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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. 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...

  3. Sodium channels as targets for volatile anesthetics

    Directory of Open Access Journals (Sweden)

    KarlF.Herold

    2012-03-01

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

  4. 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.

  5. 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.

  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. Goalpha regulates volatile anesthetic action in Caenorhabditis elegans.

    OpenAIRE

    van Swinderen, B.; Metz, L B; Shebester, L D; Mendel, J E; Sternberg, P. W.; Crowder, C. M.

    2001-01-01

    To identify genes controlling volatile anesthetic (VA) action, we have screened through existing Caenorhabditis elegans mutants and found that strains with a reduction in Go signaling are VA resistant. Loss-of-function mutants of the gene goa-1, which codes for the alpha-subunit of Go, have EC(50)s for the VA isoflurane of 1.7- to 2.4-fold that of wild type. Strains overexpressing egl-10, which codes for an RGS protein negatively regulating goa-1, are also isoflurane resistant. However, sensi...

  8. 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

  9. Rapid eye movement sleep debt accrues in mice exposed to volatile anesthetics

    Science.gov (United States)

    Pick, Jeremy; Chen, Yihan; Moore, Jason T.; Sun, Yi; Wyner, Abraham J.; Friedman, Eliot B.; Kelz, Max B.

    2011-01-01

    Background General anesthesia has been likened to a state in which anesthetized subjects are locked out of access to both rapid eye movement (REM) sleep and wakefulness. Were this true for all anesthetics, one might expect a significant REM rebound following anesthetic exposure. However, for the intravenous anesthetic propofol, studies demonstrate that no sleep debt accrues. Moreover, pre-existing sleep debts dissipate during propofol anesthesia. To determine whether these effects are specific to propofol or are typical of volatile anesthetics we tested the hypothesis that REM sleep debt would accrue in rodents anesthetized with volatile anesthetics. Methods Electroencephalographic and electromyographic electrodes were implanted in 10 mice. After 9–11 days of recovery and habituation to a 12h:12h light:dark cycle, baseline states of wakefulness, non-rapid eye movement sleep, and REM sleep were recorded in mice exposed to 6 hours of an oxygen control and on separate days to 6 hours of isoflurane, sevoflurane, or halothane in oxygen. All exposures were conducted at the onset of light. Results Mice in all three anesthetized groups exhibited a significant doubling of REM sleep during the first six-hours of the dark phase of the circadian schedule while only mice exposed to halothane displayed a significant increase in non-rapid eye movement sleep that peaked at 152% of baseline. Conclusion REM sleep rebound following exposure to volatile anesthetics suggests that these volatile anesthetics do not fully substitute for natural sleep. This result contrasts with the published actions of propofol for which no REM sleep rebound occurred. PMID:21934405

  10. [An experimental study of the computer-controlled equipment for delivering volatile anesthetic agent].

    Science.gov (United States)

    Sun, B; Li, W Z; Yue, Y; Jiang, C W; Xiao, L Y

    2001-11-01

    Our newly-designed computer-controlled equipment for delivering volatile anesthetic agent uses the subminiature singlechip processor as the central controlling unit. The variables, such as anesthesia method, anesthetic agent, the volume of respiratory loop, age of patient, sex, height, weight, environment temperature and the grade of ASA are all input from the keyboard. The anesthetic dosage, calculated by the singlechip processor, is converted into the signals controlling the pump to accurately deliver anesthetic agent into respiratory loop. We have designed an electrocircuit for the equipment to detect the status of the pump's operation, so we can assure of the safety and the stability of the equipment. The output precision of the equipment, with a good anti-jamming capability, is 1-2% for high flow anesthesia and 1-5% for closed-circuit anesthesia and its self-detecting working is reliable. PMID:12583263

  11. Hypnotic Hypersensitivity to Volatile Anesthetics and Dexmedetomidine in Dopamine β-Hydroxylase Knockout Mice

    Science.gov (United States)

    Hu, Frances Y.; Hanna, George M.; Han, Wei; Mardini, Feras; Thomas, Steven A.; Wyner, Abraham J.; Kelz, Max B.

    2012-01-01

    BACKGROUND Multiple lines of evidence suggest that the adrenergic system can modulate sensitivity to anesthetic-induced immobility and anesthetic-induced hypnosis as well. However, several considerations prevent the conclusion that the endogenous adrenergic ligands norepinephrine and epinephrine alter anesthetic sensitivity. METHODS Using dopamine β-hydroxylase (Dbh−/−) mice genetically engineered to lack the adrenergic ligands and their siblings with normal adrenergic levels, we test the contribution of the adrenergic ligands upon volatile anesthetic induction and emergence. Moreover, we investigate the effects of intravenous dexmedetomidine in adrenergic-deficient mice and their siblings using both righting reflex and processed electroencephalographic measures of anesthetic hypnosis. RESULTS We demonstrate that the loss of norepinephrine and epinephrine and not other neuromodulators copackaged in adrenergic neurons is sufficient to cause hypersensitivity to induction of volatile anesthesia. However, the most profound effect of adrenergic deficiency is retarding emergence from anesthesia, which takes two to three times as long in Dbh−/− mice for sevoflurane, isoflurane, and halothane. Having shown that Dbh−/− mice are hypersensitive to volatile anesthetics, we further demonstrate that their hypnotic hypersensitivity persists at multiple doses of dexmedetomidine. Dbh−/− mice exhibit up to 67% shorter latencies to loss of righting reflex and up to 545% longer durations of dexmedetomidine-induced general anesthesia. Central rescue of adrenergic signaling restores control-like dexmedetomidine sensitivity. A novel continuous electroencephalographic analysis illustrates that the longer duration of dexmedetomidine-induced hypnosis is not due to a motor confound, but occurs because of impaired anesthetic emergence. CONCLUSIONS Adrenergic signaling is essential for normal emergence from general anesthesia. Dexmedetomidine-induced general anesthesia does

  12. Distinctive Recruitment of Endogenous Sleep-Promoting Neurons by Volatile Anesthetics and a Non-immobilizer

    Science.gov (United States)

    Han, Bo; McCarren, Hilary S.; O'Neill, Dan; Kelz, Max B.

    2014-01-01

    BACKGROUND Numerous studies demonstrate that anesthetic-induced unconsciousness is accompanied by activation of hypothalamic sleep-promoting neurons, which occurs through both pre- and postsynaptic mechanisms. However, the correlation between drug exposure, neuronal activation, and onset of hypnosis remains incompletely understood. Moreover, the degree to which anesthetics activate both endogenous populations of GABAergic sleep-promoting neurons within the ventrolateral preoptic (VLPO) and median preoptic (MnPO) nuclei remains unknown. METHODS Mice were exposed to oxygen, hypnotic doses of isoflurane or halothane, or 1,2-dicholorhexafluorocyclobutane (F6), a nonimmobilizer. Hypothalamic brain slices prepared from anesthetic-naïve mice were also exposed to oxygen, volatile anesthetics, or F6 ex vivo, both in the presence and absence of tetrodotoxin. Double-label immunohistochemistry was performed to quantify the number of c-Fos-immunoreactive nuclei in the GABAergic subpopulation of neurons in the VLPO and the MnPO to test the hypothesis that volatile anesthetics, but not non-immobilizers, activate sleep-promoting neurons in both nuclei. RESULTS In vivo exposure to isoflurane and halothane doubled the fraction of active, c-Fos-expressing GABAergic neurons in the VLPO, while F6 failed to affect VLPO c-Fos expression. Both in the presence and absence of tetrodotoxin, isoflurane dose-dependently increased c-Fos expression in GABAergic neurons ex vivo, while F6 failed to alter expression. In GABAergic neurons of the MnPO, c-Fos expression increased with isoflurane and F6, but not with halothane exposure. CONCLUSIONS Anesthetic unconsciousness is not accompanied by global activation of all putative sleep-promoting neurons. However, within the VLPO hypnotic doses of volatile anesthetics, but not non-immobilizers, activate putative sleep-promoting neurons, correlating with the appearance of the hypnotic state. PMID:25057841

  13. 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.

  14. 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

  15. 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.

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

    International Nuclear Information System (INIS)

    Many volatile anesthetics have long been thought to affect pulmonary functions including lung ventilation (LV) and alveolar epithelial permeability (AEP). The purpose of this study is to examine the influence of volatile anesthetics on LV and AEP by noninvasive radionuclide lung imaging of technetium-99m labeled diethylene triamine pentaacetic acid radioaerosol inhalation lung scan (DTPA lung scan). Twenty patients undergoing surgery and receiving volatile anesthesia with 1% halothane were enrolled as the study group 1. The other 20 patients undergoing surgery and receiving volatile anesthesia with 1.5% isoflurane were enrolled as the study group 2. At the same time, 20 patients undergoing surgery with intravenous anesthesia drugs were included as a control group. Before surgery, 1 hour after surgery, and 1 week after surgery, we investigated the 3 groups of patients with DTPA lung scan to evaluate LV and AEP by 99mTc DTPA clearance halftime (T1/2). No significant change or abnormality of LV before surgery, 1 hour after surgery, or 1 week after surgery was found among the 3 groups of patients. In the control group, the 99mTc DTPA clearance T1/2 was 63.5±16.4, 63.1±18.4, and 62.8±17.0 minutes, before surgery, 1 hour after surgery, and 1 week after surgery, respectively. In group 1, it was 65.9±9.3, 62.5±9.1, and 65.8±10.3 minutes, respectively. No significant change in AEP before surgery, 1 hour after surgery, or 1 week after surgery was found. However, in group 2, the99mTc DTPA clearance T1/2 was 65.5±13.2, 44.9±10.5, and 66.1±14.0 minutes, respectively. A significant transient change in AEP was found 1 hour after surgery, but it recovered 1 week after surgery. We conclude that volatile anesthesia is safe for LV and AEP, and only isoflurane can induce transient change of AEP. (author)

  17. Assessing changes in volatile general anesthetic sensitivity of mice after local or systemic pharmacological intervention.

    Science.gov (United States)

    McCarren, Hilary S; Moore, Jason T; Kelz, Max B

    2013-01-01

    One desirable endpoint of general anesthesia is the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is less straightforward than it is in human patients. A widely used behavioral surrogate for hypnosis in rodents is the loss of righting reflex (LORR), or the point at which the animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency. We have developed a system to assess LORR in 24 mice simultaneously while carefully controlling for potential confounds, including temperature fluctuations and varying gas flows. These chambers permit reliable assessment of anesthetic sensitivity as measured by latency to return of the righting reflex (RORR) following a fixed anesthetic exposure. Alternatively, using stepwise increases (or decreases) in anesthetic concentration, the chambers also enable determination of a population's sensitivity to induction (or emergence) as measured by EC50 and Hill slope. Finally, the controlled environmental chambers described here can be adapted for a variety of alternative uses, including inhaled delivery of other drugs, toxicology studies, and simultaneous real-time monitoring of vital signs. PMID:24192721

  18. Specificity of intersubunit general anesthetic-binding sites in the transmembrane domain of the human α1β3γ2 γ-aminobutyric acid type A (GABAA) receptor.

    Science.gov (United States)

    Chiara, David C; Jayakar, Selwyn S; Zhou, Xiaojuan; Zhang, Xi; Savechenkov, Pavel Y; Bruzik, Karol S; Miller, Keith W; Cohen, Jonathan B

    2013-07-01

    GABA type A receptors (GABAAR), the brain's major inhibitory neurotransmitter receptors, are the targets for many general anesthetics, including volatile anesthetics, etomidate, propofol, and barbiturates. How such structurally diverse agents can act similarly as positive allosteric modulators of GABAARs remains unclear. Previously, photoreactive etomidate analogs identified two equivalent anesthetic-binding sites in the transmembrane domain at the β(+)-α(-) subunit interfaces, which also contain the GABA-binding sites in the extracellular domain. Here, we used R-[(3)H]5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl) barbituric acid (R-mTFD-MPAB), a potent stereospecific barbiturate anesthetic, to photolabel expressed human α1β3γ2 GABAARs. Protein microsequencing revealed that R-[(3)H]mTFD-MPAB did not photolabel the etomidate sites at the β(+)-α(-) subunit interfaces. Instead, it photolabeled sites at the α(+)-β(-) and γ(+)-β(-) subunit interfaces in the transmembrane domain. On the (+)-side, α1M3 was labeled at Ala-291 and Tyr-294 and γ2M3 at Ser-301, and on the (-)-side, β3M1 was labeled at Met-227. These residues, like those in the etomidate site, are located at subunit interfaces near the synaptic side of the transmembrane domain. The selectivity of R-etomidate for the β(+)-α(-) interface relative to the α(+)-β(-)/γ(+)-β(-) interfaces was >100-fold, whereas that of R-mTFD-MPAB for its sites was >50-fold. Each ligand could enhance photoincorporation of the other, demonstrating allosteric interactions between the sites. The structural heterogeneity of barbiturate, etomidate, and propofol derivatives is accommodated by varying selectivities for these two classes of sites. We hypothesize that binding at any of these homologous intersubunit sites is sufficient for anesthetic action and that this explains to some degree the puzzling structural heterogeneity of anesthetics. PMID:23677991

  19. 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

  20. 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.

  1. 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.

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

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    Bengü Gülhan Köksal

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Perez Roberto SGM

    2005-06-01

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

  4. Inhaled Anesthetic Potency in Aged Alzheimer Mice

    Science.gov (United States)

    Bianchi, Shannon L.; Caltagarone, Breanna M.; LaFerla, Frank M.; Eckenhoff, Roderic G.; Kelz, Max B.

    2016-01-01

    BACKGROUND The number of elderly patients with frank or incipient Alzheimer’s disease (AD) requiring surgery is growing as the population ages. General anesthesia may exacerbate symptoms of and the pathology underlying AD, so minimizing anesthetic exposure may be important. This requires knowledge of whether the continuing AD pathogenesis alters anesthetic potency. METHODS We determined the induction potency and emergence time for isoflurane, halothane, and sevoflurane using the minimum alveolar anesthetic concentration for loss of righting reflex as an end point in 12- to 14-mo-old triple transgenic Alzheimer (3xTgAD) mice and wild type C57BL6 controls. 3xTgAD mice model AD by harboring three distinct mutations: the APPSwe, Tau, and PS1 human transgenes, each of which has been associated with familial forms of human AD. RESULTS The 3xTgAD mice exhibited mild resistance (from 8% to 30%) to volatile anesthetics but displayed indistinguishable emergence patterns from all three inhaled anesthetics. CONCLUSIONS These results show that the genetic vulnerabilities and neuropathology associated with AD produce a small but significant decrease in sensitivity to the hypnotic actions of three inhaled anesthetics. Emergence times were not altered. PMID:19820240

  5. Effects of Anesthetic Membrane Solutes on Orientational Order in Lecithin Bilayer Membranes: a Deuterium NMR Study.

    Science.gov (United States)

    Phonphok, Nason

    The interaction of eight n-alkanols and three volatile anesthetics with bilayers of dimyristoylphosphatidylcholine (DMPC) has been studied by deuterium nuclear magnetic resonance (^2H NMR). At comparable temperatures and concentrations of solute in the bilayer, order parameters measured at the 1-methylene segment of the n-alkanols, and average order parameters for the whole alkyl chain, show a maximum for n-dodecanol. This maximum in orientational ordering also occurs for n-dodecanol at the much lower levels of solute concentration which produce anesthesia. For both n-dodecanol and n-tetradecanol, orientational ordering shows a maximum at the C-4 to C-7 methylene segments, with labels at both ends of the n-alkanol exhibiting reduced order. Unlike the longer chain n-alkanols, ordering in n-butanol decreases from the hydroxyl group end to the methyl group end of the molecule. The quadrupole splittings observed in DMPC-water systems containing perdeuterated ether, chloroform and n-hexane show that these volatile anesthetics are also ordered in the bilayer in the L _{alpha} phase. The temperature dependence of the quadrupole splitting ^2H_2O in DMPC bilayers at low hydration indicates that both the n-alkanols and volatile anesthetics do not affect water structure in the L_alpha phase, but they do so below the main phase transition. Orientational ordering at nine inequivalent sites in the headgroup region of DMPC, as well as the acyl chains, has also been measured. Every anesthetic produces a disordering at the beta-methylene of the choline, the 3-methylene segment and the 1-R site (except chloroform) of the glycerol backbone. Molecular and conformational ordering at the interfacial region of DMPC in the L _alpha phase have been examined by analysing ^2H-NMR data from multiple sites in the most rigid region of the DMPC molecule. It was found that these anesthetics change the conformation at the glycerol moiety of DMPC without changing the molecular order parameter rm S

  6. [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

  7. 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

  8. Anesthetizing the obese child

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......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...... 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...

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. A conserved behavioral state barrier impedes transitions between anesthetic-induced unconsciousness and wakefulness: evidence for neural inertia.

    Directory of Open Access Journals (Sweden)

    Eliot B Friedman

    Full Text Available One major unanswered question in neuroscience is how the brain transitions between conscious and unconscious states. General anesthetics offer a controllable means to study these transitions. Induction of anesthesia is commonly attributed to drug-induced global modulation of neuronal function, while emergence from anesthesia has been thought to occur passively, paralleling elimination of the anesthetic from its sites in the central nervous system (CNS. If this were true, then CNS anesthetic concentrations on induction and emergence would be indistinguishable. By generating anesthetic dose-response data in both insects and mammals, we demonstrate that the forward and reverse paths through which anesthetic-induced unconsciousness arises and dissipates are not identical. Instead they exhibit hysteresis that is not fully explained by pharmacokinetics as previously thought. Single gene mutations that affect sleep-wake states are shown to collapse or widen anesthetic hysteresis without obvious confounding effects on volatile anesthetic uptake, distribution, or metabolism. We propose a fundamental and biologically conserved concept of neural inertia, a tendency of the CNS to resist behavioral state transitions between conscious and unconscious states. We demonstrate that such a barrier separates wakeful and anesthetized states for multiple anesthetics in both flies and mice, and argue that it contributes to the hysteresis observed when the brain transitions between conscious and unconscious states.

  14. A Conserved Behavioral State Barrier Impedes Transitions between Anesthetic-Induced Unconsciousness and Wakefulness: Evidence for Neural Inertia

    Science.gov (United States)

    Friedman, Eliot B.; Sun, Yi; Moore, Jason T.; Hung, Hsiao-Tung; Meng, Qing Cheng; Perera, Priyan; Joiner, William J.; Thomas, Steven A.; Eckenhoff, Roderic G.; Sehgal, Amita; Kelz, Max B.

    2010-01-01

    One major unanswered question in neuroscience is how the brain transitions between conscious and unconscious states. General anesthetics offer a controllable means to study these transitions. Induction of anesthesia is commonly attributed to drug-induced global modulation of neuronal function, while emergence from anesthesia has been thought to occur passively, paralleling elimination of the anesthetic from its sites in the central nervous system (CNS). If this were true, then CNS anesthetic concentrations on induction and emergence would be indistinguishable. By generating anesthetic dose-response data in both insects and mammals, we demonstrate that the forward and reverse paths through which anesthetic-induced unconsciousness arises and dissipates are not identical. Instead they exhibit hysteresis that is not fully explained by pharmacokinetics as previously thought. Single gene mutations that affect sleep-wake states are shown to collapse or widen anesthetic hysteresis without obvious confounding effects on volatile anesthetic uptake, distribution, or metabolism. We propose a fundamental and biologically conserved concept of neural inertia, a tendency of the CNS to resist behavioral state transitions between conscious and unconscious states. We demonstrate that such a barrier separates wakeful and anesthetized states for multiple anesthetics in both flies and mice, and argue that it contributes to the hysteresis observed when the brain transitions between conscious and unconscious states. PMID:20689589

  15. 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

  16. 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...

  17. 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

  18. ANESTHETIC MANAGEMENT OF ANATROPHIC NEPHROLITHOTOMY

    OpenAIRE

    Mrs. Geetha; Tejesh; Prathima

    2013-01-01

    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 wa...

  19. 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...

  20. Volatile Metabolites

    Directory of Open Access Journals (Sweden)

    Daryl D. Rowan

    2011-11-01

    Full Text Available Volatile organic compounds (volatiles comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites.

  1. 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

  2. Decline in the Development of New Anesthetics.

    Science.gov (United States)

    Vlassakov, Kamen V; Kissin, Igor

    2016-05-01

    The number of new anesthetics approved by the USA FDA over the past 30 years (1985-2014) is much smaller than during the preceding 30 years (1955-1984): four versus ten. Investigational anesthetics clinically tested since 1990 have been almost exclusively intravenous anesthetics (nine compounds), with only one now approved by the FDA. All nine agents represent modifications of anesthetics introduced approximately 40-50 years ago; none demonstrates a truly novel mechanism of action. The apparent drought of novel anesthetics is difficult to explain. While there may be multiple reasons, we believe that one is especially noteworthy: the dramatic improvement in anesthesia safety owing to the context in which anesthetics are administered, effectively decreasing the pressure to develop new drugs with better safety margins. PMID:26922254

  3. Hair transplant and local anesthetics.

    Science.gov (United States)

    Lam, Samuel M

    2013-10-01

    Hair restoration is an art and a science that requires an experienced and dedicated surgeon and team to achieve consistently superior outcomes. In addition to discussion of local anesthetic in use for hair restoration, this article emphasizes the pearls and pitfalls that are involved at every phase of the procedure including judgment, hairline design, donor harvesting, recipient-site creation, graft preparation, and graft placement. Two recent advances in the field are highlighted: the use of regenerative medicine (platelet-rich plasma and ACell), and developments in follicular-unit extraction as an alternative to traditional linear donor harvesting. PMID:24093656

  4. Volatility Derivatives

    OpenAIRE

    Peter Carr; Roger Lee

    2009-01-01

    Volatility derivatives are a class of derivative securities where the payoff explicitly depends on some measure of the volatility of an underlying asset. Prominent examples of these derivatives include variance swaps and VIX futures and options. We provide an overview of the current market for these derivatives. We also survey the early literature on the subject. Finally, we provide relatively simple proofs of some fundamental results related to variance swaps and volatility swaps.

  5. Unraveling Interactions Between Anesthetics and the Endothelium: Update and Novel Insights.

    Science.gov (United States)

    Aguirre, José A; Lucchinetti, Eliana; Clanachan, Alexander S; Plane, Frances; Zaugg, Michael

    2016-02-01

    The vascular endothelium is one of the largest organs in the body and consists of a single layer of highly specialized cells with site-specific morphology and functions. Endothelial cells play a vital role in the regulation of vascular tone in arterial, venous, microvascular, and lymphatic vascular beds. The endothelium also coordinates angiogenesis and controls cell adhesion, fluid homeostasis, and both innate and adaptive immunity. Fundamental research has shown that general and local anesthetics markedly modulate the biological activities of endothelial cells under aerobic and ischemia-reperfusion conditions, making the endothelium an important target of anesthetics in the cardiovascular system. Halogenated volatile anesthetics provide significant anti-inflammatory actions and protect the endothelium against ischemia-reperfusion injury, despite their inhibiting effects on endothelium-dependent vasorelaxation. They provide not only acute but also potential long-term, beneficial effects. Although many effects of IV anesthetics on endothelial function are controversial, or completely unexplored, propofol and opioids appear to have the most favorable profile with respect to the preservation of endothelial function. Some opioids and ketamine have stereoselective effects on the endothelium. Finally, there is experimental evidence to suggest important effects of anesthetics on the regulation of vascular permeability, proliferation of stem cells, including endothelial progenitor cells, and promotion or inhibition of tumor growth, potentially related to alterations in angiogenesis. However, most of these findings are from in vitro experiments and await confirmation in an in vivo setting. Thus, the clinical implications of these interactions remain uncertain. PMID:26797549

  6. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  7. Benzocaine as an anesthetic for striped bass

    Science.gov (United States)

    Gilderhus, Philip A.; Lemm, Carol A.; Woods, L. Curry, III

    1991-01-01

    Benzocaine was tested as an anesthetic on juvenile and mature adult striped bass (Morone saxatilis ). Concentrations of 55 mg/L at 22 degree C to 80 mg/L at 11 degree C effectively anesthetized fish in about 3 min. Recovery was more rapid as temperature increased. Fish survived concentrations of twice the effective concentration and exposure times up to 60 min at the effective concentration. Striped bass required higher concentrations for anesthetization than had been previously demonstrated for salmonid fishes, but safety margins for both concentration and exposure time were wider than for the salmonids.

  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. 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...

  10. Anesthetic effects in Alzheimer transgenic mouse models

    OpenAIRE

    Tang, Junxia X.; Eckenhoff, Maryellen F.

    2012-01-01

    Research has improved the diagnosis of Alzheimer’s disease, and at earlier stages, but effective therapy continues to be elusive. Current effort is focused on delay. Environmental factors are thought to interact with genetics to modulate the progression of the disease, and one such environmental factor is exposure to general anesthetics. The possibility that some anesthetic effects have long-term consequences is of general interest and concern. The difficulty of studying a chronic, age-relate...

  11. On the volatility of volatility

    Science.gov (United States)

    Hsu, Stephen D. H.; Murray, Brian M.

    2007-07-01

    The Chicago Board Options Exchange (CBOE) Volatility Index, VIX, is calculated based on prices of out-of-the-money put and call options on the S&P 500 index (SPX). Sometimes called the “investor fear gauge”, the VIX is a measure of the implied volatility of the SPX, and is observed to be correlated with the 30-day realized volatility of the SPX. Changes in the VIX are observed to be negatively correlated with changes in the SPX. However, no significant correlation between changes in the VIX and changes in the 30-day realized volatility of the SPX are observed. We investigate whether this indicates a mispricing of options following large VIX moves, and examine the relation to excess returns from variance swaps. The sense in which the term “mispricing” is used is discussed in the paper.

  12. On the volatility of volatility

    CERN Document Server

    Hsu, S D H; Hsu, Stephen D. H.; Murray, Brian M.

    2006-01-01

    The Chicago Board Options Exchange (CBOE) Volatility Index, VIX, is calculated based on prices of out-of-the-money put and call options on the S&P 500 index (SPX). Sometimes called the "investor fear gauge," the VIX is a measure of the implied volatility of the SPX, and is observed to be correlated with the 30-day realized volatility of the SPX. Changes in the VIX are observed to be negatively correlated with changes in the SPX. However, no significant correlation between changes in the VIX and changes in the 30-day realized volatility of the SPX are observed. We investigate whether this indicates a mispricing of options following large VIX moves, and examine the relation to excess returns from variance swaps.

  13. Volatility in energy prices

    International Nuclear Information System (INIS)

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

  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. 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

  16. Forecasting volatility

    OpenAIRE

    Ederington, Louis H; Wei Guan

    2005-01-01

    The forecasting ability of the most popular volatility forecasting models is examined and an alternative model developed. Existing models are compared in terms of four attributes: (1) the relative weighting of recent versus older observations, (2) the estimation criterion, (3) the trade‐off in terms of out‐of‐sample forecasting error between simple and complex models, and (4) the emphasis placed on large shocks. As in previous studies, we find that financial markets have longer memories than ...

  17. 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.

  18. Intrinsic organization of the anesthetized brain.

    Science.gov (United States)

    Liang, Zhifeng; King, Jean; Zhang, Nanyin

    2012-07-25

    The neural mechanism of unconsciousness has been a major unsolved question in neuroscience despite its vital role in brain states like coma and anesthesia. The existing literature suggests that neural connections, information integration, and conscious states are closely related. Indeed, alterations in several important neural circuitries and networks during unconscious conditions have been reported. However, how the whole-brain network is topologically reorganized to support different patterns of information transfer during unconscious states remains unknown. Here we directly compared whole-brain neural networks in awake and anesthetized states in rodents. Consistent with our previous report, the awake rat brain was organized in a nontrivial manner and conserved fundamental topological properties in a way similar to the human brain. Strikingly, these topological features were well maintained in the anesthetized brain. Local neural networks in the anesthetized brain were reorganized with altered local network properties. The connectional strength between brain regions was also considerably different between the awake and anesthetized conditions. Interestingly, we found that long-distance connections were not preferentially reduced in the anesthetized condition, arguing against the hypothesis that loss of long-distance connections is characteristic to unconsciousness. These findings collectively show that the integrity of the whole-brain network can be conserved between widely dissimilar physiologic states while local neural networks can flexibly adapt to new conditions. They also illustrate that the governing principles of intrinsic brain organization might represent fundamental characteristics of the healthy brain. With the unique spatial and temporal scales of resting-state fMRI, this study has opened a new avenue for understanding the neural mechanism of (un)consciousness. PMID:22836253

  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. 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

  1. 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.

  2. 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.

  3. 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.

  4. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Directory of Open Access Journals (Sweden)

    Armstead Valerie

    2006-11-01

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

  5. Anesthetic consideration in dystrophic epidermolysis bullosa

    Science.gov (United States)

    Narejo, AS; Khan, MU; Alotaibi, WM; Khan, MM

    2016-01-01

    Epidermolysis bullosa is a group of inherited rare skin disease, characterized by bullae formation in the skin or mucous membranes. The fundamental abnormality is collagen degeneration leads to splitting of various epidermal layers. Dystrophic epidermolysis bullosa (DEB) is one of the major forms of epidermolysis bullosa. These patients often admitted to the hospital for corrective surgeries, change of dressing, contracture release, and skin grafting. Anesthetic management of these cases is always a challenge. We are reporting a case of 5-year-old boy diagnosed as a case of DEB scheduled for upper lip contracture release, skin grafting and debridement of nonhealing scars under anesthesia. In this case, we have focused mainly on the anesthetic management, preparation of the monitoring, transportation, difficulties in establishing the venous accesses, and airway management. PMID:26955322

  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. Child with aplastic anemia: Anesthetic management

    OpenAIRE

    Manpreet Kaur; Babita Gupta; Aanchal Sharma; Sanjeev Sharma

    2012-01-01

    Aplastic anemia is a rare heterogeneous disorder of hematopoietic stem cells causing pancytopenia and marrow hypoplasia with the depletion of all types of blood cells. This results in anemia, neutropenia and thrombocytopenia, which pose a challenge to both surgical and anesthetic management of such cases. We report a child with aplastic anemia who sustained traumatic ulcer on the arm and underwent split-thickness skin grafting under general anesthesia. There are only two case reports on anest...

  8. Anesthetic consideration in dystrophic epidermolysis bullosa

    OpenAIRE

    A S Narejo; Khan, M.U.; W M Alotaibi; Khan, M. M.

    2016-01-01

    Epidermolysis bullosa is a group of inherited rare skin disease, characterized by bullae formation in the skin or mucous membranes. The fundamental abnormality is collagen degeneration leads to splitting of various epidermal layers. Dystrophic epidermolysis bullosa (DEB) is one of the major forms of epidermolysis bullosa. These patients often admitted to the hospital for corrective surgeries, change of dressing, contracture release, and skin grafting. Anesthetic management of these cases is a...

  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. Mutant bacterial sodium channels as models for local anesthetic block of eukaryotic proteins.

    Science.gov (United States)

    Smith, Natalie E; Corry, Ben

    2016-05-01

    Voltage gated sodium channels are the target of a range of local anesthetic, anti-epileptic and anti-arrhythmic compounds. But, gaining a molecular level understanding of their mode of action is difficult as we only have atomic resolution structures of bacterial sodium channels not their eukaryotic counterparts. In this study we used molecular dynamics simulations to demonstrate that the binding sites of both the local anesthetic benzocaine and the anti-epileptic phenytoin to the bacterial sodium channel NavAb can be altered significantly by the introduction of point mutations. Free energy techniques were applied to show that increased aromaticity in the pore of the channel, used to emulate the aromatic residues observed in eukaryotic Nav1.2, led to changes in the location of binding and dissociation constants of each drug relative to wild type NavAb. Further, binding locations and dissociation constants obtained for both benzocaine (660 μM) and phenytoin (1 μ M) in the mutant channels were within the range expected from experimental values obtained from drug binding to eukaryotic sodium channels, indicating that these mutant NavAb may be a better model for drug binding to eukaryotic channels than the wild type. PMID:26852716

  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. Formulations, Release and Skin Penetration of Topical Anesthetics

    OpenAIRE

    Welin-Berger, Katayoun

    2001-01-01

    This thesis describes certain critical aspects of the development of semisolid topical anesthetic formulations requiring a fast onset of action. Furthermore, local anesthetics were investigated regarding their phase interaction with membrane lipids. A new long acting and topically effective local anesthetic/analgesic agent, isopropyl-methyl-[2-(3-propoxyphenoxy)-ethyl]-amine (amino diether, AD), was used as the model compound. The nonionized form of AD is liquid oil at room temperature with l...

  13. 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

  14. Maxillectomy for malignant nasopharyngeal neurofibroma: Anesthetic considerations

    Directory of Open Access Journals (Sweden)

    Shagun Bhatia Shah

    2015-01-01

    Full Text Available Neurofibromatosis-1 (NF-1 or von Recklinghausen′s disease is the most common disease inherited by a single gene and is multisystemic in nature. Anesthesia is required for excision of neurofibromas, which may cause cosmetic disfigurement, pressure effects (obstructive uropathy, hydronephrosis, kyphoscoliosis, hydrocephalus, proptosis, and superior vena cava syndrome and may undergo malignant change. We report here the anesthetic management of an NF-1 patient with a malignant change in a nasopharyngeal neurofibroma requiring left maxillectomy and split skin grafting.

  15. Effect of Local and General Anesthetics on Interfacial Water

    Science.gov (United States)

    2016-01-01

    Background Water undergoes structural change as it interfaces with hydrophilic surfaces, including the many hydrophilic surfaces within the cell. This interfacial water has become known as “Exclusion Zone (EZ) water” or “fourth-phase water” [1]. Methods We tested the hypothesis that anesthetics diminish the amount of EZ water, and that this change may correlate with functional changes in anesthesia. By using the local anesthetics Lidocaine and Bupivacaine as well as a general inhalational anesthetic, Isoflurane, we tracked the EZ size as these anesthetics were introduced. Results All three anesthetics diminished EZ size in a concentration-dependent manner at concentrations of 0.18 mM and greater for Bupivacaine, 0.85 mM and greater for Lidocaine, and 0.2% for Isoflurane. At extremely low (micromolar) concentrations, however, all three anesthetics increased EZ size. Conclusions The sharp increase of EZ size associated with micromolar anesthetic concentrations follows a similar pattern to induction of general anesthesia, from the excitation stage (Stage II) to the depression and overdose stages of surgical anesthesia (Stages III and IV). The results are consistent with the hypothesis that anesthetics may act on water, a fundamental organizational component common to all cells. PMID:27054588

  16. 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 ane......-concentration (4 percent) anesthetic formulations for blockanesthesia in the trigeminal area in cases in which there are viable alternatives....

  17. Topical Anesthetic Abuse Keratopathy and its Clinical Progression

    Directory of Open Access Journals (Sweden)

    Volkan Dayanır

    2013-08-01

    Full Text Available To report a case series with topical anesthetic abuse and to define the clinical progression of the disease. Six eyes of three topical anesthetic abuser patients with various corneal abnormalities are reviewed. Signs of the disease are presented in order to document the natural progression of the disease. A report was filed to the General Directorate of Pharmaceuticals and Pharmacy, Ministry of Health, Ankara, Turkey describing the outcome of uncontrolled use of topical anesthetic. Topical anesthetic abuse can result in serious corneal complications such as corneal epithelium defect, ring keratitis, stromal infiltrate, hypopyon, superficial and deep corneal vascularization, corneal lysis, and at last spontaneous perforation. The General Directorate of Pharmaceuticals and Pharmacy issued that topical anesthetics can only be prescribed by an ophthalmologist up to four boxes a month, the prescription must be kept for one, year and criminal action will be taken against pharmacies disregarding these provisions. (Turk J Ophthalmol 2013; 43: 289-93

  18. 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...... 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...

  19. 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.

  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. Normalization for Implied Volatility

    OpenAIRE

    Masaaki Fukasawa

    2010-01-01

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

  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. 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.

  6. The Anesthetic Management of Transcatheter Aortic Valve Implantation.

    Science.gov (United States)

    Guarracino, Fabio; Baldassarri, Rubia

    2016-06-01

    An increasing number of patients with a high risk for surgery because of advanced age and associated comorbidities that significantly increase the perioperative risk successfully undergo transcatheter aortic valve implantation (TAVI). TAVI is commonly performed under general or local anesthesia or local anesthesia plus mild sedation to achieve a conscious sedation. The anesthetic regimen generally depends on the patient's clinical profile and the procedural technical characteristics, but the center's experience and internal organization likely play an important role in anesthetic decision making. The large variation in anesthetic management among various centers and countries likely depends on the different composition of the operating team and institutional organization. Therefore, a tight interaction among the various members of the TAVI team, including the cardiac anesthetist, provides the proper anesthetic management using the chosen procedural technique. PMID:26403787

  7. Antifungal Activity of Local Anesthetics Against Candida Species

    Directory of Open Access Journals (Sweden)

    Acácio Gonçalves Rodrigues

    2000-01-01

    Full Text Available Objective: To evaluate the activity of benzydamine, lidocaine, and bupivacaine, three drugs with local anesthetic activity, against Candida albicans and non-albicans strains and to clarify their mechanism of activity.

  8. Top-down mechanisms of anesthetic-induced unconsciousness

    Directory of Open Access Journals (Sweden)

    George A. Mashour

    2014-06-01

    Full Text Available The question of how structurally and pharmacologically diverse general anesthetics disrupt consciousness has persisted since the 19th century. There has traditionally been a significant focus on “bottom-up” mechanisms of anesthetic action, in terms of sensory processing, arousal systems and structural scales. However, recent evidence suggests that the neural mechanisms of anesthetic-induced unconsciousness may involve a “top-down” process, which parallels current perspectives on the neurobiology of conscious experience itself. This article considers various arguments for top-down mechanisms of anesthetic-induced unconsciousness, with a focus on sensory processing and sleep-wake networks. Furthermore, recent theoretical work is discussed to highlight the possibility that top-down explanations may be causally sufficient, even assuming critical bottom-up events.

  9. Anesthetic management of schwannoma mimicking carotid body tumor

    OpenAIRE

    Sivasankar C

    2012-01-01

    Chitra SivasankarDepartment of Anesthesiology, Guthrie Clinic, Sayre, PA, USAAbstract: Schwannomas are rare and slow-growing neurogenic tumors for which surgery is the standard of care. However, the anesthetic management of these tumors can be challenging. This case report describes the anesthetic management of a patient who underwent carotid endarterectomy and excision of a presumed carotid body tumor. Histopathologic examination showed that the excised tissue was a schwannoma, which in this...

  10. Anesthetic management of a patient with spinocerebellar degeneration

    Directory of Open Access Journals (Sweden)

    Prasanna Vadhanan

    2011-01-01

    Full Text Available Spinocerebellar degeneration or olivopontocerebellar degeneration denotes a group of disorders of various etiologies manifesting as degenerative changes of various part of the central nervous system. We describe the anesthetic management of a patient with severe olivopontocerebellar degeneration posted for vaginal hysterectomy. A combined spinal epidural technique was performed at the level of L2-L3. The anesthetic implications of the various aspects of spinocerebellar degeneration are discussed.

  11. High throughput modular chambers for rapid evaluation of anesthetic sensitivity

    OpenAIRE

    Eckmann David M; Baumgardner James E; Pruckmayr Gregory; Chen Jingqiu; Sun Yi; Eckenhoff Roderic G; Kelz Max B

    2006-01-01

    Abstract Background Anesthetic sensitivity is determined by the interaction of multiple genes. Hence, a dissection of genetic contributors would be aided by precise and high throughput behavioral screens. Traditionally, anesthetic phenotyping has addressed only induction of anesthesia, evaluated with dose-response curves, while ignoring potentially important data on emergence from anesthesia. Methods We designed and built a controlled environment apparatus to permit rapid phenotyping of twent...

  12. Effect of Local and General Anesthetics on Interfacial Water

    OpenAIRE

    Kundacina, Nenad; Shi, Minghui; Pollack, Gerald H.

    2016-01-01

    Background Water undergoes structural change as it interfaces with hydrophilic surfaces, including the many hydrophilic surfaces within the cell. This interfacial water has become known as “Exclusion Zone (EZ) water” or “fourth-phase water” [1]. Methods We tested the hypothesis that anesthetics diminish the amount of EZ water, and that this change may correlate with functional changes in anesthesia. By using the local anesthetics Lidocaine and Bupivacaine as well as a general inhalational ane...

  13. 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...

  14. Mechanism of Anesthetic Action: Oxygen Pathway Perturbation Hypothesis

    OpenAIRE

    Hu, Huping; Wu, Maoxin

    2001-01-01

    The mechanism of anesthesia is relevant to the neural and biological aspects of cognitive sciences. Although more than 150 years have past since the discovery of general anesthetics, how they precisely work remains a mystery. We propose a novel unitary mechanism of general anesthesia verifiable by experiments. In the proposed mechanism, general anesthetics perturb oxygen pathways in both membranes and oxygen-utilizing proteins such that the availabilities of oxygen to its sites of utilization...

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

    Directory of Open Access Journals (Sweden)

    Zehra Hatipoglu

    2015-03-01

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

  16. 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...

  17. Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention

    OpenAIRE

    McCarren, Hilary S.; Moore, Jason T.; Kelz, Max B.

    2013-01-01

    One desirable endpoint of general anesthesia is the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is less straightforward than it is in human patients. A widely used behavioral surrogate for hypnosis in rodents is the loss of righting reflex (LORR), or the point at which the animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency. We have developed a system to assess LORR in 24 mice simultaneously while care...

  18. Chromosomal damage among medical staff occupationally exposed to volatile anesthetics, antineoplastic drugs, and formaldehyde

    Czech Academy of Sciences Publication Activity Database

    Mušák, L.; Šmerhovský, Z.; Halásová, E.; Osina, O.; Letková, L.; Vodičková, Ludmila; Poláková, Veronika; Buchancová, J.; Hemminki, K.; Vodička, Pavel

    2013-01-01

    Roč. 39, č. 6 (2013), s. 618-630. ISSN 0355-3140 Grant ostatní: MŠVV(SK) 26220220111; UK(SK) 1/0576/10 VEGA; MZd(SK) 2007/48-UK-13; GA MŠMT(CZ) Prvouk-P27/LF1/1 Institutional support: RVO:68378041 Keywords : anesthesiologist * antineoplastic drug * chromosomal aberration Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.095, year: 2013

  19. Activation of TRPA1 by membrane permeable local anesthetics

    Directory of Open Access Journals (Sweden)

    Kronewald Sergej

    2011-08-01

    Full Text Available Abstract Background Low concentrations of local anesthetics (LAs suppress cellular excitability by inhibiting voltage-gated Na+ channels. In contrast, LAs at high concentrations can be excitatory and neurotoxic. We recently demonstrated that LA-evoked activation of sensory neurons is mediated by the capsaicin receptor TRPV1, and, to a lesser extent by the irritant receptor TRPA1. LA-induced activation and sensitization of TRPV1 involves a domain that is similar, but not identical to the vanilloid-binding domain. Additionally, activation of TRPV1 by LAs involves PLC and PI(4,5P2-signalling. In the present study we aimed to characterize essential structural determinants for LA-evoked activation of TRPA1. Results Recombinant rodent and human TRPA1 were expressed in HEK293t cells and investigated by means of whole-cell patch clamp recordings. The LA lidocaine activates TRPA1 in a concentration-dependent manner. The membrane impermeable lidocaine-derivative QX-314 is inactive when applied extracellularly. Lidocaine-activated TRPA1-currents are blocked by the TRPA1-antagonist HC-030031. Lidocaine is also an inhibitor of TRPA1, an effect that is more obvious in rodent than in human TRPA1. This species-specific difference is linked to the pore region (transmembrane domain 5 and 6 as described for activation of TRPA1 by menthol. Unlike menthol-sensitivity however, lidocaine-sensitivity is not similarly determined by serine- and threonine-residues within TM5. Instead, intracellular cysteine residues known to be covalently bound by reactive TRPA1-agonists seem to mediate activation of TRPA1 by LAs. Conclusions The structural determinants involved in activation of TRPA1 by LAs are disparate from those involved in activation by menthol or those involved in activation of TRPV1 by LAs.

  20. 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...

  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 i......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  2. 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.

  3. 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

  4. 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...

  5. 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

  6. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.;

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection and...

  7. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.; Molin, Søren; Wilkins, K.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection and ident...

  8. Effects of Anesthetic Agent Propofol on Postoperative Sex Hormone Levels

    Science.gov (United States)

    Kim, H.; Ku, S.-Y.; Kim, H. C.; Suh, C. S.; Kim, S. H.; Choi, Y. M.

    2016-01-01

    Introduction: Several studies have found anesthetic agents including propofol in ovarian follicular fluid. However, little is known about the effect of anesthetic agents on ovarian function. We aimed to investigate whether there were differences in the postoperative levels of sex hormones when propofol was used as the anesthetic agent. Methods: A retrospective review was done of 80 patients who underwent ovarian surgery, with 72 infertile women serving as controls. Patients were included in the study if their serum estradiol (E2) and follicle stimulating hormone (FSH) levels were measured during their first postoperative menstrual cycle. Results: Patients were grouped according to the use or non-use of propofol as follows: propofol group (n = 39) and non-propofol group (n = 41). The control group did not undergo surgery. Postoperative E2 levels did not differ between the three groups, but FSH levels were significantly higher in the patients who had undergone surgery compared to controls (p < 0.05). Post-hoc analysis of E2 and FSH levels in the propofol and non-propofol groups did not show any significant differences. Conclusions: The use of propofol did not result in any differences compared to other anesthetic agents in terms of postoperative sex hormone levels after gynecologic surgery. The type of anesthetic agent does not seem to affect the postoperative levels of female sex hormones.

  9. 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...

  10. Mechanism of Anesthetic Action Oxygen Pathway Perturbation Hypothesis

    CERN Document Server

    Hu, H; Hu, Huping; Wu, Maoxin

    2001-01-01

    Although more than 150 years have past since the discovery of general anesthetics, how they precisely work remains a mystery. We propose a novel unitary mechanism of general anesthesia verifiable by experiments. In the proposed mechanism, general anesthetics perturb oxygen pathways in both membranes and oxygen-utilizing proteins such that the availabilities of oxygen to its sites of utilization are reduced which in turn triggers cascading cellular responses through oxygen-sensing mechanisms resulting in general anesthesia. Despite the general assumption that cell membranes are readily permeable to oxygen, exiting publications indicate that these membranes are plausible oxygen transport barriers. The present hypothesis provides a unified framework for explaining phenomena associated with general anesthesia and experimental results on the actions of general anesthetics. If verified by experiments, the proposed mechanism also has other significant medical and biological implications.

  11. 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

  12. 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.

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

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock ma...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....

  14. Synergism and antagonism in extracting local anesthetics from aqueous media with mixtures of solvents

    Science.gov (United States)

    Sukhanov, P. T.; Chibisova, T. V.; Korenman, Ya. I.

    2014-12-01

    The extraction of local anesthetics from aqueous media with mixtures of solvent is examined and its synergistic and antagonistic effects are determined. Synergism parameters, separation factors, constants for the formation of anesthetic complexes, and solvate numbers are calculated.

  15. 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...

  16. 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...

  17. 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

  18. Anesthetic management of cardiac patient for cataract surgery

    International Nuclear Information System (INIS)

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

  19. Crystallization of Local Anesthetics When Mixed With Corticosteroid Solutions

    Science.gov (United States)

    Hwang, Hyeoncheol; Park, Jihong; Lee, Won Kyung; Lee, Woo Hyung; Leigh, Ja-Ho; Lee, Jin Joo; Chung, Sun G.; Lim, Chaiyoung; Park, Sang Jun

    2016-01-01

    Objective To evaluate at which pH level various local anesthetics precipitate, and to confirm which combination of corticosteroid and local anesthetic crystallizes. Methods Each of ropivacaine-HCl, bupivacaine-HCl, and lidocaine-HCl was mixed with 4 different concentrations of NaOH solutions. Also, each of the three local anesthetics was mixed with the same volume of 3 corticosteroid solutions (triamcinolone acetonide, dexamethasone sodium phosphate, and betamethasone sodium phosphate). Precipitation of the local anesthetics (or not) was observed, by the naked eye and by microscope. The pH of each solution and the size of the precipitated crystal were measured. Results Alkalinized with NaOH to a certain value of pH, local anesthetics precipitated (ropivacaine pH 6.9, bupivacaine pH 7.7, and lidocaine pH 12.9). Precipitation was observed as a cloudy appearance by the naked eye and as the aggregation of small particles (300 µm, pH 7.5). Ropivacaine with dexamethasone sodium phosphate also precipitated, but it was only observable by microscope (a few crystals of 10–100 µm, pH 7.0). Bupivacaine with betamethasone sodium phosphate formed precipitates of non-aggregated smaller particles (<10 µm, pH 7.7). Lidocaine mixed with corticosteroids did not precipitate. Conclusion Ropivacaine and bupivacaine can precipitate by alkalinization at a physiological pH, and therefore also produce crystals at a physiological pH when they are mixed with betamethasone sodium phosphate. Thus, the potential risk should be noted for their use in interventions, such as epidural steroid injections. PMID:26949665

  20. 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.

  1. 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

  2. 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...

  3. 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...

  4. High throughput modular chambers for rapid evaluation of anesthetic sensitivity

    Directory of Open Access Journals (Sweden)

    Eckmann David M

    2006-11-01

    Full Text Available Abstract Background Anesthetic sensitivity is determined by the interaction of multiple genes. Hence, a dissection of genetic contributors would be aided by precise and high throughput behavioral screens. Traditionally, anesthetic phenotyping has addressed only induction of anesthesia, evaluated with dose-response curves, while ignoring potentially important data on emergence from anesthesia. Methods We designed and built a controlled environment apparatus to permit rapid phenotyping of twenty-four mice simultaneously. We used the loss of righting reflex to indicate anesthetic-induced unconsciousness. After fitting the data to a sigmoidal dose-response curve with variable slope, we calculated the MACLORR (EC50, the Hill coefficient, and the 95% confidence intervals bracketing these values. Upon termination of the anesthetic, Emergence timeRR was determined and expressed as the mean ± standard error for each inhaled anesthetic. Results In agreement with several previously published reports we find that the MACLORR of halothane, isoflurane, and sevoflurane in 8–12 week old C57BL/6J mice is 0.79% (95% confidence interval = 0.78 – 0.79%, 0.91% (95% confidence interval = 0.90 – 0.93%, and 1.96% (95% confidence interval = 1.94 – 1.97%, respectively. Hill coefficients for halothane, isoflurane, and sevoflurane are 24.7 (95% confidence interval = 19.8 – 29.7%, 19.2 (95% confidence interval = 14.0 – 24.3%, and 33.1 (95% confidence interval = 27.3 – 38.8%, respectively. After roughly 2.5 MACLORR • hr exposures, mice take 16.00 ± 1.07, 6.19 ± 0.32, and 2.15 ± 0.12 minutes to emerge from halothane, isoflurane, and sevoflurane, respectively. Conclusion This system enabled assessment of inhaled anesthetic responsiveness with a higher precision than that previously reported. It is broadly adaptable for delivering an inhaled therapeutic (or toxin to a population while monitoring its vital signs, motor reflexes, and providing precise control

  5. High throughput modular chambers for rapid evaluation of anesthetic sensitivity

    Science.gov (United States)

    Sun, Yi; Chen, Jingqiu; Pruckmayr, Gregory; Baumgardner, James E; Eckmann, David M; Eckenhoff, Roderic G; Kelz, Max B

    2006-01-01

    Background Anesthetic sensitivity is determined by the interaction of multiple genes. Hence, a dissection of genetic contributors would be aided by precise and high throughput behavioral screens. Traditionally, anesthetic phenotyping has addressed only induction of anesthesia, evaluated with dose-response curves, while ignoring potentially important data on emergence from anesthesia. Methods We designed and built a controlled environment apparatus to permit rapid phenotyping of twenty-four mice simultaneously. We used the loss of righting reflex to indicate anesthetic-induced unconsciousness. After fitting the data to a sigmoidal dose-response curve with variable slope, we calculated the MACLORR (EC50), the Hill coefficient, and the 95% confidence intervals bracketing these values. Upon termination of the anesthetic, Emergence timeRR was determined and expressed as the mean ± standard error for each inhaled anesthetic. Results In agreement with several previously published reports we find that the MACLORR of halothane, isoflurane, and sevoflurane in 8–12 week old C57BL/6J mice is 0.79% (95% confidence interval = 0.78 – 0.79%), 0.91% (95% confidence interval = 0.90 – 0.93%), and 1.96% (95% confidence interval = 1.94 – 1.97%), respectively. Hill coefficients for halothane, isoflurane, and sevoflurane are 24.7 (95% confidence interval = 19.8 – 29.7%), 19.2 (95% confidence interval = 14.0 – 24.3%), and 33.1 (95% confidence interval = 27.3 – 38.8%), respectively. After roughly 2.5 MACLORR • hr exposures, mice take 16.00 ± 1.07, 6.19 ± 0.32, and 2.15 ± 0.12 minutes to emerge from halothane, isoflurane, and sevoflurane, respectively. Conclusion This system enabled assessment of inhaled anesthetic responsiveness with a higher precision than that previously reported. It is broadly adaptable for delivering an inhaled therapeutic (or toxin) to a population while monitoring its vital signs, motor reflexes, and providing precise control over environmental

  6. 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

  7. 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 ...... are self-contained and can be read independently. There is however a common thread in the themes covered as all essays focus on the understanding of interest rate volatility, its time-variation and main determinants....

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    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...

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

    DEFF Research Database (Denmark)

    Zhu, Jie

    markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets, a...

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

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    We include simultaneously both realized volatility measures based on high-frequency asset returns and implied volatilities backed out of individual traded at the money option prices in a state space approach to the analysis of true underlying volatility. We model integrated volatility as a latent...... process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  17. 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

  18. 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...

  19. 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...

  20. 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.

  1. Epidermolysis Bullosa, Dental and Anesthetic Management: A Case Report

    OpenAIRE

    Katayoun Esfahanizadeh; Ali Reza Mahdavi; Ghassem Ansari; Masoud Fallahinejad Ghajari; Abdolreza Esfahanizadeh

    2014-01-01

    Epidermolysis bullosa (EB) is a group of rare inherited skin and mucous membrane disorders in which blister formation may arise spontaneously or following a minor friction. Various patterns of inheritance are explicated for the disease. The disease has a profound effect on oral mucosa and may result in high prevalence of dental caries. General anesthesia is sometimes the only choice for dental treatments in patients with EB. The following case report describes the dental and anesthetic manage...

  2. Intravenous lipid emulsion for treatment of local anesthetic toxicity

    OpenAIRE

    M Caroline Kosh; Miller, April D; Michels, Jill E

    2010-01-01

    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...

  3. 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.

  4. 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...

  5. Lung Physiology and Obesity: Anesthetic Implications for Thoracic Procedures

    OpenAIRE

    Alessia Pedoto

    2012-01-01

    Obesity is a worldwide health problem affecting 34% of the American population. As a result, more patients requiring anesthesia for thoracic surgery will be overweight or obese. Changes in static and dynamic respiratory mechanics, upper airway anatomy, as well as multiple preoperative comorbidities and altered drug metabolism, characterize obese patients and affect the anesthetic plan at multiple levels. During the preoperative evaluation, patients should be assessed to identify who is at ris...

  6. 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...

  7. Anesthetic management of a neonate receiving prenatal repair of gastroschisis

    OpenAIRE

    Luo, Dong; Wu, Lan; Wu, Hai; Huang, Wei; Huang, Han

    2015-01-01

    Gastroschisis requires surgical repair, which is generally performed after birth. We report a case in which a fetus with gastroschisis underwent the abdominal wall defect repair before birth. To ensure reliable operating conditions for the repair (to prevent fetal movement and crying), the fetus received deep anesthesia via placental transfer of maternally administered anesthetics. Meanwhile, the ex utero intrapartum treatment procedure was performed to ensure fetal oxygen supply, which was l...

  8. 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...

  9. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    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...... industry so far....

  10. 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. The...

  11. 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

  12. Interactions of anesthetics with the membrane-water interface

    Science.gov (United States)

    Pohorille, A.; Cieplak, P.; Wilson, M. A.

    1996-01-01

    Although the potency of conventional anesthetics correlates with lipophilicity, an affinity to water also is essential. It was recently found that compounds with very low affinities to water do not produce anesthesia regardless of their lipophilicity. This finding implies that clinical anesthesia might arise because of interactions at molecular sites near the interface of neuronal membranes with the aqueous environment and, therefore, might require increased concentrations of anesthetic molecules at membrane interfaces. As an initial test of this hypothesis, we calculated in molecular dynamics simulations the free energy profiles for the transfer of anesthetic 1,1,2-trifluoroethane and nonanesthetic perfluoroethane across water-membrane and water-hexane interfaces. Consistent with the hypothesis, it was found that trifluoroethane, but not perfluoroethane, exhibits a free energy minimum and, therefore, increased concentrations at both interfaces. The transfer of trifluoroethane from water to the nonpolar hexane or interior of the membrane is accompanied by a considerable, solvent-induced shift in the conformational equilibrium around the C-C bond.

  13. 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 (...

  14. 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...

  15. 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 ...

  16. 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...

  17. 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

  18. 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.

  19. 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...... propofol inhibition of cation-selective pLGICs occurs via a binding site contained within helices M1-M4 of individual subunits. We considered this idea by testing propofol modulation of homomeric human glycine receptors (GlyRs) and nematode glutamate-gated chloride channels (GluCls) recombinantly expressed...... substitution in the channel-forming M2 helix (EC50 = 979 ± 88 μM). When a previously identified site between adjacent subunits was disrupted by the M3 G329I substitution, both propofol inhibition and enhancement of GluCls were severely impaired (IC50 and EC50 values could not be calculated). Similarly, when...

  20. 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.

  1. 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

  2. Multivariate volatility models

    OpenAIRE

    Fengler, Matthias R.; Herwartz, Helmut

    2001-01-01

    Multivariate Volatility Models belong to the class of nonlinear models for financial data. Here we want to focus on multivariate GARCH models. These models assume that the variance of the innovation distribution follows a time dependent process conditional on information which is generated by the history of the process. In this chapter we demonstrate how to use the bigarch quantlet of XploRe to estimate the conditional covariance of a bivariate (high frequency) return process. In particular w...

  3. 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...

  4. 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...

  5. Locally stationary volatility modelling

    OpenAIRE

    Van Bellegem, Sébastien

    2011-01-01

    The increasing works on parameter instability, structural changes and regime switches lead to the natural research question whether the assumption of stationarity is appropriate to model volatility processes. Early econometric studies have provided testing procedures of covariance stationarity and have shown empirical evidence for the unconditional time-variation of the dependence structure of many financial time series. After a review of several econometric tests of covariance stationarit...

  6. 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...

  7. 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...

  8. Hand hygiene and aseptic techniques during routine anesthetic care - observations in the operating room

    OpenAIRE

    Megeus, Veronika; Nilsson, Kerstin; Karlsson, Jon; Eriksson, Bengt I.; Andersson, Annette Erichsen

    2015-01-01

    Background More knowledge is needed about task intensity in relation to hand hygiene in the operating room during anesthetic care in order to choose effective improvement strategies. The aim of this study was to explore the indications and occurrence of hand hygiene opportunities and the adherence to hand hygiene guidelines during routine anesthetic care in the operating room. Methods Structured observational data on hand hygiene during anesthetic care during 94 surgical procedures was collec...

  9. 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%.

  10. Anesthetic and postoperative management of the obstructive sleep apnea patient.

    Science.gov (United States)

    Mickelson, Samuel A

    2009-11-01

    Sleep apnea patients pose a challenge for surgeons, anesthesiologists, and surgical facilities as there is increased risk for anesthetic and postoperative complications. Precautions before and after surgery minimize these risks. Screening for sleep apnea should be done for all surgical patients. Safe perioperative management requires judicious use of narcotics and sedating medications, reducing upper airway edema, prevention of aspiration and deep vein thrombosis, blood pressure control, use of positive airway pressure, and proper postoperative monitoring. Although the literature lacks specific recommendations, the guidelines presented in this article are based on more than 20 years of experience and supported by peer-reviewed medical literature. PMID:19944343

  11. Anesthetic management of schwannoma of the base of the tongue

    Directory of Open Access Journals (Sweden)

    Upma B Batra

    2011-01-01

    Full Text Available Schwannoma arising from the base of the tongue are very rare and only a few cases have been reported so far. Definitive diagnosis is always made after a histological examination. Apart from an anticipated difficult airway with a risk of airway obstruction upon induction of general anesthesia, anesthetic concerns also include possibility of trauma to the growth and bleeding with attendant risks. We discuss the awake fiberoptic technique used for endotracheal intubation in such a case. This case report highlights the importance of detailed history taking and clinical examination, with emphasis on airway assessment and preoperative planning.

  12. 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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    anthropogenic radiative forcing of climate, as measured relative to the start of the industrial era (approximately 1750). The family of anesthetic gases includes several halogenated organic compounds that are strong greenhouse gases. In this short report, we provide an overview of the state of knowledge......Although present in the atmosphere with a combined concentration approximately 100,000 times lower than carbon dioxide (i.e., the principal anthropogenic driver of climate change), halogenated organic compounds are responsible for a warming effect of approximately 10% to 15% of the total...

  14. Anesthetic considerations in Leigh disease: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Abdullah Sulieman Terkawi

    2012-01-01

    Full Text Available Leigh disease is an extremely rare disorder, characterized by a progressive neurodegenerative course, with subacute necrotizing encephalomyelopathy. It usually presents in infancy with developmental delay, seizures, dysarthria, and ataxia. These patients may also develop episodes of lactic acidosis that usually lead to respiratory failure and death. Due to the rarity of the condition, the most appropriate anesthetic plan remains unclear. We present a patient with Leigh disease, who required general anesthesia. The pathogenesis of the disease is discussed and previous reports of perioperative care from the literature are reviewed.

  15. 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

  16. 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.

  17. Effect of anesthetics on the radiosensitivity of a murine tumor

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. Clinical Comparison: Fast-Acting and Traditional Topical Dental Anesthetic.

    Science.gov (United States)

    DiMarco, Arthur C; Wetmore, Ann O'Kelley

    2016-01-01

    A randomized, nonblinded clinical trial compared the effectiveness of an application method of a fast-acting refrigerant topical agent to a 20% benzocaine gel topical. In a split-mouth design, right and left anterior middle superior alveolar injections (N = 30) were administered with a 27-gauge needle at least 24 hours apart with preinjection topicals. Using a cotton-tipped applicator, a refrigerant topical was applied for 5 seconds and 20% benzocaine gel for 2 minutes on opposite sides at 2 separate appointments. Subjects self-reported pain perception after each injection using a visual analog scale (VAS). The mean VAS ratings demonstrated no significant difference between the 5-second application of the refrigerant (M = 16.2, SD = 17.7) and the 2-minute application of 20% benzocaine topical gel anesthetic (M = 17.9, SD = 18.2). Fifty-seven percent of the subjects reported greater pain reduction with the refrigerant, 33% reported greater pain reduction with 20% benzocaine, and 10% reported no difference. Results suggest the described method of application of a refrigerant as an oral topical anesthetic has a faster onset and provides similar benefit in pain reduction compared with 20% benzocaine gel. The refrigerant was easy to accomplish and well received by subjects, indicating potential for routine use in dentistry. PMID:27269661

  20. Nursing care in the anesthetic procedure: an integrative review.

    Science.gov (United States)

    Lemos, Cassiane de Santana; Peniche, Aparecida de Cassia Giani

    2016-02-01

    OBJECTIVE To search for the scientific evidence available on nursing professional actions during the anesthetic procedure. METHOD An integrative review of articles in Portuguese, English and Spanish, indexed in MEDLINE/PubMed, CINAHL, LILACS, National Cochrane, SciELO databases and the VHL portal. RESULTS Seven studies were analyzed, showing nurse anesthetists' work in countries such as the United States and parts of Europe, with the formulation of a plan for anesthesia and patient care regarding the verification of materials and intraoperative controls. The barriers to their performance involved working in conjunction with or supervised by anesthesiologists, the lack of government guidelines and policies for the legal exercise of the profession, and the conflict between nursing and the health system for maintenance of the performance in places with legislation and defined protocols for the specialty. Conclusion Despite the methodological weaknesses found, the studies indicated a wide diversity of nursing work. Furthermore, in countries absent of the specialty, like Brazil, the need to develop guidelines for care during the anesthetic procedure was observed. PMID:27007433

  1. 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...

  2. 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...

  3. 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...

  4. 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...

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

    Directory of Open Access Journals (Sweden)

    Vlassakov KV

    2014-12-01

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

  6. 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...... lidocaine spray proved to be a superior option as topical pharyngeal anesthetic before an UGE....

  7. 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.

  8. 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.

  9. 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

  10. 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...... 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...

  11. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Epidermolysis Bullosa, Dental and Anesthetic Management: A Case Report

    Directory of Open Access Journals (Sweden)

    Katayoun Esfahanizadeh

    2014-09-01

    Full Text Available Epidermolysis bullosa (EB is a group of rare inherited skin and mucous membrane disorders in which blister formation may arise spontaneously or following a minor friction. Various patterns of inheritance are explicated for the disease. The disease has a profound effect on oral mucosa and may result in high prevalence of dental caries. General anesthesia is sometimes the only choice for dental treatments in patients with EB. The following case report describes the dental and anesthetic management of an 12.5 -year-old girl with dystrophic type of EB. The patient was followed up every 6 months. New carious lesions were detected one year after the treatment, on the last visit. Presenting a perfect dental care to children with this disorder can be challenging for the in charge specialist, both pediatric dentist and anesthesiologist.

  18. 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.

  19. Anesthetic management for thoracic surgery in Rubinstein-Taybi syndrome.

    Science.gov (United States)

    Blazquez, E; Narváez, D; Fernandez-Lopez, A; Garcia-Aparicio, L

    2016-01-01

    Rubinstein-Taybi syndrome (RTS) is a chromosomopathy associated to molecular mutations or microdeletions of chromosome 16. It has an incidence of 1:125,000-700,000 live births. RTS patients present craniofacial and thoracic anomalies that lead to a probable difficult-to-manage airway and ventilation. They also present mental retardation and comorbidity, such as congenital cardiac defects, pulmonary structural anomalies and recurrent respiratory infections, which increase the risk of aspiration pneumonia. Cardiac arrhythmias have been reported after the use of certain drugs such as succinylcholine and atropine, in a higher incidence than in general population. There is an increased risk of postoperative apnea-hypopnea in these patients. We report the anesthetic management in a RTS patient undergoing emergent thoracic surgery due to oesophageal perforation and mediastinitis. Lung isolation was achieved with a bronchial blocker guided with a fiberoptic bronchoscope and one-lung ventilation was performed successfully. PMID:27062171

  20. Anesthetic management of a patient with congenital diaphragmatic eventration.

    Science.gov (United States)

    Chaudhary, Kapil; Anand, Raktima; Girdhar, Kiran K; Manchanda, Gunjan; Panda, Asish K; Bhalotra, Anju R

    2011-08-01

    Congenital diaphragmatic eventration is uncommon in adults and is caused by paralysis, aplasia or atrophy of the muscular fibers of the diaphragm. It may cause severe dyspnea, orthopnea and hypoxia in adult patients. Most symptomatic patients may be managed efficiently without the need for surgical correction, although any event that leads to an increase in intra-abdominal pressure puts them at the risk of spontaneous diaphragmatic rupture. This case report presents the successful anesthetic management of an adult female with congenital diaphragmatic eventration undergoing diagnostic laparoscopy and hysteroscopy using a total intravenous anesthesia technique. Essential steps to prevent any rise in intrathoracic and intra-abdominal pressures along with care to minimize intragastric volume were taken. PMID:21626261

  1. 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.

  2. Anesthetic management of laparoscopic pheochromocytoma surgery: A case report

    Directory of Open Access Journals (Sweden)

    Hakan Akelma

    2014-06-01

    Full Text Available Pheochromocytoma is a neuroendocrine tumor of the adrenal medulla chromaffin cells. It has a variable clinic indicating symptoms such as hypertension, headache, sweating, palpitations, and anxiety. Determination of vanillylmandelic acid in urine and metanephrines are accepted as the most sensitive tests for diagnosis. Computerized tomography and magnetic resonance imaging cad be used for tumor localization. Anesthetic induction and surgical manipulations usually lead to the catastrophic release of catecholamines. Thus, accurate preoperative pharmacological preparation is vital in these patients. Treatment is a complete surgical resection of the primary tumor and, if possible, metastases after banning dangerous fluctuations in hemodynamic through α-blockers. Today, laparoscopic adrenalectomy has begun to replace open surgery as a standard treatment method in many adrenal diseases. J Clin Exp Invest 2014; 5 (2: 443-446

  3. 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

  4. 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.

  5. Price volatility on the German Agricultural Markets

    OpenAIRE

    Ledebur, Oliver von; Schmitz, Jochen

    2012-01-01

    In this contribution, the development of price volatility on German agricultural markets is analyzed. We quantify the degree of price volatility for selected German agricultural markets and determine how it evolves over time and search for policy driven structural changes in volatility levels measured by the historical volatility. Based on annualised historical volatilities t test were performed to identify if the change in the volatility levels show any relationship to the process of reform ...

  6. Simultaneous determination of four local anesthetics by CE with ECL and study on interaction between procainamide and human serum albumin.

    Science.gov (United States)

    Duan, Hong-Bing; Cao, Jun-Tao; Yang, Jiu-Jun; Wang, Hui; Liu, Yan-Ming

    2016-07-01

    A new method of capillary electrophoresis (CE) coupled with tris(2, 2'-bipyridyl) ruthenium(II) electrochemiluminescence (ECL) detection has been developed to detect four local anesthetics procainamide (PAH), tetracaine (TCH), proparacaine (PCH) and cinchocaine (CIN) simultaneously. An europium (III)-doped prussian blue analogue film (Eu-PB) modified platinum electrode was prepared and applied to improve the detection sensitivity. The parameters including additives, concentration and pH of the running buffer, separation voltage and detection potential that affect CE separation and ECL detection were optimized in detail. The four local anesthetics were baseline separated and detected within 10min under the optimized conditions. The detection limits (LOD) of PAH, TCH, PCH and CIN are 5.5×10(-8), 9.6×10(-8), 2.5×10(-8) and 3.5×10(-8)molL(-1) (S/N=3), respectively. RSDs of the migration time for four analytes range from 1.2% to 2.5% within intraday and from 2.4% to 4.9% in interday, RSDs of the peak area for four analytes are from 1.7% to 3.3% within intraday and from 2.2% to 5.6% in interday, respectively. The limits of quantitation (LOQ) (S/N=10) for PAH, TCH, PCH and CIN in human urine sample are 5.9×10(-7), 9.2×10(-7), 8.3×10(-7) and 5.0×10(-7)molL(-1), separately. The recoveries (n=3) of four analytes in human urine are from 87.6% to 107.7% with less than 5.9% in RSDs. The developed method was used to determine four local anesthetics in human urine samples and investigate the interaction between PAH and human serum albumin (HSA). The number of binding sites and the binding constant of PAH with HSA were calculated to be 1.03 and 2.4×10(4)Lmol(-1), respectively. PMID:27154684

  7. NEW TOOLS FOR VOLATILITY MODELS

    OpenAIRE

    SANTILLI, MANOLA

    2014-01-01

    In the first part of this work, we propose a new estimation method of the spot volatility, based on a semi-nonparametric model, which employs the information content of a complete panel of European options, daily quoted in the market, under no arbitrage assumptions. The technique we propose is based on the idea of model-free implied volatility and exploits the observed VIX term structure to make inference on the unobserved spot volatility. We show that this new estimation method can be applie...

  8. Proton nuclear magnetic resonance and pattern recognition analysis of liver extracts from rats under different anesthetics

    International Nuclear Information System (INIS)

    Although general anesthesia is widely used in the surgical arena, the mechanisms by which general anesthetics act remain unclear. We previously described alterations in gene expression ratios in hepatic tissue taken from rats treated with anesthetics. Consequently, it is considered that anesthetics influence liver metabolism. Thus, the goal of this study was to use pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize changes in liver metabolic phenotypes in response to widely used intravenous anesthetics (propofol and dexmedetomidine) and inhalational anesthetics (sevoflurane and isoflurane). Rats were randomized into 13 groups (n = 6 in each group), and each group received one of following agents: propofol, dexmedetomidine, sevoflurane, isoflurane, or no anesthetic (control group). The liver was directly removed from rats immediately after or 24 h or 48 h after a 6-h period of anesthesia. Hydrophilic compounds were extracted from the liver and were analyzed with proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of metabolite profiles. Data were visualized by plotting principal component (PC) scores. In the plots, each point represents an individual sample. Each group was clustered separately on the plots, and the PC scores of the propofol group were clearly distinct from those of the control group and other anesthetic groups. The difference in PC scores was more pronounced immediately after completion of anesthesia when compared with 24 or 48 h after completion of anesthesia. Although the effect of intravenous anesthetics on the liver dissipated over time, the effect of inhalational anesthetics persisted. Propofol, dexmedetomidine, sevoflurane and isoflurane exert different effects on liver metabolism. In particular, liver metabolism was markedly altered after exposure to propofol. The effect of anesthesia on the liver under propofol or

  9. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    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......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...

  10. 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...

  11. 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...

  12. A Multifactor Volatility Heston Model

    OpenAIRE

    Grasselli, Martino; Da Fonseca, Jose; Tebaldi, Claudio

    2008-01-01

    We consider a model for a single risky asset whose volatility follows a multifactor (matrix)Wishart affine process, recently introduced in finance by Gourieroux and Sufana (2004). As in standard Duffie and Kan (1996) affine models the pricing problem can be solved through the Fast Fourier Transform of Carr and Madan (1999). A numerical illustration shows that this specification provides a separate fit of the long term and short term implied volatility surface and, differently from previous...

  13. The effect of preanesthetic administration of lactated Ringer solution on blood pressure in isoflurane-anesthetized horses

    Directory of Open Access Journals (Sweden)

    Brkljaca-Bottegaro Nika

    2011-01-01

    Full Text Available Hypotension induced by volatile agents is particularly notorious in horses and it is probably one of the major causes of the high anaesthetic risk in this species. In the present study we investigated the influence of 10 mL/kg lactated Ringer solution on the values of arterial blood pressure during the elective surgical procedure, administered right before the induction of anaesthesia. The goal was to establish if it was possible to lower the risk of hypotension development with this type of therapy. Nine horses divided in two groups were used in this study. All the horses were submitted to the same anesthetic regimen. The second group of horses received 10 mL/kg i.v. lactated Ringer solution in the 15 minutes time before the induction of anesthesia. The effect of lactated Ringer solution was noted at the beginning of anesthesia. Statistically significant differences among groups were noticed during the first measurement. The results indicate that the suggested method may provide a very simple way of supporting the cardiovascular system at least at the beginning of the surgical procedure.

  14. 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.

  15. 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...

  16. Comparison of propofol and thiopental as anesthetic agents for electroconvulsive therapy

    DEFF Research Database (Denmark)

    Bauer, Jeanett; Hageman, Ida; Dam, Henrik;

    2009-01-01

    OBJECTIVES: To compare propofol and thiopental as anesthetic agents for electroconvulsive therapy (ECT) with respect to seizure duration, stimulus charge, clinical effect, and cognitive side effects. METHODS: Randomized, blinded study of 62 depressed patients treated with bilateral ECT. Algorithm...

  17. 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.

  18. 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

  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. 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

  1. 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.

  2. [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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. Heterogeneous volatility cascade in financial markets

    OpenAIRE

    Gilles Zumbach; Paul Lynch

    2001-01-01

    Using high frequency data, we have studied empirically the change of volatility, also called volatility derivative, for various time horizons. In particular, the correlation between the volatility derivative and the volatility realized in the next time period is a measure of the response function of the market participants. This correlation shows explicitly the heterogeneous structure of the market according to the characteristic time horizons of the differents agents. It reveals a volatility...

  8. 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.

  9. Comparison of Intravenous Anesthetic Agents for the Treatment of Refractory Status Epilepticus

    OpenAIRE

    Michael E. Reznik; Karen Berger; Jan Claassen

    2016-01-01

    Status epilepticus that cannot be controlled with first- and second-line agents is called refractory status epilepticus (RSE), a condition that is associated with significant morbidity and mortality. Most experts agree that treatment of RSE necessitates the use of continuous infusion intravenous anesthetic drugs such as midazolam, propofol, pentobarbital, thiopental, and ketamine, each of which has its own unique characteristics. This review compares the various anesthetic agents while provid...

  10. 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

  11. Sensitivity to thermal stimulation in prairie rattlesnakes (Crotalus viridis) after bilateral anesthetization of the facial pits

    Energy Technology Data Exchange (ETDEWEB)

    Chiszar, D.; Dickman, D.; Colton, J.

    1986-01-01

    Six yearling prairie rattlesnakes (Crotalus viridis) were exposed to thermal stimuli prior to and after bilateral anesthetization of their facial pits with 2% xylocaine solution. This treatment eliminates trigeminally mediated electrophysiological responses of the pits to thermal stimulation. Nevertheless, the rattlesnakes continued to exhibit behavioral responses to thermal cues after anesthetization of the pits. An auxiliary infrared-sensitive system, nociceptors, or the common temperature sense could be responsible for these findings.

  12. Recovery from desflurane anesthesia in horses with and without post-anesthetic xylazine

    OpenAIRE

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

    2014-01-01

    The objective of this study was to compare recovery from desflurane anesthesia in horses with or without post-anesthetic xylazine. Six adult horses were anesthetized on 2 occasions, 14 d apart using a prospective, randomized crossover design. Horses were sedated with xylazine, induced to lateral recumbency with ketamine and diazepam, and anesthesia was maintained with desflurane. One of 2 treatments was administered intravenously at the end of anesthesia: xylazine [0.2 mg/kg body weight (BW)]...

  13. α2-Adrenergic Stimulation of the Ventrolateral Preoptic Nucleus Destabilizes the Anesthetic State

    OpenAIRE

    McCarren, Hilary S.; Chalifoux, Michael R.; Han, Bo; Moore, Jason T.; Meng, Qing Cheng; Baron-Hionis, Nina; Sedigh-Sarvestani, Madineh; Contreras, Diego; Beck, Sheryl G.; Kelz, Max B.

    2014-01-01

    The sleep-promoting ventrolateral preoptic nucleus (VLPO) shares reciprocal inhibitory inputs with wake–active neuronal nuclei, including the locus ceruleus. Electrophysiologically, sleep-promoting neurons in the VLPO are directly depolarized by the general anesthetic isoflurane and hyperpolarized by norepinephrine, a wake-promoting neurotransmitter. However, the integration of these competing influences on the VLPO, a sleep- and anesthetic-active structure, has yet to be evaluated in either ...

  14. The action of local anesthetics on myelin structure and nerve conduction in toad sciatic nerve.

    OpenAIRE

    Mateu, L; Morán, O; Padrón, R; Borgo, M; Vonasek, E; Márquez, G; Luzzati, V.

    1997-01-01

    X-ray scattering and electrophysiological experiments were performed on toad sciatic nerves in the presence of local anesthetics. In vitro experiments were performed on dissected nerves superfused with Ringer's solutions containing procaine, lidocaine, tetracaine, or dibucaine. In vivo experiments were performed on nerves dissected from animals anesthesized by targeted injections of tetracaine-containing solutions. In all cases the anesthetics were found to have the same effects on the x-ray ...

  15. 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

  16. Analysis on the factors associated with treatment failure of using anesthetics in refractory status epilepticus

    OpenAIRE

    Su, Ying-ying; Guo-ping REN; Wei-bi CHEN; Zhang, Yan; YE Hong; Dai-quan GAO

    2015-01-01

    Objective To analyze the related factors associated with immediate treatment failure of using anesthetics in refractory status epilepticus (RSE).  Methods Thirty patients derived from Neurocritical Care Unit of Xuanwu Hospital from January 2004 to December 2013 were divided into 2 groups (acute treatment failure group and acute treatment success group) based on the treatment outcome 6 h after intravenous injection of anesthetics. Univariate and multivariate forward Logistic regression ...

  17. 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....

  18. Major morbidity or mortality from office anesthetic procedures: a closed-claim analysis of 13 cases.

    OpenAIRE

    Jastak, J. T.; Peskin, R. M.

    1991-01-01

    A closed-claim analysis of anesthetic-related deaths and permanent injuries in the dental office setting was conducted in cooperation with a leading insurer of oral and maxillofacial surgeons and dental anesthesiologists. A total of 13 cases occurring between 1974 and 1989 was included. In each case, all available records, reports, depositions, and proceedings were reviewed. The following were determined for each case: preoperative physical status of the patient, anesthetic technique used (cl...

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

    International Nuclear Information System (INIS)

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

  20. [The influence of local anesthetics on corneal epithelium. A scanning electron microscopic study (author's transl)].

    Science.gov (United States)

    Brewitt, H; Honegger, H

    1978-09-01

    The effect of different local anesthetics (Cocain 4%, Lidocaine 2%, Proparacain) on the corneal epithelium in rabbits was examined under scanning electron microscope. The experiment was divided into three groups. Group 1 received one application of two drops of the given local anesthetic for a reaction time of 5 minutes. Group 2 received two drops of the given anesthetic after 0, 5 and 10 minutes. The cornea was excised after 15 minutes. Group 3 were measured after a single application of Proparacain using a Schiötz or hand applanation tonometer according to Draeger. After a single dose of a local anesthetic principally the same changes in the surface of the cornea were observed with all the preparations used: a distinct decrease in the number of microvilli and microplicae, disruption of the intercellular spaces and the prominence of the cell nuclei which under normal conditions are not visible. After several applications the greater toxicity of Cocain compared with the other preparations was clearly seen through the disruption of the plasma membrane and the cytoplasm. The damage effected several layers of cells. Tonometry when correctly performed causes no additional damage to the cell surface.- The effect of local anesthetics on the cell membrane can only take place after the disruption of the tear film. The results emphasize that local anesthetics should only be applied when absolutely essential. PMID:750708

  1. 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

  2. Volatile and Non-Volatile Single Electron Memory

    Directory of Open Access Journals (Sweden)

    A. Touati 

    2013-07-01

    Full Text Available Multi Tunnel Junctions (MTJs have attracted much attention recently in the fields of Single-Electron Devices (SED in particular Single-Electron Memory (SEM. In this paper, we have design and study a nano-device structure using a two dimensional array MTJs for Volatile and Non-Volatile-SEM, in order to analyze the impact of physical parameters on the performances. We investigate the single-electron circuit characteristics in our devices qualitatively, using single-electron Monte Carlo simulator SIMON.

  3. 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...

  4. 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.

  5. 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

  6. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  7. 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.

  8. 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...

  9. Forecasting Volatility Using A Continuous Time Model

    OpenAIRE

    Lopes Moreira da Veiga, Maria Helena

    2003-01-01

    This paper evaluates the forecasting performance of a continuous stochastic volatility model with two factors of volatility (SV2F) and compares it to those of GARCH and ARFIMA models. The empirical results show that the volatility forecasting ability of the SV2F model is better than that of the GARCH and ARFIMA models, especially when volatility seems to change pattern. We use ex-post volatility as a proxy of the realized volatility obtained from intraday data and the forecasts from the SV2F ...

  10. 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...

  11. Effects of anesthesia on [11C]raclopride binding in the rat brain

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Simonsen, Mette; Møller, Arne; Landau, Anne M.

    Background Very often rats are anesthetized prior to micro positron emission tomography (microPET) brain imaging in order to prevent head movements. Anesthesia can be administered by inhalation agents, such as isoflurane, or injection mixtures, such as fentanyl-fluanisone-midazolam. Unfortunately....... Materials & Methods Nine male Lew/Mol rats were assigned to either inhalation (isoflurane; N=4) or injection (fentanyl-fluanisone-midazolam; N=5) anesthesia. Catheters were surgically placed in femoral arteries and veins for blood sampling and tracer injection. After a short attenuation scan, the rats were...... PET scanned for 90 minutes after injection of [11C]raclopride. Results We found that rats anesthetized with isoflurane had double the binding potential in the striatum compared with fentanyl-fluanisone-midazolam anesthetized rats. Conclusion Our results are in agreement with other studies showing that...

  12. 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.

  13. 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.

  14. 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.

  15. A Conserved Behavioral State Barrier Impedes Transitions between Anesthetic-Induced Unconsciousness and Wakefulness: Evidence for Neural Inertia

    OpenAIRE

    Friedman, Eliot B.; Sun, Yi; Moore, Jason T.; Hung, Hsiao-Tung; Meng, Qing Cheng; Perera, Priyan; Joiner, William J.; Thomas, Steven A.; Eckenhoff, Roderic G.; Sehgal, Amita; Kelz, Max B.

    2010-01-01

    One major unanswered question in neuroscience is how the brain transitions between conscious and unconscious states. General anesthetics offer a controllable means to study these transitions. Induction of anesthesia is commonly attributed to drug-induced global modulation of neuronal function, while emergence from anesthesia has been thought to occur passively, paralleling elimination of the anesthetic from its sites in the central nervous system (CNS). If this were true, then CNS anesthetic ...

  16. 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.

  17. 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

  18. Volatility Spillovers Across Petroleum Markets

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2015-01-01

    Roč. 36, č. 3 (2015), s. 309-329. ISSN 0195-6574 R&D Projects: GA ČR GA14-24129S Keywords : Volatility spillovers * Asymmetry * Petroleum markets Subject RIV: AH - Economics Impact factor: 1.772, year: 2014 http://library.utia.cas.cz/separaty/2014/E/barunik-0438407.pdf

  19. Volatile Hydrocarbon Pheromones from Beetles

    Science.gov (United States)

    This chapter reviews literature about hydrocarbons from beetles that serve as long-range pheromones. The most thoroughly studied beetles that use volatile hydrocarbon pheromones belong to the family Nitidulidae in the genera Carpophilus and Colopterus. Published pheromone research deals with behav...

  20. Efficacy of Intra-articular Local Anesthetics in Total Knee Arthroplasty.

    Science.gov (United States)

    Fang, Rui; Liu, Zhenfeng; Alijiang, Asila; Jia, Heng; Deng, Yingjie; Song, Yucheng; Meng, Qingcai

    2015-07-01

    Pain management after total knee arthroplasty (TKA) remains among the most important challenges for patients with TKA. Intra-articular local anesthetic has been shown to reduce postoperative pain following TKA. However, studies report conflicting results. This meta-analysis evaluated the efficacy and safety of single-dose intra-articular local anesthetics for pain control after TKA. Databases (Cochrane Central Register of Controlled Trials, Embase, PubMed, Web of Science, and Chinese Biomedical Databases) were searched to identify randomized, controlled trials comparing local anesthetic with placebo in patients undergoing TKA. Data were extracted independently by 2 researchers using a standardized form. Risk of bias was assessed with the use of the Cochrane Collaboration's tool for assessing the risk of bias by 2 observers. Relative risk, standardized mean difference, and corresponding 95% confidence interval were calculated. Seventeen trials met the inclusion criteria, for a total of 1338 participants. The results showed that, compared with the placebo group, the single local anesthetic group had a significant lower pain score with rest at 4, 8, 24, and 48 hours; less opioid consumption at 24, 48, and 72 hours postoperatively; and greater range of motion at 24, 48, and 72 hours. There were no significant differences between the 2 groups in length of hospital stay, nausea and vomiting, pruritus, sedation, or deep venous thrombosis. The study findings showed that pain relief after TKA was significantly better with intra-articular local anesthetic than with placebo. PMID:26186318

  1. 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

  2. Establishment of an in vitro cell line experimental system for the study of inhalational anesthetic mechanisms.

    Science.gov (United States)

    Nagamoto, Seiji; Iijima, Norio; Ishii, Hirotaka; Takumi, Ken; Higo, Shimpei; Aikawa, Satoko; Anzai, Megumi; Matsuo, Izumi; Nakagawa, Shinji; Takashima, Naoyuki; Shigeyoshi, Yasufumi; Sakamoto, Atsuhiro; Ozawa, Hitoshi

    2016-05-01

    General anesthesia affects the expression of clock genes in various organs. Expression of Per2, a core component of the circadian clock, is markedly and reversibly suppressed by sevoflurane in the suprachiasmatic nucleus (SCN), and is considered to be a biochemical marker of anesthetic effect in the brain. The SCN contains various types of neurons, and this complexity makes it difficult to investigate the molecular mechanisms of anesthesia. Here, we established an in vitro experimental system using a cell line to investigate the mechanisms underlying anesthetic action. Development of the system comprised two steps: first, we developed a system for application of inhalational anesthetics and incubation; next, we established cultures of anesthetic-responsive cells expressing mPer2 promoter-dLuc. GT1-7 cells, derived from the mouse hypothalamus, responded to sevoflurane by reversibly decreasing mPer2-promoter-driven bioluminescence. Interestingly, the suppression of bioluminescence was found only in the serum-starved GT1-7 cells, which showed neuron-like morphology, but not in growing cells, suggesting that neuron-like characteristics are required for anesthetic effects in GT1-7 cells. PMID:27057734

  3. 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

  4. α2-Adrenergic stimulation of the ventrolateral preoptic nucleus destabilizes the anesthetic state.

    Science.gov (United States)

    McCarren, Hilary S; Chalifoux, Michael R; Han, Bo; Moore, Jason T; Meng, Qing Cheng; Baron-Hionis, Nina; Sedigh-Sarvestani, Madineh; Contreras, Diego; Beck, Sheryl G; Kelz, Max B

    2014-12-01

    The sleep-promoting ventrolateral preoptic nucleus (VLPO) shares reciprocal inhibitory inputs with wake-active neuronal nuclei, including the locus ceruleus. Electrophysiologically, sleep-promoting neurons in the VLPO are directly depolarized by the general anesthetic isoflurane and hyperpolarized by norepinephrine, a wake-promoting neurotransmitter. However, the integration of these competing influences on the VLPO, a sleep- and anesthetic-active structure, has yet to be evaluated in either brain slices in vitro or the intact organism. Single-cell multiplex RT-PCR conducted on both isoflurane-activated, putative sleep-promoting VLPO neurons and neighboring, state-indifferent VLPO neurons in mouse brain slices revealed widespread expression of α2A-, α2B- and α2C-adrenergic receptors in both populations. Indeed, both norepinephrine and the highly selective α2 agonist dexmedetomidine each reversed the VLPO depolarization induced by isoflurane in slices in vitro. When microinjected directly into the VLPO of a mouse lightly anesthetized with isoflurane, dexmedetomidine increased behavioral arousal and reduced the depressant effects of isoflurane on barrel cortex somatosensory-evoked potentials but failed to elicit spectral changes in spontaneous EEG. Based on these observations, we conclude that local modulation of α-adrenergic activity in the VLPO destabilizes, but does not fully antagonize, the anesthetic state, thus priming the brain for anesthetic emergence. PMID:25471576

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. Pyrolysis and volatilization of cocaine

    International Nuclear Information System (INIS)

    The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

  11. 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...

  12. Measuring Volatility Clustering in Stock Markets

    OpenAIRE

    Gabjin Oh; Seunghwan Kim; Cheoljun Eom; Taehyuk Kim

    2007-01-01

    We propose a novel method to quantify the clustering behavior in a complex time series and apply it to a high-frequency data of the financial markets. We find that regardless of used data sets, all data exhibits the volatility clustering properties, whereas those which filtered the volatility clustering effect by using the GARCH model reduce volatility clustering significantly. The result confirms that our method can measure the volatility clustering effect in financial market.

  13. 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. ...

  14. 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...

  15. Volatility, the Macroeconomy and Asset Prices

    OpenAIRE

    Ravi Bansal; Dana Kiku; Ivan Shaliastovich; Amir Yaron

    2012-01-01

    We show that volatility movements have first-order implications for consumption dynamics and asset prices. Volatility news affects the stochastic discount factor and carries a separate risk premium. In the data, volatility risks are persistent and are strongly correlated with discount-rate news. This evidence has important implications for the return on aggregate wealth and the cross-sectional differences in risk premia. Estimation of our volatility risks based model yields an economically pl...

  16. A nonparametric approach to forecasting realized volatility

    OpenAIRE

    Adam Clements; Ralf Becker

    2009-01-01

    A well developed literature exists in relation to modeling and forecasting asset return volatility. Much of this relate to the development of time series models of volatility. This paper proposes an alternative method for forecasting volatility that does not involve such a model. Under this approach a forecast is a weighted average of historical volatility. The greatest weight is given to periods that exhibit the most similar market conditions to the time at which the forecast is being formed...

  17. The cholinergic ligand binding material of axonal membranes

    International Nuclear Information System (INIS)

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

  18. 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...

  19. 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.

  20. 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

  1. 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

  2. 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

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

    Directory of Open Access Journals (Sweden)

    Guo-ping REN

    2015-11-01

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

  4. Environmental Volatility, Development Decisions, and Software Volatility: A Longitudinal Analysis

    OpenAIRE

    Evelyn J. Barry; Kemerer, Chris F.; Slaughter, Sandra A.

    2006-01-01

    Although product development research often focuses on activities prior to product launch, for long-lived, adaptable products like software, development can continue over the entire product life cycle. For managers of these products the challenges are to predict when and how much the products will change and to understand how their development decisions influence the timing and magnitude of future change activities. We develop a two-stage model that relates environmental volatility to product...

  5. 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

  6. 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

  7. 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...

  8. Comparison of Intravenous Anesthetic Agents for the Treatment of Refractory Status Epilepticus

    Science.gov (United States)

    Reznik, Michael E.; Berger, Karen; Claassen, Jan

    2016-01-01

    Status epilepticus that cannot be controlled with first- and second-line agents is called refractory status epilepticus (RSE), a condition that is associated with significant morbidity and mortality. Most experts agree that treatment of RSE necessitates the use of continuous infusion intravenous anesthetic drugs such as midazolam, propofol, pentobarbital, thiopental, and ketamine, each of which has its own unique characteristics. This review compares the various anesthetic agents while providing an approach to their use in adult patients, along with possible associated complications. PMID:27213459

  9. 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

  10. Anesthetic management of a patient with Kimura′s disease for superficial parotidectomy

    Directory of Open Access Journals (Sweden)

    Dalim Kumar Baidya

    2011-01-01

    Full Text Available Kimura′s disease is a rare form of chronic eosinophilic inflammatory disease with vascular proliferation involving salivary gland, skin, lymph node, and kidney. Important anesthetic concerns include increased surgical bleeding due to its vascular nature, airway involvement by the mass leading to a possible difficult airway, allergic symptoms associated with high eosinophil count and elevated IgE level and nephrotic syndrome due to involvement of kidney by the inflammatory process. There is paucity of information in the literature on the anesthetic management of Kimura′s disease. We describe the anesthesia technique and review the literature of such a case posted for superficial parotidectomy.

  11. Anesthetic issues and perioperative blood pressure management in patients who have cerebrovascular diseases undergoing surgical procedures.

    Science.gov (United States)

    Jellish, W Scott

    2006-11-01

    Patients who have cerebrovascular disease and vascular insufficiency routinely have neurosurgical and nonneurosurgical procedures. Anesthetic priorities must provide a still bloodless operative field while maintaining cardiovascular stability and renal function. Patients who have symptoms or a history of cerebrovascular disease are at increased risk for stroke, cerebral hypoperfusion, and cerebral anoxia. Type of surgery and cardiovascular status are key concerns when considering neuroprotective strategies. Optimization of current condition is important for a good outcome; risks must be weighed against perceived benefits in protecting neurons. Anesthetic use and physiologic manipulations can reduce neurologic injury and assure safe and effective surgical care when cerebral hypoperfusion is a real and significant risk. PMID:16935193

  12. Comparison of Intravenous Anesthetic Agents for the Treatment of Refractory Status Epilepticus

    Directory of Open Access Journals (Sweden)

    Michael E. Reznik

    2016-05-01

    Full Text Available Status epilepticus that cannot be controlled with first- and second-line agents is called refractory status epilepticus (RSE, a condition that is associated with significant morbidity and mortality. Most experts agree that treatment of RSE necessitates the use of continuous infusion intravenous anesthetic drugs such as midazolam, propofol, pentobarbital, thiopental, and ketamine, each of which has its own unique characteristics. This review compares the various anesthetic agents while providing an approach to their use in adult patients, along with possible associated complications.

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

    International Nuclear Information System (INIS)

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

  14. 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....

  15. 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.

  16. 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.

  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

    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.

  19. Forecasting volatility of crude oil markets

    International Nuclear Information System (INIS)

    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)

  20. 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...

  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. Market Volatility and Macroeconomic Factors

    OpenAIRE

    Gao, Kang

    2012-01-01

    This study investigates the relationship between macroeconomic factors and the stock market volatility. Following macroeconomic variables are used: industrial production, inflation rate, interest rate and exchange rate. Shanghai Exchange Composite Index, Standard & Poor’s 500, FTSE 100 and Deutscher Aktien Index are chosen to represent the China, United States, United Kingdom and Germany market. Monthly time series data of mentioned variables are the time period is from November 2001 to April...

  3. Plant volatiles mediate tritrophic interactions

    OpenAIRE

    Ninkovic, Velemir

    2002-01-01

    The effects of plant-plant interactions via volatiles (aerial allelopathy) on herbivores and their natural enemies were investigated. The model system consisted of four barley varieties, an aphid pest, Rhopalosiphum padi (L.), and a common aphid predator, ladybird, Coccinella septempunctata (L). Aerial allelopathy significantly affected plant leaf temperature and biomass allocation, favouring root growth during the vegetative period, the main period for development of R. padi populations in S...

  4. 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.

  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. 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)

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

    International Nuclear Information System (INIS)

    Binding of [3H]cocaine to synaptic membranes from whole rat brain was reversible and saturable. Nonlinear regression analysis of binding isotherms indicated two binding affinities: one with k/sub d/ = 16 nM, B/sub max/ = 0.65 pmoles/mg protein and the other with K/sub d/ = 660 nM, B/sub max/ = 5.1 pmoles/mg protein. The high-affinity binding of [3H]cocaine was sensitive to the actions of trypsin and chymotrypsin but not carboxypeptidase, and was eliminated by exposure of the membranes to 950C for 5 min. Specific binding at 2 nM was higher at pH 8.8 than at pH 7.0. Binding of [3H]cocaine (15 nM) was inhibited by increasing concentrations of Na+ ions. Several cocaine analogues, neurotransmitter uptake inhibitors and local anesthetics displaced specific [3H]cocaine binding at 2 nM with various potencies. The cocaine analogue (-)-norcocaine was the most potent (IC50 = 10 nM), while the local anesthetic tetracaine was the least potent in inhibiting [3H]cocaine binding. Several biogenic amine uptake inhibitors, including tricyclic antidepressants and phencyclidine, had IC50 values below μM concentrations

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.)

  14. 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.

  15. 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…

  16. [On the surface-anesthetic activity of some ether alcohols (author's transl)].

    Science.gov (United States)

    Riemschneider, R; Rufer, C; Chik, W H

    1978-01-01

    An account of the preparation and surface anesthetic potency of 12 ether alcohols of the type X-O-Y-OH is given in this paper. The anaesthetic intensity and effective duration of a chloronaphthalene derivative of this type lie within the range of action of cocain. PMID:582907

  17. The Effect and Safety of Steroid Injection in Lumbar Spinal Stenosis: With or Without Local Anesthetics

    Science.gov (United States)

    Song, Sung Hyuk; Ryu, Gi Hyeong; Park, Jin Woo; Lee, Ho Jun; Nam, Ki Yeun; Kim, Hyojun; Kim, Seung Yeon

    2016-01-01

    Objective To compare the long-term effect and safety of an epidural steroid injection in spinal stenosis patients, with or without local anesthetics. Methods Twenty-nine patients diagnosed with spinal stenosis were included and randomly divided into two groups. Translaminar epidural and selective nerve root spinal injection procedures were performed using steroids mixed with local anesthetics or normal saline. The effects of spinal injection procedures were measured with visual analogue scale (VAS) and functional rate index (FRI). These measurements were performed before injection, at 1 month after injection and at 3 months after injection. The occurrence of side effects was investigated each time. Results The VAS and FRI scores were significantly reduced in both the local anesthetics group and normal saline group at 1 and 3 months after the injection. However, there was no significant difference in VAS and FRI score reduction between the two groups each time. Side effects are not noted in both groups. Conclusion The spinal injection procedures using steroids mixed either with local anesthetics or normal saline have an effect in reducing pain and improving functional activities. However, there was no significant difference between the two groups in relation to side effects and the long-term effects of pain and function. PMID:26949664

  18. 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

  19. 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

    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...

  20. Experimental induction of isolated lower esophageal sphincter relaxation in anesthetized opossums.

    OpenAIRE

    Paterson, W.G.; Rattan, S; Goyal, R K

    1986-01-01

    Isolated lower esophageal sphincter (LES) relaxation, defined as a transient sphincteric relaxation unaccompanied by esophageal peristalsis, has been shown to precede most episodes of gastroesophageal reflux in humans. We studied the genesis of isolated LES relaxation in anesthetized opossums by observing the response of four components of the deglutition reflex (mylohyoid electrical activity, pharyngeal contraction, esophageal peristalsis, and LES relaxation) to pharyngeal tactile stimulatio...

  1. 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.

  2. 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.

  3. Comparison of 3 different anesthetic techniques on 24-hour recovery after otologic surgical procedures.

    Science.gov (United States)

    Jellish, W S; Leonetti, J P; Fahey, K; Fury, P

    1999-03-01

    Intravenous propofol anesthesia is better than inhalational anesthesia for otologic surgery, but cost and intraoperative movement make this technique prohibitive. This study compares a propofol sandwich anesthetic with a total propofol or inhalational anesthetic for otologic surgery to determine which produces the best perioperative conditions and least expense. One hundred twenty patients undergoing ear surgery were randomly chosen to receive an anesthetic with either isoflurane (INHAL), total propofol (TPROP), or propofol used in conjunction with isoflurane (PSAND). Postoperative wakeup and the incidence and severity of nausea, vomiting, and pain were compared among groups. Antiemetic administration and discharge times from recovery and the hospital were also compared. The groups were similar, but anesthesia times were longer in the INHAL group. Emergence from anesthesia after PSAND or TPROP was more rapid than after INHAL. Recovery during the next 24 hours was associated with less nausea and vomiting with PSAND than with INHAL. The cost of the PSAND anesthetic was similar to that of INHAL, and both were less than TPROP. PSAND anesthesia may be similar to TPROP and better than INHAL for otologic procedures. PSAND was less expensive than TPROP and produced a similar recovery profile and antiemetic effect in the 24-hour period after surgery. PMID:10064647

  4. Clinical research into anesthetic neurotoxicity: does anesthesia cause neurological abnormalities in humans?

    Science.gov (United States)

    Lei, Susan Y; Hache, Manon; Loepke, Andreas W

    2014-10-01

    General anesthetics mitigate distress and exaggerated hemodynamic responses to pain and stressful stimulation, allowing surgery and diagnostic procedures to be performed worldwide in millions of children every year. Emerging studies, mainly carried out in early postnatal laboratory animals, demonstrate widespread neuronal elimination, alteration in neuronal circuitry, and long-term neurological disabilities following exposure to all commonly used sedatives and anesthetics. These findings have raised concerns among parents, anesthesiologists, neuroscientists, and government regulators about the safety of anesthetic drugs in children, especially infants. Accumulating evidence from epidemiological studies suggests an association between surgery with anesthesia in early childhood and subsequent behavioral and cognitive abnormalities. During the Fourth Pediatric Anesthesia NeuroDevelopmental Assessment (PANDA) symposium, a meeting attended by many stakeholders, the most recent findings in the field were presented and discussed. This review summarizes the current state of clinical research into the effects of anesthetic exposure in human brain development, addresses some of the difficulties in examining the phenomenon, and introduces the most recent clinical findings presented at the PANDA symposium. The unanimous consensus among participants was that additional preclinical and clinical research efforts are urgently required to address this important concern for child health. PMID:25144503

  5. 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

  6. 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

  7. 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.

  8. 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...

  9. 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...

  10. 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

  11. 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.

  12. Volatile organic compound sensor system

    Energy Technology Data Exchange (ETDEWEB)

    Schabron, John F. (Laramie, WY); Rovani, Jr., Joseph F. (Laramie, WY); Bomstad, Theresa M. (Waxahachie, TX); Sorini-Wong, Susan S. (Laramie, WY); Wong, Gregory K. (Laramie, WY)

    2011-03-01

    Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.

  13. Volatile halogenated hydrocarbons in foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Toyoda, Masatake; Saito, Yukio [National Institute of Health Services, Tokyo (Japan)] [and others

    1995-02-01

    Volatile halogenated organic compounds were determined in foods. Statistical treatment of the data for 13 sampled from 20 families living in suburban Tokyo (Saitama prefecture) indicated that the foods were contaminated by water pollution and/or substances introduced by the process of food production. Butter and margarine were contaminated by chlorinated ethylene, ethane, and related compounds released by dry cleaning and other operations. Soybean sprouts and tofu (soybean curd) contained chloroform and related trihalomethanes absorbed during the production process. 27 refs., 6 figs., 5 tabs.

  14. 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 ...

  15. 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.

  16. 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...

  17. 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...

  18. The Lunar Volatile Resources Analysis Package

    OpenAIRE

    Morse, Andrew; Barber, Simeon; Dewar, Kevin; Pillinger, Judith; Sheridan, Simon; Wright, Ian; Gibson, Everett; Merifield, Jim; Howe, Chris; Waugh, Lester; Pillinger, Colin

    2012-01-01

    The presence and abundance of lunar volatiles is an important consideration for ISRU (In Situ Resource Utilisation) since this is likely to be a part of a strategy for supporting long term human exploration of the moon. The Lunar Volatile Resources Analysis Package (L-VRAP) is part of the provisional payload for the ESA European Lander [1] and aims to measure the abundance and chemical/isotopic composition of volatiles from regolith samples and the lunar exosphere.

  19. ’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 ...

  20. 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 ...

  1. 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...

  2. 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, ...

  3. 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...

  4. 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...

  5. Structural GARCH: The Volatility-Leverage Connection

    OpenAIRE

    Robert Engle; Emil Siriwardane

    2014-01-01

    We propose a new model of volatility where financial leverage amplifies equity volatility by what we call the "leverage multiplier." The exact specification is motivated by standard structural models of credit; however, our parametrization departs from the classic Merton (1974) model and can accommodate environments where the firm's asset volatility is stochastic, asset returns can jump, and asset shocks are nonnormal. In addition, our specification nests both a standard GARCH and the Merton ...

  6. Structural GARCH: The Volatility-Leverage Connection

    OpenAIRE

    Engle, Robert; Siriwardane, Emil Nuwan

    2015-01-01

    We propose a new model of volatility where financial leverage amplifies equity volatility by what we call the “leverage multiplier.” The exact specification is motivated by standard structural models of credit; however, our parameterization departs from the classic Merton (1974) model and can accommodate environments where the firm’s asset volatility is stochastic, asset returns can jump, and asset shocks are non-normal. In addition, our specification nests both a standard GARCH and the Merto...

  7. Volatility prediction with mixture density networks

    OpenAIRE

    Schittenkopf, Christian; Dorffner, Georg; Dockner, Engelbert J.

    1998-01-01

    Despite the lack of a precise definition of volatility in finance, the estimation of volatility and its prediction is an important problem. In this paper we compare the performance of standard volatility models and the performance of a class of neural models, i.e. mixture density networks (MDNs). First experimental results indicate the importance of long-term memory of the models as well as the benefit of using non-gaussian probability densities for practical applications. (author's abstract)

  8. [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

  9. 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.

  10. 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....

  11. 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.

  12. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    We present and test a model relating a firm's idiosyncratic cost, its exporting status, and the volatilities of its domestic and export sales. In prior models of trade, supply costs for domestic and exports were linear and thus additively separable. We introduce a nonlinear cost function in order...... to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...

  13. 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.

  14. 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

  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. Configuration of Pluto's Volatile Ices

    Science.gov (United States)

    Grundy, William M.; Binzel, R. P.; Cook, J. C.; Cruikshank, D. P.; Dalle Ore, C. M.; Earle, A. M.; Ennico, K.; Jennings, D. E.; Howett, C. J. A.; Linscott, I. R.; Lunsford, A. W.; Olkin, C. B.; Parker, A. H.; Parker, J. Wm; Protopapa, S.; Reuter, D. C.; Singer, K. N.; Spencer, J. R.; Stern, S. A.; Tsang, C. C. C.; Verbiscer, A. J.; Weaver, H. A.; Young, L. A.; Berry, K.; Buie, M. W.; Stansberry, J. A.

    2015-11-01

    We report on near-infrared remote sensing by New Horizons' Ralph instrument (Reuter et al. 2008, Space Sci. Rev. 140, 129-154) of Pluto's N2, CO, and CH4 ices. These especially volatile ices are mobile even at Pluto's cryogenic surface temperatures. Sunlight reflected from these ices becomes imprinted with their characteristic spectral absorption bands. The detailed appearance of these absorption features depends on many aspects of local composition, thermodynamic state, and texture. Multiple-scattering radiative transfer models are used to retrieve quantitative information about these properties and to map how they vary across Pluto's surface. Using parameter maps derived from New Horizons observations, we investigate the striking regional differences in the abundances and scattering properties of Pluto's volatile ices. Comparing these spatial patterns with the underlying geology provides valuable constraints on processes actively modifying the planet's surface, over a variety of spatial scales ranging from global latitudinal patterns to more regional and local processes within and around the feature informally known as Sputnik Planum. This work was supported by the NASA New Horizons Project.

  17. On the second derivative of the at-the-money implied volatility in stochastic volatility models

    OpenAIRE

    Al??s, Elisa; Le??n, Jorge A.

    2014-01-01

    In this paper we compute analytically the at-the-money second derivative of the implied volatility curve as a function of the strike price, for correlated stochastic volatility models. We obtain an expression for the short-time limit of this second derivative in terms of the first and second Malliavin derivatives of the volatility process and the correlation parameter.

  18. 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

  19. 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.

  20. Convertible Bonds: Default Risk and Uncertain Volatility

    OpenAIRE

    Huang, Haishi

    2009-01-01

    Within a default intensity approach we discuss the optimal exercise of the callable and convertible bonds. Pricing bounds for convertible bonds are derived in an uncertain volatility model, i.e. when the volatility of the stock price process lies between two extreme values.

  1. 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

  2. Fundamental uncertainty and stock market volatility

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2008-01-01

    We provide empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from participants in the Survey of Professional Forecasters over the period 1969 to 1996.

  3. VOLATILIZED LUBRICANT EMISSIONS FROM STEEL ROLLING OPERATIONS

    Science.gov (United States)

    The report gives results of a study of the volatilization of lubricants used in steel rolling. Data from nine steel mills were used to: define the volatilized portion of lubricants used in rolling; and prepare total oil, grease, and hydraulic material balances for actual and typi...

  4. 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...

  5. Asymptotics of implied volatility far from maturity

    OpenAIRE

    Michael R., Tehranchi

    2009-01-01

    This note explores the behaviour of the implied volatility of a European call option far from maturity. Asymptotic formulae are derived with precise control over the error terms. The connection between the asymptotic implied volatility and the cumulant generating function of the logarithm of the underlying stock price is discussed in detail and illustrated by examples.

  6. 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...

  7. 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.

  8. 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

    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......In spite of the fact that our knowledge on the release mechanisms of the surgical stress response is rather incomplete, several techniques are available to modulate the response. However, at present it appears that no technique is capable to effectively suppress all aspects of the injury response...... 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...

  9. 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

  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. 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...

  12. [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

  13. Rapid automated classification of anesthetic depth levels using GPU based parallelization of neural networks.

    Science.gov (United States)

    Peker, Musa; Şen, Baha; Gürüler, Hüseyin

    2015-02-01

    The effect of anesthesia on the patient is referred to as depth of anesthesia. Rapid classification of appropriate depth level of anesthesia is a matter of great importance in surgical operations. Similarly, accelerating classification algorithms is important for the rapid solution of problems in the field of biomedical signal processing. However numerous, time-consuming mathematical operations are required when training and testing stages of the classification algorithms, especially in neural networks. In this study, to accelerate the process, parallel programming and computing platform (Nvidia CUDA) facilitates dramatic increases in computing performance by harnessing the power of the graphics processing unit (GPU) was utilized. The system was employed to detect anesthetic depth level on related electroencephalogram (EEG) data set. This dataset is rather complex and large. Moreover, the achieving more anesthetic levels with rapid response is critical in anesthesia. The proposed parallelization method yielded high accurate classification results in a faster time. PMID:25650073

  14. 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....

  15. 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.

  16. 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.

  17. Risk assessment and anesthetic management of patients with Williams syndrome: a comprehensive review.

    Science.gov (United States)

    Matisoff, Andrew J; Olivieri, Laura; Schwartz, Jamie M; Deutsch, Nina

    2015-12-01

    Since the first description in 1961, several case reports have documented an increased incidence of anesthesia-related cardiac arrest in patients with Williams-Beuren syndrome, commonly known as Williams syndrome (WS). Widespread arteriopathy secondary to an elastin gene defect results in various cardiac defects, including supravalvar aortic stenosis (SVAS) and coronary artery anomalies, which can increase the risk of myocardial ischemia. Even though patients with WS are known to have increased risk of adverse events during anesthesia and sedation, they often undergo several procedures that require anesthesia during their lifetimes, and cases of perianesthetic cardiac arrest continue to be reported. To date, no prospective studies have been reported that quantify anesthetic risk in individual patients with WS. In this article, we review the clinical manifestations of WS, propose a consensus, expert-informed method to estimate anesthetic risk based on the current literature, and provide recommendations for periprocedural management of this patient population. PMID:26456018

  18. 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.

  19. 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.

  20. 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....

  1. 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...... conditional variance of e.g. the unexpected German stock return is divided into separate effects from the contemporaneous idiosyncratic variance of US bonds, US stocks, European bonds, European stocks, German bonds, and German stocks. Significant volatility-spillover effects are found. The national bond...... (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....

  2. 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 is...... a positive probability of jumps in volatility. A common factor in the volatility jumps is shown to be related to a set of financial covariates (such as variance risk premium, S&P500 volume, credit-default swap, and federal fund rates). The credit-default swap on US banks and variance risk premium...... have 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...

  3. [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

  4. 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

  5. Anesthetic management of a patient with sickle cell disease for common bile duct exploration

    Directory of Open Access Journals (Sweden)

    Sarika Subhash Ingle

    2011-01-01

    Full Text Available Patients with sickle cell disease (SCD may present to the anesthetist in different clinical settings like perioperative care, management of acute painful crisis and intensive therapy for acute respiratory failure. We describe the successful management of a 34-year-old female patient with SCD, posted for cholecystectomy with common bile duct exploration under general and epidural anesthesia. The importance of preoperative stabilization and careful anesthetic strategy is emphasized.

  6. 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...

  7. Evaluation and Management of Hypersensitivity to Local Anesthetics in Pediatric Dentistry

    OpenAIRE

    Shapira, Joseph; Rubinow, Alan

    1987-01-01

    The clinical histories of four children with a history of adverse reactions to local anesthesia and who required dental treatment are reviewed retrospectively. The children described had been referred to the allergy unit for evaluation between 1984 and 1985 and are representative of the dilemma of cases of suspected hypersensitivity to local anesthetics. The first two cases had been previously treated without the use of regional anesthesia because of a family history of atopic reactions as we...

  8. A Multidisciplinary Approach to Anesthetic Management of a Parturient with Severe Aortic Stenosis

    OpenAIRE

    Kalpana Tyagaraj; Gutman, David A.; Lynn Belliveau; Adnan Sadiq; Alok Bhutada; Feierman, Dennis E

    2015-01-01

    In order to optimize anesthetic management and avoid adverse maternal and fetal outcomes, a clear understanding of the changes in cardiovascular physiology that occur during pregnancy is paramount. The effects of normal gestation on the cardiovascular system are particularly significant in a parturient with cardiac valvular pathology. We present a case of a 27-year-old G2P0 at 37 weeks with a past medical history of diabetes, macrosomia, congenital bicuspid aortic valve with severe stenosis (...

  9. 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...

  10. The challenge of evaluating pain and a pre-incisional local anesthetic block

    OpenAIRE

    McKune, Carolyn M.; Pascoe, Peter J.; Lascelles, B Duncan X; Kass, Philip H.

    2014-01-01

    Background. Our objective was to test the effectiveness of a local anesthetic line block administered before surgery in reducing postoperative pain scores in dogs undergoing ovariohysterectomy (OVHX). Methods. This study is a prospective, randomized, blinded, clinical trial involving 59 healthy female dogs. An algometric pressure-measuring device was used to determine nociceptive threshold, and compared to three subjective pain scales. Group L/B received a line block of lidocaine (4 mg/kg...

  11. Preliminary studies on local anesthetic and antipyretic activities of Spilanthes acmella Murr. in experimental animal models

    Directory of Open Access Journals (Sweden)

    Chakraborty A

    2010-01-01

    Full Text Available Objective : Spilanthes acmella Murr. (Family: Compositae is a herb that grows throughout the tropics. It is used in the treatment of rheumatism, fever, sore throat, and hemorrhoids. A tincture of the flowers is used to relieve toothache. The leaves and flowers produce numbness of the tongue when eaten as salad. The present study was undertaken to evaluate the local anesthetic and antipyretic activities of S. acmella in experimental animal models. Materials and Methods : Aqueous extract of S. acmella Murr. (SAM was tested for local anesthetic action by (i intracutaneous wheal in guinea pigs and (ii plexus anesthesia in frogs. In both the models, 2% xylocaine was used as the standard drug. The anti-pyretic activity was determined by yeast-induced pyrexia in rats. Aspirin 300 mg/kg was used as the standard drug. Result : The test drug in concentrations of 10% and 20% produced 70.36% and 87.02% anesthesia respectively by the intracutaneous wheal compared to 97.22% anesthetic effect produced by 2% xylocaine (P<0.001. The mean onset of anesthesia with the test drug was 5.33±0.57 min compared to 2.75±0.31 min (P<0.001 for the standard drug in the plexus anesthesia model. In the anti-pyretic model, ASA in doses of 100, 200, and 400 mg produced dose-dependent reduction in mean temperature at various hours of observation. Conclusion : The present study shows that SAM has significant local anesthetic and antipyretic activities.

  12. 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 ...

  13. 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.

  14. Ventilatory response to high inspired carbon dioxide concentrations in anesthetized dogs

    OpenAIRE

    Loeppky, Jack A.; Ray Risling

    2011-01-01

    Background: The ventilation (IV ) response to inspired CO2 has been extensively studied, but rarely with concentrations >10%. Aims: These experiments were performed to determine whether I V  would increase correspondingly to higher concentrations and according to conventional chemoreceptor time delays. Materials and Methods: We exposed anesthetized dogs acutely, with and without vagotomy and electrical stimulation of the right vagus, to 20-100% CO2-balance O2.and to 0 and 10% O2-balance N2....

  15. Anesthetic management for separation of thoracopagus twins with complex congenital heart disease: a case report

    OpenAIRE

    Seo, Misook; Chung, In-Sun; Karm, Myong-Hwan; Oh, Ji Mi; Shin, Won-Jung

    2015-01-01

    Although thoracopagus twins joined at the upper chest are the most common type of conjoined twins, the separation surgery in these cases has a higher mortality rate. Here, we describe an anesthetic management approach for the separation of thoracopagus conjoined twins sharing parts of a congenitally defective heart and liver. We emphasize the importance of vigilant intraoperative hemodynamic monitoring for early detection of unexpected events. Specifically, real-time continuous monitoring of ...

  16. Anesthetic management of conjoined twins undergoing one-stage surgical separation: A single center experience

    OpenAIRE

    Zhong, He-Jiang; Li, Hong; Du, Zhi-Yong; Huan, He; Yang, Tian-De; Qi, Yue-Yong

    2013-01-01

    Objective: To summarize our experience in the anesthetic management of conjoined twins undergoing one-stage surgical separation. Methodology: Medical records of conjoined twins admitted to our hospital for treatment and considered for surgical separation from 1996 to present were retrospectively reviewed. Four cases of conjoined twins underwent one-stage surgical separation under general anesthesia. Preoperative evaluation was performed to determine the extent of anatomical conjunction and as...

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

    Directory of Open Access Journals (Sweden)

    Kapil Chaudhary

    2012-01-01

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

  18. Anesthetic and Airways Management of a Dog with Severe Tracheal Collapse during Intraluminal Stent Placement

    OpenAIRE

    Argano, M.; Gendron, K.; U. Rytz; Adami, C.

    2013-01-01

    This case report describes the anesthetic and airways management of a dog affected by 4th degree tracheal collapse and undergoing endoscope-guided intraluminal stent placement. After premedication with acepromazine and butorphanol, general anesthesia was induced with propofol and maintained with intravenous propofol and butorphanol in constant rate infusion. During intraluminal stent placement, oxygen was supplemented by means of a simple and inexpensive handmade device, namely, a ureteral ca...

  19. 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...... anesthesia modalities reduce postoperative opioid consumption in ankle fracture surgery in comparison with GA. A benefit of PNBs is indicated possibly due to an improved pain profile. Our study is retrospective and cannot predict the exact magnitude of this benefit....

  20. 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...

  1. 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

  2. Effect of prophylactic vitamin D on anesthetic outcome in children with sickle cell disease

    OpenAIRE

    Tarek Shams; Hamed Al Wadani; Ragaa El-Masry; Ossama Zakaria

    2014-01-01

    Background: Few previous studies proved that complications related to sickle cell disease (SCD) were common with regional anesthesia compared with general anesthesia while others reported no differences. This study was carried out to evaluate the role of prophylactic vitamin D on anesthetic outcome among male children with SCD undergoing circumcision. Materials and Methods: A comparative study was carried out on 58 children undergoing circumcision with the regional block under light gener...

  3. Analysis on the factors associated with treatment failure of using anesthetics in refractory status epilepticus

    Directory of Open Access Journals (Sweden)

    Ying-ying SU

    2015-11-01

    Full Text Available Objective To analyze the related factors associated with immediate treatment failure of using anesthetics in refractory status epilepticus (RSE.  Methods Thirty patients derived from Neurocritical Care Unit of Xuanwu Hospital from January 2004 to December 2013 were divided into 2 groups (acute treatment failure group and acute treatment success group based on the treatment outcome 6 h after intravenous injection of anesthetics. Univariate and multivariate forward Logistic regression analyses were used to analyze and screen the risk factors associated with immediate treatment failure, and calculate the failure rate of final outcome.  Results According to the results of univariate and multivariate Logistic regression analyses, among influencing factors such as sex, age, etiology, Acute Physiology and Chronic Health EvaluationⅡ (APACHEⅡ, type of status epilepticus (SE, type of antiepileptic drugs (AEDs, total duration of primary treatment, duration of prehospital primary treatment, duration of posthospital primary treatment, type of RSE and primary choice of anesthetics, only total duration of primary treatment was the independent risk factor for immediate treatment failure (OR = 1.007, 95%CI: 1.000-1.014; P = 0.047. The rate of immediate treatment failure of RSE by using anesthetics was 50% (15/30, and the rate of final treatment failure was 43.33% (13/30. The ratio of final treatment failure was much higher in acute treatment failure group than that in acute treatment success group (10/15 vs 3/15, P = 0.025.  Conclusions The acute treatment result of RSE depends on the total duration of primary treatment, and determinates the final result of treatment. On the basis of treating primary disease, the therapy to terminate SE or RSE should be started as early as possible. DOI: 10.3969/j.issn.1672-6731.2015.11.008

  4. 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...

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  7. 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). PMID:25806995

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

    Directory of Open Access Journals (Sweden)

    Thalita L. A. Rocha

    2015-01-01

    Full Text Available Taking into account that there are controversial antioxidative effects of inhalational anesthetics isoflurane and sevoflurane and absence of comparison of genotoxicity of both anesthetics in animal model, the aim of this study was to compare DNA damage and antioxidant status in Wistar rats exposed to a single time to isoflurane or sevoflurane. The alkaline single-cell gel electrophoresis assay (comet assay was performed in order to evaluate DNA damage in whole blood cells of control animals (unexposed; n = 6 and those exposed to 2% isoflurane (n = 6 or 4% sevoflurane (n = 6 for 120 min. Plasma antioxidant status was determined by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. There was no statistically significant difference between isoflurane and sevoflurane groups regarding hemodynamic and temperature variables (P > 0.05. Sevoflurane significantly increased DNA damage compared to unexposed animals (P = 0.02. In addition, Wistar rats anesthetized with isoflurane showed higher antioxidative status (MTT than control group (P = 0.019. There were no significant differences in DNA damage or antioxidant status between isoflurane and sevoflurane groups (P > 0.05. In conclusion, our findings suggest that, in contrast to sevoflurane exposure, isoflurane increases systemic antioxidative status, protecting cells from DNA damage in rats.

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

    Directory of Open Access Journals (Sweden)

    J. Morato-Fernandes

    2013-10-01

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

  10. 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)

  11. 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.

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

    International Nuclear Information System (INIS)

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

  13. 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.

  14. 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.

  15. General Anesthetic Conditions Induce Network Synchrony and Disrupt Sensory Processing in the Cortex.

    Science.gov (United States)

    Lissek, Thomas; Obenhaus, Horst A; Ditzel, Désirée A W; Nagai, Takeharu; Miyawaki, Atsushi; Sprengel, Rolf; Hasan, Mazahir T

    2016-01-01

    General anesthetics are commonly used in animal models to study how sensory signals are represented in the brain. Here, we used two-photon (2P) calcium activity imaging with cellular resolution to investigate how neuronal activity in layer 2/3 of the mouse barrel cortex is modified under the influence of different concentrations of chemically distinct general anesthetics. Our results show that a high isoflurane dose induces synchrony in local neuronal networks and these cortical activity patterns closely resemble those observed in EEG recordings under deep anesthesia. Moreover, ketamine and urethane also induced similar activity patterns. While investigating the effects of deep isoflurane anesthesia on whisker and auditory evoked responses in the barrel cortex, we found that dedicated spatial regions for sensory signal processing become disrupted. We propose that our isoflurane-2P imaging paradigm can serve as an attractive model system to dissect cellular and molecular mechanisms that induce the anesthetic state, and it might also provide important insight into sleep-like brain states and consciousness. PMID:27147963

  16. 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

  17. The evaluation of the effect of different anesthetic techniques on neonatal bilirubin levels

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    Fatma Eskicioğlu

    2014-01-01

    Full Text Available Objective: The aim of the present study was to determine whether different anesthetic techniques applied for vaginal delivery and cesarean section affect neonatal bilirubin levels in the first 24 hours of life .Materials and Methods: A total of 511 neonates delivered by vaginal route or cesarean section were included in the study. The neonates were classified according to method of delivery and anesthetic agents as group A (cesarean section / general anesthesia with sevoflurane, group B (cesarean section / spinal anesthesia with bupivacaine hydrochlorur , group C (vaginal delivery with episiotomy / local anesthesia with prilocaine hydrochloride and group D (vaginal delivery/ no anesthesia . The levels of neonatal serum bilirubin in the groups were compared.Results: There was no difference between group A and group B when compared in terms of neonatal bilirubin levels (p = 0.98. Depending on the use of prilocaine hydrochloride as local anesthetic agent in the vaginal delivery, there was no significant difference between the groups C and D ,who had vaginal delivery, in terms of the neonatal bilirubin levels (p = 0.99. The serum levels of bilirubin in cesarean section groups were significantly higher than those of the vaginal delivery groups (p < 0.001.Conclusion: Prilocaine hydrochloride used for episiotomy is not effective on neonatal hyperbilirubinemia. However, sevoflurane and bupivacaine hydrochloride used in cesarean section seem to be increasing bilirubin levels.

  18. Lipid Emulsions Enhance the Norepinephrine-Mediated Reversal of Local Anesthetic-Induced Vasodilation at Toxic Doses

    OpenAIRE

    Lee, Soo Hee; Sung, Hui-Jin; Ok, Seong-Ho; Yu, Jongsun; Choi, Mun-Jeoung; Lim, Jin Soo; Sohn, Ju-Tae

    2013-01-01

    Purpose Intravenous lipid emulsions have been used to treat the systemic toxicity of local anesthetics. The goal of this in vitro study was to examine the effects of lipid emulsions on the norepinephrine-mediated reversal of vasodilation induced by high doses of levobupivacaine, ropivacaine, and mepivacaine in isolated endothelium-denuded rat aorta, and to determine whether such effects are associated with the lipid solubility of local anesthetics. Materials and Methods The effects of lipid e...

  19. Does subacromial injection of a local anesthetic influence strength in healthy shoulders?: a double-blinded, placebo-controlled study

    OpenAIRE

    Farshad, Mazda; Jundt-Ecker, Michèle; Sutter, Reto; Schubert, Martin; Gerber, Christian

    2012-01-01

    BACKGROUND: Subacromial injection of a local anesthetic is used to eliminate pain as a confounding factor in clinical assessment of abduction strength in shoulders with a suspected rotator cuff tear. If strength remains diminished despite pain relief, a rotator cuff tear is likely. The effect of injecting local anesthetic into the subacromial space on the strength of a normal shoulder is unknown, although it could affect strength by impairing suprascapular or axillary nerve function. We hypot...

  20. ASSESSMENT OF LOCAL ANESTHETIC ACTIVITY OF LIGNOCAINE BY SIMULTANEOUS ADMINISTRATION OF POTASSIUM CHANNEL AGONISTS NICORANDIL IN ALBINO RATS

    OpenAIRE

    Lakkol Kiran J; Umakant Patil N; Kallappa Shivashankaramurthy G; VinodKumar C.S

    2013-01-01

    There are reports about a possible weak local anaesthetic activity of nicorandil, a potassium channel agonist (PCA). In addition, modification of local anesthetic activity of lignocaine by PCA is not clearly defined. The objective of the present study is to evaluate local anesthetic activity of nicorandil and to evaluate the influence of nicorandil on the efficacy and duration of local anesthesia by lignocaine. A total number of 84 albino rats of either sex were divided into 14 groups of 6 an...

  1. A Comparative Study of Embedded and Anesthetized Zebrafish in vivo on Myocardiac Calcium Oscillation and Heart Muscle Contraction

    OpenAIRE

    Muntean, Brian S.; Horvat, Christine M.; Behler, James H.; AbouAlaiwi, Wissam A.; Nauli, Andromeda M.; Williams, Frederick E.; Nauli, Surya M.

    2010-01-01

    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 and calcium imaging microscopy, we here show that dopamine and verapamil alter calcium signaling and muscle contraction in anesthetized zebrafish, but not in embedded zebr...

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

    OpenAIRE

    AndromedaNauli; FrederickWilliams

    2010-01-01

    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 embed...

  3. 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...

  4. Intraoperative Anesthetic Management of Patients Undergoing Glomus Tumor Resection Using a Low-Dose Isoflurane-Fentanyl Technique

    OpenAIRE

    Jellish, W.S.; J Murdoch; Leonetti, J.

    1994-01-01

    Glomus jugulare and vagale tumors present unique problems to both anesthesiologists and surgeons. The anesthetic plant must be tailored to each patient and provide hemodynamic stability, a consistent intraoperative environment, and rapid awakening after prolonged administration. In this report, we describe our anesthetic method used for paraganglioma resection, which utilizes a combination technique of low-dose isoflurane with a narcotic infusion initiated after bolus administration. Results ...

  5. 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 ...

  6. 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...

  7. 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...

  8. 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 ...

  9. Emergence from anesthesia in children undergoing ambulatory surgery- a comparison between propofol and sevoflurane using single anesthetic technique

    International Nuclear Information System (INIS)

    Objective: To compare emergence from anesthesia using total intravenous anesthesia (TIVA) with propofol and volatile induction maintenance anesthesia (VIMA) with sevoflurane, in children undergoing ambulatory inguinal herniorrhaphy. Study Design: Randomized, controlled trials. Place and Duration of Study: Shifa Hospital of Pakistan Navy, from 1st Mar 2005 to 28th Feb 2006. Patients and Methods: Eighty children, aged 5-10 years of ASA physical status I or II were divided into two groups of 40 each using random numbers table. Group P received propofol 3mg/kg for induction and 100-400 micro g/kg/min infusion for maintenance of anesthesia, while group S received sevoflurane 8% (inspired concentration) in 100% oxygen for induction and 2-3% in oxygen for maintenance of anesthesia. No sedative premedication was given. Analgesia was provided with caudal block using 0.25% bupivacaine. Speed of emergence from anesthesia was assessed by time to extubation, time to eye opening, and time to crying / stating name. A modified aldrete score system was used to evaluate recovery while Pain/Discomfort scale to assess the quality of emergence from anesthesia. These were recorded by a separate consultant anesthetist blind to the anesthetic technique. Results: Emergence from anesthesia occurred significantly quicker in the S group as compared to P group, as evident by times in minutes (mean +- SD) to extubation: 8.3+-6.9 versus 4.7+-2.6(p=0.017), eye opening: 9.1 +- 5.3 vs. 5.6 +- 2.6 (p=0.043) and crying / state name: 14.7 +-7.2 vs.11.3 +- 4.6(p=0.039). Similarly, more patients in the S group scored maximum points in the modified aldrete score at 10 min: 17 (42.5%) vs.7 (17.5%) (p=0.015), 20 min: 32 (80%) vs.23 (57.5%) (p=0.030). Although, number of patients in the S group compared to P group scoring max points in Pain-discomfort scale at 10 min: 8 (20%) vs4 (10%), p=0.210; 20 min: 6 (15%) vs.2 (5%), p=0.136 and 30 min: 4 (10%) vs. 0, p=0.130 were more, these results were not

  10. Anesthetic drug midazolam inhibits cardiac human ether-à-go-go-related gene channels: mode of action

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    Vonderlin N

    2015-02-01

    Full Text Available Nadine Vonderlin,1 Fathima Fischer,1 Edgar Zitron,1,2 Claudia Seyler,1 Daniel Scherer,1 Dierk Thomas,1,2 Hugo A Katus,1,2 Eberhard P Scholz1 1Department of Internal Medicine III, University Hospital Heidelberg, 2German Centre for Cardiovascular Research, Partner Site Heidelberg/Mannheim, Heidelberg, Germany Abstract: Midazolam is a short-acting benzodiazepine that is in wide clinical use as an anxiolytic, sedative, hypnotic, and anticonvulsant. Midazolam has been shown to inhibit ion channels, including calcium and potassium channels. So far, the effects of midazolam on cardiac human ether-à-go-go-related gene (hERG channels have not been analyzed. The inhibitory effects of midazolam on heterologously expressed hERG channels were analyzed in Xenopus oocytes using the double-electrode voltage clamp technique. We found that midazolam inhibits hERG channels in a concentration-dependent manner, yielding an IC50 of 170 µM in Xenopus oocytes. When analyzed in a HEK 293 cell line using the patch-clamp technique, the IC50 was 13.6 µM. Midazolam resulted in a small negative shift of the activation curve of hERG channels. However, steady-state inactivation was not significantly affected. We further show that inhibition is state-dependent, occurring within the open and inactivated but not in the closed state. There was no frequency dependence of block. Using the hERG pore mutants F656A and Y652A we provide evidence that midazolam uses a classical binding site within the channel pore. Analyzing the subacute effects of midazolam on hERG channel trafficking, we further found that midazolam does not affect channel surface expression. Taken together, we show that the anesthetic midazolam is a low-affinity inhibitor of cardiac hERG channels without additional effects on channel surface expression. These data add to the current understanding of the pharmacological profile of the anesthetic midazolam. Keywords: midazolam, anesthetics, human ether

  11. 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.

  12. 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

  13. Inhalation anesthetic-induced neuronal damage in the developing rhesus monkey.

    Science.gov (United States)

    Zou, Xiaoju; Liu, Fang; Zhang, Xuan; Patterson, Tucker A; Callicott, Ralph; Liu, Shuliang; Hanig, Joseph P; Paule, Merle G; Slikker, William; Wang, Cheng

    2011-01-01

    The combination of nitrous oxide gas (N(2)O) and isoflurane (ISO) vapor is commonly used in pediatric surgical procedures for human infants and children to produce unconsciousness and analgesia. Because of obvious limitations it is difficult to thoroughly explore the effects of pediatric anesthetic agents on neurons in human infants or children. Due to the complexity of the primate brain, the monkey is often the animal model of choice for developmental neurotoxicology experiments, and it is in the rhesus monkey that the phenomenon of interest (anesthetic-induced neuronal cell death in the brain) has been previously reported. Recent reports indicate that exposure of the developing brain to general anesthetics that block N-methyl-D-aspartate (NMDA)-type glutamate receptors or potentiate gamma-aminobutyric acid (GABA) receptors can trigger widespread apoptotic cell death in rodents. The present study was performed to determine whether prolonged exposure of developing nonhuman primates to a clinically relevant combination of nitrous oxide and isoflurane produces neuronal damage. Postnatal day (PND) 5-6 rhesus monkeys were exposed to N(2)O (70%) or ISO (1.0%) alone, or N(2)O plus ISO for 8 h. Inhalation of the combination of 70% N(2)O+1% ISO produces a surgical plane of anesthesia. Six hours after completion of anesthetic administration the monkeys were examined for neurotoxic effects. No significant neurotoxic effects were observed for the monkeys exposed to N(2)O or ISO alone. However, neuronal damage was apparent when N(2)O was combined with ISO as indicated by increased numbers of caspase-3-, Silver staining- and Fluoro-Jade C-positive cells in the frontal cortex, temporal gyrus and hippocampus. Electron micrographs indicated typical swelling of the cytoplasm and nuclear condensation in the frontal cortex. These data suggest that prolonged exposure to inhaled anesthetics (a combination of N(2)O and ISO) in the developing rhesus monkey results in neuronal damage, and

  14. Volatile pheromone signalling in Drosophila.

    Science.gov (United States)

    Smith, Dean P

    2012-03-01

    Once captured by the antenna, 11-cis vaccenyl acetate (cVA) binds to an extracellular binding protein called LUSH that undergoes a conformational shift upon cVA binding. The stable LUSH-cVA complex is the activating ligand for pheromone receptors present on the dendrites of the aT1 neurones, comprising the only neurones that detect cVA pheromone. This mechanism explains the single molecule sensitivity of insect pheromone detection systems. The receptor that recognizes activated LUSH consists of a complex of several proteins, including Or67d, a member of the tuning odourant receptor family, Orco, a co-receptor ion channel, and SNMP, a CD36 homologue that may be an inhibitory subunit. In addition, genetic screens and reconstitution experiments reveal additional factors that are important for pheromone detection. Identification and functional dissection of these factors in Drosophila melanogaster Meigen should permit the identification of homologous factors in pathogenic insects and agricultural pests, which, in turn, may be viable candidates for novel classes of compounds to control populations of target insect species without impacting beneficial species. PMID:24347807

  15. 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.

  16. 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.

  17. Flower volatiles, crop varieties and bee responses.

    Science.gov (United States)

    Klatt, Björn K; Burmeister, Carina; Westphal, Catrin; Tscharntke, Teja; von Fragstein, Maximilian; von Fragstein, Maximillian

    2013-01-01

    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. PMID:23977347

  18. 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

  19. 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...

  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. 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.

  2. Modelling of volatility in monetary transmission mechanism

    International Nuclear Information System (INIS)

    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

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. Volatile Organic Compunds (Environmental Health Student Portal)

    Science.gov (United States)

    ... Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Videos Games Experiments For Teachers Home Chemicals Volatile Organic Compounds ... central nervous system (the system that includes the brain and spinal chord) Some VOCs can also cause ...

  9. 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...

  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. Volatility spillovers in EMU sovereign bond markets

    OpenAIRE

    Fernández-Rodríguez, Fernandez; Gómez-Puig, Marta; Sosvilla Rivero, Simón Javier

    2015-01-01

    We analyse volatility spillovers in EMU sovereign bond markets. First, we examine the unconditional patterns during the full sample (April 1999-January 2014) using a measure recently proposed by Diebold and Yılmaz (2012). Second, we make use of a dynamic analysis to evaluate net directional volatility spillovers for each of the eleven countries under study, and to determine whether core and peripheral markets present differences. Finally, we apply a panel analysis to empirically investigate t...

  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. Neonatal withdrawal from maternal volatile substance abuse.

    OpenAIRE

    Tenenbein, M; Casiro, O. G.; Seshia, M. M.; Debooy, V. D.

    1996-01-01

    AIM: To determine whether neonates born to mothers who are volatile substance abusers are at risk for an abstinence syndrome. METHODS: A consecutive sample of infants born to volatile substance abusing mothers was studied over four years, in a university affiliated medical centre with a variable mix of primary, secondary, and tertiary care patients. Infants were clinically scored with the Finnegan Neonatal Abstinence Scoring System. Those who fulfilled a priori scoring criteria were treated w...

  14. 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.

  15. 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...

  16. Exchange rate volatility and euro area imports

    OpenAIRE

    Anderton, Robert; Skudelny, Frauke

    2001-01-01

    This paper estimates an import demand function for the euro area vis--vis its main extra-area trading partners which takes into account the possible impact of both intra- and extra-euro area exchange rate uncertainty. We derive a theoretical model which captures various mechanisms by which exchange rate volatility may influence the demand for extra-euro area imports. If importers are risk averse, the model predicts not only a negative effect of exchange rate volatility, but also substitution ...

  17. 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...

  18. Flower Volatiles, Crop Varieties and Bee Responses

    OpenAIRE

    Klatt, Björn K.; Burmeister, Carina; Westphal, Catrin; Tscharntke, Teja; von Fragstein, Maximillian

    2013-01-01

    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 ser...

  19. Essays on Economic Volatility and Financial Frictions

    OpenAIRE

    Zhao, Hongyan

    2012-01-01

    This dissertation consists of three essays in macroeconomics. The first one essay discusses the reasons of Chinese huge foreign reserves holdings. It contributes to the literature of sudden stops, precautionary saving and foreign assets holdings. In the second essay, I study the price volatility of commodities and manufactured goods. I measure the price volatility of each individual goods but not on the aggregated level and therefore the results complete the related study. The third essay exp...

  20. 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...

  1. 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...

  2. A Security Price Volatile Trading Conditioning Model

    OpenAIRE

    Leilei Shi; Yiwen Wang; Ding Chen; Liyan Han; Yan Piao; Chengling Gou

    2010-01-01

    We develop a theoretical trading conditioning model subject to price volatility and return information in terms of market psychological behavior, based on analytical transaction volume-price probability wave distributions in which we use transaction volume probability to describe price volatility uncertainty and intensity. Applying the model to high frequent data test in China stock market, we have main findings as follows: 1) there is, in general, significant positive correlation between the...

  3. Inflation Premium and Oil Price Volatility

    OpenAIRE

    Paul Castillo; Carlos Montoro

    2006-01-01

    In this paper we establish a link between the volatility of oil price shocks and a positive expected value of inflation in equilibrium (inflation premium). In doing so, we implement the perturbation method to solve up to second order a benchmark New Keynesian model with oil price shocks. In contrast with log linear approximations, the second order solution relaxes certainty equivalence providing a link between the volatility of shocks and inflation premium. First, we obtain analytical results...

  4. Inflation premium and oil price volatility

    OpenAIRE

    Castillo, Paul; Montoro, Carlos; Tuesta, Vicente

    2007-01-01

    In this paper we establish a link between the volatility of oil price shocks and a positive expected value of inflation in equilibrium (inflation premium). In doing so, we implement the perturbation method to solve up to second order a benchmark New Keynesian model with oil price shocks. In contrast with log linear approximations, the second order solution relaxes certainty equivalence providing a link between the volatility of shocks and inflation premium. First, we obtain analytical results...

  5. 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...

  6. 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...

  7. 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...

  8. Option Pricing, Historical Volatility and Tail Risks

    OpenAIRE

    Vazquez, Samuel E.

    2014-01-01

    We revisit the problem of pricing options with historical volatility estimators. We do this in the context of a generalized GARCH model with multiple time scales and asymmetry. It is argued that the reason for the observed volatility risk premium is tail risk aversion. We parametrize such risk aversion in terms of three coefficients: convexity, skew and kurtosis risk premium. We propose that option prices under the real-world measure are not martingales, but that their drift is governed by su...

  9. Arbitrage-free SVI volatility surfaces

    OpenAIRE

    Jim Gatheral; Antoine Jacquier

    2012-01-01

    In this article, we show how to calibrate the widely-used SVI parameterization of the implied volatility surface in such a way as to guarantee the absence of static arbitrage. In particular, we exhibit a large class of arbitrage-free SVI volatility surfaces with a simple closed-form representation. We demonstrate the high quality of typical SVI fits with a numerical example using recent SPX options data.

  10. 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.

  11. Enhanced tonic inhibition influences the hypnotic and amnestic actions of the intravenous anesthetics etomidate and propofol.

    Science.gov (United States)

    Kretschmannova, Karla; Hines, Rochelle M; Revilla-Sanchez, Raquel; Terunuma, Miho; Tretter, Verena; Jurd, Rachel; Kelz, Max B; Moss, Stephen J; Davies, Paul A

    2013-04-24

    Intravenous anesthetics exert a component of their actions via potentiating inhibitory neurotransmission mediated by γ-aminobutyric type-A receptors (GABAARs). Phasic and tonic inhibition is mediated by distinct populations of GABAARs, with the majority of phasic inhibition by subtypes composed of α1-3βγ2 subunits, whereas tonic inhibition is dependent on subtypes assembled from α4-6βδ subunits. To explore the contribution that these distinct forms of inhibition play in mediating intravenous anesthesia, we have used mice in which tyrosine residues 365/7 within the γ2 subunit are mutated to phenyalanines (Y365/7F). Here we demonstrate that this mutation leads to increased accumulation of the α4 subunit containing GABAARs in the thalamus and dentate gyrus of female Y365/7F but not male Y365/7F mice. Y365/7F mice exhibited a gender-specific enhancement of tonic inhibition in the dentate gyrus that was more sensitive to modulation by the anesthetic etomidate, together with a deficit in long-term potentiation. Consistent with this, female Y365/7F, but not male Y365/7F, mice exhibited a dramatic increase in the duration of etomidate- and propofol-mediated hypnosis. Moreover, the amnestic actions of etomidate were selectively potentiated in female Y365/7F mice. Collectively, these observations suggest that potentiation of tonic inhibition mediated by α4 subunit containing GABAARs contributes to the hypnotic and amnestic actions of the intravenous anesthetics, etomidate and propofol. PMID:23616535

  12. Influence of anesthetic regimens on the perioperative catecholamine response associated with onychectomy in cats.

    Science.gov (United States)

    Lin, H C; Benson, G J; Thurmon, J C; Tranquilli, W J; Olson, W A; Bevill, R F

    1993-10-01

    Plasma catecholamine concentrations in response to onychectomy were examined in 27 cats receiving different anesthetic regimens. Each cat was anesthetized with a dissociative-tranquilizer combination, and onychectomy was performed on 1 forefoot. One week later, each cat was anesthetized with the same dissociative-tranquilizer combination plus either butorphanol or oxymorphone, and onychectomy was performed on the other forefoot. Four treatment groups were studied: tiletamine-zolazepam and tiletamine-zolazepam-butorphanol combinations were administered to group-1 cats, ketamine-acepromazine and ketamine-acepromazine-butorphanol combinations were administered to group-2 cats, tiletamine-zolazepam and tiletamine-zolazepam-oxymorphone combinations were administered to group-3 cats, and ketamine-acepromazine and ketamine-acepromazine-oxymorphone combinations were administered to group-4 cats. All drug combinations were administered IM. Central venous blood samples were drawn for catecholamine analysis after injection of drug(s), after onychectomy, and 1, 2, and 4 hours after injection. Tiletamine-zolazepam alone or tiletamine-zolazepam-butorphanol prevented epinephrine release for 2 hours after injection of drug(s). Norepinephrine concentration increased significantly (P onychectomy for tiletamine-zolazepam-butorphanol and at 4 hours for tiletamine-zolazepam and tiletamine-zolazepam-butorphanol. After onychectomy, there was no difference in epinephrine values between tiletamine-zolazepam and tiletamine-zolazepam-oxymorphone. Ketamine-acepromazine prevented increases in norepinephrine and epinephrine concentrations for up to 2 hours after surgery. Addition of butorphanol to ketamine-acepromazine decreased norepinephrine values immediately after onychectomy. Addition of oxymorphone to ketamine-acepromazine resulted in lower epinephrine values 4 hours after surgery. PMID:8250399

  13. 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

  14. 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.

  15. 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

  16. 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...

  17. Enhanced tonic inhibition influences the hypnotic and amnestic actions of the intravenous anesthetics etomidate and propofol

    OpenAIRE

    Kretschmannova, Karla; Hines, Rochelle M; Revilla-Sanchez, Raquel; Terunuma, Miho; Tretter, Verena; Jurd, Rachel; Kelz, Max B.; Moss, Stephen J.; Davies, Paul A.

    2013-01-01

    Intravenous anesthetics exert a component of their actions via potentiating inhibitory neurotransmission mediated by γ-aminobutyric type-A receptors (GABAARs). Phasic and tonic inhibition are mediated by distinct populations of GABAARs, with the majority of phasic inhibition by subtypes composed of α1-3βγ2 subunits, while tonic inhibition is dependent on subtypes assembled from α4-6βδ subunits. To explore the contribution that these distinct forms of inhibition play in mediating intravenous a...

  18. Anesthetic potency and cardiopulmonary effects of sevoflurane in goats: comparison with isoflurane and halothane.

    OpenAIRE

    Hikasa, Y.; Okuyama, K; Kakuta, T; Takase, K.; Ogasawara, S

    1998-01-01

    The anesthetic potency and cardiopulmonary effects of sevoflurane were compared with those of isoflurane and halothane in goats. The (mean +/- SD) minimal alveolar concentration (MAC) was 0.96 +/- 0.12% for halothane, 1.29 +/- 0.11% for isoflurane, and 2.33 +/- 0.15% for sevoflurane. Cardiopulmonary effects of sevoflurane, halothane and isoflurane were examined at end-tidal concentrations equivalent to 1, 1.5 and 2 MAC during either spontaneous or controlled ventilation (SV or CV). During SV,...

  19. Inhibition of gastric emptying and intestinal transit in anesthetized rats by a Tityus serrulatus scorpion toxin

    OpenAIRE

    L.E.A. Troncon; A.A. Santos; V.L. Garbacio; M. Secaf; A.V. Verceze; Cunha-Melo, J R

    2000-01-01

    The effects of a fraction (T1) of Tityus serrulatus scorpion venom prepared by gel filtration on gastric emptying and small intestinal transit were investigated in male Wistar rats. Fasted animals were anesthetized with urethane, submitted to tracheal intubation and right jugular vein cannulation. Scorpion toxin (250 µg/kg) or saline was injected iv and 1 h later a bolus of saline (1.0 ml/100 g) labeled with 99m technetium-phytate (10 MBq) was administered by gavage. After 15 min, animals wer...

  20. Anesthetic management for separation of thoracopagus twins with complex congenital heart disease: a case report.

    Science.gov (United States)

    Seo, Misook; Chung, In-Sun; Karm, Myong-Hwan; Oh, Ji Mi; Shin, Won-Jung

    2015-06-01

    Although thoracopagus twins joined at the upper chest are the most common type of conjoined twins, the separation surgery in these cases has a higher mortality rate. Here, we describe an anesthetic management approach for the separation of thoracopagus conjoined twins sharing parts of a congenitally defective heart and liver. We emphasize the importance of vigilant intraoperative hemodynamic monitoring for early detection of unexpected events. Specifically, real-time continuous monitoring of cerebral oximetry using near-infrared spectroscopy allowed us to promptly detect cardiac arrest and hemodynamic deterioration. PMID:26045935

  1. 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

  2. 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)

  3. 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

  4. 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

  5. Anesthetic management in a pediatric patient with Noonan syndrome, hypopituitarism and hypothyroidism: A case report

    Directory of Open Access Journals (Sweden)

    Abdulkadir Yektaş

    2013-06-01

    Full Text Available Noonan syndrome is a genetically transmitted autosomaldominant disorder characterized by various anatomicanomalies and pathophysiologic derangements. Associatedanomalies include hyperthelorism, ptosis, micrognathia,downward sloping palpebral fissures, low-set ears,abnormal helix of ear, deeply grooved philtrum, short and/or webbed neck, low hairline and cervical vertebral anomalies.Patients with Noonan syndrome are known to presentwith challenging airways. Tracheal intubation can bedifficult because of airway and cervical vertebral anomaliesand bag mask ventilation may be difficult because ofasymmetrical face. We present a case of anesthetic managementfor Noonan syndrome. J Clin Exp Invest 2013;4 (2: 238-241Key words: Anesthesia, general, noonan syndrome, airwaymanagement

  6. A tunnel shape defect on maxillary bone after accidental injection of formocresol instead of anesthetic solution.

    Science.gov (United States)

    Ege, Bilal; Demirkol, Mehmet; Mustafa, Rawand; Aras, Mutan Hamdi

    2014-09-01

    Accidental injection or leakages of various chemical disinfectants used during root canal preparation into adjacent tissues have been shown to have deleterious effects on surrounding tissue. Formocresol (FC) is an effective intracanal disinfectant used in endodontic procedures. However, it is known to have harmful effects into adjacent tissues. The aim of this article is to present an unusual case in which a 28-year-old male patient developed gingival and bone necrosis after the accidental injection of FC instead of local anesthetic solution for tooth extraction and to review cases in the literature where complications have occurred due to the use of FC. PMID:25148635

  7. 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.

  8. Intraoperative anesthetic management of patients undergoing glomus tumor resection using a low-dose isoflurane-fentanyl technique.

    Science.gov (United States)

    Jellish, W S; Murdoch, J; Leonetti, J

    1994-01-01

    Glomus jugulare and vagale tumors present unique problems to both anesthesiologists and surgeons. The anesthetic plant must be tailored to each patient and provide hemodynamic stability, a consistent intraoperative environment, and rapid awakening after prolonged administration. In this report, we describe our anesthetic method used for paraganglioma resection, which utilizes a combination technique of low-dose isoflurane with a narcotic infusion initiated after bolus administration. Results from the last three patients anesthetized by this "balanced" technique were compared to a similar patient who received isoflurane anesthesia exclusively for a major portion of the surgical procedure. The patients receiving the balanced anesthesia required no hemodynamic support during the procedure and were awakened within 15 to 25 minutes of surgical completion. The patient receiving high-dose isoflurane, however, had a prolonged anesthetic wake-up time and did not follow verbal commands for approximately 12 hours after surgical completion. This patient also required hemodynamic support with a phenylephrine infusion during tumor resection. The balanced technique seems to be superior to a straight inhalational technique. Neurological assessment and intubation times after prolonged surgery were reduced with superb hemodynamic stability throughout. This anesthetic method produces a stable intraoperative environment and provides deep surgical anesthesia during periods when muscle relaxants cannot be utilized. PMID:17170932

  9. 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...

  10. 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

  11. 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.

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

    International Nuclear Information System (INIS)

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

  13. 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......, 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...... evaluated. PATIENTS AND METHODS: 32 patients undergoing total knee replacement with high-volume (170 mL) 0.2% ropivacaine infiltration analgesia were randomized to receive injection of 20 mL ropivacaine (0.2%) intraarticularly plus 30 mL saline in the extraarticular wound space 24 hours postoperatively or...

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

    Science.gov (United States)

    Priyanka, Mandapathi; Pradeep, Koppolu; Reddy Pathakota, Krishnajaneya

    2016-01-01

    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. PMID:27034662

  15. A Quantile Regression Approach to Estimating the Distribution of Anesthetic Procedure Time during Induction.

    Directory of Open Access Journals (Sweden)

    Hsin-Lun Wu

    Full Text Available Although procedure time analyses are important for operating room management, it is not easy to extract useful information from clinical procedure time data. A novel approach was proposed to analyze procedure time during anesthetic induction. A two-step regression analysis was performed to explore influential factors of anesthetic induction time (AIT. Linear regression with stepwise model selection was used to select significant correlates of AIT and then quantile regression was employed to illustrate the dynamic relationships between AIT and selected variables at distinct quantiles. A total of 1,060 patients were analyzed. The first and second-year residents (R1-R2 required longer AIT than the third and fourth-year residents and attending anesthesiologists (p = 0.006. Factors prolonging AIT included American Society of Anesthesiologist physical status ≧ III, arterial, central venous and epidural catheterization, and use of bronchoscopy. Presence of surgeon before induction would decrease AIT (p < 0.001. Types of surgery also had significant influence on AIT. Quantile regression satisfactorily estimated extra time needed to complete induction for each influential factor at distinct quantiles. Our analysis on AIT demonstrated the benefit of quantile regression analysis to provide more comprehensive view of the relationships between procedure time and related factors. This novel two-step regression approach has potential applications to procedure time analysis in operating room management.

  16. 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.

  17. Recovery from desflurane anesthesia in horses with and without post-anesthetic xylazine.

    Science.gov (United States)

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

    2014-04-01

    The objective of this study was to compare recovery from desflurane anesthesia in horses with or without post-anesthetic xylazine. Six adult horses were anesthetized on 2 occasions, 14 d apart using a prospective, randomized crossover design. Horses were sedated with xylazine, induced to lateral recumbency with ketamine and diazepam, and anesthesia was maintained with desflurane. One of 2 treatments was administered intravenously at the end of anesthesia: xylazine [0.2 mg/kg body weight (BW)] or an equivalent volume of saline. Recovery parameters were recorded and assessed by 2 blinded observers. A Wilcoxon signed-rank test was used to analyze recovery data. Heart rate, arterial blood pressures, and arterial blood gas data were analyzed using 2-way analysis of variance (ANOVA) for repeated measures. Values of P stand, and standing. Number of attempts to stand and quality of recovery scores were not different between groups. Administering xylazine after desflurane anesthesia resulted in longer recovery times. Recovery scores were not significantly different between groups. PMID:24688171

  18. 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.

  19. Antagonism of morphine-induced central respiratory depression by donepezil in the anesthetized rabbit

    Directory of Open Access Journals (Sweden)

    MIKI TSUJITA

    2007-01-01

    Full Text Available Morphine is often used in cancer pain and postoperative analgesic management but induces respiratory depression. Therefore, there is an ongoing search for drug candidates that can antagonize morphine-induced respiratory depression but have no effect on morphine-induced analgesia. Acetylcholine is an excitatory neurotransmitter in central respiratory control and physostigmine antagonizes morphine-induced respiratory depression. However, physostigmine has not been applied in clinical practice because it has a short action time, among other characteristics. We therefore asked whether donepezil (a long-acting acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease can antagonize morphine-induced respiratory depression. Using the anesthetized rabbit as our model, we measured phrenic nerve discharge as an index of respiratory rate and amplitude. We compared control indices with discharges after the injection of morphine and after the injection of donepezil. Morphine-induced depression of respiratory rate and respiratory amplitude was partly antagonized by donepezil without any effect on blood pressure and end-tidal C0(2. In the other experiment, apneic threshold PaC0(2 was also compared. Morphine increased the phrenic nerve apnea threshold but this was antagonized by donepezil. These findings indicate that systemically administered donepezil partially restores morphine-induced respiratory depression and morphine-deteriorated phrenic nerve apnea threshold in the anesthetized rabbit

  20. 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.