To see the other types of publications on this topic, follow the link: Cardiovascular system function.
Dissertations / Theses on the topic 'Cardiovascular system function'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Cardiovascular system function.'
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
Maa, Ming-Hokng 1977. "Alterations in cardiovascular regulation and function assessed using cardiovascular system identification." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86525.
Full textAbstract:
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (p. 65-67).
by Ming-Hokng Maa.
S.B.and M.Eng.
2
Maksuti, Elira. "Imaging and modeling the cardiovascular system." Doctoral thesis, KTH, Medicinsk bildteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-196538.
Full textAbstract:
Understanding cardiac pumping function is crucial to guiding diagnosis, predicting outcomes of interventions, and designing medical devices that interact with the cardiovascular system. Computer simulations of hemodynamics can show how the complex cardiovascular system is influenced by changes in single or multiple parameters and can be used to test clinical hypotheses. In addition, methods for the quantification of important markers such as elevated arterial stiffness would help reduce the morbidity and mortality related to cardiovascular disease. The general aim of this thesis work was to improve understanding of cardiovascular physiology and develop new methods for assisting clinicians during diagnosis and follow-up of treatment in cardiovascular disease. Both computer simulations and medical imaging were used to reach this goal. In the first study, a cardiac model based on piston-like motions of the atrioventricular plane was developed. In the second study, the presence of the anatomical basis needed to generate hydraulic forces during diastole was assessed in heathy volunteers. In the third study, a previously validated lumped-parameter model was used to quantify the contribution of arterial and cardiac changes to blood pressure during aging. In the fourth study, in-house software that measures arterial stiffness by ultrasound shear wave elastography (SWE) was developed and validated against mechanical testing. The studies showed that longitudinal movements of the atrioventricular plane can well explain cardiac pumping and that the macroscopic geometry of the heart enables the generation of hydraulic forces that aid ventricular filling. Additionally, simulations showed that structural changes in both the heart and the arterial system contribute to the progression of blood pressure with age. Finally, the SWE technique was validated to accurately measure stiffness in arterial phantoms.QC 20161115
3
Schenk, Johannes. "Examination of cardiovascular function in conscious hypertensive diabetic rats." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30318.
Full textAbstract:
This investigation was concerned with measuring aspects of cardiac function in conscious control, diabetic, hypertensive control, and hypertensive diabetic rats.
Preliminary studies were conducted to determine catheter suitability and acute responses to atropine and angiotensin II in conscious animals. The catheter-manometer was tested using a square wave impact and was shown to accurately reproduce a left ventricular pressure pulse. Intravenous atropine caused both heart rate and left ventricular +dP/dt to rise. Intravenously administered angiotensin II caused systolic blood pressure to increase dramatically. In this case heart rate fell and +dP/dt was elevated.
Hypertension was induced with deoxycorticosterone acetate (DOCA) and saline drinking water. Rats were first made diabetic with streptozotocin (60 mg/kg; i.v.). One week following this, subcutaneous DOCA (25 mg/kg) was administered twice weekly and all animals received saline drinking water. Following 2 and 5 weeks of DOCA treatment rats were catheterized and resting cardiovascular function was measured.
DOCA treatment caused increased systolic and diastolic blood pressures to occur in control and diabetic rats at 2 and 5 weeks. Bradycardia was also observed in DOCA-diabetic and DOCA-control rats at 2 and 5 weeks of treatment. Two and 5 week hypertensive diabetic and control rats exhibited elevated -dP/dt and +dP/dt. The rate of contraction was shown to be proportional to the magnitude of systolic blood pressure in all treatment groups. It is concluded that diabetic rats and control rats did not differ in their response to hypertension after 5 weeks of DOCA treatment.Medicine, Faculty of
Anesthesiology, Pharmacology and Therapeutics, Department of
Graduate
4
Heys, Michelle. "Life course determinants of cognitive function and cardiovascularrisk." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B46448160.
Full text
5
Kemp, Paul R. "Studies on cellular energetics of the heart." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257820.
Full text
6
Onyemaechi, Clinton. "Autonomic Nerve Activity and Cardiovascular Function in the Chicken Embryo (Gallus gallus)." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404516/.
Full textAbstract:
The goal of this study was to build on the historic use of the avian model of development and also to further the knowledge of autonomic nervous system (ANS) regulation of cardiovascular function in vertebrates. Vasoactive drugs sodium nitroprusside, a vasodilator and phenylephrine, a vasoconstrictor were used to study the correlation of cardiovascular function relationship with nerve activity, both sympathetic and parasympathetic (vagal). Additionally, ANG II was used to assess its effects on vagal inhibition. The present study shows that pharmacologically-induced hypertension is associated with a fall in mSNA, indicating that the capacity for sympathetic autonomic cardiovascular regulation is established by late incubation however, late-stage embryonic chickens did not show a significant increase in mSNA during hypotension. The hypotensive response of the embryo was not accompanied by the expected inhibition of vagal discharge; however a slight but insignificant reduction in vagal discharge was noted. When vagal efferent output was isolated, a significant drop in vagal efferent activity was noted in response to hypotension. The present study showed late-stage embryonic chickens lack a vagal response to hypertension in both efferent and sensory limbs. In this study, vagal discharge was reduced from baseline levels in response to Ang II. Collectively, the present study indicates that the lack of a decreased heart rate, in response to increases in Pm caused by Ang II, is due to a central inhibitory action of Ang II on the vagus. Data from the present study suggests that although autonomic interaction with the cardiovascular system in present in late-stage chicken embryos, it is still underdeveloped and possesses a limited capacity.
7
Starowicz, Sharon Ann. "A non-dimensional analysis of cardiovascular function and thermoregulation." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/101150.
Full textAbstract:
The cardiovascular system plays a vital role in protecting the body from temperature extremes due to its unique ability to store, transport, and dissipate heat. A comprehensive study of the thermoregulatory aspects of the system is severely limited by its complexity and the interdependency of its many component variables. Before a formal study can be initiated, certain fundamental properties of the cardiovascular system must be established and the physical processes associated with heat and mass transport must first be understood.
To this end, over six hundred variables relating to the system's heat transport characteristics were identified. The variables were grouped to form dimensionless quantities using the Buckingham Pi Theorem. Each dimensionless quantity, or parameter, is composed of definable physical quantities that reflect the interaction between various components of the system. From the analysis, a series of reference scales was identified and, in turn, used to facilitate the physical interpretation of each resulting parameter.
As a result of this analysis, a working set of physical and experimental quantities was derived to identify significant heat and mass transport processes involved in cardiovascular thermoregulation and to establish the relative rate at which these processes occur.M.S.
8
Chan, Hiu-ting, and 陳曉庭. "The effect of diet intake on vascular function and therapeutic effect of cardiovascular medicine in patients with cardiovascular disease." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50434342.
Full textAbstract:
Cardiovascular diseases (CVDs) remain to be the leading causes of morbidity and mortality in Hong Kong and worldwide. Among different modifiable risk factors, dietary pattern is on the major determinant for CVD and overall mortality. Other than pharmacological therapies for cardiovascular risk factors, such as hypertension, hyperlipidemia and diabetes, maintaining a healthy diet is a more sustainable method in general population to prevent CVDs. Current lifestyle intervention in the West countries focus on high intake of fruit and vegetables with more than 400g per day and limited saturated fats with less than 10% of energy, there is very limited data on impact of dietary pattern on CVDs in Chinese. Prior studies among Chinese in Hong Kong have shown that only half of the local population fell within these recommended ranges for fat, saturated fatty acid and cholesterol intakes.
Several different dietary patterns have been recommended for CVDs prevention based on: i) food groups, such as Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet; ii) macronutrients: the low-carbohydrate diet, low glycemic index diet, very-low- fat diet and iii) nutrition or vitamin supplement. However, the effect of different dietary patterns based on modulations of food group, macronutrients and particular micronutrients on vascular structure and function in Chinese subjects is unclear. In the first part of this thesis, the relationships between different dietary pattern and surrogate markers of subclinical atherosclerosis and vascular function in different high risk populations for CVDs were investigated.
In Chapter 3, we compared the assessment of dietary pattern in Chinese using different tool, including Food Frequency Questionnaire (FFQ); Dietary Record; and Dietitian assessment. In this study, we demonstrated that suitable dietary assessments tools should be chosen for the assessment of different dietary pattern, according to characteristics of assessments.
In Chapter 4, the relationship between the fruit intake and subclinical atherosclerosis as measured by carotid intimal thickness (IMT) was investigated in patient with type II diabetes mellitus (DM). Our results showed that high fruit intake was associated with lower burden of carotid atherosclerosis, independent of level of vitamin intake in patients with type II DM.
In Chapter 5, we compared the impact of high carbohydrate diet on arterial stiffness between control subjects without CVDs and patients with high risk for CVDs. Our findings showed that high carbohydrate diet mainly affected patients with established CVDs, and their increased arterial stiffness was associated with an elevation of blood pressure.
In Chapter 6, we determined the effect of dietary vitamin intake on oxidative stress in patients with high risk of CVDs. In those high risk patients for CVDs, we demonstrated that increased dietary intake of vitamin A, beta-carotene and alpha tocopherol were associated with decreased oxidative stress, but these relationships were not observed in those control subjects without CVDs. It is likely attributed to the higher systemic oxidative stress levels in patients with high risk of CVDs.
On the other hand, food intake may also affect the clinical efficacy of cardiovascular therapies. In particularly, it has been well established that herbal intake which is commonly used by Chinese can affect the anticoagulant effect of warfarin on patients with non-valvular atrial fibrillation (AF). Thus, in this second part of the thesis, we investigated the effect of concomitant herbal intake on anticoagulation control in patients with non-valvular AF treated with warfarin. Our results showed that patients with AF treated with warfarin had limited knowledge on potential interaction between herbal substances in foods and warfarin, in which increased herbal substances intake significantly reduced the percentage time of anticoagulant effect within the therapeutic range. Moreover, a single section of education on knowledge of herbal ingredients did not improve their percentage time of therapeutic range for these patients.
In conclusion, these findings suggest that dietary pattern in Chinese might have significant impact of vascular function in patients with type II DM and high risk for CVDs. Moreover, the herbal substances in the diet among Chinese could have significant impact of the therapeutic effects in some of the cardiovascular medications, such as warfarin. Future clinical studies will be needed to confirm these potential beneficial effects of particular diet intake on vascular function in patients with high risks of CVDs as well as potential interaction between herbal substances in Chinese diet and cardiovascular medications.published_or_final_version
Medicine
Doctoral
Doctor of Philosophy
9
Koon, Hon-wai Michael, and 管漢偉. "Role of endothelin-1 and nitric oxide on the cardiovascular function." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31245444.
Full text
10
Norton, Cynthia Ann. "The Effect of Whole Wild Blueberries on Endothelial Function of the Sprague-Dawley Rat as Related to Cardiovascular Disease." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/NortonCA2003.pdf.
Full text
11
Wang, Kai. "Structure-function and physiological properties of HCN-encoded pacemaker channels." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39557273.
Full text
12
Dai, Yuk-ling Eunice, and 戴毓玲. "Effect of coenzyme Q10 supplementation on mitochondrial function and vascular function in patients with cardiovascular disease." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45152949.
Full text
13
Kirby, Helen Rebecca. "Localisation and function of the RFamide peptides kisspeptin and QRFP in the cardiovascular system." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608963.
Full text
14
McCuistion, Pearl, Laura Daniel, Cerrone Foster, and Krishna Singh. "The Role of the Ataxia Telangiectasia Mutated Kinase on Diastolic and Systolic Function in Diabetic Cardiomyopathy." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/asrf/2019/schedule/132.
Full textAbstract:
In a replicating cell, the ataxia telangiectasia mutated kinase (ATM) gene induces DNA repair or cell cycle arrest in response to DNA damage. Mutations in the ATM gene have been shown to predispose individuals to insulin resistance and cardiovascular disease (CVD). CVD is a leading cause of death in the United States and diabetes has recently been identified as an increased risk factor for CVD. Diastolic dysfunction is an early indicator of CVD in diabetics. This can be caused by cardiac fibrosis or hypertrophic cardiomyopathy. Studies have also shown that females with diabetes are at an increased risk for CVD when compared to diabetic males. Therefore, the effects of ATM deficiency on diabetic heart function in both male and female mice were studied. Mice with two normal copies (WT) and one mutate copy (hKO) for the ATM gene were treated with 150 mg/kg body weight dose of streptozotocin (STZ) at ten months of age to induce diabetes. Three days following, blood glucose levels were measured. Mice with blood glucose levels above 300 mg/dL were considered diabetic and used for the study. The animals were followed over a time period of two months. Echocardiography was used to examine cardiac function. Blood flow velocity and ventricular filling parameters were measured in ATM WT and hKO diabetic mice. Contraction and relaxation times of the left ventricle were also measured in these mice. The animals were euthanized at two months post-treatment. Echocardiography revealed that ATM deficiency resulted in a greater increase in systolic function in hKO diabetic females compared to non-diabetic females with the same genotype. Systolic function in WT-diabetic female mice was not higher in non-diabetic females however it was higher compared to WT diabetic males. Interestingly, WT-diabetic female mice also experienced a higher systolic function compared to hKO-diabetic females. Doppler blood flow velocity patterns will be analyzed to determine ATM effects on diastolic dysfunction. These findings should help to better understand the physiological changes the ATM gene has in diabetic cardiomyopathy. It should also help identify if ATM deficiency is a risk factor for diabetics who also suffer from cardiovascular disease.
15
Murchie, Karen J. (Karen Jo) 1973. "Arterial function in hypertension and heart failure." Monash University, Faculty of Medicine, 2000. http://arrow.monash.edu.au/hdl/1959.1/8884.
Full text
16
Kane, Andrew David. "Redox control of fetal and postnatal cardiovascular function in health and disease." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610130.
Full text
17
Royal, Alice. "The regulation of trafficking and function of KCNQ1 potassium channels by phosphatidylinositol-4,5-bisphosphate." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/25940.
Full textAbstract:
The IKs current constitutes part of the repolarisation reserve in the human myocardium, and whilst it does not play a major role at resting heart rates, it becomes a crucial component of repolarisation in the setting of increased sympathetic tone and high heart rates. The formation of the IKs current requires the KCNQ1 α-subunit and the KCNE1 β-subunit. Mutations in either of these subunits can lead to long QT syndrome types 1 and 5, respectively. Loss-of-function mutations in the IKs channel can reduce the repolarisation reserve and lead to action potential prolongation, predisposing to lethal cardiac arrhythmias such as torsades de pointes and ventricular fibrillation. It is widely recognised that the IKs channel requires the minor membrane phospholipid PIP2 for its function, and previous work in this laboratory found that mutations in a PIP2-binding region in KCNQ1 led to retention of the channel in the endoplasmic reticulum, suggesting that PIP2 may play a role in anterograde trafficking. Here, the rapamycin-inducible dimerisation system was used to manipulate levels of PIP2 and/or PI4P at the plasma membrane or Golgi, and the effect of this on IKs channel trafficking and function was investigated using molecular biology, confocal microscopy and electrophysiology. Despite difficulties with optimising the rapamycin-induced dimerisation system, it was observed that the IKs channel does not require PIP2 for anterograde trafficking, but is heavily reliant on PIP2 for channel opening. In addition, activation of the β1-adrenergic receptor (β 1-AR) led to an increase in the IKs current amplitude. The potential interplay between β1-AR and PIP2 signalling was also explored by depleting PIP2 during β1-AR stimulation. PIP2 depletion was less effective at inhibiting the IKs current during β1-AR stimulation, but this requires further investigation. In conclusion, the results suggest that the IKs channel is reliant on PIP2 for function, but not anterograde trafficking.
18
D'Silva, Lindsay Antonio. "Longitudinal characterisation of cardiovascular haemodynamic and autonomic nervous system function in normal pregnancy." Thesis, Swansea University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678627.
Full text
19
Nelligan, Julie. "Anxiety and autonomic nervous system function during stress and recovery." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1060797984.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xiii, 127 p.; also includes graphics Includes bibliographical references (p. 91-105). Available online via OhioLINK's ETD Center
20
Esco, Michael R. Blessing Daniel L. "Cardiovascular autonomic modulation following maximal exercise Its relationship to race, VO2max, and resting heart rate variability /." Auburn, Ala, 2009. http://hdl.handle.net/10415/1626.
Full text
21
Wang, Kai, and 王凱. "Structure-function and physiological properties of HCN-encoded pacemaker channels." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557273.
Full text
22
Vedantham, Srinivasan. "Design and characterization of a high-resolution cardiovascular imager." Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0607102-164425.
Full textAbstract:
Thesis (Ph. D.)--Worcester Polytechnic Institute.Keywords: Detector design and characterization; modulation transfer function; digital fluoroscopy. Includes bibliographical references (p. 150-160).
23
Mead, Emma Jane. "Localisation and function of the kisspeptins and their receptor KISS1 in the cardiovascular system." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613164.
Full text
24
Chen, Hua. "Relationship between psychological status and vascular function in subjects with and without cardiovascular diseases." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41290409.
Full text
25
Ansakorpi, H. (Hanna). "Cardiovascular regulation in epilepsy with emphasis on the interictal state." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514271343.
Full textAbstract:
Abstract
Epilepsy is associated with changes in autonomic cardioregulatory function. Ictally, autonomic disturbances may be evident with significant changes in heart rate (HR), blood pressure (BP) and respiration. However, interictal dysfunction of autonomic cardiovascular system may be subtle and it may be recognized only by delicate tools designed for that purpose. The aim of this study was to evaluate the function of the cardiovascular autonomic regulatory system in patients with epilepsy.
Cardiovascular reflex tests were performed on patients with partial or idiopathic generalized epilepsies. Special attention was paid to temporal lobe epilepsy (TLE). An association of refractory and well controlled TLE and hippocampal sclerosis with altered cardioregulation was evaluated by using cardiovascular reflex tests and an analysis of spectral and non-linear analysis of heart rate variation (HRV).
Cardiovascular reflexes were altered both in patients with partial and idiopathic generalized epilepsies who had been treated for epilepsy with antiepileptic drugs (AEDs), whereas patients with newly, untreated epilepsy did not differ from the control subjects. Diminished cardiovascular reflexes also seemed to be associated with carbamazepine (CBZ) treatment. Various parameters of cardiovascular reflex tests and analysis of spectral and dynamic measures of HRV were diminished in patients with TLE compared to the control subejcts.
These results indicate that epilepsy, especially TLE, is associated with interictal changes of autonomic cardioregulation. Although these changes seem to be evident in patients with severe form of TLE, patients with well controlled TLE and patients without hippocampal sclerosis also have altered autonomic cardioregulatory function. These results suggest that dysfunction of the cardioregulatory system is rather associated with functional than structural changes of the inner temporal lobe in patients with TLE.
26
Ness, Katrina Frances. "Distribution and function of the oestrogen receptor β in the cardiovascular system of the mouse." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/25023.
Full textAbstract:
The aim of this thesis was to determine the distribution of ERs in the CVS and whether this was altered under pathophysiological conditions. We hypothesised that oestrogen acting through ERs modifies vascular function and contributes to regulation of blood pressure. Therefore, blood pressure and vascular function were assessed in female mice of different oestrogen status and the influence of ERβ determined by studying male ERβ knock-out (βERKO) mice and female WT mice treated with a novel ERβ antagonist. Immunoreactive ERβ was associated with nuclei of myocardial, endothelial (ETC) and vascular smooth muscle cells (VSMC) of the heart, aorta and mesenteric artery in both male and female wild type (WT) and βERKO mice. The distribution of ERβ in mouse models of atherosclerosis and myocardial infarction (MI) were not different to that of normal mice. Mean arterial blood pressure (MABP) measured in young and aged WT and βERKO mice, by implantation of a Millar catheter into the left carotid artery, was found to increase with age. However, there was no difference in MABP between βERKO and age- matched WT animals. MABP of female WT mice, as measured by radiotelemetry suggested that both endogenous and exogenous oestrogen increased MABP. Treatment of female mice with an ERβ antagonist resulted in an increase in MABP in sham ovx mice whilst MABP was reduced in mice which were of ovx+E. Mesenteric vessels isolated from sham ovx and ovx+E showed that chronic E treatment increased the sensitivity to PE. Treatment of sham ovx animals with an ER antagonist did not alter vascular function. Whilst treatment of ovx+E mice with the ERβ antagonist, led to a reduction in the sensitivity to PE and an increase in both endothelium- dependent and -independent vasodilatation.
27
Chen, Hua, and 陳華. "Relationship between psychological status and vascular function in subjects with and without cardiovascular diseases." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41290409.
Full text
28
Cruickshank, Nicholas Christopher. "The Effects Of Hypothalamic Brain-Derived Neurotrophic Factor On Catecholaminergic Regulation Of Cardiovascular Function." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/804.
Full textAbstract:
Considerable evidence supports the claim that a hyperactive sympathetic nervous system (SNS) is involved in most cases of human hypertension, and therefore a more thorough understanding of the central regulation of the SNS may help elucidate novel therapeutic options. The PVN is a key region in SNS regulation of blood pressure (BP) and heart rate (HR). Stimulation of the parvocellular PVN neurons has been shown to enhance sympathetic outflow and thereby increase BP. Brain-derived neurotrophic factor (BDNF), a modulator of neuronal activity is upregulated in the paraventricular nucleus of the hypothalamus (PVN) in response to several hypertensive stimuli such as stress and hyperosmolarity, and previous studies from our lab demonstrated that both acute injections or chronic overexpression of BDNF in the PVN elevate SNS activity and BP. However, the BDNF-mediated hypertensive mechanisms are not completely understood. PVN neurons are under tonic inhibition from NTS catecholaminergic projections under baseline condition as indicated by significant BP increase after selective lesioning of NTS NE-ergic neurons. In addition, BDNF has been shown to alter NE-ergic signaling in multiple brain regions raising the possibility that BDNF may increase SNS activity and BP by interfering with NE-ergic inhibition of PVN sympathoregulatory neurons. Therefore, we tested the hypothesis that BDNF increases SNS activity and BP in part by disabling inhibitory actions of NTS catecholaminergic projections to the PVN by altering the expression of adrenergic receptors and NET in the PVN.
First, blood pressure was recorded using radiotelemetry in male Sprague-Dawley rats following bilateral microinjections of adeno-associated viral vectors expressing green fluorescent protein (GFP) or myc-tagged BDNF in the PVN and microinjections of phosphate saline buffer (PBS) or Anti-Dopaine Beta Hydroxylase (DBH)-conjugated saporin (DSAP), a catecholaminergic neuron-specific neurotoxin, into the NTS. Blood pressure was monitored both during resting conditions and during acute stress tests. A second group of rats received bilateral microinjections of adeno-associated viral vectors expressing GFP or myc-tagged BDNF in the PVN, and were sacrificed after 5 weeks. PVN and NTS samples were then selectively isolated using a brain punch tool, and expression of TH, DBH, 1a, 1b, 2a, 1, 2 receptors, and norepinephrine transporter (NET) was analyzed using quantitative RT-PCR.
Our results show that BDNF overexpression in the PVN leads to increased expression of catecholamine synthesizing enzymes in the NTS. In addition, both BDNF overexpression in the PVN, and DSAP lesioning in the NTS increased MAP compared to control rats. However, combined treatment with BDNF and DSAP failed to have any additional hypertensive effects suggesting that BDNF treatment may abolish the inhibitory effect of NTS catecholaminergic projections. Lesioning the NTS catecholaminergic neurons didn’t appear to have a significant effect on mean arterial pressure response to the stress tests, although DSAP treatment appeared to decrease the initial heart rate response to acute stress, and this effect was most pronounced in GFP rats. These results indicate that BDNF overexpression in the PVN desensitizes sympathoregulatory neurons to inhibitory NTS catecholaminergic projections during baseline conditions.
29
Galatas, Mary V. "The Effect of Steroid Dose Regimen on the Relationship Between Lower Extremity Muscle Function and Cardiac Function in Post Heart Transplant Patients." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc2761/.
Full textAbstract:
Differences in cardiovascular/aerobic function in heart transplant patients might be attributed to the rate of corticosteroid withdrawal and/or to skeletal muscle function. This hypothesis was tested among nine male, cardiac transplant recipients. Prednisone dosage was monitored, and isokinetic strength testing was performed at 4 different time periods throughout the first year post-transplantation. Cardiovascular/aerobic measurements were obtained at the fourth time period. Pre-surgery characteristics were obtained from the patient's medical record. Significant Pearson-product moment correlations were only found between muscle function and aerobic function and between pre-surgery characteristics and cardiovascular/aerobic performance. The results of this study show no evidence that rapid reduction of prednisone dosage enhances aerobic function by benefiting skeletal muscle function.
30
Vanhook, Patricia M. "Comeback of Appalachian Female Stroke Survivors: Interrelationships of Cognition, Function, Self-Concept, Personal and Interpersonal Relationships." Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etsu-works/7445.
Full text
31
Vanhook, Patricia M. "Comeback of Appalachian Female Stroke Survivors: Interrelationships of Cognition, Function, Self-Concept, Personal and Interpersonal Relationships." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etsu-works/7446.
Full text
32
Konrad, David. "Cardiac function in experimental septic and non-septic conditions with special reference to the endothelin system /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-984-X/.
Full text
33
Cummins, James B. "Adrenergic and Cholinergic Regulation of Cardiovascular Function in Embryonic Neotropic Cormorants (Phalacrocorax basilianus)." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984219/.
Full textAbstract:
Investigations of cholinergic and adrenergic tone on heart rate (fH) and mean arterial pressure (Pm) during embryonic development have been conducted on numerous avian species. While these investigations have documented that adrenergic tone, a continuous stimulation, on fH and Pm is vital to embryonic development in the birds studied to date, development of cholinergic tone on fH has been shown to vary even within species. Further, past studies have been bias to focus primarily on precocial species while altricial species remain poorly understood in this context. The goal of this investigation was to investigate the role of cholinergic and adrenergic tone on fH and Pm of an altricial species, the neotropic cormorant (P. brasilianus) to address this bias. The embryonic neotropic cormorant possesses B-and-a adrenergic tone on fH and Pm at 70% and 90% incubation while cholinergic tone on fH occurs at 90% incubation. This pattern of control is similar to that previously reported for several species of precocial birds suggesting the development of tonic cardiovascular regulation may be conserved across avian taxa.
34
Vanhook, Patricia M. "Comeback of Appalachian Female Stroke Survivors: The Interrelationships of Cognition, Function, Self-Concept, Interpersonal, and Social Relationships." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/7437.
Full text
35
Wijesurendra, Rohan. "Potential mechanisms underlying impaired left ventricular function in atrial fibrillation : insights from multi-parametric cardiac magnetic resonance." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:7a44451f-f974-459d-8dc8-42fc2eeaacb0.
Full textAbstract:
Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant cardiovascular complications, including stroke, myocardial infarction, heart failure, and premature death. The presence of subtle left ventricular (LV) dysfunction is increasingly recognised in patients with AF, raising questions regarding the underlying pathophysiology and potential treatment strategies. I used advanced and multiparametric cardiac magnetic resonance (CMR) methods to investigate potential mechanisms that could contribute to LV dysfunction in patients with AF, controlled ventricular rate and no significant cardiovascular comorbidities (i.e., with so-called 'lone' AF). Patients were evaluated before and after catheter ablation, allowing examination of the effect of restoration of sinus rhythm and reduction in AF burden on LV structure, function, energetics, tissue characteristics, and perfusion. I demonstrated for the first time that patents with lone AF before ablation have significantly impaired ventricular energetics and a subtle reduction in LV systolic function compared to control subjects in sinus rhythm. Furthermore, there was only modest improvement (but not normalisation) in LV function following successful ablation, and myocardial energetics remained impaired despite a significant and sustained reduction in AF burden. These findings imply that lone AF may actually be the consequence (rather than the cause) of an underlying cardiomyopathy. Next, to interrogate advanced ventricular tissue characteristics (such as diffuse myocardial fibrosis) in patients with tachyarrhythmia, I developed a novel CMR method involving a systolic readout T1-mapping sequence. Methodological work in volunteers and patients with tachyarrhythmia demonstrated that this method reports clinically equivalent T1 values to the conventional diastolic readout in healthy volunteers, and was feasible in tachyarrhythmia, producing excellent quality T1 maps. When applied to the investigation of patients with AF, I demonstrated that subtle LV dysfunction in lone AF occurs in the absence of CMR evidence of diffuse myocardial fibrosis, suggesting that LV dysfunction may be reversible with appropriate and targeted therapeutic strategies initiated prior to the development of structural LV remodelling. Finally, I used quantitative perfusion imaging to determine absolute myocardial blood flow and coronary reserve in patients with AF, and determine whether microvascular coronary dysfunction could underlie impaired LV function and energetics in patients with AF. I found that myocardial perfusion is significantly reduced in patients with AF in the absence of significant epicardial coronary artery disease, both at baseline and under conditions of vasodilator stress. Lower baseline blood flow was related to reduced LV performance, and there was no significant change in perfusion after successful AF ablation. These novel findings indicate that coronary microvascular dysfunction may be an important pathophysiological mechanism in lone AF, and at least partially responsible for LV dysfunction. Overall, the findings reported in this thesis have potentially far-reaching implications for the management of patients with AF. They suggest that approaches that predominantly target rhythm control (including anti-arrhythmic medications and ablation) are insufficient to normalise the systemic and cardiometabolic phenotype in patients with AF. Further studies are needed to investigate whether novel approaches that target microvascular and energetic dysfunction in patients with AF can contribute to durable restoration of sinus rhythm and improve clinical outcomes.
36
Thore, Carl-Johan. "Pressure Estimation in the Systemic Arteries Using a Transfer Function." Thesis, Linköping University, Department of Management and Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8536.
Full textAbstract:
The aim of this thesis is to develop and study a method for estimation of the pulse pressure in centrally located arteries. Obtaining the central pulse pressure is desirable for several reasons. For example, the central pulse pressure can be used to assess aortic stiffness, which in turn is an important predictor of cardiovascular mortality. In this thesis a method of estimation based on a one--dimensional wave propagation theory applied to a physiological model of the human systemic arterial tree is studied. For the purpose of validation, recorded pressure signals from twenty four control subjects are used. Various methods for individualization of the tree model are discussed, and a method that utilizes an optimization routine is proposed.
37
Skidmore, Jay Robert. "Cardiovascular reactivity in men as a function of masculine gender role stress, Type-A behavior, and hostility." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/74220.
Full textAbstract:
Previous research on the construct and measurement of Masculine Gender Role Stress (MGRS) validates the assumption of sex differences in the appraisal of stressful situations. The present study was designed to extend the validity of the construct, MGRS, by examining its association with a set of physiological responses known as cardiovascular reactivity. Generally, such reactivity is measured in terms of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). Cardiovascular hyper-reactivity has been implicated as the major pathogenic mechanism through which psychological variables such as Type-A behavior and hostility may increase one's risk of coronary heart disease. A major underlying assumption of the dissertation is that the same gender-role socialization which leads to MGRS may also underlie development of Type-A behavior and hostility, and most importantly, cardiovascular hyper-reactivity.
Forty-eight male undergraduate students volunteered to complete questionnaires measuring MGRS, Type-A behavior, and hostility, and participated in a one-hour laboratory session in which cardiovascular reactivity was assessed. Measures of SBP, DBP, and HR were obtained during consecutive phases of the assessment: (1) relaxation baseline, (2) the first stressor, (3) relaxation baseline, (4) the second stressor. All subjects were exposed to both stressors, a Cold Pressor Task (CPT) and a structured Masculine Threat Interview (MTI) in counter-balanced order. Subjects were divided into equal groups representing lower, middle, and upper thirds of MGRS.
Results indicated that MGRS scores were significantly related to cardiovascular reactivity, specifically the SBP response. Thus, higher levels of MGRS were associated with proportionate increases in SBP reactivity. Within-subjects comparisons demonstrated no difference between stressors, the CPT versus the MTI, for SBP reactivity. Regression analyses indicated that MGRS scores were a better predictor of SBP reactivity than either Type-A behavior or hostility. Together, all three psychological variables accounted for 20% of the variance of systolic reactivity; however MGRS alone accounted for 17% of that variance. These findings add considerable support to the theoretical assumption that gender role socialization plays an important role in men's appraisal of psychological stress, and that such stress has measurable (harmful) effects on cardiovascular physiology.Ph. D.
38
Gordon, Jennifer. "Depression, the dynamic function of the autonomic nervous system and hypothalamic-pituitary-adrenal (HPA) axis, and cardiovascular disease." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110429.
Full textAbstract:
Depression is associated with an increased risk of cardiovascular disease (CVD). One possible mechanism of this effect is dysregulation of the biological stress systems, the autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis. The current thesis aimed to better understand the relationship between depression and these two systems. In the first study, the effect of major depression on heart rate recovery following exercise, a marker of ANS tone, was examined in cardiac patients. Depression was associated with poor early heart rate recovery, suggesting reduced post-exercise parasympathetic activation. The second study, which included healthy participants, examined the effect of cognitive and somatic depressive symptoms in relation to recovery of heart rate and heart rate variability, two markers of ANS tone, in response to interpersonal laboratory stressors. Both types of symptoms were found to predict post-stress recovery. The third study aimed to examine the relationship between major depression both ANS and HPA axis activity in response to a stressful diagnostic test. Furthermore, it aimed to determine whether antidepressant medication is effective in restoring a normal stress response in depressed individuals. Depressed cardiac patients exhibited elevated cortisol levels in response to the test but this effect was not seen among depressed individuals taking antidepressant medication. However, neither depression nor antidepressant use was associated with heart rate variability. As a whole, these studies suggest a modest and inconsistent relationship between depression and prolonged post-stress ANS activation. On the other hand, the relationship between depression and exaggerated HPA axis activity appears to be relatively strong. Finally, antidepressant medication may be effective in reversing the excessive HPA axis activation observed in depressed individuals.La dépression est associée à un risque élevé de maladie cardiaque. Un mécanisme qui pourrait expliquer cette association est la dysfonction du système nerveux autonome (SNA) et l'axe hypothalamo-hypophyso-surrénalien (HHS), qui sont les deux systèmes impliqués dans la réaction physiologique au stress. Cette thèse avait comme but de mieux comprendre la relation entre la dépression et ces deux systèmes. Dans la première étude, l'effet de la dépression majeure sur le rétablissement de la fréquence cardiaque après l'exercice, un marqueur de la balance autonome, a été examiné chez des patients cardiaques. La dépression était associée à un pauvre rétablissement cardiaque immédiatement après l'exercice, ce qui suggère un délai dans l'activation du système parasympathique. Dans la deuxième étude, qui incluait des participants en santé, on examinait l'effet des symptômes dépressifs cognitifs et somatiques en relation avec le rétablissement de la fréquence cardiaque et la variabilité de la fréquence cardiaque, deux marqueurs de l'activation du SNA, en réaction à des stress interpersonnels de laboratoire. Les deux types de symptômes étaient associés avec un moins bon rétablissement cardiaque après les stress. Finalement, la troisième étude examinait la relation entre la dépression majeure et l'activité du SNA et de l'axe HHS en réaction à un test diagnostique stressant. De plus, l'étude a eu comme but de déterminer si les antidépresseurs sont efficaces dans le rétablissement d'une réponse normale au stress chez les dépressifs. Les patients cardiaques dépressifs avaient un niveau de cortisol plus élevé tout au long du test, ce qui indique une activation plus forte de l'axe HHS. Cet effet n'a pas été observé chez les dépressifs qui prenaient des antidépresseurs; par contre, ni la dépression ni l'utilisation des antidépresseurs étaient associées à la variabilité de la fréquence cardiaque. Ces études suggèrent une relation modeste et inconsistante entre la dépression et une activation altérée du SNA. Par contre, la relation entre la dépression et la suractivation de l'axe HHS apparait relativement forte. Finalement, les antidépresseurs semblent être efficaces en annulant la suractivation de l'axe HHS chez les dépressifs.
39
Carpenter, Rhiannon. "Influence of regular antenatal physical exercise on cardiovascular, haemodynamic and autonomic nervous system function during and after pregnancy." Thesis, Swansea University, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678358.
Full text
40
Jessop, Darrell James. "Non-weight bearing water exercise : changes in cardiorespiratory function in elderly men and women." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28536.
Full textAbstract:
The purpose of this study was to evaluate the impact of a 5 week program
of aquatic exercise on selected cardiorespiratory parameters in the elderly
participant. Fifteen men and women (mean age 68.5 years, range 61-75 years)
were recruited voluntarily from regional adult day-care and community centre
facilities. Participants underwent a series of physiological tests before
the program started and 5 weeks later at the end of the program.
Measurements included height, weight, spirometry measurements (FVC, FEV¹ֹ⁰, VEmax), resting blood pressure, resting heart rate, exercise heart rate and VO₂max as determined by a continuous treadmill test (modified after Jones and Campbell, 1982).
Following the 5 week aquatic exercise program, the experimental group
(n = 8) showed a significant decrease in resting systolic blood pressure
(SBPR) (EXPTL:131.5Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
41
Lewandowski, Adam J. "The impact of preterm birth on the cardiovascular system in young adulthood." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:f39dbabd-9f4f-439e-9c25-1989402a263a.
Full textAbstract:
Advancements in clinical care have led to a growing cohort of preterm-born individuals now entering adulthood. Before birth, such adults were often exposed to a suboptimal intrauterine environment, and after delivery, key developmental stages that would normally occur in utero during the third trimester had to take place under ex utero physiological conditions. Through detailed cardiovascular phenotyping, this thesis investigates the cardiovascular changes in preterm-born young adults, utilising a cohort of individuals with data collection since recruitment at birth. The detailed perinatal information was first used to design nested case-control studies to investigate the effects of early lipid and glucocorticoid exposure on long-term cardiovascular physiology in individuals born preterm. It was demonstrated that intravenous lipid administration leads to an artificial elevation of total cholesterol levels in immediate postnatal life, which is associated with long-term changes in aortic and left ventricular function proportional to the degree of cholesterol elevation. Additionally, exposure to antenatal glucocorticoids relates to a regional increase in aortic arch stiffness in young adulthood, as well as changes in glucose metabolism. It was then shown that young adults born preterm have increased left ventricular mass, out of proportion to blood pressure, and a unique three-dimensional left ventricular geometry, with reduced systolic and diastolic function compared to term-born controls. Similarly, they also show distinct differences in the right ventricle, with increased right ventricular mass and a proportion having clinically impaired right ventricular systolic function. Finally, it was demonstrated that preterm-born individuals have increased circulating levels of antiangiogenic factors in young adulthood, which relate to capillary rarefaction and blood pressure elevation. These findings are of considerable public health relevance given that nearly 10% of births are now preterm. Understanding whether modification of these variations in cardiovascular structure and function prevent the development of cardiovascular disease in this growing subgroup of the population will be of future interest.
42
Lorenzoni, Alberto Gino. "Effects of alpha-tocopherol and L-arginine on cardiopulmonary function in broilers." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99345.
Full textAbstract:
Two experiments were conducted to evaluate the effects of arginine, vitamin E, and their combination on cardiopulmonary performance and nitric oxide synthase (NOS) activity in broilers undergoing cold-induced ascites (pulmonary hypertension) after an acute challenge with epinephrine. One day-old male broilers ( n = 25/treatment) were supplemented with arginine (0.3% water supplementation), vitamin E (400 IU/L or kg, water or feed supplementation; experiment 1 and 2 respectively) or both compounds, above NRC (1994) recommendations. From day 28 to 42, a catheterization was performed (n = 8/treatment) to evaluate pulmonary and mean arterial pressures, and heart rate. After recording baseline values, two injections of epinephrine (1 or 0.5 mg/kg body weight, experiment 1 and 2, respectively) were administered in a 20 min interval. The NOS activity was estimated through the conversion of 14C-arginine to 14C-citrulline in isolated pulmonary arteries ( n = 8/treatment). Overall, the time taken for pulmonary arterial pressure to return to values no different from initial baseline levels was longer for the birds consuming high levels of vitamin E (alone or in combination with arginine) compared to birds supplemented only with arginine. Although NOS activity was highly variable, birds fed with high arginine levels tended to have the lowest NOS activity. These results showed that vitamin E supplementation at the levels used in these experiments has detrimental effects on cardiopulmonary performance, and does not improve NOS activity in isolated pulmonary arteries.
43
Pithon, Karla Rocha. "Avaliação cardiorrespiratoria e da densidade mineral ossea de pacientes com lesão medular." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313751.
Full textAbstract:
Orientador: Alberto Cliquet JuniorTese (doutorado) - Universidade Estadual de Campinas. Faculdade de Ciencias Medicas
Made available in DSpace on 2018-08-15T13:59:53Z (GMT). No. of bitstreams: 1 Pithon_KarlaRocha_D.pdf: 2904510 bytes, checksum: 5e11e0764c499e8dce17f09bd0f6d191 (MD5) Previous issue date: 2010
Resumo: Pacientes com lesão medular reconhecidamente desenvolvem muitas adaptações sistêmicas. Condições, como fraqueza da musculatura respiratória, paralisia e alterações na função pulmonar e conseqüentemente o aumento do índice de doenças pulmonares, são observadas. Recentemente, o aumento de doenças cardiovasculares também tem ocorrido entre esses pacientes, além das complicações provenientes da osteoporose que já são bem conhecidas. O objetivo deste trabalho foi avaliar as alterações do sistema cardiorrespiratório e esquelético de pacientes com lesão medular em 4 estudos. O estudo 1 avaliou a variabilidade da frequência cardíaca na posição supina e sentada e arritmia sinusal respiratória (ASR) de 37 homens com e sem lesão medular. Os pacientes tetraplégicos apresentaram uma redução dos valores máximos da frequência cardíaca durante ASR. O estudo 2 avaliou a função pulmonar de 23 pacientes com tetraplegia. Os valores de capacidade vital forçada, volume expiratório forçado 1s e ventilação voluntária máxima mostraram que a capacidade pulmonar dos pacientes com lesão medular foi reduzida. O estudo 3 propôs a adaptação do teste de caminhada de 6 minutos para 9 pacientes com paraplegia completa auxiliados por marcha artificial com eletroestimulação neuromuscular e andador. O estudo 4 investigou a densidade mineral óssea e fatores de risco cardiovascular de 44 homens com e sem lesão medular. Os pacientes com lesão medular apresentaram osteoporose e/ou osteopenia e o espessamento da camada íntima-média da carótida, porém os valores do lipidograma e triglicérides foram dentro da faixa de normalidade. A pressão arterial foi menor nos pacientes tetraplégicos. Análise estatística: Os dados foram apresentados em mediana (intervalo interquartil) e/ou média (±DP) e em Box-plot. Diferenças entre grupos foram demonstradas pelo intervalo de confiança da mediana, nível de significância em 5% ou teste t pareado. Conclusões: A atuação simpática e parassimpática no coração alcançou a homeostase, quando os pacientes foram mantidos nas posições supina ou sentada e o teste de ASR mostrou uma diminuição da atuação parassimpática no coração dos pacientes tetraplégicos, possivelmente para compensar uma diminuição ou ausência da atuação simpática, devido ao comprometimento do sistema autonômico pela lesão medular. O teste de caminhada de 6 minutos foi adaptado para avaliar os pacientes com lesão medular completa e se mostrou eficiente. Já a avaliação da função pulmonar dos pacientes mostrou a necessidade de novas equações de predição baseadas em uma população específica e suas características. Por último, os resultados obtidos através da densitometria mineral óssea comprovaram a presença de osteoporose e/ou osteopenia nos pacientes com lesão medular. E um aumento na espessura da camada intima-média da carótida foi observado através da ultrassonografia de carótida. Esses dados reforçam a hipótese de uma possível associação entre essas duas patologias.
Abstract: It is known that individuals with Spinal Cord Injury (SCI) present systemic adaptation. SCI causes respiratory muscle weakness, paralysis and abnormal pulmonary function. Cardiovascular disease is also increased in spinal cord injured subjects and osteoporosis as well. The aim of this study was to assess cardio respiratory and bone diseases in subjects with SCI. Four studies were performed. The first study assessed heart rate variability in supine and seated position and respiratory sinus arrhythmia (RSA) maneuver in 37 subjects with and without SCI. Tetraplegic subjects showed the lowest values of maximal heart rate during RSA. The second study assessed pulmonary function in 23 tetraplegic subjects. Forced vital capacity, maximal voluntary ventilation, forced expired volume showed that the SCI subjects' pulmonary capacity was reduced when compared with able body subjects. The third study adapted the "6 minutes' walk test" to assess complete patients with SCI during gait therapy. The fourth study investigated the clinical presence of osteoporosis and cardiovascular risk factors in 44 subjects with and without SCI. Subjects showed osteoporosis or osteopenia and increased intima-media thickness, although lipids and triglycerides were with normal ranges. Blood pressure in tetraplegic subjects was lower than in paraplegic and control groups. Statistical Analysis: Data are expressed as median (interquartile interval) and presented in box-plot (median, 1st and 3rd quartiles, minimum and maximum). Differences between groups were demonstrated by confidence interval of median, significance level set at ? = 0.05, or mean (±SD) and paired t test. Conclusions: Sympathetic and parasympathetic nervous system allow homeostasis when the subjects are kept in supine or seated position; RSA maneuver showed a reduction in parasympathetic system action in the heart of tetraplegic subjects to compensate a reduction or loss of sympathetic action in spinal cord lesion. "Six minutes walk test" was well adapted and efficient. Pulmonary function showed the necessity to create new predicts equations based on local population characteristics. Finally, bone mineral density showed osteoporosis or osteopenia in paraplegic and tetraplegic individuals as well as increased carotid intima-media thickness measured through ultrasound exam.
Doutorado
Pesquisa Experimental
Doutor em Cirurgia
44
Karjalainen, J. (Jaana). "Cardiovascular autonomic function in coronary artery disease patients with and without type 2 diabetes:significance of physical activity and exercise capacity." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526202723.
Full textAbstract:
Abstract Coronary artery disease (CAD) and type 2 diabetes (T2D) are associated with cardiovascular autonomic dysfunction, which is widely used as a predictor of mortality in cardiovascular diseases. The determinants of autonomic dysfunction in CAD patients with or without T2D are not well known. The aim of this thesis was to examine the determinants of cardiovascular autonomic function in healthy subjects and CAD patients with and without T2D. A second aim was to study the prognostic value of autonomic function in the patient population. A third aim was to study the effects of exercise prescriptions on physical activity and exercise capacity in the patient groups. The association between heart rate (HR) variability and physical activity was examined by means of 24-hour recordings in 45 healthy adults. The determinants and prognostic value of autonomic function, measured by HR recovery, HR variability, and HR turbulence, were assessed in 1060 CAD patients (50% were patients with T2D). Physical activity was measured before and after a six-month exercise prescription in 44 CAD patients without T2D and 39 CAD patients with T2D. In healthy patients, short-term HR variability indexes and the complexity properties of HR were influenced by physical activity, whereas long-term HR variability indexes remained relatively stable at various activity levels, making them robust indexes for assessment of autonomic function during ambulatory conditions. In CAD patients, exercise capacity was the most important determinant of autonomic function in addition to physical activity, age, presence of T2D, and left ventricular systolic function. During a 2-year follow-up, autonomic dysfunction predicted cardiovascular events only in CAD patients with T2D, but did not provide independent prognostic information after multivariate adjustment when high-sensitivity C-reactive protein, a marker of inflammation, remained as an independent predictor. CAD patients with T2D were physically less active than patients without T2D. Exercise prescription promoted a more active lifestyle and improved exercise capacity in both patient groups. In conclusion, cardiovascular autonomic dysfunction in CAD patients with and without T2D is closely related to low exercise capacity and physical activity, which both can be increased by exercise prescriptions. Autonomic dysfunction predicts short-term cardiovascular events only in CAD patients with T2D, but is not as strong an independent predictor as low-grade inflammationTiivistelmä Autonomisen hermoston toiminnan häiriö on yleinen komplikaatio sepelvaltimotaudissa ja tyypin 2 diabeteksessa (T2D), ja sen tiedetään olevan itsenäinen kuolleisuutta ennustava tekijä. Autonomista säätelyä selittäviä tekijöitä ei kuitenkaan tunneta hyvin. Tässä tutkimuksessa selvitettiin autonomisen hermoston toimintaa selittäviä tekijöitä kolmessa ryhmässä: osa tutkittavista oli terveitä, osalla oli sepelvaltimotauti ja T2D, ja osalla pelkästään sepelvaltimotauti. Lisäksi tutkittiin, miten autonominen säätely vaikuttaa sepelvaltimotautipotilaiden ennusteeseen sekä miten liikuntaohjelma vaikuttaa heidän fyysiseen aktiivisuuteensa ja suorituskykyynsä. Sykevaihtelun ja fyysisen aktiivisuuden välistä yhteyttä selvittävään tutkimukseen osallistui 45 tervettä henkilöä. Autonomisen hermoston toimintaa selittäviä tekijöitä ja sen ennustearvoa tutkittiin 1060 sepelvaltimotautipotilaalta, joista puolet sairasti T2D:ta. Näistä potilaista valittiin satunnaisotannalla kuuden kuukauden liikuntaohjelmaan ja fyysisen aktiivisuuden mittauksiin 44 sepelvaltimotautipotilasta, joilla ei ollut T2D:ta, ja 39 potilasta, jotka sairastivat T2D:ta. Terveillä henkilöillä lyhyen aikavälin sykevaihtelumuuttujat olivat yhteydessä fyysiseen aktiivisuuteen, mutta pitkän aikavälin sykevaihtelumuuttujissa tätä yhteyttä ei havaittu. Sepelvaltimotautipotilailla vahvimmiksi autonomista säätelyä selittäviksi tekijöiksi osoittautuivat maksimaalinen suorituskyky, fyysinen aktiivisuus, ikä, T2D ja vasemman kammion ejektiofraktio. Poikkeava autonominen säätely ennusti sydän- ja verisuonitautitapahtumia kahden vuoden seurannan aikana vain T2D:ta sairastavilla sepelvaltimotautipotilailla, mutta sillä ei ollut itsenäistä ennustearvoa, kun vakioitiin muilla riskitekijöillä. Lopulta ainoa huonon ennusteen merkki oli tulehdustilaa kuvaava herkkä CRP. T2D:ta sairastavat sepelvaltimotautipotilaat olivat fyysisesti passiivisempia kuin pelkästään sepelvaltimotautia sairastavat. Yksilöllinen liikuntaohjelma lisäsi korkean intensiteetin fyysistä aktiivisuutta ja paransi suorituskykyä molemmissa potilasryhmissä. Tämän tutkimuksen tulokset osoittavat, että sepelvaltimotautipotilailla autonomisen hermoston toiminnan häiriö on yhteydessä vähäiseen fyysiseen aktiivisuuteen ja heikkoon fyysiseen kuntoon. Molempiin tekijöihin voidaan vaikuttaa positiivisesti liikuntaohjelmalla. Poikkeava autonominen säätely ennustaa lyhyen aikavälin sydän- ja verisuonitautitapahtumia vain T2D:ta sairastavilla sepelvaltimotautipotilailla. Se ei kuitenkaan ole yhtä vahva itsenäinen ennustaja kuin tulehdusta kuvaava herkkä CRP
45
Zarini, Gustavo G. "The Effect of Vitamin D3 Supplementation on Kidney Function and Cardiovascular Disease Markers among Hispanics and African Americans with Type 2 Diabetes." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3376.
Full textAbstract:
Serum vitamin D deficiency/insufficiency, Chronic Kidney Disease (CKD) and elevated blood pressure are important health concerns especially among minorities with type 2 diabetes. The effect of vitamin D3 supplementation (cholecalciferol) at 6,000 IU/day (d) vs. 4,000 IU/d on kidney function and cardiovascular disease markers among Hispanics and African Americans with type 2 diabetes and hypovitaminosis D (/ml) was evaluated. Subjects (n=63) were recruited from two clinics in Miami-Dade County, FL. Fasting venous blood and fresh, single-voided first morning urine samples were collected from each participant by a certified phlebotomist and analyzed by Solstas Lab Partners, Davie, FL. Linear mixed models were used to compare the interaction between time and intervention. Least Significant Difference (LSD) comparisons were used to detect significant differences within and between 4,000 IU/d and 6,000 IU/d groups from baseline, 3 and 6 months. In the 4,000 IU/d and 6,000 IU/d groups, a significant increase in serum 25-hydroxy vitamin D [25(OH)D] levels were observed from baseline [(19.9±1.1 ng/mL) and (21.4±1.3 ng/mL)] to 3 months [(36.1±2.2 ng/mL, p3 longer than 6 months may be needed to determine sustained long term effects in kidney and cardiovascular disease markers. Further research could provide more information for translation of these findings into recommendations for individuals with CKD, hypertension and type 2 diabetes. The efficacy of vitamin D3 supplementation as complementary therapy for CKD and blood pressure in minority and other ethnic groups needs further investigation in larger and longer duration randomized controlled trials.
46
Santos, Sheyla Oliveira. "Influência do hipotireoidismo gestacional experimental sobre a função cardiovascular da prole de ratas." Universidade Federal de Sergipe, 2012. https://ri.ufs.br/handle/riufs/3765.
Full textAbstract:
Gestational hypothyroidism is a prevalent disorder in pregnant women. We aimed to investigate the impact of experimental gestational hypothyroidism (EGH) on cardiovascular and autonomic nervous systems (ANS) in the offspring of rats. EGH was induced with methimazole (MMI) 0.02% in drinking water from day 9 of gestation until birth. Sixty days old offspring from MMI-treated dams (OMTD, n=13) or water-treated dams (OWTD, n=13) had femoral arteries surgically assessed for the measurements of heart rate (HR), mean (MAP), systolic (SAP) and diastolic arterial pressure (DAP), and spontaneous baroreflex sensitivity (BRS). To investigate the balance of ANS, we established the high (HF) and low frequency (LF) bands of pulse interval (PI) and LF band of SAP spectrum. OMTD had increased MAP (130.2±2.0 vs 108.8±3.0 mmHg, p < 0.001), SAP (157.3±2.9 vs 135.7±4.5 mmHg, p < 0.001) and DAP (109.7±1.9 vs 88.4±2.6 mmHg, p < 0.001) when compared to OWTD, and had lower HR (355.1±8.9 vs 386.8±9.2 bpm, p < 0.05). After spectral analysis of PI and SAP, only LF band of SAP spectrum was higher (7.2±0.8 vs 4.0±0.6 mmHg2) in OMTD under spontaneous condition. Despite bradicardia, EGH promotes spontaneous hypertension in 60 days old offspring, probably due to increased sympathetic activity to vessels, which is suggested by the higher LF of SAP. These findings suggest a critical role of maternal THs in the development of fetal cardiovascular and autonomic nervous system.Os hormônios da tireoide (HTs), tiroxina (T4) e triiodotironina (T3), são reconhecidos por influenciar o crescimento e metabolismo celulares em todo o organismo. Os HTs são fundamentais para o bom desenvolvimento embrionário. O hipotireoidismo é uma das doenças endócrinas mais frequentes, acometendo frequentemente mulheres gestantes, sobretudo na forma subclínica (HS). O suprimento de HTs para o feto em praticamente toda a gestação é de origem materna. A deficiência destes hormônios está implicada com desordens no neurodesenvolvimento fetal, assim como no desenvolvimento e diferenciação cardiovasculares. No presente estudo objetivamos investigar as repercussões do hipotireoidismo gestacional experimental (HGE) na função cardiovascular da prole quando adulta. O HGE foi induzido pela administração de metimazol (MMI), um inibidor da síntese de HTs, a 0,02%, p.o., em água de beber ad libitum, do 9º dia de gestação até o parto. A prole de mães hipotireoideas (PMH) foi acompanhada desde o nascimento (dia 0 pós-natal; 0 DPN) até 60º DPN), onde foram submetidos ao procedimento cirúrgico de canulação da artéria femoral para registro dos parâmetros cardiovasculares. Vinte e quatro horas após, foram registrados os seguintes parâmetros cardiovasculares: frequência cardíaca (FC), pressão arterial média (PAM), pressão sistólica (PS) e pressão diastólica (PD). Após coletados, os dados foram analisados para a obtenção do índice de sensibilidade do barorreflexo (SBR), dos componentes de baixa (LF) e de alta frequência (HF) da análise da variabilidade da frequência cardíaca (VFC). Foram obtidos ainda a razão LF/HF e variabilidade da PS, analisado pelo LF absoluto (LFabs). O grupo controle foi composto por prole de mães eutireoideas (PME). O peso corporal da prole foi registrado para verificação e comparação do desenvolvimento corporal de ambos os grupos. Os resultados obtidos demonstram um menor peso corporal na PMH a partir do 21 DPN perdurando até os 60 DPN (p<0,001). A PMH também apresentou FC reduzida, com aumento da PAM, PS e PD quando comparados a PME (p<0,05). Não foram observadas diferenças significativas entre os grupos na LF, HF, LF/HF. No entanto, o LFabs foi mais elevado na prole de mães induzidas ao HGE, (7,2±0,8 vs 4,0±0,6 mmHg2, p<0,01). Diante do exposto concluímos que o HGE afeta o desenvolmento corporal da prole, assim como altera o funcionamento do sistema cardiovascular, sem, aparentemente afetar o sistema nervoso autonômico de controle da função cardíaca. Contudo, apesar da bradicardia, o HGE promove hipertensão espontânea aos 60 DPN, provavelmente devido ao aumento da atividade simpática nos vasos, como demonstrado pelo alto LFabs.
47
Kawthekar, Sunil Bajirao. "Effects of arginine, vitamin E and vitamin C on cardiopulmonary function and ascites parameters in broilers exposed to cold temperature." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101856.
Full textAbstract:
Two identical experiments were conducted to evaluate the combined effects of arginine (AR), vitamin E (VE) and vitamin C (VC) on cardiopulmonary performance and ascites parameters of broilers reared under cold environmental temperature. One d old male broilers were fed a basal corn-soybean meal diet (CTL, 1.2 % AR and 40 IU VE), the basal diet supplemented with 1% AR and either 200 IU VE (AE group), or 500 mg of VC (AC group), or a combination of VE and VC (AEC group) at the same level per kg of feed. Pulmonary arterial pressure (PAP) and mean arterial pressure (MAP) were recorded in clinically healthy anesthetized birds (28-42 d old) before and after an epinephrine challenge (EPI, 0.5 mg/kg BW i.v.), Amino-guanidine Hemisulphate (AG, 100 mg/kg BW i.v.) and N-Nitro L-Arginine Methyl Ester (L-NAME 50 mg/kg BW, i.v.) at 20 min intervals. The PAP increased 30 s after EPI in all birds, but the peak PAP was lower in the AEC group than in all the other birds. After 120 s of challenge the PAP was lower in AEC birds compared to the other birds. The PAP returned to pre-EPI levels within 300 s in all groups. The PAP was increased ( P< 0.05) within 60 s after the AG and L-NAME challenge in all groups, but no differences were found among groups. Plasma nitric oxide (NO) was higher in the AEC birds than in all the other groups before and after challenge. Our results showed that birds fed AEC maintained a lower PAP than the CTL birds after EPI elicited an increase in cardiac output and this can be explained by a higher production of NO. A combination of AR, VE, and VC may have complementary effects against oxidative stress, protecting the endothelium and preserving NO function.
48
Ibinson, James W. "The study of pain with blood oxygen level dependant functional magnetic resonance imaging." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1092705600.
Full text
49
Ramo, Kasmir. "Jun Kinases in Hematopoiesis, and Vascular Development and Function: A Dissertation." eScholarship@UMMS, 2015. https://escholarship.umassmed.edu/gsbs_diss/789.
Full textAbstract:
Arterial occlusive diseases are major causes of morbidity and mortality in industrialized countries and represent a huge economic burden. The extent of the native collateral circulation is an important determinant of blood perfusion restoration and therefore the severity of tissue damage and functional impairment that ensues following arterial occlusion. Understanding the mechanisms responsible for collateral artery development may provide avenues for therapeutic intervention. Here, we identify a critical requirement for mixed lineage kinase (MLK) – cJun-NH2-terminal kinase (JNK) signaling in vascular morphogenesis and native collateral artery development. We demonstrate that Mlk2-/-Mlk3-/- mice or mice with compound JNK-deficiency in the vascular endothelium display abnormal collateral arteries, which are unable to restore blood perfusion following arterial occlusion, leading to severe tissue necrosis in animal models of femoral and coronary artery occlusion. Employing constitutive and inducible conditional deletion strategies, we demonstrate that endothelial JNK acts during the embryonic development of collateral arteries to ensure proper patterning and maturation, but is dispensable for angiogenic and arteriogenic responses in adult mice. During developmental vascular morphogenesis, MLK – JNK signaling is required for suppression of excessive sprouting angiogenesis likely via JNK-dependent regulation of Dll4 expression and Notch signaling. This function of JNK may underlie its critical requirement for native collateral artery formation. Thus, this study introduces MLK – JNK signaling as a major regulator of vascular development.
In contrast, we find that JNK in hematopoietic cells, which are thought to share a common mesodermally-derived precursor with endothelial cells, is cellautonomously dispensable for normal hematopoietic development and hematopoietic stem cell self-renewal, illustrating the highly context dependent function of JNK.
50
Ostertag, Luisa Martha. "The impact of dietary polyphenols on human platelets : integrating functional and nutrigenomic analyses." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=185749.
Full textAbstract:
This thesis aims to integrate functional and nutrigenomics analyses to examine how dietary polyphenols affect human platelet function and thus may contribute to the prevention of cardiovascular diseases. Initially, 26 low molecular weight phenolic compounds were screened for their effects on platelet aggregation and P-selectin expression in vitro. Only high, non-physiological concentrations of some phenolics showed anti-platelet effects. In parallel we conducted a systematic review of the literature to assess how polyphenol-rich foodstuffs, beverages, or extracts affect platelet function in humans. Cocoa-derived flavan-3-ols were the only class of dietary polyphenols that consistently showed anti-platelet effects in both, acute and chronic settings. Consequently we conducted an acute randomised-controlled human intervention study in which healthy volunteers consumed three different types of chocolates containing different amounts of flavan-3-ols. We found that flavan-3-ol-enriched dark chocolate beneficially affected ex vivo bleeding time, platelet aggregation and P-selectin expression. These effects were gender-dependent. Bioavailability of cocoa-derived flavan-3-ols, as assessed by a targeted metabolomics approach, was also gender-dependent. Using a platelet proteomics approach, we found subtle changes in platelet protein levels 2 h after consumption of flavan-3-ol-enriched chocolate in men, which may partly explain the observed anti-platelet effects. Finally, we assessed whether flavan-3-ols are internalised in platelets after consumption of dark chocolate. No internalisation could be found up to 2.5 h after chocolate ingestion, despite these compounds appearing in plasma. In conclusion, flavan- 3-ol-enriched dark chocolate beneficially affects platelet function in a gender-dependent way, but underpinning mechanisms are still unknown. Furthermore, current insights into their bioavailability cannot fully explain the ability of flavan-3-ols to affect platelet function. Successful future progress of research into the bioavailability and mechanisms of flavan-3- ols in vitro and in vivo will depend on the availability of pure standards for the major human metabolites of flavan-3-ols.