto's season. In preparation.

  14. Anesthetic efficacy of articaine for inferior alveolar nerve blocks in patients with symptomatic versus asymptomatic irreversible pulpitis.

    Science.gov (United States)

    Argueta-Figueroa, Liliana; Arzate-Sosa, Gabriel; Mendieta-Zeron, Hugo

    2012-01-01

    This study sought to determine the anesthetic efficacy of 4% articaine with 1:100,000 epinephrine in patients with symptomatic and asymptomatic irreversible pulpitis in mandibular posterior teeth and if individual patient factors, pulpal disease characteristics, and previous medication are correlated to local anesthetic success. A second objective was to determine the specificity and sensibility of a cold test for prediction of anesthetic success prior to endodontic treatment. Seventy patients diagnosed with irreversible pulpitis in mandibular posterior teeth received 1.6 mL of 4% articaine with 1:100,000 epinephrine for an inferior alveolar nerve block (IANB) using a metal guide. The anesthetic solution was injected with a computer-preprogrammed delivery system for local anesthesia. Endodontic access was begun 15 minutes after solution deposition; later, patients rated their discomfort using the visual analog scale (VAS). The success rate for the IA NB using articaine was 64.2% in patients with symptomatic irreversible pulpitis and 86.9% in patients with asymptomatic irreversible pulpitis. Cold test prior to root canal treatment had a specificity and sensibility of 12.5% and 87.1%, respectively. The anesthetic efficacy of articaine in irreversible pulpitis is moderately acceptable, and anesthetic success increases when the patient has been premedicated with NSAIDs. The cold test appears to be a favorable indicator for predicting anesthetic success.

  15. Interactions of the local anesthetic tetracaine with membranes containing phosphatidylcholine and cholesterol: a 2H NMR study

    International Nuclear Information System (INIS)

    Auger, M.; Jarrell, H.C.; Smith, I.C.P.

    1988-01-01

    The interactions of local anesthetic tetracaine with multilamellar dispersions of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and cholesterol have been investigated by deuterium nuclear magnetic resonance of specifically deuteriated tetracaines, DMPC and cholesterol. Experiments were performed at pH 5.5, when the anesthetic is primarily charged, and at pH 9.5, when it is primarily uncharged. The partition coefficients of the anesthetic in the membrane have been measured at both pH values for phosphatidylcholine bilayers with and without cholesterol. The higher partition coefficients obtained at pH 9.5 reflect the hydrophobic interactions between the uncharged form of the anesthetic and the hydrocarbon region of the bilayer. The lower partition coefficients for the DMPC/cholesterol system at both pH values suggest that cholesterol, which increases the order of the lipid chains, decreases the solubility of tetracaine into the bilayer. For phosphatidylcholine bilayers, it has been proposed that the charged tetracaine at low pH is located mostly at the phospholipid headgroup level while the uncharged tetracaine intercalates more deeply into the bilayer. The present study suggests that the location of tetracaine in the cholesterol-containing system is different from that in pure phosphatidylcholine bilayers: the anesthetic sits higher in the membrane. An increase in temperature results in a deeper penetration of the anesthetic into the bilayer. Moreover, the incorporation of the anesthetic into DMPC bilayers with or without cholesterol results in a reduction of the lipid order parameters both in the plateau and in the tail regions of the acyl chains, this effect being greater with the charged form of the anesthetic

  16. Local anesthetics for brain tumor resection: Current perspectives

    NARCIS (Netherlands)

    J.W. Potters (Jan Willem); M. Klimek (Markus)

    2018-01-01

    textabstractThis review summarizes the added value of local anesthetics in patients undergoing craniotomy for brain tumor resection, which is a procedure that is carried out frequently in neurosurgical practice. The procedure can be carried out under general anesthesia, sedation with local

  17. Refractometry for quality control of anesthetic drug mixtures.

    Science.gov (United States)

    Stabenow, Jennifer M; Maske, Mindy L; Vogler, George A

    2006-07-01

    Injectable anesthetic drugs used in rodents are often mixed and further diluted to increase the convenience and accuracy of dosing. We evaluated clinical refractometry as a simple and rapid method of quality control and mixing error detection of rodent anesthetic or analgesic mixtures. Dilutions of ketamine, xylazine, acepromazine, and buprenorphine were prepared with reagent-grade water to produce at least 4 concentration levels. The refraction of each concentration then was measured with a clinical refractometer and plotted against the percentage of stock concentration. The resulting graphs were linear and could be used to determine the concentration of single-drug dilutions or to predict the refraction of drug mixtures. We conclude that refractometry can be used to assess the concentration of dilutions of single drugs and can verify the mixing accuracy of drug combinations when the components of the mixture are known and fall within the detection range of the instrument.

  18. Normalization for Implied Volatility

    OpenAIRE

    Fukasawa, Masaaki

    2010-01-01

    We study specific nonlinear transformations of the Black-Scholes implied volatility to show remarkable properties of the volatility surface. Model-free bounds on the implied volatility skew are given. Pricing formulas for the European options which are written in terms of the implied volatility are given. In particular, we prove elegant formulas for the fair strikes of the variance swap and the gamma swap.

  19. Money growth volatility and the demand for money in Germany: Friedman's volatility hypothesis revisited

    OpenAIRE

    Brüggemann, Imke; Nautz, Dieter

    1997-01-01

    Recently, the Bundesbank claimed that monetary targeting has become considerably more diffcult by the increased volatility of short-term money growth. The present paper investigates the impact of German money growth volatility on income velocity and money demand in view of Friedman's money growth volatility hypothesis. Granger-causality tests provide some evidence for a velocity-volatility linkage. However the estimation of volatility-augmented money demand functions reveals that - in contras...

  20. Anesthetic Efficacy in Irreversible Pulpitis: A Randomized Clinical Trial.

    Science.gov (United States)

    Allegretti, Carlos E; Sampaio, Roberta M; Horliana, Anna C R T; Armonia, Paschoal L; Rocha, Rodney G; Tortamano, Isabel Peixoto

    2016-01-01

    Inferior alveolar nerve block has a high failure rate in the treatment of mandibular posterior teeth with irreversible pulpitis. The aim of this study was to compare the anesthetic efficacy of 4% articaine, 2% lidocaine and 2% mepivacaine, all in combination with 1:100,000 epinephrine, in patients with irreversible pulpitis of permanent mandibular molars during a pulpectomy procedure. Sixty-six volunteers from the Emergency Center of the School of Dentistry, University of São Paulo, randomly received 3.6 mL of local anesthetic as a conventional inferior alveolar nerve block (IANB). The subjective signal of lip numbness, pulpal anesthesia and absence of pain during the pulpectomy procedure were evaluated respectively, by questioning the patient, stimulation using an electric pulp tester and a verbal analogue scale. All patients reported the subjective signal of lip numbness. Regarding pulpal anesthesia success as measured with the pulp tester, the success rate was respectively 68.2% for mepivacaine, 63.6% for articaine and 63.6% for lidocaine. Regarding patients who reported no pain or mild pain during the pulpectomy, the success rate was, respectively 72.7% for mepivacaine, 63.6% for articaine and 54.5% for lidocaine. These differences were not statistically significant. Neither of the solutions resulted in 100% anesthetic success in patients with irreversible pulpitis of mandibular molars.

  1. Cimethidine pre-anesthetic. A prophylactic method against Mendelson's syndrome in cesarean section

    DEFF Research Database (Denmark)

    Qvist, N; Storm, K

    1983-01-01

    Twenty patients undergoing cesarean section received cimethidine 400 mg intramuscularly as pre-anesthetic approximately 70 minutes prior to gastric aspiration. The average pH was 5.05, as against 2.97 in the control group (p less than 0.01). No significant reduction in the aspirated volumes...... in the infants. Hence, cimethidine is a safe and useful pre-anesthetic for patients undergoing cesarean section, irrespective of indication and, consequently, much to be preferred to oral antacids....

  2. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi......The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification...... estimate alternative specifications of the model using a set of daily bipower measures for 7 stock indexes and 16 individual NYSE stocks. The estimates of the jump component confirm that the probability of jumps dramatically increases during the financial crisis. Compared to other realized volatility...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  3. Anesthetic management of cardiac patient for cataract surgery

    International Nuclear Information System (INIS)

    Farooq, F.B.; Sultan, S.T.

    2003-01-01

    We are reporting the successful anesthetic management of a 6 years old child, who had cyanotic congenital heart disease and underwent an operation for cataract extraction. Ketamine was used for the induction and maintenance of anesthesia. Ventilation was assisted manually by using laryngeal masks. (author)

  4. Evaluation of the Aesthetics of Physical Methods of Euthanasia of Anesthetized Rats

    Science.gov (United States)

    Hickman, Debra L; Johnson, Steven W

    2011-01-01

    Dissection of living brain tissue for in vitro experiments requires the use of a rapid euthanasia method. However, the method must not subject animals to unnecessary pain and must be aesthetically acceptable to experimenters. The purposes of the current study were to assess the aesthetics of 6 euthanasia methods, measure the procedure duration, and evaluate brain for pathology after each procedure. We digitally recorded euthanasia of isoflurane-anesthetized rats by 6 physical methods: anesthetic overdose, cardiac exsanguination, decapitation, closed intrathoracic transection of the great vessels and heart, thoracic percussion, and thoracotomy with rupture of great vessels. Volunteer researchers and animal caretakers watched the video and completed an associated questionnaire. Anesthetic overdose and cardiac exsanguinations were rated most aesthetically pleasing, although these procedures took the longest to complete. In contrast, decapitation and thoracic percussion were the least aesthetically pleasing, but these methods were the quickest. No demographic factor was identified that could predict whether a given euthanasia procedure would be favored for aesthetic reasons, and participants provided a wide variety of rationales for the aesthetic ratings they assigned. Although all of these euthanasia methods meet the criteria of approved methods of euthanasia of anesthetized rats as defined by the AVMA, aesthetic features and the scientific need for rapid euthanasia are both considerations in selecting a method. PMID:22330717

  5. Intrathecal opioids versus epidural local anesthetics for labor analgesia: a meta-analysis.

    Science.gov (United States)

    Bucklin, Brenda A; Chestnut, David H; Hawkins, Joy L

    2002-01-01

    Some anesthesiologists contend that intrathecal opioid administration has advantages over conventional epidural techniques during labor. Randomized clinical trials comparing analgesia and obstetric outcome using single-injection intrathecal opioids versus epidural local anesthetics suggest that intrathecal opioids provide comparable analgesia with few serious side effects. This meta-analysis compared the analgesic efficacy, side effects, and obstetric outcome of single-injection intrathecal opioid techniques versus epidural local anesthetics in laboring women. Relevant clinical studies were identified using electronic and manual searches of the literature covering the period from 1989 to 2000. Searches used the following descriptors: intrathecal analgesia, spinal opioids, epidural analgesia, epidural local anesthetics, and analgesia for labor. Data were extracted from 7 randomized clinical trials comparing analgesic measures, incidence of motor block, pruritus, nausea, hypotension, mode of delivery, and/or Apgar scores. Combined test results indicated comparable analgesic efficacy 15 to 20 minutes after injection with single-injection intrathecal opioid administration. Intrathecal opioid injections were associated with a greater incidence of pruritus (odds ratio, 14.01; 99% confidence interval, 6.9 to 28.3), but there was no difference in the incidence of nausea or in the method of delivery. Published studies suggest that intrathecal opioids provide comparable early labor analgesia when compared with epidural local anesthetics. Intrathecal opioid administration results in a greater incidence of pruritus. The choice of technique does not appear to affect the method of delivery.

  6. Anesthetic management of external cephalic version.

    Science.gov (United States)

    Chalifoux, Laurie A; Sullivan, John T

    2013-09-01

    Breech presentation is common at term and its reduction through external cephalic version represents a noninvasive opportunity to avoid cesarean delivery and the associated maternal morbidity. In addition to uterine relaxants, neuraxial anesthesia is associated with increased success of version procedures when surgical anesthetic dosing is used. The intervention is likely cost effective given the effect size and the avoided high costs of cesarean delivery. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Anesthetic considerations for a pediatric patient with Wolf-Hirschhorn syndrome: a case report

    OpenAIRE

    Tsukamoto, Masanori; Yamanaka, Hitoshi; Yokoyama, Takeshi

    2017-01-01

    Wolf-Hirschhorn syndrome is a rare hereditary disease that results from a 4p chromosome deletion. Patients with this syndrome are characterized by craniofacial dysgenesis, seizures, growth delay, intellectual disability, and congenital heart disease. Although several cases have been reported, very little information is available on anesthetic management for patients with Wolf-Hirschhorn syndrome. We encountered a case requiring anesthetic management for a 2-year-old girl with Wolf-Hirschhorn ...

  8. Intraosseous injection as an adjunct to conventional local anesthetic techniques: A clinical study

    OpenAIRE

    Mohamed Idris; Nasil Sakkir; Kishore Gopalakrishna Naik; Nandakishore Kunijal Jayaram

    2014-01-01

    Background: The achievement of successful local anesthesia is a continual challenge in dentistry. Adjunctive local anesthetic techniques and their armamentaria, such as intraosseous injection (the Stabident system and the X-tip system) have been proposed to be advantageous in cases where the conventional local anesthetic techniques have failed. Aim: A clinical study was undertaken using intraosseous injection system by name X-tip to evaluate its effectiveness in cases where inferior alve...

  9. Comparison of invasive and oscillometric blood pressure measurement techniques in anesthetized camelids.

    Science.gov (United States)

    Aarnes, Turi K; Hubbell, John A E; Lerche, Phillip; Bednarski, Richard M

    2012-08-01

    This study assessed the accuracy of the oscillometric method for arterial blood pressure (ABP) monitoring in anesthetized camelids. Twenty camelids were anesthetized and systolic ABP (SABP), mean ABP (MABP), and diastolic ABP (DABP) were measured directly and using the oscillometric method. The mean difference between SABP measurements was -9.9 ± 21.9 mmHg with a range of -76 to 54 mmHg, and the 95% limits of agreement (LOA) were -33 to 53 mmHg. The difference between DABP measurements was -1.8 ± 15.6 mmHg with a range of -81 to 36 mmHg, and the 95% LOA were -32 to 29 mmHg. The difference between MABP measurements was -2.9 ± 17.0 mmHg with a range of -81 to 36 mmHg, and the 95% LOA were -30 to 36 mmHg. Accurate ABP monitoring in anesthetized camelids cannot be accomplished using the oscillometric method.

  10. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast i......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  11. American options under stochastic volatility

    NARCIS (Netherlands)

    Chockalingam, A.; Muthuraman, K.

    2011-01-01

    The problem of pricing an American option written on an underlying asset with constant price volatility has been studied extensively in literature. Real-world data, however, demonstrate that volatility is not constant, and stochastic volatility models are used to account for dynamic volatility

  12. Proboscis extension reflex platform for volatiles and semi-volatiles detection

    Energy Technology Data Exchange (ETDEWEB)

    Wingo, Robert M. (Los Alamos, NM); McCabe, Kirsten J. (Los Alamos, NM); Haarmann, Timothy K. (Jemez Pueblo, NM)

    2010-11-30

    The present invention provides an apparatus for the detection of volatile and semi-volatile chemicals using the olfactory abilities of honey bees that are trained to respond to the presence of a specific chemical in a sample of gas with the proboscis extension reflex (PER). In particular, the geometry and arrangement of the parts of the apparatus are such that the amount of surface area in contact with the sample of gas prior to its introduction to the bees is minimized to improve the detection of particular volatile and semi-volatile that have a tendency to "stick" to contacting surfaces, especially certain chemicals associated with explosives and narcotics. According to another aspect of the present invention, a pre-concentrating means is incorporated with the device to effectively increase the concentration of "sticky" chemicals presented to the insects.

  13. A noninvasive monitoring device for anesthetics in fish

    DEFF Research Database (Denmark)

    Power, Deborah M.; Fuentes, Juan; Harrison, Adrian Paul

    2010-01-01

    A noninvasive device capable of recording both gill and lateral fin movements was assembled and used to analyze initial and post-treatment activity frequency (Hz) in fish exposed to anesthetics. Exposure of platy fish (Xiphosphorus maculatus) to saponins from quillaja bark (0.185 mM and 0.555 m...

  14. Anesthetic management of a horse with traumatic pneumothorax

    OpenAIRE

    Chesnel, Maud-Aline; Aprea, Francesco; Clutton, R. Eddie

    2012-01-01

    A traumatic pneumothorax and severe hemorrhage were present in a mare with a large thoracic wall defect, lung perforation, and multiple rib fractures. General anesthesia was induced to allow surgical exploration. We describe the anesthetic technique, and discuss the management of the ventilatory, hemodynamic, and metabolic disturbances encountered.

  15. Volatile anesthetic rescue therapy in children with acute asthma: innovative but costly or just costly?.

    Science.gov (United States)

    Char, Danton S; Ibsen, Laura M; Ramamoorthy, Chandra; Bratton, Susan L

    2013-05-01

    To describe volatile anesthesia (VA) use for pediatric asthma, including complications and outcomes. Retrospective cohort study. Children's hospitals contributing to the Pediatric Health Information System between 2004-2008. Children 2-18 years old with a primary diagnosis code for asthma supported with mechanical ventilation. Those treated with VA were compared to those not treated with VA or extracorporeal membrane oxygenation. Hospital VA use was grouped as none, 10% among intubated children. One thousand five hundred and fifty-eight patients received mechanical ventilation at 40 hospitals for asthma: 47 (3%) received VA treatment at 11 (28%) hospitals. Those receiving a VA were significantly less likely to receive inhaled b-agonists, ipratropium bromide, and heliox, but more likely to receive neuromuscular blocking agents than patients treated without VA. Length of mechanical ventilation, hospital stay (length of stay [LOS]) and charges were significantly greater for those treated with VA. Aspiration was more common but death and air leak did not differ. Patients at hospitals with VA use >10% were significantly less likely to receive inhaled b agonist, ipratropium bromide, methylxanthines, and heliox, but more likely to receive systemic b agonist, neuromuscular blocking agents compared to those treated at hospitals not using VA. LOS, duration of ventilation, and hospital charges were significantly greater for patients treated at centers with high VA use. Mortality does not differ between centers that use VA or not. Patients treated at centers with high VA use had significantly increased hospital charges and increased LOS.

  16. Non-opioid anesthetic drug abuse among anesthesia care providers: a narrative review.

    Science.gov (United States)

    Zuleta-Alarcón, Alix; Coffman, John C; Soghomonyan, Suren; Papadimos, Thomas J; Bergese, Sergio D; Moran, Kenneth R

    2017-02-01

    The objective of this narrative review is to provide an overview of the problem of non-opioid anesthetic drug abuse among anesthesia care providers (ACPs) and to describe current approaches to screening, therapy, and rehabilitation of ACPs suffering from non-opioid anesthetic drug abuse. We first performed a search of all literature available on PubMed prior to April 11, 2016. The search was limited to articles published in Spanish and English, and the following key words were used: anesthesiology, anesthesia personnel, AND substance-related disorders. We also searched Ovid MEDLINE ® databases from 1946-April 11, 2016 using the following search terms: anesthesiology OR anesthesia, OR nurse anesthetist OR anesthesia care provider OR perioperative nursing AND substance-related disorders. Despite an increased awareness of drug abuse among ACPs and improvements in preventive measures, the problem of non-opioid anesthetic drug abuse remains significant. While opioids are the most commonly abused anesthesia medications among ACPs, the abuse of non-opioid anesthetics is a significant cause of morbidity, mortality, and professional demise. Early detection, effective therapy, and long-term follow-up help ACPs cope more effectively with the problem and, when possible, resume their professional activities. There is insufficient evidence to determine the ability of ACPs to return safely to anesthesia practice after rehabilitation, though awareness of the issue and ongoing treatment are necessary to minimize patient risk from potentially related clinical errors.

  17. Comparative analysis of assessment methods for operational and anesthetic risks in ulcerative gastroduodenal bleeding

    Directory of Open Access Journals (Sweden)

    Potakhin S.N.

    2015-09-01

    Full Text Available Aim of the investigation: to conduct a comparative analysis of methods of evaluation of surgical and anesthetic risks in ulcerative gastroduodenal bleeding. Materials and methods. A retrospective analysis ofthe extent of the surgical and anesthetic risks and results of treatment of 71 patients with peptic ulcer bleeding has been conducted in the study. To evaluate the surgical and anesthetic risks classification trees are used, scale ТА. Rockall and prognosis System of rebleeding (SPRK, proposed by N. V. Lebedev et al. in 2009, enabling to evaluate the probability of a fatal outcome. To compare the efficacy ofthe methods the following indicators are used: sensitivity, specificity and prediction of positive result. Results. The study compared the results ofthe risk assessment emergency operation by using these methods with the outcome ofthe operation. The comparison ofthe prognosis results in sensitivity leads to the conclusion that the scales ТА. Rockall and SPRK are worse than the developed method of classification trees in recognizing patients with poor outcome of surgery. Conclusion. The method of classification trees can be considered as the most accurate method of evaluation of surgical and anesthetic risks in ulcerative gastroduodenal bleeding.

  18. Comparison of invasive and oscillometric blood pressure measurement techniques in anesthetized camelids

    OpenAIRE

    Aarnes, Turi K.; Hubbell, John A.E.; Lerche, Phillip; Bednarski, Richard M.

    2012-01-01

    This study assessed the accuracy of the oscillometric method for arterial blood pressure (ABP) monitoring in anesthetized camelids. Twenty camelids were anesthetized and systolic ABP (SABP), mean ABP (MABP), and diastolic ABP (DABP) were measured directly and using the oscillometric method. The mean difference between SABP measurements was −9.9 ± 21.9 mmHg with a range of −76 to 54 mmHg, and the 95% limits of agreement (LOA) were −33 to 53 mmHg. The difference between DABP measurements was −1...

  19. An estimation of the minimum effective anesthetic volume of 2% lidocaine in ultrasound-guided axillary brachial plexus block.

    LENUS (Irish Health Repository)

    O'Donnell, Brian D

    2009-07-01

    Ultrasound guidance facilitates precise needle and injectate placement, increasing axillary block success rates, reducing onset times, and permitting local anesthetic dose reduction. The minimum effective volume of local anesthetic in ultrasound-guided axillary brachial plexus block is unknown. The authors performed a study to estimate the minimum effective anesthetic volume of 2% lidocaine with 1:200,000 epinephrine (2% LidoEpi) in ultrasound-guided axillary brachial plexus block.

  20. Volatility and variance swaps : A comparison of quantitative models to calculate the fair volatility and variance strike

    OpenAIRE

    Röring, Johan

    2017-01-01

    Volatility is a common risk measure in the field of finance that describes the magnitude of an asset’s up and down movement. From only being a risk measure, volatility has become an asset class of its own and volatility derivatives enable traders to get an isolated exposure to an asset’s volatility. Two kinds of volatility derivatives are volatility swaps and variance swaps. The problem with volatility swaps and variance swaps is that they require estimations of the future variance and volati...

  1. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Anand, M.; Boyce, J. W.; Burney, D.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Klima, R. L.; Magna, T.; Ni, P.; Steenstra, E.; Tartèse, R.; Vander Kaaden, K. E.

    2018-04-01

    This abstract discusses numerous outstanding questions on the topic of endogenous lunar volatiles that will need to be addressed in the coming years. Although substantial insights into endogenous lunar volatiles have been gained, more work remains.

  2. Anesthetic considerations for a pediatric patient with Wolf-Hirschhorn syndrome: a case report.

    Science.gov (United States)

    Tsukamoto, Masanori; Yamanaka, Hitoshi; Yokoyama, Takeshi

    2017-09-01

    Wolf-Hirschhorn syndrome is a rare hereditary disease that results from a 4p chromosome deletion. Patients with this syndrome are characterized by craniofacial dysgenesis, seizures, growth delay, intellectual disability, and congenital heart disease. Although several cases have been reported, very little information is available on anesthetic management for patients with Wolf-Hirschhorn syndrome. We encountered a case requiring anesthetic management for a 2-year-old girl with Wolf-Hirschhorn syndrome. The selection of an appropriately sized tracheal tube and maintaining intraoperatively stable hemodynamics might be critical problems for anesthetic management. In patients with short stature, the tracheal tube size may differ from what may be predicted based on age. The appropriate size ( internal diameter ) of tracheal tubes for children has been investigated. Congenital heart disease is frequently associated with Wolf-Hirschhorn syndrome. Depending on the degree and type of heart disease, careful monitoring of hemodynamics is important.

  3. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  4. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2008-01-01

    This paper examines the advantages of incorporating strategic exposure to equity volatility into the investment-opportunity set of a long-term equity investor. We consider two standard volatility investments: implied volatility and volatility risk premium strategies. To calibrate and assess the risk/return profile of the portfolio, we present an analytical framework offering pragmatic solutions for long-term investors seeking exposure to volatility. The benefit of volatility exposure for a co...

  5. Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

    2015-01-01

    Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

  6. Trigeminal nerve injury associated with injection of local anesthetics

    DEFF Research Database (Denmark)

    Hillerup, Søren; Jensen, Rigmor H.; Ersbøll, Bjarne Kjær

    2011-01-01

    Background. The authors used comprehensive national registry and clinical data to conduct a study of adverse drug reactions (ADRs), in particular neurosensory disturbance (NSD), associated with local anesthetics used in dentistry. Methods. The study included data sets of annual sales of local...

  7. Physiological responses of cacharas Pseudoplatystoma reticulatum submitted to natural anesthetics

    Directory of Open Access Journals (Sweden)

    Milena Souza dos Santos Sanchez

    2014-02-01

    Full Text Available The present study the aimed to evaluate the induction time, recovery time and physiological responses of cacharas, Pseudoplatystoma reticulatum, submitted to eugenol and menthol. 42 cacharas were exposed to eugenol 100 mgL-1 (n=14 and menthol 150 mgL-1 (n=14 and the control group (n=14 which were not exposed to any anesthetics. At the time 0 and 24 hours after induction, the bloods of 7 fishes per treatment were collected to measure the hematologic parameters and plasma glucose evaluation. The recovery was conducted in aquariums free of anesthetic, and induction and recovery times were monitored. The results were submitted to analysis of variance (P0.05 for induction time, however the recovery time had a significant reduction (P<0.05 for the menthol 150 mgL-1. There was no treatment effects on hematologic parameters, except for mean corpuscular volume (VCM, which was observed an interaction effect between factors, once fish anesthetized with eugenol showed significant reduction (P<0.05 on VCM 24 hours after anesthesia. Plasma glucose values did not differ at 0 hour after induction. 24 hours after induction, both control group and fishes exposed to eugenol and menthol were significantly reduce in VCM. Eugenol at 100 mgL-1 and menthol at 150 mgL-1 may be safely induced in cachara during biometrics procedures.

  8. EFEITOS DA INFUSÃO CONTÍNUA DE CETAMINA S(+ EM EQÜINOS ANESTESIADOS PELO HALOTANO EFFECTS OF S(+-KETAMINE CONTINUOUS RATE INFUSION IN HORSES ANESTHETIZED BY HALOTHANE

    Directory of Open Access Journals (Sweden)

    José Henrique Saraiva Borges

    2010-04-01

    Full Text Available A manutenção da pressão arterial, no transanestésico, consiste grande desafio, principalmente quando se trata da espécie equina, suscetível à instabilidade cardiovascular. Por isso, torna-se imperioso utilizar técnica anestésica que mantenham estáveis os parâmetros cardiovasculares. A cetamina tem sido amplamente empregada na indução anestésica para o halotano em equinos, conferindo-lhes estabilidade cardiovascular. A cetamina S(+, recentemente disponibilizada no mercado, induz estimulação cardiovascular e possui maior potência anestésica e analgésica em relação à cetamina. Todavia, os efeitos dessa substância, administrada por infusão contínua durante a  manutenção da anestesia pelo halotano em equinos, ainda não foram avaliados. Em face da tendência atual de a infusão continuada da cetamina potencializar os anestésicos inalatórios, considerou-se pertinente avaliar os efeitos cardiovasculares e respiratórios desse isômero de cetamina em equinos anestesiados pelo halotano. Conclui-se que a infusão contínua de 0,01mg/kg/min de cetamina S(+ durante anestesia com 1,5 CAM de halotano em equinos não agravou a depressão cardiorrespiratória promovida por esse anestésico inalatório.
     
    PALAVRAS-CHAVES: Cetamina S(+, equinos, halotano, infusão contínua.

    The horse’s blood pressure is susceptible to changes induced by volatile anesthetics. Because of that, the use of anesthesic techniques which keep stable the horse´s blood pressure is essencial. Ketamine is an important induction and maintenance anesthetic agent used in the horse anesthesia practice mainly to improve the blood pressure. S(+-ketamine provides the same effects on the blood pressure, with greater analgesic results and less side effects than the normal ketamine. Although some studies have been conducted with ketamine continuous rate infusion during the halothane anesthetized horses, the S(+-ketamine has not been evaluated

  9. Preparation and evaluation of bioadhesive benzocaine gels for enhanced local anesthetic effects.

    Science.gov (United States)

    Shin, Sang-Chul; Lee, Jin-Woo; Yang, Kyu-Ho; Lee, Chi H

    2003-07-09

    This study was performed to develop new enhanced anesthetic benzocaine gels with a suitable bioadhesive property for local anesthetic effects. As the concentration of benzocaine in the HPMC gels increased up to 15%, the permeation of drug increased, thereafter slightly increased. The activation energy of drug permeation was 11.29 kcal/mol. Bioadhesive forces were also measured. The permeation rate of drug through the skin was studied using various enhancers, such as glycols, non-ionic surfactants or fatty acids. Among the enhancers used, diethylene glycol showed the most enhancing effects. Analgesic activity was examined using a tail-flick analgesimeter. According to the rat tail-flick test, the value of AUEC (0 - 360min) of 15% benzocaine gels containing diethylene glycol was 4662 +/- 200 s min, while that of gels without diethylene glycol was 3353 +/- 132 s min, showing about 1.39-fold increase in analgesic activity. Fifteen percentage of benzocaine gels containing diethylene glycol showed the most enhanced, prolonged analgesic effects, showing the maximum anesthetic effects at 240 min, while the gels without diethylene glycol showed maximum effect at 180 min.

  10. Volatility transmission and volatility impulse response functions in European electricity forward markets

    International Nuclear Information System (INIS)

    Le Pen, Yannick; Sevi, Benoit

    2008-01-01

    Using daily data from March 2001 to June 2005, we estimate a VAR-BEKK model and find evidence of return and volatility spillovers between the German, the Dutch and the British forward electricity markets. We apply Hafner and Herwartz [2006, Journal of International Money and Finance 25, 719-740] Volatility Impulse Response Function(VIRF) to quantify the impact of shock on expected conditional volatility. We observe that a shock has a high positive impact only if its size is large compared to the current level of volatility. The impact of shocks are usually not persistent, which may be an indication of market efficiency. Finally, we estimate the density of the VIRF at different forecast horizon. These fitted distributions are asymmetric and show that extreme events are possible even if their probability is low. These results have interesting implications for market participants whose risk management policy is based on option prices which themselves depend on the volatility level. (authors)

  11. Dissociative anesthetic combination reduces intraocular pressure (IOP in rabbits

    Directory of Open Access Journals (Sweden)

    Ewaldo de Mattos-Junior

    2014-02-01

    Full Text Available The aim of this study was evaluate the effects of three anesthetic combinations, ketamine-midazolam, ketamine-xylazine and tiletamine-zolazepam, on IOP in rabbits. In a experimental, blind, randomized, crossover study, six rabbits were anesthetized with each of 3 treatments in random order. Groups KM (ketamine, 30 mg/kg + midazolam, 1 mg/kg; KX (ketamine, 30 mg/kg + xylazine, 3 mg/kg; and TZ (tiletamine + zolazepam, 20 mg/kg. The drugs were mixed in the same syringe injected intramuscularly (IM into the quadriceps muscle. IOP was measured before drug administration (baseline and at 5-minute intervals for 30 minutes. The data were analyzed by a 2-way repeated measures ANOVA followed by Bonferroni test. All groups had significant decreases in IOP compared to baseline (p 0.05. Administration of either ketamine-midazolam, ketamine-xylazine, or tiletamine-zolazepam similarly decrease IOP in rabbits within 30 minutes of injection.

  12. 21 CFR 346.10 - Local anesthetic active ingredients.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Local anesthetic active ingredients. 346.10 Section 346.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ingredient: (a) Benzocaine 5 to 20 percent. (b) Benzyl alcohol 1 to 4 percent. (c) Dibucaine 0.25 to 1...

  13. The volatility of HOL

    International Nuclear Information System (INIS)

    Wren, D.J.; Sanipelli, G.

    1985-01-01

    The volatility of HOI has been measured using a mass spectrometer to analyze the gas phase above an aqueous solution. The HOI in solution was generated continuously in a flow reactor that combined I/sup -/ and OCl/sup -/ solutions. The analysis has resulted in a lower limit of 6X10/sup 3/ mol . dm/sup -3/ . atm/sup -1/ for the equilibrium constant for the reaction HOI(g)/equilibrium/HOI(aq). This value is a factor 30 greater than the best previous estimate. This new limit for HOI volatility results in higher total iodine partition coefficients, particularly for solutions with pH>8. The upper limit for the equilibrium constant is consistent with essentially zero volatility for HOI. The effect of HOI volatility on total iodine volatility is briefly discussed as a function of solution chemistry and kinetics

  14. The effect of different anesthetics on neurovascular coupling

    Science.gov (United States)

    Franceschini, Maria Angela; Radhakrishnan, Harsha; Thakur, Kiran; Wu, Weicheng; Ruvinskaya, Svetlana; Carp, Stefan; Boas, David A.

    2010-01-01

    To date, the majority of neurovascular coupling studies focused on the thalamic afferents' activity in layer IV and the corresponding large spiking activity as responsible for functional hyperemia. This paper highlights the role of the secondary and late cortico-cortical transmission in neurovascular coupling. Simultaneous scalp electroencephalography (EEG) and diffuse optical imaging (DOI) measurements were obtained during multiple conditions of event-related electrical forepaw stimulation in 33 male Sprague-Dawley rats divided into 6 groups depending on the maintaining anesthetic - alpha-chloralose, pentobarbital, ketamine-xylazine, fentanyl-droperidol, isoflurane, or propofol. The somatosensory evoked potentials (SEP) were decomposed into four components and the question of which best predicts the hemodynamic responses was investigated. Results of the linear regression analysis show that the hemodynamic response is best correlated with the secondary and late cortico-cortical transmissions and not with the initial thalamic input activity in layer IV. Baseline cerebral blood flow (CBF) interacts with neural activity and influences the evoked hemodynamic responses. Finally, neurovascular coupling appears to be the same across all anesthetics used. PMID:20350606

  15. Volume of Anesthetic in 0.5% Marcaine with 1:200,000 Epinephrine Dental Carpule

    Science.gov (United States)

    2016-04-01

    copyrighted material in the thesis manuscript entitled: "Volume of Anesthetic in 0.5% Marcaine with 1:200,000 Epinephrine Dental Carpule" Is...3. School/DepartmenUCenter: Army Postgraduate Dental School, AEGD-2 Program, Fort Hood, TX 4. Phone: (708) 227-2152 5. Type of clearance...X_Thesis _Article _Book _Poster _Presentation _Other 6. Title: "Volume of Anesthetic in 0.5% Marcaine with 1:200,000 Epinephrine Dental Carpule

  16. Wound infiltration with local anesthetics for post-operative pain relief in lumbar spine surgery

    DEFF Research Database (Denmark)

    Kjærgaard, M; Møiniche, S; Olsen, K S

    2012-01-01

    In this systematic review, we evaluated double-blind, randomized and controlled trials on the effect of wound infiltration with local anesthetics compared with the effect of placebo on post-operative pain after lumbar spine surgery.......In this systematic review, we evaluated double-blind, randomized and controlled trials on the effect of wound infiltration with local anesthetics compared with the effect of placebo on post-operative pain after lumbar spine surgery....

  17. Volatility Mean Reversion and the Market Price of Volatility Risk

    NARCIS (Netherlands)

    Boswijk, H.P.

    2001-01-01

    This paper analyzes sources of derivative pricing errors in a stochastic volatility model estimated on stock return data. It is shown that such pricing errors may reflect the existence of a market price of volatility risk, but also may be caused by estimation errors due to a slow mean reversion in

  18. Anesthetic drug wastage in the operation room: A cause for concern

    Directory of Open Access Journals (Sweden)

    Kapil Chaudhary

    2012-01-01

    Full Text Available Context: The cost of anesthetic technique has three main components, i.e., disposable supplies, equipments, and anesthetic drugs. Drug budgets are an easily identifiable area for short-term savings. Aim: To assess and estimate the amount of anesthetic drug wastage in the general surgical operation room. Also, to analyze the financial implications to the hospital due to drug wastage and suggest appropriate steps to prevent or minimize this wastage. Settings and Design: A prospective observational study conducted in the general surgical operation room of a tertiary care hospital. Materials and Methods: Drug wastage was considered as the amount of drug left unutilized in the syringes/vials after completion of a case and any ampoule or vial broken while loading. An estimation of the cost of wasted drug was made. Results: Maximal wastage was associated with adrenaline and lignocaine (100% and 93.63%, respectively. The drugs which accounted for maximum wastage due to not being used after loading into a syringe were adrenaline (95.24%, succinylcholine (92.63%, lignocaine (92.51%, mephentermine (83.80%, and atropine (81.82%. The cost of wasted drugs for the study duration was 46.57% (Rs. 16,044.01 of the total cost of drugs issued/loaded (Rs. 34,449.44. Of this, the cost of wastage of propofol was maximum being 56.27% (Rs. 9028.16 of the total wastage cost, followed by rocuronium 17.80% (Rs. 2856, vecuronium 5.23% (Rs. 840, and neostigmine 4.12% (Rs. 661.50. Conclusions: Drug wastage and the ensuing financial loss can be significant during the anesthetic management of surgical cases. Propofol, rocuronium, vecuronium, and neostigmine are the drugs which contribute maximally to the total wastage cost. Judicious use of these and other drugs and appropriate prudent measures as suggested can effectively decrease this cost.

  19. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    We present and test a model relating a firm's idiosyncratic cost, its exporting status, and the volatilities of its domestic and export sales. In prior models of trade, supply costs for domestic and exports were linear and thus additively separable. We introduce a nonlinear cost function in order...... to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...... has several testable predictions. First, larger firms have lower total and domestic sales volatilities. Second, foreign market volatility increases domestic sales volatilities for exporters. Third, exporters allocate output across both markets in order to reduce total sales volatility. We find...

  20. Time-Varying Periodicity in Intraday Volatility

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

    We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

  1. Perioperative pulmonary aspiration is infrequent and low risk in pediatric anesthetic practice.

    Science.gov (United States)

    Kelly, Christopher J; Walker, Robert W M

    2015-01-01

    Recent studies have reported perioperative pulmonary aspiration in pediatric practice to be an uncommon problem associated with low morbidity and mortality. This paper examines the recent publications in both the adult and pediatric literature and looks at some of the potential risk factors involved, both patient and anesthetic, in the development of aspiration of gastric contents. We also look at the risk of severe morbidity following pulmonary aspiration and speculate on possible reasons behind the assertion that pulmonary aspiration in pediatric anesthetic practice is rare and a low-risk event. © 2014 John Wiley & Sons Ltd.

  2. Periodontal ligament and intraosseous anesthetic injection techniques: alternatives to mandibular nerve blocks.

    Science.gov (United States)

    Moore, Paul A; Cuddy, Michael A; Cooke, Matthew R; Sokolowski, Chester J

    2011-09-01

    and Overview. The provision of mandibular anesthesia traditionally has relied on nerve block anesthetic techniques such as the Halsted, the Gow-Gates and the Akinosi-Vazirani methods. The authors present two alternative techniques to provide local anesthesia in mandibular teeth: the periodontal ligament (PDL) injection and the intraosseous (IO) injection. The authors also present indications for and complications associated with these techniques. The PDL injection and the IO injection are effective anesthetic techniques for managing nerve block failures and for providing localized anesthesia in the mandible. Dentists may find these techniques to be useful alternatives to nerve block anesthesia.

  3. Anesthetic Approach to a Patient with Epidermolysis Bullosa: A Case Report

    Directory of Open Access Journals (Sweden)

    Ersin KOKSAL

    2015-09-01

    Full Text Available Epidermolysis Bullosa (EB is characterized by fragility and formation of blisters in the skin and mucosal membranes. Due to blisters on the airway and occurring new blisters as a result of anesthetic or surgical procedures may complicate anesthesia management. In this case report, we present the anesthetic approach of a 6 years old case with EB who underwent reconstructive surgery. After premedication and optimal monitorization, intravenous (IV anesthesia and analgesia was administered. Associated with the oropharyngeal lesions and limitation to reach an adequate mouth opening, we preferred the facemask to maintain ventilation. Neither new lesions nor complications were detected during or after surgery. [J Contemp Med 2015; 5(3.000: 192-195

  4. Bupivacaine Lozenge Compared with Lidocaine Spray as Topical Pharyngeal Anesthetic before Unsedated Upper Gastrointestinal Endoscopy

    DEFF Research Database (Denmark)

    Salale, Nesrin; Treldal, Charlotte; Mogensen, Stine

    2014-01-01

    Unsedated upper gastrointestinal endoscopy (UGE) can induce patient discomfort, mainly due to a strong gag reflex. The aim was to assess the effect of a bupivacaine lozenge as topical pharyngeal anesthetic compared with standard treatment with a lidocaine spray before UGE. Ninety-nine adult...... with a lidocaine spray proved to be a superior option as topical pharyngeal anesthetic before an UGE....

  5. Local anesthetics: interaction with human erythrocyte membranes as studied by {sup 1}H and {sup 31}P nuclear magnetic resonance; Anestesicos locais: interacao com membranas de eritrocitos de sangue humano, estudada por ressonancia magnetica nuclear de {sup 1}H e {sup 31}P

    Energy Technology Data Exchange (ETDEWEB)

    Fraceto, Leonardo Fernandes; Paula, Eneida de [Universidade Estadual de Campinas, SP (Brazil). Inst. de Biologia. Dept. de Bioquimica]. E-mail: depaula@unicamp.br

    2004-02-01

    The literature carries many theories about the mechanism of action of local anesthetics (LA). We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been studied by {sup 1}H and {sup 31}P nuclear magnetic resonance spectroscopy. It was found that lidocaine (LDC) and benzocaine (BZC) bind to the membranes, increase the mobility of the protons of the phospholipids acyl chains, and decrease the mobility and/or change the structure of the polar head groups. The results indicate that lidocaine molecules are inserted across the polar and liquid interface of the membrane, establishing both electrostatic (charged form) and hydrophobic (neutral form) interactions. Benzocaine locates itself a little deeper in the bilayer, between the interfacial glycerol region and the hydrophobic core. These changes in mobility or conformation of membrane lipids could affect the Na{sup +}-channel protein insertion in the bilayer, stabilizing it in the inactivated state, thus causing anesthesia. (author)

  6. Bias correction in the realized stochastic volatility model for daily volatility on the Tokyo Stock Exchange

    Science.gov (United States)

    Takaishi, Tetsuya

    2018-06-01

    The realized stochastic volatility model has been introduced to estimate more accurate volatility by using both daily returns and realized volatility. The main advantage of the model is that no special bias-correction factor for the realized volatility is required a priori. Instead, the model introduces a bias-correction parameter responsible for the bias hidden in realized volatility. We empirically investigate the bias-correction parameter for realized volatilities calculated at various sampling frequencies for six stocks on the Tokyo Stock Exchange, and then show that the dynamic behavior of the bias-correction parameter as a function of sampling frequency is qualitatively similar to that of the Hansen-Lunde bias-correction factor although their values are substantially different. Under the stochastic diffusion assumption of the return dynamics, we investigate the accuracy of estimated volatilities by examining the standardized returns. We find that while the moments of the standardized returns from low-frequency realized volatilities are consistent with the expectation from the Gaussian variables, the deviation from the expectation becomes considerably large at high frequencies. This indicates that the realized stochastic volatility model itself cannot completely remove bias at high frequencies.

  7. Forecasting volatility of crude oil markets

    International Nuclear Information System (INIS)

    Kang, Sang Hoon; Kang, Sang-Mok; Yoon, Seong-Min

    2009-01-01

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  8. Forecasting volatility of crude oil markets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sang Hoon [Department of Business Administration, Gyeongsang National University, Jinju, 660-701 (Korea); Kang, Sang-Mok; Yoon, Seong-Min [Department of Economics, Pusan National University, Busan, 609-735 (Korea)

    2009-01-15

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  9. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil.

    Science.gov (United States)

    Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

    2017-01-01

    Awake craniotomy allows continuous monitoring of patients' neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic-sedative medication is increasing. Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used.

  10. Functional Characteristics, Electrophysiological and Antennal Immunolocalization of General Odorant-Binding Protein 2 in Tea Geometrid, Ectropis obliqua

    Directory of Open Access Journals (Sweden)

    Ya-Li Zhang

    2018-03-01

    Full Text Available As one of the main lepidopteran pests in Chinese tea plantations, Ectropis obliqua Warren (tea geometrids can severely decrease yields of tea products. The olfactory system of the adult tea geometrid plays a significant role in seeking behaviors, influencing their search for food, mating partners, and even spawning grounds. In this study, a general odorant-binding protein (OBP gene, EoblGOBP2, was identified in the antennae of E. obliqua using reverse transcription quantification PCR (RT-qPCR. Results showed that EoblGOBP2 was more highly expressed in the antennae of males than in females relative to other tissues. The recombinant EoblGOBP2 protein was prepared in Escherichia coli and then purified through affinity chromatography. Ligand-binding assays showed that EoblGOBP2 had a strong binding affinity for some carbonyl-containing tea leaf volatiles (e.g., (E-2-hexenal, methyl salicylate, and acetophenone. Electrophysiological tests confirmed that the male moths were more sensitive to these candidate tea plant volatiles than the female moths. Immunolocalization results indicated that EoblGOBP2 was regionally confined to the sensilla trichoid type-II in the male antennae. These results indicate that EoblGOBP2 may be primarily involved in the olfactory activity of male E. obliqua moths, influencing their ability to sense tea leaf volatiles. This study provides a new perspective of insect GOBPs and implies that olfactory function can be used to prevent and control the tea geometrid.

  11. Anesthetic considerations for rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction (ROHHAD) syndrome in children.

    Science.gov (United States)

    Chandrakantan, Arvind; Poulton, Thomas J

    2013-01-01

    Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction is an increasingly common diagnosis in patients who are being seen at tertiary care children's hospitals. We present two cases of anesthetics from the authors' own experience in addition to a comprehensive review of the disorder and anesthetic implications. © 2012 Blackwell Publishing Ltd.

  12. Heart rate effects of intraosseous injections using slow and fast rates of anesthetic solution deposition.

    Science.gov (United States)

    Susi, Louis; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel; Drum, Melissa

    2008-01-01

    The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heart rate (pulse). The results demonstrated the mean maximum heart rate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1 : 100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heart rate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe.

  13. [Occupational hazards, DNA damage, and oxidative stress on exposure to waste anesthetic gases].

    Science.gov (United States)

    Lucio, Lorena M C; Braz, Mariana G; do Nascimento Junior, Paulo; Braz, José Reinaldo C; Braz, Leandro G

    The waste anesthetic gases (WAGs) present in the ambient air of operating rooms (OR), are associated with various occupational hazards. This paper intends to discuss occupational exposure to WAGs and its impact on exposed professionals, with emphasis on genetic damage and oxidative stress. Despite the emergence of safer inhaled anesthetics, occupational exposure to WAGs remains a current concern. Factors related to anesthetic techniques and anesthesia workstations, in addition to the absence of a scavenging system in the OR, contribute to anesthetic pollution. In order to minimize the health risks of exposed professionals, several countries have recommended legislation with maximum exposure limits. However, developing countries still require measurement of WAGs and regulation for occupational exposure to WAGs. WAGs are capable of inducing damage to the genetic material, such as DNA damage assessed using the comet assay and increased frequency of micronucleus in professionals with long-term exposure. Oxidative stress is also associated with WAGs exposure, as it induces lipid peroxidation, oxidative damage in DNA, and impairment of the antioxidant defense system in exposed professionals. The occupational hazards related to WAGs including genotoxicity, mutagenicity and oxidative stress, stand as a public health issue and must be acknowledged by exposed personnel and responsible authorities, especially in developing countries. Thus, it is urgent to stablish maximum safe limits of concentration of WAGs in ORs and educational practices and protocols for exposed professionals. Copyright © 2017 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  14. [Intra-anesthetic arterial hypotension in elderly patients during emergency surgery: what are the risk factors?

    Science.gov (United States)

    Boubacar Ba, El Hadji; Leye, Papa Alassane; Traoré, Mamadou Mour; Ndiaye, Pape Ibrahima; Gaye, Ibrahima; Bah, Mamadou Diawo; Fall, Mamadou Lamine; Diouf, Elisabeth

    2017-01-01

    Emergency anesthesia in elderly patients aged 65 years and older is complex. The occurrence of intraoperative incidents and arterial hypotension is conditioned by patients' initial health status and by the quality of intraoperative management. This study aimed to determine the incidence of intra-anesthetic arterial hypotension in elderly patients during emergency surgery and to assess the involvement of certain factors in its occurrence: age, sex, patient's history, ASA class, anesthetic technique. We conducted a retrospective descriptive and analytical study in the Emergency Surgery Department at the Aristide Le Dantec University Hospital from 1 March 2014 to 28 February 2015. We collected data from 210 patients out of 224 elderly patients aged 65 years and older undergoing emergency anesthesias (10.93%). Data of 101 men and 109 women were included in the analysis, of whom 64.3% had at least one defect. Patients' preoperative status was assessed using American Society of Anesthesiology (ASA) classification: 71% of patients were ASA class 1 and 2 and 29% were ASA class 3 and 4. Locoregional anesthesia was the most practiced anesthetic technique (56.7%). 28 patients (13.33%) had intra-anesthetic arterial hypotension, of whom 16 under general anesthesia and 12 under locoregional anesthesia. It was more frequent in patients with high ASA class and a little less frequent in patients with PAH and underlying heart disease. Arterial hypotension in elderly patients during emergency surgery exposes the subject to the risk of not negligible intraoperative hypotension, especially in patients with high ASA class. Prevention is based on adequate preoperative assessment and anesthetic management.

  15. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  16. Effect of a New Local Anesthetic Buffering Device on Pain Reduction During Nerve Block lnjections

    Science.gov (United States)

    2014-07-10

    the anticipation of pain associated with dental care is a significant deterrent in seeking treatment. With the advent of modern local anesthesia ...eliminate pain from dental injection to include: application of topical anesthesia , tissue pressure/vibration, cold application, and buffering of the local ...anesthetic solution. In dentistry , the effect of buffering local anesthetic solutions was first studied by Gros and Laewen in 1910 and then by

  17. Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats.

    Science.gov (United States)

    Tudury, Eduardo Alberto; de Figueiredo, Marcella Luiz; Fernandes, Thaiza Helena Tavares; Araújo, Bruno Martins; Bonelli, Marília de Albuquerque; Diogo, Camila Cardoso; Silva, Amanda Camilo; Santos, Cássia Regina Oliveira; Rocha, Nadyne Lorrayne Farias Cardoso

    2017-02-01

    Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% ( P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

  18. Assessment of occupational exposure of medical personnel to inhalatory anesthetics in Poland

    Directory of Open Access Journals (Sweden)

    Małgorzata Kucharska

    2014-02-01

    Full Text Available Objectives: Despite common use of inhalatory anesthetics, such as nitrous oxide (N2O, halothane, sevoflurane, and the like, occupational exposure to these substances in operating theatres was not monitored in Poland until 2006. The situation changed when maximum admissible concentration (MAC values for anesthetics used in Poland were established in 2005 for N2O, and in 2007 for sevoflurane, desflurane and isoflurane. The aim of this work was to assess occupational exposure in operating rooms on the basis of reliable and uniform analytical procedures. Material and Methods: The method for the determination of all anesthetics used in Poland, i.e. nitrous oxide, sevoflurane, isoflurane, desflurane, and halothane, was developed and validated. The measurements were performed in 2006-2010 in 31 hospitals countrywide. The study covered 117 operating rooms; air samples were collected from the breathing zone of 146 anesthesiologists, and 154 nurses, mostly anaesthetic. The measurements were carried out during various surgical operations, mostly on adult patients but also in hospitals for children. Results: Time weighted average concentrations of the anesthetics varied considerably, and the greatest differences were noted for N2O (0.1-1438.5 mg/m3; 40% of the results exceeded the MAC value. Only 3% of halothane, and 2% of sevoflurane concentrations exceeded the respective MAC values. Conclusions: Working in operating theatres is dangerous to the health of the operating staff. The coefficient of combined exposure to anesthesiologists under study exceeded the admissible value in 130 cases, which makes over 40% of the whole study population. Most of the excessive exposure values were noted for nitrous oxide. Med Pr 2014;65(1:43–54

  19. The pharmacological effects of the anesthetic alfaxalone after intramuscular administration to dogs.

    Science.gov (United States)

    Tamura, Jun; Ishizuka, Tomohito; Fukui, Sho; Oyama, Norihiko; Kawase, Kodai; Miyoshi, Kenjiro; Sano, Tadashi; Pasloske, Kirby; Yamashita, Kazuto

    2015-03-01

    The pharmacological effects of the anesthetic alfaxalone were evaluated after intramuscular (IM) administration to 6 healthy beagle dogs. The dogs received three IM doses each of alfaxalone at increasing dose rates of 5 mg/kg (IM5), 7.5 mg/kg (IM7.5) and 10 mg/kg (IM10) every other day. Anesthetic effect was subjectively evaluated by using an ordinal scoring system to determine the degree of neuro-depression and the quality of anesthetic induction and recovery from anesthesia. Cardiorespiratory variables were measured using noninvasive methods. Alfaxalone administered IM produced dose-dependent neuro-depression and lateral recumbency (i.e., 36 ± 28 min, 87 ± 26 min and 115 ± 29 min after the IM5, IM7.5 and IM10 treatments, respectively). The endotracheal tube was tolerated in all dogs for 46 ± 20 and 58 ± 21 min after the IM7.5 and IM10 treatments, respectively. It was not possible to place endotracheal tubes in 5 of the 6 dogs after the IM5 treatment. Most cardiorespiratory variables remained within clinically acceptable ranges, but hypoxemia was observed by pulse oximetry for 5 to 10 min in 2 dogs receiving the IM10 treatment. Dose-dependent decreases in rectal temperature, respiratory rate and arterial blood pressure also occurred. The quality of recovery was considered satisfactory in all dogs receiving each treatment; all the dog exhibited transient muscular tremors and staggering gait. In conclusion, IM alfaxalone produced a dose-dependent anesthetic effect with relatively mild cardiorespiratory depression in dogs. However, hypoxemia may occur at higher IM doses of alfaxalone.

  20. Anesthetic Efficacy of Bupivacaine Solutions in Inferior Alveolar Nerve Block

    Science.gov (United States)

    Volpato, Maria Cristina; Ranali, José; Ramacciato, Juliana Cama; de Oliveira, Patrícia Cristine; Ambrosano, Glaúcia Maria Bovi; Groppo, Francisco Carlos

    2005-01-01

    The purpose of this study was to compare the anesthetic efficacy of 2 bupivacaine solutions. Twenty-two volunteers randomly received in a crossover, double-blinded manner 2 inferior alveolar nerve blocks with 1.8 mL of racemic bupivacaine and a mixture of 75% levobupivacaine and 25% dextrobupivacaine, both 0.5% and with 1 : 200,000 epinephrine. Before and after the injection, the first mandibular pre-molar was evaluated every 2 minutes until no response to the maximal output (80 reading) of the pulp tester and then again every 20 minutes. Data were analyzed using the Wilcoxon paired test and the paired t test. No differences were found between the solutions for onset and duration of pulpal anesthesia and duration of soft tissue anesthesia (P > .05). It was concluded that the solutions have similar anesthetic efficacy. PMID:16596912

  1. When pharmacologic anesthesia is precluded: the value of hypnosis as a sole anesthetic agent in dentistry.

    Science.gov (United States)

    Kleinhauz, M; Eli, I

    1993-01-01

    Occasionally, a dental patient presents his/her dentist with a history of hypersensitivity to local anesthetic agents. The symptoms may include immediate reactions to the injection procedure (dizziness, shortness of breath, tachycardia, etc), or delayed reactions to the anesthetic (swelling, urticaria, etc). Although the true incidence of local anesthetic allergy is low, such a history often involves the patient's anxiety regarding the use of the drug in question, and the dentist's apprehension to treat the "problematic" patient. In such cases, hypnosis can play a major role in controlling pain and the associated distress. In the present article, the method concerning the implementation of hypnosis to induce local anesthesia is described and illustrated through case demonstrations.

  2. NIR studies of cholesterol-dependent structural modification of the model lipid bilayer doped with inhalation anesthetics

    Science.gov (United States)

    Kuć, Marta; Cieślik-Boczula, Katarzyna; Rospenk, Maria

    2018-06-01

    The influence of cholesterol on the structure of the model lipid bilayers treated with inhalation anesthetics (enflurane, isoflurane, sevoflurane and halothane) was investigated employing near-infrared (NIR) spectroscopy combined with the Principal Component Analysis (PCA). The conformational changes occurring in the hydrophobic area of the lipid bilayers were analyzed using the first overtones of symmetric (2νs) and antisymmetric (2νas) stretching vibrations of the CH2 groups of lipid aliphatic chains. The temperature values of chain-melting phase transition (Tm) of anesthetic-mixed dipalmitoylphosphatidylcholine (DPPC)/cholesterol and dipalmitoylphosphatidylglycerol (DPPG)/cholesterol membranes, which were obtained from the PCA analysis, were compared with cholesterol-free DPPC and DPPG bilayers mixed with inhalation anesthetics.

  3. Pre-anesthetic Anxiety Level in Children with Congenital Heart Disease: Comparison between Maternal Presence during Anesthetic Induction and Midazolam Premedication

    Directory of Open Access Journals (Sweden)

    Ratna F Soenarto

    2016-09-01

    Full Text Available General anesthesia was needed by children with congenital heart disease (CHD who underwent cardiaccatheterization procedure and surgery. Pre-anesthetic anxiety in children with CHD can cause significantproblems during induction of anesthesia which leads to negative postoperative outcomes. This studycompared the role of maternal presence during anesthesia induction with midazolam premedication onpre-anesthetic anxiety level in children with CHD. Dr. Cipto Mangunkusumo National Hospital on April toSeptember 2014. Forty-five CHD patients aged 2-5 years old who underwent cardiac invasive procedurewere divided into P group (received midazolam premedication and M group (had maternal presence duringanesthesia induction. Modified Yale Pre-anxiety Scale (MYPAS was used for measuring anxiety level ineach patient during preoperative visit, on the time patient entered the procedure room and during induction ofanesthesia. There was no significant difference of MYPAS scores between the two groups in all measurementtimes. The MYPAS score results were non-anxious (median score 23.4 and the highest was at induction ofanesthesia. Inter-rater agreement test between 2 observers was good (k>0.5. In conclusion, there was nosignificant difference between the effect of maternal presence during induction of anesthesia and midazolampremedication on pre-anesthetic anxiety level in children with CHD. Keywords: pre-anesthetic anxiety, congenital heart disease, maternal presence, midazolam.   Peran Kehadiran Ibu selama Induksi Anestesia dengan PremedikasiMidazolam terhadap Tingkat Kecemasan Pra-anestesia Anak denganPenyakit Jantung Bawan Abstrak Pembiusan umum diperlukan oleh pasien dengan penyakit jantung bawaan (PJB pada saat kateterisasiatau pembedahan jantung. Kecemasan pra-anestesia dapat menimbulkan masalah saat induksi anestesiayang berdampak negatif pascapembedahan. Penelitian ini bertujuan untuk membandingkan efek premedikasimidazolam dan kehadiran ibu selama

  4. Local anesthetics and nuclear medical bone images of the equine fore limb

    International Nuclear Information System (INIS)

    Gaughan, E.M.; Wallace, R.J.; Kallfelz, F.A.

    1990-01-01

    The effects of two local anesthetic agents on the diagnostic quality of nuclear medical bone images (NMBIs) of distal parts of the equine fore limb were investigated. Local effects on bone uptake of technetium 99m methylene diphosphonate (99mTc-MDP) 4 and 24 hours after perineural and intraarticular injection of mepivacaine hydrochloride and bupivacaine hydrochloride were evaluated in the carpal and metacarpophalangeal regions of 12 horses and ponies. Neither mepivacaine hydrochloride nor bupivacaine hydrochloride significantly altered the diagnostic quality of the NMBIs. The injection and subsequent action of local anesthetics do not appear to influence local bone uptake of 99mTc-MDP significantly

  5. Local anesthetic failure associated with inflammation: verification of the acidosis mechanism and the hypothetic participation of inflammatory peroxynitrite

    Directory of Open Access Journals (Sweden)

    Takahiro Ueno

    2008-11-01

    Full Text Available Takahiro Ueno1, Hironori Tsuchiya2, Maki Mizogami1, Ko Takakura11Department of Anesthesiology, Asahi University School of Dentistry, Mizuho, Gifu, Japan; 2Department of Dental Basic Education, Asahi University School of Dentistry, Mizuho, Gifu, JapanAbstract: The presence of inflammation decreases local anesthetic efficacy, especially in dental anesthesia. Although inflammatory acidosis is most frequently cited as the cause of such clinical phenomena, this has not been experimentally proved. We verified the acidosis mechanism by studying the drug and membrane lipid interaction under acidic conditions together with proposing an alternative hypothesis. Liposomes and nerve cell model membranes consisting of phospholipids and cholesterol were treated at different pH with lidocaine, prilocaine and bupivacaine (0.05%–0.2%, w/v. Their membrane-interactive potencies were compared by the induced-changes in membrane fluidity. Local anesthetics fluidized phosphatidylcholine membranes with the potency being significantly lower at pH 6.4 than at pH 7.4 (p < 0.01, supporting the acidosis theory. However, they greatly fluidized nerve cell model membranes even at pH 6.4 corresponding to inflamed tissues, challenging the conventional mechanism. Local anesthetics acted on phosphatidylserine liposomes, as well as nerve cell model membranes, at pH 6.4 with almost the same potency as that at pH 7.4, but not on phosphatidylcholine, phosphatidylethanolamine and sphingomyelin liposomes. Since the positively charged anesthetic molecules are able to interact with nerve cell membranes by ion-paring with anionic components like phosphatidylserine, tissue acidosis is not essentially responsible for the local anesthetic failure associated with inflammation. The effects of local anesthetics on nerve cell model membranes were inhibited by treating with peroxynitrite (50 μM, suggesting that inflammatory cells producing peroxynitrite may affect local anesthesia

  6. Standardization of 2-phenoxyethanol as anesthetic for juvenile Brycon cephalus (Gunther, 1869: the use in field procedures

    Directory of Open Access Journals (Sweden)

    Inoue Luis Antônio Kioshi Aoki

    2004-01-01

    Full Text Available Hyper motility is a negative factor in fish handling procedures due to the risks of damages to the animals. Chemicals are widely used to anesthetize fish during biometry and many other handling procedures. 2-Phenoxyethanol is largely employed, but many studies are necessary about tropical fish responses. The present research evaluated the anesthesia induction time for juvenile matrinxã submitted to eight different levels of 2-phenoxyethanol. The range of 2-phenoxyethanol concentration was 250-600mg liter-1. Induction time of anesthesia decreased as a function of 2-phenoxyethanol concentrations. Fish were safely anesthetized approximately after one minute of exposure to 2-phenoxyethanol batches in concentrations above 400mg/liter, and the recover period was about one minute for all anesthetic concentrations. 2-Phenoxyethanol is a safe anesthetic for juvenile matrinxã even in exposures up to 600mg liter-1 being recommended for many field procedures of fish handling.

  7. Memory-impairing effects of local anesthetics in an elevated plus-maze test in mice

    Directory of Open Access Journals (Sweden)

    S.L. Blatt

    1998-04-01

    Full Text Available Post-training intracerebroventricular administration of procaine (20 µg/µl and dimethocaine (10 or 20 µg/µl, local anesthetics of the ester class, prolonged the latency (s in the retention test of male and female 3-month-old Swiss albino mice (25-35 g body weight; N = 140 in the elevated plus-maze (mean ± SEM for 10 male mice: control = 41.2 ± 8.1; procaine = 78.5 ± 10.3; 10 µg/µl dimethocaine = 58.7 ± 12.3; 20 µg/µl dimethocaine = 109.6 ± 5.73; for 10 female mice: control = 34.8 ± 5.8; procaine = 55.3 ± 13.4; 10 µg/µl dimethocaine = 59.9 ± 12.3 and 20 µg/µl dimethocaine = 61.3 ± 11.1. However, lidocaine (10 or 20 µg/µl, an amide class type of local anesthetic, failed to influence this parameter. Local anesthetics at the dose range used did not affect the motor coordination of mice exposed to the rota-rod test. These results suggest that procaine and dimethocaine impair some memory process(es in the plus-maze test. These findings are interpreted in terms of non-anesthetic mechanisms of action of these drugs on memory impairment and also confirm the validity of the elevated plus-maze for the evaluation of drugs affecting learning and memory in mice

  8. Anesthetic efficacy of ketamine-diazepam, ketamine-xylazine, and ketamine-acepromazine in Caspian Pond turtles (Mauremys caspica).

    Science.gov (United States)

    Adel, Milad; Sadegh, Amin Bigham; Arizza, Vincenzo; Abbasi, Hossein; Inguglia, Luigi; Saravi, Hasan Nasrollahzadeh

    2017-01-01

    The objective of this study was to assess the efficacy of different anesthetic drug combinations on the Caspian Pond turtles ( Mauremys caspica ). Three groups of the Caspian Pond turtles ( n = 6) were anesthetized with three different drug combinations. Initially, a pilot study was conducted to determine the best drug doses for the anesthetization of the turtles, and according to these results, ketamine-diazepam (120 mg/kg ketamine hydrochloride [5%] and 2 mg/kg diazepam [5%]), ketamine-acepromazine (120 mg/kg ketamine hydrochloride [5%] and 1 mg/kg acepromazine [1%]), and ketamine-xylazine (120 mg/kg ketamine hydrochloride [5%] and 1 mg/kg xylazine [2%]) were injected intramuscularly. The onset times of anesthetization and the recovery time were measured. Statistical analysis of the data was performed using one-way analysis of variance followed by t -tests, and P turtles, respectively, compared to that obtained with the ketamine-acepromazine combination and 64% (male turtles) and 50% (female turtles) shorter than that obtained with the ketamine-xylazine combination. Further, the recovery time, in male turtles, was 17% shorter in animals treated with the first drug combination than those treated with the ketamine-acepromazine combination and 37% shorter than those treated with the ketamine-xylazine combination. The recovery time, in female turtles, did not seem to be significantly different among treatments. The study showed that the ketamine-diazepam drug combination is the anesthetic combination with the fastest onset time and shortest recovery time.

  9. The application of a non-linear analysis technique to the monitoring of anesthetic effects in the rat

    NARCIS (Netherlands)

    Broek, P.L.C. van den; Egmond, J. van; Rijn, C.M. van; Dirksen, R.; Coenen, A.M.L.; Booij, L.H.D.J.; Lehnertz, K.; Elger, C.E.; Arnhold, J.; Grassberger, P.

    2000-01-01

    To find a new measure from the EEG that quantifies the effects of anesthetics during surgery, the correlation dimension (CD) of the EEG of eight rats was estimated. To get informed about the anesthetic state, the noxious induced withdrawal reflex (NIWR) was measured, i.e. the force elicited by

  10. Beyond the detergent effect: a binding site for sodium dodecyl sulfate (SDS) in mammalian apoferritin

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Renyu, E-mail: renyu.liu@uphs.upenn.edu; Bu, Weiming; Xi, Jin [University of Pennsylvania, Philadelphia, Pennsylvania (United States); Mortazavi, Shirin R. [Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Cheung-Lau, Jasmina C.; Dmochowski, Ivan J. [University of Pennsylvania, Philadelphia, Pennsylvania (United States); Loll, Patrick J., E-mail: renyu.liu@uphs.upenn.edu [Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2012-05-01

    Using X-ray crystallography and isothermal titration calorimetry, we show that sodium dodecyl sulfate (SDS) binds specifically to a pre-formed internal cavity in horse-spleen apoferritin. Although sodium dodecyl sulfate (SDS) is widely used as an anionic detergent, it can also exert specific pharmacological effects that are independent of the surfactant properties of the molecule. However, structural details of how proteins recognize SDS are scarce. Here, it is demonstrated that SDS binds specifically to a naturally occurring four-helix bundle protein: horse apoferritin. The X-ray crystal structure of the apoferritin–SDS complex was determined at a resolution of 1.9 Å and revealed that the SDS binds in an internal cavity that has previously been shown to recognize various general anesthetics. A dissociation constant of 24 ± 9 µM at 293 K was determined by isothermal titration calorimetry. SDS binds in this cavity by bending its alkyl tail into a horseshoe shape; the charged SDS head group lies in the opening of the cavity at the protein surface. This crystal structure provides insights into the protein–SDS interactions that give rise to binding and may prove useful in the design of novel SDS-like ligands for some proteins.

  11. Impact of microorganism on polonium volatilization

    International Nuclear Information System (INIS)

    Momoshima, N.; Ishida, A.; Fukuda, A.; Yoshinaga, C.

    2007-01-01

    Volatilization of polonium by microorganisms, Chromobacterium violaceum, Escherichia coli and Bacillus subtilis was examined for pure cultures in LB medium at 30 deg C, showing relative Po emission intensity 100, 10 and 1, respectively. Chromobacterium violaceum pre-cultured in LB medium without Po and suspended in water with Po showed high Po volatilization in spite of poor nutriment condition. Antibiotics inhibit volatilization of Po and cultivation at low temperature greatly reduced volatilization. The results strongly support the biological effects on Po volatilization. (author)

  12. Qualitative evaluation of coronary flow during anesthetic induction using thallium-201 perfusion scans

    Energy Technology Data Exchange (ETDEWEB)

    Kleinman, B.; Henkin, R.E.; Glisson, S.N.; el-Etr, A.A.; Bakhos, M.; Sullivan, H.J.; Montoya, A.; Pifarre, R.

    1986-02-01

    Qualitative distribution of coronary flow using thallium-201 perfusion scans immediately postintubation was studied in 22 patients scheduled for elective coronary artery bypass surgery. Ten patients received a thiopental (4 mg/kg) and halothane induction. Twelve patients received a fentanyl (100 micrograms/kg) induction. Baseline thallium-201 perfusion scans were performed 24 h prior to surgery. These scans were compared with the scans performed postintubation. A thallium-positive scan was accepted as evidence of relative hypoperfusion. Baseline hemodynamic and ECG data were obtained prior to induction of anesthesia. These data were compared with the data obtained postintubation. Ten patients developed postintubation thallium-perfusion scan defects (thallium-positive scan), even though there was no statistical difference between their baseline hemodynamics and hemodynamics at the time of intubation. There was no difference in the incidence of thallium-positive scans between those patients anesthetized by fentanyl and those patients anesthetized with thiopental-halothane. The authors conclude that relative hypoperfusion, and possibly ischemia, occurred in 45% of patients studied, despite stable hemodynamics, and that the incidence of these events was the same with two different anesthetic techniques.

  13. Qualitative evaluation of coronary flow during anesthetic induction using thallium-201 perfusion scans

    International Nuclear Information System (INIS)

    Kleinman, B.; Henkin, R.E.; Glisson, S.N.; el-Etr, A.A.; Bakhos, M.; Sullivan, H.J.; Montoya, A.; Pifarre, R.

    1986-01-01

    Qualitative distribution of coronary flow using thallium-201 perfusion scans immediately postintubation was studied in 22 patients scheduled for elective coronary artery bypass surgery. Ten patients received a thiopental (4 mg/kg) and halothane induction. Twelve patients received a fentanyl (100 micrograms/kg) induction. Baseline thallium-201 perfusion scans were performed 24 h prior to surgery. These scans were compared with the scans performed postintubation. A thallium-positive scan was accepted as evidence of relative hypoperfusion. Baseline hemodynamic and ECG data were obtained prior to induction of anesthesia. These data were compared with the data obtained postintubation. Ten patients developed postintubation thallium-perfusion scan defects (thallium-positive scan), even though there was no statistical difference between their baseline hemodynamics and hemodynamics at the time of intubation. There was no difference in the incidence of thallium-positive scans between those patients anesthetized by fentanyl and those patients anesthetized with thiopental-halothane. The authors conclude that relative hypoperfusion, and possibly ischemia, occurred in 45% of patients studied, despite stable hemodynamics, and that the incidence of these events was the same with two different anesthetic techniques

  14. Effectiveness of Hypnosis in Combination with Conventional Techniques of Behavior Management in Anxiety/Pain Reduction during Dental Anesthetic Infiltration

    Directory of Open Access Journals (Sweden)

    A. Ramírez-Carrasco

    2017-01-01

    Full Text Available Background and Objective. Anxiety/pain are experiences that make dental treatment difficult for children, especially during the time of anesthesia. Hypnosis is used in pediatric clinical situations to modify thinking, behavior, and perception as well as, recently, in dentistry; therefore the aim of this study was to evaluate the effectiveness of hypnosis combined with conventional behavior management techniques during infiltration anesthetic. Methods. Anxiety/pain were assessed with the FLACC scale during the anesthetic moment, as well as heart rate variability and skin conductance before and during the anesthetic moment, between the control and experimental group. Results. A marginal statistical difference (p=0.05 was found in the heart rate between baseline and anesthetic moment, being lower in the hypnosis group. No statistically significant differences were found with the FLACC scale or in the skin conductance (p>0.05. Conclusion. Hypnosis combined with conventional behavior management techniques decreases heart rate during anesthetic infiltration showing that there may be an improvement in anxiety/pain control through hypnotic therapy.

  15. The State of Anesthetic Services in Korea: A National Survey of the Status of Anesthesia Provider in the 2011-2013 Period

    Science.gov (United States)

    2016-01-01

    Active involvement of anesthesiologists in perioperative management is important to ensure the patients' safety. This study aimed to investigate the state of anesthetic services in Korea by identifying anesthetic service providers. From the insurance claims data of National Health Insurance for 3 yr, the Korean state of anesthetic services was analyzed. The claims for anesthesia from the medical institutions which hire their own anesthesiologist or with an anesthesiologist invitation fee are assumed to be the anesthesia performed by anesthesiologists. The annual anesthetic data were similar during the study period. In 2013, total counts of 2,129,871 were composed with general anesthesia (55%), regional anesthesia (36%) and procedural sedation with intravenous anesthetics (9%). About 80% of total cases of general anesthesia were performed in general hospitals, while more than 60% of the regional anesthesia and sedation were performed in the clinics and hospitals under 100 beds. Non-anesthesiologists performed 273,006 cases of anesthesia (13% of total) including 36,008 of general anesthesia, 143,134 of regional anesthesia, and 93,864 of sedation, mainly in the clinics and hospitals under 100 beds. All procedural sedations in the institutions without direct employed anesthesiologist were performed by non-anesthesiologists. Significant numbers of anesthesia are performed by non-anesthesiologist in Korea. To promote anesthetic services that prioritize the safety of patients, the standard to qualify anesthetic service is required. Surgeons and patients need to enhance their perception of anesthesia, and the payment system should be revised in a way that advocates anesthesiologist-performed anesthetic services. PMID:26770049

  16. Benzocaine and clove oil as anesthetics for pejerrey (Odontesthes bonariensis fingerlings

    Directory of Open Access Journals (Sweden)

    J. Morato-Fernandes

    2013-10-01

    Full Text Available Pejerrey (Odontesthes bonariensis is a native species from Rio Grande do Sul, Uruguay and Argentina where it is of great economic importance for artisanal fishing. One difficulty in laboratory research with pejerrey is related to its sensitivity, as it presents higher basal cortisol levels than other freshwater species. For this reason, the aim of this work was to evaluate the efficiency of benzocaine and clove oil as anesthetics for pejerrey fingerlings. Two experiments were done where fingerlings (57±7.8mm and 1.1±0.44g were exposed to benzocaine with concentrations between 40mgL-1 and 120mgL-1 and to clove oil with concentrations between 12mgL-1 and 75mgL-1. Survival, anesthesia induction time and recovery time for each pharmaceutics were evaluated. Both benzocaine and clove oil pharmaceutics showed efficiency as anesthetics for pejerrey fingerlings, with negative correlation between the dose of anesthetics and the anesthesia induction time. For benzocaine, the concentrations between 80mgL-1 and 100mgL-1 showed better results, as for clove oil the optimal concentrations were between 25mgL-1 and 50mgL-1. On the other hand, the anesthesia recovery time did not present significant variation on the different concentrations of the tested products. The tested products are highly metabolizable by pejerrey.

  17. Anesthetics rapidly promote synaptogenesis during a critical period of brain development.

    Directory of Open Access Journals (Sweden)

    Mathias De Roo

    Full Text Available Experience-driven activity plays an essential role in the development of brain circuitry during critical periods of early postnatal life, a process that depends upon a dynamic balance between excitatory and inhibitory signals. Since general anesthetics are powerful pharmacological modulators of neuronal activity, an important question is whether and how these drugs can affect the development of synaptic networks. To address this issue, we examined here the impact of anesthetics on synapse growth and dynamics. We show that exposure of young rodents to anesthetics that either enhance GABAergic inhibition or block NMDA receptors rapidly induce a significant increase in dendritic spine density in the somatosensory cortex and hippocampus. This effect is developmentally regulated; it is transient but lasts for several days and is also reproduced by selective antagonists of excitatory receptors. Analyses of spine dynamics in hippocampal slice cultures reveals that this effect is mediated through an increased rate of protrusions formation, a better stabilization of newly formed spines, and leads to the formation of functional synapses. Altogether, these findings point to anesthesia as an important modulator of spine dynamics in the developing brain and suggest the existence of a homeostatic process regulating spine formation as a function of neural activity. Importantly, they also raise concern about the potential impact of these drugs on human practice, when applied during critical periods of development in infants.

  18. Induction of burst suppression or coma using intravenous anesthetics in refractory status epilepticus.

    Science.gov (United States)

    Kang, Bong Su; Jung, Keun-Hwa; Shin, Jeong-Won; Moon, Jang Sup; Byun, Jung-Ick; Lim, Jung-Ah; Moon, Hye Jin; Kim, Young-Soo; Lee, Soon-Tae; Chu, Kon; Lee, Sang Kun

    2015-05-01

    General anesthetic-induced coma therapy has been recommended for the treatment of refractory status epilepticus (RSE). However, the influence of electroencephalographic (EEG) burst suppression (BS) on outcomes still remains unclear. This study investigated the impact of intravenous anesthetic-induced BS on the prognosis of RSE using a retrospective analysis of all consecutive adult patients who received intravenous anesthetic treatment for RSE at the Seoul National University Hospital between January 2006 and June 2011. Twenty-two of the 111 episodes of RSE were enrolled in this study. Of the 22 RSE patients, 12 (54.5%) were women and 18 (81.4%) exhibited generalized convulsive status epilepticus. Sixteen patients (72.7%) were classified as having acute symptomatic etiology, including three patients with anoxic encephalopathy, and others with remote symptomatic etiology. Only two patients (9.1%) had a favorable Status Epilepticus Severity Score (0-2) at admission. All patients received midazolam (MDZ) as a primary intravenous anesthetic drug for RSE treatment; three (13.6%) received MDZ and propofol, and one (4.5%) received MDZ and pentobarbital. The rates of mortality and poor outcome at discharge were 13.6% (n=3) and 54.5% (n=12), respectively. While BS was achieved in six (27.5%) patients, it was not associated with mortality or poor outcome. Induced BS was associated with prolonged hospital stay in subgroup analysis when excluding anoxic encephalopathy. Our results suggest that induction of BS for treating RSE did not affect mortality or outcome at discharge and may lead to an increased length of hospital stay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Anesthetic Management of a Child With Unspecified Mitochondrial Disease in an Outpatient Dental Setting.

    Science.gov (United States)

    Gordon, Taylor R; Montandon, Richard J

    2017-01-01

    Mitochondrial disease (MD) represents a category of metabolic disorders with a wide range of symptoms across a variety of organ systems. It occurs with an incidence of greater than 1:5000 and can be difficult to specifically diagnose because of the variety of clinical presentations and multiple genomic origins. Although phenotypically variable, MD symptoms often include hypotonia, cardiac defects, dysautonomia, and metabolic dysfunction. Mitochondrial disease presents a unique challenge in terms of anesthetic management, as many anesthetic drugs suppress mitochondrial function. Additional considerations may need to be made in order to evaluate the patient's metabolic compensation prior to surgery. This article presents an in-depth discussion of a case involving a nearly 10-year-old boy with a history of an unspecified form of MD, who presented for endodontic treatment of tooth No. 30 under deep sedation. The article also provides a thorough review of the current literature surrounding the anesthetic management of patients with MD.

  20. Local anesthetics for brain tumor resection: current perspectives

    Directory of Open Access Journals (Sweden)

    Potters JW

    2018-02-01

    Full Text Available Jan-Willem Potters, Markus Klimek Department of Anesthesiology, Erasmus MC, Rotterdam, The Netherlands Abstract: This review summarizes the added value of local anesthetics in patients undergoing craniotomy for brain tumor resection, which is a procedure that is carried out frequently in neurosurgical practice. The procedure can be carried out under general anesthesia, sedation with local anesthesia or under local anesthesia only. Literature shows a large variation in the postoperative pain intensity ranging from no postoperative analgesia requirement in two-thirds of the patients up to a rate of 96% of the patients suffering from severe postoperative pain. The only identified causative factor predicting higher postoperative pain scores is infratentorial surgery. Postoperative analgesia can be achieved with multimodal pain management where local anesthesia is associated with lower postoperative pain intensity, reduction in opioid requirement and prevention of development of chronic pain. In awake craniotomy patients, sufficient local anesthesia is a cornerstone of the procedure. An awake craniotomy and brain tumor resection can be carried out completely under local anesthesia only. However, the use of sedative drugs is common to improve patient comfort during craniotomy and closure. Local anesthesia for craniotomy can be performed by directly blocking the six different nerves that provide the sensory innervation of the scalp, or by local infiltration of the surgical site and the placement of the pins of the Mayfield clamp. Direct nerve block has potential complications and pitfalls and is technically more challenging, but mostly requires lower total doses of the local anesthetics than the doses required in surgical-site infiltration. Due to a lack of comparative studies, there is no evidence showing superiority of one technique versus the other. Besides the use of other local anesthetics for analgesia, intravenous lidocaine administration has

  1. Stochastic volatility models and Kelvin waves

    Science.gov (United States)

    Lipton, Alex; Sepp, Artur

    2008-08-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  2. Stochastic volatility models and Kelvin waves

    International Nuclear Information System (INIS)

    Lipton, Alex; Sepp, Artur

    2008-01-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics

  3. Stochastic volatility models and Kelvin waves

    Energy Technology Data Exchange (ETDEWEB)

    Lipton, Alex [Merrill Lynch, Mlfc Main, 2 King Edward Street, London EC1A 1HQ (United Kingdom); Sepp, Artur [Merrill Lynch, 4 World Financial Center, New York, NY 10080 (United States)], E-mail: Alex_Lipton@ml.com, E-mail: Artur_Sepp@ml.com

    2008-08-29

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  4. The modifying effect of anesthetic technique on the metabolic and endocrine responses to anesthesia and surgery

    DEFF Research Database (Denmark)

    Kehlet, H

    1988-01-01

    and the widespread use of the term "stress free anesthesia" in surgery is therefore not valid. However, continuous administration of local anesthetic agents in the epidural space is the most effective technique in so far as reduction of the stress response is concerned. The clinical implication of a variable...... reduction in the stress response to surgery by different anesthetic techniques remains largely unsettled, since only few controlled studies have been published on the clinical effects of pain relief and general anesthesia. However, a vast amount of data exist from controlled studies comparing regional...... anesthesia with local anesthetics and general anesthesia. The cumulative experience from these studies have demonstrated an advantageous effect on postoperative morbidity parameters such as blood loss, postoperative thromboembolic complications, pulmonary infective complications, gastrointestinal motility...

  5. Allosteric ligands and their binding sites define γ-aminobutyric acid (GABA) type A receptor subtypes.

    Science.gov (United States)

    Olsen, Richard W

    2015-01-01

    GABAA receptors (GABA(A)Rs) mediate rapid inhibitory transmission in the brain. GABA(A)Rs are ligand-gated chloride ion channel proteins and exist in about a dozen or more heteropentameric subtypes exhibiting variable age and brain regional localization and thus participation in differing brain functions and diseases. GABA(A)Rs are also subject to modulation by several chemotypes of allosteric ligands that help define structure and function, including subtype definition. The channel blocker picrotoxin identified a noncompetitive channel blocker site in GABA(A)Rs. This ligand site is located in the transmembrane channel pore, whereas the GABA agonist site is in the extracellular domain at subunit interfaces, a site useful for low energy coupled conformational changes of the functional channel domain. Two classes of pharmacologically important allosteric modulatory ligand binding sites reside in the extracellular domain at modified agonist sites at other subunit interfaces: the benzodiazepine site and the high-affinity, relevant to intoxication, ethanol site. The benzodiazepine site is specific for certain GABA(A)R subtypes, mainly synaptic, while the ethanol site is found at a modified benzodiazepine site on different, extrasynaptic, subtypes. In the transmembrane domain are allosteric modulatory ligand sites for diverse chemotypes of general anesthetics: the volatile and intravenous agents, barbiturates, etomidate, propofol, long-chain alcohols, and neurosteroids. The last are endogenous positive allosteric modulators. X-ray crystal structures of prokaryotic and invertebrate pentameric ligand-gated ion channels, and the mammalian GABA(A)R protein, allow homology modeling of GABA(A)R subtypes with the various ligand sites located to suggest the structure and function of these proteins and their pharmacological modulation. © 2015 Elsevier Inc. All rights reserved.

  6. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  7. Anesthetic technique for inferior alveolar nerve block: a new approach

    Science.gov (United States)

    PALTI, Dafna Geller; de ALMEIDA, Cristiane Machado; RODRIGUES, Antonio de Castro; ANDREO, Jesus Carlos; LIMA, José Eduardo Oliveira

    2011-01-01

    Background Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 1329% of cases. Objective Objective: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. Materials and Methods A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition) from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side), and the second following the oclusal plane (left side), a line can be achieved whose projection coincides with the left mandibular foramen. Results The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. Conclusion This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry. PMID:21437463

  8. Volatile accretion history of the Earth.

    Science.gov (United States)

    Wood, B J; Halliday, A N; Rehkämper, M

    2010-10-28

    It has long been thought that the Earth had a protracted and complex history of volatile accretion and loss. Albarède paints a different picture, proposing that the Earth first formed as a dry planet which, like the Moon, was devoid of volatile constituents. He suggests that the Earth's complement of volatile elements was only established later, by the addition of a small veneer of volatile-rich material at ∼100 Myr (here and elsewhere, ages are relative to the origin of the Solar System). Here we argue that the Earth's mass balance of moderately volatile elements is inconsistent with Albarède's hypothesis but is well explained by the standard model of accretion from partially volatile-depleted material, accompanied by core formation.

  9. Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions

    Science.gov (United States)

    2017-03-06

    WP-201317) Demonstration of Novel Sampling Techniques for Measurement of Turbine Engine Volatile and Non-volatile Particulate Matter (PM... Engine Volatile and Non-Volatile Particulate Matter (PM) Emissions 6. AUTHOR(S) E. Corporan, M. DeWitt, C. Klingshirn, M.D. Cheng, R. Miake-Lye, J. Peck...the performance and viability of two devices to condition aircraft turbine engine exhaust to allow the accurate measurement of total (volatile and non

  10. Anesthetic considerations and difficult airway management in a case of Noonan syndrome

    Directory of Open Access Journals (Sweden)

    Sukhminder Jit Singh Bajwa

    2011-01-01

    Full Text Available Noonan syndrome is a genetically transmitted autosomal dominant disorder characterized by various anatomic anomalies and pathophysiologic derangements. Anesthetic management in such cases poses a multitude of challenges, especially related to the airway management and maintenance of cardiovascular stability. We report a case of a 9-year-old male child weighing 24 kg, who was diagnosed as a case of Noonan syndrome and had undergone ligation of patent ductus arteriosus during early childhood. The child was operated on for release of bilateral neck bands under general anesthesia. The case report pertains to the successful airway and anesthetic management in the background of difficult airway and existence of various cardiac lesions.

  11. Assessing the impact on global climate from general anesthetic gases

    DEFF Research Database (Denmark)

    Andersen, Mads P. Sulbæk; Nielsen, Ole John; Wallington, Timothy J.

    2012-01-01

    anthropogenic radiative forcing of climate, as measured relative to the start of the industrial era (approximately 1750). The family of anesthetic gases includes several halogenated organic compounds that are strong greenhouse gases. In this short report, we provide an overview of the state of knowledge...

  12. Financial market volatility and contagion effect: A copula-multifractal volatility approach

    Science.gov (United States)

    Chen, Wang; Wei, Yu; Lang, Qiaoqi; Lin, Yu; Liu, Maojuan

    2014-03-01

    In this paper, we propose a new approach based on the multifractal volatility method (MFV) to study the contagion effect between the U.S. and Chinese stock markets. From recent studies, which reveal that multifractal characteristics exist in both developed and emerging financial markets, according to the econophysics literature we could draw conclusions as follows: Firstly, we estimate volatility using the multifractal volatility method, and find out that the MFV method performs best among other volatility models, such as GARCH-type and realized volatility models. Secondly, we analyze the tail dependence structure between the U.S. and Chinese stock market. The estimated static copula results for the entire period show that the SJC copula performs best, indicating asymmetric characteristics of the tail dependence structure. The estimated dynamic copula results show that the time-varying t copula achieves the best performance, which means the symmetry dynamic t copula is also a good choice, for it is easy to estimate and is able to depict both the upper and lower tail dependence structure. Finally, with the results of the previous two steps, we analyze the contagion effect between the U.S. and Chinese stock markets during the subprime mortgage crisis. The empirical results show that the subprime mortgage crisis started in the U.S. and that its stock market has had an obvious contagion effect on the Chinese stock market. Our empirical results should/might be useful for investors allocating their portfolios.

  13. Dose-dependent effects of the clinical anesthetic isoflurane on Octopus vulgaris: a contribution to cephalopod welfare.

    Science.gov (United States)

    Polese, Gianluca; Winlow, William; Di Cosmo, Anna

    2014-12-01

    Recent progress in animal welfare legislation relating to invertebrates has provoked interest in methods for the anesthesia of cephalopods, for which different approaches to anesthesia have been tried but in most cases without truly anesthetizing the animals. For example, several workers have used muscle relaxants or hypothermia as forms of "anesthesia." Several inhalational anesthetics are known to act in a dose-dependent manner on the great pond snail Lymnaea stagnalis, a pulmonate mollusk. Here we report, for the first time, on the effects of clinical doses of the well-known inhalational clinical anesthetic isoflurane on the behavioral responses of the common octopus Octopus vulgaris. In each experiment, isoflurane was equilibrated into a well-aerated seawater bath containing a single adult O. vulgaris. Using a web camera, we recorded each animal's response to touch stimuli eliciting withdrawal of the arms and siphon and observed changes in the respiratory rate and the chromatophore pattern over time (before, during, and after application of the anesthetic). We found that different animals of the same size responded with similar behavioral changes as the isoflurane concentration was gradually increased. After gradual application of 2% isoflurane for a maximum of 5 min (at which time all the responses indicated deep anesthesia), the animals recovered within 45-60 min in fresh aerated seawater. Based on previous findings in gastropods, we believe that the process of anesthesia induced by isoflurane is similar to that previously observed in Lymnaea. In this study we showed that isoflurane is a good, reversible anesthetic for O. vulgaris, and we developed a method for its use.

  14. Dynamic Estimation of Volatility Risk Premia and Investor Risk Aversion from Option-Implied and Realized Volatilities

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Gibson, Michael; Zhou, Hao

    experiment confirms that the procedure works well in practice. Implementing the procedure with actual S&P500 option-implied volatilities and high-frequency five-minute-based realized volatilities indicates significant temporal dependencies in the estimated stochastic volatility risk premium, which we in turn...

  15. Anesthetic services in Serbia

    Directory of Open Access Journals (Sweden)

    Majstorović Branislava M.

    2016-01-01

    Full Text Available Explanation the topic: Due to the development of knowledge and technology our world is becoming a global city where rapidly occur changes in political and economic milieu, such as the introduction of corporate capitalism in the economic crisis, contemporary migrations etc. Health care as a public good on one hand and as the highest individual value of each individual on the other hand, changes and suffers changes. Health care system policy insists on partnership relation of the individual with medical service providers. This refers to the a secure and accessible modern treatment of each individual and to the state as to rationalize and reduce medical costs with effective methods of treatment. Topic position in scientific/professional public: Anesthesiology is evolving along with the surgical disciplines. Highly sophisticated with organized service, anesthesiology is equally important because of the multiplicity of anesthetic services in the surgical treatment of the disease in terms of teamwork and multidisciplinary treatment of the disease. The intention is to provide a description of work, education and our results in the economic, geopolitical and cultural context of the Serbian health system policy as well as to improve safe performance, availability and cost rationalization in anesthesia. The health care system is territorially organized in Serbia. In hospitals, Serbia employs 940 anesthesiologists (1:7,575 inhabitants. According to data from the Regional Medical Chamber of Belgrade,382 anesthesiologists were registered in Belgrade out of total. Anesthesia department network is well organized in all surgical hospitals. Anesthesia services are available depending on the place of residence, type of surgical illness or injury, and the distance to the nearest clinic. Sub-specializations in the field of anesthesiology have not been introduced although pediatric, neurosurgery and cardiosurgical anesthesia have spontaniously singled, as well as

  16. Parallel Prediction of Stock Volatility

    Directory of Open Access Journals (Sweden)

    Priscilla Jenq

    2017-10-01

    Full Text Available Volatility is a measurement of the risk of financial products. A stock will hit new highs and lows over time and if these highs and lows fluctuate wildly, then it is considered a high volatile stock. Such a stock is considered riskier than a stock whose volatility is low. Although highly volatile stocks are riskier, the returns that they generate for investors can be quite high. Of course, with a riskier stock also comes the chance of losing money and yielding negative returns. In this project, we will use historic stock data to help us forecast volatility. Since the financial industry usually uses S&P 500 as the indicator of the market, we will use S&P 500 as a benchmark to compute the risk. We will also use artificial neural networks as a tool to predict volatilities for a specific time frame that will be set when we configure this neural network. There have been reports that neural networks with different numbers of layers and different numbers of hidden nodes may generate varying results. In fact, we may be able to find the best configuration of a neural network to compute volatilities. We will implement this system using the parallel approach. The system can be used as a tool for investors to allocating and hedging assets.

  17. Volatile communication in plant-aphid interactions.

    Science.gov (United States)

    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Essays on nonparametric econometrics of stochastic volatility

    NARCIS (Netherlands)

    Zu, Y.

    2012-01-01

    Volatility is a concept that describes the variation of financial returns. Measuring and modelling volatility dynamics is an important aspect of financial econometrics. This thesis is concerned with nonparametric approaches to volatility measurement and volatility model validation.

  19. Different sensitivities to competitive inhibition of benzodiazepine receptor binding of {sup 11}C-iomazenil and {sup 11}C-flumazenil in rhesus monkey brain

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Osamu; Hosoi, Rie; Kobayashi, Kaoru [Osaka Univ., Suita (Japan). Medical School; Itoh, Takashi; Gee, A.; Suzuki, Kazutoshi

    2001-04-01

    The in vivo binding kinetics of {sup 11}C-iomazenil were compared with those of {sup 11}C-flumazenil binding in rhesus monkey brain. The monkey was anesthetized with ketamine and intravenously injected with either {sup 11}C-iomazenil or {sup 11}C-flumazenil in combination with the coadministration of different doses of non-radioactive flumazenil (0, 5 and 20 {mu}g/kg). The regional distribution of {sup 11}C-iomazenil in the brain was similar to that of {sup 11}C-flumazenil, but the sensitivity of {sup 11}C-iomazenil binding to competitive inhibition by non-radioactive flumazenil was much less than that of {sup 11}C-flumazenil binding. A significant reduction in {sup 11}C-flumazenil binding in the cerebral cortex was observed with 20 {mu}g/kg of flumazenil, whereas a relatively smaller inhibition of {sup 11}C-iomazenil binding in the same region was observed with the same dose of flumazenil. These results suggest that {sup 11}C-flumazenil may be a superior radiotracer for estimating benzodiazepine receptor occupancy in the intact brain. (author)

  20. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  1. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  2. Development of bupivacaine decorated reduced graphene oxide and its local anesthetic effect-In vivo study.

    Science.gov (United States)

    Zhang, Zhi; Zhang, Xin; Li, Aixiang; Ma, Chuangen

    2018-03-01

    The present works aims to develop bupivacaine modified reduced graphene oxide (BPV/RGO), and comparative evaluation of their anesthetic effect with free bupivacaine (BPV). The prepared BPV/RGO was studied by using various spectroscopic and microscopic characterization studies. In vitro drug release from BPV/RGO was studied using HPLC analysis. The cytotoxicity of BPV/RGO was studied against fibroblast (3T3) cells. In vivo evaluation of anesthetic effects was performed on animal models. BPV/RGO showed a prolonged in vitro release and lower cytotoxicity when compared to free BPV. Also, BPV/RGO showed a significantly prolonged analgesic effect when compared to free BPV. Further, the prepared BPV/RGO drug delivery system demonstrated to function as gifted to overcome the drawbacks of free BPV and other available drug delivery systems by prolonging the anesthetic effect with poor cytotoxicity. Copyright © 2018. Published by Elsevier B.V.

  3. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  4. Increased Total Anesthetic Time Leads to Higher Rates of Surgical Site Infections in Spinal Fusions.

    Science.gov (United States)

    Puffer, Ross C; Murphy, Meghan; Maloney, Patrick; Kor, Daryl; Nassr, Ahmad; Freedman, Brett; Fogelson, Jeremy; Bydon, Mohamad

    2017-06-01

    A retrospective review of a consecutive series of spinal fusions comparing patient and procedural characteristics of patients who developed surgical site infections (SSIs) after spinal fusion. It is known that increased surgical time (incision to closure) is associated with a higher rate of postoperative SSIs. We sought to determine whether increased total anesthetic time (intubation to extubation) is a factor in the development of SSIs as well. In spine surgery for deformity and degenerative disease, SSI has been associated with operative time, revealing a nearly 10-fold increase in SSI rates in prolonged surgery. Surgical time is associated with infections in other surgical disciplines as well. No studies have reported whether total anesthetic time (intubation to extubation) has an association with SSIs. Surgical records were searched in a retrospective fashion to identify all spine fusion procedures performed between January 2010 and July 2012. All SSIs during that timeframe were recorded and compared with the list of cases performed between 2010 and 2012 in a case-control design. There were 20 (1.7%) SSIs in this fusion cohort. On univariate analyses of operative factors, there was a significant association between total anesthetic time (Infection 7.6 ± 0.5 hrs vs. no infection -6.0 ± 0.1 hrs, P operative time (infection 5.5 ± 0.4 hrs vs. no infection - 4.4 ± 0.06 hrs, P infections, whereas level of pathology and emergent surgery were not significant. On multivariate logistic analysis, BMI and total anesthetic time remained independent predictors of SSI whereas ASA status and operative time did not. Increasing BMI and total anesthetic time were independent predictors of SSIs in this cohort of over 1000 consecutive spinal fusions. 3.

  5. Core-Mantle Partitioning of Volatile Elements and the Origin of Volatile Elements in Earth and Moon

    Science.gov (United States)

    Righter, K.; Pando, K.; Danielson, L.; Nickodem, K.

    2014-01-01

    Depletions of siderophile elements in mantles have placed constraints on the conditions on core segregation and differentiation in bodies such as Earth, Earth's Moon, Mars, and asteroid 4 Vesta. Among the siderophile elements there are a sub-set that are also volatile (volatile siderophile elements or VSE; Ga, Ge, In, As, Sb, Sn, Bi, Zn, Cu, Cd), and thus can help to constrain the origin of volatile elements in these bodies, and in particular the Earth and Moon. One of the fundamental observations of the geochemistry of the Moon is the overall depletion of volatile elements relative to the Earth, but a satisfactory explanation has remained elusive. Hypotheses for Earth include addition during accretion and core formation and mobilized into the metallic core, multiple stage origin, or addition after the core formed. Any explanation for volatile elements in the Earth's mantle must also be linked to an explanation of these elements in the lunar mantle. New metal-silicate partitioning data will be applied to the origin of volatile elements in both the Earth and Moon, and will evaluate theories for exogenous versus endogenous origin of volatile elements.

  6. Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

    Directory of Open Access Journals (Sweden)

    M. S. T. Barroso

    2011-06-01

    Full Text Available Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa, whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa. The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

  7. Comparison between newer local anesthetics for myofascial pain syndrome management.

    Science.gov (United States)

    Zaralidou, A Th; Amaniti, E N; Maidatsi, P G; Gorgias, N K; Vasilakos, D F

    2007-06-01

    Myofascial pain syndromes are characterized by the presence of painful loci within muscles, tendons or ligaments, called trigger points. Infiltration of these points with local anesthetics is often used as a treatment modality. The aim of the study was to comparatively evaluate 0.25% levobupivacaine and 0.25% ropivacaine for trigger point injection regarding pain on injection, treatment efficacy and duration of symptoms remission. Sixty-eight patients, suffering from myofascial pain syndromes, were randomly assigned to two groups to receive either levobupivacaine or ropivacaine for trigger-point injection. After completion of the procedure, patients were asked to rate pain during injection and efficacy of the treatment, based on immediate relief. Two weeks later, they were asked about the duration of this relief. Statistical analysis did not reveal significant differences between groups with respect to pain during injection, efficacy of the treatment and duration of pain relief. The two local anesthetics seem to be equally effective for trigger point infiltration. (c) 2007 Prous Science. All rights reserved.

  8. Long Memory in Stock Market Volatility and the Volatility-in-Mean Effect: The FIEGARCH-M Model

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Nielsen, Morten Ørregaard; Zhu, Jie

    We extend the fractionally integrated exponential GARCH (FIEGARCH) model for daily stock return data with long memory in return volatility of Bollerslev and Mikkelsen (1996) by introducing a possible volatility-in-mean effect. To avoid that the long memory property of volatility carries over to r...

  9. Gestational trophoblastic disease with hyperthyroidism: Anesthetic management

    Directory of Open Access Journals (Sweden)

    Puneet Khanna

    2012-01-01

    Full Text Available The coexistence of hyperthyroidism with gestational trophoblastic disease is a known albeit rare clinical condition. We herein report the successful anesthetic management of such a case in our institute. There are only few case reports in literature of this association. Often, the diagnosis of hyperthyroid state is retrospective one, as it can be missed in the emergency scenario of patient requiring molar evacuation. This case report highlights the perioperative management and optimization of hyperthyroid state prior to surgical evacuation of the invasive hydatidiform mole.

  10. Residue analyses on 2-amino-4-phenylthiazole, a piscine anesthetic, in fishes, 3

    International Nuclear Information System (INIS)

    Suzuki, Akira; Shimura, Masaru; Kikuchi, Takahiko; Sekizawa, Yasuharu

    1977-01-01

    The major biotransformation product of 2-amino-phenylthiazole in rainbow trout (Salmo gairdneri irideus) was isolated from water following exposure of fish to the anesthetic. The isolated crystalline metabolite was shown by means of ultraviolet, infrared and optical rotatory dispersion spectroscopy and gas chromatography to be identical to 2-amino-4-phenylthiazole-2-N-β-mono-D-glucopyranosiduronic acid, the major biotransformation product previously found in medaka (killifish, Oryzias latipes). The major biotransformation product in carp (Cyprinus carpio) was also identified as 2-amino-4-phenylthiazole-2-N-β-mono-D-glucopyranosiduronic acid by molecular sieve, thin layer and gas chromatography. Conversion of 2-amino-4-phenylthiazole to the N-glycuronyl conjugate was 8 and 12%, respectively, in rainbow trout and carp as shown by thin layer chromatography of extracts from fish treated with 3 H-labeled anesthetic. In addition, a minor metabolite of the anesthetic in rainbow trout was isolated as a yellowish-white crystalline powder and identified as 2-acetamino-4-(4'-hydroxyphenyl)-thiazole by means of ultraviolet and infrared spectroscopy, NMR and mass spectrometry. Chromatography suggested that this same metabolite was also formed in carp but in concentrations too low for isolation and definitive identification. (auth.)

  11. Isoflurane is a suitable alternative to ether for anesthetizing rats prior to euthanasia for gene expression analysis.

    Science.gov (United States)

    Nakatsu, Noriyuki; Igarashi, Yoshinobu; Aoshi, Taiki; Hamaguchi, Isao; Saito, Masumichi; Mizukami, Takuo; Momose, Haruka; Ishii, Ken J; Yamada, Hiroshi

    2017-01-01

    Diethyl ether (ether) had been widely used in Japan for anesthesia, despite its explosive properties and toxicity to both humans and animals. We also had used ether as an anesthetic for euthanizing rats for research in the Toxicogenomics Project (TGP). Because the use of ether for these purposes will likely cease, it is required to select an alternative anesthetic which is validated for consistency with existing TGP data acquired under ether anesthesia. We therefore compared two alternative anesthetic candidates, isoflurane and pentobarbital, with ether in terms of hematological findings, serum biochemical parameters, and gene expressions. As a result, few differences among the three agents were observed. In hematological and serum biochemistry analysis, no significant changes were found. In gene expression analysis, four known genes were extracted as differentially expressed genes in the liver of rats anesthetized with ether, isoflurane, or pentobarbital. However, no significant relationships were detected using gene ontology, pathway, or gene enrichment analyses by DAVID and TargetMine. Surprisingly, although it was expected that the lung would be affected by administration via inhalation, only one differentially expressed gene was extracted in the lung. Taken together, our data indicate that there are no significant differences among ether, isoflurane, and pentobarbital with respect to effects on hematological parameters, serum biochemistry parameters, and gene expression. Based on its smallest affect to existing data and its safety profile for humans and animals, we suggest isoflurane as a suitable alternative anesthetic for use in rat euthanasia in toxicogenomics analysis.

  12. Asymmetric Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2014-01-01

    markdownabstract__Abstract__ In this paper we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized

  13. Effects of single injection of local anesthetic agents on intervertebral disc degeneration: ex vivo and long-term in vivo experimental study.

    Directory of Open Access Journals (Sweden)

    Koji Iwasaki

    Full Text Available Analgesic discography (discoblock can be used to diagnose or treat discogenic low back pain by injecting a small amount of local anesthetics. However, recent in vitro studies have revealed cytotoxic effects of local anesthetics on intervertebral disc (IVD cells. Here we aimed to investigate the deteriorative effects of lidocaine and bupivacaine on rabbit IVDs using an organotypic culture model and an in vivo long-term follow-up model.For the organotypic culture model, rabbit IVDs were harvested and cultured for 3 or 7 days after intradiscal injection of local anesthetics (1% lidocaine or 0.5% bupivacaine. Nucleus pulposus (NP cell death was measured using confocal microscopy. Histological and TUNEL assays were performed. For in vivo study, each local anesthetic was injected into rabbit lumbar IVDs under a fluoroscope. Six or 12 months after the injection, each IVD was prepared for magnetic resonance imaging (MRI and histological analysis.In the organotypic culture model, both anesthetic agents induced time-dependent NP cell death; when compared with injected saline solution, significant effects were detected within 7 days. Compared with the saline group, TUNEL-positive NP cells were significantly increased in the bupivacaine group. In the in vivo study, MRI analysis did not show any significant difference. Histological analysis revealed that IVD degeneration occurred to a significantly level in the saline- and local anesthetics-injected groups compared with the untreated control or puncture-only groups. However, there was no significant difference between the saline and anesthetic agents groups.In the in vivo model using healthy IVDs, there was no strong evidence to suggest that discoblock with local anesthetics has the potential of inducing IVD degeneration other than the initial mechanical damage of the pressurized injection. Further studies should be performed to investigate the deteriorative effects of the local injection of analgesic agents

  14. Evaluation of the effect of locally administered amitriptyline gel as adjunct to local anesthetics in irreversible pulpitis pain

    Directory of Open Access Journals (Sweden)

    Moghadamnia A

    2009-01-01

    Full Text Available Background: Amitriptyline is one of the most common tricyclic antidepressants, which binds to pain sensory nerve fibers close to the sodium channel; hence, it could interact to some degree with receptors of local anesthetics. This study was designed to assess the additional analgesic effects of 2% Amitriptyline local gel administration in irreversible pulpitis pain of the molars. Materials and Methods: This study was a randomized, double-blind clinical trial that was performed on 56 consented adult patients who did not receive enough analgesia after a lidocaine nerve block for their tooth pulpitis pain. Patients were treated with 0.2 ml of either 2% amitriptyline or placebo, which was directly injected into their mandibular molar pulp chamber after they had received two routine lidocaine injections. Patients were asked to score their pain as a mark on a 10-cm Visual Analogue Scale (VAS at different timepoints: 0 (just before gel administration, 1, 3, 5, 7, and 9 minutes after the treatments. Results: There was a 92.5% decrease in VAS scores of patients 9 minutes after amitriptyline administration compared to Time 0, while in the placebo group this difference was only 13.5%. Further, in the amitriptyline group, the VAS score at all timepoints was statistically different from Time 0 ( P < 0.01. The overall pain reduction and its trend was significantly higher in the amitriptyline group compared with the placebo group ( P < 0.001. Conclusion: Inter-pulp space administration of amitriptyline 2% gel for completing analgesia in irreversible pulpitis pain could be effective and useful as a conjunctive therapy to injections of local anesthetics.

  15. Nonparametric methods for volatility density estimation

    NARCIS (Netherlands)

    Es, van Bert; Spreij, P.J.C.; Zanten, van J.H.

    2009-01-01

    Stochastic volatility modelling of financial processes has become increasingly popular. The proposed models usually contain a stationary volatility process. We will motivate and review several nonparametric methods for estimation of the density of the volatility process. Both models based on

  16. Uncertainty of Volatility Estimates from Heston Greeks

    Directory of Open Access Journals (Sweden)

    Oliver Pfante

    2018-01-01

    Full Text Available Volatility is a widely recognized measure of market risk. As volatility is not observed it has to be estimated from market prices, i.e., as the implied volatility from option prices. The volatility index VIX making volatility a tradeable asset in its own right is computed from near- and next-term put and call options on the S&P 500 with more than 23 days and less than 37 days to expiration and non-vanishing bid. In the present paper we quantify the information content of the constituents of the VIX about the volatility of the S&P 500 in terms of the Fisher information matrix. Assuming that observed option prices are centered on the theoretical price provided by Heston's model perturbed by additive Gaussian noise we relate their Fisher information matrix to the Greeks in the Heston model. We find that the prices of options contained in the VIX basket allow for reliable estimates of the volatility of the S&P 500 with negligible uncertainty as long as volatility is large enough. Interestingly, if volatility drops below a critical value of roughly 3%, inferences from option prices become imprecise because Vega, the derivative of a European option w.r.t. volatility, and thereby the Fisher information nearly vanishes.

  17. Anesthetic technique for inferior alveolar nerve block: a new approach

    Directory of Open Access Journals (Sweden)

    Dafna Geller Palti

    2011-02-01

    Full Text Available BACKGROUND: Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 13-29% of cases. OBJECTIVE: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. MATERIAL AND METHODS: A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side, and the second following the oclusal plane (left side, a line can be achieved whose projection coincides with the left mandibular foramen. RESULTS: The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. CONCLUSION: This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry.

  18. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  19. Effects of apomorphine upon local cerebral glucose utilization in conscious rats and in rats anesthetized with chloral hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Grome, J.J.; McCulloch, J.

    1983-02-01

    The effects of the dopaminergic agonist apomorphine upon local cerebral glucose utilization in 43 anatomically discrete regions of the CNS were examined in conscious, lightly restrained rats and in rats anesthetized with chloral hydrate by means of the quantitative autoradiographic (/sup 14/C)2-deoxyglucose technique. In animals anesthetized with chloral hydrate, glucose utilization was reduced throughout all regions of the CNS from the levels observed in conscious animals. With chloral hydrate anesthesia, the proportionately most marked reductions in glucose use were noted in primary auditory nuclei, thalmaic relay nuclei, and neocortex, and the least pronounced reductions in glucose use (by 15-25% from conscious levels) were observed in limbic areas, some motor relay nuclei, and white matter. In conscious, lightly restrained rats, the administration of apomorphine effected significant increases in glucose utilization in 15 regions of the CNS, and significant reductions in glucose utilization in two regions of the CNS. In rats anesthetized with chloral hydrate, the effects of apomorphine upon local glucose utilization were less widespread and less marked than in conscious animals. The profound effects of chloral hydrate anesthesia upon local cerebral glucose use, and the modification by this anesthetic regime of the local metabolic responses to apomorphine, emphasize the difficulties which exists in the extrapolation of data from anesthetized animals to the conditions which prevail in the conscious animal.

  20. [Comparative effects of vitamin C on the effects of local anesthetics ropivacaine, bupivacaine, and lidocaine on human chondrocytes].

    Science.gov (United States)

    Tian, Jun; Li, Yan

    2016-01-01

    Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns. The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes. The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500μM was determined by Live/Dead assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species. On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaineC effectively improved the reduced chondrocyte viability and decreased the raised apoptosis levels following exposure to anesthesia. At higher doses, vitamin C was found efficient in reducing the generation of reactive oxygen species and as well down-regulate the expressions of caspases 3 and 9. Vitamin C was observed to effectively protect chondrocytes against the toxic insult of local anesthetics ropivacaine, bupivacaine and lidocaine. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  1. Comparative effects of vitamin C on the effects of local anesthetics ropivacaine, bupivacaine, and lidocaine on human chondrocytes.

    Science.gov (United States)

    Tian, Jun; Li, Yan

    2016-01-01

    Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns. The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes. The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500 μM was determined by LIVE/DEAD assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species. On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaineC effectively improved the reduced chondrocyte viability and decreased the raised apoptosis levels following exposure to anesthesia. At higher doses, vitamin C was found efficient in reducing the generation of reactive oxygen species and as well down-regulate the expressions of caspases 3 and 9. Vitamin C was observed to effectively protect chondrocytes against the toxic insult of local anesthetics ropivacaine, bupivacaine and lidocaine. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  2. Ambient Volatility of Triethyl Phosphate

    Science.gov (United States)

    2017-08-01

    of materials is predictable using Raoult’s law. This report details the measurement of the effect of water vapor partial pressure on the volatility...empirical correlation taking into account nonideal behavior was developed to enable estimation of TEPO volatility at any combination of ambient...of the second component is expected to be one-half as much as in the absence of water vapor. Similarly, the measured volatility of the second

  3. Volatility persistence in crude oil markets

    International Nuclear Information System (INIS)

    Charles, Amélie; Darné, Olivier

    2014-01-01

    Financial market participants and policy-makers can benefit from a better understanding of how shocks can affect volatility over time. This study assesses the impact of structural changes and outliers on volatility persistence of three crude oil markets – Brent, West Texas Intermediate (WTI) and Organization of Petroleum Exporting Countries (OPEC) – between January 2, 1985 and June 17, 2011. We identify outliers using a new semi-parametric test based on conditional heteroscedasticity models. These large shocks can be associated with particular event patterns, such as the invasion of Kuwait by Iraq, the Operation Desert Storm, the Operation Desert Fox, and the Global Financial Crisis as well as OPEC announcements on production reduction or US announcements on crude inventories. We show that outliers can bias (i) the estimates of the parameters of the equation governing volatility dynamics; (ii) the regularity and non-negativity conditions of GARCH-type models (GARCH, IGARCH, FIGARCH and HYGARCH); and (iii) the detection of structural breaks in volatility, and thus the estimation of the persistence of the volatility. Therefore, taking into account the outliers on the volatility modelling process may improve the understanding of volatility in crude oil markets. - Highlights: • We study the impact of outliers on volatility persistence of crude oil markets. • We identify outliers and patches of outliers due to specific events. • We show that outliers can bias (i) the estimates of the parameters of GARCH models, (ii) the regularity and non-negativity conditions of GARCH-type models, (iii) the detection of structural breaks in volatility of crude oil markets

  4. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  5. Hyperglycemia adversely modulates endothelial nitric oxide synthase during anesthetic preconditioning through tetrahydrobiopterin- and heat shock protein 90-mediated mechanisms.

    Science.gov (United States)

    Amour, Julien; Brzezinska, Anna K; Jager, Zachary; Sullivan, Corbin; Weihrauch, Dorothee; Du, Jianhai; Vladic, Nikolina; Shi, Yang; Warltier, David C; Pratt, Phillip F; Kersten, Judy R

    2010-03-01

    role in cardioprotection that is favorably modulated by volatile anesthetics and dysregulated by hyperglycemia. Enhancing the production of BH4 may represent a potential therapeutic strategy.

  6. The effect of volatility on percutaneous absorption.

    Science.gov (United States)

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  7. Local anesthetics inhibit induction of ornithine decarboxylase by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate.

    OpenAIRE

    Yuspa, S H; Lichti, U; Ben, T

    1980-01-01

    The induction of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) activity in mouse epidermal cells in vivo and in vitro occurs rapidly after exposure to the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). This induction has characteristics of a cell surface receptor-mediated process. Local anesthetics modify a variety of cellular responses mediated by membrane receptors. When cultured mouse epidermal cells were exposed to the local anesthetics lidocaine, tetracaine...

  8. General anesthetics inhibit erythropoietin induction under hypoxic conditions in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Tomoharu Tanaka

    Full Text Available Erythropoietin (EPO, originally identified as a hematopoietic growth factor produced in the kidney and fetal liver, is also endogenously expressed in the central nervous system (CNS. EPO in the CNS, mainly produced in astrocytes, is induced under hypoxic conditions in a hypoxia-inducible factor (HIF-dependent manner and plays a dominant role in neuroprotection and neurogenesis. We investigated the effect of general anesthetics on EPO expression in the mouse brain and primary cultured astrocytes.BALB/c mice were exposed to 10% oxygen with isoflurane at various concentrations (0.10-1.0%. Expression of EPO mRNA in the brain was studied, and the effects of sevoflurane, halothane, nitrous oxide, pentobarbital, ketamine, and propofol were investigated. In addition, expression of HIF-2α protein was studied by immunoblotting. Hypoxia-induced EPO mRNA expression in the brain was significantly suppressed by isoflurane in a concentration-dependent manner. A similar effect was confirmed for all other general anesthetics. Hypoxia-inducible expression of HIF-2α protein was also significantly suppressed with isoflurane. In the experiments using primary cultured astrocytes, isoflurane, pentobarbital, and ketamine suppressed hypoxia-inducible expression of HIF-2α protein and EPO mRNA.Taken together, our results indicate that general anesthetics suppress activation of HIF-2 and inhibit hypoxia-induced EPO upregulation in the mouse brain through a direct effect on astrocytes.

  9. Interior Volatile Reservoirs in Mercury

    Science.gov (United States)

    Anzures, B. A.; Parman, S. W.; Milliken, R. E.; Head, J. W.

    2018-05-01

    More measurements of 1) surface volatiles, and 2) pyroclastic deposits paired with experimental volatile analyses in silicate minerals can constrain conditions of melting and subsequent eruption on Mercury.

  10. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  11. The effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with orthodontic elastomeric separator placement

    Directory of Open Access Journals (Sweden)

    M. Abu Al-Melh

    2017-01-01

    Full Text Available Abstract Background The initial placement of orthodontic elastomeric separators can be uncomfortable and painful. Therefore, it is important to relieve this disturbing sensation to create a discomfort or pain-free orthodontic visit. The purpose of this study was to investigate the effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with the placement of orthodontic elastomeric separators. Methods Fifty subjects aging between 20–35 years were included in this study. In the maxillary arch, a lidocaine/prilocaine topical anesthetic was placed around the ginigval margins of the premolar and molar on side. On the other side, a placebo agent was placed around the ginigval margins of the premolar and molar. After two minutes, an elastomeric separator was placed between the premolar and molar on both sides. The subjects were then asked to report their findings on a Verbal Scale and a Visual Analogue Scale every second minute for a period of 10 min. The subjects were also given a questionnaire to evaluate the overall impression on the topical anesthetic use. Results The overall mean discomfort/pain score was found to be significantly lower (p < 0.001 with the topical anesthetic than with the placebo. Repeated measures ANOVA with a Greenhouse-Geisser correction determined that mean pain scores were statistically significantly low with the 10-min time duration (F (1.54,42.2 = 40.7, p = 0.001, with an estimated grand mean (8.37, 95% CI 6.75–9.98. The questionnaire responses revealed that 87% of the subjects reported an overall satisfaction and agreement with the topical anesthetic than with the placebo or no difference (13% after the initial separator placement. Conclusions The discomfort and pain resulting from the initial placement of orthodontic elastomeric separators can be significantly reduced with the lidocaine/prilocaine topical anesthetic.

  12. Transient osteoporosis of pregnancy: A case report and review of anesthetic implications

    Directory of Open Access Journals (Sweden)

    Victor Eduardo Anillo Lombana

    2013-01-01

    We reviewed the anesthetic implications of this rare disease, particularly the use of a regional technique that removes the restrictive effect of the hip pain, and therefore increases the risk of a fracture.

  13. Volcanic fluxes of volatiles. Preliminary estimates based on rare gas and major volatile calibration

    International Nuclear Information System (INIS)

    Marty, B.

    1992-01-01

    New estimates for volatile fluxes into the atmosphere and hydrosphere through volcanism have been computed using the measured fluxes of 3 He in oceans and SO 2 in the atmosphere, and the ratios between the volatiles in Mid-Ocean Ridge basalts and in high temperature volcanic gases. These estimates have been checked using independent estimates of the volcanic fluxes. This method provides a reliable means of tracing volatile fluxes, although its precision is restricted by the limited amount of data currently available. (author). 19 refs, 1 tab

  14. [The effect of colored syringes and a colored sheet on the incidence of syringe swaps during anesthetic management].

    Science.gov (United States)

    Hirabayashi, Yoshihiro; Kawakami, Takayuki; Suzuki, Hideo; Igarashi, Takashi; Saitoh, Kazuhiko; Seo, Norimasa

    2005-09-01

    Syringe swap is an important problem in anesthetic care, causing harm to patients. We examined the effect of colored syringe and a colored sheet on the incidence of syringe swaps during anesthetic management. We determined the color code. The blue-syringe contains local anesthetics; yellow-syringe, sympathomimetic drugs; and white-syringe with a red label fixed opposite the scale, muscle relaxants. The colored sheet displays the photographs of the syringe with drug name, dose and volume. The colored syringe and colored sheet were supplied for use from February 2004. We compared the incidence of syringe swaps during the period from February 2004 to January 2005 with that from February 2003 to January 2004. Although five syringe swaps were recorded from February 2003 to January 2004, in 5901 procedures, we encountered no syringe swaps from February 2004 to January 2005, in 6078 procedures. The colored syringe and colored sheet significantly decreased the incidence of syringe swaps during anesthetic management (P sheet together with colored syringes can prevent syringe swaps during anesthesia.

  15. Comparison of anesthetics in electroconvulsive therapy: an effective treatment with the use of propofol, etomidate, and thiopental.

    Science.gov (United States)

    Zahavi, Guy Sender; Dannon, Pinhas

    2014-01-01

    Electroconvulsive therapy (ECT) is considered to be one of the most effective treatments in psychiatry. Currently, three medications for anesthesia are used routinely during ECT: propofol, etomidate, and thiopental. The objective of this study was to evaluate the effects of the anesthetics used in ECT on seizure threshold and duration, hemodynamics, recovery from ECT, and immediate side effects. Our study is a retrospective cohort study, in which a comparison was made between three groups of patients who underwent ECT and were anesthetized with propofol, etomidate, or thiopental. The main effect compared was treatment dose and seizure duration. All patients were chosen as responders to ECT. Data were gathered about 91 patients (39 were anesthetized with thiopental, 29 with etomidate, and 23 with propofol). Patients in the thiopental group received a lower electrical dose compared to the propofol and etomidate group (mean of 459 mC compared to 807 mC and 701 mC, respectively, P<0.001). Motor seizure duration was longer in the thiopental group compared to propofol and etomidate (mean of 40 seconds compared to 21 seconds and 23 seconds, respectively, P=0.018). Seizure duration recorded by electroencephalography was similar in the thiopental and etomidate groups and lower in the propofol group (mean of 57 seconds in both groups compared to 45 seconds, respectively, P=0.038). Patients who were anesthetized with thiopental received a lower electrical treatment dose without an unwanted decrease in seizure duration. Thiopental might be the anesthetic of choice when it is congruent with other medical considerations.

  16. Comparison of the efficacy of two anesthetic techniques of mandibular primary first molar: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Davood Ghasemi Tudeshchoie

    2013-01-01

    Full Text Available Background: The most common technique to anesthetize mandibular primary teeth is inferior alveolar (I.A nerve block injection which induces a relatively sustained anesthesia and in turn may potentially traumatize soft-tissues. Therefore, the need of having an alternative technique of anesthesia with a shorter term but the same efficacy is reasonable. The aim of this study was a comparison of the efficacy of two anesthetic techniques of mandibular primary first molar. Materials and Methods: In this randomized crossover clinical trial, 40 children with ages ranged from 5 years to 8 years whose mandibular primary first molars were eligible for pulpotomy, were selected and divided randomly into two groups. The right and left mandibular first molars of group A were anesthetized with infiltration and I. A nerve block techniques in the first and second sessions respectively. The left and right mandibular first molars of group B were anesthetized with I.A nerve block and infiltration techniques in the first and second sessions respectively. The severity of pain were measured and recorded according to sound-eye-motor scale by a certain person. Data was analyzed using Wilcoxon Signed Rank and Mann-Whitney U tests (P < 0.05. Results: The severity of pain was lower in infiltration technique versus I.A nerve block. There were no significant differences between the severities of pain on pulpal exposure of two techniques. Conclusion: It seems that infiltration technique is more favorable to anesthetize the mandibular primary first molar compared to I.A nerve block.

  17. The effects of general anesthetics on ESR spectra of spin labels in phosphatidylcholine vesicles containing purified Na,K-ATPase or microsomal protein

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Makiko, E-mail: shibu@den.hokudai.ac.jp [Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University (Japan); Hiraoki, Toshifumi [Division of Applied Physics, Graduate School of Engineering, Hokkaido University (Japan); Kimura, Kunie; Fukushima, Kazuaki [Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University (Japan); Suzuki, Kuniaki [Department of Molecular Cell Pharmacology, Graduate School of Dental Medicine, Hokkaido University (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer We studied the effects of general anesthetics on liposome using ESR spectra. Black-Right-Pointing-Pointer Two spin labels, 5-DSA and 16-DSA, were located in different position in liposome. Black-Right-Pointing-Pointer Anesthetics did not change the environment around the spin labels in the liposome. Black-Right-Pointing-Pointer Anesthetics remained on the surface of the lipid bilayer of liposome. Black-Right-Pointing-Pointer Proteins in the liposome did not change the effects of anesthetics on liposome. - Abstract: We investigated the effects of general anesthetics on liposome containing spin labels, 5-doxyl stearic acid (5-DSA) and 16-doxyl stearic acid (16-DSA), and purified Na,K-ATPase or membrane protein of microsome using an electron spin resonance (ESR) spectroscopy. The spectra of 16-DSA in liposomes with both proteins showed three sharp signals compared with 5-DSA. The difference in the order parameter S value of 5-DSA and 16-DSA suggested that the nitroxide radical location of 5-DSA and 16-DSA were different in the membrane bilayer. The results were almost the same as those obtained in liposomes without proteins. The addition of sevoflurane, isoflurane, halothane, ether, ethanol and propofol increased the intensity of the signals, but the clinical concentrations of anesthetics did not significantly alter the S and {tau} values, which are indices of the fluidity of the membrane. These results suggest that anesthetics remain on the surface of the lipid bilayer and do not act on both the inside hydrophobic area and the relatively hydrophilic area near the surface. These results and others also suggest that the existence of Na,K-ATPase and microsomal proteins did not affect the environment around the spin labels in the liposome and the effects of anesthetics on liposome as a model membrane.

  18. A prospective-controlled study of pregnant veterinary staff exposed to inhaled anesthetics and X-rays

    International Nuclear Information System (INIS)

    Shuhaiber, S.; Radee, I. C.; Sakkar, M.; Koren, G.; Einarson, A.

    2002-01-01

    Most veterinary staff are women of reproductive age. They are exposed to 'waste' anesthetic gas and ionizing radiation in their workplace, which may endanger fetal safety. Presently, exposure of female veterinary staff to these health hazards has not been adequately addressed in the medical literature. Our primary objective was to investigate the incidence of major malformations associated with occupational exposure to inhaled anesthetics and/or radiation among pregnant veterinary staff. The secondary objective was to determine the rates of other adverse outcomes. We prospectively collected data on and followed-up women occupationally exposed to inhaled anesthetics and/or radiation in veterinary practices in Ontario, and compared them to controls matched for maternal age gestational age at the time of call to the Motherisk Program. A total of 95 women wee prospectively enrolled and followed-up. Among the participants there were 87 (93.5%) and 88 (92.8%) live births in the study and control groups, respectively. There were 4 (4.8%) major birth defects in the study group and 3 (3.4%) in the control group. The rates of spontaneous abortion were also similar, 6 (6.4%) cases in the study group and 7(7.4%) cases in the control group. These results suggest that Ontario female veterinary staff exposed to inhaled anesthetics and/or radiation do not seem to be at an increased risk for major malformations above baseline risk. (author)

  19. [Chemical components of Vetiveria zizanioides volatiles].

    Science.gov (United States)

    Huang, Jinghua; Li, Huashou; Yang, Jun; Chen, Yufen; Liu, Yinghu; Li, Ning; Nie, Chengrong

    2004-01-01

    The chemical components of the volatiles from Vetiveria zizanioides were analyzed by SPME and GC-MS. In the roots, the main component was valencene (30.36%), while in the shoots and leaves, they were 9-octadecenamide (33.50%), 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene (27.46%), and 1,2-benzendicarboxylic acid, diisooctyl ester(18.29%). The results showed that there were many terpenoids in the volatils. In shoot volatiles, there existed 3 monoterpenes, 2 sequiterpenes and 1 triterpene. Most of the volatiles in roots were sesquiterpenes.

  20. Pregnancy outcome after in utero exposure to local anesthetics as part of dental treatment: A prospective comparative cohort study.

    Science.gov (United States)

    Hagai, Aharon; Diav-Citrin, Orna; Shechtman, Svetlana; Ornoy, Asher

    2015-08-01

    Dental treatment and use of local anesthetics during pregnancy generally are considered harmless because of lack of evidence of adverse pregnancy effects. Data on the safety of dental treatment and local anesthetics during pregnancy are scant. Dental care is often a reason for concern both among women and their health care providers. The primary objective of this study was to evaluate the rate of major anomalies after exposure to local anesthetics as part of dental care during pregnancy. The authors performed a prospective, comparative observational study at the Israeli Teratology Information Services between 1999 and 2005. The authors followed 210 pregnancies exposed to dental local anesthetics (112 [53%] in the first trimester) and compared them with 794 pregnancies not exposed to teratogens. The rate of major anomalies was not significantly different between the groups (4.8% versus 3.3%, P = .300). There was no difference in the rate of miscarriages, gestational age at delivery, or birth weight. The most common types of dental treatment were endodontic treatment (43%), tooth extraction (31%), and tooth restoration (21%). Most women (63%) were not exposed to additional medications. Approximately one-half (51%) of the women were not exposed to dental radiography, and 44% were exposed to radiation, mostly bite-wing radiography. This study's results suggest that use of dental local anesthetics, as well as dental treatment during pregnancy, do not represent a major teratogenic risk. There seems to be no reason to prevent pregnant women from receiving dental treatment and local anesthetics during pregnancy. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

  1. PERUBAHAN KOMPONEN VOLATIL SELAMA FERMENTASI KECAP [Change Volatile Components During Soy Sauce Fermentation

    Directory of Open Access Journals (Sweden)

    Anton Apriyantono1

    2004-08-01

    Full Text Available A study has been conducted to investigate changes of volatile components during soy sauce fermentation. During the fermentation, many volatile components produced may contribute to soy sauce flavor. THe volatile identified by GC-MS werw classified into hydrocarbon (15, alcohol (15, aldehyde (14, ester (14, ketone (9, benzene derivative (11, fatty acid (9, furan (5, terpenoid (18, pyrazine (3, thiazole (1, pyridine (1 and sulfur containing compound (2.Concentration of compounds found in almost all fermentation steps, such as hexanal and benzaldehyde did. These compounds may be derived from raw soybean, since they were all present in raw soybean and their concentration did not change during fermentation. Concentration of palmitic acid and benzeneacetaldehyde, in general, increased during all fermentation steps. They are probably derived from lipid degradation or microorganism activities. Concentrations of some fatty acids, esters and hydrocarbons, such as linoleic acid, methyl palmitate and heptadecane increased during salt fermentation only. Concentration of some other compounds, such as 2,4 decadienal decreased or undetected during fermentation.The absence of some volatile compounds, e.g. (E-nerolidol and (E,E-famesol in boiled soybean which were previously present in raw soybean may be due to evaporation of these compounds during boiling. Some volatile compounds such as, methyl heptadecanoate and few aromatic alcohols are likely derived from Aspergillus sojae, since these compounds were identified only in 0 day koji

  2. Maximum likelihood approach for several stochastic volatility models

    International Nuclear Information System (INIS)

    Camprodon, Jordi; Perelló, Josep

    2012-01-01

    Volatility measures the amplitude of price fluctuations. Despite it being one of the most important quantities in finance, volatility is not directly observable. Here we apply a maximum likelihood method which assumes that price and volatility follow a two-dimensional diffusion process where volatility is the stochastic diffusion coefficient of the log-price dynamics. We apply this method to the simplest versions of the expOU, the OU and the Heston stochastic volatility models and we study their performance in terms of the log-price probability, the volatility probability, and its Mean First-Passage Time. The approach has some predictive power on the future returns amplitude by only knowing the current volatility. The assumed models do not consider long-range volatility autocorrelation and the asymmetric return-volatility cross-correlation but the method still yields very naturally these two important stylized facts. We apply the method to different market indices and with a good performance in all cases. (paper)

  3. Local anesthetic effects of bupivacaine loaded lipid-polymer hybrid nanoparticles: In vitro and in vivo evaluation.

    Science.gov (United States)

    Ma, Pengju; Li, Ting; Xing, Huaixin; Wang, Suzhen; Sun, Yingui; Sheng, Xiugui; Wang, Kaiguo

    2017-05-01

    There is a compelling need for prolonged local anesthetic that would be used for analgesia with a single administration. However, due to the low molecular weight of local anesthetics (LA) (lidocaine, bupivacaine, procaine, dibucaine, etc), they present fast systemic absorption. The aim of the present study was to develop and evaluate bupivacaine lipid-polymer hybrid nanoparticles (BVC LPNs), and compared with BVC loaded PLGA nanoparticles (BVC NPs). Their morphology, particle size, zeta potential and drug loading capacity were evaluated. In vitro release study, stability and cytotoxicity were studied. In vivo evaluation of anesthetic effects was performed on animal models. A facile nanoprecipitation and self-assembly method was optimized to obtain BVC LPNs, composed of PLGA, lecithin and DSPE-PEG 2000 , of ∼175nm particle size. Compared to BVC NPs, BVC LPNs exhibited prolonged in vitro release in phosphate-buffered saline (pH=7.4). Further, BVC LPNs displayed enhanced in vitro stability in 10% FBS and lower cytotoxicity (the concentration of BVC ranging from 1.0μM to 20μM). In addition, BVC LPNs exhibited significantly prolonged analgesic duration. These results demonstrate that the LPNs could function as promising drug delivery system for overcoming the drawbacks of poor stability and rapid drug leakage, and prolonging the anesthetic effect with slight toxicity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Current status of fluoride volatility method development

    Energy Technology Data Exchange (ETDEWEB)

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  5. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

  6. Modelling the Volatility-Return Trade-off when Volatility may be Nonstationary

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Iglesias, Emma M.

    In this paper a new GARCH-M type model, denoted the GARCH-AR, is proposed. In particular, it is shown that it is possible to generate a volatility-return trade-off in a regression model simply by introducing dynamics in the standardized disturbance process. Importantly, the volatility in the GARCH......, we provide an empirical illustration showing the empirical relevance of the GARCH-AR model based on modelling a wide range of leading US stock return series....

  7. Agreement between direct and indirect blood pressure measurements obtained from anesthetized Hispaniolan Amazon parrots.

    Science.gov (United States)

    Acierno, Mark J; da Cunha, Anderson; Smith, Julie; Tully, Thomas N; Guzman, David Sanchez-Migallon; Serra, Verna; Mitchell, Mark A

    2008-11-15

    To determine the level of agreement between direct and indirect blood pressure measurements obtained from healthy Hispaniolan Amazon parrots (Amazona ventralis) anesthetized with isoflurane. Validation study. 16 healthy adult Hispaniolan Amazon parrots. Parrots were anesthetized, and a 26-gauge, 19-mm catheter was placed percutaneously in the superficial ulnar artery for direct measurement of systolic, mean, and diastolic arterial pressures. Indirect blood pressure measurements were obtained with a Doppler ultrasonic flow detector and an oscillometric unit. The Bland-Altman method was used to compare direct and indirect blood pressure values. There was substantial disagreement between direct systolic arterial blood pressure and indirect blood pressure measurements obtained with the Doppler detector from the wing (bias, 24 mm Hg; limits of agreement, -37 to 85 mm Hg) and from the leg (bias, 14 mm Hg; limits of agreement, -14 to 42 mm Hg). Attempts to obtain indirect blood pressure measurements with the oscillometric unit were unsuccessful. Results suggested that there was substantial disagreement between indirect blood pressure measurements obtained with a Doppler ultrasonic flow detector in anesthetized Hispaniolan Amazon parrots and directly measured systolic arterial blood pressure.

  8. Ethyl-p-aminobenzoate (Benzocaine): efficacy as an anesthetic for five species of freshwater fish

    Science.gov (United States)

    Dawson, V.K.; Gilderhus, P.A.

    1979-01-01

    Ethyl-p-aminobenzoate (benzocaine) was tested for its efficacy as an anesthetic for rainbow trout (Salmo gairdnerii, brown trout (Salmo truttas, northern pike (Esox lucius). carp (Cyprinus carpio), and largemouth bass (Mieropterus salmoidesi. Since benzocaine is not water soluble, it was applied with acetone as a carrier. Concentrations of 100 to 200 mg!l were required for large adult northern pike, compared with 50 to 100 mg/l for small fish. Rates of sedation and recovery were slower in cold water than in warm water. Water hardness had little influence on the activity of benzocaine. Fish were anesthetized faster and recovered more slowly in acid than in alkaline water. Benzocaine produced deep anesthesia, but concentrations that rendered the fish handleable within 5 min were generally not safe for exposures longer than 15 min. Concentrations of benzocaine efficacious for fish were not acutely toxic to eggs of coho salmon (Oncorhynchus kisutch), chinook salmon (Oncorhynchus tshauiytschas, rainbow trout, brown trout, or lake trout (Salvelinus namaycush). Benzocaine is not registered for fishery use and is neither more effective nor safer than the registered anesthetic, tricaine methanesulfonate (MS-222l.

  9. Cimetidine as pre-anesthetic agent for cesarean section

    DEFF Research Database (Denmark)

    Qvist, N; Storm, K; Holmskov, A

    1985-01-01

    In a prospective randomized study of 39 consecutive cesarean sections, 20 patients received cimetidine 400 mg intramuscularly as a pre-anesthetic, an 19 control patients were given NaCl. No perinatal effects on the infants were observed by cardiotocography before delivery, and K, Na, pH, PCO2, HC...... with uncomplicated pregnancies, cimetidine was found to cross the placenta at a maternal/cord blood ratio of 3:1. The drug could not be detected in any of the infants 2 hours after delivery....

  10. Targets Involved in Cardioprotection by the Non-Anesthetic Noble Gas Helium

    NARCIS (Netherlands)

    Weber, Nina C.; Smit, Kirsten F.; Hollmann, Markus W.; Preckel, Benedikt

    2015-01-01

    Research data from the past decade indicate that noble gases like xenon and helium exert profound cardioprotection when applied before, during or after organ ischemia. Of all noble gases, especially helium, has gained interest in the past years because it does not have an anesthetic "side effect"

  11. A comparison of anesthetic agents and their effects on the response properties of the peripheral auditory system.

    Science.gov (United States)

    Dodd, F; Capranica, R R

    1992-10-01

    Anesthetic agents were compared in order to identify the most appropriate agent for use during surgery and electrophysiological recordings in the auditory system of the tokay gecko (Gekko gecko). Each agent was first screened for anesthetic and analgesic properties and, if found satisfactory, it was subsequently tested in electrophysiological recordings in the auditory nerve. The following anesthetic agents fulfilled our criteria and were selected for further screening: sodium pentobarbital (60 mg/kg); sodium pentobarbital (30 mg/kg) and oxymorphone (1 mg/kg); 3.2% isoflurane; ketamine (440 mg/kg) and oxymorphone (1 mg/kg). These agents were subsequently compared on the basis of their effect on standard response properties of auditory nerve fibers. Our results verified that different anesthetic agents can have significant effects on most of the parameters commonly used in describing the basic response properties of the auditory system in vertebrates. We therefore conclude from this study that the selection of an appropriate experimental protocol is critical and must take into consideration the effects of anesthesia on auditory responsiveness. In the tokay gecko, we recommend 3.2% isoflurane for general surgical procedures; and for electrophysiological recordings in the eighth nerve we recommend barbiturate anesthesia of appropriate dosage in combination if possible with an opioid agent to provide additional analgesic action.

  12. [Successful anesthetic management of a patient with thyroid storm using landiolol].

    Science.gov (United States)

    Fukushima, Tomihiro; Tokioka, Hiroaki; Ishii, Fumiko; Mikane, Takeshi; Oku, Satoru; Fujii, Hiromi; Katayama, Daisuke; Kawanishi, Susumu; Kosaka, Junko; Nagano, Yuri

    2007-02-01

    We report successful anesthetic management of a 38-year-old man with thyroid storm using an ultra-short acting beta blocker, landiolol. The patient was admitted to the hospital for severe abdominal pain. An emergency laparotomy was scheduled for perforated gastric ulcer under a condition of uncontrolled thyrotoxicosis. On arriving the operating room, he showed tachycardia of 140 beats x min(-1) and blood pressure of 140/75 mmHg and high fever of 39 degrees C with tremor, sweating and diarrhea. He was anesthetized with oxygen, nitrous oxide, sevoflurane and fentanyl. Heart rate was around 130 beats x min(-1), and the landiolol was given continuously at a rate of 0.02-0.04 microg x kg(-1) x min(-1). Heart rate was controlled bellow 120 beats x min(-1) without hypotension during anesthesia. Thiamazole and inorganic iodine were given through an enterostomy tube postoperatively, and heart rate decreased gradually. He was extubated on the third postoperative day without any sequelae.

  13. An overview of anesthetic procedures, tools, and techniques in ambulatory care

    Directory of Open Access Journals (Sweden)

    Messieha Z

    2015-01-01

    Full Text Available Zakaria Messieha Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA Abstract: Ambulatory surgical and anesthesia care (ASAC, also known as Same Day Surgery or Day Care in some countries, is the fastest growing segment of ambulatory surgical and anesthesia care. Over 50 million ambulatory surgical procedures are conducted annually comprising over 60% of all anesthesia care with an impressive track record of safety and efficiency. Advances in ambulatory anesthesia care have been due to newer generation of inhalation and intravenous anesthetics as well as airway management technology and techniques. Successful ambulatory anesthesia care relies on patient selection, adequate facilities, highly trained personnel and quality improvement policies and procedures. Favoring one anesthetic technique over the other should be patient and procedure-specific. Effective management of post-operative pain as well as nausea and vomiting are the final pieces in assuring success in ambulatory anesthesia care. Keywords: ambulatory anesthesia, out-patient anesthesia, Day-Care anesthesia

  14. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI

    International Nuclear Information System (INIS)

    Ciobanu, Luisa; Reynaud, Olivier; Le Bihan, Denis; Uhrig, Lynn; Jarraya, Bechir

    2012-01-01

    During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T2'*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7 T and 17.2 T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine). We showed that the brain/vessels contrast in T2'*- weighted images at 17.2 T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7 T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation. (authors)

  15. Manure application and ammonia volatilization

    NARCIS (Netherlands)

    Huijsmans, J.F.M.

    2003-01-01

    Keywords: manure application, ammonia volatilization, environmental conditions, application technique, incorporation technique, draught force, work organization, costs Livestock manure applied on farmland is an important source of ammonia (NH3) volatilization, and NH3 is a major atmospheric

  16. ANESTHETIC CONSIDERATION S IN CHRONIC OBSTRUCTIVE PULMON ARY DISEASE

    Directory of Open Access Journals (Sweden)

    Awati

    2015-03-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is a spectrum of diseases that includes emphysema, chronic bronchitis, and small airway disease. It i s characterized by progressive increased resistance to breathing. Patients with marked obstructive pulmonary disease are at increased risk for both intraoperative and Postoperative pulmonary complications. These patients require thorough preoperative prepa ration, meticulous intraoperative management & postoperative care. This article describes anesthetic considerations in a patient with COPD.

  17. Amyotrophic lateral sclerosis-A case report and mechanistic review of the association with toluene and other volatile organic compounds.

    Science.gov (United States)

    Ratner, Marcia H; Jabre, Joe F; Ewing, William M; Abou-Donia, Mohamed; Oliver, L Christine

    2018-03-01

    Unmasking of latent neurodegenerative disease has been reported following exposure to chemicals that share one or more mechanisms of action in common with those implicated in the specific disease. For example, unmasking of latent Parkinson's disease (PD) has been associated with exposure to anti-dopaminergic agents, while the progression of pre-existing mild cognitive impairment and unmasking of latent Alzheimer's disease has been associated with exposure to general anesthetic agents which promote Aβ protein aggregation. This literature review and clinical case report about a 45-year-old man with no family history of motor neuron disease who developed overt symptoms of a neuromuscular disorder in close temporal association with his unwitting occupational exposure to volatile organic compounds (VOCs) puts forth the hypothesis that exposure to VOCs such as toluene, which disrupt motor function and increase oxidative stress, can unmask latent ALS type neuromuscular disorder in susceptible individuals. © 2017 Wiley Periodicals, Inc.

  18. Inflation Volatility and the Inflation-Growth Tradeoff in India

    OpenAIRE

    Raghbendra Jha; Varsha S. Kulkarni

    2012-01-01

    This paper amends the New Keynesian Phillips curve model to include inflation volatility and tests the determinants of such volatility for India. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL (1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility along (in the ECM model) and not in the other models. Major det...

  19. Financial Development, Financial Structure, and Macroeconomic Volatility: Evidence from China

    Directory of Open Access Journals (Sweden)

    Feng Wei

    2016-11-01

    Full Text Available Using annual data from 1997–2014 of 30 provinces, municipalities, and autonomous regions, subdividing trended and cyclical volatility of macroeconomics and inflation, considering different indicators of financial development and financial structure, this paper investigated the impact of financial development and financial structure on macroeconomic volatility. The empirical results found that (1 the trended and cyclical volatility of the previous macroeconomic period had a significantly positive impact on that of the current period, and the impact of trended volatility was greater than that of cyclical volatility; (2 financial development had a significantly negative impact on macroeconomic cyclical volatility through inflation cyclical volatility, but inflation trended volatility would amplify macroeconomic volatility; financial markets have no significant effect on macroeconomic volatility; financial structure measured with the ratio of stock market turnover and the efficiency of the financial development had a significant positive impact on macroeconomic cyclical volatility; and (3 inflation trended volatility had a significantly negative impact on macroeconomic cyclical volatility and trended volatility, while inflation cyclical volatility had a significantly positive impact on macroeconomic cyclical volatility.

  20. The Effect of Topical Ocular Anesthetic Proparacaine on Conjunctival and Nasal Mucosal Flora in Dry Eye Disease Patients.

    Science.gov (United States)

    Onerci Celebi, Ozlem; Celebi, Ali Riza Cenk

    2018-04-09

    The aim of this study was to investigate the effect of topically applied ocular anesthetic proparacaine on conjunctival and nasal bacterial mucosal flora in patients with dry eye disease. A Schirmer test was done with (group 1) and without (group 2) topical anesthetic proparacaine to 40 patients in each group. Conjunctival and nasal cultures were obtained before and 10 min after performing the Schirmer test. The bacterial culture results and the isolated bacteria were recorded in two groups. Patients' mean age was 62 years (70 female, 10 male). Before the application of topical anesthetic, 50 (62.5%) and 62 (77.5%) had positive conjunctival and nasal culture, respectively, with the most commonly isolated organism being coagulase-negative Staphylococcus in each group. In group 1 the conjunctival bacterial culture positivity rate decreased from 26 (65%) to six (15%) eyes ( p 0.05). For the nasal cultures, the bacterial culture positivity rate decreased from 80% to 20% and from 75% to 65% in groups 1 ( p 0.05), respectively. Topical ocular anesthetic proparacaine has antibacterial activity in both conjunctival and nasal flora in patients with dry eye disease.

  1. Anesthetic management of a patient with sustained severe metabolic alkalosis and electrolyte abnormalities caused by ingestion of baking soda.

    Science.gov (United States)

    Soliz, Jose; Lim, Jeffrey; Zheng, Gang

    2014-01-01

    The use of alternative medicine is prevalent worldwide. However, its effect on intraoperative anesthetic care is underreported. We report the anesthetic management of a patient who underwent an extensive head and neck cancer surgery and presented with a severe intraoperative metabolic alkalosis from the long term ingestion of baking soda and other herbal remedies.

  2. Effects of Idiosyncratic Volatility in Asset Pricing

    Directory of Open Access Journals (Sweden)

    André Luís Leite

    2016-04-01

    Full Text Available This paper aims to evaluate the effects of the aggregate market volatility components - average volatility and average correlation - on the pricing of portfolios sorted by idiosyncratic volatility, using Brazilian data. The study investigates whether portfolios with high and low idiosyncratic volatility - in relation to the Fama and French model (1996 - have different exposures to innovations in average market volatility, and consequently, different expectations for return. The results are in line with those found for US data, although they portray the Brazilian reality. Decomposition of volatility allows the average volatility component, without the disturbance generated by the average correlation component, to better price the effects of a worsening or an improvement in the investment environment. This result is also identical to that found for US data. Average variance should thus command a risk premium. For US data, this premium is negative. According to Chen and Petkova (2012, the main reason for this negative sign is the high level of investment in research and development recorded by companies with high idiosyncratic volatility. As in Brazil this type of investment is significantly lower than in the US, it was expected that a result with the opposite sign would be found, which is in fact what occurred.

  3. American option pricing with stochastic volatility processes

    Directory of Open Access Journals (Sweden)

    Ping LI

    2017-12-01

    Full Text Available In order to solve the problem of option pricing more perfectly, the option pricing problem with Heston stochastic volatility model is considered. The optimal implementation boundary of American option and the conditions for its early execution are analyzed and discussed. In view of the fact that there is no analytical American option pricing formula, through the space discretization parameters, the stochastic partial differential equation satisfied by American options with Heston stochastic volatility is transformed into the corresponding differential equations, and then using high order compact finite difference method, numerical solutions are obtained for the option price. The numerical experiments are carried out to verify the theoretical results and simulation. The two kinds of optimal exercise boundaries under the conditions of the constant volatility and the stochastic volatility are compared, and the results show that the optimal exercise boundary also has stochastic volatility. Under the setting of parameters, the behavior and the nature of volatility are analyzed, the volatility curve is simulated, the calculation results of high order compact difference method are compared, and the numerical option solution is obtained, so that the method is verified. The research result provides reference for solving the problems of option pricing under stochastic volatility such as multiple underlying asset option pricing and barrier option pricing.

  4. Volatiles in the Martian regolith

    International Nuclear Information System (INIS)

    Clark, B.C.; Baird, A.K.

    1979-01-01

    An inventory of released volatiles on Mars has been derived based upon Viking measurements of atmospheric and surface chemical composition, and upon the inferred mineralogy of a ubiquitous regolith, assumed to average 200m in depth. This model is consistent with the relative abundances of volatiles (except for S) on the Earth's surface, but implies one-fifteenth of the volatile release of Earth if starting materials were comparable. All constituents are accommodated as chemical components of, or absorbed phases on, regolith materials--without the necessity of invoking unobservable deposits of carbonates, nitrates, or permafrost ice

  5. HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

    Directory of Open Access Journals (Sweden)

    Esmeraldo A. Cappelaro

    2015-03-01

    Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

  6. The efficacy of an intraosseous injection system of delivering local anesthetic.

    Science.gov (United States)

    Leonard, M S

    1995-01-01

    This article describes the clinical testing of a new system for the intraosseous delivery of local anesthesia. The author concluded that the system delivered local anesthetic very effectively (in some situations more effectively than the traditional delivery method), thus offering a great potential advantage to both dentists and patients.

  7. Ammonia volatilization from sows on grassland

    Science.gov (United States)

    Sommer, S. G.; Søgaard, H. T.; Møller, H. B.; Morsing, S.

    According to regulations, sows with piglets on organic farms must graze on pastures. Volatilization of ammonia (NH 3) from urine patches may represent a significant source of nitrogen (N) loss from these farms. Inputs of N are low on organic farms and losses may reduce crop production. This study examined spatial variations in NH 3 volatilization using a movable dynamic chamber, and the pH and total ammoniacal nitrogen (TAN) content in the topsoil of pastures with grazing sows was measured during five periods between June 1998 and May 1999. Gross NH 3 volatilization from the pastures was also measured with an atmospheric mass balance technique during seven periods from September 1997 until June 1999. The dynamic chamber study showed a high variation in NH 3 volatilization because of the distribution of urine; losses were between 0 and 2.8 g NH 3-N m -2 day -1. Volatilization was highest near the feeding area and the huts, where the sows tended to urinate. Ammonia volatilization rate was linearly related to the product of NH 3 concentration in the boundary layer and wind speed. The NH 3 in the boundary layer was in equilibrium with NH 3 in soil solution. Gross NH 3 volatilization was in the range 0.07-2.1 kg NH 3-N ha -1 day -1 from a pasture with 24 sows ha -1. Ammonia volatilization was related to the amount of feed given to the sows, incident solar radiation and air temperature during measuring periods, and also to temperature, incident solar radiation and rain 1-2 days before measurements. Annual ammonia loss was 4.8 kg NH 3-N sow -1.

  8. Differences in Motor Evoked Potentials Induced in Rats by Transcranial Magnetic Stimulation under Two Separate Anesthetics: Implications for Plasticity Studies.

    Science.gov (United States)

    Sykes, Matthew; Matheson, Natalie A; Brownjohn, Philip W; Tang, Alexander D; Rodger, Jennifer; Shemmell, Jonathan B H; Reynolds, John N J

    2016-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs) are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however, results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS), a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when selecting an

  9. Herbivore-induced blueberry volatiles and intra-plant signaling.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R

    2011-12-18

    Herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack. These HIPVs are mainly regulated by the defensive plant hormone jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA). Over the past 3 decades researchers have documented that HIPVs can repel or attract herbivores, attract the natural enemies of herbivores, and in some cases they can induce or prime plant defenses prior to herbivore attack. In a recent paper, I reported that feeding by gypsy moth caterpillars, exogenous MeJA application, and mechanical damage induce the emissions of volatiles from blueberry plants, albeit differently. In addition, blueberry branches respond to HIPVs emitted from neighboring branches of the same plant by increasing the levels of JA and resistance to herbivores (i.e., direct plant defenses), and by priming volatile emissions (i.e., indirect plant defenses). Similar findings have been reported recently for sagebrush, poplar, and lima beans. Here, I describe a push-pull method for collecting blueberry volatiles induced by herbivore (gypsy moth) feeding, exogenous MeJA application, and mechanical damage. The volatile collection unit consists of a 4 L volatile collection chamber, a 2-piece guillotine, an air delivery system that purifies incoming air, and a vacuum system connected to a trap filled with Super-Q adsorbent to collect volatiles. Volatiles collected in Super-Q traps are eluted with dichloromethane and then separated and quantified using Gas Chromatography (GC). This volatile collection method was used in my study to investigate the volatile response of undamaged branches to exposure to volatiles from herbivore-damaged branches within blueberry plants. These methods are described here. Briefly, undamaged blueberry branches are exposed to HIPVs from neighboring branches within the same plant. Using the same techniques described above, volatiles emitted from branches after exposure to HIPVs are collected and

  10. Halogenated Anesthetics Determination in Urine by SPME/GC/MS and Urine Levels Relationship Evaluation with Surgical Theatres Contamination

    Directory of Open Access Journals (Sweden)

    Serena Indelicato

    2014-01-01

    Full Text Available In this work, a new sensitive analytical method has been developed and evaluated for the determination of the most commonly used gaseous anesthetics, desflurane, sevoflurane, and this latter’s hepatic metabolite hexafluoroisopropanol (HFIP in the urine. In addition, an evaluation of anesthetics exposition on the urine levels of a small population of surgical operators has been performed and results are briefly discussed.

  11. Endogenous Lunar Volatiles: Insights into the Abundances of Volatiles in the Moon from Lunar Apatite

    Science.gov (United States)

    McCubbin, Francis

    2016-01-01

    At the time of publication of New Views of the Moon, it was thought that the Moon was bone dry with less than about 1 ppb H2O. However in 2007, initial reports at the 38th Lunar and Planetary Science Conference speculated that H-species were present in both apatites and pyroclastic volcanic lunar glasses. These early reports were later confirmed through peer-review, which motivated many subsequent studies on magmatic volatiles in and on the Moon within the last decade. Some of these studies have cast into question the post-Apollo view of lunar formation, the distribution and sources of volatiles in the Earth-Moon system, and the thermal and magmatic evolution of the Moon. The mineral apatite has been one of the pillars of this new field of study, and it will be the primary focus of this abstract. Although apatite has been used both to understand the abundances of volatiles in lunar systems as well as the isotopic compositions of those volatiles, the focus here will be on the abundances of F, Cl, and H2O. This work demonstrates the utility of apatite in advancing our understanding of lunar volatiles, hence apatite should be among the topics covered in the endogenous lunar volatile chapter in NVM II. Truncated ternary plot of apatite X-site occupancy (mol%) from highlands apatite and mare basalt apatite plotted on the relative volatile abundance diagram from. The solid black lines delineate fields of relative abundances of F, Cl, and H2O (on a weight basis) in the melt from which the apatite crystallized. The diagram was constructed using available apatite/melt partitioning data for fluorine, chlorine, and hydroxyl.

  12. A comparison of two intraosseous anesthetic techniques in mandibular posterior teeth.

    Science.gov (United States)

    Gallatin, Juliane; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel

    2003-11-01

    A number of studies have evaluated the Stabident (Fairfax Dental, Miami) intraosseous anesthesia technique. A second intraosseous technique--the X-tip system (X-tip Technologies, Lakewood, N.J.)--has been introduced, but no scientific studies have yet compared its effectiveness to that of the Stabident system. The authors undertook a study to compare the two systems' anesthetic outcomes in primary intraosseous injections in mandibular posterior teeth. The authors, using a crossover design, randomly administered a primary Stabident intraosseous injection and a primary X-tip intraosseous injection, at two separate appointments, to 41 subjects. Subjects were asked if they perceived an increase in heart rate with the intraosseous injections. The research team blind-tested each subject's first molar, second molar and second premolar with a pulp tester at two-minute cycles for 60 minutes after the injection. Anesthesia was considered successful when two consecutive pulp tester readings of 80 were obtained. Anesthetic success rates for the Stabident technique and the X-tip technique, respectively, were 93 percent and 93 percent for the first molar; 95 percent and 95 percent for the second molar; and 81 percent and 83 percent for the second premolar, with no significant differences (P > .05) between the two techniques. For both intraosseous techniques, onset of pulpal anesthesia occurred within the first two minutes, but the duration of anesthesia declined steadily over the 60 minutes. Eighty-five percent of the subjects had a perceived increase in heart rate with the Stabident injection and 93 percent with the X-tip injection, with no significant differences (P > .05) between the techniques. The two primary intraosseous injection techniques were similar regarding anesthetic success, onset, duration and perceived heart rate increases.

  13. Anesthetic and Perioperative Management of Patients With Brugada Syndrome.

    Science.gov (United States)

    Dendramis, Gregory; Paleologo, Claudia; Sgarito, Giuseppe; Giordano, Umberto; Verlato, Roberto; Baranchuk, Adrian; Brugada, Pedro

    2017-09-15

    Brugada syndrome (BrS) is an arrhythmogenic disease reported to be one among the leading causes of cardiac death in subjects under the age of 40 years. In these patients, episodes of lethal arrhythmias may be induced by several factors or situations, and for this reason, management during anesthesia and surgery must provide some precautions and drugs restrictions. To date, it is difficult to formulate guidelines for anesthetic management of patients with BrS because of the absence of prospective studies, and there is not a definite recommendation for neither general nor regional anesthesia, and there are no large studies in merit. For this reason, in the anesthesia management of patients with BrS, the decision of using each drug must be made after careful consideration and always in controlled conditions, avoiding other factors that are known to have the potential to induce arrhythmias and with a close cooperation between anesthetists and cardiologists, which is essential before and after surgery. In conclusion, given the absence of large studies in literature, we want to focus on some general rules, which resulted from case series and clinical practice, to be followed during the perioperative and anesthetic management of patients with BrS. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Electricity market price volatility: The case of Ontario

    International Nuclear Information System (INIS)

    Zareipour, Hamidreza; Bhattacharya, Kankar; Canizares, Claudio A.

    2007-01-01

    Price volatility analysis has been reported in the literature for most competitive electricity markets around the world. However, no studies have been published yet that quantify price volatility in the Ontario electricity market, which is the focus of the present paper. In this paper, a comparative volatility analysis is conducted for the Ontario market and its neighboring electricity markets. Volatility indices are developed based on historical volatility and price velocity concepts, previously applied to other electricity market prices, and employed in the present work. The analysis is carried out in two scenarios: in the first scenario, the volatility indices are determined for the entire price time series. In the second scenario, the price time series are broken up into 24 time series for each of the 24 h and volatility indices are calculated for each specific hour separately. The volatility indices are also applied to the locational marginal prices of several pricing points in the New England, New York, and PJM electricity markets. The outcomes reveal that price volatility is significantly higher in Ontario than the three studied neighboring electricity markets. Furthermore, comparison of the results of this study with similar findings previously published for 15 other electricity markets demonstrates that the Ontario electricity market is one of the most volatile electricity markets world-wide. This high volatility is argued to be associated with the fact that Ontario is a single-settlement, real-time market

  15. Anesthetic Management of a Patient with Sustained Severe Metabolic Alkalosis and Electrolyte Abnormalities Caused by Ingestion of Baking Soda

    Directory of Open Access Journals (Sweden)

    Jose Soliz

    2014-01-01

    Full Text Available The use of alternative medicine is prevalent worldwide. However, its effect on intraoperative anesthetic care is underreported. We report the anesthetic management of a patient who underwent an extensive head and neck cancer surgery and presented with a severe intraoperative metabolic alkalosis from the long term ingestion of baking soda and other herbal remedies.

  16. Asymptotic Behavior of the Stock Price Distribution Density and Implied Volatility in Stochastic Volatility Models

    International Nuclear Information System (INIS)

    Gulisashvili, Archil; Stein, Elias M.

    2010-01-01

    We study the asymptotic behavior of distribution densities arising in stock price models with stochastic volatility. The main objects of our interest in the present paper are the density of time averages of the squared volatility process and the density of the stock price process in the Stein-Stein and the Heston model. We find explicit formulas for leading terms in asymptotic expansions of these densities and give error estimates. As an application of our results, sharp asymptotic formulas for the implied volatility in the Stein-Stein and the Heston model are obtained.

  17. The Common Inhalational Anesthetic Sevoflurane Induces Apoptosis and Increases β-Amyloid Protein Levels

    Science.gov (United States)

    Dong, Yuanlin; Zhang, Guohua; Zhang, Bin; Moir, Robert D.; Xia, Weiming; Marcantonio, Edward R.; Culley, Deborah J.; Crosby, Gregory; Tanzi, Rudolph E.; Xie, Zhongcong

    2009-01-01

    Objective: To assess the effects of sevoflurane, the most commonly used inhalation anesthetic, on apoptosis and β-amyloid protein (Aβ) levels in vitro and in vivo. Subjects: Naive mice, H4 human neuroglioma cells, and H4 human neuroglioma cells stably transfected to express full-length amyloid precursor protein. Interventions: Human H4 neuroglioma cells stably transfected to express full-length amyloid precursor protein were exposed to 4.1% sevoflurane for 6 hours. Mice received 2.5% sevoflurane for 2 hours. Caspase-3 activation, apoptosis, and Aβ levels were assessed. Results: Sevoflurane induced apoptosis and elevated levels of β-site amyloid precursor protein-cleaving enzyme and Aβ in vitro and in vivo. The caspase inhibitor Z-VAD decreased the effects of sevoflurane on apoptosis and Aβ. Sevoflurane-induced caspase-3 activation was attenuated by the γ-secretase inhibitor L-685,458 and was potentiated by Aβ. These results suggest that sevoflurane induces caspase activation which, in turn, enhances β-site amyloid precursor protein–cleaving enzyme and Aβ levels. Increased Aβ levels then induce further rounds of apoptosis. Conclusions: These results suggest that inhalational anesthetic sevoflurane may promote Alzheimer disease neuropathogenesis. If confirmed in human subjects, it may be prudent to caution against the use of sevoflurane as an anesthetic, especially in those suspected of possessing excessive levels of cerebral Aβ. PMID:19433662

  18. Cleft lip and palate: recommendations for dental anesthetic procedure based on anatomic evidences

    Directory of Open Access Journals (Sweden)

    Ivy Kiemle Trindade-Suedam

    2012-02-01

    Full Text Available Patients with cleft lip and palate usually present dental anomalies of number, shape, structure and position in the cleft area and the general dentist is frequently asked to restore or extract those teeth. Considering that several anatomic variations are expected in teeth adjacent to cleft areas and that knowledge of these variations by general dentists is required for optimal treatment, the objectives of this paper are: 1 to describe changes in the innervation pattern of anterior teeth and soft tissue caused by the presence of a cleft, 2 to describe a local anesthetic procedure in unilateral and bilateral clefts, and 3 to provide recommendations to improve anesthetic procedures in patients with cleft lip and palate. The cases of 2 patients are presented: one with complete unilateral cleft lip and palate, and the other with complete bilateral cleft lip and palate. The patients underwent local anesthesia in the cleft area in order to extract teeth with poor bone support. The modified anesthetic procedure, respecting the altered course of nerves in the cleft maxilla and soft tissue alterations at the cleft site, was accomplished successfully and the tooth extraction was performed with no pain to the patients. General dentists should be aware of the anatomic variations in nerve courses in the cleft area to offer high quality treatment to patients with cleft lip and palate.

  19. Dynamic Asset Allocation Strategies Based on Volatility, Unexpected Volatility and Financial Turbulence

    OpenAIRE

    Grimsrud, David Borkner

    2015-01-01

    Masteroppgave økonomi og administrasjon- Universitetet i Agder, 2015 This master thesis looks at unexpected volatility- and financial turbulence’s predictive ability, and exploit these measures of financial risk, together with volatility, to create three dynamic asset allocation strategies, and test if they can outperform a passive and naively diversified buy-and-hold strategy. The idea with the dynamic strategies is to increase the portfolio return by keeping the portfolio risk at a low a...

  20. A nonparametric approach to forecasting realized volatility

    OpenAIRE

    Adam Clements; Ralf Becker

    2009-01-01

    A well developed literature exists in relation to modeling and forecasting asset return volatility. Much of this relate to the development of time series models of volatility. This paper proposes an alternative method for forecasting volatility that does not involve such a model. Under this approach a forecast is a weighted average of historical volatility. The greatest weight is given to periods that exhibit the most similar market conditions to the time at which the forecast is being formed...

  1. Realized Beta GARCH: A Multivariate GARCH Model with Realized Measures of Volatility and CoVolatility

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri

    We introduce a multivariate GARCH model that utilizes and models realized measures of volatility and covolatility. The realized measures extract information contained in high-frequency data that is particularly beneficial during periods with variation in volatility and covolatility. Applying the ...

  2. Flower volatiles, crop varieties and bee responses.

    Directory of Open Access Journals (Sweden)

    Björn K Klatt

    Full Text Available Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding.

  3. The multivariate supOU stochastic volatility model

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Stelzer, Robert

    Using positive semidefinite supOU (superposition of Ornstein-Uhlenbeck type) processes to describe the volatility, we introduce a multivariate stochastic volatility model for financial data which is capable of modelling long range dependence effects. The finiteness of moments and the second order...... structure of the volatility, the log returns, as well as their "squares" are discussed in detail. Moreover, we give several examples in which long memory effects occur and study how the model as well as the simple Ornstein-Uhlenbeck type stochastic volatility model behave under linear transformations....... In particular, the models are shown to be preserved under invertible linear transformations. Finally, we discuss how (sup)OU stochastic volatility models can be combined with a factor modelling approach....

  4. Forecasting Exchange Rate Volatility in the Presence of Jumps

    DEFF Research Database (Denmark)

    Busch, Thomas; Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    We study measures of foreign exchange rate volatility based on high-frequency (5-minute) $/DM exchange rate returns using recent nonparametric statistical techniquesto compute realized return volatility and its separate continuous sample path and jumpcomponents, and measures based on prices...... of exchange rate futures options, allowingcalculation of option implied volatility. We find that implied volatility is an informationallyefficient but biased forecast of future realized exchange rate volatility. Furthermore,we show that log-normality is an even better distributional approximation...... for impliedvolatility than for realized volatility in this market. Finally, we show that the jump componentof future realized exchange rate volatility is to some extent predictable, and thatoption implied volatility is the dominant forecast of the future jump component....

  5. Comparison of anesthetics in electroconvulsive therapy: an effective treatment with the use of propofol, etomidate, and thiopental

    Directory of Open Access Journals (Sweden)

    Zahavi GS

    2014-02-01

    Full Text Available Guy Sender Zahavi,1 Pinhas Dannon1,2 1Sackler School of Medicine, Tel Aviv University, Israel; 2Brain Stimulation Unit at Beer Yaakov-Ness Ziona Mental Health Center, Israel Objectives: Electroconvulsive therapy (ECT is considered to be one of the most effective treatments in psychiatry. Currently, three medications for anesthesia are used routinely during ECT: propofol, etomidate, and thiopental. The objective of this study was to evaluate the effects of the anesthetics used in ECT on seizure threshold and duration, hemodynamics, recovery from ECT, and immediate side effects. Methods: Our study is a retrospective cohort study, in which a comparison was made between three groups of patients who underwent ECT and were anesthetized with propofol, etomidate, or thiopental. The main effect compared was treatment dose and seizure duration. All patients were chosen as responders to ECT. Results: Data were gathered about 91 patients (39 were anesthetized with thiopental, 29 with etomidate, and 23 with propofol. Patients in the thiopental group received a lower electrical dose compared to the propofol and etomidate group (mean of 459 mC compared to 807 mC and 701 mC, respectively, P<0.001. Motor seizure duration was longer in the thiopental group compared to propofol and etomidate (mean of 40 seconds compared to 21 seconds and 23 seconds, respectively, P=0.018. Seizure duration recorded by electroencephalography was similar in the thiopental and etomidate groups and lower in the propofol group (mean of 57 seconds in both groups compared to 45 seconds, respectively, P=0.038. Conclusion: Patients who were anesthetized with thiopental received a lower electrical treatment dose without an unwanted decrease in seizure duration. Thiopental might be the anesthetic of choice when it is congruent with other medical considerations. Keywords: anesthesia, ECT, seizure

  6. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...

  7. General anesthetic and the risk of dementia in elderly patients: current insights

    Directory of Open Access Journals (Sweden)

    Hussain M

    2014-09-01

    Full Text Available Maria Hussain,1 Miles Berger,2 Roderic G Eckenhoff,3 Dallas P Seitz1 1Division of Geriatric Psychiatry, Department of Psychiatry, Queen’s University; 2Anesthesiology Department, Duke University Medical Center, Durham, NC, USA; 3Department of Anesthesiology and Critical Care, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA Abstract: In this review, we aim to provide clinical insights into the relationship between surgery, general anesthesia (GA, and dementia, particularly Alzheimer’s disease (AD. The pathogenesis of AD is complex, involving specific disease-linked proteins (amyloid-beta [Aß] and tau, inflammation, and neurotransmitter dysregulation. Many points in this complex pathogenesis can potentially be influenced by both surgery and anesthetics. It has been demonstrated in some in vitro, animal, and human studies that some anesthetics are associated with increased aggregation and oligomerization of Aß peptide and enhanced accumulation and hyperphosphorylation of tau protein. Two neurocognitive syndromes that have been studied in relation to surgery and anesthesia are postoperative delirium and postoperative cognitive dysfunction, both of which occur more commonly in older adults after surgery and anesthesia. Neither the route of anesthesia nor the type of anesthetic appears to be significantly associated with the development of postoperative delirium or postoperative cognitive dysfunction. A meta-analysis of case-control studies found no association between prior exposure to surgery utilizing GA and incident AD (pooled odds ratio =1.05, P=0.43. The few cohort studies on this topic have shown varying associations between surgery, GA, and AD, with one showing an increased risk, and another demonstrating a decreased risk. A recent randomized trial has shown that patients who received sevoflurane during spinal surgery were more likely to have progression of preexisting mild cognitive impairment compared to

  8. A closed-loop anesthetic delivery system for real-time control of burst suppression

    Science.gov (United States)

    Liberman, Max Y.; Ching, ShiNung; Chemali, Jessica; Brown, Emery N.

    2013-08-01

    Objective. There is growing interest in using closed-loop anesthetic delivery (CLAD) systems to automate control of brain states (sedation, unconsciousness and antinociception) in patients receiving anesthesia care. The accuracy and reliability of these systems can be improved by using as control signals electroencephalogram (EEG) markers for which the neurophysiological links to the anesthetic-induced brain states are well established. Burst suppression, in which bursts of electrical activity alternate with periods of quiescence or suppression, is a well-known, readily discernible EEG marker of profound brain inactivation and unconsciousness. This pattern is commonly maintained when anesthetics are administered to produce a medically-induced coma for cerebral protection in patients suffering from brain injuries or to arrest brain activity in patients having uncontrollable seizures. Although the coma may be required for several hours or days, drug infusion rates are managed inefficiently by manual adjustment. Our objective is to design a CLAD system for burst suppression control to automate management of medically-induced coma. Approach. We establish a CLAD system to control burst suppression consisting of: a two-dimensional linear system model relating the anesthetic brain level to the EEG dynamics; a new control signal, the burst suppression probability (BSP) defining the instantaneous probability of suppression; the BSP filter, a state-space algorithm to estimate the BSP from EEG recordings; a proportional-integral controller; and a system identification procedure to estimate the model and controller parameters. Main results. We demonstrate reliable performance of our system in simulation studies of burst suppression control using both propofol and etomidate in rodent experiments based on Vijn and Sneyd, and in human experiments based on the Schnider pharmacokinetic model for propofol. Using propofol, we further demonstrate that our control system reliably

  9. Fundamental volatility is regime specific

    NARCIS (Netherlands)

    Arnold, I.J.M.; MacDonald, R.; Vries, de C.G.

    2006-01-01

    A widely held notion holds that freely floating exchange rates are excessively volatile when judged against fundamentals and when moving from fixed to floating exchange rates. We re-examine the data and conclude that the disparity between the fundamentals and exchange rate volatility is more

  10. Warmed local anesthetic reduces pain of infiltration.

    Science.gov (United States)

    Fialkov, J A; McDougall, E P

    1996-01-01

    The effect of warming local anesthetic on the amount of pain experienced during local infiltration was tested by comparing equal volumes of 40 degrees C- and 21 degrees C-infiltrates in each of 26 subjects. Six subjects were patients undergoing excision of two benign asymptomatic nevi in separate locations, and 20 subjects were healthy adult volunteers who were injected in bilateral antebrachial sites. The warmed and room temperature solutions were randomized to each side, so that each subject received both temperature injections in random order. All subjects and the injector were blinded. The rate of injection was time-controlled (0.05 ml/sec). Following both injections, subjects were asked to rate the pain experienced at each site. In addition, the subject was asked if there was no difference, a slight difference, or a substantial difference between the two sites. A two-tailed paired t-test was used to analyze the mean difference in pain scores for all subjects. Paired analysis of the pain scores for each subject eliminated intersubject variance of pain tolerance. The mean difference in pain score between the room temperature and warmed solutions was +1.5 (p < 0.0001). Of the 21 subjects (81%) who found the warmed solution less painful, 11 (52%) found the difference to be significant, while 10 (48%) found the difference to be slight. Two subjects (8%) found no difference between the two, while 3 subjects (11%) found the colder solution slightly less painful. We conclude that warming local anesthetic to 40 degrees C prior to subcutaneous injection is a simple, inexpensive means of reducing the pain of local infiltration.

  11. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...... variance in out-of-sample evaluations rather than the squared return. We derive the theoretical results in a general framework that is not specific to the comparison of volatility models. Similar problems can arise in comparisons of forecasting models whenever the predicted variable is a latent variable....

  12. Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

    Science.gov (United States)

    Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

    2011-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

  13. Aerosol volatility in a boreal forest environment

    Science.gov (United States)

    Häkkinen, S. A. K.; ńijälä, M.; Lehtipalo, K.; Junninen, H.; Virkkula, A.; Worsnop, D. R.; Kulmala, M.; Petäjä, T.; Riipinen, I.

    2012-04-01

    Climate and health effects of atmospheric aerosols are determined by their properties such as their chemical composition. Aerosol chemical composition can be studied indirectly by measuring volatility of aerosol particles. The volatility of submicron aerosol particles (20-500 nm) was studied in a boreal forest site at SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations II) station (Vesala et al., 1998) in Hyytiälä, Finland, during 01/2008-05/2010. The instrument used for the measurements was VDMPS (Volatility Differential Mobility Particle Sizer), which consists of two separate instruments: DMPS (Differential Mobility Particle Sizer, Aalto et al., 2001) and TD (Thermodenuder, Wehner et al., 2002). Aerosol evaporation was examined by heating the aerosol and comparing the total aerosol mass before and after heating. In the VDMPS system ambient aerosol sample was heated up to temperatures ranging from 80 °C to 280 °C. The higher the heating temperature was the more aerosol material was evaporated. There was a non-volatile residual present in aerosol particles when heated up to 280 °C. This residual explained (20±8)% of the total aerosol mass. Aerosol non-volatile mass fraction was highest during winter and smallest during summer months. The role of black carbon in the observed non-volatile residual was determined. Black carbon explained 40 to 90% of the non-volatile mass. Especially during colder seasons noticeable amount of non-volatile material, something else than black carbon, was observed. According to Kalberer et al. (2004) some atmospheric organic species can form polymers that have high evaporation temperatures. Also low-volatile organic salts may contribute to the non-volatile aerosol (Smith et al., 2010). Aerosol mass composition measured directly with AMS (Aerosol Mass Spectrometer, Jayne et al., 2000) was analyzed in order to examine the properties of the non-volatile material (other than black carbon). The AMS measurements were performed

  14. Thrombotic stroke in the anesthetized monkey (Macaca mulatta): characterization by MRI - A pilot study

    International Nuclear Information System (INIS)

    Gauberti, Maxime; Gakuba, Clement; Orset, Cyrille; Obiang, Pauline; Guedin, Pierre; Balossier, Anne; Diependaele, Anne-Sophie; Young, Alan R.; Agin, Veronique; Chazalviel, Laurent; Vivien, Denis

    2012-01-01

    The lack of a relevant stroke model in large nonhuman primates hinders the development of innovative diagnostic/therapeutic approaches concerned with this cerebrovascular disease. Our objective was to develop a novel and clinically relevant model of embolic stroke in the anesthetized monkey that incorporates readily available clinical imaging techniques and that would allow the possibility of drug delivery including strategies of reperfusion. Thrombin was injected into the lumen of the middle cerebral artery (MCA) in 12 anesthetized (sevoflurane) male rhesus macaques (Macaca mulatta). Sequential MRI studies (including angiography, FLAIR, PWI, DWI, and gadolinium-enhanced T1W imaging) were performed in a 3 T clinical MRI. Physiological and biochemical parameters were monitored throughout the investigations. Once standardized, the surgical procedure induced transient occlusion of the middle cerebral artery in all operated animals. All animals studied showed spontaneous reperfusion, which occurred some time between 2 h and 7 days post-ictus. Eighty percent of the studied animals showed diffusion/perfusion mismatch. The ischemic lesions at 24 h spared both superficial and profound territories of the MCA. Some animals presented hemorrhagic transformation at 7 days post-ictus. In this study, we developed a pre-clinically relevant model of embolic stroke in the anesthetized nonhuman primate. (authors)

  15. Effects of ampicillin/sulbactam and enrofloxacin on the blood pressure of isoflurane anesthetized dogs.

    Science.gov (United States)

    Moorer, Jeremiah D; Towle-Millard, Heather A; Gross, Marjorie E; Payton, Mark E

    2013-01-01

    A blinded, prospective, randomized crossover study was performed to determine the effects of ampicillin Na/sulbactam Na and enrofloxacin on the blood pressure (BP) of healthy anesthetized dogs. Eight dogs were anesthetized three different times. They randomly received enrofloxacin, ampicillin Na/sulbactam Na, and saline. Systolic, diastolic, and mean arterial BPs (SAP, DAP, and MAP, respectively), heart rate (HR), O2 saturation of hemoglobin, end-tidal CO2 (ETCO2) concentration, inspired isoflurane concentration, end-tidal isoflurane (ETiso) concentration, respiratory rate, electrocardiogram, and body temperature were measured for 20 min prior to administration of treatment, during administration over 30 min, and for 30 min after administration. There was no significant difference in the SAP or ETiso. There was no significant change in the arterial pressure values over time in the enrofloxacin and ampicillin Na/sulbactam Na groups. The control group's MAP increased over time and was increased compared with the enrofloxacin group at times 25, 35, 45, and 55. The statistical difference between the enrofloxacin and the control groups was due to an increase in the MAP in the control group, not a decrease in the enrofloxacin group's BP. Neither enrofloxacin nor ampicillin Na/sulbactam Na caused hypotension in healthy dogs anesthetized with isoflurane and fentanyl.

  16. Sevoflurane Induces DNA Damage Whereas Isoflurane Leads to Higher Antioxidative Status in Anesthetized Rats

    Directory of Open Access Journals (Sweden)

    Thalita L. A. Rocha

    2015-01-01

    Full Text Available Taking into account that there are controversial antioxidative effects of inhalational anesthetics isoflurane and sevoflurane and absence of comparison of genotoxicity of both anesthetics in animal model, the aim of this study was to compare DNA damage and antioxidant status in Wistar rats exposed to a single time to isoflurane or sevoflurane. The alkaline single-cell gel electrophoresis assay (comet assay was performed in order to evaluate DNA damage in whole blood cells of control animals (unexposed; n = 6 and those exposed to 2% isoflurane (n = 6 or 4% sevoflurane (n = 6 for 120 min. Plasma antioxidant status was determined by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. There was no statistically significant difference between isoflurane and sevoflurane groups regarding hemodynamic and temperature variables (P > 0.05. Sevoflurane significantly increased DNA damage compared to unexposed animals (P = 0.02. In addition, Wistar rats anesthetized with isoflurane showed higher antioxidative status (MTT than control group (P = 0.019. There were no significant differences in DNA damage or antioxidant status between isoflurane and sevoflurane groups (P > 0.05. In conclusion, our findings suggest that, in contrast to sevoflurane exposure, isoflurane increases systemic antioxidative status, protecting cells from DNA damage in rats.

  17. Local anesthetic effects of Lidocaine cream: randomized controlled trial using a standardized prick pain.

    Science.gov (United States)

    Herberger, Katharina; Krause, Karoline; Maier, Kristina; Zschocke, Ina; Radtke, Marc; Augustin, Matthias

    2012-12-01

    ELA-max (4% lidocaine) and EMLA cream (lidocaine-prilocaine 2.5%) are topicals used for superficial anesthesia. Only few studies have been published on their comparative effectiveness in close-to-practice pain models. (1) To evaluate the analgesic efficacy of lidocaine cream compared with lidocaine-prilocaine cream and placebo. (2) To assess the safety and tolerability. Randomized, three-arm, double-blind trial in 40 healthy volunteers comparing the anesthetic effects of Lidocaine and lidocaine-prilocaine cream to placebo at various time points (0-120 min). A standardized pain was induced by lancet pricks and measured by a visual analogue scale. Intra-individual comparison between the test areas was performed in a cross-over design. Lidocaine showed significantly reduced pain compared to placebo at all assessment points. Pain reduction was achieved significantly earlier using lidocaine occlusively (30 min). No significant differences were found concerning the anesthetic efficacy of lidocaine and lidocaine-prilocaine cream. There were no relevant adverse events. This study confirms that a topical preparation with 4% lidocaine is an effective and safe treatment option for superficial anesthesia. It supports the claim that an occlusive application is more rapid in action. 4% lidocaine is of value as a rapidly-acting local anesthetic for the treatment of minor surgical procedures.

  18. Analysis of volatiles from irradiated yeast extract

    International Nuclear Information System (INIS)

    Liao Tao; Li Xin; Zu Xiaoyan; Chen Yuxia; Geng Shengrong

    2013-01-01

    The method for determination volatiles from irradiated yeast extract (YE) using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed in this paper. The extraction conditions were optimized with reference to the peak area and number of volatiles as aldehyde, ketone, alcohol, acid, ester and sulfur compounds. The optimized conditions of HS-SPME for volatiles in irradiated YE were: divinyl benzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber, extration time 40 min, extraction temperature 40℃. The volatiles from YE irradiated by 0-19.8 kGy were detected using HS-SPME coupled with GC-MS. The results showed that only 15 volatiles were detected from no irradiated YE and main compounds were acetic acid, 2, 3-butanediol and 1-hexanol, 2-ethyl-. There were 40 volatiles detected from irradiated YE and the main compounds were acetic acid, phenylethyl alcohol, heptanal and nonanal. Compare to no irradiated yeast extract, the aldehyde, ketone, alkene and disulfide, dimethyl were produced by irradiating process. (authors)

  19. A dynamic two-dimensional system for measuring volatile organic compound volatilization and movement in soils.

    Science.gov (United States)

    Allaire, S E; Yates, S R; Ernst, F F; Gan, J

    2002-01-01

    There is an important need to develop instrumentation that allows better understanding of atmospheric emission of toxic volatile compounds associated with soil management. For this purpose, chemical movement and distribution in the soil profile should be simultaneously monitored with its volatilization. A two-dimensional rectangular soil column was constructed and a dynamic sequential volatilization flux chamber was attached to the top of the column. The flux chamber was connected through a manifold valve to a gas chromatograph (GC) for real-time concentration measurement. Gas distribution in the soil profile was sampled with gas-tight syringes at selected times and analyzed with a GC. A pressure transducer was connected to a scanivalve to automatically measure the pressure distribution in the gas phase of the soil profile. The system application was demonstrated by packing the column with a sandy loam in a symmetrical bed-furrow system. A 5-h furrow irrigation was started 24 h after the injection of a soil fumigant, propargyl bromide (3-bromo-1-propyne; 3BP). The experience showed the importance of measuring lateral volatilization variability, pressure distribution in the gas phase, chemical distribution between the different phases (liquid, gas, and sorbed), and the effect of irrigation on the volatilization. Gas movement, volatilization, water infiltration, and distribution of degradation product (Br-) were symmetric around the bed within 10%. The system saves labor cost and time. This versatile system can be modified and used to compare management practices, estimate concentration-time indexes for pest control, study chemical movement, degradation, and emissions, and test mathematical models.

  20. Bilateral transversus abdominis plane block as a sole anesthetic technique in emergency surgery for perforative peritonitis in a high risk patient

    Directory of Open Access Journals (Sweden)

    Lipi Mishra

    2013-01-01

    Full Text Available Although transversus abdominis plane (TAP block is an effective way of providing analgesia in post-operative abdominal surgery patients; however, it can be considered as an anesthetic technique in high-risk cases for surgery. We report a case of a geriatric female with chronic obstructive pulmonary disease in the respiratory failure, hypotension, posted in an emergency with old perforation leading to peritonitis. The surgery was successfully conducted under bilateral TAP block, which was used as a sole anesthetic technique. TAP block can be considered as an anesthetic technique for abdominal surgery in moribund patients.

  1. Effect of anesthetics on the radiosensitivity of a murine tumor

    Energy Technology Data Exchange (ETDEWEB)

    Sheldon, P.W.; Chu, A.M.

    1979-09-01

    The effect of four anesthetics on the single dose of x rays required to locally control 50% of implanted MT tumors was investigated. Compared with unanesthetized animals, no change in radiosensitivity was observed if mice were irradiated under either tribromoethanol or fentanyl-fluanisone-diazepam anesthesia. However, a small but significant degree of radioprotection was observed under chloral hydrate or pentobarbital anesthesia. Hypothermia or increased hypoxia are considered unlikely mechanisms for the protection, a direct chemical action being most probable. The preferred method for immobilizing the mice in order to locally irradiate the tumors was by simple physical restraint (with care taken to minimize physiological stress). However, if anesthesia was a necessity, the present work suggests that for the MT tumor at least the nonprotecting tribromoethanol and fentanyl-fluanisone-diazepam are preferable to the protecting chloral hydrate and pentobarbital. Tribromoethanol is preferable to fetanyl-fluanisone-diazepam in that it produces a smaller drop in temperature. However, it is only a short-acting anesthetic, and prolongation of the state of anesthesia by repeated doses simply prolongs the temperature decline so that there may be no real benefit over fentanyl-fluanisone-diazepam.

  2. Effect of anesthetics on the radiosensitivity of a murine tumor

    International Nuclear Information System (INIS)

    Sheldon, P.W.; Chu, A.M.

    1979-01-01

    The effect of four anesthetics on the single dose of x rays required to locally control 50% of implanted MT tumors was investigated. Compared with unanesthetized animals, no change in radiosensitivity was observed if mice were irradiated under either tribromoethanol or fentanyl-fluanisone-diazepam anesthesia. However, a small but significant degree of radioprotection was observed under chloral hydrate or pentobarbital anesthesia. Hypothermia or increased hypoxia are considered unlikely mechanisms for the protection, a direct chemical action being most probable. The preferred method for immobilizing the mice in order to locally irradiate the tumors was by simple physical restraint (with care taken to minimize physiological stress). However, if anesthesia was a necessity, the present work suggests that for the MT tumor at least the nonprotecting tribromoethanol and fentanyl-fluanisone-diazepam are preferable to the protecting chloral hydrate and pentobarbital. Tribromoethanol is preferable to fetanyl-fluanisone-diazepam in that it produces a smaller drop in temperature. However, it is only a short-acting anesthetic, and prolongation of the state of anesthesia by repeated doses simply prolongs the temperature decline so that there may be no real benefit over fentanyl-fluanisone-diazepam

  3. Electroconvulsive therapy in the elderly: Anesthetic considerations and Psychotropic interactions

    Directory of Open Access Journals (Sweden)

    Harsh Garekar

    2017-01-01

    Full Text Available Electroconvulsive therapy (ECT has been found to be a rapid and effective treatment strategy for psychiatric and neurological conditions in the elderly, but the administration of ECT in the elderly can be challenging due to a high risk of adverse events. The increased risk can be attributed to a declined physiological reserve, the presence of physical comorbidities, and the use of multiple drugs, which interact with the electrical stimulus and the anesthetic medications used during the ECT procedure. The selection of appropriate induction agents and muscle relaxants should be guided by patient's clinical status and the psychotropic drugs being used. Modifications in the doses of psychotropic drugs also need to be carried out before ECT to reduce cardiovascular and neurological side effects. Modification in the conduct of anesthesia can also aid in augmenting seizures and in preventing common side effects of ECT. A vital step in preventing adverse events in the elderly is carrying out a thorough pre.ECT evaluation. Despite these challenges, ECT can be carried out safely in elderly patients with severe comorbidities, provided clinical ECT, and anesthetic parameters are adequately optimized.

  4. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    We examine the effect of political 'institutions' on economic growth volatility, using data from more than 100 countries over the period 1960 to 2005, taking into account various control variables as suggested in previous studies. Our indicator of volatility is the relative standard deviation of the

  5. Anesthetic activity and bio-guided fractionation of the essential oil of Aloysia gratissima (Gillies & Hook.) Tronc. in silver catfish Rhamdia quelen.

    Science.gov (United States)

    Benovit, Simone C; Silva, Lenise L; Salbego, Joseânia; Loro, Vania L; Mallmann, Carlos A; Baldisserotto, Bernardo; Flores, Erico M M; Heinzmann, Berta M

    2015-09-01

    This work aimed to determine the efficacy of the essential oil of A. gratissima as anesthetic for silver catfish, and to perform the bio-guided fractionation of essential oil aiming to isolate compounds responsible for the noted effects. Fish were submitted to anesthesia bath with essential oil, its fractions and isolated compounds to determine time of anesthetic induction and recovery. Eugenol (50 mg L(-1)) was used as positive control. Essential oil of A. gratissima was effective as an anesthetic at concentrations of 300 to 900 mg L(-1). Fish presented involuntary muscle contractions during induction and recovery. The bio-guided fractionation of essential oil furnished E-(-)-pinocamphone, (-)-caryophyllene oxide, (-)-guaiol and (+)-spathulenol. E-(-)-pinocamphone caused the same side effects observed for essential oil. (-)-Caryophyllene oxide, (-)-guaiol and (+)-spathulenol showed only sedative effects at proportional concentrations to those of the constituents in essential oil. (+)-Spathulenol (51.2 mg L(-1)) promoted deep anesthesia without side effects. A higher concentration of (+)-spathulenol, and lower or absent amounts ofE-(-)-pinocamphone could contribute to increase the activity and safety of the essential oil of A. gratissima. (+)-Spathulenol showed potent sedative and anesthetic activities in silver catfish, and could be considered as a viable compound for the development of a new anesthetic.

  6. The predictive content of CBOE crude oil volatility index

    Science.gov (United States)

    Chen, Hongtao; Liu, Li; Li, Xiaolei

    2018-02-01

    Volatility forecasting is an important issue in the area of econophysics. The information content of implied volatility for financial return volatility has been well documented in the literature but very few studies focus on oil volatility. In this paper, we show that the CBOE crude oil volatility index (OVX) has predictive ability for spot volatility of WTI and Brent oil returns, from both in-sample and out-of-sample perspectives. Including OVX-based implied volatility in GARCH-type volatility models can improve forecasting accuracy most of time. The predictability from OVX to spot volatility is also found for longer forecasting horizons of 5 days and 20 days. The simple GARCH(1,1) and fractionally integrated GARCH with OVX performs significantly better than the other OVX models and all 6 univariate GARCH-type models without OVX. Robustness test results suggest that OVX provides different information from as short-term interest rate.

  7. Anesthetic propofol attenuates the isoflurane-induced caspase-3 activation and Aβ oligomerization.

    Directory of Open Access Journals (Sweden)

    Yiying Zhang

    Full Text Available Accumulation and deposition of β-amyloid protein (Aβ are the hallmark features of Alzheimer's disease. The inhalation anesthetic isoflurane has been shown to induce caspase activation and increase Aβ accumulation. In addition, recent studies suggest that isoflurane may directly promote the formation of cytotoxic soluble Aβ oligomers, which are thought to be the key pathological species in AD. In contrast, propofol, the most commonly used intravenous anesthetic, has been reported to have neuroprotective effects. We therefore set out to compare the effects of isoflurane and propofol alone and in combination on caspase-3 activation and Aβ oligomerization in vitro and in vivo. Naïve and stably-transfected H4 human neuroglioma cells that express human amyloid precursor protein, the precursor for Aβ; neonatal mice; and conditioned cell culture media containing secreted human Aβ40 or Aβ42 were treated with isoflurane and/or propofol. Here we show for the first time that propofol can attenuate isoflurane-induced caspase-3 activation in cultured cells and in the brain tissues of neonatal mice. Furthermore, propofol-mediated caspase inhibition occurred when there were elevated levels of Aβ. Finally, isoflurane alone induces Aβ42, but not Aβ40, oligomerization, and propofol can inhibit the isoflurane-mediated oligomerization of Aβ42. These data suggest that propofol may mitigate the caspase-3 activation by attenuating the isoflurane-induced Aβ42 oligomerization. Our findings provide novel insights into the possible mechanisms of isoflurane-induced neurotoxicity that may aid in the development of strategies to minimize potential adverse effects associated with the administration of anesthetics to patients.

  8. Anesthetic Efficacy of a Combination of 4% Prilocaine/2% Lidocaine with Epinephrine for the Inferior Alveolar Nerve Block: A Prospective, Randomized, Double-blind Study.

    Science.gov (United States)

    Cook, Olivia; Nusstein, John; Drum, Melissa; Fowler, Sara; Reader, Al; Draper, John

    2018-05-01

    Prilocaine plain has a high pH and concentration (4%), which could decrease the pain of injection and increase success. The purpose of this study was to compare pain associated with anesthetic solution deposition and the degree of pulpal anesthesia obtained with the combination of prilocaine and lidocaine versus a lidocaine and lidocaine combination when used for inferior alveolar nerve blocks (IANBs). One hundred eighteen asymptomatic subjects were randomly given a combination of 1 cartridge of 4% prilocaine plain plus 1 cartridge of 2% lidocaine with 1:100,000 epinephrine or a combination of 2 cartridges of 2% lidocaine with 1:100,000 epinephrine for the IANB at 2 separate appointments. Subjects rated the pain associated with anesthetic solution deposition of injection. Mandibular teeth were tested with an electric pulp tester every 4 minutes for 57 minutes. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 17 minutes and the 80 reading was continuously sustained for 57 minutes. Comparisons for anesthetic success were analyzed using the exact McNemar test, and pain ratings associated with anesthetic solution deposition were analyzed using multiple Wilcoxon matched pairs signed rank tests; both were adjusted using the step-down Bonferroni method of Holm. Four percent prilocaine plain was significantly less painful upon anesthetic solution deposition. Pulpal anesthetic success was not significantly different between the 2 combinations. The combination of 4% prilocaine plain plus 2% lidocaine with 1:100,000 epinephrine did not increase pulpal anesthetic success for IANBs compared with a combination of 2 cartridges of 2% lidocaine with 1:100,000 epinephrine. Pain associated with anesthetic solution deposition from the first cartridge of 4% prilocaine plain was significantly less when compared with the first cartridge of 2% lidocaine with 1:100,000 epinephrine. Copyright © 2018 American Association of Endodontists. Published

  9. From micro- to nanostructured implantable device for local anesthetic delivery

    Directory of Open Access Journals (Sweden)

    Zorzetto L

    2016-06-01

    Full Text Available Laura Zorzetto,1 Paola Brambilla,1 Elena Marcello,1 Nora Bloise,2 Manuela De Gregori,3 Lorenzo Cobianchi,4,5 Andrea Peloso,4,5 Massimo Allegri,6 Livia Visai,2,7 Paola Petrini1 1Department of Chemistry, Materials and Chemical Engineering ‘G. Natta’, Politecnico di Milano, Milan, 2Department of Molecular Medicine, Centre for Health Technologies (CHT, INSTM UdR of Pavia, University of Pavia, 3Pain Therapy Service, IRCCS Foundation Policlinico San Matteo Pavia, Pavia, 4General Surgery Department, IRCCS Foundation Policlinico San Matteo, Pavia, 5Departments of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, 6Department of Surgical Sciences, University of Parma, Parma, 7Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Lab of Nanotechnology, Pavia, Italy Abstract: Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured

  10. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  11. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  12. Can we use lower volume of local anesthetic for infraclavicular brachial plexus nerve block under ultrasound guidance in children?

    Science.gov (United States)

    Ince, Ilker; Aksoy, Mehmet; Dostbil, Aysenur; Tuncer, Kutsi

    2017-09-01

    To determine if the infraclavicular brachial plexus block can be applied with lower volume of local anesthetic. Randomised, double-blinded clinical trial. 60 patients aged 5-15years with ASA I-II who underwent emergent or elective arm, forearm or hand operations were included in the study. Patients were divided into two groups randomly; standard volume local anesthetic administered group (Group S, n=30) and low volume anesthetic administered group (Group L, n=30). Postoperative pain scores, sensory and motor block durations were noted. Pain scores (Wong-Baker Face Scale) were evaluated and the results were detected to be similar at all times (30min, 1, 2, 4, 8, 12, 24h). Durations of motor block were 168(±16) minutes and 268(±15) minutes in Group L and Group S respectively and the difference was statistically significant (pblock were 385(±26) and 402(±39) in Group L and Group S respectively and no statistically significant difference was detected (p=0.064). Similar block success, postoperative sensory block durations and pain scores could be obtained during infraclavicular brachial plexus in pediatric patients with lower local anesthetic volumes. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  14. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    John Y. Campbell; Glen B. Taksler

    2002-01-01

    This paper explores the effect of equity volatility on corporate bond yields. Panel data for the late 1990s show that idiosyncratic firm-level volatility can explain as much cross-sectional variation in yields as can credit ratings. This finding, together with the upward trend in idiosyncratic equity volatility documented by Campbell, Lettau, Malkiel, and Xu (2001), helps to explain recent increases in corporate bond yields. The definitive version is available at www.blackwell-synergy.com.

  15. Permanent and transitory oil volatility and aggregate investment in Malaysia

    International Nuclear Information System (INIS)

    Ibrahim, Mansor H.; Ahmed, Huson Joher Ali

    2014-01-01

    This paper investigates the relation between aggregate investment and oil volatility and its permanent and transitory components for a developing country, Malaysia. In the paper, the components generalized autoregressive conditional heteroskedasticity (CGARCH) model is utilized to decompose conditional oil volatility into permanent oil volatility and transitory oil volatility. Respectively reflecting fundamental-driven and random shifts in oil volatility, they are expected to exert differential effects on aggregate investment. Adopting a vector autoregression (VAR) framework to allow feedback effects between aggregate investment and its determinants, the paper documents evidence supporting the adverse effects of conditional oil volatility, permanent oil volatility and transitory oil volatility on aggregate investment and real output. Interestingly, contrary to the findings for the developed markets (US and OECD), the real effects of permanent oil volatility tend to be stronger. These findings are reasonably robust to variable specification and measurements in the VAR system. Hence, there is an indication that heightened oil volatility accounts for the slumps in Malaysia's aggregate investment after the Asian financial crisis. - Highlights: • Examines the role of oil volatility in Malaysia's aggregate investment. • Makes distinction between permanent and temporary volatility using CGARCH. • Both volatility components depress investment. • Permanent volatility has larger adverse effects. • Results are robust to alternative model specifications

  16. Firm-level volatility and exports

    NARCIS (Netherlands)

    Vannoorenberghe, G.C.L.

    2012-01-01

    This paper shows that the share of exports in the total sales of a firm has a positive and substantial impact on the volatility of its sales. Decomposing the volatility of sales of exporters between their domestic and export markets, I show using an identification strategy based on a firm-specific

  17. GABAA receptor binding molecules from traditional Chinese Medicine: An in silico approach

    Directory of Open Access Journals (Sweden)

    Meng Lv

    2014-12-01

    Full Text Available The advents of how anesthesia works have helped in the discovery of anesthetic target protein. One such target protein named ϒ-aminobutyric acid (GABAA, which is the chief inhibitory neurotransmitter in the mammalian central nervous system. Asparagine at 289 position of GABAA protein within TM2 is important for its anesthetic function. This study explores Traditional Chinese Medicine (TCM against ASN 289 of GABAA for novel anesthetic compounds. The in silico approach showed gastrodin out of all compounds to be the best compound to start further analysis. It is a potential anesthetic compound suitable for the development of new drug.

  18. Modeling and forecasting petroleum futures volatility

    International Nuclear Information System (INIS)

    Sadorsky, Perry

    2006-01-01

    Forecasts of oil price volatility are important inputs into macroeconometric models, financial market risk assessment calculations like value at risk, and option pricing formulas for futures contracts. This paper uses several different univariate and multivariate statistical models to estimate forecasts of daily volatility in petroleum futures price returns. The out-of-sample forecasts are evaluated using forecast accuracy tests and market timing tests. The TGARCH model fits well for heating oil and natural gas volatility and the GARCH model fits well for crude oil and unleaded gasoline volatility. Simple moving average models seem to fit well in some cases provided the correct order is chosen. Despite the increased complexity, models like state space, vector autoregression and bivariate GARCH do not perform as well as the single equation GARCH model. Most models out perform a random walk and there is evidence of market timing. Parametric and non-parametric value at risk measures are calculated and compared. Non-parametric models outperform the parametric models in terms of number of exceedences in backtests. These results are useful for anyone needing forecasts of petroleum futures volatility. (author)

  19. Inflation, its Volatility and the Inflation-Growth Tradeoff in India

    OpenAIRE

    Raghbendra Jha; Varsha S. Kulkarni

    2013-01-01

    This paper amends the New Keynesian Phillips curve model to include inflation volatility. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL(1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility alone (in the ECM model) and not in the other models. Major determinants of inflation volatility and expected inflation ...

  20. A volatile topic: Parsing out the details of Earth's formation through experimental metal-silicate partitioning of volatile and moderately volatile elements

    Science.gov (United States)

    Mahan, B. M.; Siebert, J.; Blanchard, I.; Badro, J.; Sossi, P.; Moynier, F.

    2017-12-01

    Volatile and moderately volatile elements display different volatilities and siderophilities, as well as varying sensitivity to thermodynamic controls (X, P, T, fO2) during metal-silicate differentiation. The experimental determination of the metal-silicate partitioning of these elements permits us to evaluate processes controlling the distribution of these elements in Earth. In this work, we have combined metal-silicate partitioning data and results for S, Sn, Zn and Cu, and input these characterizations into Earth formation models. Model parameters such as source material, timing of volatile delivery, fO2 path, and degree of impactor equilibration were varied to encompass an array of possible formation scenarios. These models were then assessed to discern plausible sets of conditions that can produce current observed element-to-element ratios (e.g. S/Zn) in the Earth's present-day mantle, while also satisfying current estimates on the S content of the core, at no more than 2 wt%. The results of our models indicate two modes of accretion that can maintain chondritic element-to-element ratios for the bulk Earth and can arrive at present-day mantle abundances of these elements. The first mode requires the late addition of Earth's entire inventory of these elements (assuming a CI-chondritic composition) and late-stage accretion that is marked by partial equilibration of large impactors. The second, possibly more intuitive mode, requires that Earth accreted - at least initially - from volatile poor material preferentially depleted in S relative to Sn, Zn, and Cu. From a chemical standpoint, this source material is most similar to type I chondrule rich (and S poor) materials (Hewins and Herzberg, 1996; Mahan et al., 2017; Amsellem et al., 2017), such as the metal-bearing carbonaceous chondrites.

  1. Estimation of volatility of selected oil production projects

    International Nuclear Information System (INIS)

    Costa Lima, Gabriel A.; Suslick, Saul B.

    2006-01-01

    In oil project valuation and investment decision-making, volatility is a key parameter, but it is difficult to estimate. From a traditional investment viewpoint, volatility reduces project value because it increases its discount rate via a higher risk premium. Contrarily, according to the real-option pricing theory, volatility may aggregate value to the project, since the downside potential is limited whereas the upside is theoretically unbounded. However, the estimation of project volatility is very complicated since there is not a historical series of project values. In such cases, many analysts assume that oil price volatility is equal to that of project. In order to overcome such problems, in this paper an alternative numerical method based on present value of future cash flows and Monte Carlo simulation is proposed to estimate the volatility of projects. This method is applied to estimate the volatility of 12 deep-water offshore oil projects considering that oil price will evolve according to one of two stochastic processes: Geometric Brownian Motion and Mean-Reverting Motion. Results indicate that the volatility of commodity usually undervalue that of project. For the set of offshore projects analyzed in this paper, project volatility is at least 79% higher than that of oil prices and increases dramatically in those cases of high capital expenditures and low price. (author)

  2. Production Function of Outgassed Volatiles on Mercury: Implications for Polar Volatiles on Mercury and the Moon

    Science.gov (United States)

    Deutsch, A. N.; Head, J. W.

    2018-05-01

    We are interested in the flux of volatiles delivered to the polar regions of Mercury and the Moon through time. We integrate the production functions for volatile delivery from impacts, solar wind, and volcanism, which we focus on initially.

  3. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

    Science.gov (United States)

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

    2016-10-01

    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  4. On the non-causal link between volatility and growth

    DEFF Research Database (Denmark)

    Posch, Olaf; Wälde, Klaus

    A model highlighting the endogeneity of both volatility and growth is presented. Volatility and growth are therefore correlated but there is no causal link from volatility to growth. This joint endogeneity is illustrated by working out the effects through which economies with different tax levels...... di er both in their volatility and growth. Using a continuous-time DSGE model with plausible parametric restrictions, we obtain closedform measures of macro volatility based on cyclical components and output growth rates. Given our results, empirical volatility-growth analysis should include controls...

  5. Volatilization of iodine from soils and plants

    International Nuclear Information System (INIS)

    Wildung, R.E.; Cataldo, D.A.; Garland, T.R.

    1985-04-01

    Elevated levels of 129 I, a long-lived fission product, are present in the environment as a result of nuclear weapons testing and fuel reprocessing. To aid in understanding the anomalous behavior of this element, relative to natural I ( 127 I), in the vicinity of nuclear fuel reprocessing plants, preliminary laboratory-growth chamber studies were undertaken to examine the possible formation of volatile inorganic and organic I species in soil and plant systems. Inorganic 129 I added to soil was volatilized from both the soil and plant during plant growth, at average ratios of 2 x 10 -3 %/day soil and 9 x 10 -3 %/day foliage, respectively. Volatilization rates from soil were an order of magnitude less in the absence of growing roots. Less than 2% of soil or plant volatiles was subsequently retained by plant canopies. Volatile I, chemically characterized by selective sorption methods, consisted principally of alkyl iodides formed by both soil and plant processes. However, plants and soils containing actively growing roots produced a larger fraction of volatile inorganic I than soil alone. 14 refs., 1 fig., 3 tabs

  6. The anesthetic management of button battery ingestion in children.

    Science.gov (United States)

    Ing, Richard J; Hoagland, Monica; Mayes, Lena; Twite, Mark

    2018-03-01

    Injuries related to button battery ingestion are common in children. This review provides an outline of the epidemiology, pathophysiology, management, and anesthetic implications in children who have ingested a button battery. A literature search was conducted in the United States National Library of Medicine PubMed database using the terms "button battery ingestion" and "children' and "removal" and "surgery" and "anesthesia". Ninety-six articles published in English were found from 1983-2017, and 62 of these articles were incorporated into this review. Additionally, the Internet was searched with the terms "button battery ingestion and children" to identify further entities, organizations, and resources affiliated with button battery ingestion in children. These additional sources were studied and included in this review. Button batteries are ubiquitous in homes and electronic devices. Since 2006, larger-diameter and higher-voltage batteries have become available. These are more likely to become impacted in the esophagus after ingestion and lead to an increase in severe morbidity and mortality due to caustic tissue injury. Children at the highest risk for complications are those under six years of age who have ingested batteries > 20 mm in diameter and sustain prolonged esophageal impaction at the level of the aortic arch with the negative pole oriented anteriorly. Anesthesiologists need to know about the epidemiology, pathophysiology, complications, and anesthetic management of children who have ingested button batteries.

  7. The cardiac anesthetic index of isoflurane in green iguanas.

    Science.gov (United States)

    Mosley, Craig A E; Dyson, Doris; Smith, Dale A

    2003-06-01

    To determine the cardiac anesthetic index (CAI) of isoflurane in green iguanas and whether butorphanol affected the CAI. Prospective randomized controlled trial. 7 healthy mature iguanas. In 5 iguanas, CAI was determined after induction of anesthesia with isoflurane alone, and in 5 iguanas, CAI was determined after induction of anesthesia with isoflurane and IM administration of butorphanol (1 mg/kg [0.45 mg/lb]). Three iguanas underwent both treatments. Animals were equilibrated for 20 minutes at 1.5 times the minimum alveolar concentration (MAC) of isoflurane and observed for evidence of cardiovascular arrest. If there was no evidence of cardiovascular arrest, end-tidal isoflurane concentration was increased by 20%, and animals were allowed to equilibrate for another 20 minutes. This process was repeated until cardiovascular arrest occurred or vaporizer output could no longer be consistently increased. The CAI was calculated by dividing the highest end-tidal isoflurane concentration by the MAC. None of the iguanas developed cardiovascular arrest and all survived. Mean +/- SD highest end-tidal isoflurane concentration during anesthesia with isoflurane alone (9.2 +/- 0.60%) was not significantly different from mean concentration during anesthesia with isoflurane and butorphanol (9.0 +/- 0.43%). The CAI was > 4.32. Results suggest that the CAI of isoflurane in green iguanas is > 4.32 and not affected by administration of butorphanol. Isoflurane appears to be a safe anesthetic in green iguanas.

  8. Modification of GABA-mediated inhibition by various injectable anesthetics.

    Science.gov (United States)

    Albertson, T E; Walby, W F; Joy, R M

    1992-09-01

    Increasing doses of the injectable anesthetics etomidate, Saffan, thiopental, ketamine, and xylazine and the vehicles saline and propylene glycol were administered to urethane-anesthetized rats. Their effects in vivo on perforant pathway-evoked field excitatory post-synaptic potentials and population spikes in the hippocampal dentate gyrus were determined. The primary purpose was to ascertain whether these compounds affect hippocampal excitability in a manner consistent with their proposed mechanisms of action. Compared with their respective vehicles, thiopental, etomidate, and xylazine reduced the amplitude of population spikes to single perforant pathway stimulation by 20-30% at the highest doses tested. Xylazine also increased the latency to onset of the population spike. No other effects were observed. Using paired pulse paradigms, it was determined that etomidate produced a dramatic, prolonged reduction in granule cell excitability at interpulse intervals of 10-100 ms. The magnitude of the effect was dose related and was reversible with the discontinuance of administration of the drug. Similar changes occurred with Saffan (althesin) and thiopental. Ketamine produced a small but significant depression in granule cell excitability during intervals of 10-200 ms. Xylazine had no effect. These data corroborate the importance of a prolongation of gamma-aminobutyric acid A-mediated inhibition to the mechanism of actions of etomidate, thiopental, and Saffan at relevant exposure concentrations in vivo.

  9. Constraining the volatile budget of the lunar interior

    Science.gov (United States)

    Potts, N. J.; Bromiley, G. D.

    2017-12-01

    Measurements of volatiles (F, Cl, S, H2O) in a range of lunar samples confirm the presence of volatile material in lunar magmas. It remains unknown, however, where this volatile material is stored and when it was delivered to the Moon. On Earth, point defects within mantle olivine, and its high-pressure polymorphs, are thought to be the largest reservoir of volatile material. However, as volatiles have been cycled into and out of the Earth's mantle throughout geological time, via subduction and volcanism, this masks any original volatile signatures. As the Moon has no plate tectonics, it is expected that any volatile material present in the deep lunar interior would have been inherited during accretion and differentiation, providing insight into the delivery of volatiles to the early Earth-Moon system. Our aim was, therefore, to test the volatile storage capacity of the deep lunar mantle and determine mineral/melt partitioning for key volatiles. Experiments were performed in a primitive lunar mantle composition and run at relevant T, P, and at fO2 below the IW buffer. Experiments replicated the initial stages of LMO solidification with either olivine + melt, olivine + pyroxene + melt, or pyroxene + melt as the only phases present. Mineral-melt partition coefficients (Dx) derived for volatile material (F, Cl, S, H2O) vary significantly compared to those derived for terrestrial conditions. An order of magnitude more H2O was found to partition into lunar olivine compared to the terrestrial upper mantle. DF derived for lunar olivine are comparable to the highest terrestrial derived values whilst no Cl was found to partition into lunar olivine under these conditions. Furthermore, an inverse trend between DF and DOH hints towards coupled-substitution mechanisms between H and F under low-fO2/lunar bulk composition. These results suggest that if volatile material was present in the LMO a significant proportion could be partitioned into the lower lunar mantle. The

  10. Update on emerging regional techniques and novel local anesthetics in ambulatory anesthesia

    Directory of Open Access Journals (Sweden)

    Szafran MJ

    2015-12-01

    Full Text Available Martin J Szafran, Eldhose Abrahams, Tong Joo Gan Department of Anesthesiology, Stony Brook University, Stony Brook, NY, USA Abstract: New regional anesthetic techniques have been incorporated into the multimodal approach to postoperative analgesia. Blocks such as the transversus abdominis plane block, adductor canal block, and pectoral nerves blocks all show promise as potential tools used in opioid-sparing techniques, but at the same time have significant limitations to their utility. Novel long-acting formulations of local anesthetics further add to the possible benefit of these blocks, but their application to peripheral nerve blocks is currently being investigated and is not well defined. This review focuses on evaluating the relevant anatomy, technique, and indications of several newer peripheral nerve blocks, the emerging evidence supporting the use of liposomal bupivacaine and SABER®-Bupivacaine, and the application of both in ambulatory anesthesia. Keywords: transversus abdominis plane (TAP block, adductor canal block, pectoral nerves block, regional anesthesia, liposomal bupivacaine, SABER®-Bupivacaine

  11. Labour Demand and Exchange Rate Volatility

    OpenAIRE

    Udo Broll; Sabine Hansen

    2004-01-01

    The purpose of this paper is to assess under what conditions exchange rate volatility exerts a positive effect on a firm's labour demand. As the exchange rate volatility increases, so does the value of the export option provided the firm under study is flexible. Flexibility is important because it gives the firm option value. Higher volatility increases the potential gains from trade and may increase the demand for labour. This may explain part of the mixed empirical findings regarding the ef...

  12. Elemental volatility of HT-9 fusion reactor alloy

    International Nuclear Information System (INIS)

    Henslee, S.P.; Neilson, R.M. Jr.

    1985-01-01

    The volatility of elemental constituents from HT-9, a ferritic steel, proposed for fusion reactor structures, was investigated. Tests were conducted in flowing air at temperatures from 800 to 1200 0 C for durations of 1 to 20 h. Elemental volatility was calculated in terms of the weight fraction of the element volatilized from the initial alloy; molybdenum, manganese, and nickel were the primary constituents volatilized. Comparisons with elemental volatilities observed for another candidate fusion reactor materials. Primary Candidate Alloy (PCA), an austenitic stainless steel, indicate significant differences between the volatilities of these steels that may impact fusion reactor safety analysis and alloy selection. Scanning electron microscopy and energy dispersive spectrometry were used to investigate the oxide layers formed on HT-9 and to measure elemental contents within these layers

  13. Estimation and prediction under local volatility jump-diffusion model

    Science.gov (United States)

    Kim, Namhyoung; Lee, Younhee

    2018-02-01

    Volatility is an important factor in operating a company and managing risk. In the portfolio optimization and risk hedging using the option, the value of the option is evaluated using the volatility model. Various attempts have been made to predict option value. Recent studies have shown that stochastic volatility models and jump-diffusion models reflect stock price movements accurately. However, these models have practical limitations. Combining them with the local volatility model, which is widely used among practitioners, may lead to better performance. In this study, we propose a more effective and efficient method of estimating option prices by combining the local volatility model with the jump-diffusion model and apply it using both artificial and actual market data to evaluate its performance. The calibration process for estimating the jump parameters and local volatility surfaces is divided into three stages. We apply the local volatility model, stochastic volatility model, and local volatility jump-diffusion model estimated by the proposed method to KOSPI 200 index option pricing. The proposed method displays good estimation and prediction performance.

  14. Aspects of volatility targeting for South African equity investors

    Directory of Open Access Journals (Sweden)

    Bhekinkosi Khuzwayo

    2014-11-01

    Full Text Available We consider so-called volatility targeting strategies in the South African equity market. These strategies are aimed at keeping the volatility of a portfolio consisting of a risky asset, typically an equity index, and cash fixed. This is done by changing the allocation of the assets based on an indicator of the future volatility of the risky asset. We use the three month rolling implied volatility as an indicator of future volatility to influence our asset allocation. We compare investments based on different volatility targets to the performance of bonds, equities, property as well as the Absolute Return peer mean. We examine risk and return characteristics of the volatility targeting strategy as compared to different asset classes.

  15. Anesthetic drugs in status epilepticus: Risk or rescue?

    Science.gov (United States)

    Marsch, Stephan; Fuhr, Peter; Kaplan, Peter W.; Rüegg, Stephan

    2014-01-01

    Objective: To evaluate the risks of continuously administered IV anesthetic drugs (IVADs) on the outcome of adult patients with status epilepticus (SE). Methods: All intensive care unit patients with SE from 2005 to 2011 at a tertiary academic medical care center were included. Relative risks were calculated for the primary outcome measures of seizure control, Glasgow Outcome Scale score at discharge, and death. Poisson regression models were used to control for possible confounders and to assess effect modification. Results: Of 171 patients, 37% were treated with IVADs. Mortality was 18%. Patients with anesthetic drugs had more infections during SE (43% vs 11%; p < 0.0001) and a 2.9-fold relative risk for death (2.88; 95% confidence interval 1.45–5.73), independent of possible confounders (i.e., duration and severity of SE, nonanesthetic third-line antiepileptic drugs, and critical medical conditions) and without significant effect modification by different grades of SE severity and etiologies. As IVADs were used after first- and second-line drugs failed, there was a correlation between treatment-refractory SE and the use of IVADs, leading to insignificant results regarding the risk of IVADs and outcome after additional adjustment for refractory SE. Conclusion: Our findings heighten awareness regarding adverse effects of IVADs. Randomized controlled trials are needed to further clarify the association of IVADs with outcome in patients with SE. Classification of evidence: This study provides Class III evidence that patients with SE receiving IVADs have a higher proportion of infection and an increased risk of death as compared to patients not receiving IVADs. PMID:24319039

  16. Anesthetic Management in a Gravida with Type IV Osteogenesis Imperfecta

    Directory of Open Access Journals (Sweden)

    Elizabeth Vue

    2016-01-01

    Full Text Available Osteogenesis imperfecta (OI is an inherited disorder of the connective tissues caused by abnormalities in collagen formation. OI may present many challenges to the anesthesiologist. A literature review reveals a wide range of implications, from basic positioning to management of the difficult airway. We present the anesthetic management of a 25-year-old gravid woman with OI, fetal demise, and possible uterine rupture, admitted for an exploratory laparotomy.

  17. Cimethidine pre-anesthetic. A prophylactic method against Mendelson's syndrome in cesarean section

    DEFF Research Database (Denmark)

    Qvist, N; Storm, K

    1983-01-01

    Twenty patients undergoing cesarean section received cimethidine 400 mg intramuscularly as pre-anesthetic approximately 70 minutes prior to gastric aspiration. The average pH was 5.05, as against 2.97 in the control group (p less than 0.01). No significant reduction in the aspirated volumes was o...

  18. Volatility Forecast in Crises and Expansions

    Directory of Open Access Journals (Sweden)

    Sergii Pypko

    2015-08-01

    Full Text Available We build a discrete-time non-linear model for volatility forecasting purposes. This model belongs to the class of threshold-autoregressive models, where changes in regimes are governed by past returns. The ability to capture changes in volatility regimes and using more accurate volatility measures allow outperforming other benchmark models, such as linear heterogeneous autoregressive model and GARCH specifications. Finally, we show how to derive closed-form expression for multiple-step-ahead forecasting by exploiting information about the conditional distribution of returns.

  19. Multifractal analysis of implied volatility in index options

    Science.gov (United States)

    Oh, GabJin

    2014-06-01

    In this paper, we analyze the statistical and the non-linear properties of the log-variations in implied volatility for the CAC40, DAX and S& P500 daily index options. The price of an index option is generally represented by its implied volatility surface, including its smile and skew properties. We utilize a Lévy process model as the underlying asset to deepen our understanding of the intrinsic property of the implied volatility in the index options and estimate the implied volatility surface. We find that the options pricing models with the exponential Lévy model can reproduce the smile or sneer features of the implied volatility that are observed in real options markets. We study the variation in the implied volatility for at-the-money index call and put options, and we find that the distribution function follows a power-law distribution with an exponent of 3.5 ≤ γ ≤ 4.5. Especially, the variation in the implied volatility exhibits multifractal spectral characteristics, and the global financial crisis has influenced the complexity of the option markets.

  20. The effects of anesthetic technique and ambient temperature on thermoregulation in lower extremity surgery.

    Science.gov (United States)

    Ozer, Ayse B; Tosun, Fadime; Demirel, Ismail; Unlu, Serap; Bayar, Mustafa K; Erhan, Omer L

    2013-08-01

    The purpose of our study was to determine the effects of anesthetic technique and ambient temperature on thermoregulation for patients undergoing lower extremity surgery. Our study included 90 male patients aged 18-60 years in American Society of Anesthesiologists Physical Status groups I or II who were scheduled for lower extremity surgery. Patients were randomly divided into three groups according to anesthetic technique: general anesthesia (GA), epidural anesthesia (EA), and femoral-sciatic block (FS). These groups were divided into subgroups according to room temperature: the temperature for group I was 20-22 °C and that for group II was 23-25 °C. Therefore, we labeled the groups as follows: GA I, GA II, EA I, EA II, FS I, and FS II. Probes for measuring tympanic membrane and peripheral temperature were placed in and on the patients, and mean skin temperature (MST) and mean body temperature (MBT) were assessed. Postoperative shivering scores were recorded. During anesthesia, tympanic temperature and MBT decreased whereas MST increased for all patients. There was no significant difference between tympanic temperatures in either the room temperature or anesthetic method groups. MST was lower in group GA I than in group GA II after 5, 10, 15, 20, 60 and 90 min whereas MBT was significantly lower at the basal level (p temperature affected thermoregulation in Group GA.

  1. Anesthetic Efficacy of 4 % Articaine During Extraction of the Mandibular Posterior Teeth by Using Inferior Alveolar Nerve Block and Buccal Infiltration Techniques.

    Science.gov (United States)

    El-Kholey, Khalid E

    2017-03-01

    The study was designed to evaluate the anesthetic efficacy of 4 % articaine with 1:100,000 epinephrine (A100) in infiltration and inferior alveolar nerve block (IANB) anesthetic techniques for the pain control during extraction of the mandibular posterior teeth. This prospective randomized single-blind clinical trial included 100 patients needing extraction of at least two mandibular molars. Patients received either infiltration in the buccal vestibule opposite to the first molar supplemented with lingual infiltration or standard IANB with A100. For assessment of depth of anesthesia obtained by the two anaethetic techniques, presence or absence of pain during the extraction were rated using the visual analog scale. Fifty patients received infiltration anesthesia and fifty patients were anesthetized by IANB. The success rate of pain-free extraction after buccal infiltration was 94 %, whereas by using IANB with the same anesthetic it was 92 %. No statistical differences were detected in the success rates between the two anesthetic techniques ( P  = 0.15). Buccal Infiltration can be considered a good option during extraction of the mandibular molar and premolar teeth of course, with supplemental lingual anesthesia.

  2. QT-RR relationships and suitable QT correction formulas for halothane-anesthetized dogs.

    Science.gov (United States)

    Tabo, Mitsuyasu; Nakamura, Mikiko; Kimura, Kazuya; Ito, Shigeo

    2006-10-01

    Several QT correction (QTc) formulas have been used for assessing the QT liability of drugs. However, they are known to under- and over-correct the QT interval and tend to be specific to species and experimental conditions. The purpose of this study was to determine a suitable formula for halothane-anesthetized dogs highly sensitive to drug-induced QT interval prolongation. Twenty dogs were anesthetized with 1.5% halothane and the relationship between the QT and RR intervals were obtained by changing the heart rate under atrial pacing conditions. The QT interval was corrected for the RR interval by applying 4 published formulas (Bazett, Fridericia, Van de Water, and Matsunaga); Fridericia's formula (QTcF = QT/RR(0.33)) showed the least slope and lowest R(2) value for the linear regression of QTc intervals against RR intervals, indicating that it dissociated changes in heart rate most effectively. An optimized formula (QTcX = QT/RR(0.3879)) is defined by analysis of covariance and represents a correction algorithm superior to Fridericia's formula. For both Fridericia's and the optimized formula, QT-prolonging drugs (d,l-sotalol, astemizole) showed QTc interval prolongation. A non-QT-prolonging drug (d,l-propranolol) failed to prolong the QTc interval. In addition, drug-induced changes in QTcF and QTcX intervals were highly correlated with those of the QT interval paced at a cycle length of 500 msec. These findings suggest that Fridericia's and the optimized formula, although the optimized is a little bit better, are suitable for correcting the QT interval in halothane-anesthetized dogs and help to evaluate the potential QT prolongation of drugs with high accuracy.

  3. Detecting instability in the volatility of carbon prices

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, Julien [Univ. Paris Dauphine (France)

    2011-01-15

    This article investigates the presence of outliers in the volatility of carbon prices. We compute three different measures of volatility for European Union Allowances, based on daily data (EGARCH model), option prices (implied volatility), and intraday data (realized volatility). Based on the methodology developed by Zeileis et al. (2003) and Zeileis (2006), we detect instability in the volatility of carbon prices based on two kinds of tests: retrospective tests (OLS-/Recursive-based CUSUM processes, F-statistics, and residual sum of squares), and forward-looking tests (by monitoring structural changes recursively or with moving estimates). We show evidence of strong shifts mainly for the EGARCH and IV models during the time period. Overall, we suggest that yearly compliance events, and growing uncertainties in post-Kyoto international agreements, may explain the instability in the volatility of carbon prices. (author)

  4. Propofol (2,6-diisopropylphenol) is an applicable immersion anesthetic in the axolotl with potential uses in hemodynamic and neurophysiological experiments

    DEFF Research Database (Denmark)

    Thygesen, Mathias; Rasmussen, Mikkel Mylius; Madsen, Jesper Guldsmed

    2017-01-01

    The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some...... neurophysiological experiments this is not desirable; therefore we tested propofol as an alternative anesthetic in the axolotl. We evaluated benzocaine, MS-222, and propofol's cardiovascular effects, effects on action potential propagation in the spinal cord, and gross limb regenerative effects. We found...... that propofol is applicable as a general anesthetic in the axolotl allowing for neurophysiological experiments and yielding a stable anesthesia with significantly less cardiovascular effect than both benzocaine and MS-222. Additionally, propofol did not affect gross limb regeneration. In conclusion we suggest...

  5. Propofol (2,6-diisopropylphenol) is an applicable immersion anesthetic in the axolotl with potential uses in hemodynamic and neurophysiological experiments

    DEFF Research Database (Denmark)

    Thygesen, Mathias; Rasmussen, Mikkel Mylius; Madsen, Jesper Guldsmed

    2017-01-01

    The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some neurophysiologi......The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some...... neurophysiological experiments this is not desirable; therefore we tested propofol as an alternative anesthetic in the axolotl. We evaluated benzocaine, MS-222, and propofol's cardiovascular effects, effects on action potential propagation in the spinal cord, and gross limb regenerative effects. We found...

  6. Inorganic salts interact with oxalic acid in submicron particles to form material with low hygroscopicity and volatility

    Science.gov (United States)

    Drozd, G.; Woo, J.; Häkkinen, S. A. K.; Nenes, A.; McNeill, V. F.

    2014-05-01

    Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. While the hygroscopicities of pure salts, di-carboxylic acids (DCA), and DCA salts are known, the hygroscopicity of internal mixtures of these components, as they are typically found in the atmosphere, has not been fully characterized. Here we show that inorganic-organic component interactions typically not considered in atmospheric models can lead to very strongly bound metal-organic complexes and greatly affect aerosol volatility and hygroscopicity; in particular, the bi-dentate binding of DCA to soluble inorganic ions. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 °C. Dramatic increases in the cloud condensation nuclei (CCN) activation diameter for particles with di-valent salts (e.g., CaCl2) and relatively small particle volume fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O : C ratios are capable of forming low-volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low-particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles without the need for a phase transition.

  7. A case of uncorrected adult tetralogy of Fallot for emergency decompressive craniotomy: An anesthetic challenge!!

    Directory of Open Access Journals (Sweden)

    Amruta Vinod Hippalgaonkar

    2016-01-01

    Full Text Available Cyanotic heart disease (CHD includes those anatomical heart defects that produce a limitation in pulmonary blood flow or result in mixing of oxygenated and deoxygenated blood. Both conditions lead to decreased blood oxygen content and cyanosis. The most frequent defects seen in the outpatient adult congenital setting include tetralogy of Fallot (TOF. The cardiovascular anatomy and physiology of adult CHD is complex and requires specific knowledge of the defect and its anesthetic implications. Hence, they should receive care with multidisciplinary collaboration among anesthesiologists, cardiologists, surgeons, and intensivists. We hereby report the anesthetic management of such a case of head injury in an adult uncorrected TOF with a good outcome.

  8. Efficacy of tricaine methanesulfonate (MS-222 as an anesthetic agent for blocking sensory-motor responses in Xenopus laevis tadpoles.

    Directory of Open Access Journals (Sweden)

    Carlana Ramlochansingh

    Full Text Available Anesthetics are drugs that reversibly relieve pain, decrease body movements and suppress neuronal activity. Most drugs only cover one of these effects; for instance, analgesics relieve pain but fail to block primary fiber responses to noxious stimuli. Alternately, paralytic drugs block synaptic transmission at neuromuscular junctions, thereby effectively paralyzing skeletal muscles. Thus, both analgesics and paralytics each accomplish one effect, but fail to singularly account for all three. Tricaine methanesulfonate (MS-222 is structurally similar to benzocaine, a typical anesthetic for anamniote vertebrates, but contains a sulfate moiety rendering this drug more hydrophilic. MS-222 is used as anesthetic in poikilothermic animals such as fish and amphibians. However, it is often argued that MS-222 is only a hypnotic drug and its ability to block neural activity has been questioned. This prompted us to evaluate the potency and dynamics of MS-222-induced effects on neuronal firing of sensory and motor nerves alongside a defined motor behavior in semi-intact in vitro preparations of Xenopus laevis tadpoles. Electrophysiological recordings of extraocular motor discharge and both spontaneous and evoked mechanosensory nerve activity were measured before, during and after administration of MS-222, then compared to benzocaine and a known paralytic, pancuronium. Both MS-222 and benzocaine, but not pancuronium caused a dose-dependent, reversible blockade of extraocular motor and sensory nerve activity. These results indicate that MS-222 as benzocaine blocks the activity of both sensory and motor nerves compatible with the mechanistic action of effective anesthetics, indicating that both caine-derivates are effective as single-drug anesthetics for surgical interventions in anamniotes.

  9. Effect of relative head position on the anesthetic efficacy of inferior alveolar nerve block during endodontic treatment of patients with irreversible pulpitis.

    Science.gov (United States)

    Aggarwal, Vivek; Singla, Mamta; Miglani, Sanjay

    2018-02-01

    The purpose of this prospective randomized single-blind clinical trial was to evaluate the effect of tilting the head on the anesthetic efficacy of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. Ninety-two patients were divided into two groups: the first group received IANB and the head was tilted in the direction of the block for 15 min, whereas the second group received IANB and the head was tilted to the opposite side. Access cavity preparation was initiated after 15 min. Success was defined as no pain or faint/weak/mild pain during endodontic access preparation and instrumentation. The anesthetic success rates were analyzed by Pearson chi-square test at 5% significance levels. The same side position and opposite side position yielded 41% and 30% anesthetic success rates, respectively; there was no significant difference between the two sides. Relative head position has no effect on the anesthetic success rate of IANB.

  10. A systematic review of methodology applied during preclinical anesthetic neurotoxicity studies : important issues and lessons relevant to the design of future clinical research

    NARCIS (Netherlands)

    Disma, Nicola; Mondardini, Maria C.; Terrando, Niccolo; Absalom, Anthony R.; Bilotta, Federico

    Preclinical evidence suggests that anesthetic agents harm the developing brain thereby causing long-term neurocognitive impairments. It is not clear if these findings apply to humans, and retrospective epidemiological studies thus far have failed to show definitive evidence that anesthetic agents

  11. Clinical application of thoracic paravertebral anesthetic block in breast surgeries

    Directory of Open Access Journals (Sweden)

    Sara Socorro Faria

    2015-04-01

    Full Text Available INTRODUCTION: Optimum treatment for postoperative pain has been of fundamental importance in surgical patient care. Among the analgesic techniques aimed at this group of patients, thoracic paravertebral block combined with general anesthesia stands out for the good results and favorable risk-benefit ratio. Many local anesthetics and other adjuvant drugs are being investigated for use in this technique, in order to improve the quality of analgesia and reduce adverse effects. OBJECTIVE: Evaluate the effectiveness and safety of paravertebral block compared to other analgesic and anesthetic regimens in women undergoing breast cancer surgeries. METHODS: Integrative literature review from 1966 to 2012, using specific terms in computerized databases of articles investigating the clinical characteristics, adverse effects, and beneficial effects of thoracic paravertebral block. RESULTS: On the selected date, 16 randomized studies that met the selection criteria established for this literature review were identified. Thoracic paravertebral block showed a significant reduction of postoperative pain, as well as decreased pain during arm movement after surgery. CONCLUSION: Thoracic paravertebral block reduced postoperative analgesic requirement compared to placebo group, markedly within the first 24 h. The use of this technique could ensure postoperative analgesia of clinical relevance. Further studies with larger populations are necessary, as paravertebral block seems to be promising for preemptive analgesia in breast cancer surgery.

  12. CAM Stochastic Volatility Model for Option Pricing

    Directory of Open Access Journals (Sweden)

    Wanwan Huang

    2016-01-01

    Full Text Available The coupled additive and multiplicative (CAM noises model is a stochastic volatility model for derivative pricing. Unlike the other stochastic volatility models in the literature, the CAM model uses two Brownian motions, one multiplicative and one additive, to model the volatility process. We provide empirical evidence that suggests a nontrivial relationship between the kurtosis and skewness of asset prices and that the CAM model is able to capture this relationship, whereas the traditional stochastic volatility models cannot. We introduce a control variate method and Monte Carlo estimators for some of the sensitivities (Greeks of the model. We also derive an approximation for the characteristic function of the model.

  13. [Solidification of volatile oil with graphene oxide].

    Science.gov (United States)

    Yan, Hong-Mei; Jia, Xiao-Bin; Zhang, Zhen-Hai; Sun, E; Xu, Yi-Hao

    2015-02-01

    To evaluate the properties of solidifying volatile oil with graphene oxide, clove oil and zedoary turmeric oil were solidified by graphene oxide. The amount of graphene oxide was optimized with the eugenol yield and curcumol yield as criteria. Curing powder was characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The effects of graphene oxide on dissolution in vitro and thermal stability of active components were studied. The optimum solidification ratio of graphene oxide to volatile oil was 1:1. Dissolution rate of active components had rare influence while their thermal stability improved after volatile oil was solidified. Solidifying herbal volatile oil with graphene oxide deserves further study.

  14. Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial.

    Science.gov (United States)

    Hamdani, Mehdi; Chassot, Olivier; Fournier, Roxane

    2014-01-01

    Automated bolus delivery has recently been shown to reduce local anesthetic consumption and improve analgesia, compared with continuous infusion, in continuous sciatic and epidural block. However, there are few data on the influence of local anesthetic delivery method on local anesthetic consumption following interscalene blockade. This randomized, double-blind trial was designed to determine whether hourly automated perineural boluses (4 mL) of local anesthesia delivered with patient-controlled pro re nata (PRN, on demand) boluses would result in a reduction in total local anesthesia consumption during continuous interscalene blockade after shoulder surgery compared with continuous perineural infusion (4 mL/h) plus patient-controlled PRN boluses. One hundred one patients undergoing major shoulder surgery under general anesthesia with ultrasound-guided continuous interscalene block were randomly assigned to receive 0.2% ropivacaine via interscalene end-hole catheter either by continuous infusion 4 mL/h (n = 50) or as automated bolus 4 mL/h (n = 51). Both delivery methods were combined with 5 mL PRN boluses of 0.2% ropivacaine with a lockout time of 30 minutes. Postoperative number of PRN boluses, 24- and 48-hour local anesthetic consumption, pain scores, rescue analgesia (morphine), and adverse events were recorded. There were no significant differences in either the number of PRN ropivacaine boluses or total 48 hour local anesthetic consumption between the groups (18.5 [11-25.2] PRN boluses in the continuous infusion group vs 17 [8.5-29] PRN boluses in the automated bolus group). Postoperative pain was similar in both groups; on day 2, the median average pain score was 4 (2-6) in the continuous infusion group versus 3 (2-5) in the automated bolus group (P = 0.54). Nor were any statistically significant intergroup differences observed with respect to morphine rescue, incidence of adverse events, or patient satisfaction. In continuous interscalene blockade under

  15. Differential effects of gaseous versus injectable anesthetics on changes in regional cerebral blood flow and metabolism induced by l-DOPA in a rat model of Parkinson's disease.

    Science.gov (United States)

    Bimpisidis, Zisis; Öberg, Carl M; Maslava, Natallia; Cenci, M Angela; Lundblad, Cornelia

    2017-06-01

    Preclinical imaging of brain activity requires the use of anesthesia. In this study, we have compared the effects of two widely used anesthetics, inhaled isoflurane and ketamine/xylazine cocktail, on cerebral blood flow and metabolism in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia. Specific tracers were used to estimate regional cerebral blood flow (rCBF - [ 14 C]-iodoantipyrine) and regional cerebral metabolic rate (rCMR - [ 14 C]-2-deoxyglucose) with a highly sensitive autoradiographic method. The two types of anesthetics had quite distinct effects on l-DOPA-induced changes in rCBF and rCMR. Isoflurane did not affect either the absolute rCBF values or the increases in rCBF in the basal ganglia after l-DOPA administration. On the contrary, rats anesthetized with ketamine/xylazine showed lower absolute rCBF values, and the rCBF increases induced by l-DOPA were masked. We developed a novel improved model to calculate rCMR, and found lower metabolic activities in rats anesthetized with isoflurane compared to animals anesthetized with ketamine/xylazine. Both anesthetics prevented changes in rCMR upon l-DOPA administration. Pharmacological challenges in isoflurane-anesthetized rats indicated that drugs mimicking the actions of ketamine/xylazine on adrenergic or glutamate receptors reproduced distinct effects of the injectable anesthetics on rCBF and rCMR. Our results highlight the importance of anesthesia in studies of cerebral flow and metabolism, and provide novel insights into mechanisms mediating abnormal neurovascular responses to l-DOPA in Parkinson's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Macroeconomic Volatility and Welfare in Developing Countries

    OpenAIRE

    Loayza, Norman V.; Rancière, Romain; Servén, Luis; Ventura, Jaume

    2007-01-01

    Macroeconomic Volatility and Welfare in Developing Countries: An Introduction Norman V. Loayza, Romain Ranciere, Luis Serven, ` and Jaume Ventura Macroeconomic volatility, both a source and a reflection of underdevelopment, is a fundamental concern for developing countries. This article provides a brief overview of the recent literature on macroeconomic volatility in developing countries, highlighting its causes, consequences, and possible remedies. to reduce domestic policy-induced macroecon...

  17. Volatile liquid storage system

    International Nuclear Information System (INIS)

    Laverman, R.J.; Winters, P.J.; Rinehart, J.K.

    1992-01-01

    This patent describes a method of collecting and abating emission from a volatile liquid in an above ground storage tank. It comprises the liquid storage tank having a bottom, a vertical cylindrical circular wall having a lower edge portion joined to the bottom, and an external fixed roof, the tank having an internal floating roof floating on a volatile liquid stored in the tank, and air vent means in the tank in communication with a vapor space in the tank constituting at least the space above the floating roof when the floating roof floats on a predetermined maximum volume of volatile liquid in the tank; permitting ambient air; pumping emission laden air from the tank vapor space above the floating roof; and by means of the emissions abatement apparatus eliminating most of the emission from the emissions laden air with formation of a gaseous effluent and then discharging the resulting gaseous effluent to the atmosphere

  18. Evidence of mercury trapping in biofilm-EPS and mer operon-based volatilization of inorganic mercury in a marine bacterium Bacillus cereus BW-201B.

    Science.gov (United States)

    Dash, Hirak R; Basu, Subham; Das, Surajit

    2017-04-01

    Biofilm-forming mercury-resistant marine bacterium Bacillus cereus BW-201B has been explored to evident that the bacterial biofilm-EPS (exopolymers) trap inorganic mercury but subsequently release EPS-bound mercury for induction of mer operon-mediated volatilization of inorganic mercury. The isolate was able to tolerate 50 ppm of mercury and forms biofilm in presence of mercury. mer operon-mediated volatilization was confirmed, and -SH was found to be the key functional group of bacterial EPS responsible for mercury binding. Biofilm-EPS-bound mercury was found to be internalized to the bacterial system as confirmed by reversible conformational change of -SH group and increased expression level of merA gene in a timescale experiment. Biofilm-EPS trapped Hg after 24 h of incubation, and by 96 h, the volatilization process reaches to its optimum confirming the internalization of EPS-bound mercury to the bacterial cells. Biofilm disintegration at the same time corroborates the results.

  19. Bacterial contribution to iodine volatilization in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Amachi, S; Kasahara, M; Fujii, T [Chiba Univ., Dept. of Bioresources Chemistry, Matsudo, Chiba (Japan); Muramatsu, Y [National Inst. of Radiological Sciences, Chiba (Japan)

    2003-09-01

    The roles of microorganisms in iodine volatilization from the environment were studied. More than 100 bacterial strains were isolated from various environments such as soils, seawater and marine sediments, and were examined their capacities for volatilizing iodine. Approximately 40% of these bacteria showed significant capacities for volatilizing iodine. Gas chromatographic determinations revealed that the chemical species of gaseous iodine is methyl iodide (CH{sub 3}I). Phylogenetic analysis based on 16S ribosomal DNA showed that these 'iodine-volatilizing bacteria' are widely distributed through the bacterial domain. The iodide-methylating reaction was mediated by an enzyme protein with S-adenosyl-L-methionine (SAM) as the methyl donor. We then estimated bacterial contribution to iodine volatilization from soils. Iodine in soils was volatilized mainly as CH{sub 3}I. CH{sub 3}I emission was enhanced in the presence of glucose or yeast extract, but was inhibited by autoclaving of soils. Little CH{sub 3}I was produced under anaerobic conditions. Furthermore, the addition of streptomycin and tetracycline, antibiotics which inhibit bacterial growth, strongly inhibited CH{sub 3}I emission, while a fungal inhibitor cycloheximide caused little effect. These results suggest that iodine in soils is volatilized as CH{sub 3}I mainly by the action of aerobic soil bacteria. Similar experiment was carried out by using sea water samples. The emission of iodine from sea waters occurred biologically, and bacterial (and also other microbial) contribution was confirmed. Our results suggest that iodine is methylated and volatilized into the atmosphere as a result of bacterial activities. Since bacteria are so abundant and widespread in the environments, they may significantly contribute to global iodine volatilization. This indicates that if {sup 129}I would be released from nuclear facilities, weapons testing or ground storage of nuclear wastes, the pathway of volatilization by

  20. Topical anesthesia with eutetic mixture of local anesthetics cream in vasectomy: 2 randomized trials

    DEFF Research Database (Denmark)

    Honnens de Lichtenberg, M; Krogh, J; Rye, B

    1992-01-01

    Two paired randomized trials testing topical anesthesia with a eutetic mixture of local anesthetics (EMLA cream*) in vasectomy were performed. In 1 trial EMLA cream was applied on 1 side of the scrotum, while infiltration anesthesia into the skin and subcutaneous tissue with mepivacaine was used...... on the contralateral side. All but 1 of the 13 patients (p less than 0.05) preferred infiltration anesthesia because of pain as the incision reached the subcutaneous tissue. In the other trial 29 patients received EMLA cream on 1 side of the scrotum before bilateral mepivacaine infiltration. There was significantly...... less pain on the sides with the anesthetic cream (p less than 0.001). Many patients would pay the price of the cream. In conclusion, EMLA cream cannot replace but it can supplement infiltration anesthesia during vasectomy....

  1. Trigeminal nerve injury associated with injection of local anesthetics: needle lesion or neurotoxicity?

    DEFF Research Database (Denmark)

    Hillerup, Søren; Jensen, Rigmor H; Ersbøll, Bjarne Kjær

    2011-01-01

    BACKGROUND: The authors used comprehensive national registry and clinical data to conduct a study of adverse drug reactions (ADRs), in particular neurosensory disturbance (NSD), associated with local anesthetics used in dentistry METHODS: The study included data sets of annual sales of local anes...

  2. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...

  3. The economic value of realized volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jacobs, Kris

    2014-01-01

    Many studies have documented that daily realized volatility estimates based on intraday returns provide volatility forecasts that are superior to forecasts constructed from daily returns only. We investigate whether these forecasting improvements translate into economic value added. To do so, we ...

  4. Empirical Analysis of Stochastic Volatility Model by Hybrid Monte Carlo Algorithm

    International Nuclear Information System (INIS)

    Takaishi, Tetsuya

    2013-01-01

    The stochastic volatility model is one of volatility models which infer latent volatility of asset returns. The Bayesian inference of the stochastic volatility (SV) model is performed by the hybrid Monte Carlo (HMC) algorithm which is superior to other Markov Chain Monte Carlo methods in sampling volatility variables. We perform the HMC simulations of the SV model for two liquid stock returns traded on the Tokyo Stock Exchange and measure the volatilities of those stock returns. Then we calculate the accuracy of the volatility measurement using the realized volatility as a proxy of the true volatility and compare the SV model with the GARCH model which is one of other volatility models. Using the accuracy calculated with the realized volatility we find that empirically the SV model performs better than the GARCH model.

  5. Obstetric use of nitroglycerin: Anesthetic implications

    Directory of Open Access Journals (Sweden)

    Richa Saroa

    2013-01-01

    Full Text Available Nitroglycerin has been used in anesthetic practice for induced hypotension and managing perioperative hypertension and myocardial ischemia. Contrary to the continuous low dose infusions (5-20 mcg/min used for the same, intravenous bolus dosages are sometimes administered at the behest of obstetricians for removal of retained placenta. Use of nitroglycerine in managing retained placenta is undertaken as a last resort when other measures fail to relax the uterine smooth muscles. Intravenous nitroglycerine relaxes smooth muscle cells by releasing nitric oxide thus causing prompt cervico-uterine relaxation. However, administration of nitroglycerine in this manner is not without risks which should be kept in mind while using it for obstetric purposes. We hereby report a case of 22-year-old female scheduled for manual removal of placenta where unpredictable and unexpected hypoxemia was observed following nitroglycerine administration.

  6. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  7. Stock return, seasonality and asymmetric conditional volatility in steel & iron subsector

    Directory of Open Access Journals (Sweden)

    V. Chirila

    2015-01-01

    Full Text Available This paper presents the results obtained following the testing of five hypotheses regarding conditional return and volatility of the most listed European stocks in the steel & iron subsector. The following elements of the stocks are analysed: time variation of volatility, seasonality of return and volatility, relationship between return and volatility and volatility asymmetry. The results obtained confirm for all the analyzed stocks the existence of volatility variation in time, the lack of correlation between return and volatility, the existence of asymmetry phenomenon of volatility and the presence in some stocks of the seasonality effect both for return and volatility.

  8. Bias-reduced estimation of long memory stochastic volatility

    DEFF Research Database (Denmark)

    Frederiksen, Per; Nielsen, Morten Ørregaard

    We propose to use a variant of the local polynomial Whittle estimator to estimate the memory parameter in volatility for long memory stochastic volatility models with potential nonstation- arity in the volatility process. We show that the estimator is asymptotically normal and capable of obtaining...

  9. Volatile-mediated interactions between phylogenetically different soil bacteria

    Directory of Open Access Journals (Sweden)

    Paolina eGarbeva

    2014-06-01

    Full Text Available There is increasing evidence that organic volatiles play an important role in interactions between micro-organisms in the porous soil matrix. Here we report that volatile compounds emitted by different soil bacteria can affect the growth, antibiotic production and gene expression of the soil bacterium Pseudomonas fluorescens Pf0-1. We applied a novel cultivation approach that mimics the natural nutritional heterogeneity in soil in which P. fluorescens grown on nutrient-limited agar was exposed to volatiles produced by 4 phylogenetically different bacterial isolates (Collimonas pratensis, Serratia plymuthica, Paenibacillus sp. and Pedobacter sp. growing in sand containing artificial root exudates. Contrary to our expectation, the produced volatiles stimulated rather than inhibited the growth of P. fluorescens. A genome-wide, microarray-based analysis revealed that volatiles of all 4 bacterial strains affected gene expression of P. fluorescens, but with a different pattern of gene expression for each strain. Based on the annotation of the differently expressed genes, bacterial volatiles appear to induce a chemotactic motility response in P. fluorescens, but also an oxidative stress response. A more detailed study revealed that volatiles produced by C. pratensis triggered, antimicrobial secondary metabolite production in P. fluorescens. Our results indicate that bacterial volatiles can have an important role in communication, trophic - and antagonistic interactions within the soil bacterial community.

  10. Investment timing under hybrid stochastic and local volatility

    International Nuclear Information System (INIS)

    Kim, Jeong-Hoon; Lee, Min-Ku; Sohn, So Young

    2014-01-01

    Highlights: • The effects of hybrid stochastic volatility on real option prices are studied. • The stochastic volatility consists of a fast mean-reverting component and a CEV type one. • A fast mean-reverting factor lowers real option prices and investment thresholds. • The increase of elasticity raises real option prices and investment thresholds. • The effects of the addition of a slowly varying factor depend upon the project value. - Abstract: We consider an investment timing problem under a real option model where the instantaneous volatility of the project value is given by a combination of a hidden stochastic process and the project value itself. The stochastic volatility part is given by a function of a fast mean-reverting process as well as a slowly varying process and the local volatility part is a power (the elasticity parameter) of the project value itself. The elasticity parameter controls directly the correlation between the project value and the volatility. Knowing that the project value represents the market price of a real asset in many applications and the value of the elasticity parameter depends on the asset, the elasticity parameter should be treated with caution for investment decision problems. Based on the hybrid structure of volatility, we investigate the simultaneous impact of the elasticity and the stochastic volatility on the real option value as well as the investment threshold

  11. Postpartum tubal ligation: A retrospective review of anesthetic management at a single institution and a practice survey of academic institutions.

    Science.gov (United States)

    McKenzie, Christine; Akdagli, Seden; Abir, Gillian; Carvalho, Brendan

    2017-12-01

    The primary aim was to evaluate institutional anesthetic techniques utilized for postpartum tubal ligation (PPTL). Secondarily, academic institutions were surveyed on their clinical practice for PPTL. An institutional-specific retrospective review of patients with ICD-9 procedure codes for PPTL over a 2-year period was conducted. Obstetric anesthesia fellowship directors were surveyed on anesthetic management of PPTL. Labor and delivery unit. Internet survey. 202 PPTL procedures were reviewed. 47 institutions were surveyed; 26 responses were received. Timing of PPTL, anesthetic management, postoperative pain and length of stay. There was an epidural catheter reactivation failure rate of 26% (18/69 epidural catheter reactivation attempts). Time from epidural catheter insertion to PPTL was a significant factor associated with failure: median [IQR; range] time for successful versus failed epidural catheter reactivation was 17h [10-25; 3-55] and 28h [14-33; 5-42], respectively (P=0.028). Epidural catheter reactivation failure led to significantly longer times to provide surgical anesthesia than successful epidural catheter reactivation or primary spinal technique: median [IQR] 41min [33-54] versus 15min [12-21] and 19min [15-24], respectively (P8h and >24h post-delivery, respectively. Epidural catheter reactivation failure increases with longer intervals between catheter placement and PPTL. Failed epidural catheter reactivation increases anesthetic and operating room times. Our results and the significant variability in practice from our survey suggest recommendations on the timing and anesthetic management are needed to reduce unfulfilled PPTL procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Local Anesthetic Activity from Extracts, Fractions and Pure Compounds from the Roots of Ottonia anisum Spreng. (Piperaceae).

    Science.gov (United States)

    López, Kelvin S E; Marques, André M; Moreira, Davyson DE L; Velozo, Leosvaldo S; Sudo, Roberto T; Zapata-Sudo, Gisele; Guimarães, Elsie F; Kaplan, Maria Auxiliadora C

    2016-01-01

    Piperaceae species can be found worldwide in tropical and subtropical areas and many of them have been used for centuries in traditional folk medicine and in culinary. In Brazil, species of Piperaceae are commonly used in some communities as local anesthetic and analgesic. Countrified communities have known some species of the genus Ottonia as "anestesia" and it is a common habit of chewing leaves and roots of Ottonia species to relief toothache. The purpose of this study is to report our findings on new molecules entities obtained from the roots of Ottonia anisum Spreng, in which local anesthetic activity (sensory blockage) is demonstrated for the first time in vivo guinea pig model. Phytochemical investigation led to the isolation of three amides (pipercallosidine, piperine and valeramide) and in an enriched mixture of seven amides (valeramide, 4,5-dihydropiperlonguminine, N-isobutil-6-piperonil-2-hexenamide, piperovatine, dihydropipercallosidine, pipercallosidine and pipercallpsine). Our findings demonstrated the anesthetic potential for the methanolic extract from roots, its n-hexane partition and amides from O. anisum and it is in agreement with ethnobotanical survey.

  13. Evaluation of local anesthetic effects of Lidocaine-Ibuprofen ionic liquid stabilized silver nanoparticles in Male Swiss mice.

    Science.gov (United States)

    Jiang, Qiliang; Yu, Shashuang; Li, Xingwang; Ma, Chuangen; Li, Aixiang

    2018-01-01

    A simple approach for the synthesis of Lidocaine-Ibuprofen ionic liquid stabilized silver nanoparticles (IL-AgNPs) was reported in this work. The shape, size and surface morphology of the Lidocaine-Ibuprofen ionic liquid stabilized AgNPs were characterized by using spectroscopic and microscopic techniques such as Ultraviolet-visible spectroscopy (UV-Visible), X-ray diffraction (XRD) analysis, Selected area electron diffraction (SAED), Transmission electron microscopy (TEM). TEM analysis showed the formation of 20-30nm size of IL-AgNPs with very clear lattice fringes. SAED pattern confirmed the highly crystalline nature of fabricated IL stabilized AgNPs. EDS results confirmed the formation of nanosilver. The fabricated IL-AgNPs were studied for their local anesthetic effect in rats. The results of local anesthetic effect showed that the time for onset of action by IL-AgNPs is 10min, which is significantly higher than that for EMLA. Further, tactile test results confirmed the stronger and faster local anesthetic effect of IL-AgNPs when compared to that of EMLA. Copyright © 2017. Published by Elsevier B.V.

  14. Differences in motor evoked potentials induced in rats by transcranial magnetic stimulation under two separate anesthetics: implications for plasticity studies

    Directory of Open Access Journals (Sweden)

    Matthew Sykes

    2016-10-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS, a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when

  15. Autoradiographic methods for studying marked volatile substances (1961); Methode.d'etude autoradiographique de substances marquees volatiles (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Y; Wepierre, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The autoradiographic methods for animals used up to the present do not make it possible to localise exactly the distribution of marked volatile molecules. The Ullberg method (1954) which we have modified (Cohen, Delassue, 1959) involves cold desiccant. The method due to Pellerin (1957) avoids this desiccant but the histological comparison of the autoradiography with the biological document itself is difficult, if not impossible. Nevertheless, we have adopted certain points in the two methods and propose the following technique for the autoradiographic study of marked volatile molecules: 1- The surface of the frozen sample to be studied is prepared using a freezing microtome. 2- The last section, which is 20 {mu} thick and whose histological elements are parallel to those of the block, is dried by cooling and is used as the biological reference document for the autoradiography obtained, as is indicated in 3; 3- The radiography films are applied to the frozen block at -30 deg. C. The autoradiographs correspond to the radioactivity of the volatile molecule and of its non-volatile degradation products. 4- The radiographic film is also applied to the 20 {mu} section previously dried at -20 deg. C. This autoradiography corresponds to the radioactivity of the non-volatile degradation products of the molecule. 5- We confirmed the absence of diffusion of the volatile molecule and of pseudo-radiographic effects (photochemical and others). This method, which has enabled us to study the distribution of a carbide, para-cymene (C{sup 14}) 7, macroscopically in the case of a whole mouse and microscopically on the skin of a dog, can find general applications. (authors) [French] Les methodes d'autoradiographies sur l'animal, proposees jusqu'a present, ne permettent pas de localiser de facon precise la distribution de molecules marquees volatiles. En effet, la methode de Ullberg (1954) que nous avons modifiee (Cohen, Delassue, 1959) necessite la dessiccation par le froid. La methode

  16. The Volatility Effect: Lower Risk without Lower Return

    NARCIS (Netherlands)

    D.C. Blitz (David); P. van Vliet (Pim)

    2007-01-01

    textabstractWe present empirical evidence that stocks with low volatility earn high risk-adjusted returns. The annual alpha spread of global low versus high volatility decile portfolios amounts to 12% over the 1986-2006 period. We also observe this volatility effect within the US, European and

  17. The Short-Time Behaviour of VIX Implied Volatilities in a Multifactor Stochastic Volatility Framework

    DEFF Research Database (Denmark)

    Barletta, Andrea; Nicolato, Elisa; Pagliarani, Stefano

    error bounds for VIX futures, options and implied volatilities. In particular, we derive exact asymptotic results for VIX implied volatilities, and their sensitivities, in the joint limit of short time-to-maturity and small log-moneyness. The obtained expansions are explicit, based on elementary...... approximations of equity (SPX) options. However, the generalizations needed to cover the case of VIX options are by no means straightforward as the dynamics of the underlying VIX futures are not explicitly known. To illustrate the accuracy of our technique, we provide numerical implementations for a selection...... functions and they neatly uncover how the VIX skew depends on the specific choice of the volatility and the vol-of-vol processes. Our results are based on perturbation techniques applied to the infinitesimal generator of the underlying process. This methodology has been previously adopted to derive...

  18. Release of volatile mercury from vascular plants

    Science.gov (United States)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  19. Investigate Volatility Jumps in Chinese Stock Index Future and Spot Markets Based on Realized Volatility

    Institute of Scientific and Technical Information of China (English)

    Zhang qiang

    2014-01-01

    This paper aims to investigate Chinese stock index future and spot market's volatility jumps characteristics by using recentlydeveloped jumpstest(Barndorff-Nielsenand Shephard,2004).Thedataisoneyearhigh frequencydatafromthe period19/04/2012 to 19/04/2013. The empirical results show two important points. Firstly, the logarithm of adjusted realized volatility shows a high degree of autocorrelation and folows a normal distribution nearly perfect. These characteristics show a potential high forecast ability. Secondly,thedailyrealizedvolatilityjumpsshowalowdegreeofautocorrealtionbutwithsignificantvolatilityclusters.Ingeneral,thejumps component has a low percentage in realized volatility estimation for both future and spot market. On average, there is one significant jumpswithinevery ten continue trading days.Spotmarkets showshigherdegree of jumps,anda rapidly jumpscharacterises.It implies that jumps may transmission from spot to future market, and spot market dominate future market at some degree.

  20. Volatility forecasting for low-volatility portfolio selection in the US and the Korean equity markets

    Science.gov (United States)

    Kim, Saejoon

    2018-01-01

    We consider the problem of low-volatility portfolio selection which has been the subject of extensive research in the field of portfolio selection. To improve the currently existing techniques that rely purely on past information to select low-volatility portfolios, this paper investigates the use of time series regression techniques that make forecasts of future volatility to select the portfolios. In particular, for the first time, the utility of support vector regression and its enhancements as portfolio selection techniques is provided. It is shown that our regression-based portfolio selection provides attractive outperformances compared to the benchmark index and the portfolio defined by a well-known strategy on the data-sets of the S&P 500 and the KOSPI 200.

  1. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil

    Directory of Open Access Journals (Sweden)

    Prontera A

    2017-03-01

    Full Text Available Andrea Prontera,1 Stefano Baroni,2 Andrea Marudi,2 Franco Valzania,3 Alberto Feletti,1 Francesca Benuzzi,4 Elisabetta Bertellini,2 Giacomo Pavesi1 1Department of Neurosurgery, Nuovo Ospedale Civile SAgostino-Estense, 2Department of Anesthesiology, Nuovo Ospedale Civile SAgostino-Estense, 3Department of Neurology, Nuovo Ospedale Civile S Agostino-Estense, 4Department of Neuroscience, University of Modena and Reggio Emilia, Modena, Italy Introduction: Awake craniotomy allows continuous monitoring of patients’ neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic–sedative medication is increasing.Methods: Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management.Results: The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure.Conclusion: In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used. Keywords: dexmedetomidine, awake surgery, anesthesia

  2. Fundamental uncertainty and stock market volatility

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2008-01-01

    We provide empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from participants in the Survey of Professional Forecasters over the period 1969 to 1996.

  3. Estimation of Stochastic Volatility Models by Nonparametric Filtering

    DEFF Research Database (Denmark)

    Kanaya, Shin; Kristensen, Dennis

    2016-01-01

    /estimated volatility process replacing the latent process. Our estimation strategy is applicable to both parametric and nonparametric stochastic volatility models, and can handle both jumps and market microstructure noise. The resulting estimators of the stochastic volatility model will carry additional biases...... and variances due to the first-step estimation, but under regularity conditions we show that these vanish asymptotically and our estimators inherit the asymptotic properties of the infeasible estimators based on observations of the volatility process. A simulation study examines the finite-sample properties...

  4. Volatile flavor compounds in yogurt: a review.

    Science.gov (United States)

    Cheng, Hefa

    2010-11-01

    Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor.

  5. Long- and Short-Term Cryptocurrency Volatility Components: A GARCH-MIDAS Analysis

    Directory of Open Access Journals (Sweden)

    Christian Conrad

    2018-05-01

    Full Text Available We use the GARCH-MIDAS model to extract the long- and short-term volatility components of cryptocurrencies. As potential drivers of Bitcoin volatility, we consider measures of volatility and risk in the US stock market as well as a measure of global economic activity. We find that S&P 500 realized volatility has a negative and highly significant effect on long-term Bitcoin volatility. The finding is atypical for volatility co-movements across financial markets. Moreover, we find that the S&P 500 volatility risk premium has a significantly positive effect on long-term Bitcoin volatility. Finally, we find a strong positive association between the Baltic dry index and long-term Bitcoin volatility. This result shows that Bitcoin volatility is closely linked to global economic activity. Overall, our findings can be used to construct improved forecasts of long-term Bitcoin volatility.

  6. A Jump Diffusion Model for Volatility and Duration

    DEFF Research Database (Denmark)

    Wei, Wei; Pelletier, Denis

    by the market microstructure theory. Traditional measures of volatility do not utilize durations. I adopt a jump diffusion process to model the persistence of intraday volatility and conditional duration, and their interdependence. The jump component is disentangled from the continuous part of the price......, volatility and conditional duration process. I develop a MCMC algorithm for the inference of irregularly spaced multivariate process with jumps. The algorithm provides smoothed estimates of the latent variables such as spot volatility, jump times and jump sizes. I apply this model to IBM data and I find...... meaningful relationship between volatility and conditional duration. Also, jumps play an important role in the total variation, but the jump variation is smaller than traditional measures that use returns sampled at lower frequency....

  7. [Study on absorbing volatile oil with mesoporous carbon].

    Science.gov (United States)

    Yan, Hong-mei; Jia, Xiao-bin; Zhang, Zhen-hai; Sun, E; Yang Nan

    2014-11-01

    Clove oil and turmeric oil were absorbed by mesoporous carbon. The absorption ratio of mesoporous carbon to volatile oil was optimized with the eugenol yield and curcumol yield as criteria Curing powder was characterized by scanning electron microscopy (SEM) and differential scanning calorietry (DSC). The effects of mesoporous carbon on dissolution in vitro and thermal stability of active components were studied. They reached high adsorption rate when the absorption ratio of mesoporous carbon to volatile oil was 1:1. When volatile oil was absorbed, dissolution rate of active components had a little improvement and their thermal stability improved after volatile oil was absorbed by the loss rate decreasing more than 50%. Absorbing herbal volatile oil with mesoporous carbon deserves further studying.

  8. Gasoline taxes and revenue volatility: An application to California

    International Nuclear Information System (INIS)

    Madowitz, M.; Novan, K.

    2013-01-01

    This paper examines how applying different combinations of excise and sales taxes on motor fuels impact the volatility of retail fuel prices and tax revenues. Two features of gasoline and diesel markets make the choice of tax mechanism a unique problem. First, prices are very volatile. Second, demand for motor fuels is extremely inelastic. As a result, fuel expenditures vary substantially over time. Tying state revenues to these expenditures, as is the case with a sales tax, results in a volatile stream of revenue which imposes real costs on agents in an economy. On July 1, 2010, California enacted Assembly Bill x8-6, the “Gas Tax Swap”, increasing the excise tax and decreasing the sales tax on gasoline purchases. While the initial motivation behind the revenue neutral swap was to provide the state with greater flexibility within its budget, we highlight that this change has two potentially overlooked benefits; it reduces retail fuel price volatility and tax revenue volatility. Simulating the monthly fuel prices and tax revenues under alternative tax policies, we quantify the potential reductions in revenue volatility. The results reveal that greater benefits can be achieved by going beyond the tax swap and eliminating the gasoline sales tax entirely. - Highlights: • We examine how gasoline taxes affect government revenue volatility. • We simulate the impact of California's Gasoline Tax Swap policy. • Sales taxes are shown to magnify price volatility and government revenue volatility. • A pure excise tax policy results in less volatile fuel prices and state revenues. • We argue that reductions in both forms of volatility are welfare enhancing

  9. Biogenic volatile emissions from the soil.

    Science.gov (United States)

    Peñuelas, J; Asensio, D; Tholl, D; Wenke, K; Rosenkranz, M; Piechulla, B; Schnitzler, J P

    2014-08-01

    Volatile compounds are usually associated with an appearance/presence in the atmosphere. Recent advances, however, indicated that the soil is a huge reservoir and source of biogenic volatile organic compounds (bVOCs), which are formed from decomposing litter and dead organic material or are synthesized by underground living organism or organs and tissues of plants. This review summarizes the scarce available data on the exchange of VOCs between soil and atmosphere and the features of the soil and particle structure allowing diffusion of volatiles in the soil, which is the prerequisite for biological VOC-based interactions. In fact, soil may function either as a sink or as a source of bVOCs. Soil VOC emissions to the atmosphere are often 1-2 (0-3) orders of magnitude lower than those from aboveground vegetation. Microorganisms and the plant root system are the major sources for bVOCs. The current methodology to detect belowground volatiles is described as well as the metabolic capabilities resulting in the wealth of microbial and root VOC emissions. Furthermore, VOC profiles are discussed as non-destructive fingerprints for the detection of organisms. In the last chapter, belowground volatile-based bi- and multi-trophic interactions between microorganisms, plants and invertebrates in the soil are discussed. © 2014 John Wiley & Sons Ltd.

  10. Increased gamma-aminobutyric acid levels in mouse brain induce loss of righting reflex, but not immobility, in response to noxious stimulation.

    Science.gov (United States)

    Katayama, Sohtaro; Irifune, Masahiro; Kikuchi, Nobuhito; Takarada, Tohru; Shimizu, Yoshitaka; Endo, Chie; Takata, Takashi; Dohi, Toshihiro; Sato, Tomoaki; Kawahara, Michio

    2007-06-01

    The general anesthetic state comprises behavioral and perceptual components, including amnesia, unconsciousness, and immobility. gamma-Aminobutyric acidergic (GABAergic) inhibitory neurotransmission is an important target for anesthetic action at the in vitro cellular level. In vivo, however, the functional relevance of enhancing GABAergic neurotransmission in mediating essential components of the general anesthetic state is unknown. Gabaculine is a GABA-transaminase inhibitor that inhibits degradation of released GABA, and consequently increases endogenous GABA in the central nervous system. Here, we examined, behaviorally, the ability of increased GABA levels to produce components of the general anesthetic state. All drugs were administered systemically in adult male ddY mice. To assess the general anesthetic components, two end-points were used. One was loss of righting reflex (LORR; as a measure of unconsciousness); the other was loss of movement in response to tail-clamp stimulation (as a measure of immobility). Gabaculine induced LORR in a dose-dependent fashion with a 50% effective dose of 100 (75-134; 95% confidence limits) mg/kg. The behavioral and microdialysis studies revealed that the endogenous GABA-induced LORR occurred in a brain concentration-dependent manner. However, even larger doses of gabaculine (285-400 mg/kg) produced no loss of tail-clamp response. In contrast, all the tested volatile anesthetics concentration-dependently abolished both righting and tail-clamp response, supporting the evidence that volatile anesthetics act on a variety of molecular targets. These findings indicate that LORR is associated with enhanced GABAergic neurotransmission, but that immobility in response to noxious stimulation is not, suggesting that LORR and immobility are mediated through different neuronal pathways and/or regions in the central nervous system.

  11. Anesthetic Sevoflurane Causes Rho-Dependent Filopodial Shortening in Mouse Neurons.

    Directory of Open Access Journals (Sweden)

    Jeffrey H Zimering

    Full Text Available Early postnatal anesthesia causes long-lasting learning and memory impairment in rodents, however, evidence for a specific neurotoxic effect on early synaptogenesis has not been demonstrated. Drebrin A is an actin binding protein whose localization in dendritic protrusions serves an important role in dendritic spine morphogenesis, and is a marker for early synaptogenesis. We therefore set out to investigate whether clinically-relevant concentrations of anesthetic sevoflurane, widely- used in infants and children, alters dendritic morphology in cultured fetal day 16 mouse hippocampal neurons. After 7 days in vitro, mouse hippocampal neurons were exposed to four hours of 3% sevoflurane in 95% air/5% CO2 or control condition (95% air/5% CO2. Neurons were fixed in 4% paraformaldehyde and stained with Alexa Fluor555-Phalloidin, and/or rabbit anti-mouse drebrin A/E antibodies which permitted subcellular localization of filamentous (F-actin and/or drebrin immunoreactivity, respectively. Sevoflurane caused acute significant length-shortening in filopodia and thin dendritic spines in days-in-vitro 7 neurons, an effect which was completely rescued by co-incubating neurons with ten micromolar concentrations of the selective Rho kinase inhibitor Y27632. Filopodia and thin spine recovered in length two days after sevoflurane exposure. Yet cluster-type filopodia (a precursor to synaptic filopodia were persistently significantly decreased in number on day-in-vitro 9, in part owing to preferential localization of drebrin immunoreactivity to dendritic shafts versus filopodial stalks. These data suggest that sevoflurane induces F-actin depolymerization leading to acute, reversible length-shortening in dendritic protrusions through a mechanism involving (in part activation of RhoA/Rho kinase signaling and impairs localization of drebrin A to filopodia required for early excitatory synapse formation.

  12. The Forecast Performance of Competing Implied Volatility Measures

    DEFF Research Database (Denmark)

    Tsiaras, Leonidas

    This study examines the information content of alternative implied volatility measures for the 30 components of the Dow Jones Industrial Average Index from 1996 until 2007. Along with the popular Black-Scholes and "model-free" implied volatility expectations, the recently proposed corridor implie......, volatility definitions, loss functions and forecast evaluation settings....

  13. Analysis of clinical records of dental patients attending Jordan University Hospital: Documentation of drug prescriptions and local anesthetic injections

    Directory of Open Access Journals (Sweden)

    Najla Dar-Odeh

    2008-08-01

    Full Text Available Najla Dar-Odeh1, Soukaina Ryalat1, Mohammad Shayyab1, Osama Abu-Hammad21Department of Oral and Maxillofacial Surgery Oral Medicine and Periodontics, Faculty of Dentistry, University of Jordan, Jordan; 2Department of Prosthetic Dentistry, Faculty of Dentistry, University of Jordan, JordanObjectives: The aim of this study was to analyze clinical records of dental patients attending the Dental Department at the University of Jordan Hospital: a teaching hospital in Jordan. Analysis aimed at determining whether dental specialists properly documented the drug prescriptions and local anesthetic injections given to their patients.Methods: Dental records of the Dental Department at the Jordan University Hospital were reviewed during the period from April 3rd until April 26th 2007 along with the issued prescriptions during that period.Results: A total of 1000 records were reviewed with a total of 53 prescriptions issued during that period. Thirty records documented the prescription by stating the category of the prescribed drug. Only 13 records stated the generic or the trade names of the prescribed drugs. Of these, 5 records contained the full elements of a prescription. As for local anesthetic injections, the term “LA used” was found in 22 records while the names and quantities of the local anesthetics used were documented in only 13 records. Only 5 records documented the full elements of a local anesthetic injection.Conclusion: The essential data of drug prescriptions and local anesthetic injections were poorly documented by the investigated group of dental specialists. It is recommended that the administration of the hospital and the dental department implement clear and firm guidelines for dental practitioners in particular to do the required documentation procedure.Keywords: dental records, documentation, prescriptions, local anesthesia

  14. [Anesthetic considerations in sickle cell anemia: a case report].

    Science.gov (United States)

    Fernández-Meré, L A; Sopena-Zubiría, L A; Alvarez-Blanco, M

    2009-01-01

    Sickle cell anemia is the most common hemoglobinopathy. Advances in therapeutic techniques and anesthetic procedures have led to a considerable increase in the success of surgical procedures in these patients. We report the case of a 16-year-old black boy diagnosed with sickle cell anemia and beta-thalassemia who presented with chronic osteomyelitis of the tibia. He was scheduled for debridement of the lesion and musculocutaneous flap repair. We emphasize the importance of communication between anesthesiologists, surgeons, and hematologists in the perioperative period in order to determine the risk of complications and anticipate them.

  15. Stock market volatility and macroeconomic uncertainty

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2006-01-01

    This paper provides empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from SPF survey participants over the period from 1969 to 1996. This link is much

  16. CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS ...

    African Journals Online (AJOL)

    CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS OF CLEOME VISCOSA FROM NIGERIA. Gabriel Olatunji, Peter Weyerstahl, Stephen Oguntoye. Abstract. The major volatile constituents of the oils from the integral parts of Cleome viscosa L. from Nigeria have been identified by GC, GC/MS and 1H NMR.

  17. Comparison of continuous interscalene block and subacromial infusion of local anesthetic for postoperative analgesia after open shoulder surgery.

    Science.gov (United States)

    Baskan, Semih; Cankaya, Deniz; Unal, Hidayet; Yoldas, Burak; Taspinar, Vildan; Deveci, Alper; Tabak, Yalcin; Baydar, Mustafa

    2017-01-01

    This study compared the efficacy of continuous interscalene block (CISB) and subacromial infusion of local anesthetic (CSIA) for postoperative analgesia after open shoulder surgery. This randomized, prospective, double-blinded, single-center study included 40 adult patients undergoing open shoulder surgery. All patients received a standardized general anesthetic. The patients were separated into group CISB and group CSIA. A loading dose of 40 mL 0.25% bupivacaine was administered and patient-controlled analgesia was applied by catheter with 0.1% bupivacaine 5 mL/h throughout 24 h basal infusion, 2 mL bolus dose, and 20 min knocked time in both groups postoperatively. Visual analog scale (VAS) scores, additional analgesia need, local anesthetic consumption, complications, and side effects were recorded during the first 24 h postoperatively. The range of motion (ROM) score was recorded preoperatively and in the first and third weeks postoperatively. A statistically significant difference was determined between the groups in respect of consumption of local anesthetic, VAS scores, additional analgesia consumption, complications, and side effects, with lower values recorded in the CISB group. There were no significant differences in ROM scoring in the preoperative and postoperative third week between the two groups but there were significant differences in ROM scoring in the postoperative first week, with higher ROM scoring values in the group CISB patients. The results of this study have shown that continuous interscalene infusion of bupivacaine is an effective and safe method of postoperative analgesia after open shoulder surgery.

  18. Long Memory in STOCK Market Volatility: the International Evidence

    Science.gov (United States)

    Yang, Chunxia; Hu, Sen; Xia, Bingying; Wang, Rui

    2012-08-01

    It is still a hot topic to catch the auto-dependence behavior of volatility. Here, based on the measurement of average volatility, under different observation window size, we investigated the dependence of successive volatility of several main stock indices and their simulated GARCH(1, 1) model, there were obvious linear auto-dependence in the logarithm of volatility under a small observation window size and nonlinear auto-dependence under a big observation. After calculating the correlation and mutual information of the logarithm of volatility for Dow Jones Industrial Average during different periods, we find that some influential events can change the correlation structure and the volatilities of different periods have distinct influence on that of the remote future. Besides, GARCH model could produce similar behavior of dependence as real data and long memory property. But our analyses show that the auto-dependence of volatility in GARCH is different from that in real data, and the long memory is undervalued by GARCH.

  19. Do energy prices stimulate food price volatility? Examining volatility transmission between US oil, ethanol and corn markets

    NARCIS (Netherlands)

    Gardebroek, C.; Hernandez, M.A.

    2013-01-01

    This paper examines volatility transmission in oil, ethanol and corn prices in the United States between 1997 and 2011. We follow a multivariate GARCH approach to evaluate the level of interdependence and the dynamics of volatility across these markets. Preliminary results indicate a higher

  20. Do energy prices stimulate food price volatility? Examining volatility transmission between US oil, ethanol and corn markets

    NARCIS (Netherlands)

    Gardebroek, C.; Hernandez, M.A.

    2012-01-01

    This paper examines volatility transmission in oil, ethanol and corn prices in the United States between 1997 and 2011. We follow a multivariate GARCH approach to evaluate the level of interdependence and the dynamics of volatility across these markets. Preliminary results indicate a higher