Academic literature on the topic 'Alpha attenuation test'
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Journal articles on the topic "Alpha attenuation test"
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Lakocevic, M., N. Rajsic, Z. Sundric, P. Simonovic, and J. Marinkovic. "The alpha attenuation test: Assessment of alpha blockade efficiency in narcolepsy." Journal of the Neurological Sciences 333 (October 2013): e621. http://dx.doi.org/10.1016/j.jns.2013.07.2161.
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Stampi, Claudio, Polly Stone, and Akihiro Michimori. "A new quantitative method for assessing sleepiness: The alpha attenuation test." Work & Stress 9, no. 2-3 (April 1995): 368–76. http://dx.doi.org/10.1080/02678379508256574.
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Alloway, Christi E. D., Robert D. Ogilvie, and Colin M. Shapiro. "The Alpha Attenuation Test: Assessing Excessive Daytime Sleepiness in Narcolepsy-Cataplexy." Sleep 20, no. 4 (April 1997): 258–66. http://dx.doi.org/10.1093/sleep/20.4.258.
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Hori, M., M. Kitakaze, J. Tamai, Y. Koretsune, K. Iwai, K. Iwakura, T. Kagiya, A. Kitabatake, M. Inoue, and T. Kamada. "Alpha 2-adrenoceptor activity exerts dual control of coronary blood flow in canine coronary artery." American Journal of Physiology-Heart and Circulatory Physiology 255, no. 2 (August 1, 1988): H250—H260. http://dx.doi.org/10.1152/ajpheart.1988.255.2.h250.
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To test the hypothesis that alpha 2-adrenoceptor activity exerts a dual control of coronary blood flow, i.e., vasoconstriction and augmentation of the vasodilatory effect of adenosine, four doses of adenosine were infused into left anterior descending coronary artery before and during alpha 2-adrenoceptor stimulation or attenuation in anesthetized open-chest dogs. During a moderate alpha 2-adrenoceptor attenuation (yohimbine or rauwolscine, ic), which did not alter coronary blood flow (CBF) at the base-line condition, the hyperemic response of CBF to infused adenosine was markedly reduced, whereas during the potent attenuation both base-line CBF and adenosine-induced hyperemic CBF were significantly increased. Inversely, the moderate alpha 2-stimulation (0.03 microgram.kg-1.min-1 norepinephrine with prazosin, ic, or 0.04 microgram.kg-1.min-1 clonidine ic, under propranolol pretreatment) augmented the adenosine-induced coronary vasodilation, but the potent alpha 2-stimulation (0.3 microgram.kg-1.min-1 norepinephrine with prazosin ic, or 0.3 microgram.kg-1.min-1 clonidine ic) reduced both base-line CBF hyperemic CBF. In contrast, alpha 2-adrenoceptor activity did not affect papaverine-induced coronary vasodilation. Moreover, the reactive hyperemic flow after a brief coronary occlusion was reduced significantly during the moderate alpha 2-adrenergic attenuation, but it was augmented during the potent one. These results indicate that the moderate activation of the alpha 2-adrenoceptor augments the hyperemic response of CBF to both exogenous and endogenous adenosine, whereas the potent alpha 2-activation may mask this vasodilatory effect through the coronary vasoconstrictive effect.
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Baker, D. G., H. F. Don, and J. K. Brown. "Alpha-adrenergic and muscarinic cholinergic inhibition of ACh release in guinea pig trachea: role of neuronal K+ channels." American Journal of Physiology-Lung Cellular and Molecular Physiology 266, no. 6 (June 1, 1994): L698—L704. http://dx.doi.org/10.1152/ajplung.1994.266.6.l698.
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Our goals were to establish that an alpha 2-adrenergic agonist (clonidine) inhibits ACh release from airway nerve endings and to test effects of iberiotoxin (IBTX), an inhibitor of fast-conductance, Ca(2+)-activated K+ channels on alpha 2-adrenergic and muscarinic attenuation of ACh release. Guinea pig tracheas were mounted between electrodes in buffer containing indomethacin and neostigmine, and high-performance liquid chromatography with electrochemical detection was used to measure ACh release during electrical field stimulation. Clonidine inhibited ACh release in a concentration-dependent fashion [maximum reduction: 48 +/- 3%; 50% inhibitory constant (IC50): 0.1 microM], and idazoxan, alpha 2-adrenergic antagonist, reversed the effect. However, IBTX failed to alter clonidine-induced attenuation of ACh release. In contrast, IBTX did cause an increase in tracheal tension. In addition, IBTX failed to reverse any of the potent autoinhibitory effects of endogenous ACh. Our results confirm the presence of inhibitory alpha 2-adrenergic receptors. However, activation of IBTX-sensitive K+ channels does not appear necessary for either alpha 2-adrenergic or muscarinic cholinergic inhibition of ACh release.
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Ueno, Hiroshi, Atsumi Shimada, Shunsuke Suemitsu, Shinji Murakami, Naoya Kitamura, Kenta Wani, Yosuke Matsumoto, Motoi Okamoto, and Takeshi Ishihara. "Attenuation Effects of Alpha-Pinene Inhalation on Mice with Dizocilpine-Induced Psychiatric-Like Behaviour." Evidence-Based Complementary and Alternative Medicine 2019 (July 30, 2019): 1–12. http://dx.doi.org/10.1155/2019/2745453.
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α-Pinene, an organic terpene compound found in coniferous trees, is used as a safe food additive and is contained in many essential oils. Moreover, some studies have shown that α-pinene suppresses neuronal activity. In this study, we investigated whether inhalation of α-pinene suppresses dizocilpine (MK-801-) induced schizophrenia-like behavioural abnormalities in mice. Mice inhaled α-pinene 1 h before the first MK-801 injection. Thirty minutes after MK-801 injection, the open field, spontaneous locomotor activity, elevated plus maze, Y-maze, tail suspension, hot plate, and grip strength tests were conducted as behavioural experiments. Inhalation of α-pinene suppressed the activity of mice in the spontaneous locomotor activity test and although it did not suppress the MK-801-induced increased locomotor activity in the open field test, it remarkably decreased the time that the mice remained in the central area. Inhalation of α-pinene suppressed the MK-801-induced increased total distance travelled in the Y-maze test, whereas it did not alter the MK-801-induced reduced threshold of antinociception in the hot plate test. In the tail suspension and grip strength tests, there was no effect on mouse behaviour by administration of MK-801 and inhalation of α-pinene. These results suggest that α-pinene acts to reduce MK-801-induced behavioural abnormalities resembling those seen in neuropsychiatric disorders. Therefore, both medicinal plants and essential oils containing α-pinene may have potential for therapeutic treatment of schizophrenia.
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Sundric, Zvonko, Nenad Rajsic, Milan Lakocevic, and Emilija Nikolic-Djoric. "Comparative analysis of electroencephalographic tests of alpha activity attenuation in evaluation of involuntary falling asleep in healthy adults." Srpski arhiv za celokupno lekarstvo 138, no. 3-4 (2010): 130–35. http://dx.doi.org/10.2298/sarh1004130s.
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Introduction. Decrease of daily alertness is a common cause of accidents in the work place, especially traffic accidents. Therefore, an increasing interest exists to determine reliable indicators of a tendency to fall asleep involuntarily. Objective. To determine an optimal electroencephalographic (EEG) indicator of an involuntary tendency to fall asleep, we performed a study on neurologically healthy subjects, after one night of sleep deprivation. Total sleep deprivation was aimed at increasing daily sleepiness in healthy subjects, providing us with an opportunity to test different methods of evaluation. Methods. We applied a visual analogue scale for sleepiness (VASS), EEG registration with the specific test of alpha activity attenuation (TAA) in 87 healthy subjects. The test was performed in a standard way (sTAA) as well as in accordance with new modifications related to changes of EEG filter width in the range from 5 to 32 Hz (mTAA). Results. After sleep deprivation, we observed involuntary falling asleep in 54 subjects. The comparison of VASS results showed no differences, contrary to a more objective TAA. Between two variants of TAA, the modified test provided us with a better prediction for subjects who would fall asleep involuntarily. Conclusion. The application of a more objective EEG test in evaluation of daily alertness represents the optimal method of testing. Modified TAA attracts special attention, offering a simple solution for reliable testing of decreased daily alertness in medical services related to professional aircraft personnel.
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Nikulin, V. V., E. G. Jönsson, G. Curio, and T. Brismar. "Attenuation of long-range temporal correlations in neuronal oscillations in patients with schizophrenia." European Psychiatry 26, S2 (March 2011): 1461. http://dx.doi.org/10.1016/s0924-9338(11)73166-2.
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IntroductionAlthough schizophrenia was previously associated with affected spatial neuronal synchronization, surprisingly little is known about the temporal dynamics of neuronal oscillations in schizophrenia. However, since coordination of neuronal process in time represents an essential aspect of practically all cognitive processes, it might be strongly affected in schizophrenia patients.ObjectivesTo test the hypothesis of abnormal temporal neuronal dynamics in patients with schizophrenia.AimsWe aimed at quantification and comparisons of long-range temporal correlations (LRTCs) in patients and normal subjects.MethodsWe measured 21 patients with schizophrenia (n = 18) or schizoaffective disorder (n = 3) and 28 age and gender matched controls. Ongoing neuronal oscillations were recorded with multi-channel EEG at rest condition. EEG was analyzed with spectral analysis and with the detrended fluctuation analysis allowing quantification of LRTCs.ResultsThe amplitude of neuronal oscillations in alpha and beta frequency ranges did not differ between the patients and controls. However, LRTCs were strongly attenuated in schizophrenia patients: in centro-parietal areas and fronto-central areas for alpha and beta oscillations, respectively. In addition we observed a negative correlation between the strength of the negative symptoms and LRTCs.ConclusionsSmall values of LRTCs and their correlation with the negative symptoms in schizophrenia patients demonstrate that the temporal dynamics of neuronal oscillations are essential for normal brain functioning. Attenuated LRTCs might indicate a more intermittent neuronal dynamics possibly allowing for more random associations between neuronal activations, which in turn might relate to the occurrence of positive symptoms in schizophrenia.
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Sayeli, Vijaykumar, Jagan Nadipelly, Parimala Kadhirvelu, Binoy Varghese Cheriyan, Jaikumar Shanmugasundaram, and Viswanathan Subramanian. "Effect of flavonol and its dimethoxy derivatives on paclitaxel-induced peripheral neuropathy in mice." Journal of Basic and Clinical Physiology and Pharmacology 29, no. 5 (September 25, 2018): 525–35. http://dx.doi.org/10.1515/jbcpp-2016-0127.
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AbstractBackground:Peripheral neuropathy is the dose limiting side effect of many anticancer drugs. Flavonoids exhibit good antinociceptive effect in animal models. Their efficacy against different types of nociception has been documented. The present study investigated the effect of flavonol (3-hydroxy flavone), 3′,4′-dimethoxy flavonol, 6,3′-dimethoxy flavonol, 7,2′-dimethoxy flavonol and 7,3′-dimethoxy flavonol against paclitaxel-induced peripheral neuropathy in mice.Methods:A single dose of paclitaxel (10 mg/kg, i.p.) was administered to induce peripheral neuropathy in mice and the manifestations of peripheral neuropathy such as tactile allodynia, cold allodynia and thermal hyperalgesia were assessed 24 h later by employing Von Frey hair aesthesiometer test, acetone bubble test and hot water tail immersion test, respectively. The test compounds were prepared as a suspension in 0.5% carboxymethyl cellulose and were administered s.c. in various doses (25, 50, 100 and 200 mg/kg). The above behavioral responses were assessed prior to and 30 min after drug treatment. In addition, the effect of test compounds on proinflammatory cytokines like tumor necrosis factor-alpha (TNF-α), interleukin-1-beta (IL-1β) and free radicals was investigated by using suitablein vitroassays.Results:A dose-dependent attenuation of tactile allodynia, cold allodynia and thermal hyperalgesia was evidenced in mice treated with flavonol derivatives. The test compounds inhibited TNF-α, IL-1β and free radicals in a concentration-dependent manner.Conclusions:These results revealed that flavonol and its dimethoxy derivatives ameliorated the manifestations of paclitaxel-induced peripheral neuropathy in mice. The inhibition of proinflammatory cytokines and free radicals could contribute to this beneficial effect.
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Murphy, Jenny A., Rebecca J. Duerst, Tracy J. Smith, and Lynda A. Morrison. "Herpes Simplex Virus Type 2 Virion Host Shutoff Protein Regulates Alpha/Beta Interferon but Not Adaptive Immune Responses during Primary Infection In Vivo." Journal of Virology 77, no. 17 (September 1, 2003): 9337–45. http://dx.doi.org/10.1128/jvi.77.17.9337-9345.2003.
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ABSTRACT The herpes simplex virus (HSV) virion host shutoff (vhs) protein, the product of the UL41 (vhs) gene, is an important determinant of HSV virulence. vhs has been implicated in HSV interference with host antiviral immune responses, down-regulating expression of major histocompatibility complex molecules to help HSV evade host adaptive immunity. The severe attenuation of vhs-deficient viruses in vivo could reflect their inability to escape immune detection. To test this hypothesis, BALB/c or congenic SCID mice were infected intravaginally (i.vag.) with the HSV type 2 (HSV-2) vhs null mutant 333d41 or the vhs rescue virus 333d41R. vhs-deficient virus remained severely attenuated in SCID mice compared with rescue virus, indicating that vhs regulation of adaptive immune responses does not influence HSV pathogenesis during acute infection. Innate antiviral effectors remain intact in SCID mice; prominent among these is alpha/beta interferon (IFN-α/β). The attenuation of HSV-2 vhs mutants could reflect their failure to suppress IFN-α/β-mediated antiviral activity. To test this hypothesis, 129 and congenic IFN-α/β receptor-deficient (IFN-α/βR−/−) mice were infected i.vag. with wild-type virus, vhs null mutants 333-vhsB or 333d41, or the vhs rescue virus 333d41R. Whereas vhs-deficient viruses showed greatly reduced replication in the genital mucosa of 129 mice compared with wild-type or vhs rescue viruses, they were restored to nearly wild-type levels of replication in IFN-α/βR−/− mice over the first 2 days postinfection. Only wild-type and vhs rescue viruses caused severe genital disease and hind limb paralysis in 129 mice, but infection of IFN-α/βR−/− mice restored the virulence of vhs-deficient viruses. vhs-deficient viruses replicated as vigorously as wild-type and rescue viruses in the nervous systems of IFN-α/βR−/− mice. Restoration was specific for the vhs mutation, because thymidine kinase-deficient HSV-2 did not regain virulence or the capacity to replicate in the nervous systems of IFN-α/βR−/− mice. Furthermore, the defect in the IFN-α/β response was required for restoration of vhs-deficient virus replication and virulence, but the IFN-α/β-stimulated protein kinase R pathway was not involved. Finally, vhs of HSV-2 has a unique capacity to interfere with the IFN-α/β response in vivo, because an HSV-1 vhs null mutant did not recover replication and virulence after i.vag. inoculation into IFN-α/βR−/− mice. These results indicate that vhs plays an important role early in HSV-2 pathogenesis in vivo by interfering with the IFN-α/β-mediated antiviral response.
Dissertations / Theses on the topic "Alpha attenuation test"
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Zucca, Francesca. "Valutazione neuroergonomica di cardiologi interventisti in cath-lab mediante applicazione del protocollo di alpha attenuation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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In questa tesi viene approfondito e studiato l’andamento di uno dei ritmi principali dell’elettroencefalogramma: il ritmo alpha. Nel corso degli anni, col progredire degli studi relativi al ritmo alpha, è emerso come un aumento di tale ritmo in una determinata regione del cervello sia associato ad una ridotta attività o ad una inibizione in tale regione, ad esempio per eliminare distrattori durante compiti di working memory, mentre una riduzione del ritmo alpha denoti concentrazione, attenzione, talvolta stress, e sia comunque collegata al coinvolgimento di quella regione nel task. Inoltre, una delle regioni coinvolte nella generazione del ritmo alpha è il talamo, il quale gioca un ruolo chiave nella regolazione sonno-veglia e nella generazione e modulazione dell'attività alpha. Durante la fase iniziale del sonno si verifica infatti un forte aumento del ritmo alpha, che sembra riflettere una condizione di riduzione dell’attenzione verso l’esterno. La sonnolenza, quale si riscontra nella fase di addormentamento, genera dei cambiamenti nel ritmo alpha che tendono a rappresentare uno stato di riduzione diffusa dell’attenzione. Questo esprime una condizione di “non attenzione”. Una simile condizione avviene alla chiusura degli occhi. Infine, dalla letteratura emerge che una condizione di affaticamento mentale sembra produrre una variazione di alpha simile a quella che si verifica con un calo di attenzione. Questo elaborato, ha lo scopo di esaminare il cambiamento dell’alpha, all’interno di una popolazione di cardiologi interventisti che effettuano interventi in cath-lab presso l’ospedale universitario di Ferrara, per valutare se sia possibile monitorare una condizione di affaticamento mentale o di eccessiva sonnolenza mediante l'applicazione del protocollo di alpha attenuation.
Conference papers on the topic "Alpha attenuation test"
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Slavin, Michael J., and Jeffrey J. Gruber. "Ultrasonic Characterization of Ceramics." In ASME 1987 International Gas Turbine Conference and Exhibition. American Society of Mechanical Engineers, 1987. http://dx.doi.org/10.1115/87-gt-1.
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This paper discusses ultrasonic nondestructive evaluation (NDE) methods that are useful for ceramic characterization. These methods are: ultrasonic velocity measurements, velocity and defect C-scans and attenuation measurements. The way in which the ultrasonic measurements are influenced by the ceramic’s structure and properties is examined. The ultrasonic techniques discussed in this paper are routinely used as part of an inspection/quality control procedure of ceramics for armor and heat engine applications. Sintered beta silicon carbide (β-SiC), sintered alpha silicon carbide (α-SiC) and hot pressed titanium diboride (TiB2) have been well characterized by these techniques. Elastic modulus values as determined from velocity measurements agree very well with values measured from flexural tests. Correlations between the velocity C-scans, elastic properties and densities have also been determined. The limitations and potential of each of the ultrasonic techniques are discussed.
Reports on the topic "Alpha attenuation test"
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Schwieger, Alexandra, Kaelee Shrewsbury, and Paul Shaver. Dexmedetomidine vs Fentanyl in Attenuating the Sympathetic Surge During Endotracheal Intubation: A Scoping Review. University of Tennessee Health Science Center, July 2021. http://dx.doi.org/10.21007/con.dnp.2021.0007.
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Purpose/Background Direct laryngoscopy and endotracheal intubation after induction of anesthesia can cause a reflex sympathetic surge of catecholamines caused by airway stimulation. This may cause hypertension, tachycardia, and arrhythmias. This reflex can be detrimental in patients with poor cardiac reserve and can be poorly tolerated and lead to adverse events such as myocardial ischemia. Fentanyl, a potent opioid, with a rapid onset and short duration of action is given during induction to block the sympathetic response. With a rise in the opioid crisis and finding ways to change the practice in medicine to use less opioids, dexmedetomidine, an alpha 2 adrenergic agonist, can decrease the release of norepinephrine, has analgesic properties, and can lower the heart rate. Methods In this scoping review, studies published between 2009 and 2021 that compared fentanyl and dexmedetomidine during general anesthesia induction and endotracheal intubation of surgical patients over the age of 18 were included. Full text, peer-reviewed studies in English were included with no limit on country of study. The outcomes included post-operative reviews of decrease in pain medication usage and hemodynamic stability. Studies that were included focused on hemodynamic variables such as systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, and use of opioids post-surgery. Result Of 2,114 results from our search, 10 articles were selected based on multiple eligibility criteria of age greater than 18, patients undergoing endotracheal intubation after induction of general anesthesia, and required either a dose of dexmedetomidine or fentanyl to be given prior to intubation. Dexmedetomidine was shown to effectively attenuate the sympathetic surge during intubation over fentanyl. Dexmedetomidine showed a greater reduction in heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure than fentanyl, causing better hemodynamic stability in patients undergoing elective surgery.Implications for Nursing Practice Findings during this scoping review indicate that dexmedetomidine is a safe and effective alternative to fentanyl during induction of general anesthesia and endotracheal intubation in attenuating the hemodynamic response. It is also a safe choice for opioid-free anesthesia.