• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 203
  • 128
  • 31
  • 12
  • 9
  • 6
  • 4
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 461
  • 461
  • 461
  • 192
  • 192
  • 170
  • 161
  • 147
  • 83
  • 79
  • 68
  • 56
  • 48
  • 45
  • 43
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Tissue-specific expression of cre recombinase in the developing enteric nervous system of a Hoxb3/cre transgenic mouse strain

Chan, Yuk-yee. January 2002 (has links)
Thesis (M.Med.Sc.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 40-51). Also available in print.
52

Novel method to study autonomic nervous system function and effects of transplantation of precursor cells on recovery following spinal cord contusion injury

Nout, Yvette Stephanie, January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 185-206).
53

Cardiac autonomic regulation and lifestyle behaviors associated with the tripartite model of anxiety and depression

Juncker, Brian David, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.
54

Efeitos do treinamento resistido concêntrico e excêntrico sobre a modulação autonômica cardíaca e parâmetros cardiovasculares

Gois, Mariana de Oliveira [UNESP] 13 December 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-13Bitstream added on 2014-06-13T18:49:43Z : No. of bitstreams: 1 gois_mo_me_prud.pdf: 334951 bytes, checksum: ea8f5682903159b02b38d10927a185dc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introdução: a contração concêntrica promove maior estresse cardiovascular em relação à contração excêntrica, sobretudo por apresentar maiores valores de frequência cardíaca (FC), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD) e pressão arterial média (PAM) em estímulos agudos. Entretanto, no âmbito do treinamento, não se sabe sobre a relação custo benefício destes dois tipos de exercício. Objetivo: avaliar e comparar o efeito de um treinamento resistido, realizado com ênfase concêntrica vs excêntrica, sobre respostas cardiovasculares (PAS, PAD e FC) e autonômicas [variabilidade de frequência cardíaca (VFC)]. Casuística e métodos: o estudo foi composto por 80 homens, com idade entre 18 e 30 anos. Os sujeitos foram alocados em 4 grupos, sendo que os grupos G1 (concêntrico) e G2 (excêntrico) foram submetidos a apenas uma sessão de ER para o grupo extensor do joelho... / Introduction: the concentric contraction causes greater cardiovascular stress in relation to the eccentric contraction, mainly due to the higher values of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and means arterial pressure (MAP) in acute exercise. However, in the training, it is unknown the cost benefit of these two types of exercise. Objective: to evaluate and compare the effect of a resistance training, performed eccentric versus concentric with emphasis on cardiovascular responses (SBP, DBP and HR) and autonomic [heart rate variability (HRV)]. Methods: the study consisted of 80 men, aged between 18 and 30 years. The subjects were divided into 4 groups, with G1 (concentric) and G2 (eccentric) underwent only one session of ER for the knee extensor group [3 sets of 1 rep at 100% of 1 repetition maximum (RM )] and G3 (concentric) and G4 (eccentric) performed 10 sessions of resistance training, in which the 10th session consisted of three sets of 1 rep at 100% of 1RM, also for the knee extensor group. The volunteers were monitored in two conditions: before and 24 hours after the training and before, during and after (45 minutes) the only session of the G1 and G2... (Complete abstract click electronic access below)
55

Um novo modelo de disautonomia induzida pelo tratamento crÃnico com vincristina em ratos acordados / A NEW MODEL OF DYSAUTONOMY INDUCED BY CHRONIC VINCRISTINE TREATMENT IN AWAKE RATS

Arnaldo Aires Peixoto JÃnior 12 March 2008 (has links)
nÃo hà / A vincristina à um quimioterÃpico e seu uso à limitado devido a neuropatia perifÃrica, com acometimento autonÃmico, sensitivo e motor. Sulfato de vincristina ou salina foram injetados na veia da cauda, nas doses de 50 Âg/Kg (5 doses), 100 Âg/Kg (2-5 doses) ou 150 Âg/Kg (1, 2 ou 5 doses) a cada dois dias em 144 ratos Wistar machos (200-250 g). No dia seguinte, os animais receberam a refeiÃÃo-teste por gavagem e foram sacrificados 10 minutos apÃs. A recuperaÃÃo gÃstrica e intestinal de corante foi determinada por espectrofotometria. ConstipaÃÃo foi avaliada pelo peso colÃnico e neuropatia sensitiva pela latÃncia tÃrmica (51Â0,5ÂC). PressÃo arterial mÃdia (PAM) e freqÃÃncia cardÃaca (FC) basais e valores da PAM e FC apÃs a administraÃÃo de fenilefrina 5 Âg/Kg e atropina 0,5 mg/Kg foram usados para estudo dos baroreflexos. DiferenÃas foram avaliadas por One-Way ANOVA com P<0,05. Tratamentos crÃnicos com 5 doses de 50 Âg/Kg; 3, 4 e 5 doses de 100 Âg/Kg; 2 e 5 doses de 150 Âg/Kg causaram retardo do esvaziamento gÃstrico (EG) (P<0,05). Duas e 5 doses de 150 Âg/kg induziram constipaÃÃo e houve reduÃÃo da latÃncia tÃrmica apÃs 1 dose de 50 Âg/Kg, 100 Âg/Kg e 150 Âg/kg (P<0,05). O efeito da vincristina sobre o EG nÃo foi evidenciado uma e duas semanas apÃs o tratamento com 5 doses de 150 Âg/Kg (P>0,05). Houve reduÃÃo do tempo de latÃncia ao calor por atà duas semanas apÃs 5 doses de 150 Âg/Kg (P<0,05). Vincristina potencializou a reduÃÃo da FC induzida pela fenilefrina e aumentou a resposta cardÃaca à atropina (P<0,05). A neuropatia autonÃmica induzida pela vincristina cursa com retardo do EG, alteraÃÃes na resposta baroreflexa e aumento do peso colÃnico. A neuropatia sensitiva precede o surgimento das alteraÃÃes autonÃmicas e persiste apÃs a reversÃo destas. / Vincristine is a chemotherapy drug and its use is limited by peripheral neuropathy with autonomic, sensory and motor involvement. Vincristine sulphate or saline was injected into the tail vein at doses of 50 Âg/Kg (5 doses), 100 Âg/Kg (2-5 doses) or 150 Âg/Kg (1, 2 or 5 doses) QOD in 144 male Wistar rats (200-250g). Next day, they were gavage-fed with a test meal and sacrificed 10 minutes later. Gastric and intestinal dye recovery was determined by spectrophotometry. Basal mean arterial pressure (MAP) and heart rate (HR) and peak values of MAP and HR after i.v. phenylephrine 5 Âg/Kg and atropine 0.5 mg/Kg were used to evaluate the baroreflex responses. Differences were evaluated by One-Way ANOVA with P<0.05. Chronic treatment with 5 doses of 50 Âg/Kg; 3, 4 and 5 doses of 100 Âg/Kg; 2 and 5 doses of 150 Âg/Kg delayed gastric emptying (GE) (P<0.05). Two and 5 doses of 150 Âg/Kg induced constipation and reduction in withdrawal latencies occurred after 1 dose of 50 Âg/Kg, 100 Âg/Kg and 150 Âg/Kg (P<0.05). Vincristine (150 Âg/Kg) immediately decreased fecal output (P<0.05). The effect of vincristine on the GE was not present in rats treated with 5 doses of vincristine 150 Âg/kg one week and two weeks after the last dose (P>0.05). The withdrawal latency decrease lasted for at least 2 weeks after 5 doses of 150 Âg/Kg (P<0.05). Vincristine enhanced the HR reduction induced by phenylephrine and enhanced cardiac response to atropine (P<0.05). Vincristine-induced autonomic neuropathy courses with delayed GE, altered baroreflex responses and increased colonic weight. Sensory neuropathy preceded and outlasted these autonomic changes.
56

Cardiovascular autonomic dysfunction in Parkinsonian syndromes

Kallio, M. (Mika) 24 July 2001 (has links)
Abstract Autonomic nervous system (ANS) disturbances are common in Parkinson's disease (PD), but also in other Parkinsonian syndromes, especially in multiple system atrophy (MSA). The differentiation between various Parkinsonian syndromes may be difficult, but it is important for prognostic and therapeutic purposes. The aim of this study was to determine the ability of different analysis methods to reveal cardiovascular regulation disturbances in PD and to evaluate the diagnostic capacity of autonomic tests to differentiate between various Parkinsonian syndromes. Furthermore, this study aimed to evaluate the relationships between ANS disturbances and the clinical characteristics of PD. In addition, the cardiac autonomic function was evaluated during various sleep stages for the first time in untreated PD patients by using spectral heart rate variability (HRV) measures to determine possible sleep stage specific cardiovascular regulation disturbances. Cardiovascular autonomic reflexes were evaluated in 62 untreated and newly diagnosed PD patients, 34 PD patients under antiparkinsonian medication, 47 MSA patients and 15 patients with progressive supranuclear palsy (PSP). The usefulness of different analysis methods was evaluated in a subgroup of 32 untreated PD patients. A further 21 untreated PD patients underwent one-night polysomnography for nocturnal heart rate variability analysis. PD patients with hypokinesia/rigidity as their initial onset sign had a significantly lower max-min ratio in the deep breathing test than those patients with tremor as the initial sign. MSA patients showed significant reductions in both HRV and blood pressure responses during orthostatic provocation, whereas PSP patients had normal results. Absolute spectral measures yielded the clearest indicators separating the PD patients from the controls, while the cardiovascular reflexes proved more useful than the normalised spectral HRV measures in revealing the differences between the two groups. HRV was abnormally decreased during non-REM sleep in PD patients but not during REM sleep or the S1 sleep stage. The normalized high frequency power was significantly decreased in PD patients during sleep stages S2-4, while the standard deviation of the R-R intervals was increased during the same sleep stages, possibly corresponding to the increased motility of PD patients during these sleep stages. The clinical characteristics of PD deserve particular attention in connection with ANS disturbances, since autonomic failure seems to be more pronounced in PD patients with hypokinesia/rigidity as their initial sign. The evaluation of the autonomic function may also be helpful in the differential diagnosis of Parkinsonian syndromes. Spectral analysis methods should be implemented in the evaluation of ANS dysfunction to achieve the best possible efficacy in the differentiation of pathological responses from normal ones. Nocturnal analysis of cardiovascular regulation revealed new and interesting features of pathologic HRV in PD patients, thus when HRV is evaluated, the different sleep stages should be analysed separately.
57

Cardiovascular Effects Evoked by Airway Nociceptive Reflexes in Healthy and Cardiovascular Diseased Rats

Hooper, Justin Shane 08 April 2016 (has links)
Acute inhalation of airborne pollutants alters cardiovascular function and has been shown to have its greatest affects on individuals with pre-existing cardiovascular disease. Evidence suggests that pollutant-induced activation of airway sensory nerves via the gating of ion channels is critical to these systemic responses. Here, we have investigated the cardiovascular responses evoked by inhalation of AITC (TRPA1 agonist) and capsaicin (TRPV1 agonist) in healthy Sprague Dawley (SD) and Wistar Kyoto (WKY) rats, and cardiovascular diseased Spontaneously Hypertensive (SH) rats. Inhalation of the agonists by healthy SD and WKY rats caused significant bradycardia, atrio-ventricular (AV) block and prolonged PR-Intervals. Inhalation of TRP agonists caused differential cardiovascular responses in the cardiovascular diseased SH rats, such that the TRP agonists evoked brady-tachy with AV block and premature ventricular contractions (PVCs). Bradycardic responses to AITC were inhibited by the TRP channel blocker ruthenium red and the muscarinic antagonist atropine, but atropine did not prevent the tachycardic responses seen in the SH rats. Adrenergic inhibition with atenolol prevented the tachycardic responses, but did not prevent the bradycardic responses evoked by AITC in the SH rats. In healthy rats, AITC inhalation also caused a biphasic blood pressure response: a brief hypertensive phase followed by a hypotensive phase, while evoking hypertension in the SH rats. Atropine accentuated the hypertensive phase in all animals, while preventing the hypotension in the healthy animals. In all animals, AITC-evoked heart rate responses were not abolished by terazosin, the [U+F061]1 adrenoceptor inhibitor, which prevented the hypertensive responses. Anesthetics had profound effects on AITC-evoked bradycardia and AV block, which was abolished by urethane, ketamine and isoflurane. Nevertheless, AITC inhalation caused bradycardia and AV block in paralyzed and ventilated rats following pre-collicular decerebration. In conclusion, we provide evidence that activation of TRP channels expressed on nociceptive airway sensory nerves causes significant cardiovascular effects in healthy rats via reflex modulation of the autonomic nervous system (ANS), and that these effects are exacerbated in cardiovascular diseased rats.
58

Effects of alpha-methyldopa on the sympathetic nervous system activity in health participants

Kruger, Mariska January 2013 (has links)
Methyldopa (L-alpha-Methyl-3,4-dihydroxyphenylalanine) is a catecholamine used as an antihypertensive agent.1 Alpha-Methyldopa is not used as frequently anymore due to side effects, but it is still used especially in developing countries due to its low cost. Indications are mostly for the management of pregnancyinduced hypertension (PIH), as it is relatively safe in pregnancy compared to other antihypertensive drugs. This project is intended to increase the already-existing knowledge base of the mechanism of pharmacological action and to stimulate further investigation through research. The sympathetic nervous system is a division of the autonomic nervous system and it is responsible for the “flight-or-fight” response. It is involuntary and constantly active to maintain homeostasis in the human body. Sympathetic responses include an increase in heart rate, blood pressure and cardiac output, dilation of pupils and bronchioles, constriction of blood vessels, contraction of sphincters and inhibition of gut motility and secretions. The purpose of this study is to evaluate the activity of the sympathetic nervous system of volunteers by three different techniques (QT interval and Heart rate variability and Skin conductance) after a week of a bi-daily dosage of alphamethyldopa. All volunteers received either 250mg alpha-methyldopa orally or a placebo tablet in a randomized, double blind, placebo controlled study design. The correlation between the following techniques was also evaluated: Skin conductance as measured by the ProComp Infiniti Biofeedback apparatus, QT interval on ECG and HRV measured with Viport apparatus. A salivary sample was collected to evaluate the effect of alpha-methyldopa on salivary cortisol using an ELISA kit for analysis. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Pharmacology / unrestricted
59

The effects of a chiropractic upper cervical adjustment on the autonomic nervous system and cardiovascular system

Van Tonder, Lynelle 11 October 2011 (has links)
M.Tech. / This study was conducted to determine whether Chiropractic Spinal Adjustment Therapy (SAT) of the upper cervical spine has an effect on the normal physiological reactions that take place in the Autonomic Nervous System and Cardiovascular System whilst using the Electrocardiogram as a monitoring device. This area within Chiropractic research calls for further studies to be conducted. One hundred and twenty normotensive participants between the ages of 18 and 30 years were recruited to partake in the study via an advertisement placed in and around the University of Johannesburg Doornfontein Campus (Appendix A). Participants were assessed for exclusion criteria by completing a Full Case History (Appendix B), Pertinent Physical Examination (Appendix C), Cervical Spine Regional Examination (Appendix D) and a S.O.A.P. note (Appendix E). Participants were excluded from the study if it was revealed that they have contra-indications to Chiropractic SAT (Appendix F). The participants demonstrating upper cervical spine dysfunction were treated with a Chiropractic upper cervical SAT (Appendix J) while they were monitored for 3 minutes before, during treatment and 3 minutes after treatment by means of the Electrocardiogram to monitor the cardiovascular response. Participants were asked to read and sign the Subject Information and Consent form (Appendix G). Participants were required to complete the Patient Biographical Information Sheet (Appendix H) and the Patient Questionnaire regarding treatment experience (Appendix I)
60

Experimental studies on luteinizing hormone releasing factor in hypophysial portal blood

Fink, George January 1967 (has links)
No description available.

Page generated in 0.0909 seconds