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Sample records for binding volatile anesthetics

  1. Immune Modulation by Volatile Anesthetics.

    Science.gov (United States)

    Stollings, Lindsay M; Jia, Li-Jie; Tang, Pei; Dou, Huanyu; Lu, Binfeng; Xu, Yan

    2016-08-01

    Volatile general anesthetics continue to be an important part of clinical anesthesia worldwide. The impact of volatile anesthetics on the immune system has been investigated at both mechanistic and clinical levels, but previous studies have returned conflicting findings due to varied protocols, experimental environments, and subject species. While many of these studies have focused on the immunosuppressive effects of volatile anesthetics, compelling evidence also exists for immunoactivation. Depending on the clinical conditions, immunosuppression and activation due to volatile anesthetics can be either detrimental or beneficial. This review provides a balanced perspective on the anesthetic modulation of innate and adaptive immune responses as well as indirect effectors of immunity. Potential mechanisms of immunomodulation by volatile anesthetics are also discussed. A clearer understanding of these issues will pave the way for clinical guidelines that better account for the impact of volatile anesthetics on the immune system, with the ultimate goal of improving perioperative management. PMID:27286478

  2. Effect of four-alpha-helix bundle cavity size on volatile anesthetic binding energetics.

    Science.gov (United States)

    Manderson, Gavin A; Michalsky, Stuart J; Johansson, Jonas S

    2003-09-30

    Currently, it is thought that inhalational anesthetics cause anesthesia by binding to ligand-gated ion channels. This is being investigated using four-alpha-helix bundles, small water-soluble analogues of the transmembrane domains of the "natural" receptor proteins. The study presented here specifically investigates how multiple alanine-to-valine substitutions (which each decrease the volume of the internal binding cavity by 38 A(3)) affect structure, stability, and anesthetic binding affinity of the four-alpha-helix bundles. Structure remains essentially unchanged when up to four alanine residues are changed to valine. However, stability increases as the number of these substitutions is increased. Anesthetic binding affinities are also affected. Halothane binds to the four-alpha-helix bundle variants with 0, 1, and 2 substitutions with equivalent affinities but binds to the variants with 3 and 4 more tightly. The same order of binding affinities was observed for chloroform, although for a particular variant, chloroform was bound less tightly. The observed differences in binding affinities may be explained in terms of a modulation of van der Waals and hydrophobic interactions between ligand and receptor. These, in turn, could result from increased four-alpha-helix bundle binding cavity hydrophobicity, a decrease in cavity size, or improved ligand/receptor shape complementarity.

  3. Ubiquitin Metabolism Affects Cellular Response to Volatile Anesthetics in Yeast

    OpenAIRE

    Wolfe, Darren; Reiner, Thomas; Keeley, Jessica L.; Pizzini, Mark; Keil, Ralph L.

    1999-01-01

    To investigate the mechanism of action of volatile anesthetics, we are studying mutants of the yeast Saccharomyces cerevisiae that have altered sensitivity to isoflurane, a widely used clinical anesthetic. Several lines of evidence from these studies implicate a role for ubiquitin metabolism in cellular response to volatile anesthetics: (i) mutations in the ZZZ1 gene render cells resistant to isoflurane, and the ZZZ1 gene is identical to BUL1 (binds ubiquitin ligase), which appears to be invo...

  4. A Unitary Anesthetic Binding Site at High Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Vedula, L. Sangeetha; Brannigan, Grace; Economou, Nicoleta J.; Xi, Jin; Hall, Michael A.; Liu, Renyu; Rossi, Matthew J.; Dailey, William P.; Grasty, Kimberly C.; Klein, Michael L.; Eckenhoff, Roderic G.; Loll, Patrick J.; (Drexel-MED); (UPENN)

    2009-10-21

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA{sub A} receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.

  5. A Unitary Anesthetic-Binding Site at High Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Vedula, L.; Brannigan, G; Economou, N; Xi, J; Hall, M; Liu, R; Rossi, M; Dailey, W; Grasty, K; et. al.

    2009-01-01

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABAA receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.

  6. A Unitary Anesthetic Binding Site at High Resolution

    Energy Technology Data Exchange (ETDEWEB)

    L Vedula; G Brannigan; N Economou; J Xi; M Hall; R Liu; M Rossi; W Dailey; K Grasty; et. al.

    2011-12-31

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA{sub A} receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.

  7. Glutamatergic Neurotransmission Links Sensitivity to Volatile Anesthetics with Mitochondrial Function.

    Science.gov (United States)

    Zimin, Pavel I; Woods, Christian B; Quintana, Albert; Ramirez, Jan-Marino; Morgan, Philip G; Sedensky, Margaret M

    2016-08-22

    An enigma of modern medicine has persisted for over 150 years. The mechanisms by which volatile anesthetics (VAs) produce their effects (loss of consciousness, analgesia, amnesia, and immobility) remain an unsolved mystery. Many attractive putative molecular targets have failed to produce a significant effect when genetically tested in whole-animal models [1-3]. However, mitochondrial defects increase VA sensitivity in diverse organisms from nematodes to humans [4-6]. Ndufs4 knockout (KO) mice lack a subunit of mitochondrial complex I and are strikingly hypersensitive to VAs yet resistant to the intravenous anesthetic ketamine [7]. The change in VA sensitivity is the largest reported for a mammal. Limiting NDUFS4 loss to a subset of glutamatergic neurons recapitulates the VA hypersensitivity of Ndufs4(KO) mice, while loss in GABAergic or cholinergic neurons does not. Baseline electrophysiologic function of CA1 pyramidal neurons does not differ between Ndufs4(KO) and control mice. Isoflurane concentrations that anesthetize only Ndufs4(KO) mice (0.6%) decreased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) only in Ndufs4(KO) CA1 neurons, while concentrations effective in control mice (1.2%) decreased sEPSC frequencies in both control and Ndufs4(KO) CA1 pyramidal cells. Spontaneous inhibitory postsynaptic currents (sIPSCs) were not differentially affected between genotypes. The effects of isoflurane were similar on evoked field excitatory postsynaptic potentials (fEPSPs) and paired pulse facilitation (PPF) in KO and control hippocampal slices. We propose that CA1 presynaptic excitatory neurotransmission is hypersensitive to isoflurane in Ndufs4(KO) mice due to the inhibition of pre-existing reduced complex I function, reaching a critical reduction that can no longer meet metabolic demands. PMID:27498564

  8. Crystal structure of isoflurane bound to integrin LFA-1 supports a unified mechanism of volatile anesthetic action in the immune and central nervous systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongmin; Astrof, Nathan S.; Liu, Jin-Huan; Wang, Jia-huai; Shimaoka, Motomu; (Harvard-Med); (DFCI)

    2009-09-15

    Volatile anesthetics (VAs), such as isoflurane, induce a general anesthetic state by binding to specific targets (i.e., ion channels) in the central nervous system (CNS). Simultaneously, VAs modulate immune functions, possibly via direct interaction with alternative targets on leukocytes. One such target, the integrin lymphocyte function-associated antigen-1 (LFA-1), has been shown previously to be inhibited by isoflurane. A better understanding of the mechanism by which isoflurane alters protein function requires the detailed information about the drug-protein interaction at an atomic level. Here, we describe the crystal structure of the LFA-1 ligand-binding domain (I domain) in complex with isoflurane at 1.6 {angstrom}. We discovered that isoflurane binds to an allosteric cavity previously implicated as critical for the transition of LFA-1 from the low- to the high-affinity state. The isoflurane binding site in the I domain involves an array of amphiphilic interactions, thereby resembling a 'common anesthetic binding motif' previously predicted for authentic VA binding sites. These results suggest that the allosteric modulation of protein function by isoflurane, as demonstrated for the integrin LFA-1, might represent a unified mechanism shared by the interactions of volatile anesthetics with targets in the CNS. Crystal structure of isoflurane bound to integrin LFA-1 supports a unified mechanism of volatile anesthetic action in the immune and central nervous systems.

  9. Development of three Drosophila melanogaster strains with different sensitivity to volatile anesthetics

    Institute of Scientific and Technical Information of China (English)

    LIU Jin; HU Zhao-yang; YE Qi-quan; DAI Shuo-hua

    2009-01-01

    Background The mechanisms of action for volatile anesthetics remain unknown for centuries partly owing to the insufficient or ineffective research models. We designed this study to develop three strains derived from a wild-type Drosophila melanogaster with different sensitivities to volatile anesthetics, which may ultimately facilitate molecular and genetic studies of the mechanism involved.Methods Median effective doses (ED50) of sevoflurane in seven-day-old virgin female and male wild-type Drosophila melanogaster were determined. The sensitive males and females of percentile 6-10 were cultured for breeding sensitive offspring (S1). So did median ones of percentile 48-52 for breeding median offspring (M1), resistant ones of percentile 91-95 for breeding resistant offspring (R1). Process was repeated through 31 generations, in the 37th generation, S37,M37 and R37 were used to determine ED50 for enflurane, isoflurane, sevoflurane, desflurane, halothane, methoxyflurane,chloroform and trichloroethylene, then ED50 values were correlated with minimum alveolar concentration (MAC) values in human.Results From a wild-type Drosophila melanogaster we were able to breed three strains with high, median and low sevoflurane requirements. The ratio of sevoflurane requirements of three strains were 1.20:1.00:0.53 for females and 1.22:1.00:0.72 for males. Strains sensitive, median and resistant to sevoflurane were also sensitive, median and resistant to other volatile anesthetics. For eight anesthetics, ED50 values in three strains correlated directly with MAC values in human.Conclusions Three Drosophila me/anogaster strains with high, median and low sensitivity to volatile anesthetics, but with same hereditary background were developed. The ED50 are directly correlated with MAC in human for eight volatile anesthetics.

  10. Volatile anesthetic for the control of posthypoxic refractory myoclonic status

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    Vivek Rayadurg

    2016-01-01

    Full Text Available Posthypoxic myoclonus (Lance-Adams syndrome is characterized by myoclonus involving multiple muscle groups which is resistant to most conventional antiepileptic drugs. We present a case of hypoxic brain injury-induced myoclonic status epilepticus successfully controlled with isoflurane. The antimyoclonic effects of isoflurane are likely due to potentiation of inhibitory postsynaptic GABA A receptor-mediated currents and its effects on thalamocortical pathways. It is effective even when intravenous agents fail to control myoclonus. It may be a useful alternative to intravenous anesthetics as a third tier therapy in patients with refractory status myoclonus.

  11. Volatile anesthetics inhibit the activity of calmodulin by interacting with its hydrophobic site

    Institute of Scientific and Technical Information of China (English)

    ZHOU Miao-miao; XIA Hui-min; LIU Jiao; XU You-nian; XIN Nai-xin; ZHANG Shi-hai

    2012-01-01

    Background Volatile anesthetics (VAs) may affect varied and complex physiology processes by manipulating Ca2+-calmodulin (CaM).However,the detailed mechanism about the action of VAs on CaM has not been elucidated.This study was undertaken to examine the effects of VAs on the conformational change,hydrophobic site,and downstream signaling pathway of CaM,to explore the possible mechanism of anesthetic action of VAs.Methods Real-time second-harmonic generation (SHG) was performed to monitor the conformational change of CaM in the presence of VAs, each plus 100 μmol/L Ca2+. A hydrophobic fluorescence indicator,8-anilinonaphthalene-1-sulfonate (ANS),was utilized to define whether the VAs would interact with CaM at the hydrophobic site or not.High-performance liquid chromatography (HPLC) was carried out to analyze the activity of CaM-dependent phosphodiesterase (PDE1) in the presence of VAs.The VAs studied were ether,enflurane,isoflurane,and sevoflurane,with their aqueous concentrations 7.6,9.5,11.4 mmol/L; 0.42,0.52,0.62 mmol/L; 0.25,0.31,0.37 mmol/L and 0.47,0.59,0.71 mmol/L respectively,each were equivalent to their 0.8,1.0 and 1.2 concentration for 50% of maximal effect (EC50) for general anesthesia.Results The second-harmonic radiation of CaM in the presence of Ca2+ was largely inhibited by the VAs.The fluorescence intensity of ANS,generated by binding of Ca2+ to CaM,was reversed by the VAs.HPLC results also showed that AMP,the product of the hydrolysis of cAMP by CaM-dependent PDE1,was reduced by the VAs.Conclusions Our findings demonstrate that the above VAs interact with the hydrophobic core of Ca2+-CaM and the interaction results in the inhibition of the conformational change and activity of CaM.This in vitro study may provide us insight into the possible mechanism of anesthetic action of VAs in vivo.

  12. Volatile Anesthetics. Is a New Player Emerging in Critical Care Sedation?

    Science.gov (United States)

    Jerath, Angela; Parotto, Matteo; Wasowicz, Marcin; Ferguson, Niall D

    2016-06-01

    Volatile anesthetic agent use in the intensive care unit, aided by technological advances, has become more accessible to critical care physicians. With increasing concern over adverse patient consequences associated with our current sedation practice, there is growing interest to find non-benzodiazepine-based alternative sedatives. Research has demonstrated that volatile-based sedation may provide superior awakening and extubation times in comparison with current intravenous sedation agents (propofol and benzodiazepines). Volatile agents may possess important end-organ protective properties mediated via cytoprotective and antiinflammatory mechanisms. However, like all sedatives, volatile agents are capable of deeply sedating patients, which can have respiratory depressant effects and reduce patient mobility. This review seeks to critically appraise current volatile use in critical care medicine including current research, technical consideration of their use, contraindications, areas of controversy, and proposed future research topics. PMID:27002466

  13. Volatile Anesthetics. Is a New Player Emerging in Critical Care Sedation?

    Science.gov (United States)

    Jerath, Angela; Parotto, Matteo; Wasowicz, Marcin; Ferguson, Niall D

    2016-06-01

    Volatile anesthetic agent use in the intensive care unit, aided by technological advances, has become more accessible to critical care physicians. With increasing concern over adverse patient consequences associated with our current sedation practice, there is growing interest to find non-benzodiazepine-based alternative sedatives. Research has demonstrated that volatile-based sedation may provide superior awakening and extubation times in comparison with current intravenous sedation agents (propofol and benzodiazepines). Volatile agents may possess important end-organ protective properties mediated via cytoprotective and antiinflammatory mechanisms. However, like all sedatives, volatile agents are capable of deeply sedating patients, which can have respiratory depressant effects and reduce patient mobility. This review seeks to critically appraise current volatile use in critical care medicine including current research, technical consideration of their use, contraindications, areas of controversy, and proposed future research topics.

  14. 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.

  15. Identification of a GABAA receptor anesthetic binding site at subunit interfaces by photolabeling with an etomidate analog.

    Science.gov (United States)

    Li, Guo-Dong; Chiara, David C; Sawyer, Gregory W; Husain, S Shaukat; Olsen, Richard W; Cohen, Jonathan B

    2006-11-01

    General anesthetics, including etomidate, act by binding to and enhancing the function of GABA type A receptors (GABA(A)Rs), which mediate inhibitory neurotransmission in the brain. Here, we used a radiolabeled, photoreactive etomidate analog ([(3)H]azietomidate), which retains anesthetic potency in vivo and enhances GABA(A)R function in vitro, to identify directly, for the first time, amino acids that contribute to a GABA(A)R anesthetic binding site. For GABA(A)Rs purified by affinity chromatography from detergent extracts of bovine cortex, [(3)H]azietomidate photoincorporation was increased by GABA and inhibited by etomidate in a concentration-dependent manner (IC(50) = 30 microm). Protein microsequencing of fragments isolated from proteolytic digests established photolabeling of two residues: one within the alphaM1 transmembrane helix at alpha1Met-236 (and/or the homologous methionines in alpha2,3,5), not previously implicated in etomidate function, and one within the betaM3 transmembrane helix at beta3Met-286 (and/or the homologous methionines in beta1,2), an etomidate sensitivity determinant. The pharmacological specificity of labeling indicates that these methionines contribute to a single binding pocket for etomidate located in the transmembrane domain at the interface between beta and alpha subunits, in what is predicted by structural models based on homology with the nicotinic acetylcholine receptor to be a water-filled pocket approximately 50 A below the GABA binding site. The localization of the etomidate binding site to an intersubunit, not an intrasubunit, binding pocket is a novel conclusion that suggests more generally that the localization of drug binding sites to subunit interfaces may be a feature not only for GABA and benzodiazepines but also for etomidate and other intravenous and volatile anesthetics. PMID:17093081

  16. Common Internal Allosteric Network Links Anesthetic Binding Sites in a Pentameric Ligand-Gated Ion Channel.

    Science.gov (United States)

    Joseph, Thomas T; Mincer, Joshua S

    2016-01-01

    General anesthetics bind reversibly to ion channels, modifying their global conformational distributions, but the underlying atomic mechanisms are not completely known. We examine this issue by way of the model protein Gloeobacter violaceous ligand-gated ion channel (GLIC) using computational molecular dynamics, with a coarse-grained model to enhance sampling. We find that in flooding simulations, both propofol and a generic particle localize to the crystallographic transmembrane anesthetic binding region, and that propofol also localizes to an extracellular region shared with the crystallographic ketamine binding site. Subsequent simulations to probe these binding modes in greater detail demonstrate that ligand binding induces structural asymmetry in GLIC. Consequently, we employ residue interaction correlation analysis to describe the internal allosteric network underlying the coupling of ligand and distant effector sites necessary for conformational change. Overall, the results suggest that the same allosteric network may underlie the actions of various anesthetics, regardless of binding site. PMID:27403526

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. Bisphenol A binds to the local anesthetic receptor site to block the human cardiac sodium channel.

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    Andrias O O'Reilly

    Full Text Available Bisphenol A (BPA has attracted considerable public attention as it leaches from plastic used in food containers, is detectable in human fluids and recent epidemiologic studies link BPA exposure with diseases including cardiovascular disorders. As heart-toxicity may derive from modified cardiac electrophysiology, we investigated the interaction between BPA and hNav1.5, the predominant voltage-gated sodium channel subtype expressed in the human heart. Electrophysiology studies of heterologously-expressed hNav1.5 determined that BPA blocks the channel with a K(d of 25.4±1.3 µM. By comparing the effects of BPA and the local anesthetic mexiletine on wild type hNav1.5 and the F1760A mutant, we demonstrate that both compounds share an overlapping binding site. With a key binding determinant thus identified, an homology model of hNav1.5 was generated based on the recently-reported crystal structure of the bacterial voltage-gated sodium channel NavAb. Docking predictions position both ligands in a cavity delimited by F1760 and contiguous with the DIII-IV pore fenestration. Steered molecular dynamics simulations used to assess routes of ligand ingress indicate that the DIII-IV pore fenestration is a viable access pathway. Therefore BPA block of the human heart sodium channel involves the local anesthetic receptor and both BPA and mexiletine may enter the closed-state pore via membrane-located side fenestrations.

  20. Local anesthetic and antiepileptic drug access and binding to a bacterial voltage-gated sodium channel.

    Science.gov (United States)

    Boiteux, Céline; Vorobyov, Igor; French, Robert J; French, Christopher; Yarov-Yarovoy, Vladimir; Allen, Toby W

    2014-09-01

    Voltage-gated sodium (Nav) channels are important targets in the treatment of a range of pathologies. Bacterial channels, for which crystal structures have been solved, exhibit modulation by local anesthetic and anti-epileptic agents, allowing molecular-level investigations into sodium channel-drug interactions. These structures reveal no basis for the "hinged lid"-based fast inactivation, seen in eukaryotic Nav channels. Thus, they enable examination of potential mechanisms of use- or state-dependent drug action based on activation gating, or slower pore-based inactivation processes. Multimicrosecond simulations of NavAb reveal high-affinity binding of benzocaine to F203 that is a surrogate for FS6, conserved in helix S6 of Domain IV of mammalian sodium channels, as well as low-affinity sites suggested to stabilize different states of the channel. Phenytoin exhibits a different binding distribution owing to preferential interactions at the membrane and water-protein interfaces. Two drug-access pathways into the pore are observed: via lateral fenestrations connecting to the membrane lipid phase, as well as via an aqueous pathway through the intracellular activation gate, despite being closed. These observations provide insight into drug modulation that will guide further developments of Nav inhibitors. PMID:25136136

  1. [Binding of Volatile Organic Compounds to Edible Biopolymers].

    Science.gov (United States)

    Misharina, T A; Terenina, M B; Krikunova, N I; Medvedeva, I B

    2016-01-01

    Capillary gas chromatography was used to study the influence of the composition and structure of different edible polymers (polysaccharides, vegetable fibers, and animal protein gelatin) on the binding of essential oil components. The retention of volatile organic compounds on biopolymers was shown to depend on their molecule structure and the presence, type, and position of a functional group. The maximum extent of the binding was observed for nonpolar terpene and sesquiterpene hydrocarbons, and the minimum extent was observed for alcohols. The components of essential oils were adsorbed due mostly to hydrophobic interactions. It was shown that the composition and structure of a compound, its physico-chemical state, and the presence of functional groups influence the binding. Gum arabic and guar gum were found to bind nonpolar compounds to a maximum and minimum extent, respectively. It was demonstrated the minimum adsorption ability of locust bean gum with respect to all studied compounds.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

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

    Science.gov (United States)

    Teng, Wei-Nung; Lin, Su-Man; Niu, Dau-Ming; Kuo, Yi-Min; Chan, Kwok-Hon; Sung, Chun-Sung

    2014-10-01

    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.

  5. Interference of diabetes on volatile anesthetic-induced myocardial protection%糖尿病与吸入性麻醉药心肌保护作用研究新进展

    Institute of Scientific and Technical Information of China (English)

    李毅; 江晓菁; 师恩祎

    2009-01-01

    Volatile anesthetic pre-or post-conditioning presents protective effects against iscbemic damage of myocardium,by activating endogeneous protection mechanisms.Recent studies show that hyperglycemia may block anesthetic conditioning-induced protective effect,and that volatile anesthetics inhibit insulin release,producing hyperglycemia.Volatile anesthetic-produced myocardial protective effects may have a promising future in clinical application,and more attention should be paid on the relationship between diabetes and myocardial protection of volatile anesthetic.%目前研究表明,对于心肌缺血/再灌注(isehemic/reperfusion,I/R)损伤,适当的刺激可以激活机体的内源性保护机制,即缺血预处理(ischemic preconditioning,IPC)和缺血后处理(ischemic postconditioning,I-post),最终达到心肌保护效果.同时现有的研究发现,吸人性麻醉药同样可以诱导产生内源性的心肌保护作用,其作用机制及临床应用前景成为目前广泛关注的焦点,现就以七氟醚为代表的吸入性麻醉药的心肌保护作用及糖尿病与吸人性麻醉药心肌保护作用的关系作一简要综述.

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

    Directory of Open Access Journals (Sweden)

    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

  7. [New anesthetics].

    Science.gov (United States)

    Malamed, S F

    2000-01-01

    Since the introduction of cocaine local analgesia in 1886, and the subsequent development of procaine (1904) and other closely related ester-type compounds, dentistry has prided itself on being as close to 'painless' as possible. In the late 1940s the newest group of the local anesthetic compounds, the amides, was introduced. The initial amide local analgesic, lignocaine (Xylocaine), revolutionised pain control in dentistry worldwide. In succeeding years other amide-type local anesthetics, mepivacaine, prilocaine, bupivacaine and etidocaine, were introduced. They gave the dental practitioner a local anesthetic armamentarium which provided pulpal analgesia for periods of from 20 minutes (mepivacaine) to as long as three hours (bupivacaine and etidocaine with adrenaline). In addition these popular drugs proved to be more rapid-acting than the older ester-type drug and, at least from the perspective of allergenicity, more safe. In 1976, in Germany, the newest amide local analgesic, carticaine HCl was introduced into dentistry. Articaine (the generic name was changed) possesses properties similar to lignocaine but has additional properties which made the drug quite attractive to the general dental practitioner. In 1986 articaine was introduced in North America (Canada) where it has become the most used local anesthetic, supplanting lignocaine. Articaine has been approved for use in the United Kingdom. In this introductory discussion we review the development of articaine and discuss its place in the dental local analgesic armamentarium.

  8. Potent Inhalational Anesthetics for Dentistry.

    Science.gov (United States)

    Satuito, Mary; Tom, James

    2016-01-01

    Nitrous oxide and the volatile inhalational anesthetics have defined anxiety and pain control in both dentistry and medicine for over a century. From curious experimentation to spectacular public demonstrations, the initial work of 2 dentists, Horace Wells and William T. G. Morton, persists to this day in modern surgery and anesthesia. This article reviews the history, similarities, differences, and clinical applications of the most popular inhalational agents used in contemporary dental surgical settings.

  9. [Experimental studies on the recovery of anesthetic gases].

    Science.gov (United States)

    Marx, T; Gross-Alltag, F; Ermisch, J; Hähnel, J; Weber, L; Friesdorf, W

    1992-02-01

    The volatile anesthetic agents halothane, enflurane, and isoflurane are chlorofluorocarbons (CFC) and contribute to ozone depletion. Although the contribution is small, its importance is rising, as technical CFCs will be phased out according to the Montreal protocol (1987) and the London conference (1990) by the year 2000. Alternative procedures and CFC-free volatile agents such as des- and sevoflurane do not contribute to depletion of the ozone layer, but will not replace standard methods using volatile anesthetic agents in the near future. METHODS. In an experimental setup, we filtered anesthetic waste gases from scavenging systems of rebreathing circles by activated carbon filters. The filtered substances were desorbed by a heat chamber and condensed in a cold trap. RESULTS. By this method, it was possible to retrieve 50%-60% of the applied gases. Gas chromatographic analysis showed halothane containing traces of pollutants and isoflurane and enflurane as pure substances. DISCUSSION. The retrieval of anesthetic waste gases is easy; no sophisticated technical equipment is necessary. Purity of substances could make recycling possible and offer a method to avoid environmental pollution by volatile anesthetics. PMID:1562100

  10. 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. PMID:27283627

  11. Anesthetizing the obese child

    DEFF Research Database (Denmark)

    Mortensen, Anette; Lenz, Katja; Abildstrøm, Hanne;

    2011-01-01

    The prevalence of childhood obesity is increasing. The focus of this review is the special anesthetic considerations regarding the perioperative management of obese children. With obesity the risk of comorbidity such as asthma, obstructive sleep apnea, hypertension, and diabetes increases....... The obese child has an increased risk of perioperative complications especially related to airway management and ventilation. There is a significantly increased risk of difficult mask ventilation and perioperative desaturation. Furthermore, obesity has an impact on the pharmacokinetics of most anesthetic...... 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...

  12. Adsorbent comparisons for anesthetic gas capture in hospital air emissions.

    Science.gov (United States)

    Mehrata, Mina; Moralejo, Carol; Anderson, William A

    2016-08-23

    For the development of emission control strategies, activated carbon, zeolite, molecular sieves, and a silica gel were tested for adsorption of the newer anesthetic gases isoflurane, sevoflurane, and desflurane from air. The activated carbon Norit GCA 48 was selected for the best performance, and adsorption isotherms at room temperature were developed for the three anesthetics. Equilibrium capacities for this carbon were in the range of 500 to 1,000 mg g(-1) for these anesthetics at partial pressures ranging from 5 to 45 Torr, with the most volatile compound (desflurane) showing the least favorable adsorption. Activated carbons are therefore suggested for use as effective adsorbents in emission control of these anesthetic gases from hospitals. PMID:27222158

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

    Science.gov (United States)

    Zhou, Jing; Zhang, Na; Wang, Pan; Zhang, Shichang; Li, Daiqin; Liu, Kaiyu; Wang, Guoxiu; Wang, Xiaoping; Ai, Hui

    2015-01-01

    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 sites. The six

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

    Directory of Open Access Journals (Sweden)

    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

  15. Fluorescence competition assay for the assessment of green leaf volatiles and trans-β-farnesene bound to three odorant-binding proteins in the wheat aphid Sitobion avenae (Fabricius).

    Science.gov (United States)

    Zhong, Tao; Yin, Jiao; Deng, Sisi; Li, Kebin; Cao, Yazhong

    2012-06-01

    Odorant-binding proteins (OBPs) are important parts of insect olfactory systems, and sensitive olfaction is vital for phytophagous insects in host foraging. Electrophysiological studies are helpful in understanding olfactory sensing in Sitobion avenae (Hemiptera: Aphididae), but the functions of odorant-binding proteins in this insect are poorly understood. In this study, we used fluorescence competition assays to measure the binding specificities of SaveOBPs. The results showed that both SaveOBP2 and SaveOBP3 were superior to SaveOBP7 in binding green leaf volatiles. It was unexpected that SaveOBP7 bound trans-β-farnesene strongly, which was known as alarm pheromone of this species. Host volatiles were recognized much more easily by SaveOBP2, and the observed binding activity of SaveOBP2 equaled for tested green leaf volatiles. Our results imply that SaveOBP7 might play a more important role in aphid alarm pheromone discrimination.

  16. Virtual Screening of Plant Volatile Compounds Reveals a High Affinity of Hylamorpha elegans (Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host.

    Science.gov (United States)

    González-González, Angélica; Palma-Millanao, Rubén; Yáñez, Osvaldo; Rojas, Maximiliano; Mutis, Ana; Venthur, Herbert; Quiroz, Andrés; Ramírez, Claudio C

    2016-01-01

    Hylamorpha elegans(Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs inH. elegans as well as six new volatiles released by its native host Nothofagus obliqua(Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. oblique revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies.

  17. Anesthetic-Induced Developmental Neurotoxicity

    Institute of Scientific and Technical Information of China (English)

    Jia-RenLiu; Qian Liu; Jing Li; Sulpicio G. Soriano

    2011-01-01

    1 IntroductionMillions of newborn and infants receive anesthetic,sedative and analgesic drugs for surgery and painful procedures on a daily basis.Recent laboratory reports clearly demonstrate that anesthetic and sedative drugs induced both neuroapoptosis and neurocognitive deficits in laboratory models.This issue is of paramount interest to pediatric anesthesiologists and intensivists because it questions the safety of anesthetics used for fetal and neonatal anesthesia[1-2].In an attempt to summarize the rapidly expanding laboratorybased literature on anesthetic-induced developmental neurotoxicity (AIDN),this review will examine published reports on the characterization,mechanisms and alleviation of this phenomenon.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 21 CFR 872.6100 - Anesthetic warmer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic warmer. 872.6100 Section 872.6100 Food... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6100 Anesthetic warmer. (a) Identification. An anesthetic warmer is an AC-powered device into which tubes containing anesthetic solution are intended to...

  20. Altered states: psychedelics and anesthetics.

    Science.gov (United States)

    Icaza, Eduardo E; Mashour, George A

    2013-12-01

    The psychedelic experience has been reported since antiquity, but there is relatively little known about the underlying neural mechanisms. A recent neuroimaging study on psilocybin revealed a pattern of decreased cerebral blood flow and functional disconnections that is surprisingly similar to that caused by various anesthetics. In this article, the authors review historical examples of psychedelic experiences induced by general anesthetics and then contrast the mechanisms by which these two drug classes generate altered states of consciousness. PMID:24061599

  1. State-Dependent Inhibition of Sodium Channels by Local Anesthetics: A 40-Year Evolution.

    Science.gov (United States)

    Wang, G-K; Strichartz, G R

    2012-04-01

    Knowledge about the mechanism of impulse blockade by local anesthetics has evolved over the past four decades, from the realization that Na(+) channels were inhibited to affect the impulse blockade to an identification of the amino acid residues within the Na(+) channel that bind the local anesthetic molecule. Within this period appreciation has grown of the state-dependent nature of channel inhibition, with rapid binding and unbinding at relatively high affinity to the open state, and weaker binding to the closed resting state. Slow binding of high affinity for the inactivated state accounts for the salutary therapeutic as well as the toxic actions of diverse class I anti-arrhythmic agents, but may have little importance for impulse blockade, which requires concentrations high enough to block the resting state. At the molecular level, residues on the S6 transmembrane segments in three of the homologous domains of the channel appear to contribute to the binding of local anesthetics, with some contribution also from parts of the selectivity filter. Binding to the inactivated state, and perhaps the open state, involves some residues that are not identical to those that bind these drugs in the resting state, suggesting spatial flexibility in the "binding site". Questions remaining include the mechanism that links local anesthetic binding with the inhibition of gating charge movements, and the molecular nature of the theoretical "hydrophobic pathway" that may be critical for determining the recovery rates from blockade of closed channels, and thus account for both therapeutic and cardiotoxic actions. PMID:23710324

  2. Mini cardiopulmonary bypass: Anesthetic considerations

    OpenAIRE

    Alsatli, Raed A.

    2012-01-01

    This review article is going to elaborate on the description, components, and advantages of mini-cardiopulmonary bypass (mini-CPB), with special reference to the anesthetic management and fast track anesthesia with mini-CPB. There are several clinical advantages of mini-CPB like, reduced inflammatory reaction to the pump, reduced need for allogenic blood transfusion and lower incidence of postoperative neurological complications. There are certainly important points that have to be considered...

  3. ANESTHETIC MANAGEMENT OF ANATROPHIC NEPHROLITHOTOMY

    Directory of Open Access Journals (Sweden)

    Geetha

    2013-04-01

    Full Text Available ABSTRACT: Anatrophic nephrolithotomy is a urological procedure t hat is rarely performed in this minimally invasive endo urological era. Howeve r, it still remains an option in the management of complex staghorn calculus. A near compl ete removal of the large calculus in a single sitting will be more cost effective than mul tiple sittings required for minimally invasive procedures. We report anesthetic management of anatro phic nephrolithotomy which in many ways similar to the principles of renal transplantati on

  4. Volatility Discovery

    DEFF Research Database (Denmark)

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

    There is a large literature that investigates how homogenous securities traded on different markets incorporate new information (price discovery analysis). We extend this concept to the stochastic volatility process and investigate how markets contribute to the efficient stochastic volatility whi...

  5. 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. PMID:25885293

  6. 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.

  7. 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 i...

  8. Stochastic volatility

    OpenAIRE

    Shephard, Neil

    2005-01-01

    Stochastic volatility (SV) is the main concept used in the fields of financial economics and mathematical finance to deal with the endemic time-varying volatility and codependence found in financial markets. Such dependence has been known for a long time, early comments include Mandelbrot (1963) and Officer (1973). It was also clear to the founding fathers of modern continuous time finance that homogeneity was an unrealistic if convenient simplification, e.g. Black and Scholes (1972, p. 416) ...

  9. [Facial locoregional anesthetics: principles and precautions].

    Science.gov (United States)

    Lefort, H; Lacroix, G; Cordier, A; Bey, E; Duhamel, P

    2009-12-01

    Facial locoregional anesthetics (ALR) with nervous blocks are simple and reliable to perform, need little technical resources with a very low iatrogenic risk. These blocks allow anesthesia without deforming wound banks using the same materials as usual local anesthetic procedures. Three principal nervous blocks, in a straight line along the vertical pupil axis, allow managing - even extensive - facial wounds. Few side effects may occur which can be easily prevented. It is a good alternative to local anesthetic for the treatment of extensive and deep areas which is performed with a lower number of injections and a high rate of success. These techniques are easy to learn and practise. These anesthetic techniques allow a nice treatment of different kinds of facial wounds from simple suture to flaps.

  10. 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.

  11. Local anesthetics: dentistry's most important drugs.

    Science.gov (United States)

    Malamed, S F

    1994-12-01

    One hundred and fifty years ago, Horace Wells opened the door to local anesthetics. Since then, many advances have been made in pain control. The development of dentistry's most important drugs is highlighted here.

  12. Anesthetizing animals: Similar to humans yet, peculiar?

    OpenAIRE

    Kurdi, Madhuri S.; Ramaswamy, Ashwini H.

    2015-01-01

    From time immemorial, animals have served as models for humans. Like humans, animals too have to undergo several types of elective and emergency surgeries. Several anesthetic techniques and drugs used in humans are also used in animals. However, unlike humans, the animal kingdom includes a wide variety of species, breeds, and sizes. Different species have variable pharmacological responses, anatomy, temperament, behavior, and lifestyles. The anesthetic techniques and drugs have to suit differ...

  13. [Evoked potentials and inhalation anesthetics].

    Science.gov (United States)

    Thiel, A; Russ, W; Hempelmann, G

    1988-01-01

    Intraoperative monitoring of evoked potentials can be affected by various factors including volatile anaesthetics. These effects have to be considered in order to give correct interpretations of the obtained data. Visual evoked potentials (VEP) and auditory evoked potentials (AEP) will show strong alterations under general anaesthesia whereas brainstem auditory evoked potentials (BAEP) are slightly affected. The effects of nitrous oxide, halothane, enflurane, and isoflurane on somatosensory evoked potentials (SEP) after median nerve stimulation were studied in 35 healthy adult patients. pCO2 and tympanic membrane temperature were held constant. Simultaneous cervical and cortical SEP recording was performed using surface electrodes. After induction of anaesthesia SEP were recorded during normoventilation with 100% oxygen and after inhalation of 66.6% nitrous oxide. 10 patients received halothane at inspired concentrations of 0.5, 1.0, 1.5, and 2.0%. After nitrous oxide had been replaced by oxygen, halothane was reduced in steps of 0.5%. SEP were recorded at the end of each period (15 min). Equipotent doses of enflurane or isoflurane were administered to 15 and 10 patients, respectively. Nitrous oxide depressed early cortical SEP amplitude. Halothane, enflurane, and isoflurane caused dose dependent increases of latencies. Reduction of amplitude was most pronounced with isoflurane. Using high doses of enflurane in oxygen cortical SEP showed unusual high amplitudes associated with marked increases of latencies. Even under high concentrations of volatile anaesthetics cervical SEP were minimally affected. The effects of anaesthetic gases have to be considered when SEP are recorded intraoperatively.

  14. 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...... 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....

  15. A high-throughput approach for identification of novel general anesthetics.

    Directory of Open Access Journals (Sweden)

    Wendy A Lea

    Full Text Available Anesthetic development has been a largely empirical process. Recently, we described a GABAergic mimetic model system for anesthetic binding, based on apoferritin and an environment-sensitive fluorescent probe. Here, a competition assay based on 1-aminoanthracene and apoferritin has been taken to a high throughput screening level, and validated using the LOPAC(1280 library of drug-like compounds. A raw hit rate of approximately 15% was reduced through the use of computational filters to yield an overall hit rate of approximately 1%. These hits were validated using isothermal titration calorimetry. The success of this initial screen and computational triage provides feasibility to undergo a large scale campaign to discover novel general anesthetics.

  16. Articaine - the best choice of local anesthetic in contemporary dentistry.

    Science.gov (United States)

    Nizharadze, N; Mamaladze, M; Chipashvili, N; Vadachkoria, D

    2011-01-01

    Local anesthesia forms the foundation of pain control techniques in clinical dentistry. Within the rich local anesthetic drugs available in dentistry for the prevention and management of pain 4% articaine solutions achieve highest level of anesthetic potency and lowest systemic toxicity in all clinical situations, prior to its superlative physicochemical characteristics and the pharmacological profile. These are - low lipid solubility, high plasma protein binding rate, fast metabolization, fast elimination half time; low blood level. Articaine inactivates in both ways: in the liver and the blood serum. It has good spreading through tissues. Thus, articaine seems to be the local anesthetic of first choice in tissues with suppurative inflammation, for adults, children (over 4), elderly, pregnant women, breastfeeding women, patients suffering from hepatic disorders and renal function impairment. In Articaine solutions (1: 200,000) epinephrine is in low concentration, thus in patients at high risk adverse responses are maximally decreased. In these patients articaine should be used with careful consideration of risk/benefit ratio. Articaine solutions must not be used in persons who are allergic or hypersensitive to sulphite, due to content of Sodium metabisulfite as vasoconstrictor's antioxidant in it. Incidence of serious adverse effects related to dental anesthesia with articaine is very low. Toxic reactions are usually due to an inadvertent intravascular injection or use of excessive dose. To avoid overdoses maximum recommendation dose (MRD) must not be exceeded and aspiration test always performed prior all LA injections. In these article we introduce new graphs providing a quick and effect way to determine maximum LA dose. If the overdose reactions develop, adherence to the basic step of emergency management with end to a successful outcome in virtually all cases. PMID:21346262

  17. [Anesthetic maintenance during circular face lifting].

    Science.gov (United States)

    Parshin, V I; Pastukhova, N K

    2010-01-01

    The paper deals with the specific features of anesthetic maintenance (ketamine, diprivan, dormicum, perfalgan, promedol) during circular face lifting without artificial ventilation. All intravenous anesthesia procedures have yielded good results. Narcotic analgesics may be removed from the anesthetic maintenance scheme, ruling out the necessity of their licensing, storing, and recording. The use of perfalgan causes no hallucinogenic reactions and offers the optimum level of anesthesia. During face lifting, 2.3 +/- 0.6-hour anesthesia with spontaneous breathing is possible, safe, and warranted. PMID:20524331

  18. Neonate with hypoglycemia for pancreatectomy: Anesthetic challenge

    OpenAIRE

    Gupta, Alka; Kohli, Jasvinder Kaur; Senapati, Nihar Nalini; Sharma, Sanjeev

    2016-01-01

    Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is rare and an important cause of hypoglycemia in neonates. It can lead to brain damage or death secondary to severe hypoglycemia. We present the anesthetic management in a diagnosed case of PHHI in an 8-day-old male neonate for total pancreatectomy.

  19. Pricing Volatility Referenced Assets

    OpenAIRE

    Alan De Genaro Dario

    2006-01-01

    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) st...

  20. The sodium channel as a target for local anesthetic drugs

    Directory of Open Access Journals (Sweden)

    Harry A Fozzard

    2011-11-01

    Full Text Available Na channels are the source of excitatory currents for the nervous system and muscle. They are the target for a class of drugs called local anesthetics (LA, which have been used for local and regional anesthesia and for excitatory dysfunction problems such as epilepsy and cardiac arrhythmia. LA drugs are prototypes for new analgesic drugs. The LA drug binding site has been localized to the inner pore of the channel, where drugs interact mainly with a phenylalanine in domain IV S6. Drug affinity is both voltage- and use-dependent. Voltage-dependency is the result of changes in the conformation of the inner pore during channel activation and opening, allowing high energy interaction of drugs with the phenylalanine. LA drugs also reduce the gating current of Na channels, which represents the movement of charged residues in the voltage sensors. Specifically, drug binding to phenylalanine locks the domain III S4 in its outward (activated position, and slows recovery of the domain IV S4. Although strongly affecting gating, LA drugs almost certainly also block by steric occlusion of the pore. Molecular definition of the binding and blocking interactions may help in new drug development.

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

    International Nuclear Information System (INIS)

    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 GABAA 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 GABAA 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Opposing effects of the anesthetic propofol at pentameric ligand-gated ion channels mediated by a common site

    DEFF Research Database (Denmark)

    Lynagh, Timothy Peter; Laube, Bodo

    2014-01-01

    Propofol is an intravenous general anesthetic that alters neuronal excitability by modulating agonist responses of pentameric ligand-gated ion channels (pLGICs). Evidence suggests that propofol enhancement of anion-selective pLGICs is mediated by a binding site between adjacent subunits, whereas ...

  4. 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.

  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. Anesthetic gases and occupationally exposed workers.

    Science.gov (United States)

    Casale, Teodorico; Caciari, Tiziana; Rosati, Maria Valeria; Gioffrè, Pier Agostino; Schifano, Maria Pia; Capozzella, Assunta; Pimpinella, Benedetta; Tomei, Gianfranco; Tomei, Francesco

    2014-01-01

    The aim of this study is to estimate whether the occupational exposure to low dose anesthetic gases could cause alterations of blood parameters in health care workers. 119 exposed subjects and 184 not exposed controls were included in the study. Each worker underwent the complete blood count test (CBC), proteinaemia, leukocyte count, serum lipids, liver and kidney blood markers. The liver blood markers show statistically significant differences in health care workers compared with controls (pGGT, total bilirubin, lymphocytes and neutrophils was statistically significant in health care workers compared with controls (p<0.05). The results suggest that occupational exposure to low dose anesthetic gases could influence some haematochemical hepatic and hematopoietic parameters in exposed health care workers. PMID:24374387

  7. Opioid induced hyperalgesia in anesthetic settings.

    Science.gov (United States)

    Lee, Hyeon Jeong; Yeomans, David C

    2014-11-01

    Pain is difficult to investigate and difficult to treat, in part, because of problems in quantification and assessment. The use of opioids, combined with classic anesthetics to maintain hemodynamic stability by controlling responses to intraoperative painful events has gained significant popularity in the anesthetic field. However, several side effects profiles concerning perioperative use of opioid have been published. Over the past two decades, many concerns have arisen with respect to opioid-induced hyperalgesia (OIH), which is the paradoxical effect wherein opioid usage may decrease pain thresholds and increase atypical pain unrelated to the original, preexisting pain. This brief review focuses on the evidence, mechanisms, and modulatory and pharmacologic management of OIH in order to elaborate on the clinical implication of OIH.

  8. Mounier-Kuhn Syndrome: Anesthetic Experience

    Directory of Open Access Journals (Sweden)

    Deepu Sasikumaran Ushakumari

    2012-01-01

    Full Text Available Mounier Kuhn syndrome, or congenital tracheobronchomegaly, is an under diagnosed clinical entity with peculiar anatomical and physiological features making anesthetic care challenging. A 58-year-old chronic smoker with history of recurrent pneumonia and bronchiectasis presented for septoplasty. Thoracic imaging revealed a dilated trachea and main bronchi, tracheal and bronchial diverticuli, and chronic bronchiectasis with mediastinal lymphadenopathy. An 8.5 cuffed endotracheal tube (ETT proved too big for his glottic aperture. An 8.0 cuffed ETT with wet gauze packing yielding an adequate seal. Postoperative continuous positive airway pressure to prevent airway collapse followed awake extubation. Anesthetic concerns include grossly enlarged and weakened airways, inefficient cough mechanisms, presence of tracheal diverticuli, and post operative tracheal collapse. Anesthetic planning includes management of endotracheal cuff size. Small size yields air leak and ineffective ventilation. Large size may lead to mucosal damage. Tube dislodgement, copious secretions, chance of expiratory collapse due to the abnormally dilated and thin airways, and post operative monitoring all must be considered.

  9. Neuropeptide alterations in the tree shrew hypothalamus during volatile anesthesia

    OpenAIRE

    Fouillen, Laetitia; Petruzziello, Filomena; Veit, Julia; Bhattacharyya, Anwesha; Kretz, Robert; Rainer, Gregor; Zhang, Xiaozhe

    2013-01-01

    Neuropeptides are critical signaling molecules, involved in the regulation of diverse physiological processes including energy metabolism, pain perception and brain cognitive state. Prolonged general anesthesia has an impact on many of these processes, but the regulation of peptides by general anesthetics is poorly understood. In this study, we present an in-depth characterization of the hypothalamic neuropeptides of the tree shrew during volatile isoflurane/nitrous oxide anesthesia administe...

  10. 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

  11. A cyclodextrin formulation to improve use of the anesthetic tribromoethanol (Avertin ®

    Directory of Open Access Journals (Sweden)

    Arlene McDowell

    2014-01-01

    Full Text Available Objective: Efficacy and safety concerns have been raised in the literature with the use of tribromoethanol (TBE (Avertin ® for anesthesia in rats and mice when administered by intraperitoneal (IP injection. Despite the controversy, it remains in common usage as an anesthetic agent in laboratory rodents for short-term surgical procedures. Cyclodextrins have been shown to improve drug solubility and were investigated here as an improved anesthetic formulation for mice. Materials and Methods: The phase solubility of TBE with hydroxypropyl-β-cyclodextrin (HP-β-CD was estimated. The efficacy of two anesthetic regimens was compared in this study; the conventional TBE formulation solubilized in tert-amyl alcohol and a HP-β-CD formulation containing TBE. Mice (n = 6 were administered the formulations by IP injection and the pharmacodynamic parameters of time to induction of anesthesia, duration of anesthesia and recovery time were measured using a combined reflex score (CRS. Results and Discussion: Phase solubility studies showed a linear increase in the solubility of TBE with increasing HP-β-CD concentration and suggested >1:1 binding of the drug in the cyclodextrin complex. At a dose of 260 mg/kg the standard TBE formulation appeared to produce deeper anesthesia than the cyclodextrin formulation, with a minimum average CRS of 1.8 compared with 5.2. No post-mortem pathology was observed in mice that received either the conventional or cyclodextrin formulation. Conclusion: The cyclodextrin TBE formulation did not conclusively provide an improved anesthetic response at a dose of 260 mg/kg compared with the conventional formulation. The improved solubility of TBE with HP-β-CD and the reduced variability in anesthetic response warrants the further investigation of this formulation. This study has also identified the value of using the anticholinergic atropine in association with TBE for anesthesia.

  12. Molecular Binding Characterization with Tea Plant Volatiles of a General Odorant-binding Protein EoblGOBP2 in the Tea Geometrid, Ectropis oblique Prout (Lepidoptera:Geometridae)%茶尺蠖普通气味结合蛋白EoblGOBP2与茶树挥发物的结合功能研究

    Institute of Scientific and Technical Information of China (English)

    赵磊; 崔宏春; 张林雅; 陈玲; 余继忠; 李红亮

    2014-01-01

    As one main Lepidopteran pest in tea garden, the larvae of tea geometrid damages mainly the tea leaves, which severely reduce the yield of tea products. The olfactory system of tea geometrid plays a very important role in terms of seeking host and food. Therefore, a general odorant binding protein-EoblGOBP2, existing in the olfactory system of tea geometrid, the function binding with tea plant volatiles was studied in vitro here. Based on the cloned EoblGOBP2 gene by RT-PCR, the recombinant protein EoblGOBP2 was successfully expressed in an optimized prokaryotic prokaryotic expression system, then the binding characteristics of the purified EoblGOBP2 with 1-NPN was measured by fluorescence spectrometry. Scatchard plot analysis indicated that the dissociation constant between EoblGOBP2 and 1-NPN was 2.310μmol·L-1. In the competitive binding assays, to the seven candidate ligands, all of the relative fluorescence intensity of 1-NPN decreased more than 50%, which suggested that all of the tested ligands have strong binding capability with EoblGOBP2. The compound of dibutyl phthalate showed the maximum binding capability with EoblGOBP2, and their dissociation constant was 4.353μmol·L-1. As all of the candidate chemical ligands belong to the tea volatiles secondary metabolites, indicating that EoblGOBP2 plays an important role in the odor recognition process of olfactory identification in the olfactory system of tea geometrid.%茶尺蠖是茶园中一种重要的鳞翅目害虫,主要以幼虫取食危害茶树叶片,给茶叶生产带来了严重威胁。茶尺蠖在寻找配偶、产卵地以及觅食活动中其嗅觉系统发挥了非常重要的作用。本研究以茶尺蠖Ectropis obliqua Prout嗅觉系统中的一个普通气味结合蛋白--EoblGOBP2为研究对象,在克隆得到的EoblGOBP2基因基础上,通过对 EoblGOBP2进行原核表达、分离纯化后,利用1-NPN 的荧光竞争结合法研究了体外重组EoblGOBP2与茶树挥发物

  13. Interaction of anesthetics with neurotransmitter release machinery proteins.

    Science.gov (United States)

    Xie, Zheng; McMillan, Kyle; Pike, Carolyn M; Cahill, Anne L; Herring, Bruce E; Wang, Qiang; Fox, Aaron P

    2013-02-01

    General anesthetics produce anesthesia by depressing central nervous system activity. Activation of inhibitory GABA(A) receptors plays a central role in the action of many clinically relevant general anesthetics. Even so, there is growing evidence that anesthetics can act at a presynaptic locus to inhibit neurotransmitter release. Our own data identified the neurotransmitter release machinery as a target for anesthetic action. In the present study, we sought to examine the site of anesthetic action more closely. Exocytosis was stimulated by directly elevating the intracellular Ca(2+) concentration at neurotransmitter release sites, thereby bypassing anesthetic effects on channels and receptors, allowing anesthetic effects on the neurotransmitter release machinery to be examined in isolation. Three different PC12 cell lines, which had the expression of different release machinery proteins stably suppressed by RNA interference, were used in these studies. Interestingly, there was still significant neurotransmitter release when these knockdown PC12 cells were stimulated. We have previously shown that etomidate, isoflurane, and propofol all inhibited the neurotransmitter release machinery in wild-type PC12 cells. In the present study, we show that knocking down synaptotagmin I completely prevented etomidate from inhibiting neurotransmitter release. Synaptotagmin I knockdown also diminished the inhibition produced by propofol and isoflurane, but the magnitude of the effect was not as large. Knockdown of SNAP-25 and SNAP-23 expression also changed the ability of these three anesthetics to inhibit neurotransmitter release. Our results suggest that general anesthetics inhibit the neurotransmitter release machinery by interacting with multiple SNARE and SNARE-associated proteins.

  14. 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. PMID:25069536

  15. 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...... anesthetics (from 1995 through 2007), 292 reports to the Danish Medicines Agency, Copenhagen, Denmark, of adverse reactions to local anesthetic drugs, and a clinical sample of 115 patients with NSD associated with local anesthetics. The authors assessed lidocaine 2 percent, mepivacaine 2 percent and 3 percent...... of three of the four drugs in both national registry data and clinical data. These findings indicate that the main cause of injury was neurotoxicity resulting from administration of the local anesthetic rather than the needle penetration. Clinical Implications. Clinicians may consider avoiding use of high...

  16. Brainstem node for loss of consciousness due to GABA(A) receptor-active anesthetics.

    Science.gov (United States)

    Minert, Anne; Devor, Marshall

    2016-01-01

    The molecular agents that induce loss of consciousness during anesthesia are classically believed to act by binding to cognate transmembrane receptors widely distributed in the CNS and critically suppressing local processing and network connectivity. However, previous work has shown that microinjection of anesthetics into a localized region of the brainstem mesopontine tegmentum (MPTA) rapidly and reversibly induces anesthesia in the absence of global spread. This implies that functional extinction is determined by neural pathways rather than vascular distribution of the anesthetic agent. But does clinical (systemic-induced) anesthesia employ MPTA-linked circuitry? Here we show that cell-selective lesioning of the MPTA in rats does not, in itself, induce anesthesia or coma. However, it increases the systemic dose of pentobarbital required to induce anesthesia, in a manner proportional to the extent of the lesion. Such lesions also affect emergence, extending the duration of anesthesia. Off-target and sham lesions were ineffective. Combined with the prior microinjection data, we conclude that drug delivery to the MPTA is sufficient to induce loss-of-consciousness and that neurons in this locus are necessary for anesthetic induction at clinically relevant doses. Together, the results support an architecture for anesthesia with the MPTA serving as a key node in an endogenous network of dedicated pathways that switch between wake and unconsciousness. As such, the MPTA might also play a role in syncope, concussion and sleep.

  17. 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.

  18. Anesthetic management of an infant for aortopexy

    Directory of Open Access Journals (Sweden)

    Shruti Kumar

    2013-01-01

    Full Text Available Tracheomalacia is a rare condition characterized by weakness of tracheobronchial cartilaginous bridges. Severe weakness results in tracheal collapse during inspiration, obstructing normal airflow. Tracheomalacia may also be associated with esophageal atresia, tracheoesophageal fistula, and gastroesophageal reflux. Aortopexy is an established surgical procedure for treatment of severe tracheomalacia. A 2-month-old boy was scheduled for aortopexy. He had already undergone repair of tracheoesophageal fistula and had failed multiple attempts at extubation. Intraoperative flexible fiberoptic bronchoscopy was performed to guide the amount and direction of aortopexy for assuring the most effective tracheal decompression. Since tracheomalacia is best assessed in a spontaneously breathing patient, it was an anesthetic challenge to maintain an adequate depth of anesthesia while allowing the patient to breathe spontaneously. Throughout the intraoperative period, SpO 2 remained ≥96%. Following the procedure, the trachea was extubated and patient was able to breathe normally.

  19. Renal effects of methoxyverapamil in anesthetized rats.

    Science.gov (United States)

    Brown, B; Churchill, P

    1983-05-01

    The purpose of these experiments was to determine the renal effects of methoxyverapamil (D-600). Three groups of rats were anesthetized with sodium pentobarbital and given 0, 0.85 or 1.69 nmol/min of methoxyverapamil i.v. Increases in urine flow and Na, K and Ca excretory rates occurred, in an apparently dose-dependent manner. Plasma Na and arterial renin concentration decreased at both doses and, at the higher dose, mean arterial blood pressure and effective renal plasma flow decreased while plasma K increased. Plasma Ca, glomerular filtration rate, filtration fraction and total renal plasma flow were not affected. The findings that methoxyverapamil increased urine flow and electrolyte excretion without changing glomerular filtration rate are consistent with the hypothesis that methoxyverapamil acts directly on tubular reabsorptive mechanisms. These effects, and the effect on plasma renin concentration, could contribute to the beneficial effects of this and other Ca entry antagonists in the treatment of hypertension.

  20. Anesthetic management of transcatheter aortic valve implantation

    Directory of Open Access Journals (Sweden)

    Annalisa Franco

    2012-01-01

    Full Text Available Transcatheter aortic valve implantation (TAVI is an emergent technique for high-risk patients with aortic stenosis. TAVI poses significant challenges about its management because of the procedure itself and the population who undergo the implantation. Two devices are currently available and marketed in Europe and several other technologies are being developed. The retrograde transfemoral approach is the most popular procedure; nevertheless, it may not be feasible in patients with significant aortic or ileo-femoral arterial disease. Alternatives include a transaxillary approach, transapical approach, open surgical access to the retroperitoneal iliac artery and the ascending aorta. A complementary approach using both devices and alternative routes tailored to the anatomy and the comorbidities of the single patient is a main component for the successful implementation of a TAVI program. Anesthetic strategies vary in different centers. Local anesthesia or general anesthesia are both valid alternatives and can be applied according to the patient′s characteristics and procedural instances. General anesthesia offers many advantages, mainly regarding the possibility of an early diagnosis and treatment of possible complications through the use of transesophageal echocardiography. However, after the initial experiences, many groups began to employ, routinely, sedation plus local anesthesia for TAVI, and their procedural and periprocedural success demonstrates that it is feasible. TAVI is burdened with potential important complications: vascular injuries, arrhythmias, renal impairment, neurological complications, cardiac tamponade, prosthesis malpositioning and embolization and left main coronary artery occlusion. The aim of this work is to review the anesthetic management of TAVI based on the available literature.

  1. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Organic Compounds' Impact on Indoor Air Quality Volatile Organic Compounds' Impact on Indoor Air Quality On this page: ... Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds (VOCs) are emitted as gases from certain solids ...

  2. Differential Effects of Anesthetics on Cocaine’s Pharmacokinetic and Pharmacodynamic Effects in Brain

    OpenAIRE

    Du, Congwu; Tully, Melissa; Volkow, Nora D.; Schiffer, Wynne K; Yu, Mei; Luo, Zhongchi; Koretsky, Alan P.; Benveniste, Helene

    2009-01-01

    Most studies of cocaine’s effects on brain activity in laboratory animals are preformed under anesthesia, which could potentially affect the physiological responses to cocaine. Here we assessed the effects of two commonly used anesthetics (α-chloralose and isofluorane) on the effects of acute cocaine (1 mg/kg iv) on cerebral-blood-flow (CBF), cerebral-blood-volume (CBV), and tissue-hemoglobin-oxygenation (StO2) using optical techniques and cocaine’s pharmacokinetics and binding in the rat bra...

  3. 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".

  4. Effect of Lidocaine-Ketamine Infusions Combined with Morphine or Fentanyl in Sevoflurane-Anesthetized Pigs.

    Science.gov (United States)

    Re, Michela; Canfrán, Susana; Largo, Carlota; Gómez de Segura, Ignacioa A

    2016-01-01

    Providing lidocaine, ketamine, and an opioid greatly decreases the minimum alveolar concentration (MAC) of volatile anesthetics in dogs. However, the efficacy of this combination shows marked interspecies variation, and opioids are likely to be less effective in pigs than in other species. The aim of the study was to determine the effects of constant-rate infusion of lidocaine and ketamine combined with either morphine or fentanyl on the MAC of sevoflurane in pigs. In a prospective, randomized, crossover design, 8 healthy crossbred pigs were premedicated with ketamine and midazolam, and anesthesia was induced and maintained with sevoflurane. Pigs then received ketamine (0.6 mg/kg/h) and lidocaine (3 mg/kg/h) combined with either morphine (0.24 mg/kg/h; MLK) or fentanyl (0.0045 mg/kg/h; FLK) after a loading dose; the control group received Ringers lactate solution. The anesthetic-sparing action of the 2 infusion protocols was calculated according to the MAC, by using dewclaw clamping as the standard noxious stimulus. The sevoflurane MAC (mean ± 1 SD) was 2.0% ± 0.2%, 1.9% ± 0.4%, and 1.8% ± 0.2% in the control, MLK, and FLK groups, respectively. No differences among groups or treatments were found. In conclusion, the administration of MLK or FLK at the studied doses did not reduce the MAC of sevoflurane in pigs. PMID:27177566

  5. The anesthetic effect of alcohols and alkanes in caenorhabditis elegans (C. E. )

    Energy Technology Data Exchange (ETDEWEB)

    Anton, A.H.; Berk, A.I.; Nicholls, C.H. (Case Western Reserve Univ., Cleveland, OH (United States))

    1991-03-11

    The authors colleagues reported that the non-parasitic roundworm, C.E., was reversibly immobilized by volatile anesthetics, whose potencies were directly related to their lipid solubilities as in other animals. In further studies on this phenomenon, they tested a homologous series of organic solvents, to determine whether they also had a reversible anesthetic effect in C.E. as in other animals. Synchronized 3-1/2 day-old cultures of about 100 worms each were exposed to increasing concentrations of the alcohols (C{sub 1} - C{sub 14}) and alkanes (C{sub 5} -C{sub 10}) in 15 ml sealed bottles in a volume of 0.5 ml. The dose that reversibly immobilized 50% of the worms was determined and a straight line was plotted against the octanol/water partition coefficient (K) of each series. As with other animals, potency was directly related to the lipid solubility of these agents so that, for example, the ID{sub 50} for methanol was 1,000 mmol (K=0.12) whereas it was 0.17 mmol for heptanol (K=3,000). The alcohols were about 20 times more potent than the alkanes even though the latter were about 10 times more lipid soluble than the alcohols. In spite of these differences, the cut-off point was at C{sub 9} in the two series.

  6. [Anesthetic Management of a Patient with Central Core Disease for Scoliosis Surgery].

    Science.gov (United States)

    Jimi, Nobuo; Izumi, Kaoru; Sumiyoshi, Rieko; Mizuno, Keiichiro

    2016-06-01

    Central core disease (CCD) is a dominantly inherited congenital myopathy. CCD is also associated with muscular and skeletal abnormalities such as abnormal curvature of the spine (scoliosis), hip dislocation, and joint deformities. CCD and malignant hyperthermia (MH) are both associated with mutations in the ryanodine receptor on chromosome 19q13.1. An 11-year-old boy with CCD complicated with severe scoliosis was scheduled for spinal fusion surgery under general anesthesia. Furthermore, he had trismus caused by temporomandibular contracture. He was considered as MH susceptible. Anesthesia was managed with remifentanil and propofol without using muscle relaxtants and volatile anesthetics. We could intubate the trachea with Airtraq laryngoscope without any complications. The perioperative course was uneventful. PMID:27483668

  7. 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.

  8. Local anesthetics: dentistry's most important drugs, clinical update 2006.

    Science.gov (United States)

    Malamed, Stanley F

    2006-12-01

    Local anesthetics are the safest most effective drugs in medicine for the control and management of pain. They also represent the most important drugs in dentistry. Today, dentistry has a spectrum of local anesthetics that permit pain control to be tailored to the specific needs of the patient: short-, intermediate-, and long-acting drugs. Bupivacaine has become a standard part of the armamentarium for postsurgical pain control while articaine has become the second-most used local anesthetic in the United States since its introduction in 2000. Despite an increase in anecdotal reports of paresthesia since articaine's introduction there is yet, no supporting scientific evidence.

  9. The Timing of Acupuncture Stimulation Does Not Influence Anesthetic Requirement

    OpenAIRE

    Chernyak, Grigory; Sengupta, Papiya; Lenhardt, Rainer; Liem, Edwin; Anthony G Doufas; Sessler, Daniel I.; Akça, Ozan

    2005-01-01

    Studies suggest that acupuncture is more effective when induced before induction of general anesthesia than afterwards. We tested the hypothesis that electro-acupuncture initiated 30 minutes before induction reduces anesthetic requirement more than acupuncture initiated after induction. Seven volunteers were each anesthetized with desflurane on 3 study days. Needles were inserted percutaneously at 4 acupuncture points thought to produce analgesia in the upper abdominal area and provide genera...

  10. Pain management via local anesthetics and responsive hydrogels

    OpenAIRE

    Bagshaw, Kyle R; Hanenbaum, Curt L; Carbone, Erica J.; Lo, Kevin WH; Laurencin, Cato T.; Walker, Joseph; Nair, Lakshmi S.

    2015-01-01

    Acute and chronic pain control is a significant clinical challenge that has been largely unmet. Local anesthetics are widely used for the control of post-operative pain and in the therapy of acute and chronic pain. While a variety of approaches are currently used to prolong the duration of action of local anesthetics, an optimal strategy to achieve neural blockage for several hours to days with minimal toxicity has yet to be identified. Several drug delivery systems such as liposomes, micropa...

  11. Long QT 1 mutation KCNQ1A344V increases local anesthetic sensitivity of the slowly activating delayed rectifier potassium current

    DEFF Research Database (Denmark)

    Siebrands, Cornelia C; Binder, Stephan; Eckhoff, Ulrike;

    2006-01-01

    was to investigate whether the LQT1 mutation A344V in the S6 region of KCNQ1, at a position corresponding to the local anesthetic binding site in HERG, may render drug insensitive KCNQ1 channels into a toxicologically relevant target of these pharmacologic agents. This may suggest that LQTS constitutes not only...... a prolongation of the cardiac action potential duration and induction of early afterdepolarizations by the mutation A344V that were aggravated by local anesthetic intoxication. CONCLUSIONS: The results indicate that certain forms of the LQTS may constitute a specific pharmacogenetic risk factor for regional...

  12. Effects of anesthetic compounds on responses of earthworms to electrostimulation.

    Science.gov (United States)

    Podolak-Machowska, Agnieszka; Kostecka, Joanna; Librowski, Tadeusz; Santocki, Michal; Bigaj, Janusz; Plytycz, Barbara

    2014-01-01

    Earthworms play an important role in biomedical research, and some surgical procedures require anesthesia. Anesthetic treatments used so far usually induce convulsive body movements connected with extrusion of coelomocyte-containing coelomic fluid that may affect experimental results. Extensive movements connected with the expulsion of coelomic fluid are exploited by immunologists as a method of harvesting immunocompetent coelomocytes from worms subjected to mild electrostimulation (4.5V). The aim of the investigations was to find anesthetic drugs without unintentional coelomocyte depletion. Experiments were performed on adult specimens of Dendrobaena veneta, the coelomocytes of which consist of amoebocytes and riboflavin-storing eleocytes. Earthworm mobility was filmed and extrusion of coelomocytes was quantified by detection of eleocyte-derived riboflavin in immersion fluid. Treatments included earthworms (1) immersed either in physiological saline (controls) or in a solution of one of the tested anesthetic drugs; (2) electrostimulated immediately after anesthesia, and (3) electrostimulated a second time after a 1-hour recovery period. The well-established fish and amphibian anesthetic agent MS-222 induced coelomocyte expulsion. In contrast, solutions of the mammalian local anesthetic drug, prilocaine hydrochloride (0.25-0.5%, 5-10 min) caused temporal earthworm immobilization followed by recovery, thus showing utility as an efficient earthworm anesthetic.

  13. Intravenous lipid emulsion for treatment of local anesthetic toxicity

    Directory of Open Access Journals (Sweden)

    M Caroline Kosh

    2010-09-01

    Full Text Available M Caroline Kosh, April D Miller, Jill E Michels, , Department of Clinical Pharmacy and Outcomes Sciences, South Carolina College of Pharmacy, University of South Carolina Campus, Columbia, South Carolina, USADate of Preparation: 14th July 2010 Conflict of interest: None declaredClinical question: Is intravenous lipid emulsion a safe and effective therapy for the reversal and treatment of local anesthetic toxicity?Results: Systematic reviews, human case reports, and experimental animal studies have demonstrated the efficacy of intravenous lipid emulsion therapy in successfully reversing cardiac arrhythmias, cardiac arrest, and cardiac collapse seen with severe systemic local anesthetic toxicity. There are fewer data to support treatment of neurologic toxicities associated with local anesthetics.Implementation: Intravenous lipid emulsion 20% should be available whenever patients receive large doses of local anesthetics in operating rooms and emergency departments. Various dosing protocols have been published in the medical literature. Although the dosing protocols are based on low-level evidence, a lack of major adverse events makes lipid emulsion an appropriate therapy for treating cardiotoxic symptoms induced by local anesthetics.Keywords: intravenous lipid emulsion, local anesthetics

  14. Language, News and Volatility

    OpenAIRE

    Byström, Hans

    2014-01-01

    I use Google News TM to study the relation between news volumes and stock market volatilities. More than nine million stock market-related news stories in English and (Mandarin) Chinese are collected and the dynamics of the news volume and the stock market volatility is compared in both the Anglophone world and the Sinophone world. I find that the stock market volatility and the number of publicly available global news stories are strongly linked to each other in both languages. Contemporaneo...

  15. 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.

  16. 麻醉药的心脑保护作用:最新临床研究证据及展望%Cardio-neuroprotection of anesthetic agents: recent clinical evidence and perspectives

    Institute of Scientific and Technical Information of China (English)

    李新; 熊利泽

    2015-01-01

    Background The cardio-neuroprotective effect of anesthetics has been widely concerned but still controversial.Although strong preclinical data support that anesthetics could attenuate ischemic/hypoxic myocardial and cerebral injury,confirmative conclusions have not been demonstrated from clinical studies.We reviewed clinical trials in recent years(especially randomized controlled trials) on cardio-neuroprotection of commonly used anesthetic agents (volatile anesthetics:isoflurane,sevoflurane,intravenous anesthetics:propofol,dexmedetomidine).Among the mostly studied anesthetics that reveal the property of cardio-neuroprotection,ether-derived volatile anesthetics have shown more promising potentials than intravenous anesthetics,especially in cardiac surgeries.The cardio-neuroprotection of intravenous anesthetic dexmedetomidine was validated in heart surgery by randomized controlled trial with large sample.However,the neuroprotection of anesthetic agents is controversial,and there's lack of simple and objective evaluation indicators for it.Thus,large-scale,multicenter clinical trials are necessary in the future.%麻醉药的心脑保护作用一直广受关注,但仍存在一些争议.尽管多数临床前研究发现常用麻醉药能减轻缺血/缺氧性心脑损伤,但临床研究却未得到确定性结论.综述近年来关于麻醉药心脑保护作用的临床研究,尤其是随机对照研究,结果表明,多数常用的麻醉药(吸入性麻醉药异氟醚、七氟醚,静脉麻醉药丙泊酚、右美托咪定等)均表现出一定的心脏保护作用,其中氟烷类吸入性麻醉药较静脉麻醉药效果更明显,可显著减轻心脏手术患者的心肌损伤.静脉麻醉药中,右美托咪定对心脏手术患者的心肌保护作用在大样本临床研究中得到验证.麻醉药的脑保护作用存在较大争议,也缺少简单、客观的疗效评价指标,还应开展大规模、多中心的临床研究.

  17. Interference of anesthetics in blood alcohol analysis by HS-GC-FID: A case report.

    Science.gov (United States)

    Monteiro, C; Proença, P; Tavares, C; Castañera, A; Corte Real, F

    2016-08-01

    One of the techniques most widely used in ethanol analysis in forensic laboratories is undoubtedly the headspace gas chromatography with flame-ionization detection (HS-GC-FID) since the determination of this substance is carried out directly, without the need for additional purification procedures, which leads to increased productivity. This is a very important factor due to the high number of alcohol analysis requested to these laboratories. The presence of other volatile substances can cause a problem given the fact that they can be interferents in ethanol analysis by HS-GC-FID, which can have legal consequences related with driving under the influence of alcohol. The authors report a case of a routine analysis by HS-GC-FID for the determination of ethanol of a driver who has suffered an accident in which the use of two chromatographic columns with different polarities was essential to obtain an unequivocally identification of this substance in presence of an interfering volatile anesthetic administered in the hospital. The method was validated according to international recommendations before being introduced into routine laboratory in terms of selectivity, limits of detection (LOD), limits of quantification (LOQ), linearity, repeatability, intermediate precision, accuracy, robustness and carryover. PMID:26829337

  18. Volatility of volatility and tail risk premiums

    OpenAIRE

    Yang-Ho Park

    2013-01-01

    This paper reports on tail risk premiums in two tail risk hedging strategies: the S&P 500 puts and the VIX calls. As a new measure of tail risk, we suggest using a model-free, risk-neutral measure of the volatility of volatility implied by a cross section of the VIX options, which we call the VVIX index. The tail risk measured by the VVIX index has forecasting power for future tail risk hedge returns. Specifically, consistent with the literature on rare disasters, an increase in the VVIX inde...

  19. Phosphoproteome Profiling of SH-SY5y Neuroblastoma Cells Treated with Anesthetics: Sevoflurane and Isoflurane Affect the Phosphorylation of Proteins Involved in Cytoskeletal Regulation.

    Science.gov (United States)

    Lee, Joomin; Ahn, Eunsook; Park, Wyun Kon; Park, Seyeon

    2016-01-01

    Inhalation anesthetics are used to decrease the spinal cord transmission of painful stimuli. However, the molecular or biochemical processes within cells that regulate anesthetic-induced responses at the cellular level are largely unknown. Here, we report the phosphoproteome profile of SH-SY5y human neuroblastoma cells treated with sevoflurane, a clinically used anesthetic. Phosphoproteins were isolated from cell lysates and analyzed using two-dimensional gel electrophoresis. The phosphorylation of putative anesthetic-responsive marker proteins was validated using western blot analysis in cells treated with both sevoflurane and isoflurane. A total of 25 phosphoproteins were identified as differentially phosphorylated proteins. These included key regulators that signal cytoskeletal remodeling steps in pathways related to vesicle trafficking, axonal growth, and cell migration. These proteins included the Rho GTPase, Ras-GAP SH3 binding protein, Rho GTPase activating protein, actin-related protein, and actin. Sevoflurane and isoflurane also resulted in the dissolution of F-actin fibers in SH-SY5y cells. Our results show that anesthetics affect the phosphorylation of proteins involved in cytoskeletal remodeling pathways. PMID:27611435

  20. 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

  1. Liquid general anesthetics lower critical temperatures in plasma membrane vesicles

    CERN Document Server

    Gray, Ellyn; Machta, Benjamin B; Veatch, Sarah L

    2013-01-01

    A large and diverse array of small hydrophobic molecules induce general anesthesia. Their efficacy as anesthetics has been shown to correlate both with their affinity for a hydrophobic environment and with their potency in inhibiting certain ligand gated ion channels. Here we explore the effects that n-alcohols and other liquid anesthetics have on the two-dimensional miscibility critical point observed in cell derived giant plasma membrane vesicles (GPMVs). We show that anesthetics depress the critical temperature (Tc) of these GPMVs without strongly altering the ratio of the two liquid phases found below Tc. The magnitude of this affect is consistent across n-alcohols when their concentration is rescaled by the median anesthetic concentration (AC50) for tadpole anesthesia, but not when plotted against the overall concentration in solution. At AC50 we see a 4{\\deg}C downward shift in Tc, much larger than is typically seen in the main chain transition at these anesthetic concentrations. GPMV miscibility critic...

  2. Anesthetic Considerations for the Parturient After Solid Organ Transplantation.

    Science.gov (United States)

    Moaveni, Daria M; Cohn, Jennifer H; Hoctor, Katherine G; Longman, Ryan E; Ranasinghe, J Sudharma

    2016-08-01

    Over the past 40 years, the success of organ transplantation has increased such that female solid organ transplant recipients are able to conceive and carry pregnancies successfully to term. Anesthesiologists are faced with the challenge of providing anesthesia care to these high-risk obstetric patients in the peripartum period. Anesthetic considerations include the effects of the physiologic changes of pregnancy on the transplanted organ, graft function in the peripartum period, and the maternal side effects and drug interactions of immunosuppressive agents. These women are at an increased risk of comorbidities and obstetric complications. Anesthetic management should consider the important task of protecting graft function. Optimal care of a woman with a transplanted solid organ involves management by a multidisciplinary team. In this focused review article, we review the anesthetic management of pregnant patients with solid organ transplants of the kidney, liver, heart, or lung. PMID:27285002

  3. Costs of anesthetics and other drugs in anesthesia

    Directory of Open Access Journals (Sweden)

    Majstorović Branislava M.

    2012-01-01

    Full Text Available Introduction. Drugs are real and transparent costs of treatment, which are subject to constant monitoring and changes. The study was aimed at measuring and analyzing consumption of anesthetics and other drugs in anesthesia in the Clinical Centre of Serbia. Material and Methods. This paper is part of a five-year (2005-2009, academic, pharmacoeconomic retrospective-prospective study (the 4th phase. We calculated the costs of anesthetics and other drugs in all anesthetized patients at the Institute of Anesthesia and Reanimation, Clinical Center of Serbia in 2006. The data, obtained from the Clinical Centre of Serbia Database, were analyzed by descriptive statistical methods using computer program Microsoft Office Excel 2003 and the Statistical Package for the Social Sciences (SPSS for Windows. Results. The amount of money spent for the application of 33,187 general and 16,394 local anesthesia and 20,614 anesthesiology procedures was 83,322,046.36 RSD (Euros 1,054,705.4, which was 5.93% of the funds allocated for all drugs used at the Clinical Center of Serbia. Of the total fund for drugs, 57.8% was spent for anesthetics (local anesthetics 1.2% and muscle relaxants, whereas 42.2% was spent for other drugs in anesthesia. The highest amount was spent at the Emergency Center (35.8%, then at the Cardio-surgery (11.9% and the Neurosurgery (10.9% because of the large number and length of surgical interventions. Conclusion. There is no space for rationalizing the costs of anesthetics and other drugs in anesthesia.

  4. ANESTHETIC CHALLENGES FACED IN A CHILD WITH TREACHER - COLLINS SYNDROME

    Directory of Open Access Journals (Sweden)

    Sahajananda

    2014-01-01

    Full Text Available Anesthesiologists come across pediatric patients with rare diseases and syndromes scheduled for various operative interventions. Treacher Collins syndrome is a rare genetic disorder characterized by craniofacial deformities , the incidence being 1 in 40 , 000 - 70 , 000 births 1 - 3 . Treacher Collins syndrome (TCS poses serious problem in securing and maintaining airway due to facial deformity. Difficulty in intubation increases as the patient’s age increases. It requires meticulous planning and assessment of the airway prior to each anesthetic technique. Here we describe and discuss successful anesthet ic management of an 8 year old boy posted for cana loplasty of the right ear

  5. 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...

  6. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    profit on well-developed markets. Dynamic participation features on cross asset portfolios are at rst sight a remedy to that dilemma. Based on volatility thresholds and portfolio re-balancing, the fund engineers try to create a "volatility guaranteed" investment opportunity by surfing on the unusual high...... concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex......, interest rates and commodities. If an investor positions himself on the (volatility) market within a long/short trading framework, he typically bets on a traditional mispricing arbitrage. However as this corresponds to a call spread with equal exercise prices, this strategy alone would not generate enough...

  7. 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.

  8. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    for the realized volatility series. It emerges that during the recent financial crisis the relative weight of the daily component dominates over the monthly term. The estimates of the two factor stochastic volatility model suggest that the change in the dynamic structure of the realized volatility during...... the financial crisis is due to the increase in the volatility of the persistent volatility term. A set of Monte Carlo simulations highlights the robustness of the methodology adopted in tracking the dynamics of the parameters....

  9. Electronic dental anesthesia in a patient with suspected allergy to local anesthetics: report of case.

    Science.gov (United States)

    Malamed, S F; Quinn, C L

    1988-01-01

    A 56-year-old patient with alleged allergy to local anesthetics required restorative dental treatment. Electronic dental anesthesia was used successfully, in lieu of injectable local anesthetics, to manage intraoperative pain associated with the restoration of vital mandibular teeth.

  10. Effects of Anesthetic Management on Early Postoperative Recovery, Hemodynamics and Pain After Supratentorial Craniotomy

    OpenAIRE

    Ayrian, Eugenia; Kaye, Alan David; Varner, Chelsia L.; Guerra, Carolina; Vadivelu, Nalini; Urman, Richard D.; Zelman, Vladimir; Lumb,Philip D.; De Rosa, Giovanni; Bilotta, Federico

    2015-01-01

    Various clinical trials have assessed how intraoperative anesthetics can affect early recovery, hemodynamics and nociception after supratentorial craniotomy. Whether or not the difference in recovery pattern differs in a meaningful way with anesthetic choice is controversial. This review examines and compares different anesthetics with respect to wake-up time, hemodynamics, respiration, cognitive recovery, pain, nausea and vomiting, and shivering. When comparing inhalational anesthetics to in...

  11. Concentrations of anesthetics across the water-membrane interface; the Meyer-Overton hypothesis revisited

    Science.gov (United States)

    Pohorille, A.; Wilson, M. A.; New, M. H.; Chipot, C.

    1998-01-01

    The free energies of transferring a variety of anesthetic and nonanesthetic compounds across water-oil and water-membrane interfaces were obtained using computer simulations. Anesthetics exhibit greatly enhanced concentrations at these interfaces, compared to nonanesthetics. The substitution of the interfacial solubilites of the anesthetics for their bulk lipid solubilities in the Meyer-Overton relation, was found to give a better correlation, indicating that the potency of an anesthetic is directly proportional to its solubility at the interface.

  12. Intralipid Therapy for Inadvertent Peripheral Nervous System Blockade Resulting from Local Anesthetic Overdose

    OpenAIRE

    Ihab Kamel; Gaurav Trehan; Rodger Barnette

    2015-01-01

    Although local anesthetics have an acceptable safety profile, significant morbidity and mortality have been associated with their use. Inadvertent intravascular injection of local anesthetics and/or the use of excessive doses have been the most frequent causes of local anesthetic systemic toxicity (LAST). Furthermore, excessive doses of local anesthetics injected locally into the tissues may lead to inadvertent peripheral nerve infiltration and blockade. Successful treatment of LAST with intr...

  13. Differential regional metabolism of glucagon in anesthetized pigs

    DEFF Research Database (Denmark)

    Deacon, Carolyn F; Kelstrup, Mette; Trebbien, Ramona;

    2003-01-01

    Glucagon metabolism under basal (endogenous) conditions and during intravenous glucagon infusion was studied in anesthetized pigs by use of midregion (M), COOH-terminal (C), and NH2-terminal (N)-RIAs. Arteriovenous concentration differences revealed a negative extraction of endogenous glucagon...

  14. 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...

  15. 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, HCO...

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.

  18. Effects of anesthetics on ponto-geniculo-occipital waves from the oculomotor nucleus of the cat.

    Science.gov (United States)

    Yanagida, H; Ashizawa, N; Wakushima, Y; Yamamura, H

    1975-05-01

    Effects of anesthetics and doxapram on pontogeniculo-occipital (PGO) waves from the oculomotor nucleus were studied in acute experiments in cats paralyzed by gallamine triethiodide. The anesthetic agents studied in the present experiment (thiopental, ketamine, Innovar, nitrous oxide, and halothane) decreased, while doxapram increased, the total number of PGO waves. As the doses of anesthetics increased, PGO waves were abolished, but they returned to control levels or below control levels when the concentrations of anesthetics were decreased. The results indicate that the anesthetics studied inhibit the activity of the central mechanism associated with the oculomotor system. PGO waves may prove a useful index of the level of anesthesia. PMID:1130723

  19. Stochastic volatility selected readings

    CERN Document Server

    Shephard, Neil

    2005-01-01

    Neil Shephard has brought together a set of classic and central papers that have contributed to our understanding of financial volatility. They cover stocks, bonds and currencies and range from 1973 up to 2001. Shephard, a leading researcher in the field, provides a substantial introduction in which he discusses all major issues involved. General Introduction N. Shephard. Part I: Model Building. 1. A Subordinated Stochastic Process Model with Finite Variance for Speculative Prices, (P. K. Clark). 2. Financial Returns Modelled by the Product of Two Stochastic Processes: A Study of Daily Sugar Prices, 1961-7, S. J. Taylor. 3. The Behavior of Random Variables with Nonstationary Variance and the Distribution of Security Prices, B. Rosenberg. 4. The Pricing of Options on Assets with Stochastic Volatilities, J. Hull and A. White. 5. The Dynamics of Exchange Rate Volatility: A Multivariate Latent Factor ARCH Model, F. X. Diebold and M. Nerlove. 6. Multivariate Stochastic Variance Models. 7. Stochastic Autoregressive...

  20. Volatiles in protoplanetary disks

    CERN Document Server

    Pontoppidan, Klaus M; Bergin, Edwin A; Brittain, Sean; Marty, Bernard; Mousis, Olvier; Oberg, Karin L

    2014-01-01

    Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped...

  1. 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...

  2. Effects of anesthetic agents on systemic critical O2 delivery.

    Science.gov (United States)

    Van der Linden, P; Gilbart, E; Engelman, E; Schmartz, D; Vincent, J L

    1991-07-01

    The present study tested the hypothesis that anesthetic agents can alter tissue O2 extraction capabilities in a dog model of progressive hemorrhage. After administration of pentobarbital sodium (25 mg/kg iv) and endotracheal intubation, the dogs were paralyzed with pancuronium bromide, ventilated with room air, and splenectomized. A total of 60 dogs were randomized in 10 groups of 6 dogs each. The first group served as control (C). A second group (P) received a continuous infusion of pentobarbital (4 mg.kg-2.h-2), which was started immediately after the bolus dose. Three groups received enflurane (E), halothane (HL), or isoflurane (I) at the end-tidal concentration of 0.7 minimum alveolar concentration (MAC). The sixth group received halothane at the end-tidal concentration of 1 MAC (HH). Two groups received intravenous alfentanil at relatively low dose (AL) or high dose (AH). The last two groups received intravenous ketamine at either relatively low dose (KL) or high dose (KH). In each group, O2 delivery (Do2) was progressively reduced by hemorrhage. At each step, systemic Do2 and O2 consumption (VO2) were measured separately and the critical point was determined from a plot of Vo2 vs. Do2. The critical O2 extraction ratio (OER) in the control group was 65.0 +/- 7.8%. OER was lower in all anesthetized groups (P, 44.3 +/- 11.8%; E, 47.0 +/- 7.7%; HL, 45.7 +/- 11.2%; I, 44.3 +/- 7.1%; HH, 33.7 +/- 6.0%; AL, 56.5 +/- 9.6%; AH, 43.5 +/- 5.9%; KH, 57.7 +/- 7.1%), except in the KL group (78.3 +/- 10.0%). The effects of halothane and alfentanil on critical OER were dose dependent (P less than 0.05), whereas critical OER was significantly lower in the KH than in the KL group. Moreover, the effects of anesthetic agents on critical Do2 appeared related to their effects on systemic vascular resistance. Anesthetic agents therefore alter O2 extraction by their peripheral vascular effects. However, ketamine, with its unique sympathetic stimulant properties, had a lesser effect

  3. The implied volatility smirk

    OpenAIRE

    Zhang, JE; Xiang, Y.

    2008-01-01

    This paper provides an industry standard on how to quantify the shape of the implied volatility smirk in the equity index options market. Our local expansion method uses a second-order polynomial to describe the implied volatility-moneyness function and relates the coefficients of the polynomial to the properties of the implied risk-neutral distribution of the equity index return. We present a formal, two-way representation of the link between the level, slope and curvature of the implied vol...

  4. Vibrational Infrared Lifetime of the Anesthetic nitrous oxide gas in solution

    CERN Document Server

    Chieffo, Logan; Shattuck, Jeffrey; Hong, Mi K; Ziegler, Lawrence; Erramilli, Shyamsunder

    2006-01-01

    The lifetime of the asymmetric fundamental stretching 2218 cm$^{-1}$ vibration of the anesthetic gas nitrous oxide (N$_2$O) dissolved in octanol and olive oil is reported. These solvents are model systems commonly used to assess anesthetic potency. Picosecond time-scale molecular dynamics simulations have suggested that protein dynamics or membrane dynamics play a role in the molecular mechanism of anesthetic action. Ultrafast infrared spectroscopy with 100 fs time resolution is an ideal tool to probe dynamics of anesthetic molecules on such timescales. Pump-probe studies at the peak of the vibrational band yield a lifetime of $55 \\pm 1$ ps in olive oil and $52 \\pm 1 ps$ in octanol. The similarity of lifetimes suggests that energy relaxation of the anesthetic is determined primarily by the hydrophobic nature of the environment, consistent with models of anesthetic action. The results show that nitrous oxide is a good model system for probing anesthetic-solvent interactions using nonlinear infrared spectroscop...

  5. Explicit implied volatilities for multifactor local-stochastic volatility models

    OpenAIRE

    Matthew Lorig; Stefano Pagliarani; Andrea Pascucci

    2013-01-01

    We consider an asset whose risk-neutral dynamics are described by a general class of local-stochastic volatility models and derive a family of asymptotic expansions for European-style option prices and implied volatilities. Our implied volatility expansions are explicit; they do not require any special functions nor do they require numerical integration. To illustrate the accuracy and versatility of our method, we implement it under five different model dynamics: CEV local volatility, quadrat...

  6. Idiosyncratic volatility, stock market volatility, and expected stock returns

    OpenAIRE

    Hui Guo; Robert Savickas

    2005-01-01

    We find that the value-weighted idiosyncratic stock volatility and aggregate stock market volatility jointly exhibit strong predictive power for excess stock market returns. The stock market risk-return relation is found to be positive, as stipulated by the CAPM; however, idiosyncratic volatility is negatively related to future stock market returns. Also, idiosyncratic volatility appears to be a pervasive macrovariable, and its forecasting abilities are very similar to those of the consumptio...

  7. Is conformation a fundamental descriptor in QSAR? A case for halogenated anesthetics

    Science.gov (United States)

    Guimarães, Maria C; Duarte, Mariene H; Silla, Josué M

    2016-01-01

    Summary An intriguing question in 3D-QSAR lies on which conformation(s) to use when generating molecular descriptors (MD) for correlation with bioactivity values. This is not a simple task because the bioactive conformation in molecule data sets is usually unknown and, therefore, optimized structures in a receptor-free environment are often used to generate the MD´s. In this case, a wrong conformational choice can cause misinterpretation of the QSAR model. The present computational work reports the conformational analysis of the volatile anesthetic isoflurane (2-chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane) in the gas phase and also in polar and nonpolar implicit and explicit solvents to show that stable minima (ruled by intramolecular interactions) do not necessarily coincide with the bioconformation (ruled by enzyme induced fit). Consequently, a QSAR model based on two-dimensional chemical structures was built and exhibited satisfactory modeling/prediction capability and interpretability, then suggesting that these 2D MD´s can be advantageous over some three-dimensional descriptors. PMID:27340468

  8. [Anesthetic Management of Three Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy].

    Science.gov (United States)

    Maruyama, Naoko; Wakimoto, Mayuko; Inamori, Noriko; Nishimura, Shinya; Mori, Takahiko

    2015-08-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronically progressing or relapsing disease caused by immune-mediated peripheral neuropathy. We report the anesthetic management of three CIDP patients who underwent elective orthopedic surgeries. Owing to the risk of neuraxial anesthetics triggering demyelination, general anesthesia was selected to avoid epidural or spinal anesthesia or other neuraxial blockade. It was also judged prudent to avoid prolonged perioperative immobilization, which might compress vulnerable peripheral nerves. For Patient 1, general anesthesia was induced with propofol, remifentanil, and sevoflurane, and was maintained with sevoflurane and remifentanil. For Patients 2 and 3, general anesthesia was induced and maintained with propofol and remifentanil. For tracheal intubation, under careful monitoring with peripheral nerve stimulators, minimal doses of rocuronium (0.6-0.7 mg x kg(-1)) were administered. When sugammadex was administered to reverse the effect of rocuronium, all patients rapidly regained muscular strength. Postoperative courses were satisfactory without sequelae.

  9. Trace anesthetic gases during xenon arc photocoagulation for retinoblastoma.

    Science.gov (United States)

    Rosenberg, A M; Abramson, D H; Sussman, D; Servodidio, C; Turner, L

    1989-10-01

    In pediatric ocular examinations, administration of continuous-flow anesthetic gases containing nitrous oxide, halothane, and oxygen enables the physician to do safe, controlled, reproducible examinations. We did a study in which the levels of waste anesthetic gases were measured during xenon arc photocoagulation procedures used for retinoblastoma. Waste nitrous oxide and halothane gases measured during these procedures significantly exceeded the levels recommended by the National Institute of Safety and Health. These high levels are of particular importance because of the physician's proximity to the patient during the procedure. The high levels of waste gases may have immediate deleterious effects on the physician's functioning capacity and may also pose long-term health hazards for the physician and operating room personnel. PMID:2589745

  10. 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.

  11. Antidepressants and local anesthetics: drug interactions of interest to dentistry

    Directory of Open Access Journals (Sweden)

    Lea Rosa Chioca

    2010-10-01

    Full Text Available Introduction: Since there is a vast variety of pharmacological treatments for mental conditions, it has been increasingly more common that patients seeking dentistry treatment are continually using psychoactive drugs as antidepressants. The number of people taking antidepressants is increasing; consequently, dentists should update their knowledge on the interaction between this drug class and those used in dental daily practice, such as local anesthetics and vasoconstrictors. Objective: To conduct a literature review on this subject. Literature review and conclusion: Literature data suggest that sympathomimetic vasoconstrictors (epinephrine, norepinephrine, and phenylephrine associated with local anesthetics may potentiate the side effects of antidepressants, particularly tricyclics and MAO inhibitors, on the cardiovascular system. There are few clinical trials and preclinical studies on this subject, and most of them were carried out between the 60s and 80s. Current studies are needed, since many new antidepressant drugs with different mechanisms of action are currently marketed and being used.

  12. 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

  13. Central administration of nicotine suppresses tracheobronchial cough in anesthetized cats

    OpenAIRE

    Poliacek, I; Rose, M.J.; Pitts, T. E.; Mortensen, A.; CORRIE, L.W.; Davenport, P. W.; Bolser, D C

    2014-01-01

    We tested the hypothesis that nicotine, which acts peripherally to promote coughing, might inhibit reflex cough at a central site. Nicotine was administered via the vertebral artery [intra-arterial (ia)] to the brain stem circulation and by microinjections into a restricted area of the caudal ventral respiratory column in 33 pentobarbital anesthetized, spontaneously breathing cats. The number of coughs induced by mechanical stimulation of the tracheobronchial airways; amplitudes of the diaphr...

  14. The impact of anesthetics and hyperoxia on cortical spreading depression

    OpenAIRE

    Kudo, Chiho; Nozari, Ala; MOSKOWITZ, MICHAEL A.; Ayata, Cenk

    2008-01-01

    Cortical spreading depression (CSD), a transient neuronal and glial depolarization that propagates slowly across the cerebral cortex, is the putative electrophysiological event underlying migraine aura. It negatively impacts tissue injury during stroke, cerebral contusion and intracranial hemorrhage. Susceptibility to CSD has been assessed in several experimental animal models in vivo, such as after topical KCl application or cathodal stimulation. Various combinations of anesthetics and ambie...

  15. Anesthetic Management in a Gravida with Type IV Osteogenesis Imperfecta

    Science.gov (United States)

    Vue, Elizabeth; Davila, Juan

    2016-01-01

    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.

  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. A preliminary trial comparison of several anesthetic techniques in cats.

    OpenAIRE

    Cruz, M. L.; Luna, S P; de Castro, G B; Massone, F; Rosa, A. L.

    2000-01-01

    The aim of this study was to investigate the effect of several drug combinations (atropine, xylazine, romifidine, methotrimeprazine, midazolam, or fentanyl) with ketamine for short term anesthesia in cats. Twelve cats were anesthetized 6 times by using a cross-over Latin square protocol: methotrimeprazine was combined with midazolam, ketamine, and fentanyl; midazolam and ketamine; romifidine and ketamine; and xylazine and ketamine. Atropine was combined with romifidine and ketamine, and xylaz...

  18. Anesthetic considerations in Demons-Meigs’ syndrome: a case report

    OpenAIRE

    Fjouji, Salaheddine; Bensghir, Mustapha; Haimeur, Charki; Azendour, Hicham

    2014-01-01

    Introduction Demons-Meigs’ syndrome is characterized by the presence of a benign ovarian tumor associated with ascites and a right-sided hydrothorax. Its pathophysiology remains unclear. Anesthesia of this syndrome is a real challenge. Respiratory, hemodynamic, metabolic problems and abdominal hypertension are the main anesthetic risks. Case presentation A 52-year-old African woman with Demons-Meigs’ syndrome was admitted for elective surgery under general anesthesia. An abdominal computed to...

  19. Cortical control of hering-breuer reflexes in anesthetized rats

    OpenAIRE

    Aleksandrov VG; Mercuriev VA; Ivanova TG; Tarasievich AA; Aleksandrova NP

    2009-01-01

    Abstract It had been hypothesized that the regions of prefrontal cortex which are involved in respiratory control can modulate Hering-Breuer reflexes evoked by vagal input from pulmonary stretch receptors. In the present study, experiments were performed on urethane anesthetized spontaneously breathing Wistar rats. The expiratory-promoting reflex was evaluated from changes in expiratory time immediately after airway occlusion at the end of inspiration. The inspiratory-inhibitory reflex was es...

  20. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos;

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong...

  1. 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...

  2. [Effect of local anesthetics on the postoperative inflammatory response].

    Science.gov (United States)

    Beloeil, H; Mazoit, J-X

    2009-03-01

    Current knowledge suggests that peripheral inflammation following surgery activates and sensitizes both peripheral and central nervous system. These phenomena involved in the maintenance of the inflammatory response lead to hypersensibility, hyperalgesia and allodynia. Hyperalgesia participates in the general experience of postoperative pain and ALo in the development of chronic pain. A correlation between the ability of treatments to reduce areas of hypersensitivity surrounding the wound after surgery and their ability to reduce the incidence of chronic pain has been shown. For a long time, local anaesthetics have been used for their capacity to block nociceptive input. They can ALo modulate the inflammatory response following a surgical trauma. By inhibiting the nervous conductivity at the site of the trauma, local anesthetics attenuate the sensitization of the nervous system and therefore the inflammatory phenomena. They ALo exert intrinsic anti-inflammatory properties by modulating the local and systemic liberation of inflammatory mediators. The mechanisms involved are not clearly elucidated. Local, systemic, and spinal inflammatory mechanisms may be influenced by local anesthetics through multiple different mechanisms. The therapeutic implications of effects of local anesthetics on local, systemic, and spinal inflammatory responses merit further study. PMID:19297121

  3. The bonding of anesthetics and antibiotics on the carboxymethylcellulose

    Directory of Open Access Journals (Sweden)

    Rodić-Grabovac Branka B.

    2007-01-01

    Full Text Available The preparation of biologically active material is one of the most interesting trends in the chemical modification of cellulose. The possibility of obtaining biologically active cellulosic material by sorption of procaine hydrochloride and gentamicin sulphate on CMC was investigated in this paper. The sorption of therapeutics on CMC samples with different degree of substitution was carried out in water solutions of anesthetic and antibiotic, while the desorption was done in 0.95% NaCl solution. The amount of bonded and released therapeutics was determined by UV spe-ctrophotometry. It was found that degree of substitution of car-boxymethylcellulose and concentration of chemotherapeutic water solution have significant influence on the amount of bonded anesthetic and antibiotic. The maximum amount of bonded chemotherapeutic was 72.15 mg of procaine hydrochloride and 165.49 mg of gentamicin sulphate per gram CMC. In both cases the amounts of bonded chemotherape-utics correspond to the concentration of local anesthetic and antibiotic preparation that are used in therapeutic purposes.

  4. Albumin extravasation rates in tissues of anesthetized and unanesthetized rats

    International Nuclear Information System (INIS)

    Bovine serum albumin (BSA) labeled with 131I was injected intravenously in chronically prepared, unanesthetized rats and into pentobarbital-anesthetized rats that had received 2 ml 5% BSA to help sustain plasma volume. Initial uptake rates (clearances) in skin, skeletal muscles, diaphragm, and heart (left ventricle) were measured over 1 h. BSA labeled with 125I was injected terminally to correct for intravascular 131I-BSA. Observed clearances were in the following order in both groups of animals: heart much greater than diaphragm approximately equal to skin greater than resting skeletal muscles. Differences between unanesthetized and anesthetized animals were small and inconsistently directed. Our results suggest that the lower albumin clearances reported in the literature for anesthetized rats are not the result of their immobility or any direct effect of anesthesia on albumin transport in these tissues. The lower transport rates appear to result indirectly from changes produced by anesthesia and/or surgery in controllable parameters such as plasma volume and intravascular protein mass

  5. Implied Volatility Functions: Empirical Tests

    OpenAIRE

    Dumas, Bernard J; Fleming, Jeff; Robert E. Whaley

    1996-01-01

    Black and Scholes (1973) implied volatilities tend to be systematically related to the option's exercise price and time to expiration. Derman and Kani (1994), Dupire (1994), and Rubinstein (1994) attribute this behavior to the fact that the Black-Scholes constant volatility assumption is violated in practice. These authors hypothesize that the volatility of the underlying asset's return is a deterministic function of the asset price and time and develop the deterministic volatility function (...

  6. Volatility investing with variance swaps

    OpenAIRE

    Härdle, Wolfgang Karl; Silyakova, Elena

    2010-01-01

    Traditionally volatility is viewed as a measure of variability, or risk, of an underlying asset. However recently investors began to look at volatility from a different angle. It happened due to emergence of a market for new derivative instruments - variance swaps. In this paper first we introduse the general idea of the volatility trading using variance swaps. Then we describe valuation and hedging methodology for vanilla variance swaps as well as for the 3-rd generation volatility derivativ...

  7. Dividend Taxes and Stock Volatility

    OpenAIRE

    Ferris, Erin E. Syron

    2015-01-01

    How do dividend taxes affect stock volatility? In this paper, I use a decrease in dividend taxes as a natural experiment to identify their impact on firm's price volatility. If a risk-averse executive faces price risk through his incentive contract, changes in stock volatility due to dividend taxes may increase agency costs and therefore decrease overall welfare. Stock volatility decreased after the tax cut for firms where an executive has large holdings of shares and options relative to firm...

  8. A Theory of Volatility Spreads

    OpenAIRE

    Gurdip Bakshi; Dilip Madan

    2006-01-01

    This study formalizes the departure between risk-neutral and physical index return volatilities, termed volatility spreads. Theoretically, the departure between risk-neutral and physical index volatility is connected to the higher-order physical return moments and the parameters of the pricing kernel process. This theory predicts positive volatility spreads when investors are risk averse, and when the physical index distribution is negatively skewed and leptokurtic. Our empirical evidence is ...

  9. 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.

  10. 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

  11. 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.

  12. Randomized clinical trial of local anesthetic versus a combination of local anesthetic with self-hypnosis in the management of pediatric procedure-related pain.

    Science.gov (United States)

    Liossi, Christina; White, Paul; Hatira, Popi

    2006-05-01

    A prospective controlled trial was conducted to compare the efficacy of an analgesic cream (eutectic mixture of local anesthetics, or EMLA) with a combination of EMLA with hypnosis in the relief of lumbar puncture-induced pain and anxiety in 45 pediatric cancer patients (age 6-16 years). The study also explored whether young patients can be taught and can use hypnosis independently as well as whether the therapeutic benefit depends on hypnotizability. Patients were randomized to 1 of 3 groups: local anesthetic, local anesthetic plus hypnosis, and local anesthetic plus attention. Results confirmed that patients in the local anesthetic plus hypnosis group reported less anticipatory anxiety and less procedure-related pain and anxiety and that they were rated as demonstrating less behavioral distress during the procedure. The level of hypnotizability was significantly associated with the magnitude of treatment benefit, and this benefit was maintained when patients used hypnosis independently. PMID:16719602

  13. Trichoderma volatiles effecting Arabidopsis

    DEFF Research Database (Denmark)

    Ramadan, Metwaly; Gigolashvili, Tamara; Grosskinsky, Dominik Kilian;

    2015-01-01

    Trichoderma species are present in many ecosystems and some strains have the ability to reduce the severity of plant diseases by activating various defense pathways via specific biologically active signaling molecules. Hence we investigated the effects of low molecular weight volatile compounds...... of Trichoderma asperellum IsmT5 on Arabidopsis thaliana. During co-cultivation of T. asperellum IsmT5 without physical contact to A. thaliana we observed smaller but vital and robust plants. The exposed plants exhibit increased trichome numbers, accumulation of defense-related compounds such as H2O2, anthocyanin......, camalexin, and increased expression of defense-related genes. We conclude that A. thaliana perceives the Trichoderma volatiles as stress compounds and subsequently initiates multilayered adaptations including activation of signaling cascades to withstand this environmental influence. The prominent headspace...

  14. Stochastic Volatility Demand Systems

    OpenAIRE

    Apostolos Serletis; Maksim Isakin

    2014-01-01

    We address the estimation of stochastic volatility demand systems. In particular, we relax the homoscedasticity assumption and instead assume that the covariance matrix of the errors of demand systems is time-varying. Since most economic and fiÂ…nancial time series are nonlinear, we achieve superior modeling using parametric nonlinear demand systems in which the unconditional variance is constant but the conditional variance, like the conditional mean, is also a random variable depending on c...

  15. Inflation, volatility and growth

    OpenAIRE

    Ruth Judson; Athanasios Orphanides

    1996-01-01

    This paper re-examines the relationship between inflation, inflation volatility and growth using cross-country panel data for the past 30 years. With regard to the level of inflation, we find that in contrast to current findings which are based on cross-sectional time-average regression comparisons, exploiting the time dimension of the data reveals a strong negative correlation between inflation and income growth for all but very low inflation countries. To examine the role of inflation uncer...

  16. Volatility and Financial Intermediation

    OpenAIRE

    Joshua Aizenman; Andrew Powell

    1997-01-01

    Following the Tequila period, its after-effects in Latin America and recent events in South East Asia, the effect of volatility on emerging market economies has become an important topic of research with the domestic financial intermediation process being advanced as one of the most important transmission mechanisms. At the same time there has been continued interest in issues related to imperfect information and rationing in credit markets. In this paper, we consider an economy where risk ne...

  17. Different distribution of fluorinated anesthetics and nonanesthetics in model membrane: a 19F NMR study.

    OpenAIRE

    P. Tang; Yan, B.; Xu, Y

    1997-01-01

    Despite their structural resemblance, a pair of cyclic halogenated compounds, 1-chloro-1,2,2-trifluorocyclobutane (F3) and 1,2-dichlorohexafluorocyclobutane (F6), exhibit completely different anesthetic properties. Whereas the former is a potent general anesthetic, the latter produces no anesthesia. Two linear compounds, isoflurane and 2,3-dichlorooctofluorobutane (F8), although not a structural pair, also show the same anesthetic discrepancy. Using 19F nuclear magnetic spectroscopy, we inves...

  18. COMPARISON OF COMMON CLINICALLY USED LOCAL ANESTHETICS ON ANIMAL MODELS

    Directory of Open Access Journals (Sweden)

    Anthireddy Srinivas

    2012-08-01

    Full Text Available The animal models used in this study were Plexus anesthesia in frogs, Infiltration anesthesia in guinea pigs, Surface anesthesia in rabbits. The drugs were diluted with normal saline. Lignocaine2%: xylocaine hydrochloride injection IP, Bupivacaine 0.5%: Bupivacaine hydrochloride injections IP were prepared. Plexus anesthesia: Frog was pithed and spinal cord was destroyed up to the 3 vertebra. The abdominal pouch was filled with local anesthetic solution. Reflex activity was tested by immersing both feet of the frog every two minutes for not longer than 10 seconds into N/10 Hydrochloric acid. The time was noted. Surface anesthesia: Albino rabbits of either sex weighing 2.5 – 3.0kg ware selected. The conjunctival sac of one eye was held open, thus formed a pouch. 0.5ml of solution of the anesthetic was applied into the conjunctival sac for 30 sec. Infiltration anesthesia: Preparation of guinea pig: Guinea pigs (either sex weighing 250-300grams were used. Lignocaine produced rapid onset of plexus anesthesia in Frogs in comparison to the bupivacaine at concentration of 0.1% & 0.2% which is statistically significant. Bupivacaine is more potent than the lignocaine as a surface anesthetic agent in the Rabbit, where as lignocaine could produce surface anesthesia at concentration of 0.5% or 0.1% or both. Both bupivacaine and lignocaine produced infiltration anesthesia on intradermal injection in guinea pigs but the duration of infiltration anesthesia produced by bupivacaine is more prolonged which is statistically significant in comparison to the lignocaine at all the three concentrations tested i.e. 0.05%, 0.1% & 0.2%.

  19. Clinical features of pheochromocytoma and perioperative anesthetic management

    Institute of Scientific and Technical Information of China (English)

    罗爱伦; 郭向阳; 易杰; 任洪智; 黄宇光; 叶铁虎

    2003-01-01

    Objective To investigate clinical features of pheochromocytoma and summarize experiences of anesthetic management during the perioperative period. Methods Two hundred and fifty eight patients who were diagnosed with pheochromocytoma in our hospital were reviewed retrospectively for clinical features. According to different preoperative pharmalogical preparations, perioperative mortalities were analyzed in three periods (Period 1: January 1955-December 1975; Period 2: January 1976-December 1994; Period 3: January 1995-July 2001). In Period 3, hemodynamic changes in the patients undergoing different anesthetic methods were analyzed. Results About 5.8% (15/258) of pheochromocytoma was an integral part of multiple endocrine neoplasia (MEN) type Ⅱ or mixed type. Sixty percent (149/249) of the patients who had undergone surgery possessed evidence of catecholamine cardiac toxicity preoperatively. Impaired glucose tolerance was found in 59% (147/249) of the patients before surgery. Perioperative mortality was significantly decreased from 8% (5/60) in Period 1 to 1.2% (1/75) in Period 2 (P<0.01). No perioperative deaths occurred in Period 3. The volume infused during the operation was significantly higher both in the epidural anesthesia group (3474 ml±624 ml, P<0.01) and in the epidural plus general anesthesia group (3654 ml±475 ml, P<0.01) than in the general anesthesia group (2534 ml±512 ml). There were favorable hemodynamic characteristics in patients before removal of the tumor in the epidural anesthesia group and in the epidural plus general anesthesia group, as compared with the general anesthesia group. Conclusions A positive surgical outcome of the excision of pheochromocytoma depends on multiple factors, including careful assessment of potential vital organ damage before surgery and restoration of blood volume by establishing α-blockade preoperatively, meticulous anesthetic management of patients during surgery, and appropriate circulatory support after

  20. Update on administration of anesthetics and psychoactive drugs for pain management in China.

    Science.gov (United States)

    Gu, Weiping

    2015-06-01

    Anesthetics and psychoactive drugs could relieve diseases, if used properly. However, they can cause dependency, and their misuse or abuse could adversely affect people's health and social stability. For a long time, the Chinese government has been reinforcing the regulation on anesthetics and psychoactive drugs to ensure their legal and proper usage, and to prevent abuse. The state council issued 'the regulations on the administration of anesthetic drugs and psychotropic drugs' in 2005, based on which a legal system was established for administration of anesthetics and psychoactive drugs with the objectives of ensuring their legitimate medical utilization, and preventing illegal abuse.

  1. 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...... and transporting anesthetized pigs and reduces the risk of injury to personnel....

  2. Effects of Anesthetic Management on Early Postoperative Recovery, Hemodynamics and Pain After Supratentorial Craniotomy.

    Science.gov (United States)

    Ayrian, Eugenia; Kaye, Alan David; Varner, Chelsia L; Guerra, Carolina; Vadivelu, Nalini; Urman, Richard D; Zelman, Vladimir; Lumb, Philip D; Rosa, Giovanni; Bilotta, Federico

    2015-10-01

    Various clinical trials have assessed how intraoperative anesthetics can affect early recovery, hemodynamics and nociception after supratentorial craniotomy. Whether or not the difference in recovery pattern differs in a meaningful way with anesthetic choice is controversial. This review examines and compares different anesthetics with respect to wake-up time, hemodynamics, respiration, cognitive recovery, pain, nausea and vomiting, and shivering. When comparing inhalational anesthetics to intravenous anesthetics, either regimen produces similar recovery results. Newer shorter acting agents accelerate the process of emergence and extubation. A balanced inhalational/intravenous anesthetic could be desirable for patients with normal intracranial pressure, while total intravenous anesthesia could be beneficial for patients with elevated intracranial pressure. Comparison of inhalational anesthetics shows all appropriate for rapid emergence, decreasing time to extubation, and cognitive recovery. Comparison of opioids demonstrates similar awakening and extubation time if the infusion of longer acting opioids was ended at the appropriate time. Administration of local anesthetics into the skin, and addition of corticosteroids, NSAIDs, COX-2 inhibitors, and PCA therapy postoperatively provided superior analgesia. It is also important to emphasize the possibility of long-term effects of anesthetics on cognitive function. More research is warranted to develop best practices strategies for the future that are evidence-based. PMID:26345202

  3. The anesthetic management in the patient with Kabuki makeup syndrome

    Directory of Open Access Journals (Sweden)

    İsmail Aydın Erden

    2013-03-01

    Full Text Available Kabuki makeup syndrome is characterized by mentalretardation, characteristic facial appearance (ektropion,skeletal abnormalities, joint laxity, short stature. The syndromeis thought to be a consequence of otosomal dominantmutation. Important factors in anesthetical managementof these patients include; difficult airway, cardiologicproblems, obstructive sleeps apne, hypotoni and malignshyperthermia risks. In this case report we aimed to discussanesthesic management of a patient with Kabukisyndrome -a rare clinical entity in our country- . J Clin ExpInvest 2013; 4 (1: 116-118Key words: kabuki makeup, tympanoplasty, general anesthesia

  4. Anesthetic considerations for adults undergoing fontan conversion surgery.

    Science.gov (United States)

    Mossad, Emad B; Motta, Pablo; Vener, David F

    2013-06-01

    There are currently in North America more adults with congenital heart disease than children. This article discusses the anesthetic considerations in adults with single-ventricle physiology and prior repairs who present for Fontan conversion surgery as a demonstration of the challenges of caring for adults undergoing interventions for the repair of congenital heart defects. The care of these patients requires an understanding of the impact of passive pulmonary blood flow and single systemic ventricular physiology. The perioperative morbidity in this patient population remains high. PMID:23711650

  5. A literature review on anesthetic practice for carotid endarterectomy surgery based on cost, hemodynamic stability, and neurologic status.

    Science.gov (United States)

    Meitzner, Mark C; Skurnowicz, Julie A; Mitchell, Anne

    2007-06-01

    An extensive literature review was undertaken to evaluate the best anesthetic practice for carotid endarterectomy surgery. Two anesthetic techniques were evaluated: general anesthetic with an endotracheal tube and regional anesthetic block. Three variables were reviewed with respect to significant clinical outcomes based on anesthetic technique. Relevant literature was obtained through multiple sources that included professional journals, a professional website, and textbooks. According to the literature, there is an advantage to performing regional anesthesia with respect to cost and neurologic status. Information analyzed was inconclusive with respect to hemodynamic stability and anesthetic technique. We conclude that regional anesthesia may have some slight advantages; however, more investigation is warranted. PMID:17591300

  6. Use of eutectic mixture of local anesthetics in children.

    Science.gov (United States)

    Dutta, S

    1999-01-01

    The Eutectic Mixture of Local Anesthetics (EMLA) is a topical application, which has proved to be a useful medication for providing pain relief among children. It is an emulsion containing a 1:1 mixture of lidocaine and prilocaine. The high concentration of the uncharged anesthetic base in the microdroplets of the emulsion ensure effective skin penetration. In the pediatric population EMLA has been shown to be efficacious when it is used prior to venipuncture, cannulation, lumbar puncture, laser treatment of port wine stains, curettage of molluscum contagiosum or vaccination. For several of these indications, the efficacy has been documented by double blind controlled trials, that have used objective and quasi-objective scales for assessing pain relief. The dose of EMLA is between 0.5 to 1 gram, and the cream should be applied half to one hour prior to the procedure. Local side effects are very mild, and the only systemic side effect of importance is the risk of methemoglobinemia in young infants. The literature has conflicting reports about the safety of EMLA in neonates.

  7. 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.

  8. 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.

  9. Intraoperative magnetic resonance imaging for neurosurgical procedures: anesthetic implications.

    Science.gov (United States)

    Henrichs, Bernadette; Walsh, Robert P

    2011-02-01

    Intraoperative magnetic resonance imaging (IMRI) for tumor resection allows a neurosurgeon to pinpoint the exact location of the tumor before resection and to navigate to the tumor after the incision is made. Although the anesthetic management is not substantially different from that for other neurosurgical procedures, strategies to keep the patient and operating room personnel safe can be challenging. Because of the risk of injury by the strong force of the magnet, safety precautions with respect to anesthetic delivery must be taken. Ferrous objects must be removed and kept outside the operating room. Only MRI-compatible equipment is allowed in the MRI operating room. This includes the anesthesia machine, anesthesia cart, intubating equipment, monitors, stethoscopes, poles for intravenous solutions, and body warmers. Surgical equipment and instruments must be MRI-compatible. Absolute contraindications to entering the MRI suite include pacemakers, cochlear implants, certain cranial aneurysm clips, and metal joints or implants. Goals of anesthesia delivery during IMRI procedures include the following: (1) promoting the safety of patients and staff, (2) preventing MRI-associated accidents, (3) identifying potential equipment-related hazards, (4) recognizing limitations of physiologic monitoring, and (5) acknowledging other potential hazards such as noise. PMID:21473229

  10. Financial Market Volatility: A Survey

    OpenAIRE

    Louis O. Scott

    1991-01-01

    Volatility in financial markets has forced economists to re-examine the validity of the efficient markets hypothesis, and new empirical approaches have been applied to the study of this important issue in recent years. Many of the recent studies have found evidence of excessive volatility. In the aftermath of the stock market crash of 1987 and the perceived increase in market volatility, some economists have advocated additional market regulations. This paper presents a review of recent studi...

  11. Modeling and forecasting implied volatility

    OpenAIRE

    Ahoniemi, Katja

    2009-01-01

    This dissertation contains four essays, all of which model time series of implied volatility (IV) and assess the forecast performance of the models. The overall finding is that implied volatility is indeed forecastable, and its modeling can benefit from a new class of time series models, so-called multiplicative error models. It is often beneficial to model IV with two (or more) regimes to allow for periods of relative stability and periods of higher volatility in markets. The first essa...

  12. Path-conditional forward volatility

    OpenAIRE

    Carey, Alexander

    2006-01-01

    In derivatives modelling, it has often been necessary to make assumptions about the volatility of the underlying variable over the life of the contract. This can involve specifying an exact trajectory, as in the Black and Scholes (1973), Merton (1973) or Black (1976) models; one that depends on the level of the underlying variable as in the local volatility models of Dupire (1994), Derman and Kani (1994) and Rubinstein (1994); or fixing the parameters of a more general stochastic volatility p...

  13. Volatility, Investment and Disappointment Aversion

    OpenAIRE

    Joshua Aizenman; Nancy Marion

    1995-01-01

    This study uncovers a statistically significant negative correlation between volatility and private investment over the 1970-93 period in a set of almost fifty developing countries and provides a possible interpretation of this result by using the disappointment- aversion expected utility framework first described by Gul (1991). We consider a number of different volatility measures related to domestic policies or to external factors. As the various volatility measures tend to be positively co...

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

    NARCIS (Netherlands)

    H.P. Boswijk

    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 t

  15. 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....

  16. Bilateral Fetal Hydrothorax Requiring Intrauterine Fetal Thoracoamniotic Shunts: Anesthetic Considerations and Management

    OpenAIRE

    Hache, John J.; Emery, Stephen P.; Vallejo, Manuel C.

    2009-01-01

    After prenatal diagnosis of bilateral fetal hydrothorax, ascites, and polyhydramnios, bilateral thoracoamniotic shunts were placed at 29 weeks gestation using an ultrasound-guided, minimally invasive technique. Anesthetic care was managed using intravenous sedation and local anesthesia infiltration. The anesthetic considerations for such procedures are discussed.

  17. Bilateral Fetal Hydrothorax Requiring Intrauterine Fetal Thoracoamniotic Shunts: Anesthetic Considerations and Management

    Directory of Open Access Journals (Sweden)

    John J. Hache

    2009-01-01

    Full Text Available After prenatal diagnosis of bilateral fetal hydrothorax, ascites, and polyhydramnios, bilateral thoracoamniotic shunts were placed at 29 weeks gestation using an ultrasound-guided, minimally invasive technique. Anesthetic care was managed using intravenous sedation and local anesthesia infiltration. The anesthetic considerations for such procedures are discussed.

  18. The local anesthetic tetracaine destabilizes membrane structure by interaction with polar headgroups of phospholipids.

    Science.gov (United States)

    Shimooka, T; Shibata, A; Terada, H

    1992-03-01

    The effect of the local anesthetic tetracaine at less than 10 mM on the water permeability of the phospholipid membrane was examined using liposomes composed of various molar ratios of negatively charged cardiolipin to electrically neutral phosphatidylcholine by monitoring their osmotic shrinkage in hypertonic glucose solution at 30 degrees C. The concentration of tetracaine causing the maximum velocity of shrinkage of liposomes increased with increase in the molar ratio of cardiolipin. Tetracaine increased the zeta-potential of the negatively charged liposomal membrane toward the positive side due to the binding of its cationic form to the negatively charged polar headgroups in the membrane. The maximum velocity of water permeation induced by osmotic shock was observed at essentially the same tetracaine concentration giving a zeta-potential of the liposomal membrane of 0 mV. These concentrations were not affected by change in the sort of acyl-chain of phospholipids in the liposomes when their negative charges were the same. These results suggests that the membrane integrity is governed mainly by the electrical charge of phospholipid polar headgroups when phospholipid bilayers are in the highly fluid state, and that positively charged tetracaine molecules neutralize the negative surface charge, lowering the barrier for water permeation through phospholipid bilayers. PMID:1547263

  19. 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...... anesthetics (from 1995 through 2007), 292 reports to the Danish Medicines Agency, Copenhagen, Denmark, of adverse reactions to local anesthetic drugs, and a clinical sample of 115 patients with NSD associated with local anesthetics. The authors assessed lidocaine 2 percent, mepivacaine 2 percent and 3 percent...... of three of the four drugs in both national registry data and clinical data. These findings indicate that the main cause of injury was neurotoxicity resulting from administration of the local anesthetic rather than the needle penetration. CLINICAL IMPLICATIONS: Clinicians may consider avoiding use of high...

  20. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    2009-01-01

    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

  1. 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...

  2. Volatile organic compounds

    International Nuclear Information System (INIS)

    The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

  3. Jakartans, Institutionally Volatile

    Directory of Open Access Journals (Sweden)

    Masaaki OKAMOTO

    2014-01-01

    Full Text Available Jakarta recently has gained even more central political attention in Indonesia since Joko Widodo (Jokowi and Basuki Purnama (Ahok became, respectively, the province’s governor and vice-governor in 2012. They started a series of eye-catching and populist programmes, drawing popular support from not only the people of Jakarta, but also among Indonesians in general. Jokowi is now even the most popular candidate for the presidential election in 2014. Their rise is phenomenal in this sense, but it is understandable if we look at Jakartan voters’ behaviour and the institutional arrangement that leads to it. Jakarta, as the national capital, has a unique arrangement in that the province has no autonomous regency or city. This paper argues that this arrangement causes Jakartans to be more politically volatile and describes how this institutional arrangement was created by analysing the minutes of the meeting to discuss the laws concerning Jakarta Province.

  4. Anticholeretic effect of substance P in anesthetized dogs.

    Science.gov (United States)

    Holm, I; Thulin, L; Hellgren, M

    1978-03-01

    Nine anesthetized dogs were provided with acute common duct fistulas after exclusion of the gallbladder. Synthetic Substance P was administered as caval infusions in a dosage of 0.5-20 ng x kg-1 x min-1, duration 10 min. The output of hepatic bile, sodium and amylase decreased during infusion by 40-52 per cent at the highest doses. After termination of infusion all 3 parameters increased by 19-60 per cent above the basal level. The biliary concentration of sodium was constant, while that of amylase increased during infusion. The responses were dose-related. The anticholeresis induced by substance P might be due to inhibition of the canalicular bile fraction, which presumably is mediated by active sodium transport and independent of bile salt excretion.

  5. Eugenol as an anesthetic for juvenile common snook

    Directory of Open Access Journals (Sweden)

    Jurandir Joaquim Bernardes Júnior

    2013-08-01

    Full Text Available The objective of this work was to evaluate the efficacy of eugenol as an anesthetic for juvenile common snook, and to determine the minimum effective concentration for use in handling procedures. In the first trial, juvenile common snook were subjected to immersion baths at 25, 50, 75, 100, 125, and 150 mg L-1 eugenol concentrations, after which induction and recovery times were evaluated. In the second experiment, the lethal exposure time (LT50 at 75 mg L-1 was estimated. Minimum effective eugenol concentration was 50 mg L-1, andthe stage of deep anesthesia and recovery were, respectively, reached at 126.3 and 208.8 s. At 75 mg L-1, LT50 was 1,314 s, and induction time and recovery were also satisfactory; however, fish cannot tolerate over 229 s exposure.

  6. Anesthetic management of a child undergoing bilateral laparoscopic adrenalectomy

    Directory of Open Access Journals (Sweden)

    Mediha Turktan

    2016-03-01

    Full Text Available Pheochromocytoma is a rare catecholamine secreting neuroendocrine tumor in children. It is usually localized unilaterally in adults but often bilaterally in children. The symptoms are variable related to the level of secreted catecholamine. The most common symptoms are hypertension, tachycardia and headache. Beta blockers, alcohol consumption, injection of contrast substance and surgical procedures may lead to attacks. The most effective treatment is surgical resection. In recent years, laparoscopic surgery has been more preferred. Anesthetic management is very important in this cases. Especially, sudden hemodynamic changes may be observed during laparoscopic adrenalectomy. In our case, the control of hemodynamic changes with esmolol and norepinephrine infusion were discussed during bilaterally laparoscopic adrenalectomy in a 14-year old child with pheochromocytoma. [Cukurova Med J 2016; 41(1.000: 171-174

  7. Effect of anesthetic gas on middle ear fluid.

    Science.gov (United States)

    Tom, L W; Tsao, F; Marsh, R R; Kessler, A; Konkle, D F

    1994-07-01

    Tympanometry was performed before (preoperative) and after (intraoperative) the administration of inhalation anesthesia including nitrous oxide and halothane on 109 children undergoing myringotomy with pressure equalization tube insertion. A total of 213 preoperative tympanograms were compared with their intraoperative counterparts and the presence or absence of middle ear effusion at myringotomy. When preoperative tympanograms were consistent with pneumatized middle ears, intraoperative findings demonstrated a mean middle ear pressure increase of +147 daPa. When preoperative tympanometry suggested middle ear effusion, less than 1% demonstrated intraoperative tympanometric changes and/or findings at surgery that would support anesthesia clearing middle ear effusion. Preoperative tympanometric data were poor predictors of the presence or absence of effusion at myringotomy. The relationship between inhalation anesthetics (i.e., nitrous oxide and halothane) and middle ear fluids, and the reliability of tympanometry to predict middle ear effusion are discussed. PMID:8022245

  8. Neurotoxicity of general anesthetics: A modern view of the problem

    Directory of Open Access Journals (Sweden)

    A. M. Ovezov

    2015-01-01

    Full Text Available All general anesthetics routinely used in clinical practice are noted to have a neurotoxic effect on the brain in different animal species including primates. The negative effects observed both in young and sexually mature animals include apoptotic neuronal cell death, suppression of neurogenesis and gliogenesis, neuroinflammation, as well as learning and memory impairments. A number of epidemiologic surveys have established an association between anesthesia in patients younger than 3 to 4 years and subsequent learning disabilities and language disorders whereas others have not found this link. In middle-aged and elderly patients, anesthesia is frequently associated with the development of postoperative cognitive dysfunction. The key component of its pathogenesis (general anesthesia itself or other factors, such as operative injury, an inflammatory response, pain syndrome, intraoperative complications, underlying disease in a patient remains unelucidated. It is concluded that there is a need for additional experimental and clinical studies of the pathogenesis of these undesirable phenomena to be prevented and corrected.

  9. Anesthetic considerations for endovascular abdominal aortic aneurysm repair

    Directory of Open Access Journals (Sweden)

    Harikrishnan Kothandan

    2016-01-01

    Full Text Available Aneurysm is defined as a localized and permanent dilatation with an increase in normal diameter by more than 50%. It is more common in males and can affect up to 8% of elderly men. Smoking is the greatest risk factor for abdominal aortic aneurysm (AAA and other risk factors include hypertension, hyperlipidemia, family history of aneurysms, inflammatory vasculitis, and trauma. Endovascular Aneurysm Repair [EVAR] is a common procedure performed for AAA, because of its minimal invasiveness as compared with open surgical repair. Patients undergoing EVAR have a greater incidence of major co-morbidities and should undergo comprehensive preoperative assessment and optimization within the multidisciplinary settings. In majority of cases, EVAR is extremely well-tolerated. The aim of this article is to outline the Anesthetic considerations related to EVAR.

  10. Anesthetic considerations for endovascular abdominal aortic aneurysm repair

    Science.gov (United States)

    Kothandan, Harikrishnan; Haw Chieh, Geoffrey Liew; Khan, Shariq Ali; Karthekeyan, Ranjith Baskar; Sharad, Shah Shitalkumar

    2016-01-01

    Aneurysm is defined as a localized and permanent dilatation with an increase in normal diameter by more than 50%. It is more common in males and can affect up to 8% of elderly men. Smoking is the greatest risk factor for abdominal aortic aneurysm (AAA) and other risk factors include hypertension, hyperlipidemia, family history of aneurysms, inflammatory vasculitis, and trauma. Endovascular Aneurysm Repair [EVAR] is a common procedure performed for AAA, because of its minimal invasiveness as compared with open surgical repair. Patients undergoing EVAR have a greater incidence of major co-morbidities and should undergo comprehensive preoperative assessment and optimization within the multidisciplinary settings. In majority of cases, EVAR is extremely well-tolerated. The aim of this article is to outline the Anesthetic considerations related to EVAR. PMID:26750684

  11. Anesthetic management of robot-assisted thoracoscopic thymectomy.

    Science.gov (United States)

    Karlekar, Anil; Dutta, Devesh; Saxena, Ravindra; Sharma, Krishna Kant

    2016-01-01

    Myasthenia gravis (MG) is a rare disorder involving neuromuscular junction. In conjunction with medical therapy, thymectomy is a known modality of treatment of MG and has shown to increase the probability of remission and overall symptomatic improvement. For minimally invasive thymectomy, video-.assisted thoracoscopic surgery has been the preferred surgical approach till recently. The robotic surgical procedure must necessarily bring new challenges to the anesthesiologists to effectively meet the specific requirements of the technique. At present, there is a paucity of literature regarding the anesthetic concerns of robotic assisted thymectomy, patient in question specifically posed a challenge since different maneuvers and techniques had to be tried to obtain optimum surgical conditions with stable ventilatory and hemodynamic parameters. Concerns of patient positioning and hemodynamic monitoring have also been discussed. PMID:27625494

  12. The effects of anesthetic agents on oxidative stress

    Science.gov (United States)

    Yakan, Selvinaz; Düzgüner, Vesile

    2016-04-01

    Oxidative stress can be defined as the instability between antioxidant defense of the body and the production of free radical that causes peroxydation on the lipid layer. Free radicals are reactive oxygen species that are produced in the course of normal metabolisms of aerobe organisms and they may cause disorders in cell structure and organelles by interacting macromolecules, like lipid, protein, nucleic acids. Therefore, they may cause cardiovascular, immune system, liver, kidney illnesses and many other illnesses like cancer, aging, cataract, diabetes. It is known that many drugs used for the purpose of anesthetizing may cause lipid peroxidation in organism. For these reasons, determining the Oxidative stress index of anaesthetic stress chosen in the ones that are exposed to long term anaesthetic agents and anaesthesia appliccations, is so substantial.

  13. Cardiovascular effects of Adonis aestivalis in anesthetized sheep.

    Science.gov (United States)

    Maham, Masoud; Sarrafzadeh-Rezaei, Farshid

    2014-01-01

    Adonis aestivalis (summer pheasant-eye) is an annual plant with a crimson flower, distributed in southern Europe and Asia. The plant has large buttercup-like blossoms and soft, fern-like leaves. It blooms in spring and is often found as a weed in cereal fields. Like other Adonis spp., the plant produces cardiac glycosides. It is used in remedies for mild weakness of the heart, especially when accompanied by nervous complaints. Cardiovascular and toxic effects of a hydroalcoholic extract from the aerial parts of A. aestivalis were investigated in sheep and mice. Six male sheep were anesthetized with sodium pentobarbital and arterial blood pressure was measured with a transducer connected to the left femoral artery. Heart rate and electrocardiogram (ECG) were registered from lead base-apex ECG derivatives connected to a Powerlab recorder. Three successive equal doses (75 mg kg(-1)) of the hydroalcoholic extract of A. aestivalis intravenously administered to anesthetized sheep. Adonis aestivalis extract induced a significant bradycardia and hypotension in sheep. Various ECG abnormalities in sheep included sinus arrhythmia, shortened and depressed S-T interval, and absence of P wave and flattened or inverted T wave. In addition, ventricular arrhythmias, bradyarrhythmias, atrioventricular block, ventricular premature beats, ventricular tachycardia and ventricular fibrillation have also been observed. The acute intraperitoneal toxicity (LD50) of the extract in mice was 2150 mg kg(-1). In conclusion, bradycardia and ECG alterations induced by the extract could explain the justification of traditional use of the of Adonis aestivalis in treating cardiovascular insufficiency. PMID:25568718

  14. Inhibition of murine cardiomyocyte respiration by amine local anesthetics.

    Science.gov (United States)

    Aburawi, Elhadi H; Souid, Abdul-Kader

    2014-12-01

    The hydrophobic amino acyl amide-linked local anesthetics (e.g., lidocaine and bupivacaine) impose potent cardiac toxicity and direct mitochondrial dysfunction. To investigate these adverse events, an in vitro system was employed to measure their effects on O2 consumption (cellular respiration) by murine myocardium. Specimens were collected from the ventricular myocardium and immediately immersed in ice-cold Krebs-Henseleit buffer saturated with 95 % O2:5 % CO2. O2 concentration was determined as a function of time from the phosphorescence decay rates of Pd(II)-meso-tetra-(4-sulfonatophenyl)-tetrabenzoporphyrin. Myocardial O2 consumption was linear with time (zero-order kinetics); its rate (k, in μM O2 min(-1)), thus, was the negative of the slope of [O2] vs. time. Cyanide inhibited O2 consumption, confirming the oxidation occurred in the respiratory chain. Lidocaine and bupivacaine produced immediate and sustained inhibition of cellular respiration at plasma concentrations of the drugs (low micromolar range). Bupivacaine was twice as potent as lidocaine. The inhibition was dose-dependent, saturating at concentrations ≥30 μM. At saturating doses, lidocaine produced ~20 % inhibition and bupivacaine ~40 % inhibition. Cellular ATP was also decreased in the presence of 30 μM lidocaine or bupivacaine. The studied amines inhibited myocardial cellular respiration. This effect is consistent with their known adverse events on mitochondrial function. The described approach allows accurate assessments and comparisons of the toxic effects of local anesthetics on heart tissue bioenergetics. PMID:24254523

  15. Under Utilization of Local Anesthetics in Infant Lumbar Punctures

    Directory of Open Access Journals (Sweden)

    Gorchynski, Julie

    2008-01-01

    Full Text Available Background: Lumbar Puncture (LP is an invasive procedure frequently used to diagnose meningitis among the pediatric population. Neonates and infants have not routinely received local anesthesia prior to LP. Study Objective: To determine whether emergency medicine physicians and pediatricians use local analgesics on neonates and infants prior to performing an LP and to identify which local anesthetics, if any, were used. Methods: Prospective, cohort study of all infants, six months of age or less, that received an LP in the emergency department (ED or inpatient pediatric units for suspected meningitis during a period of year at a university tertiary care hospital. Results: A total sample population of 111 infants that received an LP within the study period. A control population of 42 adults received an LP. Only 40.4% (45/111 of the infants received local analgesia prior to LP: either 1% lidocaine, EMLA or a combination of the two. Infants were less likely to receive lidocaine or EMLA prior to LP compared to adult subjects (OR= 0.27; 95% CI0.12 to 0.62. No neonates that were less than one month of age received local procedural anesthesia by emergency medicine or pediatric physicians. ED physicians’ use of local anesthesia prior to LP increased with increasing age of the infant. The pediatricians in this study used local anesthesia prior to LP when the infant was at least five months of age. Discussion: The data objectively support recent literature regarding the under use or lack of use of analgesia prior to LP among neonates and infants. Local anesthetics should be used routinely without exception prior to performing an LP in the pediatric population.

  16. Anesthetic Activity of Alfaxalone Compared with Ketamine in Mice.

    Science.gov (United States)

    Siriarchavatana, Parkpoom; Ayers, Jessica D; Kendall, Lon V

    2016-01-01

    Alfaxalone encased in hydroxypropyl-β -cyclodextrin is a neuroactive steroid compound that has recently been approved in the United States for use as an anesthetic in dogs and cats. We evaluated the use of alfaxalone compared with ketamine, both alone and in combination with xylazine, for anesthesia of C57BL/6 mice. We assessed time to onset of anesthesia, duration of action, reflex responses, respiratory rate, and clinical signs. Alfaxalone (80 mg/kg IP) induced a light surgical plane of anesthesia in all mice, with a time to onset of 2.2 ± 0.2 min and duration of 57.1 ± 3.8 min, whereas ketamine (80 mg/kg IP) provided only sedative effects (time to onset, 5.4 ± 0.4 min; duration, 6.9 ± 0.8 min). Clinically, alfaxalone caused a spectrum of activities, including popcorn-like jumping movements after injection, intense scratching of the face, hyperresponsiveness to noise or touch, and marked limb jerking during recovery. Adding xylazine to the single-agent protocols achieved deep surgical anesthesia (duration: alfaxalone + xylazine, 80.3 ± 17.8 min; ketamine + xylazine, 37.4 ± 8.2 min) and ameliorated the adverse clinical signs. Our preliminary analysis suggests that, because of its side effects, alfaxalone alone is not a viable anesthetic option for mice. Although alfaxalone combined with xylazine appeared to be a more viable option, some mice still experienced mild adverse reactions, and the long duration of action might be problematic regarding the maintenance of body temperature and monitoring of recovery. Further studies evaluating different routes of administration and drug combinations are warranted. PMID:27423149

  17. Volatile phytochemicals as mosquito semiochemicals

    Science.gov (United States)

    Nyasembe, Vincent O.; Torto, Baldwyn

    2014-01-01

    Plant biochemical processes result in the release of an array of volatile chemical substances into the environment, some of which are known to play important plant fitness enhancing functions, such as attracting pollinators, thermal tolerance of photosynthesis, and defense against herbivores. Cunningly, phytophagous insects have evolved mechanisms to utilize these volatiles to their own advantage, either to colonize a suitable host for feeding, reproduction and oviposition or avoid an unsuitable one. The volatile compounds involved in plant–insect chemical interactions have been widely exploited in the management of agricultural pests. On the other hand, use of plant volatiles in the management of medically important insects is limited, mainly due to paucity of information on their role in disease vector–plant interactions. To date, a total of 29 plant volatile compounds from various chemical classes, including phenols, aldehydes, alcohols, ketones and terpenes, have been identified as mosquito semiochemicals. In this review, we present highlights of mosquito–plant interactions, the available evidence of nectar feeding, with particular emphasis on sources of plant attractants, methods of plant volatile collection and the candidate plant volatile compounds that attract mosquitoes to nectar sources. We also highlight the potential application of these phytochemical attractants in integrated mosquito management. PMID:25383131

  18. Interaction of local anesthetics with a peptide encompassing the IV/S4-S5 linker of the Na+ channel.

    Science.gov (United States)

    Fraceto, Leonardo F; Oyama, Sérgio; Nakaie, Clóvis R; Spisni, Alberto; de Paula, Eneida; Pertinhez, Thelma A

    2006-08-20

    The peptide pIV/S4-S5 encompasses the cytoplasmic linker between helices S4-S5 in domain IV of the voltage-gated Na+ channel, residues 1644-1664. The interaction of two local anesthetics (LA), lidocaine and benzocaine, with pIV/S4-S5 has been studied by DOSY, heteronuclear NMR 1H-15N-HSQC spectroscopy and computational methods. DOSY indicates that benzocaine, a neutral ester, exhibits stronger interaction with pIV/S4-S5 than lidocaine, a charged amine-amide. Weighted average chemical shifts, Deltadelta(1H-15N), show that benzocaine affects residues L1653, M1655 and S1656 while lidocaine slightly perturbs residues I1646, L1649 and A1659, L1660, near the N- and C-terminus, respectively. Computational methods confirmed the stability of the benzocaine binding and the existence of two binding sites for lidocaine. Even considering that the approach of studying the peptide in the presence of a co-solvent (TFE/H2O, 30%/70% v/v) has an inherently limited implication, our data strongly support the existence of multiple LA binding sites in the IV/S4-S5 linker, as suggested in the literature. In addition, we consider that LA can bind to the S4-S5 linker with diverse binding modes and strength since this linker is part of the receptor for the "inactivation gate particle". Conditions for devising new functional studies, aiming to better understand Na+ channel functionality as well as the various facets of LA pharmacological activity are proposed in this work.

  19. 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...

  20. 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.

  1. [Pediatric anesthetic during brain immaturity and neurodevelopment disorders].

    Science.gov (United States)

    Catré, Dora; Lopes, Maria Francelina; Cabrita, António Silvério; Silva Viana, Joaquim

    2014-01-01

    Introdução: Diversos estudos experimentais e clínicos sugerem que fármacos usados em anestesia pediátrica podem exercer efeitos indesejáveis sobre o sistema nervoso central imaturo. O objetivo desta revisão consistiu em avaliar os resultados e conclusões de estudos publicados na literatura sobre perturbações persistentes do neurodesenvolvimento após exposição a anestésicos de crianças em fase de imaturidade cerebral. Material e Métodos: Realizámos uma pesquisa bibliográfica em diversas bases de dados (PubMed, SciELO e Cochrane Library), utilizando os termos ‘Pediatric anesthesia OR Pediatric anesthetic OR Developing brain anesthetic OR Developing brain anesthesia AND behavior disorders’ e foram incluídos os estudos em humanos, referentes a efeitos persistentes no neurodesenvolvimento após exposição a anestésicos nos primeiros quatro anos de idade. Resultados: Dez estudos retrospetivos cumpriram os critérios de inclusão. Destes, sete sugerem alteração do neurodesenvolvimento por exposição de criança pequena à anestesia, por oposição aos resultados obtidos pelos restantes três. Discussão: Embora maioritariamente utilizem bases de dados amplas, os estudos encontrados são retrospetivos, variam nos grupos teste, incluem variáveis de confusão por vezes contornáveis e alguns apresentam incorreções na escolha da população teste e controlo que podem comprometer a fiabilidade dos resultados. Conclusão: As numerosas limitações dos poucos estudos clínicos disponíveis fazem com que a informação reportada ainda se considere insuficiente para mudar a prática clínica atual. No entanto, sendo indiscutível que se mantêm as recomendações para providenciar anestesia quando necessária, independentemente da idade, os alertas encontrados na literatura são preocupantes, existindo indicação para que sempre que possível sejam ponderadas alternativas que possam contribuir para diminuir os riscos da exposição anestésica.

  2. Inflation Volatility and Forecast Accuracy

    OpenAIRE

    Jamie Hall; Jarkko Jääskelä

    2009-01-01

    This paper examines the statistical properties of inflation in a sample of inflation-targeting and non-inflation-targeting countries. First, it analyses the time-varying volatility of a measure of the persistent component of inflation. Based on this measure, inflation-targeting countries (Australia, Canada, New Zealand, Sweden and the United Kingdom) have experienced a relatively more pronounced fall in the volatility of inflation than non-inflation-targeting countries (Austria, France, Germa...

  3. Stochastic volatility and stochastic leverage

    OpenAIRE

    Veraart, Almut; Veraart, Luitgard A. M.

    2009-01-01

    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 correlationparameter between the asset return and the stochastic volatility process. We provide a systematictreatment 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 analyticallytractable and allo...

  4. Volatility Smile and Delta Hedging

    OpenAIRE

    Stolbov, Anatoly

    2014-01-01

    The thesis describes and applies two parametric option pricing models which partially ease the well-known discrepancy between real world and Black-Scholes model. Stochastic volatility and jumps encompassed by Heston and SVJ models explain implied volatility smile and its heterogeneous term-structure. Both models are calibrated to market data observed for EURUSD currency options on January 23, 2015. While SVJ model provided a better fit for the market, especially for mid-term expiry smile curv...

  5. Binding Procurement

    Science.gov (United States)

    Rao, Gopalakrishna M.; Vaidyanathan, Hari

    2007-01-01

    This viewgraph presentation reviews the use of the binding procurement process in purchasing Aerospace Flight Battery Systems. NASA Engineering and Safety Center (NESC) requested NASA Aerospace Flight Battery Systems Working Group to develop a set of guideline requirements document for Binding Procurement Contracts.

  6. 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

    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...

  7. The Effects of Anesthetic Technique on Postoperative Opioid Consumption in Ankle Fracture Surgery

    DEFF Research Database (Denmark)

    Christensen, Kristian P; Møller, Ann M; Nielsen, Jesper Kjær;

    2015-01-01

    OBJECTIVES: To investigate the impact of common anesthetic techniques on postoperative opioid consumption in ankle fracture surgery. MATERIALS AND METHODS: We performed a retrospective cohort study on 622 patients with isolated ankle fractures undergoing primary reconstructive surgery. Patients...

  8. Determination of Anesthetic Effects of Some Medicinal Plants on Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792

    Directory of Open Access Journals (Sweden)

    Seçil METİN

    2015-04-01

    Full Text Available In this study, anesthetics effects of spearmint (Menta piperita oil and lavandula (Lavandula angustifolia oil as alternative to clove (Eugenia caryophylatta oil were evaluated on rainbow trout (Oncorhynchus mykiss. Fish were exposed to different concentrations of the essential oils (30, 40, 50, 100, 150 and 200 mg l-1 for induction of anesthesia. Results showed that induction time decreased with increasing of the concentration of the clove oil and spearmint oil. However, recovery time increased with increasing of the concentration of this anesthetics. 40 and 50 mg l-1 doses of clove oil and 200 mg l-1 of mint oil were showed similar anesthetic effect. Lavandula oil was showed sedative effects on rainbow trout. These findings suggested that spearmint oil is useful anesthetics for rainbow trout.

  9. Effects of Theophylline on Anesthetized Malignant Hyperthermia-Susceptible Pigs

    Directory of Open Access Journals (Sweden)

    Marko Fiege

    2011-01-01

    Full Text Available Background. Theophylline was shown to induce contracture development in porcine malignant hyperthermia (MH susceptible (MHS skeletal muscles in vitro. The purpose of the current study was to investigate the in vivo effects of theophylline in MHS and MH normal (MHN swine. Methods. MH-trigger-free general anesthesia was performed in MHS and MHN swine. Theophylline was administered intravenously in cumulative doses up to 93.5 mg⋅kg-1. The clinical occurrence of MH was defined by changes of central-venous pCO2, central-venous pH, and body core temperature. Results. Theophylline induced comparable clinical alterations in the anesthetized MHS and MHN swine, especially in regard to hemodynamic data. No pig developed hypermetabolism and/or MH according to defined criteria. All animals died with tachycardia followed by ventricular fibrillation. Conclusions. The cumulative theophylline doses used in this study were much higher than doses used therapeutically in humans, as demonstrated by measured blood concentrations. Theophylline is thus not a trigger of MH in genetically determined swine.

  10. Anesthetic Management of a Pediatric Patient With Wilsons Disease

    Science.gov (United States)

    Baykal, Mehmet; Karapolat, Sami

    2010-01-01

    Wilsons disease, characterized by cirrhosis, extrapyramidal symptoms and Kayser-Fleischer corneal rings, is a rare hereditary disease of human copper metabolism. Clinical findings in Wilsons disease are complex and neurological symptoms such as tremor, dysarthria, rigid dystonia, seizures, psychiatric disorders, acute liver failure, chronic hepatitis or cirrhosis may develop. A 4-year-old male patient was operated for traumatic depressed skull fracture and intracerebral hematoma. He was diagnosed with Wilsons disease at the age of 2.5 years and treated with zinc sulphate and D-penicillamine. General anesthesia was induced with propofol, fentanyl, atracurium, and maintained with isoflurane, and oxygen. No complications were encountered during the operation or in the postoperative period. We concluded that general anesthesia can successfully be given to Wilsons disease patients using an anesthetic agent, the metabolism of which is least affected by the liver disease, one that induces least hepatic toxicity. By close follow-up of patients clinically and biochemically, it is possible to reduce the complication rates to a minimum. Keywords Wilson's Disease; Craniocerebral trauma; Thoracic injuries; General anesthesia; Surgery PMID:21811529

  11. Central administration of nicotine suppresses tracheobronchial cough in anesthetized cats.

    Science.gov (United States)

    Poliacek, I; Rose, M J; Pitts, T E; Mortensen, A; Corrie, L W; Davenport, P W; Bolser, D C

    2015-02-01

    We tested the hypothesis that nicotine, which acts peripherally to promote coughing, might inhibit reflex cough at a central site. Nicotine was administered via the vertebral artery [intra-arterial (ia)] to the brain stem circulation and by microinjections into a restricted area of the caudal ventral respiratory column in 33 pentobarbital anesthetized, spontaneously breathing cats. The number of coughs induced by mechanical stimulation of the tracheobronchial airways; amplitudes of the diaphragm, abdominal muscle, and laryngeal muscles EMGs; and several temporal characteristics of cough were analyzed after administration of nicotine and compared with those during control and recovery period. (-)Nicotine (ia) reduced cough number, cough expiratory efforts, blood pressure, and heart rate in a dose-dependent manner. (-)Nicotine did not alter temporal characteristics of the cough motor pattern. Pretreatment with mecamylamine prevented the effect of (-)nicotine on blood pressure and heart rate, but did not block the antitussive action of this drug. (+)Nicotine was less potent than (-)nicotine for inhibition of cough. Microinjections of (-)nicotine into the caudal ventral respiratory column produced similar inhibitory effects on cough as administration of this isomer by the ia route. Mecamylamine microinjected in the region just before nicotine did not significantly reduce the cough suppressant effect of nicotine. Nicotinic acetylcholine receptors significantly modulate functions of brain stem and in particular caudal ventral respiratory column neurons involved in expression of the tracheobronchial cough reflex by a mecamylamine-insensitive mechanism. PMID:25477349

  12. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

  13. Anesthetic and surgical complications in 219 cases of myotonic dystrophy.

    Science.gov (United States)

    Mathieu, J; Allard, P; Gobeil, G; Girard, M; De Braekeleer, M; Bégin, P

    1997-12-01

    The objective of this study was to assess the frequency, type, and severity of perioperative complications after a first surgery under general anesthesia in patients with myotonic dystrophy (DM) and to measure the association with suspected risk factors. Numerous cases of perioperative complications in DM patients have been reported. Hazards have been associated with the use of thiopentone, suxamethonium, neostigmine, and halothane. A retrospective study of perioperative complications was conducted for 219 DM patients who had their first surgery under general anesthesia at the Chicoutimi Hospital. The overall frequency of complications was 8.2% (18 of 219). Most complications (16 of 18) were pulmonary, including five patients with acute ventilatory failure necessitating ventilatory support, four patients with atelectasis, and three patients with pneumonia. Using multivariate analysis, we found that the risk of perioperative pulmonary complications (PPC) was significantly higher after an upper abdominal surgery (odds ratio (OR), 24.4; 95% CI, 4.0 to 149.3) and for patients with a severe muscular disability, as assessed by the presence of proximal limb weakness (OR, 14.1; 95% CI, 1.5 to 134.4). The likelihood of PPC was not related to any specific anesthetic drug. Because of the increased risk of PPC, careful monitoring during the early postoperative period, protection of upper airways, chest physiotherapy, and incentive spirometry are mandatory in all symptomatic DM patients, particularly those with a severe muscular disability or those who have undergone an upper abdominal surgery.

  14. [Anesthetic management of a patient with Mulvihill-Smith syndrome].

    Science.gov (United States)

    Kuribayashi, Junya; Yamada, Tatsuya; Morisaki, Hiroshi; Takeda, Junzo

    2007-07-01

    Mulvihill-Smith syndrome is a rare disease that belongs to progeroid syndromes. This syndrome is characterized by a senile face with an underdeveloped lower half, short stature, microcephaly, multiple pigmented nevi, immunodeficiency, hearing loss, and high-pitched voice. We report anesthetic management of a 27-year-old woman, 138 cm and 27 kg, with this syndrome, who underwent removal of mandibular cyst, partial resection of tongue and keratoplasty. Anesthesia was induced with fentanyl, propofol and vecuronium. There was difficulty in maintaining adequate ventilation with a face mask for children, and we used a mask for infants. Her Cormack grade was rated 3 but her trachea could be intubated assisted by BURP procedure. Anesthesia was maintained with sevoflurane, nitrous oxide and oxygen supplemented with fentanyl. The changes of blood pressure during anesthesia were extraordinary, suggesting the presence of advanced arteriosclerosis. The postoperative course was uneventful, with stable hemodynamics, and the patient was discharged from the hospital on 9th postoperative day. Anesthesia for Mulvihill-Smith syndrome should be performed with caution for the potential risk of difficult airway and unstable hemodynamics. PMID:17633848

  15. Urotensin Ⅱ inhibits carotid sinus baroreflex in anesthetized male rats

    Institute of Scientific and Technical Information of China (English)

    Yu-ming WU; Hong-mei XUE; Lin XIAO; Rui-rong HE

    2007-01-01

    Aim: To study the effects of urotensin Ⅱ (UV) on the carotid sinus baroreflex (CSB). Methods: The functional curve of carotid sinus baroreflex was measured by recording changes in arterial pressure in anesthetized male rats with perfused isolated carotid sinus. Results: UⅡ at the concentration of 3 nmol/L had no effect on the CSB, while at the concentration of 30, 300 and 3000 nmol/L inhibited the CSB, shifting the functional curve of the baroreflex upward and to the right. There was a marked decrease in peak slope and reflex decrease in blood pressure. These effects of UⅡ were concentration-dependent. Pretreatment with verapamil (an antagonist of the L-type calcium channel, 10 μmol/L) partially eliminated the above effects of UⅡ (300 nmol/L) on the CSB. Pretreatment with BIM-23127 (3 μmol/L),an antagonist of human and rat UⅡ receptors, abolished the actions of UⅡ on the CSB. Pretreatment with, NG-nitro-L-arginine methyl ester (L-NAME) 100 μmol/L did not affect the inhibitory effects of UⅡ (300 nmol/L) on the CSB. Conclusion: These data suggest that UⅡ exerts an inhibitory action on the isolated CSB. Such an action of UV is predominantly mediated by the UⅡ receptors in vascular smooth muscles, resulting in the opening of L-type calcium channels.

  16. Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis).

    Science.gov (United States)

    Jensen, Bjarke; Elfwing, Magnus; Elsey, Ruth M; Wang, Tobias; Crossley, Dane A

    2016-01-01

    Coronary circulation of the heart evolved early within ectothermic vertebrates and became of vital importance to cardiac performance in some teleost fish, mammals and birds. In contrast, the role and function of the coronary circulation in ectothermic reptiles remains largely unknown. Here, we investigated the systemic and coronary arterial responses of five anesthetized juvenile American alligators (Alligator mississippiensis) to hypoxia, acetylcholine, adenosine, sodium nitroprusside, isoproterenol, and phenylephrine. We recorded electrocardiograms, monitored systemic blood pressure, blood flows in both aortae, and blood flow in a major coronary artery supplying most of the right ventricle. Coronary arterial blood flow was generally forward, but there was a brief retrograde flow during a ventricular contraction. Blood pressure was significantly changed in all conditions. Acetylcholine decreased coronary forward flow, but this response was confounded by the concomitant lowered work of the ventricles due to decreased heart rate and blood pressure. Coronary forward flow was poorly correlated with heart rate and mean arterial pressure across treatments. Overall changes in coronary forward flow, significant and not significant, were generally in the same direction as mean arterial pressure and ventricular power, approximated as the product of systemic cardiac output and mean arterial pressure. PMID:26436857

  17. Respiratory-related hypoglossal nerve activity: influence of anesthetics.

    Science.gov (United States)

    Hwang, J C; St John, W M; Bartlett, D

    1983-09-01

    In decerebrate, vagotomized, paralyzed, and ventilated cats, phrenic and respiratory-related hypoglossal discharges were evident at normocapnic normoxia or hyperoxia. Both increased progressively in hypercapnia or hypoxia. With increasing drive, onset of inspiratory hypoglossal activity began earlier relative to phrenic onset; an early expiratory hypoglossal burst was also observed. Following subanesthetic doses of chloralose, halothane, ketamine, or pentobarbital, hypoglossal activity was depressed much more than phrenic discharge. In moderate hypercapnia or hypoxia, phrenic activity increased more than hypoglossal, whereas, at high drive, the latter rose more sharply in some cats. Electromyograms of the diaphragm and genioglossus were recorded in intact awake cats to determine if their responses and those of decerebrates are comparable. Respiratory-related genioglossal discharge was evident in normocapnia. We conclude that anesthesia suppresses hypoglossal motor activities much more than those of the bulbospinal-phrenic system. Data for decerebrate cats and unanesthetized cats or humans provide no evidence of a differential distribution of chemoreceptor afferents on hypoglossal and bulbospinal-phrenic neurons, as suggested by results in anesthetized animals. PMID:6629915

  18. Hydrogen sulfide facilitates carotid sinus baroreflex in anesthetized rats

    Institute of Scientific and Technical Information of China (English)

    Lin XIAO; Yu-ming WU; Hao ZHANG; Yi-xian LIU; Rui-rong HE

    2006-01-01

    Aim:To study effects of hydrogen sulfide (H2S)on the carotid sinus baroreflex (CSB).Methods:The functional curve of the carotid sinus baroreflex was measured by recording changes in arterial pressure in anesthetized male rats with perfused carotid sinus.Results:H2S(derived from sodium hydrosulfide)at concentrations of 25,50,and 100 μmol/L facilitated the CSB,shifting the functional curve of the baroreflex downward and to the left.There was a marked increase in peak slope(PS)and reflex decrease in blood pressure(RD).Effects were concentration-dependent.Pretreatment with glibenclamide(20 μmol/L),a KATP channel blocker,abolished the above effects of H2S on CSB.Pretreatment with Bay K8644 (an agonist of calcium channels;500 nmol/L)eliminated the effect of H2S on CSB.An inhibitor of cystathionine γ-lyase(CSE),DL-propargylglycine(PPG;200 μmol/L),inhibited CSB in male rats and shifted the functional curve of the baroreflex upward and to the right.Conclusion:These data suggest that exogenous H2S exerts a facilitatory role on isolated CSB through opening KATP channels and further closing the calcium channels in vascular smooth muscle.Endogenous H2S may activate the activity of the CSB in vivo.

  19. Anesthetic Management of a Pediatric Patient with Arginase Deficiency

    Directory of Open Access Journals (Sweden)

    Abdulkadir Atım

    2011-09-01

    Full Text Available Arginase deficiency is an autosomal recessive disorder of the urea cycle in which a defect in conversion of arginine to urea and ornithine leads to hyperammonemia. Patients with urea cycle disorders may show increased protein catabolism due to inadequate intake of energy, protein and essential amino acids; infections, fever and surgery. A 12-year-old girl with arginase deficiency, ASA II who weighed 40 kg was scheduled for bilateral adductor, quadriceps and gastrocnemius tenotomies. She had mental retardation, spasticity and flexion posture of thelower limbs. Metabolic homeostasis was restored with appropriate diet. Successful anesthetic management allowed the patient to be discharged 48 hours after surgery. Increased levels of arginine and ammonia during or after surgery may lead to serious complications such as hypotension, cerebral edema, convulsions, hypothermia and spasticity. Thus special attention must be given to metabolic homeostasis and nutrition of the patients with arginase deficiency in the perioperative period. Primary goals should be to minimize stress levels by effective anxiolysis, provide an adequate amount of protein-free energy with proper fluid management and to obtain an effective preemptive and postoperative analgesia. In addition to a high level of knowledge, successful anesthesia requires professional communication among nursing staff, dietitians, pediatric metabolism specialist, surgeon and anesthesiologist.

  20. Extended duration local anesthetic agent in a rat paw model.

    Science.gov (United States)

    Ickowicz, D E; Golovanevski, L; Domb, A J; Weiniger, C F

    2014-07-01

    Encapsulated local anesthetics extend postoperative analgesic effect following site-directed nerve injection; potentially reducing postoperative complications. Our study aim was to investigate efficacy of our improved extended duration formulation - 15% bupivacaine in poly(DL-lactic acid co castor oil) 3:7 synthesized by ring opening polymerization. In vitro, around 70% of bupivacaine was released from the p(DLLA-CO) 3:7 after 10 days. A single injection of the optimal formulation of 15% bupivacaine-polymer or plain (0.5%) bupivacaine (control), was injected via a 22G needle beside the sciatic nerve of Sprague-Dawley rats under anesthesia; followed (in some animals) by a 1cm longitudinal incision through the skin and fascia of the paw area. Behavioral tests for sensory and motor block assessment were done using Hargreave's hot plate score, von Frey filaments and rearing count. The 15% bupivacaine formulation significantly prolonged sensory block duration up to at least 48 h. Following surgery, motor block was observed for 48 h following administration of bupivacaine-polymer formulation and rearing was reduced (returning to baseline after 48 h). No significant differences in mechanical nociceptive response were observed. The optimized bupivacaine-polymer formulation prolonged duration of local anesthesia effect in our animal model up to at least 48 h. PMID:24726301

  1. Anterior and posterior tibial anesthetic block in diabetic foot surgery.

    Directory of Open Access Journals (Sweden)

    José Julio Ojeda González

    2004-12-01

    Full Text Available Fundament: Diabetes Mellitus is a disease of high and increasing prevalence and its complications follow a parallel course. Its morbidity is derived from its own complications which are produced at a long or short term and peripheral vascular disease hihglights among them.Objective: to check the usefulness of the anterior and posterior blockade of the tibia for the surgery of the diabetic foot. Method: Prospective study carried out from January to December 2003 at the University Hospital ¨Dr. Gustavo Aldereguía Lima¨ to patients who are carriers of a diabetic foot and who were initially assisted at the service of Angiology and later at the service of Anesthesiology when the surgical procedures were decided. All the patients were applied an anterior and posterior blockade of the tibial nerve . The variables measured were: age, weight, height, surgical time, type of surgery, cardiac frequency medium arterial pressure, and classification of patients according to the American Association of Anesthesiology All the patients were applied a scale for assessing pain in three different moments.Result: There was a predominance of females . The blockade of the posterior tibial nerve with lidocaine 1 % in different points permitted the performance of the surgical techniques proposed. The anesthetic procedure was favorable, and economic since the patients did not requiere of the use of analgesic in the post operatory stage.

  2. Cortical control of hering-breuer reflexes in anesthetized rats

    Directory of Open Access Journals (Sweden)

    Aleksandrov VG

    2009-12-01

    Full Text Available Abstract It had been hypothesized that the regions of prefrontal cortex which are involved in respiratory control can modulate Hering-Breuer reflexes evoked by vagal input from pulmonary stretch receptors. In the present study, experiments were performed on urethane anesthetized spontaneously breathing Wistar rats. The expiratory-promoting reflex was evaluated from changes in expiratory time immediately after airway occlusion at the end of inspiration. The inspiratory-inhibitory reflex was estimated from changes in inspiratory time provoked by airway occlusion at the end of expiration. The results indicate that electrical microstimulation of the responsive sites within the insular cortex significantly weakened both expiratory-promoting and inspiratory-inhibitory reflex. Activation of the infralimbic cortex depressed expiratory-promoting reflex, but inspiratory-inhibitory reflex was enhanced. These results suggest that stimulation of the prefrontal cortex influences vagally mediated control of the respiratory phases timing and several regions of the prefrontal cortex modulate distinct sets of neurons in the network controlling inspiratory and expiratory phases of a breath cycle.

  3. 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.

  4. 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....

  5. 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....

  6. Precautionary practices for administering anesthetic gases: A survey of physician anesthesiologists, nurse anesthetists and anesthesiologist assistants.

    Science.gov (United States)

    Boiano, James M; Steege, Andrea L

    2016-10-01

    Scavenging systems and administrative and work practice controls for minimizing occupational exposure to waste anesthetic gases have been recommended for many years. Anesthetic gases and vapors that are released or leak out during medical procedures are considered waste anesthetic gases. To better understand the extent recommended practices are used, the NIOSH Health and Safety Practices Survey of Healthcare Workers was conducted in 2011 among members of professional practice organizations representing anesthesia care providers including physician anesthesiologists, nurse anesthetists, and anesthesiologist assistants. This national survey is the first to examine self-reported use of controls to minimize exposure to waste anesthetic gases among anesthesia care providers. The survey was completed by 1,783 nurse anesthetists, 1,104 physician anesthesiologists, and 100 anesthesiologist assistants who administered inhaled anesthetics in the seven days prior to the survey. Working in hospitals and outpatient surgical centers, respondents most often administered sevoflurane and, to a lesser extent desflurane and isoflurane, in combination with nitrous oxide. Use of scavenging systems was nearly universal, reported by 97% of respondents. However, adherence to other recommended practices was lacking to varying degrees and differed among those administering anesthetics to pediatric (P) or adult (A) patients. Examples of practices which increase exposure risk, expressed as percent of respondents, included: using high (fresh gas) flow anesthesia only (17% P, 6% A), starting anesthetic gas flow before delivery mask or airway mask was applied to patient (35% P; 14% A); not routinely checking anesthesia equipment for leaks (4% P, 5% A), and using a funnel-fill system to fill vaporizers (16%). Respondents also reported that facilities lacked safe handling procedures (19%) and hazard awareness training (18%). Adherence to precautionary work practices was generally highest among

  7. Anesthetic Management for Whole Lung Lavage in Patients with Pulmonary Alveolar Proteinosis.

    Science.gov (United States)

    Tan, Zihui; Tan, Keng Tiong Jerry; Poopalalingam, Ruban

    2016-04-15

    Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by the deposition of lipoproteinaceous materials in the bronchoalveolar tree. Whole lung lavage was introduced in the 1960s and remains a treatment of choice for PAP. The main anesthetic challenge of whole lung lavage is maintaining adequate oxygenation during the procedure. We describe 2 interesting patients with PAP, the anesthetic challenges faced during the lung lavage, and discuss the management strategies adopted in each case. PMID:26795910

  8. EFFECTIVENESS OF THE ANESTHETIC AQUI-S® 20E IN MARINE FINFISH AND ELASMOBRANCHS.

    Science.gov (United States)

    Silbernagel, Constance; Yochem, Pamela

    2016-04-01

    Immersion anesthetics are used in hatchery settings by veterinarians, field biologists, and laboratory researchers to aid in handling finfish for medical procedures, research purposes, and moderating perceived stress responses. The only Food and Drug Administration- (FDA) approved anesthetic for food fish, tricaine methanesulfonate, requires a 21-d withdrawal period prior to harvest. Ten percent eugenol (AQUI-S® 20E) has been gaining momentum for FDA approval because of its 0-d withdrawal time if fish are not of harvestable size within 72 h of exposure. We performed two trials to determine appropriate anesthetic doses for two cultured marine finfish: Atractoscion nobilis (white seabass, WSB) and Seriola lalandi (California yellowtail, YT). Fish were held in a treated water bath for 10 min or until opercular beat rate slowed to a rate of <2 beats/min. Based on these results, we conducted a field trial with wild Paralabrax maculatofasciatus (spotted bay bass), Paralabrax nebulifer (barred sand bass), Paralichthys californicus (California halibut), Triakis semifasciata (leopard shark), and Mustelus californicus (grey smooth-hound) at a single dosing regime, with animals held 5-10 min in anesthetic baths. Anesthetic dosing of 35-55 mg L(-1) provided relatively fast induction and good anesthetic maintenance in cultured and wild finfish. Anesthetic induction times were comparable among S. lalandi and A. nobilis at 35-mg L(-1) to 75-mg L(-1) doses, but recovery times were variable. Mortality rates of 20-90% were observed at higher doses (75 mg L(-1) and 100 mg L(-1), A. nobilis; 55 mg L(-1) and 75 mg L(-1), S. lalandi). The apparent increase in sensitivity of S. lalandi may have been associated with nutritional stress in the fish tested. There were no differences in time to anesthesia or recovery among wild finfish species tested at a single dose. Anesthetic induction, maintenance, and recovery were less predictable in the elasmobranch species tested and additional

  9. Blood biochemical changes in mice after administration of a mixture of three anesthetic agents.

    Science.gov (United States)

    Ochiai, Yuichiro; Iwano, Hidetomo; Sakamoto, Takako; Hirabayashi, Manabu; Kaneko, Eiji; Watanabe, Toshihiko; Yamashita, Kazuto; Yokota, Hiroshi

    2016-07-01

    Currently, from the viewpoint of animal welfare, anesthesia or analgesia is required during experimental procedures in animals that are likely to cause pain. A part of these anesthetics have been reported to influence a blood biochemical level. It is important for us to understand the effect of the anesthetic on blood biochemistry when we choose the anesthetic agent to be used in experiments. In this study, we examined the blood biochemical changes in mice after administration of a new mixture of three anesthetic agents -medetomidine / midazolam / butorphanol (MMB). We subcutaneously administered two dose combinations of MMB (0.45 / 6 / 7.5 and 0.9 / 12 / 15 mg/kg) in mice, followed by administration of atipamezole, for reversal of anesthetic effects, after 1 hr. Thereafter, blood biochemistry was assessed at 1, 4 and 24 hr after MMB administration. We observed that MMB administration caused a transient increase in blood sugar, inorganic phosphorus, potassium and creatine kinase levels. These, however, returned to the reference range 24 hr after MMB administration. In conclusion, MMB changes the levels of some blood biochemical parameters, but not to an extent that would threaten health. However, when using laboratory animals, this effect of MMB may influence the experimental results, depending on the experimental content. Hence, the choice of anesthetic agents used in laboratory animals should be based on detailed knowledge of their pharmacological effects. PMID:26902544

  10. 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.

  11. Q型烟粉虱化学感受蛋白CSP1与植物挥发物的结合特征%Binding Characterization of Chemosensory Protein CSP1 in the Bemisia tabaci Biotype Q with Plant Volatiles

    Institute of Scientific and Technical Information of China (English)

    吴帆; 张晓曼; 赵磊; 崔旭红; 李红亮; 罗晨

    2015-01-01

    α-蒎烯(KD值分别为26.47、39.43、54.01和83.46µmol∙L-1),且3-蒈烯具有较强的竞争结合能力,能在200µmol∙L-1时将1-NPN报告子相对荧光值竞争至约40%。【结论】Q型烟粉虱CSP1蛋白能与测试的多种寄主植物挥发物产生较为广谱的结合能力,尤其与对烟粉虱有趋避性的挥发物的结合更强,表明CSP1很有可能参与Q型烟粉虱对非寄主植物的趋避行为,这对揭示其入侵寄主选择行为生理机制具有重要意义。%[Objective]The objective of this study is to clone the ORF (open reading frame) of chemosensory protein 1 (CSP1) from Bemisia tabaci biotype Q, and characterize the binding profiles of CSP1 with some candidate plants volatiles.[Method] By means of full-length ORF primer, reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify the full-length ORF BtCSP1, which was then cloned into the pET-30a (+)/BL21 (DE3) prokaryotic expression vector after double enzyme digestion. The recombinant BtCSP1 protein was expressed and purified by the method of Ni2+-agroase affinity chromatograph. The protein concentration was measured with Bradford method. The competitive fluorescence assay was used to analyze the binding properties of BtCSP1 with general plant volatiles with different chemical structures. As a suitable fluorescence reporter in studies of insect GOBPs’ function in vivo, N-phenyl-1-naphthylamine (1-NPN) was used to titrate the BtCSP1 solution until the fluorescence emission peak at maximum wavelength of BtCSP1 completely quenched. Then all plant volatiles were added into BtCSP1-1-NPN complex, respectively. The dissociation constants K D data represented the affinity of BtCSP1 with ligands were calculated by the Scatchard equation. [Result] BtCSP1 protein was successfully expressed after induction of 1 mmol·L-1 of IPTG, then purified by Ni2+affinity column with gradient imidazole as washing solutions, finally dialyzed sufficiently using PBS buffer. The working

  12. 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...

  13. Anesthetic management in a patient with Kindler′s syndrome

    Directory of Open Access Journals (Sweden)

    Sohan Lal Solanki

    2011-01-01

    Full Text Available A 35-year-old male with pan-anterior urethral stricture was scheduled to undergo perineal urethrostomy. He was a known case of Kindler′s syndrome since infancy. He was having a history of blister formation, extensive poikiloderma and progressive cutaneous atrophy since childhood. He had a tendency of trauma-induced blisters with clear or hemorrhagic contents that healed with scarring. The fingers were sclerodermiform with dystrophic nails and inability to completely clench the fist. Airway examination revealed thyromental distance of 7 cm with limited neck extension, limited mouth opening and mallampatti class III with a fixed large tongue. He was reported as grade IV Cormack and Lehane laryngoscopic on previous anesthesia exposure. We described the anesthetic management of such case on guidelines for epidermolysis bullosa. In the operating room, an 18-G cannula was secured in the right upper limb using Coban TM Wrap. The T-piece of the cannula was than inserted into the slit and the tape was wrapped around the extremity. The ECG electrodes were placed on the limbs and fixed with Coban TM . Noninvasive blood pressure cuff was applied over the wrap after wrapping the arm with Webril® cotton. Oral fiberoptic tracheal intubation was done after lubricating the laryngoscope generously with a water-based lubricant with 7-mm endotracheal tube. Surgery proceeded without any complication. After reversing the residual neuromuscular block, trachea was extubated once the patient became awake. He was kept in the postanesthesia care unit for 2 hours and then shifted to urology ward.

  14. Capsaicin facilitates carotid sinus baroreceptor activity in anesthetized rats

    Institute of Scientific and Technical Information of China (English)

    HaoZHANG; Yi-xianLIU; Yu-mingWU; Ze-minWANG; Rui-rongHE

    2004-01-01

    AIM: To study the effect of capsaicin on carotid sinus baroreceptor activity (CBA). METHODS: The functional curve of carotid baroreceptor (FCCB) was constructed and the functional parameters of carotid sinus baroreceptor were measured by recording sinus nerve afferent discharge in anesthetized rats with perfused isolated carotid sinus. RESULTS: Low-concentration of capsaicin (0.2μmol/L) had no significant effect on CBA, while perfusion of the isolated carotid sinus with middle-concentration of capsaicin (1μmol/L) could shift FCCB to the left and upward,with peak slope (PS) increased from (2.47%±0.14%)/mmHg to (2.88%±0.10%)/mmHg (P<0.05) and peak integral value of carotid sinus nerve discharge (PIV) enhanced from 211%±5% to 238%±6% (P<0.01). The threshold pressure (TP) and saturation pressure (SP) were significantly decreased from 68.0±1.1 to 62.7±1.0mmHg (P<0.01) and from 171.0±1.6 to 165.0±0.6 mmHg (P<0.01). By perfusing with high-concentration of capsaicin (5μmol/L), FCCB was shifted to the left and upward further and the changes of the functional parameters such as PS, TP, and SP were concentration-dependent. Pretreatment with ruthenium red (100μmol/L), an antagonist of vanilloid receptor subtype 1 (VR1), blocked the effect of capsaicin on CBA. Preperfusion with glibenclamide(20μmol/L), a KATP channel blocker, could eliminate the effect of capsaicin on CBA. CONCLUSION: Capsaicin exerts a facilitatory role on the isolated carotid baroreceptor in a concentration-dependent manner. The facilitatory action of capsaicin may be attributed to the opening of KATP channels mediated by VR1.

  15. Capsaicin facilitates carotid sinus baroreceptor activity in anesthetized rats

    Institute of Scientific and Technical Information of China (English)

    Hao ZHANG; Yi-xian LIU; Yu-ming WU; Ze-min WANG; Rui-rong HE

    2004-01-01

    AIM: To study the effect of capsaicin on carotid sinus baroreceptor activity (CBA). METHODS: The functional curve of carotid baroreceptor (FCCB) was constructed and the functional parameters of carotid sinus baroreceptor were measured by recording sinus nerve afferent discharge in anesthetized rats with perfused isolated carotid sinus.RESULTS: Low-concentration of capsaicin (0.2 μmol/L) had no significant effect on CBA, while perfusion of the isolated carotid sinus with middle-concentration of capsaicin (1 μmol/L) could shift FCCB to the left and upward,with peak slope (PS) increased from (2.47 %±0.14 %)/mmHg to (2.88 %±0.10 %)/mmHg (P<0.05) and peak integral value of carotid sinus nerve discharge (PIV) enhanced from 211%±5 % to 238 %±6 % (P<0.01). The threshold pressure (TP) and saturation pressure (SP) were significantly decreased from 68.0±1.1 to 62.7±1.0mmHg (P<0.01) and from 171.0±1.6 to 165.0±0.6 mmHg (P<0.01). By perfusing with high-concentration of capsaicin (5 μmol/L), FCCB was shifted to the left and upward further and the changes of the functional parameters such as PS, TP, and SP were concentration-dependent. Pretreatment with ruthenium red (100 μmol/L), an antagonist of vanilloid receptor subtype 1 (VR1), blocked the effect of capsaicin on CBA. Preperfusion with glibenclamide(20 μmol/L), a KATp channel blocker, could eliminate the effect of capsaicin on CBA. CONCLUSION: Capsaicin exerts a facilitatory role on the isolated carotid baroreceptor in a concentration-dependent manner. The facilitatory action of capsaicin may be attributed to the opening of KATP channels mediated by VR1.

  16. Pain and efficacy of local anesthetics for central venous access

    Directory of Open Access Journals (Sweden)

    William C Culp Jr

    2008-11-01

    Full Text Available William C Culp Jr1, Mohammed Yousaf2, Benjamin Lowry1, Timothy C McCowan3, William C Culp21Division of Cardiothoracic Anesthesiology, Scott and White Hospital, The Texas A&M University College of Medicine, Temple, TX, USA; 2Division of Interventional Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; 3Department of Radiology, University of Mississippi Medical Center, Jackson, MS, USAPurpose: To compare pain during injection and efficacy of analgesia of local anesthetics during central venous line placement.Methods: Sixty-two patients were studied in a randomized, double-blinded prospective fashion. Patients received 1% lidocaine (L, buffered 1% lidocaine (LB, or 2% chloroprocaine (CP injected around the internal jugular vein for procedural analgesia for central venous access. Patients reported pain via a standard linear visual analog scale, with 0 representing no pain and 10 being the worst pain imaginable.Results: Overall patient perception of pain was better with CP and L than LB with mean scores of CP 2.4, L 2.6, LB 4.2. Pain with injection mean scores were CP 2.1, L 2.5, LB 3.2. Pain with catheter placement scores were CP 2.5, L 1.7, LB 3.4. Operator assessment of overall pain values were CP 1.9, L 2.2, LB 3.4. LB consistently scored the worst, though compared with CP, this only reached statistical significance in overall patient pain and pain at catheter insertion compared with L.Conclusion: Though chloroprocaine scored better than lidocaine in 3 of 4 parameters, this trend did not achieve statistical significance. Adding sodium bicarbonate to lidocaine isn’t justified in routine practice, nor is routine replacement of lidocaine with chloroprocaine.Keywords: local anesthesia, analgesia, central venous access, lidocaine, chloroprocaine

  17. Magnesium sulfate inhibits sufentanil-induced cough during anesthetic induction

    Science.gov (United States)

    An, Li-Jun; Gui, Bo; Su, Zhen; Zhang, Yang; Liu, Hai-Lin

    2015-01-01

    Sufentanil-induced cough is a common phenomenon during the induction of anesthesia. This double-blind, randomized, and placebo-controlled study was designed to investigate the effects of prophylactic magnesium sulfate (MgSO4) on the incidence and severity of sufentanil-induced cough. A total of 165 patients who were scheduled for elective surgery under general anesthesia were allocated into three groups (I, II, and III; n = 55 each) that were injected with either 50 ml of normal saline, 30 or 50 mg/kg of MgSO4 (diluted with normal saline into 50 ml). One minute following the injection, all patients were injected with 1.0 μg/kg of sufentanil within 5 s. The incidence and severity of cough were recorded 30 s after the sufentanil injection. The hemodynamic parameters and plasma magnesium concentration of the patients were also noted. Three patients dropped out the study due to an obvious burning sensation during the injection of 50 mg/kg of MgSO4. Although the injection of 50 mg/kg of MgSO4 increased the plasma magnesium level, the increase remained within the therapeutic range (2-4 mmol/L). The incidence of cough was much higher in group I than in groups II and III (47.1% vs. 16.4% and 7.6%, respectively, P < 0.05). Compared with group I, group III had the lowest incidence of mild cough and both groups II and III had lower incidence of moderate and severe cough (P < 0.05). There were no differences in the hemodynamic data at three timepoints among the three groups. In conclusion, sufentanil-induced cough may be suppressed effectively and safely by prophylactic use of 30 mg/kg of MgSO4 during anesthetic induction. PMID:26550339

  18. 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.

  19. Rhenium volatilization in waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai; Pierce, David A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Hrma, Pavel, E-mail: pavel.hrma@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland, WA 99352 (United States)

    2015-09-15

    Highlights: • Re did not volatilize from a HLW feed until 1000 °C. • Re began to volatilize from LAW feeds at ∼600 °C. • The vigorous foaming and generation of gases from salts enhanced Re evaporation in LAW feeds. • The HLW glass with less foaming and salts is a promising medium for Tc immobilization. - Abstract: We investigated volatilization of rhenium (Re), sulfur, cesium, and iodine during the course of conversion of high-level waste melter feed to glass and compared the results for Re volatilization with those in low-activity waste borosilicate glasses. Whereas Re did not volatilize from high-level waste feed heated at 5 K min{sup −1} until 1000 °C, it began to volatilize from low-activity waste borosilicate glass feeds at ∼600 °C, a temperature ∼200 °C below the onset temperature of evaporation from pure KReO{sub 4}. Below 800 °C, perrhenate evaporation in low-activity waste melter feeds was enhanced by vigorous foaming and generation of gases from molten salts as they reacted with the glass-forming constituents. At high temperatures, when the glass-forming phase was consolidated, perrhenates were transported to the top surface of glass melt in bubbles, typically together with sulfates and halides. Based on the results of this study (to be considered preliminary at this stage), the high-level waste glass with less foaming and salts appears a promising medium for technetium immobilization.

  20. Aid Volatility and Poverty Traps

    OpenAIRE

    Pierre-Richard Agénor; Joshua Aizenman

    2007-01-01

    This paper studies the impact of aid volatility in a two-period model where production may occur with either a traditional or a modern technology. Public spending is productive and "time to build" requires expenditure in both periods for the modern technology to be used. The possibility of a poverty trap induced by high aid volatility is first examined in a benchmark case where taxation is absent. The analysis is then extended to account for self insurance (taking the form of a first-period c...

  1. 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...

  2. Factors affecting the volatilization of volatile organic compounds from wastewater

    Directory of Open Access Journals (Sweden)

    Junya Intamanee

    2006-09-01

    Full Text Available This study aimed to understand the influence of the wind speed (U10cm, water depth (h and suspended solids (SS on mass transfer coefficient (KOLa of volatile organic compounds (VOCs volatilized from wastewater. The novelty of this work is not the method used to determine KOLa but rather the use of actual wastewater instead of pure water as previously reported. The influence of U10cm, h, and SS on KOLa was performed using a volatilization tank with the volume of 100-350 L. Methyl Ethyl Ketone (MEK was selected as a representative of VOCs investigated here in. The results revealed that the relationship between KOLa and the wind speeds falls into two regimes with a break at the wind speed of 2.4 m/s. At U10cm 2.4 m/s, KOLa increased more rapidly. The relationship between KOLa and U10cm was also linear but has a distinctly higher slope. For the KOLa dependency on water depth, the KOLa decreased significantly with increasing water depth up to a certain water depth after that the increase in water depth had small effect on KOLa. The suspended solids in wastewater also played an important role on KOLa. Increased SS resulted in a significant reduction of KOLa over the investigated range of SS. Finally, the comparison between KOLa obtained from wastewater and that of pure water revealed that KOLa from wastewater were much lower than that of pure water which was pronounced at high wind speed and at small water depth. This was due the presence of organic mass in wastewater which provided a barrier to mass transfer and reduced the degree of turbulence in the water body resulting in low volatilization rate and thus KOLa. From these results, the mass transfer model for predicting VOCs emission from wastewater should be developed based on the volatilization of VOCs from wastewater rather than that from pure water.

  3. 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.

  4. 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.

  5. Comparative effects of different anesthetic regimens on the oculocardiac reflex

    Directory of Open Access Journals (Sweden)

    MR Safavi

    2007-11-01

    Full Text Available Background: The oculocardiac reflex (OCR, which is most oftenencountered during strabismus surgery in children, may cause bradycardia,arrhythmias, and cardiac arrest following a variety of stimuli arising in ornear the eyeball. The main purpose of this study was to evaluate the effects ofvarious anesthetic regimens on modulation of the cardiovascular response of theOCR during strabismus surgery.Patients and Methods: Three hundred American Society of Anesthesia (ASAphysical status I-II patients, scheduled for elective strabismus surgery undergeneral anesthesia, randomly allocated in a double blind fashion to one of threeanesthetic regimens of group P ( propofol 2 mg/kg, alfentanil 0.02 mg/kg, andatracurium 0.5 mg/kg at induction , group K (ketamine racemate 2mg/kg,alfentanil 0.02 mg/kg, and atracurium 0.5 mg/kg at induction and group T(thiopental 5mg/kg, alfentanil 0.02 mg/kg, and atracurium 0.5 mg/kg atinduction. Mean arterial pressure (MAP and heart rate (HR were recorded justbefore and at 1, 15, 30, 45, and 60 min after induction. OCR was defined as a 20beats/min change in HR induced by traction compared with basal value.Results: Mean heart rate (± SD during the course of surgery in group Pwas significantly slower than in the K group (111.90 ± 1.10 vs. 116.7 ± 0.70respectively, P<0.05 .Mean HR changes (± SD in group K was significantlyhigher than in P group (11.2 ± 1.44 vs. 8.7 ± 1.50 respectively, P<0.05. Meanarterial pressure changes (± SD were significantly lower in group P than ingroup K or T patients (12.5 ± 1.13 vs. 19.3±0.80 or 18.9±0.91 respectively,P<0.05. Frequency of OCR was significantly lower in group K than group T or Ppatients (9% vs. 16% or 13% respectively, P<0.05.Conclusion: Induction of anesthesia with ketamine is associated withleast cardiovascular changes induced by OCR during strabismus surgery.

  6. Mechanisms for vasopressin effects on intraocular pressure in anesthetized rats

    Science.gov (United States)

    Balaban, C. D.; Palm, D. E.; Shikher, V.; Searles, R. V.; Keil, L. C.; Severs, W. B.

    1997-01-01

    Continuous intracameral infusions of a balanced salt solution (0.175 microliter min-1) have been reported to raise intraocular pressure (IOP) in anesthetized rats. Palm et al. (1995) previously reported that this effect was attenuated significantly by inclusion of arginine-vasopressin (AVP, 10 ng 0.175 microliter-1) in the infusate. This study used experimental and computer simulation methods to investigate factors underlying these changes in IOP. First, constant intracameral infusions of artificial cerebrospinal fluid (aCSF) at different fixed rates (0.049-0.35 microliter min-1) were used to estimate the outflow resistance. Secondly, IOP responses were measured during an 2 hr intracameral infusion of either aCSF or AVP that was the sum of a small constant component (0.05 microliter min-1) and a larger periodic component (0.25 microliter min-1, cycling for 4 min on, then 4 min off); the mean infusion rate was 0.175 microliter min-1. As shown previously for 0.175 microliter min-1 constant infusions, the periodic aCSF infusion induced a significant rise in IOP that was attenuated by AVP administration. Complex demodulation analysis and the estimated gain parameter of a second order transfer function fit to the periodic responses indicated that outflow resistance increased significantly during the infusions in both aCSF and AVP groups, but that the indices of resistance did not differ significantly between aCSF and AVP infused eyes. This finding implies that changes in outflow resistance do not explain the difference in IOP responses to intracameral aCSF and AVP. The two responses differed significantly, though, in damping factors, such that the aCSF responses were considerably more underdamped than the AVP responses. It is hypothesized that aCSF-induced increase in IOP reflects both (1) a small component reflecting increased outflow resistance and (2) a larger non-resistive component. Since the non-resistive component is insensitive to pretreatment with acetazolamide

  7. Modeling the Volatility in Global Fertilizer Prices

    NARCIS (Netherlands)

    P-Y. Chen (Ping-Yu); C-L. Chang (Chia-Lin); C-C. Chen (Chi-Chung); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe main purpose of this paper is to estimate the volatility in global fertilizer prices. The endogenous structural breakpoint unit root test and alternative volatility models, including the generalized autoregressive conditional heteroskedasticity (GARCH) model, Exponential GARCH (EGARC

  8. 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.

  9. 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.

  10. [Anesthetic circle system failure caused by a plastic film--a case report].

    Science.gov (United States)

    Hara, Naoki; Tanaka, Tomohiro; Minami, Toshiaki

    2006-02-01

    A 44-year-old woman, ASA I, with breast cancer was scheduled for mastectomy. The anesthetic induction was performed by inhalation of 5% sevoflurane and 66% nitrous oxide in oxygen. After the loss of eyelash reflex assisted ventilation was initiated. At this point, the capnograph indicated inspired carbon dioxide tension of 18mmHg. Anesthetic machine check was soon carried out again. A visual check of non-return valves detected a plastic film, 18 x 21mm large, caught in the expiratory valve. This plastic film impaired complete occlusion of the orifice for the expiratory gas flow. As a result, the patient was rebreathing carbon dioxide. After removing it, the wave form of the capnograph was normalized and end-tidal carbon dioxide tension decreased immediately from 45mmHg to 33mmHg. As we did not detect any foreign matters at the non-return valves on anesthetic machine check before use, the plastic film might have already existed in the disposable corrugated tube before use. The capnograph is a useful device for detecting anesthetic circle system failure in such a case. It is important that the patients' airway is separated from the anesthetic circle system through the use of a filter to prevent foreign matter from being inhaled. PMID:16491902

  11. Investigation of the transdermal transport of charged local anesthetics in the presence of triterpene saponin glycosides.

    Science.gov (United States)

    Pino, Christopher J; Scherer, Michael A; Shastri, V Prasad

    2014-04-01

    Percutaneous absorption and transdermal delivery of water-soluble drugs have proven to be challenging due to their low permeability through skin. Avicins which are triterpene saponin glycosides (TSGs) derived from the desert plant Acacia victoriae have not been investigated to date as chemical penetration enhancers due to their higher molecular weight (MW 2,000 Da). It was recently shown that avicins exhibit remarkable mobility across skin lipids in spite of their large size due to their unique chemical structure. In this study, the permeation of local anesthetics, lidocaine-HCl, prilocaine-HCl, and bupivacaine-HCL from aqueous vehicle, across full-thickness porcine skin was investigated in the presence of F094-a mixture of avicins. F094 was capable of enhancing the permeability of all three anesthetics from aqueous formulations at extremely low concentrations ranging from 0.1 to 1 % w/v. The enhancement, which ranged from 2- to 5-fold, was surprisingly independent of molecular weight of the anesthetics and showed clear correlation with aqueous phase solubility of the anesthetics. Since F094 was found to have no impact on the octanol/water partition coefficients of the anesthetics, this suggests that TSGs like avicins most likely impact the aqueous pathways (pericellular/pores within lipids) and as such represent an alternative means of enhancing the transdermal transport of charged drugs from water-based formulations. PMID:25786727

  12. History of T-cain: a local anesthetic developed and manufactured in Japan.

    Science.gov (United States)

    Tobe, Masaru; Saito, Shigeru

    2015-10-01

    In many anesthesia textbooks written in English, lidocaine, tetracaine, bupivacaine, ropivacaine, and chloroprocaine are listed as useful local anesthetics for spinal anesthesia. In contrast, T-cain is not included in these lists, even though it has been reported to be suitable for spinal anesthesia in Japan. T-cain was developed as a local anesthetic in the early 1940s by Teikoku Kagaku Sangyo Inc. in Itami, Japan, by replacing a methyl group on tetracaine (Pantocaine(®)) with an ethyl group. T-cain was clinically approved for topical use in Japan in November 1949, and a mixture of dibucaine and T-cain (Neo-Percamin S(®)) was approved for spinal use in May 1950. Simply because of a lack of foreign marketing strategy, T-cain has never attracted global attention as a local anesthetic. However, in Japan, T-cain has been used topically or intrathecally (as Neo-Percamin S(®)) for more than 60 years. Other than the side effects generally known for all local anesthetics, serious side effects have not been reported for T-cain. In fact, several articles have reported that T-cain decreases the neurotoxicity of dibucaine. In this historical review, the characteristics of T-cain and its rise to become a major spinal anesthetic in Japan are discussed. PMID:26302690

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

    Directory of Open Access Journals (Sweden)

    Lenise de Lima Silva

    2013-06-01

    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

  14. Space filling of β-cyclodextrin and β-cyclodextrin derivatives by volatile hydrophobic guests

    OpenAIRE

    Sophie Fourmentin; Anca Ciobanu; David Landy; Gerhard Wenz

    2013-01-01

    The inclusion of volatile derivatives of benzene and cyclohexane in β-cyclodextrin (β-CD), hydroxypropyl-β-CD, and hydrophilic β-CD-thioethers was investigated by static headspace gas chromatography (HS-GC) and molecular modelling. The obtained binding constants strongly increase with the amount of space filling of the CD cavity and the salt concentration. β-CD thioethers show a 3–10 times higher binding potential than native β-CD.

  15. 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...... (stock) volatilities are mainly influenced by bond (stock) effects. Global, regional, and local volatility effects are all important. The introduction of the euro is associated with a structural break....

  16. Stock Market Volatility and Corporate Investment

    OpenAIRE

    Zuliu Hu

    1995-01-01

    Despite concerns are often voiced on the so called “excess volatility” of the stock market, little is known about the implications of market volatility for the real economy. This paper examines whether the stock market volatility affects real fixed investment. The empirical evidence obtained from the US data shows that market volatility has independent effects on investment over and above that of stock returns. Volatility and its changes are negatively related to investment growth. To the ext...

  17. Can risk aversion explain stock price volatility?

    OpenAIRE

    Stephen F. LeRoy

    2013-01-01

    Why are the prices of stocks and other assets so volatile? Efficient capital markets theory implies that stock prices should be much less volatile than actually observed, reflecting an unrealistic assumption that investors are risk neutral. If instead investors are assumed to be risk averse, predicted volatility is higher. However, models that incorporate investor avoidance of risk can explain real-world stock price volatility only under levels of risk aversion that are unrealistically high. ...

  18. Asymmetric Volatility Risk : Evidence from Option Markets

    OpenAIRE

    Jackwerth, Jens; Vilkov, Gregory

    2013-01-01

    Using non-parametric methods to model the dependencies between risk-neutral distributions of the market index (S&P 500) and its expected volatility (VIX), we show how to extract the expected risk-neutral correlation between the index and its future expected volatility. Comparing the implied correlation to its realized counterpart reveals a significant risk premium priced into the index-volatility correlation, which can be interpreted as the compensation for the fear of rising volatility durin...

  19. Nonparametric methods for volatility density estimation

    NARCIS (Netherlands)

    B. van Es; P. Spreij; H. van Zanten

    2011-01-01

    Stochastic volatility modeling 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 discrete

  20. 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...... of funding liquidity constraints suggesting an economic channel for the effect....

  1. Ammonia volatilization from intensively managed dairy pastures.

    NARCIS (Netherlands)

    Bussink, D.W.

    1996-01-01

    The objectives of this thesis are (i) to quantify NH 3 volatilization from grassland, (ii) to gain understanding of the NH3 volatilization processes on grassland and (iii) to study measures how to reduce NH 3 volatilization from gra

  2. Laparoscopic colectomy in an adult with single ventricle physiology: Anesthetic implications and management

    Directory of Open Access Journals (Sweden)

    Kelly J Zach

    2015-01-01

    Full Text Available Increasing numbers of adult patients with complex congenital heart conditions are presenting for noncardiac surgery later in life. These disorders can present challenges for surgical and anesthesia providers. Specifically, single ventricle lesions offer anatomic and physiologic concerns during the perioperative period. Single ventricle physiology represents a delicate balance between systemic and pulmonary blood flow. Any alterations in blood flow through these systems can produce undesirable hemodynamic changes, especially during the perioperative period. We present a case of an adult patient with a single left ventricle who presented for laparoscopic total colectomy due to inflammatory bowel disease. His abnormal anatomy coupled with the hemodynamic disruptions caused by laparoscopy presented significant anesthetic challenges. We highlight the anesthetic concerns of single ventricle physiology, specifically pertaining to laparoscopic surgery. We provide recommendations for safely managing these patients perioperatively. With detailed preoperative evaluation and close hemodynamic monitoring during the perioperative period, these patients can experience successful surgical and anesthetic outcomes.

  3. On Beyond Lidocaine: Reconsidering Local Anesthetics in Tumescent Liposuction-A Critical Review.

    Science.gov (United States)

    Hsia, Henry C

    2016-02-01

    The use of tumescent solution in liposuction is now considered standard of care; however, much debate still exists regarding its ideal components, especially surrounding the inclusion of local anesthetics. This article reviews the discussion regarding the use of local anesthetics in tumescent liposuction and how it may evolve in the future. The need for local anesthetic additives in tumescent liposuction has been questioned, and the use of longer-acting agents discouraged; however, increasing number of reports in recent years have described the increasingly widespread use of tumescent anesthesia where a wetting solution is infiltrated to achieve anesthesia in an operative field for procedures other than liposuction. More high-level evidence, such as randomized controlled clinical trials, will be required; however, it should be possible to develop a useful standardized algorithm that can guide surgeons to optimize patient safety as well as patient experience. PMID:26808738

  4. Effects of a standardized anesthetic protocol on hematologic variables in healthy cats.

    Science.gov (United States)

    Dhumeaux, Marc P; Snead, Elisabeth C R; Epp, Tasha Y; Taylor, Susan M; Carr, Anthony P; Dickinson, Ryan M; Leis, Marina L

    2012-10-01

    This study evaluated the effects of an anesthetic protocol using intravenous ketamine and midazolam, and intramuscular buprenorphine on hematologic variables in cats. Twelve healthy adult cats had blood collected for a complete blood count before and after the induction of anesthesia. There were significant decreases in red blood cell counts, hemoglobin concentrations and hematocrits after the induction of anesthesia. On average, red blood cell counts and hematocrits decreased by 25%, and hemoglobin concentrations decreased by 24%. Based on hematocrit, 3/12 samples (25%) taken while the cats were anesthetized would have been interpreted as belonging to anemic patients while none of the cats would have been considered anemic before anesthesia. This study suggests that a complete blood count performed on blood taken under anesthesia with this anesthetic protocol should be interpreted cautiously in order to not make a false diagnosis of anemia. PMID:22577050

  5. Anesthetic Management of a Patient With Charcot-Marie-Tooth Disease.

    Science.gov (United States)

    Ohshita, Naohiro; Oka, Saeko; Tsuji, Kaname; Yoshida, Hiroaki; Morita, Shosuke; Momota, Yoshihiro; Tsutsumi, Yasuo M

    2016-01-01

    Charcot-Marie-Tooth disease (CMTD) is a hereditary peripheral neuropathy and is characterized by progressive muscle atrophy and motor-sensory disorders in all 4 limbs. Most reports have indicated that major challenges with general anesthetic administration in CMTD patients are the appropriate use of nondepolarizing muscle relaxants and preparation for malignant hyperthermia in neuromuscular disease. Moderate sedation may be associated with the same complications as those of general anesthesia, as well as dysfunction of the autonomic nervous system, reduced perioperative respiratory function, difficulty in positioning, and sensitivity to intravenous anesthetic agents. We decided to use intravenous sedation in a CMTD patient and administered midazolam initially and propofol continuously, with total doses of 1.5 mg and 300 mg, respectively. Anesthesia was completed in 3 hours and 30 minutes without adverse events. We suggest that dental anesthetic treatment with propofol and midazolam may be effective for patients with CMTD.

  6. Anesthetic Management of a Patient With Charcot-Marie-Tooth Disease.

    Science.gov (United States)

    Ohshita, Naohiro; Oka, Saeko; Tsuji, Kaname; Yoshida, Hiroaki; Morita, Shosuke; Momota, Yoshihiro; Tsutsumi, Yasuo M

    2016-01-01

    Charcot-Marie-Tooth disease (CMTD) is a hereditary peripheral neuropathy and is characterized by progressive muscle atrophy and motor-sensory disorders in all 4 limbs. Most reports have indicated that major challenges with general anesthetic administration in CMTD patients are the appropriate use of nondepolarizing muscle relaxants and preparation for malignant hyperthermia in neuromuscular disease. Moderate sedation may be associated with the same complications as those of general anesthesia, as well as dysfunction of the autonomic nervous system, reduced perioperative respiratory function, difficulty in positioning, and sensitivity to intravenous anesthetic agents. We decided to use intravenous sedation in a CMTD patient and administered midazolam initially and propofol continuously, with total doses of 1.5 mg and 300 mg, respectively. Anesthesia was completed in 3 hours and 30 minutes without adverse events. We suggest that dental anesthetic treatment with propofol and midazolam may be effective for patients with CMTD. PMID:27269665

  7. 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...

  8. Evaluation of Surface anesthetic action of Aqueous Extract of Piper Betel leaf On Rabbit Cornea

    Directory of Open Access Journals (Sweden)

    Dr.T.Jayasree

    2014-07-01

    Full Text Available Aim: Piper betel Linn. (Piperaceae commonly known as betel leaf and the habit of betel chewing is widely prevalent in most parts of India. It is claimed to have aphrodisiac, laxative, antimicrobial, mucolytic, antiinflammatory and euphoric properties and proven antimutagenic and anti-carcinogenic effect. It is commonly observed that chewing of betel leaf produces numbness in the mouth, suggesting a possible local anesthetic effect. This observation prompted us to take this study . The aim of the study was to evaluate the local anesthetic activity of betel leaf extract after autoclaving the extract of betel leaf. Materials and methods: Extract of plain betel leaf, was tested for surface anesthetic activity using rabbits. Aqueous extraction of Piper betel leaf (AEPBL done by Soxhelts apparatus .Twenty male Rabbit’s were taken and divided in to four groups each group contain 5 animals, Group I - Standard (2% xylocaine, Group II - Test 0.3% (AEPBL, Group III - Test 0.6 % (AEPBL,Group IV - Test 12 % (AEPBL was instilled in conjunctival sac of right eyes. Standard protocol was followed to elicit light reflex, corneal reflex and to measure pupillary size after instilling the test drugs in the eye. There was dose dependent increase in onset and duration of local anesthetic activity with 6% and 12% doses of alcoholic extract of Piper betel leaf. Results: Betel leaf showed significant surface anesthetic activity comparable to that of Xylocaine. Conclusion: As a surface anesthetic, the onset was as quick as xylocaine and the duration was shorter than xylocaine

  9. 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

  10. Forecast performance of implied volatility and the impact of the volatility risk premium

    OpenAIRE

    Ralf Becker; Adam Clements; Christopher Coleman-Fenn

    2009-01-01

    Forecasting volatility has received a great deal of research attention, with the relative performance of econometric models based on time-series data and option implied volatility forecasts often being considered. While many studies find that implied volatility is the preferred approach, a number of issues remain unresolved. Implied volatilities are risk-neutral forecasts of spot volatility, whereas time-series models are estimated on risk-adjusted or real world data of the underlying. Recent...

  11. 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...... develop a new class of affine discrete-time option valuation models that use daily returns as well as realized volatility. We derive convenient closed-form option valuation formulas, and we assess the option valuation properties using Standard & Poor’s (S&P) 500 return and option data. We find...... that realized volatility reduces the pricing errors of the benchmark model significantly across moneyness, maturity, and volatility levels....

  12. Real options valuation with changing volatility

    Directory of Open Access Journals (Sweden)

    Miroslav Čulík

    2016-03-01

    Full Text Available This paper aims at the valuation of real options with changing volatility. Volatility change is a typical feature of real investment projects, where the riskiness of cash flow generated by the project can change significantly during the project life span. In this paper, there is explained how the problem of changing volatility can be considered if binomial lattice and replication strategy is used for real option valuation. There are recombining and non-recombining lattice used and constant and increasing volatility are analysed and results compared. In situation when volatility is changing, two approaches overcoming this problem are employed and compared.

  13. Exponential Smoothing, Long Memory and Volatility Prediction

    DEFF Research Database (Denmark)

    Proietti, Tommaso

    Extracting and forecasting the volatility of financial markets is an important empirical problem. The paper provides a time series characterization of the volatility components arising when the volatility process is fractionally integrated, and proposes a new predictor that can be seen as extension...... originally by Hosking. We investigate the properties of the volatility components and the forecasts arising from these specification, which depend uniquely on the memory and the moving average parameters. For statistical inference we show that, under mild regularity conditions, the Whittle pseudo...... methods for forecasting realized volatility, and that the estimated model confidence sets include the newly proposed fractional lag predictor in all occurrences....

  14. Myocardial perfusion of infarcted and normal myocardium in propofol-anesthetized minipigs using 82Rubidium PET

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Larsen, Bjarke Follin; Kastrup, Jens;

    2016-01-01

    challenges. Animals, which have been anesthetized during PET acquisition, might react differently to used stress medications, and therefore difficulties might exist while evaluating the resulting PET images using standard software packages from commercial vendors optimized for human hearts. Furthermore...... propofol, used for anesthesia, can influence myocardial perfusion and coronary flow reserve due to its vasorelaxant effect, and interactions might exist between propofol and used stress agents, potentially affecting the result of the examination. We present cardiac 82Rb-PET studies performed in propofol-anesthetized...

  15. Algorithmic complexity as an index of cortical function in awake and pentobarbital-anesthetized rats.

    Science.gov (United States)

    Shaw, F Z; Chen, R F; Tsao, H W; Yen, C T

    1999-11-15

    This study introduces algorithmic complexity to measure characteristics of brain functions. The EEG of the rat was recorded with implanted electrodes. The normalized complexity value was relatively independent of data length, and it showed a simpler and easier calculation characteristic than other non-linear indexes. The complexity index revealed significant differences among awake, asleep, and anesthetized states. It may be useful in tracking short-term and long-term changes in brain functions, such as anesthetized depth, drug effects, or sleep-wakefulness.

  16. Use of anesthetic arthrography in the identification of the source of chronic posttraumatic hindfoot disability

    International Nuclear Information System (INIS)

    Selective anesthetic arthrography was performed in 18 patients to define precisely the source of chronic posttraumatic hindfoot pain. A solution composed of local anesthetic and iodinated contrast material was injected into the hindfoot articulations, and the clinical response was determined. Although there was close correlation between pain relief and abnormalities depicted with both routine radiography and CT, both imaging methods tended to underestimate the severity of articular involvement, and plain film findings in five patients were misleading as to the site of pain origin. Long-term follow-up evaluation in nine patients who underwent arthrodesis on the basis of arthrographic findings indicated satisfactory results in eight

  17. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  18. Chirospecific analysis of plant volatiles

    Science.gov (United States)

    Tkachev, A. V.

    2007-10-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  19. Chirospecific analysis of plant volatiles

    International Nuclear Information System (INIS)

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  20. 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)

  1. Stochastic Volatility and DSGE Models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller

    This paper argues that a specification of stochastic volatility commonly used to analyze the Great Moderation in DSGE models may not be appropriate, because the level of a process with this specification does not have conditional or unconditional moments. This is unfortunate because agents may...... as a result expect productivity and hence consumption to be inifinite in all future periods. This observation is followed by three ways to overcome the problem....

  2. Merger Information and Share Volatility

    OpenAIRE

    Ramachandran, Remya

    2013-01-01

    The study undertakes to examine the effect of merger announcement in the market under different market conditions. Effect of Merger information release is analyzed by using share price reaction to information. Price and Volume reaction during specific periods when the markets sharply moved up and down were also considered to know whether the sharp movements in the market have any significant impact in price volatility.

  3. Stock Market Volatility under Sanctions

    OpenAIRE

    Hojatallah Goudarzi

    2014-01-01

    Since 1979, Iran has faced with unilateral and multilateral harsh sanctions due to its nuclear energy program. These sanctions have resulted in significant problem to both sanctioned and sanctioning parties. Given the fact that sanctions have had significant impacts on Iran’s economy and since Iran stock market is the barometer of its economy, it is assumed that sanctions affect the Iranian stock market as well. To test this hypothesis, this study studied the Iranian stock market volatility d...

  4. Local anesthesia for extracorporeal shock wave lithotripsy: a study comparing eutetic mixture of local anesthetics cream and lidocaine infiltration

    DEFF Research Database (Denmark)

    Honnens de Lichtenberg, M; Miskowiak, J; Mogensen, P;

    1992-01-01

    A study of the anesthetic efficacy of a eutetic mixture of local anesthetics (EMLA cream) versus lidocaine infiltration in extracorporeal shock wave lithotripsy (ESWL) was done. A total of 46 patients had 30 gm. of EMLA cream applied to the skin over the kidney and 45 had subcutaneous infiltration...

  5. Anesthetic Management of a Patient with Sustained Severe Metabolic Alkalosis and Electrolyte Abnormalities Caused by Ingestion of Baking Soda

    OpenAIRE

    Jose Soliz; Jeffrey Lim; Gang Zheng

    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.

  6. Isoflurane anesthetic hypersensitivity and progressive respiratory depression in a mouse model with isolated mitochondrial complex I deficiency

    NARCIS (Netherlands)

    Roelofs, S.; Manjeri, G.R.; Willems, P.H.G.M.; Scheffer, G.J.; Smeitink, J.A.M.; Driessen, J.J.

    2014-01-01

    BACKGROUND: Children with mitochondrial disorders are frequently anesthetized for a wide range of operations. These disorders may interfere with the response to surgery and anesthesia. We examined anesthetic sensitivity to and respiratory effects of isoflurane in the Ndufs4 knockout (KO) mouse model

  7. 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.

  8. 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.

    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 trans

  9. Forecasting volatility for options valuation

    International Nuclear Information System (INIS)

    The petroleum sector plays a neuralgic role in the basement of world economies, and market actors (producers, intermediates, as well as consumers) are continuously subjected to the dynamics of unstable oil market. Huge amounts are being invested along the production chain to make one barrel of crude oil available to the end user. Adding to that are the effect of geopolitical dynamics as well as geological risks as expressed in terms of low chances of successful discoveries. In addition, fiscal regimes and regulations, technology and environmental concerns are also among some of the major factors that contribute to the substantial risk in the oil industry and render the market structure vulnerable to crises. The management of these vulnerabilities require modern tools to reduce risk to a certain level, which unfortunately is a non-zero value. The aim of this paper is, therefore, to provide a modern technique to capture the oil price stochastic volatility that can be implemented to value the exposure of an investor, a company, a corporate or a Government. The paper first analyses the regional dependence on oil prices, through a historical perspective and then looks at the evolution of pricing environment since the large price jumps of the 1970s. The main causes of oil prices volatility are treated in the third part of the paper. The rest of the article deals with volatility models and forecasts used in risk management, with an implication for pricing derivatives. (author)

  10. Formation of organic nanoparticles from volatile microemulsions.

    Science.gov (United States)

    Margulis-Goshen, Katrin; Netivi, Hadas Donio; Major, Dan T; Gradzielski, Michael; Raviv, Uri; Magdassi, Shlomo

    2010-02-15

    A method for preparation of nanoparticles of poorly water-soluble organic materials is presented. By this method, an oil-in-water microemulsion containing a volatile solvent with dissolved model material, propylparaben, undergoes solvent evaporation and conversion into nanoparticles by spray drying. The resulting powder can be easily dispersed in water to give a clear, stable dispersion of nanoparticles with a high loading of propylparaben. By filtration of this dispersion it was found that more than 95wt.% of the dispersed propylparaben is in particles of less than 450nm. X-ray diffraction revealed that propylparaben is present as nanocrystals of 40-70nm. After dispersion of the powder in water, formation of large crystals rapidly occurs. Addition of polyvinylpyrrolidone (PVP) prevented crystal growth during dispersion of the powder in water. The inhibition of propylparaben crystal growth by PVP was studied by molecular dynamic simulations that addressed the binding of PVP to the propylparaben crystal. A comparison was made between PVP and polyvinylalcohol, which did not display crystal inhibition properties. PMID:19919861

  11. Local anesthetics after total knee arthroplasty: intraarticular or extraarticular administration? A randomized, double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Andersen, L.O.; Kristensen, B.B.; Husted, H.;

    2008-01-01

    BACKGROUND: High-volume local infiltration analgesia with additional intraarticular and wound administration of local anesthetic has been shown to be effective after knee replacement, but the optimum site of administration of the local anesthetic (i.e. intraarticular or extraarticular) has not been...... or to receive 20 mL ropivacaine (0.2%) intraarticularly plus 30 mL ropivacaine (0.2%) in the extraarticular wound space 24 hours postoperatively. Pain intensity at rest and with mobilization was recorded for 4 hours after administration of additional local anesthetics. RESULTS: Intensity of pain at rest, during...... flexion, or straight leg lift was not statistically significantly different between the two groups, but there was a tendency of improved analgesia with administration of additional local anesthetic in the extraarticular wound space. INTERPRETATION: The optimal site of administration of local anesthetic...

  12. Tranexamic Acid in Anesthetic Management of Surgical Procedures.

    Science.gov (United States)

    Mayeux, Jessica; Alwon, Kathy; Collins, Shawn; Hewer, Ian

    2016-06-01

    Blood loss during surgical procedures poses a grave risk to the patient, but transfusion is costly and associated with adverse outcomes. Antifibrinolytics, however, offer an economical and effective means of decreasing blood loss associated with surgical procedures. Tranexamic acid (TXA) is an antifibrinolytic that blocks lysine-binding sites of fibrinogen and fibrin, preventing the breakdown of existing clots. This journal course reviews extensive research demonstrating that antifibrinolytics such as TXA decrease blood loss and in some studies reduce allogeneic transfusion requirements. In addition, this journal course addresses concerns that use of antifibrinolytics increases embolic events, reviews research that demonstrates TXA does not increase the incidence of vascular occlusive events, and describes methods of TXA use in cardiac and orthopedic surgical procedures, neurosurgery, and obstetrics. The Certified Registered Nurse Anesthetist should consider the possibility, on a case-by-case basis, of using TXA in surgical procedures to reduce blood loss with minimal adverse effects. PMID:27501656

  13. Molecular insights into the local anesthetic receptor within voltage-gated sodium channels using hydroxylated analogues of mexiletine

    Directory of Open Access Journals (Sweden)

    Jean-François eDesaphy

    2012-02-01

    Full Text Available We previously showed that the β-adrenoceptor modulators, clenbuterol and propranolol, directly blocked voltage-gated sodium channels, whereas salbutamol and nadolol did not (Desaphy et al., 2003, suggesting the presence of two hydroxyl groups on the aromatic moiety of the drugs as a molecular requisite for impeding sodium channel block. To verify such an hypothesis, we synthesized five new mexiletine analogues by adding one or two hydroxyl groups to the aryl moiety of the sodium channel blocker and tested these compounds on hNav1.4 channels expressed in HEK293 cells. Concentration-response relationships were constructed using an holding potential of -120 mV at 0.1 Hz (tonic block and 10 Hz (use-dependent block stimulation frequencies. The half-maximum inhibitory concentrations (IC50 were linearly correlated to drug lipophilicity: the less lipophilic the drug, minor was the block. The same compounds were also tested on F1586C and Y1593C hNav1.4 channel mutants, to gain further information on the molecular interactions of mexiletine with its receptor within the sodium channel pore. Alteration of tonic block suggests that the aryl moiety of mexiletine may interact either directly or indirectly with Phe1586 in the closed sodium channel to produce low-affinity binding block, and that this interaction depends on the electrostatic potential of the drug aromatic tail. Alteration of use-dependent block suggests that addition of hydroxyl groups to the aryl moiety may modify high-affinity binding of the drug ammine terminal to Phe1586 through cooperativity between the two pharmacophores, this effect being mainly related to drug lipophilicity. Mutation of Tyr1593 further impaired such cooperativity. In conclusion, these results confirm our former hypothesis showing that the presence of hydroxyl groups to the aryl moiety of mexiletine greatly reduced sodium channel block, and provide molecular insights into the intimate interaction of local anesthetics with

  14. Combined mucopolysaccharidosis type VI and congenital adrenal hyperplasia in a child: Anesthetic considerations

    Directory of Open Access Journals (Sweden)

    Abhishek Bansal

    2012-01-01

    Full Text Available We present a child posted for magnetic resonance imaging of brain under general anesthesia with the rare combination of mucopolysachharidosis type VI and congenital adrenal hyperplasia. The presence of both these disorders has important anesthetic implications. The pathophysiology of this rare combination of disease is reviewed with emphasis on the anesthesia management.

  15. Anesthetic management of Shah–Waardenburg syndrome: Experience of two cases and review of literature

    OpenAIRE

    Uday S Ambi; Adarsh, E. S.; Ramesh Hatti; Vijaymahantesh Samalad

    2012-01-01

    Waardenburg syndrome (WS) is a rare autosomally inherited and genetically heterogeneous disorder of neural crest cell development. Literature regarding the anesthetic management of these cases is limited. We present 2 cases of Shah-Waardenburg syndrome and discuss them in the context of review of previously published cases.

  16. Anesthetic management of Shah-Waardenburg syndrome: Experience of two cases and review of literature

    Directory of Open Access Journals (Sweden)

    Uday S Ambi

    2012-01-01

    Full Text Available Waardenburg syndrome (WS is a rare autosomally inherited and genetically heterogeneous disorder of neural crest cell development. Literature regarding the anesthetic management of these cases is limited. We present 2 cases of Shah-Waardenburg syndrome and discuss them in the context of review of previously published cases.

  17. Taking the Headaches out of Anesthetizing "Drosophila": A Cheap & Easy Method of Constructing Carbon Dioxide Staging

    Science.gov (United States)

    Artiss, Thomas; Hughes, Bobby

    2007-01-01

    Carbon dioxide is an excellent alternative to conventional methods of anesthetizing fruit flies as it is non-flammable and odorless. We have devised a method of constructing carbon dioxide stages used to keep "Drosophila" immobilized cheaply and easily using empty micropipette tip containers. (Contains 6 figures.)

  18. Comparing different fentanyl concentrations added to local anesthetic mixture in peribulbar block for cataract surgery

    Directory of Open Access Journals (Sweden)

    Inas Kamel

    2016-04-01

    Conclusion: Adding Fentanyl at concentrations ⩾ 2–3 μg/ml to the local anesthetic mixture (Lidocaine and Hyaluronidase for regional peribulbar block provides safe and effective method in improving postoperative analgesia in patients undergoing cataract surgery.

  19. What is the optimal anesthetic protocol for measurements of cerebral autoregulation in spontaneously breathing mice?

    Science.gov (United States)

    Wang, Zhenghui; Schuler, Beat; Vogel, Olga; Arras, Margarete; Vogel, Johannes

    2010-12-01

    Autoregulation, an important feature of the cerebral circulation, is affected in many diseases. Since genetically modified mice are a fundamental tool in biomedical research, including neuro(bio)logy also in this specie measurements of cerebral autoregulation (CA) are mandatory. However, this requires anesthesia that unfortunately significantly impacts cerebral perfusion and consequently might distort CA measurements directly or by altering arterial pCO(2). The latter can be avoided by artificial ventilation but requires several control measurements of blood gases, each consuming at least 100 μl of blood or 5% of a mouse's blood volume. To avoid such diagnostic hemorrhage, we systematically analyzed the effect of different common anesthetic protocols used for rodents in spontaneously breathing mice on CA measured with Laser speckle perfusion imaging. Halothane, Isoflurane and Pentobarbital abrogated CA and Ketamin/Xylazine as well as Chloralose had a moderate reproducibility. In contrast, the rather rarely used anesthetic Ethomidate applied in low doses combined with local anesthetics had the best reproducibility. Although with this anesthesia the lower CA limit was lower than with Ketamin/Xylazine and Chloralose as reported in the handful of papers so far dealing with CA in mice, we suggest Ethomidate as the anesthetic of choice for CA measurements in spontaneously breathing mice.

  20. An Anesthetic Drug Demonstration and an Introductory Antioxidant Activity Experiment with "Eugene, the Sleepy Fish"

    Science.gov (United States)

    Barcena, Homar; Chen, Peishan

    2016-01-01

    Students are introduced to spectrophotometry in comparing the antioxidant activity of pure eugenol and oil of cloves from a commercial source using a modified ferric reducing antioxidant power (FRAP) assay. The extraction of the essential oil from dried cloves is demonstrated to facilitate discussions on green chemistry. The anesthetic properties…

  1. 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.

  2. Evaluation of the aesthetics of physical methods of euthanasia of anesthetized rats.

    Science.gov (United States)

    Hickman, Debra L; Johnson, Steven W

    2011-09-01

    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.

  3. Anesthetic management of a patient with stiff-person syndrome and thymoma: a case report

    Institute of Scientific and Technical Information of China (English)

    QIN Xiang; WANG Dong-xin; WU Xin-min

    2006-01-01

    @@ Stiff-person syndrome (SPS, also called stiff-man syndrome) is a rare neurological disease with autoimmune features. It is characterized by fluctuating and progressive muscle rigidity, and episodic spasm that prominently involve axial and limb musculature.1,2 Herein we report a case of anesthetic management of a patient with SPS for thymectomy and review several other cases.

  4. 静脉麻醉药的研究进展%Research progress of intravenous anesthetics

    Institute of Scientific and Technical Information of China (English)

    浦鹏飞

    2012-01-01

    Intravenous anesthetics is classified into the barbiturates and non-barbiturates. Although great progress has been made in the intravenous anesthetic pharmacokinetic-pharmacodynamic knowledge and intravenous anesthesia, no intravenous anesthetics at the present is considered to be ideal in all respects. Therefore, it is still urgent to find approaches to create an ideal anesthetic state, which is secure, smooth and easy to control.%静脉麻醉药主要分为巴比妥类药物和非巴比妥类药物,虽然静脉麻醉药药代动力学-药效学知识和静脉麻醉技术均取得了长足进步,但目前还无一种在各方面都十分理想的静脉麻醉药,所以实现安全、易控、平稳和苏醒迅速的理想麻醉状态仍是摆在我们面前最严峻的问题.

  5. 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.

  6. Dexmedetomidine as an anesthetic adjuvant in laparoscopic surgery: An observational study using entropy monitoring

    Directory of Open Access Journals (Sweden)

    Poonam S Ghodki

    2012-01-01

    Full Text Available Background: Dexmedetomidine is a highly selective α2 agonist with properties of sedation, analgesia and anxiolysis, making it an ideal anesthetic adjuvant. Using an anesthetic adjuvant that decreases requirement of anesthetics and analgesics may predispose the patient to awareness. We monitored the depth of anesthesia (DOA using entropy to avoid unwanted awareness under anesthesia. Materials and Methods: 30 patients, American Society of Anesthesiologists grade I and II, aged between 18 to 50 years of either gender undergoing laparoscopic surgeries under general anesthesia were studied. Loading dose infusion of dexmedetomidine was started 1 mcg/kg for 15 minutes and patients were premedicated. Routine induction with propofol and fentanyl was carried out, and maintenance infusion of dexmedetomidine 0.2 mcg/kg/hr was given. Patients were monitored with standard monitoring, and in addition, the DOA was monitored with entropy. Results: A 62.5% reduction (0.75 mg/kg in the induction dose of propofol was observed, with a 30% less end-tidal concentration of isoflurane requirement for maintenance of anesthesia, while maintaining the adequate DOA. Conclusion: Dexmedetomidine is an effective anesthetic adjuvant that can be safely used in laparoscopy without the fear of awareness under anesthesia.

  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. Are one or two dangerous? Lidocaine and topical anesthetic exposures in children.

    Science.gov (United States)

    Curtis, Liesl A; Dolan, Teresa Sullivan; Seibert, H Edward

    2009-07-01

    Topical anesthetics are found in a variety of prescription and non-prescription preparations, from teething gels to hemorrhoid creams. In 2003, there were 8576 exposures to local/topical anesthetics reported to the American Association of Poison Control Centers, with 67% of cases in the age group younger than 6 years old. This report reviews the available literature involving topical anesthetic exposures in children younger than 6 years old, including the National Library of Medicine's Pub Med database (limited to English language) and data from POISINDEX. Additionally, we reviewed the American Association of Poison Control Centers' annual reports from 1983 to 2003. There were 7 deaths in this age range from topical anesthetics. Although the number of deaths is low, the fact that there have been deaths reveals the serious nature of the toxicity that can result from these readily available non-prescription analgesics. Toxicity may result from topical absorption, ingestion, or aspiration. Additionally, toxicity can result from unintentional as well as therapeutic mishaps. Although the number of cases is limited, these medications can be toxic at low doses-which, in children younger than 6 years of age, may amount to as little as a teaspoon.

  9. 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.

  10. 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

  11. 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.

  12. Challenges for the cataract surgeon treating people with dementia: a qualitative study exploring anesthetic choices

    Directory of Open Access Journals (Sweden)

    Jefferis JM

    2014-09-01

    Full Text Available Joanna Mary Jefferis,1–3 Michael Patrick Clarke,1,3 John-Paul Taylor,2 Katie Rhian Brittain4 1Newcastle Eye Centre, Royal Victoria Infirmary, 2Institute for Ageing and Health, 3Institute of Neurosciences, 4Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK Background: In light of the growing number of people with dementia and age-related cataract, as well as changing anesthetic practices for cataract surgery, this study aimed to explore the experiences of cataract surgeons in managing patients with dementia and making anesthetic decisions.Methods: This was a qualitative study using semistructured interviews with senior cataract surgeons from two centers in England. Fourteen surgeons were interviewed, and a thematic approach informed by grounded theory was used for the analysis.Results: Choice of anesthesia for people with dementia was a central theme arising from the data. Surgeons varied in their thresholds for using general anesthesia. Decisions about suitability for local anesthesia were limited by time constraints and generally made rapidly and based on instinct; dementia was not always apparent at the point of preassessment. Surgeons used a variety of topical, sub-Tenon’s, and sharp needle blocks for people with dementia. Surgeons discussed techniques to help patients tolerate local anesthesia, such as clear communication, a primary nurse, hand-holding, and support from an anesthetist. However, within our sample, some surgeons had had negative experiences of operating on people with dementia, where an incorrect judgment had been made that they could tolerate local anesthetic cataract surgery. Conclusion: This study highlights the differing practices of cataract surgeons when making anesthetic choices for people with dementia and the challenges they face. In order to avoid the situation of a patient with dementia becoming distressed during awake surgery, increased time at preassessment and anesthetic support

  13. 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...

  14. Towards a volatility index for the Italian stock market

    OpenAIRE

    Silvia Muzzioli

    2010-01-01

    The aim of this paper is to analyse and empirically test how to unlock volatility information from option prices. The information content of three option based forecasts of volatility: Black-Scholes implied volatility, model-free implied volatility and corridor implied volatility is addressed, with the ultimate plan of proposing a new volatility index for the Italian stock market. As for model-free implied volatility, two different extrapolation techniques are implemented. As for corridor imp...

  15. Floral volatiles: from biosynthesis to function.

    Science.gov (United States)

    Muhlemann, Joëlle K; Klempien, Antje; Dudareva, Natalia

    2014-08-01

    Floral volatiles have attracted humans' attention since antiquity and have since then permeated many aspects of our lives. Indeed, they are heavily used in perfumes, cosmetics, flavourings and medicinal applications. However, their primary function is to mediate ecological interactions between flowers and a diverse array of visitors, including pollinators, florivores and pathogens. As such, they ultimately ensure the plants' reproductive and evolutionary success. To date, over 1700 floral volatile organic compounds (VOCs) have been identified. Interestingly, they are derived from only a few biochemical networks, which include the terpenoid, phenylpropanoid/benzenoid and fatty acid biosynthetic pathways. These pathways are intricately regulated by endogenous and external factors to enable spatially and temporally controlled emission of floral volatiles, thereby fine-tuning the ecological interactions facilitated by floral volatiles. In this review, we will focus on describing the biosynthetic pathways leading to floral VOCs, the regulation of floral volatile emission, as well as biological functions of emitted volatiles. PMID:24588567

  16. Volatile Constituents of Zhumaria Majdae

    Directory of Open Access Journals (Sweden)

    Yazdanparst

    1993-07-01

    Full Text Available Capillary gas chromatography mass spectrometry (GC- MS analyses of a sample of essential oil of zhumaria Linalool ned by simple water distillation of the pulverized air - dired leaves and flowers of the plant indicated that Linalool and comphor are the two major constituents of the volatile oil. Sylvestrene , y -terpinene, a- Pinene, b - carene, camphene, and Epiborneol constitute the other main components of the essential oil. The GC - MS chromatogram indicated the presence of more than fifty - components in the oil, most of them were present in trace amounts. In this study, the chemical structures of twenty of these consti tuents were elucidated using GC - MS analysis.

  17. Determination of volatile compounds of pine honeys

    OpenAIRE

    SİLİCİ, Sibel

    2011-01-01

    The volatile compounds of 13 Turkish pine (Pinus brutia Ten.) honey samples were characterized by solid phase microextraction (SPME) analysis, followed by gas chromatography-mass spectrometry (GC-MS) analysis. A total of 42 volatile compounds were identified, but volatile compounds such as nonana1, benzene, 4-hexen-3-ol, alpha-pinene, and 2-heptanone were recognized to be specific floral origin markers of the pine honey. The SPME extraction method was proposed as an alternative way to carry o...

  18. The Volatility of Thai Rice Price

    OpenAIRE

    A. H. Baharom; Radam, Alias; Habibullah, M.S.; Hirnissa, M.T

    2009-01-01

    This study was conducted to explore the varying volatility of world rice price for the period 1961 to 2008 using monthly data. The paper provides estimates of two GARCH models, namely, GARCH and EGARCH which were used to capture the stochastic variation and asymmetries in the world rice price. The results indicate that EGARCH model gives better estimate of the volatility of world rice price. Furthermore the EGARCH model was able to describe the asymmetric volatility in the world price of rice...

  19. Institutional Weakness and Stock Price Volatility

    OpenAIRE

    Galina B. Hale; Razin, Assaf; Tong, Hui

    2006-01-01

    We find an empirical regularity that stronger creditor protection reduces the volatility of stock market prices. We analyze two distinct mechanisms that characterize equity price volatility: government guarantees and creditor protection. Using a Tobin q model, we demonstrate that weak creditor protection that gives rise to government guarantees and tightens credit constraints, increases stock price volatility. Empirically, accounting for the probability of financial crises, we find that gover...

  20. Credit Derivative Pricing with Stochastic Volatility Models

    OpenAIRE

    Carl Chiarella; Samuel Chege Maina; Christina Nikitopoulos-Sklibosios

    2011-01-01

    This paper proposes a framework for pricing credit derivatives within the defaultable Markovian HJM framework featuring unspanned stochastic volatility. Motivated by empirical evidence, hump-shaped level dependent stochastic volatility specifications are proposed, such that the model admits finite dimensional Markovian structures. The model also accommodates a correlation structure between the stochastic volatility, default-free interest rates and credit spreads. Default free and defaultable ...

  1. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    Campbell, John; Taksler, Glen

    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.

  2. ’North-East Volatility Wind’ Effect

    OpenAIRE

    Pučkovs, A; Matvejevs, A

    2014-01-01

    This paper describes volatility forecasting approach applicable for stock indexes, allowing to reveal the instability of financial time series initially. This approach is based on time series (signal) decomposition into components by using wavelet filtering with subsequent volatility evolution research of each signal component. According to research, a slight increase in volatility in the low-frequency components of the signal leads to significant disturbances in high-frequency components ...

  3. Realizing Smiles: Pricing Options with Realized Volatility

    OpenAIRE

    Corsi, Fulvio; Fusari, Nicola; Davide LA VECCHIA

    2009-01-01

    We develop a stochastic volatility option pricing model that exploits the informative content of historical high frequency data. Using the Two Scales Realized Volatility as a proxy for the unobservable returns volatility, we propose a simple (affine) but effective long-memory process: the Heterogeneous Auto-Regressive Gamma (HARG) model. This discrete–time process, combined with an exponential affine stochastic discount factor, leads to tractable risk-neutral dynamics. The explicit change of ...

  4. Volatility Spreads and Expected Stock Returns

    OpenAIRE

    Turan G. Bali; Armen Hovakimian

    2009-01-01

    This paper investigates whether realized and implied volatilities of individual stocks can predict the cross-sectional variation in expected returns. Although the levels of volatilities from the physical and risk-neutral distributions cannot predict future returns, there is a significant relation between volatility spreads and expected stock returns. Portfolio level analyses and firm-level cross-sectional regressions indicate a negative and significant relation between expected returns and th...

  5. B-spline techniques for volatility modeling

    OpenAIRE

    Corlay, Sylvain

    2013-01-01

    This paper is devoted to the application of B-splines to volatility modeling, specifically the calibration of the leverage function in stochastic local volatility models and the parameterization of an arbitrage-free implied volatility surface calibrated to sparse option data. We use an extension of classical B-splines obtained by including basis functions with infinite support. We first come back to the application of shape-constrained B-splines to the estimation of conditional expectations, ...

  6. Climate Volatility and Poverty Vulnerability in Tanzania

    OpenAIRE

    Ahmed, Syud Amer; Diffenbaugh, Noah S.; Hertel, Thomas W.; Ramankutty, Navin; Rios, Ana R.; Rowhani, Pedram

    2009-01-01

    Climate volatility will increase in the future, with agricultural productivity expected to become increasingly volatile as well. For Tanzania, where food production and prices are sensitive to the climate, rising climate volatility can have severe implications for poverty. We develop and use an integrated framework to estimate the poverty vulnerabilities of different socio-economic strata in Tanzania under current and future climate. We find that households across various strata are similarly...

  7. 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.

  8. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    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......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...

  9. [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. PMID:25975033

  10. Evaluating Energy Sector Investments: Calculating Volatility

    Directory of Open Access Journals (Sweden)

    Edson de Oliveira Pamplona

    2013-01-01

    Full Text Available A major task in assessing risks of investment projects is defining the approach to calculating the project’s volatility. Looking at assorted estimation techniques, this paper calculates their volatilities. The techniques originate from authors in the area and involve project-specific variables of uncertainty. These techniques are applied to a case of electricity distribution through real options. Results are then compared. The difference between the calculated volatilities was low, leaving, in the case of the project evaluated here, the decision unchanged. The paper’s contribution consists of providing a detailed presentation of calculating volatility by the methods cited and by comparing the results obtained by its application.

  11. Regolith Volatile Recovery at Simulated Lunar Environments

    Science.gov (United States)

    Kleinhenz, Julie; Paulsen, Gale; Zacny, Kris; Schmidt, Sherry; Boucher, Dale

    2016-01-01

    Lunar Polar Volatiles: Permanently shadowed craters at the lunar poles contain water, 5 wt according to LCROSS. Interest in water for ISRU applications. Desire to ground truth water using surface prospecting e.g. Resource Prospector and RESOLVE. How to access subsurface water resources and accurately measure quantity. Excavation operations and exposure to lunar environment may affect the results. Volatile capture tests: A series a ground based dirty thermal vacuum tests are being conducted to better understand the subsurface sampling operations. Sample removal and transfer. Volatiles loss during sampling operations. Concept of operations, Instrumentation. This presentation is a progress report on volatiles capture results from these tests with lunar polar drill prototype hardware.

  12. Diabetes Mellitus and Some Egyptian's Volatile Oils

    Directory of Open Access Journals (Sweden)

    Fahmy Gad Elsaid

    2008-03-01

    Full Text Available Background: Diabetes mellitus as a metabolic disorder is characterized by hyperglycemia, dyslipidemia and deflection in protein metabolism. Natural products as a fashion remedy was undertaken and this study was designed to search the role of anise, fennel, thyme volatile oils and -terpinene (a bioactive constituent extracted from caraway and cumin volatile oils to deal with the biochemical changes in sera, liver and muscle of streptozotcin (STZ-induced diabetic rats. Material and methods: Thirty rats (Sprague dawelly were divided into three groups: control group; diabetic group, STZ-induced diabetic rats and diabetic & volatile oils group. The STZ-induced diabetic & volatile oil group was orally administered with different volatile oils by gavage (2 ml/ kg body weight and subdivided into four subgroups: diabetic & anise; diabetic & fennel; diabetic & thyme and diabetic & - terpinene. Results: There were highly significant increase in sera glucose, total lipids, total cholesterol, and triglycerides in diabetic rats. Liver and muscle malondialdehyde (MDA and protein carbonyl (PC, superoxide dismutase, catalase and glutathione-s-transferase activities were remodeling after administration of different volatile oils. Sera insulin, liver glucose-6-phosphate dehydrogenase, liver and muscle glycogen was highly significantly decreased in diabetic rats. On the other hand, the alleviation in these parameters was highly noticed in the different diabetic & volatile oil subgroups. Conclusion: The counter effects of different volatile oils upon these changes reflect the antihyperglycemia and antioxidant roles of these volatile oils with a different range in STZ-induced diabetic rats

  13. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  14. Tolerance of local anesthetic for transrectal ultrasound-guided prostate biopsy: our experience and a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, M.R.E.; Bryant, N.J.; Brown, J.A.; Tiwari, P.; Cooperberg, P.L.; Wong, A.D. [St Paul' s Hospital, Ultrasound Dept., Vancouver, British Columbia (Canada)]. E-mail: twong@providcencehealth.bc.ca

    2006-06-15

    To determine whether local anesthetic injection or gel reduced pain during transrectal ultrasound-guided prostate biopsies and whether there was significant difference between quadrant and apex-only anesthesia. Between September 2001 and May 2002, 240 male patients with elevated prostate-specific antigen and (or) abnormal digital rectal examination were randomized into 1 of 4 groups: 1) transrectal lidocaine gel, 2) quadrant lidocaine injections, 3) apex-only lidocaine injections, or 4) no local anesthetic. Patients scored their pain on a numerical rating scale where 0 indicated no pain and 10 indicated worst pain. We analyzed mean and standard deviations of scores, using a 1-way analysis of variance (ANOVA) and post hoc multiple comparisons with Tukey's honestly significant difference (HSD) studentized range test to determine whether there were significant differences across the groups. There was no significant difference between local anesthetic gel (mean 3.1, SD 1.9) and no anesthetic (mean 3.5, SD 1.9) or between quadrant (mean 1.7, SD 1.7) and apex-only (mean 2.0, SD 1.8) local anesthetic injections. There was significant difference between quadrant injections (mean 1.7, SD 1.7) and no local anesthetic (mean 3.5, SD 1.9) and between apex-only injections (mean 2.0, SD 1.8) and no local anesthetic (mean 3.5, SD 1.9). There was significant pain reduction with local anesthetic injections but not with gel, and since there was no significant difference in efficacy between quadrant and apex-only injections, we recommend apex-only local anesthetic injections for transrectal ultrasound-guided prostate biopsies because it simplifies the injection procedure. (author)

  15. Stochastic Spot/Volatility Correlation in Stochastic Volatility Models and Barrier Option Pricing

    OpenAIRE

    Mark Higgins

    2014-01-01

    Most models for barrier pricing are designed to let a market maker tune the model-implied covariance between moves in the asset spot price and moves in the implied volatility skew. This is often implemented with a local volatility/stochastic volatility mixture model, where the mixture parameter tunes that covariance. This paper defines an alternate model where the spot/volatility correlation is a separate mean-reverting stochastic variable which is itself correlated with spot. We also develop...

  16. A quest to increase safety of anesthetics by advancements in anesthesia monitoring: scientometric analysis

    Directory of Open Access Journals (Sweden)

    Vlassakov KV

    2015-05-01

    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 anesthesia monitoring over the past 40 years using scientometric analysis. The following scientometric indexes were used: popularity indexes (general and specific, representing the proportion of articles on either a topic relative to all articles in the field of anesthetics (general popularity index, GPI or the subfield of anesthesia monitoring (specific popularity index, SPI; index of change (IC, representing the degree of growth in publications on a topic from one period to the next; and index of expectations (IE, 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. Publications on 33 anesthesia-monitoring topics were assessed. Our analysis showed that over the past 40 years, the rate of rise in the number of articles on anesthesia monitoring was exponential, with an increase of more than eleven-fold, from 296 articles over the 5-year period 1974–1978 to 3,394 articles for 2009–2013. This rise profoundly exceeded the rate of rise of the number of articles on general anesthetics. The difference was especially evident with the comparison of the related GPIs: stable growth of the GPI for anesthesia monitoring vs constant decline in the GPI for general anesthetics. By the 2009–2013 period, among specific monitoring topics introduced after 1980, the SPI index had a meaningful magnitude (≥1.5 in 9 of 24 topics: Bispectral Index (7.8, Transesophageal Echocardiography (4.2, Electromyo­graphy (2.8, Pulse Oximetry (2.4, Entropy (2.3, Train-of-four (2.3, Capnography (1.9, Pulse Contour (1.9, and Electrical Nerve Stimulation for neuromuscular monitoring (1.6. Only one of these topics (Pulse

  17. Molecular Insights into the Local Anesthetic Receptor within Voltage-Gated Sodium Channels Using Hydroxylated Analogs of Mexiletine.

    Science.gov (United States)

    Desaphy, Jean-François; Dipalma, Antonella; Costanza, Teresa; Carbonara, Roberta; Dinardo, Maria Maddalena; Catalano, Alessia; Carocci, Alessia; Lentini, Giovanni; Franchini, Carlo; Camerino, Diana Conte

    2012-01-01

    We previously showed that the β-adrenoceptor modulators, clenbuterol and propranolol, directly blocked voltage-gated sodium channels, whereas salbutamol and nadolol did not (Desaphy et al., 2003), suggesting the presence of two hydroxyl groups on the aromatic moiety of the drugs as a molecular requisite for impeding sodium channel block. To verify such an hypothesis, we synthesized five new mexiletine analogs by adding one or two hydroxyl groups to the aryloxy moiety of the sodium channel blocker and tested these compounds on hNav1.4 channels expressed in HEK293 cells. Concentration-response relationships were constructed using 25-ms-long depolarizing pulses at -30 mV applied from an holding potential of -120 mV at 0.1 Hz (tonic block) and 10 Hz (use-dependent block) stimulation frequencies. The half-maximum inhibitory concentrations (IC(50)) were linearly correlated to drug lipophilicity: the less lipophilic the drug, minor was the block. The same compounds were also tested on F1586C and Y1593C hNav1.4 channel mutants, to gain further information on the molecular interactions of mexiletine with its receptor within the sodium channel pore. In particular, replacement of Phe1586 and Tyr1593 by non-aromatic cysteine residues may help in the understanding of the role of π-π or π-cation interactions in mexiletine binding. Alteration of tonic block suggests that the aryloxy moiety of mexiletine may interact either directly or indirectly with Phe1586 in the closed sodium channel to produce low-affinity binding block, and that this interaction depends on the electrostatic potential of the drug aromatic tail. Alteration of use-dependent block suggests that addition of hydroxyl groups to the aryloxy moiety may modify high-affinity binding of the drug amine terminal to Phe1586 through cooperativity between the two pharmacophores, this effect being mainly related to drug lipophilicity. Mutation of Tyr1593 further impaired such cooperativity. In conclusion, these

  18. Option valuation models with stochastic volatility

    OpenAIRE

    Šigut, Jiří

    2012-01-01

    This work describes stochastic volatility models and application of such models for option pricing. Models for underlying asset and then pricing models for options with stochastic volatility are derived. Black-Scholes and Heston-Nandi models are compared in empirical part of this work.

  19. Analyzing volatile compounds in dairy products

    Science.gov (United States)

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  20. 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

  1. 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.

  2. Climate volatility and poverty vulnerability in Tanzania

    OpenAIRE

    Ahmed, Syud Amer; Diffenbaugh, Noah S.; Hertel, Thomas W.; Lobell, David B.; Ramankutty, Navin; Rios, Ana R.; Rowhani, Pedram

    2009-01-01

    Climate models generally indicate that climate volatility may rise in the future, severely affecting agricultural productivity through greater frequency of yield-diminishing climate extremes, such as droughts. For Tanzania, where agricultural production is sensitive to climate, changes in climate volatility could have significant implications for poverty. This study assesses the vulnerabil...

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

    International Nuclear Information System (INIS)

    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 (KGL) were measured for halogenated volatile organic compounds (VOCs), namely 1-chlorobutane, methoxyflurane, pentafluoropropan-1-ol, heptafluorobutan-1-ol, α,α,α-trifluorotoluene, and toluene in aqueous solutions of natural α-, β-, and γ-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.

  4. 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.

  5. Clustered volatility in multiagent dynamics

    CERN Document Server

    Youssefmir, M; Youssefmir, Michael; Huberman, Bernardo

    1995-01-01

    Large distributed multiagent systems are characterized by vast numbers of agents trying to gain access to limited resources in an unpredictable environment. Agents in these system continuously switch strategies in order to opportunistically find improvements in their utilities. We have analyzed the fluctuations around equilibrium that arise from strategy switching and discovered the existence of a new phenomenon. It consists of the appearance of sudden bursts of activity that punctuate the fixed point, and is due to an effective random walk consistent with overall stability. This clustered volatility is followed by relaxation to the fixed point but with different strategy mixes from the previous one. This phenomenon is quite general for systems in which agents explore strategies in search of local improvements.

  6. Heightened motor and sensory (mirror-touch) referral induced by nerve block or topical anesthetic.

    Science.gov (United States)

    Case, Laura K; Gosavi, Radhika; Ramachandran, Vilayanur S

    2013-08-01

    Mirror neurons allow us to covertly simulate the sensation and movement of others. If mirror neurons are sensory and motor neurons, why do we not actually feel this simulation- like "mirror-touch synesthetes"? Might afferent sensation normally inhibit mirror representations from reaching consciousness? We and others have reported heightened sensory referral to phantom limbs and temporarily anesthetized arms. These patients, however, had experienced illness or injury of the deafferented limb. In the current study we observe heightened sensory and motor referral to the face after unilateral nerve block for routine dental procedures. We also obtain double-blind, quantitative evidence of heightened sensory referral in healthy participants completing a mirror-touch confusion task after topical anesthetic cream is applied. We suggest that sensory and motor feedback exist in dynamic equilibrium with mirror representations; as feedback is reduced, the brain draws more upon visual information to determine- perhaps in a Bayesian manner- what to feel.

  7. Modelling the anesthetized brain with ensembles of neuronal and astrocytic oscillators

    Science.gov (United States)

    Hansard, T.; Hale, A. C.; Stefanovska, A.

    2013-01-01

    We propose a minimalistic model of the anesthetized brain in order to study the generation of rhythms observed in electroencephalograms (EEGs) recorded from anesthetized humans. We propose that non-neuronal brain cells-astrocytes-play an important role in brain dynamics and that oscillation-based models may provide a simple way to study such dynamics. The model is capable of replicating the main features (i.e. slow and alpha oscillations) observed in EEGs. In addition, this model suggests that astrocytes are integral to the generation of slow EEG (˜0.7 Hz) rhythms. By including astrocytes in the model we take a first step towards investigating the interaction of the brain and cardiovasular system which are primarily connected via astrocytes. The model also illustrates that rich nonlinear dynamics can arise from basic oscillatory "building blocks" and therefore complex systems may be modelled in an uncomplicated way.

  8. [Anesthetic considerations in laparoscopy for removal of a kidney from a live donor].

    Science.gov (United States)

    Monsma, M; Gómez, G; Vidal, A; Vera, C D; Barberá, M

    2010-05-01

    Kidney transplantation is the main therapeutic alternative for patients with end-stage renal failure. However, the main constraint at present is the lack of available organs. Removal of a kidney from a live donor is a better option than conventional transplantation of a cadaver-donated organ. Among the advantages are a shorter waiting time for the organ recipient and greater assurance of graft quality and survival. The postoperative conditions made possible by laparoscopic surgery have encouraged the donation of tissues by live donors. Anesthetic treatment for patients undergoing laparoscopic surgery must be based on an understanding of the pathophysiologic changes that occur in this type of procedure so that complications can be prevented. This review provides an update of progress in laparoscopic surgery and the repercussions of anesthetic management, particularly with respect to anesthesia for kidney donors. PMID:20527345

  9. Anesthetic management of a child with relapsing polychondritis:a case report

    Institute of Scientific and Technical Information of China (English)

    JI Cun-liang; ZHANG Bing-xi; HU Gui-zhi

    2009-01-01

    @@ Relapsing polychondritis (RP) is a rare disorder of unknown cause.It is characterized by recurrent inflammation of cartilage and connective tissue.Airway complications are the most serious manifestations.1,2 The anesthetic management of patients with RP is challenging.Airway management is of primary importance because of the potential for collapse of supporting airway structures with resulting inability to intubate and ventilate the patient) Although it tends to occur in middle age (>40 years),it has been reported in younger individuals.Herein we report a case of anesthetic management of a child with RP for tracheotomy combined with insertion of T tube stent and review several other cases.

  10. 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

  11. Anesthetic considerations of an emergency decompressive craniotomy complicated with Ebstein's anomaly and atrial septal defect

    Institute of Scientific and Technical Information of China (English)

    XIN Xin; TANG Shuai; WANG Ling; ZHAO Jing; LI Gui-lin; GUO Li-lin; HUANG Yu-guang

    2011-01-01

    Despite considerable published papers regarding Ebstein's anomaly (EA) patients receiving open-heart tricuspid valve replacement, non-cardiac emergency surgeries were rarely reported. We report a case of emergency decormpressive craniotormy in a patient with EA. Anesthesiologists should pay special attention to the complications and anesthetic management during the non-cardiac surgeries performed in EA patients.hile papers regarding Ebstein's anomaly (EA)patients receiving open-heart tricuspid valve replacement are numerous, the reports of non-cardiac emergency surgeries have not been to the same degree.We report a case of emergency decompressive craniotomy in a patient with EA. This case report describes the symptoms and anesthetic management during the surgery.

  12. The temperature dependence of lipid membrane permeability, its quantized nature, and the influence of anesthetics

    CERN Document Server

    Blicher, Andreas; Fidorra, Matthias; Winterhalter, Mathias; Heimburg, Thomas

    2008-01-01

    We investigate the permeability of lipid membranes for fluorescence dyes and ions. We find that permeability reaches a maximum close to the chain melting transition of the membranes. Close to transitions, fluctuations in area and compressibility are high, leading to an increased likelihood of spontaneous lipid pore formation. Fluorescence Correlation Spectroscopy (FCS) reveals the permeability for rhodamine dyes across 100 nm vesicles. Using FCS, we find that the permeability of vesicle membranes for fluorescence dyes is within error proportional to the excess heat capacity. To estimate defect size we measure the conductance of solvent-free planar lipid bilayer. Microscopically, we show that permeation events appear as quantized current events. Further, we demonstrate that anesthetics lead to a change in membrane permeability that can be predicted from their effect on heat capacity profiles. Depending on temperature, the permeability can be enhanced or reduced. We demonstrate that anesthetics decrease channel...

  13. The cochlear implantation surgery: A review of anesthetic considerations and implications

    Directory of Open Access Journals (Sweden)

    Sukhminder Jit Singh Bajwa

    2013-01-01

    Full Text Available The advancement in the technology of the cochlear implants has resulted in increasing trend of cochlear implantation in both the children and elderly population. The anesthesiologist is faced with the task of smoothly conducting the surgery without any interference in the stimulation techniques used. The preoperative evaluation is mainly focused on the presence of any congenital anomalies in these patients which may affect anesthetic technique. The reduction of anxiety of the patient as well as the parents of small children is an important aspect of the preoperative visit. Intraoperatively the anesthetic technique chosen should not interfere with the stimulation of the cochlear implant electrode assembly. The postoperative management is mainly focused at prevention of agitation and good analgesia. A close cooperation between the surgeon and the anesthesiologist is essential for a positive outcome in this surgery. The current review focuses on the important anesthesia aspects related to cochlear implant surgery.

  14. Evaluation of anesthetic effect of ropivacaine in surgery of chronic periapical lessions

    Directory of Open Access Journals (Sweden)

    Tijanić Miloš

    2010-01-01

    Full Text Available Introduction. Ropivacaine is used in orthopedcs, gyneacology, surgery, ophtamology, whereas experience about its usage in dentistry is still limited. The aim of this research was to compare the anesthetic effect between local anesthetics ropivacaine and bupivacaine, in surgical disposals of chronical periapical lessions in maxilla. Material and methods. The study included the patients that had indications for surgical removal of chronical periapical lessions at one of the frontal teeth of upper jaw. The total total number of examinees was 60, and they were devided in two groups. Ropivacaine chloride (0.75% was used as a local anesthetic in one group (Naropin® 0,75%; Astra Zeneca, and in the other one bupivacaine chloride (0.5% (Vexelit® 0,5%; Zdravlje. The autors applied 1,8 ml of block anesthesia for the n. infraorbitalis (intraoral approach as well as 0,2 ml of the local anesthetic from the palatine side for the final branches of n. nasopalatinus in order to observe the folloving anesthetic parameters. I. Beginning of anesthesia was followed by the appearence of upper lip numbness. II. Pain rating scale according to Sisk was used for the objective measurement of the anesthesia quality. III. The pain intensity during the intervention was measured by visual analogous scale, on which the patient denoted the intensity of pain he had felt during the intervention. IV. Duration of anesthetic effect - it is followed by soft tissues numbness. Results and discussion. After the ropivacaine application anesthesia effect started in 1.57 min. and after the usage of bupivacaine in 1.67 min. The mean duration of soft tissue numbness after the application of ropivacaine was 321 minutes. Bupivacaine had a shorter anesthetic effect - 296.5 minutes. The quality of anesthesia after the usage of ropivacaine was assessed by the surgeons with average mark - 1.76. Interventions in which this anesthetic was used were performed with minimal pain and without additional

  15. 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....

  16. A Comprehensive Review of Volatile Data Forensics

    Directory of Open Access Journals (Sweden)

    Dilpreet Singh Bajwa

    2016-05-01

    Full Text Available Volatile data forensics is a new challenging field required attention. Volatile data forensics must consider be a part of digital forensic process rather than individual process. It provides important and crucial information not acquired by following traditional forensic process. While we are following traditional forensic process, the important information like current state of system, running processes, open ports, recent established connections, username and passwords, unencrypted data and keys, traces of malwares and anti-forensic activities may be missed out which are present in volatile memory of system while system is in running state.. Volatile data is a source of this type of information and leads investigation fast in right direction. This paper provides a detailed view of need, challenges, tools, techniques required for volatile data forensics and importance of this field in digital investigation process.

  17. Volatility jumps and their economic determinants

    DEFF Research Database (Denmark)

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

    The volatility of financial returns is characterized by rapid and large increments. We propose an extension of the Heterogenous Autoregressive model to incorporate jumps into the dynamics of the ex-post volatility measures. Using the realized-range measures of 36 BNYSE stocks, we show that there ......The volatility of financial returns is characterized by rapid and large increments. We propose an extension of the Heterogenous Autoregressive model to incorporate jumps into the dynamics of the ex-post volatility measures. Using the realized-range measures of 36 BNYSE stocks, we show...... predictive power on expected jump moves, thus confirming the common interpretation that sudden and large increases in equity volatility can be anticipated by credit deterioration of the US bank sector as well as changes in the market expectations of future risks. Finally, the model is extended to incorporate...

  18. Price volatility in wind dominant electricity markets

    DEFF Research Database (Denmark)

    Farashbashi-Astaneh, Seyed-Mostafa; Chen, Zhe

    2013-01-01

    High penetration of intermittent renewable energy sources causes price volatility in future electricity markets. This is specially the case in European countries that plan high penetration levels. This highlights the necessity for revising market regulations and mechanisms in accordance to genera......High penetration of intermittent renewable energy sources causes price volatility in future electricity markets. This is specially the case in European countries that plan high penetration levels. This highlights the necessity for revising market regulations and mechanisms in accordance...... electricity markets. High price volatility is unappreciated because it imposes high financial risk levels to both electricity consumers and producers. Additionally high price variations impede tracking price signals by consumers in future smart grid and jeopardize implementation of demand response concepts....... The main contribution of this paper is to quantify volatility patterns of electricity price, as penetration level of wind power increases. Results explain a direct relationship between wind penetration and electricity price volatility in a quantitative manner....

  19. Empirical analysis of structural change in Credit Default Swap volatility

    International Nuclear Information System (INIS)

    The purpose of this paper is to study the structural change in Credit Default Swap volatility. We use statistical properties and a network approach to better understand the behavior of CDS volatility. We hypothesize that structural change occurs in CDS index during a financial crisis and it requires subperiod analysis, rather than full period analysis, to investigate properly. Our results show that the probability of large volatility is related to the structure of volatility but it is more significantly related to the size of volatility. Both the memory property and the size of volatility are confirmed to have dependence on the structure of volatility. The linked degree of CDS volatilities is highly related to the probability of large volatility and its predictability, regardless of structural change in volatility. Another interesting result is that the CDS volatility of a country is more related to the behavior of other volatilities, not the geographical location

  20. [Intern(euron)al affairs : The role of specific neocortical interneuron classes in the interaction between acetylcholine and GABAergic anesthetics].

    Science.gov (United States)

    Liebig, L; Grasshoff, C; Hentschke, H

    2016-08-01

    Acetylcholine is a neuromodulator which is released throughout the central nervous system and plays an essential role in consciousness and cognitive processes including attention and learning. Due to its 'activating' effect on the neuronal and behavioral level its interaction with anesthetics has long been of interest to anesthesiologists. It is widely held that a reduction of the release of acetylcholine by general anesthetics constitutes part of the anesthetic effect. This notion is backed by numerous human and animal studies, but is also in seeming contradiction to findings that acetylcholine activates specific classes of inhibitory neurons: if acetylcholine excites elements within the neuronal network responsible for the release of the inhibitory neurotransmitter γ-aminobutyric acid (GABA), its withdrawal should diminish, not enhance, the effect of anesthetics.Focusing on cortical circuits, we present an overview of recent advances in cellular neurophysiology, particularly the interactions between inhibitory neuron classes, which provide insights on the interaction between acetylcholine and GABA. PMID:27380048

  1. The Role of Needle Purging in Reducing Transfer of Microorganisms From Local Anesthetic Cartridge Diaphragms

    OpenAIRE

    Nelson, Barbara A.; Rawson, Raymond D.; Hiatt, Hermi D.

    1985-01-01

    The literature is reviewed to demonstrate the significant amount of contamination on the external surface of the anesthetic cartridge diaphragm. Current methods of cartridge diaphragm decontamination to prevent injection of pathogens are discussed. A series of bacteriologic tests were conducted to determine the probability of transfer of pathogens from the diaphragm surface through the needle lumen of three different sizes to the deposition site. Results of needle purging suggest that a signi...

  2. 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

  3. Anesthetic implications of total anomalous systemic venous connection to left atrium with left isomerism

    OpenAIRE

    Parimala Prasanna Simha; Muralidhara Danappa Patel; Jagadeesh, A. M.

    2012-01-01

    Total anomalous systemic venous connection (TASVC) to the left atrium (LA) is a rare congenital anomaly. An 11-year-old girl presented with complaints of palpitations and cyanosis. TASVC with left isomerism and noncompaction of LV was diagnosed after contrast echocardiogram and computed tomography angiogram. The knowledge of anatomy and pathophysiology is essential for the successful management of these cases. Anesthetic concerns in this case were polycythemia, paradoxical embolism and rhythm...

  4. Vagal-dependent nonlinear variability in the respiratory pattern of anesthetized, spontaneously breathing rats

    OpenAIRE

    Dhingra, R. R.; Jacono, F. J.; Fishman, M; Loparo, K. A.; Rybak, I. A.; Dick, T E

    2011-01-01

    Physiological rhythms, including respiration, exhibit endogenous variability associated with health, and deviations from this are associated with disease. Specific changes in the linear and nonlinear sources of breathing variability have not been investigated. In this study, we used information theory-based techniques, combined with surrogate data testing, to quantify and characterize the vagal-dependent nonlinear pattern variability in urethane-anesthetized, spontaneously breathing adult rat...

  5. 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.

  6. Chiral selective effects of doxazosin enantiomers on blood pressure and urinary bladder pressure in anesthetized rats

    Institute of Scientific and Technical Information of China (English)

    Shi-ping MA; Lei-ming REN; Ding ZHAO; Zhong-ning ZHU; Miao WANG; Hai-gang LU; Li-hua DUAN

    2006-01-01

    Aim: To study chiral selective effects of doxazosin enantiomers on blood pressure and urinary bladder pressure in anesthetized rats. Methods: In anesthetized rats, the carotid blood pressure, left ventricular pressure of the heart and the urinary bladder pressure were recorded. Results: Administration of S-doxazosin at 0.25, 2.5, 25, and 250 nmol/kg iv produced a dose-dependent decrease in blood pressure, but its depressor effect was significantly weaker than that induced by R-doxazosin and racemic-doxazosin (rac-doxazosin), and the ED30 values (producing a 30% decrease in mean arterial pressure) of R-doxazosin, rac-doxazosin and S-doxazosin were 15.64,45.93, and 128.81, respectively. Rac-doxazosin and its enantiomers administered cumulatively in anesthetized rats induced a dose-dependent decrease in the left ventricular systolic pressure and ±dp/dtmax, and the potency order of the 3 agents was R-doxazosin >rac-doxazosin >S-doxazosin. Rac-doxazosin and its enantiomers decreased the vesical micturition pressure dose-dependently at 2.5,25, and 250 nmol/kg, and the inhibitory potency among the 3 agents was not significantly different. Conclusion: S-doxazosin decreases the carotid blood pressure and left ventricular pressure of the heart less than R-doxazosin and rac-doxazosin, but its effect on the vesical micturition pressure is similar to R-doxazosin and rac-doxazosin, indicating that S-doxazosin has chiral selectivity between cardiovascular system and urinary system in anesthetized rats.

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

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    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.

  8. Anesthetic management of a patient with Huntington's chorea -A case report-

    OpenAIRE

    Kang, Jong-Man; Chung, Jun-Young; Han, Jin Hee; Kim, Yung-Suk; Lee, Bong Jae; Yi, Jae-Woo

    2013-01-01

    Huntington's chorea is a rare hereditary disorder of the nervous system. It is inherited as an autosomal dominant disorder and is characterized by progressive chorea, dementia and psychiatric disturbances. The best anesthetic technique is yet to be established for these patients with increased risk of aspiration due to involvement of pharyngeal muscles and an exaggerated response to sodium thiopental and succinylcholine. The primary goal in general anesthesia for these patients is to provide ...

  9. In vivo assessment of arterial stiffness in the isoflurane anesthetized spontaneously hypertensive rat

    OpenAIRE

    Morgan, Eric E.; Casabianca, Andrew B; Khouri, Samer J; Kalinoski, Andrea L. Nestor

    2014-01-01

    Background Rodent models are increasingly used to study the development and progression of arterial stiffness. Both the non-invasive Doppler derived Pulse Wave Velocity (PWV) and the invasively determined arterial elastance index (EaI) have been used to assess arterial stiffness in rats and mice, but the need for anesthetic agents to make these in vivo estimates may limit their utility. Thus, we sought to determine: 1) if known differences in arterial stiffness in spontaneously hypertensive r...

  10. Brainstem Regions Involved in the Expiration Reflex. A c-fos Study in Anesthetized Cats

    OpenAIRE

    Poliacek, Ivan; Halasova, Erika; Jakus, Jan; Murin, Peter; Barani, Helena; Stransky, Albert; Bolser, Donald C.

    2007-01-01

    Expression of the immediate-early gene c-fos, a marker of neuronal activation, was employed to localize brainstem neuronal populations functionally related to the expiration reflex (ER). Twelve spontaneously breathing, non-decerebrate, pentobarbital anesthetized cats were used. The level of Fos-like immunoreactivity (FLI) in 6 animals with repetitive ERs mechanically induced from the glottis (296±9 ERs) was compared to FLI in 6 control non-stimulated cats. Respiratory rate, arterial blood pre...

  11. Do Local Anesthetics Containing Epinephrine Affect Blood Pressure in the Elderly?

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    Ayse Arpaci

    2014-11-01

    Full Text Available Aim: Dental procedures are often performed under local anesthesia. Vasoconstrictors added to local anesthetics might have unwanted effects in the elderly and in patients with comorbid diseases. The aim of this study was to evaluate the effects of local anesthetics containing epinephrine on blood pressure in elderly patients undergoing dental procedures. Material and Method: The study included 479 patients (age, 67.37±6.62 who underwent tooth extraction. Patient demographics, current health conditions, and blood pressure values were recorded before local anesthesia and at 5 minutes after anesthesia administration. Patients were divided into 4 groups: Group I (n=272 received 40 mg articaine/0.012 mg epinephrine (Ultracain® D-S Forte; Group II (n=196 received 40 mg articaine/0.01 mg epinephrine (Maxicaine FORT; Group III (n=6 received 40 mg articaine/0.006 mg epinephrine (Ultracain® D-S; and Group IV (n=5 received 40 mg articaine/0.005 mg epinephrine (Maxicaine. Statistical analyses were performed using SPSS version 20.0. Results: A total of 479 patients were included in the analysis. Hypertension and diabetes were the most frequently reported comorbidities among these patients. Blood pressure values after administration of anesthesia were higher than those recorded before the procedure in all groups. Discussion: Local anesthetics containing epinephrine are not associated with a significant increase in blood pressure in elderly patients undergoing dental procedures. Obtaining a detailed clinical history may reduce the risk of procedure-related morbidity.

  12. Efficiency of eugenol as anesthetic for the early life stages of Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Ribeiro, Paula A P; Miranda-Filho, Kleber C; Melo, Daniela C de; Luz, Ronald K

    2015-03-01

    In aquaculture, activities with anesthetic compounds are usually used in order to ensure the welfare of farmed fish, allowing handling out of water with decreased trauma by stress. Presently, there is no information about anesthetic action of eugenol in early life stages of Nile tilapia (Oreochromis niloticus). The objective of this study was to evaluate different concentrations of eugenol for larvae and juveniles of Nile tilapia. Sixty animals were used for each group of weight, group I = 0.02 g; group II = 0.08 g; group III = 0.22 g; group IV = 2.62 g; and group V = 11.64 g. The eugenol concentrations tested were 50, 75, 100, 125, 150 and 175 mg L-1. No mortality was reported during the tests with eugenol. Tilapia larvae with 0.02 g and juveniles around 11.64 g can be anesthetized with eugenol concentrations between 150 and 175 mg L-1, since they determine the shortest sedation time (23 and 72 seconds, for the group of lowest and highest weights, respectively).

  13. Sevoflurane Induces DNA Damage Whereas Isoflurane Leads to Higher Antioxidative Status in Anesthetized Rats

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    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.

  14. Temporal changes in ventricular function assessed echocardiographically in conscious and anesthetized mice.

    Science.gov (United States)

    Rottman, Jeffrey N; Ni, Gemin; Khoo, Michelle; Wang, Zhizhang; Zhang, Wei; Anderson, Mark E; Madu, Ernest C

    2003-11-01

    The mouse is an important model system for cardiovascular biology, with echocardiography a critical tool for noninvasive measurement of cardiac morphology and function. The feasibility and short-term temporal consistency of repeated echocardiographic measurements in conscious mice has not been previously evaluated. We performed serial 2-dimensional guided M-mode transthoracic echocardiographic measurements at 5- to 10-minute intervals over 60 minutes in conscious mice and in mice treated with 1 of 3 anesthetic regimens: ketamine and acepromazine (n = 14); pentobarbital (n = 14); and ketamine and xylazine (n = 13). Unanesthetized mice received intraperitoneal saline (n = 6) or no injection (n = 7). In sequentially repeated measurements over 1 hour in conscious mice, none of the measured or derived echocardiographic parameters differed from baseline, whereas all 3 anesthetic regimens produced significant, prolonged, and temporally variable decreases in heart rate and fractional shortening. The relationship between heart rate and fractional shortening was not altered by anesthetic choice. Serial echocardiographic assessments of cardiac function, dimension, and mass can be performed with high reproducibility in conscious mice.

  15. Evaluation of common anesthetic and analgesic techniques for tail biopsy in mice.

    Science.gov (United States)

    Jones, Carissa P; Carver, Scott; Kendall, Lon V

    2012-11-01

    Tail biopsy in mice is a common procedure in genetically modified mouse colonies. We evaluated the anesthetic and analgesic effects of various agents commonly used to mitigate pain after tail biopsy. We used a hot-water immersion assay to evaluate the analgesic effects of isoflurane, ice-cold ethanol, ethyl chloride, buprenorphine, and 2-point local nerve blocks before studying their effects on mice receiving tail biopsies. Mice treated with ethyl chloride spray, isoflurane and buprenorphine, and 2-point local nerve blocks demonstrated increased tail-flick latency compared with that of untreated mice. When we evaluated the behavior of adult and preweanling mice after tail biopsy, untreated mice demonstrated behavioral changes immediately after tail biopsy that lasted 30 to 60 min before returning to normal. The use of isoflurane, isoflurane and buprenorphine, buprenorphine, 2-point nerve block, or ethyl chloride spray in adult mice did not significantly improve their behavioral response to tail biopsy. Similarly, the use of buprenorphine and ethyl chloride spray in preweanling mice did not improve their behavioral response to tail biopsy compared with that of the untreated group. However, immersion in bupivacaine for 30 s after tail biopsy decreased tail grooming behavior during the first 30 min after tail biopsy. The anesthetic and analgesic regimens tested provide little benefit in adult and preweanling mice. Given that tail biopsy results in pain that lasts 30 to 60 min, investigators should carefully consider the appropriate anesthetic or analgesic regimen to incorporate into tail-biopsy procedures for mice.

  16. Cardioprotective effects of anesthetic preconditioning in rats with ischemia-reperfusion injury: propofol versus isoflurane

    Institute of Scientific and Technical Information of China (English)

    Xing TAO; Ling-qiao LU; Qing XU; Shu-ren LI; Mao-tsun LIN

    2009-01-01

    Objective: We compare the cardioprotective effects of anesthetic preconditioning by propofol and/or isoflurane in rats with ischemia-reperfusion injury. Methods: Male adult Wistar rats were subjected to 60 min of anterior descending coronary artery occlusion followed by 120 min of reperfusion. Before the long ischemia, anesthetics were administered twice for 10 min followed by 5 min washout. Isoflurane was inhaled at I MAC (0.016) in I group, whereas propofol was inhaled intravenously at 37.5 mg/(kg.h) in P group. A combination ofisoflurane and propofol was administered simultaneously in I+P group. Results: In control (without anesthetic preconditioning, C group), remarkable myocardial infarction and apoptosis accompanied by an increased level of cardiac troponin T were noted 120 rain after ischemia-reperfusion. As compared to those of control group, I and P groups had comparable cardioprotection. In addition, I+P group shares with I and P groups the comparable cardioprotective effects in terms of myocardial infarction and cardiac troponin T elevation. Conclusion: A combination of isoflurane and propofol produced no ad-ditional cardioprotection.

  17. Cleft lip and palate: recommendations for dental anesthetic procedure based on anatomic evidences

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    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.

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

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    Tomoharu Tanaka

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.

  19. Effect of needle design on pain from dental local anesthetic injections.

    Science.gov (United States)

    McPherson, Joanna Saenz; Dixon, Sara A; Townsend, Richard; Vandewalle, Kraig S

    2015-01-01

    The purpose of this randomized, double-blind clinical study was to evaluate the effectiveness of a larger-bore compared with a standard-bore dental local anesthetic needle of the same gauge in reducing pain during inferior alveolar (IA) and long buccal (LB) nerve block injections. Twenty active duty military or Department of Defense beneficiaries undergoing dental treatment were anesthetized using a split-mouth design with 4 anesthetic dental injections. Both sides of the mouth received IA nerve block and LB nerve injections, one using the 27-gauge large-bore Septoject XL needle and other using a 27-gauge standard-bore Septoject needle. Patients rated the pain experienced with each method using a visual analogue scale (VAS). The IA injection mean VAS score and standard deviation were 38.9 ± 22.7 mm and 37.1 ± 22.4 mm, respectively, for the larger and standard-bore needles. The LB injection mean VAS score and standard deviation were 33.5 ± 22.8 mm and 35.1 ± 19.6 mm, respectively, for the larger and standard-bore needles. The data were analyzed with a paired t test (α = .05). No significant difference was found between the IA (P = .70) or LB injections (P = .73). The use of a larger-bore 27-gauge needle did not reduce pain on injection compared with the standard-bore 27-gauge needle.

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

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    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.

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

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    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.

  2. Thrombotic stroke in the anesthetized monkey (Macaca mulatta): characterization by MRI - A pilot study

    International Nuclear Information System (INIS)

    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)

  3. Effects of topical anesthetic and flexible fiberoptic laryngoscopy on professional sopranos.

    Science.gov (United States)

    Jacobs, Margaret A; Kenny, Dianna T

    2005-12-01

    This study examined the acoustic and perceptual effects of topical anesthetic and flexible fiberoptic laryngoscopy (FFL) against a control condition on the singing voices of ten professional sopranos. Recordings of a section of an aria, various scales, and a messa di voce exercise were obtained in the three experimental conditions. Acoustic analyses of the same aria section recorded during the three conditions were similar with respect to the distribution of energy across the spectrum (LTAS) and vibrato rate and extent. The ability of the participants to achieve their highest and lowest notes or to complete the messa di voce was also not affected by the anesthetic or FFL. Perceptual ratings of a variety of parameters by experienced singing teachers also revealed little difference across conditions with only "appropriate velopharyngeal closure" found to differ in one comparison. These results indicate that highly experienced operatic sopranos are either not affected by or appear to have the ability to compensate for the presence of anesthetic and the FFL. The most likely explanation is that this group of singers relied on a solid vocal technique. Results will need to be replicated on less accomplished singers before concluding that this medical procedure does not affect the operatic singing voice. PMID:16301108

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

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    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.

  5. Efficacy of epidural local anesthetic and dexamethasone in providing postoperative analgesia: A meta-analysis

    Science.gov (United States)

    Jebaraj, B; Khanna, P; Baidya, DK; Maitra, S

    2016-01-01

    Background: Dexamethasone is a potent anti-inflammatory, analgesic, and antiemetic drug. Individual randomized controlled trials found a possible benefit of epidural dexamethasone. The purpose of this meta-analysis is to estimate the benefit of epidural dexamethasone on postoperative pain and opioid consumption and to formulate a recommendation for evidence-based practice. Materials and Methods: Prospective, randomized controlled trials comparing the analgesic efficacy of epidural local anesthetic and dexamethasone combination, with local anesthetic alone for postoperative pain management after abdominal surgery, were planned to be included in this meta-analysis. PubMed, PubMed Central, Scopus, and Central Register of Clinical Trials of the Cochrane Collaboration (CENTRAL) databases were searched for eligible controlled trials using the following search words: “Epidural”, “dexamethasone”, and “postoperative pain”, until February 20, 2015. Results: Data from five randomized control trials have been included in this meta-analysis. Epidural dexamethasone significantly decreased postoperative morphine consumption (mean difference −7.89 mg; 95% confidence interval [CI]: −11.66 to −3.71) and number of patients required postoperative rescue analgesic boluses (risk ratio: 0.51; 95% CI: 0.41-0.63). Conclusion: The present data shows that the addition of dexamethasone to local anesthetic in epidural is beneficial for postoperative pain management. PMID:27375389

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

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    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.

  7. Esmolol reduces anesthetic requirements thereby facilitating early extubation; a prospective controlled study in patients undergoing intracranial surgery

    OpenAIRE

    Asouhidou, Irene; Trikoupi, Anastasia

    2015-01-01

    Background Adequate cerebral perfusion pressure with quick and smooth emergence from anesthesia is a major concern of the neuroanesthesiologist. Anesthesia techniques that minimize anesthetic requirements and their effects may be beneficial. Esmolol, a short acting hyperselective β-adrenergic blocker is effective in blunting adrenergic response to several perioperative stimuli and so it might interfere in the effect of the anesthetic drugs on the brain. This study was designed to investigate ...

  8. Local Anesthetics Induce Apoptosis in Human Thyroid Cancer Cells through the Mitogen-Activated Protein Kinase Pathway

    OpenAIRE

    Yuan-Ching Chang; Yi-Chiung Hsu; Chien-Liang Liu; Shih-Yuan Huang; Meng-Chun Hu; Shih-Ping Cheng

    2014-01-01

    Local anesthetics are frequently used in fine-needle aspiration of thyroid lesions and locoregional control of persistent or recurrent thyroid cancer. Recent evidence suggests that local anesthetics have a broad spectrum of effects including inhibition of cell proliferation and induction of apoptosis in neuronal and other types of cells. In this study, we demonstrated that treatment with lidocaine and bupivacaine resulted in decreased cell viability and colony formation of both 8505C and K1 c...

  9. A note on the pricing and hedging of volatility derivatives

    OpenAIRE

    Sam Howison; A. Rafailidis; H.O. Rasmussen

    2001-01-01

    We consider the pricing of volatility products and especially volatility and variance swaps. Under risk-neutral valuation we provide closed form formulae for volatility-average and variance swaps. Also we provide a general partial differential equation for derivatives that have an extra dependence on an average of the volatility. We give approximate solutions of this equation for volatility products written on assets for which the volatility process fluctuates on a timescale that is fast comp...

  10. On the pricing and hedging of volatility derivatives

    OpenAIRE

    Howison, Sam; Rafailidis, Avraam; Rasmussen, Henrik

    2003-01-01

    We consider the pricing of a range of volatility derivatives, including volatility and variance swaps and swaptions. Under risk-neutral valuation we provide closed-form formulae for volatility-average and variance swaps for a variety of diffusion and jump-diffusion models for volatility. We describe a general partial differential equation framework for derivatives that have an extra dependence on an average of the volatility. We give approximate solutions of this equation for volatility produ...

  11. Forecasting Volatilities of Corn Futures at Distant Horizons

    OpenAIRE

    Wu, Feng; Guan, Zhengfei

    2010-01-01

    Accurately forecasting volatility at distant horizons is critical for managing long-term risk in agriculture. Given the poor performance of GARCH-type models at long-term volatility forecast, we develop a risk-adjusted implied volatility, which adjust the risk-neutral implied volatility by correctly accounting for the volatility risk premium. The paper evaluates the performance of the new implied volatility in the corn futures market relative to two alternative forecasts- a three-year moving ...

  12. A comparative study of embedded and anesthetized zebrafish in vivo on myocardiac calcium oscillation and heart muscle contraction

    Directory of Open Access Journals (Sweden)

    Brian eMuntean

    2010-12-01

    Full Text Available The zebrafish (Danio rerio has been used as a model for studying vertebrate development in the cardiovascular system. In order to monitor heart contraction and cytosolic calcium oscillations, fish were either embedded in methylcellulose or anesthetized with tricaine. Using high-resolution differential interference contrast (DIC and calcium imaging microscopy, we here show that dopamine and verapamil alter calcium signaling and muscle contraction in anesthetized zebrafish, but not in embedded zebrafish. In anesthetized fish, dopamine increases the amplitude of cytosolic calcium oscillation with a subsequent increase in heart contraction, whereas verapamil decreases the frequency of calcium oscillation and heart rate. Interestingly, verapamil also increases myocardial contraction. Our data further indicate that verapamil can increase myocardial calcium sensitivity in anesthetized fish. Taken together, our data reinforce in vivo cardiac responses to dopamine and verapamil. Furthermore, effects of dopamine and verapamil on myocardial calcium and contraction are greater in anesthetized than embedded fish. We suggest that while the zebrafish is an excellent model for a cardiovascular imaging study, the cardio-pharmacological profiles are very different between anesthetized and embedded fish.

  13. A quest to increase safety of anesthetics by advancements in anesthesia monitoring: scientometric analysis.

    Science.gov (United States)

    Vlassakov, Kamen V; Kissin, Igor

    2015-01-01

    The aim of this study was to assess progress in the field of anesthesia monitoring over the past 40 years using scientometric analysis. The following scientometric indexes were used: popularity indexes (general and specific), representing the proportion of articles on either a topic relative to all articles in the field of anesthetics (general popularity index, GPI) or the subfield of anesthesia monitoring (specific popularity index, SPI); index of change (IC), representing the degree of growth in publications on a topic from one period to the next; and index of expectations (IE), 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. Publications on 33 anesthesia-monitoring topics were assessed. Our analysis showed that over the past 40 years, the rate of rise in the number of articles on anesthesia monitoring was exponential, with an increase of more than eleven-fold, from 296 articles over the 5-year period 1974-1978 to 3,394 articles for 2009-2013. This rise profoundly exceeded the rate of rise of the number of articles on general anesthetics. The difference was especially evident with the comparison of the related GPIs: stable growth of the GPI for anesthesia monitoring vs constant decline in the GPI for general anesthetics. By the 2009-2013 period, among specific monitoring topics introduced after 1980, the SPI index had a meaningful magnitude (≥1.5) in 9 of 24 topics: Bispectral Index (7.8), Transesophageal Echocardiography (4.2), Electromyography (2.8), Pulse Oximetry (2.4), Entropy (2.3), Train-of-four (2.3), Capnography (1.9), Pulse Contour (1.9), and Electrical Nerve Stimulation for neuromuscular monitoring (1.6). Only one of these topics (Pulse Contour) demonstrated (in 2009-2013) high values for both IC and IE indexes (76 and 16.9, respectively), indicating significant recent progress. We suggest that rapid growth in the field of

  14. Analyzing binding data.

    Science.gov (United States)

    Motulsky, Harvey J; Neubig, Richard R

    2010-07-01

    Measuring the rate and extent of radioligand binding provides information on the number of binding sites, and their affinity and accessibility of these binding sites for various drugs. This unit explains how to design and analyze such experiments.

  15. 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.

  16. Volatility persistence in crude oil markets

    International Nuclear Information System (INIS)

    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

  17. 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 have raised concern that climate change could increase food insecurity by reducing grain yields in the coming decades. However, commodity price volatility is also influenced by other factors, 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 United States, which causes US corn price volatility to increase sharply in response to global warming projected to occur 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.

  18. One Fundamental and Two Taxes: When Does a Tobin Tax Reduce Financial Price Volatility?

    OpenAIRE

    Yongheng Deng; Xin Liu; Shang-Jin Wei

    2014-01-01

    We aim to make two contributions to the literature on the effects of transaction costs on financial price volatility. First, by using a research design with three ingredients (a common set of companies simultaneously listed on two stock exchanges; binding capital controls; different timing of changes in transaction costs), we obtain a control group that has identical corporate fundamentals as the treatment group and is therefore far cleaner than any in the existing literature. We apply the re...

  19. 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.

  20. Modelling of volatility in monetary transmission mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel [Department of Statistics and Operation Analysis, Faculty of Business and Economics, Mendel University in Brno, Zemědělská 1, 61300, Brno (Czech Republic); Bednářová, Petra [Institute of Technology and Business, Okružní 517/10, 370 01, České Budějovice (Czech Republic)

    2015-03-10

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

  1. Cyclodextrin-based microsensors for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, B.; Johnson, S.; Shi, J.; Yang, Xiaoguang

    1997-10-01

    Host-guest chemistry and self-assembly techniques are being explored to develop species selective thin-films for real-time sensing of volatile organic compounds (VOCs). Cyclodextrin (CD) and calixarene (CA) molecules are known to form guest-host inclusion complexes with a variety of organic molecules. Through the control of the cavity size and chemical functionality on the rims of these bucket-like molecules, the binding affinities for formation of inclusion complexes can be controlled and optimized for specific agents. Self-assembly techniques are used to covalently bond these reagent molecules to the surface of acoustic transducers to create dense, highly oriented, and stable thin films. Self-assembly techniques have also been used to fabricate multilayer thin film containing molecular recognition reagents through alternating adsorption of charged species in aqueous solutions. Self-assembly of polymeric molecules of the SAW device was also explored for fabricating species selective interfaces.

  2. Lunar In-Situ Volatile Extraction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A method of extracting volatile resources from the Lunar regolith is proposed to reduce the launch mass and cost of bringing such resources from the Earth to enable...

  3. Volatile profile of wine Teran PTP

    Directory of Open Access Journals (Sweden)

    Helena BAŠA ČESNIK

    2015-11-01

    Full Text Available Teran PTP is a protected wine with a recognized traditional denomination produced from a grapevine variety ‘Refošk’ in winegrowing district Kras in Slovenia (European Union, 2009; Pravilnik, 2008. The aromatic profile of 82 Teran PTP wines produced in years 2011, 2012 and 2013 was monitored. Intotal the content of 16 volatile compounds was determined. The volatile compounds from wine were extracted following the liquid-liquid extraction and determined with a GC-MS method. The odour activity values and relative odour contributions were calculated for each volatile compound identified. Among sensorial important volatiles the highest odour activity values were determined for ethyl octanoate, ethyl hexanoate, isoamyl acetate and ethyl butyrate. Other research papers also showed, that all red wines investigated except one contained ethyl octanoate, ethyl hexanoate, isoamyl acetate and ethyl butyrate above sensory thresholds.

  4. 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.

  5. Asymmetry and Leverage in Conditional Volatility Models

    NARCIS (Netherlands)

    M.J. McAleer (Michael)

    2014-01-01

    markdownabstract__Abstract__ The three most popular univariate conditional volatility models are the generalized autoregressive conditional heteroskedasticity (GARCH) model of Engle (1982) and Bollerslev (1986), the GJR (or threshold GARCH) model of Glosten, Jagannathan and Runkle (1992), and the e

  6. Assessing relative volatility/intermittency/energy dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko S.; Schmiegel, Jürgen

    2014-01-01

    process in particular. This estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, but it is also applicable in other areas. We develop a probabilistic asymptotic theory for realised relative power variations of Brownian semistationary processes......, and introduce inference methods based on the theory. We also discuss how to extend the asymptotic theory to other classes of processes exhibiting stochastic volatility/intermittency. As an empirical application, we study relative energy dissipation in data of atmospheric turbulence.......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...

  7. MEASURING COMMODITY PRICE VOLATILITY AND THE WELFARE CONSEQUENCES OF ELIMINATING VOLATILITY.

    OpenAIRE

    Moledina, Amyaz A.; Roe, Terry L.; Shane, Mathew

    2004-01-01

    Commodity price volatility in international markets has been used to justify numerous policy interventions, including the need for buffer stocks and counter-cyclical payments. The common measure of volatility, the standard deviation or coefficient of variation, likely overstates the actual variation faced by economic agents. By making a distinction between its predictable and unpredictable components, volatility is found to be low, suggesting that significant welfare gains may be unattainable...

  8. 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

  9. Malaria Parasites Produce Volatile Mosquito Attractants

    OpenAIRE

    Kelly, Megan; Su, Chih-Ying; Schaber, Chad; Crowley, Jan R.; Hsu, Fong-Fu; Carlson, John R.; Odom, Audrey R.

    2015-01-01

    ABSTRACT The malaria parasite Plasmodium falciparum contains a nonphotosynthetic plastid organelle that possesses plant-like metabolic pathways. Plants use the plastidial isoprenoid biosynthesis pathway to produce volatile odorants, known as terpenes. In this work, we describe the volatile chemical profile of cultured malaria parasites. Among the identified compounds are several plant-like terpenes and terpene derivatives, including known mosquito attractants. We establish the molecular ident...

  10. Implied Volatility Surface: Construction Methodologies and Characteristics

    OpenAIRE

    Cristian Homescu

    2011-01-01

    The implied volatility surface (IVS) is a fundamental building block in computational finance. We provide a survey of methodologies for constructing such surfaces. We also discuss various topics which can influence the successful construction of IVS in practice: arbitrage-free conditions in both strike and time, how to perform extrapolation outside the core region, choice of calibrating functional and selection of numerical optimization algorithms, volatility surface dynamics and asymptotics.

  11. Investors Behavior under Changing Market Volatility

    OpenAIRE

    Daviou, Agustin; Paraschiv, Florentina

    2014-01-01

    This paper analyzes the reaction of the S&P 500 returns to changes in implied volatility given by the VIX index, using a daily data sample from 1990 to 2012. We found that in normal regimes increases (declines) in the expected market volatility result in lower (higher) subsequent stock market returns. Thus, investors enter into selling positions upon a perception of increased risk for their equity investments, while they enter into long positions when they perceive an improved environment for...

  12. Valuation equations for stochastic volatility models

    OpenAIRE

    Bayraktar, Erhan; Kardaras, Constantinos; Xing, Hao

    2012-01-01

    We analyze the valuation partial differential equation for European contingent claims in a general framework of stochastic volatility models where the diffusion coefficients may grow faster than linearly and degenerate on the boundaries of the state space. We allow for various types of model behavior: the volatility process in our model can potentially reach zero and either stay there or instantaneously reflect, and the asset-price process may be a strict local martingale. Our main result is ...

  13. Volume, Volatility and Public News Announcements

    OpenAIRE

    Bollerslev, Tim; Li, Jia; Xue, Yuan

    2016-01-01

    We provide new empirical evidence for the way in which financial markets process information. Our results are based on high-frequency intraday data along with new econometric techniques for making inference on the relationship between trading intensity and spot volatility around public news announcements. Consistent with the predictions derived from a theoretical model in which investors agree to disagree, our estimates for the intraday volume-volatility elasticity around the most important n...

  14. 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.

  15. Volatile compounds of functional dairy products

    OpenAIRE

    Iličić Mirela D.; Milanović Spasenija D.; Carić Marijana Đ.; Kanurić Katarina G.; Vukić Vladimir R.; Hrnjez Dajana V.; Ranogajec Marjan I.

    2012-01-01

    Volatile compounds, affecting flavour of traditional and probiotic fresh cheese, were determined. Functional dairy product-fresh cheese was produced from milk of 2.5% fat content and milk of 4.2% fat content, under the semi-industrial conditions. The traditional starter culture Flora Danica (FD) and a combination of probiotic starter ABT-1 and FD (ABT-1:FD=1:1) were applied as starters. The volatile fractions were isolated by employing the combined simultaneous distillation-extraction t...

  16. Investor attention and FX market volatility

    OpenAIRE

    Goddard, John; Kita, Arben; Wang, Qingwei

    2015-01-01

    We study the relationship between investors’ active attention, measured by a Google search volume index (SVI), and the dynamics of currency prices. Investor attention is correlated with the trading activities of large FX market participants. Investor attention comoves with contemporaneous FX market volatility and predicts subsequent FX market volatility, after controlling for macroeconomic fundamentals. In addition, investor attention is related to the currency risk premium. Our results sugge...

  17. Stock Market Volatility and the Business Cycle

    OpenAIRE

    Burkhard Raunig; Johann Scharler

    2010-01-01

    In this paper we provide a review of the literature on the link between stock market volatility and aggregate demand. In particular, we focus on the implications of the so-called uncertainty hypothesis according to which it is primarily the uncertainty associated with stock market fluctuations that influences aggregate demand. Empirical studies find that stock market volatility indeed feeds back into the real economy.

  18. CREDIT DERIVATIVES PRICING WITH STOCHASTIC VOLATILITY MODELS

    OpenAIRE

    CARL CHIARELLA; SAMUEL CHEGE MAINA; CHRISTINA NIKITOPOULOS SKLIBOSIOS

    2013-01-01

    This paper proposes a model for pricing credit derivatives in a defaultable HJM framework. The model features hump-shaped, level dependent, and unspanned stochastic volatility, and accommodates a correlation structure between the stochastic volatility, the default-free interest rates, and the credit spreads. The model is finite-dimensional, and leads (a) to exponentially affine default-free and defaultable bond prices, and (b) to an approximation for pricing credit default swaps and swaptions...

  19. Intraday volatility forecasting: analysis of alternative distributions

    OpenAIRE

    Paulo Sérgio Ceretta; Fernanda Galvão de Barba; Kelmara Mendes Vieira; Fernando Casarin

    2011-01-01

    Volatility forecasting has been of great interest both in academic and professional fields all over the world. However, there is no agreement about the best model to estimatevolatility. New models include measures of skewness, changes of regimes and different distributions; few studies, though, have considered different distributions. This paper aims to investigate how the specification of a distribution influences the performance of volatility forecasting on Ibovespa intraday data, using the...

  20. Optimal directional volatile transport in retronasal olfaction

    OpenAIRE

    Ni, Rui; Michalski, Mark H.; Brown, Elliott; Doan, Ngoc; Zinter, Joseph; Ouellette, Nicholas T.; Gordon M Shepherd

    2015-01-01

    We have analyzed adaptations of the human airway to enhance transport of food volatiles underlying retronasal smell during expiration as well as limit transport in the opposite orthonasal direction toward the lung during inspiration. We show experimentally using an anatomically based flow dynamic model that the structure of the human airway at the back of the mouth enhances the entrainment of volatiles during expiration and minimizes it during inspiration. Unexpectedly, this effect is largest...

  1. 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....

  2. Long-memory volatility in derivative hedging

    Science.gov (United States)

    Tan, Abby

    2006-10-01

    The aim of this work is to take into account the effects of long memory in volatility on derivative hedging. This idea is an extension of the work by Fedotov and Tan [Stochastic long memory process in option pricing, Int. J. Theor. Appl. Finance 8 (2005) 381-392] where they incorporate long-memory stochastic volatility in option pricing and derive pricing bands for option values. The starting point is the stochastic Black-Scholes hedging strategy which involves volatility with a long-range dependence. The stochastic hedging strategy is the sum of its deterministic term that is classical Black-Scholes hedging strategy with a constant volatility and a random deviation term which describes the risk arising from the random volatility. Using the fact that stock price and volatility fluctuate on different time scales, we derive an asymptotic equation for this deviation in terms of the Green's function and the fractional Brownian motion. The solution to this equation allows us to find hedging confidence intervals.

  3. 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.

  4. Stable Local Volatility Calibration Using Kernel Splines

    Science.gov (United States)

    Coleman, Thomas F.; Li, Yuying; Wang, Cheng

    2010-09-01

    We propose an optimization formulation using L1 norm to ensure accuracy and stability in calibrating a local volatility function for option pricing. Using a regularization parameter, the proposed objective function balances the calibration accuracy with the model complexity. Motivated by the support vector machine learning, the unknown local volatility function is represented by a kernel function generating splines and the model complexity is controlled by minimizing the 1-norm of the kernel coefficient vector. In the context of the support vector regression for function estimation based on a finite set of observations, this corresponds to minimizing the number of support vectors for predictability. We illustrate the ability of the proposed approach to reconstruct the local volatility function in a synthetic market. In addition, based on S&P 500 market index option data, we demonstrate that the calibrated local volatility surface is simple and resembles the observed implied volatility surface in shape. Stability is illustrated by calibrating local volatility functions using market option data from different dates.

  5. Enthalpy/entropy compensation effects from cavity desolvation underpin broad ligand binding selectivity for rat odorant binding protein 3.

    Science.gov (United States)

    Portman, Katherine L; Long, Jed; Carr, Stephen; Briand, Loïc; Winzor, Donald J; Searle, Mark S; Scott, David J

    2014-04-15

    Evolution has produced proteins with exquisite ligand binding specificity, and manipulating this effect has been the basis for much of modern rational drug design. However, there are general classes of proteins with broader ligand selectivity linked to function, the origin of which is poorly understood. The odorant binding proteins (OBPs) sequester volatile molecules for transportation to the olfactory receptors. Rat OBP3, which we characterize by X-ray crystallography and NMR, binds a homologous series of aliphatic γ-lactones within its aromatic-rich hydrophobic pocket with remarkably little variation in affinity but extensive enthalpy/entropy compensation effects. We show that the binding energetics are modulated by two desolvation processes with quite different thermodynamic signatures. Ligand desolvation follows the classical hydrophobic effect; however, cavity desolvation is consistent with the liberation of "high energy" water molecules back into bulk solvent with a strong, but compensated, enthalpic contribution, which together underpin the origins of broad ligand binding selectivity.

  6. Effects of different general anesthetics on serum hemolysis and hepatic and muscular glycogenolysis in rats

    Directory of Open Access Journals (Sweden)

    E.F.A. Machado

    2009-11-01

    Full Text Available Anesthetics can affect the structure and biological function of tissues and systems differentially. The aim of the present study was to compare three injectable anesthetics generally used in experiments with animals in terms of the degree of hemolysis and glycogenolysis occurring after profound anesthesia. Twenty-four male Wistar rats (330-440 g were divided into three groups (N = 8: chloral hydrate (CH, ketamine + xylazine (KX, Zoletil 50® (zolazepam and tiletamine + xylazine (ZTX. After deep anesthesia, total blood was collected. The liver and white (WG and red gastrocnemius (RG muscles were also immediately removed. The degree of serum hemolysis was quantified on the basis of hemoglobin concentration (g/L. Hepatic and muscular glycogen concentrations (mmol/kg wet tissue were quantified by the phenol-sulfuric method. The CH and KX groups exhibited serum hemolysis (4.0 ± 2.2 and 1.9 ± 0.9 g/L, respectively; P < 0.05 compared to the ZTX group, which presented none. Only KX induced elevated glycogenolysis (mmol/kg wet tissue in the liver (86.9 ± 63.2 and in WG (18.7 ± 9.0 and RG (15.2 ± 7.2; P < 0.05. The CH and ZTX groups exhibited no glycogenolysis in the liver (164.4 ± 41.1 and 176.8 ± 54.4, respectively, WG (28.8 ± 4.4, 32.0 ± 6.5, respectively or RG (29.0 ± 4.9; 25.3 ± 8.6, respectively. Our data indicate that ZTX seems to be an appropriate general anesthetic for studies that seek to simultaneously quantify the concentration of glycogen and serum biochemical markers without interferences. ZTX is reasonably priced, found easily at veterinary markets, quickly induces deep anesthesia, and presents a low mortality rate.

  7. Alveolar subphase pH in the lungs of anesthetized rabbits.

    OpenAIRE

    Nielson, D W; Goerke, J; Clements, J. A.

    1981-01-01

    We measured the pH of the alveolar subphase fluid by puncturing the most superficial alveoli of the exposed lungs of anesthetized rabbits with H+-selective and nonselective KCl microelectrodes. In these experiments, we bathed the lung surface with paraffin oil or buffered Ringer's solutions that had a CO2 tension of 40 Torr (1 Torr = 133.3 Pa) and found an alveolar pH of 6.92 +/- 0.01 (mean +/- sEM). When the pH of the surface buffer was below 6.7 or above 7.5, alveolar pH varied with surface...

  8. Mechanisms of pentazocine-induced ventilatory depression and antinociception in anesthetized rats.

    Science.gov (United States)

    Kimura, Satoko; Ohi, Yoshiaki; Haji, Akira

    2016-03-01

    This study was performed to clarify mechanisms underlying pentazocine-induced ventilatory depression and antinociception. Spontaneous ventilation and hind leg withdrawal response against nociceptive thermal stimulation were simultaneously recorded in anesthetized rats. Pentazocine decreased minute volume resulting from depression of the ventilatory rate and tracheal airflow, and prolonged the latency of withdrawal response. Pre-treatment of β-funaltorexamine, but not nor-binaltorphimine, significantly attenuated pentazocine-induced ventilatory depression, while either antagonist weakened its analgesic potency. Comparing with effects of fentanyl and U50488, the present results suggest that ventilatory depression induced by pentazocine is mediated by mainly μ receptors and analgesia by both μ and κ receptors. PMID:27021234

  9. Can children undergoing ophthalmologic examinations under anesthesia be safely anesthetized without using an IV line?

    Directory of Open Access Journals (Sweden)

    Vigoda M

    2011-04-01

    Full Text Available Michael M Vigoda, Azeema Latiff, Timothy G Murray, Jacqueline L Tutiven, Audina M Berrocal, Steven GayerBascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USAPurpose: To document that with proper patient and procedure selection, children undergoing general inhalational anesthesia for ophthalmologic exams (with or without photos, ultrasound, laser treatment, peri-ocular injection of chemotherapy, suture removal, and/or replacement of ocular prosthesis can be safely anesthetized without the use of an intravenous (IV line. Children are rarely anesthetized without IV access placement. We performed a retrospective study to determine our incidence of IV access placement during examinations under anesthesia (EUA and the incidence of adverse events that required intraoperative IV access placement.Methods: Data collected from our operating room (OR information system includes but is not limited to diagnosis, anesthesiologist, surgeon, and location of IV catheter (if applicable, patient’s date of birth, actual procedure, and anesthesia/procedure times. We reviewed the OR and anesthetic records of children (>1 month and <10 years who underwent EUAs between January 1, 2003 and May 31, 2009. We determined the percentage of children who were anesthetized without IV access placement, as well as the incidence of any adverse events that required IV access placement, intraoperatively.Results: We analyzed data from 3196 procedures performed during a 77-month period. Patients’ ages ranged from 1 month to 9 years. Overall, 92% of procedures were performed without IV access placement. Procedure duration ranged from 1–39 minutes. Reasons for IV access placement included parental preference for antinausea medication and/or attending preference for IV access placement. No child who underwent anesthesia without an IV line had an intraoperative adverse event requiring insertion of an IV line.Conclusion: Our data suggest that for

  10. Anesthetic implications of total anomalous systemic venous connection to left atrium with left isomerism

    Directory of Open Access Journals (Sweden)

    Parimala Prasanna Simha

    2012-01-01

    Full Text Available Total anomalous systemic venous connection (TASVC to the left atrium (LA is a rare congenital anomaly. An 11-year-old girl presented with complaints of palpitations and cyanosis. TASVC with left isomerism and noncompaction of LV was diagnosed after contrast echocardiogram and computed tomography angiogram. The knowledge of anatomy and pathophysiology is essential for the successful management of these cases. Anesthetic concerns in this case were polycythemia, paradoxical embolism and rhythm abnormalities. The patient was successfully operated by rerouting the systemic venous connection to the right atrium.

  11. Influence of various anesthetic drugs on the intraocular pressure of cats.

    Science.gov (United States)

    Hahnenberger, R W

    1976-04-14

    Cats with one normal eye and one eye with experimental glaucoma were trained to tolerate tonometry while conscious. They were then given the general anesthetic agents pentobarbital, ketamine, and CI-744 in the lowest and twice the lowest dosages which permitted tonometry in untrained cats. Pentobarbital lowered intraocular pressure (IOP) by 20-50%. Ketamine raised IOP by about 10%. CI-744 had essentially no effect on IOP. The two conpoments of CI-744, tiletamine (CI-634) and zolazepam (CI-716) were given individually in the doses in which they had been given as part of CI-744. Tiletamine had no effect on IOP, while zolazepam lowered IOP by about 10%. PMID:1083696

  12. Peripartum Anesthetic Management and Genomic Analysis of Rare Variants in a Patient with Familial Pulmonary Fibrosis.

    Science.gov (United States)

    Sugino, Shigekazu; Bortz, Brandon J; Vaida, Sonia; Karamchandani, Kunal; Janicki, Piotr K

    2015-11-15

    A 29-year-old patient, 32 weeks' pregnant, with a history of familial interstitial fibrosis, was treated for acute hypoxemia after admission to the intensive care unit. Within 48 hours, this was followed by an emergent cesarean delivery, under general anesthesia, due to acute respiratory failure. Successful perinatal obstetric and anesthetic management resulted in the delivery of a baby and recovery of the mother. Subsequent genomic analysis using next-generation sequencing of the patient's entire exome revealed that she was a carrier of a deleterious mutation in the TERT gene, previously associated with the hereditary forms of interstitial fibrosis. PMID:26576048

  13. Adverse reactions following administration of an ionic iodinated contrast media in anesthetized dogs.

    Science.gov (United States)

    Vance, Amanda; Nelson, Matthew; Hofmeister, Erik H

    2012-01-01

    This retrospective study was conducted to identify hemodynamic alterations associated with the administration of an ionic iodinated contrast media in dogs. Case records of 49 dogs that were anesthetized for computed tomography scanning were reviewed. Values for heart rate (HR) and direct arterial pressure were obtained. Overall, 37% of dogs had a ≥20% change in either HR or systolic arterial pressure from baseline values. Four dogs (8%) became tachycardic and two dogs (4%) became bradycardic. Eight dogs (16%) became hypertensive and two dogs (4%) became hypotensive. A significant proportion of dogs experienced changes in HR and blood pressure following IV administration of an ionic iodinated contrast media under general anesthesia.

  14. Utility of CT scanning in anesthetic management for the patients with stenosis of the trachea

    International Nuclear Information System (INIS)

    The anesthetic management of six cases with tracheal stenosis due to goiter or mediastinal tumor was discussed in this paper. After evaluating not only the size and the transient shape of the trachea but also the quality and quantity of the tumor around the trachea by CT scanning, we could choose the optimal way of introduction and the size of endotracheal tube. If extreme stenosis of the trachea was revealed by CT scanning, awake intubation is preferred to prevent complications, which tended to occur during and after the induction of anesthesia with thiopental and succinylcholine chloride. (author)

  15. Development of transmucosal patch loaded with anesthetic and analgesic for dental procedures and in vivo evaluation

    Science.gov (United States)

    Nidhi, Malviya; Patro, M Nagaraju; Kusumvalli, Somisetty; Kusumdevi, Vemula

    2016-01-01

    Most of the dental surgeries require preoperative anesthetic and postoperative analgesic for painless procedures. A multidrug transmucosal drug delivery system loaded with lignocaine (Lig) base for immediate release and solid lipid nanoparticles (SLNs) of diclofenac (Dic) diethylamine for prolonged release was developed. SLNs were prepared by solvent emulsion–evaporation method with Precirol ATO 5 and Geleol as lipids and Pluronic F 68 as surfactant and optimized with Box–Behnken design for particle size and entrapment efficiency. SLNs were incorporated into the transmucosal patch (TP) prepared with hydroxypropyl cellulose-LF (HPC-LF) and with a backing layer of ethyl cellulose. Optimized SLNs and TP were characterized for Fourier transform infrared spectrophotometry, differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, in vitro release, ex vivo permeation through porcine buccal mucosa, Caco-2 permeability, and residual solvent analysis by gas chromatography. The TP was also evaluated for swelling index, in vitro residence time, tensile strength, and mucoadhesive strength. Preclinical pharmacokinetic, pharmacodynamic, and histopathological studies by application of TP on the gingiva of New Zealand rabbits were carried out. Particle size and entrapment efficiency of the optimized SLN “S8” were determined as 98.23 nm and 84.36%, respectively. The gingival crevicular fluid and tissue concentrations were greater than plasma concentrations with increase in Cmax and area under the curve (AUC) of Lig and Dic when compared to the control group. Pain perception by needle prick showed prolonged combined anesthetic and analgesic effect. The developed TP loaded with Lig base and Dic diethylamine-SLNs exhibited immediate and complete permeation with tissue accumulation of Lig followed by controlled prolonged release and tissue accumulation of Dic at the site of application. Thus, it could be anticipated from the in vivo studies that the

  16. Evaluation of the anesthetic effects of MS222 in the adult Mexican axolotl (Ambystoma mexicanum

    Directory of Open Access Journals (Sweden)

    Zullian C

    2016-01-01

    Full Text Available Chiara Zullian,1 Aurore Dodelet-Devillers,1 Stéphane Roy,2 Pascal Vachon1 1Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, 2Département de Stomatologie, Faculté de Médecine Dentaire, Montréal, Québec, Canada Abstract: The Mexican axolotl (Ambystoma mexicanum is a unique research model in several fields of medicine, where surgical and invasive procedures may be required. As yet, little is known about the efficacy of MS222 (tricaine methanesulfonate, which is the most commonly used anesthetic agent in amphibians. The main objectives of this study were to evaluate the anesthetic effects and physiological changes in adult axolotls following a 20-minute immersion bath, containing progressive MS222 concentrations starting at 0.1%. Depth of anesthesia and physiological changes were evaluated every 15 minutes post-MS222 exposure with the following parameters: righting behavior, withdrawal reflex, acetic acid test response, heart rate, and blood oxygen saturation, as well as cloacal and body surface temperatures. A 20-minute exposure in a 0.1% MS222 immersion bath (n=6 animals had no anesthetic effects on adult axolotls after 20 minutes of exposure. With a 0.2% MS222 solution, all axolotls (n=9 were deeply anesthetized at 15 minutes, and 80% were still unresponsive at 30 minutes postexposure. Blood oxygen saturation and heart rate were slightly, but significantly, increased when compared with the baseline value and remained stable up to recovery. There was no significant increase in surface and cloaca temperatures, compared with baseline. With the 0.4% MS222 solution, the duration of anesthesia lasted for 90 minutes to at least 120 minutes (n=3 animals and this concentration was deemed too high. In conclusion, a 20-minute immersion bath with 0.2% MS222 may be used for short procedures (15–30 minutes requiring anesthesia of adult axolotls. Keywords: Ambystoma mexicanum

  17. 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

  18. 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.

  19. 全身麻醉药在脊髓内的作用机制%Subcortical mechanisms of general anesthetics

    Institute of Scientific and Technical Information of China (English)

    杨静; 张宏

    2008-01-01

    The spinal cord plays an important role in two general anesthetic end-points: analgesia and immobility in response to a noxious stimulus. The spinal components that may contribute to anesthetic actions include the central termination of sensory primary afferent neurons, interneurones and the cell bodies and initial axon segments of motor neurons, which are contained in dorsal horn and ventral horn respectively. Different general anesthetics have both presynaptic and postsynaptic effects to produce analgesia and immobility via multitude of cellular and subcellular sites identified as potential targets of anaesthetic action, such as diverse ligand-gated ion channels etc. This review will focus on anesthetic targets and molecular mechanisms mediated analgesia and immobility of general anesthetics in spinal cord.%脊髓是全身麻醉药抑制伤害性刺激体动反应和抗伤害效应的重要作用部位,含有不同配体门控离子受体等多个可能介导麻醉效应的靶点.不同药物在脊髓内经各自特异靶点通过多种分子机制发挥作用.现就全身麻醉药制动和镇痛效应在脊髓内的作用位点和分子机制作一综述.

  20. Influence of general anesthetics on brain development%全身麻醉药对脑发育的影响

    Institute of Scientific and Technical Information of China (English)

    蒋燕; 陈萍

    2008-01-01

    The mortality of neonatal anesthesia is decreasing with the development of anestheisia. Pharmacological blockade of Nmethyl-D-aspartate (NMDA) type glutamate receptors or over stimulation of γ-aminobutyric acid type A receptors has been reported to induce neuron apoptosis in the period of brain peak development. In view of the mechanisms of general anesthetics on central nervous system, the influence of anesthetic agents on brain development becomes the researching focus. Clarifying the mechanisms of anesthetics affecting brain development is very important for the rational use of anesthetics in neonates, as well as for the exploitation of new anesthetics.%随着麻醉领域的不断发展,新生儿麻醉的死亡率明显下降.一系列的研究表明,在脑发育高峰期,药物性阻断N-甲基-D-天(门)冬氨酸受体或过度激动γ-氨基丁酸A型受体会诱发神经细胞凋亡.鉴于全麻药在中枢神经系统的作用机制,麻醉药物对脑发育的影响成为人们研究的热点,其机制的阐明可能对新生儿麻醉用药的合理选用及新药的开发具有指导意义.

  1. Research Progress in Safety of Fish Anesthetics%鱼用麻醉剂安全性研究进展

    Institute of Scientific and Technical Information of China (English)

    吕书为; 雷红涛; 孙远明

    2012-01-01

    鱼用麻醉剂能有效降低鱼类长途运输过程中的伤亡率,已在某些国家渔业生产中广泛应用,但其残留及安全性问题一直受到关注。目前有关鱼用麻醉剂的综述很少,为此本文对鱼用麻醉剂的类别、毒理学研究结果、麻醉剂在鱼体中积累与净化的影响因素等进行了综述,并对我国鱼用麻醉剂的使用和管理提出了部分建议。%Fish anesthetics can efficiently reduce the casualty rate of fish during long-distance transportation.Therefore,fish anesthetics have been widely used in fishery production in some countries.However,the residues of such anesthetics and the safety of fish have gained public concerns.In the present paper,the toxicology and the factors affecting accumulation and elimination of anesthetic residues are reviewed.Several prospects and suggestions are also provided for the future application and administration of fish anesthetics in China.

  2. The forced walking test: a novel test for pinpointing the anesthetic-induced transition in consciousness in mouse.

    Science.gov (United States)

    Hwang, Eunjin; Kim, Seunghwan; Shin, Hee-Sup; Choi, Jee Hyun

    2010-04-30

    In consciousness or anesthesia studies, pinpointing the precise moment of consciousness or anesthetic transition has been challenging because of the variable lag time between a treatment and its induced response. Here, we describe a novel behavioral method, a forced walking test, which pinpoints the moment of the anesthetic-induced loss of motion (LOM) without handling the animals manually. The mouse is forced to walk on a treadmill, and an anesthetic drug is administered into the peritoneum via a previously secured injection route. The physical activity and the angle of head posture are tracked using a motion sensor preinstalled on the animal's head. The moments of LOM and recovery of motion (ROM) are identified from the physical activity parameters obtained by the sensor. Comparison of our method with the conventional loss-of-righting-reflex assay showed that the time point of LOM was not significantly different between the two methods when examined with two different types of anesthetic agents, propofol and ketamine/xylazine cocktail. In addition, the electrophysiological signals simultaneously acquired in the cortex and the thalamus of the mouse during the forced walking test showed that the brain rhythms induced by ketamine/xylazine anesthesia were generated and terminated in a time-locked manner with respect to LOM and ROM, respectively. In conclusion, the forced walking test allows an objective and precise detection of anesthetic-induced LOM, as well as ROM during awakening from anesthesia, in test animals.

  3. A 5-angstrom theory in the mechanisms of volatile anesthetic agents%吸入麻醉药作用机制的5埃理论

    Institute of Scientific and Technical Information of China (English)

    何绍明

    2007-01-01

    在过去的20多年中,对吸入麻醉药作用机制的合理解释大量增多,同时也提出了更多目前还不能回答的问题.Eger等提出了吸入麻醉药产生对伤害性刺激无体动反应的作用靶位可能是两个相距5埃的位点的假设,简称5埃理论.现就相关问题作一综述.

  4. How Relevant is Volatility Forecasting for Financial Risk Management?

    OpenAIRE

    Peter F. Christoffersen; Francis X. Diebold

    1997-01-01

    It depends. If volatility fluctuates in a forecastable way, then volatility forecasts are useful for risk management; hence the interest in volatility forecastability in the risk management literature. Volatility forecastability, however, varies with horizon, and different horizons are relevant in different applications. Existing assessments are plagued by the fact that they are joint assessments of volatility forecastability and an assumed model, and the results vary not only with the horizo...

  5. Point mutations at the local anesthetic receptor site modulate the state-dependent block of rat Na v1.4 sodium channels by pyrazoline-type insecticides.

    Science.gov (United States)

    Silver, Kristopher S; Soderlund, David M

    2007-05-01

    Pyrazoline-type insecticides (PTIs) selectively block sodium channels at membrane potentials that promote slow sodium channel inactivation and are proposed to interact with a site that overlaps the local anesthetic (LA) receptor site. Mutagenesis studies identified two amino acid residues in the S6 segment of homology domain IV (Phe-1579 and Tyr-1586 in the rat Na(v)1.4 sodium channel) as principal elements of the LA receptor. To test the hypothesis that PTIs bind to the LA receptor, we constructed mutated Na(v)1.4/F1579A and Na(v)1.4/Y1586A cDNAs, expressed native and mutated channels in Xenopus oocytes, and examined the effects of these mutations on channel block by three PTIs (indoxacarb, its bioactivation product DCJW, and RH3421) by two-electrode voltage clamp. DCJW and RH3421 had no effect on Na(v)1.4 channels held at -120mV but caused a slowly developing block upon depolarization to -30mV. Estimated IC(50) values following 15min of exposure were 1 and 4muM for DCJW and RH3421, respectively. Indoxacarb failed to block Na(v)1.4 channels under all experimental conditions. Sensitivity to block by DCJW and RH3421 at -30mV was significantly reduced in Na(v)1.4/F1579A channels, a finding that is consistent with the impact of this mutation on drug binding. In contrast to its effect on drug binding, the Y1586A mutation increased the sensitivity of Na(v)1.4 channels held at -30mV to all three compounds, conferring modest sensitivity to indoxacarb and increasing sensitivity to DCJW and RH3421 by 58- and 16-fold, respectively. These results provide direct evidence for the action of PTIs at the LA receptor.

  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...

  7. Volatiles released by endophytic Pseudomonas fluorescens promoting the growth and volatile oil accumulation in Atractylodes lancea.

    Science.gov (United States)

    Zhou, Jia-Yu; Li, Xia; Zheng, Jiao-Yan; Dai, Chuan-Chao

    2016-04-01

    Atractylodes lancea is a well-known, but endangered, Chinese medicinal plant whose volatile oils are its main active components. As the volatile oil content in cultivated A. lancea is much lower than that in the wild herb, the application of microbes or related elicitors to promote growth and volatile oil accumulation in the cultivated herb is an important area of research. This study demonstrates that the endophytic bacterium Pseudomonas fluorescens ALEB7B isolated from the geo-authentic A. lancea can release several nitrogenous volatiles, such as formamide and N,N-dimethyl-formamide, which significantly promote the growth of non-infected A. lancea. Moreover, the main bacterial volatile benzaldehyde significantly promotes volatile oil accumulation in non-infected A. lancea via activating plant defense responses. Notably, the bacterial nitrogenous volatiles cannot be detected in the A. lancea - Pseudomonas fluorescens symbiont while the benzaldehyde can be detected, indicating the nitrogenous volatiles or their precursors may have been consumed by the host plant. This study firstly demonstrates that the interaction between plant and endophytic bacterium is not limited to the commonly known physical contact, extending the ecological functions of endophyte in the phytosphere and deepening the understandings about the symbiotic interaction. PMID:26874622

  8. Implicit Volatility versus Statistical Volatility: an Exercise Using Options and Telemar S.A. Stock

    Directory of Open Access Journals (Sweden)

    Marcelo Savino Portugal

    2004-06-01

    Full Text Available The main goal this article was to find the best way of making forecast about future volatility using implicit or statistic forecast. The work is based on Telemar S.A. shares data from 21/09/1998 to 21/10/2002 and Telemar S.A. shares data from 2/10/2000 to 21/10/2002. The implicit volatility was obtained using back-out procedure from the Black-Scholes model. The statistics forecasts were obtained using weighted moving average models, GARCH, EGARCH and FIGARCH models. The Wald statistic shows that EGARCH and FIGARCH models are efficient and are not biased forecasts for Telemar S.A. absolute variation between t and t + 1. The volatility evaluation during the maturity time of an option, rejects the hypothesis that implicit volatility is the best forecast to future volatility and the Wald statistic show that FIGARCH model is an efficient and not biased forecast.

  9. Anesthetic Management of Direct Laryngoscopy and Dilatation of Subglottic Stenosis in a Patient with Severe Myasthenia Gravis

    Directory of Open Access Journals (Sweden)

    Hesham A. Elsharkawy

    2012-01-01

    Full Text Available We describe the anesthetic management of a patient with severe myasthenia gravis and tracheal stenosis; the patient was scheduled for direct laryngoscopy and dilatation. The combination of myasthenia gravis and tracheal obstruction presents several difficulties for anesthetic management. The airway is shared; therefore, any complications are also shared by the anesthesiologist and bronchoscopists. The potential for respiratory compromise in patients undergoing the two procedures requires that anesthesiologists be familiar with the underlying disease state, as well as the interaction of anesthetic and nonanesthetic drugs in a case involving myasthenia gravis. We reviewed the literature and report our experience in this case. There is no strong evidence for choosing one approach to general anesthesia over another for bronchoscopy. Careful preoperative planning and experience in airway management and jet ventilation are crucial to prevent an adverse outcome and obtain favorable results.

  10. [A regular internal auditing and registration of critical incidents regarded as safety maintenance elements within the anesthetic management of patients].

    Science.gov (United States)

    Vinogradov, V L; Likhvantsev, V V; Alekseev, A A

    2004-01-01

    The paper summarizes a 5-year experience of evaluating the safety of anesthetic management of patients with thermal lesions treated at the department of thermal lesions of Vishnevsky's Institute of Surgery, Russia's Academy of Medical Sciences. Regular internal auditings, based on the principles of registering the critical incidents, the course of 1473 general anesthesia managements was analyzed in 168 patients. The conclusion is that the introduction of protocols of anesthetic management as well as a regular monitoring over meeting the fixed targets cut the total frequency of critical incidents from 2.85 to 1.19 as estimated per one general anesthesia. Finally the authors suggest a concept whose essence in that the operation of the modern anesthesiology department must be based on a scientifically substantiated technology of anesthetic management.

  11. Topical amethocaine (Ametop) is superior to EMLA for intravenous cannulation. Eutectic mixture of local anesthetics.

    LENUS (Irish Health Repository)

    Browne, J

    2012-02-03

    PURPOSE: A eutectic mixture of local anesthetics (EMLA) is commonly used to provide topical anesthesia for intravenous (i.v.) cannulation. One of its side effects is vasoconstriction, which may render cannulation more difficult. A gel formulation of amethocaine (Ametop) is now commercially available. The aim of this study was to compare EMLA and Ametop with regard to the degree of topical anesthesia afforded, the incidence of vasoconstriction and the ease of i.v. cannulation. METHODS: Thirty two ASA I adult volunteers had a #16 gauge i.v. cannula inserted on two separate occasions using EMLA and Ametop applied in a double blind fashion for topical anesthesia. Parameters that were recorded after each cannulation included visual analogue pain scores (VAPS), the presence of vasoconstriction and the ease of cannulation, graded as: 1 = easy, 2 = moderately difficult, 3 = difficult and 4 = failed. RESULTS: The mean VAPS +\\/- SD after cannulation with Ametop M was 12+\\/-9.9 and with EMLA was 25.3+\\/-16.6 (P = 0.002). Vasoconstriction occurred after EMLA application on 17 occasions and twice after Ametop (P = 0.001). The grade of difficulty of cannulation was 1.44+\\/-0.88 following EMLA and 1.06+\\/-0.25 with Ametop (P = 0.023). CONCLUSIONS: Intravenous cannulation was less painful following application of Ametop than EMLA. In addition, Ametop caused less vasoconstriction and facilitated easier cannulation. Its use as a topical anesthetic agent is recommended, especially when i.v. access may be problematic.

  12. Calcium and protons affect the interaction of neurotransmitters and anesthetics with anionic lipid membranes.

    Science.gov (United States)

    Pérez-Isidoro, Rosendo; Ruiz-Suárez, J C

    2016-09-01

    We study how zwitterionic and anionic biomembrane models interact with neurotransmitters (NTs) and anesthetics (ATs) in the presence of Ca(2+) and different pH conditions. As NTs we used acetylcholine (ACh), γ-aminobutyric acid (GABA), and l-glutamic acid (LGlu). As ATs, tetracaine (TC), and pentobarbital (PB) were employed. By using differential scanning calorimetry (DSC), we analyzed the changes such molecules produce in the thermal properties of the membranes. We found that calcium and pH play important roles in the interactions of NTs and ATs with the anionic lipid membranes. Changes in pH promote deprotonation of the phosphate groups in anionic phospholipids inducing electrostatic interactions between them and NTs; but if Ca(2+) ions are in the system, these act as bridges. Such interactions impact the physical properties of the membranes in a similar manner that anesthetics do. Beyond the usual biochemical approach, we claim that these effects should be taken into account to understand the excitatory-inhibitory orchestrated balance in the nervous system. PMID:27362370

  13. A Survey of Perioperative and Postoperative Anesthetic Practices for Cesarean Delivery

    Directory of Open Access Journals (Sweden)

    Leinani Aiono-Le Tagaloa

    2009-01-01

    Full Text Available The aim of this survey was to review cesarean delivery anesthetic practices. An online survey was sent to members of the Society of Obstetric Anesthesia and Perinatology (SOAP. The mode of anesthesia, preferred neuraxial local anesthetic and opioid agents, postoperative analgesic regimens, and monitoring modalities were assessed. 384 responses from 1,081 online survey requests were received (response rate = 36%. Spinal anesthesia is most commonly used for elective cesarean delivery (85% respondents, with 90% of these respondents preferring hyperbaric bupivacaine 0.75%. 79% used intrathecal fentanyl and 77% used morphine (median [range] dose 200 mcg [50–400]. 91% use respiratory rate, 61% use sedation scores, and 30% use pulse oximetry to monitor for postoperative respiratory depression after administration of neuraxial opioids. Postoperative analgesic regimens include: nonsteroidal anti-inflammatory agents, acetaminophen, oxycodone, and hydrocodone by 81%, 45%, 25%, and 27% respondents respectively. The majority of respondents use spinal anesthesia and neuraxial opioids for cesarean delivery anesthesia. There is marked variability in practices for monitoring respiratory depression postdelivery and for providing postoperative analgesia. These results may not be indicative of overall practice in the United States due to the select group of anesthesiologists surveyed and the low response rate.

  14. Alteration of canine left ventricular diastolic function by intravenous anesthetics in vivo. Ketamine and propofol.

    Science.gov (United States)

    Pagel, P S; Schmeling, W T; Kampine, J P; Warltier, D C

    1992-03-01

    Diastolic function has been shown to influence overall cardiac performance significantly, but the effect of intravenous anesthetics on diastolic function has not been previously characterized in vivo. The effects of ketamine and propofol on two indices of left ventricular diastolic function were examined in chronically instrumented dogs. Because autonomic nervous system function may significantly influence the systemic hemodynamic actions produced by intravenous anesthetics in vivo, experiments were performed in the presence of pharmacologic blockade of the autonomic nervous system. Two groups comprising a total of 14 experiments were performed using 7 dogs instrumented for measurement of aortic and left ventricular pressure, the maximum rate of increase of left ventricular pressure (dP/dt), subendocardial segment length, and cardiac output. Systemic hemodynamics and diastolic function were recorded and evaluated in the conscious state and after a 20-min equilibration at 25-, 50-, and 100-mg.kg-1.h-1 infusion doses of ketamine or propofol. Ventricular relaxation was described using the time constant of isovolumetric relaxation (tau) assuming a nonzero asymptote of ventricular pressure decay. Regional chamber stiffness, an index of passive ventricular filling, was described using an exponential equation relating segment length to ventricular pressure between minimum ventricular pressure and the onset of atrial systole.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1539854

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

    Directory of Open Access Journals (Sweden)

    Mohamed Idris

    2014-01-01

    Full Text Available 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 alveolar nerve block has failed to provide pulpal anesthesia. Materials and Methods: Sixty adult patients selected were to undergo endodontic treatment for a mandibular molar tooth. Inferior alveolar nerve block was given using 4% articaine with 1:100,000 epinephrine. Twenty-four patients (40% had pain even after administration of IAN block; intraosseous injection was administered using 4% articaine containing 1:100,000 epinephrine, using the X-tip system. The success of X-tip intraosseous injection was defined as none or mild pain (Heft-Parker visual analog scale ratings ≤ 54 mm on endodontic access or initial instrumentation. Results: Intraosseous injection technique was successful in 21 out of 24 patients (87.5%, except three patients who had pain even after supplemental X-tip injection. Conclusion: Within the limits of this study, we can conclude that supplemental intraosseous injection using 4% articaine with 1:100,000 epinephrine has a statistically significant influence in achieving pulpal anesthesia in patients with irreversible pulpitis.

  16. Clinical features and anesthetic management of multiple endocrine neoplasia as sociated with pheochromocytoma

    Institute of Scientific and Technical Information of China (English)

    罗爱伦; 郭向阳; 任洪智; 黄宇光; 叶铁虎

    2003-01-01

    Objective To investigate clinical features and anesthetic management of multiple endocrine neoplasia (MEN) associated with pheochromocytoma.Methods Medical records of patients who were diagnosed as multiple endocrine neoplasia a ssociated with pheochromocytoma in our hospital from April 1977 to April 2001 were reviewed retrospectively. The demographic data, clinical presentations, fami ly history, biochemical examinations, type of MEN, sequence of different surgica l procedures, anesthetic methods and hemodynamics during surgery were analyzed. Results Thirteen cases of MEN associated with pheochromocytoma were investigated, accounting for 6% (13/213) of the pheochromocytoma patients admitted into our hospital. Nine of the 13 patients presented as type Ⅱa MEN (Sipple syndrome), on e as type Ⅱb MEN, and three as mixed MEN. Four patients with typeⅡa MEN had a family history of similar disease. Five patients with other coexisting endocri ne disorders first underwent excision of the pheochromocytomas, although only tw o had hypertensive symptoms at the time of admittance. Seven patients without h istories of hypertension received surgical treatment for pheochromocytoma second ly. The excision of pheochromocytoma was performed under general anesthesia in 8 patients and epidural block in 4 patients. Marked hemodynamic fluctuation was recorded in 8 patients. No perioperative death was recorded. Conclusion Pheochromocytoma may be linked to other endocrine disorders during MEN, either as the main clinical presentation or most frequently as an occult tumor. Recognition of this feature of pheochromocytoma is of importance to the improvement of diagnosis and treatment both for pheochromocytoma and MEN.

  17. Mirror syndrome and anesthetic management%镜像综合征与麻醉

    Institute of Scientific and Technical Information of China (English)

    徐振东; 刘志强

    2016-01-01

    Background Mirror syndrome is a rare entity associated with pregnancy.It is related to an increase in fetal mortality and maternal morbility.Clinicians are still short of experience of treating mirror syndrome.There are great risks during anesthesia for patients with mirror syndrome.Objective To review the risks and challenges of mirror syndrome occurred in obstetric surgery.Content This paper describes the pathophysiology and complications of mirror syndrome,and analyze the anesthetic management of mirror syndrome.Trend Awareness of the syndrome is important and we should be care for this type anesthetic management.%背景 镜像综合征是产科中一类罕见的并发症,危及母婴安全,目前临床对其认识不足.镜像综合征的病理生理较为特殊,麻醉管理有较大的风险. 目的 了解镜像综合征对麻醉管理的可能威胁或挑战. 内容 综述镜像综合征的病理生理、并发症及其与临床麻醉的关系. 趋向 产科麻醉中应警惕该类产科并发症,做好相应的麻醉管理.

  18. ANESTHETIC MANAGEMENT OF A PATIENT WITH SITUS INVERSUS POSTED FOR LAPAROSCOPIC CHOLECYSTECTOMY

    Directory of Open Access Journals (Sweden)

    Sudhir

    2014-04-01

    Full Text Available Situs inversus totalis is a congenital visceral malrotation anomaly that results from disturbances in establishment of left-right asymmetry and it is characterized by total transposition of thoracic and abdominal viscera, and the predicted incidence is one in 10, 000 among the general population. In a patient with situs inversus totalis, not just the diagnosis of any acute abdomen pathology is difficult but equally challenging is the anesthetic management during the respective surgical procedure. We are reporting a patient who had situs inversus totalis and was operated for laparoscopic cholecystectomy under general anesthesia with I-gel, a new supraglottic airway device as an airway conduit. Though the problems related to such patients are mainly of surgical feasibility, an anesthesiologist must be aware of the associated problems of both, situs inversus and the laparoscopy. The present case report lays an emphasis on the potential difficulties during anesthetic management and its various implications. To the best of our knowledge, we report the first case in India of a successful laparoscopic cholecystectomy in a patient with situs inversus totalis with use of I-gel.

  19. New Updates Pertaining to Drug Delivery of Local Anesthetics in Particular Bupivacaine Using Lipid Nanoparticles

    Science.gov (United States)

    Beiranvand, Siavash; Eatemadi, Ali; Karimi, Arash

    2016-06-01

    Lipid nanoparticles (liposomes) were first described in 1965, and several work have led to development of important technical advances like triggered release liposomes and drug-loaded liposomes. These advances have led to numerous clinical trials in such diverse areas such as the delivery of anti-cancer, antifungal, and antibiotic drugs; the delivery of gene medicines; and most importantly the delivery of anesthesia drugs. Quite a number of liposomes are on the market, and many more are still in developmental stage. Lipid nanoparticles are the first nano-medicine delivery system to be advanced from laboratory concept to clinical application with high considerable clinical acceptance. Drug delivery systems for local anesthetics (LAs) have caught the interest of many researchers because there are many biomedical advantages connected to their application. There have been several formulation techniques to systemically deliver LA that include encapsulation in liposomes and complexation in cyclodextrins, nanoparticles, and to a little extent gold nanoparticles. The proposed formulations help to decrease the LA concentration utilized, increase its permeability, and most importantly increase the localization of the LA for a long period of time thereby leading to increase in the duration of the LA effect and finally to reduce any local and systemic toxicity. In this review, we will highlight on new updates pertaining to drug delivery of local anesthetics in particular bupivacaine using lipid nanoparticles.

  20. HEMATOLOGICAL AND SERUM BIOCHEMICAL VALUES IN ANESTHETIZED CAPTIVE TASMANIAN DEVILS (SARCOPHILUS HARRISII).

    Science.gov (United States)

    Hope, Katharine L; Peck, Sarah

    2016-06-01

    The Tasmanian devil (Sarcophilus harrisii) population has decreased by estimates of 80% in the past 20 yr due to the effects of devil facial tumor disease (DFTD). In the process of creating a DFTD-free insurance population, the captive population and the number of institutions housing devils worldwide has increased tremendously. In order to provide the best husbandry and veterinary care for these captive animals, it is essential to know normal hematology and biochemistry values for the species. Baseline reference intervals (RIs) were determined for hematology and biochemistry variables for 170 healthy anesthetized captive Tasmanian devils and significant sex and age differences were determined. Higher relative neutrophil counts, hemoglobin, mean corpuscular hemoglobin (MCH), creatinine, creatine phosphokinase, and cholesterol were seen in males compared to females, whereas higher white cell counts (WBC) and lymphocyte counts (absolute and relative) were seen in females. Subadults have higher red blood cell counts, WBC, lymphocytes (absolute and relative), calcium and phosphorus, alkaline phosphatase, glutamate dehydrogenase, glucose, and albumin than adults; whereas, adults have higher relative neutrophils, relative eosinophils, mean corpuscular volume, MCH, platelets, total solids, total plasma proteins, globulins, and chloride than subadults. This study provides a comprehensive report of hematology and serum biochemistry RIs for healthy captive anesthetized Tasmanian devils and offers invaluable diagnostic information to care for the growing captive population of this endangered marsupial. PMID:27468030

  1. [Anesthesia for geriatric patients : Part 2: anesthetics, patient age and anesthesia management].

    Science.gov (United States)

    Herminghaus, A; Löser, S; Wilhelm, W

    2012-04-01

    Part 2 of this review on geriatric anesthesia primarily describes the multiple influences of age on the pharmacokinetics and pharmacodynamics of different anesthetic agents and their impact on clinical practice. In the elderly the demand for opioids is reduced by almost 50% and with total intravenous anesthesia the dosages of propofol and remifentanil as well as recovery times are more determined by patient age than by body weight. As a result depth of anesthesia monitoring is recommended for geriatric patients to individually adjust the dosing to patients needs. With muscle relaxants both delayed onset of action and prolonged duration of drug effects must be considered with increasing age and as this may lead to respiratory complications, neuromuscular monitoring is highly recommended. The following measures appear to be beneficial for geriatric patients: thorough preoperative assessment, extended hemodynamic monitoring, use of short-acting anesthetics in individually adjusted doses best tailored by depth of anesthesia monitoring, intraoperative normotension, normothermia and normocapnia, complete neuromuscular recovery at the end of the procedure and well-planned postoperative pain management in order to reduce or avoid the use of opioids.

  2. New Updates Pertaining to Drug Delivery of Local Anesthetics in Particular Bupivacaine Using Lipid Nanoparticles.

    Science.gov (United States)

    Beiranvand, Siavash; Eatemadi, Ali; Karimi, Arash

    2016-12-01

    Lipid nanoparticles (liposomes) were first described in 1965, and several work have led to development of important technical advances like triggered release liposomes and drug-loaded liposomes. These advances have led to numerous clinical trials in such diverse areas such as the delivery of anti-cancer, antifungal, and antibiotic drugs; the delivery of gene medicines; and most importantly the delivery of anesthesia drugs. Quite a number of liposomes are on the market, and many more are still in developmental stage. Lipid nanoparticles are the first nano-medicine delivery system to be advanced from laboratory concept to clinical application with high considerable clinical acceptance. Drug delivery systems for local anesthetics (LAs) have caught the interest of many researchers because there are many biomedical advantages connected to their application. There have been several formulation techniques to systemically deliver LA that include encapsulation in liposomes and complexation in cyclodextrins, nanoparticles, and to a little extent gold nanoparticles. The proposed formulations help to decrease the LA concentration utilized, increase its permeability, and most importantly increase the localization of the LA for a long period of time thereby leading to increase in the duration of the LA effect and finally to reduce any local and systemic toxicity. In this review, we will highlight on new updates pertaining to drug delivery of local anesthetics in particular bupivacaine using lipid nanoparticles. PMID:27342601

  3. Comparative Evaluation of Pain Scores during Periodontal Probing with or without Anesthetic Gels

    Directory of Open Access Journals (Sweden)

    Ashank Mishra

    2016-01-01

    Full Text Available Context. The initial periodontal examination which includes full-mouth periodontal probing is one of the discomforting procedures for a patient. Aim. To evaluate the efficacy of two local anesthetic gels in the reduction of pain during periodontal probing using Florida probe in CGP patients in comparison with manual probing. Materials and Methods. Ninety systemically healthy patients with moderate to severe CGP patients were recruited. In each patient, the quadrants were randomly assigned to manual probing with UNC-15 probe, probing with Florida probe, and Florida probing with lidocaine 10% gel and with benzocaine 20% gel. In the quadrants undergoing probing with anesthetic gels, the sites were isolated and the gel was injected using syringe and a blunt-end cannula. Pain was measured using 10 mm horizontal VAS. Statistical Analysis. The analysis was carried out using SPSS version 18. The comparison of mean VAS scores was done using repeated measures ANOVA with post hoc Bonferroni test. Results. Mean VAS for manual probing was significantly more than Florida probing. Further, the mean VAS score for Florida probing was higher than the two gels. Conclusion. It is suggested that the gels might be useful in reducing pain experienced during full-mouth periodontal probing in patients with CGP.

  4. Optimal directional volatile transport in retronasal olfaction.

    Science.gov (United States)

    Ni, Rui; Michalski, Mark H; Brown, Elliott; Doan, Ngoc; Zinter, Joseph; Ouellette, Nicholas T; Shepherd, Gordon M

    2015-11-24

    The ability of humans to distinguish the delicate differences in food flavors depends mostly on retronasal smell, in which food volatiles entrained into the airway at the back of the oral cavity are transported by exhaled air through the nasal cavity to stimulate the olfactory receptor neurons. Little is known whether food volatiles are preferentially carried by retronasal flow toward the nasal cavity rather than by orthonasal flow into the lung. To study the differences between retronasal and orthonasal flow, we obtained computed tomography (CT) images of the orthonasal airway from a healthy human subject, printed an experimental model using a 3D printer, and analyzed the flow field inside the airway. The results show that, during inhalation, the anatomical structure of the oropharynx creates an air curtain outside a virtual cavity connecting the oropharynx and the back of the mouth, which prevents food volatiles from being transported into the main stream toward the lung. In contrast, during exhalation, the flow preferentially sweeps through this virtual cavity and effectively enhances the entrainment of food volatiles into the main retronasal flow. This asymmetrical transport efficiency is also found to have a nonmonotonic Reynolds number dependence: The asymmetry peaks at a range of an intermediate Reynolds number close to 800, because the air curtain effect during inhalation becomes strongest in this range. This study provides the first experimental evidence, to our knowledge, for adaptations of the geometry of the human oropharynx for efficient transport of food volatiles toward the olfactory receptors in the nasal cavity. PMID:26553982

  5. Modeling and forecasting petroleum futures volatility

    International Nuclear Information System (INIS)

    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)

  6. Modeling and forecasting petroleum futures volatility

    Energy Technology Data Exchange (ETDEWEB)

    Sadorsky, Perry [York Univ., Schulich School of Business, Toronto, ON (Canada)

    2006-07-15

    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)

  7. Modelling oil price volatility with structural breaks

    International Nuclear Information System (INIS)

    In this paper, we provide two main innovations: (i) we analyze oil prices of two prominent markets namely West Texas Intermediate (WTI) and Brent using the two recently developed tests by Narayan and Popp (2010) and Liu and Narayan, 2010 both of which allow for two structural breaks in the data series; and (ii) the latter method is modified to include both symmetric and asymmetric volatility models. We identify two structural breaks that occur in 1990 and 2008 which coincidentally correspond to the Iraqi/Kuwait conflict and the global financial crisis, respectively. We find evidence of persistence and leverage effects in the oil price volatility. While further extensions can be pursued, the consideration of asymmetric effects as well as structural breaks should not be jettisoned when modelling oil price volatility. - Highlights: ► We analyze oil price volatility using NP (2010) and LN (2010) tests. ► We modify the LN (2010) to account for leverage effects in oil price. ► We find two structural breaks that reflect major global crisis in the oil market. ► We find evidence of persistence and leverage effects in oil price volatility. ► Leverage effects and structural breaks are fundamental in oil price modelling.

  8. Optimal directional volatile transport in retronasal olfaction.

    Science.gov (United States)

    Ni, Rui; Michalski, Mark H; Brown, Elliott; Doan, Ngoc; Zinter, Joseph; Ouellette, Nicholas T; Shepherd, Gordon M

    2015-11-24

    The ability of humans to distinguish the delicate differences in food flavors depends mostly on retronasal smell, in which food volatiles entrained into the airway at the back of the oral cavity are transported by exhaled air through the nasal cavity to stimulate the olfactory receptor neurons. Little is known whether food volatiles are preferentially carried by retronasal flow toward the nasal cavity rather than by orthonasal flow into the lung. To study the differences between retronasal and orthonasal flow, we obtained computed tomography (CT) images of the orthonasal airway from a healthy human subject, printed an experimental model using a 3D printer, and analyzed the flow field inside the airway. The results show that, during inhalation, the anatomical structure of the oropharynx creates an air curtain outside a virtual cavity connecting the oropharynx and the back of the mouth, which prevents food volatiles from being transported into the main stream toward the lung. In contrast, during exhalation, the flow preferentially sweeps through this virtual cavity and effectively enhances the entrainment of food volatiles into the main retronasal flow. This asymmetrical transport efficiency is also found to have a nonmonotonic Reynolds number dependence: The asymmetry peaks at a range of an intermediate Reynolds number close to 800, because the air curtain effect during inhalation becomes strongest in this range. This study provides the first experimental evidence, to our knowledge, for adaptations of the geometry of the human oropharynx for efficient transport of food volatiles toward the olfactory receptors in the nasal cavity.

  9. A survey to access knowledge and practice among dentists regarding local anesthetic dosage in three cities of Uttarakhand

    Directory of Open Access Journals (Sweden)

    Laxman Singh Kaira

    2014-01-01

    Full Text Available Objective: Local anesthetics are the most commonly used drugs in routine dentistry. Although they are considered effective and safe in controlling pain during dental procedures, complications related to their use appear inevitable. Many dentists use these drugs routinely but are unaware of the dose calculations required and the maximum safe and effective dose of the drug. Materials and Methods: This study was aimed to determine the knowledge that general dental practitioners and dental specialists, in three different cities in India, have regarding dose calculations and the maximum-dose required of the most commonly used local anesthetics. A one page survey questionnaire was used in this study and data were analyzed using standard SPSS statistical program version 11, software (SPSS Inc. Chicago, Illinois, USA. Results: The respondents comprised 71.4% general dental practitioners and 28.5% dental specialists, with ages ranging from 26 to 50 years; Nearly 75% of the total respondent was males and 25% females. Nearly 69% of the respondents were unaware of the maximum recommended dose for use on adult, healthy patients and 81% were still confused about the maximum numbers of syringes containing 2% lignocaine with adrenaline that can be given to a patient. A total of 49% of general dental practitioners and specialists do not perform aspiration when injecting local anesthetics, whereas only 38% performed the aspiration in inferior nerve block technique, while only 12% performed aspiration in all types of injection techniques. A high percentage of the dentists (84% who responded are unaware of how to calculate the local anesthetic dose and 31% of them encountered complications during, or after, local anesthetic administration. Conclusion: General practitioners and dental specialists appear to have an inadequate knowledge about local anesthetics maximum-dose and dose calculations; further educational courses are recommended to update them regarding such

  10. Use of continuous local anesthetic infusion in the management of postoperative split-thickness skin graft donor site pain.

    Science.gov (United States)

    Hernandez, Jorge L Reguero; Savetamal, Alisa; Crombie, Roselle E; Cholewczynski, Walter; Atweh, Nabil; Possenti, Paul; Schulz, John T

    2013-01-01

    Donor sites from split-thickness skin grafts (STSG) impose significant pain on patients in the early postoperative period. We report the use of continuous local anesthetic infusion as a method for the management of postoperative STSG donor site pain. Patients undergoing single or dual, adjacent STSG harvest from the thigh (eight patients) or back (one patient) were included in this study. Immediately after STSG harvest, subcutaneous catheters were placed for continuous infusion of local anesthetic. Daily donor site-specific pain severity scores were prospectively recorded in nine patients receiving local anesthetic infusion. Patient characteristics, technical aspects, and postoperative complications were identified in the study. The thigh was the anatomic location chosen for most donor sites. A single catheter was placed for donor sites limited to 4 inches in width or less. A dual catheter system was used for those wider than 4 inches. An elastomeric pump delivered continuously a total of 4 ml/hr of a solution of 0.5% bupivacaine. The average anesthetic infusion duration was 3.1 days. A substantial decrease in worst, least, and average donor site pain scores was found from the first 24 hours to the second postoperative day in our patients, a treatment trend that continued through postoperative day 3. One patient developed minor anesthetic leakage from the catheter insertion site; and in three cases, accidental dislodgement of the catheters occurred. There were no cases of donor site secondary infection. All donor sites were completely epithelialized at 1-month follow-up. Continuous local anesthetic infusion is technically feasible and may represent an option for postoperative donor site pain control after STSG harvesting. Relative cost-benefit of the technique remains to be determined. PMID:23271060

  11. Insight into the modulation of Shaw2 Kv channels by general anesthetics: structural and functional studies of S4-S5 linker and S6 C-terminal peptides in micelles by NMR.

    Science.gov (United States)

    Zhang, Jin; Qu, Xiaoguang; Covarrubias, Manuel; Germann, Markus W

    2013-02-01

    The modulation of the Drosophila Shaw2 Kv channel by 1-alkanols and inhaled anesthetics is correlated with the involvement of the S4-S5 linker and C-terminus of S6, and consistent with stabilization of the channel's closed state. Structural analysis of peptides from S4-S5 (L45) and S6 (S6c), by nuclear magnetic resonance and circular dichroism spectroscopy supports that an α-helical conformation was adopted by L45, while S6c was only in an unstable/dynamic partially folded α-helix in dodecylphosphocholine micelles. Solvent accessibility and paramagnetic probing of L45 revealed that L45 lies parallel to the surface of micelles with charged and polar residues pointing towards the solution while hydrophobic residues are buried inside the micelles. Chemical shift perturbation introduced by 1-butanol on residues Gln320, Thr321, Phe322 and Arg323 of L45, as well as Thr423 and Gln424 of S6c indicates possible anesthetic binding sites on these two important components in the channel activation apparatus. Diffusion measurements confirmed the association of L45, S6c and 1-butanol with micelles which suggests the capability of 1-butanol to influence a possible interaction of L45 and S6c in the micelle environment.

  12. Permanent and transitory oil volatility and aggregate investment in Malaysia

    International Nuclear Information System (INIS)

    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

  13. The volatility of stock market prices.

    Science.gov (United States)

    Shiller, R J

    1987-01-01

    If the volatility of stock market prices is to be understood in terms of the efficient markets hypothesis, then there should be evidence that true investment value changes through time sufficiently to justify the price changes. Three indicators of change in true investment value of the aggregate stock market in the United States from 1871 to 1986 are considered: changes in dividends, in real interest rates, and in a direct measure of intertemporal marginal rates of substitution. Although there are some ambiguities in interpreting the evidence, dividend changes appear to contribute very little toward justifying the observed historical volatility of stock prices. The other indicators contribute some, but still most of the volatility of stock market prices appears unexplained. PMID:17769311

  14. Valuation equations for stochastic volatility models

    CERN Document Server

    Bayraktar, Erhan; Xing, Hao

    2010-01-01

    We study the valuation partial differential equation for European contingent claims in a general framework of stochastic volatility models. The standard Feynman-Kac theorem cannot be directly applied because the diffusion coefficients may degenerate on the boundaries of the state space and grow faster than linearly. We allow for various types of model behavior; for example, the volatility process in our model can potentially reach zero and either stay there or instantaneously reflect, and asset-price processes may be strict local martingales under a given risk-neutral measure. Our main result is an extension of the standard Feynman-Kac theorem in the context of stochastic volatility models. Sharp results on the existence and uniqueness of classical solutions to the valuation equation are obtained using a combination of probabilistic and analytical techniques. The role of boundary conditions is also discussed.

  15. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    -based models are both rejected against the general dynamic factor model, (ii) the factors driving the surface are highly persistent, (iii) for the restricted models option Delta is preferred over the more often used strike relative to spot price as measure for moneyness.......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...... features for representing the surface and its dynamics: a general dynamic factor model, restricted factor models designed to capture the key features of the surface along the moneyness and maturity dimensions, and in-between spline-based methods. Key findings are that: (i) the restricted and spline...

  16. Total iron binding capacity

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  17. 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

  18. Volatile compound formation during argan kernel roasting.

    Science.gov (United States)

    El Monfalouti, Hanae; Charrouf, Zoubida; Giordano, Manuela; Guillaume, Dominique; Kartah, Badreddine; Harhar, Hicham; Gharby, Saïd; Denhez, Clément; Zeppa, Giuseppe

    2013-01-01

    Virgin edible argan oil is prepared by cold-pressing argan kernels previously roasted at 110 degrees C for up to 25 minutes. The concentration of 40 volatile compounds in virgin edible argan oil was determined as a function of argan kernel roasting time. Most of the volatile compounds begin to be formed after 15 to 25 minutes of roasting. This suggests that a strictly controlled roasting time should allow the modulation of argan oil taste and thus satisfy different types of consumers. This could be of major importance considering the present booming use of edible argan oil.

  19. A note on Black Scholes implied volatility

    Science.gov (United States)

    Chargoy-Corona, Jesús; Ibarra-Valdez, Carlos

    2006-10-01

    An approximate formula for the Black-Scholes implied volatility is given by means of an asymptotic representation of the Black-Scholes formula. This representation is based on a variable change that reduces the number of meaningful variables from five to three. It is stated clearly which is the family of functions we are going to work, specially the inverse of the normal accumulative function. Estimates for the error in the resulting approximate formulas for both the option value and the volatility are obtained as well.

  20. Assessment of waste management of volatile radionuclides

    International Nuclear Information System (INIS)

    This document presents a review of the Technologies for Waste Management of the Volatile Radionuclides of iodine-129, krypton-85, tritium, and carbon-14. The report presents an estimate of the quantities of these volatile radionuclides as are produced in the nuclear power industry. The various technologies as may be used, or which are under investigation, to immobilize these nuclides and to contain them during storage and in disposal are discussed. Also, the alternative disposal options as may be applied to isolate these radioactive wastes from the human environment are presented. The report contains information which was available through approximately January 1978

  1. PROCESS FOR TREATING VOLATILE METAL FLUORIDES

    Science.gov (United States)

    Rudge, A.J.; Lowe, A.J.

    1957-10-01

    This patent relates to the purification of uranium hexafluoride, made by reacting the metal or its tetrafluoride with fluorine, from the frequently contained traces of hydrofluoric acid. According to the present process, UF/sub 6/ containing as an impurity a small amount of hydrofluoric acid, is treated to remove such impurity by contact with an anhydrous alkali metal fluoride such as sodium fluoride. In this way a non-volatile complex containing hydrofluoric acid and the alkali metal fluoride is formed, and the volatile UF /sub 6/ may then be removed by distillation.

  2. Local Volatility Calibration Using An Adjoint Proxy

    Directory of Open Access Journals (Sweden)

    Gabriel TURINICI

    2008-11-01

    Full Text Available We document the calibration of the local volatility in a framework similar to Coleman, Li and Verma. The quality of a surface is assessed through a functional to be optimized; the specificity of the approach is to separate the optimization (performed with any suitable optimization algorithm from the computation of the functional where we use an adjoint (as in L. Jiang et. al. to obtain an approximation; moreover our main calibration variable is the implied volatility (the procedure can also accommodate the Greeks. The procedure performs well on benchmarks from the literature and on FOREX data.

  3. Plant Hormone Binding Sites

    OpenAIRE

    Napier, Richard

    2004-01-01

    • Aims Receptors for plant hormones are becoming identified with increasing rapidity, although a frustrating number remain unknown. There have also been many more hormone‐binding proteins described than receptors. This Botanical Briefing summarizes what has been discovered about hormone binding sites, their discovery and descriptions, and will not dwell on receptor functions or activities except where these are relevant to understand binding.

  4. Analysis of binding heterogeneity.

    NARCIS (Netherlands)

    Nederlof, M.M.

    1992-01-01

    Binding heterogeneity, due to different functional groups on a reactive surface, plays an important role in the binding of small molecules or ions to many adsorbents, both in industrial processes and in natural environments. The binding heterogeneity is described by a distribution of affinity consta

  5. Differential Postoperative Effects of Volatile Anesthesia and Intraoperative Remifentanil Infusion in 7511 Thyroidectomy Patients

    Science.gov (United States)

    Jo, Jun-Young; Choi, Seong-Soo; Yi, Jung Min; Joo, Eun Young; Kim, Ji Hyun; Park, Se Ung; Sim, Ji-Hoon; Karm, Myong-Hwan; Ku, Seungwoo

    2016-01-01

    Abstract Although remifentanil is used widely by many clinicians during general anesthesia, there are recent evidences of opioid-induced hyperalgesia as an adverse effect. This study aimed to determine if intraoperative remifentanil infusion caused increased pain during the postoperative period in patients who underwent a thyroidectomy. A total of 7511 patients aged ≥ 20 years, who underwent thyroidectomy between January 2009 and December 2013 at the Asan Medical Center were retrospectively analyzed. Enrolled patients were divided into 2 groups: group N (no intraoperative remifentanil and only volatile maintenance anesthesia) and group R (intraoperative remifentanil infusion including total intravenous anesthesia and balanced anesthesia). Following propensity score matching analysis, 2582 patients were included in each group. Pain scores based on numeric rating scales (NRS) were compared between the 2 groups at the postoperative anesthetic care unit and at the ward until 3 days postoperation. Incidences of postoperative complications, such as nausea, itching, and shivering were also compared. The estimated NRS pain score on the day of surgery was 5.08 (95% confidence interval [CI] 4.97–5.19) in group N patients and 6.73 (95% CI 6.65–6.80) in group R patients (P < 0.001). There were no statistically significant differences in NRS scores on postoperative days 1, 2, and 3 between the 2 groups. Postoperative nausea was less frequent in group R (31.4%) than in group N (53.5%) (P < 0.001). However, the incidence of itching was higher in group R (4.3%) than in group N (0.7%) (P < 0.001). Continuous infusion of remifentanil during general anesthesia can cause higher intensity of postoperative pain and more frequent itching than general anesthesia without remifentanil infusion immediately after thyroidectomy. Considering the advantages and disadvantages of continuous remifentanil infusion, volatile anesthesia without opioid may be a good choice for minor

  6. Multiple Transmembrane Binding Sites for p-Trifluoromethyldiazirinyl-etomidate, a Photoreactive Torpedo Nicotinic Acetylcholine Receptor Allosteric Inhibitor*

    OpenAIRE

    Hamouda, Ayman K.; Stewart, Deirdre S.; Husain, S. Shaukat; Cohen, Jonathan B.

    2011-01-01

    Photoreactive derivatives of the general anesthetic etomidate have been developed to identify their binding sites in γ-aminobutyric acid, type A and nicotinic acetylcholine receptors. One such drug, [3H]TDBzl-etomidate (4-[3-(trifluoromethyl)-3H-diazirin-3-yl]benzyl-[3H]1-(1-phenylethyl)-1H-imidazole-5-carboxylate), acts as a positive allosteric potentiator of Torpedo nACh receptor (nAChR) and binds to a novel site in the transmembrane domain at the γ-α subunit interface. To extend our unders...

  7. The pharmacokinetics and pharmacodynamics of ketamine in dogs anesthetized with enflurane.

    Science.gov (United States)

    Schwieger, I M; Szlam, F; Hug, C C

    1991-04-01

    The plasma concentration vs. anesthetic effect relationships for ketamine are not well known. It is desirable to establish stable and predictable drug concentrations in plasma (and brain) in order to define such relationships. As a prelude to pharmacodynamic studies, we investigated ketamine pharmacokinetics in eight dogs anesthetized with enflurane and correlated ketamine concentration in plasma (KET) with its ability to reduce the enflurane concentration required for anesthesia (enflurane EC50: MAC--the end-tidal concentration at which half the dogs moved in response to clamping of the tail and half did not move). Four dogs (Group 1) received ketamine 10 mg/kg iv over 30 sec. Blood for determination of KET was collected repeatedly over the 5-h period following injection. Based on the pharmacokinetic parameters determined for Group 1, four dogs in Group 2 received ketamine as a continuous infusion of 300 micrograms.kg-1.min-1 for 5 hr accompanied by an initial loading dose (26 mg/kg administered over 20 min) designed to produce a stable KET of 20 micrograms/ml of plasma. Enflurane MAC and KET were determined regularly during the infusion and for 5 hr after discontinuation of the infusion. There were no significant differences in the following pharmacokinetic parameters determined for Group 1 vs. Group 2: t1/2 beta = 122 +/- 9 vs. 141 +/- 40 min (mean +/- SD) and CL = 18.1 +/- 5.9 vs. 13.9 +/- 2.5 ml.kg-1.min-1, respectively. When administered as a continuous infusion (Group 2), KET remained relatively stable at 22.1 +/- 4.6 micrograms/ml for 5 hr. The degree of MAC reduction remained relatively stable at 73% during the continuous infusion. Finally, the enflurane MAC reduction vs. KET was established over a wide range of plasma concentrations in 4 additional dogs (Group 3). This study determined that the pharmacokinetics of ketamine were consistent under two different experimental conditions and demonstrated the relationship between plasma concentration and

  8. Anesthetic complications including two cases of postoperative respiratory depression in living liver donor surgery

    Directory of Open Access Journals (Sweden)

    David Beebe

    2011-01-01

    Full Text Available Background: Living liver donation is becoming a more common means to treat patients with liver failure because of a shortage of cadaveric organs and tissues. There is a potential for morbidity and mortality, however, in patients who donate a portion of their liver. The purpose of this study is to identify anesthetic complications and morbidity resulting from living liver donor surgery. Patients and Methods: The anesthetic records of all patients who donated a segment of their liver between January 1997 and January 2006 at University of Minnesota Medical Center-Fairview were retrospectively reviewed. The surgical and anesthesia time, blood loss, hospitalization length, complications, morbidity, and mortality were recorded. Data were reported as absolute values, mean ± SD, or percentage. Significance (P < 0.05 was determined using Student′s paired t tests. Results: Seventy-four patients (34 male, 40 female, mean age = 35.5 ± 9.8 years donated a portion of their liver and were reviewed in the study. Fifty-seven patients (77% donated the right hepatic lobe, while 17 (23% donated a left hepatic segment. The average surgical time for all patients was 7.8 ± 1.5 hours, the anesthesia time was 9.0 ± 1.3 hours, and the blood loss was 423 ± 253 ml. Forty-six patients (62.2% received autologous blood either from a cell saver or at the end of surgery following acute, normovolemic hemodilution, but none required an allogenic transfusion. Two patients were admitted to the intensive care unit due to respiratory depression. Both patients donated their right hepatic lobe. One required reintubation in the recovery room and remained intubated overnight. The other was extubated but required observation in the intensive care unit for a low respiratory rate. Twelve patients (16.2% had complaints of nausea, and two reported nausea with vomiting during their hospital stay. There were four patients who developed complications related to positioning during the

  9. Are exchange rates excessively volatile? And what does "excessively volatile" mean, anyway?

    OpenAIRE

    Gordon M. Bodnar; Leonardo Bartolini

    1996-01-01

    Using data for the major currencies from 1973 to 1994, we apply recent tests of asset price volatility to re-examine whether exchange rates have been excessively volatile with respect to the predictions of the monetary model of the exchange rate and of standard extensions that allow for sticky prices, sluggish money adjustment, and time-varying risk premia. Consistent with previous evidence from regression-based tests, most of the models that we examine are rejected by our volatility-based te...

  10. 比较亚麻醉剂量氯胺酮和七氟醚用于麻醉的临床效果%Comparison of Clinical Anesthetic Effects between Sub-anesthetic Ketamine and Sevoflurane

    Institute of Scientific and Technical Information of China (English)

    王洪宇

    2015-01-01

    目的:对比七氟醚与亚麻醉剂量氯胺酮用于临床麻醉效果。方法对2013年4月-2014年9月入诊该院的100例需实施麻醉的患者按照50例为一组分成两组,观察组使用亚麻醉剂量氯胺酮,对照组使用七氟醚,观察并记录两组麻醉效果及不良反应发生情况,同时进行组间对比。结果观察组总体麻醉效果优于对照组,其总体用药量较少、起效时间较短,完全阻滞时间同样短于对照组(P<0.01);观察组患者治疗后均未出现任何不良反应,对照组中有9例出现恶心症状(P<0.01)。结论临床使用亚麻醉剂量氯胺酮的麻醉效果显著优于七氟醚,且不会引起不良反应症状发生,临床可推广应用。%Objective To compared the clinical anesthetic effects of sub-anesthetic ketamine and sevoflurane. Methods 100 pa-tients to be narcotized were divided into the observation group and the control group, with 50 patients in each group. The observa-tion group was given sub-anesthetic ketamine and the control group was given sevoflurane. The anesthetic effect and adverse reac-tion of both groups were observed, recorded and compared. Results The anesthetic effect of the observation group was better than that of the control group, with less dosage, efficacy time, and complete retardant time (P<0.01). The patients of the observation group had no adverse reaction after treatment, while 9 patients of the control group had nausea symptom (P<0.01). Conclusion The clinical anesthetic effect of sub-anesthetic ketamine is significantly better than that of sevoflurane. Ketamine will not cause any adverse reaction, and thus is worth clinical promotion.

  11. Analyzing radioligand binding data.

    Science.gov (United States)

    Motulsky, Harvey; Neubig, Richard

    2002-08-01

    Radioligand binding experiments are easy to perform, and provide useful data in many fields. They can be used to study receptor regulation, discover new drugs by screening for compounds that compete with high affinity for radioligand binding to a particular receptor, investigate receptor localization in different organs or regions using autoradiography, categorize receptor subtypes, and probe mechanisms of receptor signaling, via measurements of agonist binding and its regulation by ions, nucleotides, and other allosteric modulators. This unit reviews the theory of receptor binding and explains how to analyze experimental data. Since binding data are usually best analyzed using nonlinear regression, this unit also explains the principles of curve fitting with nonlinear regression.

  12. Recovery of volatile bioproducts by pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Boeddeker, K.W.

    1994-01-01

    Organophilic prevaporation is linkened to steam distillation in the recovery of volatile bioproducts of fermentation or plant origin. Potential applications are to biosynthetic chemicals (e.g., EtOH; BuOH), aroma compounds (e.g., gamma-decalactone; 6-pentyl-2-pyrone), and essential oils. Unlike steam distillation, pervaporation may be combined with an active fermenter. (orig.)

  13. Do Macroeconomic Announcements Cause Asymetric Volatility?

    NARCIS (Netherlands)

    P. de Goeij (Peter); W.A. Marquering (Wessel)

    2002-01-01

    textabstractIn this paper we study the impact of macroeconomic news announcements on the conditional volatility of stock and bond returns. Using daily returns on the S&P 500 index, the NASDAQ index, and the 1 and 10 year U.S. Treasury bonds, for January 1982 - August 2001, some interesting results e

  14. Permeation of volatile compounds through starch films

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.; Feil, H.; Dijk, van C.; Hennink, W.E.

    2004-01-01

    The aim of this study was to gain insight into the factors that affect the permeation of volatiles through starch films. These films were obtained by casting gelatinized starch/water/glycerol mixtures. The films were dried and conditioned under different conditions (temperature and relative humidity

  15. Volatile components from Anthriscus sylvestris (L.) Hoffm

    NARCIS (Netherlands)

    Bos, R.; Koulman, A; Woerdenbag, H.J.; Quax, Wim; Pras, N.

    2002-01-01

    The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated, whil

  16. Volatile terpenoids from aeciospores of Cronartium fusiforme.

    Science.gov (United States)

    Laseter, J. L.; Weete, J. D.; Walkinshaw, C. H.

    1973-01-01

    Identification of the terpenoids present in the volatile fraction from aeciospores of the gall rust fungus Cronartium fusiforme. The major monoterpenoid hydrocarbons found to be present with only traces of camphene include alpha-pinene, beta-pinene, delta(3)-carene, myrcene, linonene, beta-phellandrene, and delta-terpinene. A number of monoterpenoid alcohols, acyclic sesquiterpenes, and aromatic compounds were also present.

  17. Explaining output volatility: The case of taxation

    DEFF Research Database (Denmark)

    Posch, Olaf

    the second moment of output growth rates without (long-run) effects on the first moment. Taking the model to the data, we exploit observed heterogeneity patterns to estimate effects of tax rates on macro volatility using panel estimation, explicitly modeling the unobserved variance process. We find a strong...

  18. Bayesian Vector Autoregressions with Stochastic Volatility

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.

    1996-01-01

    This paper proposes a Bayesian approach to a vector autoregression with stochastic volatility, where the multiplicative evolution of the precision matrix is driven by a multivariate beta variate.Exact updating formulas are given to the nonlinear filtering of the precision matrix.Estimation of the au

  19. Linux Incident Response Volatile Data Analysis Framework

    Science.gov (United States)

    McFadden, Matthew

    2013-01-01

    Cyber incident response is an emphasized subject area in cybersecurity in information technology with increased need for the protection of data. Due to ongoing threats, cybersecurity imposes many challenges and requires new investigative response techniques. In this study a Linux Incident Response Framework is designed for collecting volatile data…

  20. biogenic aerosol precursors: volatile amines from agriculture

    Science.gov (United States)

    Kuhn, Uwe; Sintermann, Jörg; Spirig, Christoph; Ammann, Christof; Neftel, Albrecht

    2010-05-01

    Information on the occurrence of volatile biogenic amines in the atmosphere is marginal. This group of N-bearing organic compounds are assumed to be a small, though significant component of the atmospheric N-cycle, but are not accounted for in global assessments due to the scarceness of available data. There is increasing evidence for an important role of biogenic amines in the formation of new particulate matter, as well as for aerosol secondary growth. Volatile amines are ubiquitously formed by biodegradation of organic matter, and agriculture is assumed to dominantly contribute to their atmospheric burden. Here we show that the mixing ratios of volatile amines within livestock buildings scale about 2 orders of magnitude lower than NH3, confirming the few literature data available (e.g., Schade and Crutzen, J. Atm. Chem. 22, 319-346, 1995). Flux measurements after manure application in the field, mixing ratios in the headspace of manure storage pools, and concentrations in distilled manure all indicate major depletion of amines relative to NH3 during manure processing. We conclude that the agricultural source distribution of NH3 and amines is not similar. While for NH3 the spreading of manure in the field dominates agricultural emissions, the direct release from livestock buildings dominates the budget of volatile biogenic amines.