To see the other types of publications on this topic, follow the link: Halothane.

Dissertations / Theses on the topic 'Halothane'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Halothane.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Provenat, Véronique. "Les effets toxiques et allergiques de l'halothane." Paris 5, 1989. http://www.theses.fr/1989PA05P046.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Zhang, Ke. "Cardiac electrophysiology and cardiotoxicity of halothane /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487676261012213.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Knight, Trudy Lynn. "The molecular basis of halothane-induced hepatotoxicity." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321782.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Siadat, Pajouh Majid 1959. "GENERATION OF HALOTHANE INDUCED ANTIBODY IN GUINEA PIGS AND ITS POSSIBLE ROLE IN THE PATHOGENESIS OF HALOTHANE INDUCED LIVER INJURY." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276363.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

LAUNAY, FREDERIC. "Toxicologie de l'halothane." Strasbourg 1, 1991. http://www.theses.fr/1991STR15020.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Molliex, Serge. "Effets de l'halothane sur les pneumocytes II de rat en culture primaire." Saint-Etienne, 1991. http://www.theses.fr/1991STET6417.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Vinh, Vu Huu. "Comparative contractile effects of halothane and sevoflurane in rat aorta." Kyoto University, 2001. http://hdl.handle.net/2433/150545.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Goddard, Helen. "Electrophysiological effects of fentanyl, halothane and isoflurane on guinea-pig isolated ventricular myocytes." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:58f6f4e2-aaa9-4913-a7c2-5568e2f8d72f.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Torske, Kristine E. "An evaluation of epidural oxymorphone and bupivacaine during halothane anesthesia in dogs." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0026/NQ31906.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Darling, John R. "The effects of halothane, isoflurane and sevoflurane on hepatic and renal function." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261937.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Southwood, Olwen Irene. "Studies on the genetics and dynamics of the halothane gene in pigs." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/14460.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Harris, Natalie K. "Gas detection using semiconducting polymers." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262652.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Gérard, Alain. "Determination des caracteristiques cliniques de la crise d'hyperthermie maligne per-anesthesique : analyse d'une serie de 95 propositus classes par les tests de contracture halothane et cafeine." Lille 2, 1994. http://www.theses.fr/1994LIL2M147.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Brown, Alan Perry. "Generation and expression of halothane derived protein adducts in the guinea pig liver." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186218.

Full text
Abstract:
The volatile anesthetic halothane can be bioactivated in the liver to the reactive intermediate, trifluoroacetyl chloride, which is capable of covalently modifying liver protein. The product of this reaction is trifluoroacetyl-N-ε-amino lysine, which can act as a foreign epitope in altering both protein immunogenicity and antigenicity. Protein adduct formation appears to be responsible for the development of both an acute and an immune-mediated hepatotoxicity. The goal of this research project was to detect, quantify, and characterize the formation of protein adducts in the guinea pig liver, following exposure to halothane. This species provides the most accurate animal model for halothane hepatitis to date. An in vitro liver slice system was used to study the conditions for the production of protein adducts during halothane exposure. Covalent binding to slice protein occurred in a linear fashion over the time course of exposure, and was concentration dependent. Oxidative metabolism of halothane was required for adduct production. Adduct formation occurred to specific and identifiable proteins. The majority of the protein adducts in the liver slice were localized to cytosolic glutathione-S-transferase (GST). GST can be released from the liver slice, transporting the adduct to the extracellular environment. Guinea pigs were anesthetized with halothane to compare the results obtained in vitro, with what occurs in the whole animal. Covalent binding to liver protein occurred predominately in the microsomal fraction. The protein adducts identified in the guinea pigs corresponded to those seen in liver slices. GST was identified as a target for the acid chloride intermediate in the liver of these animals. Covalent binding to cytosolic protein was dependent on liver glutathione content. A specific relationship between adduct formation to cytosolic protein and glutathione concentration was further demonstrated using an in vitro bioactivation system. GST may catalyze the reaction between the electrophile and glutathione. Liver glutathione content appears to mediate the degree and selectivity of covalent binding to target proteins. The development of halothane induced hepatotoxicity may be related to the interactions between its reactive intermediate, glutathione, and GST.
APA, Harvard, Vancouver, ISO, and other styles
15

Lyons, Jeremy D. M. "Effects of anaesthesia and nutrition on immunology and hepatic function in adults and children." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326386.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Sassou-Toussaint, Etchrivi. "Effet de l'halothane sur les propriétés mécaniques intrinsèques du muscle squelettique : application à l'hyperthermie maligne." Lille 1, 1995. http://www.theses.fr/1995LIL10054.

Full text
Abstract:
L'hyperthermie maligne (hm) est une myopathie génétiquement déterminée. L'anomalie génétique est situé sur le chromosome 19 (locus q12-13. 2) proche de celui codant pour le récepteur à la ryanodine. La susceptibilité à l'hm est dépistée par des tests de contracture musculaire halothane-caféine réalisés in vitro sur des biopsies musculaires. La première partie de cette étude a permis de mettre en évidence la relation qui existe entre la contracture et les paramètres mécaniques du couplage contraction-relaxation et leurs modifications respectives chez le muscle squelettique sensible à l'hm. Nous avons montré que l'halothane exerce un effet lusitrope négatif sur le muscle sensible à l'hm sans modifier les paramètres d'inotropie alors qu'il améliore les paramètres de contractilité sur le muscle normal. La vératrine (agoniste sodique) et l'acide cyclopiazonique (cpa) (inhibiteur de la ca2+-atpase) potentialisent la contracture induite par l'halothane sur le muscle sensible à l'hm, renforcent ses effets lusitropes négatifs et entraînent le développement d'un effet inotrope négatif. Ces effets peuvent s'interpréter comme une modification des propriétés mécaniques intrinsèques du muscle. La seconde partie de notre étude a montré que l'halothane active la libération du calcium par le réticulum sarcoplamique (rs). Les fibres pelées de type I (lente) et de type II (rapide) provenant des sujets sensibles à l'hm présentent une grande réactivité à l'halothane comparée à celle des sujets non sensibles à l'hm et ceci indépendamment du type de fibre (I ou II). L'halothane diminue la sensibilité au calcium des protéines contractiles et la tension maximale des fibres de type I, mais n'a aucun effet sur les fibres de type II. En conclusion, nos résultats suggèrent que la contracture se développant dans les muscles sensibles à l'hm est étroitement liée à une modification des propriétés mécaniques intrinsèques des muscles sensibles à l'hm. Une hypersensibilité du canal calcique réticulaire serait à l'origine de l'hyperréactivité à l'halothane du muscle sensible à l'hyperthermie maligne.
APA, Harvard, Vancouver, ISO, and other styles
17

Onimus, Jerome. "Dose test en anesthesie locoregionale pediatrique : evaluation de la lidocaine 1 % adrenalinee chez l'enfant anesthesie par halothane." Lille 2, 1994. http://www.theses.fr/1994LIL2M272.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Wodey, Eric. "Role de la po2 dans la toxicite hepatique de l'halothane : etude sur primoculture d'hepatocyte de rat." Rennes 1, 1992. http://www.theses.fr/1992REN1M131.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Chiari, Pascal. "Effets cardiovasculaires du propofol : a propos d'une etude experimentale ; effets sur les debits sanguins regionaux et l'hemodynamique globale et regionale myocardique compares a l'halothane chez le chien." Lyon 1, 1993. http://www.theses.fr/1993LYO1M258.

Full text
APA, Harvard, Vancouver, ISO, and other styles
20

Heyer, Laurent. "Effets respiratoires du propofol et de l'halothane chez le jeune enfant." Lyon 1, 1993. http://www.theses.fr/1993LYO1M336.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Jaramillo, Cárdenas Jairo [UNESP]. "Estudo comparativo entre a lindocaína e a acupuntura no tratamento da taquicardia ventricular induzida com infusão contínua de dopamina em equinos sob anestesia geral com halotano." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/103779.

Full text
Abstract:
Made available in DSpace on 2014-06-11T19:32:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02Bitstream added on 2014-06-13T18:44:21Z : No. of bitstreams: 1 jaramillocardenas_j_dr_botfmvz.pdf: 242577 bytes, checksum: 5dcc866f1ed70acb337558dd3e761c21 (MD5)
Universidade Estadual Paulista (UNESP)
A alta mortalidade relacionada a anestesia na espécie eqüina em relação à outras espécies, se deve principalmente à depressão cardiovascular. A taquicardia ventricular (TV) é uma das possíveis arritmias observadas durante a anestesia, classicamente tratada com lidocaina. Objetivou-se avaliar os efeitos cardiorrespiratórios da TV induzida por dopamina, na anestesia por halotano em eqüinos, comparando o efeito da lidocaina e acupuntura para o tratamento deste. Seis eqüinos divididos em três grupos (GC: grupo controle; GA: grupo tratado com acupuntura e GL: grupo tratado com lidocaina), foram estudados para comparar o efeito da lidocaina como método convencional, e da acupuntura nos pontos bilaterais associados: pericárdio 6 (Pc 6 - Neiguan) e Coração 7 (C 7 - Shenmen), na TV induzida pela dose arritmogênica da dopamina (DAD). Os eqüinos foram anestesiados três vezes cada um com xilazina, éter gliceril guaiacol, tiopental e halotano com intervalo de uma semana entre cada anestesia. Foram avaliados os parâmetros cardiovasculares (freqüência cardíaca, pressão arterial e eletrocardiografia), respiratórios (freqüência respiratória, capnografía, saturação de hemoglobina e hemogasometría) e escore de recuperação. A DAD foi determinada a partir da infusão de 70 æg/kg/min IV durante 10 minutos sem interrupção, preenchendo o critério determinado como arritmogênico, pela presença de 4 ou mais complexos ventriculares prematuros seguidos, com duração de pelo menos quinze segundos ou TV sustentada. O tempo médio de aparecimento da DAD ou da TV foi de 6,05 0,45 minutos nos animais não tratados e a TV se reverteu espontaneamente aos 2,7 0,2 minutos. O grupo tratado com acupuntura reverteu a TV em um tempo médio de 1,8 0,2 (P<0,05) em comparação do grupo tratado com lidocaina 1,3 0,2 (P<0,01), ambos se mostrando eficientes no tratamento da TV de eqüinos anestesiados com halotano.
The high mortality related to anesthesia in the equine species compared to other species is mainly due to cardiovascular depression. Ventricular tachycardia (VT) is one of the possible arrhythmias observed during the anesthesia classically treated with lidocaine. The purpose of this study was to evaluate the cardio respiratory effects of VT induced by dopamine in horses anesthetized with halothane, comparing the effect of lidocaine and acupuncture for its treatment. Six horses were allocated to three treatments (CG: control group, AG: acupuncture treated group and LG: lidocaine treated group) and were evaluate to compare the effects of lidocaine as a conventional treatment and the acupuncture in the associated bilateral points: pericardium 6 (Pc 6- Neiguan) and heart 7 (H7 - Shenmen) in VT induced by the arrhythmogenic dose of dopamine (ADD). The horses were anesthetized three times each one using xylazine, guaifenesin, thiopental and halothane with one week interval between each anesthesia. Cardiovascular (heart rate, arterial pressure and ECG) and respiratory (respiratory rate, capnometry, hemoglobin saturation and blood gas analysis) parameters and recovery score were evaluated. The ADD was determined by the infusion of 70 mg/Kg/min during 10 minutes without interruption fulfilling the arrhythmogenic criteria by the presence of 4 or more ectopic ventricular contractions during at least 15 seconds or sustained ventricular tachycardia. The mean time for the occurrence of VT or ADD was 6,05 l 0,45 minutes for control animals and the VT reverted spontaneously at 2,7 l 0,2 minutes. The group treated with acupuncture reverted the VT in a mean time of 1,8 l 0,2 (P<0,05) compared to the group treated with lidocaine 1,3l0,2 (P<0,01), both of them showing to be efficacious for the treatment of VT on horses anesthetized with halothane.
APA, Harvard, Vancouver, ISO, and other styles
22

Giovanelli, Debora. "Electrochemical detection of gases." Thesis, University of Oxford, 2004. http://ora.ox.ac.uk/objects/uuid:fd447153-b6dd-4be1-aae5-4ece5dc36856.

Full text
Abstract:
This thesis discusses diverse electrochemical strategies for the determination of the concentration of the gases hydrogen sulfide, ammonia and halothane. The chemical tagging of sulfide by a variety of structurally diverse substituted benzoquinone species was studied over a wide range of pH (22S in the range 20-200 μM. More sensitive (LoD= 1 (μM) amperometric detection of sulfide was obtained at modified nickel electrodes in acidic media in which sulfide was stripped from the nickel oxide layer. This approach was exploited further by using nickel modified screen printed carbon (Ni-SPC) electrodes as economical and disposable sensors for sulfide. Next, two different strategies for determining gaseous ammonia in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluromethylsulfonyl)imide, [EMIM][N(Tf)2], and in DMF are described. The first approach exploits the effect of ammonia as a proton acceptor species on the anodic oxidation of hydroquinone, resulting in a linear detection range from 10 to 95 ppm ammonia (LoD= 4.2 ppm). The second approach is based on the direct oxidation of ammonia in either DMF or [EMIM][N(Tf)2]. The possibility of photochemically induced electrocatalytic processes within microdroplets containing p-chloranil (2,3,5,6-tetrachloro-1,4-benzoquinone, TCBQ) was examined as a means of detecting the anaesthetic gas halothane.

Finally, two of the more promising routes for sulfide detection were studied at elevated temperatures (up to 70 °C) with a view to developing H2S sensors capable of meeting the demands of oilfield applications.
APA, Harvard, Vancouver, ISO, and other styles
23

Khazzaka, Aline. "Les protéines de choc thermique-70 kDa (HSPs 70) chez le porc suite à un stress." Lyon 1, 2006. http://www.theses.fr/2006LYO10186.

Full text
Abstract:
Les protéines de choc thermique (hsps) sont des familles de protéines parfaitememnt conservées à travers l'évolution des sxpèces, induites par un choc thermique ou bien par d'autres stresseurs environnementaux. Ce sont des chaperons moléculaires, elles protègent les cellules du stress et facilitent le reploiement et la maturation des protéines cellulaires. Le présent travail consite à étudier la réponse au stress des hsps 70 chez le porc de génotypes NN, Nn et nn au locus halothane (HAL) au niveau sanguin, musculaire et cellulaire. In vitro, le génotype HAL affecte la réponse hsps 70 à tous les niveaux étudiés dans ce travail. Un préconditionnement au stress (c'est à dire le traitement préalable de l'organisme avant le stress proprement dit dans le but de surexpreimer précocement les hsps 70) protège les fibroblastes en culture contre le stress thermique. Il confère une réponse normale des hsps 70 au stress chez les porcs nn. Par contre, les études in vivo n'ont pas montré de relations entre les hsps 70, le préconditionnement au stress et la qualité de la viande chez le porc
Heat shock proteins (hsps) consist of a family of conserved proteins induced by heat shock and other environmental stressors. They play a role of molecular chaperones protecting cells against stress and facilitating the fording and the maturation of cellular proteins. The aim of this work was to study the hsps 70 response to stress in pigs of the three halothane (HAL) genotypes (NN, Nn and nn) in the blood, the semi-membranous muscles and cultured fibroblasts. HAL affected the hsps 70 response in vitro at different levels of the organism. Preconditioning leads to an overexpression of hsps 70 protecting cells from heat damage. It confers a normal hsps 70 response to stress in the nn animals. In vivo studies did not show any corelation between hsps 70, preconditioning and meat quality in pigs
APA, Harvard, Vancouver, ISO, and other styles
24

David, Jean-Stéphane. "Étude in vitro de l'effet sur myocarde sain et pathologique d'agents de l'anesthésie." Lyon 1, 2006. http://www.theses.fr/2006LYO10034.

Full text
Abstract:
Les effets de différents produits de l'anesthésie ont été étudiés à l'aide d'un modèle de muscle papillaire. Chez le rat, la protamine a induit un effet inotrope négatif marqué qui s'accompagnait d'une contracture du muscle probablement en relation avec une surcharge calcique intracytosolique. De plus, la réponse inotrope aux agonistes α- et β- adrénergiques était abolie alors que la réponse lusitrope était préservée, suggérant une action en aval de la chaine des phosphorylations AMPc dépendante. Sur le myocarde diabétique, l'effet des gaz halogénés était plus important et en relation avec une baisse de la sensibilité des myofilaments au Ca2+. La potentialisation de l'effet inotrope positif des agonistes β-adrénergiques était préservée en présence de sévoflurane et d'isoflurane mais pas d'halothane. Chez le hamster, le sévoflurane a induit un effet inotrope positif. La nifédipine abolissait cet effet chez le hamster sain alors qu'elle le potentialisait chez le hamster cardiomyopathe
The effects of different anesthetic agents were studied thanks to a papillary muscle model. In rat, protamine induced a negative inotropic effect which was associated to a muscle contracture probably related to calcium overload. Moreover, inotropic response to α - and β-adrenoceptor stimulation was abolished whereas the lusitropic response was preserved, suggesting a site of action situated downstream from cAMP-mediated phosphorylation. In diabetic myocardium, effect of halogenated gas was more important and related to a decrease in myofilament Ca2+ sensitivity. Potentiation of the positive inotropic effect of β-adrenoceptor agonist was preserved in presence of sevoflurane and isoflurane but not halothane. In hamster, sevoflurane induced a positive inotropic effect. Nifedipine abolished it in healthy hamster but enhanced it in cardiomyopathic hamster
APA, Harvard, Vancouver, ISO, and other styles
25

Green, Brent Kenneth II. "The Effects of Genotype, Chromium Picolinate Supplementation, Sex, and Their Interactions on Growth Performance, Carcass Characteristics, and Muscle Quality in Pigs." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/35853.

Full text
Abstract:
Two trials (n = 160) were conducted to evaluate the effects of the halothane gene, chromium picolinate supplementation, and sex on growth performance, carcass characteristics, and meat quality in pigs. Halothane negative (NN) and halothane carrier (Nn) pigs (barrows, gilts) were supplemented with either 0 or 200 ppb chromium picolinate from 28.7 to 107.3 kg. There were no differences between genotypes for ADG or G/F. Chromium had no significant effect on any growth, carcass, or muscle quality characteristics, although chromium-fed pigs were slightly fatter.

Barrows gained faster (P < .001) and consumed more feed (P < .001) than gilts, yielding heavier (P < .001) carcasses, and heavier (P < .05) wholesale cuts. Gilts had less backfat (P < .001) and larger (P < .01) LMA, and tended to gain more efficiently than barrows.

Carrier pigs had lower pH values, higher CIE L* values, higher drip loss, and lower protein solubility (P < .05), all indicators of decreased quality. Chromium supplementation resulted in pork with higher (P<.05) CIE a*, CIE b*, and Chroma C values. Halothane carrier barrows and all gilts that were not fed chromium had lower lipid muscle content than NN barrows (P < .05).

Gilts had higher CIE L* and a* values (P < .001), less lipid, and higher moisture percentage (P < .02) than barrows. Chromium picolinate did not negatively affect pork muscle quality.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles
26

McKinney, Maurice Stanley. "Aspects of cardiac function and the influence of age during anaesthesia with isoflurane and halothane." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333778.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Kobata, Robert Steven 1954. "AN AUTOMATED METHOD OF MEASURING ISOLATED MUSCLE CONTRACTION (VERAPAMIL, HALOTHANE, CALCIUM-CHLORIDE, MAGNESIUM SULFATE, GUINEA PIG)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/277003.

Full text
APA, Harvard, Vancouver, ISO, and other styles
28

Jaramillo, Cárdenas Jairo. "Estudo comparativo entre a lindocaína e a acupuntura no tratamento da taquicardia ventricular induzida com infusão contínua de dopamina em equinos sob anestesia geral com halotano /." Botucatu : [s.n.], 2006. http://hdl.handle.net/11449/103779.

Full text
Abstract:
Orientador: Stelio Pacca Loureiro Luna
Banca: Denise Saretta Schwartz
Banca: Denise Fantoni
Banca: Renata Navarro Cassu
Banca: Francisco Teixeira Neto
Resumo: A alta mortalidade relacionada a anestesia na espécie eqüina em relação à outras espécies, se deve principalmente à depressão cardiovascular. A taquicardia ventricular (TV) é uma das possíveis arritmias observadas durante a anestesia, classicamente tratada com lidocaina. Objetivou-se avaliar os efeitos cardiorrespiratórios da TV induzida por dopamina, na anestesia por halotano em eqüinos, comparando o efeito da lidocaina e acupuntura para o tratamento deste. Seis eqüinos divididos em três grupos (GC: grupo controle; GA: grupo tratado com acupuntura e GL: grupo tratado com lidocaina), foram estudados para comparar o efeito da lidocaina como método convencional, e da acupuntura nos pontos bilaterais associados: pericárdio 6 (Pc 6 - Neiguan) e Coração 7 (C 7 - Shenmen), na TV induzida pela dose arritmogênica da dopamina (DAD). Os eqüinos foram anestesiados três vezes cada um com xilazina, éter gliceril guaiacol, tiopental e halotano com intervalo de uma semana entre cada anestesia. Foram avaliados os parâmetros cardiovasculares (freqüência cardíaca, pressão arterial e eletrocardiografia), respiratórios (freqüência respiratória, capnografía, saturação de hemoglobina e hemogasometría) e escore de recuperação. A DAD foi determinada a partir da infusão de 70 æg/kg/min IV durante 10 minutos sem interrupção, preenchendo o critério determinado como arritmogênico, pela presença de 4 ou mais complexos ventriculares prematuros seguidos, com duração de pelo menos quinze segundos ou TV sustentada. O tempo médio de aparecimento da DAD ou da TV foi de 6,05 0,45 minutos nos animais não tratados e a TV se reverteu espontaneamente aos 2,7 0,2 minutos. O grupo tratado com acupuntura reverteu a TV em um tempo médio de 1,8 0,2 (P<0,05) em comparação do grupo tratado com lidocaina 1,3 0,2 (P<0,01), ambos se mostrando eficientes no tratamento da TV de eqüinos anestesiados com halotano.
Abstract: The high mortality related to anesthesia in the equine species compared to other species is mainly due to cardiovascular depression. Ventricular tachycardia (VT) is one of the possible arrhythmias observed during the anesthesia classically treated with lidocaine. The purpose of this study was to evaluate the cardio respiratory effects of VT induced by dopamine in horses anesthetized with halothane, comparing the effect of lidocaine and acupuncture for its treatment. Six horses were allocated to three treatments (CG: control group, AG: acupuncture treated group and LG: lidocaine treated group) and were evaluate to compare the effects of lidocaine as a conventional treatment and the acupuncture in the associated bilateral points: pericardium 6 (Pc 6- Neiguan) and heart 7 (H7 - Shenmen) in VT induced by the arrhythmogenic dose of dopamine (ADD). The horses were anesthetized three times each one using xylazine, guaifenesin, thiopental and halothane with one week interval between each anesthesia. Cardiovascular (heart rate, arterial pressure and ECG) and respiratory (respiratory rate, capnometry, hemoglobin saturation and blood gas analysis) parameters and recovery score were evaluated. The ADD was determined by the infusion of 70 mg/Kg/min during 10 minutes without interruption fulfilling the arrhythmogenic criteria by the presence of 4 or more ectopic ventricular contractions during at least 15 seconds or sustained ventricular tachycardia. The mean time for the occurrence of VT or ADD was 6,05 l 0,45 minutes for control animals and the VT reverted spontaneously at 2,7 l 0,2 minutes. The group treated with acupuncture reverted the VT in a mean time of 1,8 l 0,2 (P<0,05) compared to the group treated with lidocaine 1,3l0,2 (P<0,01), both of them showing to be efficacious for the treatment of VT on horses anesthetized with halothane.
Doutor
APA, Harvard, Vancouver, ISO, and other styles
29

Pottie, Robert George. "A CLINICAL STUDY OF INHALANT ANAESTHESIA IN DOGS." University of Sydney, 2004. http://hdl.handle.net/2123/559.

Full text
Abstract:
A clinical trial was undertaken using three different inhalant anaesthetic agents and one intravenous anaesthetic agent in dogs undergoing routine desexing surgery. Healthy adult dogs undergoing either ovariohysterectomy or castration were assessed as to their demeanour, with the more excitable dogs being placed in groups receiving premedication with acepromazine and morphine. All dogs were then randomly assigned an anaesthetic agent for induction of general anaesthesia. The agents were the inhalants halothane, isoflurane and sevoflurane, and the intravenous agent propofol. Inhalant inductions were undertaken using a tight fitting mask attached to a standard anaesthetic machine with a rebreathing circuit, with the maximum dose of inhalant available from a standard vaporiser. Propofol inductions were undertaken via intravenous catheter. Dogs induced with propofol were randomly assigned one of the three inhalant agents for maintenance. Those induced by inhalant agent were maintained using the same agent. The surgical procedure was undertaken in standard fashion, as was recovery from anaesthesia. All dogs received the non-steroidal anti-inflammatory agent meloxicam. Data collection was divided into three stages: induction, maintenance, and recovery from anaesthesia. Variables measured at induction of anaesthesia were time to intubation, number of intubation attempts, tolerance of mask, quality of induction and quality of transfer to the maintenance stage. Standard variables for monitoring of anaesthesia were recorded throughout the maintenance of anaesthesia. Variables measured at recovery were time to righting, time to standing and quality of recovery. The mean time to intubation when using the newer inhalant sevoflurane (196.2 � 14.8sec, mean � SE) was not significantly different to that for halothane (221.4 � 14.0sec) or isoflurane (172.4 � 15.0sec). Time to intubation with isoflurane was significantly faster than with halothane. Mean time to intubation with propofol (85.4 � 7.7sec) was significantly faster than that for any of the three inhalants. Choice of inhalant had no effect on quality of induction. The use of premedication significantly improved the quality of induction. The use of propofol for induction likewise significantly improved the quality of induction. Standard cardiorespiratory variables measured during the maintenance phase of anaesthesia remained within normal clinical ranges for all three inhalants, and were therefore not further analysed. Choice of inhalant agent had no significant effect on the time to righting or standing in recovery. The use of propofol for induction had no effect on these variables. Animals placed in groups receiving premedication had significantly longer times to righting and standing. The oesophageal temperature at the end of the procedure had a significant effect on times to righting and standing, with lower temperatures contributing to slower recoveries. Independent of procedure time, male dogs had shorter times to righting than female dogs.
APA, Harvard, Vancouver, ISO, and other styles
30

Baudy, Yves. "L'examen ophtalmologique sous anesthésie générale de courte durée chez l'enfant." Montpellier 1, 1989. http://www.theses.fr/1989MON11156.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Juvin, Philippe. "Régulation du métabolisme des pneumocytes II : effets des halogénés et des particules diesel." Paris 7, 2001. http://www.theses.fr/2001PA077263.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Gatecel, Claire. "Incidence de l'halothane et de l'isoflurane sur les debits sanguins arteriels hepatiques et veineux porte chez l'homme mesures par methode doppler pulse avec microcapteurs implantes : validation de la methode." Rennes 1, 1992. http://www.theses.fr/1992REN1M022.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Ito, Tatsuya. "Reversible inhibition of hypoxia-inducible factor 1 activation by exposure of hypoxic cells to the volatile anesthetic halothane." Kyoto University, 2002. http://hdl.handle.net/2433/149718.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Sobair, Abbas Taha Hamza. "The influence of body temperature on MAC of halothane in the rabbit determined using controlled mechanical and heat stimulation." Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/30002.

Full text
Abstract:
The determination of the minimum alveolar concentration (MAC) of any inhalation anaesthetic requires repeated application of the stimulus. The investigation of the influence of body temperature on MAC in the same animal, requires even more applications of the stimulus. The use of what is commonly known as a "supramaximal stimulus", beyond which there is no increase in MAC with any further increase in stimulus intensity, is generally held to provide for the reproducibility of MAC. However, there are many conflicting reports with regard to the MAC values obtained using "supramaximal stimuli" and with the interpretation of results. In this study the unreliability of the "supramaximal stimulus", in the form of tail clamping using a haemostat for the determination of MAC of halothane in the rabbit, was established. The use of this technique was demonstrated, both grossly and histologically, to cause severe trauma and lacerations that may have altered the sensitivity of the sensory mechanisms as indicated by the great variability in the values of MAC obtained on subsequent determinations in the same animal. Also, the technique appeared to disregard modern physiological concepts on receptor thresholds, inflammation and hyperalgesia. Therefore, it was decided to explore more reliable techniques of stimulation. Controlled mechanical and heat stimulators were devised and used for the determination of MAC of halothane in the rabbit as the body temperature was manipulated to test the effect of environmental heating or cooling on MAC. The mechanical stimulator is a form of pincer driven by compressed air, and is operated from a control panel with a manual trigger. It is capable of delivering a precise stimulus at a preselected pressure to the target site (ear pinna). The stimulus was calculated in terms of Newtons per unit surface area after calibration of the device using gram weights.
APA, Harvard, Vancouver, ISO, and other styles
35

Freeman, Lisa C. "The effects of halothane on impulse propagation in Purkinje fibers and across the Purkinje-muscle junction during [alpha]-adrenergic stimulation /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487673114114476.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Hashiguchi(Ikeda), Mitsuko. "Halothane inhibits an intermediate conductance Ca[2+]-activated K[+] channel by acting at the extracellular side of the ionic pore." Kyoto University, 2004. http://hdl.handle.net/2433/145289.

Full text
APA, Harvard, Vancouver, ISO, and other styles
37

Nyström, Per-Erik. "Quantitative trait loci in pig production /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5712-2.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Júnior, Ewaldo de Mattos. "Avaliação biespectral, cardiorrespiratória e hemogasométrica em cadelas submetidas a ovariosalpingohisterectomia, tratadas com acepromazina associada ou não a meperidina e anestesiadas com halotano, isofluorano ou sevofluorano." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/10/10137/tde-17112008-153956/.

Full text
Abstract:
O presente estudo teve como objetivo avaliar os efeitos do halotano, isofluorano e sevofluorano sobre o índice biespectral, parâmetros cardiorrespiratórios e hemogasométricos em cadelas submetidas a ovariosalpingohisterectomia. Foram utilizadas 48 cadelas, sem raça definida, com peso médio de 15,09±4,29 kg, com idade média de 3,9±1,23 anos, encaminhadas para realização do procedimento de orivariosalpingohisterectomia. Os animais foram distribuídos aleatoriamente em seis grupos de oito animais, sendo designados como AH, AMH, AI, AMI, AS e AMS. Os animais dos grupos AH, AI e AS receberam acepromazina na medicação pré-anestésica na dose de 0,1 mg.kg-1 por via intramuscular. Já os animais dos grupos AMH, AMI e AMS receberam na medicação pré-anestésica acepromazina, na dose de 0,05 mg.kg-1, associada a meperidina, na dose de 3 mg.kg-1, administrados por via intramuscular. A indução da anestesia foi realizada com o auxílio de propofol, na dose de 5 mg.kg-1, lentamente por meio da via intravenosa. Uma vez que os animais apresentaram relaxamento mandibular foi realizada a entubação orotraqueal, sendo em seguida conectada ao circuito valvular circular do aparelho de anestesia, e mantidas em respiração espontânea com halotano (grupos AH e AMH), isofluorano (grupos AI e AMI) ou sevofluorano (grupos AS e AMS), diluídos em oxigênio a 100%. Foram mensurados o índice biespectral (BIS), eletromiografia (EMG), freqüência cardíaca (FC), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), pressão arterial média (PAM), temperatura retal, freqüência respiratória (FR), tensão de dióxido de carbono no final da expiração (ETCO2), saturação periférica de oxigênio na oxi-hemoglobina (SpO2), relação entra a pressão parcial de oxigênio no sangue arterial e a fração inspirada de oxigênio hemogasometria arterial (pH, PaCO<2, PaO2, HCO3- e DB). Os parâmetros verificados e registrados em todos os grupos desde M0 até M5, sendo estes: M0; 15 minutos após a administração da medicação pré-anestésica, M1; 10 minutos de manutenção anestésica, M2; ligadura do pedículo ovariano direito, M3; sutura da musculatura, M4; sutura de pele, M5; 10 minutos após o fim da administração do anestésico. Em todos os grupos houve forte correlação do índice biespectral e a fração expirada de anestésico. Quanto ao índice biespectral, o grupo AMH apresentou índices inferiores em M2 quando comparado com AI, AMI e AS; neste mesmo momento AI apresentou índices superiores em relação a AMS. Não houve diferença entre os grupos estudados em relação aos parâmetros cardiovasculares. Todos os agentes causaram depressão respiratória, evidenciado pelo incremento na PaCO2, e a ocorrência de acidemia. Conclui-se que os três agentes avaliados possuíram correlação inversa com o índice biespectral, o grupo AMS apresentou valores inferiores de BIS, todos os agentes promoveram estabilidade cardiovascular e de maneira semelhante, desencadearam depressão respiratória e acidemia.
The objective of this study was evaluation effects of the halothane, isoflurane and sevoflurane on bispectral index, cardiopulmonary and hemogasometrics parameters in bitches undergoing ovariohysterectomy. Fourth-eight mongrel bitches (weight: 15,09±4,29 kg) with 3,9±1,23 years old, send to HOVET-USP for surgical procedure of ovariohysterectomy. The animals were randomly allocated in six grupos of eight animals, designed with AH, AMH, AI, AMI, AS e AMS. The animals of the AH, AI and AS group were premedicated with acepromazine (0,1 mg.kg-1, i.m.) and the animals of the AMH, AMI and AMS groups receive acepromazine (0,05 mg.kg-1, i.m.) and meperidine (3 mg.kg-1, i.m.). Fifteen minutes later, propofol was titrated to allow endotracheal intubation and connected in valvular circuit of anesthesia machine and was maintained in spontaneously breathing with halotane (groups AH and AMH), isoflurane (AI and AMI) and sevoflurane (AS and AMS) in 100% oxygen delivery. Bispectral index (BIS), heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), rectal temperature (RT), respiratory rate (RR), end-tidal of carbon dioxide (ETCO2), peripheral oxihemoglobin saturation, relationship of the arterial oxygen pressure and inspiration fraction of oxygen, inspiration fraction of anesthetics, end-tidal anesthetics, and gasometrical parameters (pH, PaCO2, PaO2, HCO3- and BD) was evaluated. The parameters was evaluated in all groups in moments M0 to M5, M0 fifteen minutes after de pre-medication administration; M1, ten minutes of anesthetic maintains; M2, transfixation of left ovarian; M3 muscle suture; M4, skin suture, M5, ten minutes of the end of anesthetic. All groups were having strong correlation of the bispectral index and end-tidal anesthetic. The AMH group has minor values of bispectral index in M2 when compare with AI, AMI and AS groups; in this moment AI group present to values when compare with AMS. The cardiovascular parameters havent difference between groups. All agents caused reduction of respiratory function, evidenced for increase in PaCO2 and acidemia. The tree agents has inverse correlation with bispectral index, the AMS group, present minor values of BIS, all agents promoted cardiovascular stability and decrease of respiratory function.
APA, Harvard, Vancouver, ISO, and other styles
39

Gray, Deborah Lynn. "The effects of cocaine and two major metabolites on epinephrine induced cardiac arrhythmias, electrocardiographic parameters, and mortality in halothane anesthetized male Sprague-Dawley rats /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487682558446853.

Full text
APA, Harvard, Vancouver, ISO, and other styles
40

Mercier, Frédéric. "Anesthésiques halogènes et réactivité bronchique : étude chez le cobaye et chez l'homme." Paris 5, 2002. http://www.theses.fr/2001PA05WO72.

Full text
Abstract:
L'halothane, l'isolflurane et le sévoflurane sont de puissants bronchodilatateurs chez l'animal et chez l'homme. Néanmoins, ces effets n'ont jamais été étudiés lors du réveil anesthésique, bien qu'une hyporéactivité trachéale in vitro ait été suggérée chez l'animal après une anesthésie générale. Le desflurane est un bronchodilatateur chez l'animal mais pas chez l'homme ; aucune étude n'a été réalisée sur la bronche humaine isolée jusqu'à présent. Dans la première publication, nous avons étudié 7 sujets asthmatiques deux fois et à une semaine d'intervalle. Un test à la méthacholine a été effectué, suivi d'une courte inhalation d'isoflurane à faible concentration pendant 8 minutes versus placebo (oxygène pur). Aucune amélioration significative du VEMS et du DEM50 n'a été constatée 3,6,9 et 19 minutes après la fin de l'inhalation d'isolflurane. Dans la deuxième publication, la réactivité trachéale de 8 paires de cobayes a été précisée in vitro, 24 heures après une anesthésie générale de 120 minutes à l'halothane, 1,5% versus placebo (oxygène pur). Les courbes concentration-réponse cumulatives à histamine et au KC1 ont été similaires dans les deux groupes, ainsi que les contractions à acétylcholine, ou celles au carbachol dans des bains sans calcium. De plus, quand l'halothane ou l'isoflurane ont été administrés directement in vitro, la relaxation induite a intégralement disparu 30 minutes après leur arrêt. Il n'y a donc pas d'hyporéactivité trachéobronchique "protectrice" après une anesthésie à l'halothane ou à l'isoflurane. Inversement, les études in vitro de réactivité bronchique ne sont pas biaisées par une anesthésie générale préalable des animaux. Dans la troisième publication, l'halothane, l'isolflurane et le desflurane ont provoqué une relaxation bronchique concentration-dépendante sur des bronches humaines in vitro. Cette relaxation était plus prononcée sur les bronches faiblement précontractées. La relaxation était similaire pour les trois halogénés sur les bronches proximales. En revanche, l'halothane (et dans une moindre mesure l'isoflurane) était plus puissant que le desflurane sur les bronches distales. Le glibenclamide a atténué l'effet relaxant distal des trois halogénés de façon comparable. Cette étude in vitro confirme donc en partie la disparité de bronchoréactivité rapportée chez l'homme anesthésié au desflurane par rapport à l'animal.
APA, Harvard, Vancouver, ISO, and other styles
41

Kaikarienė, Veslava. "Laukinių ir naminių kiaulių HAL geno tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140305_141919-10643.

Full text
Abstract:
Šiuo tyrimo tikslas buvo ištirti laukinių ir naminių kiaulių halotano geną. Tyrimo metodika. Tyrimas atliktas 2012-2013 m. LSMU Biologinių sistemų ir genetinių tyrimų institute K. Janušausko gyvūnų genetikos laboratorijoje. Viso, HAL geno atžvilgiu, ištirta 137 kiaulė (45 šernai, 5 Vietnamietiškos kiaulės, 12 Pekariai, 25 Landrasai, 25 Jorkšyrai ir 25 Pjetrėnai). Kiaulių šeriai buvo naudojami kaip genetinės medžiagos šaltinis. Halotano geno nustatymui buvo atliekama polomerazės grandininės reakcija (PGR). HAL geno įtakai mėsinėms ir penėjimosi savybėms įvertinti buvo atrinkti mišrūnai LxJxP (45) auginti Valstybinėje kiaulių veislininkystės stotyje. Penėjimosi ir mėsinių savybių duomenys gauti iš Valstybinės kiaulių kontrolinio penėjimo stoties Kauno skyriaus. Rezultatai ir išvados. Iš 75 tirtų naminių kiaulių 88 proc. buvo NN ir 12 proc. Nn genotipo. Visos (62) laukinė kiaulės buvo NN genotipo. Aukščiausias n alelio dažnis nustatytas pas Pjetrėnų (p<0,01) veislės kiaules lyginant su Landrasais ir Joršyrais. Tuo tarpų N alelio didžiausias dažnis rastas pas Jorkšyrų veislės kiaules. Kadangi visos tirtos laukinės kiaulės neturėjo streso geno (n) alelio galima daryti prielaidą, jog jos yra atsparesnės stresui. Mūsų tyrimų duomenimis HAL geno homozigotinių ir heterozigotinių kiaulių mėsinių ir penėjimosi savybių rodikliai skiriasi. Šiltos skerdėnos masė, skerdenos puselės ilgis ir bekono puselės ilgis buvo didesni pas NN genotipo namines kiaules. Pas heterozygotinius individus... [toliau žr. visą tekstą]
The aim of present study was to research halothane gene in wild and domestic pigs. Research methodology. Research was performed during 2012 – 2013 year in LSMU Biological Systems and Genetic Research Institute of K. Janusauskas Animals Genetic Laboratory. Samples for DNA testing were collected from wild and domestic pigs. Fattening and meat quality data were obtained from the State of Pigs Control fattening Station of Kaunas Department. A total of 137 pigs (45 wild boars, 5 Vietnamese pigs, 12 Pecari, 25 Landrace, 25 Yorkshire and 25 Pietrian) were tested for halothane genotype. For the effect of HAL gene on meat and fattening properties, 45 crossbreeds (LxJxP) from State Pigs Breeding Station were selected. Plucked hair was used as a source of genomic DNA. All tested animals were characterized as normal homozygotes (NN), heterozygotes (Nn) or recessive homozygotes following amplification of a target region of the HAL gene using the polymerase chain reaction (PCR), followed by a restriction endonuclease assay. The resulting PCR was digested with the restriction enzyme Alw21I, followed by agarose gel electrophoresis. Results and conclusions. In 75 tested domestic pigs, 88 % were NN and 12 % were Nn genotype. In 62 tested wild pigs all animals were NN genotipe. The frequency of n allele was higher (p<0.01) in Petrian pigs (0.25 for n) than in Landrase (0.1 for n) and Yorkshire (0.05 for n). The frequency of N allele was higher in Yorkshire than in the rest of the tested... [to full text]
APA, Harvard, Vancouver, ISO, and other styles
42

Yerle-Bouissou, Martine. "Contribution à la carte génique du porc par hybridation moléculaire in situ sur des chromosomes en métaphase et en fin de prophase : application à l'étude du gène halothane." Toulouse, INSA, 1990. http://www.theses.fr/1990ISAT0018.

Full text
Abstract:
L'analyse du genome chez l'homme et la souris est maintenant tres avancee grace a l'etablissement de cartes geniques detaillees. La situation est tout a fait differente dans le cas des especes domestiques ou les cartes geniques sont encore sommaires ou inexistantes. L'objectif de ce travail est d'une part, de contribuer a l'etablissement d'une carte physique globale pour l'espece porcine et d'autre part, de realiser la carte fine du chromosome 6, qui porte un gene d'interet zootechnique: le gene de sensibilite a l'halothane (hal). Nous avons etabli le caryotype des chromosomes porcins en fin de prophase, multipliant par deux le nombre de bandes g obtenues par rapport au caryotype standard. Nous avons developpe la technique d'hybridation moleculaire in situ sur des chromosomes en metaphase et en fin de prophase. A l'aide de cette technique, nous avons localise des genes moyennement repetes: l'interferon et le complexe majeur d'histocompatibilite ainsi qu'un gene unique codant pour la nucleoside phosphorylase. Concernant l'etude du gene hal, cinq marqueurs ont ete localises et ordonnes sur le chromosome 6 (ssc6). Cette etude nous a permis de montrer que le chromosome 6 (region: centromereq2. 1 et q. 2. 2q2. 5) est en partie homologue aux chromosomes 1 (region pterp36. 13) et 19 (region q13. 1q13. 2) humain. Grace aux resultats obtenus, un atelier pilote charge de l'etablissement d'une carte genique complete du porc, va etre developpe
APA, Harvard, Vancouver, ISO, and other styles
43

Freitag, F?bio Batista. "Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17028.

Full text
Abstract:
Made available in DSpace on 2014-12-17T15:28:53Z (GMT). No. of bitstreams: 1 FabioBF_DISSERT.pdf: 6339300 bytes, checksum: d864db11d9029d4bcca9a2aaf6e2f131 (MD5) Previous issue date: 2013-08-27
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Processing in the visual system starts in the retina. Its complex network of cells with different properties enables for parallel encoding and transmission of visual information to the lateral geniculate nucleus (LGN) and to the cortex. In the retina, it has been shown that responses are often accompanied by fast synchronous oscillations (30 - 90 Hz) in a stimulus-dependent manner. Studies in the frog, rabbit, cat and monkey, have shown strong oscillatory responses to large stimuli which probably encode global stimulus properties, such as size and continuity (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Moreover, simultaneous recordings from different levels in the visual system have demonstrated that the oscillatory patterning of retinal ganglion cell responses are transmitted to the cortex via the LGN (Castelo-Branco et al., 1998). Overall these results suggest that feedforward synchronous oscillations contribute to visual encoding. In the present study on the LGN of the anesthetized cat, we further investigate the role of retinal oscillations in visual processing by applying complex stimuli, such as natural visual scenes, light spots of varying size and contrast, and flickering checkerboards. This is a necessary step for understanding encoding mechanisms in more naturalistic conditions, as currently most data on retinal oscillations have been limited to simple, flashed and stationary stimuli. Correlation analysis of spiking responses confirmed previous results showing that oscillatory responses in the retina (observed here from the LGN responses) largely depend on the size and stationarity of the stimulus. For natural scenes (gray-level and binary movies) oscillations appeared only for brief moments probably when receptive fields were dominated by large continuous, flat-contrast surfaces. Moreover, oscillatory responses to a circle stimulus could be broken with an annular mask indicating that synchronization arises from relatively local interactions among populations of activated cells in the retina. A surprising finding in this study was that retinal oscillations are highly dependent on halothane anesthesia levels. In the absence of halothane, oscillatory activity vanished independent of the characteristics of the stimuli. The same results were obtained for isoflurane, which has similar pharmacological properties. These new and unexpected findings question whether feedfoward oscillations in the early visual system are simply due to an imbalance between excitation and inhibition in the retinal networks generated by the halogenated anesthetics. Further studies in awake behaving animals are necessary to extend these conclusions
O processamento da informa??o visual se inicia na retina. A sua complexa rede de c?lulas com diferentes propriedades permite que a informa??o visual seja codificada em canais paralelos e transmitida para o n?cleo geniculado lateral (LGN) e o c?rtex. Na retina, tais respostas est?o frequentemente acompanhadas por oscila??es sincronizadas de alta frequ?ncia (30 90 Hz) em uma maneira dependente do est?mulo. Como demonstrado em estudos na r?, coelho, gato e macaco, respostas oscilat?rias ocorrem em geral a est?mulos relativamente grandes, podendo codificar propriedades globais do est?mulo como o tamanho e continuidade (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Al?m disso, registros simult?neos em diferentes n?veis do sistema visual t?m mostrado que o padr?o de oscila??o nas c?lulas ganglionares retinianas ? transmitido para o c?rtex visual via LGN (Castelo-Branco et al., 1998). De uma forma geral, esses resultados sugerem que oscila??es sincronizadas em uma maneira feedforward s?o importantes na codifica??o da informa??o visual. No presente estudo feito no LGN de gatos anestesiados, investigamos o papel das oscila??es retinianas no processamento de informa??o visual atrav?s da apresenta??o de est?mulos complexos, como cenas naturais, pixels aleat?rios no tempo e espa?o, al?m de grades em movimento. Esse ? um importante passo para o entendimento de mecanismos de codifica??o em condi??es naturais, j? que grande parte dos estudos que investigaram o papel de oscila??es retinianas utilizaram-se de est?mulos simples e estacion?rios. An?lises de correla??o de respostas neuronais (spiking responses) confirmaram resultados pr?vios mostrando que respostas oscilat?rias na retina (observadas aqui a partir de registros no LGN) dependem do tamanho e estacionariedade do est?mulo. Para filmes de cenas naturais (em escala de cinza e preto e branco) oscila??es apareceram apenas por breves momentos provavelmente quando os campos receptores foram dominados por padr?es extensos e cont?nuos (para ambas as escalas). As atividades oscilat?rias parecem ser dependentes de uma massa cr?tica de c?lulas ativadas sugerindo que esse padr?o regular de atividade surge atrav?s de intera??es horizontais na retina. Nossos resultados mostram, al?m disto, que surpreendentemente oscila??es da retina no gato s?o dependentes da anestesia mediada por halotano. Na aus?ncia deste, atividades oscilat?rias estiveram ausentes independentemente das caracter?sticas dos est?mulos visuais. Resultados semelhantes foram obtidos para o isoflurano, anest?sico com propriedades farmacol?gicas similares. Esse novo e inesperado resultado nos faz questionar se oscila??es feedforward no sistema visual n?o seriam resultado de um desequil?brio entre correntes de excita??o e inibi??o nas redes retinianas gerado pelos anest?sicos halogenados. Experimentos futuros em animais acordados ser?o necess?rios para confirmar essas conclus?es
APA, Harvard, Vancouver, ISO, and other styles
44

Gueugniaud, Pierre-Yves. "Contractilité myocardique et agents anesthésiques halogénés : de l'étude expérimentale in vitro à l'approche clinique par débitmétrie aortique écho-Doppler." Lyon 1, 1998. http://www.theses.fr/1998LYO1T221.

Full text
APA, Harvard, Vancouver, ISO, and other styles
45

Saunier, Claude François. "Interactions entre l'anesthésie générale et le système noradrénergique du Locus Coeruleus : approche expérimentale chez le rat." Lyon 1, 1997. http://www.theses.fr/1997LYO1T238.

Full text
APA, Harvard, Vancouver, ISO, and other styles
46

Singaram, Vinod Krishnan. "The Role of Neuronal Leak Channels in Anesthesia." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1339372305.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Orliaguet, Gilles. "Effets diaphragmatiques des médicaments utilisés en anesthésie au cours du développement postnatal." Paris 6, 2002. http://www.theses.fr/2002PA066278.

Full text
APA, Harvard, Vancouver, ISO, and other styles
48

Kuhn, Mathias. "Vergleichende Untersuchung von Halothan und Isofluran während laparoskopischer Eingriffe beim Pferd." [S.l. : s.n.], 2003. http://dol.uni-leipzig.de/pub/2003-52.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Schmucker, Nicola. "Duplexsonographische Untersuchung kopfversorgender Gefässe beim Pferd unter Halothan-Narkose in verschiedenen Lagerungen /." [S.l.] : [s.n.], 1997. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Wenger, Sandra. "Die Kurznarkose zur Ferkelkastration mit Halothan : eine Feldstudie zur Überprüfung der Machbarkeit, des Aufwandes und der Kosten /." [S.l.] : [s.n.], 2001. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

Full text
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography